Biomedical subjects
Publications and source records attributed to S Sharma.
In this report, we describe an adult with a large intracranial arteriovenous malformation which mimicked a cardiac lesion. The patient presented with predominant cardiac symptoms, a prominent continuous murmur and signs of arterial run-off. The diagnosis was confirmed by digital subtraction angiography. We report the case to highlight the rare presentation.
The rare association of tetralogy of Fallot, rudimentary formation of the leaflets of the pulmonary valve, and anomalous origin of the left pulmonary artery from the ascending aorta is described in a two-month-old infant. The diagnosis was made by cardiac catheterisation and angiography.
Rain water was collected and analysed from a reference site, Dayalbagh and Taj Ganj, near the Taj Mahal in Agra. The ionic components Ca, Mg, Na, K, NH(4), Pb, Fe, Zn, SO(4), HCO(3), Cl and F were analysed along with pH, alkalinity and conductance. The average pH of rain water at both sites is 7.05. There is a dominance of alkaline components, particularly Ca. The rain water chemistry shows the importance of calcareous soil-derived materials in controlling the pH of rain water.
We have compared the diagnostic accuracy of left coronary and laevo-phase pulmonary angiograms in detecting left atrial thrombi in 27 consecutive patients with rheumatic mitral stenosis who underwent both these procedures prior to open-heart surgery. In 10 patients, both procedures were 'positive' for thrombus, confirmed at subsequent surgery in all instances (true positive). Both procedures were negative for thrombus in 11 patients, and none of these patients showed thrombi at subsequent surgery (true negative). Left coronary angiography only was positive for thrombus in one patient in whom no thrombus was found at surgery. Laevo-phase pulmonary angiography only was positive for thrombus in five patients, two of whom had thrombus at subsequent surgery. The sensitivity, specificity and predictive accuracy of left coronary angiogram were 83.3% and 93.3% and 90.9% and that of laevo-phase pulmonary angiogram 100%, 80% and 80% respectively. Laevo-phase pulmonary angiograms showed higher sensitivity and left coronary angiograms showed higher specificity for angiographic diagnosis. However, the differences were found to be statistically insignificant. Angiography is a reliable method for detecting left atrial thrombi if both left coronary and pulmonary angiograms are performed and both procedures are positive or negative for thrombus.
Extracranial carotid artery aneurysms secondary to accidental injury are rare. We have seen eight lesions of this type in the last 10 years. The aneurysm was produced by blunt trauma in four patients, penetrating shrapnel injury in two, stabbing and electrical injury in one each. The left side was involved in seven patients. The internal and common carotid artery were each involved in four patients and the lesion was unilocular in five. These lesions often produce non-specific symptoms and may mimic neoplastic or inflammatory masses: a mistaken diagnosis of tonsillar abscess in one patient resulted in incision and drainage before an intravenous digital subtraction angiogram (IV-DSA) correctly identified the abnormality. IV-DSA is ideal for pre-operative assessment of these patients. Awareness of these lesions is essential since definitive surgical repair is possible. All patients in the present study underwent successful surgical repair.
We have assessed the diagnostic accuracy of a flat or concave left mid-cardiac border (the region of the left atrial appendage) on conventional postero-anterior chest radiographs as a predictor of the presence of thrombi in the left atrium or its appendage in 80 patients with rheumatic mitral stenosis who subsequently underwent open-heart surgery. Forty-six patients (Group I) were found to have left atrial thrombus at surgery whereas 34 patients (Group II) showed no evidence of thrombosis. Only 22 of 46 patients in Group I showed a flat or concave left mid-cardiac border (sensitivity, 48%; specificity, 53%; positive predictive value, 58%). Furthermore in Group 1, the thrombus involved the left atrial appendage in 33 patients. In this subgroup only 14 patients showed a flat or concave left mid-cardiac border (sensitivity, 42%; specificity, 49%; positive predictive value, 37%). The presence of flatness or concavity in the left mid-cardiac border on conventional posterior-anterior chest radiographs in patients with rheumatic mitral stenosis is an unreliable indicator of the presence of thrombi in the left atrium or its appendage.
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We studied the changes in pial arteriolar diameter during hypoxia and 60 and 120 min after restoration of normoxia, using the closed cranial window technique in artificially ventilated and normocapnic rats. Pial arteriolar diameter increased 16 +/- 4% during hypoxia (PaO2 less than 25 mm Hg, lasting 10 min). Although blood pressure (BP), heart rate (HR), and blood gases returned to prehypoxic level when measured at 60 and 120 min after hypoxia, pial arterial diameter decreased significantly (13 +/- 5 and 16 +/- 6% below control levels, respectively). This posthypoxic vasoconstriction was reversed by treatment of the brain surface with L-660,711 (10(-5) M), a specific leukotriene D4 receptor antagonist. These data suggest that leukotrienes may be involved in delayed cerebral vasoconstriction that follows a brief period of hypoxia.
Fifteen siderophore producing urinary isolates of Escherichia coli were compared for aerobactin and enterochelin production in trypticase soy broth and pooled normal human urine. Significant increase in siderophore production (both phenolate and hydroxamate) was observed when organisms were grown in urine. Mouse kidney pathogenic potential of the strains grown in urine was compared with that of bacteria grown in trypticase soy broth in an ascending model of pyelonephritis in female Swiss Webster mice. Organisms grown in urine and instilled into a mouse bladder demonstrated markedly enhanced renal pathogenicity (p less than 0.01). Further information about the influence of urinary constituents on siderophore production could help in understanding the pathogenesis of pyelonephritis.
