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Biomedical subjects

P Dhar

Publications and source records attributed to P Dhar.

At least 37 records · Page 2Linked to original sources
PubMed2001

Apoptosis induced by peste des petits ruminants virus in goat peripheral blood mononuclear cells.

The ability of peste des petits ruminants virus (PPRV) to induce apoptosis in goat peripheral blood mononuclear cell (PBMC) culture was investigated. Goat PBMC were infected with PPRV and the infectivity was confirmed by cytopathic effect, demonstration of presence of infectious viral progeny and expression of viral antigens in the lymphocytes, cultured in vitro. Infected PBMC showed morphological features of apoptosis. DNA extracted from PPRV-infected cells displayed laddering pattern in agarose gel electrophoresis. Infected cells also showed significantly higher apoptotic indices measured by bisbenzimide staining than control cells. Electronmicrographs of PPRV-infected PBMC revealed features typical of apoptosis such as peripheral condensation of chromatin, blebbing of plasma membrane, fragmentation of nucleus and cell leading to formation of apoptotic bodies. Our results suggest that PPRV can induce apoptosis, in vitro, in goat lymphocytes.

Animals↗
PubMed2001

Chest radiograph interpretation skills of anesthesiologists.

OBJECTIVE: To assess the skills of anesthesiologists in the interpretation of chest radiographs. DESIGN: Randomized evaluation conducted among anesthesiologists and radiologists. SETTING: Postgraduate Assembly of the New York State Society of Anesthesiologists in 1999, and the Department of Radiology, New York University Medical Center. PARTICIPANTS: A total of 61 anesthesiologists (48 attending physicians; 13 residents); control group of 8 radiology residents (all participants volunteered). INTERVENTIONS: After completing a demographic survey, participants were asked to review a series of 10 chest radiographs. A brief clinical scenario accompanied each radiograph. No time limit was set for these interpretations. MEASUREMENTS AND MAIN RESULTS: The demographic characteristics of the anesthesiology participants included university faculty (46%), private group practitioners (41%), independent practitioners (11%), and 1 participant with an unspecified type of practice. Additional training among the participants included internal medicine (31%), surgery (19%), and pediatrics (3%); 34% did not specify any additional training. Of the participants, 92% were involved in cases requiring general anesthesia; 96% managed patients in the recovery room; and 34% managed patients in the intensive care unit. Of participants, 80% usually order chest radiographs, but only 42% interpret the films themselves. Misdiagnosed radiographs included pneumothorax by 11% of participants, free air under the diaphragm by 41%, bronchial perforation from a nasogastric tube by 28%, right mainstem intubation by 20%, superior vena cava perforation from a central venous catheter by 31%, normal film by 75%, negative pressure pulmonary edema by 16%, left lower lobe collapse by 80%, pulmonary infarction from a pulmonary artery catheter by 29%, and tension pneumothorax by 41%. Overall scores of the attending physicians were not significantly different from that of residents (p > 0.05). The control group of radiology residents scored significantly better (mean, 83.7; p = 0.009) than the anesthesia residents (mean, 62.8) and anesthesia attending physicians (mean, 62.5). CONCLUSION: Anesthesiologists are deficient in skills for the interpretation of chest radiographs. The skill level of university-based physicians is not greater than physicians in private practice, and skill level does not improve with level of training or experience. Most anesthesiologists rely on radiologists for interpretative results. Further training during the residency years may help improve diagnostic skills.

Anesthesiology↗
PubMed2001

Blind orotracheal intubation with the intubating laryngeal mask versus fibreoptic guided orotracheal intubation with the Ovassapian airway. A pilot study of awake patients.

