A plasma-membrane progesterone receptor in human sperm is switched on by increasing intracellular free calcium

Recent studies have revealed the presence of an atypical progesterone receptor on the plasma membrane of a relatively small subpopulation of human sperm cells. In this study, we show that the receptor is present in many cells in a latent form and that the receptor function in these cells is switched on asynchronously by increasing intracellular free Ca2+ levels. Under physiological conditions, this process occurs during sperm capacitation, but it can be mimicked by a short sperm exposure to the Ca(2+)-mobilizing agent thapsigargin. These observations suggest a role of Ca2+ as a modulator of nongenomic steroid effects on the cell surface.

Solubilized human zona pellucida competes with a fucosylated neoglycoprotein for binding sites on the human sperm surface

OBJECTIVE

To evaluate the implication of fucose binding sites on the sperm surface in the sperm-zona pellucida (ZP) binding by examining the ability of a fucosylated neoglycoprotein to compete with solubilized zona proteins for sperm binding.

DESIGN

The binding of a fucosylated neoglycoprotein to spermatozoa was analyzed in relation to sperm capacitation and the actual acrosomal status. The effect of solubilized ZP material on the binding was examined.

SETTING

Private hospital, public research center, and university department.

PATIENTS, PARTICIPANTS

Healthy volunteers with normal sperm parameters.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Fluorescence signal detected by fluorescence-activated cell sorting or fluorescence microscopy on spermatozoa incubated with fluorescein isothiocyanate-labeled fucosylated neoglycoprotein.

RESULTS

There was a small subpopulation of spermatozoa that showed a strong binding activity for the fucosylated neoglycoprotein, and the size of this subpopulation increased with the time of exposure to capacitating conditions. The binding sites were located on the head (mainly on the acrosomal region) of acrosome-intact spermatozoa. The neoglycoprotein binding was competitively inhibited by solubilized ZP.

CONCLUSIONS

The data show that a commercially available fucosylated neoglycoprotein competes with solubilized ZP proteins for binding sites on the sperm surface. Further research into the relationship between the neoglycoprotein binding and zona binding is warranted to evaluate the potential diagnostic usefulness of this neoglycoprotein.

Progesterone action on the human sperm surface is potentiated by an egg-associated acrosin activator

The progesterone-induced Ca2+ influx and acrosomal exocytosis in human sperm are recently described examples of non-genomic steroid action on the cell surface. These progesterone effects are known to be inhibited by synthetic protease inhibitors. In this study we tested a hypothesis that a physiological activator of the sperm protease acrosin modulates the sperm response to progesterone. It was found that the activator augments the amplitude of the progesterone-induced Ca2+ transient and accelerates the progesterone-induced acrosomal exocytosis. These observations suggest a physiological significance of the modulation of nongenomic steroid effects by protease regulators.

Sperm treatment with pentoxifylline improves the fertilizing ability in patients with acrosome reaction insufficiency

OBJECTIVE

To test whether pentoxifylline, a drug previously shown to sensitize spermatozoa from normal samples to the action of acrosome reaction stimuli, can be used to improve the fertilizing ability of spermatozoa from patients with acrosome reaction insufficiency.

DESIGN

Prospective analysis of pentoxifylline effects on the acrosome reaction and zona-free egg penetration; retrospective comparison of IVF results with and without the use of pentoxifylline.

SETTING

Private hospital, public research center, and university-based laboratory.

PATIENTS

In vitro fertilization patients selected on the basis of a previous acrosome reaction test.

INTERVENTIONS

None in the experimental part; IVF-ET in the clinical part of this study.

MAIN OUTCOME MEASURES

Frequency of the acrosome reaction, rate of penetration of zona-free eggs, normal fertilization in IVF attempts.

RESULTS

Pentoxifylline improves the acrosome reaction scores and zona-free egg penetration rates in patients with acrosome reaction insufficiency. Preliminary clinical experience shows an improvement of IVF results in these patients.

CONCLUSIONS

In vitro pentoxifylline treatment of spermatozoa to be used in IVF improves the sperm fertilizing ability in patients with acrosome reaction insufficiency. However, the effect of pentoxifylline on the acrosome reaction should be tested individually in each patient before the application of the drug in this new indication.

Stimulation of protein tyrosine phosphorylation by a progesterone receptor on the cell surface of human sperm

