Types of hepatitis A) Hepatitis A It is the inflammation of liver from the hepatitis A virus. HEA virus is generally found in the stools and blood of an infected person about 15- 45 days before symptoms occur and during the first week of illness. Usually spread by fecal-oral contact, or fecal-infected food and water. … Read more
Introduction Anaerobic bacteria require incubation without oxygen. However, some anaerobes (e.g. Clostridium histolyticum) are aero-tolerant which may produce some growth on the surface of aerobic plates. There are some bacteria which are strict anaerobes (Clostridium tetani). Anaerobiosis can be established by the following methods. Methods of Anaerobiosis 1) By displacement of oxygen i) Cultivation in … Read more
Introduction to Interferons Interferons are low molecular weight protein, produced by virus infected cells. These, itself induces the formation of a second protein inhibiting the transcription of viral mRNA. These are produced by the host cell in response to the virus particle, viral nucleic acid and non-viral agents. Non-viral agents include synthetic polynucleotides such as … Read more
The cultivation of viruses from material taken from lesions is an important step in the diagnosis of many viral diseases. Studies of the basic biology and multiplication processes of human viruses also require that they are grown in the laboratory under experimental conditions. Human pathogenic viruses can be propagated in three types of cell systems. … Read more
Antibodies, which are also called immunoglobulin, are proteins which are protective in nature. Usually produced by the immune system in response to the presence of a foreign substances that can be bacteria, virus, fungi or any other living forms. There are various factors affecting antibody production. They are as follows: a) Age The embryo is immunologically … Read more
Complement shows various biological functions which are listed here below: 1. Immune adherence and opsonization This involves the covalent binding of complement proteins to the surface of microbial membranes. This opsonization or coating by complement proteins promotes adherence of the opsonized microbial components to the cell membranes of phagocytic cells. Phagocytic cells (macrophages, neutrophils) have … Read more
Alternative Pathway The alternate pathway bypasses C1, C4, C2 components and starts at C3 step. It is generally activated by non-immunological means such as bacterial surfaces and their components (e.g. endotoxin, microbial polysaccharides). Some other factors such as inulin, zymosan, yeast walls, cobra venom are also responsible for activation of this pathway. However, the mechanism … Read more
Introduction to Complement Complement is the name given to a system of some non-specific proteins present in normal human and animal serum. These proteins have got the ability to lyse or damage cells (bacteria, virus, tumour cells) and to stimulate some antigen and antibody reactions. This system consists of approximately 20 serum proteins which include … Read more
Introduction Innate immunity is also known as native immunity. It is a resistance with which a person or lower animal is born and is non-specific. This type of immunity is present throughout our life. It may be of various types like species immunity, racial immunity or individual immunity. Various factors like age, hormones, nutrition, etc. … Read more
Introduction The process of ingestion of bacteria or other material by phagocytes and amoeboid protozoans is called phagocytosis. Macrophages and neutrophils show a high capacity for the physical engulfment of particles such as microorganisms or microbial fragments from their immediate extracellular environment. There are other various cells which show this process as well. For engulfing … Read more