Impact of Fetal Exposure to Endocrine Disrupting Chemical Mixtures on FOXA3 Gene and Protein Expression in Adult Rat Testes.

Perinatal exposure to endocrine disrupting chemicals (EDCs) has been shown to affect male reproductive functions. However, the effects on male reproduction of exposure to EDC mixtures at doses relevant to humans have not been fully characterized. In previous studies, we found that in utero exposure to mixtures of the plasticizer di(2-ethylhexyl) phthalate (DEHP) and the soy-based phytoestrogen genistein (Gen) induced abnormal testis development in rats. In the present study, we investigated the molecular basis of these effects in adult testes from the offspring of pregnant SD rats gavaged with corn oil or Gen + DEHP mixtures at 0.1 or 10 mg/kg/day. Testicular transcriptomes were determined by microarray and RNA-seq analyses. A protein analysis was performed on paraffin and frozen testis sections, mainly by immunofluorescence. The transcription factor forkhead box protein 3 (FOXA3), a key regulator of Leydig cell function, was identified as the most significantly downregulated gene in testes from rats exposed in utero to Gen + DEHP mixtures. FOXA3 protein levels were decreased in testicular interstitium at a dose previously found to reduce testosterone levels, suggesting a primary effect of fetal exposure to Gen + DEHP on adult Leydig cells, rather than on spermatids and Sertoli cells, also expressing FOXA3. Thus, FOXA3 downregulation in adult testes following fetal exposure to Gen + DEHP may contribute to adverse male reproductive outcomes.

Comprehensive mapping of NICU developmental care nursing interventions and related sensitive outcome indicators: a scoping review protocol.

INTRODUCTION: Neurodevelopmental outcomes of preterm infant are still a contemporary concern. To counter the detrimental effects resulting from the hospitalisation in the neonatal intensive care unit (NICU), developmental care (DC) interventions have emerged as a philosophy of care aimed at protecting and enhancing preterm infant's development and promoting parental outcomes. In the past two decades, many authors have suggested DC models, core measures, practice guidelines and standards of care but outlined different groupings of interventions rather than specific interventions that can be used in NICU clinical practice. Moreover, as these DC interventions are mostly implemented by neonatal nurses, it would be strategic and valuable to identify specific outcome indicators to make visible the contribution of NICU nurses to DC. OBJECTIVES: The overarching objective of this review is to identify the nature, range, and extent of the literature regarding DC nursing interventions for preterm infants in the NICU. The secondary twofold objectives are to highlight interventions that fall into identified categories of DC interventions and suggest nursing-sensitive outcome indicators related to DC interventions in the NICU. INCLUSION CRITERIA: Papers reporting on or discussing a DC nursing intervention during NICU hospitalisation will be included. METHODS AND ANALYSIS: The Joanna Briggs Institute's methodology for scoping reviews will be followed. CINAHL, MEDLINE, Embase, PubMed, Web of Science, Scopus, ProQuest and PsycInfo databases from 2009 to the present will be searched. Any type of paper, published in English or French, will be considered. Study selection and data extraction will be conducted by pairs of two review authors independently. A qualitative content analysis will be conducted. ETHICS AND DISSEMINATION: No Institutional Review Board ethical approbation is needed. Results of this review will be presented in scientific meetings and published in refereed papers.

Q fever aortic infection causing an aortoduodenal fistula after endovascular aneurysm repair.

An aortoduodenal fistula is a rare complication of endovascular aortic aneurysm repair. Q fever infection is known for its vascular tropism, and arterial fistulas have been reported in association with Coxiella burnetii infections. We report the case of a 78-year-old patient who had developed an aortoduodenal fistula secondary to vascular Q fever 5 years after he had been treated with an aortic endograft. Explantation of the endograft, autogenous reconstruction using the neo-aortoiliac system procedure, and duodenal repair were performed as a curative surgical treatment of this serious vascular condition. At the 9-month follow-up examination, the patient showed no signs of recurrent vascular infection and was instructed to complete an 18-month antibiotic regimen.

