Medical Dictionary-Definitions to Medical Terminologies
Medical DictionaryIntroduction to medical terminologies
|Acinus||Any group of cells that looks like a berry with multiple lobes is called an acinus. Alveolar sacs in the lungs and the berry-shaped apex of exocrine glands, where the secretion is produced, are examples of acinar structures.|
|Antitumorigenic||The term “antitumorigenic” refers to actions, elements or agents that counteract or inhibit the formation and development of tumors. These actions or agents can hinder the processes that facilitate the growth and proliferation of cancer cells, and thereby suppress the development of cancer.
Antitumorigenic factors can be:
1. Tumor suppressor genes: These are genes that regulate cells and prevent them from growing and dividing too rapidly or in an uncontrolled way. If these genes are functioning correctly, they can stop the development of tumors. TP53 is a well-known example of a tumor suppressor gene.
2. Certain immune cells: Immune cells such as cytotoxic T-cells, and natural killer cells can identify and destroy cancer cells, preventing the formation and growth of tumors.
3. Antitumorigenic drugs: These are drugs designed to inhibit specific pathways that tumors use for their growth and proliferation. Examples include chemotherapy, radiation therapy, immunotherapies, and targeted therapies like kinase inhibitors or monoclonal antibodies.
4. Healthy lifestyle habits: Regular physical activity, a healthy diet, and the avoidance of tobacco and excessive alcohol can also have antitumorigenic effects by helping maintain a healthy immune system and reducing the risk of certain types of cancers.
Understanding antitumorigenic mechanisms and factors is vital for developing strategies to prevent and treat cancer. Researchers are constantly studying these processes to find novel cancer therapies and improve existing treatment strategies.
|Barrett’s Esophagus (BE)||Barrett’s Esophagus (BE) is a condition in which the cells lining the lower part of your esophagus (the long tube that carries food from your throat to your stomach) begin to change and resemble cells of the small intestine. This change results from long-term exposure to stomach acid, or gastroesophageal reflux disease (GERD). While Barrett’s Esophagus itself doesn’t usually cause symptoms, GERD often does, with symptoms like frequent heartburn and chest pain.
It’s of particular interest because it increases the risk of developing esophageal adenocarcinoma, a serious and often deadly type of esophageal cancer. But only a small fraction of people with Barrett’s Esophagus develop this cancer.
Management of Barrett’s Esophagus might include periodic endoscopic examinations with biopsies to monitor the condition and check for dysplasia – abnormal, precancerous cells. If there is dysplasia, doctors might recommend endoscopic procedures, such as radiofrequency ablation, or surgery.
The strategies to reduce the risk of Barrett’s esophagus are similar to the strategies to manage GERD and include lifestyle modifications such as maintaining a healthy weight, avoiding food triggers, not eating before bedtime, and raising the head of your bed. Alcohol and tobacco also increase the risk.
Barrett’s Esophagus is a relatively common condition, with about 1 in every 20 Americans suffering from it. It’s typically found in people in their 50s or older, and it’s more common in men and in Caucasians. As with many health issues, early detection and management are the best ways to prevent serious complications.
|Benign prostatic hyperplasia (BPH)||Prostate enlargement, or benign prostatic hyperplasia (BPH), is a frequent problem for elderly men. Urinary discomfort, such as a decrease in urine output from the bladder, may be distressingly brought on by an overgrown prostate gland. It may also affect the kidneys, bladder, or urinary tract.|
|Benign Tumor||Tumors that don’t spread to other body parts are considered benign. They don’t go to other areas of the body or neighboring areas. Benign tumors develop slowly and usually have clear boundaries. A benign tumor is not typically a cause for concern.|
|Cancer heterogeneity||Cancer heterogeneity refers to the observation that different cancer cells within the same tumor can demonstrate variability in several characteristics, including their gene expression, metabolism, motility, immunogenicity, and proliferative and metastatic potential. This arises from genetic mutations, epigenetic changes, and influences from the tumor microenvironment.|
|Chemokines||Chemokines are a family of small proteins that play crucial roles in cell signaling. The term “chemokine” is derived from “chemotactic cytokine,” which basically signifies their ability to induce directed chemotaxis in nearby responsive cells; in other words, they can provoke cells to move toward a higher concentration of the chemokine.
Chemokines are primarily involved in the recruitment of leukocyte cells (white blood cells) to sites of infection and inflammation. There are approximately 50 chemokines identified in humans, which are capable of binding to around 20 different cell surface chemokine receptors.
The interaction between chemokines and their receptors leads to a range of responses, most notably the migration of immune cells to the site of injury during an inflammatory response. They can also mediate the movement of cells in other biological processes, such as embryogenesis, angiogenesis (formation of new blood vessels), and lymphocyte trafficking.
In addition to their physiological roles, chemokines are also implicated in various pathological conditions, including autoimmunity, cancer, and inflammatory diseases. For example, in the context of cancer, chemokines can either promote or inhibit cancer progression and metastasis. This dual action makes them intriguing targets for therapeutic intervention.
In summary, chemokines are essential for the immune response and represent a dynamic area of research in immunology, inflammation, and a broad array of diseases and disorders.
|Chemokine (C-X-C motif) ligand 8 (CXCL8) or IL-8 in Cancer||Chemokine (C-X-C motif) ligand 8 (CXCL8), also known as Interleukin-8 (IL-8), is a type of signaling molecule known as a chemokine. CXCL8/IL-8 is produced by a variety of cells, including immune cells and cancer cells, and it primarily acts to recruit neutrophils, a type of white blood cell, to sites of inflammation or injury.
In the context of cancer, CXCL8/IL-8 has been found to play a significant role in many types of malignancies, contributing to numerous stages of cancer progression through various mechanisms:
1. Promotion of angiogenesis: Angiogenesis, the formation of new blood vessels, is crucial for tumor growth and survival as it provides oxygen and nutrients to the rapidly dividing cells. CXCL8/IL-8 is a potent promoter of angiogenesis.
2. Direct effect on cancer cells: CXCL8/IL-8 can enhance the survival and proliferation of cancer cells. It can also influence the epithelial-mesenchymal transition, a process thought to be important in cancer metastasis.
