Relationship between zona pellucida-induced acrosome reaction,sperm morphology,sperm-zona pellucida binding,and in vitro fertilization

OBJECTIVE: To evaluate the possible relationships between sperm morphology, acrosome responsiveness to solubilized human zona pellucida, and sperm-zona binding potential among [1] consecutive andrology referrals and [2] randomly selected in vitro fertilization (IVF) cases. DESIGN: Prospective analytical study. SETTING: Academic training hospital.Randomly selected couples consulting for infertility. INTERVENTION(S): Acrosome reaction response to solubilized human zona pellucida was recorded. MAIN OUTCOME MEASURE(S): We determined the difference in the percentage of sperm that acrosome reacted after exposure to solubilized zona pellucida and spontaneous acrosome reaction. The results were expressed as percentage zona induced acrosome reaction (ZIAR). RESULT(S): Data were analyzed using correlation coefficients (r) and receiver operator characteristics (ROC curve analyses). The ROC curve analyses indicated ZIAR to be a sensitive indicator for fertilization failure during IVF therapy, with sensitivity and specificity of 81% and 75%, respectively. For andrology referrals, a positive and statistically significant correlation existed between ZIAR data and sperm morphology (r = 0.65) and sperm-zona binding (r = 0.57). CONCLUSION(S): ZIAR results provide further information regarding dysfunctional sperm and can be used as an additional diagnostic test. Our results predicted fertilization failure during IVF treatment.     

T cell costimulation by the hepatitis C virus envelope protein E2 binding to CD81 is mediated by Lck

Binding of the hepatitis C virus (HCV) envelope protein E2 to CD81 provides a costimulatory signal for human T cells. This phenomenon may play a role in liver damage and autoimmune manifestations associated with HCV infection. Here we show that cross-linking of CD81 by HCV E2 induced a calcium flux in T cells that depends on Lck since it was blocked by PP1 and absent in Lck-deficient Jurkat T cells. In wild-type Jurkat cells, Lck was activated by CD81 cross-linking, and CD81, like Lck, was found in lipid rafts. Indeed, the integrity of the raft compartment was required for the induction of a calcium flux by E2, since methyl-beta-cyclodextrin abolished this response. A requirement for TCR/CD3 expression was indicated by the absence of a calcium flux following E2 stimulation of TCR/CD3-deficient Jurkat cells. CD81 cross-linking increased and prolonged the anti-CD3-induced tyrosine phosphorylation of TCR1 and of other proteins, indicating that the CD81-mediated signal converges with the TCR/CD3 signaling cascade at its most upstream step. In conclusion, we propose that the costimulatory effects of HCV E2 on T cells depend on CD81 cross-linking that activates Lck through raft aggregation and thus leads to enhanced TCR signaling.     

Low-birth-weight neonates exhibit a physiological set-point to regulate CO2: an untapped potential to minimize volutrauma-associated lung injury

The objective of this article is to determine whether low-birth-weight (LBW) infants have the capacity to modulate minute ventilation to achieve a CO (2) set-point within ranges acceptable to clinicians during a procedure designed to identify the best dynamic compliance loops. By using dynamic flow-loop mechanics, we performed a prospective stepwise reduction of tidal volume (by reduction of peak inspiratory pressure, keeping end-expiratory pressure constant), in a group of LBW infants to identify the steepest slope of the dynamic flow-loop. We used flow-synchronized, assist-control mechanical ventilation with termination sensitivity set at 5%. Vital signs and blood gases were assessed every 15 minutes at each stepped-pressure change during the first hour after enrollment and after 12 hours, to evaluate oxygenation and ventilation. Peak inspiratory pressure (PIP) was selected at the lowest level that achieved target range blood gases. The acute reduction of PIP and the resulting lower tidal volume was initially associated with an increase in the spontaneous respiratory rate in the first hour that also was associated with a significant decrease in patient-selected inspiration time. After 12 hours, the spontaneous respiratory rate returned to baseline; the peak PaCO(2) was 43.8 +/- 2.03 (mean +/- SEM). LBW infants have the capacity to alter respiratory rate to change minute ventilation in response to a reduction of tidal volume created by lowering the PIP. Using this model of endogenous CO(2) challenge in ventilated infants, we conclude that LBW neonates have the capacity to select a CO(2) set-point. This approach suggests an important avenue through which a clinician can minimize volutrauma through a reduction of PIP and use of expiratory trigger to limit excessive PIP and an overall lower mean airway pressure.     

