Expression profiles of neotropical termites reveal microbiota-associated, caste-biased genes and biotechnological targets.

Termites are well recognized by their complex development trajectories, involving dynamic differentiation process between non-reproductive castes, workers and soldiers. These insects are associated with endosymbiotic microorganisms, which help in lignocellulose digestion and nitrogen metabolism. Aiming to identify genes harbouring biotechnological potential, we analyzed workers and soldiers RNA-Seq data of three neotropical termites: Heterotermes tenuis (Isoptera: Rhinotermitidae), Velocitermes heteropterus (Isoptera: Termitidae) and Cornitermes cumulans (Isoptera: Termitidae). We observed differences in the microbiota associated with each termite family, and found protists' genes in both Termitidae species. We found an opposite pattern of caste-biased gene expression between H. tenuis and the termitids studied. Moreover, the two termitids are considerably different concerning the number of differentially expressed genes (DEGs). Functional annotation indicated considerable differences in caste-biased gene content between V. heteropterus and C. cumulans, even though they share similar diet and biological niche. Among the most DEGs, we highlighted those involved in caste differentiation and cellulose digestion, which are attractive targets for studying more efficient technologies for termite control, biomass digestion and other biotechnological applications.

Uterine vascular resistance and other maternal factors associated with the risk of developing hypertension during pregnancy

Gestational hypertension and pre-eclampsia are important causes of perinatal morbidity. The objective of the present study was to determine the increase in relative risk for developing hypertensive disorders of pregnancy based on the evaluation of pregnant women between 20 and 25 weeks of gestation, and to correlate the findings at this period with the outcome of pregnancy. We conducted a prospective cohort study, with a convenience sample of 1417 patients evaluated at this gestational age, of which 1306 were contacted at childbirth. We detected an increased relative risk of 2.69 (95%CI: 1.86 to 3.89) associated with pulsatility index of the uterine arteries, a 2.8 increase (95%CI: 1.58 to 5.03) in relative risk attributed to maternal age above 35 years, a 1.68 increase (95%CI: 1.17 to 2.40) attributed to parity greater than or equal to 3, and a 5.35 increase (95%CI: 4.18 to 6.85) attributed to chronic hypertension and obesity, with a progressive increase in relative risk according to the degree of overweight, i.e., grades 1, 2, 3, and morbid obesity (2.58, 3.06, 5.84, and 7.28, respectively).

Uterine vascular resistance and other maternal factors associated with the risk of developing hypertension during pregnancy.

Gestational hypertension and pre-eclampsia are important causes of perinatal morbidity. The objective of the present study was to determine the increase in relative risk for developing hypertensive disorders of pregnancy based on the evaluation of pregnant women between 20 and 25 weeks of gestation, and to correlate the findings at this period with the outcome of pregnancy. We conducted a prospective cohort study, with a convenience sample of 1417 patients evaluated at this gestational age, of which 1306 were contacted at childbirth. We detected an increased relative risk of 2.69 (95%CI: 1.86 to 3.89) associated with pulsatility index of the uterine arteries, a 2.8 increase (95%CI: 1.58 to 5.03) in relative risk attributed to maternal age above 35 years, a 1.68 increase (95%CI: 1.17 to 2.40) attributed to parity greater than or equal to 3, and a 5.35 increase (95%CI: 4.18 to 6.85) attributed to chronic hypertension and obesity, with a progressive increase in relative risk according to the degree of overweight, i.e., grades 1, 2, 3, and morbid obesity (2.58, 3.06, 5.84, and 7.28, respectively).

Guanosine enhances glutamate uptake and oxidation, preventing oxidative stress in mouse hippocampal slices submitted to high glutamate levels.