In utero exposure to low doses of genistein and di-(2-ethylhexyl) phthalate (DEHP) alters innate immune cells in neonatal and adult rat testes.

BACKGROUND: Although humans are exposed to mixtures of endocrine disruptor chemicals, few studies have examined their toxicity on male reproduction. We previously found that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di(2-ethylhexyl) phthalate (DEHP) altered gene expression in adult rat testes. OBJECTIVES: Our goal was to investigate the effects of fetal exposure to GEN-DEHP mixtures at two doses relevant to humans on testicular function and transcriptome in neonatal and adult rats. MATERIALS AND METHODS: Pregnant SD rats were gavaged with vehicle, GEN or DEHP, alone or mixed at 0.1 and 10 mg/kg/day, from gestation day 14 to birth. Fertility, steroid levels, and testis morphology were examined in neonatal and adult rats. Testicular transcriptomes were examined by gene array and functional pathway analyses. Cell-specific genes/proteins were determined by quantitative real-time PCR and immunohistochemistry. RESULTS: GEN-DEHP mixtures increased the rates of infertility and abnormal testes in adult rats. Gene array analysis identified more genes exclusively altered by the mixtures than individual compounds. Altered top canonical pathways included urogenital/reproductive developmental and inflammatory processes. GEN-DEHP mixtures increased innate immune cells and macrophages markers at both doses and ages, more strongly and consistently than DEHP or GEN alone. Genes exclusively increased by the mixture in adult testis related to innate immune cells and macrophages included Kitlg, Rps6ka3 (Rsk2), Nr3c1, Nqo1, Lif, Fyn, Ptprj (Dep-1), Gpr116, Pfn2, and Ptgr1. DISCUSSION AND CONCLUSION: These findings demonstrate that GEN-DEHP mixtures at doses relevant to human induce adverse testicular phenotypes, concurrent with age-dependent and non-monotonic changes in testicular transcriptomes. The involvement of innate immune cells such as macrophages suggests immediate and delayed inflammatory responses which may contribute to testicular dysfunction. Moreover, these effects are complex and likely involve multiple interactions between immune and non-immune testicular cell types that will entail further studies.

Identification of Sec23ip, Part of 14-3-3γ Protein Network, as a Regulator of Acute Steroidogenesis in MA-10 Leydig Cells.

Testosterone production occurs in the Leydig cells of the testes and is essential for virilization, development, reproduction, and quality of life. Although the steroidogenic proteins involved in cholesterol conversion to testosterone (T) are well characterized, the causes of reduced T during fetal, neonatal, and adult life remain uncertain. It is well established that normal cellular function is achieved through fine-tuning of multiple rather than single protein networks. Our objective was to use mass spectrometry (MS)-based proteomics to identify which cellular pathways, other than the steroidogenic machinery, influence testosterone production in MA-10 mouse tumor Leydig cells. The 14-3-3 family of scaffolds mediate protein-protein interactions facilitating the crosstalk between protein networks. We previously showed that in MA-10 cells, 14-3-3γ is a critical regulator of steroidogenesis. Therefore, identifying proteins that interact with 14-3-3γ during steroidogenesis could provide clues into the other networks involved. Using liquid chromatography (LC)-MS, we identified 688 proteins that interact with 14-3-3γ and thus potentially impact MA-10 cell steroidogenesis. The identified proteins belong to multiple protein networks, including endoplasmic reticulum-Golgi cargo sorting and vesicle biogenesis, micro ribonucleic acid-induced gene silencing, inflammation, and vesicle trafficking, to name a few. We found that silencing one of the candidates, Sec23ip, a protein known to be involved in vesicle trafficking, resulted in decreased steroidogenesis. We further showed that in Sec23ip-silenced MA-10 cells, cholesterol mobilization from the cytoplasmic membrane to mitochondria is impaired. Taken together these data suggest that Sec23ip is involved in cholesterol trafficking to supply cholesterol for acute steroidogenesis through its interactions with 14-3-3γ.

Cyclooxygenase 2 (COX2) expression and prostaglandin synthesis in neonatal rat testicular germ cells: Effects of acetaminophen and ibuprofen.

