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Biomedical subjects

V Malhotra

Publications and source records attributed to V Malhotra.

At least 73 records · Page 4Linked to original sources
PubMed1997

Fine-needle aspiration diagnosis of carotid body tumor: report of a case and review of experience with cytologic features in four cases.

A 45-yr-old female presented with a left upper cervical swelling of 4 yr duration. The clinical suspicion of carotid body tumor (CBT) was confirmed by imaging findings, fine-needle aspiration (FNA) cytology, and histology of the resected tumor. Review of our experience with four cases including the present one during 10 yr (1984-1994) showed that the age of the patients ranged from 35 to 45 yr with a mean of 40.8 yr. All four cases were females and had left-sided upper cervical swelling. Clinically one case was diagnosed as cervical lymphadenopathy and there was clinical suspicion of CBT in two cases. Findings of digital subtraction angiogram in four cases and ultrasonography including Doppler ultrasound vascular imaging in three cases were consistent with CBT. The cytodiagnosis was CBT in three cases and inadequate (blood only) in one case. The analysis of detailed cytologic features in three cases revealed blood-rich aspirate with poor to moderate cellularity, indistinct cell outline, and acinar formation. Giant bare nuclei, spindle-shaped tumor cells, and cytoplasmic granulations were observed in two cases each. Histopathology of the resected tumors in two cases confirmed the cytodiagnosis of CBT. FNA cytology played a useful role in arriving at a tissue diagnosis of this rare neoplasm.

Adult↗
PubMed1997

Contrast echocardiography displays increased subendocardial perfusion after nitroglycerin administration.

A mechanism proposed to contribute to the antianginal effect of nitroglycerin is a redistribution of coronary blood flow to the subendocardium. Contrast echocardiography combines ultrasound with echogenic contrast agents to assess regional myocardial perfusion. This study aims to assess the effect of nitroglycerin on myocardial transmural perfusion with contrast echocardiography in humans. Nine patients scheduled for coronary angiography received 300 microg intracoronary nitroglycerin. Contrast echocardiographic studies were performed before and immediately after the administration of intracoronary nitroglycerin. Videodensitometric analysis was performed off-line to measure subendocardial and subepicardial opacification. Subendocardial opacification greater than subepicardial opacification increased from six of 13 patients before nitroglycerin administration to 11 of 13 after nitroglycerin administration (p <0.05). Similarly, these observations increased from nine of 13 patients to 13 of 13 after nitroglycerin administration during diastole (p <0.05). Contrast echocardiography demonstrates increased subendocardial perfusion after the administration of nitroglycerin in these patients.

Angina Pectoris↗
PubMed1997

Acute renal failure in the elderly: a demographic and clinical study of patients in eastern India.

A total of 638 patients with acute renal failure (ARF) of diverse etiology were studied over a period of 9 years (July 1985-Dec, 1994) of which 96 (15%) patients were classified as elderly ARF with mean age of 72.5 years. Medical causes accounted for 80% of geriatric ARF while 20% patients, had ARF of surgical origin. Decreased renal perfusion resulting from gastroenteritis was the predominant (52.8%) cause of ARF in the medical group. Nephrotoxic ARF and ARF due to F. malaria were seen in 10 and 7 patients respectively. Obstructive uropathy was observed in 12 patients in surgical group and in remaining 8 patients ARF developed following various surgical procedures. ARF in association with multiorgan failure was not observed in our study. Mortality was seen in 24 patients (25%). The causes of mortality were GI bleed (6), peripheral circulatory failure (5), hyperkalemia (4) and sepsis (4). Thus medical ARF remains the major cause of acute renal failure in elderly patients in our study in contrast to ARF associated with multiorgan failure and surgery in developed countries.

Acute Kidney Injury↗
PubMed1996

Diagnosis and outcome of isolated rectal tuberculosis.

PURPOSE: Segmental colonic tuberculosis commonly involves the ascending, transverse, or sigmoid colon. Rectal involvement in tuberculosis is uncommon and poorly characterized. This study describes the clinical presentation, endoscopic features, and outcome of isolated rectal tuberculosis. METHODS: Isolated rectal tuberculosis was defined as focal lesions of the rectum in the absence of radiologically demonstrable lesions in the small and large bowel on barium contrast studies. Diagnosis of rectal tuberculosis was based on characteristic endoscopic appearance of lesions, histopathologic features of tuberculosis in biopsy/ resected material, and response to antitubercular therapy. RESULTS: Eight patients with rectal tuberculosis were seen during a four-year period at our hospital. Hematochezia was the most common presenting feature (88 percent), followed by constitutional symptoms (75 percent) and constipation (37 percent). Rectal examination revealed a tight stricture within 10 cm of the anal verge in seven patients. Barium enema showed stricture of variable length, with focal areas of deep mucosal ulceration and increase in presacral space. Proctoscopic findings were tight stricture (7), nodularity with ulceration (6), and multiple aphthous ulcers (1). Granulomatous infiltration was detected in seven of eight patients in biopsy material obtained at endoscopy (6) or surgery (1). Cessation of hematochezia, resolution of constitutional symptoms, and weight gain were seen in all patients following treatment with antitubercular drugs. CONCLUSION: Our data suggest that tubercular involvement of rectum, although uncommon, is an important cause of rectal strictures in India. Response to antitubercular chemotherapy is uniformly good, and surgery is seldom required in these patients.

