Chronic ω-3 fatty acids supplementation promotes beneficial effects on anxiety, cognitive and depressive-like behaviors in rats subjected to a restraint stress protocol

Recent evidence has demonstrated dietary influence on the manifestation of different types of behaviors induced by stressor tasks. The present study examined the impact of ω-3 polyunsaturated fatty acids (PUFAs) supplementation in an early phase of the brain development with the goal of preventing or even attenuating the occurrence of stress-related behaviors such as depressive-like behaviors, anxiety and cognitive dysfunctions in male rats subjected to restraint stress. Our results indicated that the supplementation regimen successfully counteracted the anxiogenic effects of stress as evidenced by the rats' increased exploration time in the aversive arms of the elevated plus maze. The forced swimming test indicated that immobility and swimming were more deeply influenced by PUFAs supplementation, thereby demonstrating an antidepressant effect. Furthermore, cognitive function was shown to be intensely affected by restraint stress, but the effects were surprisingly counteracted by the PUFAs supplementation. Lastly, plasmatic corticosterone levels were demonstrated to be drastically increased by the restraint stress; however, PUFAs supplementation promoted a reduction of this stress-related hormone to levels that were comparable to those observed in the control group. Our results suggested that the mechanisms underlying these effects are possibly associated with the reduction of corticosterone levels promoted by the PUFAs supplementation in the stress-induced animals. Further studies to examine the participation of PUFAs in mediating different behaviors in rats subjected to restraint stress are warranted.     

McNemar chi2 test revisited: comparing sensitivity and specificity of diagnostic examinations

When evaluating a novel diagnostic examination for clinical use, it should be compared with a reference standard, defined as the best available examination, which may include clinical and laboratory criteria. The novel examination and reference standard's results are usually presented in the form of a 2 x 2 table, which allows calculation of sensitivity, specificity and accuracy. It has been recommended that the measures of statistical uncertainty should be reported, such as the 95% confidence interval, when evaluating the accuracy of diagnostic examinations. Comparing the difference in sensitivity or specificity of a novel examination with the reference standard is important when evaluating its usefulness. The McNemar chi(2) test, used to compare discordance of two dichotomous responses, can be applied for this purpose. However, applying the McNemar test to a 2 x 2 table for comparing the accuracy of examinations is not recommended, since this test is sensitive to the proportion of positive versus negative subjects. Moreover, if the novel examination has higher sensitivity than the one considered as the reference standard, constructing a classic 2 x 2 table would result in low specificity of the novel examination. Thus, in order to compare sensitivities and specificities between examinations, this table is inappropriate and an independent reference standard is necessary. In this article, we propose the use of the McNemar chi(2) test to compare sensitivities between examinations using a 2 x 2 table exclusively among diseased patients, defined by a set of criteria and follow-up of patients. Likewise, specificities can be compared applying the McNemar test among healthy individuals.     

Schwann cell expression of an oligodendrocyte-like remyelinating pattern after ethidium bromide injection in the rat spinal cord

Schwann cells are recognized by their capacity of producing single internodes of myelin around axons of the peripheral nervous system. In the ethidium bromide (EB) model of primary demyelination in the brainstem, it is observed the entry of Schwann cells into the central nervous system in order to contribute to the myelin repair performed by the oligodendrocytes that survived to the EB gliotoxic action, being able to even remyelinate more than one axon at the same time, in a pattern of repair similar to the oligodendroglial one. The present study was developed in the spinal cord to observe if Schwann cells maintained this competence of attending simultaneously different internodes. It was noted that, on the contrary of the brainstem, Schwann cells were the most important myelinogenic cells in the demyelinated site and, although rare, also presented the capacity of producing more than one internode of myelin in distinct axons.     

Human fetal skeletal muscle contains a myogenic side population that expresses the melanoma cell-adhesion molecule

Muscle side population (SP) cells are rare myogenic progenitors distinct from satellite cells, the known tissue-specific stem cells of skeletal muscle. Studies in mice demonstrated that muscle SP cells give rise to satellite cells in vivo. Given that muscle SP cells are heterogeneous, it has been difficult to prospectively enrich for myogenic progenitors within the SP fraction, particularly from human tissue. Further, conditions that favor the expansion of human muscle SP cells while retaining their myogenic potential have yet to be reported. In this study, human fetal muscle SP and main population (MP) cells were purified based on the expression of melanoma cell adhesion molecule (MCAM), a marker we previously reported to enrich for cells with myogenic potential. To define the relationship between MCAM expression and the degree of myogenic commitment, single cells were analyzed for the expression of myogenic-specific markers. Myogenic factors strongly associated with MCAM expression in single cells, particularly Myf5. Different MCAM+ populations, including SP cells, were expanded and assayed for fusion potential in vitro and engraftment potential in vivo. All MCAM+ subpopulations fused robustly into myotubes in vitro, whereas the MCAM- subpopulations did not. Further, MCAM+ SP cells exhibited the highest fusion potential in vitro and were the only fraction to engraft in vivo, although at low levels, following propagation. Thus, MCAM can be used to prospectively enrich for myogenic muscle SP cells in human fetal muscle. Moreover, we provide evidence that human MCAM+ SP cells have intrinsic myogenic activity that is retained after propagation.     

