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HIV-1-associated nephropathy (HIVAN) is a severe complication of HIV-1 infection. To gain insight into the pathogenesis of kidney disease in the setting of HIV, a transgenic (Tg) mouse model [CD4C/HIV-negative regulator factor (Nef)] was used in which HIV-1 nef expression is under control of regulatory sequences (CD4C) of the human CD4 gene, thus allowing expression in target cells of the virus. These Tg mice develop a collapsing focal segmental glomerulosclerosis associated with microcystic dilatation, similar to human HIVAN. To identify kidney cells permissive to the CD4C promoter, CD4C reporter Tg lines were used. They showed preferential expression in glomeruli, mainly in mesangial cells. Breeding CD4C/HIV Tg mice on 10 different mouse backgrounds showed that HIVAN was modulated by host genetic factors. Studies of gene-deficient Tg mice revealed that the presence of B and T cells and that of several genes was dispensable for the development of HIVAN: those involved in apoptosis (Trp53, Tnfsf10, Tnf, Tnfrsf1b, and Bax), in immune cell recruitment (Ccl3, Ccl2, Ccr2, Ccr5, and Cx3cr1), in nitric oxide (NO) formation (Nos3 and Nos2), or in cell signaling (Fyn, Lck, and Hck/Fgr). However, deletion of Src partially and that of Hck/Lyn largely abrogated its development. These data suggest that Nef expression in mesangial cells through hematopoietic cell kinase (Hck)/Lck/Yes novel tyrosine kinase (Lyn) represents important cellular and molecular events for the development of HIVAN in these Tg mice., (Copyright © 2023 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) infection causes myelodysplasia, anemia, and accumulation of inflammatory monocytes (CD14 + CD16 + ) through largely unknown cellular and molecular pathways. The mouse cells thought to be equivalent to human CD14 + CD16 + cells are CD11b + Gr1 + myeloid-derived suppressor cells (MDSC). We used HIV transgenic (Tg) mouse models to study MDSC, namely, CD4C/Nef Tg mice expressing nef in dendritic cells (DC), pDC, CD4 + T, and other mature and immature myeloid cells and CD11c/Nef Tg mice with a more restricted expression, mainly in DC and pDC. Both Tg strains showed expansion of granulocytic and CD11b + Gr1 low/int cells with MDSC characteristics. Fetal liver cell transplantation revealed that this expansion was stroma-independent and abrogated in mixed Tg/non-Tg 50% chimera. Tg bone marrow (BM) erythroid progenitors were decreased and myeloid precursors increased, suggesting an aberrant differentiation likely driving CD11b + Gr1 + cell expansion, apparently cell autonomously in CD4C/Nef Tg mice and likely through a bystander effect in CD11c/Nef Tg mice. Hck was activated in Tg spleen, and Nef-mediated CD11b + Gr1 + cell expansion was abrogated in Hck/Lyn-deficient Nef Tg mice, indicating a requirement of Hck/Lyn for this Nef function. IL-17 and granulocyte colony-stimulating factor (G-CSF) were elevated in Nef Tg mice. Increased G-CSF levels were normalized in Tg mice treated with anti-IL-17 antibodies. Therefore, Nef expression in myeloid precursors causes severe BM failure, apparently cell autonomously. More cell-restricted expression of Nef in DC and pDC appears sufficient to induce BM differentiation impairment, granulopoiesis, and expansion of MDSC at the expense of erythroid maturation, with IL-17→G-CSF as one likely bystander contributor. IMPORTANCE HIV-1 and SIV infection often lead to myelodysplasia, anemia, and accumulation of inflammatory monocytes (CD14 + CD16 + ), with the latter likely involved in neuroAIDS. We found that some transgenic (Tg) mouse models of AIDS also develop accumulation of mature and immature cells of the granulocytic lineage, decreased erythroid precursors, and expansion of MDSC (equivalent to human CD14 + CD16 + cells). We identified Nef as being responsible for these phenotypes, and its expression in mouse DC appears sufficient for their development through a bystander mechanism. Nef expression in myeloid progenitors may also favor myeloid cell expansion, likely in a cell-autonomous way. Hck/Lyn is required for the Nef-mediated accumulation of myeloid cells. Finally, we identified G-CSF under the control of IL-17 as one bystander mediator of MDSC expansion. Our findings provide a framework to determine whether the Nef>Hck/Lyn>IL-17>G-CSF pathway is involved in human AIDS and whether it represents a valid therapeutic target.