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In a study group of 40 children who had been admitted to hospital with acute encephalitis, the disease was due to infection with Japanese encephalitis virus (JEV). Three children developed recurrence of disease 8-9 months later. No virus had been isolated from these three patients during the acute stage of their illness, but virus was recovered from all during the recurrence phase by co-cultivation of their peripheral blood mononuclear cells in primary mouse embryo fibroblast cultures. Virus was also recovered by co-cultivation of peripheral blood mononuclear cells collected 8 months after their acute disease from three out of eight randomly selected asymptomatic children within the study group but not from similar cultures set up from JEV-seronegative children used as controls. Virus was also isolated by co-cultivation of T lymphocytes of asymptomatic children as detected by indirect immunofluorescence or by inoculation in mice.
In 1986, 50 patients with stages II and III carcinoma of the cervix were entered into this prospective randomized study. Twenty-five cases (Group I) were treated only by radical radiation whereas remaining 25 cases (Group II) received local hyperthermia in addition to radical radiation. Hyperthermia was delivered by intracavitary brachyhyperthermia approach using an endotract applicator. Both the groups were followed up for a minimum period of 18 months. Group II patients achieved better local control (14 out of 20 evaluable cases) than the Group I patients (11 out of 22 evaluable cases). A disturbing observation was the increased incidence of distant metastasis in Group II (4 out of 23 cases) as compared to Group I (1 out of 23 cases), though most of them remained disease free locally. The increasing use of hyperthermia in the management of various cancers needs to be reviewed in this context.
Non-steroidal anti-inflammatory drugs (NSAID) have been shown to decrease calcium excretion in the experimental animal, in human volunteers and in calcium stone formers. Paraplegics tend to be hypercalciuric during the first 2 years after their injury and this is said to be a predisposing factor for stone formation in these patients. The effect of the NSAID diclofenac sodium was studied in 12 traumatic paraplegics who had sustained their injury 1 to 6 months previously; 24-h urine samples collected before and 2 weeks and 4 weeks after oral diclofenac sodium 50 mg tds were analysed for calcium, uric acid, glycosaminoglycans (GAGs) and volume. There were no significant changes in urinary volume, uric acid and GAGs excretion. However, urinary calcium concentration and 24-h calcium excretion decreased significantly following 2 weeks' and 4 weeks' treatment with diclofenac sodium.
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Seven patients (four adults, three children) with discrete subaortic membranous stenosis underwent balloon dilatation using a single or double balloon technique with reduction in systolic gradient across the membrane from 100.42 +/- 19.23 to 29.14 +/- 12.54 mmHg (P less than 0.001). Echocardiography demonstrated thin membranes in all the patients and postprocedure torn fragments could be visualized. The excellent hemodynamic benefits are sustained during 4-24 months follow-up. The results indicate that transluminal balloon dilatation can be a safe and effective treatment for thin subaortic membrane.
41 (38 males, 3 females) patients with aplastic anemia received fetal liver infusion (FLI) from 74 abortuses with gestation periods of 8-32 (Median(M)-16) weeks and cell dose of 0.004-11.1 x 10(8) (M-2.3 x 10(8)) from September, 1976 until November, 1987. 35 persons received single FLI; those with recurrence or no response received two or more FLI. 8 received two; 7, three; 2, four; and 1, six FLI. There was a slow and incomplete autologous hematopoietic improvement in 40% and expected survival of 52% at 1 year, 45% at 2 yr, and 37% at 5 yr (Kaplan Meier estimate). There was rise in fetal hemoglobin (Hb), 0-15.7%, (M-3.5) among responders in 3-20 (M-6) months. Patients who survived for more than 12 months had, on average, a longer duration of disease (4 months or more), and higher granulocyte and platelet counts. Statistically, however, these differences were not significant. Reticulocyte count was significantly lower in those who survived beyond 12 months. 1 patient developed acute undifferentiated leukemia 3 yr post-FLI. The study indicates that fetal liver infusion is likely to benefit about 40% of individuals suffering from severe aplastic anemia. Longer surviving patients, however, may be at risk of developing clonal diseases.
Opsonization of nontypeable Haemophilus influenzae with antibody is critical for the interaction between the organism and human polymorphonuclear leukocytes (PMNs). Nontypeable H. influenzae opsonized in fresh antibody-positive serum induced the release of 42.5 +/- 17.9 ng of leukotriene B4 per ml from PMNs after 20 min of incubation at 37 degrees C. On the other hand, opsonization of the organisms in fresh antibody-negative serum stimulated the release of significantly smaller amounts of leukotriene B4 by the PMNs. Simultaneous determinations of phagocytosis demonstrated similar patterns of response. A small amount (26.7 +/- 7.6%) of unopsonized nontypeable H. influenzae was phagocytosed by PMNs during 20 min of incubation at 37 degrees C. In contrast, 89.3 +/- 2.0% of nontypeable H. influenzae opsonized in fresh antibody-positive serum was phagocytosed during the same incubation period (P less than 0.001). Removal of complement through heat inactivation at 56 degrees C for 30 min did not significantly affect phagocytosis. These data suggest that the humoral immune response to nontypeable H. influenzae plays an important role in the inflammatory process and may contribute to the production of middle ear effusions in otitis media.
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