Nitrogen species in drinking water indicate potential exposure pathway for Balkan Endemic Nephropathy.

This study explored two hypotheses relating elevated concentrations of nitrogen species in drinking water and the disease Balkan Endemic Nephropathy (BEN). Drinking water samples were collected from a variety of water supplies in both endemic and non-endemic villages in the Vratza and Montana districts of Bulgaria. The majority of well water samples exceeded US drinking water standards for nitrate + nitrite. No statistically significant difference was observed for any of the nitrogen species between villages classified as endemic and non-endemic. Other constituents (sodium, potassium and chloride) known to be indicators of anthropogenic pollution were also found at elevated concentrations and all followed the order wells > springs > taps. This ordering coincides with the proximity of human influences to the water sources. Our results clearly establish an exposure pathway between anthropogenic activity and drinking water supplies, suggesting that the causative agent for BEN could result from surface contamination.

Effects of extender, incubation temperature, and added seminal plasma on capacitation of cryopreserved, thawed boar sperm as determined by chlortetracycline staining.

The effect on apparent capacitation status of frozen-thawed (FT), washed boar sperm was examined in capacitation-supporting medium at 39 degrees C without added seminal plasma (SP) or supplemented with either 10 or 20% (v/v) boar SP. The thawed sperm from three boars were washed to remove the egg yolk-based freezing medium (EY) and then incubated for 1-8h after addition of SP. Capacitation status of the sperm was determined microscopically using chlortetracycline staining patterns. At 1h after the addition of 10 or 20% (v/v) SP, capacitated sperm decreased from 59.7 to 30.3% and from 59.5 to 26.8%, respectively (P<0.001). Subsequent studies examined the effect of 10% SP on capacitation status of FT sperm extended in either phosphate buffered saline or commercial thawing extender with or without prior washing of sperm to remove EY and incubated at 17 or 39 degrees C. No effect of SP resulted from addition to sperm when EY remained or when the temperature was maintained at 17 degrees C (P>0.1). These results indicate that SP appears able to reverse capacitation of FT boar sperm, but that this effect is dependent on both temperature and composition of the thawing extender.

Effect of cooling and seminal plasma on the capacitation status of fresh boar sperm as determined using chlortetracycline assay.

Insemination of sows with frozen-thawed spermatozoa results in lower fertility, in part due to spermatozoa having undergone a capacitation-like reaction. The present study employed chlortetracycline (CTC) staining analysis to investigate the effect of adding 20% (v/v) boar seminal plasma (SP) to boar spermatozoa on the temporal progress of capacitation and the acrosome reaction in spermatozoa cooled to 5 degrees C or incubated at 39 degrees C. Based on CTC staining patterns, seminal plasma appeared to reverse capacitation in spermatozoa that had undergone capacitation while incubated at 39 degrees C in a capacitation-supporting medium from 59.7 to 36.6% capacitated (P<0.001). Similarly, the addition of SP to boar spermatozoa cooled to 5 degrees C resulted in both the prevention of the capacitation-like reaction, and the reversal of an established capacitation-like reaction from 63.3 to 34.2% capacitated (P<0.001). These observations indicated that some constituent(s) of boar SP both prevent spermatozoa from undergoing capacitation as well as reverse capacitation in spermatozoa that have already undergone the process.

Gestational and lactational exposure of male mice to diethylstilbestrol causes long-term effects on the testis, sperm fertilizing ability in vitro, and testicular gene expression.

The objective of the study was to determine the long-term effects of gestational and lactational exposure to diethylstilbestrol (DES; 0, 0.1, 1, and 10 microg/kg maternal body weight) on mouse testicular growth, epididymal sperm count, in vitro fertilizing ability, and testicular gene expression using cDNA microarrays and real-time PCR in mice on postnatal day (PND) 21, 105, and 315. In the high dose group there was a persistent decrease in the number of Sertoli cells, and sperm count was decreased on PND315 (P < 0.05). Sperm motion was unaffected; however, the in vitro fertilizing ability of epididymal sperm was decreased in the high dose group on both PND105 (P < 0.001) and PND315 (P < 0.05). Early and latent alterations in the expression of genes involved in estrogen signaling (estrogen receptor alpha), steroidogenesis (steroidogenic factor 1, 17alpha-hydroxylase/C17,20-lyase, P450 side chain cleavage, steroidogenic acute regulatory protein, and scavenger receptor class B1), lysosomal function (LGP85 and prosaposin), and regulation of testicular development (testicular receptor 2, inhibin/activin beta C, and Hoxa10) were confirmed by real-time PCR. The results demonstrate that early exposure to DES causes long-term adverse effects on testicular development and sperm function, and these effects are associated with changes in testicular gene expression, even long after the cessation of DES exposure.