Question

1-What is the difference between T lymphocyte cell and the Natural Killer cell? 2-Please write how humoral immunity and cellular immunity combat microorganisms? What is the difference of this action? 3-What is a Cytokine Storm? 4-What are CD8 cells? 5-What is the general prognosis for Infectious Mononucleosis? 6-What does TORCH stand for? 7-What is a Prion infection? 8-Why still are not vaccines against Hepatitis C virus? 9-Which markers specifically define Chronic Hepatitis B? 10-Why Diphteria infectious disease is increasing its frequency in USA? 11-How is feasible to break down the Dengue virus chain of infection? 12-What are you currently doing not to be contaminated with the Coronavirus agent?

Answer 1

1. NK cells were first noticed for their ability to kill tumour cells without any priming or prior activation (in contrast to cytotoxic T cells, which need priming by antigen presenting cells). ... Cancer cells and infected cells often lose their MHC I, leaving them vulnerable to NK cell killing.

Natural killer (NK) cells and natural killer T (NKT) cells are two types of important cells in innate immunity. ... The main difference between NK cells and NKT cells is that NK cells are large granular lymphocytes while NKT cells are a type of T cells.

2. The extracellular spaces are protected by the humoral immune response, in which antibodies produced by B cells cause the destruction of extracellular microorganisms and prevent the spread of intracellular infections. The activation of B cells and their differentiation into antibody-secreting plasma cells

Humoral immunity secretes antibodies to fight against antigens, whereas cell-mediated immunity secretes cytokines and no antibodies to attack the pathogens. The Humoral immunity is rapid or quick in their action against antigens, while the Cell-mediated immunity show delay though permanent action against any pathogens.

3. A severe immune reaction in which the body releases too many cytokines into the blood too quickly. Cytokines play an important role in normal immune responses, but having a large amount of them released in the body all at once can be harmful. A cytokine storm can occur as a result of an infection, autoimmune condition, or other disease. It may also occur after treatment with some types of immunotherapy. Signs and symptoms include high fever, inflammation (redness and swelling), and severe fatigue and nausea. Sometimes, a cytokine storm may be severe or life threatening and lead to multiple organ failure. Also called hypercytokinemia.

4. CD8-positive T cells are a critical subpopulation of MHC class I-restricted T cell and are mediators of adaptive immunity. They include cytotoxic T cells, which are important for killing cancerous or virally infected cells, and CD8-positive suppressor T cells, which restrain certain types of immune response

CD8+ (cytotoxic) T cells, like CD4+ Helper T cells, are generated in the thymus and express the T-cell receptor. ... CD8+ T cells (often called cytotoxic T lymphocytes, or CTLs) are very important for immune defence against intracellular pathogens, including viruses and bacteria, and for tumour surveillance.

5. Most people with mono recover completely with no long-term problems. The fatigue associated with the condition may persist for a few months after the fever and other symptoms have resolved. Severe complications as described above are very rare.

6. The full form of TORCH is toxoplasmosis, rubella cytomegalovirus, herpes simplex, and HIV. However, it can also contain other newborn infections. Sometimes the test is spelled TORCHS, where the extra "S" stands for syphilis.

7. Prions are misfolded proteins with the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals.

8. Among the difficulties that have hampered the development of a vaccine against HCV there are its extreme genetic variability, the lack of small animal models for testing vaccines, and the fact that a cell culture system supporting the production of infectious HCV and allowing studies on virus neutralization in vitro .

With an estimated 3% of the world’s population chronically infected, hepatitis C virus (HCV) represents a major health problem for which an efficient vaccination strategy would be highly desirable. Indeed, chronic hepatitis C is recognized as one of the major causes of cirrhosis, hepatocarcinoma and liver failure worldwide and it is the most common indication for liver transplantation, accounting for 40–50% of liver transplants. Much progress has been made in the prevention of HCV transmission and in therapeutic intervention. However, even if a new wave of directly acting antivirals promise to overcome the problems of low efficacy and adverse effects observed for the current standard of care, which include interferon-a and ribavirin, an effective vaccine would be the only means to definitively eradicate infection and to diminish the burden of HCV-related diseases at affordable costs. Although there is strong evidence that the goal of a prophylactic vaccine could be achieved, there are huge development issues that have impeded reaching this goal and that still have to be addressed. In this article we address the question of whether an HCV vaccine is needed, whether it will eventually be feasible, and why it is so difficult to produce.

9. Hepatitis B surface antigen (HBsAg) is the hallmark of HBV infection and is the first serological marker to appear in acute hepatitis B, and persistence of HBsAg for more than 6 months suggests chronic HBV infection.

Anti‐HBc IgM (hepatitis B core antibody) is observed during acute infection.
Anti‐HBc (total antibody against HBV core antigen) indicates the presence of IgM
and/or IgG against the core antigen. A positive total anti‐HBc with negative anti‐
HBc IgM antibodies indicates resolved infection.
HBeAg (hepatitis B envelope antigen) is viral protein associated usually with a
high viral load and high infectivity.
Anti‐HBe (antibody to HBeAg) usually indicates decreasing HBV DNA.
Anti‐HBs is a neutralizing antibody..

