bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is hypospadias a genetic, endocrine or environmental disease, or still an unexplained malformation?
Authors: Kalfa Nicolas , Philibert Pascal , Sultan Charles 
Published: July 2008

SummaryHypospadias is one of the most frequent genital malformations in the male newborn and results from an abnormal penile and urethral development. This process requires a correct genetic programme, time‐ and space‐adapted cellular differentiation, complex tissue interactions, and hormonal mediation through enzymatic activities and hormonal transduction signals. Any disturbance in these regulations may induce a defect in the virilization of the external genitalia and hypospadias. This malformation thus appears to be at the crossroads of various mechanisms implicating genetic and environmental factors. The genes of penile development (HOX, FGF, Shh) and testicular determination (WT1, SRY) and those regulating the synthesis [luteinizing hormone (LH) receptor] and action of androgen (5α reductase, androgen receptor) can cause hypospadias if altered. Several chromosomal abnormalities and malformative syndromes include hypospadias, from anterior to penoscrotal forms. More recently, CXorf6 and ATF3 have been reported to be involved. Besides these genomic and hormonal factors, multiple substances found in the environment can also potentially interfere with male genital development because of their similarity to hormones. The proportion of hypospadias cases for which an aetiology is detected varies with the authors but it nevertheless remains low, especially for less severe cases. An interaction between genetic background and environment is likely.
The effects of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin on foetal male rat steroidogenesis
Authors: Adamsson A. , Simanainen U. , Viluksela M. , Paranko J. , Toppari J. 
Published: July 2008

Summary2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin (TCDD) is the most toxic and widely investigated dioxin congener. In utero and lactational exposure to TCDD results in developmental and reproductive defects that are the most sensitive endpoints for TCDD toxicity. TCDD has a potential to interfere with steroid metabolism, but the mechanisms by which this occurs are not well understood. In this study, we investigated the effects of TCDD on prenatal rat steroidogenesis. Pregnant Sprague–Dawley female rats were treated once with TCDD (0, 0.3 or 1 μg/kg) by gavage on embryonic day (ED) 11 and the expression levels of androgen (AR) and estrogen receptors (ER), steroidogenic enzymes (P450scc and 3β‐HSD) and four regulatory factors (StAR, SF‐1, GATA‐4 and Insl‐3) involved in foetal Leydig cell and adrenal function were analysed on ED 19.5. Hormonal status of male foetuses was determined by measuring testicular testosterone (T) levels, plasma luteinizing hormone (LH) and corticosterone concentrations. In utero exposure to TCDD reduced intratesticular T of foetal males (significant at 0.3 μg/kg TCDD) and tended to reduce the protein expression of ERα and AR of foetal male rat testis. Foetal male rat plasma LH levels were significantly reduced at the dose of 1 μg/kg TCDD, while corticosterone levels tended to be increased possibly because of the TCDD‐induced stress. Only minor alterations in steroidogenesis were observed in rat adrenal. mRNA expression of developmental regulatory factors was not influenced by foetal TCDD exposure, except for significantly reduced adrenal SF‐1. The results demonstrate that maternal exposure to TCDD suppressed testicular steroidogenesis of 19.5‐day‐old foetal male Sprague–Dawley rat. The highest dose of TCDD (1 μg/kg) had also an effect on pituitary LH secretion. Our data implicate that TCDD has direct testicular and pituitary effects on foetal male rat but with different dose–responses. These changes can lead to impaired steroidogenesis and it may result in the maldevelopment of the testis and weaken masculinization.
Epigenetic regulation and downstream targets of the Rhox5 homeobox gene
Authors: Shanker S. , Hu Z. , Wilkinson M. F. 
Published: July 2008

