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Biomedical subjects

A Dhar

Publications and source records attributed to A Dhar.

At least 55 records · Page 3Linked to original sources
PubMed1996

Role of platelet-activating factor in skeletal muscle ischemia-reperfusion injury.

These studies indicate that PAF, a known stimulator of aggregation, secretory and/or contractile activity of platelets, neutrophils, smooth muscle and other cells, is produced by skeletal muscle during IRI. The maximum increase occurs at 10 to 15 minutes and continues for at least an hour. Infusions of PAF into skeletal muscle subjected to 20 minutes of ischemia and 20 hours of reperfusion resulted in tissue necrosis similar to that produced by 5 hours of ischemia and 20 hours of reperfusion. 25 mg/kg of pentoxifylline, infused immediately prior to reperfusion of ischemic skeletal muscle, decreased PAF production and muscle necrosis. It was also demonstrated that skeletal muscle necrosis can be reduced by infusion of PAF antagonists (WEB-2086) into the muscle immediately prior to reperfusion. Thus, PAF has an important role in skeletal muscle IRI and additional studies of PAF inhibition during IRI are warranted.

Animals↗
PubMed1996

Intensive care unit admission following successful cardiopulmonary resuscitation: resource utilization, functional status and long-term survival.

A retrospective review of consecutive admissions (n = 285) to a university hospital intensive care unit (ICU) following cardiopulmonary resuscitation was conducted to determine long-term outcome, length of stay (LOS), and ICU resource consumption. Ninety-four patients (33%) survived to hospital discharge. Hospital survivors had longer ICU LOS than non-survivors (5.1 +/- 0.8 vs. 2.8 +/- 0.4 days, P < 0.001) and longer hospital stays (22.5 +/- 3.7 vs. 2.9 +/- 1.2 days, P < 0.001). Average laboratory and pharmacy costs per admission were greater in hospital survivors than non-survivors. Most patients returned to their pre-arrest homes functionally independent and 58% of hospital survivors were alive 2 years after discharge. It is possible that attempts to appropriately limit therapy in patients with poor prognosis may help direct resources towards patients who will benefit.

Activities of Daily Living↗
PubMed1996

The human ovarian granulosa cell: a stereological approach.

The human ovarian granulosa cell is perhaps the most widely studied endocrine cell, but little quantitative structural information exists for this cell. In the present study new and traditional stereological probes have been employed to provide quantitative structural information on these functionally important cells. Granulosa cells were obtained from follicular aspirations from 10 women during in vitro fertilisation procedures. Initially 2 methods were used to estimate the mean nuclear volume of these cells: the mean number weighted nuclear volume was estimated by the Selector and the mean volume weighted nuclear volume by the point sampled intercept method. It was found that the difference between the 2 volume estimates was only 8.5%. The volume weighted mean nuclear volume was used as an estimate of nuclear volume. This was subsequently corrected (taking the percentage difference as the empirical bias) and combined with fractional cell volumes (Vv) to produce estimates of cell, mitochondrial, lipid and nucleolar volume. The proportion of the cell occupied by the nucleus had a remarkably low interindividual variation (CV = 7.6%). The proportion of the nucleus occupied by euchromatin also had a striking low variation (CV < 6%). All other cellular parameters had CVs of less than 35%. The lipid composition of these cells showed the greatest interindividual variability, with a CV of 42% for relative and 54% for absolute volume. The present study outlines a simple protocol for the quantitation of granulosa cell structure using new unbiased stereological probes and providing baseline structural information.

Cell Nucleus↗
PubMed1996

Pancrease divisum: five years' experience in a teaching hospital.

AIM: To study the frequency and significance of pancreas divisum. METHODS: Retrospective analysis of all pancreatograms carried out between July 1989 and June 1994. RESULTS: The 809 pancreatograms performed included 207 in patients with pancreatitis (acute 74, chronic 133), 330 with biliary disease, 238 with obscure abdominal pain and 34 with pancreatic malignancy. Of these, 30 patients (3.7%) were diagnosed to have pancreas divisum - 26 had type I variant, one had type II variant and three had type III variant. Accessory papillary cannulation was attempted in 10 patients; 8 were successful, with dorsal ductography confirming pancreas divisum in all of them. Two of these 8 patients had changes of chronic pancreatitis in the dorsal duct. The frequency of pancreas divisum in patients with pancreatitis (19 of 207, 9.2%) was significantly higher than in patients with biliary diseases and those with obscure abdominal pain (11 of 568, 1.9%; p < 0.001). CONCLUSIONS: Pancreas divisum is not an uncommon condition in India and its frequency in patients with idiopathic pancreatitis is higher than that in patients with other abdominal conditions. It should be looked for in any case of idiopathic pancreatitis.

