Concerted synergy between viral-specific IgG and CD8 + T cells is critical for clearance of an HCV-related rodent hepacivirus.

BACKGROUND AND AIMS: Evidence assessing the role of B cells and their antibodies, or lack thereof, in the spontaneous resolution of acute HCV infection is conflicting. Utilization of a strictly hepatotropic, HCV-related rodent hepacivirus (RHV) model circumvents many of the challenges facing the field in characterizing the immunological correlates of dichotomous infection outcomes. This study seeks to elucidate the importance of B cells in the clearance of acute RHV infection. APPROACH AND RESULTS: µMT mice were infected i.v. with RHV and found to develop chronic infection for over a year. Wild-type (WT) mice depleted of B cells also exhibited persistent viremia that resolved only upon B cell resurgence. The persistent infection developed by B1-8i and AID cre/cre mice revealed that antigen-specific, class-switched B cells or their antibodies were crucial for viral resolution. Virus-specific CD8 + and CD4 + T cells were characterized in these mice using newly developed major histocompatibility complex class I and II tetramers and ex vivo peptide stimulation. Immunoglobulin G (IgG) was purified from the serum of RHV- or lymphocytic choriomeningitis virus Armstrong-infected mice after viral clearance and passively transferred to AID cre/cre recipients, revealing viral clearance only in αRHV IgG recipients. Further, the transfer of αRHV IgG into B cell-depleted recipients also induced viral resolution. This ability of RHV-specific IgG to induce viral clearance was found to require the concomitant presence of CD8 + T cells. CONCLUSIONS: Our findings demonstrate a cooperative interdependence between immunoglobulins and the T cell compartment that is required for RHV resolution. Thus, HCV vaccine regimens should aim to simultaneously elicit robust HCV-specific antibody and T cell responses for optimal protective efficacy.

Home-Use Transcranial Direct Current Stimulation for the Treatment of a Major Depressive Episode: A Randomized Clinical Trial.

Importance: Transcranial direct current stimulation (tDCS) is moderately effective for depression when applied by trained staff. It is not known whether self-applied tDCS, combined or not with a digital psychological intervention, is also effective. Objective: To determine whether fully unsupervised home-use tDCS, combined with a digital psychological intervention or digital placebo, is effective for a major depressive episode. Design, Setting, and Participants: This was a double-blinded, sham-controlled, randomized clinical trial with 3 arms: (1) home-use tDCS plus a digital psychological intervention (double active); (2) home-use tDCS plus digital placebo (tDCS only), and (3) sham home-use tDCS plus digital placebo (double sham). The study was conducted between April 2021 and October 2022 at participants' homes and at Instituto de Psiquiatria do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil. Included participants were aged 18 to 59 years with major depression and a Hamilton Depression Rating Scale, 17-item version (HDRS-17), score above 16, a minimum of 8 years of education, and access to a smartphone and internet at home. Exclusion criteria were other psychiatric disorders, except for anxiety; neurologic or clinical disorders; and tDCS contraindications. Interventions: tDCS was administered in 2-mA, 30-minute prefrontal sessions for 15 consecutive weekdays (1-mA, 90-second duration for sham) and twice-weekly sessions for 3 weeks. The digital intervention consisted of 46 sessions based on behavioral therapy. Digital placebo was internet browsing. Main Outcomes and Measures: Change in HDRS-17 score at week 6. Results: Of 837 volunteers screened, 210 participants were enrolled (180 [86%] female; mean [SD] age, 38.9 [9.3] years) and allocated to double active (n = 64), tDCS only (n = 73), or double sham (n = 73). Of the 210 participants enrolled, 199 finished the trial. Linear mixed-effects models did not reveal statistically significant group differences in treatment by time interactions for HDRS-17 scores, and the estimated effect sizes between groups were as follows: double active vs tDCS only (Cohen d, 0.05; 95% CI, -0.48 to 0.58; P = .86), double active vs double sham (Cohen d, -0.20; 95% CI, -0.73 to 0.34; P = .47), and tDCS only vs double sham (Cohen d, -0.25; 95% CI, -0.76 to 0.27; P = .35). Skin redness and heat or burning sensations were more frequent in the double active and tDCS only groups. One nonfatal suicide attempt occurred in the tDCS only group. Conclusions and Relevance: Unsupervised home-use tDCS combined with a digital psychological intervention or digital placebo was not found to be superior to sham for treatment of a major depressive episode in this trial. Trial Registration: ClinicalTrials.gov Identifier: NCT04889976.

