Author: Mokhtar

  • Introduction to stem cells and differentiation of MSCs

    Introduction to stem cells and differentiation of MSCs

    The use of stem cells in bone grafting applications continues to grow in popularity. This is partly due to aging patient populations that require more advanced materials for successful surgical outcomes. At the same time, surgeons are seeking more advanced technologies to treat these patients.

    Stem cells are unique in that they can be stimulated by their environment to change, or “differentiate,” into bone cells. Some advanced synthetic bone graft materials even have the ability to stimulate stem cells to become bone cells. But what exactly is meant by the broad term “stem cells” and what benefits do they promise? This blog covers an introduction to the biology of stem cells and how stem cells can be used specifically for bone regeneration.

    Introduction to stem cells

    Although their clinical use remains controversial, embryonic stem cells have an astonishing power to transform into virtually any organ or tissue under specific chemical and physical conditions. These cells are called “pluripotentfrom the Latin root multi- meaning a lot of. Other types of stem cells, also called “multipotent” or “adult stem cells,” are more differentiated, meaning they can form into a more limited variety of tissues. For bone regeneration applications, adult stem cells are used can or are autologous stem cells (coming by the patient who is there treated, also known as autotransplant) or like a allograftwhich means, allogeneic stem cells (coming by another person, usually a corpse). Of course, any bone graft product containing donated allogeneic stem cells (cellular allografts) must comply with a number of FDA regulations and protocols to ensure its safety and assess its effectiveness.

    One type of adult stem cell Ordinaryly associated with bone grafting applications is a mesenchymal stem cellor MSC. This cells were first identified in the middle70s. MSCs are partially differentiated, which makes them capable of producing a variety of structural or stromal tissues, such as bones, cartilage, tendons, muscles, blood, and thick (Figure 1). They are limited to these tissue types becauseusand they Are embryological derived from by the mesoderm, hence the term monthsenchymal. In contrastthe ectoderm is responsible for forms skin and the central nervous system, while the endoderm is responsible for the functional cells of the main internal organs, such as the liver, pancreas, and kidneys.

    Differentiation potential of mesenchymal stem cells (MSCs).
    Figure 1: Differentiation potential of mesenchymal stem cells (MSCs).

    MSCs are found throughout the body, particularly pericytes that are embedded in the structural components of microvascular walls. Therefore, bone marrow is particularly rich in MSCs. MSCs are spindle-shaped, but not particularly unique in their morphology. Because they replicate easily, they grow on tissue culture plates as “colony-forming units” or CFUs. They are best identified chemically by specific antigens, called “Clusters of Differentiation”, in their cell membranes, such as CD105 and CD44. MSCs are rare, accounting for less than 0.1% of nucleated cells in the body, and they continue to decline with age. Although MSCs can replicate more than 50 times, their doubling rate is slow, more than 1-3 days, and decreases with age.

    Allogeneic MSCs can be used in patients because they are thought to immune privileged. This means that they do not contain important HLA (Human Leucocyte Antigens) antigenic components in their cell membranes that the patient recipient sees as foreign. Therefore, they are not detected by the patient’s immune system when they are implanted. In contrast, HLA compatibility Is required for every organ transplant to prevent rejection. MSCs can therefore theoretically be used to treat any patient without concerns about histocompatibility.

    Mesenchymal Use of stem cells in bone transplantation

    Bone is one of the most easily regenerated structural tissues, so it is no surprise that MSCs are readily available in bone marrow. For this reason, bone marrow aspirate (which is harvested from cancellous bone) is widely used in combination with other bone graft materials. Due to the popularity of bone marrow-derived stem cells, tissue banks eventually found a way to process allograft bone while keeping the donor MSCs alive. Today, both mesenchymal stem cells (MSCs) and more differentiated stem cells, osteoprogenitor cells (OPCs) (Figure 1) are harvested from cadaver bone. These MSCs and OPCs are then added to DBM (demineralized bone matrix) and/or cancellous bone chips from the same donor to create a variety of allograft stem cell products.

    There is much debate about the efficacy of transplanted MSCs and OPCs. It is not clear whether these cells actually survive, let alone divide into viable cells, after transplantation. However, there is data to support that they act as paracrine cells (signaling cells) by releasing cytokines and other growth factors into their environment. In this way, they indirectly stimulate bone regeneration, rather than directly differentiating into osteoblasts.

    The future of stem cells in bone regeneration

    Modern process techniques have very extended access to stem cells for use in surgeryFor procedures requiring bone tissue graftsurgeons are expected to use mesenchymal Rod cells, osteoancestor cells, And related technologies to grow new bone andd patients help to heal more complete. While stem cell Their use remains a topic of debate, but these cells show promise in the field of bone regeneration and will likely continue to play a role in future bone regeneration technologies.

