Haemoglobin adducts of acrylonitrile and ethylene oxide in acrylonitrile workers, dependent on polymorphisms of the glutathione transferases GSTT1 and GSTM1

Fifty-nine persons with industrial handling of low levels of acrylonitrile (AN) were studied. As part of a medical surveillance programme an extended haemoglobin adduct monitoring [N-(cyanoethyl)valine, CEV; N- (methyl)valine, MV; N-(hydroxyethyl)valine, HEV] was performed. Moreover, the genetic states of the polymorphic glutathione transferases GSTM1 and GSTT1 were assayed by polymerase chain reaction (PCR). Repetitive analyses of CEV and MV in subsequent years resulted in comparable values (means, 59.8 and 70.3 μg CEV/1 blood; 6.7 and 6.7 μg MV/1 blood). Hence, the industrial AN exposures were well below current official standards. Monitoring the haemoglobin adduct CEV appears as a suitable means of biomonitoring and medical surveillance under such exposure conditions. There was also no apparent correlation between the CEV and HEV or CEV and MV adduct levels. The MV and HEV values observed represented background levels, which apparently are not related to any occupational chemical exposure. There was no consistent effect of the genetic GSTM1 or GSTT1 state on CEV adduct levels induced by acrylonitrile exposure. Therefore, neither GSTM1 nor GSTT1 appears as a major AN metabolizing isoenzyme in humans. The low and physiological background levels of MV were also not influenced by the genetic GSTM1 state, but the MV adduct levels tended to be higher in GSTT1- individuals compared to GSTT1 + persons. With respect to the background levels of HEV adducts observed, there was no major influence of the GSTM1 state, but GST- individuals displayed adduct levels that were about 1/3 higher than those of GSTT1+ individuals. The coincidence with known differences in rates of background sister chromatid exchange between GSTT1- and GSTT1 + persons suggests that the lower ethylene oxide (EO) detoxification rate in GSTT1- persons, indicated by elevated blood protein hydroxyethyl adduct levels, leads to an increased genotoxic effect of the physiological EO background.

Stress, the hippocampus and the HPA axis: Implications for the development of psychotic disorders

The experience of stress is commonly implicated in models of the onset of psychotic disorders. However, prospective studies investigating associations between biological markers of stress and the emergence of psychotic disorders are limited and inconclusive. One biological system proposed as the link between the psychological experience of stress and the development of psychosis is the Hypothalamic-Pituitary-Adrenal (HPA) axis. This paper summarizes and discusses evidence supporting a role for HPA-axis dysfunction in the early phase of schizophrenia and related disorders. METHOD A selective review of psychiatric and psychological research on stress, coping, HPA-axis, the hippocampus and psychotic disorders was performed, with a particular focus on the relationship between HPA-axis dysfunction and the onset of psychotic disorders. RESULTS Individual strands of past research have suggested that the HPA-axis is dysfunctional in at least some individuals with established psychotic disorders; that the hippocampus is an area of the brain that appears to be implicated in the onset and maintenance of psychotic disorders; and that an increase in the experience of stress precedes the onset of a psychotic episode in some individuals. Models of the onset and maintenance of psychotic disorders that link these individual strands of research and strategies for examining these models are proposed in this paper. CONCLUSIONS The current literature provides some evidence that the onset of psychotic disorders may be associated with a higher rate of stress and changes to the hippocampus. It is suggested that future research should investigate whether a relationship exists between psychological stress, HPA-axis functioning and the hippocampus in the onset of these disorders. Longitudinal assessment of these factors in young people at 'ultra' high risk of psychosis and first-episode psychosis cohorts may enhance understanding of the possible interaction between them in the early phases of illness.

Endurance exercise and DNA stability: Is there a link to duration and intensity?

