Mouse antibody of IgM class is prone to non-enzymatic cleavage between CH1 and CH2 domains

Abstract IgM is a multivalent antibody which evolved as a first line defense of adaptive immunity. It consists of heavy and light chains assembled into a complex oligomer. In mouse serum there are two forms of IgM, a full-length and a truncated one. The latter contains μ’ chain, which lacks a variable region. Although μ’ chain was discovered many years ago, its origin has not yet been elucidated. Our results indicate that μ’ chain is generated from a full-length heavy chain by non-enzymatic cleavage of the protein backbone. The cleavage occurred specifically after Asn209 and is prevented by mutating this residue into any other amino acid. The process requires the presence of other proteins, preferentially with an acidic isoelectric point, and is facilitated by neutral or alkaline pH. This unique characteristic of the investigated phenomenon distinguishes it from other, already described, Asn-dependent protein reactions. A single IgM molecule is able to bind up to 12 epitopes via its antigen binding fragments (Fabs). The cleavage at Asn209 generates truncated IgM molecules and free Fabs, resulting in a reduced IgM valence and probably affecting IgM functionality in vivo

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Uso da sequência FLAIR-EPI na análise da esclerose mesial temporal EPI-FLAIR sequence in the evaluation of mesial temporal sclerosis

O objetivo deste estudo é analisar as alterações morfológicas e de intensidade de sinal das regiões hipocampais em pacientes, com epilepsia temporal fármaco-resistente. Para tal, estudamos 8 pacientes com esclerose mesial temporal, utilizando aparelhagem de RM de 1,5T, com sequências Spin Eco - SE, Fast Spin Eco - FSE, Fluid Atenuation Inversion Recovery, com Eco Planar Imaging - FLAIR-EPI. Observamos a superioridade da sequência FLAIR na detecção do aumento da intensidade de sinal da região hipocampal, particularmente com cortes coronais, em relação às sequências SE e FSE, com a vantagem de ser uma técnica de rápida execução. A sequência STIR evidenciou adelgaçamento da cortical do hipocampo, na metade dos casos que apresentavam alteração de sinal.<br>The purpose of this study is to evaluate morpholologycal and signal intensity changes in the hippocampus in patients with medically intractable temporal lobe epilepsy. We studied 8 patients with mesial temporal sclerosis using a 1.5 -T MR and the following sequences Spin Eco- SE, Fast Spin Echo- FSE, Fluid Atenuation Inversion Recovery Echo Planar Imaging - FLAIR-EPI. We noticed a sensitive increase signal intensity on FLAIR- EPI sequences, particularly, in coronal images, than on SE and FSE sequences. The STIR sequence showed a cortical hippocampus atrophy in half of the cases, in whom signal abnormalities were present

Desafios da atenção básica em saúde: a experiência de Vila Mariana, São Paulo, Brasil Challenges in primary health care: the experience in Vila Mariana District, São Paulo, Brazil

Este artigo apresenta resultados de estudo de caso visando identificar desafios na oferta de atenção básica à saúde em um distrito de saúde da cidade de São Paulo, Brasil, considerando integralidade como dispositivo organizador do trabalho neste nível de atenção. Foram estudadas as cinco unidades que compõem a rede de atenção básica à saúde no distrito considerado. Os dados foram coletados mediante observação dos fluxos e rotinas de atendimento, realização de entrevistas com gerentes e profissionais de diferentes formações e ainda realização de grupos focais com equipes de saúde da família. A análise mostra um descompasso entre as características da clientela e suas necessidades presumidas e as ofertas dos serviços, e heterogeneidade nas percepções dos profissionais sobre seu trabalho. Falta de profissionais, de tempo, e dificuldades para encaminhamentos foram os principais problemas apontados pelos entrevistados.<br>This article presents the results of a case study aimed at identifying challenges for the delivery of primary health care in a health district in the city of São Paulo, Brazil, considering comprehensiveness as a central device for organizing work at this level of care. Five units in the district's primary care network were studied. We collected the data by observing work routines and flows, conducting interviews with managers and health professionals from different backgrounds, and through focus groups with family health teams. The analysis shows a mismatch between users' characteristics and their presumed needs and the heterogeneity of the health professionals' perceptions concerning their work. Lack of staff and time and difficulties with referrals were the main problems identified by interviewees