Relation of human sperm acrosin activity and fertilization in vitro

The aim of the study described here was to determine the possible contribution of the acrosin activity test to routine semen analysis in enhancing the precision of the prognosis of IVF success in a group of patients in which the contribution of the egg factor to infertility was ruled out (20 cases) compared to a control IVF group (39 cases). Semen analysis, acrosin activity and acrosome ultrastructure were determined for all semen samples. The group with high fertilization rates was comprised of normozoospermic patients while the group with low fertilization rates was comprised of astheno-teratozoospermic patients. The mean acrosin level of the positive IVF group was significantly higher than that of the negative group (51.7 ± 33.2 and 28.6 ±13.7, respectively). Two parameters: per cent motile spermatozoa and acrosin level, were found to have a significant positive correlation with subsequent successful IVF ( r = 0.36, P < 0.006; r = 0.37, P < 0.004, respectively); and agenesis of the acrosome was found to have a significant negative correlation ( r = -0.33, P < 0.01). The ability of these parameters to correctly predict fertilization success was 59%, with 5% false positive, among which 15.4% was predicted solely by the acrosin level (above 54 μIU 10⁶ cells⁻¹) and 23% solely by per cent motile spermatozoa (above 50%). Abnormalities of the acrosome ultrastructure did not contribute further to the correct classification. The apparent clinical benefit of the acrosin level test is discussed.     

Adenosine triphosphate and motility characteristics of fresh and cryopreserved human spermatozoa

The concentration of ATP and the motility of human spermatozoa was measured in fresh and cryopreserved cells from the same 15 ejaculates. No coherent picture of the relationship between motility and ATP concentration emerged in whole semen or in spermatozoa washed by repeated centrifugation and resuspension in Biggers Whitten and Whttingham medium. This may have been due to the presence of dead spermatozoa and contaminating cells. After preparation on a Percoll gradient, the ATP concentration in fresh and cryopreserved spermatozoa was the same (6±0.7 nmol/10⁸ spermatozoa) but 85±2.5% of the fresh spermatozoa were progressively motile with an average path velocity of 55±3.5 pm/s compared to corresponding values of 33±5.3% and 44±3.4 μm/s in frozen/thawed spermatozoa. This suggests that the poor motility of cryopreserved spermatozoa does not result from deficient ATP production. No relationship was found between ATP concentration and the ability of motile spermatozoa in the ejaculate to survive freezing.     

Hemodynamic and Cardiometabolic Effects of Prenalterol in Patients with Gram Negative Septic Shock

The hernodynamic eflects of prenalterol, a new inotropic agent, were investigated in 10 patients with gram negative septic shock. In four of the patients, coronary sinus blood flow (CSF) and myocardial oxygen and lactate extraction were also determined. After baseline hemodynamic measurements, prenalterol was infused intravenously over a 10-min period to a total dose of 150 pg/kg. All patients responded within 15 min after completion of prenalterol infusion by increasing mean arterial pressure from 57±11 to 75 ± 20 mmHg (7.58f 1.46 to 9.97±2.66 kPa), (+32%), ( P<0.01 ) and cardiac index from 2.65±0.40 to 3.80±0.47 l min^-l m^-2 (+44%) ( P < 0.001). There was no change in heart rate or systemic vascular resistance, nor were any arrhythmias recorded. The urinary output increased significantly. After prenalterol, CSF increased from 185kl 4 to 246±14 ml.min-¹, (+33%), (P<0.001) and myocardial oxygen and lactate extraction rose from 19.8±2.1to26.6±2.1 ml O₂.min^-1, (+ 34%) (P<0.00l) andfrom33.2±2.3 to44.7k2.1 μmol.min^-1, (+35%), (P<0.001), respectively. The total body oxygen consumption increased from 287f 13 to 348±23 ml O₂.min^-1, (+21 %), ( P<0.01 ) and the arterial lactate concentration decreased from 5.61±0.55 to 3.94±0. 16 mmol.l^-1, (- 30%), (P<0.01), suggesting improved tissue perfusion. The results demonstrate that prenalterol is a potent, highly selective inotropic agent inducing the same magnitude of increase in blood pressure and cardiac output as reported for dopamine in septic shock.     