It is commonly accepted that regular moderate intensity physical activity reduces the risk of developing many diseases. Counter intuitively, however, evidence also exists for oxidative stress resulting from acute and strenuous exercise. Enhanced formation of reactive oxygen and nitrogen species may lead to oxidatively modified lipids, proteins and nucleic acids and possibly disease. Currently, only a few studies have investigated the influence of exercise on DNA stability and damage with conflicting results, small study groups and the use of different sample matrices or methods and result units. This is the first review to address the effect of exercise of various intensities and durations on DNA stability, focusing on human population studies. Furthermore, this article describes the principles and limitations of commonly used methods for the assessment of oxidatively modified DNA and DNA stability. This review is structured according to the type of exercise conducted (field or laboratory based) and the intensity performed (i.e. competitive ultra/endurance exercise or maximal tests until exhaustion). The findings presented here suggest that competitive ultra-endurance exercise (>4h) does not induce persistent DNA damage. However, when considering the effects of endurance exercise (<4h), no clear conclusions could be drawn. Laboratory studies have shown equivocal results (increased or no oxidative stress) after endurance or exhaustive exercise. To clarify which components of exercise participation (i.e. duration, intensity and training status of subjects) have an impact on DNA stability and damage, additional carefully designed studies combining the measurement of DNA damage, gene expression and DNA repair mechanisms before, during and after exercise of differing intensities and durations are required.

Clinical factors associated with the humoral immune response to influenza vaccination in chronic obstructive pulmonary disease

Background and objective Individuals with chronic obstructive pulmonary disease (COPD) are at a high risk of developing significant complications from infection with the influenza virus. It is therefore vital to ensure that prophylaxis with the influenza vaccine is effective in COPD. The aim of this study was to assess the immunogenicity of the 2010 trivalent influenza vaccine in persons with COPD compared to healthy subjects without lung disease, and to examine clinical factors associated with the serological response to the vaccine. Methods In this observational study, 34 subjects (20 COPD, 14 healthy) received the 2010 influenza vaccine. Antibody titers at baseline and 28 days post-vaccination were measured using the hemagglutination inhibition assay (HAI) assay. Primary endpoints included seroconversion (≥4-fold increase in antibody titers from baseline) and the fold increase in antibody titer after vaccination. Results Persons with COPD mounted a significantly lower humoral immune response to the influenza vaccine compared to healthy participants. Seroconversion occurred in 90% of healthy participants, but only in 43% of COPD patients (P=0.036). Increasing age and previous influenza vaccination were associated with lower antibody responses. Antibody titers did not vary significantly with cigarette smoking, presence of other comorbid diseases, or COPD severity. Conclusion The humoral immune response to the 2010 influenza vaccine was lower in persons with COPD compared to non-COPD controls. The antibody response also declined with increasing age and in those with a history of prior vaccination.

Risedronate in adults with osteogenesis imperfecta type I: Increased bone mineral density and decreased bone turnover, but high fracture rate persists

Summary Bisphosphonates can increase bone mineral density (BMD) in children with osteogenesis imperfecta (OI). In this study of adults with OI type I, risedronate increased BMD at lumbar spine (but not total hip) and decreased bone turnover. However, the fracture rate in these patients remained high. Introduction Intravenous bisphosphonates given to children with OI can increase BMD and reduce fracture incidence. Oral and/or intravenous bisphosphonates may have similar effects in adults with OI. We completed an observational study of the effect of risedronate in adults with OI type I. Methods Thirty-two adults (mean age, 39 years) with OI type I were treated with risedronate (total dose, 35 mg weekly) for 24 months. Primary outcome measures were BMD changes at lumbar spine (LS) and total hip (TH). Secondary outcome measures were fracture incidence, bone pain, and change in bone turnover markers (serum procollagen type I aminopropeptide (P1NP) and bone ALP). A meta-analysis of published studies of oral bisphosphonates in adults and children with OI was performed. Results Twenty-seven participants (ten males and seventeen females) completed the study. BMD increased at LS by 3.9% (0.815 vs. 0.846 g/cm 2, p=0.007; mean Z-score, -1.93 vs. -1.58, p=0.002), with no significant change at TH. P1NP fell by 37% (p=0.00041), with no significant change in bone ALP (p=0.15). Bone pain did not change significantly (p=0.6). Fracture incidence remained high, with 25 clinical fractures and 10 major fractures in fourteen participants (0.18 major fractures per person per year), with historical data of 0.12 fractures per person per year. The meta-analysis did not demonstrate a significant difference in fracture incidence in patients with OI treated with oral bisphosphonates. Conclusions Risedronate in adults with OI type I results in modest but significant increases in BMD at LS, and decreased bone turnover. However, this may be insufficient to make a clinically significant difference to fracture incidence.

