Biology human body


  • Holiday feasting can leave you feeling bloated and uncomfortable.
  • Experts share ways to ease your stomach discomfort this holiday season.
  • Knowing your triggers, swapping foods, and limiting alcohol can all help make holiday meals more pleasant.

A full and heavy belly can mean great things were just consumed, but it can also mean uncomfortable things are about to happen.

For many Americans, that feeling is just par for the course during holiday celebrations.

According to research from the Calorie Control Council, a typical Thanksgiving dinner is packed with over 3,000 calories. That’s almost double the recommended calorie intake for adult women based on the 2020-2025 Dietary Guidelines for AmericansTrusted Source.

And stomachs can only hold so much food before they hit their capacity.

For instance, on average, an adult’s stomach is similar in size to a clenched fistTrusted Source. It can hold about 2.5 ounces if it’s emptyTrusted Source and expand to hold around 1 quart.

As you fill your stomach up to its capacity, doing so can cause discomfort, including indigestion and even nausea.

To help banish that overfed, lethargic, bloated feeling, nutrition experts say the following 5 tips can help reduce intestinal discomfort during the holiday season.

1. Recognize your triggers

As a guest of a party, you might find yourself at the mercy of what the host is serving, which can mean you might not know exactly what ingredients they are using to prepare their food.

However, knowing ahead of time what ingredients trigger discomfort can help eliminate bloat.

“Whether it’s dairy, gluten, or some other food, being aware of food intolerances and other triggers is important so you can avoid or limit them in order to prevent digestive issues like bloating,” Michael Hartman, PhD, nutrition expert, told Healthline.

He suggested asking the host before the party what they intend on serving and what ingredients are in the food.

“The last thing they want is for you to feel unwell,” said Hartman.

To identify foods that trigger bloat, Erin Palinski-Wade, registered dietitian and author of Belly Fat Diet For Dummies, recommended keeping a daily food record and looking for patterns.

“It is best to track the food you eat, the portions, the timing, emotions at the time (happy, stressed, etc.) as well as any symptoms you feel,” she told Healthline. “This can allow you to look for patterns to identify foods that may cause bloat as well as help you to see if other factors such as stress may be aggravating your symptoms.”

2. Don’t save calories for the party

Eating consistently throughout the day can help keep you from over-eating at the party.

“Waiting too long in-between meals until you are ravenous can often lead to eating too fast and too much, which can trigger an increase in bloating,” said Palinski-Wade.

Instead of “saving” all your calories for a big meal, she said to eat consistent meals and snacks to support digestion throughout the day.

“Watch out for foods that may trigger bloat, such as large amounts of cruciferous vegetables at one sitting, eating more fiber than you generally would without building up, or eating meals with large amounts of fats, sodium, and added sugar,” she said.

3. Make food swaps 

Whether you’re the host or know what the host will be serving at the party, you can provide alternative options to choose from.

“If you’re trying to build a healthy relationship with food, there are simple healthy holiday food swaps you can make,” said Hartman.

For instance, if dairy-filled cheese balls and crackers are a typical appetizer at your holiday dinner table, he said to try mixing it up this year with hummus, pita, and fresh veggies.

Instead of buttery mashed potatoes, consider switching to a sweet potato alternative.

“And, rather than going for a rice dish that’s high in starch, reach for legumes which are rich in potassium, a mineral that helps flush out excess bloat-causing sodium,” Hartman said.

Palinski-Wade suggested using milk in replacement of heavy cream to cut the fat in recipes and reduce large amounts of salt by using flavorful spices like cinnamon and nutmeg.

If swapping feels overwhelming or like too much work, she said to stick to eating in moderation. Her favorite strategy for doing this at holiday meals is to review all food offerings first before adding them to her plate.

“Then build a balanced plate filling 1/3 with produce, 1/3 with lean protein, and the remaining 1/3 with any favorite side dishes,” she said. “This allows you to enjoy all the offerings without overdoing it, which can help reduce bloat.”

3. Make food swaps 

Whether you’re the host or know what the host will be serving at the party, you can provide alternative options to choose from.

“If you’re trying to build a healthy relationship with food, there are simple healthy holiday food swaps you can make,” said Hartman.

For instance, if dairy-filled cheese balls and crackers are a typical appetizer at your holiday dinner table, he said to try mixing it up this year with hummus, pita, and fresh veggies.

Instead of buttery mashed potatoes, consider switching to a sweet potato alternative.

“And, rather than going for a rice dish that’s high in starch, reach for legumes which are rich in potassium, a mineral that helps flush out excess bloat-causing sodium,” Hartman said.

Palinski-Wade suggested using milk in replacement of heavy cream to cut the fat in recipes and reduce large amounts of salt by using flavorful spices like cinnamon and nutmeg.

If swapping feels overwhelming or like too much work, she said to stick to eating in moderation. Her favorite strategy for doing this at holiday meals is to review all food offerings first before adding them to her plate.

“Then build a balanced plate filling 1/3 with produce, 1/3 with lean protein, and the remaining 1/3 with any favorite side dishes,” she said. “This allows you to enjoy all the offerings without overdoing it, which can help reduce bloat.”

4. Add leafy greens to your plate

Vegetables like spinach, kale, bok choy, asparagus, and chard have a high-water content and are also low in calories and packed with vitamins, minerals, and fiber. “[They] work well to reduce bloating,” said Hartman.

While eating vegetables regularly is a great way to add fiber to the diet, Palinski-Wade cautioned that increasing fiber gradually is the best way to promote healthy bowel movements and reduce bloat.

“If you increase your vegetable intake quickly without adjusting to an added fiber intake, this may result in more bloat,” she said. “Also, if you do not increase your water intake as you increase fiber, this can lead to bloat and constipation as well.”

She recommended adding an extra half cup of leafy greens every 3 days to slowly increase your intake to improve digestion without the bloat.

“Cruciferous vegetables like broccoli can cause more gas as well, so these are often best to enjoy cooked versus raw to lessen the impact on bloat,” said Palinski-Wade.

5. Limit alcoholic drinks 

While alcoholic drinks are often part of celebrating the holidays, drinking alcohol after eating heavy meals can make a swollen stomach worse.

“Alcohol is an inflammatory substance that can slow digestion and increase water retention, making you feel lethargic. It can also lead to swelling in the body, which can result in gas, discomfort, and bloating,” said Hartman.

To prevent dehydration and up your water intake, Palinski-Wade said to leave visual reminders like setting your water bottle out where you can see it during the day. She also suggested setting an alarm on your phone to encourage you to sip on water or use an app to track your intake.

“Spacing water out helps to prevent bloat, but don’t try to chug water all at once since that may increase bloat as well,” she said.

To moderate alcohol intake, Palinski-Wade said it’s best to keep to drinking one glass of an alcoholic beverage for women and two glasses for men per day. Plus, for every glass of alcohol you consume, drink at least one glass of water.

“During holiday celebrations, try incorporating fun mocktails made with sparkling water and 100% juice as a delicious way to enjoy the celebration without the added bloat the next day,” she said.

Her favorite go-to concoction is 1 cup of seltzer water with ¼ cup tart cherry juice and a slice of lime “for an antioxidant-rich drink that looks just like a fancy glass of wine.”

Hartman suggested ditching the mulled wine and spiked eggnog and opting for a nonalcoholic cider or punch instead.


Biology human body

SMall Incision Lenticule Extraction (SMILE)

The goal of laser vision correction (LVC) is to eliminate or reduce the need for glasses and contact lenses. LVC treats three basic refractive errors: myopia (nearsightedness), astigmatism (blurring of vision due to non-spherical shape of the eye), and hyperopia (farsightedness).

During an LVC procedure, the cornea — the clear dome on the surface of the eye — is reshaped in order to correct the refractive error. The different techniques to perform LVC are laser in situ keratomileusis (LASIK), phototherapeutic refractive keratectomy (PRK), and small incision lenticule extraction (SMILE).


LASIK, the most commonly performed laser vision correction procedure in the US and the most famous of the techniques, was approved by the FDA in 1998. It is well known for its quick recovery. LASIK combines the application of excimer laser and a hinged corneal flap. The excimer laser is a computer-controlled laser that allows precise control over the amounts of tissue that are removed from the cornea. The corneal flap is a layer of the cornea that is folded back to provide access to a deeper layer of the cornea that is reshaped by the excimer laser during the procedure.

