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At least 19 recordsLinked to original sources
PubMed1978

The effect of antibody against a purified sperm-coating antigen on human sperm.

A purified fraction of human seminal plasma containing a sperm-coating antigen and two minor contaminants was used to immunize rabbits by intravenous route. An antiserum containing only the antibody against the sperm-coating antigen as examined by immunoelectrophoresis was obtained from one rabbit. The effect of this antiserum on human sperm was examined by sperm-immobilization and sperm-agglutination tests. The results revealed that the antibody against the purified sperm-coating antigen was incapable of immobilzing or agglutinating human sperm. This indicates that the purified sperm-coating antigen is unlikely to be useful as an antifertility antigen for immunologic fertility control.

Agglutination Tests↗
PubMed1979

Factors affecting sperm motility. II. Human sperm velocity and percentage of motility as influenced by semen dilution.

Spermatozoal velocity and percentage of motility were analyzed objectively with the multiple exposure photography method before and after specimens from fertile and infertile men were diluted in their own seminal plasma or normal saline. No significant change in percentage of motility was found in samples diluted up to 1:6 in both kinds of diluents. However, a significant relative increase (up to 25% of the original velocity) was found when a specimen was diluted with its own seminal plasma, and an even greater increase (up to 37% of the original velocity) was found when it was diluted with saline. Compared with undiluted specimens, there was no delayed effect on spermatozoal motility when semen was diluted with saline after up to 4 hours' incubation time. Contrary to the findings in animal and human semen described by others, there was no deleterious effect on sperm motility with this kind and rate of dilution and duration of time. The assumption that the increase in sperm velocity caused by dilution is not excitatory but is due only to a decrease of seminal fluid viscosity and a reduced number of spermatozoa which interfere with sperm free movement is discussed. We recommend evaluation of spermatozoal motility in diluted specimens in addition to evaluation of the original specimen in any routine semen analysis in order to determine true spermatozoal motility potential under optimal conditions.

Culture Media↗
PubMedDate not supplied

Human sperm penetration into zona-free hamster oocytes as a test to evaluate the sperm fertilizing ability.

Human sperm entry into zona-free hamster oocytes was used to test the fertile ability of spermatozoa from semen samples of men attending an Infertility Clinic. Sperm chromatin dispersion as seen under the phase-contrast microscope, was used as criterion for sperm entry. The ultrastructural study showed that the behaviour of the gamete membranes during fusion did not basically differ from that of normal fertilization. Eighty four samples were classed as normal (according to the spermiogram) but only 62 (74%) gave a positive test, as compared to only 30 (32%) positive test of 95 samples with abnormal spermiograms. Eight hundred and ten oocytes inseminated with spermatozoa from normal samples gave a 25% penetration, while 1046 oocytes inseminated with spermatozoa from abnormal samples gave a 7% penetration. The normality of hamster oocytes was demonstrated by contemporary insemination with human and hamster spermatozoa. While the percentages of human sperm penetration remained low, hamster sperm penetration was over 70%. The present bioassay is recommended as an additional parameter to the spermiograms for the study of male fertility.

Animals↗
PubMed2026

Mitochondrial uncoupler BAM15 attenuates cryopreservation-induced damage in human sperm by stabilizing mitochondrial homeostasis†.

Human sperm cryopreservation is essential for sperm banking and assisted reproduction, yet freeze-thaw stress promotes oxidative injury that reduces motility and damages the acrosome and nuclear DNA. Here, we tested whether the mitochondrial uncoupler BAM15 improves post-thaw human sperm quality and examined mechanisms linked to mitochondrial homeostasis. Ejaculates were cryopreserved using a standard protocol supplemented with graded concentrations of BAM15. After thawing, total and progressive motility and viability were assessed. Flow cytometry quantified the DNA fragmentation index and the proportion of high DNA stainability cells. Mitochondrial membrane potential, intracellular reactive oxygen species, and lipid peroxidation were measured to evaluate mitochondrial function and oxidative status. Ultrastructural preservation of the acrosome, plasma membrane, midpiece mitochondria, and flagellar axoneme was examined by transmission electron microscopy. Compared with untreated controls, BAM15 increased total and progressive motility and improved viability. BAM15 reduced DNA fragmentation and decreased high DNA stainability, indicating enhanced genomic integrity. Consistently, BAM15 improved mitochondrial membrane potential while suppressing intracellular reactive oxygen species and lipid peroxidation, supporting attenuation of freeze-thaw oxidative damage. Transmission electron microscopy further revealed more continuous acrosomal and plasma membranes, fewer swollen or vacuolated midpiece mitochondria, and improved preservation of axonemal architecture. Collectively, these findings identify BAM15 as a promising cryopreservation supplement that stabilizes mitochondrial homeostasis and improves the functional and structural quality of human sperm after thawing.