A variant in LIN28B is associated with 2D:4D finger-length ratio, a putative retrospective biomarker of prenatal testosterone exposure

The ratio of the lengths of an individual's second to fourth digit (2D:4D) is commonly used as a noninvasive retrospective biomarker for prenatal androgen exposure. In order to identify the genetic determinants of 2D:4D, we applied a genome-wide association approach to 1507 11-year-old children from the Avon Longitudinal Study of Parents and Children (ALSPAC) in whom 2D:4D ratio had been measured, as well as a sample of 1382 12- to 16-year-olds from the Brisbane Adolescent Twin Study. A meta-analysis of the two scans identified a single variant in the LIN28B gene that was strongly associated with 2D:4D (rs314277: p = 4.1 x 10(-8)) and was subsequently independently replicated in an additional 3659 children from the ALSPAC cohort (p = 1.53 x 10(-6)). The minor allele of the rs314277 variant has previously been linked to increased height and delayed age at menarche, but in our study it was associated with increased 2D:4D in the direction opposite to that of previous reports on the correlation between 2D:4D and age at menarche. Our findings call into question the validity of 2D:4D as a simplistic retrospective biomarker for prenatal testosterone exposure.

Determinants of outcome in critically ill patients

Assessment of the outcome of critical illness is complex. Severity scoring systems and organ dysfunction scores are traditional tools in mortality and morbidity prediction in intensive care. Their ability to explain risk of death is impressive for large cohorts of patients, but insufficient for an individual patient. Although events before intensive care unit (ICU) admission are prognostically important, the prediction models utilize data collected at and just after ICU admission. In addition, several biomarkers have been evaluated to predict mortality, but none has proven entirely useful in clinical practice. Therefore, new prognostic markers of critical illness are vital when evaluating the intensive care outcome. The aim of this dissertation was to investigate new measures and biological markers of critical illness and to evaluate their predictive value and association with mortality and disease severity. The impact of delay in emergency department (ED) on intensive care outcome, measured as hospital mortality and health-related quality of life (HRQoL) at 6 months, was assessed in 1537 consecutive patients admitted to medical ICU. Two new biological markers were investigated in two separate patient populations: in 231 ICU patients and 255 patients with severe sepsis or septic shock. Cell-free plasma DNA is a surrogate marker of apoptosis. Its association with disease severity and mortality rate was evaluated in ICU patients. Next, the predictive value of plasma DNA regarding mortality and its association with the degree of organ dysfunction and disease severity was evaluated in severe sepsis or septic shock. Heme oxygenase-1 (HO-1) is a potential regulator of apoptosis. Finally, HO-1 plasma concentrations and HO-1 gene polymorphisms and their association with outcome were evaluated in ICU patients. The length of ED stay was not associated with outcome of intensive care. The hospital mortality rate was significantly lower in patients admitted to the medical ICU from the ED than from the non-ED, and the HRQoL in the critically ill at 6 months was significantly lower than in the age- and sex-matched general population. In the ICU patient population, the maximum plasma DNA concentration measured during the first 96 hours in intensive care correlated significantly with disease severity and degree of organ failure and was independently associated with hospital mortality. In patients with severe sepsis or septic shock, the cell-free plasma DNA concentrations were significantly higher in ICU and hospital nonsurvivors than in survivors and showed a moderate discriminative power regarding ICU mortality. Plasma DNA was an independent predictor for ICU mortality, but not for hospital mortality. The degree of organ dysfunction correlated independently with plasma DNA concentration in severe sepsis and plasma HO-1 concentration in ICU patients. The HO-1 -413T/GT(L)/+99C haplotype was associated with HO-1 plasma levels and frequency of multiple organ dysfunction. Plasma DNA and HO-1 concentrations may support the assessment of outcome or organ failure development in critically ill patients, although their value is limited and requires further evaluation.