Glutamate (Glu) is the main mammalian brain neurotransmitter. Concerning the glutamatergic neurotransmission, excessive levels of glutamate in the synaptic cleft are extremally harmful. This phenomenon, named as excitotoxicity is involved in various acute and chronic brain diseases. Guanosine (GUO), an endogenous guanine nucleoside, possesses neuroprotective effects in several experimental models of glutamatergic excitotoxicity, an effect accompanied by an increase in astrocytic glutamate uptake. Therefore, the objective of this study was to investigate the involvement of an additional putative parameter, glutamate oxidation to CO2, involved in ex-vivo GUO neuroprotective effects in mouse hippocampal slices submitted to glutamatergic excitotoxicity. Mice were sacrificed by decapitation, the hippocampi were removed and sliced. The slices were incubated for various times and concentrations of Glu and GUO. First, the concentration of Glu that produced an increase in L-[14C(U)]-Glu oxidation to CO2 without cell injury was determined at different time points (between 0 and 90 min); 1000 µM Glu increased Glu oxidation between 30 and 60 min of incubation without cell injury. Under these conditions (Glu concentration and incubation time), 100 µM GUO increased Glu oxidation (35%). Additionally, 100 µM GUO increased L-[3,4-3H]-glutamate uptake (45%) in slices incubated with 1000 µM Glu (0-30 min). Furthermore, 1000  µM Glu increased reactive species levels, SOD activity, and decreased GPx activity, and GSH content after 30 and 60 min; 100 µM GUO prevented these effects. This is the first study demonstrating that GUO simultaneously promoted an increase in the uptake and utilization of Glu in excitotoxicity-like conditions preventing redox imbalance.

Detection of the mecA gene in Staphylococcus spp. isolated from the nasal cavity of pigs - Preliminary data / [Detecção do gene mecA em Staphylococcus spp. isolados da cavidade nasal de suínos - dados preliminares]

O objetivo deste estudo foi realizar a caracterização genética de Staphylococcus spp. resistentes a meticilina isolados de suínos. Foram coletadas 30 amostras de swab nasal de suínos, abatidos em um frigorífico com Serviço de Inspeção Federal. Os isolados foram submetidos a análises macro e microscópicas que, em seguida, para detectar a resistência bacteriana, foram submetidos a ensaios fenotípicos da sensibilidade aos antimicrobianos. Posteriormente, as amostras resistentes a oxacilina, foram submetidas à reação em cadeia pela polimerase (PCR) para verificar a presença do gene mecA. Das 30 amostras analisadas, foram isolados 12 (40%) Staphylococcus spp. coagulase positiva, e 18 (60%) coagulase negativa, e, dentre os isolados, 26 (86,66%) foram resistentes a oxacilina sendo possível detectar o gene mecA em seis (23%) amostras. Este estudo evidencia a presença de genes de resistência em microrganismos comuns a microbiota de animais de produção que podem ser transmitidos ao homem. Além de chamar a atenção para a frequência e quantidade de antimicrobianos aos quais estes animais são expostos durante toda sua vida, podendo ser considerado um problema para a saúde única.(AU)

Paracoccidioidomycosis of the Central Nervous System: CT and MR Imaging Findings.

BACKGROUND AND PURPOSE: Paracoccidioidomycosis is a fungal infection mainly caused by the thermodimorphic fungus Paracoccidioides. The purpose of our study was to demonstrate the neuroimaging findings from 24 patients with CNS paracoccidioidomycosis. MATERIALS AND METHODS: We performed a retrospective analysis focusing on the radiologic characteristics of CNS paracoccidioidomycosis. The 24 selected patients underwent MR imaging and/or CT, and the diagnosis was made by the presence of typical neuroimaging features, combined with fungus isolation, a serologic test, or the presence of disseminated disease. RESULTS: Headache was the most common neurologic symptom, while the pseudotumoral form was the most common pattern. The number of lesions ranged from 1 to 11, with most localized on the frontal lobe with >2-cm lesions. CT showed mainly hypoattenuating lesions, whereas MR imaging demonstrated mainly hyposignal lesions on T1WI and T2WI. Furthermore, ring enhancement was present in most patients. The "dual rim sign" on SWI occurred in 100% of our patients with lesions of >2 cm. CONCLUSIONS: The diagnosis of CNS paracoccidioidomycosis is difficult. Nevertheless, imaging examinations can play an important role in the diagnosis and evaluation of the disease.