3. Modulation of the tumor immune environment: CXCL8/IL-8’s role in attracting neutrophils can contribute to an immune-suppressive tumor environment, supporting tumor growth and helping cancer cells avoid detection by the immune system.
4. Metastasis: CXCL8/IL-8 can assist in the migration and invasion of cancer cells, critical stages in the metastatic process where cancer spreads from the original tumor to other sites in the body.
Given these roles in cancer progression, CXCL8/IL-8 and its receptors have been proposed as potential therapeutic targets. However, targeting such a common and versatile molecule is challenging, and much remains to be understood about its functions and interactions in cancer. Continued research in this area is crucial to develop novel strategies to prevent or treat cancer.
|Chemotherapy||Chemotherapy is a type of cancer treatment that uses one or more anti-cancer drugs to kill or stop the growth of cancer cells. It is a systemic therapy, meaning it affects the entire body by going through the bloodstream.
Chemotherapy works by targeting rapidly dividing cells, which is a characteristic of cancer cells. However, certain healthy cells in your body also divide and grow quickly (like those in your mouth, intestines, and hair follicles), and chemotherapy can affect these as well, leading to some of the common side effects such as hair loss and nausea.
There are more than 100 chemotherapy drugs, and they can be used alone or in combination, depending on the type of cancer, its stage of progression, and the patient’s overall health.
Some of the major classes of chemotherapy drugs include alkylating agents, antimetabolites, anti-tumor antibiotics, topoisomerase inhibitors, mitotic inhibitors, and corticosteroids.
Chemotherapy may aim to:
– Cure: completely destroy the cancer in the body.
– Control: stop the cancer from spreading and keep it from growing.
– Palliation: alleviate symptoms caused by cancer.
While chemotherapy can be effective, it can also cause side effects because it can harm healthy cells that divide quickly. Common side effects include fatigue, hair loss, infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects often improve or resolve once treatment is completed.
There’s ongoing research for developing new chemotherapy drugs and methods to increase their efficiency and reduce side effects. This includes targeted therapy, immunotherapy, and personalized medicine. Always speak to your healthcare provider to understand your treatment options and potential side effects.
|Cytokines||Cytokines are a broad category of small proteins that are critically important in cell signaling. Their primary role is in modulating the immune system. These proteins are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes, and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells.
Cytokines exert various effects on the immune system and regulate the balance between humoral and cell-based immune responses. They are integral in stimulating the production of blood cells from the bone marrow, triggering cells to move to sites of infection, trauma or inflammation, and stimulating or inhibiting the growth and maturation of cells.
Different cytokines can also be grouped into functional classes. For instance, “interferons” can activate immune responses to viruses, “interleukins” mediate communication between white blood cells, “tumor necrosis factors” (TNFs) can cause cell death, and “colony stimulating factors” stimulate bone marrow to produce white and red blood cells.
It’s crucial to note that cytokine activity is complex, overlapping, and can be pro-inflammatory (supporting the body’s immune response to injury or infection), or anti-inflammatory (minimizing tissue damage from prolonged inflammation), depending on the context. Examples of pro-inflammatory cytokines include TNF-alpha, IL-6, and IL-1 beta, while IL-10 and TGF-beta are often anti-inflammatory.
Moreover, any imbalance in cytokine production, or dysfunction in their interaction, can lead to a variety of medical conditions, including sepsis, cancer, autoimmune disorders, and infectious diseases. These characteristics make cytokines important targets for the development of drugs and therapies engineered to either harness or mitigate their effects.
For example, cytokine blocking agents, like anti-TNF drugs, can be used to treat inflammation in diseases like rheumatoid arthritis. On the other hand, drugs such as interferon beta are used in diseases like multiple sclerosis to boost the immune response.
|ELISA immunoassay||Enzyme-Linked Immunosorbent Assays (ELISAs) are immunoassay methods that take advantage of the specific binding that happens between an antibody and an antigen. They are a rapid and efficient technique for measuring the amount or presence of a specific substance in a sample.
ELISAs can take several formats or configurations, including:
1. Direct ELISA: This method directly attaches the antibody to an enzyme. The labeled antibody binds directly to the sample antigen. When the substrate is added, the enzyme on the antibody causes a color response signifying the presence of the antigen. This simple setup lacks amplification, so it’s less sensitive than other ELISA methods.
2. Indirect ELISA: The sample antigen is bound to the surface and then is exposed to an unlabeled primary antibody. A labeled secondary antibody specific to the primary antibody is applied, which can bind and induce a color response with the substrate. This method provides signal amplification because several secondary antibodies can bind to a single primary antibody.
3. Sandwich ELISA: This format involves the attachment of “capture” antibodies to the solid phase. The antigen in the sample binds to these antibodies. A second, “detection”, antibody then binds to another site on the antigen, which gives a binding ‘sandwich.’ The detection antibody is linked to an enzyme or a secondary antibody with a conjugated enzyme that creates the color response. This approach is highly sensitive as it has two levels of antibody specificity.
4. Competitive ELISA: Also known as inhibition ELISA. Sample antigen competes with a reference standard antigen for binding to an antibody that has been immobilized in a microtiter plate well. Detection is based on the inverse relationship between the ELISA signal and the antigen concentration because the signal decreases as the antigen concentration increases.
Each type of ELISA has its strengths and optimal uses. The choice of method often depends on the sample and the specific needs of the experiment, including considerations of time, cost, complexity, sensitivity, and specificity.
|Epithelial-to-mesenchymal transition (EMT)||The Epithelial-to-Mesenchymal Transition (EMT) is a key developmental process where epithelial cells, which line the body’s surface and cavities, undergo biochemical changes to transform into a mesenchymal cell phenotype.
Epithelial cells are usually characterized by their polarity, tightly-packed organization, and attachment to a basal lamina. They have limited migratory capacity and are not invasive.
Mesenchymal cells, on the other hand, are multipotent stromal cells that can differentiate into various cell types. They’re characterized by their lack of polarity, loosely organized structure, enhanced migratory capacity, invasiveness, enhanced resistance to apoptosis, and greatly increased production of extracellular matrix components.