Tipagem das células do infiltrado inflamatório peritumoral em carcinoma de células escamosas da mucosa bucal: correlação com expressão de Ki67

O emprego de técnicas imunoistoquímicas, utilizando marcadores biológicos como o Ki67, que permite a avaliação do índice de proliferação celular em neoplasias malignas, vem sendo preconizado como um importante caminho de investigação do comportamento biológico das neoplasias malignas, tendo como consequências contribuições para o estabelecimento do prognóstico e desenvolvimento de novos protocolos terapêuticos. Neste trabalho, utiliza-se o método imunoistoquímico da avidina-biotina-peroxidase avaliada a expressão de Ki67 no parênquima de amostras de carcinomas de células escamosas da mucosa bucal com diferentes graus de diferenciação histológica. Além disso, a quantificação da área de infiltrado inflamatório foi avaliada. Os resultados demonstraram que a resposta imunológica celular é o principal mecanismo de defesa no carcinoma de células escamosas da mucosa bucal, expressada pelo grande número de linfócitos T e macrófagos e a expressão de Ki67 está relacionado ao índice mitótico e, consequentemente, à proliferação celular e, também, à diferenciação da neoplasia.

Entre crânios analógicos e imagens digitais: alguns antecedentes históricos e culturais das tecnologias de neuro-imageamento

Nos últimos anos, temos nos deparado com a difusão maciça e a popularização crescente de descrições biológicas para aspectos outrora pensados como mentais, sociais, ou relacionais. Visível em diversas arenas leigas e científicas, esta tendência freqüentemente elege o cérebro como o órgão privilegiado da sua atenção. A cada semana é divulgada uma nova localização cerebral correlacionada os mais variados aspectos comportamentais e ou de personalidade. Acompanhando este movimento, é notável o esforço intelectual e financeiro despendido nos últimos anos no campo da saúde mental, no sentido de fazer avançar pesquisas cujo foco central é a descoberta das bases neurobiológicas dos transtornos mentais. Esta tendência apontaria na direção de uma fusão entre a psiquiatria e a neurologia em uma disciplina única, de teor fisicalista, chamada por alguns de cerebrologia. Dentre os acontecimentos que serviram de alicerce para a legitimação e a popularização desta tendência, o desenvolvimento nas últimas décadas de novas técnicas e tecnologias de visualização médica, como a tomografia por emissão de pósitrons (PET scan) e a ressonância magnética funcional (fMRI), foi fundamental. Elas permitiram a construção de imagens das mais diversas categorias nosográficas construídas no campo psiquiátrico, veiculando tacitamente uma série de pressupostos e promessas. Malgrado o imaginário cultural sustentado por estas tecnologias e todo o esforço despendido nas últimas décadas no sentido de se tentar localizar os marcadores biológicos dos transtornos psiquiátricos, não há, até o presente momento, nenhum resultado conclusivo que autorize o diagnóstico por imagem de nosografias como a esquizofrenia, a depressão, e muito menos o jogo patológico. Apesar de todo o alarde midiático e dos montantes milionários direcionados para pesquisas nesta área, os resultados concretos obtidos até agora não estão livres das mais ferozes controvérsias. Entretanto, ainda que estejamos muito longe da construção de mapas precisos para as perturbações mentais é espantoso o poder de convencimento que as neuro-imagens comportam na atualidade. Os scans são exibidos como verdades visuais, ou fatos acerca das pessoas e do mundo, numa proporção muito superior aos dados que apresentam. Alguns críticos chamam este aspecto de neurorealismo, ou de retórica da auto-evidência. A intenção deste trabalho é problematizar o poder persuasivo que as neuro-imagens detém na contemporaneidade, especialmente quando utilizadas com a finalidade diagnóstica no campo da saúde mental. Se estas imagens transmitem uma ideia de neutralidade, transparência imediata e auto-evidência, este trabalho almeja inseri-las num contexto sócio-histórico, a partir do qual puderam adquirir sentido, familiaridade e valor de verdade. O ponto de partida é o de que elas estão localizadas no cruzamento de dois movimentos históricos distintos: o das ilustrações médicas, em sua relação com a produção de conhecimento objetivo; e o das pesquisas acerca da localização no córtex cerebral de comportamentos complexos e traços de personalidade. Além de estabelecer algumas condições históricas de possibilidade para a emergência de um neo-localizacionismo cerebral, mediado pelas novas tecnologias de imageamento, pretende-se enfatizar algumas descontinuidades com projetos anteriores e marcar a influência do contexto cultural da atualidade para o sucesso e poder persuasivo deste tipo de tecnologia.

