[Transition in kidney transplantation]. / Transition en transplantation rénale.

Transition from pediatric to adult care in renal transplantation has emerged as a critical step in the life of a young kidney recipient. During this phase, young patients are faced with the physiological and psychological changes associated with adolescence that can lead to non-compliance and potentially graft loss. To date, there is not a unique accepted model of transition, however it has been proved that the presence of a multidisciplinary team including specialists in adolescent management and in the transition from pediatric to adult transplant care is beneficial during this at-risk phase. The goal of this team is to ensure a progressive transition of the patients according to a precise plan and time line.

[Factors influencing the return to work after transplantation in 61 renal or liver recipient]. / Facteurs influençant le retour au travail après transplantation chez 61 patients rénaux ou hépatiques.

The rate of return to work after transplantation is generally low, however this improves the quality of life of recipients. The aim of our study was to investigate the low rate after transplantation in 61 renal or liver patients followed at the Transplant Center (CTO) of the CHUV in Lausanne, and to analyse the occupational, individual and medical factors which may influence it. 39% of recipients returned to work after transplantation. The factors and

The developmental genetics of Hirschsprung's disease.

Hirschsprung's disease (HSCR), also known as aganglionic megacolon, derives from a congenital malformation of the enteric nervous system (ENS). It displays an incidence of 1 in 5000 live births with a 4:1 male to female sex ratio. Clinical signs include severe constipation and distended bowel due to a non-motile colon. If left untreated, aganglionic megacolon is lethal. This severe congenital condition is caused by the absence of colonic neural ganglia and thus lack of intrinsic innervation of the colon due in turn to improper colonization of the developing intestines by ENS progenitor cells. These progenitor cells are derived from a transient stem cell population called neural crest cells (NCC). The genetics of HSCR is complex and can involve mutations in multiple genes. However, it is estimated that mutations in known genes account for less than half of the cases of HSCR observed clinically. The male sex bias is currently unexplained. The objective of this review is to provide an overview of the pathophysiology and genetics of HSCR, within the context of our current knowledge of NCC development, sex chromosome genetics and laboratory models.

Phosphorylation of GATA4 serine 105 but not serine 261 is required for testosterone production in the male mouse.

BACKGROUND: GATA4 is a transcription factor essential for male sex determination, testicular differentiation during fetal development, and male fertility in the adult. GATA4 exerts part of its function by regulating multiple genes in the steroidogenic enzyme pathway. In spite of these crucial roles, how the activity of this factor is regulated remains unclear. OBJECTIVES: Studies in gonadal cell lines have shown that GATA4 is phosphorylated on at least two serine residues-serine 105 (S105) and serine 261 (S261)-and that this phosphorylation is important for GATA4 activity. The objective of the present study is to characterize the endogenous role of GATA4 S105 and S261 phosphorylation in the mouse testis. MATERIALS AND METHODS: We examined both previously described GATA4 S105A mice and a novel GATA4 S261A knock-in mouse that we generated by CRISPR/Cas9 gene editing. The male phenotype of the mutants was characterized by assessing androgen-dependent organ weights, hormonal profiles, and expression of multiple testicular target genes using standard biochemical and molecular biology techniques. RESULTS: The fecundity of crosses between GATA4 S105A mice was reduced but without a change in sex ratio. The weight of androgen-dependent organs was smaller when compared to wild-type controls. Plasma testosterone levels showed a 70% decrease in adult GATA4 S105A males. This decrease was associated with a reduction in Cyp11a1, Cyp17a1, and Hsd17b3 expression. GATA4 S261A mice were viable and testis morphology appeared normal. Testosterone production and steroidogenic enzyme expression were not altered in GATA4 S261A males. DISCUSSION AND CONCLUSION: Our analysis showed that blocking GATA4 S105 phosphorylation is associated with decreased androgen production in males. In contrast, S261 phosphorylation by itself is dispensable for GATA4 function. These results confirm that endogenous GATA4 action is essential for normal steroid production in males and that this activity requires phosphorylation on at least one serine residue.

[Prevalence of undernutrition in 143 patients before liver transplantation. The Lausanne experience between 1997 and 2005]. / Prévalence de la dénutrition chez 143 adultes en bilan prétransplantation hépatique. Experience lausannoise de 1997 a 2005.

The prevalence of undernutrition was prospectively studied in 143 patients before liver transplantation between 1997 and 2005. Nutritional assessment is a particularly tricky problem in cirrhosis and mid-arm muscle circumference is considered as the best reliable anthropometric tool. In this prospective study, prevalence rate is very high (61%) and undernutrition is more frequent in alcoholic cirrhotic patients. In conclusion, these patients should benefit from an early dietician intervention before liver transplantation.

