Biomedical subjects
Publications and source records attributed to R Ray.
The synthesis of 1 alpha,25-dihydroxyvitamin D3-3 beta-[N-(4-azido-2-nitro-[2,6-3H] phenyl)]glycinate, a radiolabeled photoaffinity analog of 1,25-dihydroxyvitamin D3, is described.
Clinical efficacy of buprenorphine in controlling withdrawal symptoms was compared against clonidine among 44 opiate dependent males. Subjective and objective withdrawal symptoms were assessed by withdrawal rating scales daily for 10 days. The subjects were randomly assigned to fixed dose schedule of either buprenorphine (0.6-1.2 mg per day, sublingually) or clonidine (0.3-0.9 mg per day, oral) for 10 days. Buprenorphine was found superior to clonidine in alleviating most of the subjective and objective opiate withdrawal symptoms. Subjective symptoms declined earlier among the subjects receiving buprenorphine. No untoward side-effects of buprenorphine were noticed.
Erythrocyte ALDH activity was assayed in alcoholic (n = 70) and nonalcoholic (n = 40) subjects. In general, alcoholics without any prior medications (n = 57) were found to have a decreased ALDH activity (mean +/- SD: 3.38 +/- 1.7 mU; p less than 0.001) as compared to control group (5.10 +/- 1.57 mU). However, a group of alcoholics who were detoxified with benzodiazepines (n = 13) prior to blood collection for enzyme assay were found to have higher ALDH activity (4.92 +/- 2.46 mU; p less than 0.05) as compared to alcoholics who were not detoxified. In vitro experiments demonstrated that both diazepam (DZM) and chlordiazepoxide (CDP) could activate the ALDH. The magnitude of enzyme activation by DZM and CDP appear to correlate with their relative potency of tranquilizing effect. Further, the observed ability of DZM to reverse the inhibition of ALDH mediated by disulfiram may explain the biochemical basis of the reported ability of benzodiazepines (BDZ) to reduce the intensity of disulfiram ethanol reaction (DER).
Highly specific binding of 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)) by vitamin D receptor (VDR), a nuclear transcriptional factor, activates a genomic mechanism that is manifested in the multiple biologic properties of 1alpha,25(OH)(2)D(3). Numerous synthetic analogs of 1alpha,25(OH)(2)D(3) have been employed to study the interaction between 1alpha,25(OH)(2)D(3) and VDR, and to identify structural markers in 1alpha,25(OH)(2)D(3) that are important for VDR-binding. On the other hand the three-dimensional structure of VDR remained elusive till very recently. In the present study we employed affinity labeling (by 1alpha,25-dihydroxyvitamin D(3)-3-bromoacetate, 1alpha,25(OH)(2)D(3)-3-BE) of VDR to identify C(288) as the anchoring residue for the 3-hydroxyl group of 1alpha,25(OH)(2)D(3) inside the ligand-binding domain of VDR (VDR-LBD). In addition we carried out mutation/hormone-binding analyses to determine the importance of M(284) and W(286) toward hormone binding. We incorporated this information with the three-dimensional structure of the LBD of progesterone receptor to develop a homology-extension model of VDR-LBD. This model identified several amino acid residues as ligand-contact points inside the LBD. Mutational and hormone-binding analyses of these residues verified the structure-functional authenticity of this model, in comparison with the crystal structure of VDR, bound to 1alpha,25(OH)(2)D(3).
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Cardiac myxoma is the commonest tumour of heart. The histogenesis of this lesion is controversial as its origin has often been debated between the thrombogenic and neoplastic theories. We analysed DNA ploidy and proliferation indices of 30 cardiac myxomas which include 25 sporadic and five familial cases by image cytometry and proliferating cell nuclear antigen immunostaining. Of the 25 cases, 18 were aneuploid, three diploid and four tetraploid. Four of the five familial cases including the recurrent lesions were aneuploid. Poor tissue preservation precluded ploidy analysis in one familial case. The proliferation index of the sporadic cases ranged from 0.4 to 36.1 percent. The familial cases showed proliferation index between 10.2 and 22 percent. In addition to cardiac myxoma, proliferation index was assessed in 10 cardiac thrombi where it ranged from three to 58 percent. This study suggests that cardiac myxoma can be best interpreted as a neoplasm with a slow growth potential.
Cardiac tumours are uncommon. Of these, myxomas have generated significant interest, not only because it is the commonest cardiac neoplasm but also because of controversial theories regarding its histogenesis. We encountered 78 cases of cardiac myxoma in our centre between 1976 and 1997. These included 73 sporadic cases and five cases from a single family of mother, daughter and son. The familial cases had recurrent, biatrial cardiac myxomas. Histopathologic analysis, immunohistochemical study, electron microscopic evaluation and DNA ploidy analysis done in some of these cases revealed evidence in support of the neoplastic nature of this entity. This communication sums up our observations and literature related to the histogenesis of cardiac myxoma.
