Epidemiologic Study and Genotyping of BK Virus in Renal Transplant Recipients

BK virus (BKV) infection occurs during childhood and remains latent in the urinary tract. The virus is reactivated in immunosuppressed patients, particularly in those with cellular immunity deficiency, allowing its detection in urine and blood. Nephropathy caused by the virus in renal transplantation recipients may lead to graft failure. The purpose of this study is to know the prevalence of BKV variables in renal transplantation recipients and to evaluate their clinical evolution through molecular methods of “in house” development. Urine and peripheral blood samples from 66 renal transplantation recipients from the province of Buenos Aires, Argentina, were systematically analyzed every 3 months as well as when there was graft dysfunction. Renal biopsies, which were included in the BKV detection study, were performed on those patients with graft dysfunction. Genotyping of 24 BKVs was performed, and the following distribution was found: 21 (87.5%) belonged to subtype I, 3 (12.5%) to subtype II. BKV belonging to subtypes III or IV were not found. As regards subtype I subgroups, the following were identified: 1 (4.76%) from Ia, 10 (47.61%) from Ib1 and 10 (47.61%) from Ib2. Presence of subgroup Ic was not shown. Viremia presented in 33.33% of cases, whereas 75% corresponded to subgroup Ib 1. Genotype Ib1 is prevailing in Southeast Asia, while Ib2 is prominent in Europe. Although an important proportion of the inhabitants of the province of Buenos Aires are European descendants, the prevailing genotype is Ib1, the Asian type. Genotyping might be related to the evolution of the disease in the recipient.     

Characteristics of Liver Transplantation in Argentina: A Multicenter Study

Introduction

There is a lack of information regarding outcomes after liver transplant in Latin America.

Identification of a somatic mutation in the RHEB gene through high depth and ultra-high depth next generation sequencing in a patient with Hemimegalencephaly and drug resistant Epilepsy

Malformations of cortical development are a frequent cause of drug-resistant Epilepsy and developmental delay. Hemimegalencephaly is a Malformation of cortical development characterized by enlargement of all or a part of one cerebral hemisphere. Germline and somatic mutation in genes belonging to the Mammalian Target of Rapamycin (mTOR) pathway has been identified in patients suffering from epilepsy secondary to Hemimegalencephaly and focal cortical dysplasia. We present here a patient suffering from severe neonatal Epilepsy since 3 h of life secondary to Hemimegalencephaly, requiring an anatomic hemispherectomy surgical procedure for seizure control, where by means of next-generation sequencing at an ultra-high depth coverage, we were able to identify a novel somatic mutation in the RHEB gene (NM_005614: c.119A > T: p. Glu40Val). The histopathological diagnosis was Cortical Dysplasia type IIB determined by the presence of dysmorphic neurons of variable size with nuclear alteration and balloon cells in the context of Hemimegalencephaly, which are similar to that have been demonstrated in hyperactivating RHEB models. This is the first report of a somatic mutation in RHEB gene in a patient suffering from Epilepsy secondary to Hemimegalencephaly. It highlights different current topics in the fields of genetics of Malformations of cortical development: a-somatic mosaicism is not uncommon in these neurodevelopmental disorders; b-the molecular diagnostic approach should involve the use of state-of-the-art methods and the sampling of different tissues; c-new findings might facilitate therapeutics discoveries while providing an improved understanding of normal brain development.     

Low doses of urban air particles from Buenos Aires promote oxidative stress and apoptosis in mice lungs

Air pollution consists of a wide range of gaseous and particulate pollutants. Exposure to particulate matter (PM) can cause oxidative stress within the lung, which in turn can negatively impact health. The mechanisms by which PM causes oxidative stress include the release of trace metals or organic components from the particle. Previously, we have characterized urban air particles from downtown Buenos Aires (UAP-BA) and, by using in vivo animal studies, found that they are able to generate lung inflammation. Purpose: We studied lung responses to low doses of UAP-BA (15 µg), with special emphasis on oxidative balance. Methods: We assessed cell viability, total cell number (TCN) and cell differential (CD) on bronchoalveolar lavages (BAL), oxidative metabolism in lung homogenates by tertbutylhydroperoxide-initiated chemiluminescence (CL), thiobarbituric reactive substances (TBARS), total reactive antioxidant potential (TRAP), reduced glutathione (GSH), and apoptosis in lung sections. Results: We found that low UAP-BA exposure increases TCN, modifies CD, and decreases cell viability in the BAL. In lung homogenates, TBARS and CL rose while TRAP and GSH showed no alteration when compared to controls. Occurrence of apoptosis evaluated by TUNEL assay was markedly augmented in UAP-BA exposed animals. Conclusions: Our data further implicate oxidative stress as a possible inducer of apoptosis in lungs from animals exposed to low concentrations of this urban environmental contaminant.     

The International Council of Ophthalmology 360-degree assessment tool: development and validation

Background

The Accreditation Council for Graduate Medical Education and other organizations recommend 360-degree assessments for evaluation of interpersonal and communication skills, professional behaviours, and some aspects of patient care and system-based practice. No such tool has been developed for ophthalmology or received international content validation.

Hemodynamics and coronary angiography in idiopathic hypertrophic subaortic stenosis

One hundred eighteen patients with idiopathic hypertrophic subaortic stenosis were studied with cardiac catheterization and coronary arteriography. In 112 a gradient across the left ventricular outflow tract was present in the resting state. Seventeen of the 61 patients who had right heart catheterization had a mild resting gradient across the right ventricular outflow tract, that was considered clinically and hemodynamically insignificant. Ninety-five patients (80 percent) had a left ventricular end-diastolic pressure greater than 10 mm Hg; 60 percent had mitral regurgitation that was of mild degree in most cases. Almost 20 percent had coexistent coronary atherosclerosis (25 percent incidence rate in subjects aged 40 years or older). Patients with associated severe coronary atherosclerosis had a lower intraventricular gradient at rest than other patients. Coronary atherosclerosis appears to be a coincidental condition. The need for objective evaluation of the coronary circulation is emphasized.     

Coincidence of cytogenetic markers in four murine cell lines

Foreign body tumorigenesis was induced by the subcutaneous implantation of a plastic or glass cylinder in BALB/c mice; the inoculation of human neoplastic cells significantly increased the incidence of these anaplastic sarcomas. Of 15 tumors studied, four presented the same markers: one induced with and three without human neoplastic cell inoculation within the foreign body. The markers observed were double minutes (DM), a long acrocentric marker (MLA), and a metacentric marker (MM). The DM are a number of small often tiny chromosomal structures appearing in pairs together with chromosomes of ordinary size. MLA is a long acrocentric derived from a translocation in tandem between chromosomes #1 and #16. MM is due to centric fusion of two chromosomes #10. Numerical anomalies consisted of gains of the same chromosomes types. It is postulated that these coincident findings are related to the foreignbody tumorigenesis.     

Pulmonary Artery Pressure and Lung Water During Extracorporeal Circulation in Experimental Pulmonary Insufficiency

Use of the membrane oxygenator has been advocated in the management of severe respiratory insufficiency. We have compared this method to conventional therapy in an experimental model in which 23 dogs were subjected to aspiration with 0.1 N HCl and 18 were supported with a volume respirator and positive end-expiratory pressure or placed on partial bypass using a membrane oxygenator for 12 to 24 hours. Adequate oxygenation (PO₂ > 100 mm Hg) was achieved with the membrane oxygenator. The increase in lung weight during conventional therapy was significantly greater than during membrane oxygenator support.Extracorporeal support during recovery from severe pulmonary injury allows pulmonary artery pressure to be controlled and reduces the expected increase in lung water.