Polycomb represses a gene network controlling puberty via modulation of histone demethylase Kdm6b expression.

Female puberty is subject to Polycomb Group (PcG)-dependent transcriptional repression. Kiss1, a puberty-activating gene, is a key target of this silencing mechanism. Using a gain-of-function approach and a systems biology strategy we now show that EED, an essential PcG component, acts in the arcuate nucleus of the hypothalamus to alter the functional organization of a gene network involved in the stimulatory control of puberty. A central node of this network is Kdm6b, which encodes an enzyme that erases the PcG-dependent histone modification H3K27me3. Kiss1 is a first neighbor in the network; genes encoding glutamatergic receptors and potassium channels are second neighbors. By repressing Kdm6b expression, EED increases H3K27me3 abundance at these gene promoters, reducing gene expression throughout a gene network controlling puberty activation. These results indicate that Kdm6b repression is a basic mechanism used by PcG to modulate the biological output of puberty-activating gene networks.

Administration of High-Dose Methylprednisolone Worsens Bone Loss after Acute Spinal Cord Injury in Rats.

The administration of high-dose methylprednisolone (MP) for 24-48 h after traumatic spinal cord injury (SCI) has been shown to improve functional recovery. The known adverse effects of MP on skeletal muscle and the immune system, though, have raised clinically relevant safety concerns. However, the effect of MP administration on SCI-induced bone loss has not been evaluated to date. This study examined the adverse effects of high-dose MP administration on skeletal bone after acute SCI in rodents. Male rats underwent spinal cord transection at T3-T4, which was followed by an intravenous injection of MP and subsequent infusion of MP for 24 h. At 2 days, animals were euthanized and hindlimb bone samples were collected. MP significantly reduced bone mineral density (-6.7%) and induced deterioration of bone microstructure (trabecular bone volume/tissue volume, -18.4%; trabecular number, -19.4%) in the distal femur of SCI rats. MP significantly increased expression in the hindlimb bones of osteoclastic genes receptor activator of nuclear factor-κB ligand (RANKL; +402%), triiodothyronine receptor auxiliary protein (+32%), calcitonin receptor (+41%), and reduced osteoprotegerin/RANKL ratio (-72%) compared to those of SCI-vehicle animals. Collectively, 1 day of high-dose MP at a dose comparable to the dosing regimen prescribed to patients who qualify to receive this treatment approach with acute SCI increased loss of bone mass and integrity below the level of lesion than that of animals that had SCI alone, and was associated with further elevation in the expression of genes involved in pathways associated with osteoclastic bone resorption than that observed in SCI animals.

Colombian Association of Rheumatology. Consensus on recommendations to decrease and discontinue biological therapy in patients with rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis / Asociación Colombiana de Reumatología. Consenso sobre recomendaciones para disminución y descontinuación de la terapia biológica en pacientes con artritis reumatoide, espondilitis anquilosante y artritis psoriásica

A B S T R A C T Objective: The objective of this study was to establish recommendations for the reduction and discontinuation of biological disease-modifying antirheumatic drugs, with the aim of becoming a guide document for health professionals involved in the management of patients with rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. Materials and methods: The recommendations were established through consensus by a panel of experts in rheumatology, and based on the analysis of available scientific evidence obtained from systematic reviews and the clinical experience of the panellists. Results: A total of 33 rheumatoid arthritis related studies were included, with 6 psoriatic arthritis related, and 9 ankylosing Spondylitis related. The recommendations for the reduction of biological therapies were made by establishing a plan to determine when and how to reduce the biological disease-modifying antirheumatic drugs in patients with these 3 diseases, and in some cases lead to the discontinuation of these treatments. Conclusion: The recommendations established in this document will serve as a guide to improve the efficiency of biological therapy in these diseases, reduce the variability in clinical practice, and establish an adequate risk/benefit ratio.

RESUMEN Objetivo: El objetivo de este estudio fue establecer recomendaciones para la disminución y descontinuación de la terapia biológica con el fin de que se convierta en un documento guía para los profesionales de la salud involucrados en el manejo de pacientes con artritis reumatoide, espondilitis anquilosante y artritis psoriásica. Materiales y métodos: Las recomendaciones fueron establecidas mediante consenso desarrollado a través de un panel de expertos en reumatología, basado en el análisis de la evidencia científica disponible obtenida de revisiones sistemáticas y sobre la experiencia clínica de los panelistas. Resultados: Se incluyeron 33 estudios relacionados con artritis reumatoide, 6 de artritis psoriásica y 9 de espondilitis anquilosante. Las recomendaciones para la disminución de las terapias biológicas se realizaron estableciendo un plan para determinar cuándo y cómo reducir los fármacos biológicos modificadores de enfermedades reumáticas en pacientes con estas 3 enfermedades y en algunos casos conducir a la descontinuación de estos tratamientos. Conclusión: Las recomendaciones establecidas en este documento servirán de guía para mejorar la eficiencia de la terapia biológica en estas enfermedades, reducir la variabilidad en la práctica clínica y establecer de manera adecuada una relación riesgo/beneficio.