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A 37-year-old female underwent heart transplantation for giant cell myocarditis. The patient died within three-and-a-half months of cardiac transplantation. Postmortem specimens from the heart and lung showed multiple necrotizing granulomas with numerous acid-fast bacilli. Polymerase chain reaction done on both the postmortem samples confirmed the presence of atypical mycobacterial infection. This fatal case of atypical mycobacteriosis in a cardiac transplant patient is reported for its rarity.
A 40-year-old man, a known case of Wolff-Parkinson-White syndrome, was admitted to the hospital in an unconscious state. In spite of medical treatment, the patient died within two hours of admission. At autopsy, the deceased was found to have aspergillosis involving the interatrial septum, aortic valve and root of the aorta. The rest of the organs were unremarkable. The patient did not show any obvious signs of being immunocompromised. We report this case of isolated cardiac aspergillosis in an apparently healthy individual.
Epithelial differentiation in cardiac myxoma is a rare phenomenon. Out of 104 surgically excised specimens, we studied 3 cases of cardiac myxoma with glandular differentiation. All the cases had well formed glands in addition to the myxoma cells lying in a myxoid background. Detailed histochemical and immunohistochemical studies suggest that the epithelial islands in cardiac myxoma show an enteric phenotype.
Intravenous injection of N-methyl-D,L-aspartic acid (NMDLA) into mice produces characteristic convulsions followed by death. The present study was designed to determine the degree of blockade of these seizures/mortality by compounds acting at various subsites on the N-methyl-D-aspartic acid (NMDA) receptor complex (competitive and noncompetitive antagonists, as well as inhibitors of the strychnine-insensitive glycine subsite, and Zn++ subsite agonists), and also calcium channel blockers, clinically used anticonvulsants, plus selected compounds with activities or structures similar to specific agents chosen. Activity among compounds was correlated to in vitro potency regarding inhibition of binding of MK801 to the ionic channel subsite associated with the NMDA receptor. Furthermore, all compounds were examined for antiseizure properties with respect to tonic hindlimb extension elicited by maximal electroshock (MES) and clonus induced by pentylenetetrazol (PTZ). Drugs were subsequently classified according to their spectra of efficacy in these tests. The following characteristics emerged: 1) agents active at all 3 NMDA mechanisms (convulsions/mortality/MK801 binding) plus MES and PTZ, were MK801 and CPP [3-(2-carboxypiperazin-4-yl) propyl-1-phosphonic acid]; 2) active at all the NMDA mechanisms and MES were ketamine and dextromethorphan; 3) active against NMDLA-induced convulsions/mortality, MES and PTZ, but not MK801 binding, were doxepin, desipramine and diazepam; 4) active against NMDLA-induced convulsions/mortality and MES were des-Me-doxepin, flunarizine and remacemide; 5) active against NMDLA-induced convulsions/mortality and PTZ was nisoldipine; 6) active against only NMDLA-induced convulsions/mortality were chlorpheniramine and iproniazid; 7) active in the MES and PTZ tests were phenobarbital, pentobarbital and valproate; 8) active in the MES test alone were phenytoin and carbamazepine; 9) active against PTZ only was ethosuximide; 10) active only in the in vitro MK801 binding assay were HA966, 7-Cl-kynurenate and AP7 (2-amino-7-phosphonoheptanoic acid); and 11) no demonstrable actions had AP4 (2-amino-4-phosphonobutyric acid) and mianserin. In conclusion, inhibition of NMDLA-induced convulsions/mortality in vivo is not necessarily correlated to a noncompetitive displacement of MK801 binding to NMDA receptor sites in vitro, nor is inhibition of NMDA-elicited convulsions/mortality correlated with a specific ability of a compound to inhibit either MES or PTZ seizures.
BACKGROUND: Histamine receptor antagonists have been shown to induce tumor-infiltrating lymphocytes (TILs) in colonic cancers and improve survival. The role of histamine receptor anatagonists in breast cancer is unclarified. AIM: To evaluate the role of histamine receptor antagonists in inducing (TILs) in breast cancer. METHOD: Forty-five patients with operable breast cancers (25 cases who received preoperative famotidine and 20 controls) were studied for the effect of famotidine in inducing TILs and survival in breast cancer. RESULTS: Significant TILs were seen in 75% (18/24) of cases as opposed to 35% (7/20) controls. In logistic regression analysis the only variable found to be predictive of TILs was famotidine, odds ratio 7.324 (1.693-31.686) P=0.008. In Cox's regression presence of TILs was favorably associated with improved disease free survival at a median follow up of 35.56 months. The hazard ratio for disease relapse was 3.327 (1.174-9.426) P=0.024 in TIL negative as compared to TIL positive patients. Famotidine use alone was not significant in the original model, however, on incorporation of quadrant of involvement in addition to other established prognostic factors in the above multivariate model, it assumed borderline significance with a hazard ratio for disease free survival 3.404 (1.005-11.531, P=0.049). CONCLUSIONS: Preoperative short course famotidine induces TILs in breast cancer. Patients with TILs demonstrable in tumor specimens had an improved disease free survival. Famotidine may improve disease free survival in breast cancer and these findings need validation in larger population subsets.
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