Adolescent↗
PubMed1996

Efficacy of low-dose alpha interferon therapy in HBV-related chronic liver disease in Asian Indians: a randomized controlled trial.

BACKGROUND/AIMS: Interferon therapy has been shown to be effective in Western patients with chronic hepatitis due to hepatitis B viral infection, but not in Asian Chinese. Its efficacy in Asian Indian subjects with chronic HBV infection is not known. METHODS: Forty-one patients with HBV-related chronic liver disease received randomly either: (a) recombinant alpha 2b interferon (n = 20) 3 MIU, subcutaneously, three times a week for 4 months, or (b) no treatment (n = 21). Patients were followed up for 12 months after completion of therapy. RESULTS: In the interferon-treated group, complete response (loss of HBV-DNA and HBeAg) was significantly higher than spontaneous clearance in the control group (50% vs. 4.8% p < 0.05). Seroconversion to anti-HBe was seen in 35% of the treated and 4.8% of the control group (p < 0.05) at 4 months; it was noticeably higher in patients with chronic hepatitis than in those with cirrhosis. In the responders, alanine aminotransferase levels nearly normalized. One year after interferon therapy, HBeAg and HBV-DNA clearance was observed in 65% of patients, with HBsAg clearance in 15%. Reactivation was not seen in any patient. Side-effects were transient and minimal. CONCLUSION: Low-dose recombinant alpha interferon therapy is quite effective and safe in Asian Indians with chronic liver disease due to hepatitis B infection.

Alanine Transaminase↗
PubMed1996

Membrane fusion in organelle biogenesis.

Intracellular membrane fusion is a fascinating reaction that is crucial for cellular function. Several components of the membrane fusion machinery have been identified, although a precise understanding of the fusion mechanism is lacking. More recent studies are revealing novel proteins that regulate membrane fusion during organelle assembly.

Adenosine Triphosphatases↗
PubMed1996

Acute renal failure in falciparum malaria--increasing prevalence in some areas of India--a need for awareness.

Twenty-six cases (4.8%) from a total of 540 patients with acute renal failure (ARF) of diverse aetiology had ARF in association with falciparum malaria. Their ages ranged from 15 to 85 years (mean 31.2). Urinary sediment abnormalities and proteinuria (less than 1 g/24 h) were observed in 15 (57.7%) cases. The probable underlying factors leading to ARF were: volume depletion 17 (65.3%), intravascular haemolysis 8 (30.8%), hyperparasitaemia 8 (30.8%), cholestatic jaundice 6 (23%), and hypotension 5 (19.2%). Dialysis therapy was required in 15 patients (57.7%) as they had severe renal failure, and the remaining 11 patients improved with supportive measures. All patients received antimalarial therapy. The clinical course of ARF was consistent with acute tubular necrosis in 20 patients. Six cases were subjected to percutaneous renal biopsy. One patient showed histological features of necrotizing glomerulonephritis along with acute tubulointerstitial nephritis. The biopsies in the other five patients showed features of acute tubular necrosis in three, and acute interstitial oedema with patchy tubular necrosis in two. The mortality rate was 30.8%. Thus falciparum malaria, which has been an important cause of ARF in certain highly endemic zones of India, is showing an increasing prevalence in other parts such as Eastern Uttar Pradesh due to an imbalance between the increasing population and inadequate sanitary facilities, which further worsen during floods.

Acute Kidney Injury↗
PubMed1996

Loss of contrast intensity during systole in the left ventricular cavity with the use of the contrast agent Albunex. An analysis of its correlation with pressure and velocity.

RATIONALE AND OBJECTIVES: Several investigators have observed a decrease in video intensity in the left ventricular cavity during systole when using contrast echocardiography. It has been suggested that this phenomenon is related to microbubble instability. The authors propose that this phenomenon is, in part, related to the effects of pressure and velocity on the acoustic reflectance of ultrasound contrast agents. METHODS: Using an in vitro flow tube model and varying concentrations of Albunex contrast agent, the effects of pressure and velocity on microbubble video intensity were investigated. Velocity and pressure were varied independently and the imaging tube was scanned using three transducer frequencies at different concentrations of Albunex. Contrast video intensity was analyzed using high and low velocities (at constant pressure) and high and low pressures (at constant velocity). In addition, the fluid from the system was collected and imaged in a nonflowing reservoir tank to investigate the video intensity of the microbubbles when exposed to variable velocity and pressure. RESULTS: The video-intensity measurements were inversely and irreversibly related to ambient pressure changes (independent of velocity) in a tube model. However, video intensity varied inversely but reversibly with velocity (independent of pressure). This observation could not be explained simply by the "laminar flow" theory, by a change in transducer angulation, nor by a change in ultrasound imaging frame rate. This phenomenon was limited to Albunex microbubbles and was not observed with a contrast medium (corn starch) devoid of the acoustic properties of Albunex.