Mature human sperm initiate a rapid Ca2+ influx and the acrosomal exocytosis in response to progesterone. Recent evidence indicates that both events can be induced by antibody-mediated cross-linking of a sperm surface progesterone receptor. In many other systems in which signal is generated by receptor cross-linking, protein phosphorylation on tyrosine residues is involved in the signal transduction across the plasma membrane. In this study we examined whether tyrosine phosphorylation is implicated in the function of the sperm surface progesterone receptor, too. The effect of progesterone on the phosphorylation of proteins from a sperm membrane lysate was evaluated by in vitro kinase assay and by phosphoamino acid analysis using [gamma-32P]ATP as precursor. These experiments revealed a selective increase in the tyrosine phosphorylation of a 94-kilodalton phosphoprotein in the presence of progesterone. To decide whether the progesterone-induced increase in protein tyrosine phosphorylation is actually due to the hormone action on the cell surface, living sperm were treated with a cell-impermeant progesterone receptor agonist, and the resulting changes in the cellular level of phosphotyrosine proteins were examined. These experiments showed a clear relationship between the agonist binding and an increase in the phosphotyrosine concentration in the respective cells. This relationship was lost in the presence of genistein, which also efficiently inhibited the phosphorylation of the 94-kilodalton protein and the progesterone-induced acrosomal exocytosis. These results lead to the hypothesis that protein tyrosine phosphorylation is involved in signal transduction through the sperm surface progesterone receptor and may be implicated in nongenomic steroid effects in other cell types.

Insights into the function of a sperm-surface progesterone receptor: evidence of ligand-induced receptor aggregation and the implication of proteolysis

Human spermatozoa have recently been introduced as a model for the study of rapid, nongenomic effects of steroids on the cell. Indirect evidence suggests the presence of a novel type of progesterone receptor on the cell surface; some cellular responses mediated by the receptor have been shown to be sensitive to protease inhibitors, but the molecular identity and the mode of function of this receptor are not known. Recent biochemical evidence showed that Ca2+ influx and a Ca(2+)-dependent exocytotic event (the acrosome reaction) can be induced in human sperm by antibody-mediated aggregation of the cell-surface progesterone receptor. These data suggested that progesterone receptor aggregation, occurring after ligand binding, may represent an early reaction in the signal transduction pathway. In this study we used cytological methods to examine ligand-induced changes in the distribution of the progesterone receptor in the sperm plasma membrane. We also examined the effects of trypsin and of trypsin inhibitors on the function of the receptor. Under the conditions of this study, neither trypsin nor trypsin inhibitors affected sperm viability, motility, or the acrosome reaction. However, the trypsin treatment completely abolished the ligand-binding activity of the sperm progesterone receptor. On the other hand, trypsin inhibitors did not influence the ligand binding despite their inhibitory effect on the ligand-induced exocytosis. The treatment with trypsin inhibitors was thus used to prevent the exocytotic reaction and so to preserve the plasma membrane for the study of ligand-induced receptor migration. The distribution of ligand-receptor complexes in the sperm acrosomal region remained homogeneous during incubation at 4 degrees C, but warming to 37 degrees C entailed a rapid formation of patches, followed by migration of the complexes towards the sperm equatorial region and ending by a virtually complete disappearance of the complexes from the anterior acrosomal region. It is concluded that aggregation is an early response of the sperm-surface progesterone receptor to ligand binding, that trypsin inhibitors block the function of the receptor downstream of the aggregation, and that some mechanism must exist in the plasma membrane to protect the ligand-binding site from digestion while permitting the protease action in the signal transduction mechanism.

Differential sensitivity of progesterone- and zona pellucida-induced acrosome reactions to pertussis toxin

Pertussis toxin-sensitive guanine nucleotide-binding regulatory proteins (G proteins) have previously been shown to mediate the zone pellucida-induced acrosome reaction in mammalian sperm. In this study we compared the inhibitory effect of pertussis toxin on the zona-induced acrosome reaction in human spermatozoa with that on the reaction induced by progesterone, another physiological acrosome reaction-promoting stimulus associated with the ovulated oocyte. Up to the concentration of 1 microgram/ml, pertussis toxin did not produce any direct effects on the acrosome reaction frequency nor did it influence sperm movement and viability. However, preincubation of spermatozoa with the toxin at a concentration of 100 ng/ml completely abolished the increase in the acrosome reaction frequency upon subsequent exposure to solubilized zona pellucida material. In contrast, the same treatment did not impair the ability of spermatozoa to initiate the acrosome reaction in response to progesterone. Moreover, the preincubation with pertussis toxin did not modify the changes in the intracellular concentration of calcium ions occurring after progesterone addition. These data suggest that different physiological stimuli may utilize different signal transduction pathways to induce the human sperm acrosome reaction.

Fast acrosome reaction measure: a highly sensitive method for evaluating stimulus-induced acrosome reaction

OBJECTIVE

To test a new method for evaluation of stimulus-induced acrosome reaction (AR). To determine whether this method, based on the definition of a specific staining pattern of recently reacted spermatozoa, brings an advantage of increased sensitivity as compared with a standard procedure.

DESIGN

The hypothesis that a specific staining pattern with fluorescein-labeled Pisum sativum agglutinin corresponds to recently acrosome-reacted spermatozoa was tested by analyzing the frequency of this pattern at different time points after addition of ionophore A23187, an artificial AR inducer. The AR results obtained with a new method based on this relationship were compared with those obtained with a standard method of AR evaluation.

SETTING

Private hospital, public research center, and a university-based research laboratory.

PARTICIPANTS

Healthy sperm donors.

