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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The concentrations of calcium, magnesium, and zinc were measured by atomic absorption spectrometry. The concentrations of all three cations were found to be strongly correlated with one another and with acidity (pH). Analysis of the relative concentrations in prostatic fluid, split ejaculates, and whole seminal plasma confirmed an almost exclusively prostatic origin of these cations. Semen quality, as judged by motility, vitality, concentration, and morphology of spermatozoa, was inversely related to cation concentrations. Therefore, we recommend adoption of the measurement of seminal divalent cations as part of the routine andrologic examination.
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PMID:The cation composition of the seminal plasma and prostatic fluid and its correlation to semen quality. 2 90

Retrograde ejaculation is an uncommon but treatable form of male infertility. Successful recovery of motile spermatozoa from a post-ejaculatory urine for artificial insemination is dependent on careful regulation of osmolarity and acidity of the bladder contents into which the ejaculate emanates, and the separation of the motile spermatozoa from the debris and cells which are found in these specimens. A pregnancy established by artificial insemination of spermatozoa recovered from bladder contents of a patient suffering from retrograde ejaculation is presented. The techniques for preparing the urinary bladder for spermatozoal survival and the removal of debris and cells by delicate centrifugation are discussed.
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PMID:A new sperm collection method for treatment of retrograde ejaculation. 197 66

Extensive testing of collagen sponge as a vaginal contraceptive (mechanical and chemical) showed that the original expectations regarding the safety, convenience, and efficacy were not met. The collagen sponge was tested both as a cylinder and as a diaphragm and used as such or impregnated with spermicidal detergent or with zinc salt. The collagen sponge must be larger than 6 cm in diameter in order to serve as a mechanical barrier that will not be dislodged during physical activity. This creates problems with the ease of insertion and with the partners' awareness of the barrier. When the collagen sponge containing ejaculate is left in the vagina greater than 48 hours, it develops an offensive odor. The original acidity of the collagen sponge (pH 3.5, 0.1 mol/L) is soon neutralized by the large volume of alkaline vaginal secretions. In vitro studies showed that up to 10 mg of nonoxynol 9 per milliliter of growth medium did not inhibit the growth of Staphylococcus aureus. These effects, as well as the large surface area of the resilient sponge, present a potential risk for growing staphylococci within the collagen sponge. The capacity of the collagen sponge to absorb a large volume of cervical and vaginal fluid produced two symptoms that were annoying to the volunteers: an awareness of either vaginal dryness during intercourse or, conversely, saturation of the sponge from the vagina. Postcoital studies showed viable spermatozoa in the cervical mucus in 25% of the tests with the nonmedicated cylindrical sponge but in only 6% of tests with the sponge containing nonoxynol 9. The results of clinical trials conducted at four centers support the view that collagen sponge as a vaginal contraceptive barrier method is inconvenient to both partners, not effective enough to compete with present methods of vaginal contraception, and possibly might be unsafe because of the capacity to grow bacteria. Despite the negative end result of this goal-oriented research, we believe that our studies have contributed to a better understanding of vaginal physiologic features, the safety and effectiveness of spermicidal detergents, and the mechanisms of vaginal malodor. Although the acceptability study showed some advantages of the collagen sponge over the rubber diaphragm, the overall acceptability of the collagen sponge diaphragm was no better than that of the rubber diaphragm. For all these reasons, including the possible risk of an increased incidence of toxic shock syndrome, we have discontinued further testing of either type of collagen sponge as a vaginal barrier method.
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PMID:Collagen sponge as vaginal contraceptive barrier: critical summary of seven years of research. 298 68

Chlamydia trachomatis is one of the most common causative agents of ascending genital infection. The mechanisms by which microorganisms spread to the upper genital tract are, however, by and large still unknown. Attachment of serovars D, H, and I of C. trachomatis to human spermatozoa was observed in in vitro experiments. The specimens were studied by immunofluorescence tests using monoclonal antibodies to C. trachomatis and transmission electron microscopy. The adherence of chlamydiae to spermatozoa was enhanced by increasing the acidity of the test environment, that is, from pH 8.0 to 4.0, by increasing the concentration of chlamydial cells in relation to spermatozoa, and by increasing the incubation time (up to 1 hour). Sperm penetration tests, using capillary tubes filled with albumen from hen's eggs, revealed that spermatozoa, when progressing forward, can carry chlamydiae attached to them.
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PMID:In vitro tests of the adherence of Chlamydia trachomatis to human spermatozoa. 637 85