Grazing criteria for perennial peanut (Arachis pintoi cv. Amarillo) consumed by sheep in rotational stocking / Critérios de pastejo para amendoim forrageiro (Arachis pintoi cv. Amarillo) consumido por ovelhas em sistema rotacionado

The objective of work was to study the productive profile of perennial peanut in a rotational stocking environment under different criteria. The treatments corresponded to pre-grazing height of 14 and 18cm or 95% of light interception (LI) distributed in a completely randomized design. The studied variables were forage mass, percentage of structural components, forage mass and the structural components in the lower and upper canopy strata. The entrance criterion of 18cm in height, despite having higher forage mass, presented lower percentage of leaves and higher percentage of stems and forage losses. The criteria of 14cm and 95% light interception presented similar production between them and the highest rate of forage accumulation. In all criteria, in the upper strata of pasture a higher percentage of leaves were found. The criteria of 95% LI and 14cm in height presented the best productive performances. The entry criterion of 18cm presented a higher mass of pre-grazing forage with lower percentage of dead material, but with higher forage losses, resulting from senescent leaves. Due to changes in the structural components, as grazing cycles increase, the interception of 95% of the incident light by the perennial peanut occurs at lower heights.(AU)

O objetivo do presente trabalho foi estudar o perfil produtivo do amendoim forrageiro em um ambiente rotacionado, sob diferentes critérios. Os tratamentos corresponderam à altura de pré-pastejo de 14 e 18cm ou 95% de intercepção de luz (LI), distribuídos em delineamento inteiramente ao acaso. As variáveis estudadas foram massa forrageira, porcentagem de componentes estruturais, densidade da massa forrageira e densidade dos componentes estruturais nos estratos do dossel inferior e superior. O critério de entrada de 18cm de altura, apesar de ter maior massa forrageira, apresentou menor porcentagem de folhas e maior porcentagem de hastes e perdas de forragem. Os critérios de interceptação de luz de 14cm e 95% apresentaram produção similar entre eles e a maior taxa de acumulação de forragem. Em todos os critérios, no estrato superior de pastagem, foi encontrada maior porcentagem de folhas. Os critérios de 95% LI e 14cm de altura apresentaram os melhores desempenhos produtivos. O critério de entrada de 18cm apresentou maior massa de forragem pré-pastagem com menor porcentagem de material morto, mas com maiores perdas de forragem, resultantes de folhas senescentes. Devido às mudanças nos componentes estruturais, à medida que os ciclos de pastagem aumentam, a intercepção de 95% da luz incidente pelo amendoim forrageiro ocorre em alturas mais baixas.(AU)

Role of plasma PlGF, PDGF-AA, ANG-1, ANG-2, and the ANG-1/ANG-2 ratio as predictors of preeclampsia in a cohort of pregnant women.

INTRODUCTION: Preeclampsia affects 3-5% of pregnancies worldwide and is the primary cause of maternal-fetal and neonatal mortality. Previous studies show that alterations in maternal concentrations of angiogenic factors, such as PlGF, PDGF AA, ANG-1, and ANG-2, may play fundamental roles in the pathophysiology of the disease. OBJECTIVE: Determine whether the PlGF, PDGF AA, ANG-1, and ANG-2 are predictors of preeclampsia occurrence in a prenatal cohort study. PATIENTS AND METHODS: This is a case-control study associated with a prospective cohort of pregnant women, with gestational ages between 20 and 25 weeks, composed of 30 pregnant women with preeclampsia (PE) and 90 healthy pregnant women (HP). The plasma concentrations of the markers were determined using the ELISA method. The comparison between the case and control groups was performed using the t test on the SAS® 9.4 software. Also, ROC curves were constructed to evaluate the predictive potential of the biomarkers. RESULTS: Differences in the concentrations of PlGF, PDGF AA, ANG-1 and ANG-2, and the ANG-1/ANG-2 ratio were not observed between the PE and the HP groups. The predictive capacity of the biomarkers was assessed using ROC curves, in which the area under the curve for PlGF AUC = 0.55; PDGF AA AUC = 0.55; ANG-1 AUC = 0.47; ANG-2 AUC = 0.51, and the ANG-1/ANG-2 ratio AUC = 0.57. CONCLUSION: In pregnant women, with gestational ages between 20 and 25 weeks significant differences in biomarker concentrations between groups PE and HP were not observed. The ROC curves showed that the biomarkers were ineffective as preeclampsia predictors in the analyzed cohort.

