Biomedical subjects
S Sharma
Publications and source records attributed to S Sharma.
Clinical and experimental mycotic keratitis caused by Aspergillus terreus and the effect of subconjunctival oxiconazole treatment in the animal model.
Aspergillus terreus was isolated from a case of Keratomycosis. The patient, a 50 year old, female presented with a large corneal ulcer with hypopyon. The direct microscopic examination of the scrapings revealed hyaline, thin, septate and branched hyphae. In vitro some antimycotics (amphotericin B, 5-fluorocytosine, oxiconazole, amorolfine and ketoconazole) were tested against A. terreus by agar dilution method. Ketoconazole with MIC of 3 micrograms/ml after 7 days of incubation was most effective followed by oxiconazole (10 micrograms/ml). Experimental corneal ulcer was produced by injecting intralamellary 0.1 ml of the spore suspension containing 10 x 10(6) cfu/ml into the eyes of previously immunocompressed albino rabbits. Histopathologic examination showed infiltration and large destruction of the corneal stroma. Subconjunctival oxiconazole therapy exhibited complete cure. Based on our findings, a clinical evaluation of oxiconazole in human keratomycosis seems to be justified.
Isozyme polymorphism of endo-beta-1,4-glucanase in Aspergillus nidulans.
An electrophoretic survey of the natural populations of Aspergillus nidulans, the A. nidulans group, and various species belonging to the genus Aspergillus from diverse geographical areas of India was carried out to determine the isozyme polymorphism of endoglucanase. The data revealed the presence of three forms of endoglucanase designated EG I, EG II, and EG III. In some isolates, EG I and EG II were present separately; in others, instead of two separate bands, one thick band was detected, which was designated EG I. In natural isolates of A. nidulans and the A. nidulans group, EG III was detected in most, but not all, isolates, while EG I and EG II were always present. However, in various other species of the genus Aspergillus, EG II was totally lacking. In all the populations at the EG I and EG II region, seven electrophoretic variants each were detected, and at the EG III region four variants were seen. The data suggest that there may be two structural genes for endoglucanase, one coding for proteins in the EG I/EG II zone and another for protein in the EG III zone.
In vitro growth of urinary Escherichia coli related to siderophore production.
Thirty seven strains of Escherichia coli isolated from the urine of patients with acute symptomatic urinary tract infection were examined for siderophore production: hydroxamate (aerobactin) and phenolate (enterochelin). All the strains were found to produce varying amounts of enterochelin. With the chemical assay, 24.3% strains were aerobactin producers, while 43.2% were positive in the bio-assay. All the aerobactin producers carried the aerobactin receptor on their surface. Attempts to correlate siderophore production with growth in minimal and iron-depleted medium showed that there was a positive quantitative correlation between enterochelin production and growth of organisms under iron depletion. Aerobactin production failed to give an additional advantage of growth to strains producing enterochelin.
Percutaneous balloon angioplasty of congenital aortic stenosis and associated aortic coarctation in an adult.
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Limitations in developing gossypol acetic acid as a male contraceptive.
Highly purified gossypol acetic acid (5 mg/day; oral) alone and in combination with potassium chloride (0.25 mg/day; oral) was tested in adult male langurs for 120 days to evaluate reversibility of its antifertility action and possible hypokalemia. The treatment resulted in severe oligospermia with impairment of sperm motility. Sperm morphological defects were evident. The functional activities of accessory sex glands and libido remained unimpaired. Occurrence of hypokalemia was found more pronounced in the gossypol alone group. Extensive renal potassium loss was evident and conversely the renal excretion of sodium decreased markedly. The activities of serum transaminases increased significantly. Other parameters of blood and of urine did not show any marked alterations. Complete reversal of the above changes was evident following 90 to 105 days of withdrawal of treatment. In conclusion, the oligospermia achieved was reversible and the hypokalemic response of langurs is similar to human and not related to impurity of the drug.
Schmidt's syndrome: a rare cause of puberty menorrhagia.
Schmidt's syndrome, also known as polyglandular deficiency syndrome, is the presence of Addison's disease and hypothyrodism in a single patient. It is usually associated with other autoimmune disorders like vitiligo, diabetes mellitus, myasthenia gravis. A rare case of an 18-year-old girl having Schmidt's syndrome and vitiligo who presented with puberty menorrhagia is reported. A brief review of the literature is also given.
Severe pulmonary hypertension in rheumatoid arthritis.
We report a patient with seropositive rheumatoid arthritis who had clinical and haemodynamic findings of severe pulmonary arterial hypertension. Histopathology proved this to be plexogenic rather than thromboembolic. We report the case to highlight this rare association.
Coronary arteriovenous fistula in tetralogy of Fallot: an unusual association.
