Differentially Expressed Proteins in Nitric Oxide-Stimulated NIH/3T3 Fibroblasts: Implications for Inhibiting Cancer Development

PURPOSE: Recent evidence shows that nitric oxide (NO) may exhibit both pro-cancer and anti-cancer activities. The present study aimed to determine the differentially expressed proteins in NO-treated NIH/3T3 fibroblasts in order to investigate whether NO induces proteins with pro-cancer or anti-cancer effects. MATERIALS AND METHODS: The cells were treated with 300 microM of an NO donor 3,3-bis-(aminoethyl)-1-hydroxy-2-oxo-1-triazene (NOC-18) for 12 h. The changed protein patterns, which were separated by two-dimensional electrophoresis using pH gradients of 4-7, were conclusively identified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis of the peptide digests. RESULTS: Seventeen differentially expressed proteins were identified in NOC-18-treated cells. Nine proteins [vinculin protein, keratin 19, ubiquitous tropomodulin, F-actin capping protein (alpha1 subunit), tropomyosin 3, 26S proteasome-associated pad1 homolog, T-complex protein 1 (epsilon subunit) N(G)-dimethylarginine dimethylaminohydrolase, and heat shock protein 90] were increased and eight proteins (heat shock protein 70, glucosidase II, lamin B1, calreticulin, nucleophosmin 1, microtubule-associated protein retinitis pigmentosa/end binding family member 1, 150 kD oxygen-regulated protein precursor, and heat shock 70-related protein albino or pale green 2) were decreased by NOC-18 in the cells. Thirteen proteins are related to the suppression of cancer cell proliferation, invasion, and metastasis while two proteins (heat shock protein 90 and N(G)-dimethylarginine dimethylaminohydrolase) are related to carcinogenesis. The functions of 150 kD oxygen-regulated protein precursor and T-complex protein 1 (epsilon subunit) are unknown in relation to carcinogenesis. CONCLUSION: Most proteins differentially expressed by NOC-18 are involved in inhibiting cancer development.

The Peroxisome Proliferator-Activated Receptor delta Agonist, GW501516, Inhibits Angiogenesis through Dephosphorylation of Endothelial Nitric Oxide Synthase

OBJECTIVE: Peroxisome proliferator-activated receptor delta (PPAR-delta) is an ubiquitously expressed nuclear receptor that has been implicated in adipose tissue formation, brain development, and atherosclerosis. Despite mouse studies demonstrating that PPAR-delta activation has favorable anti-atherogenic properties by improving systemic lipid profiles, the relationship between PPAR-delta agonist and angiogenesis is unknown. We hypothesized that PPAR-delta ligands modulate the angiogenesis. METHODS: To test this hypothesis we treated primary cultures of bovine aortic endothelial cells with PPAR-delta specific ligand, GW501516 (50-800 nM) for 6 h. RESULTS: GW501516 dose-dependently decreased nitric oxide production without alteration in endothelial nitric oxide synthase (eNOS) expression. Analysis with phospho-specific antibodies against eNOS demonstrated that GW501516 significantly decreased the phosphorylation of eNOS at Serine1179 (eNOS-Ser1179). Concurrently, GW501516 also decreased the Akt phosphorylation. GW501516 did not affect endothelial cell proliferation or induce apoptosis. However, GW501516 inhibited endothelial cell migration, and tube formation in a high nanomolar concentration. The inhibition of endothelial cell tube formation by GW501516 was prevented by addition of the nitric oxide donor, DETA NONOate (5 microM). GW501516 was also found to inhibit angiogenesis in vivo in the chicken chorioallantoic membrane assay. CONCLUSION: These results provide that high nanomolar range of GW501516 inhibits angiogenesis by a mechanism involving dephosphorylation of eNOS-Ser1179.