LASIK has a much quicker and more comfortable recovery compared to PRK. After LASIK, patients typically experience a scratching and burning sensation that significantly improves within one day. Most patients have excellent vision the day after LASIK. In the first week especially, patients need to be mindful of the corneal flap, which has a small chance of moving or dislocating with rubbing or hard blinking. Even months after the procedure, there is a small risk of flap dislocation with significant trauma.


The FDA approved SMILE, the latest advance in laser vision surgery, in 2016. It has been shown to be as effective and safe as LASIK, and it is currently available for the treatment of myopia and myopic astigmatism. SMILE combines advantages of PRK and LASIK: it requires only a small incision, does not require a flap, and has a quick, LASIK-like recovery, with the additional benefit of no postoperative restrictions.

With one laser and in approximately 30 seconds, a thin contact lens-shaped layer just beneath the surface of the cornea is created with the laser. This layer is then removed through a tiny 2–3 mm opening, and the surrounding tissues heal together. The procedure is extremely comfortable, with a quick recovery, and requires no postoperative restrictions (unlike LASIK and PRK). It also avoids any potential risk of flap complications, in contrast to LASIK. The SMILE procedure is growing in popularity, but it is currently not as widely available as LASIK and PRK in the US. As surgeons and laser centers continue to adopt the technology, the volume of procedures is expected to grow.

On the day of the SMILE procedure, as with LASIK, most patients experience a sensation that they have something in their eye, as well as tearing and burning for several hours afterward. Visual recovery is quite rapid, and after one to two days most patients have 20/20 vision. With no postoperative restrictions after SMILE, patients are back to all normal activities, including wearing makeup and working out, the next day. One downside of SMILE is that certain prescriptions, including farsightedness, cannot be treated. The most common risks of SMILE are over- or undercorrection of the prescription, dry eye, or more rarely, visual distortions including halos.

SMILE has become a first-choice option for many patients. Many police and army combat personnel are now choosing this flapless option.

Laser vision correction is generally safe and effective

Laser vision surgery is not without risks, and there are times when a patient will experience either an over- or undercorrection of their prescription, as well as issues with healing or dry eye. Everyone’s body can respond differently, and even in a single individual, the left eye may heal differently from the right eye.

Overall, however, all LVC techniques are predictable and safe, with excellent results and minimal risks. It is important to see an experienced surgeon for a consultation. He or she can recommend the best technique for each patient.

Biology human body

The Current Role of Stem Cells in Orthopaedic 


With an increased emphasis on evidence based medicine, there has been an increasing focus on the pathophysiology of orthopaedic injuries and disease processes, and their impact on overall outcome. Traditional treatment strategies are evolving to encompass tailored approaches that account for age, occupation and patient expectation. Newer strategies for management are routinely implemented and encouraged in an effort to improve patient outcomes. It is to achieve these objectives that regenerative medicine which utilizes the use of stem cells and tissue engineering has newly emerged.


Stem Cells: Undeveloped biological cells capable of proliferation, self-renewal, conversion to differentiated cells and regenerating tissues1.

Totipotent cells: These are cells that can develop into all cell types in the human body and can also form extra embryonic and placental cells. The cells of the early stages of the embryo are the only totipotent cells and are not in clinical use due to ethical concerns2.

Pluripotent cells: Cells that can develop into cells of all the three germ layers (endoderm, ectoderm or mesoderm). Cells of late stages of embryo after the blastocyst stage are pluripotent cells2.

Multipotent cells: These are cells that can develop into more than one but not all germ layers. Adult stem cells and cord blood cells are multipotent cells2.

Types of Stem Cells:

Embryonic Stem Cells (Pre-natal): These cells are obtained from the blastocyst stage of the embryo. Pluripotent in the truest sense, they have a capacity to form into any tissue of the body and multiply in an unlimited manner. This is predominantly due to the phenomenon of asymmetric division – production of one stem and one non-stem daughter cell3. These properties, however, also make them prone to tumorigenesis4. This and the necessity of harvest from embryos causes safety and ethical dilemma.

Adult Stem cells (Post-natal): These cells are obtained later in life after the embryonic stage. They are multipotent, undifferentiated cells located among specialized tissues with a primary function of their maintenance and repair. Mesenchymal stem cells (MSC), which originate from the mesoderm, are a type of adult stem cells that have a good potential to develop into adipocytes, chondrocytes, myoblasts and osteoblasts.

Sources of Stem cells:

Stem cells can be obtained from bone marrow, periosteum, adipose tissue, placenta, umbilical cord, blood, human amniotic fluid, dental pulp, synovial tissue, skin and skeletal muscle. Among these, bone marrow, adipose tissue and muscle derived MSCs are most commonly used as they are easily obtained and abundantly available1.

Isolation of Stem cells:

Stem cells may be “unselected cells” obtained from autologous bone marrow after centrifugation or “selected” and enhanced in culture utilizing their affinity to tissue plastics. Cost involved, time to culture, risk of infection and loss of function in vitro are factors preventing regular clinical use of cultured MSCs. It should be noted that absolute number and the purity of cells obtained from cultures is higher, an important factor for clinical effect5. The posterior iliac crest has been shown to have a higher yield for MSCs as compared to anterior in case of bone marrow aspiration6.

Route of administration:

Stem cells may be directly applied into a lesion either surgically or via local injection with a suitable scaffold/carrier. MSCs may be taken through initial phases of differentiation, forming bone or cartilage precursors under laboratory conditions and then implanted into lesions. In addition, MSCs may be administered intravenously. Their ability to migrate systemically and colonize the bone marrow after a peripheral injection has been utilized for treatment of Osteogenesis Imperfecta7.

Mechanism of action:

In addition to differentiation into bone, muscle, cartilage, ligament or tendon cells, MSCs also have a paracrine effect whereby they secrete growth factors and cytokines such as bone morphogenic proteins (BMPs), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF). These play an important role in angiogenesis, repair, cell survival and proliferation. MSCs also have the ability to migrate to the site tissue injury to modulate an inflammatory response8. Genetically modified MSCs for long term release of growth factors are being currently developed.

Role of Mesenchymal Stem Cells in Orthopaedic Surgery:

MSCs have an ability to develop into any mesodermal tissue. Thus, they can be prompted to form precursor cells to develop into tissues including bone, cartilage, muscle, tendon, and ligament. The use of stem cells for various orthopaedic challenges is outlined below.

Trauma and bone defects:

Nonunion/Delayed union and bone defects following trauma, tumor or infection are challenging aspects of orthopaedic surgery that may require biologic augmentation for optimum healing. Autologous cancellous graft is the current ‘gold standard’, but limited supply and donor site morbidity limit their use. Allografts and bone graft substitutes are routinely used to augment bone healing. However, poor graft integration and osteonecrosis of the graft remain primary issues with this method. Bone marrow aspirates that contain stem cells in a proportion of 1:10,000 to 1:1,000,000 of nucleated cells have been successfully used to enhance healing of non-unions5. Tissue engineering, involving the use of stem cells with scaffolds such as hydroxyapatite (HA), demineralized bone matrix (DBM) and tri-calcium phosphate (TCP), have been studied and found to be useful for bridging bone defects9. Due to absence of an extracellular matrix to grow on, MSCs alone have not proven to be beneficial for filling defects caused by simple/aneurysmal bone cysts10. Healing rates, are however, enhanced when these are used in conjunction with scaffolds.

Spine and peripheral nerve surgery:

Spine Fusion: 

Neen et al, in a prospective study, showed that unselected stem cells used with HA scaffolds had similar healing rates as autologous grafting; thereby preventing donor site morbidity11. Similar results were obtained by Gan et al using β-TCP12.

Intervertebral Disc Degeneration: 

Intervertebral disc degeneration is one of the most common causes of backache in a young productive population. Despite the high prevalence there is no treatment available which reverses the primary pathology. Animal experiments have shown increased proteoglycan content and maintenance of disc height with percutaneous stem cell injections13. Clinical trials are in progress to evaluate these results in humans with positive interim results14.