Male-specific colon motility dysfunction in the TashT mouse line.

BACKGROUND: In Hirschsprung disease (HSCR), the absence of myenteric neural ganglia in the distal bowel prevents motility and thereby causes functional intestinal obstruction. Although surgical resection of the aganglionic segment allows HSCR children to survive this condition, a number of patients still suffer from impaired motility despite having myenteric ganglia in their postoperative distal bowel. Such phenomenon is also observed in patients suffering from other enteric neuropathies and, in both cases, colonic dysmotility is believed to result from abnormalities of myenteric ganglia and/or associated interstitial cells of Cajal (ICC). To better understand this, we used a recently described HSCR mouse model called TashT. METHODS: Intestinal motility parameters were assessed and correlated with extent of aganglionosis and with neuronal density in ganglionated regions. The neural composition of the myenteric plexus and the status of ICC networks was also evaluated using immunofluorescence. KEY RESULTS: TashT(Tg/Tg) mice display a strong male bias in the severity of both colonic aganglionosis and hypoganglionosis, which are associated with male-specific reduced colonic motility. TashT(Tg/Tg) male mice also exhibit a specific increase in nNos(+) neurons that is restricted to the most distal ganglionated regions. In contrast, Calretinin(+) myenteric neurons, Sox10(+) myenteric glial cells, and cKit(+) ICC are not affected in TashT(Tg/Tg) mice. CONCLUSIONS AND INFERENCES: Male-specific impairment of colonic motility in TashT(Tg/Tg) mice is associated with both severe hypoganglionosis and myenteric neuronal imbalance. Considering these parameters in the clinic might be important for the management of postoperative HSCR patients.

Expression and regulation of transcripts encoding two members of the NR5A nuclear receptor subfamily of orphan nuclear receptors, steroidogenic factor-1 and NR5A2, in equine ovarian cells during the ovulatory process.

Steroidogenic factor-1 (SF-1, NR5A1a) is a member of the NR5A nuclear receptor subfamily and has been implicated as a key transcriptional regulator of all ovarian steroidogenic genes in vitro. To establish links between the expression of SF-1 and that of the steroidogenic genes in vivo, the objectives of this study were to clone equine SF-1 and examine the regulation of its messenger RNA (mRNA) in follicular cells during human CG (hCG)-induced ovulation. The equine SF-1 primary transcript was cloned by a combination of RT-PCR techniques. Results showed that the transcript was composed of a 5'-untranslated region (UTR) of 161 bp, an open reading frame (ORF) of 1386 bp that encodes a highly-conserved 461-amino acid protein, and a 3'-UTR of 518 bp. The cloning of SF-1 also led to the unexpected and serendipitous isolation of the highly-related orphan nuclear receptor NR5A2, which was shown to include a 5'-UTR of 243 bp, an ORF of 1488 bp, and a 3'-UTR of 1358 bp. The NR5A2 ORF encodes a 495-amino acid protein that is 60% identical to SF-1, including 99%-similar DNA-binding domains. Northern blot analysis revealed that SF-1 and NR5A2 were expressed in all major steroidogenic tissues, with the exception that NR5A2 was not present in the adrenal. Interestingly, NR5A2 was found to be, by far, the major NR5A subfamily member expressed in the preovulatory follicle and the corpus luteum. Using a semiquantitative RT-PCR/Southern blotting approach, the regulation of SF-1 and NR5A2 mRNAs in vivo was studied in equine follicular cells obtained from preovulatory follicles isolated between 0 and 39 h post hCG. Results showed that the theca interna was the predominant site of SF-1 mRNA expression in the follicle, and that hCG caused a significant decrease in SF-1 levels between 12-39 h in theca interna and between 24-39 h post hCG in granulosa cells (P < 0.05). In contrast, the granulosa cell layer was the predominant, if not the sole, site of NR5A2 mRNA expression in the follicle. Importantly, NR5A2 was much more highly expressed in granulosa cells than SF-1. The administration of hCG caused a significant decrease in NR5A2 transcripts in granulosa cells at 30, 36, and 39 h post hCG (P < 0.05). Thus, this study is the first to report the concomitant regulation of SF-1 in theca interna and granulosa cells throughout the ovulation/luteinization process, and to demonstrate the novel expression and hormonal regulation of NR5A2 in ovarian cells. Based on the marked expression of NR5A2 in equine granulosa and luteal cells and on mounting evidence of a functional redundancy between SF-1 and NR5A2 in other species, it is proposed that NR5A2 may play a key role in the regulation of gonadal steroidogenic gene expression.

Porcine steroidogenic factor-1 gene (pSF-1) expression and analysis of embryonic pig gonads during sexual differentiation.