Objective: To describe comorbidities and concomitant medications in patients initiating treatment for hepatitis C virus (HCV) infection with direct-acting antiviral (DAA) regimens in Belgium., Methods: This was a noninterventional, observational, multicenter study of data from patient charts. Adult patients with HCV infection receiving second-generation DAA therapy were included. Comorbidities were assessed at the time of HCV treatment initiation. Concomitant medications were recorded at the time of diagnosis and at treatment initiation. Potential clinically relevant drug-drug interactions (DDIs) were assessed based on information available at www.hep-druginteractions.org. The primary objective was to describe concomitant medication use ; secondary objectives were to describe modifications in concomitant therapies and comorbidities., Results: 405 patients were included. A total of 956 comorbidities were reported by 362 patients (median, 2 ; range, 0-15). The most common comorbidities were hypertension (27.2%) ; HIV coinfection (22.5%), and type 2 diabetes mellitus (14.3%). Overall, 1455 concomitant medications were being taken by 365 patients (90.1% ; median, 3 ; range 0-16). The most common concomitant medications were psycholeptics (28.6%), antiviral agents (24.2%), and medications for acid-related disorders (21.0%) Overall, 74/365 (20.3%) patients receiving a concomitant medication required an adaptation to their concomitant medication. The medications that most frequently required change were drugs for acid-related disorders (n = 14) and antiviral drugs (n = 5) ; those that were most frequently stopped were lipid-modifying drugs (n = 25) and drugs for acid-related disorders (n = 13)., Conclusion: Physicians are aware of the potential for DDIs with DAAs, but improved alignment between clinical practice and theoretical recommendations is required., (© Acta Gastro-Enterologica Belgica.)

Objectives:  The roundworm Ascaris lumbricoides is one of the most prevalent parasites belonging to the class of the soil-transmitted helminths. Infections are most common in developing countries with a tropical climate where sanitation and hygiene are poor. However, prevalence of ascariasis in industrialized countries is increasing because of immigration and increasing number of refugees., Methods:  We report a case of ascariasis in a female patient who was admitted to our hospital after she had left the informal refugee camp of Calais in the north of France., Results:  After colonoscopic removal of the worm and treatment with mebendazole during three days the patient's symptoms had completely resolved. Medical treatment with benzimidazole derivatives is easy and inexpensive. To prevent parasitic infections in larger populations, mass drug administration should be repeated periodically and must be implemented along with additional measures such as improvements to water, sanitation and hygiene (WASH). These WASH programs have been proven to be highly effective, but access and follow-up are expensive and very difficult to organize in refugee camps, even in wealthy, industrialized countries., Conclusions: Despite being an old, well-known parasitic disease, ascariasis might reappear in certain populations at risk in industrialized countries. Detection, treatment and follow-up of these patients, and the organization of preventive measures remain challenging.

