Search PubMed⌕ Search

Biomedical subjects

A Roy

Publications and source records attributed to A Roy.

At least 199 records · Page 11Linked to original sources

Aetiology of secondary depression in male alcoholics.

BACKGROUND: Secondary depression is common among primary alcoholics. However, its aetiology is poorly understood. METHOD: Forty men with primary alcoholism, abstinent for two weeks or more, with a secondary major depressive episode were compared with forty matched never-depressed primary alcoholic controls for risk factors for depression and recent life events. RESULTS: In the six months before the onset of depression depressed alcoholics had experienced significantly more life events, more life events with negative impact, more dependent events caused by alcohol, and more independent events. Significantly more depressed alcoholics than controls had a family history of depression, a family history of suicidal behaviour and had themselves attempted suicide. CONCLUSION: Having recent life events, particularly events with negative impact, and a family history of depression are risk factors for secondary depression in alcoholics.

Adult↗

Biomarkers of environmental benzene exposure.

Environmental exposures to benzene result in increases in body burden that are reflected in various biomarkers of exposure, including benzene in exhaled breath, benzene in blood and urinary trans-trans-muconic acid and S-phenylmercapturic acid. A review of the literature indicates that these biomarkers can be used to distinguish populations with different levels of exposure (such as smokers from nonsmokers and occupationally exposed from environmentally exposed populations) and to determine differences in metabolism. Biomarkers in humans have shown that the percentage of benzene metabolized by the ring-opening pathway is greater at environmental exposures than that at higher occupational exposures, a trend similar to that found in animal studies. This suggests that the dose-response curve is nonlinear; that potential different metabolic mechanisms exist at high and low doses; and that the validity of a linear extrapolation of adverse effects measured at high doses to a population exposed to lower, environmental levels of benzene is uncertain. Time-series measurements of the biomarker, exhaled breath, were used to evaluate a physiologically based pharmacokinetic (PBPK) model. Biases were identified between the PBPK model predictions and experimental data that were adequately described using an empirical compartmental model. It is suggested that a mapping of the PBPK model to a compartmental model can be done to optimize the parameters in the PBPK model to provide a future framework for developing a population physiologically based pharmacokinetic model.

Air Pollutants↗

Admission criteria for inpatient substance abuse/dependence rehabilitation: implications for managed care.

In view of recent trends toward the replacement of traditional inpatient rehabilitation programs with nonresidential services, we examined the extent to which patients currently admitted to inpatient rehabilitation for alcohol or drug abuse/dependence met published criteria suggesting a preferential need for inpatient or residential care. Over 90% of almost 300 veterans with a primary DSM-III R diagnosis of alcohol or substance abuse/dependence, admitted to six New York Metropolitan Area Veterans Administration Medical Centers for inpatient rehabilitation, met at least one criterion dimension considered indicative of a need for such services, with over two-thirds meeting two or more dimensions. These findings suggest a continuing need for initial primary inpatient or residential rehabilitation for such patients.

Adult↗

Fine needle aspiration cytology of ophthalmic lesions.

Forty cases of ophthalmic lesions were subjected to fine needle aspiration cytology for pre-operative diagnosis which included retinoblastomas (5 cases), inflammatory and neoplastic lesions of the eyelid and lacrimal glands (29 cases) and extra-ocular orbital lesions (6 cases) inclusive of 3 cases of rhabdomyosarcomas. The lesions were distributed in both the eyes almost in equal proportions. Histological confirmation was obtained in 85% of cases; false positive in only one case with malignant neoplasm of the eyelid and false negative also in only one case with inflammatory pseudotumour which were, histologically, proved to be adenoma of tarsal gland and lymphocytic lymphoma respectively.

Biopsy, Needle↗

Bronchogenic carcinoma in young adults.

Clinicopathological features of 26 cases of bronchogenic carcinoma in patients below the age of 40 years have been studied and compared with 271 cases of bronchogenic carcinoma occurring in elderly patients. There was female preponderance (19.23%) in the younger study group compared to the elderly group (6.6%) and increased incidence of smokers in the younger group (57.6% versus 79.3%) and had achieved statistical significance (p < 0.001). Majority (20 out of 26) had a rural background. All the patients were symptomatic at the time of diagnosis and all the 26 cases except one belonged to advanced stage. The incidence of squamous cell carcinoma was almost same for both the age groups. Eighteen of the 26 cases had received antituberculosis chemotherapy by general practitioners before referral to the specialists. Twenty patients were treated initially by palliative radiotherapy and then by chemotherapy.

Adult↗

Application of peptide ELISA in tribal malaria of Madhya Pradesh.