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  • How Oral Bacteria Affect Your Overall Health

    How Oral Bacteria Affect Your Overall Health

    A recent review in the magazine Nature Reviews Microbiology investigated the interactions between the oral and gut microbiomes and their joint effect on human health.

    Authors Jack A. Gilbert of the University of California San Diego and Erica M. Hartmann of Northwestern University found that while oral microorganisms can invade the gastrointestinal tract and contribute to gut dysbiosis, the mechanisms and broader implications of these interactions require further investigation.

    ImageForNews 786026 17217965109158885Review Article: The Inner Microbiome and Human Health. Image Credit: Lightspring / Shutterstock

    The importance of the gut microbiome

    The human body is home to a wide variety of microorganisms that play an essential role in health by supporting the immune system and defending against pathogens. However, they can also contribute to chronic diseases.

    Dysbiosis, or disruptions in these microbial communities, has been linked to metabolic and autoimmune diseases and gastrointestinal problems. The gut and oral cavity are two important areas with dense microbial populations.

    The oral microbiome is influenced by diet and environment and has been linked to oral diseases such as gingivitis and periodontitis. It affects the health of the entire body by influencing the microbial populations in the digestive and respiratory tracts.

    The gut microbiome, shaped by genetics, diet and lifestyle, is crucial for immune responses and infection prevention. Understanding the interactions between the gut and oral microbiomes is essential to understanding their impact on diseases such as colorectal cancer (CRC) and inflammatory bowel disease (IBD).

    The oral cavity is a gateway

    The gastrointestinal tract begins at the mouth and extends to the anus, including organs such as the liver, pancreas, and gallbladder. The oral cavity, highly vascularized and home to diverse microbial communities, serves as the primary entry point for microbes into the body.

    It hosts more than 770 bacterial species in various microenvironments, such as the buccal mucosa, tongue and dental plaque. Important genera include Streptococcus, VeillonellaAnd Meant to beThe gut microbiome, mainly anaerobic and consisting of species such as Bacteroides And Ruminococcishares some taxons with the oral cavity, but specific physical and chemical barriers generally prevent oral microbes from colonizing the intestines.

    However, under conditions such as low stomach acidity or antibiotic use, oral bacteria can migrate to the gut, potentially contributing to disease. Understanding this microbial transfer from the mouth to the gut is crucial to investigating its role in health and disease.

    The mouth-gut connection

    The oral cavity, which is susceptible to conditions such as tooth decay, oral cancer, and periodontal disease (gingivitis and periodontitis), plays an important role in overall health. Periodontal disease involves the destruction of tissues around the teeth due to an inflammatory response to plaque and microbes.

    Gingivitis, a reversible inflammation of the gums, can develop into periodontitis if left untreated, causing deeper tissue damage and bone loss. Research suggests a strong link between oral health and gut disease.

    Periodontal pathogens, such as P. gingivalis And F. nucleatumcan migrate from the mouth to the intestines, contributing to conditions such as IBD. These bacteria promote inflammation and disrupt the microbial balance of the intestines.

    Studies have found higher levels of oral bacteria in the guts of individuals with IBD, suggesting a role for the mouth-gut axis in these diseases. Additionally, the oral microbiome has been linked to CRC. Oral bacteria such as F. nucleatum may influence tumor growth and treatment resistance in colon cancer.

    This connection underscores the importance of oral health in preventing and treating systemic diseases. Understanding these connections may lead to better prevention and treatment strategies for bowel diseases and cancers.

    Oral health and general health

    Poor oral health, especially periodontitis, can have a major impact on the entire body. Oral bacteria can travel through the gastrointestinal tract and bloodstream and contribute to various diseases.

    Periodontitis causes low-grade systemic inflammation, which can disrupt the body’s health and promote diseases such as IBD and cardiovascular disease. It increases the levels of pro-inflammatory cytokines in the blood, indicating an ongoing inflammatory response.

    Oral health affects the body through the bone marrow, among other things. The inflammation caused by periodontitis stimulates the production of immune cells, which leads to increased inflammatory responses elsewhere.

    Another mechanism involves periodontal bacteria that directly affect distant organs by releasing toxins that promote inflammation and diseases such as rheumatoid arthritis and atherosclerosis. In addition, oral health directly affects the gut. Bacteria from the mouth can colonize the gut and worsen conditions such as IBD.