Via de sinalização mTOR no carcinoma urotelial da bexiga

Trabalho de Projeto apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Análises Laboratoriais Especializadas, área de especialização em Análise Biomédica

Tryptophan degradation in irritable bowel syndrome: evidence of indoleamine 2,3-dioxygenase activation in a male cohort

Background: Irritable bowel syndrome (IBS) is a common disorder that affects 10–15% of the population. Although characterised by a lack of reliable biological markers, the disease state is increasingly viewed as a disorder of the brain-gut axis. In particular, accumulating evidence points to the involvement of both the central and peripheral serotonergic systems in disease symptomatology. Furthermore, altered tryptophan metabolism and indoleamine 2,3-dioxygenase (IDO) activity are hallmarks of many stress-related disorders. The kynurenine pathway of tryptophan degradation may serve to link these findings to the low level immune activation recently described in IBS. In this study, we investigated tryptophan degradation in a male IBS cohort (n = 10) and control subjects (n = 26). Methods: Plasma samples were obtained from patients and healthy controls. Tryptophan and its metabolites were measured by high performance liquid chromatography (HPLC) and neopterin, a sensitive marker of immune activation, was measured using a commercially available ELISA assay. Results: Both kynurenine levels and the kynurenine:tryptophan ratio were significantly increased in the IBS cohort compared with healthy controls. Neopterin was also increased in the IBS subjects and the concentration of the neuroprotective metabolite kynurenic acid was decreased, as was the kynurenic acid:kynurenine ratio. Conclusion: These findings suggest that the activity of IDO, the immunoresponsive enzyme which is responsible for the degradation of tryptophan along this pathway, is enhanced in IBS patients relative to controls. This study provides novel evidence for an immune-mediated degradation of tryptophan in a male IBS population and identifies the kynurenine pathway as a potential source of biomarkers in this debilitating condition.

Effective detection of celiac disease using salivary anti-transglutaminase.

Comment

Evaluation of HER2, p53, bcl-2, topoisomerase II-alpha, heat shock proteins 27 and 70 in primary breast cancer and metastatic ipsilateral axillary lymph nodes.

