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Biomedical subjects

L S Chawla

Publications and source records attributed to L S Chawla.

At least 19 recordsLinked to original sources
PubMed2001

Hemodialysis central venous catheter tip fracture with embolization into the pulmonary artery.

We describe the first reported case of spontaneous hemodialysis catheter fracture and embolization. We also include a summary of similar cases not previously reported in the literature that appear in the Food and Drug Administration records as medical equipment malfunctions. Our patient presented with a cough and was initially treated for presumptive pneumonia. A chest radiograph indicated that the tip of the catheter had fractured and migrated into a distal branch of the pulmonary artery. The catheter was replaced, but the tip could not be retrieved because of its peripheral location. Possible causes and consequences of this underreported complication are discussed.

AIDS-Associated Nephropathy↗
PubMed2001

Zinc nutritional status modifies renal osteodystrophy in uremic rats.

BACKGROUND: Previous studies from our laboratories suggested that zinc depletion reduces the circulating level of 1,25-dihydroxycholecalciferol (1,25(OH)2D, calcitriol) in calcium- and phosphorus-depleted rats with normal renal function, and rats with uremia. Since calcitriol synthesis is in part dependent on renal function, we studied levels of circulating vitamin D metabolites, PTH response, mineral balance and bone histomorphometry in animals with different zinc nutritional and renal functional status. METHODS: Fifty-eight male Sprague-Dawley rats were pair-fed zinc-replete (+) or -deplete (-) diets for two weeks. Thereafter, half of each paired group underwent nephrectomy (N), while half had sham (S) operations. Animals were observed for eight weeks after surgery. External mineral balances of zinc, calcium, phosphate and magnesium were determined before surgery, and 1, 2 and 7 weeks after surgery. Plasma creatinine, zinc, calcium, phosphorus, magnesium, 25-hydroxycholecalciferol, calcitriol and PTH were determined at sacrifice. Static and dynamic bone histomorphometry was determined by standard techniques. RESULTS: After an 8-week observation period, zinc-depleted animals had lower plasma zinc levels, and nephrectomized animals had lower creatinine clearances than respective controls at sacrifice. Plasma calcium and phosphorus concentrations were similar in all four groups at sacrifice. Plasma magnesium concentrations were similar in groups with renal insufficiency, regardless of zinc nutritional status. Plasma 25-hydroxycholecalciferol and calcitriol levels were similar in all groups. There was no difference between mean PTH concentration in sham-operated animals, regardless of zinc nutritional status. Although nephrectomized groups' PTH levels were increased compared to S controls, PTH levels were increased in +Zn/N animals compared to the -Zn/N group. Zinc-deplete groups had consistent negative net zinc balance, however, there was no consistent effect of nephrectomy on external calcium, phosphorus, or magnesium balance, when nephrectomized groups of different zinc nutritional status were compared. Nephrectomized animals had histomorphometric changes indicative of higher bone turnover and abnormal mineralization. Zinc deficiency was associated with less evidence of increased parathyroid hormone activity on bone in nephrectomized rats. CONCLUSIONS: Zinc depletion limits the increase in plasma PTH concentration and the expression of secondary hyperparathyroid bone disease during the development of renal insufficiency in the renal ablation model of uremia in rats. The mechanism underlying this effect is unknown, but may involve a direct effect of zinc on the synthesis, release, metabolic clearance, and/or action of PTH on the cellular level, on the interrelationship of calcitriol and PTH, or a direct effect of zinc on bone mineral metabolism. These data highlight the potential relevance of zinc nutritional status to mineral metabolism in patients with chronic renal insufficiency and end-stage renal disease.

Animals↗
PubMed1995

Endothelium-derived relaxing factor is important in mediating the high output state in chronic severe anemia.

