L-Arginine transport and nitric oxide (NO) synthesis (L-arginine/NO pathway) are stimulated by insulin, adenosine or elevated extracellular D-glucose in human umbilical vein endothelial cells (HUVEC). Adenosine uptake via the human equilibrative nucleoside transporters 1 (hENT1) and 2 (hENT2) has been proposed as a mechanism regulating adenosine plasma concentration, and therefore its vascular effects in human umbilical veins. Thus, altered expression and/or activity of hENT1 or hENT2 could lead to abnormal physiological plasma adenosine level. We have characterized insulin effect on adenosine transport in HUVEC cultured in normal (5 mM) or high (25 mM) D-glucose. Insulin (1 nM) increased overall adenosine transport associated with higher hENT2-, but lower hENT1-mediated transport in normal D-glucose. Insulin increased hENT2 protein abundance in normal or high D-glucose, but reduced hENT1 protein abundance in normal D-glucose. Insulin did not alter the reduced hENT1 protein abundance, but blocked the reduced hENT1 and hENT2 mRNA expression induced by high D-glucose. Insulin effect on hENT1 mRNA expression in normal D-glucose was blocked by N G -nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and mimicked by S-nitroso-Nacetyl-L,D-penicillamine (SNAP, NO donor). L-NAME did not block insulin effect on hENT2 expression. In conclusion, insulin stimulation of overall adenosine transport results from increased hENT2 expression and activity via a NO-independent mechanism. These findings could be important in hyperglycemia-associated pathological pregnancies, such as gestational diabetes, where plasma adenosine removal by the endothelium is reduced, a condition that could alter the blood flow from the placenta to the fetus affecting fetus growth and development.

Chile has become a popular destination for migrants from South America and the Caribbean (low- and middle-income countries migration). Close to 200.000 Haitian migrants have arrived in Chile. Infectious and non-infectious disease burden among the Haitian adult population living in Chile is unknown. This study aimed to acquire the basic health information (selected transmissible and non-transmissible conditions) of the Haitian adult population living in Chile. A cross-sectional survey was performed, inviting Haitian-born residents in Chile older than 18 years old. Common conditions and risk factors for disease were assessed, as well as selected transmissible conditions (HIV, HBV, and HCV). 498 participants (60.4% female) from 10 communities in two regions of Chile were surveyed. Most subjects had never smoked (91.5%), and 80% drank less than one alcohol unit per month. The mean BMI was 25.6, with 45% of participants having a normal BMI (20–25). Hypertension was present in 31.5% (33% in the 25–44 age group). Prevalence of HIV was 2.4% (95 CI 1.3–4.2%), hepatitis B (HBsAg positive) was 3.4% (95 CI 2.1–5.5%), and hepatitis C was 0% (95 CI 0.0–0.9%). Quality of life showed a significant prevalence of depression and anxiety markers, particularly in those arriving in Chile less than 1 year ago. Low prevalence of obesity, diabetes, smoking, and drinking and estimated cardiovascular risk were found. Nonetheless, hypertension at a younger age, disproportionately higher prevalence of HIV and HBV infection and frequent markers of anxiety and depression were also found. Public policies for detecting and treating hypertension, HIV, and HBV screening, offering HBV vaccination, and organizing mental health programs for Haitian immigrants, are urgently needed.

Immature oocytes were recovered from ovarian Iollicles at 0, 2 , 4, 6, 8 and 10 hours after a n ovulating injection of HCG. The envelopes (cumulus, corona cells and zona pellucida) of these oocytes were removed by enzymic treatment. The naked oocytes were incubated in vitro with capacitated spermatozoa to study the rate of sperm entry.A close correlation existed between the appearance of the ability of the oocyte to effectively interact with capacitated spermatozoa and the stage of nuclear maturation. The lowest percentage of sperm entry into zona-free oocytes was observed at zero and two hours after the HCG injection. The nuclei of these oocytes were at the germinal vesicle stage and early first meiotic metaphase respectively. A significant increase i n the rate of sperm entry was observed in oocytes recovered four hours after the HCG injection. The nuclei of these oocytes were still at the first meiotic metaphase. Percentages of sperm entry similar to controls were observed in oocytes recovered 6, 8 and 10 hours after the HCG injection.Germinal vesicle breakdown and a delay period for nuclear and cytoplasmic materials to interact, seem to be two important factors before gamete fusion can take place.At the turn of the century, Delage ('01) working with oocytes of Asterias, showed a close correlation between nuclear and cytoplasmic maturation. When oocytes were cut in two halves before the breakdown of the germinal vesicle, only the nucleated halves cleaved as a result of fertilization, but when the operation was performed immediately after the rupture of the nuclear membrane, cleavage took place in both halves. Delage concluded that the breakdown of the germinal vesicle was responsible for what he called "cytoplasmic maturation."Further evidence of the importance of germinal vesicle in cytoplasm maturation was brought forward by Dettlaff, Nikitina and Stroeva ('64) working with amphibian oocytes. In their experiments they transplanted nuclei from blastula into enucleated oocytes. Development was normal when the enucleation was performed after the breakdown of the germinal vesicle, but if enucleation was performed before the germinal vesicle breakdown, the eggs failed to cleave.The completion of meiosis is not a prerequisite for fertilization since in some animals the oocytes can be fertilized at the germinal vesicle stage (Nereis, spisula) while in others this phenomenon can be accomplished at the first (Ciona, Chaetopterus) or second (all vertebrates with the exception of the dog and fox) meiotic metaphase or even after the completion of meiosis (Coelenterates) (see Austin and Walton, '60, for discussion). The mammalian oocyte is ovulated when the nucleus has reached the second meiotic metaphase and it will remain in this condition until it is fertilized.Oocytes of different mammalian species have been matured in vitro (Chang, '55; Edwards, '65) and fertilized in vivo (Chang, '55) and in vitro (Edwards, Bavister and Steptoe, '69; Cross and Brinster, '70). Moreover mouse oocytes matured and fertilized i...

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