39 resultados para Subsites


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Survival statistics from the incident cases of the Vaud Cancer Registry over the period 1974-1980 were computed on the basis of an active follow-up based on verification of vital status as to December 31, 1984. Product-moment crude and relative 5 to 10 year rates are presented in separate strata of sex, age and area of residence (urban or rural). Most of the rates are comparable with those in other published series from North America or Europe, but survival from gastric cancer (24% 5-year relative rates) tended to be higher, and that from bladder cancer (about 30%) lower than in most other datasets. No significant difference in survival emerged according to residence in urban Lausanne vs surrounding (rural) areas. Interesting indications according to subsite (higher survival for the pyloric region vs the gastric fundus, but absence of substantial differences for various colon subsites), histology (higher rates for squamous carcinomas of the lung, seminomas of the testis or chronic lymphatic leukemias as compared with other histotypes), or site of origin (higher survival for lower limb melanomas), require further quantitative assessment from other population-based series. A Cox proportional hazard model applied to melanomatous skin cancers showed an independent favorable effect on long-term prognosis of female gender and adverse implications for advanced age, stage at diagnosis and tumor site other than lower limb.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The U.S. Environmental Protection Agency (EPA) is completing a third five-year review of the E.I. du Pont de Nemours & Co., Inc., County Road X-23 Superfund site in Lee County, Iowa. The site is also known as the Baier and McCarl subsites. The EPA is inviting public comment on whether the current site remedy continues to be protective of public health and the environment. The Iowa Department of Public Health in cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to review the current status of the Baier and McCarl subsites and to provide an evaluation of the public health status of these subsites. The information in this health consultation was current at the time of writing. Data that emerges later could alter this docum ent’s conclusions and recommendations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE: To provide information on the effects of alcohol and tobacco on laryngeal cancer and its subsites. METHODS: This was a case-control study conducted between 1992 and 2000 in northern Italy and Switzerland. A total of 527 cases of incident squamous-cell carcinoma of the larynx and 1297 hospital controls frequency-matched with cases on age, sex, and area of residence were included. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using multiple logistic regression. RESULTS: In comparison with never smokers, ORs were 19.8 for current smokers and 7.0 for ex-smokers. The risk increased in relation to the number of cigarettes (OR = 42.9 for > or = 25 cigarettes/day) and for duration of smoking (OR = 37.2 for > or = 40 years). For alcohol, the risk increased in relation to number of drinks (OR = 5.9 for > or = 56 drinks per week). Combined alcohol and tobacco consumption showed a multiplicative (OR = 177) rather than an additive risk. For current smokers and current drinkers the risk was higher for supraglottis (ORs 54.9 and 2.6, respectively) than for glottis (ORs 7.4 and 1.8) and others subsites (ORs 10.9 and 1.9). CONCLUSIONS: Our study shows that both cigarette smoking and alcohol drinking are independent risk factors for laryngeal cancer. Heavy consumption of alcohol and cigarettes determined a multiplicative risk increase, possibly suggesting biological synergy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Evidence of associations between single nutrients and head and neck cancer (HNC) is still more limited and less consistent than that for fruit and vegetables. However, clarification of the protective mechanisms of fruit and vegetables is important to our understanding of HNC etiology. We investigated the association between vitamin C intake from natural sources and cancer of the oral cavity/pharynx and larynx using individual-level pooled data from ten case-control studies (5,959 cases and 12,248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. After harmonization of study-specific exposure information via the residual method, adjusted odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using unconditional multiple logistic regression models on quintile categories of 'non-alcohol energy-adjusted' vitamin C intake. In the presence of heterogeneity of the estimated ORs among studies, we derived those estimates from generalized linear mixed models. Higher intakes of vitamin C were inversely related to oral and pharyngeal (OR = 0.54, 95% CI: 0.45-0.65, for the fifth quintile category versus the first one, p for trend<0.001) and laryngeal cancers (OR = 0.52, 95% CI: 0.40-0.68, p for trend = 0.006), although in the presence of heterogeneity among studies for both sites. Inverse associations were consistently observed for the anatomical subsites of oral and pharyngeal cancer, and across strata of age, sex, education, body mass index, tobacco, and alcohol, for both cancer sites. The inverse association of vitamin C intake from foods with HNC may reflect a protective effect on these cancers; however, we cannot rule out other explanations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Evidence for the possible effect of vitamin E on head and neck cancers (HNCs) is limited. METHODS: We used individual-level pooled data from 10 case-control studies (5959 cases and 12 248 controls) participating in the International Head and Neck Cancer Epidemiology (INHANCE) consortium to assess the association between vitamin E intake from natural sources and cancer of the oral cavity/pharynx and larynx. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models applied to quintile categories of nonalcohol energy-adjusted vitamin E intake. RESULTS: Intake of vitamin E was inversely related to oral/pharyngeal cancer (OR for the fifth vs the first quintile category=0.59, 95% CI: 0.49-0.71; P for trend <0.001) and to laryngeal cancer (OR=0.67, 95% CI: 0.54-0.83, P for trend <0.001). There was, however, appreciable heterogeneity of the estimated effect across studies for oral/pharyngeal cancer. Inverse associations were generally observed for the anatomical subsites of oral and pharyngeal cancer and within covariate strata for both sites. CONCLUSION: Our findings suggest that greater vitamin E intake from foods may lower HNC risk, although we were not able to explain the heterogeneity observed across studies or rule out certain sources of bias.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

SCOPE: Only a few studies analyzed the role of allium vegetables with reference to head and neck cancers (HNC), with mixed results. We investigated the potential favorable role of garlic and onion within the International Head and Neck Cancer Epidemiology (INHANCE) Consortium. METHODS AND RESULTS: We analyzed pooled individual-level data from eight case-control studies, including 4590 cases and 7082 controls. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between garlic and onion intakes and HNC risk. Compared with no or low garlic use, the ORs of HNC were 0.95 (95% CI 0.71-1.27) for intermediate and 0.74 (95% CI 0.55-0.99) for high garlic use (p for trend = 0.02). The ORs of HNC for increasing categories of onion intake were 0.91 (95% CI 0.68-1.21) for >1 to ≤3 portions per week, and 0.83 (95% CI 0.60-1.13) for >3 portions per week (p for trend = 0.02), as compared to <1 portion per week. We found an inverse association between high onion intake and laryngeal cancer risk (OR = 0.69; 95% CI 0.54-0.88), but no significant association for other subsites. CONCLUSIONS: The results of this pooled-analysis support a possible moderate inverse association between garlic and onion intake and HNC risk. This article is protected by copyright. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) is considered to be a distinct clinical entity with better prognosis than the classical tobacco- and alcohol-associated tumors. The increasing incidence of this neoplasia during the last decades highlights the need to better understand the role of HPV in the development of these cancers. Although the proportion of HNSCC attributed to HPV varies considerably according to anatomical site, overall approximately 25% of all HNSCC are HPV-DNA positive, and HPV-16 is by far the most prevalent type. In this review we discuss the existing evidence for a causal association between HPV infection and HNSCC at diverse anatomical head and neck subsites.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Insect chymotrypsins are distinctively sensitive to plant protein inhibitors, suggesting that they differ in subsite architecture and hence in substrate specificities. Purified digestive chymotrypsins from insects of three different orders were assayed with internally quenched fluorescent oligopeptides with three different amino acids at P1 (Tyr, Phe, and Leu) and 13 amino acid replacements in positions P1`, P2, and P3. The binding energy (Delta G(s), calculated from Km values) and the activation energy (Delta G(T)(double dagger), determined from k(cat)/K-m values) were calculated. The hydrophobicities of each subsite were calculated from the efficiency of hydrolysis of the different amino acid replacements at that subsite. The results showed that except for S1, the other subsites (S2, S3, and S1`) vary among chymotrypsins. This result contrasts with insect trypsin data that revealed a trend along evolution, putatively associated with resistance to plant inhibitors. In spite of those differences, the data suggested that in lepidopteran chymotrypsins S2 and S1` bind the substrate ground state, whereas only S1` binds the transition state, supporting aspects of the present accepted mechanism of catalysis. 