OBJECTIVES: We evaluated the endothelial and vascular smooth muscle function in patients with chronic severe anemia to determine whether increased basal nitric oxide levels contribute to the systemic vasodilation and high cardiac output seen in these patients. BACKGROUND: Patients with chronic severe anemia have a high output state due to a low systemic vascular resistance. However, the cause of the low vascular resistance is unclear. Because hemoglobin is a potent inhibitor of endothelium-derived relaxing factor, we postulated that in chronic severe anemia, low circulating hemoglobin results in reduced inhibition of endothelium-derived relaxing factor. The basal endothelium-derived relaxing factor activity therefore increases, and this contributes significantly to the low systemic vascular resistance and the hyperdynamic state seen in this condition. METHODS: Hemodynamic variables and forearm blood flow (using plethysmography) were measured in eight patients with chronic severe anemia before (hematocrit 16 +/- 2% [mean +/- SD]) and within 24 h of red blood cell transfusion (n = 6, hematocrit 30 +/- 1%) and in six control subjects. The effect on baseline blood flow of blocking endothelium-derived relaxing factor activity with NG-monomethyl-L-arginine was investigated. In addition, the effects of both endothelium-dependent and endothelium-independent vasodilators on forearm blood flow were tested. RESULTS: Baseline forearm blood flow was markedly increased in untreated patients (6.5 +/- 1.2 ml/min per 100 ml) compared with that in control subjects (2.8 +/- 0.7 ml/min per 100 ml, p < 0.0001, 95% confidence interval [CI] for difference -5 to -2.5). Red blood cell transfusion significantly reduced blood flow in the anemic patients to 3.5 +/- 1.1 ml/min per 100 ml (p < 0.001, 95% CI for difference -4.9 to -1.9), which was not significantly different from that in control subjects; increased systemic vascular resistance (796 +/- 141 to 1,230 +/- 151 dynes.s.cm-5, p < 0.001); and decreased cardiac output (4.9 +/- 0.6 to 3.5 +/- 0.5 liters/min per m2, p < 0.001). NG-monomethyl-L-arginine (16 mumol/min), a specific inhibitor of endothelium-derived relaxing factor, reduced forearm blood flow by an equal amount (p = 0.9, 95% CI for difference -0.7 to 0.8) in control subjects (0.98 +/- 0.39 ml/min) and treated patients (1.03 +/- 0.8 ml/min) but caused a threefold greater decrease in flow (2.9 +/- 0.9 ml/min) in untreated patients (p = 0.0003, 95% CI for difference between untreated patients and control subjects 1.1 to 2.7). These findings suggest increased basal endothelium-derived relaxing factor activity in patients with anemia. Stimulated forearm blood flows (both endothelium dependent and endothelium independent) were similar in all groups, confirming normal endothelial and smooth-muscle function. CONCLUSIONS: These findings support the hypothesis that enhanced basal endothelium-derived relaxing factor activity makes an important contribution to the low systemic vascular resistance in chronic severe anemia.

Adult↗
PubMed1995

Esophageal candidiasis following omeprazole therapy: a report of two cases.

Esophageal candidiasis was diagnosed at endoscopy in two patients receiving omeprazole therapy. There was no clinical evidence of immunosuppression or any obstructive lesion in the esophagus. There was prompt response of oral ketoconazole. These cases suggest that marked acid reduction may predispose to esophageal candidial infection.

Abdominal Pain↗
PubMed1994

Serum pepsinogen levels in patients with gastro-duodenal lesions.

Serum pepsinogen (SP) levels were studied in 100 patients with gastroduodenal lesions, and 100 healthy volunteers. SP levels were significantly elevated in patients with duodenal ulcer (DU) and duodenitis compared to the controls. SP values above 150 ug Tyr/ml/24 hr were highly suggestive of duodenal ulcer disease. Age and sex of patients and controls did not influence SP levels. The mean values of SP in North India were found to be lower in both normal and DU subjects compared to the west.

Duodenal Diseases↗
PubMed1993

Ascitic fluid cholesterol in differential diagnosis of ascites.

Cholesterol was estimated in ascitic fluid of 89 patients (29 malignant and 60 non-malignant ascites). Mean ascitic cholesterol level was significantly higher in malignant ascites (89.52 mg/dl) as compared to non-malignant ascites (29.93 mg/dl). At a cut off value of 48 mg/dl, the sensitivity, specificity, positive and negative predictive value and overall diagnostic accuracy for diagnosing malignant ascites is 96.5%, 96.6%, 93.3%, 98.3% and 96.6% respectively. Ascitic fluid cholesterol estimation is an easy and reliable test for differentiating malignant ascites from non-malignant ascites.