Renal effects of temocapril hydrochloride (CS-622) in patients with benign nephrosclerosis

SUMMARY: The short-term effects of temocapril, a new angiotensin-converting enzyme inhibitor (ACE-I), on renal function were investigated in 10 patients with benign nephrosclerosis (56.2 ± 7.2 years, mean ± SD). Renal plasma flow and glomerular filtration rate (GFR) were examined before and after 12-week administration, using ¹³¹I-hippuran and ^99mTc-DTPA, respectively. Temocapril (mean 4.5 mg/day) decreased systolic and diastolic blood pressure (from 162 ± 6 to 140 ± 12 mmHg, P <0.001, and from 101 ± 5 to 89 ± 8 mmHg, P <0.001, respectively). Temocapril increased both renal plasma flow (from 323 ± 67 to 367 ± 72 mL/min/1.73 m² P <0.05) and GFR (from 74 ± 14 to 81 ± 15 mL/min/1.73 m², P <0.05). These data show that short-term administration of temocapril improves renal function in patients with benign nephrosclerosis.     

Impedance cardiography in cardiac surgery patients: abnormal body weight gives unreliable cardiac output measurements

Background: To study the accuracy of cardiac output measurement by means of Electrical Impedance Cardiography (EIC) in post-cardiac surgery patients.
Methods: In a prospective study, we compared cardiac output measurements by means of thermodilution (COTD) with impedance cardiographic-derived values (CO^EIC) in 37 mechanically ventilated patients after cardiac surgery. Both methods were used simultaneously.
Results: CO^EIC values were weakly correlated with CO^TD in the total group when the equation of Sramek-Bernstein was employed to calculate CO^EIC (r=0.60, P < 0.001, mean difference and standard deviation: -0.06±1.25 l-min^-1). After exclusion of the 12 patients whose body weight differed >15% from their ideal body weight, no significant difference was found between the mean values (5.40±1.80 l-min^-1 (CO^EIC) vs 5.31±1.69 l-min^-1, n=25) while the correlation coefficient increased substantially (r=0.85, P < 0.001, mean difference and standard deviation: 0.09±0.96 l-min^-1).
Conclusions: The results of this study indicate that weight is a very important factor in unreliable measurement of CO by impedance cardiography in cardiac surgery patients. The calculation equation as proposed by Sramek and Bernstein is not accurate enough in patients with more than 15% of weight deviation. Therefore, the use of impedance cardiography in these patients is of limited value until an accurate correction factor has been developed.     

The influence of sperm/zona pellucida collision rates on zona binding

Summary. The satisfying success rates reported with intra-cytoplasmic sperm injection (ICSI) urged clinicians and scientists to re-address the emphasis in the management of the male factor patient towards gamete manipulation in order to circumvent the underlying problem causing fertilization failure. We have designed a study to (i) calculate the collision rate of a sperm population with the human zona pellucida, using a mathematical hypothesis and (ii) use the calculated collision rate to evaluate subsequent zona binding results obtained under hemizona assay conditions. Microdroplets were used to co-incubate sperm and human oocytes in order to evaluate zona binding. Using microvolumes, the track followed by sperm, as well as the maximum distance travelled were employed to calculate the collision rate of sperm and zona pellucida. The sperm concentrations of swim up samples were adjusted to 4 × 10⁶ and 0.8 × 10⁶ sperm ml⁻¹. Five separate droplets each of 20 μl containing 4 × 10⁶ sperm ml⁻¹ (80000 motile sperm) and 200 μl containing 0.8 × 10⁶ sperm ml⁻¹ (160000 motile sperm), respectively, were prepared. Both volumes were incubated for 18 h at 37°C. The mean (±SD) number of spermatozoa tightly bound to hemizona, incubated in 20 μl and 200 μl sperm droplets, was 2444±612 and 548±315, respectively ( P = 0.0001). The results can be used as a guideline to calculate the optimum insemination concentration needed for a specific sperm population to ensure the maximum collision rates with the oocyte.     