MAIN OUTCOME MEASURE

Changes in the frequency of specific sperm-staining patterns.

RESULTS

A specific sperm-staining pattern with P. sativum agglutinin was shown to be associated with a recently occurred AR, whereas the absence of staining was typical of reactions having occurred a longer time ago. This phenomenon was used to define a formula for fast AR measure after stimulus addition. An increased sensitivity provided by this formula as compared with a standard evaluation was demonstrated.

CONCLUSIONS

Fast AR measure is a simple, easy-to-perform method for AR evaluation. It is particularly suitable for testing the effects of rapidly acting stimuli.

Effects of phosphodiesterase inhibitors caffeine and pentoxifylline on spontaneous and stimulus-induced acrosome reactions in human sperm

OBJECTIVE

To determine whether the phosphodiesterase inhibitors caffeine and pentoxifylline influence the acrosome reaction in the conditions in which they are currently used as sperm movement enhancers.

DESIGN

The frequency of acrosome reaction occurring spontaneously in capacitating media or induced by physiological (follicular fluid [FF]) and artificial (ionophore A23187) stimuli was compared in the presence and absence of the phosphodiesterase inhibitors.

SETTING

Private hospital and research laboratory.

PATIENTS, PARTICIPANTS

Patients undergoing routine semen examination before in vitro fertilization (no pathology detected) and healthy sperm donors.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Percentage of acrosome-reacted sperm determined with the use of fluorescein-labeled Pisum sativum agglutinin as acrosomal stain.

RESULTS

Caffeine alone augmented the frequency of acrosome reaction, but this effect was not observed with pentoxifylline alone. However, pentoxifylline increased sperm responsiveness to the acrosome reaction-inducing stimuli, FF and ionophore A23187.

CONCLUSIONS

The promotion of spontaneous acrosome reaction may counteract the benefits from application of caffeine as motility stimulant. On the other hand, the sensitization to physiological acrosome reaction stimuli is expected to contribute to the improvement of sperm fertilizing ability by pentoxifylline and make this drug a potential candidate for the treatment of acrosome reaction anomalies.

Sperm plasma membrane integrity measurement: a combined method

Sperm plasma membrane characteristics were measured by a combined method consisting of the hypo-osmotic swelling test and staining with either the eosine Y (HOS-eosine test) or propidium iodide dye (HOS-propidium test). Sperm samples were washed and resuspended in BWW medium (fraction I). Aliquots of the washed spermatozoa were treated by a swim-up technique to select motile spermatozoa (fraction II). After separation of motile cells, residual sperm pellets were treated separately (fraction III). These three fractions were subjected to the hypo-osmotic swelling test, lipid peroxidation measurement, and the HOS-eosine and HOS-propidium tests. The HOS-eosine test makes it possible to distinguish 4 types of spermatozoa: type 1: HOS+/eosine-; type 2: HOS-/eosine-; type 3: HOS-/eosine+ and type 4: HOS+/eosine+ (Fig. 1). HOS-propidium test shows equal results as HOS-eosine test. Fraction I spermatozoa showed 55.2 +/- 3.6% type 1; 12.6 +/- 1.0 type 2; 28.0 +/- 2.9 type 3; and 4.2 +/- 0.6 type 4 cells. Fraction II spermatozoa were characterized by high percentages of type 1 cells, low percentages of types 3 and 4, and very low values of lipid peroxidation (5 times smaller than fraction I). Fraction III showed a low percentage of type 1, a high percentages of the other types, and an enhanced value of lipid peroxidation (2 times higher than fraction I). The prognostic value of the HOS-eosine test was evaluated in an IVF programme. Preliminary results show that a high incidence of types 2 and 4 spermatozoa is often associated with fertilization failure.

Defective function of a nongenomic progesterone receptor as a sole sperm anomaly in infertile patients

OBJECTIVE

To compare the function of a novel nongenomic progesterone (P) receptor on the human sperm surface (mediating the P-induced acrosome reaction) in spermatozoa from fertile donors and from infertile patients. To examine the possible implication of defective P receptor function as an etiologic factor in unexplained male infertility.

DESIGN

Progesterone binding and P effects were assessed in sperm from infertile patients and compared with corresponding parameters for sperm from healthy donors.

SETTING

Private hospital, medical research center, and a university-based andrological laboratory.

PATIENTS, PARTICIPANTS

Sperm samples were from infertile patients (no pathology detected in their wives) attending our infertility clinic and from healthy sperm donors.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Progesterone binding sites were visualized with a fluorescein-labeled protein-P conjugate. Indo 1-AM (a fluorescent indicator of intracellular free Ca2+) was used to measure P-induced Ca2+ influx. Progesterone-induced acrosome reaction was monitored after acrosomal staining with Pisum sativum agglutinin.

RESULTS

Among 8 patient sperm samples with normal spermiogram values (of 53 examined), 5 showed a reduced percentage of P-binding spermatozoa and an abnormal response to the hormone in terms of Ca2+ influx and the acrosome reaction.

