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Biomedical subjects

T E Reed

Publications and source records attributed to T E Reed.

At least 19 recordsLinked to original sources
PubMed1992

Decline in cognitive performance in aging twins. Heritability and biobehavioral predictors from the National Heart, Lung, and Blood Institute Twin Study.

The present study examined the contribution of genetic factors to Digit Symbol performance and its decline in 23 monozygotic twin pairs (mean age at examination 1, 57.1 years) and 21 dizygotic twin pairs (mean age at examination 1, 56.3 years). These men were assessed twice during a 5-year interval as part of the National Heart, Lung, and Blood Institute Twin Study. The prevalence of decline (a change, greater than 1 SD) during the 5-year interval was 35% and 39% for monozygotic and dizygotic twins, respectively. The pairwise concordance for decline was 45% in monozygotic and 8% in dizygotic twin pairs, suggesting a possible role for genetic factors in the decline in Digit Symbol performance in this sample. A comparison of baseline biologic and behavioral characteristics within monozygotic twin pairs discordant for decline in Digit Symbol performance revealed that decliners had higher initial systolic blood pressures, lower serum cholesterol levels, and lower heart rates than nondecliners.

Aged↗
PubMed1990

Genetic variation at the immunoglobulin allotype loci in Creoles of Trinidad.

The sera of a sample of 204 Creoles from Trinidad were tested for the presence of polymorphic gene complexes occurring on immunoglobulin light- and heavy-chain molecules including the allotypic markers IGKC 1, IGHA2 1 and 2, IGHG1 A, X, F, and Z, and IGHG3 G, G5, B0, B1, B3, B4, B5, C3, C5, S, and T. Nine IGHG (GM) haplotypes occur in polymorphic frequencies (greater than .01) in this population, including known African, Asian, Caucasian, and Amerindian marker haplotypes. Significant differences (P less than .01) were found in the frequency distributions of three IGHG (GM) haplotypes and the frequency of IGKC*1 in these data and data from Creole populations of Belize and St. Vincent. The Creoles of Trinidad and St. Vincent are more similar in IGHG (GM) haplotype distributions than are Trinidad and Belize populations. Previous testing has revealed no significant differences between St. Vincent and Belize Creoles at the Ig allotypic loci. Analysis of migration patterns in the Caribbean suggests that different rates of Asian migration have maintained regional diversity at these loci, while continuous gene flow from the eastern Caribbean to Trinidad has had a relative homogenizing effect on the gene pools of this area.

Chi-Square Distribution↗
PubMed1987

Sperm from some infertile men may consist of several populations.

In the hamster ovum penetration (HOP) test, when ova have equal penetrability and sperm have equal penetrating ability, the distribution of zona-free hamster ova classified by number of penetrating human sperm is expected to follow the Poisson distribution (PD). This study reports tests for PD in HOP tests on 9 infertile patients and 11 normal controls. The data, presented in detail, show the expected PD in the control group. In contrast, 3 patients had HOP tests with definite non-PDs, whereas 5 patients have clearcut PDs. The cause of non-PD is unknown, but could result from differences among motile sperm in penetrating ability.

Adult↗
PubMed1987

Confirmation of an abnormal (non-Poisson) distribution of sperm from some infertile men in the hamster-ovum test.

The present study was carried out to investigate an earlier report that stated that some men of infertile couples (patients), but not normal donors, have an abnormal (non-Poison) distribution of penetrating sperm among ova in the hamster-ovum test. Semen samples from 60 men, 24 proven fathers and 36 patients, were analyzed for agreement with the theoretical Poisson distribution (PD). Most of the fathers (23 of 24) fit PD well, but 10 of the patients did not. The overall (group) fit of fathers is good, but that of the patients is poor. Patients, but not fathers, are heterogeneous in their agreement with PD; about 25% fit poorly whereas more than 50% fit well. The 25% fitting poorly may often be those patients who are truly infertile (even when their wives are actually fertile).

Adult↗
PubMed1986

Similarities and differences in acute cardiovascular responses to alcohol among normal men of European, Japanese, and Chinese ancestry: a univariate and multivariate analysis.