Background and Aim: Hepatitis C viral infection (HCV) has become a curable disease due to the development of direct acting antivirals (DAA). The WHO has set a target to eliminate HCV completely. Therefore, people who inject drugs (PWID) also need to be treated. In this study, we compared the real-life uptake and outcome of DAA treatment for HCV in PWID and non-PWID., Methods: We performed a nation-wide, retrospective cohort study in 15 hospitals. All patients who were treated with simeprevir-sofosbuvir, daclatasvir-sofosbuvir, or ombitasvir/paritaprevir ritonavir-dasabuvir between December 2013 and November 2015 were included., Results: The study population consisted of 579 patients: 115 PWID (19.9%) and 464 non-PWID (80.1%). Of the PWID 18 were active PWID (15.6%), 35 still received opiate substitution therapy (OST) (30.4%) and 62 were former PWID without OST (53.9%). PWID were more infected with genotype 1a and 3 (p=0.001). There were equal rates of side-effects (44.7% vs. 46.6%; p=0.847), similar rates of treatment completion (95.7% vs 98.1%; p=0.244) and SVR (93.0% vs 94.8%; p=0.430) between PWID and non-PWID, respectively., Conclusion: PWID, especially active users, are underserved for DAA treatment in real life in Belgium. Reimbursement criteria based on fibrosis stage make it difficult to treat PWID. Treatment adherence is similar in PWID and the general population, even in patients with active abuse. DAA were safe and effective in PWID despite the higher prevalence of difficult-to-treat genotypes. Based on these data more efforts to treat PWID are needed and policy changes are necessary to reach the WHO targets., (Copyright © 2017 Elsevier B.V. All rights reserved.)

We present a case of a 52-year old female patient with intermittent gastrointestinal bleeding and iron deficiency anaemia. Repeated endoscopic investigation revealed no diagnosis, but contrast-enhanced computed tomography showed a splenic artery pseudo-aneurysm secondary to chronic alcoholic pancreatitis. A distal pancreatectomy and splenectomy was performed. Hemosuccus pancreaticus is an uncommon cause of gastrointestinal bleeding, most frequently associated with chronic pancreatitis. Erosion of a peripancreatic artery by a pseudocyst can cause a pseudoaneurysm and rupture occurs in up to 10% of the cases. Bleeding from a pseudocyst wall or rupture of an atherosclerotic or traumatic aneurysm is rare. Angiography, contrast-enhanced computed tomography and endoscopic findings can be diagnostic in the majority of cases. Angiographic embolization or surgery are both therapeutic options depending on underlying nonvascular pancreas related indications requiring surgery. We discuss diagnostic pitfalls and current therapeutic strategies in the management of this disease., (© Acta Gastro-Enterologica Belgica.)

Most chemotherapy regimens in colorectal cancer treatment are 5-fluorouracil (5-FU)/leucovorin or capecitabine-based. Cardiotoxicity is a less common but potentially lethal complication of 5-FU or capecitabine treatment, and some physicians might be unfamiliar with treatment alternatives. Rechallenging should be avoided because it carries a high risk of recurrence of the cardiac symptoms and prophylactic treatment is not always protective. Possible alternative treatment options to be considered are to replace the oral capecitabine or intravenous 5-FU by a 5-FU bolus regimen, by uracil-tegafur or tegafur/gimeracil/oteracil, both oral fluoropyrimidines combining a 5-FU prodrug with a dihydropyrimidine dehydrogenase (DPD) inhibitor, or by raltitrexed, a thymidilate synthase inhibitor whose metabolism is independent of DPD. Patients with advanced colorectal cancer and fluoropyrimidine-induced cardiotoxicity can be treated with other non-fluoropyrimidine related chemotherapy, either as a single agent, combined, or in combination with biological agents. In this report we discuss the different alternative treatment options., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We investigated the presence of XMRV in a cohort of Quebec patients with chronic fatigue syndrome (CFS). DNA was purified from activated peripheral blood mononuclear cells (PBMCs) and PCR was used to detect XMRV gag and env in 72 patients. Anti-XMRV antibodies were searched in sera of 62 patients by Western blot analysis. Attempts to detect XMRV antigens was made, using immunofluorescence with Gag anti-p30 antiserum on activated PBMC from 50 patients. Plasma viremia was measured by RT-PCR on 9 subjects. Finally, detection of infectious virus in 113 CFS subjects was made by co-culture of PHA+IL-2 activated PBMC with human LNCaP carcinoma cells, and by infecting the same susceptible cells with plasma, using a reverse transcriptase (RT) assay as a readout in both experiments. No detection of XMRV footprints nor infectious virus was detected with any of the approaches, in any of the tested individuals., (Copyright © 2011 Elsevier Inc. All rights reserved.)