Dual influences of early life stress induced by limited bedding on walking adaptability and Bdnf/TrkB and Drd1/Drd2 gene expression in different mouse brain regions.

Introduction Evidence suggests early life stress impairs development, quality of life and increases vulnerability to disease. One important aspect of the stress experience is its impact on cognitive-motor performance, which includes the ability to adapt walking according to the environmental conditions. This study aimed to investigate how early-life stress affects walking adaptability of mice, while investigating BDNF/TrkB and Drd1/Drd2 expression in different brain regions. Methods Briefly, we exposed male C56BL/6 to the limited bedding protocol (LB) from post-natal day (PND) 2 to PND9 and then tested animals in the ladder walking task at PND60. RT-qPCR was used to investigate gene expression in the mPFC, hippocampus, motor cortex and cerebellum 2 h after the task Results LB induced a wide range of variability and therefore two distinct subgroups of animals within the LB group were established: a) superior performance (LB-SP); and b) inferior performance (LB-IP), compared to controls. Additionally, Drd1 gene expression was increased in the mPFC of LB-IP animals and in the cerebellum of LB-SP animals, while Drd2 expression was reduced in the hippocampus of the LB-IP group. BDNF exon IV gene expression in the mPFC and motor cortex was increased in both the LB-IP and LB-SP subgroups. TrkB gene expression in the hippocampus was reduced in the LB-IP group. A strong negative correlation was found between walking adaptability performance and BDNF exon IV gene expression in the motor cortex. Conversely, a positive correlation was found between walking adaptability performance and TrkB expression in the mPFC and a negative correlation in the hippocampus. Both Drd1 and Drd2 gene expression were negatively correlated with the ability to adapt walking. Conclusions Overall, our findings suggest exposure to early life stress leads to distinct walking adaptability phenotypes, which may be related to Drd1, Drd2, Bdnf exon IV and TrkB gene expression in brain regions that influence walking adaptability.

Clinical Implications caused by the agenesis of the RectusAbdominal Muscle’s (MRA) inferior venter

The rectus abdominal muscle is part of the anterior abdominal wall, having three to six bellies. In only oneof the 106 dissections already made in the “Faculdade de Ciências Médicas de Minas Gerais” AnatomyLaboratory was found a male cadaver who did not have inferior venter of this muscle bilaterally. Instead, at theleft side, was found a tendon that measured 5.5 cm laterally and 12 cm medially, and at the right side, therewas the same variation with a 15.5 cm length tendon, rising in the upper branch of the pubis and crest pubis.Despite being a rare variation, individuals who have showed it have increased potential for physiological andsurgical complications, in case they need interventions using inferior rectus abdominis muscle venter’s snips.

Cytokine production in lungs and adrenal glands of high and low antibody producing mice infected with Paracoccidioides brasiliensis.