Spinal cord and peripheral nerve injuries: 

Spinal cord and peripheral nerve injuries have a significant impact on quality of life of affected individuals. Animal studies have highlighted some positive effects of MSC use via intrathecal and local administration, however, the response seen in clinical studies is mixed15. In an animal study, Tamaki et al, demonstrated that muscle derived MSCs aided in successful regeneration of a crushed peripheral nerve16. Further prospective clinical studies are necessary to establish the role of MSCs in managing these patients.

Articular cartilage:

Articular cartilage is a highly specialized tissue with a poor intrinsic capacity to repair itself. The goal of any cartilage procedure is to restore its integrity so that it can withstand the wear and tear of daily activity.

Focal cartilage damage: 

Since Pridie introduced subchondral drilling in the late 1950s, various procedures such as microfracture and abrasionplasty have been developed to recruit MSCs from adjacent bone marrow to proliferate into chondrocytes. Unfortunately, these procedures result in the formation of an inferior quality nonhyaline cartilage. Data on use of MSCs with suitable scaffolds in cartilage healing is mostly based on animal studies, with a few human case series showing improved healing and better function after autologous MSC implantation techniques17.

Osteoarthritis (OA): 

Due to their role in inhibiting the catabolic activity of matrix metalloproteinases (MMP), MSCs have been shown to have a beneficial effect in OA18. In a recent study, Sato et al showed that guinea pigs with age related OA treated with MSC laden hyaluronic injections had better cartilage regeneration with higher type II collagen and lower MMP content19. Except for a few case series which show some clinical improvement there is a paucity of trials with human subjects which study the effect of MSCs on OA20.

High tibial Osteotomy (HTO) and Arthoplasty: 

In a randomized control trial, Dallari et al showed that lyophilized bone chips treated as grafts with platelet gels and MSCs had higher rate of osteointegration in HTOs21. With appropriate use of nanotechnology to make optimum implant surfaces, MSCs have a great potential to revolutionize joint replacement surgery by facilitating osteointegration. Three dimensional scaffolds with MSCs may be used in the future to form autologous osteochondral grafts suitable for a ‘biologic’ arthroplasty22.

Avascular Necrosis:

Avascular Necrosis (AVN) of the head of femur is one of the most debilitating disorders in young patients. It is characterized by a decreased blood supply to the bone and associated increase in intraosseous pressure. The integrity of the subchondral plate is one of the most important deciding factor between head preserving (core decompression, bone grafting, femoral osteotomies) or head sacrificing (hip resurfacing/arthroplasty) procedures. Stem cells have angiogenic and osteogenic properties. Early stages of AVN are amenable to treatment with stem cell concentrate injection combined with routine retrograde procedures such as core decompression. Bone marrow aspirates administered after core decompression have been shown to be beneficial in AVN. Stem cells were isolated and used in a study by Rastogi et al where 60 hips in early stages of AVN were randomized to be treated either with core decompression and bone marrow injection or with core decompression and injection of isolated stem cells23. Two year follow up showed a better functional outcome and better radiographic healing in the stem cell group.

Wound Healing:

Although not typical in orthopaedic practice, poorly healing wounds are commonly encountered in treating patients with risk factors such as diabetes or open fractures. MSC treatment of acute and chronic wounds results in accelerated wound closure with increased epithelialization, granulation tissue formation and angiogenesis24.

Bone-Tendon interface and Tendon Healing:

Numerous commonly employed surgical procedures such as anterior cruciate ligament reconstruction, rotator cuff repair or retrocalcaneal bursa excisions depend on optimum healing of the bone-tendon interface. Fibrovascular scar formed during healing possesses inferior biochemical and mechanical properties. MSCs have been shown to promote early healing of the bone tendon interface by increasing the proportion of Sharpey’s fibers. MSCs used with bone morphogenic protein 2 (BMP-2) are associated with improved biomechanical properties of the bone tendon interface including stiffness and maximal load. A recent study by Adams et al showed that rats with Achilles tendon tear treated with stem cell-bearing sutures have higher failure strength and better histological properties25. Unselected MSCs were used for ultrasound-guided injections in a case series by Pascual-Garrido et al for chronic patellar tendinopathy with good clinical results26.

Paediatric Orthopaedics:

Osteogenesis Imperfecta (OI): 

This is a heterogenous group of diseases with abnormality of type I collagen primarily leading to increased susceptibility to fractures, slow growth and loss of bone mass. Systemic infusion of allogenic MSCs by Horwitz et al in six children with OI showed improvement in bone mass and bone growth acceleration7.

Physeal injuries: 

Bone bridge formation is an adverse complication following traumatic, infectious or other insult on the physis, leading to angular and/or longitudinal deformities. In a pig study, Planka et al showed that MSCs with scaffolds used in physeal defects differentiated into chondrocytes forming hyaline cartilage and prevented bony bridge formation27. Currently, there are no clinical studies to support this.


In spite of tremendous advances in drug therapy, osteoporosis plays a significant role in overall health of geriatric patients. Increasing age is associated with decrease in number and function of osteoblasts and osteoprogenitor cells. Systemic infusion of MSCs has failed to promote bone formation due to their inability to migrate to the surface of the bone, a critical step for bone formation. In an animal study, Guan et al used MSCs modified to express certain surface proteins which enabled them to migrate to the periosteum leading to increased trabecular bone formation and bone mass28. Concepts such as these are positive steps towards utilizing MSCs for a generalized disease like osteoporosis.

Muscular dystrophies:

These are group of conditions wherein muscle fibers are replaced by fibrotic and adipose tissues, due to genetic mutations in several muscle proteins, which are essential for normal muscle function. There is no cure for these patients and treatment is focused on comfort care, respiratory assistance and delaying loss of function. Local and systemic transplantation of well differentiated myoblasts is associated with poor cell survival, limited migration from injection site and immune rejection. In a phase I clinical trial, Torrente et al showed that muscle derived stem cells with specific surface markers were safely transplanted in eight boys with no side effects29. Genetically modified MSCs are being developed for potential use of these cells in Muscular dystrophies.

Biology human body

Embryos in glass!

The recipe for mammalian life is simple: take an egg, add sperm and wait. But two new papers demonstrate that there’s another way. Under the right conditions, stem cells can divide and self-organize into an embryo on their own. In studies published in Cell1 and Nature2 this month, two groups report that they have grown synthetic mouse embryos for longer than ever before. The embryos grew for 8.5 days, long enough for them to develop distinct organs — a beating heart, a gut tube and even neural folds.

The process is far from perfect. Just a tiny fraction of the cells develop these features and those that do don’t entirely mimic a natural embryo. But the work still represents a major advance that will help scientists to see organ development in unprecedented detail. “This is very, very exciting,” says Jianping Fu, a bioengineer at the University of Michigan in Ann Arbor. “The next milestone in this field very likely will be a synthetic stem-cell based human embryo,” he says.

The two research teams achieved the feat using similar techniques. Magdalena Zernicka-Goetz, a developmental and stem-cell biologist with laboratories at the University of Cambridge, UK, and the California Institute of Technology in Pasadena, has been working on this problem for a decade. “We started with only embryonic stem cells,” she says. “They can mimic early stages of development, but we couldn’t take it any further.” Then, a few years ago, her team discovered3 that when they added stem cells that give rise to the placenta and yolk sac, their embryos developed further. Last year, they demonstrated4 that they could use this technique to culture embryos until day 7. In their latest paper, published in Nature today, Zernicka-Goetz’s team describes how they grew embryos for another 1.5 days.

Embryos in glass

Zernicka-Goetz’s team did so with the help of a technique developed by Jacob Hanna, a stem-cell biologist at the Weizmann Institute of Science in Israel, who has also been working on this problem for years. Last year, Hanna’s team reported5 that they had developed a device that allowed them to culture natural mouse embryos for an unprecedented length of time outside the uterus. This incubator, which kept the embryos going from day 5 to day 11, takes aspects of a previous technology — in which the embryos reside in glass vials that rotate on a ferris-wheel-like system — and adds ventilation. The ventilation system controls the mixture of oxygen and carbon dioxide going into the vials, and the pressure.

