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Biomedical subjects

H T Epstein

Publications and source records attributed to H T Epstein.

6 recordsLinked to original sources
PubMed1979

Three parameters affecting interlitter variations.

We studied 3 parameters affecting average body weight differences between mouse litters and have arrived at an approximation of the contribution that each makes to such differences. These parameters are birth weight, genetically based growth potential variations, and maternal competence. We have developed methods for controlling these parameters and show that through their application we can reduce litter-average body weight differences from our normal value of more than 24% to about 3%. The vanished 21% consists of 12% due to differences in maternal competence, 6% due to growth potential differences, and 3% due to initial weight differences.

Age Factors↗
PubMed1978

The relationship between brain weight and head circumference from birth to age 18 years.

A relation between head circumference and brain weight of humans is generally believed to exist, but the literature contains only two studies which exhibit a quantitative aspect of the relation, showing that brain weight is proportional to the cube of the head circumference from birth through age 3.5 years. By assembling data from autopsy records, we have been able to show that this cubic relationship holds through brain maturation at around age 18 years.

Adolescent↗
PubMed1978

The effect of litter size on weight gain in mice.

The body weights of rodents at weaning are generally believed to be inversely related to the number of animals in the litter during the birth-to-weaning period. Quantitative data for rats have been published, but not for mice. Using carefully matched litters, we have measured the average body weights of mice raised in litters containing 2, 4, 6, and 12 pups relative to the average body weight of litters of eight pups. Except for the 2 pup litters, the inverse relation was found to hold. It is also shown that the pattern of average weaning weight as a function of litter size is the same as previously published by two other groups using rats.

Aging↗
PubMed1977

Construction of low-variability litters of preweaning mice.

Mouse litter variation at weaning stems from a combination of genetic makeup, intrauterine experience, and postnatal maternal care. The 1st 2 factors may be matched at birth by making up separate litters out of littermate pairs whose birth weights are equal (+/-.02 g). Maternal competence may be matched by exchanging the mothers between the 2 cages each day. These tactics yield litters at weaning whose variability has been very much reduced. The range of litter-average body weights has been reduced from about 40 percent to about 5 percent and the range of litter-average brain weights has been reduced from about 15 percent to about 1-2 percent.

Animals↗
PubMed1977

Rodent brain growth stages: an analytical review.

Study of data in the literature on rat and mouse brain growth from birth to weaning reveals a stagewise growth in average brain weight. Rapid growth occurs in the intervals between days 0-6, 8-12, and 17-23 after birth. Slow growth periods then lie in the intervals 6-8, 12-17, and after 23 days. The first slow growth period is signalled by events occurring at its end: substantial acceleration of synthesis of RNA, DNA, protein, and myelin. The second slow growth period is characterized by at least a 3-day interval during which there is very little increase in average brain weight compared with what occurs just before and just after that period; the correlation among 12 studies is highly significant. Implications are discussed for cross-species' extrapolation of findings about brain development.

Age Factors↗