11.

Healthcare exists in an ever-changing world, so there is a continuing need for medical professionals to be able to identify and address new and existing health issues. For example, it’s important to remember the links related to an infection in order to help prevent the spread of it.

The term “chain of infection” refers to the conditions (links) that must be met in order for an infectious disease to spread. The idea of breaking the chain of infection means stopping at least one of those links, thus preventing it from starting again. If unchecked, certain infections can spread rapidly through the chain.

Listed below are the six links in the chain of infection, as well as ways to break that chain.

• Pathogen or infectious agent — the infection cause
• Reservoir or carrier — the person, animal or environmental source
• Portal of exit — the way the infection comes out of the body, such as through the respiratory tract, skin contact, mucus or blood
• Means of transmission — how it is spread or passed along, which can be:
  • Direct transmission – from contact or droplets in the air
  • Indirect transmission — can be airborne, vehicle-borne (food, water, blood) or vector-borne (ticks, fleas, mosquitoes and other sources)

• Portal of entry — the portal of exit is also commonly the portal of entry; that is, where the infection originates in one host and moves to another
• New host — the next person to get the infection (starting the new chain)

Here are ways to help reduce the spread of airborne infections:

• Control air pressure to ensure a clean-air environment.
• Monitor and measure air pressure.
• Use HEPA filters to remove airborne particles.
• Set physical barriers.

12.

Know how it spreads

• COVID-19 spreads easily from person to person, mainly by the following routes:
  • Between people who are in close contact with one another (within 6 feet).
  • Through respiratory droplets produced when an infected person coughs, sneezes, breathes, sings or talks.
    • Respiratory droplets cause infection when they are inhaled or deposited on mucous membranes, such as those that line the inside of the nose and mouth.
• People who are infected but do not have symptoms can also spread the virus to others.

Less common ways COVID-19 can spread

• Under certain circumstances (for example, when people are in enclosed spaces with poor ventilation), COVID-19 can sometimes be spread by airborne transmission.
• COVID-19 spreads less commonly through contact with contaminated surfaces.

Everyone Should

Wash your hands often

• Wash your hands often with soap and water for at least 20 seconds especially after you have been in a public place, or after blowing your nose, coughing, or sneezing.
• It’s especially important to wash:
  • Before eating or preparing food
  • Before touching your face
  • After using the restroom
  • After leaving a public place
  • After blowing your nose, coughing, or sneezing
  • After handling your mask
  • After changing a diaper
  • After caring for someone sick
  • After touching animals or pets
• If soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol. Cover all surfaces of your hands and rub them together until they feel dry.
• Avoid touching your eyes, nose, and mouth with unwashed hands

Avoid close contact

• Inside your home: Avoid close contact with people who are sick.
  • If possible, maintain 6 feet between the person who is sick and other household members.
• Outside your home: Put 6 feet of distance between yourself and people who don’t live in your household.
  • Remember that some people without symptoms may be able to spread virus.
  • Stay at least 6 feet (about 2 arms’ length) from other people.
  • Keeping distance from others is especially important for people who are at higher risk of getting very sick.

Cover your mouth and nose with a mask when around others

• Masks help prevent you from getting or spreading the virus.
• You could spread COVID-19 to others even if you do not feel sick.
• Everyone should wear a mask in public settings and when around people who don’t live in your household, especially when other social distancing measures are difficult to maintain.
  • Masks should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance.
• Do NOT use a mask meant for a healthcare worker. Currently, surgical masks and N95 respirators are critical supplies that should be reserved for healthcare workers and other first responders.
• Continue to keep about 6 feet between yourself and others. The mask is not a substitute for social distancing.

Cover coughs and sneezes

• Always cover your mouth and nose with a tissue when you cough or sneeze or use the inside of your elbow and do not spit.
• Throw used tissues in the trash.
• Immediately wash your hands with soap and water for at least 20 seconds. If soap and water are not readily available, clean your hands with a hand sanitizer that contains at least 60% alcohol.

Clean and disinfect

• Clean AND disinfect frequently touched surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.
• If surfaces are dirty, clean them. Use detergent or soap and water prior to disinfection.
• Then, use a household disinfectant. Most common EPA-registered household disinfectantsexternal icon will work

Monitor Your Health Daily

• Be alert for symptoms. Watch for fever, cough, shortness of breath, or other symptoms of COVID-19.
  • Especially important if you are running essential errands, going into the office or workplace, and in settings where it may be difficult to keep a physical distance of 6 feet.
• Take your temperature if symptoms develop.
  • Don’t take your temperature within 30 minutes of exercising or after taking medications that could lower your temperature, like acetaminophen.
• Follow CDC guidance if symptoms develop.