After Hanna’s paper came out last year, his team shared part of their incubator with other developmental and stem-cell biologists. “The brain of this machine we shared with everyone who asked for it,” he says, including Zernicka-Goetz and her colleagues, who tweaked it slightly for their experiments. In a paper published in Cell on 1 August, Hanna’s team describes how they used the system to also grow embryos for 8.5 days. Full gestation in mice is about 20 days.

That period is long enough for the brain regions to develop, the heart to start beating, and the neural and gut tubes to form. These synthetic embryos look a lot like natural embryos that form when mouse sperm meets egg, but they “were not 100% identical”, Hanna says. “You can see some defects and some changes in the organ size.”

Each team grew their embryos by combining three different cell types, and Hanna’s team also managed to create all three types from naïve embryonic stem cells. “It offers a way to simplify the process,” Hanna says. “You can start everything from one population.” Zernicka-Goetz’s team reported a similar accomplishment in a preprint published6 on bioRxiv (In their Nature paper, the researchers relied on placenta precursor cells from a cell line to create the embryos.)

Brain development

Zernicka-Goetz’s team also conducted an experiment in which they knocked out a gene called Pax6, which has a key role in brain development. When they eliminated this gene, the mouse heads didn’t develop correctly, mimicking what occurs in natural embryos that lack that gene. The result demonstrates “that the system is actually functional”, says Zernicka-Goetz.

“These two papers, they empower one another,” says Martin Pera, a stem-cell biologist at the Jackson Laboratory Center for Precision Genetics in Bar Harbor, Maine. “Two very skilled groups can really produce rather similar results independently.”

For researchers, these synthetic models have many advantages over natural embryos created from eggs and sperm. Because they grow outside of the uterus, they’re much easier to observe. They’re also easier to manipulate using genome-editing tools. “We can perturb, we can manipulate, we can knock out every possible mouse or human gene,” Fu says. That could make them useful for uncovering the role of different genes in birth defects or developmental disorders. Zernicka-Goetz plans to use this model to understand why pregnancies fail.

Hanna hopes to use the technique to develop human synthetic embryos that can be a source of new organs and tissues for people who need them.

What about humans?

But translating this work into humans won’t be easy. Researchers have coaxed human stem cells to become blastocysts and even to mimic some aspects of gastrulation — when the early embryo organizes into distinct layers composed of different cell types. But reaching the stage of organ formation in human cells, which happens about a month after fertilization, presents a significant technical challenge. Still, Ali Brivanlou, a developmental biologist at Rockefeller University in New York, is optimistic. “The field is not too far away.”

And the more advanced these embryos become, the greater the ethical concerns. One key question is whether these synthetic structures should be considered embryos, a point of debate in the field. The International Society for Stem Cell Research has long advised against culturing human embryos past day 14 (equivalent to day 6 in a mouse) — roughly when the ‘primitive steak’ appears, the structure that marks the beginning of gastrulation. In 2021, the society removed the limit and issued news guidelines saying that such research should have a compelling scientific rationale, and should use the minimum number of embryos necessary to achieve the scientific objective.

Still, Pera sees a need for a continued conversation about the ethics of such models. Researchers have been working on human embryo models for years without much opposition. But he worries about a backlash as researchers begin to develop human embryo models that start developing organs. “The reaction to that could jeopardize this whole field of research,” he says. “It’s important that people know what is being proposed and that it’s done with some kind of ethical consensus,” adds Pera. “We have to go cautiously.”

Biology human body

Most Common Cancers in Women

What are the most common cancers in women?

The most common types of cancer among women in the U.S. are skin, breast, lung, colorectal and uterine. Cervical and ovarian cancer affect only women and are also a significant cause of cancer worldwide. With early detection, cancer is more likely to be treated successfully.

What is breast cancer?

Breast cancer is the most common cancer in women other than skin cancer. It occurs in the breast cells and can spread to the lymph nodes under the arms. In the U.S. this year, there will be an estimated 276,480 new cases of invasive breast cancer in women and 2,620 cases in men.

Risk factors that increase your likelihood of developing breast cancer include:

  • Drinking alcohol
  • Being obese or overweight
  • Living a sedentary lifestyle
  • Not becoming pregnant
  • Not breastfeeding
  • Use of birth control, particularly oral contraceptives
  • Hormone therapy after menopause

There is no definite way to avoid breast cancer, but there are precautions you can take. Consume a healthy diet, be physically active, breastfeed if you have children and see your healthcare provider annually for routine screenings. Women, and men, who have a strong family history of breast cancer may want to have genetic testing to learn if they’ve inherited a mutation of the BRCA1 or BRCA2 genes.

Normally, BRCA1 and BRCA2 are tumor suppressor genes that play a primary role in stopping abnormal cell growth in breasts, ovaries and other cells. If one of these genes is broken, it can increase the risk of developing cancer. When a parent carries a BRCA gene mutation, their male and female children have a 50% chance of inheriting it.

If you think you may have inherited a BRCA1 or BRCA2 genetic mutation, a genetic counselor can provide testing and advise you and your family on your risk. The screening involves a simple blood test. About 1 in every 500 women in the United States has a BRCA1 or BRCA2 gene mutation.

What are the common signs and symptoms of breast cancer?

If any of these breast or nipple changes occur, make an appointment to see your healthcare provider.

  • Breast lump
  • Nipple changes
  • Dimpling in your breast (like an orange peel)
  • Swollen breast
  • Lump in your underarm
  • Nipple discharge – particularly concerning is spontaneous or bloody discharge. Stimulation of the breasts, hormones, pregnancy and lactation can cause normal nipple discharge.
  • Breast or nipple pain
  • Nipple retraction (inward into the breast)
  • Red, itchy, scaly or thick skin on your breast

How does breast cancer start? 

  • Hereditary breast cancer can occur if you have inherited a genetic mutation in one of the BRCA genes from your parents.
  • Acquired breast cancer develops from changes that take place in the breast throughout your life. Acquired genetic mutations can result from radiation, cancer-causing chemicals and other unknown environmental factors.

Early detection of breast cancer in women

One of the best ways to screen for breast cancer is to visit your healthcare provider. By having an annual breast screening, you can take charge of your breast health. The University of Kansas Health System recommends all women begin screening mammograms at age 40

What is ovarian cancer?

Another common cancer in women is ovarian cancer, which is the abnormal growth of cells in the ovaries and fallopian tubes. Ovarian cancer occurs when cells grow out of control and form tumors on the ovaries and fallopian tubes.

The American Cancer Society projects 21,750 new cases of ovarian cancer in 2020. The following risk factors may increase your likelihood of developing ovarian cancer:

  • Obesity
  • Diabetes
  • History of talcum powder use in the genital area
  • Endometriosis
  • Hormonal replacement therapy 
  • Smoking
  • Polycystic ovary syndrome
  • A positive family history of breast, uterine, cervical, bowel or ovarian cancer or Lynch syndrome

There is no screening available to detect ovarian cancer, but you may be at higher risk if you carry a genetic mutation known as BRCA1 or BRCA2. Talk with a genetic counselor to learn more and request genetic testing. 

What are the common signs and symptoms of ovarian cancer?

  • Vaginal bleeding (past menopause)
  • Abnormal vaginal discharge
  • Pelvic pain
  • Lower back or abdominal pain
  • Bloating
  • Feeling full quickly
  • Difficulty eating
  • Nausea
  • Pelvic pressure
  • Menstrual changes
  • Weight loss
  • A change in bathroom habits
    • Frequent or urgent urination
    • Frequent or urgent bowel movements
    • Constipation

How does ovarian cancer start?

Ovarian cancer begins with tumors on or in the ovaries and fallopian tubes. Cancerous epithelial tumors are the most common type of ovarian cancer. The following are subtypes of ovarian carcinoma:

  1. Serous carcinoma
  2. Endometrioid carcinoma
  3. Clear cell carcinoma
  4. Mucinous carcinomas

Early detection of ovarian cancer in women

Early detection of ovarian cancer is challenging as cancer symptoms can be vague and are often not acute or intense. That’s why it is critical to know your body and listen to any changes. Trust yourself and schedule an appointment to see your gynecologic healthcare provider.

