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Biomedical subjects

M M Reddy

Publications and source records attributed to M M Reddy.

At least 55 records · Page 3Linked to original sources
PubMed1992

Evidence of two distinct epithelial cell types in primary cultures from human sweat gland secretory coil.

The human sweat gland secretory coil (SC) is comprised of myoepithelial (ME) and two types of secretory epithelial cells. The secretory cells include beta-adrenergic-sensitive (beta-S) cells [responsive to the beta-adrenergic agonist isoproterenol (IPR)] and beta-adrenergic insensitive (beta-I) cells. We have grown segments of SC in primary culture and found that under the conditions described here, only epithelial cells form outgrowths as indicated by morphological and physiological properties. As in the native SC epithelium, the secretory cells in primary culture were comprised of polygonal epithelial cells with a characteristic hyperpolarization of cell potentials (Vm) to cholinergic stimulation by mecholyl (magnitude of change of Vm = delta Vm = 21.5 +/- 1.3 mV, mean +/- SE, n = number of cells = 44). We have found both beta-S and beta-I cells as determined by unstimulated membrane potentials, sensitivity to IPR, and K+ conductance (GK+). The frequency distribution of unstimulated cells indicated two distinct populations of cells, one with high membrane potentials (Vm = -63 +/- 2.6 mV), which correlated with beta-S cells, and a second with low membrane potentials (Vm = -22 +/- 1.5 mV), which correlated with the beta-I cells. IPR depolarized the Vm of beta-S cells (delta Vm = 11.0 +/- 0.8 mV, n = 25) without affecting the Vm of beta-I cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1992

Circulating elevated levels of soluble CD23, interleukin-4, and CD20+CD23+ lymphocytes in atopic subjects with elevated serum IgE concentrations.

Circulating IgE protein levels, leukocyte counts, lymphocyte subsets, IL-4, and soluble CD23 levels were quantitated in 43 atopic and 19 nonatopic subjects. Mean values of IgE protein levels, total eosinophil counts, CD20+CD23+ cells (B cells with low-affinity IgE receptor), IL-4 and sCD23 levels were elevated in atopic patients compared with nonatopic controls. The results suggest that sCD23, IL-4, and CD20+CD23+ lymphocytes may play a role in the increased production of IgE in atopic subjects in a manner similar to that observed by other investigators in prior in vitro studies.

Adult↗
PubMed1991

Quantitative changes in T helper inducer (CD4+ CD45RA-), T suppressor inducer (CD4+ CD45RA+), T suppressor (CD8+ CD11b+), and T cytotoxic (CD8+ CD11b-) subsets in human immunodeficiency virus infection.

To determine changes in subsets of CD4 and CD8 in relation to HIV infection and progression to AIDS, we quantitated peripheral blood lymphocytes obtained from 17 heterosexual controls, 22 asymptomatic HIV-seronegative and 18 HIV-seropositive intravenous drug users. 50 patients with AIDS-related complex (ARC), and 9 patients with AIDS using an EPICS "C" flow cytometer by two-color analysis. Both T helper inducer (CD4+ CD45RA-) and suppressor inducer (CD4+ CD45RA+) lymphocytes were decreased significantly in patients with ARC or AIDS. In contrast, T cytotoxic (CD8+ CD11b-) cells were significantly increased and accompanied by a significant decrease in the T suppressor (CD8+ CD11b+) subset in patients with ARC or AIDS. These results suggest that both T helper inducer and T suppressor inducer subsets of the CD4+ population and the T suppressor subset of CD8+ are depleted after HIV infection, while the T cytotoxic subset of CD8+ was increased after HIV infection.

AIDS-Related Complex↗
PubMed1991

Evaluation of HIV P24 antigen, beta 2-microglobulin, neopterin, soluble CD4, soluble CD8, and soluble interleukin-2 receptor levels in patients with AIDS or AIDS-related complex treated with 2',3'-dideoxyinosine (ddI).