SummaryThe discovery of the Rhox homeobox gene cluster on the X chromosome opens up new vistas in the regulation of reproductive processes in mammals. In mice, this cluster comprises more than 30 genes that are selectively expressed in reproductive tissues. A subset of Rhox genes are androgen and AR regulated in postnatal and adult Sertoli cells, making them candidates to mediate androgen‐dependent steps during spermatogenesis. The best characterized of these androgen/AR‐regulated genes is Rhox5 (Pem), the founding member of the Rhox gene cluster. Targeted deletion of Rhox5 in mice causes male subfertility marked by increased germ‐cell apoptosis and decreased sperm count and motility. Microarray analyses identified a wide variety of genes regulated by Rhox5 in Sertoli cells. One of them is the tumour suppressor UNC5C, a pro‐apoptotic molecule previously only known to be involved in brain development. Targeted deletion of Unc5c causes decreased germ‐cell apoptosis in postnatal and adult testes, indicating that it also has a role in spermatogenesis and supporting a model in which Rhox5 promotes germ‐cell survival by downregulating Unc5c. Rhox5 has two independently regulated promoters that have distinct expression patterns. The unique tissue‐specific and developmentally regulated transcription pattern of these two promoters appear to be controlled by DNA methylation. Both promoters are methylated in tissues in which they are not expressed, suggesting that DNA methylation serves to repress Rhox5 expression in inappropriate cell types and tissues. In summary, the Rhox gene cluster is an epigenetically regulated set of genes encoding a large number of transcription factors that are strong candidates to regulate gametogenesis and other aspects of reproduction.
Evaluation of MENT on primary cell cultures from benign prostatic hyperplasia and prostate carcinoma
Authors: Mendoza Patricia , Sánchez Catherine , Contreras Héctor R. , Vergara Jorge , Acevedo Cristian , Cabezas Juan , Huidobro Christian , Noé Gabriela , Castellón Enrique A. 
Published: July 2008

Summary7‐alpha‐Methyl‐19‐Nortestosterone (MENT) is a synthetic androgen more potent than testosterone (T) and cannot be reduced at 5‐alpha position. No important effects of MENT on prostate growth have been reported. However, little is known about the effect of MENT on benign prostatic hyperplasia (BPH) or prostate carcinoma (CaP). We evaluate the effect of MENT, T and dihydrotestosterone (DHT) on secretion, proliferation and gene expression of primary cell cultures from human BPH and CaP. Moreover, the effect of these androgens was examined in the presence of finasteride to determine the influence of the 5‐alpha reductase (5‐AR) activity on the androgenic potency. BPH and CaP primary cultures were treated with 0, 1, 10 and 100 nmof T, MENT or DHT during 24 and 48 h. Prostate‐specific antigen (PSA) was measured by micro particles immunoassay and proliferation rate by spectrophotometric assay (MTT) and by the immunochemical detection of the proliferation marker Ki‐67. Gene expression of FGF8b (androgen sensitive gene) was evaluated by semi‐quantitative RT‐PCR. Results showed that MENT treatments increased PSA secretion and proliferation rate with a potency ranged between T and DHT. Similar effects of MENT were observed in both BPH and CaP cultures. The studies with finasteride showed that in BPH and CaP cells, the conversion of T into DHT significantly contributes to its effect on the proliferation and PSA secretion, and corroborated the resistance of MENT to the 5‐AR. The effect of MENT on the gene expression of FGF8b in CaP cells was similar to T and lower than DHT. It is concluded that MENT increases proliferative and secretory activities and gene expression on pathological prostate cells although in less extent than the active metabolite DHT. Furthermore, the fall of endogenous concentration of T during MENT treatment anticipates that this androgen will be of low impact for the prostate.
Staphylococcus aureus haem oxygenases are differentially regulated by iron and haem
Authors: Reniere Michelle L. , Skaar Eric P. 
Published: July 2008

SummaryIron acquisition is a vital process for most pathogenic bacteria, as iron is a limiting nutrient during infection. Staphylococcus aureus, an increasingly important pathogen, acquires iron from host haem via elaboration of the iron‐regulated surface determinant system (Isd). IsdG and IsdI are haem oxygenases that have been proposed to degrade exogenous haem in the bacterial cytoplasm as a mechanism to liberate free iron for use as a nutrient source. Herein, we report that IsdG and IsdI are both important for S. aureus growth on haemin as a sole iron source and are necessary for full S. aureus pathogenesis. Investigations into the regulation of these enzymes revealed that IsdG and IsdI are differentially regulated by iron and haem through both transcriptional and post‐transcriptional mechanisms. Additionally, IsdI was found to be expressed in infected tissues at the sites of abscess formation, suggesting that abscesses are iron‐starved microenvironments inside the host. These findings suggest that S. aureus differentially regulates IsdG and IsdI in response to alterations in iron and haem availability during infection.
Novel mechanism of outer membrane targeting of proteins in Gram‐negative bacteria
Authors: Ferrandez Yann , Condemine Guy 
Published: July 2008