Cocaine-induced genital reflexes during paradoxical sleep deprivation and recovery

Paradoxical sleep deprivation (PSD) for 96 h together with cocaine administration elicits genital reflexes (penile erection [PE] and ejaculation [EJ]) in rats. Our objective was to examine genital reflexes after periods of 24, 48, 72, 96, 120, and 144 h of PSD and during a 4-day recovery period in acute cocaine-administered rats. After 24 h of PSD followed by cocaine administration, animals started to display PE and EJ, peaking in the 96th h of PSD, whereas PE and EJ were absent in control animals. The effects of more than 96 h of PSD decrease genital reflexes as observed after 120 and 144 h. Genital reflexes were present in the recovery periods but diminished gradually during the period evaluated. Even short periods of PSD probably cause supersensitivity of dopamine (DA) receptors and exacerbate the effects of cocaine on dopaminergic pathways to induce frequent PE and EJ.     

Rapid prenatal diagnosis of sickle cell diseases using oligonucleotide ligation assay coupled with laser-induced capillary fluorescence detection

Prenatal diagnosis of sickle cell diseases has been available for several years, and our laboratory has performed over 1000 prenatal diagnoses. However, currently available techniques are labor-intensive and time-consuming, and thus the diagnosis is delayed, making the mother's decision difficult. We describe a rapid, high-throughput technique based on the ligation assay coupled with automated capillary fluorescence detection. This new approach allows the diagnosis of both Hgb S and Hgb C to be available in a few hours. We have utilized this technique in 30 prenatal diagnoses and found it to be in complete agreement with the standard diagnoses.     

Birth of a healthy baby after transfer of embryos that were cryopreserved for 8.9 years

OBJECTIVE: To report successful pregnancy from embryos that had been cryopreserved for 8.9 years. DESIGN: Case report. SETTING: Fertility clinic of the University of Buenos Aires School of Medicine. PATIENT(S): A 43-year-old woman with ovarian failure and a 45-year-old man with nonobstructive azoospermia underwent embryo donation.I NTERVENTION(S): Five embryos that had been cryopreserved and stored since 1989 were thawed in 1998 and donated to an infertile couple. Endometrial preparation was performed with 17beta-estradiol and progesterone. The four embryos with better morphologic characteristics were transferred into the uterus. MAIN OUTCOME MEASURE(S): Post-thaw embryo survival, pregnancy, and birth. RESULT(S): Embryo survival was satisfactory as assessed by morphology. Pregnancy was confirmed by ultrasonography. A healthy baby weighing 2120 g was delivered by cesarean section at 36 weeks. CONCLUSION(S): Human 8-cell embryos may be viable after extended storage and can result in successful pregnancy.     

Randomized trial of alcohol versus triple dye for umbilical cord care

Over a 4-month period, all infants admitted to the well-baby nursery were enrolled in a prospective study designed to compare cord separation times between infants treated with triple dye once, followed by daily alcohol application, to infants treated with daily alcohol application alone. Follow-up phone calls were done 7 days after discharge, with weekly calls until cord separation occurred. The objective was to determine whether the umbilical cord care regimen of triple dye followed by alcohol has an advantage over the alternative regimen of alcohol alone, with regard to cord separation, parenting, or healthcare caretaker preferences. In total, 634 infants were enrolled, with 599 infants (94%) completing the study. Infants in the alcohol alone group had a shorter cord separation time by 3 days (10 versus 13 days) (p < 0.0001). There was no reported increase in infection, and monetary savings were noted. We conclude that alcohol applied once a day appears to be a safe and effective means of promoting cord detachment.