2008 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The inhibition of human cysteine cathepsins B, L, S and K was evaluated by a set of hypervalent tellurium compounds (telluranes) comprising both organic and inorganic derivatives. All telluranes studied showed a time-and concentration-dependent irreversible inhibition of the cathepsins, and their second-order inactivation rate constants were determined. The organic derivatives were potent inhibitors of the cathepsins and clear specificities were detected, which were parallel to their known substrate specificities. In all cases, the activity of the tellurane-inhibited cathepsins was recovered by treatment of the inactivated enzymes with reducing agents. The maximum stoichiometry of the reaction between cysteine residues and telluranes were also determined. The presented data indicate that it is possible to design organic compounds with a tellurium(IV) moiety as a novel warhead that covalently modifies the catalytic cysteine, and which also form strong interactions with subsites of cathepsins B, L, S and K, resulting in more specific inhibition.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A thrombin-like enzyme, named BjussuSP-I, isolated from Bothrops jararacussu snake venom, is an acidic single-chain glycoprotein with M-r = 61,000, pI similar to 3.8 and 6% sugar. BjussuSP-I shows high proteolytic activity upon synthetic substrates, such as S-2238 and S-2288. It also shows procoagulant and kallikrein-like activity, but is unable to act on platelets and plasmin. These activities are inhibited by specific inhibitors of this class of enzymes. The complete cDNA sequence of BjussuSP-I with 696 bp encodes open reading frames of 232 amino acid residues, which conserve the common domains of thrombin-like serine proteases. BjussuSP-I shows a high structural homology with other thrombin-like enzymes from snake venoms where common amino acid residues are identified as those corresponding to the catalytic site and subsites S1, S2 and S3 already reported. In this study, we also demonstrated the importance of N-linked glycans, to improve thrombin-like activity of BjussuSP-I toxin. (c) 2007 Elsevier Masson SAS. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose of this work was to purify a protease from Penicillium waksmanii and to determine its biochemical characteristics and specificity. The extracellular protease isolated that was produced by P. waksmanii is a serine protease that is essential for the reproduction and growth of the fungus. The protease isolated showed 32 kDa, and has optimal activity at pH 8.0 and 35 C towards the substrate Abz-KLRSSKQ-EDDnp. The protease is active in the presence of CaCl2, KCl, and BaCl, and partially inhibited by CuCl2, CoCl2 and totally inhibited by AlCl3 and LiCl. In the presence of 1 M urea, the protease remains 50 % active. The activity of the protease increases 60 % when it is exposed to 0.4 % nonionic surfactant-Triton X-100 and loses 10 % activity in the presence of 0.4 % Tween-80. Using fluorescence resonance energy transfer analysis, the protease showed the most specificity for the peptide Abz-KIRSSKQ-EDDnp with k cat/K m of 10,666 mM-1 s-1, followed by the peptide Abz-GLRSSKQ-EDDnp with a k cat/K m of 7,500 mM -1 s-1. Basic and acidic side chain-containing amino acids performed best at subsite S1. Subsites S2, S3, S′ 2, and S′ 1, S ′ 3 showed a preference for binding for amino acids with hydrophobic and basic amino acid side chain, respectively. High values of k cat/K m were observed for the subsites S2, S3, and S′ 2. The sequence of the N-terminus (ANVVQSNVPSWGLARLSSKKTGTTDYTYD) showed high similarity to the fungi Penicillium citrinum and Penicillium chrysogenum, with 89 % of identity at the amino acid level. © 2012 Springer Science+Business Media New York.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Metagenomics has been widely employed for discovery of new enzymes and pathways to conversion of lignocellulosic biomass to fuels and chemicals. In this context, the present study reports the isolation, recombinant expression, biochemical and structural characterization of a novel endoxylanase family GH10 (SCXyl) identified from sugarcane soil metagenome. The recombinant SCXyl was highly active against xylan from beechwood and showed optimal enzyme activity at pH 6,0 and 45°C. The crystal structure was solved at 2.75 Å resolution, revealing the classical (β/α)8-barrel fold with a conserved active-site pocket and an inherent flexibility of the Trp281-Arg291 loop that can adopt distinct conformational states depending on substrate binding. The capillary electrophoresis analysis of degradation products evidenced that the enzyme displays unusual capacity to degrade small xylooligosaccharides, such as xylotriose, which is consistent to the hydrophobic contacts at the +1 subsite and low-binding energies of subsites that are distant from the site of hydrolysis. The main reaction products from xylan polymers and phosphoric acid-pretreated sugarcane bagasse (PASB) were xylooligosaccharides, but, after a longer incubation time, xylobiose and xylose were also formed. Moreover, the use of SCXyl as pre-treatment step of PASB, prior to the addition of commercial cellulolytic cocktail, significantly enhanced the saccharification process. All these characteristics demonstrate the advantageous application of this enzyme in several biotechnological processes in food and feed industry and also in the enzymatic pretreatment of biomass for feedstock and ethanol production. © 2013 Alvarez et al.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)