SummaryIn Gram‐negative bacteria, all the proteins destined for the outer membrane are synthesized with a signal sequence that is cleaved, either by the signal peptidase LepB for integral outer membrane proteins or by LspA for lipoproteins, when they cross the cytoplasmic membrane. The Dickeya dadantii protein PnlH does not possess a cleavable signal sequence but is anchored in the outer membrane by an N‐terminal targeting signal. Addition of the 41 N‐terminal amino acids of PnlH is sufficient for anchoring various hybrid proteins in the outer membrane. This targeting signal presents some of the characteristics of a Tat (twin arginine translocation) signal sequence but without an obvious cleavage site. We found that the Tat translocation pathway is required for the targeting process. This new mechanism of outer membrane protein targeting is probably widespread as PnlH was also addressed to the outer membrane when expressed in Escherichia coli. As PnlH was not detected as a substrate by Tat signal sequence prediction programmes, this would suggest that there may be many other unknown Tat‐dependent outer membrane proteins.
Sexual selection, sexual size dimorphism and Rensch’s rule in Odonata
Authors: SERRANO‐MENESES M. A. , CÓRDOBA‐AGUILAR A. , AZPILICUETA‐AMORÍN M. , GONZÁLEZ‐SORIANO E. , SZÉKELY T. 
Published: July 2008

AbstractOdonata (dragonflies and damselflies) exhibit a range of sexual size dimorphism (SSD) that includes species with male‐biased (males > females) or female‐biased SSD (males < females) and species exhibiting nonterritorial or territorial mating strategies. Here, we use phylogenetic comparative analyses to investigate the influence of sexual selection on SSD in both suborders: dragonflies (Anisoptera) and damselflies (Zygoptera). First, we show that damselflies have male‐biased SSD, and exhibit an allometric relationship between body size and SSD, that is consistent with Rensch’s rule. Second, SSD of dragonflies is not different from unit, and this suborder does not exhibit Rensch’s rule. Third, we test the influence of sexual selection on SSD using proxy variables of territorial mating strategy and male agility. Using generalized least squares to account for phylogenetic relationships between species, we show that male‐biased SSD increases with territoriality in damselflies, but not in dragonflies. Finally, we show that nonagile territorial odonates exhibit male‐biased SSD, whereas male agility is not related to SSD in nonterritorial odonates. These results suggest that sexual selection acting on male sizes influences SSD in Odonata. Taken together, our results, along with avian studies (bustards and shorebirds), suggest that male agility influences SSD, although this influence is modulated by territorial mating strategy and thus the likely advantage of being large. Other evolutionary processes, such as fecundity selection and viability selection, however, need further investigation.
Frequency of independent origins of viviparity among caecilians (Gymnophiona): evidence from the first ‘live‐bearing’ Asian amphibian
Authors: GOWER D. J. , GIRI V. , DHARNE M. S. , SHOUCHE Y. S. 
Published: July 2008

AbstractViviparity is reported for Gegeneophis seshachari (Gymnophiona: Caeciliidae) from a gravid female containing four oviductal foetuses. The oviducts are highly vascularized and contain patches of thickened, layered tissue similar to foetal gut contents. Gegeneophis seshachari probably resemble other viviparous caecilians in having foetuses that ingest thickened oviduct lining using specialized deciduous teeth. This is the first report of viviparity in Asian amphibians and Indo‐Seychellean caeciliids. Gegeneophis is the only caecilian genus known to include oviparous and viviparous species, and G. seshachari is the smallest known viviparous caecilian. Phylogenetic analysis of mitochondrial DNA sequences supports assignment of G. seshachari to a monophyletic Gegeneophis. Character optimization indicates that viviparity has evolved independently at least four times within Gymnophiona – a rate of incidence relative to the number of extant species that is higher than for other vertebrate groups except squamate reptiles. Our findings strengthen the proposal that caecilian reproduction demands further attention.
Spatial and temporal prokaryotic variability in the northern Adriatic Sea
Authors: Del Negro Paola , Celussi Mauro , Crevatin Erica , Paoli Alessandro , Bernardi Aubry Fabrizio , Pugnetti Alessandra 
Published: July 2008

