Medical Blog

All warm blooded animals are susceptible to the rabies virus, which is endemic in many countries but not in Britain. The main reservoirs of virus are wild animals, some of which may be carriers. There may infect domestic pets which then become the main source of human infection. The virus multiply in the salivary glands and are present in large number in saliva. They enter the body throug skin abrasions and are believed to travel to the brain along the nerves. The incubation period varies from about 2 weeks to several months, possibly reflecting the distance viruses travel between the site of entry and the brain. Extensive damage to the basal nuclei, mid brain , medulla oblangata and the posterior root ganglia of the peripheral nerves causes meningial irritation, extreme hyperaesthesia, muscle spasm and convulsions. In the advanced stages muscle spasm may alternate with flaccid paralysis and death is usually due to respiratory muscle spasm or paralysis.
Not all people exposed to virus contract rabies, but in those who do , the mortality rate is high.

This is not a disease in it self. It is a sign of abnormal bilirubin metabolism and excretion. Bilirubin, produced from the breakdown of haemoglobin, is usually conjugated in the liver and excreted in the bile.Conjugation the process of adding certain groups to the bilirubin molecule, makes it water soluble and greatly enhances its removal from the blood , an essential step in excretion.
Unconjugated bilirubin, which is fat soluble has a toxic effect on brain. However it is unable to cross the blood - brain barrier until the plasma level rises above 340mol\1 , but when it does it may cause neurological damage, fits.
Jaundice develops when there is an abnormality at some stage in the metabolic sequence caused by one or more factors.eg..
Excess hamolysis of red blood cells with the production of more bilirubin than the liver can deal with
Abnormal liver function that may cause,
Incomplete uptake of unconjugated bilirubin by hepatocytes
In effected conjugation of bilirubin. Interference with bilirubin secretion into the bile.
Obstruction to the flow of bile from the liver to the duodenum

This is an acute inflammatory condition of the salivary glands ,especially the parotids. It is caused by the mumps virus .one of the parainfluenza group. The virus is inhaled in infected droplets and during the 18 - 21 day incubation period viruses multiply elsewhere in the body before spreading to the salivary gland. The virus is present in saliva for about 7 days before and after symptoms appear so infection may spread to others during his 2 week period. They may also spread to .
The pancreas, causing pancreatitis.
The testes, causing orchitis after puberty and some times atrophy of the glands and sterility.
The brain, causing meningitis or meningoencephalitis .

Compression of a facial nerve in the temporal bone foramen causes paralysis of facial muscles with drooping and loss of facial expression on the affected side .The immediate cause is inflammation and oedema of the nerve but the underlying cause is unknown .The onset may be sudden or develop over several hours .distortion of the features is due to muscle tone on the unaffected side , the affected side being expressionless . Recovery is usually complete within a few months .

this is a congenital abnormality which may not be noticed until the onset of mentruation.when complete(imperforate), the hymen forms a barriers in the vagina.blood accumulate in the vagina,uterus and uterine tubes wityh each menstural cycle,and its may enter the periotoneal cavity and cause peritonitis.the uterine tubes may becomes obstructed by coagulated  blood,leading to infertility.

Author:someswara

shocks occurs when the metabolic needs of the cells are not being met because of inadequate blood flow.in effects,there is a reducation in circulating blood volume,in blood pressure and n cardiac tisue  hypoxia,an inadequate supply of the nutrients and the accumulation of waste products.A number of different types of shock are described:

·                     hypovolaemic

·                     cardiogenic

·                     septic

·                     neurogenic

·                     anaphylactic

Hypovolaemic shocks:

this oocurs when the blood volume is reduced by 15 to 25%.reduced venous return and in turn cardiac output may occur following:

·                     serve haemorrhage whole blood lost

·                     extensive superficial burns serum is lost and blood cells at the site of the burns are destroyed

·                     serve vomiting and diarrhoea water and electrolytes are lost

·                     perforation of an organ allowing its conent to enters the peritoneal cavity(peritonitis)

Cardiogenic shocks:

this occurs in accute heart diseases when the damaged heart muscle cannot maintain an adequate cardiac output,e.g. in myocardial infractionSeptic shocks(bacteraemic,endotoxic)this is caused by severe infections in which endotoxins are released into the circulation from dead gram-negative bacteria,e.g. enterobactreia,pseudomonas.  the mode of action of the toxins is not clearly understood.it may be that they cause an apparent reducation in the blood volume because of vasodilation and pooling of the blood in the large veins.this reduces the venous return to the heart and the cardiac output.