CONCLUSIONS

Defective function of a sperm surface P receptor is described in some cases of male infertility. The observed fluorescence microscopic patterns of hormone binding may be used to further investigate receptor activity in unexplained male infertility.

Selective expression of a progesterone receptor on the human sperm surface

OBJECTIVE

To visualize progesterone (P) binding sites on the sperm surface, examine the relationship between hormone binding and hormone action (acrosome reaction), and determine the size of the hormone-responsive sperm subpopulation.

DESIGN

Kinetic analysis of P binding was combined with the assessment of the hormone effect using a fluorescent acrosomal marker.

SETTING

Private hospital, medical research center, and a university-based andrological laboratory.

PATIENTS, PARTICIPANTS

Sperm samples were from healthy volunteers with normal spermiogram values.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Progesterone binding was analyzed by fluorescence microscopy and flow cytometry using P coupled to fluorescein isothiocyanate-labeled bovine serum albumin. Tetramethylrhodamine isothiocyanate-labeled Pisum sativum agglutinin was used as acrosomal marker in double-labeling experiments.

RESULTS

After in vitro capacitation, only few spermatozoa (approximately 10%) were able to bind P to the cell surface, but most of these cells subsequently generated the acrosome reaction in response to hormone binding.

CONCLUSIONS

The expression of P receptor sites on the human sperm surface is a major factor controlling the P-induced acrosome reaction. Further studies are warranted to explore if defective expression of the receptor can compromise fertility.

Influence of stabilization occlusal splints on sternocleidomastoid and masseter electromyographic activity

The present work was conducted in order to determine the effect of stabilization occlusal splints on electromyographic (EMG) activity of sternocleidomastoid and masseter muscles, in subjects with tenderness to palpation in these muscles. A full-arch maxillary stabilization occlusal splint was made for each of 14 subjects. Tonic EMG activity, as well as during saliva swallowing and maximal voluntary clenching, was recorded with and without a stabilization occlusal splint inserted. Similar tonic, as well as maximal voluntary clenching EMG activity, with and without the stabilization occlusal splint, was observed. During saliva swallowing, the activity in both muscles was significantly lower with the stabilization occlusal splint. This suggests that daytime use of the stabilization occlusal splint might improve tenderness to palpation in the studied muscles, since the frequency of swallowing function is higher during waking hours.

Progesterone action through aggregation of a receptor on the sperm plasma membrane

Rapid steroid effects, reported in several cell types, have pointed out the possibility of non-genomic mechanisms of action, presumably on cell surface receptors. Here we analyzed the effects of antibody-mediated aggregation of a novel type of progesterone receptor on the plasma membrane of human sperm cells. We report that aggregation of hormone-receptor complexes induces Ca2+ influx and a Ca(2+)-dependent exocytotic event in this system. These data suggest a possible mechanism for rapid steroid-induced events. Further research is warranted to examined if a similar mechanism is involved in rapid steroid effects in other cell types.

Distinction between true acrosome reaction and degenerative acrosome loss by a one-step staining method using Pisum sativum agglutinin

When western blots of human sperm proteins solubilized by acid extraction (presumably mainly acrosomal proteins) or by sodium dodecyl sulfate (SDS) were probed with biotin-conjugated Pisum sativum agglutinin (PSA), distinct sets of proteins were labelled in both preparations. When smears of human spermatozoa were treated with methanol either for 30 s or for 15 min and then exposed to FITC-conjugated PSA, the resulting fluorescence pattern essentially depended on the time of methanol treatment. With the longer treatment, fewer spermatozoa showed selective acrosomal labelling and more were labelled uniformly throughout, without a clear predilection for a single sperm region. With the shorter time of methanol treatment, the poorly topographically differentiated, whole-cell labelling was typical of dead spermatozoa as confirmed by a close correlation between the percentages of spermatozoa showing this type of labelling and of those stained supravitally with Hoechst 33258. The preferential whole-cell labelling of dead spermatozoa with PSA is considered to be due to increased availability of the nonacrosomal set of PSA-reactive sites in dead spermatozoa after a short treatment with methanol, whereas this treatment is probably not sufficient to expose most of these sites when applied to living spermatozoa. The simplicity of the staining protocol makes this method feasible in routine work in a number of clinical and research applications.

Sperm plasma membrane integrity in fertile and infertile men

Sperm plasma membrane characteristics were analysed by a combined method, the HOS-eosine test (HOS-E test), that consists of the hypoosmotic swelling test (HOS test), and the eosine-Y staining. Semen samples were categorized into four groups (Normo-, Oligo-, Astheno-, and Oligoasthenozoospermic) and subjected to the standard analysis (spermiogram), HOS test, eosine-nigrosine test (reflecting sperm viability); and HOS-E test. HOS-E test makes it possible to distinguish four groups of spermatozoa: type 1, HOS+/eosine-; type 2, HOS-/eosine-; type 3, HOS-/eosine+; and type 4, HOS+/eosine+. Normozoospermic samples showed 61.2 +/- 1.4% type 1, 9.2 +/- 0.8% type 2, 22.6 +/- 1.1% type 3, and 6.8 +/- 0.6% type 4 spermatozoa. Oligozoospermic samples showed no significant differences in these values, whereas asthenozoospermic samples showed a higher percentage of types 3 and 4 and a lower percentage of type 1. Oligoasthenozoospermic samples showed high percentages of types 2, 3, and 4 and a low percentage of type 1. Sperm plasma membrane integrity is a necessary condition for motility and fertilization. So, it is not surprising that semen samples with abnormal motility showed a HOS-E result indicative of a defective plasma membrane.