Host genetic variation guides hepacivirus clearance, chronicity, and liver fibrosis in mice.

BACKGROUND AIMS: Human genetic variation is thought to guide the outcome of HCV infection, but model systems within which to dissect these host genetic mechanisms are limited. Norway rat hepacivirus, closely related to HCV, causes chronic liver infection in rats but causes acute self-limiting hepatitis in typical strains of laboratory mice, which resolves in 2 weeks. The Collaborative Cross (CC) is a robust mouse genetics resource comprised of a panel of recombinant inbred strains, which model the complexity of the human genome and provide a system within which to understand diseases driven by complex allelic variation. APPROACH RESULTS: We infected a panel of CC strains with Norway rat hepacivirus and identified several that failed to clear the virus after 4 weeks. Strains displayed an array of virologic phenotypes ranging from delayed clearance (CC046) to chronicity (CC071, CC080) with viremia for at least 10 months. Body weight loss, hepatocyte infection frequency, viral evolution, T-cell recruitment to the liver, liver inflammation, and the capacity to develop liver fibrosis varied among infected CC strains. CONCLUSIONS: These models recapitulate many aspects of HCV infection in humans and demonstrate that host genetic variation affects a multitude of viruses and host phenotypes. These models can be used to better understand the molecular mechanisms that drive hepacivirus clearance and chronicity, the virus and host interactions that promote chronic disease manifestations like liver fibrosis, therapeutic and vaccine performance, and how these factors are affected by host genetic variation.

All-day passive radiative cooling using common salts.

Radiative cooling materials underperform compared to their theoretical potential due to parasitic heating from contact with ambient air. Solutions to this problem can be expensive or complex to fabricate. Here, a potentially inexpensive, simply fabricated material that improves cooling performance by reducing parasitic heating was created using naturally abundant salts. NaCl and KCl are not typically considered for radiative cooling because of their high hygroscopicity and low mechanical strength; however, these compounds are highly infrared-transparent and can be fabricated into aerogel-like foam structures to provide thermally insulating properties. The salt foams, described herein, scattered (reflected) visible light, transmitted infrared radiation, and provided thermal insulation. They were packaged into mechanical supporting panels to avoid physical disruption and the nanostructure was stabilized to moisture by adding an anti-caking agent. The panels were able to keep an underlying surface below ambient temperature for a full 24 hour cycle and reduced parasitic heating rate by more than half (compared to an uncovered surface). The panels were able to cool a variety of underlying surfaces, even highly absorbing surfaces that are normally well above ambient temperature during the day. This work demonstrates an affordable, easily produced, electricity-free cooling technology with potential to be manufactured for large-scale practical applications.

Análisis preliminar de alimentos para la población vegana/vegetariana. ¿son buenos aportadores de minerales de interés nutricional? / Preliminary analysis of foods for the vegan/vegetarian population. Are they good suppliers of minerals of nutritional interest?

