# causes of latent period

Association Between World Trade Center Exposure and Excess Cancer Risk. You may be familiar with this "breast cancer gene" due to the awareness raised by Angelina Jolie. What causes the latent period during excitation-contraction coupling? Ubuntu 20.04: Why does turning off "wi-fi can be turned off to save power" turn my wi-fi off? I'm new to chess-what should be done here to win the game? LATENT PERIOD. What is the application of rev in real life? Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. These recipes focus on antioxidant-rich foods to better protect you and your loved ones. Menopause can often last well into a womans 50s. This is a lab question I cant find the answer in the lab manual or in the text book. Edit: The latent period is the short delay between the muscle action potential and the beginning of muscle tension development. What is the difference between muscle fascicle and muscle bundle? However, the MERS-CoV virus is different than other coronaviruses, including SARS-CoV, and had never been … MathJax reference. Use MathJax to format equations. ", Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Men and women may vary in their susceptibility to exposure. The latency period for cancer is defined as the amount of time that elapses between the initial exposure to a carcinogen (cancer-causing substance) and the diagnosis of cancer. I mean, a chemical synapse is pretty much a 10-ms event if I am not mistaken, so that's not the bottleneck. The Latent Period Age Range: 6 to Puberty Erogenous Zone: Sexual Feelings Are Inactive . A latent period is the duration of time between initial exposure to a carcinogen, contaminant, or toxin and the onset of irreversible symptoms/conditions associated with the exposure such as chronic diseases, cancer, and benign and/or malignant tumors. This does not mean that there is a cancer conspiracy going on, or that corporations are releasing carcinogens to make money on chemotherapy drugs down the line. The period may be short, such as with the exposure to radioactive substances in Hiroshima and Nagasaki and development of leukemia, or it may be relatively long, such as the average time between exposure to asbestos and the later development of mesothelioma. But in some cases, the bacteria infect the body but do not cause any symptoms (latent TB), or the infection begins to cause symptoms within weeks, months or even years (active TB). We know that many chemicals can be absorbed through our skin. The latency period can vary tremendously depending on the particular cancer-causing substance being evaluated and the specific cancer or cancers it causes. Obviously, smoking does cause cancer, but due to the latency period of decades, we could not have made a clear assessment of risk in the analogy. Children develop social skills, values and relationships with peers and adults outside of the family. Less well known is that women who carry a BRCA2 mutation have double the risk of developing lung cancer if they also smoke. Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. A latent viral infection usually does not cause any noticeable symptoms and can last a long period of time before becoming active and causing symptoms. Asking for help, clarification, or responding to other answers. It's helpful when talking about latency periods to first review the definition of carcinogens. Latent or active TB. For people who suffered heavier exposure, such as asbestos miners and insulation workers, the latency period typically lies between 12 and 20 years, though even shorter latency periods are possible. Did China's Chang'e 5 land before November 30th 2020? If a product recommends wearing gloves (in the fine print) wear gloves. Doru Paul, MD, is triple board-certified in medical oncology, hematology, and internal medicine. There is concern that the risk of lung cancer will be greater in the future, and understanding the concept of the latency period can help explain why we do not know more at this time. Understanding the latency period also helps to explain one of the reasons why it is so difficult to study causation with cancer. Time taken for the stimulus to travel along the nerve to the neuromuscular junction, Time taken for the impulse to cross the neuromuscular junction and to stimulate the muscle, Time taken for the excitation-contraction coupling to occur, Time taken by the lever to overcome the inertia of rest. A latent infection is an infection that is hidden, inactive, or dormant. Group 4 - Probably not carcinogenic to humans. Carcinogenicity is not an exact science—we do not know for certain whether an exposure will cause cancer. How is the Q and Q' determined the first time in JK flip flop? There is a small time delay from the arrival of the action-potential until the Ca-ions are released and reach the required concentration in the cell for contraction. For this reason, many studies (retrospective studies) look back in time. I accidentally added a character, and then forgot to write them in for the rest of the series. All these binding and conformation changes take a small time to be completed, and thus causes a small delay. Time taken to overcome the vicous resistance of the muscle. In addition, substances with a long latency period are more likely to result in cancer when the exposure occurs early in life simply because people may live long enough for the cancer to develop. Your answer is basically a summing up of events, and not a dedicated answer to the question from m y understanding of PO's intentions. Another example of the importance of a latency period arises in discussions about cell phone use and brain cancer. From: Models of Seizures and Epilepsy, 2006. The bacteria enter your body through minor cuts or abrasions in your skin