Electrocardiographic alterations during treatment of mucocutaneous leishmaniasis with meglumine antimoniate and allopurinol

The electrocardiographic (ECG) changes in Bolivian patients with mucocutaneous leishmaniasis, treated with meglumine antimoniate and allopurinol, were evaluated. Electric changes due to the antimonial compound appeared in 45% of the patients, and consisted of repolarization alteration, principally affecting the T wave and the S-T segment. The changes disappeared within 2 months following the end of the antimonial treatment. In patients with associated Chagas disease and leishmaniasis, antimonial therapy did not aggravate the ECG changes characteristic of Chagasic cardiopathy.

Inhibition of natural killer activity in porcine mononuclear cells by African swine fever virus

The coincubation at 37 degrees C for 24 hours of swine peripheral blood mononuclear cells with African swine fever virus inhibited in part the natural killer activity shown by cells incubated without the virus. This inhibition depended on the dose of the virus and on the time that cells were incubated with it. When the virus preparation was fractionated by ultracentrifugation, most of the inhibitory activity was found in the sedimented fraction, where viral particles were present; however, the loss of inhibitory activity in respect to the whole virus preparation indicated that some inhibitory activity was present in the supernatant fraction, probably as factors released by infected cells. Most of the inhibitory activity shown by the sedimented fraction was lost when the virus was inactivated by ultraviolet radiation, indicating an active role of virus infectivity in the inhibition.

Expression of D-mannose binding sites on human spermatozoa: comparison of fertile donors and infertile patients

OBJECTIVE

The hypothesis that defective expression of D-mannose binding sites (presumptive elements of the sperm-zona pellucida binding mechanism) is related to male infertility was tested.

DESIGN

Experiments were performed on sperm samples from two groups of men classified, respectively, as fertile and infertile, based on their reproductive history.

SETTING

The study was carried out in an andrologic laboratory of a University Hospital.

PATIENTS, PARTICIPANTS

Fertile men were healthy sperm donors; infertile men were patients with fertility problems.

INTERVENTIONS

D-mannose binding sites were visualized by fluorescence microscopy using a mannosylated neoglycoprotein probe.

MAIN OUTCOME MEASURES

The hypothesis as reported in the objective section was formulated before data collection and was not modified thereafter.

RESULTS

Sperm from fertile men displayed a characteristic pattern of changes in the expression of D-mannose binding sites during in vitro capacitation. This pattern was altered in sperm from infertile men.

CONCLUSIONS

If the relationship between defective expression of D-mannose binding sites and decreased sperm fertilizing ability is validated by parallel tests of sperm-zona binding, it may be used for development of chemical tests replacing the current ones using human zonae pellucidae.

Bilateral mammary abscess and uveitis caused by Brucella melitensis--report of a case

Soft tissue locations of Brucella are a rare finding. We report the isolation of Brucella melitensis from a suspected breast tumour of a woman who also showed signs of uveitis. Three weeks after surgical drainage and despite antimicrobial therapy a new abscess developed on the other breast whose culture also yielded Brucella. As observed, unusual localization of brucellosis without previous penetrating injury may be the only manifestation of chronic infection.

Effect of follicular fluid on sperm movement characteristics

Human spermatozoa previously washed from seminal plasma and incubated in capacitating medium were exposed to human follicular fluid (FF) for different time periods and their movement characteristics were examined by computer-assisted digital image analysis. No differences from control samples were observed after short exposures (15 minutes and 2 hours). When the exposure was prolonged to 6 hours, spermatozoa incubated in the presence of FF displayed significant differences in some movement characteristics as compared with samples incubated without FF supplement. When only rapidly moving sperm subpopulations were considered, these effects of FF were similar to those produced by a short incubation with the solubilized cumulus oophorus matrix as described previously. After 24 hours of incubation, there was a remarkable beneficial effect of FF on motility preservation. Possible physiological and clinical implications are discussed.

