RESUMEN
Studies evaluating the crude protein (CP) supplementation strategies across the year for grazing cattle and its association with the enzymes involved in the urea cycle and muscle and mammary gland developments are scarce. Thus, we aimed to evaluate the effect of supplementation with different levels of CP on the expression of genes involved in the urea cycle and muscle and mammary gland development of Holstein × Gyr crossbreed heifers grazing intensively managed Brachiaria decumbens throughout the year. Thirty-eight heifers with average initial BW of 172.5 ± 11.15 kg (mean ± SE) and 8.2 ± 0.54 mo of age were randomly assigned to 1 of 4 treatments: 3 protein supplements (SUP) fed at 5g/kg of body weight, plus a control group (CON, non-supplemented animals). The supplement CP levels evaluated were: 12, 24, and 36%. The study was divided into 4 seasons: rainy, dry, rainy-dry transition (RDT), and dry-rainy transition (DRT). On the penultimate day of each season, ultrasound images of the carcass and mammary gland were taken. Five animals from each treatment were randomly chosen on the last day of each season, and liver and muscle tissue biopsies were performed. The target genes were the mammalian target of rapamycin (mTOR) and adenosine monophosphate-activated protein kinase (AMPK) in the muscle samples. Carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), argininosuccinate synthetase (ASS), arginosuccinate lyase (ASL), and arginase (ARG) were evaluated in the liver samples. Data were analyzed using PROC GLIMMIX of the SAS with repeated measures. We observed a greater rib eye area (cm2) and fat thickness (mm) in SUP animals than in non-supplemented animals. However, we did not observe differences among SUP levels for both variables. No effects of supplementation were detected on mammary gland development. Nevertheless, seasonal effects were observed, where the RDT and dry season had the most and least accumulated fat in the mammary gland. In muscle, we observed greater expression of AMPK in non-supplemented animals than SUP animals. On the other hand, no differences were observed in gene expression between SUP and non-supplemented animals and among SUP animals for mTOR. Season affected both AMPK and mTOR; heifers had a greater AMPK gene expression on rainy than RDT. For mTOR, we observed greater gene expression in RDT and DRT than in rainy. No differences were observed among RDT, dry, and DRT, and between dry and rainy seasons for mTOR. We observed greater CPS, ASL, and ARG gene expression in SUP animals than in non-supplemented animals. Among SUP animals, supplement CP linearly affected CPS. In conclusion, the supplementation strategy did not affect mammary gland development and mTOR expression in muscle tissue. However, we observed a seasonal effect on mammary gland development and AMPK and mTOR expression. The CP supplementation increased the rib eye area and fat thickness, directly affecting AMPK expression in the muscle. Moreover, the CP supplementation increased urea cycle enzyme expression, indicating greater urea production in the liver.
Asunto(s)
Proteínas Quinasas Activadas por AMP , Suplementos Dietéticos , Bovinos , Animales , Femenino , Músculos , Urea , Serina-Treonina Quinasas TOR , Alimentación Animal/análisis , Dieta/veterinaria , MamíferosRESUMEN
Nitrate can be a source of NPN for microbial growth at the same time that it reduces ruminal methane production. The objective of this study was to evaluate the effects of 2 encapsulated nitrate products used as urea replacers on blood and rumen constituents, methane emission, and growth performance of lambs. Eighteen Santa Inês male lambs (27 ± 4.9 kg) were individually allotted to indoor pens and assigned to a randomized complete block design with 6 blocks and 3 dietary treatments: control (CTL) = 1.5% urea, ENP = 4.51% encapsulated nitrate product (60.83% NO3(-) in the product DM), and ENP+CNSL = 4.51% ENP containing cashew nut shell liquid (60.83% NO3(-) and 2.96% cashew nut shell liquid [CNSL] in the product DM). Diets were isonitrogenous with 60:40 concentrate:forage (Tifton 85 hay) ratio. The experiment lasted for 92 d and consisted of 28 d for adaptation (a weekly 33% stepwise replacement of CTL concentrate by nitrate-containing concentrates) and 64 d for data collection. The ENP and ENP+CNSL showed greater (P < 0.05) red blood cell counts than CTL. Blood methemoglobin (MetHb) did not differ (P > 0.05) among treatments, with mean values within normal range and remaining below 1.1% of total hemoglobin. There was an increase (P < 0.05) in total short-chain fatty acids concentration at 3 h postfeeding for ENP, with an additional increase (P < 0.05) observed for ENP+CNSL. No treatment effects (P > 0.05) were observed on acetate to propionate ratio. Methane production (L/kg DMI) was reduced (P < 0.05) with nitrate inclusion, recording 28.6, 19.1, and 19.5 L/kg DMI for CTL, ENP, and ENP+CNSL, respectively. Addition of CNSL did not result (P > 0.05) in further reduction of methane production when compared with ENP. Final BW, DMI, ADG, and feed efficiency were similar (P > 0.05) among treatments. Values for DMI were 1.11, 1.03, and 1.04 kg/d and for ADG were 174, 154, and 158 g for CTL, ENP, and ENP+CNSL, respectively. In conclusion, encapsulated nitrate products showed no risks of toxicity based on MetHb formation. The products persistently reduced methane production without affecting performance. Inclusion of cashew nut shell liquid in the product formulation had no additional benefits on methane mitigation.