Curcumin induces differentiation of embryonic stem cells through possible modulation of nitric oxide-cyclic GMP pathway

Curcumin, an active ingredient of dietary spice used in curry, has been shown to exhibit anti-oxidant, anti-inflammatory and anti-proliferative properties. Using EB directed differentiation protocol of H-9 human embryonic stem (ES) cells; we evaluated the effect of curcumin (0-20 μmol/L) in enhancing such differentiation. Our results using real time PCR, western blotting and immunostaining demonstrated that curcumin significantly increased the gene expression and protein levels of cardiac specific transcription factor NKx2.5, cardiac troponin I, myosin heavy chain, and endothelial nitric oxide synthase during ES cell differentiation. Furthermore, an NO donor enhanced the curcumin-mediated induction of NKx2.5 and other cardiac specific proteins. Incubation of cells with curcumin led to a dose dependent increase in intracellular nitrite to the same extent as giving an authentic NO donor. Functional assay for second messenger(s) cyclic AMP (cAMP) and cyclic GMP (cGMP) revealed that continuous presence of curcumin in differentiated cells induced a decrease in the baseline levels of cAMP but it significantly elevated baseline contents of cGMP. Curcumin addition to a cell free assay significantly suppressed cAMP and cGMP degradation in the extracts while long term treatment of intact cells with curcumin increased the rates of cAMP and cGMP degradation suggesting that this might be due to direct suppression of some cyclic nucleotide-degrading enzyme (phosphodiesterase) by curcumin. These studies demonstrate that polyphenol curcumin may be involved in differentiation of ES cells partly due to manipulation of nitric oxide signaling.

Fatores da dieta e tumores de cérebro / Dietary factors and brain tumors / Factores dietéticos y los tumores cerebrales

As hipóteses sobre a associação entre fatores da dieta e tumores de cérebro relacionam-se aos compostos N-nitroso como favorecedores do desenvolvimento desses tumores e ao papel de antioxidantes dietéticos atuando como protetores, através da inibição da nitrosação dos precursores dos compostos N -nitroso. O objetivo deste artigo é identificar fatores da dieta associados aos tumores primários de cérebro em indivíduos adultos (??20 anos). Trata-se de um estudo caso-controle de base populacional, realizado na Região Metropolitana de Salvador, estado da Bahia, Brasil. Foram realizadas análises de regressão logística para a estimativa das razões de chances ajustadas e respectivos intervalos de confiança a 95 porcento. Os resultados apontam uma associação inversa para o maior consumo de laticínios (OR igual 0,32; 95 porcento IC: 0,13 ? 0,80) e vitamina C (OR igual 0,34; 95 porcento IC: 0,13 ? 0,88) para todos os tumores de cérebro agrupados. Para os tumores não-astrocíticos o maior consumo de refrigerantes (OR igual 0,20; 95 porcento IC: 0,06 ? 0,63) demonstrou efeito protetor. Conclui-se que os fatores da dieta podem atuar de forma diferente entre os tumores de cérebro; o efeito protetor das vitaminas antioxidantes, especialmente a vitamina C, sugere que o maior consumo de legumes e frutas pode diminuir o risco para o desenvolvimento desses tumores.

The hypotheses about the association between dietary factors and brain tumors are related to N-nitroso compounds as promoters of development of these tumors and the role of dietary antioxidants acting as guards, through the inhibition of nitrosation of precursors of N-nitroso compounds.The aim of this paper is to identify dietary factors associated with primary brain tumors in adults (??20 years). This is a population-based case-control study conducted in the metropolitan area of Salvador,Bahia, Brazil. Logistic regression estimated adjusted odds ratios and confidence intervals at 95percent. Theresults indicate an inverse association for the highest intake of dairy products (OR equal 0.32, 95 percent CI: 0.13 - 0.80) and vitamin C (OR equal 0.34, 95 percent CI: 0.13 to 0.88) for all grouped brain tumors. For nonastrocytic tumors, the highest consumption of soft drinks (OR equal 0.20, 95 percent CI: 0.06 to 0.63) demonstrated a protective effect. It was concluded that dietary factors may act differently among brain tumors; the protective effect of antioxidant vitamins, especially vitamin C, suggests that a higher consumption of vegetables and fruits can reduce the risk of developing these tumors.