Cadmium, lead, selenium, and zinc in semen of occupationally unexposed men

Summary. Concentrations of cadmium, lead, selenium, and zinc were determined in semen and seminal plasma of 22 volunteers by atomic absorption spectrometry. Additionally conventional semen parameters and, by means of computer videomicrography, motion parameters of spermatozoa were evaluated. Concentrations of Cd, Pb, and Zn determined in semen were not significantly different from those measured in seminal plasma. However, selenium levels were significantly higher in semen (53.8 ± 22.9 μg 1⁻¹) than in seminal plasma (40.4 ± 15.5 μg 1⁻¹, P <0.01). The investigated semen samples on average contained low levels of Cd (0.4 ± 0.23 μg 1⁻¹) and Pb (9.8 ± 6.5 μg 1⁻¹). Studies on the intra-individual variability revealed the following average coefficients of variation (%) for element concentrations: Pb (70), Cd (53), Se (27), and Zn (23); and for semen parameters: total sperm count (46), sperm concentration (37), motility (22), ejaculate volume (21), linearity (19), linear velocity (11), curvilinear velocity (10), and percentage of normally formed sperm (9). Significant positive correlations were detected between semen selenium levels and sperm concentration ( r =0.51, P <0.05), and percentage of normally formed sperm ( r =0.46, P <0.05), respectively. Sperm motility ( r =0.53, P <0.02), linear ( r = 0.76, P <0.001) and curvilinear velocity ( r = 0.64, P < 0.002) were significantly correlated with semen cadmium levels.     

Seminal fibronectin-like antigen and transferrin concentrations in infertile and fertile men

Summary.  Fibronectin like antigen (Fn) and transferrin (Trs) levels were measured in the seminal plasma of 40 fertile and 102 infertile men. The concentrations of both proteins were significantly ( P <0.001) higher in the fertile controls compared to the infertile groups. The levels of Fn and Trs (mean value ± SEM) in the fertile men were 857.9 ± 9.8 μg ml^-1 and 164.0 ± 6.5 μg ml^-1, respectively; in the azoospermic men ( n = 17) 552.7 ± 24.65 μg ml^-1 and 20.7 ± 2.19 μg ml^-1, respectively; in the group of severe oligozoospermia ( n = 35) 568.34 ± 25.7 μg ml^-1 and 31.1 ± 4.18 μg ml^-1, respectively; in the moderate oligozoospermic group ( n = 8) 572.50 ± 47.9 μg ml^-1 and 43.4 ± 15.4 μg ml^-1 respectively, and in the asthenozoospermic group ( n = 26) 512.76 ± 40.4 μg ml^-1 and 47.0 ± 7.9 μg ml^-1, respectively. Of special interest was the finding from a group of 16 normospermic men (partners of couples with unexplained infertility) who showed significantly lower levels of Fn like antigen, 632.5 ± 26.9 μg ml^-1 ( P <0.001) and Trs 41.8 ± 6.94 μg ml^-1 ( P <0.0001) compared to normals. No correlation was found between Fn levels with either Trs or FSH levels or sperm count. In conclusion, our results indicate that male infertility is associated with changes in seminal plasma Fn like antigen concentrations and that it can be possibly used as an index of sperm fertilizing capacity.     

Relationship of sperm superoxide dismutase-like activity with other sperm-specific enzymes and experimentally induced lipid peroxidation in infertile men

Summary. Superoxide dismutase-like activity (SOD-like), isoenzyme lactate dehydrogenase-C4 (LDH-C4) and NADH-diaphorase activities in spermatozoa have been investigated from 58 normozoospermic and 27 oligozoospermic men. Significantly higher SOD-like, LDH-C4 and diaphorase activities ( P <0.01, P <0.005 and P <0.0001, respectively) were detected in spermatozoa from oligozoospermic men, compared to the activities found in normozoospermic samples. SOD-like activity (mean±SE) in oligozoospermic samples amounted to 8.3±1.6 U 10⁻⁸ spermatozoa, while in spermatozoa in normozoospermic men with a sperm concentration above 20 million of spermatozoa per ml amounted to 4.2±0.5 U 10⁻⁸. There was a close correlation between the SOD-like activity and biochemical indicators of the presence of residual cytoplasm i.e. isoenzyme LDH-C4 and NADH-diaphorase (r = 0.53 and r = 0.66 in normozoospermic and r = 0.63 and r = 0.54 in oligozoospermic men, respectively). A positive relationship between SOD-like activity and experimentally-induced lipid peroxidation was detected in 54 infertile men (r = 0.30; P <0.05). These findings suggest that a higher level of superoxide dismutase-like activity may reflect a defect in the development or maturation of spermatozoa and, thereby, a decreased fertility potential. Hence, determination of SOD-like activity may give information on the state of maturity of human spermatozoa, while its role in the antioxidative protection remains to be determined.     