Asunto(s)
Anacardium , Metano/metabolismo , Nitratos/farmacología , Extractos Vegetales/farmacología , Rumen/química , Ovinos/crecimiento & desarrollo , Alimentación Animal/análisis , Animales , Dieta/veterinaria , Masculino , Nitratos/química , Extractos Vegetales/química , Ovinos/sangre , Ovinos/metabolismoAsunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Terapia Neoadyuvante , Adulto , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Quimioterapia Adyuvante , Cisplatino/administración & dosificación , Docetaxel , Femenino , Fluorouracilo/administración & dosificación , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Taxoides/administración & dosificaciónRESUMEN
The effects of chromium picolinate (CrPic) oral supplementation on the performance and ruminal protozoa population in sheep was investigated. Twenty-four male lambs were treated with four different levels of CrPic: placebo, 0.250, 0.375 and 0.500mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Feed intake was measured three times a week. Lambs were weighed every 2 weeks. Ruminal content was sampled five times during the trial to quantify ruminal protozoa. No difference (p>0.05) between treatments was recorded for any parameter measured: initial and final mean body weight, dry matter intake, daily gain and total body weight gain. There was a negative linear relationship between Cr supplementation and protozoa count (p=0.0013) with no additional decrease when CrPic supplemental levels were higher than 0.375mg/day. Therefore, Cr supplementation must be carried out carefully and more studies need to address stressed animals or possible toxic effects of Cr in the animal itself or to the ruminal protozoa population.
Asunto(s)
Ácidos Picolínicos/farmacología , Rumen/fisiología , Rumen/parasitología , Ovinos/crecimiento & desarrollo , Alimentación Animal , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , MasculinoRESUMEN
A espécie Cymbopogon citratus, conhecida como capim-limão, é amplamente utilizada popularmente para fins medicinais e tem o uso nas indústrias farmacêuticas, alimentícias, de cosméticos e perfumaria. Devido à necessidade de conhecimentos específicos na área de pré-processamento, o presente trabalho tem a finalidade de equacionar e analisar alguns aspectos da secagem, que permitam prever as alterações na qualidade do produto. Folhas da referida espécie foram submetidas a cortes em diferentes comprimentos e à secagem em diferentes temperaturas. Aos dados experimentais, ajustaram-se diferentes equações para a modelagem das curvas de secagem. Realizaram-se também avaliações do produto seco, referentes à cor e ao teor do óleo essencial. Os resultados evidenciam que o modelo de Page Modificado é o que melhor se ajusta aos dados experimentais. A temperatura de 50ºC mostrou-se a mais indicada para a secagem da espécie, resultando em produto com menor perda do óleo essencial e maior preservação da cor verde.
The species Cymbopogon citratus, known as lemon grass, is widely used for medicinal purpose and in the pharmaceutical, food, cosmetic and perfumery industries. Due to the need for more specific knowledge of pre-processing management, this work aims to equate and analyze some drying aspects that allow preview the product quality alterations. The leaves from this species were cut at different lengths and dried at different temperatures. Different equations for modeling the drying curves were adjusted to the experimental data. The dried product was also evaluated for color and essential oil content. The results showed that the Modified Page model resulted in the best adjustment for the experimental data. The temperature of 50°C was the best for drying the species leaves, resulting in less essential oil loss and higher green color maintenance.
