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Biomedical subjects

A Rubinstein

Publications and source records attributed to A Rubinstein.

At least 163 records · Page 9Linked to original sources

Detection of HIV in fetal central nervous system tissue.

Neurological disease is a common finding in children with AIDS and in others without signs of disease but with evidence of congenital HIV-1 infection. To investigate the possibility that HIV-1 can infect fetal central nervous system (CNS) tissue and therefore possibly serve as the substrate for the abnormal neurodevelopment characteristic of pediatric AIDS, eight abortus CNS samples (one set of twins) from seven HIV-1-seropositive intravenous drug users (IVDUs) and eight control abortus CNS samples from eight HIV-1-seronegative IVDUs were analyzed for HIV-1 infection. HIV-1 nucleic acid was detected only after the use of polymerase chain reaction (PCR) in three of eight CNS samples from HIV-seropositive IVDUs but not in samples from seronegative subjects. In situ hybridization confirmed that HIV-1 DNA sequences were in cells in the CNS parenchyma of two of the three positive samples. This study demonstrates that HIV-1 can infect human fetal CNS tissue in vivo, but that the use of PCR may be necessary for its detection.

AIDS Dementia Complex↗

Spinal cord blood flow in the rat under normal physiological conditions.

Regional spinal cord blood flow (SCBF) was measured in a group of rats under conditions of normothermia, normocarbia, normoxia, and normal blood pressure, using the hydrogen clearance technique. Regional SCBF in the cervical white matter was 26.8 +/- 1 (SE) ml/100 g/min and in the cervical gray matter 53.6 +/- 2.5; in the thoracic white matter it was 22.2 +/- 2.4 ml/100 g/min and in the thoracic gray matter 41.2 +/- 12/6 ml/100 g/min; and in the lumbar gray matter it was 52.3 +/- 1.9 ml/100 g/min. The effect of changes in blood pressure on SCBF (autoregulation) was investigated in nine rats. We have observed that SCBF remains relatively constant in the blood pressure range of 45 to 165 mm Hg and assumes a passive flow below or above this range.

Animals↗

Beta-2-microglobulin concentrations in pediatric human immunodeficiency virus infection.

Serum concentrations of beta-2-microglobulin (B2-M) were correlated with disease outcome in 40 children infected by the human immunodeficiency virus. Serum B2-M serum concentrations below 3.0 mg/100 ml or decreasing concentrations were indicative of a stable disease course but were also noted preterminally in lymphopenic children. Of 20 patients with B2-M concentrations above 3.0 mg/liter, 12 had a progressive disease course and 8 remained stable. In the latter 8 patients the B2-M values decreased with time. Elevated B2-M concentrations were also noted in infants younger than 1 year of age and denoted active human immunodeficiency virus infection. B2-M serum concentrations are a useful prognostic marker in human immunodeficiency virus-infected children.

Child↗

Hematologic manifestations in pediatric HIV infection: severe anemia as a prognostic factor.

The hematologic profile of 100 symptomatic children infected by the human immunodeficiency virus (HIV) was evaluated and compared to HIV uninfected infants with transplacentally acquired maternal anti-HIV antibodies, and to HIV-negative infants born to i.v. drug-abusing HIV uninfected mothers. Anemia was present in 94% of HIV-infected infants and was a major predictor of disease progression. In 91% of patients having a hematocrit (HcT) less than 25%, the disease course was rapidly fatal. Leukopenia and thrombocytopenia occurred in 47 and 33% of HIV infected patients, respectively. Neutropenia was most severe in children with opportunistic infections. There was no evidence of suppression of any component of hematopoiesis by passively acquired antibodies to HIV.

Anemia↗

Effects of congenital HIV infection on neurodevelopmental status of babies in foster care.

High rates of neurological complications related to congenital HIV infection have been reported, but often it has been difficult to delineate those clinical impairments specifically related to viral infection of the developing nervous system. The present study attempted to hold causative environmental factors constant by comparing the neurodevelopmental and growth status of two matched control groups of infants in foster care, one HIV seronegative and one seropositive. All were over the age of 15 months and had been born to seropositive mothers. The seropositive group showed significantly more neurological involvement than the seronegative group, and a different pattern of cognitive deficits. There were no significant differences in growth measures between the two groups. Babies born to HIV seropositive mothers were generally at high risk for developmental impairments.

