Biomedical subjects
Publications and source records attributed to N K Khan.
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Cyclooxygenases (COX-1 and COX-2) catalyze the conversion of arachidonic acid to prostaglandins (PGs). PGs play a significant role in bone metabolism in health and disease. Conventional non-selective, non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors (COXIBs) are widely used in patients with musculoskeletal conditions and as a post-surgical analgesics. Due to their effects on PG synthesis, these drugs have been hypothesized to affect the healing process of bone fractures and orthopedic surgical sites. A variety of experimental models of bone, ligament, and tendon repair have assessed the effects of these selective and non-selective COX inhibitors in animals, but with variable outcomes. At this time, large-scale, robust clinical study data do not exist, limiting the relevant assessment of experimental animal data to humans. Here, we provide a critical review of available data on the role of PGs and the effect of COX inhibitors on bone, tendon, and ligament repair. Collectively, this assessment suggests potential involvement of PGs in the healing process of these tissues via modulation by non-selective NSAIDs and selective COX-2 inhibitors.
Robust epidemiological data on the incidence of myocardial infarction (MI) are hard to find, but synthesis of data from a number of sources indicates that the average hospital in the UK should admit about two patients with a first MI and one recurrent MI per 1000 population per year. Possibly the most relevant data on the incidence, prevalence, and persistence of post-MI heart failure can be derived from the TRACE study. Most patients will develop heart failure or major left ventricular systolic dysfunction (LVSD) at some time after an MI, most commonly during the index admission. In up to 20% of cases this will be transient, but such patients still have a poor prognosis. There is likely to be around one patient discharged per thousand population per year with heart failure or major LVSD after an acute MI. It is important to organise care structures to ensure that patients with post-MI heart failure and LVSD are identified and managed appropriately.
Increased prostaglandins (PGs) are associated with many inflammatory pathophysiological conditions; and are synthesized from arachidonic acid by either of 2 enzymes, cyclooxygenase-1 (COX-1) or -2 (COX-2). Recent epidemiologic, expression, and pharmacologic studies suggest COX-2 derived metabolites also play a functional role in the maintenance of tumor viability, growth and metastasis. Archival and/or prospectively collected human tissues were prepared for immunohistochemistry, and representative cases assayed via Western blot, RT-PCR, or TAQman analysis. Consistent overexpression of COX-2 was observed in a broad range of premalignant, malignant, and metastatic human epithelial cancers. COX-2 was detected in ca. 85% of the hyperproliferating, dysplastic, and neoplastic epithelial cells, and in the existing and angiogenic vasculature within and adjacent to hyperplastic/neoplastic lesions. These data collectively imply COX-2 may play an important role during premalignant hyperproliferation, as well as the later stages of invasive carcinoma and metastasis in various human epithelial cancers.
A study was undertaken to determine the extent of morbidity associated with asthma and to audit the management of asthma in two out-patient clinics of two district hospitals. Patients were recruited for the study during a 3-month period from December 1990 to February 1991. Seventy asthmatic patients were studied. Eighty-six percent of the patients had their sleep disturbed by asthma, 77% took daily medication regularly, 63% felt that their activities were restricted by asthma, 60% had at least one acute exacerbation in the preceding six months. Of those who had their peak expiratory flow rate (PEFR) measured, 40% had a PEFR below 50% predicted, and only 11% had normal PEFR (greater than 80% predicted). The morbidity of asthma was thus considerable. On the other hand, the drug treatment of these asthmatics was grossly inadequate. They were prescribed on average 2.1 item of drugs, which for most patients comprised an oral beta agonist and a theophylline. Only 43% of the patients received inhaler therapy, but no patients were given steroids, inhaled or oral. The drug treatment was unrelated to the severity of patients' asthma. Further, objective measurement of severity was under-used in the assessment of asthma, only 8.5% of patients ever had their PEFR recorded. This study has found that asthma is poorly managed in out-patient clinics. We need to improve the training of doctors in the optimal management of asthma.
Two hundred and ten cases of diphtheria of both sexes and all ages with seasonal incidence and area prevalences were studied. Therapeutic trial of corticosteroid hormone was done in all cases of diphtheria studied. It was found that cortisone along with conventional drug therapy, the death rate came down to 68%. Age incidence of our cases had similar pattern with current literatures where as we observed some deviation in sex and seasonal incidence.