Sperm forward motility is negatively affected by short-term exposure to altitude hypoxia.

Human exposure to altitude is a model to study the role of oxygen in different areas of physiology and pathophysiology. The aim of this study was to evaluate whether a short exposure to hypoxia (5 days) combined with exercise, at altitude ranging from 900 m above sea level to 5895 m above sea level (Kilimanjaro Expedition) can modify seminal and reproductive hormonal parameter levels in human beings. During the ascent, blood oxygen saturation at 3.848 m above sea level was found to be decreased when compared to sea level (P < 0.02). The sperm forward motility at sea level after the expedition showed a significant reduction ​​(P < 0.02). There were no changes in other seminal parameters among those compared. Determination of the hormonal plasma concentrations showed that baseline values of follicle-stimulating hormone, total testosterone, prolactin and oestradiol were unchanged at sea level after the hypoxic experience, with respect to baseline values at sea level. On the other hand, luteinising hormone levels after altitudes trekking significantly increased compared to levels before the expedition (P < 0.05). Because of the short-term exposure, we can assume that the reduced forward motility described here may result from the effects of the acute altitude hypoxia on spermatozoa during the epididymal transit where they mature acquiring their motility.

Serum from patients with erectile dysfunction inhibits circulating angiogenic cells from healthy men: relationship with cardiovascular risk, endothelial damage and circulating angiogenic modulators.

Erectile dysfunction (ED) is an early manifestation of arteriosclerosis associated with endothelial damage/dysfunction and to a blunted ability of cultured mononuclear circulating cells (MNCs) to differentiate circulating angiogenic cells (CACs), putatively involved in endothelial damage repair. Here we explored effects of human serum (HS) from patients with ED and cardiovascular risk factors (VRFs) but no clinical atherosclerosis, on cultured MNCs of healthy men to differentiate CACs and to form colonies. Effect of HS on number of CACS and of colony forming units (CFUs) was correlated with circulating markers of endothelial damage and with angiogenic modulators. MNCs from healthy men were cultured in standard conditions or with 20% HS from 35 patients with ED and from 10 healthy men. CACs were identified after 7 days of culture by uptake of acetylated low-density lipoprotein with concomitant binding of Ulex europaeus agglutinin I. CFUs were counted after 5 days of culture. Enzyme-linked immunosorbent assays assessed plasmatic soluble (s) form of E-selectin, Endothelin (ET)-1, tissue type plasminogen activator (tPA), vascular endothelial growth factor (VEGF)(165) and sVEGF receptor (R)-1. The number of CACs and of CFUs from healthy men was reduced after culturing MNCs with HS compared to standard medium. The inhibitory effect was significantly higher with HS from ED patients with higher or lower VRF exposure compared to healthy men. Inhibition was positively correlated with VRFs exposure, with ED severity, with common carotid artery intima media thickness measured using B-mode ultrasound, and to a lesser extent with plasmatic sE-Selectin, sET-1 and sVEGFR-1. Dysfunction of cells involved in vascular homoeostasis is induced by soluble factors still unknown and already present in a very initial systemic vascular disease in men with ED and VRFs.

Beta-chemokine receptor CCR5 in human spermatozoa and its relationship with seminal parameters.

BACKGROUND: Chemokine receptor CCR5, the main HIV-1 coreceptor, is present in the human spermatozoa. This study aimed to investigate (i) whether the percentage of CCR5-positive spermatozoa varies under conditions associated with changes in the membrane architecture, such as capacitation and fixation/permeabilization procedures; (ii) whether there is any relationship between individual variability in sperm CCR5 expression and semen parameters. METHODS AND RESULTS: In cytometric analysis, the percentage of CCR5-positive unfixed spermatozoa varied from approximately 10 to approximately 60%, and it significantly decreased after 5 h capacitation. The percentage of CCR5-positive spermatozoa was increased to more than 90% following fixation and permeabilization, suggesting the existence of large intracellular pools of the receptor. Immunocytochemistry showed positive staining in the anterior region of the sperm head. In ejaculates from male partner of 102 infertile couples, the CCR5 expression rate significantly correlated with sperm count, total sperm number and forward motility, but not with sperm morphology. In stepwise analysis, only forward motility entered into the model; however, this explained only approximately 8% of the variability in CCR5 expression. Interquartile analysis showed significant differences between the first and fourth quartiles of CCR5 expression for all semen parameters, except morphology. CONCLUSIONS: The percentage of CCR5-positive spermatozoa may vary under conditions associated with changes in membrane architecture and spermatozoa showed large intracellular pools of CCR5. A lower expression of CCR5 in asthenozoospermia seems to be suggested; however, it would only partially contribute to the inter-individual variability in the CCR5 expression. A genetic basis can be hypothesized to explain the variability.