Humans↗
PubMed1979

Replacement of protamine by F1 histone during reactivation of fused human sperm nuclei.

Rabbit antisera, specific for the histones F1, F2a2, F2b, F3 and for protamine were used to monitor a possible transition from protamine towards somatic-type histones during sperm nucleus reactivation, following human sperm fusion with mouse fibroblasts. Mature human sperm nuclei were shown to contain the histones F2a2, F2b, F3 and protamine, but were missing F1 histone by immuno cytochemistry using the indirect fluorescence method. However, a gradual disappearance of protamine from fused sperm nuclei, could be observed during the first 24 h of reactivation. Subsequently, F1 histone could be detected in increasing concentrations in 60% of reactivated sperm nuclei, during the next four days. The shift from protamine towards F1 histone could also be visualized cytochemically via staining with brilliant sulphaflavine, which appears to discriminate between sperm nuclei on the basis of their F1 histone content.

Animals↗
PubMed1979

Fine structure of human sperm chromatin.

The fine structure of human sperm chromatin is revealed by electron microscopy. Human sperm chromatin is characterized by fibers composed of discrete spherical organizational units not unlike somatic nucleosomes. During the decondensation process fibers composed of joined spherical units of both 400-A and 150-A diameters were observed.

Chromatin↗
PubMed1978

Inhibition of viral reverse transcriptase and human sperm DNA polymerase by anti-sperm antibodies.

The IgG fraction of serum from a rabbit immunized with detergent-prepared human sperm nuclei inhibited the DNA polymerase activities in human sperm and seminal fluid as well as the partially purified reverse transcriptase of the baboon endogenous type-C retrovirus (BEV). The analogous enzymes from lysates of oncogenic type-C viruses was unaffected. IgG from the serum of individual partners from infertile marriages similarly inhibited both purified BEV reverse transcriptase and human sperm DNA polymerase, but not a DNA polymerase isolated from human prostatic fluid. The data suggest that BEV reverse transcriptase and the human sperm DNA polymerase are antigenically related. Furthermore, the sperm appears to be auto-antigenic and the antibodies thus formed may be capable of interfering with reproductive success.

Antigens↗
PubMed2025

Membrane potential and feedback dynamics regulate CatSper-mediated progesterone signaling in human sperm.

Activation of the sperm-specific Ca2+ channel CatSper by progesterone evokes rapid changes in intracellular Ca2+ in human sperm that are required for fertilization. However, the mechanisms regulating the progesterone-induced Ca2+ signals have remained elusive. Here, we used quantitative kinetic fluorimetry with fast voltage-sensitive fluorescent indicators to investigate how progesterone affects the membrane potential (Vm) of human sperm. Additionally, we employed the FASTM technique to simultaneously record at millisecond time resolution changes in both Vm and intracellular Ca2+. We show that progesterone evokes a rapid pulse-like depolarization and repolarization. The depolarization is caused by Ca2+ influx through CatSper, which pulls Vm away from a resting membrane potential (Vrest) of -65 mV set by the sperm-specific K+ channel Slo3. We further show that Vm- and Ca2+-dependent mechanisms limit the CatSper-mediated Ca2+ influx, thereby promoting repolarization and enabling K+ efflux through Slo3 channels to restore Vrest. Our findings demonstrate that non-genomic progesterone signaling in human sperm is regulated by negative feedback on CatSper and involves a dynamic interplay between CatSper and Slo3 in controlling Vm. We anticipate that our novel kinetic, quantitative Vm recording and Vm/Ca2+-multiplexing techniques will reveal additional molecular mechanisms underlying CatSper-mediated Ca2+ signaling in human sperm both in health and disease.

CatSper↗
PubMed2026

Molecular architecture and spatial organization of proteasomes in the human sperm nucleus.