Las hipótesis sobre la asociación entre factores dietéticos y los tumores cerebrales están relacionadas con los compuestos N-nitroso como promotores del desarrollo de estos tumores y el papel de los antioxidantes dietéticos en calidad de protectores, a través de la inhibición de la nitrosación de los precursores de compuestos N-nitroso. El objetivo de este artículo es identificar los factores de la dieta asociados a los tumores primarios de cerebro en individuos adultos (??20 años). Se trata de un estudio caso-control de base en la población, llevado a cabo en el área metropolitana de Salvador, Bahia, Brasil. Se analizaron análisis mediante regresión logística para estimar razones de posibilidades ajustadas y los respectivos intervalos de confianza al 95 por ciento. Los resultados indican una asociación inversa para el mayor consumo de productos lácteos (OR igual 0,32, IC 95 por ciento: 0,13 a 0,80) y vitamina C (OR igual 0,34, IC 95por ciento: 0,13 a 0,88) de todos los tumores cerebrales agrupados. Para los tumores no Astrocíticos, el mayor consumo de refrescos (OR igual 0,20, IC 95 por ciento: 0,06 a 0,63) demostró un efecto protector. Se concluyó que los factores dietéticos pueden actuar de forma diferente entre los tumores cerebrales; el efecto protector de las vitaminas antioxidantes, especialmente vitamina C, sugiere que um mayor consumo de legumbres y frutas puede disminuir el riesgo de desarrollar estos tumores.

Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects (NTDs) in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China.</p><p><b>METHODS</b>Data were derived from a population based case-control study of major external birth defects in four counties of Shanxi Province. Participants included 519 NTDs cases identified between 2003 and 2007 and 694 healthy controls. Exposure information was collected within 1 week after delivery. Multivariable non-conditional Logistic regression model was used to estimate the adjusted odds ratio (OR) controlling for potential confounding variables.</p><p><b>RESULTS</b>The risk of NTDs was positively associated with the frequency of the consumption of pickled vegetables by the mother. Compared with pickled vegetables consumption at < 1 meal/week, the adjusted OR for consumption at 1 - 3, 4 - 6, and > 6 meals/week were 1.3 (95% confidence interval (CI): 1.0, 1.8), 1.9 (1.1, 3.2), and 3.6 (1.9, 6.9), respectively. A protective effect was found for maternal meat consumption at ≥ 1 meal/week (adjusted OR: 0.6, 95%CI: 0.4, 0.7) and egg or milk consumption at ≥ 1 meal/week (adjusted OR: 0.6, 95%CI: 0.4, 0.8).</p><p><b>CONCLUSION</b>Maternal periconceptional consumption of pickled vegetables may increase the risk for NTDs in Shanxi Province.</p>

Study on semi-synthetic transforming technology for the natural product of isocorydione / 药学学报

Transforming technology for semi-synthesized isocorydione from the natural product ofisocorydine was studied. The factors affecting on the reaction yield were investigated. UV spectrophotometry was used to indicate the semi-synthesized yield of isocorydione. The optimum reaction conditions were determined as following: reacting for 12 h in the solution of sodium dihydrogen phosphate at pH 10, the temperature was 25 degrees C and the ratio of isocorydine to Fremy's radical was 1 : 2. Under the optimum conditions, the yield could reach up to 50.0%. The molecular structure of isocorydione was elucidated by X-ray single-crystal diffraction analysis for the first time.

Dinâmicas de trânsito e degradação da fibra em detergente neutro em bovinos alimentados com forragem tropical de baixa qualidade e compostos nitrogenados / Transit and degradation dynamics of neutral detergent fiber in cattle fed low-quality tropical forage and nitrogenous compounds

Avaliaram-se as dinâmicas de trânsito e degradação da fibra em detergente neutro (FDN) em bovinos alimentados com forragem tropical de baixa qualidade e compostos nitrogenados. Foram utilizadas cinco novilhas Holandês x Zebu fistuladas no rúmen. A alimentação volumosa basal dos animais foi constituída por feno de capim-braquiária (Brachiaria decumbens Stapf.), com 5,08 por cento de proteína bruta (PB), com base na matéria seca (MS), fornecido ad libitum. Os cinco tratamentos avaliados foram definidos de acordo com o nível de suplementação proteica (0, 3, 5, 7 e 9 pontos percentuais acima do nível de PB da forragem). Como fonte de compostos nitrogenados, empregou-se mistura de ureia:sulfato de amônia:albumina (4,5:0,5:1,0). O experimento foi estruturado segundo delineamento em quadrado latino 5 x 5. Os níveis médios de PB nas dietas foram de 5,28; 8,08; 9,82; 11,87 e 13,63 por cento, com base na MS. Verificou-se elevação linear (P<0,05) da fração potencialmente degradável da FDN até o nível de 8,62 por cento de PB, com platô estimado de 47,92 por cento da FDN. Verificou-se efeito quadrático (P<0,05) sobre a taxa de degradação da fração potencialmente degradável da FDN em função dos níveis de PB da dieta, com máxima resposta estimada sobre 13,39 por cento de PB. O fluxo ruminal de partículas fibrosas apresentou relação linear-response-plateau em função do nível de PB na dieta (P<0,05), com ponto crítico para o início do platô sobre 7,59 por cento de PB.