AbstractThe prokaryotic community, both in terms of abundance and activity (exoenzymatic hydrolysis of proteins, polysaccharides and phosphorylated molecules and leucine uptake), was investigated seasonally for a 3‐year period (2004–2006) in the Gulf of Venice (northern Adriatic Sea). By focusing on spatial and temporal variability, the prokaryote dynamics showed significant variations on a horizontal and seasonal scale, but no substantial differences were observed among years. The basin‐scale variability was mainly influenced by allochthonous inputs from the Po river and the Venice Lagoon, which were the main source of nutrients, acting as a ‘bottom up’ control on prokaryotes. On a seasonal scale, all the microbial parameters (except the polysaccharide degradation) showed significant variations following the temperature fluctuations. The annual rate of change was very low for all the chemical, physical and biological parameters and only the abundance and phosphatase activity of the prokaryotes differed significantly among years.
Influence of hospital and surgeon volumes on operative time, blood loss and perioperative complications in radical nephrectomy
Authors: Yasunaga Hideo , Yanaihara Hitoshi , Fuji Kohzo , Matsuyama Yutaka , Deguchi Nobuhiro , Ohe Kazuhiko 
Published: July 2008

Objectives:  We conducted a nationwide multi‐center survey using medical record‐based data to investigate the relationship between hospital/surgeon volumes and various outcomes, including operative time, volume of blood loss, and incidence of perioperative complications, in radical nephrectomy for renal cell carcinoma.Methods:  We investigated a total of 1704 patients who underwent radical nephrectomy at 461 hospitals in Japan between November 2006 and February 2007. The association between hospital/surgeon volumes and operative time, volume of blood loss, and incidence of perioperative complications were independently analyzed using multivariate regression analysis against age, gender, operation site, cancer stage, serum creatinine levels, comorbid conditions, and surgical technique (open surgery or minimally invasive surgery).Results:  Neither hospital volume nor surgeon volume was a significant predictor of operative time or volume of blood loss. We did not identify any association between hospital volume and perioperative complications. High‐volume (> 100) surgeons were unlikely to have perioperative complications compared to low‐volume (< 20) surgeons, but the relation was not significant (odds ratio, 0.50; 95% confidence intervals, 0.14–1.87; P = 0.30).Conclusions:  Volume–outcome relationships were not confirmed for radical nephrectomy. According to our study, the justification of regionalizing radical nephrectomy to centers of excellence is not yet clear.
Are topical oestrogens useful in faecal incontinence? Double‐blind randomized trial
Authors: Pinedo G. , García E. , Zárate A. J. , León F. , Bellolio F. , Molina M. E. , Viviani P. , Zúñiga Á. 
Published: July 2008

AbstractBackground  Histopathological studies have shown the presence of oestrogenic receptors in the anal sphincter, which presumes a role in muscular trophism for circulating oestrogens. This could explain the increase in faecal incontinence (FI) in postmenopausal women.Objective  To evaluate the effect of topical oestrogens (TE) in controlling symptoms of FI in postmenopausal women.Hypothesis  The application of TE in postmenopausal women with FI improves continence.Method  We performed a prospective double‐blind randomized trial applying TE to the anal mucosa in postmenopausal women with FI. Study period: 2005–2006. The patients were randomized into two groups: I – topical estriol, II – placebo. In both groups, the ointment was applied three times daily for a period of 6 weeks. We compared Wexner’s FI score and the FI quality of life scale, before commencing and after 6 weeks of application.Results  In this period we evaluated 36 patients. Average age: 67 years (48–84). Group I: 18 patients and group II: 18 patients, one patient was excluded. Wexner’s FI score in group I was 11 (5–18) and 7 (0–19) with pre‐ and postapplication respectively (P = 0.002). Wexner’s FI score in group II was 12 and 9 with pre‐ and postapplication respectively (P = 0.013). When we compared the results between both groups, this was not statistically significant (P = 0.521).Conclusion  There is improvement of continence in both groups that had the ointment applied; nonetheless this study could not show that TE improves FI more than a placebo does.
Staged or simultaneous resection of synchronous liver metastases from colorectal cancer – a systematic review
Authors: Hillingsø J. G. , Wille‐Jørgensen P. 
Published: July 2008