Acrosin activation follows its surface exposure and precedes membrane fusion in human sperm acrosome reaction

Evidence has accumulated suggesting multiple roles of acrosin in fertilization, including its participation in early steps of gamete recognition and binding. However, the implication of acrosin in many of these processes is not compatible with its presumptive sequestration within the sperm acrosome until a late phase of the acrosome reaction. In an earlier study (J. Tesarik, J. Drahorad, J. Peknicova, 1988, Fertil. Steril. 50, 133–141), we reported the binding of an anti-acrosin monoclonal antibody (MO-AKR.1) to the plasma membrane overlying the acrosome of human spermatozoa starting the acrosome reaction. In this study, we characterized further this antibody with regard to its reactivity with different forms of acrosin and found that it recognizes specifically an active form of this enzyme and does not react with its proenzyme form. MO-AKR.1 was thus used as a probe for in situ analysis of acrosin activation during the acrosome reaction. When suspensions of living spermatozoa were incubated with MO-AKR.1 and with another monoclonal antibody (T6) directed to an intra-acrosomal cytoskeletal protein, significantly more spermatozoa reacted with the former antibody than with the latter; this indicated that some of the spermatozoa showing acrosin immunoreactivity carried activated acrosin on the cell surface, while their acrosome was still impermeable to intra-acrosomal-directed probes. The size of this particular sperm subpopulation was increased by the action of follicular fluid (a natural acrosome reaction inducer), but not ionophore A23187 (an artificial acrosome reaction inducer); it corresponded to the proportion of spermatozoa showing acrosin immunoreactivity on the plasma membrane but neither intra-acrosomal staining nor perceptible membrane perturbations when examined by immunoelectron microscopy. When spermatozoa were pre-incubated with protease inhibitors before the addition of acrosome reaction-inducing agents, the percentage of cells binding MO-AKR.1 was markedly reduced. These data suggest that limited acrosin activation on the sperm plasma membrane is an early event in the physiological acrosome reaction.

Inhibitory effect of African swine fever virus on lectin-dependent swine lymphocyte proliferation

The incubation of swine peripheral blood mononuclear cells (PBMC) with African swine fever (ASF) virus preparations strongly inhibited the proliferative response of lymphocytes to PHA and other lectins. The inhibition, which persisted after inactivation of the virus by UV radiation, was dependent upon the dose and the time that virus preparations were present in cultures. When virus preparations were fractionated by ultracentrifugation, the inhibitory activity resulted to be soluble, whereas no activity was found in the sedimented viral fraction. However, the preincubation during 4 days of this sedimented fraction with swine PBMC, before the addition of the mitogen, restored the inhibitory activity. The results obtained suggest that the inhibition is mediated by one or more soluble factors released by swine PBMC after coincubation with ASF virus in a time dependent process. These factors show a molecular weight between 40 and 80 kDa by gel filtration chromatography. The inhibitory activity described in the present paper is an indication of inhibition of lymphocyte function produced by ASF virus which can help to understand how this virus escapes from the host immune system.

Hypoosmotic swelling test in normo-, oligo-, astheno- and oligoasthenozoospermic men before and after swim-up separation of spermatozoa

Semen samples from a total 58 men were examined by routine semen analyses and the hypoosmotic swelling test. Samples were classified as normal, oligo-, astheno- or oligoasthenozoospermic on the basis of spermatogram findings. The latter three groups showed a significant decrease in the percentage of HOS positive forms in comparison to normal spermograms. All these samples were treated with the swim up technique to select motile spermatozoa, using a procedure similar to that routinely employed in clinical settings for homologous intrauterine insemination (IUI). Following swim-up, the ejaculate supernatant and residual precipitate were subjected to the hypoosmotic swelling test (HOS test), and the percentage of normal forms was determined in the three groups. The results showed greater percentages of HOS positive, normal and HOS positive-normal forms in the group of normal individuals than in any of the other three groups. The supernatant used in IUI showed a significant increase in percentage HOS positive spermatozoa, normal forms and spermatozoa which were both normal and HOS positive in comparison with the other two groups in normal and oligozoospermic samples, but not in samples which presented suboptimal motility (astheno- and oligozoospermia). In conclusion, the swim-up technique is effective in separating high-quality spermatozoa in normo- and oligozoospermic samples, although its effectiveness with astheno- and oligoasthenozoospermic samples should be questioned.

Zinc levels in seminal plasma of fertile and infertile men

Zinc levels were measured in seminal plasma from 78 men classified on the basis of spermogram analyses into five groups: normo-, oligo-, astheno-, oligoastheno- and azoospermia. Higher zinc levels were found in seminal plasma from the group of asthenozoospermia men in comparison to normo-, oligoastheno- (p less than 0.001), oligo- and azoospermia men (p less than 0.01), while no significant differences appeared when other group pairs were compared. Seminal plasma zinc levels were positively correlated with sperm density (r = 0.6358, p less than 0.01) in asthenozoospermia men, whereas a significant negative correlation was seen in all groups between percentage forms showing normal progressive motility and zinc concentration in seminal plasma. Although zinc is required in seminal plasma for normal spermatozoon functionality, excessively high levels of this ion may be related with defective motility in asthenozoospermia samples.