Normal young adult males residing in Hawaii (46 of European ancestry, 30 Japanese, 27 Chinese) were tested for changes in heart rate and blood pressure following a dose of 0.59 g of ethanol/kg. The two Oriental groups did not differ in mean changes but, when pooled, differed from Europeans, having increased heart rate and decreased blood pressure. Within-race analyses showed that, contrary to the literature, all three groups have great interindividual differences in cardiovascular responses. In addition, the three races show a basically similar multivariate response: blood pressure more variable than heart rate and blood pressure changes uncorrelated with heart rate changes.

Adult↗
PubMed1984

Variability in serologically detected male antigen titer and some resulting problems: a critical review.

Seroologically detected male antigen" (also called H-Y antigen) was first described in normal male mammals but now appears to occur in normal female mammals as well. "Serologically detected male predominant" (SDMP) antigen is a more appropriate name since the titer in normal males usually exceeds that of normal females. As we show, in each sex there is a considerable inter-individual variability in SDMP antigen titer, and in moderate-to-large size samples the low end of the male range of titers usually coincides with the high end of the female range. Several major problems arise from failure to recognize and/or to deal adequately with this normal variation in SDMP antigen titer. The chief problem is that the "controls" used (often a single individual) may be inadequate and misleading, leading to unjustified designation of samples as "positive", "negative", or even "deviant" ("intermediate", "reduced") for SDMP antigen titer. Other problems include deficiencies in technique and lack of statistical control for test and sample variability. Adequate attention to these problems, especially to the normal variability in SDMP antigen titer, could reduce the contradictions and inconsistencies which have troubled this field.

Animals↗
PubMed1980

Acute effects of ethanol in vivo on neuromuscular transmission.

The effects in vivo of acute doses of ethanol on impulse transmission in the region of the neuromuscular junction are poorly known. These effects were studied with a new procedure, using mouse tails in a constant temperature chamber to study the delay in nerve-to-muscle impulse transmission. A saline control and five ethanol doses (0.5, 1.0, 1.4, 2.0, 4.24 g/kg) were used with 96 mice. The interval ("residual latency", RL), between (a) the peak of the compound nerve action potential and (b) the first peak of the associated compound muscle action potential, was measured. Ethanol was given IP and tail nerve stimulations were done at 4 min intervals to 16 min post-ethanol. The mean pre-ethanol RL was 0.93 +/- 0.01 (SE) msec; about 25% of this time should be synaptic delay and the remainder is nerve and muscle fiber conduction time. Individual post-ethanol relative RL (RRL) values were calculated for each moue, based on its pre-ethanol value. With doses of 1.0 g/kg and higher there was a mean increase in RRL; at 16 min this increase was 0.8 to 4.4% (all p less than 0.01). At 0.5 g/kg, and also at higher doses, there was a significantly (p less than 0.01) increased variance in RRL 8 to 16 min post-ethanol. A marked correspondence between mean RRL and ataxia is apparent. This appears to be the first in vivo demonstration of acute effects of ethanol on neuromuscular transmission. The methods and mice used may comprise a useful animal model for detecting acute effects of low doses of ethanol on synaptic function.

Animals↗
PubMed1978

Marked individual variability in heart rate "normalization" by ethanol.

In order to test Kissin's (1974) concept of "normalization" by ethanol (deviant prealcohol parameter values becoming less deviant after alcohol) in nonalcoholics, data on unselected mice and nonalcoholic humans were analyzed. These data were on heart rates (HR) of 1055 HS mice and 24 young adults, measured before and after receiving a dose of ethanol (mice: 1.4g/kg, i.p.;humans: 1.3g/kg, oral). Both mice and humans, on the average, show marked "normalization" inintially low HR usually increasing after alcohol, and initially high HR usually decreasing. The correlation between (1) deviation in HR from the prealcohol mean and (2) change in HR after alcohol was -0.803 for mice and -0.538 for humans. There is very great individual variability, however, in the degree of this normalizing response, some individuals normalizing strongly and others not at all. Although first described in alcoholics, strong normalization by alcohol of several psychophysiological parameters is now known to occur in mice and seems likely to occur in some nonalcoholic humans. The possible relevance of these results to predisposition to alcoholism remains to be shown.

Animals↗
PubMed1978

Racial comparisons of alcohol metabolism: background, problems, and results.

The background of and problems in making comparisons among different racial groups in their rates of alcohol metabolism are reviewed. The results of five studies are discussed. It is concluded that the variation among races in rate of alcohol metabolism is not different in kind than variation among individuals within a given race. There are good reasons to expect the former variation to be smaller than the latter.

Alcohol Oxidoreductases↗