EMT plays a crucial role in numerous developmental processes including mesoderm formation and neural tube formation during embryogenesis. However, EMT is also thought to be involved in wound healing, tissue regeneration, and organ fibrosis. In addition, EMT has been implicated in promoting the progression of diseases such as cancer as it is thought to be a critical mechanism for cancer metastasis, where cancer cells gain the ability to spread to other parts of the body.
EMT is triggered by various signaling pathways including TGF-beta, Wnt, Notch, and receptor tyrosine kinases. Various transcription factors such as Snail, Slug, ZEB1, ZEB2, and Twist also play key roles in promoting EMT.
Studies into EMT may provide insights into new therapeutic strategies in various diseases, including the development of anti-cancer strategies aimed at preventing metastasis.
|Esophageal adenocarcinoma (EAC)||Esophageal adenocarcinoma (EAC) is a type of cancer that forms in the lining of the lower part of the esophagus, near the stomach. It is one of the two main types of esophageal cancer, with the other being squamous cell carcinoma.
EAC is often associated with a condition called Barrett’s esophagus, which causes the cells in the lower part of the esophagus to become abnormal, often due to chronic acid reflux. However, only a small percentage of people with Barrett’s esophagus develop EAC.
Symptoms of EAC may include difficulty swallowing, unintended weight loss, chest pain, heartburn, and indigestion. Treatment options for EAC can include surgery, radiation, chemotherapy, targeted therapy, immunotherapy, and endoscopic treatments. The choice of treatment often depends on the stage of the cancer and the general health of the patient.
If you or a loved one has been diagnosed with esophageal adenocarcinoma or if you are experiencing symptoms, you should consult with a healthcare professional who can provide you with the most appropriate medical advice.
|High-Grade Dysplasia (HGD)||High-Grade Dysplasia (HGD) refers to a pre-cancerous condition where there is significant abnormal growth and development of cells. This condition is more serious than low-grade dysplasia (LGD) because the cells are more abnormal and a higher percentage of them are affected.
High-grade dysplasia is often an indication that cancer may develop if left untreated, although progression to cancer is not guaranteed in every case. High-grade dysplasia can occur in various parts of the body, such as the cervix, esophagus, or colon. The biopsy of suspected areas and subsequent microscopic examination are typically used to diagnose this condition.
In most cases, high-grade dysplasia doesn’t cause symptoms. It’s often discovered during regular screenings, such as a Pap test or colonoscopy. However, in cases such as Barrett’s esophagus, a patient might experience gastroesophageal reflux disease (GERD) symptoms, which can include persistent heartburn and acid reflux.
Treatment for HGD depends on the location, size of the affected area, patient’s overall health, and associated risks. In many cases, physicians will recommend the removal of the dysplastic cells or tissue due to the high risk of progression to cancer. This can be done through surgical methods or less invasive techniques, depending on the circumstances.
For example, in the case of high-grade dysplasia in Barrett’s esophagus, treatment options can include endoscopic resection (removing abnormal tissues with a scope), radiofrequency ablation (using heat to remove abnormal cells), or even esophagectomy (removal of part of the esophagus) in more severe cases.
After treatment, patients usually require regular screenings to ensure the dysplasia does not return. It’s also important to address the underlying risk factors if possible, such as treating GERD in the case of Barrett’s esophagus or encouraging smoking cessation if the dysplasia is in the lung tissue.
|Histopathology||Histopathology is a branch of pathology that involves the microscopic examination of tissue in order to study the manifestations of disease. The discipline involves studying samples taken from patients during a procedure called a biopsy, and it’s a key tool in diagnosing many conditions, especially cancer.
The word histopathology itself is derived from three Greek words: “histos” meaning tissue, “pathos” meaning disease, and “logos” meaning study, which together translate to “the study of diseased tissue.”
The process of histopathology often involves several steps:
1. Tissue Collection: Tissues are often collected during surgery or biopsy, and the sample is sent to a pathology laboratory.
2. Fixation and Processing: The sample is preserved (usually in a solution called formalin) to prevent tissue decay. The preserved tissue is then processed and embedded in a block of paraffin wax to provide support for the delicate tissue.
3. Sectioning: Thin slices of the tissue (sections) are cut from the paraffin block using a microtome and then mounted onto microscope slides.
4. Staining: The tissue sections are stained to highlight the different structures and cells. The most common staining technique is Hematoxylin and Eosin (H&E) staining, which stains cell nuclei blue and the rest of the cell pink.
5. Microscopic Examination: The stained slides are then examined under a microscope by a pathologist who looks at the architecture of the tissue and the appearance of individual cells to make a diagnosis.
Histopathologists don’t just identify diseases; they also provide information about the grade of a cancer, its aggressiveness, and the extent of its spread within the tissue – all crucial details in developing an effective treatment plan. With the advent of new techniques like digital pathology and molecular diagnostics, histopathology continues to play a crucial role in personalized medicine.
|IHC-Pancytokeratin test||To determine the concentration of Pancytokeratin (Panck) in biopsy tissue, a test is run on the sample of tissue. It is done before, during, and after therapy for epithelial carcinomas to confirm the diagnosis. IHC Marker Pan Ck Immunohistochemistry Biopsy Tissue is another name for this analysis. Breast cancer biopsy tissue may be stained using immunohistochemistry (IHC), whether it is fresh or frozen. This step is essential for developing an effective treatment strategy.
The IHC-Pan cytokeratin test requires no unique preparation. Before getting an IHC-Pan cytokeratin test done, it’s important to let your doctor know about any sensitivities or drugs you’re taking. The particular instructions you follow from your doctor will depend on your situation.
The IHC-Pancytokeratin test is often used to determine whether or not cancer cells inside a tumor express high levels of the HER2 receptor protein. Overproducing HER2 receptors may contribute to cancer progression by sending excessive signals to cells to proliferate and disseminate. Pancytokeratin (Panck) immunohistochemistry on biopsy tissue often yields positive staining in diagnosing epithelial-origin tumors across both sexes and ages.
