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Biomedical subjects

J P Holt

Publications and source records attributed to J P Holt.

13 recordsLinked to original sources
PubMed2006

Effects of a high-fiber diet and frequent feeding on behavior, reproductive performance, and nutrient digestibility in gestating sows.

A study was conducted to determine the effects of feeding a corn-soybean meal (control) diet vs. a corn-soybean meal-40% soybean hulls (high fiber) diet, as well as the frequency of feeding (once vs. twice daily), on the welfare and performance of gestating sows. Two hundred thirty-nine mixed-parity sows were assigned to a 2 x 2 factorial arrangement of treatments. Sows fed once daily received their entire meal at 0730, whereas sows fed twice daily received one-half of their feed allotment at 0730 and the other half at 1430. The behavior of 68 focal sows (> or = 16 sows per treatment combination) was observed on d 1 postweaning, and on d 40 and d 80 of gestation. The percentage of time standing, lying, sitting, feeding, inactive, and performing stereotypic behaviors was determined. Saliva samples were collected to determine cortisol concentrations. Sow BW and backfat depth were determined on d 0, 40, and 80 of gestation, within 24 h of farrowing, and at weaning. An energy and nitrogen digestibility study was conducted using 36 sows assigned to each of the 4 treatment combinations. Over a 24-h period, the sows fed the high-fiber diet spent less time lying (P < 0.05) than the sows fed the control diet. The frequency of feeding did not affect sow behavior measured over a 24-h period. During mealtimes, sows fed the high-fiber diet spent more time feeding (P < 0.05) than sows fed the control diet. Feeding the high-fiber diet did not affect stereotypic behavior measured over 24 h or during mealtimes. Neither diet nor feeding frequency affected salivary cortisol concentration. Sows fed the high-fiber diet gained less BW and lost backfat (P < 0.05) during gestation compared with sows fed the control diet, whereas sows fed once daily gained less BW and lost backfat (P < 0.05) compared with sows fed twice daily. Sows fed the high-fiber diet had fewer pigs born (P < 0.05) compared with sows fed the control diet. Feeding frequency had no effect on size or weight gain of litters. Sows fed the high-fiber diet exhibited lower digestibility of DM, energy, and N (P < 0.05) compared with sows fed the control diet. Feeding a high-fiber diet utilizing soybean hulls or increasing feeding frequency did not enhance the welfare of sows by reducing stereotypic behaviors nor did it improve reproductive performance.

Animal Feed↗
PubMed1987

Quantitative histochemistry of late luteal phase human endometrium.

New techniques are needed to evaluate the luteal phase endometrium in the infertility patient. Toward this goal, we have applied quantitative microbiochemical techniques to the determination of enzyme activities in microdissected samples of each endometrial cell type (i.e., epithelial and stromal) from individual endometrial biopsies. Preliminary data on eight control patients are presented to establish a normal range of epithelial and stromal lactate dehydrogenase (LDH), beta-hydroxyacyl-CoA-dehydrogenase (beta-OH-acyl-CoA-DH), and citrate synthase (CS) enzyme activities. Significantly higher enzyme activities were found in the epithelial cell type, compared with the stromal cell type for all three enzymes. Mean enzyme activities for the eight patients, comparing epithelial to stromal values, respectively, were (1) LDH, 39.9 versus 15.4; (2) CS, 4.0 versus 1.2; and (3) beta-OH-CoA-DH, 3.9 versus 2.3 mol/kgD/hour. Enzyme activities are expressed as moles of substrate reacting per kilogram dry weight per hour (mol/kgD/hour).

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1987

Rat uterine microbiochemistry: metabolic enzyme activities stimulated by 17-beta-estradiol are localized in epithelial cells.