AIDS Dementia Complex↗

Pregnancy outcomes among mothers infected with human immunodeficiency virus and uninfected control subjects.

Between June 26, 1985, and Feb. 24, 1989, 101 seropositive pregnant women and 129 seronegative pregnant women from the same prenatal clinics in Brooklyn and the Bronx were recruited into a prospective study of human immunodeficiency virus infection in pregnant women and their offspring. This report details the course of pregnancy and short-term neonatal outcomes of 91 seropositive women and 126 seronegative women who gave birth during the study period. Seropositive mothers were significantly more likely to have sexually transmitted diseases (17.6% vs 7.1%, p = 0.017) and medical complications (43.0% vs 25%, p = 0.006) during pregnancy. No other obstetric complications (e. g., chorioamnionitis, endometritis, toxemia, or placental problems) were associated with serologic status. After controlling for confounding variables (drug use, tobacco use, age of mother, and clinic), we found that the mother's serologic status was not significantly associated with birth weight, gestational age, head circumference, or Apgar scores among live infants. For example, after adjustment on confounders we found that children born to seropositive mothers weighed about 7 gm more than children of seronegative mothers (95% confidence interval, -180 to 194 gm). We conclude that in this population human immunodeficiency virus infection has little demonstrable impact on the status at birth of live neonates.

Adult↗

Mother-to-infant transmission of human immunodeficiency virus type 1: association with prematurity or low anti-gp120.

In a prospective study of pregnant women infected with human immunodeficiency virus type 1 (HIV-1) in Brooklyn, New York, USA, 16 (29%) of 55 evaluable infants were infected with HIV-1. 9 infants had paediatric acquired immunodeficiency syndrome, 6 had less severe clinical manifestations of HIV-1 infection, and 1 was symptom-free but was seropositive for HIV-1 beyond 15 months of age. The 10 infants born at 37 weeks of gestation or earlier were at higher risk of HIV-1 infection than infants born at 38 weeks of gestation or later (60% vs 22%) but the median age at appearance of disease was approximately 5 months in both groups. The HIV-1 transmission rate was not associated with predelivery levels of maternal T cells, anti-p24, or neutralising antibodies but it was higher, among full-term infants, for those with mothers in the lowest third of the distribution of anti-gp120 levels (53%). On immunoblot, transmitting mothers lacked a gp120 band but not other bands. Protection was not associated with antibody to recombinant peptides from the hypervariable region of the major neutralising gp120 epitope, and the anti-gp120 endpoint dilution titre was similar in transmitting and non-transmitting mothers. Mothers of uninfected full-term infants appear to confer immunological protection against HIV-1 infection of their offspring by way of a high-affinity antibody to a gp120 epitope, whose specificity has importance for vaccine development and possibly perinatal immunotherapy.

Acquired Immunodeficiency Syndrome↗

Prognostic factors and life expectancy in children with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia.

Eighteen children with the acquired immunodeficiency syndrome (AIDS) were diagnosed as having Pneumocystis carinii pneumonia (PCP) by either open lung biopsy or bronchoalveolar lavage. Seven patients (39%) died during the acute illness. Alveolar-arterial oxygen gradients at the time of presentation and lactate dehydrogenase levels did not distinguish survivors from nonsurvivors. Total lymphocyte and T4 cell counts were low in children who died during the initial PCP infection but had considerable overlap with survivors. Response to phytohemagglutinin was measured in 5 of the 7 patients who died initially. In these patients, the mean phytohemagglutinin response was 1977 cpm. Of the 11 early survivors, 10 died within 27 months after PCP. Mean phytohemagglutinin response was 46,079 cpm in patients who died within 1 year, and 44,768 cpm in those who died later. Only 1 child is still alive 5 years after PCP illness. Children with AIDS and PCP infection have high initial mortality and poor long-term prognosis. Response to phytohemagglutinin is helpful in predicting who will survive initial PCP infection.

Acquired Immunodeficiency Syndrome↗

The effect of caffeine ingestion on physical performance after prolonged exercise.