Resumen Introducción: recientemente, se ha evidenciado gran desarrollo de variados productos destinados a la población vegetariana/vegana. Sin embargo, su valor nutricional no ha sido estudiado en profundidad. El objetivo del presente estudio fue evaluar aporte potencial (AP) y porcentaje de cobertura de requerimientos diarios (%RD) de hierro, calcio y zinc de alimentos dirigidos a poblaciones adolescente y adulta vegetariana/vegana. Materiales y método: se analizaron cinco medallones (4 comerciales, 1 casero) y once bebidas (9 comerciales, 4 de ellas c/jugo frutal y 2 caseras) elaborados con materias primas vegetales. Se estableció el AP de Fe, Ca y Zn en los productos considerando su contenido y dializabilidad porcentual (D%). Se calculó, para una porción de alimento, el porcentaje de cobertura del requerimiento diario de estos minerales. Resultados: el contenido de los minerales en los medallones fue: [Fe] 1,64-4,21 mg%; [Ca] 104-213 mg% y [Zn] 0,53-3,57 mg%; en las bebidas se observó: [Fe] 0,24-2,39 mg%; [Ca] 71-214 mg% y [Zn] 0,18-0,79 mg%. La D% en medallones fue: Fe 7,3-11,9; Ca 10,2-18,2 y Zn 17,0-21,4 y para las bebidas, Fe 5,2-32,8; Ca 6,4-35,7 y Zn 5,9-33,9. El %RD para adolescentes, considerando una porción de medallones fue: Fe mujeres 3,0-9,0%; hombres 5,0-16%; Ca 0,7-6,8% y Zn 1,5-3,9% y para adultos fue: Fe mujeres 3,0-10%; hombres 7,0-20%; Ca 0,6-5,8% y Zn 2,0-5,1%. Al considerar las bebidas, el %RD para adolescentes fue: Fe mujeres 2,0-28%; hombres 4,0-53%; Ca 0,4-22% y Zn 1,3-9,5%. Para adultos fue: Fe mujeres 2,0-31%; hombres 5,0-64%; Ca 0,3-19% y Zn 1,8-12%. Conclusiones: en los medallones se observó bajo %RD para los minerales estudiados. Las bebidas con agregado de jugos de naranja o manzana aportaron cantidades significativas de hierro. El %RD para zinc y calcio de los dieciséis alimentos fue bajo (ambos grupos estudiados). Consecuentemente, para cubrir los requerimientos de estos minerales habría que combinar adecuadamente los alimentos que se consumen.

Abstract Introduction: recently, there has been great development of various products aimed at the vegetarian/vegan population. However, its nutritional value has not been studied in depth. The objective of this study was to evaluate potential intake (PI) and percentage of coverage of daily requirements (% RD) of iron, calcium and zinc from foods aimed at adolescent and adult vegetarian/vegan populations Materials and method: five medallions (4 commercial, 1 homemade) and eleven beverages (9 commercial, 4 of them with fruit juice and 2 homemade) made with vegetable raw materials were analyzed. The PI of Fe, Ca and Zn was established in the products considering their content and percentage dialyzability (D%). It was calculated, for a portion of food, the percentage of coverage of the daily requirement of these minerals. Results: the mineral content in the medallions was: [Fe] 1.64-4.21 mg%; [Ca] 104-213 mg% and [Zn] 0.53-3.57 mg%; in beverages it was observed: [Fe] 0.24-2.39 mg%; [Ca] 71-214 mg% and [Zn] 0.18-0.79 mg%. The D% in medallions was: Fe 7,3-11,9; Ca 10.2-18.2 and Zn 17.0-21.4 and for beverages, Fe 5.2-32.8; Ca 6.4-35.7 and Zn 5.9-33.9. The %RD for adolescents, considering a portion of medallions was: Fe women 3.0-9.0%; men 5.0-16%; Ca 0.7-6.8% and Zn 1.5-3.9% and for adults it was: Fe women 3.0-10%; men 7.0-20%; Ca 0.6-5.8% and Zn 2.0-5.1%. When considering beverages, the %RD for adolescents was: Fe women 2.0-28%; men 4.0-53%; Ca 0.4-22% and Zn 1.3-9.5%. For adults it was: Fe women 2.0-31%; men 5.0-64%; Ca 0.3-19% and Zn 1.8-12%. Conclusions: in the medallions, low % RD was observed for the minerals studied. Drinks with added orange or apple juices provided significant amounts of iron. The %RD for zinc and calcium of the sixteen foods was low (both groups studied). Consequently, to meet the requirements of these minerals, it would be necessary to properly combine the foods consumed.