Neurogenic shocks(vasovagal attack,fainting):

the cause include sudden acute pain,severe emotional experince,spinal anaesthesia and spinal cord damage.parasympathetic nerve impluse reduce the heart rate,and in turn,the cardiac output.the venous return may also be reduced by the pooling of blood in dilated veins.these changes effectively reduce the blood supply to the brain,causing fainting.the period of unconsciousness is usually of short duration.

Anaphylactic shock:

in the allergy reaction an antigens interacts with an antibody and a variety of response can occurs .in severe cases,the chemicals released,e.g.histamine,bradykinin,produce widespread vasodilation and constriction of bronchiolar smooth muscle(bronchospam).the vasodilation profoundly reduces the venous return and the cardiac output resulting in the tissue hypoxia.bronchospasm reduces the amount of the air entering the lungs,increasing the tissue hypoxia.

author:someswara.        

Respiratory allergies are one of the most common afflication of childhood in fact many allergies are more prevalent in childhood often abating with age. As with adults ,respiration allergies in children are most likely to appear in the form of allergic rhinitis and asthma.
Asthma symptoms in children can be varied and subtle. It is vital that parents learn how to describe them. Look for coughing episodes,especially at night or during exercising (children will also often complain of a sore throat after exercise).

this term suggests inflammatory conditions of the glomerulus, but there  are several types of GN and inflammatory changes are not always present. in many cases immune complexes damage the glomerulli.these are formed when antigens combine either within the kidney or elsewhere  in the body ,and they circulate in the blood.when immune complexes lodges in the walls of the glomeruli they often cause an inflammatory response that impairs glomerular function.other immune mechanisms are also implicated in GN.

classification of GN is complex and based on a number of features :the cause,immunological characteristics and finding on microscopy.microscopic distinction is based on:

the extent of damage:

diffuse:affecting all glomeruli

focal:affecting some glomeruli

appearence:

proliferative: increased number of the cells in the glomeruli .

membranous:thickening of the glomerular basement membrane.

Inflammation of the meninges may occur following a compound fracture of the skull that is accompained by leakage of CSF and blood from the site,providing a route of entry for microbes.the escape of CSF and blood may be through: 1)skin in compound fractures me the skull 2)middle ear, in fracture of the temporal bone(CSF otorrhoea) 3)nose, in the fracture me sphenoid,ethmoid or frontal bones when the air sinuses are involved (CSF rhinorrhoea).

If you are banking on a vitamin supplement daily to make up for any deficiencies in your diet,you bargained for,
researchers in europe have carried out a study and found that people who rely on vitamin pills, instead of eating a healthy diet of fresh fruits and vegetables,are doing more harm than good.
According to them,three supplements,vitamin A,vitamin E and beta carotene,can increase mortality rates among those taking them.however,vitamin C and selenium pills have no effects as such.
“our finding contradict the findings of observational studies claiming that antioxidants(commonly found in vitamin supplements) improve health,”british media quoted lead researcher goran bjelakovic of copenhagen universisty hospital in denmark as saying.
The researchers combined results of a number of clinical trials to judge the overall effects of vitamin pills.they analysed 47 low-bias trials,involving 180,938 people and found that vitamin supplements as a whole increased their death rate by five percent. When the supplements were taken seperately, beta carotene increased death rates by seven per cent, vitamin A by 16 per cent, and vitamin E by four per cent . Vitamin C gave contradictory results, but when given singly or in combination with other vitamins in good quality trails, increased the death rate by six per cent, the researchers found. They, however, noticed that selenium was the only supplement to emerge with any credit, it can cut death rates by ten per cent when given on its own or as supplements, but’ the result is not statisitically significant.’