or mucous membranes. Theres no set age when menopause should start, but usually a woman will enter menopause in her mid-40s to mid-50s. I think this pretty much sums up the steps necessary from neuro-muscular junction until contraction, but what is the rate-limiting step? Thank you, {{form.email}}, for signing up. I found this article and where they exactly measured things. Types and Ratings of Different Carcinogens in Our Environment, An Overview of Genetic Testing for Lung Cancer. According to the Center for Menstrual Disorders and Reproductive Choice, the average age for menopause is 51. The linked wiki page has real good detailed information. Late-onset menopause ref… Take the time to read material data safety sheets for all chemicals you work with. With cancer, exposure to ionizing radiation in utero is more likely to result in cancer than exposure during other periods of life. Early-life exposures to infectious agents and later cancer development. These IHI’s are the starting points for an evaluation of latent causes. python-is-python3 package in Ubuntu 20.04 - what is it and what does it actually do? The particular substance (some exposures are much more likely to result in cancer than others). A common example is noted in the relationship between tobacco use and lung cancer. If you are feeling anxious, remember again that most cancers are caused by a combination of factors, and you do have some control over many of these. How Is Lung Cancer Different in Non-Smokers? If a woman is 55 or older and still hasnt begun menopause, doctors would consider it late-onset menopause. Immunosuppression (an inadequately functioning immune system) whether due to medical conditions, chemotherapy, or other immune suppressive drugs, raises the chances of a. Felice, M., Rossi, J., Alonso, C. et al. The genus coronavirus includes viruses that infect animals, cause the common cold in humans, and caused the 2003 SARS outbreak in China. In contrast, the latent period is the interval between disease onset and the clinical detection of disease, either by screening or as a … Examples which you may be familiar with include asbestos, radon, tobacco smoke, and arsenic. Limiting processed foods and red meats can help ward off cancer risk. That said, even when one of our cells develops mutations, most of these cells do not go on to become cancerous tumors. In the peripheral blood, lack of lymph cells (lymphopenia) commences immediately, reaching a peak within 24 to 36 hours. At some points in life, the body is more susceptible to carcinogens than at others (This may be easier to understand when compared with some infections. While this thought could lead some to avoid new products and head for the hills, a little common sense and caution are likely all that is needed to keep yourself safe. Making statements based on opinion; back them up with references or personal experience. Our immune system is well equipped with cells that get rid of abnormal and damaged cells, but cancer cells are different. Syphilis is contagious during its primary and secondary stages, and sometimes in the early latent period.Less commonly, syphilis may spread through direct unprotected close contact with an active lesion (such as during kissi… During the latent period for this type, the lymph nodes, spleen and bone marrow begin to atrophy, leading to underproduction of all types of blood cells (pancytopenia). A latent period allows study of alterations of anatomy and physiology before, during, and after onset of epileptogenesis and the model, therefore, may be ideal for experiments focused on underlying cellular mechanisms and antiepileptogenic strategies. Why is the latency period important and how does it make determining the causes of cancer difficult? The latent period is usually about 10 ms. Taken from Textbook of Practical Physiology Edition 2, by GK Pal & Pravati Pal. Latent period information including symptoms, causes, diseases, symptoms, treatments, and other medical and health issues. The latent period is the short delay between the muscle action potential and the beginning of muscle tension development. People may feel fine for many years—during the latency period—before it becomes clear that there is an association between smoking and several types of cancer. Without treatment, the infected person will continue to have syphilis in their body even though there are no signs or symptoms. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Latent Period. Lactic fermentation related question: Is there a relationship between pH, salinity, fermentation magic, and heat? Veham, V., Verma, M., and S. Mahbir. We simply don't have the resources, monetary input, or time to study the carcinogenicity and possible latency period of every chemical used in commerce. The latency period was significantly shorter for secondary blood-related cancers than for solid tumors. The average latency period for solid tumors was 110 months, but with this period of time ranging from 25 to 236 months. What physiological processes within a muscle cause the latent period in a muscle fiber? Latent period- the period of time that elapses between the generation of an action potential in a muscle cell and the start of muscle contraction 2. Is it ok for me to ask a co-worker about their surgery? After someone defines the first parallel points of IHI’s, the probe into the latent causes can begin in earnest. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. We know that chemotherapy—while it can sometimes cure these cancers—can also be a carcinogen which causes other cancers down the line. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. For example, an infection with cytomegalovirus may cause severe birth defects when contacted early in pregnancy, but only a mild syndrome with fatigue at another time). Another similar slotted arm is soldered in the same place vertically for attach- Latent period (epidemiology), the time interval between when an individual is infected by a pathogen and when he or she becomes capable of infecting other susceptible individuals. In other words, the jury is still out on the exact risk between cell phone use and cancer. Categories include: It's also very important to point out that cancer is most often a "multifactorial disease" which develops as a result of an accumulation of mutations in cells, not as the result of a single mutation (there are some exceptions, mostly with blood-related cancers). It is always essential to remember that a difference exists … What is meant by a muscle fiber being glycerinated? Ⓒ 2020 About, Inc. (Dotdash) — All rights reserved, Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time. Centers for Disease Control and Prevention. Which of the four inner planets has the strongest magnetic field, Mars, Mercury, Venus, or Earth? Below is a picture about the molecular mechanism ofof muscle contraction taken from this wiki page. It's been argued by some people that if cell phone use is a risk factor for brain cancer we should be seeing a significant increase in these tumors. Second Neoplasms in Children Following a Treatment for Acute Leukemia and/or Lymphoma: 29 Years of Experience in a Single Institution in Argentina. The most common route of transmission is through contact with an infected person's sore during sexual activity. Minimum Latency and Types or Categories of Cancer. Is it possible to just construct a simple cable serial↔︎serial and send data from PC to C64? Which processes are during the latent period of ventricular contraction? Edit 2: I found a good and simple ppt/pdf about AP propagation and muscle contraction here. Gender. Background: A novel human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified in China in December 2019. contraction period - tension increases (cross-bridges are swivelling) Latent Stage. This is what I'm talking about. If we were to begin a study today looking at a particular substance, we may not have results for decades. As opposed to active infections, where a virus or bacterium is actively replicating and potentially causing symptoms, latent infections are essentially static. Li, J., Cone, J., Kahn, A. et al. Sign up and get your guide! Carcinogens are substances in our environment which are thought to raise the risk of developing cancer. Protect your skin and lungs. There are several variables that influence both the likelihood that a carcinogen may result in the development of cancer and the period of time (latency period) between exposure and the diagnosis of cancer. Latent period may refer to: . Since these studies are not carefully thought out ahead of time (like prospective studies) there are often many questions left unanswered. This is what I'm talking about. BRCA2 is a tumor suppressor gene. Menopause that occurs before a woman is in her mid-40s is known as early or premature menopause. Until a substance has been evaluated over a significant length of time, we can't know for certain what the potential risk may be. HIV weakens a person's immune system so it can't fight the TB germs. Please help. Please help. The latency period depends on the duration and intensity of exposure. These types of viruses are known as latent viruses and may cause latent infections. Tuberculosis (TB) is a potentially serious infectious disease that mainly affects your lungs. Is there any solution beside TLS for data-in-transit protection? The Latent Period of Skeletal Muscle This prevents any distortion such as was found to occur if the free end of the wire rested on a knife edge. MAINTENANCE WARNING: Possible downtime early morning Dec 2, 4, and 9 UTC…, “Question closed” notifications experiment results and graduation. What this means is that there is an elapsed period of time called a latency period between exposure to a cancer-causing substance and the first signs of cancer. 1, B), to which the muscle is attached when pulling vertically. The International Association for Research on Cancer divides carcinogens based on the likelihood that they cause cancer. We proposed a model to analyze the real situation and follow-up trend of the epidemic in the US. Induction Period and Latency. One reason that this risk is unclear is the latency period. Time is required for calcium release, diffusion, and binding to troponin. Thanks for contributing an answer to Biology Stack Exchange! While blood-related cancers such as myeloma and non-Hodgkin lymphoma tend to have shorter latency periods, those of solid tumors such as lung cancer are often much longer. What physiological processes in a muscle cause the latent period in a muscle fiber? The concept of latency period can help explain why we are still uncertain about the danger of exposures to people who were involved in the clean-up efforts after 911. There are many reasons why it is important to be aware of the latency period with cancer. There is limited support for many of its key epidemiologic features, including the incubation period for clinical disease (coronavirus disease 2019 [COVID-19]), which has important implications for surveillance and control activities. During this stage, the superego continues to develop while the id's energies are suppressed. Related terms: Bacteriophages latent period: [ pēr´e-od ] an interval or division of time; the time for the regular recurrence of a phenomenon. In infectious diseases it is often identical to the incubation period, but not always. These include depleted muscle glycogen stores, … The case is similar when it comes to cigarette smoking and lung cancer. Viruses capable of latency may initially cause an