Antiviral Evaluation of New Synthetic Bioconjugates Based on GA-Hecate: A New Class of Antivirals Targeting Different Steps of Zika Virus Replication.

Re-emerging arboviruses represent a serious health problem due to their rapid vector-mediated spread, mainly in urban tropical areas. The 2013-2015 Zika virus (ZIKV) outbreak in South and Central America has been associated with cases of microcephaly in newborns and Guillain-Barret syndrome. We previously showed that the conjugate gallic acid-Hecate (GA-FALALKALKKALKKLKKALKKAL-CONH2)-is an efficient inhibitor of the hepatitis C virus. Here, we show that the Hecate peptide is degraded in human blood serum into three major metabolites. These metabolites conjugated with gallic acid were synthesized and their effect on ZIKV replication in cultured cells was evaluated. The GA-metabolite 5 (GA-FALALKALKKALKKL-COOH) was the most efficient in inhibiting two ZIKV strains of African and Asian lineage at the stage of both virus entry (virucidal and protective) and replication (post-entry). We also demonstrate that GA-metabolite 5 does not affect cell growth after 7 days of continuous treatment. Thus, this study identifies a new synthetic antiviral compound targeting different steps of ZIKV replication in vitro and with the potential for broad reactivity against other flaviviruses. Our work highlights a promising strategy for the development of new antivirals based on peptide metabolism and bioconjugation.

African ZIKV lineage fails to sustain infectivity in an in vitro mimetic urban cycle.

Zika virus (ZIKV) is an arbovirus maintained in nature in two distinct cycles of transmission: urban and sylvatic. Each cycle includes specific vertebrate and invertebrate hosts, and through alternate infections, a conserved consensus sequence is maintained that might vary depending on the cycle. The current study aimed to investigate the ability of ZIKVAF and ZIKVBR to maintain an infectious cycle by alternating passages in cells mimicking the urban (UC) and semi-sylvatic (SC) cycles. The complete genome of the original inoculum and the last passages for each cycle were sequenced by Sanger. Ten passages were performed, as planned, for ZIKVBR UC, ZIKVAF SC, and ZIKVBR SC. ZIKVBR SC showed significant variation in viral titers along the passages, suggesting that the virus is not well adapted to the non-human primate host. ZIKVAF passage in UC was abrogated in the third passage, showing the inability of the African lineage to sustain cycles in human cells, suggesting a low capacity to establish an urban cycle. Several mutations were found in both strains along the passages, but not occurring at equivalent positions. Further studies are needed to elucidate whether any of these specific mutations affect viral fitness. ZIKV strains behave differently in artificial transmission cycles in vitro: Brazilian ZIKV was able to establish urban and semi-sylvatic cycles in vitro. African ZIKV proved unable to cycle among human and mosquito cells and is compatible only with the semi-sylvatic cycle. The main mutations arose in the NS2A region after artificial transmission cycles for both ZIKV strains but not at equivalent positions.

Genomic landscapes of ovarian clear cell carcinoma from latin countries reveal aberrations linked to survival and progression.

BACKGROUND: Ovarian clear cell carcinomas (OCCCs) are rare, aggressive and chemoresistant tumors. Geographical and ethnic differences in the incidence of OCCC have been reported with a higher incidence in Asiatic countries. There is a paucity of information regarding OCCC in Latin America (LA) and other countries. METHODS: Here, we characterized two cohorts of 33 patients with OCCC from LA (24 from Brazil and 9 from Costa Rica) and a cohort of 27 patients from Spain. Genomic analysis was performed for 26 OCCC using the OncoScan platform. Tumors were classified according to their genomic landscapes into subgroups. Clinical parameters were related to the frequency of genomic aberrations. RESULTS: The median overall survival (OS) was not significantly different between the cohorts. Genomic landscapes were characterized by different homologous recombination deficiency (HRD) levels. No difference in the distribution of genomic landscapes profiles was detected between patients from the different cohorts. OCCCs with MYC-amplified tumors harboring a concomitant loss of a region in chromosome 13q12-q13 that includes the BRCA2 gene had the longest OS. In contrast, patients carrying a high number (> 30) of total copy number (CN) aberrations with no concomitant alterations in MYC and BRCA2 genes presented the shortest OS. Furthermore, amplification of the ASH1L gene was also associated with a shorter OS. Initial-stage OCCCs with early progression were characterized by gains in the JNK1 and MKL1 genes. CONCLUSIONS: Our results provide new data from understudied OCCC populations and reveal new potential markers for OCCCs.