[Effects of different methods of ovarian stimulation in adult rats]

The in vitro fecundation programs normally use different ovarian stimulation agents. The purpose of the present study was to compare the effects of some of these agents on indices of ovulation and serum levels of estradiol, progesterone, and FSH. Treatments studied consisted of clomiphene citrate, PMSG alone and in combination with clomiphene citrate, pure human FSH and epimestrol. The data obtained show PMSG alone and PMSG plus clomiphene citrate to be the most effective treatments, in terms of number of oocytes harvested. No differences were noted between serum levels of oestradiol, progesterone and FSH.

Testosterone implants into the lateral septum of male rats, a positive effect on LH and FSH secretion

After two days, testosterone implanted into the lateral septum increased serum levels of LH and FSH in male Wistar rats. As measured by RIA, LH in animals with testosterone implanted in them in comparison to those with an empty cannula was 0.220 +/- 0.015 vs. 0.111 +/- 0.019 ng/ml; p less than 0.001 and FSH was 3.20 + 0.21 vs. 1.50 + 0.21 ng/ml; p less than 0.001. Serum testosterone was not increased to a statistically significant extent by the implants (4.12 +/- 0.54 vs. 2.87 +/- 0.42 ng/ml; ns). It was concluded that testosterone or possibly one of its metabolites acting in the lateral septum facilitates the release of LH and FSH.

[Influence of body weight on gonadotrophins and steroid hormone levels in menstruating women]

In order to study the effect of obesity or underweight on gonadotropins and steroid hormone levels, serum concentrations of FSH, LH. Testosterone, Estradiol, Estrone, 17-OH-Progesterone and SHBG were measured by RIA in obese, underweight and control women, all menstruating in the follicular phase. Serum concentrations of all parameters measured did not differ significantly in the underweight and control groups. All obese women had higher levels of estrone than the control group, and only obese patients with a body mass index above 39 showed a lower SHBG level than that of the control group. The data suggest that the increased levels of estrone could play a role in the amenorrhea of obese women.

Calcium metabolism in post-menopausal women

To investigate some parameters involved in postmenopausal calcium metabolism we have measured FSH, LH, estradiol (E2), parathyroid hormone (PTH) calcitonin (CT), 25-hydroxy-vitamin D3 (25-OH-D3), total calcium (CaT) and ionic calcium (Ca++) serum levels in 20 healthy postmenopausal women and 20 premenopausal women. The results reported show that the decrease of estradiol levels are associated with a significant decrease in 25-OH-D3 serum levels, possibly as result of a lower concentration of vitamin D binding protein, which is extremely sensitive to changes in oestrogen levels. The PTH levels were similar in both groups studied, which might be explained together with increased ionic calcium levels in postmenopausal women, by decreased parathyroid sensitivity to the blocking action of Ca++.

[Hypothalamo-hypophyseo-gonadal axis in individuals with chronic renal insufficiency subjected to hemodialysis]

The role of pituitary and sexual hormones in 21 patients with chronic renal failure (CRF) and related impotence and loss of libido who were being treated by hemodialysis and in 15 normal male controls has been studied. In both groups the serum levels of FSH, LH and TSH, PRL before and after injection of both LHRH and TRH were measured as well as the basal levels of Testosterone (T) and Estradiol (E2). The results show similar values for testosterone in both groups and statistically significant higher basal values for FSH, LH, TSH and PRL and lower basal values for E2 in CRF patients.

Role of the septum on LH, FSH and prolactin secretion in male rats

Serum concentrations of luteinizing hormone (LH) follicle-stimulating hormone (FSH), prolactin (PRL) and testosterone were measured by radioimmunoassay in male Wistar rats: (a) Four days after a septal lesion (n = 19) and (b) Just following electrical stimulation of the septum (n = 15). Septal lesions induced a significant decrease in serum LH (16.37 +/- 2.01 vs. 30.27 +/- 2.08 ng/ml; p less than 0.001) and testosterone concentrations (0.53 +/- 0.05 vs. 1.01 +/- 0.14 ng/ml; p less than 0.02). No significant changes were observed for FSH or PRL levels. Electrical septal stimulation induced an increase in serum levels of LH (211.5 +/- 46.4 vs. 29.6 +/- 11.5 ng/ml; p less than 0.01) and FSH (703 +/- 83 vs. 378 +/- 57 ng/ml; p less than 0.01), without changes in PRL or testosterone concentrations. From these data we conclude that in male rats the septum may play a role in the mechanisms controlling gonadotropins release by the anterior pituitary gland.

Effects of sulpiride on levels of FSH, LH and steroid hormones

In order to study the effects of prolactin upon the gonadotrophins and steroid hormones, hyperprolactinaemia was induced by the administration of sulpiride. 12 men between the ages of 18 and 20 were given 3 capsules of 50 mg of sulpiride daily for a period of 15 days, and the following parameters being measured before and after the treatment: (prolactine, FSH, LH, testosterone, estradiol, ACTH and DHEA-S) by RIA, (cortisol) by fluorimetry and (etiocholanone, androsterone, pregnandiol, pregnantriol, pregnantriolone, 11-keto etiocholanone and 11-OH androsterone) by gas chromatography. Our results show that on termination of the treatment there was a significant rise in the prolactin and DHEA-S serum levels and a drop in the FSH serum levels but not of LH. In addition there was a marked increase in all the androgen levels studied, (etiocholanone, androsterone and 11-keto etiocholanone) with the exception of testosterone.