A recently developed peptide ELISA method was used for monitoring the efficacy of malaria control programme in the tribal areas of Madhya Pradesh. Both crude Pf antigen and synthetic nonapeptide were used in ELISA for seroepidemiological studies. Both antigen responded equally well but the synthetic peptide had advantages of purity, defined characteristic and easy availability. Population of Mandla protected by vector control measures showed lower antibody titre and lower percentage positivity compared to the unprotected population of Jabalpur. A 0-5 yrs sentinel population from Haldwani almost seronegative has been taken as control.

Animals↗

[Reduction of blood loss in orthotopic liver transplantation with the use of aprotinin].

UNLABELLED: The impact of aprotinin on blood losses during orthotopic liver transplantation (OLT) has been studied retrospectively. PATIENTS AND METHODS: From September 1984 to July 1995, 152 patients underwent 168 OLT in our center. Seventy three patients (group I) received epsilon-aminocaproic acid as an antifibrinolytic agent and 95 patients (group II) received aprotinin. RESULTS: There was a significant reduction in the mean duration of the surgery (I = 743 +/- 25 min; II = 302 +/- 10 min; p < 0.001) and in the post reperfusion time (I = 282 +/- 13 min; II = 126 +/- 6 min; p < 0.001) in the group II. The need for blood products during the operation was also reduced (blood units; I = 21.7 +/- 2.3 units; II = 4.6 +/- 0.4 units; p < 0.001). There was less infectious and hemorrhagic complications requiring reoperation in group II. We have not seen an increased incidence of thrombotic complications in the patients receiving aprotinin. Other variables such as the use of hemoclips, veno-venous bypass and the type of preservation solution were also considered. CONCLUSION: Aprotinin use during OLT is efficient and superior to epsilon-aminocaproic acid in reducing blood losses. Combined with the non-utilisation of a veno-venous by-pass and the use of hemoclips, it helps reduce the operating time and the postoperative complications.

Adult↗

Clearance by the liver in cirrhosis. III. Propranolol uptake by the isolated perfused human liver.

In cirrhosis, intrahepatic shunts and capillarization of sinusoids can result in impaired extraction of substrates by the liver irrespective of the metabolic capacity of the liver (intact hepatocyte theory). To evaluate the role of anomalies of uptake in impaired drug disposition, we studied the steady-state hepatic clearance and single-pass hepatic uptake of propranolol in isolated perfused livers obtained from patients with cirrhosis at the time of transplantation and from organ donors with normal liver architecture. The kinetics of propranolol transport in the liver were characterized by means of the multiple-indicator dilution technique, and the outflow pattern of propranolol in the hepatic veins was resolved into throughput material, which had swept past the hepatocytes along with albumin, and returning material, which had entered the cells but returned in the outflow after escaping cellular sequestration and metabolism. The steady-state clearance of propranolol was decreased in cirrhotics compared with organ donors, and the outflow profile differed between the two groups. In cirrhotic livers, half of the propranolol in the outflow consisted of throughput material and the other half of returning material; in organ donors, all of the propranolol in the outflow was returning material. In the presence of albumin and alpha 1-acid glycoprotein in the perfusate, about 80-85% of propranolol was protein bound; removal of albumin and alpha 1-acid glycoprotein from the perfusate it cirrhotic livers resulted in an increase in the free fraction of propranolol, an increase in steady-state extraction, and a decrease in the throughput component of propranolol in the outflow. We conclude that impaired uptake of protein-bound propranolol, as a result of capillarization and intrahepatic shunts, contributes to its impaired elimination in cirrhosis.

Biological Transport↗

The v-Rel oncoprotein blocks apoptosis and proteolysis of I kappa B-alpha in transformed chicken spleen cells.

The v-Rel oncoprotein of the avian Rev-T retrovirus malignantly transforms chicken spleen cells in vivo and in vitro. We previously described two temperature-sensitive (ts) mutants of v-Rel (v-G37E and v-R273H) that show a ts ability to transform chicken spleen cells and to bind to DNA in vitro. We now show that spleen cell lines transformed by ts v-Rel proteins at the permissive temperature undergo apoptosis when cells are shifted to the nonpermissive temperature. The levels of most proteins (including v-Rel, p53, c-Myc, Rb and Bcl-2) do not change in these cells even at advanced stages of apoptosis. However, the chicken I kappa B-alpha protein (also called p40), which is in a complex with v-Rel in transformed cells, is degraded when ts v-Rel-transformed cells are shifted to the nonpermissive temperature. In v-R273H-transformed cells, p40 is degraded without the appearance of proteolytic intermediates. In contrast, in v-G37E-transformed cells, p40 is cleaved to an intermediate species that is missing approximately 3-4 kDa from its amino terminus. This truncated form of p40 is found in a detergent-insoluble fraction and can also be detected in wild-type v-Rel-transformed cells that are induced to undergo apoptosis by treatment with cycloheximide. Both ts v-Rel proteins are ts for interaction with p40 in vitro. The results reported here indicate that v-Rel blocks a normal pathway of programmed cell death and that I kappa B-alpha can undergo multiple degradative pathways, which can be induced by alterations in the structure of the Rel protein to which it is bound.