    Treatment of periodontal disease can reduce systemic inflammation and improve symptoms of chronic disease, demonstrating the bidirectional relationship between oral health and systemic disease. Addressing oral health is therefore crucial for overall health and management of systemic disease.

    Conclusions

    Changes in oral bacteria can affect gut health, leading to systemic inflammation and various diseases. The relationship between the oral cavity and the gut is bidirectional, but the exact mechanisms remain unclear.

    More research is needed to understand how oral bacteria influence chronic diseases and to develop better models to study these interactions. Future studies should resolve the oral-gut-microbiome axis at the strain level to confirm the role of oral bacteria in chronic diseases and investigate the role of translocated strains in gut-microbiome-related diseases via in vivo and in vitro models.

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  • Vitamin D in the summer: better bones

    Vitamin D in the summer: better bones

    SunshadeNow that summer has arrived, it’s time to take advantage of the free vitamin D that the sun offers. Sun exposure is the ideal way to help us reach the minimum vitamin D level of 32 ng/mL, with an optimum of 50 to 60 ng/mL.

    I also encourage you to get outside as much as possible, because we are all part of nature. Being outside can bring our bodies into harmony with the natural world around us. I use this time of year to play golf and tennis, swim in the lake, bike, kayak, hike, grow vegetables, and get outside in any way I can. Even with all the benefits of being outside, I still get a lot of questions about sun exposure, so here are my recommendations, as well as some important information about sunscreen:

    Better Bones Guidelines for Sun Exposure (Year-Round!)

    • It is best to expose the entire body to the sun for short periods of 15-20 minutes each day (without sunscreen).

    • People with very dark skin need 4 to 6 times more sunlight exposure than people with light skin.

    • After this initial period, use sunscreen if necessary to prevent burning.

    • The usable ultraviolet radiation is strongest between 10am and 2pm.

    • In northern or southern latitudes, far from the equator, longer exposure is necessary, especially in spring and autumn.

    • In climates at northern or southern latitudes, far from the equator, very little to no vitamin D is produced in the skin during the winter months.

    • If your shadow is shorter than you, you can make vitamin D from sunlight. If your shadow is longer than you, you know you are not exposed to that small spectrum of ultraviolet radiation that makes vitamin D.

    Protect yourself from both the harmful sun and the wrong sunscreens

    Just as important as protecting yourself from the sun is avoiding the potentially harmful effects of sunscreen ingredients that can contribute to your overall toxic load. If you’re going to be wearing sunscreen while spending extended periods of time outdoors, keep these tips in mind to help you decipher product labels:

    • Avoid the ingredients vitamin A (retinyl palmitate) and oxybenzone. Safer options are titanium dioxide and zinc oxide. I prefer those with zinc oxide as the active ingredient.

    • Use natural and organic beauty and body care products whenever possible. Many of the chemical ingredients in personal care products are not only toxins, but also allergens and skin irritants. Do a little research before choosing a sunscreen, since it is classified as both a cosmetic and a drug.

    • “Organic” and “natural” do not always mean “safe.” When in doubt, avoid products with long lists of unpronounceable ingredients to prevent exposure to synthetic toxins and carcinogens.

    • Another way to reduce exposure is to avoid any product that lists “fragrance” as an ingredient, or whose label list ends with the words “…and other ingredients.” Sunscreen manufacturers are not required to list ingredients, even those that are carcinogenic or have been granted “trade secret” status by the FDA.

    You can learn more about the benefits of vitamin D in my article, “Vitamin D: Its Benefits Are Greater Than Ever Thought.” And keep in mind that you want to have those levels year-round, so I recommend getting a vitamin D test at the end of both summer and winter to check for any variations.

    Doctor Susan BrownI am Dr. Susan E. BrownI am a clinical nutritionist, medical anthropologist, writer and motivational speaker speakerLearn my proven 6-step natural approach to healthy bones in my online courses.



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  • Foothills Sports Medicine Physical Therapy Restores Network Status with United Healthcare |  Foothills Physical Therapy & Sports Medicine

    Foothills Sports Medicine Physical Therapy Restores Network Status with United Healthcare | Foothills Physical Therapy & Sports Medicine

    Foothills Sports Medicine Physical Therapy (Foothills), Arizona’s largest and most respected provider of musculoskeletal and physical therapy services, is pleased to announce that after months of diligent negotiations, an agreement has been reached with UnitedHealthcare (UHC). Effective August 1, 2024, Foothills will once again be an in-network provider for UHC’s commercial insurance and Medicare Advantage plans, providing thousands of patients covered by these plans with access to high-quality physical therapy services.

    View our full list of providers