A Longitudinal Study of Pubertal Development in Boars Investigation of the Relationships Between Gonadal and Epididymal Development and Plasma Luteinizing Hormone and Testosterone Profiles

A longitudinal study was undertaken to evaluate the course of gonadal and epididymal development, and the concurrent endocrine changes during the period of sexual maturation, in Large White x Landrace boars.
Twenty-four animals were castrated sequentially at ages ranging from 43 to 241 days. Increases in testicular weights were more highly correlated with body weight (r = 0.953, P <0.001) and age (r = 0.919, P <0.001) than were similar increases in epilidymal weights (r = 0.558 and 0.593, P < 0.01, respectively). The age at onset of spermatogenesis varied between boars in the range 90 to 127 days. First observations of spermatozoa in seminiferous and epididymal tubules were made at 127 and 146 days of age respectively. Epididymal spermatozoal reserves per epididymis (ESR) were zero prior to 146 days of age; from that age mean ESR values increased progressively from 5.54 times 10⁹ to 130 times 10⁹ at 241 days of age.
Longitudinal profiles of luteinizing hormone (LH) and testosterone secretion were investigated by assaying plasma samples collected at fortnightly intervals from each of ten boars aged 42 to 236 days. Until 82 days of age mean LH levels were low (0.20–1.25 ng/ml), then rose to a peak of 2.19 ng/ml at 110 days. Later LH levels declined gradually and after 166 days fluctuated between 0.5 and 1.0 ng/ml. Mean testosterone levels also were low in the prepubertal period (0.10–0.27 ng/ml), then between 110 and 138 days increased from 0.60 to 8.00 ng/ml. Subsequently testosterone concentrations fell slowly, then except for an isolated peak of 7.73 ng/ml at 194 days, fluctuated between 1.40 and 3.80 ng/ml. Castration ***     

Blood Density Monitoring During Dialysis

Abstract Continuous monitoring of blood density (BD) was preformed in 4 stable dialysis patients in 20 sessions using a density meter based on a mechanical oscillator technique. Mean predialysis and postdialysis BDs were 1.0427 ± 0.0031 g/cm³ and 1.0502 ± 0.0055 g/cm respectively. For similar predialysis to postdialysis total body water reduction, significant difference in the mean BD increase was found between hypotensive and nonhy-potensive groups (1.29 ± 0.07%, 0.47 ± 0.12%, respectively; p < 0.001). Eight hypotensive episodes occurred during 6 sessions. The mean value of the blood density changes slope (dBD/dt) during the 5 min preceding a hypotensive episode increased about 2.5 times more than did the mean of the predialysis to postdialysis blood density slope (27.6 ± 2.2 g/cm³ min 10^-5, 10.5 ± 0.4 g/cm³ min 10^-5 respectively; p < 0.001) under the condition of a constant ultrafiltration rate of 18.9 ± 0.6 ml/min. Continuous monitoring of blood density allows abrupt change in plasma volume to be identified and seems to have a potential utility to the prevention of symptomatic hypotension episodes in patients receiving hemodialysis.     

Catalase supplementation on thawed bull spermatozoa abolishes the detrimental effect of oxidative stress on motility and DNA integrity

