Search PubMed⌕ Search

Biomedical subjects

V Kumar

Publications and source records attributed to V Kumar.

At least 703 records · Page 39Linked to original sources
PubMed1986

Placental transfer and fetal distribution of 3H-retinoic acid in rats.

The placental transfer of 3H-retinoic acid in vitamin A deprived and vitamin A supplemented pregnant female rats was studied on 20th day of gestation and compared with 3H-retinyl acetate. Radiolabelled compounds were administered to pregnant mothers orally in groundnut oil six hours before sacrifice. The distribution of radioactivity of the two compounds was studied in maternal intestine, liver and plasma and fetal brain, heart liver lung and placenta. The transfer of 3H-retinoic acid across placenta was restricted as compared to that of 3H-retinyl acetate which may explain the reason why retinoic acid does not support fetal growth.

Animals↗
PubMed1986

Carry-over effects of long and short photoperiods on body fattening and gonadal weight of blackheaded bunting (Emberiza melanocephala).

A study was made of the carry-over effect of long photoperiods followed by short photoperiods ou the fattening and gonadal response in a photoperiodic migratory species, the Blackheaded Bunting (Emberiza melanocephala). The effect was studied in photosensitive and then in photostimulated birds. Two experiments were performed: experiment I with photosensitive males and experiment II with photosensitive males exposed to 30 long photoperiods. In both of them, five groups were submitted to the following treatments for 30 days: Group S, a short daily photoperiod; Group L, a long daily photoperiod; Group LS, alternating long and short daily photoperiods; Group L 2S, one long with two short daily photoperiods; Group L 3S, one long with three short daily photoperiods. The results showed that the inductive effect of long days or the inhibitory effect of short days was affected by intervening reversed daylengths.

Adipose Tissue↗
PubMed1986

Turnover of pancreas phospholipids in rats fed inadequate dietary protein.

Effect of feeding rice diets with and without lysine and threonine supplementation has been studied on phospholipid turnover of rat pancreas and compared to rats fed casein diet at 20% protein level. Rice diet without amino acid supplementation significantly reduced the levels of pancreas PC, PE, PI, PS and Sph and increased that of total cholesterol and TG. Incorporation of palmitate-1-14C, labelled choline, labelled methionine and NaH2(32)PO4 into PC and of palmitate-1-14C into TG was significantly reduced in rats fed unsupplemented rice diet. Incorporation of NaH2(32)PO4 into pancreas PI, DPI, TPI, PA, LPA and into IP, IP2', IP3 and GPI was significantly reduced in rats fed unsupplemented rice diet.

Animals↗
PubMed1985

Trypsin-resistant forms of human growth hormone have diabetogenic and insulin-like activities.

Although diabetogenic and insulin-like activities are intrinsic properties of the growth hormone (GH) molecule, it has been frequently suggested that the hormone must be proteolytically processed for these activities to be expressed. If this is correct, then derivatives of GH having resistance to appropriate proteolytic attack might not have diabetogenic and/or insulin-like activity. The purpose of the present study was to prepare derivatives of human GH that are resistant to digestion by trypsin and to determine whether they possess diabetogenic or insulin-like activity. Three derivatives were prepared from purified native human GH in which lysine residues were modified with methyl acetimidate, citraconic anhydride or S-ethyl-thioltrifluoroacetate, and one in which arginine residues were modified with camphorquinone-10-sulfonic acid. Comparisons of peptide maps of tryptic digests of these derivatives with that of unmodified human GH indicated that all four were resistant to proteolysis by trypsin. All of these trypsin-resistant forms of human GH were found to possess significant growth-promoting, diabetogenic and insulin-like activities, although all activities were attenuated to some extent in each derivative. The relative potencies of the human GH derivatives in a radioimmunoassay for human GH were somewhat similar to their order of potency in the growth-promoting and diabetogenic assays. These results suggest that if proteolytic processing of the GH molecule is involved in the expression of one or more of its biological activities, such processing probably does not involve a trypsin-like proteinase.

Adipose Tissue↗
PubMed1985

Systemic absorption and cardiovascular effects of phenylephrine eyedrops.