In a randomized, prospective pilot study, we compared awake blind orotracheal intubation using the intubating laryngeal mask airway (blind-ILM) with awake fibreoptic-guided orotracheal intubation using an Ovassapian airway (FOS-OA). Fifty-four patients (ASA 1 to 3, aged 18 to 85 years) requiring awake intubation for elective surgery were randomly allocated by coin toss into two groups: 31 patients were intubated blindly through the ILM (blind-ILM) and 23 were intubated using fibreoptic guidance through the Ovassapian airway (FOS-OA). Sedation to a target clinical end-point (spontaneous eye-closing, but responsive to verbal command) was obtained with fentanyl/midazolam and a cricothyroid puncture was performed with 3 ml lignocaine 4%. The oropharynx was then topicalized until tolerance of a Guedel airway was achieved. The number of failed attempts (maximum of three allowed), overall success rates, the time from insertion of the airway to capnographic (blind-ILM) or fibreoptic (FOS-OA) confirmation of intubation or until three failed attempts, and cardiovascular responses before and during intubation, were recorded. The first time (blind-ILM, 25/31 [81%]; FOS-OA, 20/23 [87%], P = 0.6) and overall (blind-ILM, 26/31 [84%]; FOS-OA, 22/23 [96%], P = 0.2) intubation success rates were similar. The mean +/- SD time to intubation was shorter for the blind-ILM group (104 +/- 65 vs 158 +/- 115 sec, P = 0.05). There were no clinically significant differences in blood pressure or heart rate between groups. Compared with baseline values, there was no cardiovascular response to intubation in either group. We conclude that the blind-ILM and FOS-OA techniques have similar success rates and cardiovascular responses, but intubation is slightly quicker with the blind-ILM technique.

Adult↗
PubMed2000

Development and evaluation of a monoclonal antibody based competitive enzyme-linked immunosorbent assay for the detection of rinderpest virus antibodies.

A competitive enzyme-linked immunosorbent assay has been standardised for the detection of antibodies to rinderpest virus in sera from cattle, sheep and goats. The test uses a neutralising monoclonal antibody (MAb) directed against the haemagglutinin protein of rinderpest virus. The test is specific for rinderpest, as it failed to detect antibodies to peste des petits ruminants virus in convalescent goat sera. A 45% inhibition of the binding of the MAb to the antigen was used as the cut-off point for deciding the rinderpest status of the test samples. The specificity and sensitivity of the test and the stability of the test reagents were determined and compared to the results obtained using a commercial kit with approximately 1,200 serum samples from cattle, sheep and goats in India. The current test compared very well with the commercial kit. The test is expected to be extremely useful for sero-monitoring and sero-surveillance of rinderpest in countries which are actively pursuing a rinderpest eradication programme.

Animals↗
PubMed1999

Dietary effects of conjugated octadecatrienoic fatty acid (9 cis, 11 trans, 13 trans) levels on blood lipids and nonenzymatic in vitro lipid peroxidation in rats.

The present study examined the antioxidant activity of conjugated octadecatrienoic fatty acid (9 cis,11 trans,13 trans-18:3), alpha-eleostearic acid, of karela seed (Momordica charantia), fed to rats for 4 wk. The growth pattern of rats and the effect on plasma cholesterol and high density lipoprotein (HDL) cholesterol and peroxidation of plasma lipid, lipoprotein, eryhrocyte membrane, and liver lipid were measured. Rats were raised on diets containing sunflower oil mixed with three different levels of conjugated trienoic fatty acid (9c,11t,3t-18:3) 0.5, 2, and 10% by weight; the control group was raised with sunflower oil as dietary oil as the source of linoleic acid (9c,12c-18:2). The growth pattern of the three experimental groups of rats showed no significant difference compared to the control group of rats, but the group with 10% 9c,11t,13t-18:3 had slightly higher body weight than the control group of rats. Concentrations of total cholesterol, HDL-cholesterol, and non-HDL-cholesterol in plasma were similar in all four groups. Plasma lipid peroxidation was significantly lower in the case of 0.5% 9c,11t,13t-18:3 group than the control group and the 2 and 10% 9c,11t,13t-18:3 dietary groups as well. Lipoprotein oxidation susceptibility test with 0.5, 2, and 10% 9c,11t,13t-18:3 dietary groups was significantly less susceptible to lipoprotein peroxidation when compared with sunflower oil dietary group, and the dietary group with 0.5% 9c,11t,13t-18:3 showed least susceptibility. There was significant lowering in erythrocyte ghost membrane lipid peroxidation in the 0.5, 2, and 10% 9c,11t,13t-18:3 dietary groups compared to the sunflower oil groups. Nonenzymatic liver tissue lipid peroxidation was significantly lower in the group of rats raised on 0.5% 9c,11t,13t-18:3, but the groups on 2 and 10% 9c,11t,13t-18:3 acid did not show any significant difference compared with the control group of rats.