Those who are BRCA positive should see a gynecologic oncologist to perform additional screenings for ovarian cancer. Women with possible ovarian cancer symptoms can receive the following tests:

  • CA-125 blood draw: Evaluates your blood for a protein that is elevated in those with cancer. However, other reasons can cause it to become elevated like your menstrual cycle, endometriosis or pregnancy.
  • Transvaginal ultrasound: An ultrasound probe that is inserted into your vagina to examine your pelvic organs.

What is cervical cancer?

Another common cancer in women is cervical cancer. More than 500,000 new cases of cervical cancer were diagnosed worldwide in 2018. The ACS projects 13,800 new cases of cervical cancer in the U.S. in 2020.

The following risk factors increase your possibility of developing cervical cancer:

  • Contracting human papillomavirus or HPV (accounts for 90% or more of all cervical cancer cases)
  • Abnormal pap smear
  • Smoking
  • HIV or AIDS infection
  • Using birth control pills for more than 5 years
  • Giving birth to 3 or more children
  • Having multiple sex partners

There are ways to decrease your risk for cervical cancer:

  • HPV vaccine that protects against the high-risk types of HPV that cause vaginal, vulvar and cervical cancer
  • Quitting smoking (or never starting)
  • Using condoms for sexual intercourse

What are the common signs and symptoms of cervical cancer?

Cervical cancer does not show signs or symptoms early on. However, as the disease advances, it can cause abnormal vaginal bleeding or discharge (like after sex).

How does cervical cancer start?

Cervical cancer occurs as a result of a genetic change in the DNA of healthy cervical cells. The cells grow and multiply at an abnormal rate, eventually forming cancerous tumors. Most of the time, cancer is caused by HPV.

Early detection of cervical cancer in women

A Pap test and HPV screening can detect cervical cancer early. You should begin having a Pap test when you become sexually active or turn 21. You should have a Pap test every 3 years or combined Pap/HPV test every 5 years until age 65. You can also receive the HPV vaccine up to the age of 45. Talk with your healthcare provider to learn more about the HPV vaccine.

To perform the screening, your provider will collect a small sample of cervical cells:

  • The Pap smear looks for precancerous cell changes on the cervix that have the potential to become cervical cancer if left untreated.
  • The HPV test looks for the virus that causes abnormal cell changes to the cervix.

If any abnormalities are found during your screening exams, your healthcare provider will determine whether you need a follow-up screening or if you require additional testing.

What is uterine cancer?

Cancer of the uterine lining is also known as endometrial cancer. It is the most commonly diagnosed gynecologic malignancy. The uterus, or womb, is an organ that is hollow and pear-shaped. Menstrual cycles and fetal development occur here.

Uterine cancer is more likely to occur in women age 55 and over. In 2020, the ACS estimates 65,620 new cases of uterine cancer will be diagnosed. While there is no way to prevent uterine cancer, your risk may be less if you take oral contraceptives, use progesterone with your estrogen hormone replacement therapy and maintain a healthy weight.

Risk factors include:

  • Hormone replacement therapy (estrogen without progesterone)
  • Obesity
  • Taking tamoxifen for breast cancer
  • Diabetes
  • Family history of cancer or Lynch syndrome

What are the common signs and symptoms of uterine cancer?

  • Bleeding after menopause
  • Spotting between periods
  • Bloody, malodorous discharge

How does uterine cancer start?

Uterine cancer occurs in the cells that form the lining of the uterus (endometrium). When the cells grow out of control and crowd out healthy cells, they can become cancerous.

Early detection of uterine cancer in women

Have regular screenings with your healthcare provider. The Pap test does not screen for endometrial cancer, so discuss warning signs with your healthcare provider if you are concerned.

If you experience symptoms, your healthcare provider can perform an endometrial biopsy, which involves collecting cells from your endometrial lining. The test is conducted with a pipette through your cervix.

What is lung cancer?

Lung cancer, a leading cancer in women, affects the lungs – 2 spongy organs that help you breathe in oxygen and release carbon dioxide. The windpipe is called the trachea, which further breaks into the bronchia, bronchioles and alveoli. Lung cancer can occur in any of these locations.

For 2020, the ACS projects 228,820 new diagnoses of lung cancer.

The main risk factors for lung cancer are smoking or secondhand smoke. The best lifestyle choice to make is to quit smoking, never start smoking and avoid secondhand smoke at all costs. It’s never too late to quit smoking. Call 1-800-QUIT-NOW (800-784-8669) to connect directly with your state’s quit line and speak to a specially trained counselor to help you stop smoking.

What are the common signs and symptoms of lung cancer?

  • Shortness of breath
  • A prolonged and lasting cough
  • Chest pain
  • Bloody mucous

How does lung cancer start?

Lung cancer occurs when abnormal cells grow out of control in the lungs. As the cells continue to develop, they form a tumor. If the tumor spreads beyond the lungs, it is called metastases. Metastatic lung cancer is when lung cancer spreads beyond the lungs.

Early detection of lung cancer in women

The ACS recommends screening for current or former smokers ages 55-74. Talk with your healthcare provider about having an annual low-dose CT scan to determine your risk for lung cancer. Low-dose CT scans can identify lung cancer in its early stage, while it is still highly treatable.

What is colorectal cancer?

Colorectal cancer affects the large and small intestines, which includes the rectum. The following factors increase your risk for developing colorectal cancer:

  • Being African American
  • Being over age 50
  • Having a family history of colorectal cancer (more than 1 family member)
  • Having a family history of Lynch syndrome or familial adenomatous polyposis
  • Having a personal history of polyps or colorectal cancer
  • Having chronic inflammatory intestinal disease (ulcerative colitis or Crohn’s disease)

The following lifestyle factors may also increase your risk of developing colorectal cancer:

  • A low-fiber, high-fat diet
  • Diabetes
  • Obesity
  • Sedentary lifestyle
  • Alcohol
  • Smoking
  • Radiation therapy for cancer

Cancer can occur in any part of the colon:

  • Cecum
  • Ascending colon
  • Transverse colon
  • Descending colon
  • Sigmoid colon

In 2020, there will be an estimated 148,000 new cases of colorectal cancer diagnosed in the U.S. 

  • When cancer is limited to the large bowel, it is colon cancer.
  • The rectum is the last few inches of the large intestine that starts at the end of your colon and ends when it reaches the short, narrow passage leading to the anus. If cancer occurs in this area, it is called rectal cancer.
  • When cancer involves both the rectum and the large intestine, it is colorectal cancer.

What are the common signs and symptoms of colorectal cancer?

Some symptoms can be confused with symptoms of irritable bowel syndrome or other gastrointestinal disease. However, if you notice any of the following, contact your healthcare provider immediately. Symptoms of colorectal cancer include:

  • Dark, bloody, thin or tarry stools from bleeding or obstruction in your GI tract.
  • Constipation or diarrhea or any other change in your stools
  • Significant abdominal pain or cramps
  • Weakness and fatigue unrelated to lifestyle
  • Unexplained weight loss
  • Increased bowel movements due to a tumor that is on or near your intestines

How does colorectal cancer start?

Abnormal growths, called polyps, can form in the colon or rectum. These abnormal growths, left untreated, can turn into cancer and grow through the walls of the colon and into the rectum. If they spread to other areas in the body, it is known as metastatic cancer.

Early detection of colorectal cancer in women

Screening tests in several different ways:

  1. Stool test – checks your stool for signs of polyps or cancer annually
  2. Sigmoidoscopy – a short, thin, flexible, lighted tube inserted into your rectum every 5 years
  3. Colonoscopy – like a sigmoidoscopy, but a longer tube, to scope your intestines through your anus every 10 years

Screening guidelines broken down by age:

  • 18-39: Screening is not necessary unless you have a strong family history of colorectal cancer, Lynch syndrome, familial adenomatous polyposis, or a condition like ulcerative colitis or Crohn’s disease.
  • 40-49: Some colorectal cancer screening recommendations begin at age 45. Talk with your healthcare provider to see which test is best for you.
  • 50+: Colonoscopy every 10 years or as recommended by your healthcare provider.

These screening standards are for healthy adults. Depending on your particular situation, you may need to be tested more often. Determining what is right for you can be confusing because cancer screening recommendations vary. Talk with your healthcare provider to understand what’s right for you.

