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Biomedical subjects

H D Moore

Publications and source records attributed to H D Moore.

At least 91 records · Page 5Linked to original sources

Localization by monoclonal antibodies of various surface antigens of hamster spermatozoa and the effect of antibody on fertilization in vitro.

To determine the importance during fertilization of various plasma membrane components of the hamster spermatozoon, monoclonal antibodies were generated in the mouse against specific sperm surface antigens. BALB/C mice were immunized with washed hamster spermatozoa from the cauda epididymidis and immune splenocytes fused with myeloma cells (P3 X 63 Ag8). The sperm-specific immunoglobulins were detected in hybridoma cultures by a solid-phase assay (ELISA). Five monoclonal antibodies bound specifically to the surface of intact hamster spermatozoa, three immunoglobulins to restricted regions of the head and tail plasmalemma as detected by immunofluorescence. In two cases, the affinity of the membrane antigen was modified during passage through the epididymis. Monoclonal antibodies to the sperm head or to the head and tail inhibited fertilization in vitro by blocking sperm attachment to the zona pellucida and the oolemma.

Animals↗

The structure and epididymal maturation of the spermatozoon of the common marmoset (Callithrix jacchus).

Maturation of the spermatozoon of the common marmoset (Callithrix jacchus) during epididymal transit was investigated using light and electron microscopy. Except for the caudal migration of the cytoplasmic droplet there were no apparent ultrastructural modifications, although interesting morphological features of the sperm head were observed such as the substructure of the acrosome and a waist at the equatorial region. Alteration to the plasmalemma during maturation was reflected by an increasing capacity of the sperm surface to bind wheat germ agglutinin (recognising n-acetyl-d-glucosamine) but not ricin communis or concanavalin agglutinins. This change was concomitant with the development of sperm fertilising capacity in this species.

Acrosome↗

Ultrastructural aspects of spermatogenesis in the common marmoset (Callithrix jacchus).

The pattern of normal spermatogenesis in the common marmoset, Callithrix jacchus, is described and a system classifying the spermatogenic cycle into nine successive stages is presented. In contrast to most previous studies of spermatogenesis, the classification system developed in this study depends more upon the recognition of characteristic cell associations rather than upon identification of particular steps of spermatid development. The structurally simple acrosome of the marmoset spermatozoon displays insufficiently clear morphological changes during spermatid elongation to allow this to be used as a key to spermatogenic classification. Ultrastructural aspects of spermatogenesis in the marmoset are also described; in general, these correspond to similar descriptions of this process in other primates.

Animals↗

Development of the oocyte-penetrating capacity of spermatozoa in the human epididymis.

The development of the penetrating capacity of human epididymal spermatozoa has been assessed in vitro using zona-free hamster oocytes. Spermatozoa were recovered from epididymal tissue of men undergoing vasectomy or epididymovasostomy. The results suggest that human spermatozoa first develop the potential to penetrate oocytes in the proximal corpus region. Spermatozoa recovered from more proximal sites of the excurrent duct failed to bind or fuse with zona-free hamster eggs although a small proportion (3%) in the caput region were capable of progressive motility. The data are discussed in relation to biochemical changes to human spermatozoa during maturation.

Adult↗

Localization of delta 5-3 beta- and 17 beta-hydroxysteroid dehydrogenase activity in the efferent ducts, epididymis and vas deferens of the rabbit, hamster and marmoset monkey.

The presence and distribution of delta 5-3 beta-hydroxysteroid dehydrogenase (delta 5-3 beta-HSD: EC 1.1.1.51) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD: EC 1.1.1.51) were studied histochemically in the excurrent ducts of the rabbit, hamster and marmoset monkey. Dehydroepiandrosterone (DHEA) and testosterone were used as substrates for delta 5-3 beta-HSD and 17 beta-HSD respectively, while phenanthroline monohydrate was used to eliminate non-specific staining due to other tissue dehydrogenases. The rabbit possessed least enzyme activity, which was confined to tubules in the middle segment of the epididymis. Enzyme activity was demonstrable throughout the excurrent ducts of the hamster and marmoset, with maximal staining occurring in the middle segment of the epididymis in both species. The region of maximum activity of hydroxysteroid dehydrogenase is where spermatozoa first develop their fertilizing capacity.

17-Hydroxysteroid Dehydrogenases↗

Glycoprotein secretions of the epididymis in the rabbit and hamster: localization on epididymal spermatozoa and the effect of specific antibodies on fertilization in vivo.

To assess the functional significance of glycoprotein secretions of the rabbit and hamster epididymis during sperm maturation and fertilization, antibodies have been raised against acidic protein fractions isolated from epididymal fluid. Specific antiserum was elicited against each of three rabbit glycoproteins designated R1, R2, and R3 with isoelectric points of pI 3.45, 4.15, and 4.65 respectively, and against one hamster glycoprotein (Hl), pI 3.40. Epididymal glycoproteins on the surface of washed spermatozoa from various regions of the epididymis were localized by the fluorescent antibody technique and by sperm agglutination with antiserum. They were first detected on restricted regions of spermatozoa from the distal caput and corpus epididymidis and each antigen had a characteristic binding pattern. The effect of specific antibodies on fertilization in vivo was tested in rabbits by preincubating cauda epididymal spermatozoa with heat-treated antiserum or univalent immunoglobulin fragments before their deposition into oviducts of does induced to ovulate. In all cases, fertilization rates were significantly reduced (P less than or equal to 0.05) compared with controls, the most effective antiserum being against glycoprotein antigen R1 found only on the anterior acrosome of spermatozoa. Heat-treated antiserum against H1 glycoprotein placed in the bursal cavity of ovulating females significantly inhibited fertilization in the hamster (P less than or equal to 0.005). These results are discussed in relation to the modification to the sperm plasmalemma during maturation.