We studied 24 patients undergoing vitreoretinal surgery to compare the systemic absorption and cardiovascular effects of 2.5% aqueous and 10% viscous ophthalmic solutions of phenylephrine hydrochloride. Plasma levels measured in patients receiving two drops of 10% viscous solution were consistently higher ten, 20, and 60 minutes after instillation (P less than .02). Although the mean systolic and diastolic blood pressure was generally higher with the 10% viscous solution, the difference was not statistically significant. Blood pressure was high in several isolated cases. Because maximum plasma levels are achieved within ten to 20 minutes after topical instillation, phenylephrine eyedrops should be administered under close observation so that if an adverse reaction occurs it can be readily treated.

Absorption↗
PubMed1985

Evaluation of methods for detection of anticentromere antibodies and other antinuclear antibodies.

Our immunologic studies of twenty-five patients with acrosclerosis with severe acral involvement, twenty-seven patients with most or all of the signs of CREST syndrome, twenty-two patients with systemic lupus erythematosus as positive controls, and ninety-one blood donors as negative controls centered on an evaluation of eight antigenic substrates, including four types of human cells for the detection of anticentromere antibodies (ACA) and other antinuclear antibodies (ANA). The ACA, which occurred only among the patients with most or all of the signs of CREST syndrome, could be detected reliably on human cell lines HEp-2 and KB but not on a mouse cell line or on the three types of tissue sections examined. Comparisons of human HEp-2 and KB cell lines from four sources indicated that HEp-2 cells are the best of the substrates tested for detection of ACA. Since rodent tissue sections give negative reactions with ACA, they are indicated for confirmation. In general, results varied with the type and source of antigen used. Thus ANA findings need to be expressed not only in terms of the titers of the antibodies and the pattern(s) of their reactions but also in terms of the type of antigen or substrate used, its source, and the diagnostic significance of findings in the given test system.

Animals↗
PubMed1985

Temazepam in fast dispensing dosage form as a premedication for children.

Forty-seven children aged between four and 11 years received temazepam 0.5 mg/kg in a novel fast dispensing dosage form. The preparation was well accepted and associated with few side-effects. Satisfactory sedation and anxiolysis was obtained in over 93% of patients. The relative merits of a variety of routes of administration of premedicant drugs for children are discussed and the advantages of buccally administered formulations for this age group are presented.

Administration, Oral↗
PubMed1985

Anticentromere antibody: an immunological marker of a subset of systemic sclerosis.

Our clinical and immunological studies of 114 cases of systemic sclerosis, 54 of Raynaud's disease and 46 of other connective tissue diseases, centered on the diagnostic and prognostic significance of anticentromere antibodies (ACA). The ACA occurred in 21 of 84 patients with acrosclerosis, in four of 54 patients with Raynaud's disease but in none of 30 patients with diffuse scleroderma or transitional form, acrosclerosis-diffuse scleroderma, or 46 cases of other connective tissue diseases. The ACA-positive patients had no contracture or immobilization of the fingers, the indurations and/or indurative oedema were confined to fingers and usually no other types of ANA were detected. However, systemic involvement and the course of the disease were comparable in ACA-negative and ACA-positive acrosclerosis patients. The studies indicate that there is a subset of acrosclerosis with minimal indurations confined to the fingers, and ACA appears to be its serological marker. We propose to use the term CREST for this subset, which to date has not been exactly defined and is regarded by some authors as synonymous with acrosclerosis.

Adult↗
PubMed1985

Linear IgA bullous dermatosis. An immunologically defined disease.

Linear IgA bullous dermatosis (LABD) can mimic bullous pemphigoid (BP) and/or dermatitis herpetiformis (DH) both clinically and histologically. LABD, however, can be distinguished from BP and DH by direct immunofluorescent (IF) demonstration of linear IgA deposits along the basement membrane zone. A retrospective study of 234 cases of BP, 27 cases of LABD, 60 cases of DH, and 20 cases of cicatricial pemphigoid (CP) revealed that BP patients are significantly older than LABD or DH patients and LABD patients are significantly older than DH patients. BP and CP occur more frequently in women (65-70%) than LABD or DH (44-48%). The frequencies of C3 deposits in the basement membrane zone (BMZ) are significantly higher in BP (85%) compared with LABD (18.5%) and DH (28.3%). LABD patients varied in their response to various therapeutic agents. Some responded to corticosteroids and some to sulfones alone, whereas others required a combination of corticosteroids and sulfones.