Asunto(s)
Cymbopogon , Conservación de Alimentos/métodos , /análisis , Análisis de Varianza , Color , Calorimetría , Aceites Volátiles , Plantas MedicinalesRESUMEN
In the time period January 1998-December 2000, a case-control study on squamous cell cancer of the oesophagus was conducted in Montevideo, Uruguay. The main objective of the study was to estimate the odds ratios (ORs) associated with main food groups. For this purpose, 166 patients afflicted with squamous cell oesophageal cancer and 664 hospitalised controls were frequency matched on age and sex. Both series of patients were administered with a structured questionnaire. Aside from queries related with tobacco smoking, alcohol drinking and maté drinking, patients were interviewed with a food-frequency questionnaire (FFQ) on 64 items, representative of the usual Uruguayan diet. Red meat, salted meat and boiled meat displayed strong direct associations (OR for red meat 2.4, 95% CI 1.4-4.2). On the other hand, fish and total white meat showed moderate protective effect (OR for total white meat 0.5, 95% CI 0.3-0.9). Total fruit intake displayed a strong inverse association (OR 0.2, 95% CI 0.1-0.4), whereas total vegetable consumption presented a weak inverse association (OR for total vegetable intake 0.7, 95% CI 0.4-1.2). These results suggest that vegetables, mainly cooked vegetables, are rich in thermolabile protective substances. On the other hand, boiled (stewed) meat, which is ingested at high temperature could be, like maté, a risk factor for squamous cell cancer of the oesophagus.
Asunto(s)
Carcinoma de Células Escamosas/epidemiología , Neoplasias Esofágicas/epidemiología , Conducta Alimentaria , Alimentos , Adulto , Anciano , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas , Carcinoma de Células Escamosas/etiología , Carcinoma de Células Escamosas/prevención & control , Estudios de Casos y Controles , Neoplasias Esofágicas/etiología , Neoplasias Esofágicas/prevención & control , Femenino , Frutas , Humanos , Masculino , Carne , Persona de Mediana Edad , Oportunidad Relativa , Plantas Comestibles , Plantas Medicinales , Factores de Riesgo , Fumar/efectos adversos , Encuestas y Cuestionarios , Nicotiana , Uruguay/epidemiología , VerdurasRESUMEN
Individuals with atrophic gastritis (n = 863) were recruited to participate in a chemoprevention trial in Nariño, Columbia. The volunteers were randomly assigned to intervention therapies, which included antibiotic treatment for Helicobacter pylori infection, and then daily dietary supplementation with antioxidant micronutrients in a 2(3) factorial design. Biopsies were obtained according to a specified protocol from designated areas in the stomach for each individual at baseline (before intervention therapy), at year 3, and at year 6. A systematic sample of 160 participants was selected from each of the eight treatment combinations, and the first exon of KRAS was examined for mutations. At year 3, the data indicated that individuals with KRAS mutations in their baseline premalignant stomach biopsies were 3.74 times as likely to progress to a higher premalignant stage than those who lacked baseline mutations (P = 0.04; C. Gong et al., Cancer Epidemiol. Biomark. Prevy. 8:167-171, 1999). However, after 6 years, baseline KRAS mutations failed to predict histological progression. Also, KRAS mutation in 72-month biopsies did not predict histological progression.
