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Biomedical subjects

H D Moore

Publications and source records attributed to H D Moore.

At least 109 records · Page 6Linked to original sources
PubMed1976

The binding of labelled basic proteins by boar spermatozoa.

Seminal plasma basic proteins were labelled with 131I. The efficiency of the labelling was studied by superimposing protein density traces on a radioactive fractionation plot. These labelled proteins were incubated with spermatozoa and shown to bind more readily to spermatozoa from boars after the removal of the vesicular glands than to spermatozoa obtained from their normal litter mates. Most of the labelled protein became bound to the membranes which were isolated by sucrose density gradient centrifugation. The membranes were separated into two bands which equilibrated at the relative densities of 1-150 and 1-165. These fractions consisted of membrane vesicles of different size; the smaller band on the gradient, which equilibrated at 1-165, consisted of denser membrane material.

Animals↗
PubMed1976

Seminal plasma proteins and the reaction of spermatozoa from intact boars and from boars without seminal vesicles to cooling.

Spermatozoa from intact boars and from boars without seminal vesicles were resuspected in diluent and cooled at different rates to 0 degrees C. Glutamic oxaloacetic transaminase and lactate dehydrogenase activities were greater in the diluents which had contained spermatozoa from intact boars than in those which contained spermatozoa from animals without seminal vesicles. The incubation of seminal plasma from an intact boar with spermatozoa from a vesiculectomized animal before cooling also increased the enzyme activity in the diluent. The factors responsible for this effect were associated with the basic protein fractions of boar seminal plasma, in particular the proteins with haemagglutinating activity which may have been adsorbed onto the spermatozoa. Spermatozoa were exposed to colloidal Fe(OH)2+ to determine by electron microscopy the charge on the surface of the plasma membrane of washed epididymal spermatozoa and ejaculated spermatozoa from intact and vesiculectomized boars. Epididymal spermatozoa bound the positively charged particles more readily than the ejaculated spermatozoa from the intact boars, due to the absence of membrane-bound protein.

Animals↗
PubMed1975

The removal of the seminal vesicles from the boar and the effects on the semen characteristics.

A technique is described for the removal of the seminal vesicles from the boar. The operation was carried out on twelve animals and six of the animals were subsequently trained for semen collection. The seminal plasma from the boars after surgery compared with normal litter mates had a more watery consistency and did not form the characteristic gelduring ejaculation. The sperm concentration was 49% lower while the total reduction of sperm number ejaculate was 78% in the experimental animals, but the ratio of living to dead spermatozoa remained unchanged. The concentrations of citrate and protein were significantly depressed in the seminal plasma of the animals after surgery and the pH increased; the osmolarity remained unchanged. In semination of gilts with the semen from experimental boars revealed no significant loss of fertility compared with the normal controls. Animals slaughtered up to 17 months after surgery showed no regeneration of the seminal vesicles.

Animals↗
PubMed1975

Isoelectric focusing of boar spermatozoa.

The isoelectric points of washed spermatozoa from intact boars and from boars after removal of the seminal vesicles were determined using isoelectric focusing on natural pH gradients. Normal boar spermatozoa focused at a higher pH than spermatozoa from boars without seminal vesicles. The isoelectric point of the latter was increased to a value approaching normal by preincubation in normal seminal plasma. This indicates that seminal plasma alters the membrane surface charge of boar spermatozoa on ejaculation.

Animals↗
PubMedDate not supplied

Neuropeptide Y: behavioral effects in the golden hamster.

Neuropeptide Y (NPY) is found abundantly in nervous tissues of vertebrate species including the golden hamster. Centrally-administered NPY has been reported to elicit ingestive behaviors in the rat, squirrel, pig, mouse, and chick. To assess NPY's behavioral effects in a New World rodent that does not increase food intake after deprivation, NPY was injected intracerebroventricularly (10.0-0.04 micrograms/5 microliter) in home-caged golden hamsters with ad lib access to food, water and 5% w/v ethanol solution. Food and fluid intakes, and behavior displays were monitored after NPY injection. NPY promptly increased short-term food intake and observed feeding behaviors at 10.0, 3.3, 1.1, and 0.37 micrograms NPY, but there was no effect on 24 hr food intake. Water and ethanol intakes were increased only at 10.0 and 0.37 micrograms NPY, respectively. Resting behaviors decreased at NPY doses that increased feeding, but there were no consistent effects of NPY on any other category of behavior. Results demonstrate that NPY potently stimulates short-term food intake and decreases resting behavior in the golden hamster. The lack of compensatory food intake in deprived hamsters cannot be explained as an insensitivity to the putative orexigenic function of endogenous neuropeptide Y.

Alcohol Drinking↗
PubMedDate not supplied

In vitro manipulation of gametes and embryos for evaluating the effect of chemicals on germ cell function and developmental potential.