BACKGROUND: In infants, fever is often treated with acetaminophen or ibuprofen, two antipyretic and analgesic drugs inhibiting cyclooxygenases (COXs), enzymes catalyzing prostaglandin production. Infancy represents a critical developmental period when neonatal germ cells/gonocytes differentiate to spermatogonial stem cells required for spermatogenesis. OBJECTIVES: (a) Determine the expression of Cox2 and associated genes in postnatal day (PND)3 rat gonocytes compared to spermatogonia. (b) Examine whether acetaminophen or ibuprofen disrupts neonatal gonocyte functions. (c) Determine whether neonatal gonocytes produce prostaglandins and whether this process is altered by acetaminophen and ibuprofen. MATERIALS AND METHODS: The expression of Cox2 and related genes was determined by gene arrays and qPCR. Cox2 protein levels were determined by immunocyto/histochemistry and immunoblots. The effects of acetaminophen and ibuprofen on PND3 gonocyte viability, apoptosis, proliferation, and differentiation were examined alone and with a proliferation cocktail or differentiation factor. Prostaglandins were examined by immunocyto/histochemistry and LC-MS. RESULTS: Cox2 and related genes are highly expressed in gonocytes and spermatogonia. Acetaminophen and ibuprofen did not affect gonocyte survival or apoptosis, but they increased gonocyte proliferation. Ibuprofen significantly reduced RA-induced Stra8 expression, indicating an inhibitory effect on differentiation. Ibuprofen combined with RA decreased Cox2 mRNA and protein expression. PGE2 and PGF2α were produced by neonatal gonocytes and decreased by acetaminophen and ibuprofen. DISCUSSION: The concomitant decrease of Stra8 expression, Cox2 expression, and PGE2 and PGF2a production in gonocytes co-treated with RA suggests that Cox2 plays a role in PND3 gonocyte differentiation. The effects of acetaminophen and ibuprofen on proliferation suggest a negative relationship between Cox2 and proliferation. Treating neonates with acetaminophen or ibuprofen could disrupt gonocyte development, leading to adverse reproductive effects. CONCLUSION: Understanding COX2 role in neonatal gonocytes and the potential risk of acetaminophen and ibuprofen treatment of infants may help prevent male reproductive pathologies.

Staged surgical treatment of a primary duodenocaval fistula in a patient with metastatic nonseminomatous germ cell tumor.

Endovascular exclusion of aortoenteric fistula has been described as a bridge to definitive open repair surgery. However, little is known about transposing this technique to treat duodenocaval fistula. We report a case of a 20-year-old man who presented with a duodenocaval fistula arising from a metastatic nonseminomatous germ cell tumor. A staged technique using an initial endovenous exclusion of the fistula permitted stabilization of the patient and completion of his chemotherapy regimen. Subsequently, the stent graft was explanted with concomitant autogenous caval reconstruction, allowing the patient to be cancer free at 1-year follow-up.

Protective Role of Peroxiredoxins against Reactive Oxygen Species in Neonatal Rat Testicular Gonocytes.

Peroxiredoxins (PRDXs) are antioxidant enzymes that protect cells from oxidative stress and play a role in reactive oxygen species (ROS)-mediated signaling. We reported that PRDXs are critical for human fertility by maintaining sperm viability and regulating ROS levels during capacitation. Moreover, studies on Prdx6-/- mice revealed the essential role of PRDX6 in the viability, motility, and fertility competence of spermatozoa. Although PRDXs are abundant in the testis and spermatozoa, their potential role at different phases of spermatogenesis and in perinatal germ cells is unknown. Here, we examined the expression and role of PRDXs in isolated rat neonatal gonocytes, the precursors of spermatogonia, including spermatogonial stem cells. Gene array, qPCR analyses showed that PRDX1, 2, 3, 5, and 6 transcripts are among the most abundant antioxidant genes in postnatal day (PND) 3 gonocytes, while immunofluorescence confirmed the expression of PRDX1, 2, and 6 proteins. The role of PRDXs in gonocyte viability was examined using PRDX inhibitors, revealing that the 2-Cys PRDXs and PRDX6 peroxidases activities are critical for gonocytes viability in basal condition, likely preventing an excessive accumulation of endogenous ROS in the cells. In contrast to its crucial role in spermatozoa, PRDX6 independent phospholipase A2 (iPLA2) activity was not critical in gonocytes in basal conditions. However, under conditions of H2O2-induced oxidative stress, all these enzymatic activities were critical to maintain gonocyte viability. The inhibition of PRDXs promoted a two-fold increase in lipid peroxidation and prevented gonocyte differentiation. These results suggest that ROS are produced in neonatal gonocytes, where they are maintained by PRDXs at levels that are non-toxic and permissive for cell differentiation. These findings show that PRDXs play a major role in the antioxidant machinery of gonocytes, to maintain cell viability and allow for differentiation.