Biology Covid-19 human body

Monkeypox in India

On 17 July, a suspected case of Monkeypox was reported in Andhra Pradesh’s Vijayawada in a child who recently returned from Saudi Arabia. However, the blood samples of the child tested negative, said Superintendent GGH Hospital Nageshwara Rao

With over 6,000 cases across 60 countries and 3 deaths, Monkeypox reported its first case in India on 14 July, 2022.

A 35 year-old Keralite who returned from the UAE tested positive for the virus. India on Thursday reported its first case of monkeypox in Kerala. The infected person, a man, returned to the state from the United Arab Emirates (UAE) four days ago and was hospitalised after showing signs of the virus, Kerala health minister Veena George confirmed.

On 17 July, a suspected case of Monkeypox was reported in Andhra Pradesh’s Vijayawada in a child who recently returned from Saudi Arabia. However, the blood samples of the child tested negative, said Superintendent GGH Hospital Nageshwara Rao.

Indian government on Monkeypox

After the first confirmed case, the Indian government deployed a multi-disciplinary team to the southern state to tackle the outbreak.

The Indian Council of Medical Research (ICMR) trained 15 research and diagnostic laboratories across the country for early detection of the virus. “To help country’s preparedness for Monkey Pox detection, 15 Virus Research & Diagnostic Laboratories across the country, which are geographically well distributed & strategically located, have already been trained in the diagnostic test by ICMR -NIV, Pune,” the ICMR said on Twitter.

The Health Ministry on 15 July issued guidelines for the management of the disease after the first monkeypox case was detected.

As per the ministry’s guidelines, international passengers should avoid close contact with sick people, contact with dead or live wild animals and others.

It also advised the international travellers from eating or preparing meat from wild game (bushmeat) or using products (creams, lotions, powders) derived from wild animals from Africa.

Apart from this, International passengers should also avoid contact with contaminated materials used by sick people such as clothing, bedding or materials used in healthcare settings, or that came into contact with infected animals, said the ministry’s guidelines.

In addition, if people develop symptoms suggestive of monkeypox like fever and skin rash and were in an area where monkeypox has been reported or had come in contact with a person who might have monkeypox are advised to immediately consult the nearest health facility.

Steps taken by Kerala government:

Apart from this, Kerala too stepped up vigil to prevent the spread of monkeypox, issuing special alerts to five districts – Thiruvananthapuram, Kollam, Pathanamthitta, Alappuzha and Kottayam. The state also intensified surveillance at airports.

State Health Minister Veena George on 17 July said that the Health Department is observing those with chicken pox or similar symptoms in order to ensure that they do not have monkeypox. 

She said random samples would be tested to ascertain whether anyone else was infected. 

She said training for monkeypox prevention is being held in a comprehensive manner and till now over 1,200 health workers have been trained. 

“The health condition of the patient who was confirmed with the infection is stable. No one else has been diagnosed with the disease yet. All his contacts are under observation. The Health Department is constantly in touch with his contacts and speaks to them twice a day over phone to enquire about their mental and physical health,” the Minister said.

Monkeypox symptoms: 

Most monkeypox patients experience only fever, body aches, chills and fatigue. People with more serious illness may develop a rash and lesions on the face and hands that can spread to other parts of the body.

It starts with what we call macules. These are just red areas. Then it progresses to papules. This is something you can feel, World Health Organization’s (WHO) Dr Rosamund Lewis said, as reported by BBC.

Those red lumps and bumps then start to blister, and fill with a whitish fluid. In time, they start drying out and scab over. Eventually, the scabs will heal and drop off.

A monkeypox rash usually starts on the face – sometimes in the mouth too – and then the arms and legs, hands and feet, as well as the trunk of the body.

Earlier, on 15 July, AIIMS’ Department of Medicine Additional Professor Piyush Ranjan assured that there is no reason to worry, but he cautioned that monkeypox can be fatal for children as compared to the covid virus. “No reason to worry as the monkeypox virus’s infectivity is very less though it can be fatal for children as compared to the covid virus,” ANI quoted Piyush Ranjan as saying. 

Elaborating on the symptoms, Dr. Ranjan said that monkeypox symptoms are like smallpox and chickenpox. “At the onset, patients will have fever, and enlargement of lymph nodes. After 1-5 days, they may report rashes on the face, palms & soles. They may have rashes in the cornea leading to blindness,” he added.

Though, the World Health Network (WHN) announced monkeypox outbreak a pandemic, the World Health Organisation (WHO) announced that it will hold an emergency meeting next week to assess if monkeypox should be declared a global emergency. 

Last month, the agency said the outbreak did not yet warrant the declaration but said it would review issues such as the possibility that monkeypox might be infecting more vulnerable populations like children, and whether the virus is causing more severe disease.

Biology Covid-19 human body

COVID-19 & Heart Problems

Can COVID-19 damage the heart?

Yes: Although COVID-19 is primarily a respiratory or lung disease, the heart can also suffer.

Temporary or lasting damage to heart tissue can be due to several factors:

Lack of oxygen. As the virus causes inflammation and fluid to fill up the air sacs in the lungs, less oxygen can reach the bloodstream. The heart has to work harder to pump blood through the body, which can be dangerous in people with preexisting heart disease. The heart can fail from overwork, or insufficient oxygen can cause cell death and tissue damage in the heart and other organs.

Myocarditis: inflammation of the heart. The coronavirus may infect and damage the heart’s muscle tissue directly, as is possible with other viral infections, including some strains of the flu. The heart may also become damaged and inflamed indirectly by the body’s own immune system response.

Coronavirus infection also affects the inner surfaces of veins and arteries, which can cause blood vessel inflammation, damage to very small vessels and blood clots, all of which can compromise blood flow to the heart or other parts of the body. “Severe COVID-19 is a disease that affects endothelial cells, which form the lining of the blood vessels,” Post says.

Stress cardiomyopathy. Viral infections can cause cardiomyopathy, a heart muscle disorder that affects the heart’s ability to pump blood effectively. When attacked by a virus, the body undergoes stress and releases a surge of chemicals called catecholamines, which can stun the heart. Once the infection resolves, the stressor has ended and the heart can recover.

Cytokine Storm: A Serious Coronavirus Complication

Most serious of all, Gilotra says, is the possibility of the immune system launching an attack on the invading virus that is so severe that it destroys healthy tissues.

When responding to infection with the coronavirus, the body releases a flood of proteins called cytokines that help cells communicate with one another and fight the invaders.

In some people, perhaps due to a genetic difference, this normal defensive event is exaggerated, leaving them vulnerable to a cytokine storm. In a cytokine storm, the immune system response causes inflammation that can overwhelm the body, destroying healthy tissue and damaging organs such as the kidneys, liver and heart.

A cytokine storm and its resulting heart damage can also affect the heart’s rhythm. “Serious ventricular arrhythmias due to a cytokine storm can be catastrophic,” Gilotra says.

A cytokine storm is difficult to survive. Current research is exploring the possible benefit of using immune-suppressing drugs to treat patients with COVID-19 who experience this serious complication.

Heart Rate and COVID-19

After you have had COVID-19, if you are experiencing a rapid heartbeat or palpitations, you should contact your doctor. A temporary increase in heart rate can be caused by a lot of different things, including dehydration. Make sure you are drinking enough fluids, especially if you have a fever. Symptoms of a rapid or irregular heart rhythm may include:

  • Feeling your heart beat rapidly or irregularly in your chest (palpitations)
  • Feeling lightheaded or dizzy, especially upon standing
  • Chest discomfort

How can I tell if I have developed a heart problem after COVID-19?

In some people, heart rates can vary from fast to slow, unrelated to exertion, for no apparent reason. But, Post says, shortness of breath, chest pain or palpitations after having COVID-19 is a common complaint. “Any of these problems could be related to the heart, but they could also be due to other factors, including the aftermath of being very ill, prolonged inactivity and spending weeks convalescing in bed.”

Shortness of Breath

“You want to consult a doctor if any of your symptoms are severe, especially shortness of breath,” Post says. She recommends using a commercially available O2 (oxygen) saturation monitor.

