Biomedical subjects
Publications and source records attributed to R Roy.
The prospect of surgery normally evokes anxiety, which, given the idiosyncracies of human nature, will be experienced differently by different individuals. This article examines some of the theoretical considerations of stress in general, proceeds to a discussion of stress as it is experienced by patients facing surgery, then examines the clinical application and benefits of psychological preparation of surgical patients.
Explore the source record for details and available documents.
Anti-B cell, anti-T cell, and antiperipheral blood lymphocyte antibodies were investigated in the sera from 115 cadaveric kidney graft recipients pre- and post-transplantation. These antibodies were characterized: optimal temperature for cytotoxicity (4 C or 22 C), immunoglobulin class (IgG or IgM), and reactivity after platelet absorption, and thereafter defined according to their influence on the graft survival. Patients with IgM anti-B cell antibodies, reacting mostly at 4 C, the activity of which could not be removed by platelet absorption, have a prognosis of the graft as good as those with no antibody, i.e., the graft function (serum creatinine and severity of rejection) at 3 years was comparable between those two groups. However, when the anti-B cell antibodies unabsorbable on platelets are of IgG class and detected at 4 C and 22 C, the graft outcome is poorer (P less than 0.025 at 3 months). A similar prognosis is observed in patients with antiperipheral blood lymphocyte antibodies of IgG or IgM class, absorbable or not on platelets (P less than 0.05). Lymphocytotoxic antibodies of the IgG class are always associated with a poor graft outcome. On another hand, the cold anti-B cell antibodies of the IgM class are not associated with graft failure but no enhancing effect could be seen.
The presence of cross-reactive (CR) antigens of the HLA-A and B specificities between donor and recipient carries a better graft outcome than an HLA match not taking it into account. This influence of CR antigens has been observed in the case of cadaver kidneys matched only for none or one HLA antigen. If two or more antigens are matched this effect is not seen anymore. This improved graft survival could not be explained on the basis of the number of transfusion nor the incidence of cytotoxic antibodies.
Explore the source record for details and available documents.
A simple, rapid, sensitive, and reliable ELISA test for the detection of urinary human chorionic gonadotropin (hCG) has been developed using penicillinase (EC no. 3.5.2.6) as the label and a microtiter ELISA plate as a solid support for antibody. The results of the test is assessed visually for the dark blue that indicates the presence of hCG. A minimum of 500 mU of hCG/ml of urine can be detected easily and the test can be completed in 2 hours with good precision. Accurate negative results are obtained in urine samples of normally ovulatory women, postmenopausal women, and adult males, suggesting that the physiologic concentrations of luteinizing hormone do not influence the assay results. In samples referred for pregnancy detection 95.5% accurate results were obtained when compared with histopathologic and/or clinical findings. There were 2 false-negative results, and only in 4 of 132 subjects studied were false-positive results obtained. This test, if properly performed, should prove a valuable tool in the detection of hCG as early as 30 to 35 days from the last menstrual period.
The effect of a mild weight-lifting program on the progress of glucocorticoid-induced atrophy was investigated. Groups of rats were either injected daily for 6 weeks with triamcinolone acetonide, 1 mg/kg (group S), subjected to a weight-lifting program 4 times per week (group T), or subjected to the injection and weight-lifting programs concurrently (group ST). The training program, besides decreasing the normal body weight gain of control (group C) rats, had no effects on gastrocnemius and soleus muscles. In group ST, the extent of gastrocnemius atrophy was less severe than in group S, and the mean areas of all fiber types were greater in similar proportion. Gastrocnemius muscles were also tetanically stronger (g, g/g body weight) in group ST than group S. The soleus muscles of groups ST and S were similar in all indices of size and strength, except for a significantly decreased fast-twitsch-oxidative-glycolytic (FOG) mean fiber area in the ST seleus muscles. The extent of fast-twitsch muscle atrophy resulting from chronic glucocorticoid treatment can be lessened by mild weight-lifting exercise. Differences in fiber area responses between soleus and gastrocnemius may reflect recruitment and/or metabolic differences of similar fiber types in the two muscles.