Interrelationship between muscle fitness in childhood and bone mineral density in adulthood: mediation analysis of muscle fitness in adulthood.

BACKGROUND: This study was aimed to examine the relationship between muscular fitness indicators in childhood and areal bone mineral density (aBMD) in adulthood and to verify whether the relationship is mediated by performance on muscular fitness indicators in adulthood. METHODS: A sample of 138 healthy adults (69 males; 22.3 years) were followed after a previous assessment at the age of 7-10 years. Stature, body mass and muscular fitness indicators (handgrip strength, standing long jump and sit-ups tests) were assessed in childhood and adulthood. Additionally, total body, upper limbs, lower limbs, right femoral neck and lumbar spine aBMD was assessed in adulthood using dual X-ray absorptiometry. Analysis included descriptive statistics; t-test or Mann-Whitney U-test for comparison between males and females, multiple linear regression for the prediction aBMD from muscular fitness indicators in childhood, mediation analysis of the respective muscular fitness indicators in adulthood and the relationship between muscular fitness indicators in childhood and aBMD. RESULTS: Males were stronger compared to females regarding muscular fitness indicators in childhood and adulthood, and presented higher mean values for aBMD in adulthood, except for lumbar spine (p < 0.05). Regression analysis revealed that some muscular fitness indicators in childhood showed significant positive relationship with bone health indicators in adulthood, such as: handgrip strength and total body aBMD (ß = 0.005; R2 = 0.35; p = 0.040) and upper limbs aBMD (ß = 0.005; R2 = 0.55; p = 0.019); and sit-ups test was a significant predictors of lumbar spine BMD (ß = 0.003; R2 = 0.06; p = 0.039). Mediation analysis pointed out the following: adulthood handgrip strength mediated relationships between childhood handgrip strength and total aBMD (indirect effect (IE) = 0.0025; 95%CI = 0.0005-0.0048), and upper limbs aBMD (IE = 0.0040; 95%CI = 0.0017-0.0069). CONCLUSIONS: Muscular fitness indicators in childhood showed significant relationship with bone health indicators in adulthood and the sit-ups test in childhood had direct effect on lumbar spine aBMD in adulthood. Adulthood handgrip strength mediated the relationship between childhood handgrip strength and total body and upper limb aBMD, pointing out that muscular fitness in childhood may be a aBMD determinant in adulthood, especially when higher muscle fitness performance is maintained in adulthood.

DETERMINACIÓN DE LA ESTABILIDAD DE ÁCIDO ASCÓRBICO Y RETINOL EN PREPARACIONES REFORZADAS CON PRODUCTOS ALIMENTICIOS FORTIFICADOS / STABILITY ANALYSIS OF ASCORBIC ACID AND RETINOL IN REFORZED MEALS WITH FORTIFIED PRODUCTS