We previously reported that truncation of Notch1 (N1) by provirus insertion leads to overexpression of both the intracellular (N1(IC)) and the extracellular (N1(EC)) domains. We produced transgenic (Tg) mice expressing N1(EC) in T cells and in cells of the myeloid lineage under the regulation of the CD4 gene. These CD4C/N1(EC) Tg mice developed vascular disease, predominantly in the liver: superficial distorted vessels, cavernae, lower branching of parenchymal vessels, capillarized sinusoids, and aberrant smooth muscle/endothelial cell topography. The disease developed in lethally irradiated normal mice transplanted with Tg bone marrow or fetal liver cells as well as in Rag-/- Tg mice. In nude mice transplanted with fetal liver cells from (ROSA26 x CD4C/N1(EC)) F1 Tg mice, abnormal vessels were of recipient origin. Transplantation of Tg peritoneal macrophages into normal recipients also induced abnormal vessels. These Tg macrophages showed impaired functions, and their conditioned medium inhibited the proliferation of liver sinusoid endothelial cells in vitro. The Egr-1 gene and some of its targets (Jag1, FIII, FXIII-A, MCP-1, and MCP-5), previously implicated in hemangioma or vascular malformations, were overexpressed in Tg macrophages. These results show that myeloid cells can be reprogrammed by N1(EC) to induce vascular malformations through a paracrine pathway.

Loss of heterozygosity (LOH) at human chromosome bands 1p32-36 and 10q23-26 is frequent in various human tumors, including breast cancers, and is thought to reflect the loss of tumor-suppressor genes (TSGs). To map such genes, high-resolution LOH analysis was performed on 93 Erbb2-induced mammary tumors from (BALB/c x C57BL/6) F1 MMTV/Erbb2 transgenic mice. A panel of 24 microsatellite markers specific to the region of mouse chr4, homologous to human 1p31-36, and 16 markers specific to the mouse chr19 region, homologous to human 10q23-26 were used. In addition, lower-density mapping was performed on the remaining portion of mouse chr4 [homologous to human 9p13, 9p21-24, 9q21-22, 9q31-34 (12 markers)] and chr19 [homologous to 9q21, 9p24, 11q12-13 (9 markers)]. Several distinct, discrete, and discontinuous LOH regions flanked by areas of heterozygosity were identified, 22 on chr4 and 14 on chr19. Among these, 13 were mapped in the region of homology with human 1p31-36 (between D4Mit153 and D4Mit254) and 9 in the region of homology with human 10q23-26 (between D19Mit46 and D19Mit6). Although several LOH loci span a large interval, many are relatively short (1-4 Mb), and a few span an interval of <1 Mb. This allelotyping represents the highest density of LOH loci yet mapped in these chromosomal regions. The presence of numerous LOH regions in alternation with regions of heterozygosity, consistent with mitotic recombination as a mechanism for generating such a mosaic pattern, suggests the presence of several TSGs in these regions and should facilitate their identification.

Objective: It is well established that various ENT disorders and symptoms may be a manifestation of gastroesophageal reflux disease (GERD). Measuring proximal esophageal acid exposure might be useful in the evaluation of patients with suspected reflux-related ENT manifestations, but the limited available data are conflicting. The aim of the present study was to study the determinants of proximal esophageal acid exposure (PR) and to evaluate the clinical usefulness of ambulatory proximal pH monitoring., Methods: Twenty healthy controls and 346 patients with suspected reflux disease underwent typical and atypical GERD symptom assessment, endoscopy, esophageal manometry and ambulatory combined dual esophageal pH, and Bilitec duodeno-gastro-esophageal reflux exposure (DGER) monitoring. The presence of pathological PR and its relation to symptom pattern and distal esophageal acid exposure (DR) and DGER exposure were analyzed., Results: Fifty-seven patients (16%) had pathological PR. Demographic characteristics, symptom pattern, and manometric findings did not differ in patients with normal or pathological PR. Patients with pathological PR had significantly higher DR and DGER. The multivariate analysis identified only pathological DR as an independent risk factor for the presence of pathological PR (odds ratio 4.515, 95% CI 2.48-8.23, p < 0.0001). Only 20 patients (6%) had pathological proximal reflux without pathological distal acid reflux., Conclusion: The findings of the present article do not support routine proximal esophageal pH monitoring as a clinical tool: PR does not differentiate patients with typical or atypical GERD manifestations and depends mainly on DR.

