Medicine Hack

The aminoglycoside group includes gentamicin, amikacin, netilmicin, kanamycin, tobramycin, streptomycin, paromomycin and neomycin. These drugs have a good action against aerobic gram-negative bacteria. They are rapidly bactericidal. Bacterial killing is concentration dependent: The higher the concentration, the greater is the rate at which bacteria are killed. As noted above, some of the names end by -micin while others by -mycin. The reason behind this lies in the origin of the antibiotics. All the antibiotics ending with -mycin are either natural products or semisynthetic derivatives of compounds produced by a variety of soil actinomycetes notably Streptomyces . Those ending with -micin are derived from other actinomycetes e.g Micromonospora.

 INTRODUCTION  The Gram stain was developed in 1884 by the Danish bacteriologist Hans Christian Gram. It is one of the most useful staining procedures because it classifies bacteria into two large groups:  1) gram-positive and  2) gram-negative.  PROCEDURE  1) A heat-fixed smear is flooded with a basic purple dye, usually crystal violet. Because the purple stain imparts its color to all cells, it is referred to as a primary stain . 2) After 1 minute, the crystal violet is drained off and washed with distilled water. The smear is then covered with Gram's iodine, a mordant or helper . When the iodine is washed off, both gram-positive and gram-negative bacteria appear dark violet or purple. 3) Next, the slide is washed with alcohol (95% ethanol) or an alcohol-acetone solution. This solution is a decolorizing agent which removes the purple from the cells of some species but not from others. When the procedure is carried out, the slide is held at an angle and 95% ethanol is

It all started when Alexander Fleming discarded some of his culture plates that had been contaminated with mold. But fortunately, he had a second look to those cultures afterwards. He was amazed to see that in the area around the mold, the growth of bacteria was inhibited. The mold was identified as Penicillium notatum, the active inhibitor named penicillin. Above is a photo taken by Alexander Fleming in 1928.

He was a Dutch merchant and amateur scientist. He was probably the first person to observe live micro-organisms under magnifying lenses. He made a series of drawings of what he called as 'animalcules' i.e. small animals. He observed these by looking through his single-lens microscope at rainwater, his own feces and scrapings from his teeth. He made the drawings shown below.

Definition: Chickenpox is a benign viral disease of childhood, characterized by an exanthematous vesicular rash. It is an extremely common and contagious condition. It is caused by the varicella-zoster virus which is a herpes virus and contains a double stranded DNA in its center. Epidemiology: Age group affected- 5 to 9 years. The infection can be there at other ages too but it is less frequent. It is highly contagious and it affects all races and both sexes equally. The attack rate is around 90% among seronegative persons. Pathogenesis: Incubation period- 10 to 21 days but is usually 14 to 17 days. Patients are infectious around 48 hours from onset of vesicular rash, during the period of vesicular formation (around 4-5 days) and until all vesicles are crusted. Transmission occurs by respiratory route. The virus is believed to be localized in the nasopharynx, in the reticulo-endothelial system. It then enters the blood. This stage of viremia is characterized by diffused ski

It is a diarrheal disease and is commonly seen in cases of food poisoning. Pathogenesis: Man acquires this infection by ingesting contaminated water or food. Water is usually infected by feaces from an infected animal or human. Poultry and eggs also comprise an important source of salmonella. The organisms may be present on the outer shell or even in the yolk. The clinical syndromes that can occur in man includes gastroenteritis, enteric fever and septicaemia. In the case of enterocolitis, the salmonella bacilli attach themselves to the microvilli of the ileal mucosa by means of adhesins and then invade the cells. They cause massive efflux of fluids and electrolytes. Clinical presentaion: There is large volume watery diarrhea, fever, headache, chills, abdominal pain and tenesmus. In simple uncomplicated cases, the diarrhea will last for 3-7 days. Diagnosis is made by stool culture. The disease is self limited. Treatment consists only of correcting any fluid and electrolyte

It is caused by an organism known as Bacillus anthracis. The latter is a gram positive, spore-forming rod that is found in soil. The spores can remain viable for years. Anthrax came to public notice in September 2001 when it was used as a bioweapon delivered through the U.S Postal System causing infection in 22 persons of whom 5 died. In the past i.e. during World War II , anthrax was studied mainly for its potential use as a biological weapon but following the Biological and Toxin Weapons Convention Treaty in 1972, such research was no longer allowed. Still, some nations and extremist groups do work on this agent secretly. There are 3 major clinical forms of anthrax: 11)       Gastrointestinal anthrax – from ingestion of contaminated meat 22)       Cutaneous   anthrax – from introduction of spores through opening in skin 33)       Inhalational anthrax- inhalation of spores that deposit in the alveolar spaces. The inhalational form is the one usually used for biot