Circulating HIV P24 antigen, beta 2-microglobulin, neopterin, soluble CD4, soluble CD8, and soluble interleukin-2 receptor were measured in 13 zidovudine-intolerant patients (8 with ARC and 5 with AIDS) treated with dideoxyinosine (ddI). Measurements were made at baseline and at several intervals during therapy. Mean levels of HIV P24 antigen decreased early and significantly (P less than 0.01) after 2 weeks of ddI administration and remained low at weeks 8 and 12. In addition, mean SCD8 levels decreased late and significantly (P less than 0.02) after 16 weeks of ddI treatment and remained low at 24 weeks. In contrast, ddI administration had no substantial effect on mean levels of beta 2-microglobulin, neopterin, soluble CD4, and soluble interleukin-2 receptor. ddI administration appears to have been associated with early reduction of HIV P24 antigen levels and later reduction of SCD8 mean levels in these patients.

AIDS-Related Complex↗
PubMed1991

Intracellular potassium activity and the role of potassium in transepithelial salt transport in the human reabsorptive sweat duct.

We have measured the intracellular potassium activity, [K+]i and the mechanisms of transcellular K+ transport in reabsorptive sweat duct (RSD) using intracellular ion-sensitive microelectrodes (ISMEs). The mean value of [K+]i in RSD is 79.8 +/- 4.1 mM (n = 39). Under conditions of microperfusion, the [K+]i is above equilibrium across both the basolateral membrane, BLM (5.5 times) and the apical membrane, APM (7.8 times). The Na+/K+ pump inhibitor ouabain reduced [K+]i is insensitive to the Na+/K+/2 Cl- cotransport inhibitor bumetanide in the bath. Cl- substitution in the lumen had no effect on [K+]i. In contrast, Cl- substitution in the bath (basolateral side) depolarized BLM from -26.0 +/- 2.6 mV to -4.7* +/- 2.4 mV (n = 3; *indicates significant difference) and decreased [K+]i from 76.0 +/- 15.2 mM to 57.7* +/- 12.7 mM (n = 3). Removal of K+ in the bath decreased [K+]i from 76.3 +/- 15.0 mM to 32.3 +/- 7.6 mM (n = 4) while depolarizing the BLM from -32.5 +/- 4.1 mV to -28.3* +/- 3.0 mV (n = 4). Raising the [K+] in the bath by 10-fold increased [K+]i from 81.7 +/- 9.0 mM to 95.0* +/- 13.5 mM and depolarized the BLM from -25.7 +/- 2.4 mV to -21.3* +/- 2.9 mV (n = 4). The K+ conductance inhibitor, Ba2+, in the bath also increased [K+]i from 85.8 +/- 6.7 mM to 107.0* +/- 11.5 mM (n = 4) and depolarized BLM from -25.8 +/- 2.2 mV to -17.0* +/- 3.1 mV (n = 4). Amiloride at 10(-6) M increased [K+]i from 77.5 +/- 18.8 mM to 98.8* +/- 21.6 mM (n = 4) and hyperpolarized both the BLM (from -27.5 +/- 1.4 mV to -46.0* +/- 3.5 mV, n = 4). However, amiloride at 10(-4) M decreased [K+]i from 64.5 +/- 0.9 mM to 36.0* +/- 9.9 mM and hyperpolarized both the BLM (from -24.7 +/- 1.4 mV to -43.5* +/- 4.2 mV) and APM (from -18.3 +/- 0.9 mV to -43.5* +/- 4.2 mV, n = 6). In contrast to the observations at the BLM, substitution of K+ or application of Ba2+ in the lumen had no effect on the [K+]i or the electrical properties of RSD, indicating the absence of a K+ conductance in the APM.(ABSTRACT TRUNCATED AT 400 WORDS)

Amiloride↗
PubMed1991

Light-enhanced dark respiration in mesophyll protoplasts from leaves of pea.

The respiratory oxygen uptake by mesophyll protoplasts of pea (Pisum sativum cv Arkel) was stimulated up to threefold after 15 minutes of illumination at an intensity of 1250 microeinsteins per square meter per second in the presence of 5 millimolar bicarbonate at 30 degrees C. The extent of light-enhanced dark respiration (LEDR) increased progressively with duration of preillumination. The LEDR exhibited two phases. The initial high rate of respiration decreased in about 10 minutes to a lower steady value similar to that before illumination. The promotion of LEDR by the presence of bicarbonate and inhibition by glyceraldehyde or 3-(3,4-dichlorophenyl)-1,1-dimethylurea suggested that LEDR was dependent on products of photosynthetic carbon assimilation/electron transport. Thus, the photosynthetic products exert a markedly quick influence on dark respiration in mesophyll protoplasts.