Asunto(s)
Gastritis Atrófica/complicaciones , Genes ras/genética , Marcadores Genéticos , Lesiones Precancerosas/genética , Antioxidantes/uso terapéutico , Biopsia , Transformación Celular Neoplásica , Análisis Mutacional de ADN , Progresión de la Enfermedad , Humanos , Valor Predictivo de las Pruebas , Neoplasias Gástricas/prevención & controlRESUMEN
OBJECTIVE: Our purpose was to find out if morphometric techniques can document long term changes in gastric antral atrophy after curing Helicobacter pylori infection with or without dietary supplementation with antioxidant micronutrients. METHODS: Study subjects were 132 adult volunteers from a Colombian region with high gastric cancer rates. Participants were randomly assigned to ascorbic acid, beta-carotene, and anti-H. pylori treatment, following a factorial design. Gastric biopsies were obtained at baseline and after 72 months of intervention. Atrophy was evaluated by a standard visual analog scale and by morphometry. RESULTS: Statistically significant changes in antral atrophy were detected with morphometric techniques after intervention in subjects who received anti-H. pylori treatment. A nonsignificant trend was also observed with visual scores. This effect was greater among those who were free of infection at the end of the trial. After accounting for the effect of anti-H. pylori treatment, no significant effect was noted for dietary supplementation with ascorbic acid and/or beta-carotene. CONCLUSIONS: We conclude that gastric atrophy improves significantly after long term control of H. pylori infection. This effect can be demonstrated both by conventional histological grading and by morphometry.
Asunto(s)
Antibacterianos/uso terapéutico , Ácido Ascórbico/uso terapéutico , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/patología , Helicobacter pylori , Antro Pilórico/patología , beta Caroteno/uso terapéutico , Adulto , Anciano , Atrofia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
BACKGROUND: Previous research has identified a high risk of gastric carcinoma as well as a high prevalence of cancer precursor lesions in rural populations living in the province of Nariño, Colombia, in the Andes Mountains. METHODS: A randomized, controlled chemoprevention trial was conducted in subjects with confirmed histologic diagnoses of multifocal nonmetaplastic atrophy and/or intestinal metaplasia, two precancerous lesions. Individuals were assigned to receive anti-Helicobacter pylori triple therapy and/or dietary supplementation with ascorbic acid, beta-carotene, or their corresponding placebos. Gastric biopsy specimens taken at baseline were compared with those taken at 72 months. Relative risks of progression, no change, and regression from multifocal nonmetaplastic atrophy and intestinal metaplasia were analyzed with multivariate polytomous logistic regression models to estimate treatment effects. All statistical tests were two-sided. RESULTS: All three basic interventions resulted in statistically significant increases in the rates of regression: Relative risks were 4.8 (95% confidence interval [CI] = 1.6-14.2) for anti-H. pylori treatment, 5. 1 (95% CI = 1.7-15.0) for beta-carotene treatment, and 5.0 (95% CI = 1.7-14.4) for ascorbic acid treatment in subjects with atrophy. Corresponding relative risks of regression in subjects with intestinal metaplasia were 3.1 (95% CI = 1.0-9.3), 3.4 (95% CI = 1.1-9.8), and 3.3 (95% CI = 1.1-9.5). Combinations of treatments did not statistically significantly increase the regression rates. Curing the H. pylori infection (which occurred in 74% of the treated subjects) produced a marked and statistically significant increase in the rate of regression of the precursor lesions (relative risks = 8.7 [95% CI = 2.7-28.2] for subjects with atrophy and 5.4 [95% CI = 1.7-17.6] for subjects with intestinal metaplasia). CONCLUSIONS: In the very high-risk population studied, effective anti-H. pylori treatment and dietary supplementation with antioxidant micronutrients may interfere with the precancerous process, mostly by increasing the rate of regression of cancer precursor lesions, and may be an effective strategy to prevent gastric carcinoma.