Rumen transit and degradation dynamics of neutral detergent fiber (NDF) in cattle fed low-quality tropical forage and nitrogenous compounds were evaluated. Five crossbred heifers fitted with rumen cannulae were used. The animals were fed ad libitum with signal grass (Brachiaria decumbens Stapf.) hay, which had crude protein (CP) content of 5.08 percent in dry matter (DM). The five treatments were defined according to the level of CP in the diet (0, 3, 5, 7, and 9 percentile points above the CP level of the roughage). The supplement was a mixture of urea, ammonium sulfate, and albumin (4.5:0.5:1.0, respectively). The experiment was carried out according to a 5 x 5 Latin square design. The average CP levels in the diets were: 5.28, 8.08, 9.82, 11.87, and 13.63 percent in DM basis. The potentially degradable fraction of NDF was linearly increased (P<0.05) by CP levels in diet until 8.62 percent CP. From this point, there was stabilization of estimates (47.92 percent of NDF). The degradation rate of potentially degradable NDF showed a quadratic response (P<0.05) to CP levels, with maximal response at 13.39 percent of CP. The ruminal rate of passage of fibrous particles showed a linear-response-plateau (P<0.05) according to CP levels in the diet, with plateau beginning at 7.59 percent of CP.

Effects of ascorbic acid supplementation in ileum myenteric neurons of streptozotocin-induced diabetic rats / Efeitos da suplementação do ácido ascórbico nos neurônios mientéricos do íleo de ratos diabéticos induzidos por estreptozootocina

The exacerbation of the oxidative stress and of the polyol pathway which impair damage myenteric plexus are metabolic characteristics of diabetes. The ascorbic acid (AA) is an antioxidant and an aldose reductase inhibitor, which may act as neuroprotector. The effects of AA supplementation on the density and cellular body profile area (CP) of myenteric neurons in STZ-induced diabetes in rats were assessed. Four groups with five animals each were formed: normoglycemic (C); diabetic (D); AA-treated diabetic (DS) and AA-treated normoglycemic (CS). Dosagen of 50mg of AA were given, three times a week, for each animal (group DS and CS). Ninety days later and after euthanasia, the ileum was collected and processed for the NADPH-diaphorase technique. There were no differences (P>0.05) in the neuronal density among the groups. The CP area was lower (P<0.05) in the DS and CS groups, with a higher incidence of neurons with a CP area exceeding 200µm² for groups C and D. The AA had no influence on the neuronal density in the ileum but had a neuroprotective effect, preventing the increase in the CP area and allowing a higher number of neurons with a CP area with less than 200µm².

A exacerbação do estresse oxidativo e da via do poliol que comprometem o plexo mioentérico são alterações metabólicas características do diabetes. O ácido ascórbico (AA) é antioxidante e inibidor da aldose redutase, podendo atuar como neuroprotetor. Verificaram-se os efeitos da suplementação com AA sobre o número e a área do perfil do corpo celular (PC) de neurônios mioentéricos em ratos diabéticos induzidos por estreptozootocina. Formaram-se quatro grupos com cinco animais cada: normoglicêmico (C); diabético (D); diabético tratado com AA (DS); e normoglicêmico tratado com AA (CS). Três vezes por semana administrou-se 50mg de AA para cada animal (grupos DS e CS). Após 90 dias e eutanásia com tiopental, o íleo foi coletado e processado para a técnica da NADPH-diaforase. Não se observaram diferenças (P>0,05) na densidade neuronal entre os grupos. A área do PC foi menor (P<0,05) para os grupos DS e CS, com incidência maior de neurônios com área do PC superior a 200µm² para os grupos C e D. Concluiu-se que o AA não influenciou a densidade neuronal do íleo, mas foi neuroprotetor prevenindo o aumento na área do PC e possibilitando maior incidência de neurônios com área de PC inferior a 200µm².