Introducción: La elaboración de comidas caseras implica pérdidas de vitaminas según el procedimiento de cocción. El uso de alimentos reforzados ayudaría a cubrir las recomendaciones nutricionales durante periodos críticos de la vida. El objetivo de este estudio piloto experimental es analizar la variación de las concentraciones de retinol y ácido ascórbico, en preparaciones reforzadas que incluyeron un cereal fortificado y analizar su valor como estrategia alimentaria. Material y métodos: El retinol y el ácido ascórbico se seleccionaron como indicadores de labilidad para tres recetas con diferentes procedimientos de cocción elaboradas de manera casera en condiciones reproducibles. El retinol se analizó mediante HPLC y el ácido ascórbico mediante electroforesis capilar en una muestra y HPLC en otras, debido a los límites de detección de cada método. Resultados: Según el método, el retinol aumentó su concentración en las muestras post-cocción debido a la pérdida de agua por evaporación (14% entre las reforzadas) o la redujo debido a las condiciones de temperatura, pH o presencia de oxígeno por cocciones a horno o fuego directo (5% y 22% respectivamente). Las muestras reforzadas cocidas presentaron un aumento del 18% - 20% frente a las no reforzadas. La cocción por conducción (sartén) u horno (corrientes de convección por aire) generó una pérdida parcial (13% y 24% respectivamente) de ácido ascórbico. La pérdida fue total en cocción a fuego directo y mayor relación superficie/volumen. Las muestras reforzadas cocidas presentaron un aumento de 90% cuando la vitamina se conservó. Las variaciones finales de concentración estuvieron relacionadas con las concentraciones iniciales y los métodos de cocción con diferentes formas de transferencia de calor y presiones parciales de O2. Conclusiones: Las vitaminas estudiadas son inestables en las comidas tras la cocción doméstica, aunque su pérdida es parcial; por lo tanto, reforzar las preparaciones con productos alimentarios reforzados sería una estrategia útil para cubrir los micronutrientes en situaciones críticas, en sistemas con baja densidad nutricional y diferentes consistencias

Introduction: Homemade meals elaboration implies vitamins losses in different cooking procedures. Using reinforced food would cover nutrient recommendations during critical periods of life. The aim of this experimental pilot study was to evaluate the variation of ascorbic acid and retinol concentrations in reinforced meals with fortified cereals and to analyze their value as a feeding strategy. Materials and Methods: These vitamins were selected as indicators of lability in three recipes with different cooking procedures prepared at home under reproducible conditions. Retinol was analysed through HPLC and Ascorbic Acid by capillary electrophoresis in one sample and HPLC in others because of detection limit of each methods. Results: According to cooking method, Retinol increased its concentration in post-cooking samples due to water evaporation (14% among enriched) or reduced it due to temperature, pH or presence of oxygen by oven or direct cooking (5% and 22% respectively). Between cooked samples, reinforced sample presented an 18% - 20% increase versus non-enriched one. Cooking by conduction (frying pan) or oven (air convection currents) generated a partial loss (13% and 24% respectively) of ascorbic acid. The loss was total in direct fire firing and higher surface/volume ratio. Cooked reinforced samples showed a 90% increase when the vitamin was preserved. Final concentration variations were related to initial concentrations and cooking methods involving different forms of heat transfer and partial pressures of O2.Conclusions: Vitamins studied were shown to be unstable in meals after domestic cooking, although their loss is partial. Therefore,reinforcing preparations with fortified food products would be a useful strategy to cover micronutrients in critical situations, in food preparations with low nutritional density and different consistencies

Dermatological manifestations of hematologic neoplasms. Part II: nonspecific skin lesions/paraneoplastic diseases

Abstract Cutaneous manifestations occur in the course of hematologic malignancies and precede, accompany or occur late in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, immunosuppression resulting from the hematologic disease itself or its treatment. The dermatologist must be aware of these conditions that may be helpful both in the diagnosis of the underlying disease and in reducing patient morbidity. This review (part II) addresses the paraneoplastic dermatological changes associated with systemic hematologic malignancies.

Effect of Demographics and Time to Sample Processing on the qPCR Detection of Pathogenic Leptospira spp. from Human Samples in the National Reference Laboratory for Leptospirosis, Brazil.