A 23-year-old man was admitted to the hospital because of dyspnea. Chest X-ray showed reticulo-nodular opacities. The crazy paving appearance on high-resolution CT was highly suggestive of pulmonary alveolar proteinosis. Histologic examination confirmed the diagnosis. Pulmonary alveolar proteinosis is a rare disease but an important diagnosis to make as treatment with pulmonary lavage is curative in a large proportion of patients.

REC102 is a meiosis-specific early exchange gene absolutely required for meiotic recombination in Saccharomyces cerevisiae. Sequence analysis of REC102 indicates that there are multiple potential regulatory elements in its promoter region, and a possible regulatory element in the coding region. This suggests that the regulation of REC102 may be complex and may include elements not yet reported in other meiotic genes. To identify potential cis-regulatory elements, phylogenetic footprinting analysis was used. REC102 homologues were cloned from other two Saccharomyces spp. and sequence comparison among the three species defined evolutionarily conserved elements. Deletion analysis demonstrated that the early meiotic gene regulatory element URS1 was necessary but not sufficient for proper regulation of REC102. Upstream elements, including the binding sites for Gcr1p, Yap1p, Rap1p and several novel conserved sequences, are also required for the normal regulation of REC102 as well as a Rap1p binding site located in the coding region. The data in this paper support the use of phylogenetic comparisions as a method for determining important sequences in complex promoters., (Copyright 2002 John Wiley & Sons, Ltd.)

We have recently demonstrated that a novel somatically mutated B220(-) memory B cell subset rapidly dominates the secondary immune response to (4-hydroxy-3-nitrophenyl) acetyl (NP). Upon adoptive transfer with Ag, B220(+)NP(+) memory B cells produce large numbers of B220(-)NP(+) B cells that can rapidly differentiate into plasma cells. Therefore, it is not clear whether the novel B220(-) memory compartment is a consequence of secondary Ag challenge or whether it develops as a stable memory subset after initial Ag challenge. In this study, we demonstrate the gradual emergence of B220(-)NP(+) B cells in the spleen to maximal numbers 3 wk after initial Ag exposure. Like their B220(+) counterparts, the B220(-) B cells initially appear unmutated at days 5-7; however, the majority rapidly accumulate affinity increasing mutations by days 9-14 of the primary immune response. More extensive cell surface phenotype (GL7(-)BLA-1(-)CD24(-)CD43(+)) argues strongly against germinal center localization and direct analysis in situ places a cohort of B220(-)CD11b(+)NP(+) B cells in the red pulp of the spleen and not in the MZs. These data provide direct evidence for the development of B220(-) memory B cells as a unique cellular consequence of primary Ag exposure. The cellular dynamics and molecular attributes of these unique memory B cells suggest they are distinct cellular products of the germinal center reaction in the primary response and are maintained long-term in the spleen and bone marrow.

