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Biomedical subjects

S M Khan

Publications and source records attributed to S M Khan.

At least 37 records · Page 2Linked to original sources
PubMed1995

Prevalence of streptococcal sorethroat in the school children of Dhaka.

Beta Haemolytic Streptococcal (BHS) infections and their sequelae Rheumatic Fever (RF) and Glomerulonephritis (GN) have a world wide distribution and so pose an important health problem. Reports show that there is considerable variation in the number of isolations from different groups. Present study intended to find out the health status of the school children in relation to streptococcal throat infection, in Dhaka Cantonment. It was a cross sectional, observational study. During one year period total six hundred and one (601) children were examined from one school of Dhaka Cantonment. Prevalence of streptococcus was found to be 22% among the study population with highest rate (67%) for group-G among BHS positive cases. True streptococcal infection was found in 8.7% cases & 2.2% cases were true GABHS positive cases. GABHS was significantly higher in large size families. Females and children from lower socioeconomic group were at higher risk. Females and children of large families may require special attention regarding prevention of streptococcal infection and RF/RHD prevention programme.

Adolescent↗
PubMed1994

The nonactivated estrogen receptor (naER) of the goat uterus is a tyrosine kinase.

The nonactivated estrogen receptor (naER) has been isolated and purified to absolute homogeneity from the goat uterine cytosol. It is a 66-kDa protein, sedimenting at 4.2 S on linear sucrose density gradients and having a Stokes radius of 36 A. It displays high affinity and specificity for estradiol and diethyl stilbestrol with a Kd of 1 x 10(-10) M. CNBr peptide analysis reveals that it has a primary structure distinctly different from that of the regular estrogen receptor even though anti-ER antibody cross-reacts with the nonactivated ER. The protein gains access to the DNA only upon dimerization with the estrogen receptor activation factor (E-RAF), a DNA-binding protein having no capacity to bind estradiol. Analysis reveals that both naER and E-RAF are protein kinases. While the E-RAF is a serine kinase, naER functions as a tyrosine kinase. No protein kinase activity is displayed by the regular estrogen receptor. The protein kinase activity of the naER is inhibited in the presence of estradiol. Similarly, the protein kinase activities associated with the proteins disappear when the naER and E-RAF are brought together.

Animals↗
PubMed1993

T-cell-rich B-cell lymphoma presenting as liver disease.

We describe a series of eight cases of T-cell-rich B-cell lymphoma diagnosed on liver biopsy and collected over a period of 15 years. Of seven cases that were referred from elsewhere, in only one was the correct diagnosis of B-cell lymphoma suggested. Common errors included misdiagnosis as inflammatory disease on histology, and misinterpretation as T-cell lymphoma on immunohistochemistry. However, the cases had a distinct morphological appearance and immunohistochemical profile. They showed a lymphohistiocytic or granulomatous infiltrate, usually centred on portal tracts and containing abundant small T-cells and scanty B-cell blasts. All patients had an atypical clinical presentation which favoured non-neoplastic liver disease. In seven cases liver involvement represented Stage IV disease and in one case disease was confined to the liver consistent with a primary hepatic lymphoma. Despite combination chemotherapy, the prognosis was poor with no patients surviving beyond 15 months from diagnosis. We believe T-cell-rich B-cell lymphoma to be an under-recognized subset of non-Hodgkin's lymphoma that may mimic primary liver disease.

Aged↗
PubMed1992

Increased thermal stability of proteins in the presence of naturally occurring osmolytes.

