Volume et profil de consommation d’alcool des élèves et des camarades scolaires comme prédicteurs de l’agression et de la victimisation: une analyse multiniveaux auprès d’adolescents suisses

Volume and profile of alcohol consumption among students and classmates as predictors of aggression and victimization: a multilevel analysis among Swiss adolescents

Objective:  

To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels.     

Dual β-Catenin and γ-Catenin Loss in Hepatocytes Impacts Their Polarity through Altered Transforming Growth Factor-β and Hepatocyte Nuclear Factor 4α Signaling

Hepatocytes are highly polarized epithelia. Loss of hepatocyte polarity is associated with various liver diseases, including cholestasis. However, the molecular underpinnings of hepatocyte polarization remain poorly understood. Loss of β-catenin at adherens junctions is compensated by γ-catenin and dual loss of both catenins in double knockouts (DKOs) in mice liver leads to progressive intrahepatic cholestasis. However, the clinical relevance of this observation, and further phenotypic characterization of the phenotype, is important. Herein, simultaneous loss of β-catenin and γ-catenin was identified in a subset of liver samples from patients of progressive familial intrahepatic cholestasis and primary sclerosing cholangitis. Hepatocytes in DKO mice exhibited defects in apical-basolateral localization of polarity proteins, impaired bile canaliculi formation, and loss of microvilli. Loss of polarity in DKO livers manifested as epithelial-mesenchymal transition, increased hepatocyte proliferation, and suppression of hepatocyte differentiation, which was associated with up-regulation of transforming growth factor-β signaling and repression of hepatocyte nuclear factor 4α expression and activity. In conclusion, concomitant loss of the two catenins in the liver may play a pathogenic role in subsets of cholangiopathies. The findings also support a previously unknown role of β-catenin and γ-catenin in the maintenance of hepatocyte polarity. Improved understanding of the regulation of hepatocyte polarization processes by β-catenin and γ-catenin may potentially benefit development of new therapies for cholestasis.

A hallmark of epithelial cells is polarization, which is achieved by the orchestration of external cues, such as cellular contact, extracellular matrix, signal transduction, growth factors, and spatial organization.¹ Hepatocytes in the liver show a unique polarity by forming several apical and basolateral poles within a cell.² The apical poles of adjacent hepatocytes form a continuous network of bile canaliculi into which bile is secreted, whereas the basolateral membrane domain forms the sinusoidal pole, which secretes various components, such as proteins or drugs, into the blood circulation.³ Loss of hepatic polarity has been associated with several cholestatic and developmental disorders, including progressive familial intrahepatic cholestasis (PFIC) and primary sclerosing cholangitis (PSC).^4,5 Although the molecular mechanisms governing hepatocyte polarity have been extensively studied in the in vitro systems, there is still a significant gap in our understanding of how polarity is established within the context of tissue during development or maintained during homeostasis.^6,7 Similarly, the molecular pathways contributing to hepatic polarity are not entirely understood, and a better comprehension of hepatic polarity regulation is thus warranted.Previous studies have confirmed the role of hepatocellular junctions, such as tight and gap junctions, in the maintenance of hepatocyte polarity.^8,9 Studies done in vitro and in vivo have shown that loss of junctional proteins, such as zonula occludens protein (ZO)-1, junctional adhesion molecule-A, and claudins, lead to impairment of polarity and distorted bile canaliculi formation.10, 11, 12, 13 In addition, proteins involved in tight junction assembly, such as liver kinase B1, are also involved in polarity maintenance.¹⁴ Among adherens junction proteins, various in vitro cell culture models have confirmed the role of E-cadherin in the regulation of hepatocyte polarity, possibly through its interaction with β-catenin.^15,16 However, there is a lack of an in vivo model to study the role of adherens junction proteins in hepatocyte polarity and their misexpression contributing to various liver diseases.β-Catenin plays diverse functions in the liver during development, regeneration, zonation, and tumorigenesis.17, 18, 19 The relative contribution of β-catenin as part of the adherens junction is challenging to study because like in other tissues, γ-catenin compensates for the β-catenin loss in the liver.^20,21 To address this redundancy, we previously reported a hepatocyte-specific β-catenin and γ-catenin double-knockout (DKO) mouse model was reported.²² Simultaneous deletion of β-catenin and γ-catenin in mice livers led to cholestasis, partially through the breach of cell-cell junctions. However, more comprehensive understanding of the molecular underpinnings of the phenotype is needed.In the current study, prior preclinical findings of dual β-catenin and γ-catenin loss were extended to a subset of PFIC and PSC patients. In vivo studies using the murine model with hepatocyte-specific dual loss of β-catenin and γ-catenin showed complete loss of hepatocyte polarity compared to the wild-type controls (CONs). Loss of polarity in DKO liver was accompanied by epithelial-mesenchymal transition (EMT), activation of transforming growth factor (TGF)-β signaling, and reduced expression of hepatocyte nuclear factor 4α (HNF4α). Our findings suggest that β-catenin and γ-catenin and in turn adherens junction integrity, are critical for the maintenance of hepatocyte polarity, and any perturbations in this process can contribute to the pathogenesis of cholestatic liver disease.     