Tuberculosis in day-to-day medical practice and the boomerang effect of neglect

The scope of this study was to understand the perceptions and feelings of physicians dealing with tuberculosis (TB) in Rio de Janeiro. Eleven physicians working in a large public hospital were interviewed using a semi-structured questionnaire. The interpretation of the interviews was based on hermeneutic-dialectic phenomenology. The answers were analyzed in order to identify and understand their live TB-related experiences from their statements. Among the categories that emerged, neglect was chosen as the focus of this article in its four dimensions: respect, responsibility, conditions of care and discomfort. The boomerang effect of neglect was perceived during interviews with physicians: the one who neglects is also neglected. Other reported feelings included lack of motivation, anger, and frustration. The mental health of physicians is a preoccupation because of overwork in inadequate conditions. The question that arises is how health staff working in such environments can adequately care for their patients. We conclude that in order to achieve TB control as well as other health system goals, human resource policies that respond to physicians' job needs should be implemented.     

Attending to Warning Signs of Primary Immunodeficiency Diseases Across the Range of Clinical Practice

Purpose

Patients with primary immunodeficiency diseases (PIDD) may present with recurrent infections affecting different organs, organ-specific inflammation/autoimmunity, and also increased cancer risk, particularly hematopoietic malignancies. The diversity of PIDD and the wide age range over which these clinical occurrences become apparent often make the identification of patients difficult for physicians other than immunologists. The aim of this report is to develop a tool for educative programs targeted to specialists and applied by clinical immunologists.

Methods

Considering the data from national surveys and clinical reports of experiences with specific PIDD patients, an evidence-based list of symptoms, signs, and corresponding laboratory tests were elaborated to help physicians other than immunologists look for PIDD.

Results

Tables including main clinical manifestations, restricted immunological evaluation, and possible related diagnosis were organized for general practitioners and 5 specialties. Tables include information on specific warning signs of PIDD for pulmonologists, gastroenterologists, dermatologists, hematologists, and infectious disease specialists.

Conclusions

This report provides clinical immunologists with an instrument they can use to introduce specialists in other areas of medicine to the warning signs of PIDD and increase early diagnosis. Educational programs should be developed attending the needs of each specialty.     

Microsatellites from rubber tree (Hevea brasiliensis) for genetic diversity analysis and cross-amplification in six Hevea wild species

Hevea brasiliensis is native to the Amazonian rain forest and an important source of natural rubber. Twenty seven polymorphic microsatellite loci were isolated and characterized from a GA–CA enriched genomic library of H. brasiliensis. The number of alleles ranged from 2 to 20. The observed and expected heterozygosity ranged from 0.13 to 0.88 and from 0.00 to 0.89, respectively. Cross-species amplification of the markers developed for H. brasiliensis was successful in the wild Hevea species H. guianensis, H. rigidifolia, H. nitida, H. pauciflora, H. benthamiana and H. camargoana. The data indicated a high degree of sequence homology in the microsatellite flanking regions of these species. The developed SSR loci are a potential powerful tool for studies of population genetics, genetic diversity and gene flow among Hevea species.     

Immunoglobulin G subclass concentrations and infections in children and adolescents with severe asthma

It was the aim of this study to investigate possible dysfunctions of the humoral immune system in asthmatic children with frequent respiratory infections. Forty‐one severe asthmatics (7–15 years of age), classified according to the Second Brazilian Consensus in Asthma (1998), were divided into two groups: group I (n = 12) had recurrent respiratory infections; and group II (n = 29) were without recurrent respiratory infections. Immunoglobulin (Ig)G, IgA and IgM levels (nephelometry), and IgE (radioimmunoassay) and IgG subclasses (enzyme‐linked immunosorbent assay), were evaluated using standard methods. Asthmatics with recurrent infections presented with worse clinical evolution, an increased number of hospital admissions, and a higher need of medication than the children without recurrent infections. There were no significant differences between the mean values of IgG, IgA or IgM levels, or IgE or IgG subclasses, in patients of both groups. A complete IgA deficiency was detected in two patients of group I (one was associated with IgG subclass deficiency). Deficiency of one or more IgG subclasses was verified in eight of 12 (66%) children from group I and in 16/29 (55%) from group II. The following deficiencies were found in both groups: IgG₃ (10/41), IgG₄ (three of 41), IgG₂ (two of 41), IgG₁ (one of 41), IgG₃‐IgG₄ (four of 41), IgG₁‐IgG₃ (two of 41), and IgG₁‐IgG₃‐IgG₄ (one of 41). There were a higher proportion of children with low IgG₄ levels in group I than in group II (p = 0.01). To conclude, IgA and IgG subclass deficiencies were detected in both severely asthmatic groups, with a predominance of IgG₃ subclass deficiency. However, low IgG subclass levels appear not to be a suitable predictor of the development of infections in asthmatic children.     

Inborn errors of immunity associated with characteristic phenotypes

ObjectivesThe aim of the report is to describe the main immunodeficiencies with syndromic characteristics according to the new classification of Inborn Errors of Immunity.Data sourceThe data search was centered on the PubMed platform on review studies, meta-analyses, systematic reviews, case reports and a randomized study published in the last 10 years that allowed the characterization of the several immunological defects included in this group.Data synthesisImmunodeficiencies with syndromic characteristics include 65 immunological defects in 9 subgroups. The diversity of clinical manifestations is observed in each described disease and may appear early or later, with variable severity. Congenital thrombocytopenia, syndromes with DNA repair defect, immuno-osseous dysplasias, thymic defects, Hyper IgE Syndrome, anhidrotic ectodermal dysplasia with immunodeficiency and purine nucleoside phosphorylase deficiency were addressed.ConclusionsImmunological defects can present with very different characteristics; however, the occurrence of infectious processes, autoimmune disorders and progression to malignancy may suggest diagnostic research. In the case of diseases with gene mutations, family history is of utmost importance.