The tissue sample for IHC-Pancytokeratin analysis is taken during surgery. Under local anesthesia, a surgical biopsy may be performed. This evaluation is often carried out in a clinical environment, with the patient sedated with medication. The surgeon makes a one- to two-inch incision in the breast and removes the abnormal lump and, in some cases, a small amount of surrounding normal-appearing tissue called the “margin.” A mammography or ultrasound may be used to locate a lump that is too small to feel; if this is the case, a radiologist may implant a tiny wire to label the suspicious area before the surgeon performs the biopsy. Again, towards the end of the biopsy operation, a marker is often put internally at the biopsy site. For a number of days after the operation is done, you may feel some discomfort.
|Interleukin-6 (IL-6) in Cancer||Interleukin-6 (IL-6) is a multifunctional cytokine, a type of signaling molecule that plays a vital role in immune response, inflammation, and the regulation of metabolic processes. However, in the context of cancer, IL-6 can have complex and often pro-tumorigenic effects.
In many types of cancers, higher levels of IL-6 are associated with advanced disease stages, aggressive disease behavior, and poorer prognosis. The involvement of IL-6 in cancer is believed to occur through several mechanisms:
1. Cell Proliferation: IL-6 can stimulate the growth of cancer cells, promoting proliferation and survival. It does this through several signaling pathways, particularly the JAK/STAT3 pathway.
2. Angiogenesis: IL-6 can promote angiogenesis – the formation of new blood vessels. Tumors need blood vessels to supply oxygen and nutrients to grow beyond a certain size.
3. Inflammation: Chronic inflammation contributes to several cancer-promoting biological capabilities. IL-6, as a pro-inflammatory cytokine, can contribute to an environment that enables tumor progression.
4. Immune Suppression: High levels of IL-6 can lead to an immunosuppressive tumor microenvironment, where normal immune responses are downregulated, allowing the tumor to evade the body’s immune response.
5. Metastasis: There is evidence that IL-6 can promote cancer metastasis – the spread of cancer cells from the primary tumor to other parts of the body.
Given its multiple roles in cancer progression, IL-6 is being investigated as a potential target for cancer therapy. Some anti-IL-6 and anti-IL-6 receptor monoclonal antibodies have shown promising results in preclinical and clinical settings for some types of cancer. However, further research is needed to fully understand the complex roles of IL-6 in different types of cancers and its potential as a therapeutic target.
|Immune Cells||Immune cells, also known as white blood cells or leukocytes, are vital components of the immune system, which defends the body against both infectious disease and foreign materials. They can be broadly classified into two main categories: the innate immune cells and the adaptive immune cells.
Innate immune cells:
1. Neutrophils: These are the most abundant type of white blood cell and are among the first to arrive at the site of an infection.
2. Monocytes/Macrophages: Monocytes circulate in the bloodstream, and when they move into tissues, they differentiate into macrophages. They respond to infections and also help with the removal of dead or damaged cells.
3. Dendritic Cells: They are specialized in antigen presentation to help activate T cells.
4. Natural Killer (NK) Cells: These cells have the ability to kill virus-infected cells or tumor cells without prior sensitization.
5. Mast Cells: They play a key role in inflammation and allergy reactions.
Adaptive immune cells (also called lymphocytes):
1. T cells (T lymphocytes): They come in several different forms with different functions, including helper T cells, cytotoxic T cells, and regulatory T cells. Helper T cells coordinate immune responses by communicating with other cells, while cytotoxic T cells are primarily involved in killing infected cells.
2. B cells (B lymphocytes): B cells are responsible for producing antibodies, which are proteins that can latch onto harmful invaders and mark them for destruction.
Effector cells, such as cytotoxic T cells and activated macrophages, actually carry out the attack on the antigen. Meanwhile, memory cells “remember” antigens and respond more aggressively and rapidly during future encounters with these antigens.
|Immune microenvironment||The immune microenvironment, also referred to as the tumor microenvironment in the context of cancer, is an incredibly important factor for understanding how diseases such as cancer function and how they can be treated.
The immune microenvironment consists of the conditions directly surrounding cells. This includes both physical and biochemical elements, such as the presence of other cells or proteins, the structural support, or matrix for cells, oxygen levels, pH, and nutrient availability.
In the context of the immune response to tumors, the immune microenvironment includes both immune cells that body uses to kill tumor cells (such as cytotoxic T cells), and elements that the tumor uses to subvert and resist the immune response (such as regulatory T cells).
The immune microenvironment is a current area of active research in cancer biology, as we now understand that the immune system plays a critical role not only in initially preventing the development of cancer (through elimination of pre-cancerous cells) but also in mediating resistance to therapy and potential eradication of established tumors.
Harnessing the power of the immune system through manipulating the immune microenvironment is at the forefront of new therapies being developed. This includes a wide range of strategies, from cancer vaccines, immune checkpoint inhibitors, to so-called “adoptive cell transfer” where patient’s immune cells are genetically modified to recognize their tumors.
Understanding and investigating these microenvironments can be crucial to developing and implementing effective treatments. It helps us comprehend why certain treatments might work in one scenario but not another, or why a drug that showed promise in the lab doesn’t always have the desired effect in patients. It is a complex field with many variables, and it’s a significant focus in current cancer and immune system research.
|Immune modulatory therapy||Immune modulatory therapy, also known as immunomodulatory therapy or immunotherapy, involves using the body’s own immune system to treat disease. Such therapies primarily have been developed to combat cancer, but they can also be used in the treatment of other conditions, like autoimmune diseases, allergies, and infections.
The immune system has powerful defensive capabilities, and scientists have found ways to enhance and direct these abilities to fight off diseases more effectively. Immunotherapy works in a variety of ways:
1. Immune checkpoint inhibitors: These drugs block proteins that stop the immune system from attacking cancer cells. Examples include drugs like pembrolizumab (Keytruda) and nivolumab (Opdivo), which block the PD-1/PD-L1 pathway.
2. Cancer vaccines: These are substances that stimulate the immune system to destroy specific cancer cells. They can be used for prevention or treatment. An example is the HPV vaccine, which prevents cancer caused by human papillomavirus.
3. CAR-T therapy: In this treatment, a type of immune cell called a T cell is removed from a patient’s body and genetically altered to produce a special receptor called a Chimeric Antigen Receptor (CAR). The genetically modified cells are then infused back into the patient where they can recognize and destroy cancer cells. Examples include Kymriah and Yescarta.
4. Cytokines: These are proteins that the immune system uses for communication. Medications that act as or block specific cytokines can stimulate the immune system to attack cancer cells or reduce inflammation. Examples are interferon and interleukin-2.