Journal Article↗
PubMed1991

Human immunodeficiency virus type-1 infection of homosexual men is accompanied by a decrease in circulating B cells.

As part of the multidisciplinary effort to characterize the natural history of human immunodeficiency virus type 1 (HIV-1) infection, the cell-surface phenotypes of lymphocytes from a cohort of homosexual men were analyzed in detail and related to clinical and laboratory parameters associated with HIV-1 infection. The present study represents a cross-sectional analysis of coded specimens from 153 homosexual men, of whom 74 were seronegative and 79 seropositive for HIV-1. Fewer circulating B lymphocytes (CD19+) were found in HIV-1-seropositive subjects relative to a seronegative reference group. HIV seropositivity was not associated with decreased numbers of CD8+ T cells or activated T cells, which suggests that the number of circulating B cells specifically decreased. In addition to CD19, B cells were measured by CD20 and CD21 in a subset of subjects, and decreases in circulating CD20+ and CD21+ B cells were also apparent in HIV-1-seropositive subjects. The decrease in B-cell numbers was present at the earliest stages of HIV-1 infection (asymptomatic, clinically silent) and became more pronounced at more advanced stages of HIV-1 infection. The absolute B-cell numbers correlated with absolute CD4+ cell numbers (r = 0.59, p less than 0.001). These data suggest that HIV-1 infection is associated with progressive, selective decreases in the numbers of circulating CD4+ T cells and B cells.

Antigens, CD↗
PubMed1990

Elevated levels of circulating immune complexes in human immunodeficiency virus infection.

Circulating immune complexes were quantitated in asymptomatic intravenous drug abusers (IVDA), male homosexuals, and patients with lymphadenopathy or acquired immunodeficiency syndrome (AIDS) by two different methods. Circulating immune complexes were elevated in HIV-seronegative IVDAs and male homosexuals, probably reflecting viral infections such as cytomegalovirus (CMV). Circulating immune complexes were also elevated in HIV-seropositive IVDAs and male homosexuals and in patients with lymphadenopathy or AIDS, reflecting infections such as CMV and HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Effect of azidothymidine on soluble CD4 levels in patients with AIDS or AIDS-related complex.

Circulating soluble CD4 (sCD4) levels were measured in 20 patients (11 with the acquired immunodeficiency syndrome [AIDS] and 9 with AIDS-related complex [ARC]) treated with azidothymidine (AZT) and in 12 patients (nine with AIDS and three with ARC) who were in the placebo group. The mean CD4 level in the AZT treatment group at baseline was 41 +/- 12 (SEM) U/ml. After 4 wk of treatment, the mean level decreased to 23 +/- 5; it was 29 +/- 10, 31 +/- 14, and 21 +/- 5 at 8, 12, and 16 wk of therapy, respectively. No significant changes were observed in the placebo group. These results suggest that AZT administration may be associated with reduced sCD4 levels in these patients.

AIDS-Related Complex↗
PubMed1990

Natural killer cell activity in a longitudinal dietary fat intervention trial.

It has been hypothesized that dietary fat may affect natural killer (NK) cell activity, a factor of potential importance in early tumor surveillance. Fourteen men successfully completed an intervention trial designed to test the effect of dietary fat on NK activity in humans. Study subjects lowered their fat intake to an average of 22% of calories as fat and consumed two dietary supplements (of coconut and safflower oils), in a cross-over design. These supplements resulted in large changes in the ratio of polyunsaturated to saturated fatty acids (1.73 to 0.34, on average). Results of a general linear model in which we fitted covariates on exercise, body mass, intervention sequence, and various dietary predictors revealed a significant effect of decreased total dietary fat intake on increased NK activity at an E/T ratio of 100:1 (about 0.79% increase for each absolute percent of calories as fat, P = 0.04). Similar results were obtained at E/T ratios of 50:1 and 25:1. No other nutritional predictor was significantly associated with NK activity at any E/T ratio.

Adult↗
PubMed1990

Effect of azidothymidine (AZT) on HIV P24 antigen, beta 2-microglobulin, neopterin, soluble CD8, soluble interleukin-2 receptor and tumor necrosis factor alpha levels in patients with AIDS-related complex or AIDS.