The effect of toxicants on gamete fertilizing capacity in mammals can be measured by direct assessment of fertilization and embryo development. Alternatively, an indirect assessment can be made by measuring physiological and biochemical parameters related to sperm and oocyte function. To increase the sensitivity of fertilization assays in vivo, inseminations should be undertaken with the minimum number of viable spermatozoa for adequate conception rates. Internal controls may be used to reduce animal and experimental variation. Fertilization in vitro allows gamete interactions to be investigated in detail but, for maximum conception, sperm/egg ratios 10(3)-10(4) times greater than at the site of fertilization in vivo are required. Several indirect assessments of sperm function show promise as diagnostic markers of infertility. These include sperm penetration into zona-free hamster oocytes and computerized measurements of sperm velocity. In vitro culture of embryos provides a means of assessing the potential of germ cells to promote normal development, although considerable species variation exists with respect to events such as implantation. It is envisaged that in vitro techniques will become increasingly important for screening and monitoring the effects of toxic agents on reproductive processes.

Animals↗
PubMedDate not supplied

Contribution of epididymal factors to sperm maturation and storage.

In fertile men, the majority of epididymal spermatozoa acquire the potential to fertilize (assessed with sperm function assays) on passage into the corpus and cauda regions of the epididymis. Although secretions of the epididymal epithelium are clearly important for sperm maturation and survival, their role in this process has yet to be fully determined. Alterations in epididymal sperm membranes may result from the incorporation of protein, sugar and lipid determinants. Most probably, factors of epididymal origin act in concert with constitutional changes to spermatozoa, which together permit full sperm function. Epididymal spermatozoa incubated with epididymal epithelial cell cultures can undergo some maturation in vitro, which can lead to the development of sperm fertilizing capacity. Co-incubations of human sperm with epididymal epithelial cultures, at 37 degrees C with medium replenished every other day, led to 50% of spermatozoa retaining motility after 8 days. In one case, a few spermatozoa survived for 17 days, the inherent maximal survival time of human spermatozoa in situ. An important aspect of coculture experiments is that close interactions between spermatozoa and epithelial cells can be examined in detail. This coculture technique may yield important information related to epididymal sperm maturation and storage.

Animals↗
PubMedDate not supplied

Measurement of intracellular calcium concentration and plasma membrane potential in human spermatozoa using flow cytometry.

We report 2 novel approaches using flow cytometry to measure intracellular calcium concentration and plasma membrane potential in human spermatozoa. Both approaches have the potential to measure different responses in subpopulations of cells, which is particularly useful when studying heterogeneous populations such as human spermatozoa. Intracellular calcium concentration ([Ca2+]i) was measured using the probe indo-1/AM. This allowed measurements to be made that were independent of variation in cell size and dye loading. It also enabled dead cells to be directly identified and excluded from the analyses without the need for counterstaining. Mean basal [Ca2+]i was determined as 50 nM (25-75 nM range) and, in response to the agonist progesterone (20 microM), this increased transiently to 195 nM (125-285 nM range) before declining to approximately half the maximal level within 2 minutes (values in parentheses correspond to the range of values typically found within a sperm population from 1 sample). These results are comparable with previously published data on whole sperm populations. Sperm membrane potential (VM) was assayed using the probe DiOC6(3). In carefully controlled experiments, a marked depolarization of the plasma membrane potential of capacitated spermatozoa was observed in response to progesterone (20 microM). Following in vitro capacitation, the sperm plasma membrane potential became hyperpolarized compared with the noncapacitated state. Therefore, this technique may be used to assay for sperm capacitation in vitro.

Calcium↗
PubMedDate not supplied

Abdominal aortic aneurysms.

The dangers of any abdominal aortic aneurysm are discussed, and the disastrous combination of an aneurysm and abdominal pain emphasised. These anerysms can be divided into 4 groups. The presentation and operative mortality for each group is discussed, as is the long term survival, state of the peripheral circulation and general health after operation. How results can be improved is considered. It is concluded that all such aneyrysms should be operated upon because of the good immediate and long term results in comparison with those not operated upon.

Aorta, Abdominal↗
PubMedDate not supplied

Fertilizing capacity of rat spermatozoa is correlated with decline in straight-line velocity measured by continuous computer-aided sperm analysis: epididymal rat spermatozoa from the proximal cauda have a greater fertilizing capacity in vitro than those from the distal cauda or vas deferens.