Organisms and cellular systems which have adapted to stresses such as high temperature, desiccation, and urea-concentrating environments have responded by concentrating particular organic solutes known as osmolytes. These osmolytes are believed to confer protection to enzyme and other macromolecular systems against such denaturing stresses. Differential scanning calorimetric (DSC) experiments were performed on ribonuclease A and hen egg white lysozyme in the presence of varying concentrations of the osmolytes glycine, sarcosine, N,N-dimethylglycine, and betaine. Solutions containing up to several molar concentrations of these solutes were found to result in considerable increases in the thermal unfolding transition temperature (Tm) for these proteins. DSC scans of ribonuclease A in the presence of up to 8.2 M sarcosine resulted in reversible two-state unfolding transitions with Tm increases of up to 22 degrees C and unfolding enthalpy changes which were independent of Tm. On the basis of the thermodynamic parameters observed, 8.2 M sarcosine results in a stabilization free energy increase of 7.2 kcal/mol for ribonuclease A at 65 degrees C. This translates into more than a 45,000-fold increase in stability of the native form of ribonuclease A over that in the absence of sarcosine at this temperature. Catalytic activity measurements in the presence of 4 M sarcosine give kcat and Km values that are largely unchanged from those in the absence of sarcosine. DSC of lysozyme unfolding in the presence of these osmolytes also results in Tm increases of up to 23 degrees C; however, significant irreversibly occurs with this protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Betaine↗
PubMed1992

Ischaemic colitis: clinical, radiological and pathological correlation in three cases.

The clinical and plain radiographic findings in three patients presenting with ischaemic colitis are presented. The radiographic signs were atypical in that featureless dilatation of the large bowel was present with no evidence of gas within the bowel wall or 'thumbprinting', and changes were not localized to the left colon. No thrombotic or embolic vascular occlusion was evident on examination of the resected specimens. We attempt to correlate the pathological and radiological findings, and emphasize the importance of considering this diagnosis in elderly patients who have a dilated featureless colon on plain radiographs.

Aged↗
PubMed1992

Localized amyloidosis of the lower genitourinary tract: a clinicopathological and immunohistochemical study of nine cases.

A series of nine cases of localized amyloidosis of the lower genitourinary tract are reported. The patients comprised six males and three females with an age range of 50-79 years at initial presentation. Clinically and on cystoscopy, the lesions were often diagnosed as neoplasms. Histologically, seven cases had typical features of localized amyloid deposits, while two cases had an unusual appearance with a florid histiocytic and giant cell reaction. Using an immunoperoxidase staining method the deposits were non-reactive with antibodies to serum amyloid A protein, prealbumin and beta 2 microglobulin, while equivocal immunoreactivity was seen with anti-light chain antibodies.

Aged↗
PubMed1991

Differential scanning calorimetry of bovine rhodopsin in rod-outer-segment disk membranes.

Rhodopsin-containing retinal rod disk membranes from cattle have been examined by differential scanning calorimetry. Under conditions of 67 mM phosphate pH 7.0, unbleached rod outer segment disk membranes gave a single major endotherm with a temperature of denaturation (Tm) of 71.9 +/- 0.4 degrees C and a thermal unfolding calorimetric enthalpy change (delta Hcal) of 700 +/- 17 kJ/mol rhodopsin. Bleached rod outer segment disk membranes (membranes that had lost their absorbance at 498 nm after exposure to orange light) gave a single major endotherm with a Tm of 55.9 +/- 0.3 degrees C and a delta Hcal of 520 +/- 17 kJ/mol opsin. Neither bleached nor unbleached rod outer segment disk membranes gave endotherms upon thermal rescans. When thermal stability is examined over the pH range of 4-9, the major endotherms of both bleached and unbleached rod outer segment disk membranes were found to show maximum stability at pH 6.1. The observed delta Hcal values for bleached and unbleached rod outer segment disk membranes exhibit membrane concentration dependences which plateau at protein concentrations beyond 1.5 mg/mL. For partially bleached samples of rod outer segment disk membranes, the calorimetric enthalpy change for opsin appears to be somewhat dependent on the degree of bleaching, indicating intramembrane nearest neighbor interactions which affect the unfolding of opsin. Delta Hcal and Tm are particularly useful for assessing stability and testing for completeness of regeneration of rhodopsin from opsin. Other factors such as sample preparation and the presence of low concentrations of ethanol also affect the delta Hcal values while the Tm values remain fairly constant. This shows that the delta Hcal is a sensitive parameter for monitoring environmental changes of rhodopsin and opsin.

Animals↗
PubMed1990

Cancer pain can be relieved.

In Pakistan, 70% of cancer patients with daily pain were found to be suffering severe pain. Cancer pain could be largely prevented by such inexpensive drugs as acetylsalicylic acid, codeine, and oral morphine.

Adolescent↗