Animals↗
PubMed1998

Bile duct obstruction due to portal biliopathy in extrahepatic portal hypertension: surgical management.

BACKGROUND: Varices can develop in and around the bile duct in the presence of portal hypertension, especially when it is caused by extrahepatic portal vein thrombosis. The term 'portal biliopathy' is used to describe changes in the bile duct due to these varices, which may cause bile duct obstruction. This paper reviews experience of the surgical management of patients with symptomatic portal biliopathy. METHODS: Nine patients with extrahepatic portal vein obstruction with symptomatic portal biliopathy. were reviewed retrospectively. RESULTS: Eight patients presented with jaundice, two had abdominal pain and one had recurrent cholangitis. Endoscopic retrograde cholangiography revealed abnormality of the bile duct wall, with stricture in eight patients and bile duct calculi in two. Portasystemic shunting relieved jaundice in five of seven patients, and in two a second-stage hepaticojejunostomy was required. CONCLUSION: Symptomatic biliary obstruction in patients with extrahepatic portal hypertension may be relieved by a portasystemic shunt. Rarely biliary bypass may be required and is rendered safer by previous portasystemic shunting to decompress the pericholedochal varices. A direct approach to the biliary tract without a preliminary shunt may be hazardous and is frequently unnecessary.

Adolescent↗
PubMed1998

Nutritional characteristics of oil containing conjugated octadecatrienoic fatty acid.

The nutritive value of conjugated octadecatrienoic fatty acid (C18:3 Delta9,11,13alpha-elaeostearic acid) as occurs in karela seed (Momordica charantia) oil was studied. When rats were fed at the 20% level for 6 weeks, the growth pattern of rats and the food efficiency ratio showed a slightly significant difference compared to the group raised on linseed oil with non-conjugated octadecatrienoic acid (C18:3 Delta9,12,15alpha-linolenic acid) as control. The concentrations of total cholesterol, triglyceride, VLDL-cholesterol, LDL-cholesterol and LDL/HDL-cholesterol in serum were significantly higher in karela oil than in linseed oil. The liver lipid profile showed no difference. The total lipid as well as phospholipid concentrations of heart lipid were significantly higher in karela oil. The brain weight of the linseed oil group was significantly higher than the karela group. The brain phospholipid concentration of the karela oil group was significantly higher than that of the linseed oil group.

Animals↗
PubMed1997

Surgical management of pancreatic necrosis presenting with locoregional complications.

BACKGROUND: Local complications of pancreatic necrosis may occur after surgery, but when they occur spontaneously render surgical treatment more hazardous and impair prognosis. METHODS: A retrospective review was carried out of 83 patients who underwent surgery for pancreatic necrosis from 1988 to 1995, to determine the incidence, type, treatment and outcome of locoregional complications caused by pancreatic necrosis associated with acute pancreatitis. RESULTS: Seventeen patients (20 per cent) were identified to have intra-abdominal complications with pancreatic necrosis either before operation or at the time of surgery. The majority of patients had a delay in intervention (mean 46 days). At presentation ten of the 17 patients had one or more organ system failures. Fourteen patients had gastrointestinal tract involvement, two had involvement of the biliary tract and one patient had a splenic rupture. Six patients died. CONCLUSIONS: In patients with pancreatic necrosis, development of locoregional complications is associated with a high mortality rate. The presence of gastrointestinal bleeding, peritonitis, jaundice or pneumoperitoneum in such patients suggests the presence of a complication of the necrotic process and should prompt early intervention. Early referral of patients with severe acute pancreatitis to specialized units may reduce the risk of locoregional complications.

Acute Disease↗
PubMed1997

Segment III cholangiojejunostomy for carcinoma of the gallbladder.

Jaundice in patients of advanced carcinoma of the gallbladder requires palliation for the distressing symptoms of pruritus and cholangitis. Intrahepatic segment III duct cholangiojejunostomy is a means for alleviating the obstruction with malignant porta block. The authors reviewed their experience with this procedure in 48 patients of carcinoma of the gallbladder. All patients had jaundice; pruritus was present in 44 (92%) and cholangitis in 14 (29%). The level of obstruction was determined preoperatively by percutaneous transhepatic cholangiography. In 32 patients the block was below the level of the bifurcation of the right and left ducts, and 16 patients had a block involving the confluence, isolating the two lobes of the liver. Following segment III cholangiojejunostomy, pruritus was relieved in all and cholangitis in 86% of patients. At the end of 6 weeks a significant fall in serum bilirubin and alkaline phosphatase levels was seen with both types of hilar obstruction. Varying degrees of pain relief was also noted in 75% of patients. Segment III biliary bypass is an effective, one-time, reliable means of palliation for carcinoma of the gallbladder with hilar obstruction. Its efficacy appears to depend on the duration and depth of the jaundice and on the anatomy of the biliary ductal system in the left hemiliver rather than on the type of hilar obstruction.