Proteasomes are fundamental for protein homeostasis and genome integrity and essential in spermatogenesis and fertilization. However, their presence, composition and role within the sperm nucleus are a subject of debate. Here we use in situ cryo-electron tomography in human sperm cells to elucidate the molecular architecture of nuclear proteasomes, which cluster in DNA-free, nuclear cavities within the sperm nucleus. We show that the main population of proteasomes consists of 20S core particles, with a smaller fraction of 20S capped by PA200 activator. Using single-particle cryo-electron microscopy of purified native human sperm proteasomes, we elucidate the features of the essential testis-specific subunit α4s, reporting the presence of a unique splice variant. We resolve a native peptide in the catalytic β2 subunit, providing insight into the proteolysis mechanism and PA200-mediated enhancement of trypsin activity. We show nuclear enrichment of proteasomes during sperm-cell differentiation in human testis tissue, with 20S and PA200 clustering following meiosis, at the spermatid stage. Our findings shed light on the organization and compositional diversity of nuclear proteasomes in human sperm cells, as well as their catalytic function.

Humans↗
PubMed1979

Effects of antisera on human sperm penetration of zona-free hamster ova.

Human sperm, after treatment with a 10% concentration of rabbit or rhesus monkey normal sera and antisera, were evaluated for fertilizing potential by incidence of zona-free hamster ova penetrated by the sperm as evidenced by the presence of swollen sperm heads and male pronuclei. Compared with the basic medium alone, treating sperm with normal sera tended to increase the percentage of ova penetrated whereas antisera against sperm, sperm extract, and testis caused significant decreases in ova penetrated. A Fab preparation of these antisera exhibited similar inhibitory effects. Antisera Fab treatment of the zona-free ova prior to exposure to sperm had no effect on penetration rate.

Animals↗
PubMed1977

Glucose-6-phosphate dehydrogenase (G6PD) activity of human sperm.

Sperm from normal human donors and a G6PD-A- individual were examined for x-linked glucose-6-phosphate dehydrogenase activity and autosomally linked 6-phosphogluconate dehydrogenase activity. With the use of fluorescence microscopy, we divised a procedure to visualise in individual sperm cells the fluorescence of reduced coenzyme NADPH formed by each of the two enzymes in the presence of appropriate substrates. We found significant differences in the population distribution of sperm expressing each of the two activities, and the ratio of the two activities in sperm homogenate is very different from the one found in erythrocyte lysates. The possibility of haploid gene expression has been considered in interpreting these results.

Electrophoresis, Disc↗
PubMed1979

A simple inexpensive method for objective assessment of human sperm movement characteristics.

A simple, objective method is described for obtaining a well-defined and diversified set of human sperm movement characteristics. These data are suitable for comprehensive statistical comparisons of sperm suspensions. One-second time-exposure photomicrographs are taken with dark-field illumination of slides prepared from semen, cervical mucus, or artificial media. The negatives are projected as a filmstrip and are analyzed on a specially designed console. The filmstrips can be taken and developed in 15 minutes without darkroom facilities, and a complete analysis of the film requires an additional 15 to 20 minutes. Fifty spermatozoa are examined to determine percentage motility, and movement characteristics are recorded for 15 spermatozoa. With these data the swimming trajectories of individual spermatozoa can be reconstructed retrospectively. The sperm suspension as a whole is described in terms of percentage motility, mean swimming speed, percentage of progressive spermatozoa, mean swimming speed of progressive spermatozoa, percentage of straight-swimming spermatozoa, percentage of rolling spermatozoa, and percentage of yawing spermatozoa.

Humans↗
PubMed1978

Use of microimmobilization and microagglutination assays for attempted detection of HLA antigens and beta2 microglobulin on human sperm.

Microtechniques for detecting sperm agglutinating and immobilizing antibodies are described. These assays are proved to be useful in the study of anti-sperm antibodies in the sera of vaseectomized men and the serum of a rhesus monkey immunized with human sperm. However, using various antisera against beta2 microglobulin and HLA region antigens, including Ia antigens, in these assays, very little, if any, activity was found against sperm. Absorption and inhibition tests also could not show a significant amount of these antigens on sperm. Although no HLA region antigens could be detected in the seminal plasma by inhibition tests, a large amount of beta2 microglobulin was found. It is suggested that some beta2 microglobulin could be adsorbed onto sperm, since mouse sperm was shown to pick up beta2 microglobulin after incubation with human seminal plasma. The maximum amounts of HLA region antigens and beta2 microglobulin in the seminal plasma are estimated.

