PubMed Health⌕ Search

Biomedical subjects

S Aziz

Publications and source records attributed to S Aziz.

At least 19 recordsLinked to original sources
PubMed1992

Variation of the hyperacuity gap function with age.

Responses to hyperacuity stimuli are processed in quite a different manner by the central nervous system than many other stimuli such as resolution targets or increment threshold stimuli. With increased attention being paid to visual response in aging individuals, it is important to study how these response paradigms are affected by age. In this analysis, otherwise normal observers 20 to 85 years of age were studied. The hyperacuity gap test was used. As defined, this is a vernier test using a two-point test array. This particular format was chosen because the resultant data are less distorted by image blur, scatter, and astigmatism than other designs we have studied. The gap or feature separation between the two small targets (which were aligned vertically) was increased logarithmically using octave steps and the hyperacuity threshold (setting variance) was measured for each step. No systematic variation of vernier hyperacuity threshold was found with increasing age within the range of ages or gaps tested. This is important because it can serve as a valuable control and reference for other clinical studies of aging.

Adult↗
PubMed1992

Diagnosis of pleural effusions.

Sixty patients of pleural effusion with different aetiology are described. Various microbiological and biochemical parameters were done simultaneously in blood and pleural fluid to differentiate tuberculosis and non-tuberculosis effusions. Some biochemical tests were thought to be helpful in differential diagnosis but no single parameter was found diagnostic. Routine investigations of pleural fluid, sputum and pleural biopsy still remain the best method of diagnosis.

Alkaline Phosphatase↗
PubMed1992

Byssinosis in ginning factories of rural Sindh.

Frequency of byssinosis in 276 workers from 5 ginning factories of rural Sindh are described. Twenty-four (9%) had byssinosis, 178 were asymptomatic and the remaining 74 had other respiratory symptoms. Chronic obstructive pulmonary disease was present both in symptomatic and asymptomatic workers and was equally distributed amongst smokers and non-smokers. A possible involvement of some factors other than cigarette smoking is discussed.

Byssinosis↗
PubMed1991

Recognition, management, and prevention of Clostridium septicum abscess in immunosuppressed patients.

Spontaneous gas gangrene due to Clostridium septicum is a rapidly progressing disease that usually ends in fatal toxemia. We report three cases of asymptomatic C septicum abscesses to document the clinical course of this entity and to establish guidelines for its prevention and treatment. In contrast to previously reported data, C septicum infections can produce abscesses in solid organs, the retroperitoneum, and the extremities. These lesions often occur in patients with cancer, producing liver abscesses without gas formation that may be misinterpreted as metastatic carcinoma. Symptoms may be minimal or nonspecific before fulminant toxemia. Asymptomatic bacteremia should prompt a search for unsuspected cancer and an abscess. Computed tomography is the diagnostic modality of choice. The treatment consists of surgical débridement of necrotic tissue in concert with an appropriate course of antibiotics. We have found recurrences after adequate débridement and short-term antibiotic therapy, suggesting that prolonged and even lifelong prophylactic oral penicillin G potassium may be necessary to prevent further recurrences.

Abscess↗
PubMed1991

Quantification of metamorphopsia using hyperacuity techniques.

We have developed a new technique for quantification of metamorphopsia using a simplified and modified Amsler grid. Furthermore, the technique used is a bisection task, a form of hyperacuity determination. This allows for very fine assessments of metamorphopsia even in the presence of cataracts.

Aged↗
PubMed1991

Protein electrophoresis in tuberculosis.

Serum electrophoresis was done in 31 patients with pulmonary tuberculosis and 62 age and sex matched controls. Protein values amongst controls were higher than those described by others. In tuberculosis there was significant decrease in total proteins, and albumin with corresponding increase in globulin, mainly due to an increase in gamma globulin fraction. There was no significant increase in alpha-2 levels. Decrease in albumin/alpha-2 ratio was significant in sputum positive cases, but it was due to reduction in albumin rather than increase in alpha-2 globulin. Decrease in albumin/alpha-2 ratio in this study was not diagnostic of tubercular activity.

Adult↗
PubMed1990

Molecular characterization and nonradioactive detection of beta-thalassemia in Malaysia.

The spectrum of beta-thalassemia mutations in Malaysia has been determined in 45 beta-thalassemia chromosomes using dot blot hybridization of the polymerase chain reaction amplified DNA and direct DNA sequencing. Eleven different molecular defects, including those previously detected in Chinese, Asian Indians, and American blacks, and a novel frameshift mutation causing beta zero-thalassemia were detected. Since this novel mutation, a T deletion in codon 15 creates a new restriction site for EcoRII enzyme; the mutation could be detected by EcoRII digestion of the appropriate amplified fragment. The results of the present study provide additional information on the molecular heterogeneity of beta-thalassemia in this population. We also demonstrated the nonradioactive detection method of the beta-thalassemia mutation based upon the digoxigenin-labeled oligonucleotide probes.