Adult↗
PubMed1997

Reoperative surgery for choledochal cysts.

BACKGROUND: Complications often follow if a choledochal cyst is treated simply by drainage, either internal or external. This study reviews 17 patients who had had previous cystoenterostomy (n = 9) or external drainage (n = 8) and who required reoperation and cyst excision. METHODS: The study was a retrospective review including ten women and seven men managed over 9 years. The indications for reoperation were stone formation (10 patients), pancreatitis (three), portal hypertension (two) and hepatic abscess (one); two patients were asymptomatic. RESULTS: Definitive surgery with cyst excision was possible in all patients who had previously had external cyst drainage and in seven of nine who had had previous cystoenterostomy. There were no deaths. Two postoperative biliary leaks and two duodenal fistulas resolved spontaneously. CONCLUSION: Excision of a choledochal cyst is possible and desirable even after a previous drainage operation. In severely ill patients with a complication of choledochal cyst, external drainage may be a preferable initial manoeuvre.

Adolescent↗
PubMed1996

Effect of pressure on transmural fluid flow in different de-endothelialised arteries.

The effect of pressure on filtration across different de-endothelialised arteries has been studied experimentally, and the existing theoretical model is validated. Segments of different arteries are excised, de-endothelialised and cannulated. Bovine serum albumin Krebs solution is used as perfusate. Transmural water flux is measured by following the movement of an air bubble in a calibrated capillary, which connects the artery to a pressure reservoir; the pressure of which is varied. The hydraulic conductivity Lp is calculated from the flux values. Using available experimental parameters in the case of the thoracic and abdominal aorta, a theoretical model is validated using the experimental results. As the elastic constant for the carotid artery is not available, the theoretical model is used to calculate the elastic constant at different transmural pressures. The values calculated are in the range -4.9 x 10(-8) to -5.7 x 10(-9) cm2 dyne-1 between 50 and 135 mm Hg. Both theoretical and experimental results show a decrease in Lp values with an increase in transmural pressure for the thoracic and abdominal aorta, whereas a different trend is observed in the case of the carotid artery. The Lp values increase at 90 mm Hg, as compared with 50 mm Hg, and with a further increase in transmural pressure the values decrease.

Animals↗
PubMed1996

Trends and outcomes after prenatal diagnosis of congenital cardiac malformations by fetal echocardiography in a well defined birth population, Atlanta, Georgia, 1990-1994.

OBJECTIVES: In this study we used a population-based approach to assess the impact of fetal echocardiography on a well defined birth population with nearly complete ascertainment of cardiac defects. BACKGROUND: Although fetal echocardiography is being used more frequently in the prenatal diagnosis of congenital cardiac malformations, its impact on the diagnosis and surveillance of cardiac defects has not been described in defined populations. METHODS: All stillborn and live-born infants with diagnosed cardiac defects and whose mothers resided in the metropolitan Atlanta area from January 1990 through December 1994 were ascertained through an established birth defects surveillance system. All fetuses with cardiac defects diagnosed prenatally by a pediatric of cardiac defects, diagnostic trends and adverse fetal outcomes were described. RESULTS: We identified 1,589 infants with congenital cardiac malformations, for a live-birth prevalence rate of 8.1/1,000 (95% confidence interval [CI] 7.8 to 8.6). Overall, 97 (6.1%) of these cases of cardiac malformations were diagnosed prenatally. The proportion of cardiac defects diagnosed prenatally rose from 2.6% in 1990 to 12.7% in 1994, a nearly fivefold increase. The proportion of cardiac defects diagnosed prenatally during the study varied by the type of defect, from a low of 4.7% for atrial septal defects to a high of 28% for hypoplastic left heart syndrome. Prenatally diagnosed cardiac malformations were associated with a high incidence of infant mortality (30.9%, 95% CI 2.4 to 5.4) and fetal wastage (17.5%, 95% CI 6.2 to 11.3). CONCLUSIONS: These data show that fetal echocardiography is being used increasingly in the prenatal diagnosis of congenital cardiac malformations in metropolitan Atlanta. Few pregnancy terminations were reported as a result of such diagnoses. However, the study had limited power (10%) to detect a meaningful decrease in birth prevalence rates for congenital heart disease. In addition, survival of infants was not improved after prenatal diagnosis with fetal echocardiography.

