49 research outputs found
Inquérito soroepidemiológico sobre malária em escolares de Marabá, Pará
Realizou-se inquérito sorológico para malária em escolares de Marabá — Pará, por meio de testes de imunofluorescência (IP) para anticorpos IgG e IgM, tendo como antÃgenos P. falciparum e P. gallinaceum, e teste de hemaglutinação (HAg) com P. gallinaceum. O teste IF-IgG com P. falciparum foi positivo em 6,94% dos 389 indivÃduos estudados e o de P. gallinaceum em 11,56%, havendo concordância entre ambos os testes em 88,68% das amostras. No total, observou-se 14,91% de casos reagentes em qualquer dos testes. O teste com P. gallinaceum se mostrou mais abrangente provavelmente devido a maior prevalência na região de infecções por P. vivax. Ao se dividir a população estudada em faixas etárias de 6 a 10 anos (grupo A) e de 11 a 16 anos (grupo B), observou-se diferença significativa de reatividade ao teste IF-IgG com P. falciparum (2,68% para A e 10,94% para B) mas não com P. gallinaceum (10,10% para A e 12,97% para B). Para os testes IF-IgM houve positividade de 2,83% na população, e para o teste de HAg de 1,80%, sem diferença significativa entre os grupos etários A e B
Energy Metabolism in H460 Lung Cancer Cells: Effects of Histone Deacetylase Inhibitors
BACKGROUND: Tumor cells are characterized by accelerated growth usually accompanied by up-regulated pathways that ultimately increase the rate of ATP production. These cells can suffer metabolic reprogramming, resulting in distinct bioenergetic phenotypes, generally enhancing glycolysis channeled to lactate production. In the present work we showed metabolic reprogramming by means of inhibitors of histone deacetylase (HDACis), sodium butyrate and trichostatin. This treatment was able to shift energy metabolism by activating mitochondrial systems such as the respiratory chain and oxidative phosphorylation that were largely repressed in the untreated controls. METHODOLOGY/PRINCIPAL FINDINGS: Various cellular and biochemical parameters were evaluated in lung cancer H460 cells treated with the histone deacetylase inhibitors (HDACis), sodium butyrate (NaB) and trichostatin A (TSA). NaB and TSA reduced glycolytic flux, assayed by lactate release by H460 cells in a concentration dependent manner. NaB inhibited the expression of glucose transporter type 1 (GLUT 1), but substantially increased mitochondria bound hexokinase (HK) activity. NaB induced increase in HK activity was associated to isoform HK I and was accompanied by 1.5 fold increase in HK I mRNA expression and cognate protein biosynthesis. Lactate dehydrogenase (LDH) and pyruvate kinase (PYK) activities were unchanged by HDACis suggesting that the increase in the HK activity was not coupled to glycolytic flux. High resolution respirometry of H460 cells revealed NaB-dependent increased rates of oxygen consumption coupled to ATP synthesis. Metabolomic analysis showed that NaB altered the glycolytic metabolite profile of intact H460 cells. Concomitantly we detected an activation of the pentose phosphate pathway (PPP). The high O(2) consumption in NaB-treated cells was shown to be unrelated to mitochondrial biogenesis since citrate synthase (CS) activity and the amount of mitochondrial DNA remained unchanged. CONCLUSION: NaB and TSA induced an increase in mitochondrial function and oxidative metabolism in H460 lung tumor cells concomitant with a less proliferative cellular phenotype
Sleep study, respiratory mechanics, chemosensitive response and quality of life in morbidly obese patients undergoing bariatric surgery: a prospective, randomized, controlled trial
<p>Abstract</p> <p>Background</p> <p>Obesity is a major public health problem in both developed and developing countries alike and leads to a series of changes in respiratory physiology. There is a strong correlation between obesity and cardiopulmonary sleep disorders. Weight loss among such patients leads to a reduction in these alterations in respiratory physiology, but clinical treatment is not effective for a long period of time. Thus, bariatric surgery is a viable option.</p> <p>Methods/Design</p> <p>The present study involves patients with morbid obesity (BMI of 40 kg/m<sup>2 </sup>or 35 kg/m<sup>2 </sup>to 39.9 kg/m<sup>2 </sup>with comorbidities), candidates for bariatric surgery, screened at the Santa Casa de Misericórdia Hospital in the city of Sao Paulo (Brazil). The inclusion criteria are grade III morbid obesity, an indication for bariatric surgery, agreement to participate in the study and a signed term of informed consent. The exclusion criteria are BMI above 55 kg/m<sup>2</sup>, clinically significant or unstable mental health concerns, an unrealistic postoperative target weight and/or unrealistic expectations of surgical treatment. Bariatric surgery candidates who meet the inclusion criteria will be referred to Santa Casa de Misericórdia Hospital and will be reviewed again 30, 90 and 360 days following surgery. Data collection will involve patient records, personal data collection, objective assessment of HR, BP, neck circumference, chest and abdomen, collection and analysis of clinical preoperative findings, polysomnography, pulmonary function test and a questionnaire on sleepiness.</p> <p>Discussion</p> <p>This paper describes a randomised controlled trial of morbidly obese patients. Polysomnography, respiratory mechanics, chemosensitive response and quality of life will be assessed in patients undergoing or not undergoing bariatric surgery.</p> <p>Trial Registration</p> <p>The protocol for this study is registered with the Brazilian Registry of Clinical Trials - ReBEC (RBR-9k9hhv).</p
Computational Insights on the Competing Effects of Nitric Oxide in Regulating Apoptosis
Despite the establishment of the important role of nitric oxide (NO) on apoptosis, a molecular- level understanding of the origin of its dichotomous pro- and anti-apoptotic effects has been elusive. We propose a new mathematical model for simulating the effects of nitric oxide (NO) on apoptosis. The new model integrates mitochondria-dependent apoptotic pathways with NO-related reactions, to gain insights into the regulatory effect of the reactive NO species N2O3, non-heme iron nitrosyl species (FeLnNO), and peroxynitrite (ONOO−). The biochemical pathways of apoptosis coupled with NO-related reactions are described by ordinary differential equations using mass-action kinetics. In the absence of NO, the model predicts either cell survival or apoptosis (a bistable behavior) with shifts in the onset time of apoptotic response depending on the strength of extracellular stimuli. Computations demonstrate that the relative concentrations of anti- and pro-apoptotic reactive NO species, and their interplay with glutathione, determine the net anti- or pro-apoptotic effects at long time points. Interestingly, transient effects on apoptosis are also observed in these simulations, the duration of which may reach up to hours, despite the eventual convergence to an anti-apoptotic state. Our computations point to the importance of precise timing of NO production and external stimulation in determining the eventual pro- or anti-apoptotic role of NO