How antibiotics cause bacteria mediated damage to the intestine?

As you all know certain antibiotics when taken orally can cause gastro-intestinal tract disturbances and sometimes it can extend to serious side effects. All these symptoms and signs occur due to the disturbance of the normal flora of the gut. As you know there are susceptible and resistant bacterias to a antibiotic of choice. When that antibiotic is administered the susceptible bacterias die or the growth is retarded. But now the resistant bacterias do not die and those have a better chance of overgrowing since all the other bacterias in the gut are less in number.

Pseudomembranous colitis

One classical example for this is Pseudo membranous colitis. It is an acute inflammatory condition of the colon where a membranous exudate is produced. Sometimes this can be lethal.

Pathogenesis of Pseudomembranous colitis

When the antibiotic Clindamycin is given to a patient most of the bacterias in the colon die except Clostridium difficile which present in very small numbers in the normal flora of a healthy individuals. Now an overgrowth of Clostridium difficile occur in the gut. Certain strains of Clostridium difficile can produce toxins.(pathogenic strains produce two toxic polypeptides,designated A and B. Toxin A is an enterotoxin that causes excessive fluid secretion , but also stimulates an inflammatory response and has some cytopathic effects. Toxin B is a cytotoxin. These toxins can cause the death of gastrointestinal epithelial cells and finally a pseudomembrane is produced. Complications include gastro-intestinal tract bleeding, perforation of the gut and peritonitis.

Treatment

Treatments include avoiding the causative antibiotic and oral metronidazole (Vancomycin is also used.)This condition is also known as antibiotic associated colitis.

Laboratory identification of Clostridium difficile
Cultured from stools using routine anaerobic procedures. Toxin can be demonstrated in stool extracts.

References

Wikipedia - Pseudomembranous colitis

CPK enzyme

CPK enzyme ( also known as creatine phosphokinase and creatine kinase) is the enzyme which is responsible for the conversion of creatine to creatine phosphate. CPK enzyme plays a very important in skeletal muscle since it creatine phosphate system is important for the sudden energy requirements in the skeletal muscle. CPK enzyme is also abandontely found in brain and smooth muscle. During the conversion of 1 mol of creatine to creatine phosphate CPK enzyme converts 1mol of ATP to ADP. CPK Enzyme has several isoforms. Those isoforms are CPK-BB, CPK-MB, CPK-MM. The CPK-MM type is known as the skeletal muscle type of the CPK enzyme. CPK-BB type is known as the Brain type of the CPK enzyme.Only within the myocardial cells more than 5% of CPK-MB activity can be observed. Due to this fact CPK-MB isoform of the CPK Enzyme is used to diagnose myocardial cell damage and CPk enzyme palys a major role in the diagnosis of myocardial infarctions-heart attacks. This enzyme is also important in the diagnosis of various myopathies. Usually in muscle dystrophies plasma level of CPK enzyme is elevated. To differentiate the source of CPK enzyme isoform speific enzyme assays of other markers should be used.
Eg: CPK enzyme and Troponin I in myocardial infarctions.
CPK enzyme and myoglobin in muscle damage.
Fot more information about this read CPK Test and CPK Blood Test

Importance of plants in human life?

Importance of plants in human life?

In every way humans are dependent on plants. For food, medicines, air purification, carbon cycle, nitrogen cycle and etc. But in addition to these now this has a much higher importance. It is in global warming. When the humans started burning fossil fuels carbon dioxide concentration in the atmosphere started increasing.Importance of plants in human life Carbon dioxide is a green house gas and it keeps infrared rays within the earth atmosphere and help increasing the temperature. In the upcoming years this will become more and more important in human life.

Another importance in human life is for medicines. As you all know quinine, a very potent antimalarial drug discovered from the plant cinchona. (Actually it was first discovered by an African tribe) Not humans are facing more and more challenges from emerging and re-emerging diseases. For an example HIV the most dangerous and devastating disease in the word I may say up to now does not have an effective cure. But plants may have a good answer for with. People in the Indian subcontinent and Sri Lanka have used plant extracts as very effective remedies for many conditions.