The potential protective effect of catalase supplementation during in vitro culture of frozen/thawed bull spermatozoa was investigated. Frozen/thawed semen collected from three fighting bulls was diluted in phosphate buffered saline (PBS) and incubated at 37 °C under different experimental conditions: Control, Catalase (CAT) (200 U/mL), Oxidant (OXI) (100 μ m Fe²⁺/1 m m ascorbate), and Catalase + Oxidant (CAT/OXI). We assessed sperm motility, acrosomal integrity, viability and chromatin status (SCSA®) at 0, 2 and 6 h of incubation. Our results showed that catalase abolished the effect of the oxidant, protecting spermatozoa against reactive oxygen species, and improving both sperm motility and chromatin status during incubation. The OXI treatment significantly reduced the percentage of motile sperm after 6 h of incubation. The statistical model also showed that there were differences in sperm motility between CAT/OXI (20.8 ± 2.9%) and OXI (11.6 ± 7.6%) ( p  < 0.001). There were no significant effects of OXI on sperm viability, acrosomal status or proportion of abnormal tails. %DFI (spermatozoa with moderate or high DNA Fragmentation Index) was significantly higher on OXI ( p  < 0.001). Catalase prevented DNA fragmentation even in the presence of the oxidant (%DFI: 30.3 ± 0.8% OXI vs. 17.4 ± 0.7% CAT/OXI). We conclude that catalase supplementation after thawing could protect bull spermatozoa against oxidative stress, and it could improve media used for processing thawed spermatozoa.     

Gonadal and Extragonadal Sperm Reserves of the Brazilian Nelore Zebu (Bos indicus)

Summary: Gonadal and extragonadal sperm reserves were estimated through hemocytometric method in six Nelore zebu bulls, aging 4–6 years, with normal spermatogenesis, and kept at sexual rest. Gonadal sperm reserve was estimated to be 47.8 ± 5.8 times 10⁶ sperm cells/g testis parenchyma and 9.8 ± 1.7 times 10⁹ sperm cells/testis. Using a time divisor of 4.94 days the daily sperm production was estimated to be 10.0 ± 0.9 times 10⁶ sperm cells/g testis parenchyma/day and 2.0 ± 0.3 times 10⁹ sperm cells/testis/day. Epididymal sperm reserve amounted 11.9 ± 1.6 times 10⁹ spermatozoa/organ, distributed as follows: 35.3 ± 3.6% in the head, 16.9 ± 1.7% in the body and 47.7 ± 3.7% in the tail.
Zusammenfassung: Gonadale und extragonadale Spermareserven des brasilianischen Nelore-Zebu (Bos indicus)
Bei sechs Nelore-Zebubullen im Alter von vier bis sechs Jahren mit normaler Spermatogenese und unter sexueller Karenz wurden mit einer haemocytometrischen Methode die gonadalen und extragonadalen Spermareserven bestimmt. Für die gonadale Spermareserve wurden Werte von 47.8 ± 5.8 times 10⁶ Spermatozoen/g Hodenparenchym und 9.8 ± 1.7 times 10⁹ Spermatozoen/Hoden gefunden. Unter Benutzung eines Zeitdivisors von 4.94 Tagen berechnet sich die tägliche Spermaproduktion zu 10.0 ± 0.9 times 10⁶ Spermatozoen/g Hodenparenchym/Tag und 2.0 ± 0.3 times 10⁹ Spermatozoen/Hoden/Tag. Die Spermareserve im Nebenhoden betrug 11.9 ± 1.6 times 10⁹ Spermatozoen/Nebenhoden in folgender Verteilung: 35.3 ± 3.6% im Nebenhodenkopf, 16.9 ± 1.7% im Nebenhodenkörper und 47.7 ± 3.7% im Nebenhodenschwanz.     

Intrathoracic and pulmonary blood volume during CO2-pneumoperitoneum in humans

Background : Induction of CO₂-pneumoperitoneum may have significant effects on systemic and pulmonary haemodynamics. We hypothesized, that intrathoracic (ITBV) and pulmonary blood volume (PBV) are affected during intra-abdominal CO₂-insufflation, which may be pronounced by positional changes of the patient.
Methods : Sixteen anaesthetized patients were studied before, during and after CO₂-pneumoperitoneum for laparoscopic cholecystectomy. A dye indicator technique was used to assess ITBV and PBV. In addition, gas exchange and haemodynamics were recorded.
Results : In the supine position, induction of CO₂-pneumoperitoneum had no effects on ITBV, PBV and cardiac output. Mean systemic arterial pressure increased from 10.9±1.5 kPa (82±11 mmHg) to 12.7±1.5 kPa (95±11 mmHg, P<0.01). In the reverse Trendelenburg position ITBV decreased from 19.8±5.1 ml . kg^-1 to 16.7±3.7 ml . kg¹ ( P <0.05) during CO₂-insufflation, but increased to control values after 20 min. PBV decreased from 4.2±1.2 ml . kg^-1 to 3.4±1.1 ml . kg^-1 (P<0.05) and remained decreased during CO₂-pneumoperitoneum. Calculated venous admixture was unchanged throughout the study. Deflation of CO₂-pneumoperitoneum increased ITBV (22.4±5.2 ml . kg^-1, P<0.05) and cardiac output above control values.
Conclusions : In anaesthetized-paralyzed patients in the reverse Trendelenburg position intra-abdominal CO₂-insufflation is associated with significant alterations of ITBV and PBV. The release of CO₂-pneumoperitoneum is associated with a re-distribution of blood into the thorax.     