While immune modulatory therapies have shown promise, they can also pose significant risks, including severe and sometimes deadly immune-related side effects, due to the potential overactivation of the immune system. However, ongoing research aims to improve the effectiveness of these therapies while minimizing their side effects.
|Immunology||Immunology is a branch of biology that covers the study of the immune system in all organisms. The immune system is our defense against infections and diseases. It includes various types of cells (like T cells, B cells, and phagocytes), tissues (like lymphoid tissue), and proteins (like antibodies and cytokines).
Immunologists research how the immune system works, how it fights off pathogens (like bacteria, viruses, and parasites), how it can fail and lead to diseases, and how it can be harnessed or modulated to treat diseases.
There are several subfields within immunology:
1. Infectious Disease Immunology: The study of the immune response to various pathogens.
2. Cancer Immunology: Focuses on how the immune system interacts with cancer cells.
3. Transplant Immunology: Studies the immune response to transplanted organs or tissues.
4. Autoimmunity and Inflammation: Researches diseases where the immune system improperly attacks the body’s own cells.
5. Vaccine Development: Studies how to stimulate the immune response to prevent infectious diseases.
6. Immunodeficiency: Studies diseases where parts of the immune system fail to provide an adequate response.
The field of immunology is ever-growing and developing. With the advent of new techniques and technologies, our understanding of the immune system continues to expand, leading to novel treatments and therapeutics, such as new vaccines and immunotherapies for cancer.
|Immunosuppressive microenvironment||The immunosuppressive microenvironment refers to the conditions within a specific area in the body, like a tumor, where the immune system’s usual functions are dampened or inhibited. Such environments can prevent the immune system from effectively attacking cancerous cells or other harmful agents. These immunosuppressive regions can be created when cells within the area produce signaling molecules that inhibit the action of immune cells.
Tumors, for instance, are known for creating immunosuppressive microenvironments around themselves as a defense mechanism against the body’s immune system. They can release chemicals that attract types of immune cells known as regulatory T cells (Tregs) and Myeloid Derived Suppressor Cells (MDSCs), which dampen the immune response. They can also express molecules such as PD-L1, which bind to PD-1 on T cells and inhibit their function.
The study of these immunosuppressive microenvironments is a crucial part of cancer research. Understanding how these environments are created and maintained can lead to novel therapies to combat them. For example, immune checkpoint inhibitors, like pembrolizumab and nivolumab, are drugs that essentially “release the brakes” on the immune system by blocking PD-1 or PD-L1, enabling immune cells to attack cancer cells more effectively.
It’s also worth noting that the balance of the immune response is delicate and complex, and while overcoming immunosuppression is beneficial in treating diseases like cancer, preventing or managing excessive immune responses is also critical in treating autoimmune diseases. Therefore, understanding these immune microenvironments not only provides strategies to enhance the immune response when needed, but also to suppress it when necessary.
|Immunotherapy||Immunotherapy is a type of cancer treatment that helps your immune system fight cancer. The immune system helps your body fight infections and other diseases. It is made up of white blood cells and organs and tissues of the lymph system.
Immunotherapy works in two ways:
1. Stimulating your own immune system to work harder or smarter to attack cancer cells
2. Giving you immune system components, such as man-made immune system proteins.
There are different types of Immunotherapies, including:
1. Monoclonal Antibodies (mAbs): These are laboratory-made molecules that can act as substitute antibodies that can restore, enhance, or mimic the immune system’s attack on cancer cells. They are designed to bind to antigens that are generally more numerous on the surface of cancer cells, compared to healthy cells.
2. Immune Checkpoint Inhibitors: These medicines basically take the ‘brakes’ off the immune system, which helps it recognize and attack cancer cells. Examples include drugs such as Nivolumab (Opdivo) and Pembrolizumab (Keytruda), both of which target the PD-1 checkpoint, among others like CTLA-4 checkpoint.
3. Cancer Vaccines: These are substances introduced into the body to cause an immune response against certain diseases. While most people are familiar with vaccines against infectious diseases, there are also vaccines to help prevent or treat cancer.
4. Adoptive Cell Transfer: In this treatment, immune cells are taken from your tumor. These cells are modified in the lab to make them more effective at killing cancer cells, they are then multiplied and given back to you via a blood transfusion.
5. Immune System Modulators: These medications enhance the body’s immune response against cancer. They might affect different parts of an immune response, like boosting the action of certain white blood cells, suppressing the action of regulator cells, or promoting the enhanced action of antibodies.
Immunotherapy is increasingly showing promising results across a variety of cancer types. However, not all cancers respond to immunotherapy, and it’s successful only for a subset of patients. Ongoing research is aimed at better understanding which patients are most likely to benefit from this type of treatment, and how to boost its efficacy.
|Induced Pluripotent Stem Cells (iPSCs)||Induced Pluripotent Stem Cells (iPSCs) are a type of pluripotent stem cells that are generated directly from adult cells. Pluripotent means these cells have the ability to differentiate into any cell type of the three germ layers (ectoderm, mesoderm or endoderm). Therefore, they have the potential to produce any cell or tissue the body might need to repair itself.
iPSCs were first generated by Shinya Yamanaka’s team at Kyoto University, Japan, in 2006. They achieved this by introducing four specific genes, known as Yamanaka factors (Oct4, Sox2, Klf4, and c-Myc), into adult mouse fibroblasts using viral vectors. This process reprogrammed these somatic cells back to their embryonic state.
iPSC technology has revolutionized field of regenerative medicine. Because iPSCs can be derived directly from adult tissues, they not only bypass the need for embryos, but can also be made in a patient-matched manner, which means that each individual could have their own pluripotent stem cell line. These could then be used to produce transplantation therapies that would be completely immunocompatible.
Additionally, they represent a powerful tool for studying the mechanisms of diseases in vitro, testing new drugs, and understanding human development.
Despite their potential, we must also acknowledge that there are still multiple challenges to be faced, including the low efficiency and slow kinetics of cell reprogramming, managing the risk of tumor formation, and achieving fully functional and safe cells for transplantation.
|Low-Grade Dysplasia (LGD)||Low-Grade Dysplasia (LGD) refers to a condition where there is a mild abnormal growth or development of cells and tissues. This term is often used to describe changes that are seen under the microscope, typically in the context of a biopsy from an organ such as the colon, esophagus, or cervix.