Animals↗

An assessment of the fertilizing ability of spermatozoa in the epididymis of the marmoset monkey (Callithrix jacchus).

The fertilizing ability of spermatozoa from differ regions of the epididymis of the marmoset monkey, Callithrix jacchus, was assessed by determining their rate of fusion with zonaless hamster ova in vitro. This technique tests for functional competence and was validated using epididymal spermatozoa of the hamster whose fertility have been measured previously by in vivo fertilization experiments. The results suggest that some marmoset spermatozoa first acquire the ability to fertilize in the distal caput and proximal corpus epididymidis although the majority become fertile on reaching the proximal cauda region. Acquisition of fertilizing capacity was associated with a change in the degree and character of sperm motility. However, it is considered that modifications to the sperm plasmalemma which allow capacitation and the acrosome reaction to occur are of primary importance for sperm fertility. The development of sperm fertilizing ability in the marmoset is discussed in relation to that in other primates.

Animals↗

Effects of castration on specific glycoprotein secretions of the epididymis in the rabbit and hamster.

Mature male rabbits and hamsters were bilaterally castrated and their epididymides were examined, at 2, 4, 7, 9 and 14 days after operation, for the presence of several glycoproteins by using monospecific antisera and indirect immunoperoxidase labelling. In the rabbit, there was a reduction in the glycoprotein reaction product in the epithelium of the proximal caput epididymidis by 2-4 days after castration, and the staining was weak or absent by 7-9 days. Compared with controls, there was also a marked decrease in the intensity of reaction product to glycoprotein in the lumen of the proximal and distal corpus epididymidis 2-4 days after castration although spermatozoa still filled the duct in this region. Glycoprotein was present in the distal cauda epididymidis at 14 days but staining diminished as spermatozoa were cleared from the tract. In the hamster, epididymal glycoproteins were apparently less critically dependent on androgens than those in the rabbit, reaching a weak but constant level in the proximal region by 7-9 days after castration and remaining at the same intensity in the distal cauda epididymidis throughout the study. These results suggest that the secretion of specific glycoproteins by the mammalian epididymis is related to androgen levels and to sperm maturation.

Animals↗

Plasma concentrations of oestradiol-17 beta and progesterone, and laparoscopic observations of the ovary in the puma (Felis concolor) during oestrus, pseudopregnancy and pregnancy.

Plasma levels of oestradiol and progesterone in 3 pumas during oestrus and artificially induced pregnancy and pseudopregnancy were determined by radioimmunoassay. During oestrus, basal levels of oestradiol (5-30 pg/ml) were interrupted by surges of 30-375 pg/ml at intervals of 17-25 days. Considerable variation occurred between and within animals. Periods of oestrus and follicular development were confirmed by laparoscopy and vaginal smear patterns. Absence of an increase in plasma progesterone following elevated levels of oestradiol and failure to observe corpora lutea in the ovary indicated that ovulation was probably not spontaneous. Plasma oestradiol values rose dramatically in response to PMSG but were low during pseudopregnancy until the return to oestrus. During pregnancy surges of oestradiol occurred at mid-term and immediately before parturition. Ovulation, confirmed by laparoscopy, occurred 24-48 h after hCG and progesterone levels (usually less than 2 ng/ml) then increased to reach 150-300 ng/ml on Days 24-28. In the pseudopregnant animals progesterone concentrations had returned to baseline by Days 45-50 but during pregnancy progesterone remained elevated, declining only gradually to basal values by Day 85. A minor peak of progesterone, coincident with the pre-partum oestradiol surge, occurred on Day 87, 1 week before parturition on Day 95.

Animals↗

Short-term effects of androgen withdrawal on the structure of different epithelial cells in the rat epididymis.

Rat spermatozoa are highly dependent on the milieu of the normal epididymis for their maturation and survival, and die within a few days after androgenic support of the epididymal epithelium is withdrawn. The immediate changes in the ultrastructural organization of the epithelial cells of the rat epididymis, 2, 4, 6 and 14 days following castration have been monitored by morphometric analysis of localized regions of the caput and cauda epididymidis. While castration results in greater endocytosis by principal cells (Moore and Bedford, '79), many of their early structural changes following androgen withdrawal (disappearance of vesicles from the cell apex, reduction in rough endoplasmic reticulum, a drop in the volume of the Golgi cisternae and increase in lysosome content) seem indicative of inhibition of a secretory function. By contrast with the regressive response of the principal cell, the ultrastructure of clear cells in the cauda and of apical cells in the caput region appeared unchanged up to 14 days after castration. The implications of this evidence for specialized functions, and the suggestion of a differential androgen dependence among major cell types of the epididymal epithelium, are discussed briefly.

Androgens↗

The differential absorptive activity of epithelial cells of the rat epididymus before and after castration.

Horseradish peroxidase introduced into the lumen of the rat epididymis was taken up by the columnar cells of the epithelium by five minutes and more so after longer periods. The apical cells and particularly the clear cells in the caput and cauda epididymis, respectively, showed significantly greater endocytotic activity than the principal cell in both locations. Within 14 days after castration, however, such differences in absorptive activity among the various cell types were essentially obscured because of increased endocytosis by the androgen-deficient principal cells. The results are discussed briefly in terms of the function of different epithelial cell types and secretory/absorptive activity in the epididymis.

Absorption↗

The results of treatment for complete prolapse of the rectum in the adult patient.

A method of anterior fixation of the bowel in complete prolapse of the rectum is described. The treatment is based on the concept that abdominal pressure should be directed on the bowel against the pubis rather than directly onto the perineum. The results have been universally successful, without mortality and with excellent functional results.

Adult↗