Short-term post-implantation dynamics of in vitro engineered human microvascularized adipose tissues.

Engineered adipose tissues are developed for their use as substitutes for tissue replacement in reconstructive surgery. To ensure a timely perfusion of the grafted substitutes, different strategies can be used such as the incorporation of an endothelial component. In this study, we engineered human adipose tissue substitutes comprising of functional adipocytes as well as a natural extracellular matrix using the self-assembly approach, without the use of exogenous scaffolding elements. Human microvascular endothelial cells (hMVECs) were incorporated during tissue production in vitro and we hypothesized that their presence would favor the early connection with the host vascular network translating into functional enhancement after implantation into nude mice in comparison to the substitutes that were not enriched in hMVECs. In vitro, no significant differences were observed between the substitutes in terms of histological aspects. After implantation, both groups presented numerous adipocytes and an abundant matrix in addition to the presence of host capillaries within the grafts. The substitutes thickness and volume were not significantly different between groups over the short-term time course of 14 days (d). For the microvascularized adipose tissues, human CD31 staining revealed a human capillary network connecting with the host microvasculature as early as 3 d after grafting. The detection of murine red blood cells within human CD31+ structures confirmed the functionality of the human capillary network. By analyzing the extent of the global vascularization achieved, a tendency towards increased total capillary network surface and volume was revealed for prevascularized tissues over 14 d. Therefore, applying this strategy on thicker reconstructed adipose tissues with rate-limiting oxygen diffusion might procure added benefits and prove useful to provide voluminous substitutes for patients suffering from adipose tissue loss or defects.

In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity.

Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health.

Stimulatory effects of combined endocrine disruptors on MA-10 Leydig cell steroid production and lipid homeostasis.

Previous work in our laboratory demonstrated that in-utero exposure to a mixture of the phytoestrogen Genistein (GEN), and plasticizer DEHP, induces short- and long-term alterations in testicular gene and protein expression different from individual exposures. These studies identified fetal and adult Leydig cells as sensitive targets for low dose endocrine disruptor (ED) mixtures. To further investigate the direct effects and mechanisms of toxicity of GEN and DEHP, MA-10 mouse tumor Leydig cells were exposed in-vitro to varying concentrations of GEN and MEHP, the principal bioactive metabolite of DEHP. Combined 10µM GEN+10µM MEHP had a stimulatory effect on basal progesterone production. Consistent with increased androgenicity, the mRNA of steroidogenic and cholesterol mediators Star, Cyp11a, Srb1 and Hsl, as well as upstream orphan nuclear receptors Nr2f2 and Sf1 were all significantly increased uniquely in the mixture treatment group. Insl3, a sensitive marker of Leydig endocrine disruption and cell function, was significantly decreased by combined GEN+MEHP. Lipid analysis by high-performance thin layer chromatography demonstrated the ability of combined 10µM combined GEN+MEHP, but not individual exposures, to increase levels of several neutral lipids and phospholipid classes, indicating a generalized deregulation of lipid homeostasis. Further investigation by qPCR analysis revealed a concomitant increase in cholesterol (Hmgcoa) and phospholipid (Srebp1c, Fasn) mediator mRNAs, suggesting the possible involvement of upstream LXRα agonism. These results suggest a deregulation of MA-10 Leydig function in response to a combination of GEN+MEHP. We propose a working model for GEN+MEHP doses relevant to human exposure involving LXR agonism and activation of other transcription factors. Taken more broadly, this research highlights the importance of assessing the impact of ED mixtures in multiple toxicological models across a range of environmentally relevant doses.