Effects of Radix Ginseng and Radix Ophiopogonis extract (SMF) on protein S-nitrosylation in ischemic myocardial tissue / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of Radix Ginseng and Radix Ophiopogonis extract (SMF) on protein S-nitrosylation in rats myocardial with ischemia/reperfusion injury (MI/RI).</p><p><b>METHOD</b>Myocardial ischemia/reperfusion in rats were produced by occlusion of the left anterior descending coronary artery. To study the cardioprotective effects of SMF on the acute MI/RI rats, the serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), and nitric oxide (NO) were determined. The change of the expression of endothelial nitric oxide synthase (eNOS) was detected by Western blot. The content of related S-nitrosylation proteins in myocardial tissue was measured by Biotin-Switch method.</p><p><b>RESULT</b>SMF significantly decreased the serum levels of CK and LDH as well as increased the serum levels of NO and the expression of eNOS in myocardial tissue. The contents of S-nitrosylation proteins were significantly increased from (4.42 +/- 0.60) micromol x g(-1) to (8.78 +/- 1.37) micromol x g(-1). The molecular weight of the majority S-nitrosylation proteins were in the range of 90 x 10(3)-117 x 10(3).</p><p><b>CONCLUSION</b>Increased expression of eNOS and NO induced by SMF may activate S-nitrosylation of many proteins in rat hearts. The change of the activities or functions of those proteins by S-nitrosylation may be an important mechanism for myocardial protective effects of SMF.</p>

Estudo do efeito da S-nitroso-N-acetilcisteína na lesão de isquemia/reperfusão em fígado esteatótico de ratos / Study of S-nitroso-N-acetylcysteine effect on ischemia/reperfusion lesion in steatotic livers of rats

INTRODUÇÃO: A esteatose é a doença hepática crônica mais frequente na população. Seus efeitos lesivos hepáticos podem adicionar-se aos efeitos da isquemia e reperfusão (I/R) nos transplantes de fígado e cirurgias hepáticas. Em ambos, o estresse oxidativo e o dano na microcirculação são importantes fatores na gênese da lesão hepática. Vários antioxidantes já foram testados em modelos experimentais de esteatose e I/R e mostraram benefício, entre eles a N-acetilcisteína (NAC). O óxido nítrico (NO) tem efeito controverso sobre a lesão de I/R, entretanto em baixas doses pode ser benéfico à microcirculação hepática. A S-nitroso-Nacetilcisteína (SNAC) fornece a NAC e também NO. Esta droga foi testada mostrando benefício em modelos experimentais de esteatose e I/R de músculo esquelético. Contudo, ainda não foi testada na lesão de I/R em fígados esteatáticos. MÉTODOS: Foram estudados 34 ratos machos Wistar divididos em 4 grupos: grupo I (n=8) - sem esteatose tratados com solução salina; grupo II (n=8) - sem esteatose tratados com SNAC; grupo III (n=9) - com esteatose tratados com solução salina; grupo IV (n=9) - com esteatose tratados com SNAC. A indução da esteatose foi realizada com dieta aproteica. Os animais foram submetidos a isquemia hepática parcial (70%) por um período de 1 hora e um período de reperfusão de 4 horas. A droga foi administrada por via intraperitoneal. Foram avaliados histologia, respiração mitocondrial e estresse oxidativo (MDA) hepáticos, transaminases séricas e mieloperoxidase e extravasamento do corante azul de Evans pulmonares. RESULTADOS: Não houve diferença entre os grupos I e II em todas as variáveis avaliadas (histologia, função mitocondrial (RCR e ADP/O), transaminases (AST e ALT), azul de Evans e mieloperoxidase pulmonares), encontrando-se apenas uma tendência a menor estresse oxidativo (MDA) (p = 0,07) no fígado isquêmico do grupo tratado (grupo II)...