Leptospirosis diagnosis by MAT requires antibody levels that are typically present only after the first week of symptoms, many days after infection. To improve testing capacity and to develop a fast and reliable solution for the diagnosis of this disease in the first few days after clinical manifestations, the National Reference Laboratory for Leptospirosis/WHO Collaborating Center in Brazil implemented a duplex molecular method by qPCR for human samples for the detection of the gene lipL32, conserved in pathogenic Leptospira spp. In this paper, we describe the overall performance of this protocol in the first 3 months as a standard routine. Detection of pathogenic Leptospira spp. DNA was similar between blood, plasma, and tissue samples, with a limit of detection as low as one cell per sample, and among 391 samples from suspected cases, 174 (44.6%) were positive. The average RNASEP1 control gene detection cycle thresholds (Ct) were 28.4 and 29.8 for positive and negative samples, respectively. The median sample collection interval from the beginning of symptoms was 3 days for positive and 4 days for negative samples, respectively. Neither age, sex, nor the time intervals between sample collection and DNA extraction significantly influenced the results. Surprisingly, positivity was related to the time between DNA extraction and the qPCR reaction. These data support the use of this routine as a diagnostic approach to strengthen the molecular detection of leptospirosis and to develop new strategies.

Molecular Determinants of Mouse Adaptation of Rat Hepacivirus.

The lack of robust immunocompetent animal models for hepatitis C virus (HCV) impedes vaccine development and studies of immune responses. Norway rat hepacivirus (NrHV) infection in rats shares HCV-defining characteristics, including hepatotropism, chronicity, immune responses, and aspects of liver pathology. To exploit genetic variants and research tools, we previously adapted NrHV to prolonged infection in laboratory mice. Through intrahepatic RNA inoculation of molecular clones of the identified variants, we here characterized four mutations in the envelope proteins responsible for mouse adaptation, including one disrupting a glycosylation site. These mutations led to high-titer viremia, similar to that observed in rats. In 4-week-old mice, infection was cleared after around 5 weeks compared to 2 to 3 weeks for nonadapted virus. In contrast, the mutations led to persistent but attenuated infection in rats, and they partially reverted, accompanied by an increase in viremia. Attenuated infection in rat but not mouse hepatoma cells demonstrated that the characterized mutations were indeed mouse adaptive rather than generally adaptive across species and that species determinants and not immune interactions were responsible for attenuation in rats. Unlike persistent NrHV infection in rats, acute resolving infection in mice was not associated with the development of neutralizing antibodies. Finally, infection of scavenger receptor B-I (SR-BI) knockout mice suggested that adaptation to mouse SR-BI was not a primary function of the identified mutations. Rather, the virus may have adapted to lower dependency on SR-BI, thereby potentially surpassing species-specific differences. In conclusion, we identified specific determinants of NrHV mouse adaptation, suggesting species-specific interactions during entry. IMPORTANCE A prophylactic vaccine is required to achieve the World Health Organization's objective for hepatitis C virus elimination as a serious public health threat. However, the lack of robust immunocompetent animal models supporting hepatitis C virus infection impedes vaccine development as well as studies of immune responses and viral evasion. Hepatitis C virus-related hepaciviruses were discovered in a number of animal species and provide useful surrogate infection models. Norway rat hepacivirus is of particular interest, as it enables studies in rats, an immunocompetent and widely used small laboratory animal model. Its adaptation to robust infection also in laboratory mice provides access to a broader set of mouse genetic lines and comprehensive research tools. The presented mouse-adapted infectious clones will be of utility for reverse genetic studies, and the Norway rat hepacivirus mouse model will facilitate studies of hepacivirus infection for in-depth characterization of virus-host interactions, immune responses, and liver pathology.

Characterization of a TatA/TatB binding site on the TatC component of the Escherichia coli twin arginine translocase.