Base Sequence↗
PubMed1990

Criteria for diagnosis in pulmonary tuberculosis.

In a retrospective study, case records of 1061 patients treated with antituberculosis drugs were examined to assess the criteria for diagnosis in each case. Seventy six percent had sputum examined for A.F.B. and 45% had mantoux test done. Five hundred and eighty one (55%) were diagnosed on radiology alone, while 262 (25%) had positive sputum for A.F.B. Only 50 (5%) of cases had positive Mantoux in addition to positive sputum and radiological changes. Practical significance of this practice is discussed.

Adolescent↗
PubMed1990

Hepatotoxicity to different antituberculosis drug combinations.

Hepatotoxicity to different combinations of anti-tuberculosis drugs containing, Rifampicin (R), Streptomycin (S), Isoniazid (H), Pyrazinamide (Z) and Myambutol (E) is described in 47 patients who completed 6 to 9 months therapy. Seven cases (15%) showed signs of toxicity and in 4 patients (8.5%) the drugs had to be withdrawn. Two patients developed hepatitis, one with jaundice and the other with fever and deranged liver functions, while others 2 developed severe hypersensitivity reactions. Burning palms, difficulty in micturition, itching and giddiness were complained of by one patient each, which settled in due course without recourse to withdrawal of drugs.

Antitubercular Agents↗
PubMed1990

Unconventional lymphocytes involved in rejection of xenogeneic heart grafts.

In this report, the efficacy of cyclosporine A and two monoclonal antibodies, anti-L3T4 and anti-Lyt-2.2, was assessed on first-set rejection of cardiac xenografts. Neither cyclosporine nor anti-Lyt-2.2 monoclonal antibody prolonged the survival of heart xenografts. Anti-L3T4 enhanced acceptance of rat hearts transplanted to C57BL/6 mice 5-fold relative to that observed in control recipients; it did not, however, prolong acceptance of hamster hearts transplanted to mice. Histologic analysis indicated that the cellular infiltrate within rejected hearts was composed of greater than 95% lymphocytes; of these, greater than 99% were Thy-1- and sIg-. These results suggest that rejection of xenogeneic hearts is mediated by unconventional lymphoid cells. This is discussed in the context of whether rejection of allografts and xenografts occur by similar or dissimilar mechanisms.

Animals↗
PubMed1986

Effort-related axillosubclavian vein thrombosis. A new theory of pathogenesis and a plea for direct surgical intervention.

Four cases of effort-related axillosubclavian thrombosis are described. The pathogenesis of this disorder is related to an anatomic constriction of the vein by the clavicle and first rib complex associated with repetitive trauma to the vein and resultant changes in the vein wall itself. Therapy must, therefore, not only address the superimposed thrombosis but must also provide a reliable correction of the constricting mechanism and the resultant lesion in the proximal subclavian vein. Our operative approach resulted in a full return to daily activities and no recurrence or persistence of symptoms in our series. Although early intervention is advisable, patients who present with long-standing venous occlusion should also be considered for operation. Medical therapy, consisting either of anticoagulation or thrombolytic therapy, results in an unsatisfactory clinical outcome because it does not correct the underlying mechanical abnormality.

Adult↗
PubMed1986

Improved lung preservation using Euro-Collins solution for flush-perfusion.

Satisfactory extended preservation of the lung has been difficult to obtain. This study investigated the influence of different total volumes and flow rates during flush-perfusion of the lung, and their effect on pulmonary artery pressure, flow distribution, regional lung temperature and functional performance of the lungs following transplantation after 24 hours. Fifteen mongrel dogs served as donors of the heart and lung block. Cold modified Euro-Collins solution was used as flush perfusate. Pulmonary artery and perfusion-line pressures were measured. The regional lung temperature was measured at one minute intervals with 5 myocardial temperature probes. Flow distribution was determined with micro-aggregated albumin labelled with Technetium 99. The heart-lung block was harvested, the right lung removed, and samples taken for gamma-counting. The left lung was stored in cold Euro-Collins solution and then transplanted. The inspired oxygen fraction (FiO2) was set at 0.4 and was kept constant throughout the procedure and the entire postoperative course. There were 3 groups of 5 animals each. In group A, the flush perfusate was administered at a total volume of 20 cc/kg over a period of 6 minutes. In group B the same volume of perfusate was administered at a pulmonary artery pressure (PAP) of 18 to 20 mmHg, resulting in a considerably shorter perfusion time (1.3 minutes). In group C 60 cc/kg of perfusate were given at the same flow rate as in group B, also resulting in PAP of 18 to 20 mmHg, but the perfusion time was increased to 4 minutes. Thus, groups B and C investigated the effect of increased pressure and volume of perfusate, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