The objective of the present experiments was to study some properties of fowl spermatozoa which may play a role in the sperm storage and emptying mechanism of the uterovaginal sperm storage tubules (SST) of the hen. The effects exerted by different amino acids (aspartic acid, Asp; glutamic acid, Glu; gamma-aminobutyric acid, GABA; glycine, Gly) and by the pH of the environment at 24 and 39 degrees C on the motility and agglutination of cock spermatozoa were studied in vitro. The spermatozoa did not show agglutination in the presence of Asp and Glu, and became immobilised if the concentration of Glu or the acidity of the environment was increased. In neutral solutions of GABA and Gly or in a faintly alkaline solution characteristic plait-like conglomerations could be seen. The motility of spermatozoa immobilised by Glu could be restored in a varying degree by the addition of GABA or Gly. At a temperature of 24 degrees C, the spermatozoa became immobilised in a medium of pH 6.0 while showed maximum motility at pH 7.1. At 39 degrees C, the spermatozoa were immobilised at higher pH (6.2) and required a pH value as high as 7.4-7.5 to show the highest motility. Spermatozoa inactivated in an acidic solution could be immediately mobilised by alkalisation of the medium, irrespective of the Ca2+ content of the solution. Thus, Ca2+ was not found to play a role in the reactivation of spermatozoa. Nevertheless, marked differences were observed in the maintenance of sperm motility between solutions either containing or lacking Ca2+. As the concentration changes of the above-mentioned amino acids and the pH changes were found to affect the motility and agglutination of spermatozoa in vitro, they may influence also the regulatory mechanism of the uterovaginal SST during the egg-formation cycle in vivo.
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PMID:Motility and agglutination of fowl spermatozoa in media of different amino acid content and pH value in vitro. 890 46

Changes induced by human sexual arousal serve reproductive and recreational functions. The current sexual phase model (desire, excitation, orgasm, and resolution) conveys little about this duarchy. Lack of spontaneous sexual desire in a third of nonclinic females indicates that the D phase needs splitting into D1 (the spontaneous [endogenous] activation of desire) and D2 (desire activated by sexual excitation at and during the E phase). Attempts to link D1 with reproduction by studies monitoring it over the menstrual cycle revealed a D1 peak just before or at ovulation, but its reliability is criticized because of the poor identification of the time of ovulation. Sexual arousal initiates enhanced genital blood flow, leading to the formation of a neurogenic transudate, lubricating the vagina, partly buffering its acidity, and increasing its oxygen tension all features that enhance spermatozoal function and survival. Orgasm occurs with vaginal and uterine contractions. The latter have been misinterpreted as powering rapid sperm transport to facilitate fertilization, but such fast transport would lead to the tubal deposition of noncapacitated, incompetent spermatozoa. Vagino-cervico elevation, however, delays rapid sperm transport and allows the initiation of decoagulation and sperm capacitation before the elevation resolves. The fastest transport of spermatozoa from cervix to the fallopian tubes occurs in the nonaroused female by uterine/subendometrial smooth muscle peristalsis. There is some evidence that even this may be reduced for a time after coitus, adding to the transport delay. If a number of the changes induced by sexual arousal are inadequately expressed, sexual as well as reproductive dysfunctions could arise.
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PMID:The physiology of sexual arousal in the human female: a recreational and procreational synthesis. 1223 7

The diaphragm is one of the least accepted methods of birth control by adolescents. It consists of a cup made of latex with a metallic ring at its base, its diameter ranges from 50 to 105 mm, and in its concave part a spermatocide can be placed to immobilize and destroy spermatozoa. It acts as a physical barrier to sperm at the cervical canal. By maintaining vaginal acidity and by making it difficult for cervical mucus to neutralize the vaginal ph, a hostile environment is created for spermatozoa. Its failure rate is 24-29 pregnancies per 100 women years. The right size has to be fitted to allow for the 3-5 cm increase in the depth of the vagina during sexual excitation in nullipara. It can be inserted 4-6 hours prior to intercourse in order not to interfere with sexual spontaneity, and removal should not occur until 8 hours later. Indication is for adolescents with infrequent sexual activity, those who stopped using the pill, or whose IUD had been removed. It is contraindicated for various medical conditions and infections. Toxic shock syndrome can occur, it it stays in too long. It offers some protection against sexually-transmitted diseases and cervical neoplasm due to the lack contact with the seminal fluid. Allergic reactions to spermatocides can occur in addition to various side effects due to ill-fitting diaphragms. The low acceptability by teenagers is attributable to its lower rate of effectiveness than the pill and little motivation for its use, although it should be recommended for those who are afraid of the side effects of the pill and IUD.
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PMID:[The diaphragm and the adolescent]. 1228 26