Lactate dehydrogenase (LDH; EC 1.1.1.27), citrate synthase (CS; EC 4.1.3.7), and beta-hydroxyacyl-CoA-dehydrogenase (beta-OH-acyl-CoA-DH; EC 1.1.1.35) activities were determined in each of the three major cell types of rat uterus, i.e., epithelial, stromal, and smooth muscle, using quantitative microanalytical techniques. Adult ovariectomized rats were treated with 17-beta-estradiol to determine the time course and dose response (0.025-50 micrograms/300-g rat) effect of estrogen on enzyme activity of each type of uterine cell. The use of "oil well" and enzyme-cycling microtechniques to determine the time course and the dose responses of enzyme activity changes required microassays involving 1595 microdissected single cell specimens. Estradiol treatment increased epithelial LDH, CS and beta-OH-acyl-CoA-DH activity but had no effect on these enzymes in the stroma or in smooth muscle cells. The estradiol-stimulated peak enzyme activities on Day 4 in the intervention group are compared with those in the ovariectomized rat controls as follows: LDH, 44.5 +/- 3.5 vs 22.3 +/- 3.9; CS, 3.5 +/- 0.2 vs 1.5 +/- 0.6; beta-OH-acyl-CoA-H, 3.5 +/- 0.32 vs 2.2 +/- 0.2 (mean +/- standard deviation; mol/kg/hr). Stromal cell activities (LDH, 7.4 +/- 1.0; CS, 1.2 +/- 0.2; beta-OH-acyl-CoA-DH, 0.9 +/- 0.1) were significantly lower than epithelial cell levels and were similar to smooth muscle levels. Therefore, even in the ovariectomized animal epithelial cells have markedly higher metabolic activity compared with adjacent cells. The enzyme activities are expressed as moles of substrate reacting per kilogram of dry weight per hour. All three enzymes exhibited a 17-beta-estradiol-induced dose response between 0.025-0.15 micrograms/300-g rat. The three enzymes studied all had similar response patterns to estrogen. The effect of estradiol was restricted to epithelial cells, with enzyme activities increasing to maximal levels after approximately 96 hr of hormone treatment. This study therefore not only confirms the specific and differential metabolic responses of uterine cells to estradiol treatment, but clearly demonstrates that marked metabolic differences exist between epithelial cells and stromal or smooth muscle uterine cells.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1984

Danazol treatment increases serum enzyme levels.

Six of seven women treated for endometriosis with daily administrations of 800 mg of danazol over 4.7 to 9 months developed one or more mildly abnormal serum enzyme levels. All seven patients had normal pretreatment enzyme levels and were evaluated after 2.5 to 5 months of drug therapy and again 1 to 2.5 months following completion of drug therapy. Danazol therapy was associated with statistically significant increases in the following serum enzyme levels: creatine phosphokinase, lactate dehydrogenase, serum glutamic oxaloacetic transaminase, and serum glutamic pyruvic transaminase. Mean serum enzyme increases ranged from 25% to 86% greater than the mean pre-drug-therapy level. Alkaline phosphatase levels were not altered by the danazol treatment. Following completion of danazol therapy, all enzyme levels were within the normal range except serum glutamic pyruvic transaminase, which was approaching normal. High-dose danazol treatment (800 mg daily) is associated with mild elevations of specific serum enzymes, and these changes appear to resolve spontaneously after cessation of treatment.

5'-Nucleotidase↗
PubMed1981

Geometric similarity of aorta, venae cavae, and certain of their branches in mammals.

The diameters of the aorta and venae cavae at various points throughout their lengths, the diameters of their major branches, and the lengths of various aortic and vena caval segments were measured in plastic corrosion casts of the arterial and venous systems of the normal adult mouse, rat, rabbit, dog, goat, horse, and cow, extending over a body weight range of 38,000-fold (arterial) and 1,100-fold (venous). It is shown that the diameters and lengths of these vessels are described by power-law equations relating the particular diameter or length to body weight (BW) raised to a particular diameter or length to body weight (BW) raised to a particular power, i.e., diameter = a BWb. Equations for the diameters and lengths of the vessels are given for slightly distended vessels and for vessels distended in the physiological range.

Animals↗
PubMed1972

Laser temperature-jump technique for relaxation studies of the ionic conductances in myelinated nerve fibers.

A temperature-jump technique for single nodes of Ranvier has been developed using a pulsed laser system. The temperature perturbation was accomplished by firing the laser beam obtained from a neodymium rod through the solution surrounding a single node. The temperature step was achieved within 1 msec using the laser in the normal mode of operation. During the voltage-clamped steady-state current a temperature jump from 4 degrees C increased the current to a new steady-state value within the time course of the T-jump. This finding suggests that the maximum potassium permeability P(K) has a rapid relaxation time and that the steady-state value of n (the value of potassium permeability divided by its maximum value) is relatively independent of temperature. T-jumps applied during the voltage-clamped sodium currents showed that the sodium permeability changed with a relaxation time that was also shorter than the duration of the normal mode laser output. T-jumps observed during a hyperpolarization or at the resting potential showed no detectable conductance change. When a T-jump immediately preceded a voltage clamp pulse the technique was then used to investigate the effect of changes in the steady-state temperature on the ionic conductances. It was found that the magnitude of the change in membrane current due to a T-clamp was directly related to the level of cathodal polarization.

Animals↗