“Shortness of breath by itself is not always a sign of a serious problem, but if you have that symptom along with low O2 (below 92%), that is a reason to be concerned.” Sometimes people are short of breath with exertion after COVID-19 because they have been less active for a long time and need to gradually build their fitness level back up.

A diagnosis of heart failure after COVID-19 is rare. But if you have shortness of breath or leg swelling after COVID-19, you should contact your doctor, who may recommend evaluation by a cardiologist if tests indicate you are at risk.

COVID-19 Chest Pain

What about lingering chest pain, another common post-COVID complaint? “Chest pain may be nothing serious, but if you are having severe chest pain, get help, especially if it is persistent or if you are also having nausea, shortness of breath or lightheadedness: These could be symptoms of a heart attack.”

“If you have chest pain when you inhale, you might have lung inflammation. Sudden, severe chest pain could be a blood clot in the lung (pulmonary embolism),” Post says.

People recovering from the coronavirus sometimes show symptoms of a condition known as POTS (postural orthostatic tachycardia syndrome). Researchers are exploring whether or not there is a link.

POTS isn’t directly a cardiac problem, but a neurologic one that affects the part of the nervous system that regulates heart rate and blood flow. The syndrome can cause rapid heartbeats when you stand up, which can lead to brain fog, fatigue, palpitations, lightheadedness and other symptoms.

Can COVID-19 symptoms mimic a heart attack?

Yes. People with COVID-19 can have symptoms similar to those of a heart attack, including chest pain, shortness of breath and changes on their echocardiogram (ultrasound of the heart) or EKG. But often when these patients are given an angiogram, there is no evidence of a major blockage in the heart’s blood vessels, which would indicate a heart attack in progress.

Symptoms of myocarditis can also mimic those of a heart attack. Also, viral infections such as COVID-19 can cause very small blood clots to form, which can block tiny blood vessels and cause pain.

People with signs and symptoms of a heart attack should seek urgent medical attention and not manage these symptoms at home.

Is a heart attack more likely after COVID-19?

That depends: Post says that “heart attack” has several different forms. A type 1 heart attack, caused by a blood clot blocking one of the heart’s arteries, is rare during or after COVID-19 infection.

“Type 2 heart attacks are more common with COVID-19,” she says. “This heart attack can be caused by increased stress on the heart, such as a fast heartbeat, low blood oxygen levels or anemia, because the heart muscle isn’t getting enough oxygen delivered in the blood in order do this extra work. We have seen this in people with acute coronavirus disease, but it is less common in those who have survived the illness.”

“Blood tests have shown that during COVID-19, some people have elevated levels of a substance called troponin in their blood, along with EKG changes and chest pain.” Elevated troponin levels are a sign of damaged heart tissue. Sometimes this is from a heart attack. This is less commonly seen after COVID-19.

“During acute COVID-19, elevated troponin levels with an abnormal EKG are linked to higher mortality, but not in patients with a normal EKG,” Post says.

What about heart problems in children after COVID-19?

In general, children who get sick with the coronavirus do not have serious problems as often as adults do. An uncommon but serious complication of COVID-19 called multisystem inflammatory syndrome in children, or MIS-C, can cause serious heart damage, cardiogenic shock or death.

Some children who survive MIS-C can be left with abnormal heart rhythms and stiffened heart muscle that prevents the heart from relaxing normally and beating properly. MIS-C has some similar characteristics to Kawasaki disease.

Is heart damage caused by COVID-19 permanent?

Post says that if symptoms are due to a cardiac cause, recovery depends on the severity of injury. “Very few people have a severe heart attack, such as an acute myocardial infarction, or MI, due to COVID-19,” she says.

Still, heart imaging can reveal minor changes in the heart muscle of some COVID-19 survivors. Post notes that some studies on athletes recovering from the coronavirus have shown some scarring, but stresses that some of these studies did not compare these results with those who had not had COVID-19. How long these minor changes persist — and how they affect heart health — are not yet known. Experts are developing protocols and recommendations for which athletes should get cardiac testing before returning to play.

COVID-19 can also affect the strength of the heart pumping, Post says, but subtle abnormalities in heart pumping are not likely to cause people problems.

A person recovering from COVID-19 may benefit from physical therapy, breathing exercises and, most of all, time. Post advises anyone recovering from COVID-19 should expect a gradual course of recovery, and should not expect a rapid return to their normal activity levels.

Can having COVID-19 make an existing heart condition worse?

“A heart condition could be exacerbated by severe COVID, but not likely after mild or asymptomatic cases,” Post says. “But the effects of the coronavirus on preexisting heart disease are not yet known.”

Can heart problems show up long after COVID-19 recovery?

If you have had COVID-19, recovered and feel all right now, should you worry? Are heart problems likely to show up later on?

Post emphasizes that many of these questions do not have clear answers yet. SARS-CoV-2 was isolated in 2019, and a large number of COVID-19 survivors have only been recovering since 2020. “It is hard to know exactly how the disease will affect people’s hearts long term, and this is just one area of intense concern among researchers

Biology human body

Foods in osteoporosis

Eating a healthy diet rich in essential nutrients such as calcium, vitamin D, and protein can help reduce the risk of osteoporosis. In addition, limiting caffeine and alcohol intake may be beneficial for bone health, especially among older adults.

Worldwide, 1 in 3 females and 1 in 5 males over the age of 50 will be affected by a broken bone due to osteoporosis, and osteoporosis or low bone mass affects 54%Trusted Source of Americans.

A person’s diet can affect bone health, so people must consider nutrition to maintain their bone mass.

This article discusses how nutrients affect the bones and which foods are best to eat and avoid.

How diet affects bone health

Bone does not remain static throughout life — it is constantly breaking down and rebuilding as part of normal bone metabolism.

Two main types of cellsTrusted Source, osteoblasts and osteoclasts, participate in this process. Osteoblasts form new bone, while osteoclasts break down old bone in a process called resorption.

However, if bone metabolism becomes unbalanced, bones can become less dense, weaker, and brittle. As a result, a doctor may diagnose low bone mass or osteoporosis.

Several factorsTrusted Source can cause bone loss, including aging, menopause, and certain medications.

Moreover, consuming key nutrients for bone health can help to reduce the risk of osteoporosis and keep bones healthy.

Individuals should ensure to include the following nutrients and foods in their diet to keep bones healthy:


The National Institute of Arthritis and Musculoskeletal and Skin Diseases advises that low calcium intake throughout life has an association with low bone mass and high fracture rates.

From 51 years, females require 1,200 milligrams (mg) of calcium daily, and males need 1,000 mg.

People can ensure they consume calcium by including dairy or soy products, fish with bones, and leafy green vegetables in their diets.

The following shows the calcium content of some common foods:

  • fortified oatmeal, packet: 350 mg calcium
  • sardines, canned in oil, with edible bones, 3 ounces (oz): 324 mg calcium
  • cheddar cheese, 1.5 oz, shredded: 306 mg calcium
  • milk, nonfat, 1 cup: 302 mg calcium
  • tofu, firm, with calcium, 0.5 cup: 204 mg calcium
  • orange juice, fortified with calcium, 6 oz: 200–260 mg calcium
  • baked beans, 1 cup: 142 mg calcium

Vitamin D

The body needs vitamin D to absorb calcium, and a deficiency of vitamin D could cause the weakening of the bones and skeleton.

Experts recommend that individuals up to 70 years have a daily intake of 600 IU (International Units) of vitamin D.

People over age 70 should increase their uptake to 800 IU daily, which they can also obtain from supplements.

People can get vitamin D from sunlight and food. The following foodsTrusted Source contain vitamin D:

  • egg yolks
  • oily fish such as salmon, trout, mackerel, and tuna
  • beef liver
  • cheese
  • mushrooms that producers have treated with UV light
  • milk, margarine, orange juice, and cereals that manufacturers have fortified with vitamin D


Research suggests that protein can be both beneficial and detrimental to bone health, as different studies have produced different results on the effects of protein on bone health.

However, according to the Framingham OsteoporosisTrusted Source study, there is a link between low protein intake and greater bone loss and hip fractures in older adults.

The study concluded that the combination of sufficient protein and calcium intake appears to benefit bone mineral density (BMD).