Steatosis is the most frequent chronic liver disease in general population. Steatosis can make ischemia/reperfusion (I/R) lesions worse in liver transplants and hepatic surgeries. Oxidative stress and hepatic microcirculatory damage are related to generation of steatosis and I/R lesions. Several antioxidant drugs, for example the N-acetylcysteine (NAC), have been already used in steatotic and I/R experimental models, and showed better outcome in treated groups. The nitric oxide (NO) has controversial effects on I/R, however, in low doses it can improve hepatic microcirculation. The S-nitroso-N-acetylcysteine (SNAC) releases NAC and NO. It ameliorated oxidative stress in experimental models of steatosis and skeletal muscle I/R. In contrast, this drug has never been used in steatotic liver I/R. METHODS: thirty four male Wistar rats were studied and divided in four groups: group I (n=8) - without steatosis and treated with saline solution; group II (n=8) - without steatosis and treated with SNAC; group III (n=9) - with steatosis and treated with saline solution; group IV (n=9) - with steatosis treated with SNAC. Aproteic diet was used for steatosis induction. The animals underwent a partial hepatic ischemia (70%) for 1 hour and reperfusion for 4 hours. The drug was administrated intraperitoneally. The parameters evaluated were hepatic histology, mitochondrial respiration and oxidative stress (MDA), seric transaminasis and pulmonary mieloperoxidasis and Evans blue extravasation. RESULTS: There were not any difference between groups I and II in all parameters evaluated (histology, mithocondrial function (RCR and ADP/O), transaminasis (AST and ALT), pulmonary Evans blue extravasation and mieloperoxidasis), and it showed only tendency of less oxidative stress (MDA) (p=0,07) in ischemic liver of treated group (group II). The comparison between groups III...

Level of nitrate and nitrite contents in drinking water of selected samples received at AFPGMI, Rawalpindi

Contamination of drinking water by nitrates is an evolving public health concern since nitrate can undergo endogenous reduction to nitrite and nitrosation of nitrites can form N-nitroso compounds, which are potent carcinogens. The carcinogenic feature of N-nitroso compounds has been well established. Nitrites can lead among infants to the disease called methemoglobinemia [blue baby syndrome]. There is a strong relationship between nitrate concentration and recurrent diarrhoea and also other illnesses. The aim of this study was to evaluate the level of nitrate and nitrite contents in some drinking water samples. In this study we analysed 162 water samples received at Water Quality Control Laboratory, AFPGMI, Rawalpindi for their nitrate and nitrite contents. Out of these 162 water samples, 153 [94%] and 133 [82%] samples had nitrate and nitrite contents in varying concentrations, while 64 [40%] and 22 [14%] had nitrate and nitrite concentrations more than Pakistani standards. Given the potential health risk associated with the presence of toxicants like nitrates and nitrites in water sources used for drinking yet the scarcity of available data, there is a need to evaluate these waters and develop strategies to reduce and prevent their contamination

Microbiota do megaesôfago e carcinogênese / Megaesophagus microbiota and carcinogenesis

INTRODUÇAO: O risco de desenvolvimento de carcinoma esofágico em portadores de megaesôfago é 33 vezes superior ao da populaçäo em geral. Possível explicaçäo para este fenômeno poderia estar relacionada à produçäo de compostos N-nitrosos na luz do órgäo, a partir da transformaçäo de nitratos da dieta em nitritos, mediada por bactérias em suspensäo no líquido de estase e com o contato crônico destes carcinógenos com a mucosa esofágica. OBJETIVO: Analisar a microbiota esofágica em pacientes portadores de megaesôfago de etiologia chagásica, com especial atençäo para a presença de bactérias com capacidade de reduçäo de nitratos. CASUíSTICA: Foram estudados prospectivamente 15 pacientes portadores de megaesôfago chagásico com idades variando de 28 a 73 anos, sendo 9 do sexo feminino e 6 do sexo masculino, que foram divididos em 3 grupos iguais de 5, de acordo com o grau de dilataçäo do esôfago, segundo a classificaçäo de Rezende et al. (Grau I, Grau II e Grau III). MÉTODO: A coleta do líquido de estase para estudo microbiológico era realizada através de sonda de Levine nº 14, que era passada pela boca, por dentro de uma cânula de intubaçäo orotraqueal nº 7,5, mantendo-se sua extremidade escondida, a fim de evitar sua contaminaçäo. RESULTADOS: Foram obtidas 93,3 por cento de culturas positivas com grande variedade de microrganismos e predomínio de aeróbios Gram-positivos e anaeróbios. As concentrações de microrganismos foram tanto maiores, quanto maior o grau de dilataçäo do esôfago. Entre os microrganismos encontrados, o Staphylococcus sp, Corynebacterium sp, Peptostreptococcus sp e a Veillonella sp foram aqueles identificados como tendo a capacidade de reduçäo de nitratos a nitritos. CONCLUSÄO: No megaesôfago chagásico há bactérias na luz do órgäo com capacidade de reduçäo de nitratos da dieta, passo importante na produçäo de compostos N-nitrosos.