Poikilocapnic hypoxic ventilatory response in humans during 0.85 MAC isoflurane anesthesia

Ventilatory responses to hypoxia (HVR) were investigated using poikilocapnic conditions (i.e. end–tidal CO₂'s allowed to seek it's own level) in 15 cardio–pulmonary healthy patients who were first studied awake and then at 0.85 MAC isoflurane. The influence of hypercapnia (HyperCapnic Ventilatory Response, HCVR) was also elucidated. Pneumotachography, capnography and airway occlusion pressures at 0.1 s (P < u) were used before and during both mild hypoxia (end–tidal O₂ tension 8.7 kPa) and hypercapnia achieved by an inspired CO₂ concentration of 5%. HCVR was attenuated by 60% during anesthesia ( P < 0.01). In the awake state , five of the 15 patients decreased HVR during hypoxia as compared with during normoxia. This resulted in a V_E that on average increased by 0.6 l–min^-1 ( P < 0.05) whereas P_E0₁ was unchanged. In the anesthetized state , no case of decreased HVR was seen and hypoxia induced a mean V_E increase (±s.d.) by 1.0± 0.2 lmin^-1 ( P < 0.001) and a P_E0₁ that on average was improved by 0.63 ± 0.27 cm H₂O ( P < 0.01). It is suggested that when the aim is to evaluate the influence of volatile anesthetic agents on HVR and to quantitate its clinical relevance during and immediately after anesthesia, a poikilocapnic technique should be used. It is concluded that the poikilocapnic HVR to P_F.o₂'s of 8.7 kPa was maintained during 0.85 MAC isoflurane.     

Semen characteristics in pubertal boys. I. Semen quality after first ejaculation

Semen specimens from 134 pubertal boys were examined, and some 274 assays were made. An analysis of the biological quality of semen in relation to the period of time after first ejaculation brings high values of statistical dependence of the volume of semen, its liquefaction, spermatozoal concentration, percentage of morphologically normal forms of spermatozoa, and normal spermatozoal motility on the period of time after first ejaculation. Normal figures for semen volume, semen liquefaction, spermatozoal concentration, and morphology are observed 12-14 months after first ejaculation. The percentage of normally motile spermatozoa becomes standard 21-23 months after first ejaculation. There were changes in semen characteristics from azoospermia through cryptozoospermia, oligozoospermia, and asthenozoospermia to normospermia. Azoospermia dominates until the fifth month after the first ejaculation, oligozoospermia from the sixth to the eleventh month, asthenozoospermia from the twelfth to the twentieth month, and normospermia from the twenty-first month.     

The correlates and alleged biochemical background of the resazurin reduction test in semen

Reduction of the blue dye resazurin to pink resorufin is used to estimate the concentration of metabolically active spermatozoa in semen samples. In order to quantify the reduction of resazurin, a spectrophotometric method was developed measuring the change from blue to pink in the butanol extracted colour. The biochemical mechanisms involved in the reduction of resazurin by motile spermatozoa and seminal plasma were investigated. Addition of NADH + H⁺ to sperm suspension or seminal plasma increased the reduction of resazurin. The reduction reaction was inhibited by high concentrations of dicoumarol, a specific inhibitor of the diaphorase enzyme, in a dose-dependent manner. It is suggested that the sperm diaphorase enzyme transfers electrons from NADH + H⁺ to resazurin, reducing it to resorufin.
The degree of resazurin reduction was strongly correlated with the concentration of motile spermatozoa recovered from the 90% Percoll fraction ( r  = 0.98, p  < 0.001). A positive correlation was also found between the reducing capacity of seminal plasma ( n  = 62) on the one hand, and sperm concentration ( r  = 0.72, p  < 0.0001), progressive motility ( r  = 0.45, p  < 0.01), normal morphology ( r  = 0.50, p  < 0.01), and γ-glutamyltransferase ( r  = 0.36, p  < 0.05) on the other hand.
These findings, together with our previous observations that the reduction reaction is inhibited by reactive oxygen species and polymorphonuclear white blood cells, increase our understanding of the biochemical basis of the resazurin test and may provide better insight into the interpretation of this test.     