Albumins↗
PubMed1995

The formation of Golgi stacks from vesiculated Golgi membranes requires two distinct fusion events.

We have reconstituted the fusion and assembly of vesiculated Golgi membranes (VGMs) into functionally active stacks of cisternae. A kinetic analysis of this assembly process revealed that highly dispersed VGMs of 60-90 nm diameter first fuse to form larger vesicles of 200-300 nm diameter that are clustered together. These vesicles then fuse to form tubular elements and short cisternae, which finally assemble into stacks of cisternae. We now provide evidence that the sequential stack formation from VGMs reflects two distinct fusion processes: the first event is N-ethyl-maleimide (NEM)-sensitive factor (NSF) dependent, and the second fusion event requires an NSF-like NEM-sensitive ATPase called p97. Interestingly, while the earliest steps in stack formation share some similarities with events catalyzing fusion of transport vesicles to its target membrane, neither GTP gamma S nor Rab-GDI, inhibitors of vesicular protein traffic, inhibit stack formation.

Carrier Proteins↗
PubMed1995

Reconstitution of vesiculated Golgi membranes into stacks of cisternae: requirement of NSF in stack formation.

We have developed an in vitro system to study the biochemical events in the fusion of ilimaquinone (IQ) induced vesiculated Golgi membranes (VGMs) into stacks of cisternae. The Golgi complex in intact normal rat kidney cells (NRK) is vesiculated by treatment with IQ. The cells are washed to remove the drug and then permeabilized by a rapid freeze-thaw procedure. VGMs of 60 nm average diameter assemble into stacks of Golgi cisternae by a process that is temperature dependent, requires ATP and a high speed supernatant from cell extract (cytosol), as revealed by immunofluorescence and electron microscopy. The newly assembled stacks are functionally active in vesicular protein transport and contain processing enzymes that carry out Golgi specific modifications of glycoproteins. The fusion of VGMs requires NSF, a protein known to promote fusion of transport vesicles with the target membrane in the exocytic and endocytic pathways. Immunoelectron microscopy using Golgi specific anti-mannosidase II antibody reveals that VGMs undergo sequential changes in their morphology, whereby they first fuse to form larger vesicles of 200-300-nm average diameter which subsequently extend into tubular elements and finally assemble into stacks of cisternae.

Adenosine Triphosphate↗
PubMed1995

Acute renal failure in eastern India.

The present study included 426 patients with acute renal failure age range 7 months to 85 years, during 8-year period (1984-1992). Medical, surgical and obstetric causes were responsible for ARF in 68.3, 17.8, and 14% of cases respectively. The main aetiological factors encountered were volume depletion secondary to gastrointestinal fluid loss (35.2%), acute glomerulonephritis (10.3%), nephrotoxin (8.6%), falciparum malaria (4.2%), obstructive uropathy (13%), post-abortal (10.5%), and miscellaneous factors (1.4%) of patients. The overall mortality was 19.2%. Thus our observation revealed that diarrhoeal diseases (35.2%), obstructive uropathy (13.3%), and septic abortion (10.5%) were the main causes for ARF in medical, surgical, and obstetric groups respectively. In contrast to our studies, acute renal failure associated with diarrhoeal diseases, septicaemia, falciparum malaria and septic abortion are rare in European countries.

Acute Kidney Injury↗
PubMed1995

Granulomatous hepatitis: a retrospective study.

51 cases of granulomatous hepatitis were seen among 1234 liver biopsies over a 10 year period. Tuberculosis was the commonest cause seen in 55 percent of cases. Other causes included leprosy, sarcoidosis, histoplasmosis, brucellosis, amoebic liver abscess, lymphoma and malignant granuloma. 12 percent of cases remained undiagnosed. Clinically these patients presented with pyrexia and hepatosplenomegaly. Jaundice was uncommon. Many showed elevated alkaline phosphatase levels, anaemia and raised ESR Granulomatous hepatitis of unknown aetiology with FUO was seen in 6 percent cases only.

Granuloma↗
PubMed1994

Location of Golgi membranes with reference to dividing nuclei in syncytial Drosophila embryos.

The role of cytoskeletal elements in the cellularization of syncytial Drosophila embryos is becoming evident; however, the distribution and role of organelles such as the Golgi complex, essential for membrane biogenesis, remain unknown. We have cloned a Golgi-membrane-associated polypeptide, beta-COP, from Drosophila. Immunocytochemical studies of syncytial Drosophila embryos with anti-Drosophila beta-COP antibody reveal that Golgi membranes are spatially segregated from the rapidly dividing nuclei. In early embryos, the Golgi membranes are located in the embryonic cortex and nuclei are confined to the core. This distribution of Golgi membranes may serve in preparation of the embryonic cortex for the accommodation of nuclei upon their eventual migration to the cortex and in biogenesis of the excessive plasma membrane needed for cellularization of syncytial embryos.

Amino Acid Sequence↗