Mice genetically selected for high (H) and low (L) antibody production (HIV-A and LIV-A) were used in an experimental model of paracoccidioidomycosis. In a previous work, it was observed that male HIV-A animals were more susceptible to the infection due to adrenal gland damage. Male HIV-A and LIV-A animals were intravenously inoculated with Paracoccidioides brasiliensis (strain 18) and sacrificed 2, 4, 6, 8 and 10 weeks after inoculation. At each time interval, lungs and adrenals were removed to estimate recoverability of the fungus, as well as to determine Th1 (IFN-gamma, TNF-alpha) and Th2 (IL-4 and IL-10) cytokine profiles. While viable fungi recoverability from the lungs of HIV-A mice was higher after 4 and 8 weeks, there was less fungal recovery from the adrenals of LIV-A animals after the 2nd week, with total fungal elimination after the 8th week. With regard to Th2 cytokines, there was an inhibition in IL-4 production in the organs from infected animals, the extent of which varied according to the organ and the time period after initiation of infection. IL-10 production was found to be lower in both organs. Determination of Th1 cytokines revealed that IFN-gamma production increased in both organs, mainly in the adrenal of LIV-A after 8 and 10 weeks, when these animals showed a total fungal elimination. A significant difference was observed between HIV-A and LIV-A concerning TNF-alpha production in both organs and at all recovery times, in that LIV-A produced a higher level of this cytokine, mainly in the adrenal. These results may explain the high susceptibility of HIV-A to P. brasiliensis infection, is due, at least in part, to adrenal involvement. The higher production of Th1 cytokines by LIV-A in comparison to HIV-A mice may account for LIV-A resistance to P. brasiliensis infection. Our data reveal the importance of this experimental model in the study of the adrenal involvement in paracoccidioidomycosis, since this gland may be highly compromised in the patients, leading to the development of Addison's Disease.

Avaliação do potencial de uso do extrato bruto da fermentação por Streptomyces Viridosporus T7 A em medicinaveterinária / Evaluation of the potential applicability of Streptomyces Viridosporus T7 A crude fermentation extract in veterinary medicine / Evaluación del potencial de uso del extracto bruto de la fermentación por Streptomyces viridosporus T7A en medicina veterinaria

Desde a sua descoberta como produtoras de antibióticos, as bactérias do gênero Streptomyces têm sido muito estudadas, em função de seu grande interesse para a indústria. A maioria das cepas de Streptomyces sintetiza substâncias antibacterianas, antifúngicas, antitumorais, antiparasitárias, herbicidas e enzimas, que têm empregos em medicina e agricultura, bem como em vários processos biotecnológicos. Neste trabalho estudou-se a aplicação do extrato bruto enzimático obtido da fermentação por Streptomyces viridosporus T7A para uso veterinário. O extrato bruto enzimático foi submetido a testes de atividade antimicrobiana e de inocuidade, em cultivo celular e em camundongos. Observou-se efeito inibidor sobre cepas patogênicas Gram positivas (Staphylococcus aureus), porém não sobre bactérias Gram negativas (Salmonella sp., Pseudomonas sp. e Escherichia coli). Em cultivo celular, o extrato mostrou ausência de toxicidade e efeito citoprotetor, e em camundongos foi inócuo, e teve influência positiva no peso final nos grupos tratados.

Since discovered as antibiotics producers, Streptomyces genus bacteria had been studied to a great extent, because their great industrial interest. Most of the Streptomyces strains synthesize antibacterial, antifungal, antineoplastic, antiparasitic, and herbicide substances, as well as enzymes, which are used in medicine, agriculture and other biotechnological processes. We studied the potential applicability of Streptomyces viridosporus T7A crude fermentation extract in veterinary medicine. The antimicrobial properties of enzymatic crude extract were tested against pathogenic bacteria strains, and its innocuity was tested both in cellular cultives and mice. It was observed inhibitory effect against pathogenic Gram positive bacteria (Staphylococcus aureus), but not against pathogenic Gram negative bacteria (Salmonella sp., Pseudomonas sp., and Escherichia coli). In cellular cultives, the extract showed citoprotector effect and absence of toxicity. In mice, it was innocuous and had positive influence on the final weight in the treated groups.