Adult↗
PubMed1996

Effect of steady shear stress on fluid filtration through the rabbit arterial wall in the presence of macromolecules.

1. Transport properties of the arterial wall in general and endothelial cells in particular are known to be sensitive to fluid flow generated shear stress. 2. The effect of steady wall shear stress was studied in vitro on transmural water filtration in the presence of a control perfusate (10 mg/mL bovine serum albumin) and a test perfusate (50 mg/mL Dextran 500). The latter is a macromolecule with certain physical properties comparable to those of the circulating low density lipoproteins. Dextran 500 is a neutral polysaccharide carrying no charge groups. 3. Male rabbits were anaesthetized with sodium pentobarbital and one of the common carotid arteries was cannulated and excised. 4. Fluid flux across the artery wall was measured at a constant transmural pressure (150 cm H2O) in the presence and absence of luminal flow of the perfusate. 5. Luminal flow produced an average increase by 21% in the filtration flux relative to its value under static conditions with 10 mg/mL bovine serum albumin in the perfusate. In the presence of 50 mg/mL Dextran 500 in the perfusate an average reduction by 36% was observed in fluid flux when luminal flow was imposed in the artery. 6. The increase in flux with the control perfusate may be due to a structural alteration of the glycocalyx fibre matrix caused by flow imposed shear stress. The observed decrease in flux with 50 mg/mL Dextran 500 may be accounted for by the deformation of the dextran polymer chains when subjected to shear stress. Although intact molecules are likely to be excluded by the glycocalyx, parts of the chain may insert themselves in the network and enhance the steric exclusion of water. Also, decreased hydration of the medial interstitium may increase medial resistance to fluid transport.

Analysis of Variance↗
PubMed1996

Internal pancreatic fistulae with serous effusions in chronic pancreatitis.

BACKGROUND: Serous effusions in chronic pancreatitis are infrequent but persistent. These occur usually as a consequence of internal pancreatic fistulae and commonly involve the pleural cavity or peritoneum. METHODS: To assess strategies in operative management, the records of 12 patients who underwent surgery for internal pancreatic fistula with underlying chronic pancreatitis were reviewed retrospectively. Seven patients had pancreatic ductal calculi. Three cases underwent external drainage. Three cases with leaking pseudocysts underwent cystojejunostomy-en-Y. Three cases with ductal dilatation or calculi underwent lateral pancreaticojejunostomy and three patients had caudal pancreatectomy for distal disease. RESULTS: Eight patients were completely controlled of all symptoms, with no sequelae. One case each had recurrent pancreatitis and ascites but did not require re-operation. There were two deaths: one with massive haematemesis and one with pre-existent multi-organ failure and sepsis. CONCLUSIONS: Pancreatic duct stones may be causally associated with internal pancreatic fistulae. Delineation of ductal anatomy and pathological aberrations of the pancreas, including determination of the leak site, was of paramount importance in planning surgery. Peroperative ductography proved the most useful in this regard.

Adolescent↗
PubMed1996

Choledochal cysts--differences in children and adults.

Choledochal cysts in children and adults may behave differently. To identify these differences the records of 49 patients (22 children and 27 adults) who underwent surgery for choledochal cysts over a period of 7 years were analysed retrospectively. In two adult patients who had undergone a previous cholecystectomy an acquired malformation could not be excluded. Cholangitis was more common in adults. Choledochal cysts in children were predominantly Type I cystic lesions, whereas Type IV cysts were more common in adult patients. Anomalies of the pancreatic duct and associated hepatobiliary problems were seen exclusively in adults and the latter can make excision of the cyst more difficult and complicated. To prevent the development of complications choledochal cysts should be excised as soon as they are detected.

Adolescent↗