The twin arginine transport (Tat) pathway exports folded proteins across the cytoplasmic membranes of prokaryotes and the thylakoid membranes of chloroplasts. In Escherichia coli and other Gram-negative bacteria, the Tat machinery comprises TatA, TatB and TatC components. A Tat receptor complex, formed from all three proteins, binds Tat substrates, which triggers receptor organization and recruitment of further TatA molecules to form the active Tat translocon. The polytopic membrane protein TatC forms the core of the Tat receptor and harbours two binding sites for the sequence-related TatA and TatB proteins. A 'polar' cluster binding site, formed by TatC transmembrane helices (TMH) 5 and 6 is occupied by TatB in the resting receptor and exchanges for TatA during receptor activation. The second binding site, lying further along TMH6, is occupied by TatA in the resting state, but its functional relevance is unclear. Here we have probed the role of this second binding site through a programme of random and targeted mutagenesis. Characterization of three stably produced TatC variants, P221R, M222R and L225P, each of which is inactive for protein transport, demonstrated that the substitutions did not affect assembly of the Tat receptor. Moreover, the substitutions that we analysed did not abolish TatA or TatB binding to either binding site. Using targeted mutagenesis we introduced bulky substitutions into the TatA binding site. Molecular dynamics simulations and crosslinking analysis indicated that TatA binding at this site was substantially reduced by these amino acid changes, but TatC retained function. While it is not clear whether TatA binding at the TMH6 site is essential for Tat activity, the isolation of inactivating substitutions indicates that this region of the protein has a critical function.

Dermatological manifestations of hematologic neoplasms. Part I: secondary specific skin lesions

Abstract Cutaneous manifestations occur during the course of hematologic malignancies and precede, follow, or are late events in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, and immunosuppression resulting from the hematologic neoplasia itself or its treatment. The dermatologist must be aware of these conditions, which can help both in the diagnosis of the underlying disease and in the reduction of patient morbidity. This review (part I) addresses skin lesions associated with direct infiltration by systemic hematologic malignancies.

Dermatological manifestations of hematologic neoplasms. Part II: nonspecific skin lesions/paraneoplastic diseases.

Cutaneous manifestations occur in the course of hematologic malignancies and precede, accompany or occur late in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, immunosuppression resulting from the hematologic disease itself or its treatment. The dermatologist must be aware of these conditions that may be helpful both in the diagnosis of the underlying disease and in reducing patient morbidity. This review (part II) addresses the paraneoplastic dermatological changes associated with systemic hematologic malignancies.

Basal cell carcinomas of the scalp after radiotherapy for tinea capitis: Clinicopathological study in a case series of 96 patients with analysis of 427 tumours.

BACKGROUND/OBJECTIVES: Low-dose X-ray radiotherapy to treat tinea capitis during childhood is a well-known risk factor for scalp basal cell carcinomas (BCCs). Post-radiotherapy BCCs are often multiple, and it has been suggested that they display more aggressive features. Our main objective was to study the clinicopathological aspects of post-radiotherapy BCCs to evaluate their biological behaviour and identify features that may differ from other BCCs. METHODS: We performed an observational, retrospective study assessing multiple clinical and pathological characteristics of patients with post-radiotherapy BCCs. RESULTS: We studied 96 patients with 427 post-radiotherapy scalp BCCs. Post-radiotherapy BCCs were often multiple (median of 4 lesions/patient, ranging from 1 to 54). Significant comorbidities included a high incidence of thyroid disease and meningiomas. Recurrences were observed in 23% of patients, but there may be confounding factors, such as referral bias, heterogenous treatment modalities and occurrence of new tumours due to field effect. We found a high incidence of infundibulocystic BCCs (in 14.6% of patients and corresponding to 5.4% of the total number of tumours), trichoblastomas (5.2%) and neurofibromas of the scalp (10%). CONCLUSIONS: This study is consistent with the occurrence of multiple lesions (sometimes numerous) and a relatively high tendency for recurrence in post-radiotherapy BCCs, as suggested by previous studies. We also found a high incidence of the infundibulocystic variant and a higher risk of follicular tumours and neurofibromas, which suggests that radiotherapy may influence the type of differentiation of BCCs and contribute to induce neoplasms of different cell lines.