Therefore, eating a diet with sufficient protein and calcium seems wise. Protein-rich foods include:

Micronutrients and antioxidants in fruits and vegetables

The Framingham Osteoporosis Study identified that people with a higher fruit and vegetable intake had better BMD and less bone loss.

The nutrients in fruits and vegetables that the study indicated are beneficial to bone health includeTrusted Source:

2017 cross-sectional studyTrusted Source of Chinese people aged 40–75 years found that a higher fruit and vegetable intake correlates with higher BMD and lowers the risk of osteoporosis.

Additionally, a 2019 meta-analysisTrusted Source found moderate-quality evidence that increasing a person’s fruit and vegetable intake by at least one serving per day decreases the risk of fractures.

Foods to limit or avoid

In addition to eating a healthy diet to support bone health, people should be aware of some detrimental foods and drinks.


According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, overconsumption of salt can cause the kidneys to excrete calcium.

Therefore, people who have a low calcium intake should avoid adding salt to food or eating too many processed foods that can contain excess salt.

Foods containing oxalates and phytates

The Bone Health and Osteoporosis Foundation advises that some substances in food can interfere with the body’s ability to absorb calcium.

These include phytates in beans, wheat bran, and legumes and oxalates in spinach and beets. Soaking and cooking these foods can help to reduce these compounds.


Experts advise that alcohol negatively affects bone health for several reasons.

Firstly, drinking excessive alcohol can interfere with the body’s absorption of calcium and vitamin D.

In addition, chronic heavy drinking can disrupt hormones, such as elevating cortisol levels, which can break down more bone. Males may produce less testosterone, a hormone that has links to bone formation, while females may notice irregular menstrual cycles. Irregular menstrual cycles can reduce the amount of estrogen in the body, which increases the risk of osteoporosis.

Moreover, people under the influence of alcohol are more at risk of falls and bone fractures.


A 2021 study found that 800 mg of caffeine consumed in 6 hours increased the clearance of calcium by the kidneys by 77%Trusted Source.

An older studyTrusted Source suggests that as coffee may increase the amount of calcium the body excretes in urine, people should not drink more than three cups per day, especially if they are older.

Additionally, the Bone Health and Osteoporosis Foundation advises that caffeine in soft drinks such as colas can have the same adverse effects.

Learn 11 ways to increase bone density naturally.


To protect bones throughout life, people should eat a healthy diet containing essential nutrients and engage in physical activity.

Calcium, vitamin D, and protein are vital protective nutrients and vitamins, minerals, and antioxidants in fruit and vegetables.

Older adults may wish to limit coffee to three cups per day and avoid excessive alcohol.

Avoiding excessive alcohol and salt may be beneficial for everyone for overall health and well-being, especially those who have limited calcium intake.

Biology Covid-19 human body

SARS-CoV-2 Variants Develop in Chronic, Immunosuppressed Patients

SARS-CoV-2 variants have been a key player in the conversation, and public health response, of the COVID-19 pandemic. But where do COVID-19 variants originate? Now, new research reveals that the many SARS-CoV-2 variants are likely formed in chronic COVID-19 patients who suffer from immunosuppression. The research suggests that a weakened antibody response, particularly in the lower airways of these chronic patients, may prevent full recovery from the virus and drive the virus to mutate many times during a lengthy infection. The virus’ ability to survive and reproduce in the immunosuppressed patient’s body—without restriction—leads to the evolution of many variants.

Furthermore, the variants found among those chronically ill with COVID-19 bear many of the same mutations in their evolution as those present in variants-of-concern (VOC) for severe illness—particularly those mutations associated with evading antibodies. The new findings indicate that while rapidly-spreading variants are rare among the many strains borne from immunosuppressed patients, the likelihood increases and they do arise when global infection rates boom.

Since the start of COVID-19, the rate at which the virus evolves has been somewhat puzzling to Adi Stern, PhD, professor of biotechnology at the Shmunis School of Biomedicine and Cancer Research at the Wise Faculty of Life Sciences at Tel Aviv University. During the first year of the pandemic, a relatively slow but constant rate of mutations was observed. However, since the end of 2020, the world has witnessed the emergence of variants that are characterized by a large number of mutations, far exceeding the rate observed during the first year. Various scientific hypotheses about the link between chronic COVID-19 patients and the rate of the accumulation of mutations have surfaced, but nothing definitive has been proven.

“The coronavirus,” noted Stern, “is characterized by the fact that in every population, there are people who become chronically infected. In the case of these patients, the virus remains in their body for a lengthy period of time, and they are at high risk for recurrent infection. In all of the cases observed so far, these were immunocompromised patients. In biological evolutionary terms, these patients constitute an “incubator” for viruses and mutations—the virus persists in their body for a long time and succeeds in adapting to the immune system, by accumulating various mutations.”

The study searched for drivers of VOC-like emergence by consolidating sequencing results from a set of 27 chronic infections in patients at the Tel Aviv Sourasky Medical Center.

According to Stern, the results reveal a complex picture; although no direct connection was found between anti-COVID-19 drug treatment and the development of variants, the researchers discovered that it is likely the weakened immune system of immunocompromised patients that creates pressure for the virus to mutate.

Most substitutions in this set, the authors noted, reflected lineage-defining VOC mutations; however, a subset of mutations associated with successful global transmission was absent from chronic infections.

In fact, the researchers found that there were chronic patients who showed a pattern of apparent recovery, followed by recurring viral infection. In all of these patients, a mutated form of the virus emerged, suggesting that recovery had not been achieved; this is partially reminiscent of HIV following inadequate drug treatment.

Upon closer examination of some patients, the researchers found that when such a pattern of apparent recovery is observed (based on negative nasopharyngeal swabs), the virus continues to thrive in the lungs of the patients. The researchers, therefore, suggest that the virus accumulates mutations in the lungs, and then traverses back to the upper respiratory tract.

The authors believe that they found evidence for dynamic polymorphic viral populations in most patients, suggesting that a compromised immune system selects for antibody evasion in particular niches in a patient’s body. In addition, there is a tradeoff between antibody evasion and transmissibility and that extensive monitoring of chronic infections is necessary to further understanding of VOC emergence

Biology human body

stem cells advance & medicine

Stem cells could help medicine in three general ways: cell-based therapies, drug discovery and basic knowledge. Cell therapies would use stem cells, or cells grown from stem cells, to replace or rejuvenate damaged tissue. Scientists also want to use stem cells to understand disease and find drugs that might treat it.

Embryonic stem cells could be used to make more specialized tissues that have been lost to disease and injury. For tissues that are constantly replaced, like blood and skin, stem cells would probably be replaced directly. Researchers are also exploring ways to use stem cells to treat diabetes, Parkinson’s disease, spinal cord injury, heart disease and vision and hearing loss, among others.

As of April 2007, however, no therapies using cells derived from embryonic stem cells have been tested in humans. The efficacy of stem cell therapies depends on the introduced cells arriving where they are needed and either replacing or rejuvenating damaged cells. They should not contain undifferentiated embryonic stem cells, and either the cells, the patient or both should be treated so that the patient’s immune system will not attack the transplants.

As an alternative to cell therapies, some researchers are looking for traditional drugs that would prompt adult stem cells to come out of hiding and replace damaged tissuesIn one early study, rats with a strokelike injury had more control over their movement after being treated with a compound that stimulates stem cells in the brain.

Embryonic stem cells could be grown into more specialized cells for screening potential drugs. Cultures of cancer cells are already used for screening cancer drugs, and growing embryonic stem cells into heart, liver or nerve cells could be useful for testing drugs that affect those organs. Ideally, the human cells could be custom-made to represent the genetic diversity and traits typical of people who suffer from the disease being studied. Right now, potential drug molecules are tested first in mice and rats, but results of these animal tests do not always correlate with what happens in humans. Drugs that poison a human liver, for example, might do no harm to a rat’s.Many scientists think that testing pollutants and potential drugs on cells grown from human embryonic stem cells could be more accurate than current tests. This could mean that fewer animals would be killed for research and also make research faster and cheaper. However, if such experiments are to work, scientists will have to develop techniques to make sure that the cells and culture conditions remain constant; otherwise, differences between experiments could be due to factors other than the drug candidates being tested.