A congenital coronary arteriovenous fistula is a rare anomaly, and only two cases have been previously reported in association with tetralogy of Fallot. We report one more patient with tetralogy of Fallot who had an associated fistulous communication between the left circumflex coronary artery and the coronary sinus. It is important to localize these left to right shunts preoperatively in order to plan optimal surgical management.
Effects of NGF and dibutyryl cAMP on neuronal differentiation of embryonal carcinoma cells.
The P19S18O1A1 embryonal carcinoma cell line is capable of neuronal differentiation and is therefore useful in studying neuronal development and the influence of growth modulators on neuronal differentiation. We report here on the effects of nerve growth factor (NGF) and dibutyryl cyclic adenosine monophosphate (db cAMP), individually and combined, on differentiation of P19S18O1A1 cells. NGF alone did not induce any significant neuron-like changes in cultures exposed to NGF for as long as 12 days. Treatment with db cAMP resulted in changes in a significant population of the cells, including development of a neuron-like morphology, seen at both the light and electron microscopic level, loss of stage-specific embryonic antigen expression and the appearance of two neuronal markers, neurofilament protein and neuron-specific enolase. These changes were similar to changes seen when embryonal carcinoma (EC) cells are treated with retinoic acid. NGF in combination with dibutyryl cyclic adenosine monophosphate brought about similar changes as dibutyryl cyclic adenosine monophosphate alone, and was therefore not synergistic for induction of neuronal properties. In retinoic acid-treated cultures, the neuron-like cells had ultrastructural features very similar to neurons in non-tumorous, normal tissue, with typical organelles, such as one nucleolus, neurotubules and neurofilaments, while db cAMP-treated EC cells showed similar findings at the electronmicroscopic level. The results suggest that db cAMP can induce the neuronal phenotype in EC cells alone without pre-treatment with retinoic acid.
Echocardiographic recognition of tubercular submitral left ventricular aneurysm extending into left atrium.
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Percutaneous supra-aortic angioplasty in a high risk coronary patient.
We have performed percutaneous angioplasty of the innominate and carotid arterial stenoses in a high risk patient with proximal disease involving the vessels arising from the aortic arch and seriously limiting blood flow to all four cerebral vessels. The patient also had severe left main and triple vessel coronary artery disease. The role of supra-aortic angioplasty in this clinical setting is discussed.
The incidence and patterns of pulmonary artery involvement in Takayasu's arteritis.
The pulmonary arterial anatomy in 44 patients with Takayasu's arteritis was examined by intravenous digital subtraction angiography (IV-DSA) on an outpatient basis using centrally delivered, small-volume, bolus injections of an ionic, water soluble contrast medium. Diagnostic pulmonary angiograms were obtained in 42 patients (95.4%) without complication. Angiographically evident pulmonary arterial involvement was seen in six patients (14.3%). The pulmonary involvement was not suspected clinically in any patient and the chest radiographs were abnormal in only two patients (33%). The angiographic spectrum of systemic arterial involvement was the same irrespective of the presence or absence of pulmonary arterial involvement. The pulmonary arterial pressures were measured in two patients with abnormal pulmonary angiograms and were found normal. Follow up IV-DSA in one of these patients 16 months after immuno-suppressive therapy showed no change in the pulmonary angiographic picture.
The association between aneurysm formation and systemic hypertension in Takayasu's arteritis.
We have studied the incidence and patterns of aneurysm formation in 88 consecutive patients with Takayasu's arteritis by utilizing digital subtraction pan-aortoarteriography by the intravenous and/or intra-arterial route. Seventy-two patients underwent initial intravenous angiography of which 64 (89%) were diagnostic. All the intra-arterial studies (n = 24) were diagnostically adequate. Arterial aneurysms were seen in eight patients (9.1%) and the saccular variety (75%) was the most common. Clinical and angiographic features of these eight patients were compared with those of the remaining patients. No major differences were observed except that longstanding uncontrolled hypertension was present in all patients with aneurysm formation. In comparison, hypertension was observed in 30 (49.2%) of the remaining 61 patients in whom clinical details were available. Angiographic localization of the aneurysm is important since there are no clinical features that distinguish these patients and rupture of a strategically located aneurysm can prove fatal. The association between hypertension and aneurysm formation suggests that hypertension in these patients should be aggressively managed at the onset of disease. In this regard percutaneous transluminal renal angioplasty may prove a possible management adjunct.
Left coronary angiography in the pre-operative diagnosis of thrombosis of the left atrium or its appendage in rheumatic mitral stenosis.