The purpose of this study was to determine the effect of caffeine ingestion on physical performance after prolonged endurance exercise. Twenty three trained male volunteers participated in a 40-km march and were divided into two groups, matched for caffeine clearance rate and aerobic capacity. The experimental group ingested, prior to the march, a caffeinated drink at a dose of 5 mg.kg-1 body mass and at the 3rd and 5th h of marching an additional drink at a dose of 2.5 mg.kg-1 body mass. The control group ingested a drink of equal volume at the same times. Upon termination of the march each subject performed a cycle ergometer test at an intensity of 90% maximal oxygen consumption. Time to exhaustion and rate of perceived exertion (RPE) were recorded. Blood samples were drawn predrink, at the 3rd and 5th h of marching and immediately after the cycle ergometer test, and were analysed for caffeine, free fatty acids (FFA), lactate and glucose levels. Plasma FFA levels increased during the march (p less than 0.05), with no significant difference between groups. Lactate levels increased in the experimental group (p less than 0.05), with no significant change in the control group. Glucose levels did not change significantly in either group. After the cycle ergometer test, lactate levels were significantly higher in the experimental, as compared to the control group (3.77 +/- 0.33 vs 2.52 +/- 0.35 mmol.l-1, respectively). There was no significant difference between treatments in the time to exhaustion on the cycle ergometer, but RPE was different (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Non-symmetric subcutaneous lipomatosis associated with familial combined hyperlipidaemia.

A family with familial combined hyperlipidaemia in which affected members had nonsymmetric subcutaneous lipomatosis (NSSCL) is described. Affected members had high serum levels of total cholesterol, low density lipoprotein (LDL) cholesterol and high density lipoprotein (HDL) cholesterol. By contrast, family members without NSSCL had normal lipid levels. There was also a correlation between the degree of hyperlipidaemia and the amount of subcutaneous lipomas. The occurrence of hyperlipidaemia in family members with NSSCL suggests the existence of a genetic linkage between these two characteristics, but did not show any association with HLA haplotyping. To our knowledge this association between lipid abnormalities and NSSCL has not been previously reported.

Adolescent↗

Spinal cord pathology in pediatric acquired immunodeficiency syndrome.

We examined the spinal cords from 15 consecutive autopsies of infants and children with AIDS using a battery of histochemical and immunocytochemical stains, and in four cases, electron microscopy. Corticospinal tract (CST) signs were a notable clinical finding in 14; however, the age of onset, rate of progression, severity of dysfunction, and duration varied among patients. Ten cases had pathologic changes in the CST. In four of the ten cases, the changes were consistent with an "axonopathy" since axons and myelin were both diminished in the CST. These cases may represent CST wallerian degeneration, since they had marked injury to cerebral white matter in the form of chronic inflammation with multinucleated cells, gliosis, and myelin pallor. In five cases, with an average age at death of 31 months, the CST showed poor myelination with relative preservation of axons. These cases may represent delayed myelination or possibly cytokine-mediated injury to newly formed myelin since the CST is one of the last tracts to myelinate in the spinal cord. One child with primary CNS lymphoma had a complicated pattern of spinal injury due to unilateral CST wallerian degeneration possibly superimposed upon delayed myelination, in addition to patchy areas of demyelination associated with perivascular lymphomatous infiltrates. Four children with mild CST signs, ranging in age from 5 to 6 months, had CST myelin pallor that was consistent with the degree of myelination expected for age. We did not find vacuolar myelopathy similar to that seen in adult AIDS, but did note focal vacuolar changes in the thoracic posterior columns in the oldest child.

Acquired Immunodeficiency Syndrome↗

Effect of direction of pressure change on obtaining airtight seals in tympanometry.

To determine the effect of change in pressure direction on obtaining a seal during tympanometry, an ascending approach (-/+) was attempted when the traditional, descending approach (+/-) was unsuccessful in maintaining an airtight seal. Results revealed that a seal was achieved using the ascending direction in twelve ears when the descending method failed; in only four ears, neither method was successful.

Acoustic Impedance Tests↗

Background, epidemiology, and impact of HIV infection in children.

There was substantial difficulty in the early years of the HIV epidemic in confirming the presence of this infection in children. Serological testing finally allowed the identification of a spectrum of clinical expressions. An understanding gradually developed about the serious central nervous system involvement in children, which is more direct and intense than that usually seen in adults. My early personal experiences in this work were described.

Acquired Immunodeficiency Syndrome↗