Adsorption↗
PubMed1977

Immunodetection of a human chorionic gonadotropin-like substance in human sperm.

The presence of a human chorionic gonadotropin (hCG)-like substance in human spermatozoa is reported. A highly sensitive immunocytochemical procedure was utilized (double-antibody immunofluorescence technique). Rabbit anti-hCG or rabbit anti-hCG beta-subunit was used as the first antibody. A positive fluorescence reaction was found in all human specimens analyzed and in positive controls (choriocarcinoma cells). No fluorescence was detected in other species studied (sheep, pig, goat, horse, bull, and guinea pig), nor in the negative controls. These findings open a new research area on the physiologic role of this hCG-like substance in human reproduction.

Antigen-Antibody Reactions↗
PubMed2025

Short-term diet intervention comprising of olive oil, vitamin D, and omega-3 fatty acids alters the small non-coding RNA (sncRNA) landscape of human sperm.

Offspring health outcomes are often linked with epigenetic alterations triggered by maternal nutrition and intrauterine environment. Strong experimental data also link paternal preconception nutrition with pathophysiology in the offspring, but the mechanism(s) routing effects of paternal exposures remain elusive. Animal experimental models have highlighted small non-coding RNAs (sncRNAs) as potential regulators of paternal effects. Here, we characterised the baseline sncRNA landscape of human sperm and the effect of a 6-week dietary intervention on their expression profile. This study involves sncRNAseq profiling, that was performed on a subset (n = 17) of the participants enrolled in the PREPARE trial: 9 from the control group and 8 from the intervention group. 5'tRFs, miRNAs and piRNAs were the most abundant sncRNA subtypes identified; their expression was associated with age, BMI, and sperm quality. Nutritional intervention with olive oil, vitamin D and omega-3 fatty acids altered expression of 3 tRFs, 15 miRNAs and 112 piRNAs, targeting genes involved in fatty acid metabolism and transposable elements in the sperm genome. PREPARE Trial registration number: ISRCTN50956936, Trial registration date: 10/02/2014.

Humans↗
PubMed1979

[Round cells of human sperm].

Many round cells are found whose number may become conspicuous. These cells may originate as well from germinal as from somatic lines. Electron microscopy is the only way to distinguish the two kinds of origin. In some specimens germinal cells predominate (spermattids, plurinuclear cells), in others there are many phagocytic cells which may ingest a great number of spermatozoa and this phenomeon may stimulate an azoospermy by failure of spermatogenesis. The study of human sperm (or testicular biopsies) by electron microscopy is needed to obtain the necessary information in order to orient diagnosis, prognosis and therapy.

Cell Nucleus↗
PubMed1977

Stabilization of adenylate energy charge and its relation to human sperm motility.

The adenylate energy charge of human ejaculated spermatozoa was studied when the sperm motility was perturbed by varying pH, prolonged incubation, and caffeine. Between pH 8 and 9, which was optimal for the sperm motility, the energy charge was in the physiological range of 0.8 to 0.9. Above pH 9, the mobility, ATP content, and adenine nucleotide pool declined rapidly but the energy charge was maintained slightly below 0.8. Below pH 8, the motility also dropped drastically, but the ATP, nucleotide pool, and energy charge fell only slightly. Prolonged incubations of the spermatozoa decreased the motility, ATP, and nucleotide pool. However, the energy charge would remain above 0.6. Caffeine stimulation of the motility caused a rapid fall of ATP and the reduction of the physiological energy charge by 0.2 unit, unless glucose was added. Imidazole which reduced the caffeine-stimulated motility did not alter the physiological energy charge of the spermatozoa. The study showed that the spermatozoa could maintain the energy charge above 0.6 under stress.

Adenine Nucleotides↗
PubMed1977

In vitro stimulation of human sperm motility by acetylcarnitine.

An increase in motility of ejaculated human spermatozoa was observed after the addition of acetylcaritine or carnitine. Similar results were also obtained in the diluted semen with 25--30% initial motilities. However, indirect evidence suggests that carnitine is converted to acetylcarnitine prior to its stimulatory action. In addition, this stimulation was shown to be the result of no increase in ionic strength nor any change in the levels of ATP.

Acetylcarnitine↗