Desde que fueran descubiertas como productoras de antibióticos, las bacterias del género Streptomyces vienen siendo muy estudiadas, por tener gran interés para la industria. La mayoría de las variedades de Streptomyces sintetiza substancias antibacterianas, antifúngicas, antitumorales, antiparasitarias y herbicidas, así como enzimas que se usan en medicina, agricultura y otros procesos biotecnológicos. En este trabajo, se estudió el potencial de uso del extracto bruto de la fermentación por Streptomyces viridosporus T7A en medicina veterinaria. Las propiedades antimicrobianas del extracto bruto enzimático fueran testadas contra bacterias patogénicas, así como se testó su inocuidad tanto en cultivos celulares cuanto en ratones. Se observó efecto inhibitorio sobre bacterias patogénicas Gram positivas (Staphylococcus aureus), pero no sobre bacterias Gram negativas (Salmonella sp., Pseudomonas sp. y Escherichia coli). En cultivo celular, el extracto mostró ausencia de toxicidad y efecto citoprotector, y en ratones fue inocuo, y ha influenciado positivamente el peso final de los grupos tratados.

The mental health of graduate students at the Federal University of São Paulo: a preliminary report

We present data regarding the care provided to graduate level health professionals at the mental health center of the Federal University of São Paulo. From September 1996 to September 2003, 146 graduate students (99 in the Master's degree program and 47 in the Doctoral program) were attended. This population was predominantly female (68.5 percent), with a mean (± SD) age of 28.6 ± 4.42 years, not married (71.9 percent). Most of the subjects were professionals who had not graduated from the Federal University (78.1 percent). The students who sought help for psychological and/or psychiatric problems were classified into two categories: situational-adaptive crises and psychopathological crises. The main diagnoses were depression and anxiety disorders (44 percent) causing 4.5 percent of the subjects to be temporarily suspended from their graduate studies; 19.2 percent reported that they had used psychotropic drugs within the previous month, and 47.9 percent referred to sleep disturbances. Suicidal tendencies were mentioned by 18 percent of those interviewed. Students with emotional disturbances and academic dysfunctions should be recognized at an early stage, and it is fundamental for them to have access to mental health programs that provide formal, structured and confidential care. Thus, it is important that professors and advisors in graduate programs build a warm and affective learning environment. If we consider the expressive growth in Brazilian scientific production resulting from the implementation of an extensive national system of graduate education, it is important to focus efforts on enhancing and upgrading the mental health care system.

The mental health of graduate students at the Federal University of São Paulo: a preliminary report.

We present data regarding the care provided to graduate level health professionals at the mental health center of the Federal University of São Paulo. From September 1996 to September 2003, 146 graduate students (99 in the Master's degree program and 47 in the Doctoral program) were attended. This population was predominantly female (68.5%), with a mean (+/- SD) age of 28.6 +/- 4.42 years, not married (71.9%). Most of the subjects were professionals who had not graduated from the Federal University (78.1%). The students who sought help for psychological and/or psychiatric problems were classified into two categories: situational-adaptive crises and psychopathological crises. The main diagnoses were depression and anxiety disorders (44%) causing 4.5% of the subjects to be temporarily suspended from their graduate studies; 19.2% reported that they had used psychotropic drugs within the previous month, and 47.9% referred to sleep disturbances. Suicidal tendencies were mentioned by 18% of those interviewed. Students with emotional disturbances and academic dysfunctions should be recognized at an early stage, and it is fundamental for them to have access to mental health programs that provide formal, structured and confidential care. Thus, it is important that professors and advisors in graduate programs build a warm and affective learning environment. If we consider the expressive growth in Brazilian scientific production resulting from the implementation of an extensive national system of graduate education, it is important to focus efforts on enhancing and upgrading the mental health care system.

Did Sutton and Boveri propose the so-called Sutton-Boveri chromosome hypothesis?