In utero exposure to di-(2-ethylhexyl) phthalate induces testicular effects in neonatal rats that are antagonized by genistein cotreatment.

Fetal exposure to endocrine disruptors (EDs) is believed to predispose males to reproductive abnormalities. Although males are exposed to combinations of chemicals, few studies have evaluated the effects of ED mixtures at environmentally relevant doses. Our previous work showed that fetal exposure to a mixture of the phytoestrogen genistein (GEN) and the plasticizer di-(2-ethylhexyl) phthalate (DEHP) induced unique alterations in adult testis. In this follow-up study, we examined Postnatal Day 3 (PND3) and PND6 male offspring exposed from Gestational Day 14 to parturition to corn oil, 10mg/kg GEN, DEHP, or their combination, to gain insight into the early molecular events driving long-term alterations. DEHP stimulated the mRNA and protein expression of the steroidogenic enzyme HSD3B, uniquely at PND3. DEHP also increased the mRNA expression of Nestin, a Leydig progenitor/Sertoli cell marker, and markers of Sertoli cell (Wt1), gonocyte (Plzf, Foxo1), and proliferation (Pcna) at PND3, while these genes were unchanged by the mixture. Redox (Nqo1, Sod2, Sod3, Trx, Gst, Cat) and xenobiotic transporter (Abcb1b, Abcg2) gene expression was also increased by DEHP at PND3, while attenuated when combined with GEN, suggesting the involvement of cellular stress in short-term DEHP effects and a protective effect of GEN. The direct effects of GEN and mono-(2-ethylhexyl) phthalate, the principal bioactive metabolite of DEHP, on testis were investigated in PND3 organ cultures, showing a stimulatory effect of 10 µM mono-(2-ethylhexyl) phthalate on basal testosterone production that was normalized by GEN. These effects contrasted with previous reports of androgen suppression and decreased gene expression in perinatal rat testis by high DEHP doses, implying that neonatal effects are not predictive of adult effects. We propose that GEN, through an antioxidant action, normalizes reactive oxygen species-induced neonatal effects of DEHP. The notion that these EDs do not follow classical dose-response effects and involve different mechanisms of toxicity from perinatal ages to adulthood highlights the importance of assessing impacts across a range of doses and ages.

Role of retinoic acid and platelet-derived growth factor receptor cross talk in the regulation of neonatal gonocyte and embryonal carcinoma cell differentiation.

Neonatal gonocytes are direct precursors of spermatogonial stem cells, the cell pool that supports spermatogenesis. Although unipotent in vivo, gonocytes express pluripotency genes common with embryonic stem cells. Previously, we found that all-trans retinoic acid (RA) induced the expression of differentiation markers and a truncated form of platelet-derived growth factor receptor (PDGFR)ß in rat gonocytes, as well as in F9 mouse embryonal carcinoma cells, an embryonic stem cell-surrogate that expresses somatic lineage markers in response to RA. The present study is focused on identifying the signaling pathways involved in RA-induced gonocyte and F9 cell differentiation. Mitogen-activated protein kinase kinase (MEK) 1/2 activation was required during F9 cell differentiation towards somatic lineage, whereas its inhibition potentiated RA-induced Stra8 expression, suggesting that MEK1/2 acts as a lineage specification switch in F9 cells. In both cell types, RA increased the expression of the spermatogonial/premeiotic marker Stra8, which is in line with F9 cells being at a stage before somatic-germline lineage specification. Inhibiting PDGFR kinase activity reduced RA-induced Stra8 expression. Interestingly, RA increased the expression of PDGFRα variant forms in both cell types. Together, these results suggest a potential cross talk between RA and PDGFR signaling pathways in cell differentiation. RA receptor-α inhibition partially reduced RA effects on Stra8 in gonocytes, indicating that RA acts in part via RA receptor-α. RA-induced gonocyte differentiation was significantly reduced by inhibiting SRC (v-src avian sarcoma [Schmidt-Ruppin A-2] viral oncogene) and JAK2/STAT5 (Janus kinase 2/signal transducer and activator of transcription 5) activities, implying that these signaling molecules play a role in gonocyte differentiation. These results suggest that gonocyte and F9 cell differentiation is regulated via cross talk between RA and PDGFRs using different downstream pathways.

