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Biomedical subjects

S Chawla

Publications and source records attributed to S Chawla.

At least 55 records · Page 3Linked to original sources
PubMed1991

Cardio-vascular effects of vecuronium & pancuronium in patients undergoing elective closed mitral valvotomy.

Vecuronium, a monoquaternary analogue of pancuronium, the neuromuscular blocker, was compared with pancuronium in 50 patients undergoing elective closed mitral valvotomy. The patients were randomly divided into two groups of 25 each, and the muscle relaxants were administered in a dose of 0.1 mg/kg body weight. Both the agents produced identical intubating conditions at 3 min. Vecuronium showed a significantly shorter onset of action, as compared to pancuronium. The latter significantly increased the heart rate throughout the period of study whereas vecuronium significantly decreased the heart rate, 25 min after administration. There was significant increase in the mean arterial pressure (MAP) at tracheal intubation in both the groups, which persisted throughout the period of study in pancuronium group. There was a significant fall in MAP at 30 min after relaxant in vecuronium group. The incidence of arrythmias was similar and significant in both the groups. Vecuronium, thus showed a quicker onset of action with minimal haemodynamic effects, as compared to pancuronium in patients undergoing closed mitral valvotomy.

Adolescent↗
PubMed1991

ERCP in the evaluation of choledochal cyst due to anomalous pancreatobiliary junction.

With the application of endoscopic retrograde cholangio pancreatography (ERCP), the association of anomalous pancreatobiliary junction and choledochal cyst is being increasingly recognized. We describe here the ERCP findings in three patients who had this anomaly in association with fusiform (Type I) choledochal cyst. Two of our patients also had evidence of pancreatitis. The importance of ERCP in the preoperative assessment of such patients is highlighted.

Adolescent↗
PubMed1989

A prospective evaluation of a triple-drug regimen containing cisplatin, vinblastine, and dacarbazine (CVD) for metastatic melanoma.

Based on the independent activity of cisplatin, vinblastine, and dimethyl-triazeno-imidazole-carboxamide (DTIC) (CVD), a combination of these agents was used in the treatment of patients with advanced melanoma. Vinblastine was used in a dose of 1.6 mg/m2/d for 5 days, DTIC was used in a dose of 800 mg/m2 intravenously (IV) on day 1, and cisplatin was used in a dose of 20 mg/m2/d for 4 days starting on day 2 of chemotherapy. The courses of chemotherapy were repeated at 3-week intervals. All patients were premedicated with antiemetics, and IV hydration was used before cisplatin. Fifty-two consecutive patients were registered and 50 were evaluable for response. Two patients achieved a complete response (CR) and 18 patients had a partial response (PR) for an overall response rate of 40% (95% confidence interval, 27% to 55%). The median duration of response was 9 months and the median survival time of the responders was 12 months. The overall median survival time of patients treated on this protocol was 9 months. The treatment was associated with significant toxicity consisting of nausea, vomiting, diarrhea, and partial hair loss. Additionally, neutropenia with a median nadir granulocyte count of 500/microliters was observed, and significant anemia required blood transfusions in a majority of the patients after three to four courses of chemotherapy. The dose-limiting toxicity was peripheral neuropathy which required discontinuation of cisplatin after six to eight courses of chemotherapy. We believe that this triple-drug regimen has significant activity that appears to be superior to the single-agent activity of these drugs, both in terms of increased response rate and duration of response.

Adult↗
PubMed1989

Small cell osteosarcoma. A clinicopathologic study of 27 cases.