AbstractObjective  A systematic review of the literature was undertaken to estimate the differences in length of hospital stay, morbidity, mortality and long‐term survival between staged and simultaneous resection of synchronous liver metastases from colorectal cancer to determine the level of evidence for recommendations of a treatment strategy.Method  A Pub‐med search was undertaken for studies comparing patients with synchronous liver metastases, who either had a combined or staged resection of metastases. Twenty‐six were considered and 16 were included based on Newcastle Ottawa Quality Assessment Scale. All studies were retrospective and had a general bias, because the staged procedure was significantly more often undertaken in patients with left‐sided primary tumours and larger, more numerous and bi‐lobar metastases. Analyses of primary outcomes were performed using the random effects model.Results  For the reason of the heterogeneity of the observational studies, no odds ratios were calculated. In 11 studies, there was a tendency towards a shorter hospital stay in the synchronous resection group. Fourteen studies compared total perioperative morbidity and lower morbidity was observed in favour of a combined resection. Fifteen studies compared perioperative mortality, which seemed to be lower with the staged approach. Eleven studies compared 5‐year survival, which seemed to be similar in the two groups.Conclusion  No randomized controlled trials were identified, and hence a meta‐analysis was not performed. The evidence level is II to III with grade C recommendations. Synchronous resections can be undertaken in selected patients, provided that surgeons specialized in colorectal and hepatobiliary surgery are available.
Heartless and primitive? 3D reconstruction of the polar acochlidian gastropod Asperspina murmanica
Authors: Neusser Timea P. , Martynov Alexander V. , Schrödl Michael 
Published: July 2008

AbstractThis study re‐examines in detail the microanatomy of the Arctic opisthobranch Asperspina murmanica, the only acochlidian that was described as retaining a well‐developed mantle cavity, and evaluates its supposedly basal position within the Acochlidia. Several specimens were recollected at the type locality in Russia. Spicules and radulae were studied by scanning electron microscopy. Semithin sections were prepared and a computer‐based three‐dimensional reconstruction of all major organ systems was made using amira software. Our results show significant differences from the original description, e.g. the nervous system shows paired rhinophoral and gastro‐oesophageal ganglia and large aggregations of precerebral accessory ganglia, whereas the presence of a postulated posterior genital ganglion can be excluded; the radula is asymmetric; the circulatory system includes a small heart; and the reproductive system comprises a sac‐like ampulla and three female glands. The most surprising discrepancy to the original description refers to the complete absence of any mantle cavity. The gonopore, anus and nephropore open separately to the exterior. Instead of being aberrant or basal, A. murmanica fits well with other Asperspina species and comes closest to the Mediterranean Asperspina rhopalotecta. The monotypic genus/family Minicheviella/Minicheviellidae Starobogatov (1983) is confirmed as a junior synonym of Asperspina/Asperspinidae Rankin (1979).
Sensillary morphology on the rostral apex and their possible role in prey location behaviour of the carnivorous stinkbug, Eocanthecona furcellata (Wolff) (Heteroptera: Pentatomidae)
Authors: Usha Rani Pathipati 
Published: July 2008

Abstract Eocanthecona furcellata (Wolff), the carnivorous heteropteran, demonstrates interesting feeding mechanisms that suggest the involvement of the antennal and labial tip sensilla. This study was conducted to identify the morphology of various sensilla present on the labial tip of this insect using scanning electron microscopy. Four morphologically different types of trichoid sensilla comprise the largest and most numerous sensilla and occur throughout the surface of the labial tip. Three new and unique types of sensilla were discovered. Long hairs with profusely branched shafts are present at the entrance of the rostral groove. An oval‐shaped peg surrounded by sensory hairs with branched shafts and a short, stout peg encircled by a group of long hair‐like sensilla was found among the sensilla population of two lobes. The morphology of the new sensilla is given and possible functions of individual receptors are suggested on morphological grounds.
Industry‐funded fishing license reduction good for both profits and conservation
Authors: Martell Steven J. , Walters Carl , Sumaila Ussif Rashid 
Published: July 2008

AbstractFor many commercial fisheries, reductions in fishing effort would likely result in higher long‐term catches and improved incomes per fisherman. But fishing licenses are perceived as though they were property rights, which can imply relatively high costs for publicly funded buyback programmes to reduce fishing effort. Instead of the public buying out fishing licenses, it can make good business sense for license holders to expect the public to pay for protection against new licenses, and to proceed under this protection to finance buybacks of licenses themselves. The short‐run costs of such an investment are outweighed by long‐term gains in annual incomes and the transfer value of licenses at the time of individual retirement, especially in fisheries that are severely overfished.