Ascites↗
PubMed1992

Atrial fibrillation following electrical injury.

The development of atrial fibrillation in 2 patients, following an electrical shock is reported. One patient, with an underlying pre-excitation syndrome, had to be cardioverted due to rapid ventricular rate and hypotension. The other, with normal conduction, tolerated the arrhythmia well and atrial fibrillation reverted spontaneously after 24 hours.

Adult↗
PubMed1992

Indolent gastric carcinoma.

A 55 year old woman presenting with epigastric pain and dyspeptic symptoms was diagnosed to have gastric carcinoma on endoscopic biopsy independently on two occasions. She was subsequently asymptomatic without any specific therapy till she developed gastric outlet obstruction and weight loss four years later. Histology of the resected specimen revealed an adenocarcinoma infiltrating the serosa without any evidence of metastasis.

Adenocarcinoma↗
PubMed1990

Course and prognosis of ulcerative colitis.

A study of 50 patients (23 males and 27 females) of ulcerative colitis, who were on follow-up showed that maximum number of patients had the disease before the age of 50 years. At the onset, the activity of the disease was severe in 44%, moderate in 32% and mild in 24% of cases. The commonest clinical course of the disease was chronic intermittent type (48%), followed by single attack with subsequent remission (42%). Chronic continuous type was seen in 10% patients only. There was no correlation of the extent of the bowel involvement with the clinical course. The precipitating factors for the onset or reactivation of the disease appeared to be emotional disturbances in 18% and pregnancy in 8%. The complications, both local and systemic, were not frequent. Serious complications like massive haemorrhage, perforation, toxic megacolon and carcinoma colon were not seen at all.

Colitis, Ulcerative↗
PubMed1989

Endoscopic and histopathological study of duodenitis.

Fifty patients who presented with symptoms suggestive of disease related to peptic acidity having endoscopic evidence of duodenitis were analysed. Endoscopic duodenal biopsy was done in all these patients. Histologically duodenitis was labelled if there was infiltration of epithelial layer. Male to female ratio was found to be 3:2. Duration of symptoms in the patients ranged from less than one month to more than 5 years. Possible aetiological factors like drugs, alcohol and smoking were established in 26 patients (52%), drugs being the commonest (26%). Stool examination showed cyst or ova of parasites in 8 patients (16%). Endoscopically multiple hyperaemic patches were seen in 15 (30%), erosions in 19 (38%), coarse mucosal folds in 5 (10%), nodules in 2 (4%) and multiple lesions in 9 (18%) patients. Histological and endoscopical correlationship was established in 40 (80%) cases.

Adolescent↗
PubMed1989

Jaundice in Plasmodium falciparum.

Thirty-two patients of smear positive Plasmodium falciparum malaria having jaundice were analysed retrospectively. Majority of the cases were in the age group of 31-40 years. Serum bilirubin levels ranged from 2 mg to 40 mg%. Fourteen (42.6%) had serum bilirubin above 10 mg%. Conjugated bilirubinaemia was found in twenty one patients (65.5%), unconjugated in 4 (12.5%) while 7 patients (21.8%) had a mixed pattern. Serum transaminases were high in 21.8% patients. Twenty five patients (78%) had associated azotaemia, 11(34.3%) had intravascular haemolysis and 3(9.3%) had possible cerebral malaria. Hepatosplenomegaly was seen in all the 32 patients. Mortality was 21% but none died of hepatic encephalopathy. Histologically the most consistent finding in liver biopsies was reticulo-endothelial cell hyperplasia. Pigmentation in kupffer cells, fatty change, sinusoidal and portal infiltration and cholestasis were the other features seen.

Adult↗
PubMed1987

Levels of arsenic in alcohol-related liver disease.

Increased levels of arsenic were found in serum and urine and in hair and nails of patients suffering from alcohol-related liver disease (ALD). Various surveys were conducted in different places to find the cause for high arsenic in ALD. It was found that patients were consuming 'home made brew' which was contaminated with arsenic.

Alcoholic Beverages↗