We report a study of 27 patients with small cell osteosarcoma (SCO), 17 from the M. D. Anderson Cancer Center (MDAH) and ten from the Pediatric Oncology Group (POG). There were 12 male patients and 15 female patients; 19 were white, five were black, and three were Hispanic. They ranged from 6 to 28 years of age with a median of 14 years. Histologically there were three patterns: Ewing's-like, lymphoma-like, and spindle cell. All cases showed osteoid formation and a few had chondroid areas. There was cytoplasmic glycogen in ten cases. Initial treatment for MDAH patients included intraarterial infusion of cisplatin in ten, amputation in four, partial mandibulectomies in two, and biopsy with local radiotherapy and systemic chemotherapy in one. All POG patients had resection or amputation followed by adjuvant chemotherapy. Twelve patients are alive, of whom nine have had significant follow-ups for 25 to 90 months. Fourteen patients are dead of lung, spine, and brain metastases from 1 to 23 months after initial diagnosis. One patient is alive with lung relapse at 4 months. In summary, SCO is a high-grade variant of osteosarcoma, with an incidence of up to 4% of all osteosarcomas, that affects patients of the same age group and has the same anatomic location as conventional osteosarcoma. Currently, SCO appears to have a prognosis that is the same as or slightly worse than that of conventional osteosarcoma. Furthermore, although intraarterial infusion is effective for the primary tumors in the bone, distant metastases are difficult to control.

Adolescent↗
PubMed1989

The clinical spectrum of anomalous pancreatobiliary junction.

Anomalous junction of pancreatobiliary ducts (AJPB) is known to be associated with choledochal cyst and gallbladder cancer. This report describes our experience with eight patients with AJPB, six of whom were diagnosed at endoscopic retrograde cholangiography and two at transhepatic cholangiography. Four of the patients with AJPB had an associated congenital choledochal cyst, two had a normal biliary tree and one each had inspissated bile syndrome and cholangiocarcinoma. The last two associations have not been previously described. It is felt that the clinical spectrum of AJPB may unfold further with the widespread use of the cholangiographic techniques.

Adult↗
PubMed1989

Double blind study on the efficacy and safety of tetrabamate and chlordiazepoxide in the treatment of the acute alcohol withdrawal syndrome.

1. Efficacy and safety of tetrabamate and chlordiazepoxide in the treatment of the acute or Primary Alcohol Withdrawal Syndrome (PAWS) were assessed during a randomized double blind clinical trial, carried out on sixty male alcoholic in-patients. 2. The two drugs were administered four times a day in double dummy conditions, according to a fixed-flexible decreasing dosage schedule (six days basic regimen). 3. Drug efficacy was measured daily throughout the study period using a battery of standard instruments for collecting quantitative clinical, behavioral, psychopathological and laboratory data. Side effects were daily recorded. 4. Tetrabamate was found to be as efficient as chlordiazepoxide in reducing the intensity of the PAWS, improving sleep and vital signs rapidly and alleviating anxiety progressively. 5. Tetrabamate was found particularly beneficial for severe tremor. Psychomotor and mood scores consistently favored tetrabamate, suggesting psychoanaleptic properties of this compound (increased diurnal vigilance). 6. Side effects were minimal with tetrabamate and generally of weak intensity with chlordiazepoxide. 7. The results of this study indicate that tetrabamate may represent a new alternative drug of choice for the therapy of the acute alcohol withdrawal syndrome.

Adult↗
PubMed1989

Cholangiographically guided aspiration cytology in the management of malignant biliary obstruction.

Fifteen patients with malignant biliary obstruction were subjected to fine needle aspiration cytology (FNAC) under fluoroscopic guidance. Fourteen (93%) of them were correctly diagnosed to have a malignancy at FNAC. Simultaneous with FNAC or at a later date, all the patients underwent percutaneous biliary drainage with a drop in serum bilirubin from a mean of 23.2 mg/dl to 8.5 mg/dl. Ten patients were subjected to exploratory laparotomy and biopsy at which the diagnosis of FNAC was confirmed in nine of them. The tenth patient with a negative yield at FNAC had a 1.0 cm cholangiocarcinoma. The usefulness of FNAC combined with biliary drainage as an alternative to surgery is highlighted.

Adenoma, Bile Duct↗
PubMed1987

Capgras syndrome: a case report from Zimbabwe.

A case of Capgras syndrome in a black Zimbabwean patient is described. The syndrome occurs in the setting of a schizophrenic illness, but psychodynamic factors are readily identified despite the patient's different cultural background.