acute infection before becoming dormant. Structural causes of epilepsy include neurodegenerative diseases, traumatic brain injury, stroke, brain tumor, infections of the central nervous system, and status epilepticus (a prolonged seizure or a series of seizures occurring in quick succession). The latency period, in this case, would be defined as the length of time between the onset of smoking, and the later development and diagnosis of lung cancer. cause (the overheated bearing). Relaxation phase- period of time from peak tension until the end of muscle contraction MERS is caused by a virus referred to as "MERS-CoV" from the coronavirus genus; MERS-CoV means Middle East respiratory syndrome coronavirus. The latent (hidden) stage of syphilis is a period of time when there are no visible signs or symptoms of syphilis. I'm sorry I didn't make that clear. What might this mean for people who have been exposed to toxic chemicals, such as the workers involved in rescue and recovery after the World Trade Center tragedy? The average latency period for hematologic (blood-related) cancers such as leukemias and lymphomas was 51 months but varied from 10 to 110 months. Cancer may be related to either short-term high levels of exposure or long-term low levels of exposure. The basis for selecting minimum latencies for specific types or categories of cancer is described in the sections below. Unlike type 1, however, this destruction is a somewhat slow process. However, at the outset it is important to understand that the scientific literature assessing minimum latency periods for specific types of cancer is scarce. The action potential causes Ca2+ ions to be released in the cells, that is needed for muscle fiber contraction. The cause of syphilis is a bacterium called Treponema pallidum. See more. But the crucial difference between the two pathogens is a related metric called the “latent period”. On the molecular level there is a protein called troponin (this is bacically located on the actin filament along with tropomyosin and obscures the myosin binding site(s)), that bind calcium and then undergoes conformational change - this also adds up to the delay. Genetic susceptibility. For example, at least 40 years if the latency period of a carcinogen was 40 years. The only systematic study of roughly a thousand firemen and rescue workers found that seven years after the tragedy, there was a 19% excess risk of cancer at all sites. Do Bluetooth Headphones Really Cause Cancer? HIV is capable of viral latency, as seen in the reservoirs of latent HIV-infected cells that persist in a person’s body despite antiretroviral therapy (ART). It can take many years between an exposure and the later development of cancer. For women, estrogen may also play a role in lung cancer development. Early latent syphilis is latent syphilis where infection occurred within the past 12 months. What physiological processes in a muscle cause the latent period in a muscle fiber? There are several hypotheses about the causes of muscular fatigue. Which game is this six-sided die with two sets of runic-looking plus, minus and empty sides from? After this - the conformational change of troponin - myosin and actin can bind together and contraction can occur through conformational changes. The type of cancer that results from exposure. Latent period Some of these include: You may have heard that people who assisted in rescue and recovery efforts after 911 have an increased risk of developing cancer. It's important to note, however, that if tobacco smoking started and became common at the same time that cell phone use took off, we still would be wondering if tobacco could cause cancer. A 2017 study looked at secondary cancers in people with acute leukemia. A clear example of a genetic influence on cancer development is seen in people with Down syndrome, who have an, Other medical conditions. Based on studies to date, there does appear to be an excess cancer risk among these people. latent period - no change in length; time during which impulse is traveling along sarcolemma & down t-tubules to sarcoplasmic reticulum, calcium is being released, and so on (in other words, muscle cannot contract instantaneously!) rev 2020.12.2.38094, The best answers are voted up and rise to the top, Biology Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. Latent periods of about 8–16 hours after exposure may occur in patients with toxic pulmonary oedema and extrinsic allergic alveolitis (hypersensitivity pneumonitis). For example, it's thought by some (but not others) that women are more likely to develop lung cancer with the same amount of tobacco exposure. Contraction phase- starts at he end of the latent period and ends when muscle tension peaks 3. The cumulative number of confirmed cases in the United States exceeded one million on 29 April 2020, becoming the country of the most serious pandemic in the world. Some of the carcinogens noted in dust and debris include asbestos, silica, benzene, and polycyclic aromatic hydrocarbons. The latency period can vary tremendously depending on the particular cancer-causing substance being evaluated and the specific cancer or cancers it causes. The induction period is the interval between the time of action of a component cause and the time of initiation of disease. If a product recommends using good ventilation, open windows or turn on an exhaust fan. For example, the risk of lung cancer and mesothelioma for people who are both exposed to asbestos and smoke is greater than if you simply added these risks together. This is a lab question I cant find the answer in the lab manual or in the text book. At the other extreme, slow accumulation of mineral dusts may lead to disease symptoms many years later. It only takes a minute to sign up. To