Explore the source record for details and available documents.
Bronchopneumonia was observed at the necropsy of a North Atlantic pilot whale (Globicephala melaena). The areas of necrosis were well circumscribed clusters, disseminated throughout the left lung. Streptococcus equi was isolated in pure culture from the lung parenchyma, pharynx and pericardial fluid.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Partially purified Met-tRNAf binding factor, eIF-2, was phosphorylated by using heme-regulated inhibitor (HRI). Phosphorylated eIF-2 was freed from HRI by phosphocellulose column chromatography. Analysis by isoelectric focusing showed 100% phosphorylation of the 38,000-dalton subunit of eIF-2. Both eIF-2 and eIF-2(P) formed ternary complexes with Met-tRNAf and GTP with almost the same efficiency, and in both cases the ternary complex formation was drastically inhibited by prior addition of Mg2+. However, whereas the ternary complexes formed with eIF-2 could be stimulated by Co-eIF-2C at 1 mM Mg2+ and dissociated by Co-eIF-2B at 5 mM Mg2+, the ternary complexes formed with eIF-2(P) were unresponsive to both Co-eIF-2B and Co-e-IF-2C. Also, under conditions of eIF-2 phosphorylation, HRI drastically inhibited AUG-dependent Met-tRNAf binding to 40S ribosomes. However, HRI (in the presence of ATP) had no effect on the joining of preformed Met-tRNAf . 40S . AUG complex to the 60S ribosomal subunit to form Met-tRNAf-80S . AUG complex. These studies suggest that HRI inhibits protein synthesis initiation by phosphorylation of the 38,000-dalton subunit of eIF-2. HRI-phosphorylated eIF-2 does not interact with at least two other protein factors, Co-eIF-2B and Co-eIF-2C, and is thus inactive in protein synthesis initiation.
The presence of a dioxaspiro or a fused bicyclic ring system resulting from a diastereoselective intramolecular acetalization of keto diol or keto alcohol units respectively, is a unique structural feature among a number of biologically important natural products. The particular bond arrangement around the ketal carbon atom is, in part, a reflection of the preference for anomeric stereoselection in nature, either at the site of acetalization or in its vicinity. This phenomenon manifests itself in the constitutional structures of several ionophores (polyether type), in the antibiotic spectinomycin as well as other natural products. Synthetic efforts in this area will be discussed, with particular emphasis on spectinomycin as a challenging target.
The peptide chain initiation factor, Co-EIF-1 has been purified to homogeneity. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the homogeneous preparation gives a single protein band corresponding to a molecular weight of approximately 20,000. In the crude preparation, Co-EIF-1 exists in two molecular forms: Co-EIF-1H (Mr = 200,000) and Co-EIF-1L (Mr = 20,000). Both forms are equally active in all the reactions studied. Upon heating, the heavy form (Co-EIF-1H) is completely converted into the light form (Co-EIF-1L). Radioactively labeled [14C]Co-EIF-1 was prepared by reductive alkylation using [14C]formaldehyde and borohydride. [14C]Methyl-Co-EIF-1 binds specifically to EIF-1; EIF-1.[14C]Co-EIF-1 complex was analyzed by gel (Sephadex G-100) filtration. EIF-1.Co-EIF-1 complex is distinctly more stable towards heat than EIF-1 alone and the quarternary complex, Met-tRNAf.EIF-1.Co-EIF-1.GTP is more resistant to aurintricarboxylic acid than the ternary complex, Met-tRNAf.EIF-1.GTP. Both the quarternary complex, Met-tRNAf.EIF-1.Co-EIF-1.GTP, and the ternary complex, Met-tRNAf.EIF-1.GTP, are equally sensitive to Mg2+ in the presence of EIF-2 (TDF). In the presence of Co-EIF-1, the initial rate of Met-tRNAf binding to 40 S ribosomes was significantly increased.
Explore the source record for details and available documents.