IVF of porcine oocytes has been carried out in many laboratories. However, polyspermic fertilization is still a major issue to be solved. It is well known that besides the nucleus, oocyte organelles and the cytoplasm have to undergo a final maturation process before they become fully competent for fertilization. Until now, it is still uncertain whether the zona pellucida (ZP) must also undergo a maturation process and what impact the maturation status may have on sperm recognition and monospermic fertilization. Our data show that the ZP undergoes biochemical changes in the final maturation phase of the oocyte prior to fertilization. During zona maturation, the induction of the acrosome reaction in spermatozoa bound to the zona pellucida shows a different time pattern. Additionally, it was shown by 2D gel electrophoresis that after maturation, ZPA moved 0.8 pI units and ZPB/ZPC 1.3 pI units in the direction of the anode, indicating increased acidity. These preliminary studies indicate that the maturation processes of the oocyte involves biochemical and functional alterations in the zona pellucida. In addition, the morphology of the porcine ZP was investigated before and after maturation at the GVI and metaphase II stage as well as 1h after onset of IVF. No significant consistent structural changes were seen between immature oocytes and those matured in vitro for 48 h. However, at 24 h, the zona structures were more similar to those in in vivo matured oocytes. This phenomenon needs to be elucidated. So far, the only way to avoid polyspermic penetration is to reduce the number of spermatozoa per oocyte used for IVF. The amount depends on the treatment of the sperm and has to be set for each individual boar.
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PMID:Zona pellucida characteristics and sperm-binding patterns of in vivo and in vitro produced porcine oocytes inseminated with differently prepared spermatozoa. 1562 4

Polyspermic fertilization is still a major issue in porcine IVF systems. New information is available to characterize the zona pellucida (ZP) at different developmental stages by scanning electron microscopy (SEM) and by confocal microscopy to show the distribution of ZP glycoproteins. SEM images indicated no differences between in vivo and in vitro matured oocytes; however a change in the surface structure between immature and matured oocytes, as well as between mature oocytes and preimplantation embryos was obvious. In addition, spermatozoa were more tightly fixed in the ZP of in vivo produced compared to the ZP of in vitro produced embryos. The ZP undergoes biochemical changes during maturation prior to fertilization. The acidity of the ZP increases during maturation as indicated by a shift of 1.3 pl units for ZPB/ZPC and 0.8 pl units for ZPA in 2D gel electrophoresis, which is based on increasing sulfation of the oligosaccharides during maturation. Mass spectrometry in combination with in-gel deglycosylation allowed the mapping of new glycosylation sites. Functionality of the ZP also depends on its maturation status. Induction of the acrosome reaction was delayed when capacitated spermatozoa were exposed to immature oocytes.
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PMID:Structural, biochemical and functional aspects of sperm-oocyte interactions in pigs. 1686 27

In the epididymis, spermatozoa acquire their ability to become motile and to fertilize an egg. A luminal acidic pH and a low bicarbonate concentration help keep spermatozoa in a quiescent state during their maturation and storage in this organ. Net proton secretion is crucial to maintain the acidity of the luminal fluid in the epididymis. A sub-population of epithelial cells, the clear cells, express high levels of the proton-pumping V-ATPase in their apical membrane and are important contributors to luminal acidification. This review describes selected aspects of V-ATPase regulation in clear cells. The assembly of a particular set of V-ATPase subunit isoforms governs the targeting of the pump to the apical plasma membrane. Regulation of V-ATPase-dependent proton secretion occurs via recycling mechanisms. The bicarbonate-activated adenylyl cyclase is involved in the non-hormonal regulation of V-ATPase recycling, following activation of bicarbonate secretion by principal cells. The V-ATPase is also regulated in a paracrine manner by luminal angiotensin II by activation of the angiotensin II type 2 receptor (AGTR2), which is located in basal cells. Basal cells have the remarkable property of extending long and slender cytoplasmic projections that cross the tight junction barrier to monitor the luminal environment. Clear cells are activated by a nitric oxide signal that originates from basal cells. Thus, a complex interplay between the different cell types present in the epithelium leads to activation of the luminal acidifying capacity of the epididymis, a process that is crucial for sperm maturation and storage.
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PMID:Regulation of luminal acidification in the male reproductive tract via cell-cell crosstalk. 1944 84


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