The porcine steroidogenic factor-1 gene (pSF-1) was cloned using a combination of genomic and RT-PCR based cloning methods. pSF-1 consists of an open reading frame of 1383 nt corresponding to a deduced amino acid sequence of 461 aa, similar to bovine and human SF-1. Sequence homologies between pSF-1 and human, bovine and mouse molecules indicate strong evolutionary conservation at both the nt and aa levels. Northern analysis of pSF-1 expression in adult steroidogenic tissues correlated with porcine steroidogenic acute regulatory protein gene (pStAR) and porcine side chain cleavage (pP450scc) gene expression. Notably, pSF-1 expression was readily detected in neonatal testes, absent at 3 weeks of age, and again readily detected at 3 months and in adult testes. pSF-1 expression was weak but detectable in placental tissues at various times of gestation, and was correlated with pStAR and pP450scc expression, indicating classical steroidogenesis in this organ. In developing gonads from 6-12 weeks of gestation, i.e. during the time of sex differentiation in the pig, Northern analysis demonstrated increasing expression of PSF-1 in fetal testes and no expression in ovaries. This expression pattern was paralleled for pStAR, pP450scc, and porcine Müllerian inhibitory substance (pMIS), consistent with pSF-1 involvement in both steroid and protein hormone secretions of the developing testes during sex differentiation. Porcine SRY HMG-box related gene-9 (pSOX-9) expression also paralleled that of pSF-1 in developing testes. In contrast, DSS-AHC critical region on the X chromosome, gene 1 (pDAX-1) was expressed predominantly in the developing ovaries, indicating a possible reciprocal regulation of pSF-1 and pDAX-1 genes in developing pig testes and ovaries.

Porcine and bovine steroidogenic acute regulatory protein (StAR) gene expression during gestation.

We have generated complete complementary DNA (cDNA) sequences for the porcine steroidogenic acute regulatory protein (StAR) gene, using a combination of genomic PCR amplification and reverse transcription-PCR amplification of pig ovarian cDNA. Porcine StAR cDNA consists of 855 bp and shares 90.2%, 87.3%, 84.3%, and 83.9% homologies with bovine, human, mouse, and rat StAR cDNA at the nucleotide level, and 89.1%, 88.8%, 86.7%, and 86.3% homologies with bovine, human, mouse, and rat StAR protein at the deduced amino acid level. Northern analysis of porcine StAR showed that it is expressed in adult and fetal steroidogenic tissues, including adult testes and ovaries and adult adrenal glands as well as steroidogenic tissues of pregnancy, including developing fetal testes, corpus luteum, and pregnancy, but not the fetal ovary. Major hybridizing bands of 1.8 and 1.1 kilobases were demonstrated. In contrast to human StAR, porcine StAR was not expressed in adult or fetal kidneys. Expression of porcine StAR by the pig placenta is in contrast to human StAR, which is not expressed by the human placenta. Northern analysis of bovine cotyledons using a homologous probe for bovine StAR showed that StAR is also expressed by the placenta in the bovine animal. With respect to placental expression of StAR, variations may exist among mammalian species.

Analysis of T cell receptor beta chain expression by isoelectric focusing following gene amplification and in vitro translation.

We describe a new approach to analysis of T cell receptor diversity based on isoelectric focusing of in vitro translation products of amplified V region genes. The method is illustrated by analysis of V beta 2 profiles in peripheral blood lymphocytes from normal donors. The primers used for V beta 2 analysis spanned the V-(D-)J junction and included the segment from amino acid residue position 53 in the variable region to residue 132 of the constant region. The isoelectric focusing patterns display approximately 13-14 bands of varying intensity. Differences in expression of V beta 2-derived peptides were detected in comparisons of the isoelectric focusing profiles from different individuals, suggesting that the method may be useful for detecting genetically determined, immune response related or disease associated differences in Tcr V region expression. The major isoelectric focusing bands have been interpreted as representing groups of V beta 2 sequences sharing J beta region and NDN region charge similarity. Quantitative differences were detected in V beta 2 profiles of CD4 and CD8 T cell subpopulations indicating there may be selection for different charge characteristics in NDNJ sequences in the two T cell subsets. The method provides a new dimension for the detection of perturbations in the T cell repertoire.

Genetic manipulation of sex differentiation and phenotype in domestic animals.

In mammals, a gene based sex determination system ensures that approximately 50% of offspring will be of the male sex and 50% will be of the female sex. In domestic animal production systems, this ratio is not always ideal. Recent advances in our understanding of the molecular biology of sex determination and differentiation, as well as in the control of gene expression and the direct modification of animal genomes, allows us to consider methods for the direct genetic manipulation of sexual phenotype.