Consequences of xenoestrogen exposure on male reproductive function in spottail shiners (Notropis hudsonius).

There is limited information on the physiological consequences associated with exposure to xenoestrogens under field conditions. The objectives of this study were to determine the presence of estrogenic chemicals in the St. Lawrence River and their effects on male reproduction in the spottail shiner (Notropis hudsonius). Hepatic vitellogenin (VTG) mRNA levels in immature shiners indicate extensive estrogenic contamination spanning almost 50 km both upstream and downstream from the island of Montreal. Stages of spermatogenesis were assessed in fish captured at sites having varying levels of estrogenic contamination. In control fish, 95% had testis of either stage IV (50%) or stage V (45%) of spermatogenesis. At Ile Dorval, where VTG mRNA levels are moderate, fish had testes of stage III (38%) and IV (45%) and only 15% of fish were at spermatogenic stage V. In contrast, at Ilet Vert and Ile Beauregard, located in the sewage effluent plume from the City of Montreal and where hepatic VTG mRNA levels are high in fish, none of the fish were at stage V and 8% of fish at Ilet Vert were at stage II of development. Sperm concentration and various motility parameters were significantly lower in shiners from Ilet Vert as compared with those from Iles de la Paix (reference). Histological analyses of testes revealed that more than one-third of the fish captured at sites with the highest estrogenic contamination displayed intersex, a condition in which ovarian follicles were developing within the testis. These data indicate that there is significant estrogenic contamination in the St. Lawrence River that is associated with impaired reproductive function in male fish.     

The toddler who is falling off the growth chart

Growth monitoring is an essential part of paediatric health care, from birth through adolescence. Growth and nutritional problems often occur between 18 months and three years of age. Health care professionals involved in the care of children need to follow growth closely in this period, be able to evaluate a toddler whose growth seems to be faltering, and know when and how to intervene.     

Mutation analysis of RyR2 gene in patients after arrhythmic storm

IntroductionMutations of RyR2 gene encoding calcium channel of sarcoplazmatic reticulum are the cause of congenital catecholaminergic polymorphic ventricular tachycardia. The aim of this study was to test the hypothesis that RyR2 variants can increase occurrence of malignant arrhythmias in patients with structural heart diseases.MethodsThe investigated group consisted of 36 patients with structural heart diseases with ICD implanted who suffered arrhythmic storm. In the control group there were 141 patients with coronary artery disease who were hospitalized at our department owing to an acute coronary event and they were alive at least 3 years after the index event. Thus, they could be considered as a group with a low risk of sudden cardiac death. In all of them mutation analysis of RyR2 gene was performed.ResultsWe detected 16 different sequence changes of RyR2 gene in both groups. None of the found nucleotide polymorphisms led to amino acid changes, were located close to splice sites or had any similarity to known splicing enhancer motifs. The occurrence of these variants was not different in both groups.ConclusionsThe prevalence of RyR2 gene variants was not different in cases versus controls suggesting a limited role of this gene in the arrhythmogenesis in structural heart disease patients.     

Deletion of the Uracil Permease Gene Confers Cross-Resistance to 5-Fluorouracil and Azoles in Candida lusitaniae and Highlights Antagonistic Interaction between Fluorinated Nucleotides and Fluconazole

We characterized two additional membrane transporters (Fur4p and Dal4p) of the nucleobase cation symporter 1 (NCS1) family involved in the uptake transport of pyrimidines and related molecules in the opportunistic pathogenic yeast Candida lusitaniae. Simple and multiple null mutants were constructed by gene deletion and genetic crosses. The function of each transporter was characterized by supplementation experiments, and the kinetic parameters of the uptake transport of uracil were measured using radiolabeled substrate. Fur4p specifically transports uracil and 5-fluorouracil. Dal4p is very close to Fur4p and transports allantoin (glyoxyldiureide). Deletion of the FUR4 gene confers resistance to 5-fluorouracil as well as cross-resistance to triazoles and imidazole antifungals when they are used simultaneously with 5-fluorouracil. However, the nucleobase transporters are not involved in azole uptake. Only fluorinated pyrimidines, not pyrimidines themselves, are able to promote cross-resistance to azoles by both the salvage and the de novo pathway of pyrimidine synthesis. A reinterpretation of the data previously obtained led us to show that subinhibitory doses of 5-fluorocytosine, 5-fluorouracil, and 5-fluorouridine also were able to trigger resistance to fluconazole in susceptible wild-type strains of C. lusitaniae and of different Candida species. Our results suggest that intracellular fluorinated nucleotides play a key role in azole resistance, either by preventing azoles from targeting the lanosterol 14-alpha-demethylase or its catalytic site or by acting as a molecular switch for the triggering of efflux transport.