The Great Tumaco, Colombia Earthquake of 12 December 1979

Southwestern Colombia and northern Ecuador were shaken by a shal-low-focus earthquake on 12 December 1979. The magnitude 8 shock, located near Tumaco, Colombia, was the largest in northwestern South America since 1942 and had been forecast to fill a seismic gap. Thrust faulting occurred on a 280- by 130-kilometer rectangular patch of a subduction zone that dips east beneath the Pacific coast of Colombia. A 200-kilometer stretch of the coast tectonically subsided as much as 1.6 meters; uplift occurred offshore on the continental slope. A tsunami swept inland immediately after the earthquake. Ground shaking (intensity VI to IX) caused many buildings to collapse and generated liquefaction in sand fills and in Holocene beach, lagoonal, and fluvial deposits.

Plasmid-determined resistance to fosfomycin in Serratia marcescens

Multiple-antibiotic-resistant strains of Serratia marcescens isolated from hospitalized patients were examined for their ability to transfer antibiotic resistance to Escherichia coli by conjugation. Two different patterns of linked transferable resistance were found among the transconjugants. The first comprised resistance to carbenicillin, streptomycin, and fosfomycin; the second, and more common, pattern included resistance to carbenicillin, streptomycin, kanamycin, gentamicin, tetracycline, chloramphenicol, sulfonamide, and fosfomycin. The two types of transconjugant strains carried a single plasmid of either 57 or 97 megadaltons in size. Both of these plasmids are present in parental S. marcescens strains resistant to fosfomycin. The 57-megadalton plasmid was transformed into E. coli.

Saturation kinetics for steady-state pulmonary CO transfer

Steady-state diffusing capacity of the lungs for carbon monoxide (DLCO) was measured in 13 anesthetized, paralyzed dogs ventilated at constant tidal volume and rate, using four different inspired CO levels (190, 600, 1,110, and 2,000 ppm). DLCO increased and reached a maximum as the inspired CO level was raised from 190 to 600 ppm. Further increases in inspired CO concentration were accompanied by a decrease in inspired CO concentration were accompanied by a decrease in DLCO. CO dead space and Pao2 remained constant at all inspired O2 levels. In some experiments a second set of measurements was made, the results of which were similar to those of the first set. The results cannot be explained by changes in CO back pressure, pulmonary capillary volume, or reaction rate of CO with hemoglobin, but can be explained if there is carrier-mediated CO transport in the alveolar capillary membrane.

Intramuscular lorazepam versus pentobarbital premedication: a comparison of patient sedation, anxiolysis, and recall

In a double-blind, controlled study in 40 veterans, IM lorazepam was significantly superior to IM pentobarbital as a preoperative sedative and in ability to suppress the memory of events of the operative day. A trend was noted (not statistically in this small series) toward greater patient acceptance of lorazepam. No important adverse effects or changes in vital signs occurred with either agent.

Comparison of Various Carbon Adsorbents and Quantitative Elution and Separation of Forty-two Pesticides from a Carbon-Solka Floe Cleanup Column

Ten different carbons were investigated as adsorbents in a column cleanup procedure for extracts of lettuce and carrots. Organochlorine pesticides were eluted with 175 nil of 1.5% acetonitrile in hexane. The quantitative elution of 13 pesticides as a mixture with and without the presence of carrot or lettuce extract was determined by gas-liquid chromatography (GLC) with electron capture detection (ECD). The mean recovery values for each pesticide from all carbons, excluding Norit A neutral, ranged from 87 to 106% with a coefficient of variation (C) of 3 to 11. In the presence of plant extracts the individual pesticide recoveries for 6 carbons ranged from 75 lo 99% with a C of 6 to 16. All pesticides from 9 individual carbons had mean recovery values ranging from 93 to 108% with a C of 5 to 10. In the presence of plant extracts these values were 81 to 100% with a C of 8 to 12. Four carbons (Darco G60, Darco S51, Nuchar C-190N, Norit FQP) were considered satisfactory in the cleanup procedure. The procedure was applied to quantitative elution of 42 pesticides representing insecticides, fungicides, and herbicides from a Darco G60-Solka Floe cleanup column. The mean per cent recoveries (3 determinations) ranged from 82 to 112 with C from 2 to 10 for 38 compounds. The mean per cent recovery of EPN was 108 with a C of 13. The per cent recoveries of three compounds were considered low: Thimet 72, Daconil 73, and Guthion 77. Twenty of the pesticides as three mixtures containing 2, 4, and 14 compounds were added to plant extracts of carrots, potatoes, wheat, and pineapples. The mean per cent recovery values ranged from 81 to 108 with a C range of 2 to 10 for 17 compounds