Elucidating the genetic architecture of reproductive ageing in the Japanese population.

Population studies elucidating the genetic architecture of reproductive ageing have been largely limited to European ancestries, restricting the generalizability of the findings and overlooking possible key genes poorly captured by common European genetic variation. Here, we report 26 loci (all P < 5 × 10-8) for reproductive ageing, i.e. puberty timing or age at menopause, in a non-European population (up to 67,029 women of Japanese ancestry). Highlighted genes for menopause include GNRH1, which supports a primary, rather than passive, role for hypothalamic-pituitary GnRH signalling in the timing of menopause. For puberty timing, we demonstrate an aetiological role for receptor-like protein tyrosine phosphatases by combining evidence across population genetics and pre- and peri-pubertal changes in hypothalamic gene expression in rodent and primate models. Furthermore, our findings demonstrate widespread differences in allele frequencies and effect estimates between Japanese and European associated variants, highlighting the benefits and challenges of large-scale trans-ethnic approaches.

Trithorax dependent changes in chromatin landscape at enhancer and promoter regions drive female puberty.

Polycomb group (PcG) proteins control the timing of puberty by repressing the Kiss1 gene in hypothalamic arcuate nucleus (ARC) neurons. Here we identify two members of the Trithorax group (TrxG) of modifiers, mixed-lineage leukemia 1 (MLL1), and 3 (MLL3), as central components of an activating epigenetic machinery that dynamically counteracts PcG repression. Preceding puberty, MLL1 changes the chromatin configuration at the promoters of Kiss1 and Tac3, two genes required for puberty to occur, from repressive to permissive. Concomitantly, MLL3 institutes a chromatin structure that changes the functional status of a Kiss1 enhancer from poised to active. RNAi-mediated, ARC-specific Mll1 knockdown reduced Kiss1 and Tac3 expression, whereas CRISPR-Cas9-directed epigenome silencing of the Kiss1 enhancer selectively reduced Kiss1 activity. Both interventions delay puberty and disrupt reproductive cyclicity. Our results demonstrate that an epigenetic switch from transcriptional repression to activation is crucial to the regulatory mechanism controlling the timing of mammalian puberty.

Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression.

In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty.

Shigellosis in Subjects with Traveler's Diarrhea Versus Domestically Acquired Diarrhea: Implications for Antimicrobial Therapy and Human Immunodeficiency Virus Surveillance.

An increase of sexually transmitted shigellosis is currently being reported in developed countries. In addition, travel-related shigellosis can introduce resistant strains that could be disseminated within this new scenario. Epidemiological features and antimicrobial susceptibility of shigellosis depending on where infection was acquired were investigated. From 2008 to 2013, subjects with shigellosis were studied. Patients were classified according to acquisition of Shigella as traveler's diarrhea (TD) or domestically acquired diarrhea (DAD). Ninety cases of shigellosis were identified: 76 corresponding to the TD group and 14 to the DAD group. In the DAD group, most of patients were human immunodeficiency virus (HIV)-positive men who have sex with men (MSM), being shigellosis associated to male sex (P = 0.007) and HIV infection (P < 0.0001). S. sonnei (47.8%) and S. flexneri (42.2%) were the predominant species. The highest resistance was detected for trimethoprim/sulfamethoxazole (SXT) (81.8%), followed by ampicillin (AMP) (37.8%) and ciprofloxacin (CIP) (23.3%). Resistant Shigella strains were more frequent in subjects with TD than those with DAD, although only for CIP the difference was significant (P = 0.034). Continuous monitoring of patients with shigellosis is necessary to control the spread of resistant Shigella strains and for effective therapy. Men with shigellosis who have not traveled to an endemic area should be screened for HIV infection.

Enfermedades metabólicas óseas: análisis clínico y radiológico en cinco casos / Metabolic bone diseases: clinical and radiologic analysis in five cases

El estudio de la enfermedad metabólica ósea es amplio y complejo. La enfermedad ósea más reconocida por médicos de todas las especialidades es la osteoporosis, probablemente debido a su elevada frecuencia. No obstante, es importante reconocer que existen numerosas entidades que afectan el metabolismo óseo de diferentes formas, llevando a fragilidad ósea, aumento del riesgo de fractura, osteoporosis u osteocondensación, de acuerdo a cada caso particular. Tanto el diagnóstico clínico como el reconocimiento de la alteración metabólica subyacente son importantes porque la identificación de la anormalidad específica se constituye en la base para el tratamiento. Se presentan 5 casos diferentes en los que un trastorno metabólico conlleva a una patología ósea específica; se discute la patogenia de las calcificaciones arteriales y se presenta una entidad mixta que nosotros llamamos osteoporomalacia.