Rat spermatozoa recovered from different regions of the excurrent ducts of 10 adult males (proximal cauda epididymidis [PC], distal cauda epididymidis [DC], and vas deferens [VD]) were assessed by in vitro fertilization (LVF) using limited sperm numbers, and by continuous evaluation of motility parameters during 5 hours of incubation in vitro with automated computer-aided sperm analysis (CASA). Spermatozoa from the PC region fertilized (68 +/- 6%) a significantly greater (P < or = 0.005) number of oocytes than those from the DC (44 + 5%) or VD (47 +/- 7%). For pooled samples from all three regions, the mean fertilization rate (51 +/- 14%) was less tan for spermatozoa from the PC (P < 0.05) but was not significantly different from spermatozoa from the DC or VD. For each time point and sample, 1,592 +/- 428 sperm tracks were analyzed. CASA was verified by comparison with manual still-frame analysis of video recordings, by repeated analysis of the same or different samples of spermatozoa, and by examination of computer tracks. The coefficients of variation for various motion parameters suggested that the CASA obtained a high degree of precision. There were no significant differences in motility parameters for spermatozoa recovered from equivalent regions of the left or right tract or in motility parameters for spermatozoa from different regions of the tract immediately after recovery. However, during incubation in vitro, spermatozoa from the DC or VD regions exhibited a marked decline in straight-line velocity (VSL) compared with spermatozoa from the PC region. The reduction in VSL (combined values from right and left tract) for DC or VD spermatozoa compared with PC spermatozoa was significant at 2.5 hours of incubation (P < or = 0.05) and highly significant (P < or = 0.005) by the end of the incubation period. Differences in average path velocity (VAP) were also apparent after 4 hours (p < or = 0.05), but no significant differences were observed for measurements of curvilinear velocity (VCL) or lateral bead displacement (ALH). Overall, the decline in VSL over 5 hours was highly correlated (P < or = 0.001) with the outcome of fertilization in vitro. In contrast, initial VSL and changes in VCL of spermatozoa were not correlated with fertilization rate. These results indicate that the in vitro fertilizing capacity of rat spermatozoa is correlated with 1) the decline in straight-line velocity (VSL) as measured by repeated CASA during incubation in vitro and 2) with the site of recovery of mature rat spermatozoa from the distal excurrent duct. It is suggested that the deterioration of the quality of rat spermatozoa in the distal epididymidis and vas deferens during storage may occur sooner than previously realized, and therefore care must be taken when recovering samples for fertility assessment. In keeping with findings in other species, immediate "snapshot" analysis of rat motility was a poor predictor of sperm fertility. In contrast, continuous CASA provided significant information for determining sperm fertilizing capacity and will be a useful technique for reproductive toxicology.

Animals↗
PubMedDate not supplied

Choice of operating conditions to minimize sperm subpopulation sampling bias in the assessment of boar semen by computer-assisted semen analysis.

The performance of a computer-assisted semen analysis system was evaluated for use with washed boar spermatozoa. Accuracy was tested using a computer graphics-generated series of spots moving along horizontal, vertical, and diagonal paths, with both straight and sinusoidal trajectories. Observed and expected values agreed to better than +/- 5%, and there was exact agreement in many cases. Reproducibility was tested by making 10 measurements of a single prerecorded sequence of boar spermatozoa. Coefficients of variation were < 3% for all sperm motion parameters tested. Setup conditions affecting the sample statistics of sperm populations were examined. Search radius (10 settings) and minimum track point (10 settings) were varied factorially to evaluate their biasing effects upon population sampling and accuracy. Low search radius (< 12 microns) or high minimum track point values (> 26 frames) precluded measurements of rapidly moving cells and thus led to selection of slow-moving cells. High search radius (> 16 microns) and low minimum track point settings (< 22 frames) led to erroneous tracking and poor data quality. Suitable settings for these setup parameters (search radius = 13 microns; minimum track points = 24) were chosen for use in subsequent fertility trials because they caused the least sampling bias.

Animals↗
PubMedDate not supplied

Continuous assessment of human spermatozoa viability during cryopreservation.

Cryomicroscopy has enabled direct observation of freezing and thawing of human spermatozoa. When used with a fluorescent viability kit, sperm membrane damage was not apparent down to temperatures of -5 degrees C, but significant damage occurred after thawing (55% of spermatozoa had damaged membranes). Semen samples were cooled or frozen to temperatures (at decrements of 10 degrees C) from 0 degree C to -110 degrees C. At all these temperatures the proportion of live to membrane-damaged cells remained constant. Samples held at temperatures above -30 degrees C were not adversely affected. Below -30 degrees C there was a gradual increase in the proportion of membrane-damaged cells on thaw and a decrease in the number of live cells recovering motility. At temperatures between -50 degrees C and -60 degrees C there was an equal proportion of live motile, immotile, and membrane-damaged cells. It is concluded that some irreversible damage to spermatozoa was a result of freezing processes in cells frozen to -30 degrees C or less, but most of the cryodamage was incurred during thawing, possibly due to recrystallization.

Cell Survival↗