Separation of human spermatozoa with hyaluronic acid induces, and Percoll® inhibits, the acrosome reaction

The effect on the acrosome reaction of human spermatozoa of two widely used sperm separation media, hyaluronic acid (Sperm Select®) and Percoll®, was studied. Viable and highly motile fractions of human spermatozoa were separated from seminal plasma using self-migration on a Percoll® gradient. After translocation of separated spermatozoa from the Percoll® solution to a culture medium, serum, Percoll® or hyaluronic acid (Sperm Select®) was added to aliquots of the spermatozoa containing culture medium. At increasing time intervals, the influx of ⁴⁵Ca²⁺ into spermatozoa was measured and the concentration of viable spermatozoa that had undergone the acrosome reaction was analysed using the triple stain technique. Serum was found to be necessary to support sperm motility and viability. Compared to culture medium with serum only, addition of hyaluronic acid induced influx of ⁴⁵Ca²⁺ and the acrosome reaction, whilst Percoll® inhibited both of these actions. Hyaluronic acid (Sperm Select®) added to spermatozoa separated by a 'swim-up' method induced, and the addition of Percoll® inhibited, influx of ⁴⁵Ca²⁺ when compared to the addition of culture medium with serum only. This study demonstrates that both hyaluronic acid (Sperm Select®) and Percoll® affect the acrosome reaction and the prerequisite for Ca²⁺ influx in human spermatozoa. These effects should be taken into consideration when using these media for preparation of spermatozoa for insemination or for fertilization in vitro.     

Left Ventricular Mass Is Associated With Ventricular Repolarization Heterogeneity One Year After Renal Transplantation

Ventricular repolarization heterogeneity (VRH) is associated with the risk of arrhythmia and cardiac death. This study investigated the association between VRH and left ventricular mass (LVM) in renal transplant recipients 1 year after transplantation. Echocardiography and 5-min 12-lead electrocardiogram were recorded and GFR was estimated (eGFR) in 68 nondiabetic patients. Beat-to-beat QT interval variability algorithm was used to calculate SDNN-QT and rMSSD-QT indices of VRH. To quantify QT interval variability relative to heart rate fluctuations, QTRR index was calculated. Left ventricular hypertrophy (LVH) was present in 44 patients (65%). LVM and incidence of LVH were increased in 28 patients with eGFR <60 mL/min/1.73 m² compared with 40 patients with eGFR ≥60 mL/min/1.73 m² (248 ± 61 g and 86% vs. 210 ± 46 g and 50%, respectively; p < 0.01). A direct correlation was found between LVM and SDNN-QT (R = 0.47, R²= 0.23; p < 0.001), rMSSD-QT (R = 0.27; R²= 0.10; p = 0.034), and QTRR (R = 0.55; R²= 0.31; p < 0.001) indices. In conclusion, greater LVM is associated with increased VRH in renal transplant recipients, providing a link with the high risk of arrhythmia and cardiac death, specifically in patients with decreased graft function .     

Current status of reproductive function in Japanese fertile men: international collaborative project on a study of partners of pregnant women

The data on reproductive function in 255 Japanese fertile men resident in the Kawasaki/Yokohama area in Japan were described. The sperm concentration was 107.9 ± 97.4 × 10⁶/mL. The semen volume was 3.2 ± 1.5 mL and percentage motile spermatozoa (grade A + B in WHO criteria) was 56.8% ± 14.7%. The evidence for secular changes in semen quality and other changes in male reproductive health is inconclusive, although regional differences would appear to be stronger. The present study is the first large-scaled prospective survey on the reproductive function of Japanese normal men proven fertility, which was planned as an international comparative study.