Exposure level of total N-nitroso compounds in residents of high-and low-risk areas for esophageal cancer in southern / 中华预防医学杂志

<p><b>OBJECTIVE</b>To assess the exposure level of total N-nitroso compounds (TNOCs) in the residents of high- and low-risk areas for esophageal cancer in southern China.</p><p><b>METHODS</b>Samples of duplicate plate diets and 12 hr overnight urine were collected from 120 male adults in each of the 2 areas, a high-risk area (Nanao county) and a low-risk area (Lufeng county) for esophageal cancer. The 240 male healthy subjects (35 - 64 years old) were selected by a 3-stage random cluster sampling procedure. Levels of TNOC, N-nitrosamino acids (NAAs) and volatile N-nitroso compounds (VNOC) in the samples were measured by Thermo Energy Analyzer.</p><p><b>RESULTS</b>The detectable rate (95%) of diet TNOC, daily dietary TNOC intake (4.25 +/- 0.84) micromol/day, 12-hr urinary TNOC excretion levels (1.76 +/- 0.23 ng/12 h) and daily dietary intake of VNOC (266 +/- 31.2 microg/day) in the high-risk area were all significantly higher than those of the low-risk area. Oesophageal cancer mortality rates were positively and significantly associated with daily dietary TNOC intake and 12-hr urinary TNOC excretion. Urinary NAAs excretion levels were not different in the two areas.</p><p><b>CONCLUSION</b>The results suggest that TNOCs may be implicated in the etiology of esophageal cancer in southern China.</p>

Associaçäo entre fatores da dieta e tumores de cérebro em adultos: uma revisäo da literatura / Association between dietary factors and brain tumors in adults: a review

Desenvolveu-se uma revisäo da literatura científica publicada entre 1986 e 1999, sobre a associaçäo entre fatores da dieta e os tumores de cérebro em adultos, com o objetivo de descrever as associaçöes observadas e discutir os aspectos metodológicos que possam influenciar os resultados observados. De um modo geral, os estudos revisados parecem apontar na direçäo de uma associaçäo moderada entre os fatores da dieta e os tumores de cérebro; há evidências de que o consumo de compostos N-nitroso possa favorecer o desenvolvimento desses tumores, e de que o consumo de vegetais e frutas pode ter papel na sua inibiçäo. A participaçäo dos respondentes substitutos nos estudos analisados, pode ter introduzido viés de memória nas informaçöes levantadas e contribuído para a inconsistência dos achados. As investigaçöes epidemiológicas sobre a associaçäo da dieta com estes tumores devem considerar a análise de outros fatores alimentares, além dos compostos N-nitroso. É necessário precisar os períodos de exposiçäo que devem ser investigados e contar com criteriosa metodologia, de modo a prevenir a ocorrência de tendenciosidades relacionadas com a seleçäo dos controles e minimizar os efeitos do viés de memória.