Dysplasia is a pre-cancerous condition, part of a spectrum of changes that may eventually lead to cancer. However, it’s important to note that not all dysplasia will progress to cancer. The stages usually progress from low-grade dysplasia (mild abnormalities and fewer altered cells) to high-grade dysplasia (more serious abnormalities and a higher proportion of altered cells) before developing into cancer.
Low-grade dysplasia often does not cause any symptoms. In many cases, it is discovered during routine screenings, such as a colonoscopy or a Pap smear. After the identification of dysplasia, physicians typically recommend close monitoring with repeated tests or biopsies to keep track of any progression. In some instances, if the risk of progression is high, they may suggest removing the dysplastic cells or tissue.
The strategy depends largely on where the dysplasia is located and the patient’s overall health status. For instance, in Barrett’s Esophagus (a condition where the normal tissue lining the esophagus changes to tissue resembling the lining of the intestine), low-grade dysplasia is closely followed, and any shift towards high-grade dysplasia usually prompts intervention.
The goal of managing dysplasia is to intercept any progression towards cancer, and when possible, to revert the tissue back to its normal state. It’s worth noting that lifestyle changes, like quitting smoking or changing diet, can sometimes be beneficial, depending on the dysplasia’s location and cause.
|Lymphoid cells (Lymphocytes)||Lymphoid cells, also known as lymphocytes, are a type of white blood cell that plays a crucial role in the body’s immune system. They are primarily involved in the adaptive immune response, which is the body’s targeted fight against specific pathogens or toxins.
Lymphoid cells come in several types, each with its own unique function:
1. B cells, also known as B lymphocytes, are responsible for the production of antibodies. Each B cell is programmed to make one specific antibody, which will recognize one specific antigen (foreign substance). When a B cell encounters its triggering antigen, it will proliferate and develop into plasma cells which produce the specific antibody that recognises and binds to the antigen.
2. T cells, or T lymphocytes, are involved in killing infected host cells, activating other immune cells, and regulating immune responses. There are several types of T cells. CD4+ T cells, or helper T cells, aid B cells in making antibodies and assist in stimulating CD8+ T cells. CD8+ T cells, also known as cytotoxic T cells, can kill cells that are infected with viruses or that are otherwise damaged or dysfunctional.
3. Natural Killer (NK) cells are a component of the innate immune system which do not require activation to kill infected cells. They play a pivotal role in defending against tumors and cells infected by viruses.
In addition to these main categories, there are several subtypes of both B and T cells that perform specialized roles within the immune system. Lymphoid cells are produced in the bone marrow, and then migrate to parts of the lymphatic system such as the lymph nodes, spleen, and thymus for maturation and activation.
|Malignant Tumor||A malignant tumor, also known as cancer, is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. Unlike a benign tumor, which forms a compact mass and stays in one spot, a malignant tumor invades nearby tissues and can detach, move to other locations in the body, and form new tumors, a process known as metastasis.
Malignancy is what differentiates benign tumors (which are generally harmless and can be easily removed) from cancerous tumors. Malignant tumors pose more serious health risks because they grow very quickly, invade nearby tissues, can not always be completely removed, and may come back even after being removed.
Malignant tumors can occur anywhere in the body and can be of many types, including carcinoma (skin or tissues lining internal organs), sarcoma (bone, cartilage, fat, muscle, blood vessels or other connective tissue), leukemia (bone marrow and other blood-forming tissues), lymphoma and myeloma (cells of the immune system), and more.
The primary treatment for malignant tumors often involves surgery to remove the tumor, with radiation therapy, chemotherapy, immunotherapy, or targeted therapies being used before or after surgery, or as the main treatment in cases where surgery isn’t an option. The treatment will depend on the type and stage of the cancer, as well as the patient’s overall health.
|Myeloid-derived cells||Myeloid-derived cells are a broad category of cells that originate from a common progenitor in the bone marrow, known as a myeloid progenitor cell. Myeloid cells include various types of white blood cells, each with different roles in the immune system:
1. Monocytes are large white blood cells that circulate in the blood. They can migrate to tissues and differentiate into macrophages, performing phagocytosis of pathogens and dead or damaged cells.
2. Macrophages patrol for pathogens and also remove dead or dying cells. They can present antigens to T cells, activating the adaptive immune response.
3. Granulocytes, including neutrophils, eosinophils, and basophils, are named for the granules they contain, which can be released to kill pathogens.
– Neutrophils are the most common type of white blood cell, and they are often the first responders to microbial infection.
– Eosinophils are involved in the response to parasitic infections and play a role in allergic reactions.
– Basophils are involved in allergic reactions and can release chemical mediators like histamine.
4. Mast cells also participate in allergic reactions and are important for defense against certain parasites.
5. Dendritic cells act as messengers between the innate and adaptive immune systems. They capture foreign substances, degrade them, and present the fragments to T cells to initiate an adaptive response.
6. Megakaryocytes are responsible for producing platelets, which are critical for blood clotting.
7. Erythrocytes (Red Blood Cells), though they do not participate in immune defense, are also derived from myeloid precursors.
Each type of myeloid cell has a unique function and role to play in a healthy immune response. They are essential for both the innate immune response, which delivers an immediate, nonspecific attack against any invading substance, and in facilitating the adaptive immune response, more specific and tailored to the particular pathogen at hand.
|Oncology||Oncology is a branch of medicine that specializes in the diagnosis and treatment of cancer. It is a vital field in medicine, given the high prevalence and potential fatality of various forms of cancer.
Oncologists are medical doctors who specialize in diagnosing, treating, and providing care for patients who have cancer. There are different types of oncologists who specialize in treating certain types of cancer and providing certain types of treatment. They include:
1. Medical Oncologists: They typically lead a patient’s treatment plan and coordinate with other specialists. They’re responsible for systemic therapy such as chemotherapy, immunotherapy, targeted therapy, or hormone therapy.
2. Surgical Oncologists: They specialize in the removal of tumors and nearby tissue during surgery. They also perform biopsies (taking tissue samples to better diagnose certain types of cancer).