Animals↗

Some aspects of the causes of enhanced immune response of in vitro frozen ascites fibrosarcoma tumor cells in mice.

Estimation of 3 M KCl-extracted ascites fibrosarcoma (AFS) tumor cell membrane peripheral proteins in native and frozen tumor cells showed approximately a three-, four-, and fivefold increase per 1 x 10(6) cells of single-, three-, and programmed three-cycle frozen AFS tumor cells, respectively, compared to the same number of native cells, indicating an increase in surface membrane protein concentration with freezing. The 10% gel (homogeneous) electrophoretic (SDS-PAGE) study of 3 M KCl-extracted native and frozen cell membrane proteins showed (i) membrane proteins of native cells resolve into many more components compared to those of any frozen membranes, i.e., single, three, and programmed three cycle, the components decreasing in that order; (ii) the concentration of larger-molecular-weight protein fractions (> or = 75 kDa) decreases while those of smaller fractions (14 to 24 kDa) increase in frozen cells, with the maximum being in the programmed three-cycle frozen group. In contrast, the native cell membrane is rich in higher-molecular-weight proteins (> or = 75 kDa) with concentrations slowly decreasing toward lower-molecular weight fractions. Thus, the probable reasons for increased immune response of animals immunized with frozen AFS tumor cells are (i) absolute increase in cell surface protein concentrations as given by 3 M KCl extraction of cell membrane peripheral protein estimation in AFS tumor cells postfreeze; (ii) cell-surface protein pattern which is heterogeneous before freezing becomes relatively more homogeneous following freezing of AFS tumor cells; and (iii) depolymerization and breaking of higher-molecular-weight components which increase the concentration of terminal-sequence antigenic determinants and increase accessibility of determinant grouping by removing steric hindrance following freezing.

Animals↗

Affinity purification of human plasma vitamin D-binding protein.

During the course of our studies to probe the vitamin D ligand-binding domains of vitamin D-binding protein and vitamin D receptor, we developed a synthetic procedure to modify the 3 beta-hydroxyl group of vitamin D3 and its 25-hydroxy- and 1,25-dihydroxy metabolites with a 3'-aminopropylether group. In the present study we have coupled 25-hydroxyvitamin D3-3 beta-3'-aminopropylether to an activated Sepharose matrix. Using this stable and reusable affinity matrix we have purified human vitamin D-binding protein from human plasma to homogeneity.

Binding Sites↗

Use of OKT3 monoclonal antibody as induction therapy for control of rejection in liver transplantation.

This report details a single center's experience with OKT3 induction immunosuppression for liver transplantation. One hundred ninety-nine consecutive, unselected adult liver recipients received OKT3 therapy for 9-10 days combined with low-dose steroids and azathioprine. Cyclosporine was begun to overlap with the last few days of OKT3 therapy. The average dose of OKT3 was 45 mg. Fifty-two patients (26.1%) experienced 57 episodes of acute rejection. The median time of onset of rejection was 18 days after grafting. Seventy-eight percent of the rejection episodes were steroid-sensitive. Recurrent rejection was uncommon and the need for OKT3 retreatment was infrequent. One year actuarial graft and patient survival was 79.7% and 82.3% respectively. Based on this evidence, it appears that OKT3 prophylaxis provides good control of acute rejection with a very low incidence of recurrent rejection.

Acute Disease↗

Aminopropylation of vitamin D hormone (1 alpha,25-dihydroxyvitamin D3), its biological precursors, and other steroidal alcohols: an anchoring moiety for affinity studies of sterols.

In this communication we describe a simple two-step procedure for the conversion of several steroidal alcohols to their aminopropyl ether derivatives. To demonstrate the usefulness of this procedure we synthesized a second-generation photoaffinity labeling analog of 1 alpha,25-dihydroxyvitamin D3, and a 25-hydroxyvitamin D3 derivative containing a long and chemically stable tether. Utilities of these aminopropyl ether derivatives of steroids in various affinity studies of receptor proteins are discussed.

Alcohols↗