Adolescent↗
PubMed1985

Thyroid disease in patients with dementia of the Alzheimer type.

The authors compared the frequencies of prior thyroid disease, thyroid medication use, and abnormal serum thyroxine levels in 61 patients with dementia of the Alzheimer type (DAT) with those of 38 control subjects. They found that the 33 women with DAT had a 24.2% frequency of prior thyroid disease, comparable with that found in a previous epidemiologic study. The 19 female controls, however, had a similar frequency, failing to support a previously reported association between DAT and thyroid disease.

Aged↗
PubMed1985

Specificity of the Crithidia luciliae method for detecting anti-DNA antibodies. Effect of absorption for lipoproteins.

Using the immunofluorescent (IF) assay with Crithidia luciliae smears, anti-native (n) DNA antibodies were detected in the sera of 12 of 20 systemic lupus erythematosus (SLE) patients, in 1 of 6 mixed connective tissue disease cases, in 2 of 38 patients with systemic sclerosis but in none of the sera from 96 normal subjects. All anti-nDNA antibodies were associated with antinuclear antibodies (ANA). However, occasionally sera were encountered in routine screening which appear to be positive for anti-DNA antibodies but negative for ANA. Studies of such sera indicate that this is a nonspecific reaction which can be abolished by treating sera with dextran sulfate or heparin. Treatment of SLE sera with these agents had no effect on their anti-nDNA antibody activity. Absorption of sera with Aerosil eliminated the false positive reactions with C. luciliae; however, this treatment also removed immunoglobulins, ANA and anti-nDNA antibodies. Evidence is reviewed which points to a role of complexes of low density lipoprotein and IgG in the nonspecific binding reactions with C. luciliae which is seen as false positive reactions for anti-nDNA antibodies.

Adsorption↗
PubMed1985

Stimulation of genetic resistance to marrow grafts in mice by interferon-alpha/beta.

Lethally irradiated mice were infused with syngeneic, H-2 allogeneic, parental strain, or H-2 heterozygous bone marrow cells. They were injected daily with rabbit anti-mouse interferons (IFN)-alpha/beta or gamma or with IFN-alpha/beta. The growth of donor-derived cells was judged 5 days later by measuring splenic incorporation of 5-iodo-2'-deoxyuridine-125I into DNA. Antibodies to IFN-alpha/beta, but not to IFN-gamma, weakened genetic (both hybrid and allogeneic) resistance to marrow cell grafts. IFN-alpha/beta stimulated hybrid and allogeneic resistance, the latter even in genetically "poor responder" mice. Mice pretreated with silica, which weakens genetic resistance, were stimulated by IFN-alpha/beta to resist incompatible marrow cell grafts; however, IFN-alpha/beta failed to reverse the effects of antiasialo GM1 serum on marrow graft rejection. IFN-alpha/beta did not inhibit the growth of syngeneic marrow cells and did not stimulate resistance to H-2 heterozygous bone marrow cells. We propose that genetic resistance occurs in two discrete steps. In the first step, hemopoietic histocompatibility (Hh) antigens are recognized by one host cell type, and this recognition leads to IFN-alpha/beta secretion by a silica-sensitive cell. In the second step, asialo GM1-positive natural killer cells stimulated by IFN-alpha/beta recognize Hh antigens on marrow stem cells and cause rejection. The defects in resistance observed in genetically poor responder mice and in mice treated with silica appear to involve the first step in recognition. The lack of rejection of H-2 heterozygous (Hh-) marrow cells by parental strain mice injected with IFN-alpha/beta indicated that specific Hh recognition is critical in the second step of genetic resistance.

Animals↗