Biliary Tract Diseases↗
PubMed1995

Biliary obstruction due to pancreatic insulinoma.

Pancreatic insulinomas are rare tumors and their association with polycystic disease of the liver is uncommon. We report here a patient with pancreatic insulinoma with hepatic metastasis and biliary obstruction presenting with neuroglycopenic symptoms and cholestasis on a background of polycystic liver disease.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1995

Effect of pentoxifylline on tissue injury and platelet-activating factor production during ischemia-reperfusion injury.

PURPOSE: Pentoxifylline lessens the metabolic derangements associated with ischemia-reperfusion injury. This study evaluated the effects of pentoxifylline on platelet-activating factor (PAF) production and tissue injury during skeletal muscle ischemia-reperfusion injury. METHODS: The isolated canine gracilis muscle model was used. Group 1 muscles were subjected to 5 hours of ischemia and 20 hours of reperfusion (n = 10); group 2 muscles received pentoxifylline, 15 mg/kg, systemic infusion 10 minutes before reperfusion (n = 6); group 3 muscles received pentoxifylline, 25 mg/kg, systemic infusion 10 minutes before reperfusion (n = 6). PAF was measured from muscle venous effluent by the scintillation proximity assay method. Muscle injury was assessed by vital staining and planimetry. RESULTS: PAF levels in group 2 were decreased at 10, 15, and 30 minutes of reperfusion compared with group 1 but did not reach significance. PAF levels in group 3 were decreased at all times of reperfusion compared with group 1 but attained significance only at 10 minutes of reperfusion (p < 0.05). No significant differences in muscle weight were noted among the three groups. No differences in the extent of muscle necrosis was observed between group 1 (77.26% +/- 20.38%) and group 2 (60.49% +/- 23.97%) (p = 0.08); there was a significant reduction in the extent of muscle necrosis in group 3 (44.55% +/- 21.47%) compared with group 1 (p < 0.05). CONCLUSIONS: The administration of pentoxifylline at 25 mg/kg before reperfusion of ischemic skeletal muscle decreased significantly the extent of muscle necrosis and PAF levels in the venous effluents at all times of reperfusion (significantly at 10 minutes). These results suggest that pentoxifylline may decrease tissue injury of ischemia-reperfusion by inhibiting the production of PAF during critical periods of reperfusion.

Animals↗
PubMed1994

Electrotransjection of pp60v-src monoclonal antibody inhibits activation of phospholipase C in platelets. A new mechanism for platelet-activating factor responses.

Antibodies to pp60v-arc and phosphotyrosine were introduced into rabbit platelets using an electropermeabilization technique. The presence of these antibodies inside platelets was detected by flow cytometry. Platelet-activating factor (PAF)-stimulated phospholipase C activity (inositol phosphate production) and aggregation were dramatically inhibited in platelets transjected with either of these antibodies. Incubation of these antibodies with intact cells (i.e. nonpermeabilized) or electrotransjection of several nonspecific antibodies/agents (e.g. goat anti-mouse IgG, mouse serum, human platelet glycoprotein Ib monoclonal antibody, and fetal calf serum) into platelets had no effect on the PAF responses. trpE (another isotype-matched control antibody of pp60v-src) and pp56lck polyclonal antibody (another src-related kinase not present in platelets) also had no effect on PAF-induced aggregation and inositol phosphate production in permeabilized platelets. This indicates that the effect of internalized pp60v-src antibody is direct and specific in platelets. Stimulation of platelets by PAF increased the association and phosphorylation of both pp60c-src (60 kDa) and phospholipase C gamma 1 (145 kDa). This study provides the first evidence in platelets for a direct and specific involvement of pp60c-src in PAF-mediated phospholipase C activation and aggregation response.

Animals↗
PubMed1994

The embryology and management of congenital pouch colon associated with anorectal agenesis.