The study of metabolic bone disease is broad and complex. The most widely recognized bone disease by physicians of all specialties is osteoporosis, probably due to its high frequency. However, it is important to recognize that there are numerous entities that affect bone metabolism in different ways, leading to brittle bones, increased risk of fracture, osteoporosis or osteocondensation, according to each particular case. Both the clinical diagnosis and recognition of the underlying metabolic abnormality are important because they identify the specific abnormality that will be the base for treatment. There were 5 different cases in which a metabolic disorder leads to specific bone pathology, we discuss the pathogenesis of arterial calcifications and presents a mixed entity we call osteoporomalacia.

Atención psicosocial integral en enfermedad catastrófica (Atinar) / Integrative Psychosocial Care in Catastrophic Illness

La enfermedad médico-quirúrgica catastrófica (EMQ-C) se define como una enfermedad aguda o prolongada, usualmente considerada como amenazante para la vida o con el riesgo de dejar discapacidad residual importante. La EMQ-C , a menudo, conlleva trastornos psicosociales que afectan de manera importante su evolución, porque alteran el proceso de rehabilitación, los hábitos saludables y la calidad de vida y, además, limitan la adherencia al tratamiento. Por lo tanto, para ofrecer un tratamiento a la persona quien la padece, es necesario desarrollar modelos que permitan identificar y tratar integralmente todos los aspectos médicos, psicológicos y sociales. La legislación colombiana, desde la aprobación de la Ley 100 de 1993, reglamentó la atención integral de la EMQ-C. No obstante, el desarrollo de programas de atención integral que incluyan lo psicosocial ha sido lento. Se presenta un modelo teórico de atención psicosocial integral en EMQ-C, que sigue los lineamientos de la medicina biopsicosocial de Ángel, junto a un modelo denominado medicina cognitiva , desarrollado previamente por uno de los autores (HR). El modelo incluye aspectos y procedimientos necesarios para su funcionamiento ajustado a la ley colombiana.

Medical Surgical Catastrophic Illness (MSIC) is defined as an acute or chronic lifethreatening disease or with risk of important disability. MSI-C is frequently associated with Psychosocial Disorders influencing the outcome due to effects on the rehabilitation process, quality of life and compliance. The development of integrative models of care that cover medical, psychological and social aspects is necessary in order to offer treatment to the person with MSI-C. Since Law 100 of 1993 was passed, Colombia ruled an integrative model of care for catastrophic illness. Noteworthy, implementation of these programs has been slow. In this article a theoretical model of integrative psychosocial care that follows recommendations of Engel's Biopsychosocial Model and the Cognitive Medicine model developed by one of the authors (HR). The model includes necessary aspects and procedures for its implementation according to Colombian Law.

Susceptibility to protease inhibitors in HIV-2 primary isolates from patients failing antiretroviral therapy.

BACKGROUND: Current protease inhibitors (PIs) are designed against HIV-1, and information on their performance against HIV-2 clinical isolates is scarce. METHODS: Genetic and phenotypic analyses using all available PIs were performed in five HIV-2 primary isolates from two patients on regular follow-up who failed PI-HAART. RESULTS: HIV-2 proteases before therapy showed amino acids associated with resistance in HIV-1 (pro10V, pro32I, pro36I, pro46I, pro47V, pro71V and pro73A). Phenotypic results showed that indinavir, saquinavir, lopinavir and tipranavir had full activity against wild-type HIV-2. However, a susceptibility reduction was noticed for nelfinavir (6.6-fold) and amprenavir (31-fold). During therapy with lopinavir, one patient developed proV47A, which translated into high-level resistance (13.4- to 41-fold) to indinavir, lopinavir and amprenavir, and hypersusceptibility to saquinavir. All isolates from the other patient had multiple mutations after several PIs failed (proV10I, proV33L, proI54M, proV71I and proI82F). The acquisition of mutations 54M and 82F along with naturally occurring changes resulted in multi-PI-resistant viruses (33- to >1000-fold), and only saquinavir retained full activity. CONCLUSIONS: Naturally occurring secondary mutations or polymorphisms in the HIV-2 protease may decrease the activity of nelfinavir and amprenavir. Moreover, upon selection of primary resistance mutations, pre-existing secondary changes might play an important role in the acquisition of a multi-PI resistance phenotype in HIV-2.