3. Radiation Oncologists: They specialize in treating cancer with radiation therapy.
4. Gynecologic Oncologists: They specialize in diagnosing and treating women’s reproductive cancers, such as ovarian and cervical cancer.
5. Hematologic Oncologists: They specialize in diagnosing and treating blood cancers like leukemia, lymphoma, and myeloma.
6. Pediatric Oncologists: They specialize in treating children with cancer.
The field of oncology advances continually, and treatment typically involves a multi-disciplinary team approach, often with regular tumor boards and team discussions, to provide the best personalized treatment plan for individual patients.
Moreover, clinical research trials are a key aspect of oncology, as this is the way that new treatments are tested and eventually brought into routine clinical practice. From developing pioneering techniques in radiation therapy to utilizing genetically engineered T-cells to kill cancer cells, to personalized medicine & oncogenomics, the field of oncology remains at the cutting edge of medical science.
|Orthotopic tumor||An orthotopic tumor is a type of tumor that is implanted or transplanted into the organ of origin in an animal model. For instance, if researchers are studying liver cancer, they would implant the tumor cells into the liver of an animal model, replicating the environment of the tumor as closely as possible.
This method is considered to reflect the tumor environment in humans more accurately than when the tumor is implanted in an arbitrary location, such as under the skin. As such, orthotopic models are often used when researching cancer because they provide a more relevant setting for studying tumor growth, progression, and response to therapeutics.
It’s important to note that these kind of studies should be performed obeying stringent ethical guidelines for handling and care of animals used in research purpose.
|Prostate Cancer (PCa)||Prostate cancer develops in the prostate gland. The prostate, shaped like a little walnut, is a gland in men responsible for making the seminal fluid that carries and nurtures sperm. Among the most frequent cancers in men is cancer of the prostate. Some prostate cancers may not be dangerous because they develop slowly and stay inside the prostate gland. Although some forms of prostate cancer develop gradually and might necessitate no treatment, others may be expanded quickly and are far more dangerous. Timely screening of prostate cancer increases the likelihood of a good treatment outcome because the disease is more likely localized to the prostate gland.|
|Protumorigenic||The term “protumorigenic” refers to factors that promote the formation and growth of tumors. These factors can be various types of cells, molecules, or even processes within the body that contribute to the initiation and progression of cancer.
Protumorigenic factors can be:
1. Cancer cells themselves: These cells can release signals that promote their own growth, survival, and spread. They can also recruit other cells to their environment that can aid in their growth and survival.
2. Cells in the tumor microenvironment: Certain types of immune cells can become ‘hijacked’ by cancer cells and promote tumor growth instead of fighting it. Additionally, cancer-associated fibroblasts can secrete factors that aid in tumor growth and create a physical scaffold for the tumor.
3. Molecules such as oncoproteins or growth factors: These can be produced by cancer cells or other cells in the tumor environment. They can drive cell proliferation, inhibit cell death, and promote angiogenesis (the formation of new blood vessels to feed the tumor).
4. Genetic or epigenetic changes: Mutations in certain genes can result in proteins that drive tumor growth. Additionally, changes in the way DNA is packaged and read (epigenetics) can upregulate oncogenes (genes that have the potential to cause cancer) or downregulate tumor suppressor genes.
Understanding these protumorigenic factors and how they contribute to cancer progression is a key area of cancer research. This knowledge can be used to develop targeted therapies that specifically inhibit these factors or turn the body’s immune system against the tumor.
|TP53 Tumor Suppressor Gene||TP53 is a gene that provides instructions for making a protein called tumor protein p53 (or p53). This protein acts as a tumor suppressor, which means it regulates cell division by keeping cells from growing and dividing too rapidly or in an uncontrolled way.
P53 is crucial in multicellular organisms, where it prevents cancer. When DNA in a cell becomes damaged by agents like toxic chemicals, radiation or ultraviolet (UV) light, this protein plays a critical role in determining whether the DNA will be repaired or the damaged cell should self-destruct (undergo apoptosis). If the DNA can be repaired, p53 activates other genes to fix the damage. If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors.
Mutations in the TP53 gene are associated with a variety of human cancers, including lung, colorectal, breast, ovarian, bladder cancer and many more. These mutations lead to the production of a p53 protein that cannot regulate cell growth and division effectively. As a result, cells with damaged or mutated DNA can continue to divide and may form a tumor.
One particular condition related to TP53 mutations is Li-Fraumeni syndrome, an inherited condition that greatly increases the risk of developing several types of cancer. Some specific forms of TP53 mutations that drive cancer growth are being investigated as potential targets for new cancer drugs.
Scientists have called TP53 the “guardian of the genome” because of its role in preventing cancer. However, it’s one of the most commonly mutated genes in people with cancer, making the study of this gene and its functions critical to cancer research.
|Transforming Growth Factor-Beta (TGF-β) in Cancer||Transforming Growth Factor-Beta (TGF-β) is a multifunctional cytokine, or signaling protein, that has an important role in regulating cell growth, differentiation, and immune responses. TGF-β has a complex and paradoxical role in cancer, acting as both a tumor suppressor and a tumor promoter depending on the context.
In the early stages of tumorigenesis, TGF-β often acts as a tumor suppressor. It can inhibit cell proliferation, induce apoptosis (programmed cell death), and help maintain genomic stability, effectively preventing the formation and growth of tumors.
However, as cancers progress, they can become resistant to the growth-inhibitory effects of TGF-β. At this point, the cytokine can start promoting tumor progression through several mechanisms:
1. Epithelial-Mesenchymal Transition (EMT): TGF-β can induce EMT, a process by which epithelial cells gain invasive and migratory capabilities, facilitating cancer metastasis (spread to other parts of the body).
2. Immune Evasion: TGF-β can help cancers evade the immune system, for example, by inhibiting the proliferation and function of immune cells, thereby creating an immunosuppressive tumor microenvironment.
3. Angiogenesis: TGF-β can promote the formation of new blood vessels (angiogenesis), supplying tumors with crucial nutrients and oxygen.
4. Extracellular Matrix Remodeling: TGF-β can stimulate the remodeling of the tissue around the tumor, facilitating its growth and invasion.