Adult↗
PubMed1986

On the pathogenesis and therapy of dementia of the Alzheimer type: some neuropathological, biochemical, genetic and pharmacotherapeutic considerations.

The extensive literature on dementia of Alzheimer type (DAT) testifies to the enormous progress achieved in the clinical and biochemical delineation of this disease. Newly developed laboratory and imaging techniques are also being applied to the diagnosis of DAT. Nevertheless, unequivoval diagnosis still relies primarily on morphological data from biopsy or autopsy. An overview is presented of major morphological changes occurring at different levels of organization in the central nervous system (CNS) in DAT. Currently formulated etiopathogenic hypotheses of DAT are reviewed and discussed in the context of morphological alterations. Some of the recombinant DNA methods, that are currently available for gene analysis, are described. Some approaches for studying Alzheimer specific genes using the above methods have been suggested. Finally, a critical overview of the current pharmacotherapeutic armamentarium used in DAT and senile dementia is presented. The efficacy, side effects, and the main mechanisms of action of the two categories of drug therapy -supposed etiopathogenic and symptomatic- are presented.

Aluminum↗
PubMed1986

Ethanol metabolizing system in Drosophila. Aldehyde dehydrogenase: functional aspects in adult and during development.

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities were determined in adult flies from several Drosophila species endowed with widely different tolerance to ethanol (ETOH). Plotting ALDH against ADH activities resulted in a high correlation coefficient (r = 0.966). This finding was confirmed in developmental studies. From early larval stage up to late adult life, DH and ALDH activities demonstrated almost parallel profiles. In the highly ETOH tolerant species D. melanogaster (D.m.), ADH and ALDH profiles were U-shaped: high activities in larvae, low activities in pupae and high activities in adults. In D. simulans (D.s.), a species less tolerant to ETOH, the profiles were L-shaped: high activities in larvae but low activities in both pupae and adults. Interestingly, similar activities (ADH and ALDH) were observed in the larvae of both species. Subcellular distribution studies of larval ALDH in both species revealed that the total ALDH activity is largely contributed by a mitochondrial high affinity enzyme. ALDH activity, clearly distinguishable from aldehyde oxidase (ALDOX), was visualized through analytical isoelectric focusing of the subcellular fractions. The estimated pIs for D.m. and D.s. were 4.9 and 5.2 respectively, thus different from those of ADH. The key biological role initially attributed to Drosophila ALDH is further supported by the present data. In addition the Drosophila developmental model opens new avenues for research on the study of genetic regulation of ADH and ALDH expression.

Alcohol Oxidoreductases↗
PubMed1982

Osseous manifestations in congenital syphilis: a study of 55 cases.

Radiology plays an important role in the early diagnosis of congenital syphilis. Osseous manifestations in 55 cases of congenital syphilis have been analysed and their radiological appearances described. In addition to the common findings of metaphysitis, periostitis and osteitis of the long bones, unusual involvement of the skull, mandible, nasal septum, scapulae and short bones of the hands and feet was observed.

Bone Diseases↗
PubMed1980

Biochemical correlates of tolerance in rodents and in Drosophila. Possible role of alcohol dehydrogenase, aldehyde dehydrogenase and superoxide dismutase.

In the rat, prolonged exposure to ethanol (ETOH) vapor induced an acquired increase in tolerance. After a single ETOH administration, the duration of recovery was decreased by 20% as compared to control animals and the rate of ETOH elimination from blood was increased by 27%. From the data obtained on liver enzymes--alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and superoxide dismutase (SOD)--it is suggested that the increased ALDH activity would be the consequence of an increased formation of the product of ETOH oxidation, the acetaldehyde. This over-production would not be accounted for by ADH. It is assumed that among others, the coupled reaction SOD-catalase would represent a possible alternate pathway. Data on Drosophila demonstrate that initial tolerance to ETOH is well correlated with ADH activity. It is suggested that ETOH metabolites (mainly acetaldehyde) would act also as determinant of this initial tolerance. The value of Drosophila as animal model for the study of behavioral and biochemical correlates of initial tolerance is discussed.

Alcohol Oxidoreductases↗