BACKGROUND: Breast cancer is a heterogeneous disease. Predictive biological markers (BM) of responsiveness to therapy need to be identified. Evaluation of BM is mainly done at the primary site. However, in the adjuvant therapy of breast cancer, the main goal is control of micrometastases. It is still unknown whether heterogeneity in the expression of BM between the primary site and its micrometastases exists. OBJECTIVE: To evaluate the expression of some BM with potential predictive value from the primary breast cancer site and metastatic ipsilateral axillary lymph nodes. PATIENTS AND METHODS: Focality (percentage of positive cells) and intensity staining scores were evaluated for each marker. Freshly cut sections (4 microm) from embedded blocks of breast cancer fixed in formalin or bouin were put onto superfrost slides (Menzel-Gläser). Protein expression was evaluated immunohistochemically (IHC) using monoclonal antibodies against: topo II-alpha (clone KiS1, 1 microg/ml, Roche) with a trypsine pre-treatment (P); HSP27 (clone G3.1, 1/60, Biogenex), HSP70 (clone BRM.22, 1/80, Biogenex) and HER2 (clone CB11, 1/40, Novocastra; without P); p53 (clone D07, 1/750, Dako) and bcl-2 (clone 124, 1/60, Dako) with citrate buffer as P. RESULTS: Overall, the percentage of discordant marker status in the primary tumour and its metastatic lymph nodes was 2% for HER2, 6% for p53, 15% for bcl-2, 19% for topoisomerase II-alpha, 24% for HSP27 and 30% for HSP70. For the subgroup of patients with positive BM in the primary tumour, the percentage of discordance was 6% for HER2, 7% for p53, 14% for bcl-2, 19% for HSP70, 21% for topoisomerase II-alpha and 36% for HSP27. For the subgroup of patients with positive BM in the lymph nodes, the percentage of discordance was 9% for bcl-2, 15% for HER2 and p53, 21% for topoisomerase II-alpha, 22% for HSP27 and 25% for HSP70. CONCLUSIONS: 1) No biological marker had 100% concordant results. 2) Although some discordant cases might be explained by the limitations of the IHC technique, future studies aiming to evaluate the predictive value of BM in the adjuvant therapy of breast cancer should take into account a possible difference in BM expression between the primary and the metastatic sites.

Evaluation of tumor response, disease control, progression-free survival, and time to progression as potential surrogate end points in metastatic breast cancer.

PURPOSE: Overall survival (OS) can be observed only after prolonged follow-up, and any potential effect of first-line therapies on OS may be confounded by the effects of subsequent therapy. We investigated whether tumor response, disease control, progression-free survival (PFS), or time to progression (TTP) could be considered a valid surrogate for OS to assess the benefits of first-line therapies for patients with metastatic breast cancer. PATIENTS AND METHODS: Individual patient data were collected on 3,953 patients in 11 randomized trials that compared an anthracycline (alone or in combination) with a taxane (alone or in combination with an anthracycline). Surrogacy was assessed through the correlation between the end points as well as through the correlation between the treatment effects on the end points. RESULTS: Tumor response (survival odds ratio [OR], 6.2; 95% CI, 5.3 to 7.0) and disease control (survival OR, 5.5; 95% CI, 4.8 to 6.3) were strongly associated with OS. PFS (rank correlation coefficient, 0.688; 95% CI, 0.686 to 0.690) and TTP (rank correlation coefficient, 0.682; 95% CI, 0.680 to 0.684) were moderately associated with OS. Response log ORs were strongly correlated with PFS log hazard ratios (linear coefficient [rho], 0.96; 95% CI, 0.73 to 1.19). Response and disease control log ORs and PFS and TTP log hazard ratios were poorly correlated with log hazard ratios for OS, but the confidence limits of rho were too wide to be informative. CONCLUSION: No end point could be demonstrated as a good surrogate for OS in these trials. Tumor response may be an acceptable surrogate for PFS.

Le rôle de l'hormone anti-müillerienne dans la régulation du fonctionnement de l'ovaire. Revue de la littérature

Anti-mullerian hormone, also called AMH, belongs to the large family of transforming growth factor P. Its role in the sexual differentiation of male fetus is now well known. Recently, AMH has been demonstrated to play an important role in the ovarian function. In fact, AMH seems to regulate the kinetics of follicular development, inhibiting the follicular recruitment and the follicular growth. Thus, this intra-gonadic cybernin could be a decisive determinant of the rapidity of follicular pool exhaustion. Today, some experimental data from the literature suggest that AMH could be a reliable marker of ovarian reserve. This review summarizes the present knowledge about AMH and its role in physiology but also in ovarian pathology.