Circulating HIV P24 antigen, beta 2-microglobulin, neopterin, soluble CD8, soluble interleukin-2 receptor and TNF alpha levels were measured in 20 patients (9 with ARC and 11 with AIDS) treated with azidothymidine (AZT) and in 12 patients (3 with ARC and 9 with AIDS) who were in a placebo group. Mean levels of HIV P24 antigen, beta 2-microglobulin, neopterin and SCD8 decreased significantly (P less than 0.05) after 12 to 16 weeks of AZT administration. SIL-2R and TNF alpha serum levels did not appear to change in association with AZT therapy. No changes were observed in the placebo group except that TNF alpha levels appeared to increase after 12 to 16 weeks. These results suggest that AZT administration may have led to reduced HIV P24 antigen, beta 2-microglobulin, neopterin and SCD8 mean levels in these patients.

AIDS-Related Complex↗
PubMed1990

Elevated levels of CD4 antigen in sera of human immunodeficiency virus-infected populations.

CD4 antigen levels in sera from asymptomatic intravenous drug users and homosexuals and patients with lymphadenopathy, acquired immunodeficiency syndrome-related complex, or acquired immunodeficiency syndrome were quantitated. Like soluble CD8, CD4 antigen levels were elevated in human immunodeficiency virus-seronegative asymptomatic intravenous drug users and homosexuals, probably reflecting infections such as cytomegalovirus, Epstein-Barr virus, and hepatitis B virus infections. The sera from human immunodeficiency virus-seropositive groups of patients with human immunodeficiency virus infection also had elevated levels of CD4 antigen, presumably reflecting infections like cytomegalovirus and human immunodeficiency virus infections.

AIDS-Related Complex↗
PubMed1989

Effect of azidothymidine (AZT) on P24 antigen levels in patients with AIDS-related complex and AIDS.

Circulating HIV P24 antigen levels at baseline and following AZT therapy were measured in 9 patients with ARC and 11 patients with AIDS. Eight of these patients had no detectable levels of P24. The P24 antigen levels in the remaining 12 patients decreased significantly after AZT treatment. Following discontinuation of AZT treatment in 2 patients, the P24 antigen levels went up. These results clearly demonstrate the efficacy of AZT in reducing P24 antigen levels in circulation.

AIDS-Related Complex↗
PubMed1989

Dietary fat and natural-killer-cell activity.

An intervention trial designed to lower the amount of fat in the diet was conducted to test the effect of reduced fat consumption (LF diet) on activity of natural killer (NK) cells in humans. Of 26 men enrolled initially, 17 successfully completed the intervention and lowered their fat intake to less than 30% of calories as fat. Data were analyzed in two ways. The paired t test showed a marked increase in NK-cell activity from baseline to the end of the LF-diet intervention (t = 4.77, p = 0.0002). Results of a general linear model showed an effect of lowering total dietary fat on increased NK-cell activity (approximately 0.53% increase for each absolute percent of calories as fat, p = 0.14) for all men and a highly significant effect in a subset of men who ate greater than 25% of calories as fat at baseline (approximately 1.22% increase, p = 0.009). These results were obtained after changes in total caloric intake, weight, exercise, and other fat-related covariates were accounted for.

Adult↗
PubMed1989

Cross-sectional study of immunologic abnormalities in intravenous drug abusers on methadone maintenance in New York City.

One hundred and ninety-nine patients with a history of intravenous drug abuse, and enrolled on the St Luke's-Roosevelt Hospital Center Methadone Program, had baseline evaluations performed from September 1984 to April 1987. The study was designed to examine immunologic parameters associated with HIV seropositivity and those predictive of progression to AIDS-related complex (ARC) and AIDS. Sixty-four patients (32%) had antibodies to HIV by enzyme-linked immunosorbent assay (ELISA), with confirmation by Western blot and none of these patients had ARC or AIDS at the time of initial evaluation. The mean values for white blood-cell count, absolute lymphocyte count, proportion and absolute CD4, and CD4/CD8 ratio were decreased significantly in the HIV-seropositive group compared with the HIV-seronegative group. On the other hand, levels of circulating beta 2-microglobulin, SCD8, SIL-2R, and HIV p24 antigen were significantly elevated in the HIV-seropositive group compared with the HIV-seronegative group.

AIDS-Related Complex↗