Multiple endocrine cell types in thyroid medullary carcinoma

Summary 10 cases of thyroid medullary carcinoma (TMC) have been studied ultrastructurally and histochemically. Well differentiated calcitonin-producing C cells were present in all tumours, being prevalent in 9 cases. 5-Hydroxytryptamine (5HT) storing cells were found in two cases, somatostatin immunoreactive cells in at least 5 cases and ACTH-immunoreactive cells in 4 cases. Ultrastructurally, at least 3 types of apparently non-C cells were observed. Type 1 cells with large, poorly osmiophilic granules resembling those of gastroenteropancreatic D cells, were present in 6 cases; they appeared to correlate well with somatostatin immunoreactive cells. Type 2 cells with large osmiophilic granules were found in 5 cases; they resembled ACTH-MSH cells of the human pituitary and may correspond to the ACTH-immunoreactive cells of light microscopy. Type 3 cells with small granules and an unknown function were found in 6 cases, always in scarce number. It is concluded that TMC, although mainly made up of C cells, usually contains large proportions of other endocrine cell types.Supported in part by grant N. 75.00630.04 from the Italian National Research Council (C.N.R.). P.F. is a fellow of the Fondazione Anna Villa Rusconi, Varese     

Colorectal polyposis with mixed juvenile and adenomatous patterns

Summary An unusual form of colorectal polyposis is described displaying juvenile, adenomatous and mixed patterns in a 17-year-old girl. Although juvenile polyposis is generally considered to be non-neoplastic in nature, in both the present and in other case reports histological findings support a neoplastic nature. Since an increase in the incidence of large bowel carcinomas has been found in subjects with a previous diagnosis of juvenile polyposis, these patients should be considered to be at risk, and submitted to follow up.     

Intertubular capillary changes in kidney allografts: a morphologic investigation on 61 renal specimens.

A total of 61 kidney allograft specimens (51 biopsies and 10 nephrectomies) from 44 patients were investigated. Transplant glomerulopathy (TGP) was found in 38 specimens. Electron microscopy disclosed peculiar intertubular capillary changes (ITCC) in 47 specimens (all those showing TGP and nine without TGP). They were characterized by splitting and multilayering of the basement membranes. TGP and ITCC were graded and found mild (in 23 and 22 specimens), moderate (in 11 and 16 specimens), and severe (in four and nine specimens). Both worsened with time lapse from transplantation. When both were compared in single specimens, their grading was similar or, with a few exceptions, more severe for ITCC. TGP and ITCC were more frequent in biopsies with morphologic evidence of rejection and less frequent in patients treated with Cyclosporine A. Repeated biopsies and nephrectomies were studied in 10 patients and a somewhat more precocious appearance of ITCC than of TGP was found. Earlier and more severe ITCC were found in two patients who had had two transplants as compared to those with one. Morphologic similarities between TGP and ITCC suggest a common pathogenetic mechanism related to endothelial damage. The association to the histological evidence of rejection as well as the apparently protective activity of Cyclosporine A could support the involvement of an immune-mediated mechanism in agreement with what is reported in literature. The constant association of ITCC and TGP and its possible more precocious appearance enforce the diagnostic value of the former, which allows to infer the presence or the subsequent development of TGP even in biopsies where glomeruli are lacking.     

Optimizing Disclosure of HIV Status to a Diverse Population of HIV-Positive Youth at an Urban Pediatric HIV Clinic

PurposeThe purpose of the study was to increase the proportion of youth living with HIV (YLWH) aged ≥11 years who undergo developmentally appropriate disclosure about their HIV status.MethodsA quality improvement project was initiated at an urban pediatric HIV clinic between July 2018 and March 2020. The primary outcome measure was the proportion of YLWH aged ≥11 years who were disclosed to about their HIV status. The proportion of undisclosed YLWH who had documented nondisclosure status was also assessed as a process measure. Plan-Do-Study-Act (PDSA) cycles for change included monthly clinic staff check-ins to discuss new disclosures, quarterly team meetings to discuss strategies to improve disclosure, and modifying a clinic note template to prompt providers to document disclosure status. Annotated run charts were used to analyze the data.ResultsBefore the first PDSA cycle, 26/46 (57%) of the target population of YLWH aged ≥11 years had their HIV status disclosed to them, and none of the undisclosed youth had disclosure status documented in their medical record. After 20 months and six PDSA cycles, the proportion of YLWH aged ≥11 years disclosed to about their HIV status increased to 80% and the proportion of undisclosed YLWH with documentation of their disclosure status increased to 100%.ConclusionsSeveral interventions integrated throughout the pediatric HIV care process were associated with an increase in the proportion of YLWH with developmentally appropriate HIV disclosure and documentation of disclosure status, an important psychosocial aspect of care in these individuals.     

Pentachlorophenol exposure in women with gynecological and endocrine dysfunction.

Exposure to wood preservatives containing pentachlorophenol (PCP) was detected in 65 women who consulted the Endocrinological Department of the University Hospital of Obstetrics and Gynecology, Heidelberg, Germany, because of gynecological problems. Blood PCP levels ranged from 20.7 to 133 microg per liter of serum. One hundred and six women with similar clinical conditions, corresponding age and body weight, no PCP exposure in history, and PCP levels below 20 microg per liter of serum served as control group. Significant associations were found between serum PCP concentrations, age, and different parameters of the endocrine system. PCP may act centrally on a hypothalamic or suprahypothalamic level which may result in mild ovarian and adrenal insufficiency. PCP may, therefore, play a role in the increasing infertility problem.