Due to its dual role, targeting TGF-β in cancer therapy is complex. However, several approaches are being investigated, including the use of antibodies to neutralize TGF-β, inhibitors of the TGF-β receptors, antisense oligonucleotides, and vaccines. Understanding the precise mechanisms and context-dependent effects of TGF-β in cancer can help develop effective therapeutic strategies.
|Tumor Microenvironment (TME)||The Tumor Microenvironment (TME) refers to the surrounding environment where the tumor exists, including the surrounding blood vessels, immune cells, fibroblasts, extracellular matrix, signaling molecules, and other components. It’s a dynamic system that continually interacts with the tumor cells.
A variety of cell types are found within the TME:
1. Cancer Cells: The primary component of the tumor, these cells proliferate uncontrollably and have the potential to spread to other parts of the body.
2. Cancer-associated fibroblasts (CAFs): These are the most common cells in the TME. They play a major role in generating the structural architecture of the TME and secreting growth factors and cytokines that promote tumor growth.
3. Immune cells: Different immune cells, like T cells, B cells, Natural Killer cells, macrophages, dendritic cells, and myeloid-derived suppressor cells, exist in the TME and can have varying effects on tumor growth.
4. Endothelial Cells: These cells line the inside of blood and lymph vessels and can aid in tumor growth and metastasis.
5. Pericytes: These cells wrap around the endothelial cells of capillaries and venules throughout the body. They play a key role in angiogenesis, a process critical to tumor growth.
Signaling molecules, like chemokines and cytokines, are present, creating a complex network of signaling pathways regulating tumor behavior. The extracellular matrix, composed of various proteins and glycans, plays an essential role in cell adhesion, cell-to-cell communication, and differentiation.
The TME plays a significant role in tumor progression, metastasis, immune response, and therapeutic resistance. As such, it presents numerous possibilities for therapeutic targets, from modulating immune cell responses to redirecting signaling pathways, making it a key area of study in cancer research.
|TCR, or T-Cell Receptor||TCR, or T-Cell Receptor, is a protein complex found on the surface of T cells, which are a type of white blood cell that plays a crucial role in the immune system.
The TCR complex recognizes and binds to specific antigens presented by antigen-presenting cells (APCs) via Major Histocompatibility Complex (MHC) molecules. Once an antigen is recognized, the T cell activates and carries out functions such as killing infected cells or helping other cells in the immune response.
The TCR is unique in its diversity, which is generated through a process called V(D)J recombination. This essentially means that each T cell’s receptor could theoretically recognize a different antigen, allowing the immune system to respond to a wide array of pathogens. This diversity is key to the adaptability and specificity of the adaptive immune response.
In summary, TCRs are vital for the immune system’s function, enabling T cells to recognize and respond to a diverse range of antigens.
|Vaccination||Vaccines are what?
Vaccines may be administered in the form of injections (shots), liquids, tablets, or nasal sprays, and their purpose is to train the immune system to detect and destroy potentially dangerous microorganisms. Vaccines exist, for instance, to stave against illness brought on by:
Viruses, such as the influenza and COVID-19 viruses
T. diphtheriae, p. pertussis, and other bacteria
For what purposes do various immunizations serve?
Vaccines can be one of Several Varieties
Live-attenuated vaccinations contain a reduced strain of the pathogen.
The infectious agent is rendered harmless with inactivated vaccinations.
Vaccines of the subunit, recombinant, polysaccharide, and conjugate types only use a small portion of the whole virus or bacteria.
Vaccine toxoids that use the bacterium’s own toxic byproduct.
Messenger RNA is the active ingredient in mRNA vaccines; it instructs your cells to produce a protein (or fragment of a protein) characteristic of the pathogen.
The genetic material used in viral vector vaccines directs your cells to produce a protein mimicking the pathogen. Some vaccinations also include a separate, harmless virus to aid in the delivery of the genetic material to the cells.
Vaccines may stimulate an immune response in a variety of ways. The immunological response is the body’s natural defense mechanism against invaders. Germs that might cause illness are among these compounds.
The immunological response entails what exactly?
The immunological response consists of many stages:
When a pathogen invades, your immune system treats it as a foreign invader.
The immune system aids the body in its battle against the infection.
The infection is stored in the memory of your immune system. If the germ tries infiltrating again, it will be met with force. This “memory” safeguards you against contracting the illness that the germ causes. We name this kind of defense “immunity.”
Immunization and vaccination: What are they, and how do they work?
Protection from a disease is achieved by immunization. Nonetheless, it may also imply the same thing as vaccination: getting a vaccine to be protected against a disease.
What are the advantages of vaccines?
Vaccines serve an essential purpose by warding against a wide variety of potentially deadly illnesses. These illnesses have the potential to be fatal. Vaccine immunity is preferable to natural immunity since it is less dangerous. Some vaccinations, in fact, provide a stronger immune response after vaccination than they would after contracting the illness themselves.
Vaccines provide more than just immunity, however. Community immunity also benefits from their presence.
So, what exactly is herd immunity?
Vaccines are often touted for their ability to promote community immunity, often known as herd immunity.
Infectious diseases may swiftly spread across a population, affecting many individuals. An epidemic might develop if enough individuals get infected. However, the spread of a disease is slowed when enough individuals have been immunized against it. Having everyone in the community protected in this way reduces the likelihood that the illness will spread.
People who are unable to get some immunizations benefit greatly from community immunity. Their compromised immune systems, for instance, may prevent them from receiving a vaccination. Some people may be allergic to the components of the vaccination. Some immunizations should not be given to infants until they are older. All of them may be safer if they have access to community immunity.
Can we trust vaccines?
Immunizations don’t pose any health risks. Before being sold in the United States, they must pass stringent safety tests.
A vaccination schedule is what?
A vaccination schedule, often known as an immunization schedule, details which vaccines are recommended for specific demographics of the population. Information about who should be vaccinated, how often, and how much is included. The vaccination schedule in the United States is publicized annually by the CDC.
Adults and children alike should adhere to the recommended vaccination regimen. By keeping to the program, they will be able to get protection against illnesses at the optimal period.
|What is a tumor?||A tumor is an abnormal mass of tissue that arises when cells proliferate uncontrollably or fail to die off at the appropriate times. Malignant tumors are cancerous, whereas benign ones are not (cancer). Even if they become rather big, benign tumors don’t harm the surrounding tissue or invade other organs.|