Forty-one infants with a pouch colon malformation accompanied by a high anorectal anomaly were treated between January 1986 and December 1990. The 41 cases constituted 9% of all anorectal malformations and 15.2% of high defects managed during this period. There were 32 boys and nine girls; three of the girls had an associated cloaca. Many of the babies presented in poor condition, with gross abdominal distension caused by the distended colonic pouch. The typical radiological feature was an enormously distended colonic shadow occupying more than 50% of the width of the abdomen. At the time of surgery, the patients were classified into 4 subgroups based on the length of the normal colon. All but three infants had a high wide fistula, with the genitourinary tract consisting of a colovesical fistula in males and a colovaginal or colocloacal fistula in females. Frequent associated malformations included duplication of the appendix and vesicoureteric reflux. The operations performed initially were a window colostomy of the pouch with or without division-ligation of the fistula, end-colostomy after fistula ligation, or subtotal pouch excision with tubularization of the remaining colon and end-colostomy. Thirteen of the 41 patients have undergone a definitive pull-through operation using the posterior sagittal approach, including two children in whom one-stage reconstruction of a cloaca was performed. Standardized management of this complex anomaly is proposed for the initial operation and for definitive reconstruction.

Abnormalities, Multiple↗
PubMed1994

Lichenoid photoeruptions in human immunodeficiency virus infection.

BACKGROUND: The clinical features of lichenoid eruptions in the setting of human immunodeficiency virus (HIV) infection are poorly described. Idiopathic lichen planus is rarely reported. All patients (n = 32) with a histologic diagnosis of a lichenoid eruption or photodermatitis at the University of California, San Francisco, over a 15-month period were reviewed and studied. OBSERVATIONS: Twelve of the 32 patients were HIV infected, and all 12 had photodistributed eruptions. Ten of 12 patients had received photosensitizing medication (usually nonsteroidal anti-inflammatory drugs or sulfamethoxazole/trimethoprim) at the onset of eruption. Most patients were black (10 of 12), and all had acquired immunodeficiency syndrome and a helper T-cell count of less than 50 cells per cubic milliliter. Nine patients had lichenoid eruptions, two showed histopathologic features of lichen niditus, and one had a photodistributed subacute dermatitis. Two patients with lichenoid eruptions developed marked depigmentation. No cases of lichen planus were found in HIV-infected persons. CONCLUSION: Lichenoid photoeruptions are seen in advanced HIV disease (CD4, < 0.05 x 10(9)L), and black patients are disproportionately affected. Idiopathic lichen planus in HIV-infected patients seems to be less common than lichenoid photoeruptions. Previously reported cases of idiopathic lichen planus in HIV-infected patients may represent lichenoid photodermatitis.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Epigastric heteropagus.

Incomplete parasitic twinning with the parasite attached at the host's epigastrium is extremely rare. We report a case of epigastric parasitic twinning where the parasite with a well-developed pelvis and lower limbs had accessory pelvic organs and was attached to the host above an omphalocele. The parasite was excised and the omphalocele managed conservatively by mercurochrome application. A review of the four previously reported cases is presented along with a discussion of the possible etiopathogenesis and nomenclature of this condition.

Abnormalities, Severe Teratoid↗
PubMed1993

An unusual form of caudal duplication (dipygus).

An unusual case of caudal duplication is presented in which the infant had an extra lower limb with 14 digits attached to an accessory parasitic pelvis situated in the midline subpubic area. Duplication of the external genitalia was also present. Successful excision of the accessory limb and reconstruction of the genitalia was performed in the neonatal period.

Abnormalities, Multiple↗
PubMed1993

Accessory limb attached to the back.

The authors report on a newborn with an accessory malformed leg attached to the back. The limb was associated with a teratomatous mass adjacent to its attachment site. The embryology and nomenclature of this malformation is discussed briefly.

Back↗
PubMed1993

Novel oxidative cleavage of C17-C20 bond in pregnane by a Pseudomonas sp.

Oxidative cleavage of the C17-C20 bond in progesterone by Pseudomonas sp. is reported. Transformation occurred under in vivo conditions. The bioconverted products were characterized as 1,4-androstadien-3,17-dione and 17 beta-hydroxy-1,4-androstadien-3-one. The steroid nucleus was not further degraded although the test organism had the capacity to induce dehydrogenation at C1 of this alpha, beta-conjugated steroid.

Androstadienes↗