The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. This study focuses on the rapid expression of B cell memory upon antigen recall in vivo, and the replenishment of quiescent B cell memory that follows. Based on expression of CD138 and B220, we reveal a unique and major subtype of antigen-specific memory B cells (B220(-)CD138(-)) that are distinct from antibody-secreting B cells (B220(+/)-CD138(+)) and B220(+)CD138(-) memory B cells. These nonsecreting somatically mutated B220(-) memory responders rapidly dominate the splenic response and comprise >95% of antigen-specific memory B cells that migrate to the bone marrow. By day 42 after recall, the predominant quiescent memory B cell population in the spleen (75-85%) and the bone marrow (>95%) expresses the B220(-) phenotype. Upon adoptive transfer, B220(-) memory B cells proliferate to a lesser degree but produce greater amounts of antibody than their B220(+) counterparts. The pattern of cellular differentiation after transfer indicates that B220(-) memory B cells act as stable self-replenishing intermediates that arise from B220(+) memory B cells and produce antibody-secreting cells on rechallenge with antigen. Cell surface phenotype and Ig isotype expression divide the B220(-) compartment into two main subsets with distinct patterns of integrin and coreceptor expression. Thus, we identify new cellular components of B cell memory and propose a model for long-term protective immunity that is regulated by a complex balance of committed memory B cells with subspecialized immune function.

Loss of heterozygosity (LOH) analysis was performed on 62 mammary tumors that were induced in (BALB/c x C57BL/6)F1 mouse mammary tumor virus/neu transgenic mice. Eighty-six simple sequence length polymorphism markers were used to cover all of the somatic chromosomes. Frequency of LOH was observed to be significant for chromosomes 4 (50%), 19 (32%), and 8 (21%). On chromosome 4, at least three distinct regions of allelic deletions could be identified: one proximal to 22 cM; the second close to the p16INK4a/p15INK4b locus, which is commonly deleted in various tumors; and the third one in the proximity of Mom1. The frequency of LOH on chromosome 19 was the same for the four markers used. Our data suggested the presence of two distinct LOH loci, one proximal to 47 cM and the other at the distal region. On chromosome 8, possibly two distinct LOH loci could be recognized, one around 52 cM and the other one at 67 cM or distal to it. These regions map close to E-cadherin (Cdh1) and M-cadherin (Cdh15) loci, respectively. Because LOH sites are thought to harbor tumor suppressor genes, this allelotype screening has allowed the mapping of putative tumor suppressor genes that may be implicated, in collaboration with the erbB-2/neu oncogene, in the development of mammary tumors in these transgenic mice.

We have constructed transgenic (Tg) mice expressing the entire human immunodeficiency virus type 1 (HIV-1) coding sequences in cells targeted by HIV-1 infection in humans. These Tg mice developed a severe AIDS-like disease leading to early death (< 1 month). They developed muscle wasting, severe atrophy and fibrosis of lymphoid organs, tubulointerstitial nephritis, and lymphoid interstitial pneumonitis. In addition the expression of RANTES was increased in various tissues of these Tg mice relative to that in the normal controls. Disease appearance was correlated with the levels of transgene expression. The numerous pathologies observed in these mice are remarkably similar to those observed in human AIDS and, more specifically, in pediatric AIDS.

In the yeast, Saccharomyces cerevisiae, several genes appear to act early in meiotic recombination. HOP1 and RED1 have been classified as such early genes. The data in this paper demonstrate that neither a red nor a hop1 mutation can rescue the inviable spores produced by a rad52 spo13 strain; this phenotype helps to distinguish these two genes from other early meiotic recombination genes such as SPO11, REC104, or MEI4. In contrast, either a red1 or a hop1 mutation can rescue a rad50S spo13 strain; this phenotype is similar to that conferred by mutations in the other early recombination genes (e.g., REC104). These two different results can be explained because the data presented here indicate that a rad50S mutation does not diminish meiotic intrachromosomal recombination, similar to the mutant phenotypes conferred by red1 or hop1. Of course, RED1 and HOP1 do act in the normal meiotic interchromosomal recombination pathway; they reduce interchromosomal recombination to approximately 10% of normal levels. We demonstrate that a mutation in a gene (REC104) required for initiation of exchange is completely epistatic to a mutation in RED1. Finally, mutations in either HOP1 or RED1 reduce the number of double-strand breaks observed at the HIS2 meiotic recombination hotspot.