Disruption of rat testis development following combined in utero exposure to the phytoestrogen genistein and antiandrogenic plasticizer di-(2-ethylhexyl) phthalate.

Fetal exposure to environmental endocrine disruptors (EDs) is thought to contribute to reported idiopathic increases in adult male reproductive abnormalities. Although humans are exposed to myriad EDs from conception to adulthood, few studies have evaluated the effects of combined EDs on male reproduction. In the present study, we demonstrate that simultaneous gestational exposure to the phytoestrogen genistein and the antiandrogenic plasticizer di-(2-ethyhexyl) phthalate (DEHP) induces long-term alterations in testis development and function. Pregnant Sprague Dawley rats were gavaged from Gestational Day 14 to birth with corn oil, genistein, DEHP, or their mixture at 10 mg/kg/day, a dose selected from previous dose-response studies using single chemicals for its lack of long-term testicular effects. Hormonal and testicular end points were examined in adult male offspring. Serum testosterone levels were unchanged. However, significant increases were observed in testis weight and in the expression of mast cell markers in testes from adult rats exposed gestationally to combined compounds. The ED mixture also altered the mRNA expression of Sertoli cell makers Wt1 and Amh and germ cell markers cKit and Sox17, measured by quantitative real-time PCR (qPCR), suggesting long-term disruption in testis function and spermatogenesis. Alterations in germ cell markers might reflect direct effects on fetal gonocytes or indirect effects via primary targeting of somatic cells, as suggested by differentially regulated Leydig cell associated genes (Hsd3b, Anxa1, Foxa3, and Pdgfra), determined by gene expression array, qPCR, and protein analyses. The two chemicals, when given in combination, induced long-term reproductive toxicity at doses not previously reported to produce any conspicuous long-term effects. Our study therefore highlights a need for a more comprehensive evaluation of the effects of ED mixtures.

Interdependence of platelet-derived growth factor and estrogen-signaling pathways in inducing neonatal rat testicular gonocytes proliferation.

We previously found that platelet-derived growth factor (PDGF) and 17beta-estradiol stimulate gonocyte proliferation in a dose-dependent, nonadditive manner. In the present study, we report that gonocytes express RAF1, MAP2K1, and MAPK1/3. Inhibition of RAF1 and MAP2K1/2, but not phosphoinositide-3-kinase, blocked PDGF-induced proliferation. AG-370, an inhibitor of PDGF receptor kinase activity, suppressed not only PDGF-induced proliferation but also that induced by 17beta-estradiol. In addition, RAF1 and MAP2K1/2 inhibitors blocked 17beta-estradiol-activated proliferation. The estrogen receptor antagonist ICI 182780 inhibited both the effects of 17beta-estradiol and PDGF. PDGF lost its stimulatory effect when steroid-depleted serum or no serum was used. Similarly, 17beta-estradiol did not induce gonocyte proliferation in the absence of PDGF. The xenoestrogens genistein, bisphenol A, and DES, but not coumestrol, stimulated gonocyte proliferation in a dose-dependent and PDGF-dependent manner similarly to 17beta-estradiol. Their effects were blocked by ICI 182780, suggesting that they act via the estrogen receptor. AG-370 blocked genistein and bisphenol A effects, demonstrating their requirement of PDGF receptor activation in a manner similar to 17beta-estradiol. These results demonstrate the interdependence of PDGF and estrogen pathways in stimulating in vitro gonocyte proliferation, suggesting that this critical step in gonocyte development might be regulated in vivo by the coordinated action of PDGF and estrogen. Thus, the inappropriate exposure of gonocytes to xenoestrogens might disrupt the crosstalk between the two pathways and potentially interfere with gonocyte development.