The "Sutton-Boveri chromosome hypothesis" attempted to establish a parallel between cytological chromosome behavior and the principles followed by Mendelian factors. Today, this hypothesis is well accepted; however, it was not completely accepted at its proposal (1902-3). The aim of the present study is to elucidate the meaning of the chromosome hypothesis based on the original scientific works, taking into account the scientific context of that time. The negative treatment this hypothesis received is evaluated. I conclude that it was unfair to include Boveri's name beside that of Sutton's as one of the proponents of the chromosome hypothesis of Mendelian heredity, because he did not publish any hypothesis of that kind during the relevant period (1902-1903). Moreover, no coherent chromosome hypothesis existed during that period. Sutton and other researchers of that time were strongly influenced both by cytological knowledge grounded in observations and theoretical presuppositions that led to interpretations with no observational basis. The chromosome hypothesis was not proposed as a result of experimental cytological research.

Stressors in ICU: perception of the patient, relatives and health care team.

OBJECTIVE: To compare the evaluation of the stressors present in the intensive care unit (ICU) from the point of view of the patient, relatives and the multiprofessional team and to identify differences and similarities with regard to the perception of stressors in order to optimize patient care. DESIGN: Cross-sectional analytical survey. SETTING: General ICU of a private hospital. PATIENTS AND PARTICIPANTS: From April 1st to June 30th, 1996, 50 ICU patients during the first week of their ICU stay, 50 of their respective relatives and 50 members of the professional team directly involved in the care of these patients. MEASUREMENTS AND RESULTS: The Intensive Care Unit Environmental Stressor Scale (ICUESS) was administered to all patients. The relatives and health care professionals were asked to complete the ICUESS on the basis of their perception of the patient's stressors. Being in pain, having tubes in the nose or mouth, being restrained by tubes and being unable to sleep were considered by the patients, relatives and health care professionals as the main stressors. The professional team evaluated the intensity of the stressors higher than either the family or the patient. No statistical significance was detected between the intensity of the stressors as evaluated by the patient and the intensity evaluated by relatives and by the professional team. CONCLUSIONS: Being in pain, being unable to sleep and having tubes in the nose and/or mouth were pointed out as the major stressors by the three groups. There was no statistically significant correlation between the total stress scores of the patients and their relatives (r = 0.193), between the patients and the team (r = -0.002), or between the total scores of the team and the relatives (r = -0.185). The results suggest that the views of the relatives and the professional team concerning the stressors have some similar points compared to the evaluation made by the patient himself, although the intensity of the evaluation for each group corresponds to its own perception.

[McClung and gender determination: from wrong to right]. / McClung e a determinacao do sexo: do equivoco ao acerto.

Focusing primarily on McClung's hypothesis linking the extra chromosome (X) to gender determination, the article studies some contributions derived from the initial stages in development of the chromosome theory of gender determination. The arguments of McClung and others are analyzed, along with the reaction of the era's scientific community. Although McClung's hypothesis was wrong, it triggered a series of research studies that eventually led to clarification of the question. Even mistaken hypotheses, when adopted for investigation and testing, can contribute to scientific development.

[Stress nature and magnitude during medical residency training]. / Natureza e magnitude do estresse na residência médica.

The stressful nature of Residency training has been largely discussed in the literature. The aim of this paper is to present some data about the stress of training and its effects on residents and on the quality of patient's care. The magnitude of stress results from the interaction of three categories of stresses: professional, situational and personal. The main behavioral disturbances and professional dysfunctions are described and the importance of these data for planning, organization and evaluation of Residency programs is emphasized.

Natureza e magnitude do estresse na residência médica / Stress nature and magnitude during medical residency training

A natureza estressante do treinamento na Residência Médica tem sido amplamente discutida na literatura. O objetivo deste artigo é apresentar dados sobre os principais fatores estressantes do treinamento e os efietos desse estresse nos residentes e na qualidade da assistência prestada aos pacientes. A magnitude do estresse, durante o treinamento na Residência Médica, resulta da interaçäo de três tipos de estresse: profissional, situacional e pessoal. Säo descritos os principais distúrbios comportamentais e disfunçöes profissionais que afetam os residentes, salientando-se a importância do conhecimento desses dados para o planejamento, organizaçäo e avaliaçäo de programas de Residência Médica.