Dynamics of the global tyrosine phosphorylation during capacitation and acquisition of the ability to fuse with oocytes in human spermatozoa.

Phosphorylation of tyrosine residues in cellular proteins represents a major event during sperm capacitaton, but its relationship with the acquisition of sperm-fertilizing ability is still unclear. In this study we explored the relationship between the kinetics of the global tyrosine phosphorylation, monitored with a flow cytometric assay, and the acquisition of the human sperm ability to fuse with oocytes, evaluated with the progesterone-enhanced hamster egg penetration test. Sperm tyrosine phosphorylation appeared to be an early event in the capacitation process, with a 3.6-fold mean increase within 1 h of capacitation, but at this time sperm-oocyte fusion was extremely poor compared with that observed at 5 h of capacitation. Capacitation in calcium-free medium produced a 2-fold mean increase in tyrosine phosphorylation compared with that seen in complete capacitation medium both at 1 h and 5 h of capacitation, whereas sperm-oocyte fusion significantly increased only at 1 h, remaining unchanged at 5 h of capacitation. The cAMP analog, N,2-O-dibutyryladenosine 3',5'-cyclic monophosphate (dbcAMP), prevented the inhibitory effect of seminal plasma on tyrosine phosphorylation but not on sperm-oocyte fusion. In conclusion, these results suggest that the acquisition of sperm-fertilizing ability is always associated with an increase of the global tyrosine phosphorylation, but tyrosine phosphorylation does not necessarily reflect the acquisition of the sperm-fertilizing ability. Flow cytometry assay, a reliable technique to quickly quantify the global levels of the human sperm tyrosine phosphorylation, could be useful for a further elucidation of the biological meaning of this process, with the perspective of its clinical use as a measure of the sperm-fertilizing potential.

RANTES and human sperm fertilizing ability: effect on acrosome reaction and sperm/oocyte fusion.

Beta-chemokine, regulated on activation and normally T-cell expressed and presumably secreted (RANTES), is present in both the male and female genital tract fluids where its levels increase in diseases related to infertility, such as endometriosis and male genital tract infections. beta-Chemokine receptors (CCR3 and CCR5) are expressed on freshly ejaculated human sperm cells and a sperm chemoattractant effect for RANTES has been reported. No information exists on other possible roles of RANTES on sperm functions involved in the fertilization process. In the present study, the exposure of sperm suspensions to high concentrations of the chemokine, comparable to those observed in inflammatory diseases, significantly decreased the stimulatory effect exerted by progesterone on sperm/oocyte fusion, evaluated by means of the hamster egg penetration test. Accordingly, a large proportion of spermatozoa preincubated under capacitating conditions with high concentrations of RANTES underwent a premature acrosome reaction (AR) that prevented subsequent progesterone-induced AR. Finally, sperm samples exposed to the same high levels of chemokine showed a significant increase in the intracellular levels of cAMP, which is involved in capacitation and AR dynamics. These results indicate a negative interference of high levels of RANTES on the sperm fertilizing ability, thereby suggesting a potential contribution of this chemokine to subfertility associated with endometriosis and genital tract inflammatory diseases.

High resolution computed tomography (HRCT) assessment of beta 2-agonist induced bronchodilation in chronic obstructive pulmonary disease patients.

The evaluation of airway obstruction reversibility in chronic obstructive pulmonary disease (COPD) patients is currently performed by means of an indirect assessment of drug inducing variations in pulmonary function tests. Imaging techniques, especially high resolution computed tomography (HRCT), usually provide a complete evaluation of lung parenchyma (bronchial and vascular structures), but so far they have never been applied to visualize the effects on the bronchopulmonary tree of some pharmacologic stimuli (beta 2 adrenergic agonist), currently used in clinical practice to disclose the presence of airway reversibility. In order to assess the possible role of HRCT in this setting, five COPD patients have been subjected to a double functional radiologic evaluation before and after salbutamol-induced broncho-dilation, with a rigorous assessment of bronchial diameter changes by means of "bronchus-vessel" ratio, currently used for diagnosing bronchiectasis in COPD patients. The results of this experimental study enable us to visualize drug induced broncho-dilation, with a direct assessment of airway reversibility in these patients, and to show a good correlation between functional and HRCT findings, raising the possibility of evaluation COPD patients with abnormal spirometric results or with early signs of lung involvement.

Pulmonary involvement in tuberous sclerosis complex: presentation of a case.

A clinical case of a pulmonary involvement in Tuberous Sclerosis Complex is reported. This rare involvement (1%) is characterized by either interstitial disease or bullae; therefore, pneumothorax is likely to happen in lung parenchyma. Furthermore this complication induces a progressive serious respiratory failure until the death of the patient.