Multipronged intervention strategy to control an outbreak of Clostridium difficile infection (CDI) and its impact on the rates of CDI from 2002 to 2007.

OBJECTIVE: At the end of 2002, a new, more virulent strain of Clostridium difficile, designated BI/NAP1, was the cause of a massive outbreak of infection in the province of Quebec. This particular strain was associated with a dramatic increase in morbidity and mortality among affected patients in 2003-2004. We tested and implemented a multipronged infection control approach to curtail the rate of C. difficile infection (CDI). DESIGN: Five-year observational study. SETTING: A 554-bed, acute care tertiary hospital, the largest single medical center in Quebec, Canada. METHODS: To curtail the magnitude of the outbreak, we implemented a global strategy consisting of rapid C. difficile testing for all hospitalized patients who had at least 1 occurrence of liquid stool, the rapid isolation of patients infected with C. difficile in a dedicated ward with a specially trained housekeeping team, a global hand hygiene program, and the hiring of infection control practitioners. Antibiotic consumption at the institutional level was also monitored during the 5-year surveillance period. Cases of hospital-acquired CDI per 1,000 admissions were continuously monitored on a monthly basis during the entire surveillance period. RESULTS: The highest recorded CDI rate was 42 cases per 1,000 admissions in January 2004. Once additional infection control resources were put in place, the rate decreased significantly during the period from April 2005 to March 2007. During the 2003-2004 period, there were 762 cases of CDI (mean annual rate, 37.28 cases per 1,000 admissions) recorded in our study, compared with 292 cases of CDI (14.48 cases per 1,000 admissions) during the 2006-2007 period (OR, 0.379 [95% CI, 0.331-0.435]; p< .001), a 61% reduction. In March 2007, the equivalent of 4 full-time equivalent infection control practitioners were in place, which gave a ratio of 0.96 infection control practitioners per 133 beds in use, compared with the ratio of 0.24 infection control practitioners per 133 beds in use in 2003, and the total number of hours dedicated to cleaning and housekeeping increased by 26.2%. The total amount of antibiotics used in the hospital did not vary significantly from 2002 to 2007, although there were changes in the classes antibiotic used. CONCLUSION: The implementation of a multipronged intervention strategy to control the outbreak of CDI significantly improved the overall situation at the hospital and underlined the importance of investing in stringent infection control practices.

Expression of CD103 identifies human regulatory T-cell subsets.

BACKGROUND: Analysis of naturally occurring T regulatory CD4+ (nTreg) cells in human diseases is hampered by the lack of specific surface marker. Indeed, the CD25 antigen, which is typically used to identify nTreg cells, is also expressed on activated effector T cells. OBJECTIVE: We sought to examine whether CD4+ T cells bearing CD103 are suppressor cells, regardless of CD25 coexpression. METHODS: We first compared freshly isolated tonsillar CD103+ CD25- cells with their CD103- CD25high counterparts for their capacity to suppress T-cell response and their expression of FoxP3 mRNA. Next CD103 was induced on neonatal or adult CD4+ T cells stimulated with allogeneic dendritic cells, and the CD103+ and CD103- fractions were compared as above. RESULTS: Tonsillar CD4+ CD103+ CD25- T cells displayed comparable suppressive activity and contained similar amounts of FoxP3 mRNA as their CD103- CD25high counterparts. In vitro-generated alloantigen-primed CD103+ cells coexpressed CD25, suppressed T-cell activation, and contained more FoxP3 mRNA than the CD103- CD25+ cells isolated from the same cultures. Finally, neonatal alloreactive cells contained more CD103+ Treg cells than their adult counterparts and, unlike the latter, became hyporesponsive to the priming alloantigens. CONCLUSIONS: The examination of CD103 and CD25 coexpression allows identification of 3 subsets of human CD4+ nTreg cells, and the detection of CD103 on CD4+ T cells identifies nTreg cells, regardless of CD25 coexpression. CLINICAL IMPLICATIONS: The greater induction of CD103+ suppressor cells by cord blood should be related to its successful clinical use as an alternative to adult bone marrow transplantation.