Dieta e fatores ambientais associados aos tumores de cérebro em adultos: um estudo caso-controle no Rio de Janeiro / Diet and environmental factors associated to the tumors of brain in adults

Os tumores do cérebro vêm ganhando importância devido ao aparente aumento da sua incidência e por sua alta letalidade. Nao está, ainda, esclarecido se a elevaçao das taxas de tumores cerebrais é reflexo da modificaçao do risco de desenvolver a doença, ou se é conseqüência da melhoria dos métodos de diagnóstico, porque, apesar dos avanços na pesquisa epidemiológica e de genética molecular, a etiologia dos tumores de cérebro permanece desconhecida. A investigaçao da associaçao entre fatores da dieta e tumores de cérebro tem considerado os compostos N-nitroso como favorecedores do desenvolvimento desses tumores e as vitaminas C e E atuando como protetores. Desenvolve-se na Regiao Metropolitana do Rio de Janeiro um estudo caso-controle de base hospitalar com o objetivo de determinar a magnitude da associaçao entre fatores de risco ambientais e os tumores de cérebro em adultos. Sao definidos como casos indivíduos de 30-65 anos, residentes na mesma regiao, internados em hospitais específicos com tumor primário de cérebro. Os controles sao indivíduos internados nas mesmas instituiçoes, pareados por sexo e freqüencia de idade, residentes na mesma área, excluídos os que tiverem diagnóstico de câncer ou de nosologias que tenham os componentes da dieta entre os seus fatores de risco. Para a obtençao dos dados utiliza-se um questionário com questoes referentes à exposiçao a fatores de risco diversos como campos eletromagnéticos, exposiçoes ocupacionais, radiaçao ionizante; defensivos agrícolas, contato com animais uso de tabaco, álcool e medicamentos, antecedents familiares de câncer, história de traumatismo craniano e os padroes de alimentaçao na adolescência e no ano anterior ao diagnóstico. Explora algumas questoes mais relevantes que emergem no estudo da epidemiologia dos tumores de cérebro, particularmente, os métodos empregados na avaliaçao do papel que os fatores da dieta exercem no desenvolvimento destes tumores.

Chelation behaviour of some lanthanide [III], scandium [III], yttrium [III], thorium [IV] and uranium [VI] complexes with some hydroxy nitrosocoumarins

The stability constants of the lanthanide ions [La, Ce, Pr, Nd, Sm, Gd, Dy, Er and Yb]; Sc, Y, Th and UO22+ ions with some hydroxy nitrosocoumarins were determined in 40% ethanol-water mixture at 25 degree and 0.1 ionic strength. It was found that the stability constants of the complexes increased with increasing ionic radii, from Y to Sm. The so called Gadolinium break was observed with heavier lanthanides. Sc and Th complexes possessed the highest stability constants. The potentiometric measurements and conductimetric titrations showed that 1: 1 and 1: 2 [M: L] complexes were invariably formed

Spectral studies of complexes of some trivalent transition metals with isonitrosodibenzoylmethane and isonitrosothiodibenzoylmethane

The complexes of isonitrosodibenzoylmethane and isonitrosothiodibenzoylmethane with Cr [III], Fe [III] and Go [III] were synthesized and analytically characterized. In terms of the IR and Nujol Mull Spectra of the respective chelates, the mode of bonding and the stereochemistry of the investigated systems were discussed

Teor de nitrito residual, e ocorrência de compostos n-nitrosos em produtos curados de carne comercializados em Recife PE / Nitrite level and presence of N-nitroso compounds in meat industrialized products in the supermarkets in Recife

O nível de nitrito residual foi determinado em 17 produtos curados de carne obtidos em supermercados e indústrias de Recife-Pe. A determinaçäo do nível de nitrito residual nos produtos obtidos nos supermercados, mostraram que todos obedeciam os limites estipulados pela Legislaçäo Brasileira e Internacional (nível máximo de nitrito de sódio detectado 62,4 ppm). O nível de nitrito destes produtos também foram determinados durante 28 dias a 5oC. Neste período foi observada uma diminuiçäo geral nos níveis de nitrito acima de 90 por cento. Seis produtos foram analisados para verificar a presença de compostos N-nitrosos dos quais quatro apresentaram reaçäo positiva para estes compostos

La exposición exógena y endógena a los compuestos N-nitroso: necesidad de prevención en América Latina / Exogenous and endogenous exposure to N-nitroso compounds: need of its prevention in Latin America

Se discuten algunos resultados científicos actualizados y la posible significación de la exposición exógena y endógena a los compuestos N-nitroso; se analizan las limitaciones para la evaluación y el control de este problema, y se señala la necesidad de acometer algunas tareas relacionadas en los países de América Latina