learn more, see our tips on writing great answers. Revised May 1, 2013. Different components of a cause can act at different times, so they can have different induction times as illustrated in the image below. Like type 1, LADA is caused by the immune system destroying the insulin-producing beta cells in the pancreas. Soldered at right-angles (horizon- tally) atthis endofthetorsionwireis ashort, slottedlever-arm(fig. Latent period definition, the interval between exposure to a carcinogen, toxin, or disease-causing organism and development of a consequent disease. The bacteria that cause tuberculosis are spread from one person to another through tiny droplets released into the air via coughs and sneezes.Once rare in developed countries, tuberculosis infections began increasing in 1985, partly because of the emergence of HIV, the virus that causes AIDS. The latency period can vary greatly with different carcinogens, but even with a single carcinogen, there can be variations in both the latency period and the type of cancers which arise. This is the time between becoming infected and being able to spread the disease to others. The cancers which appear to be increased so far include prostate cancer, thyroid cancer, myeloma, and non-Hodgkin’s lymphoma. Conducted in Argentina, the study followed people with acute leukemias or lymphomas to determine both the incidence of secondary cancers (cancers caused by cancer treatments) and the average latency period between the treatment of the original leukemia or lymphoma and the development of secondary cancer. He is an associate professor of clinical medicine at Weill Cornell Medical College and attending physician in the Department of Hematology Oncology at the New York Presbyterian Weill Cornell Medical Center. Virus - Virus - Latency: Inapparent infections (those that do not cause specific signs and symptoms) often result after exposure to picornaviruses, influenza viruses, rhinoviruses, herpesviruses, and adenoviruses but less frequently to measles and chickenpox viruses. Edit: As noted above, there are many substances we are exposed to each and every day that have the potential to cause cancer. Roughly one percent of survivors developed secondary cancer. So as for the whole muscle, not for just one cell the delay is caused by the things listed in the above quote - although excitation-contraction (EC) coupling and force transmission (things I have described earlier) take place in every single muscle cell that is in a specific muscle fiber. Thus, each component cause may have a different induction period (the interval between the exposure's presence and disease onset). What is? Is it illegal to carry someone else's ID or credit card? Will grooves on seatpost cause rusting inside frame? These exposures may include radiation, chemicals, ultraviolet light, and even cancer-causing viruses. An example of the multifactorial causation of cancer could be women who smoke and also have a BRCA2 gene mutation. But this illness comes from a fungus that lives in the soil, and a few cases are serious. How does an electrical impulse spread in a muscle fiber spread from the motor end plate? A disease may have incubated but remains latent, or dormant, within the body. In other words, most often a number of factors work together to either produce or prevent a cancer. Is there a word for "science/study of art"? In most healthy people, the immune system is able to destroy the bacteria that cause TB. Valley fever’s symptoms start out much like those of the flu. a precise determination of minimum latency periods difficult. For example, you are probably familiar with cigarette smoking as a risk factor for lung cancer. For example, the varicella-zoster virus infects many cells throughout the body and causes chickenpox, characterized by a rash of blisters covering the skin. Read our, Medically reviewed by Douglas A. Nelson, MD, Factors That May Affect the Latency Period, World Trade Center Rescue and Recovery Workers and Cancer, Example of Variations in Latency Period Even With a Single Carcinogen, How to Use This Concept for Cancer Risk Reduction. Why does Taproot require a new address format? Age at exposure. How do I respond as Black to 1. e4 e6 2.e5? You may have heard about people being exposed to asbestos and developing mesothelioma many years later. association between smoking and several types of cancer, increased likelihood of developing leukemia, Group 2A - Probably carcinogenic to humans, Group 2B - Possibly carcinogenic to humans, Group 3 - Unclassifiable as to carcinogenicity in humans. Plausibility of an Implausible First Contact. By What Mechanism Does Heat Cause Muscle Relaxation? site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. To clarify my answer (taken from the linked article): Electromechanical delay (EMD) was described as a time elapse between the onset of muscle electrical activation and onset of force production, reflecting both electrochemical processes [i.e., synaptic transmission, propagation of the action potential, excitation-contraction (EC) coupling] and mechanical processes [i.e., force transmission along the active and passive parts of the series elastic components (SECs)]. In some cases, exposures to carcinogens can be more than additive. At this time, we simply do not know. We hare now hearing people ask whether those involved in the clean-up efforts have an elevated risk of lung cancer. Why did the scene cut away without showing Ocean's reply? What is the connection between exercise and muscle growth. While an infection is latent, it may hide from the immune system and/or be difficult to treat with drugs and other therapies. A "latent period" is the lag time between exposure to a disease-causing agent and the onset of the disease the agent causes.