We studied the utility of pre-operative selective left coronary angiograms for detecting thrombosis in the left atrium or its appendage in 81 patients with rheumatic mitral stenosis, who subsequently underwent open-heart surgery. Thrombus was predicted by the angiographic demonstration of neovascularity seen as a bunch of small vessels arising from the circumflex branch of the left coronary artery coursing superiorly to the region of the left atrial appendage and terminating in a network of smaller vascular channels with a blush of contrast medium coalescing into small 'lakes'. This pooling of contrast medium was considered essential for positive angiographic diagnosis. Based on these criteria, the angiographic diagnosis of thrombus was made in 27 patients. Thrombus was found in 33 patients at surgery. Selective left coronary angiography had a sensitivity of 72.7%, specificity of 92.7% and predictive value of 88.8% for detecting thrombi in the left atrium or its appendage. Coronary angiography should be performed in all the patients with mitral stenosis who are undergoing cardiac catheterization especially if balloon mitral valvoplasty or closed mitral valvotomy are planned.
Raised stool and serum IgA levels in undernourished infants with chronic diarrhoea and associated parasitic infestations.
Sixty children with chronic diarrhoea, age ranging from 9 months to 3 years and 15 normal healthy children of same age group, all belonging to the low socio-economic families formed the basis of this study. Fifty-six out of these 60 children were undernourished and were marasmic. Stool examination showed enteropathogenic E. coli in 24 (40 per cent), Ascaria lumbricoides in 12 (20 per cent) and Giardia lamblia in 6 (10 per cent). Coeliac disease was detected in 2 (3 per cent) and combined IgA-IgG deficiencies were found in one case (2 per cent). No cause could be found in 15 (25 per cent) cases. Multiple aetiological factors were found in 7 (12 per cent) cases. Stool IgA levels were significantly elevated in the patients than in the controls and more so in the patients with giardiasis and also in patients with coeliac disease. Serum IgA levels were remarkably raised in the patients with diarrhoea due to enteropathogenic E. coli, indicating probable spilling of gut-associated IgA into the circulation. No IgA was detected in the stool of a dysgammaglobulimic patient, who had both serum IgA and IgG deficiencies.
How does posture influence the haemodynamic assessment of a cardiovascular drug? Experience with nicardipine.
The extent to which posture altered the haemodynamic response to slow calcium channel blocker nicardipine was evaluated in 22 male patients with angiographically confirmed coronary artery disease. Patients were randomly allocated to supine or upright posture and an otherwise identical protocol performed in each group. At rest, following a control saline period, four doses of the drug (log cumulative dosage: 1.25, 2.5, 5.0, and 10.0 mg) were administered by i.v. infusion over a total period of 40 min; haemodynamic indices were recorded during the 3-5 min following each 5 min infusion. The exercise effects of the drug, in each posture, were determined by comparison of a control predrug exercise with observations at the same workload following the maximal cumulative dose. Nicardipine reduced resting mean blood pressure (MBP) and systemic vascular resistance index (SVRI) in both postures, the decrease being more pronounced when upright (MBP, -12%, -18%; p less than 0.01: SVRI, -30%, -46%; p less than 0.01). The increases in cardiac index (CI) and stroke volume index (SVI) were higher when upright (29 and 54% vs. 10 and 27%; p less than 0.01). Pulmonary artery occluded pressure (PAOP) increased by 29% when upright, without change when supine. On exercise, the effects for HR, MBP, CI, SI, and SVRI responses were independent of posture; however, a qualitative difference was apparent for PAOP (-17% vs. +14%; p less than 0.05). Thus, although the actions of nicardipine were qualitatively similar, quantitative differences related to posture were confirmed. These differences appeared to relate to posture-related baseline haemodynamic differences between the groups but with similar postnicardipine absolute values.
Haemodynamic and radionuclide effects of amlodipine in coronary artery disease.
1. The haemodynamic and radionuclide effects of a new long-acting slow-calcium channel blocking agent, amlodipine, were evaluated in 32 patients with coronary artery disease. 2. Haemodynamic measurements in 24 patients were made at rest and 10 to 15 min after 20 mg i.v. amlodipine. Amlodipine significantly reduced systemic arterial blood pressure and vascular resistance index with an increased heart rate and augmented cardiac index. Cardiac stroke volume index rose and stroke work fell without change in pulmonary artery occluded pressure (PAOP). 3. The exercise effects were determined by comparison of measurements during 4 min of supine bicycle exercise at a fixed workload before and after drug treatment. During dynamic exercise, amlodipine reduced systemic arterial pressure and vascular resistance index. Exercise cardiac index, stroke volume index and heart rate were higher. The left ventricular filling pressure was significantly reduced. 4. Radionuclide parameters were studied in 16 patients at rest and on exercise; ejection fraction was unaltered following amlodipine. 5. Pre-therapy haemodynamic values correlated with response following amlodipine for resting mean blood pressure, systemic vascular resistance and exercise PAOP. 6. Thus, the immediate impact of amlodipine in stable coronary artery disease was to reduce left ventricular afterload and thereby improve cardiac pumping performance.