Shailesh Koirala 
ROCK ENGINEERING Rock engineering is the application of science of rock mechanics, engineering geology and other related discipline to the civil engineering construction. ROCK MECHANICS Rock mechanics is the theoretical and applied science of the mechanical behavior of rock mass. ROCK: Compact, indurated natural material (composed of one or more mineral) that requires drilling, blasting … Read more
Jaundice is a clinical condition characterized by the yellow color of the white of the eyes (sclera) and skin. It is caused by the deposition of bilirubin due to its elevated levels in the serum. Hyper-bilirubinemia is often used to represent the increased concentration of serum bilirubin. The normal serum total bilirubin concentration is in … Read more
Bordetella pertussis is a small non-motile, non-sporing ovoid. Gram negative cocco-bacillus. It measures about 1-1.5µm x 0.3µm and is haemolytic. Capsulated (fresh isolates from patients), strict aerobes and fastidious. On staining with toludine blue, metachromatic granules are seen. The genes coding for B. pertussis virulence factors are under the control of two sets of genes, which … Read more
Gonococcus is considered to be a strict human parasite. Various attempts were done to infect animals. But all had failed until recently when chimpanzees have been experimentally infected. Gonococcus is generally found only in cases of acute, chronic or asymptomatic infection. But not found in healthy carriers like meningococccus. The latter may account for 70-80% … Read more
The non-capsulated variety of Haemophilus influnzae is a very common commensal in upper respiratory tract. 60-80% cases have been found related to non-capsulated strains in the different surveys conducted in urban communities. This was carried in the throat or naso-pharynx of young children and the rates of 3 to 4% was of capsulated type notably … Read more
Botulism literally stands for sausage (botulus, Latin- sausage). The food poisoning in early days was generally caused by ingestion of poorly cooked sausage. Clostridium botulinum is worldwide in distribution. Its spores are found in wide evironment like soil, animal manure, vegetables, fruits, leaves and sea mud. It is a gram-positive, large, non-capsulated bacillus. Generally … Read more
Streptococcus are gram positive, catalase negative cocci. Are spherical or ovoid, 0.5-1µ in diameter, arranged in chains, non-motile and non-sporing. They may become gram negative in ageing culture when the bacteria die. Some of the strains possess capsules made up of hyaluronic acid while some of the strains possess capsules composed of polysaccharide. Human beings … Read more
Antigenicity is the ability to combine specifically with the final products of the responses i.e. secreted antibodies and/or surface receptors on T cells. All molecules having the property of immunogenicity also have the property of antigenicity but the reverse is not true. Some small molecules are antigenic but they are not able to induce a … Read more
The sequence of events leading to cholera is basically simple and confined to the gut. The food and drink contaminated by cholera vibrios if ingested results to disease though small dosage is present. The organisms begin to multiply in the alkaline medium of the small intestine after passing the acid barrier of the stomach juices. … Read more
It is a type of agglutination test. This test is used to detect presence of serum agglutinins (H and O) in patient’s serum with typhoid and paratyphoid fevers. At the end of first week, the antibody for Salmonella starts to appear in serum. During the third week, the antibody for Salmonella rises sharply in enteric … Read more