Asunto(s)
Antibacterianos/uso terapéutico , Antioxidantes/uso terapéutico , Ácido Ascórbico/uso terapéutico , Gastritis Atrófica/tratamiento farmacológico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/efectos de los fármacos , Lesiones Precancerosas/tratamiento farmacológico , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/prevención & control , Estómago/patología , beta Caroteno/uso terapéutico , Adulto , Anciano , Biopsia , Transformación Celular Neoplásica , Progresión de la Enfermedad , Quimioterapia Combinada , Femenino , Gastritis Atrófica/sangre , Gastritis Atrófica/microbiología , Gastritis Atrófica/patología , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/patología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/sangre , Lesiones Precancerosas/patología , Remisión Espontánea , Riesgo , Estómago/microbiología , Neoplasias Gástricas/sangre , Neoplasias Gástricas/patología , Resultado del TratamientoRESUMEN
Eight hundred sixty-three subjects with atrophic gastritis were recruited to participate in an ongoing chemoprevention trial in Nariño, Colombia. The participants were randomly assigned to intervention therapies, which included treatment to eradicate Helicobacter pylori infection followed by daily dietary supplementation with antioxidant micronutrients in a 2 x 2 x 2 factorial design. A series of biopsies of gastric mucosa were obtained according to a specified protocol from designated locations in the stomach for each participant at baseline (before intervention therapy) and at year three. A systematic sample of 160 participants was selected from each of the eight treatment combinations. DNA was isolated from each of these biopsies (n = 320), and the first exon of KRAS was amplified using PCR. Mutations in the KRAS gene were detected using denaturing gradient gel electrophoresis and confirmed by sequence analysis. Of all baseline biopsies, 14.4% (23 of 160) contained KRAS mutations. Among those participants with atrophic gastritis without metaplasia, 19.4% (6 of 25) contained KRAS mutations, indicating that mutation of this important gene is likely an early event in the etiology of gastric carcinoma. An important association was found between the presence of KRAS mutations in baseline biopsies and the progression of preneoplastic lesions. Only 14.6% (20 of 137) of participants without baseline KRAS mutations progressed from atrophic gastritis to intestinal metaplasia or from small intestinal metaplasia to colonic metaplasia; however, 39.1% (9 of 23) with baseline KRAS mutations progressed to a more advanced lesion after 3 years [univariate odds ratio (OR), 3.76 (P = 0.05); multivariate OR adjusted for treatment, 3.74 (P = 0.04)]. In addition, the specificity of the KRAS mutation predicted progression. For those participants with G-->T transversions at position 1 of codon 12 (GGT-->TGT), 19.4% (5 of 17) progressed (univariate OR, 2.4); however, 60.0% (3 of 5) of participants with G-->A transitions at position 1 of codon 12 (GGT-->AGT) progressed (univariate OR, 8.7; P = 0.004 using chi2 test).
Asunto(s)
Gastritis Atrófica/patología , Genes ras/genética , Mutación/genética , Lesiones Precancerosas/patología , Neoplasias Gástricas/patología , Análisis de Varianza , Antioxidantes/uso terapéutico , Biopsia , Transformación Celular Neoplásica/genética , Quimioprevención , Codón/genética , ADN/análisis , ADN/genética , Suplementos Dietéticos , Progresión de la Enfermedad , Exones/genética , Femenino , Estudios de Seguimiento , Predicción , Mucosa Gástrica/patología , Gastritis Atrófica/genética , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Humanos , Masculino , Metaplasia , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Mutación Puntual/genética , Lesiones Precancerosas/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/prevención & controlRESUMEN
BACKGROUND: Cangshan County of Shandong Province has one of the lowest rates of gastric cancer (GC) in China. While intestinal metaplasia (IM) and dysplasia (DYS) are less common in Cangshan than in areas of Shandong at high risk of GC, these precursor lesions nevertheless affect about 20% of adults age > or = 55. SUBJECTS AND SETTING: In order to evaluate determinants of IM and DYS in Cangshan County, a low risk area of GC a survey was conducted among 214 adults who participated in a gastroscopic screening survey in Cangshan County in 1994. METHOD: A dietary interview and measurement of serum Helicobacter pylori antibodies were performed. RESULTS: The prevalence of H. pylori was lowest (19%) among those with normal gastric mucosa, rising steadily to 35% for superficial gastritis (SG), 56% for chronic atrophic gastritis (CAG), 80% for IM, and 100% for DYS. The prevalence odds of precancerous lesions were compared with the odds of normal histology or SG. The odds ratio (OR) or CAG associated with H. pylori positivity was 4.2 (95% confidence interval [CI] : 1.7-10.0), while the OR of IM/DYS associated with H. pylori positivity was 31.5 (95% CI: 5.2-187). After adjusting for H. pylori infection, drinking alcohol was a risk factor for CAG (OR = 3.2, 95% CI: 1.1-9.2) and IM/DYS (OR = 7.8, 95% CI: 1.3-47.7). On the other hand, consumption of garlic showed non-significant protective effects and an inverse association with H. pylori infection. CONCLUSIONS: The findings of this study suggest that infection with H. pylori is a risk factor and garlic may be protective, in the development and progression of advanced precancerous gastric lesions in an area of China at relatively low risk of GC.
Asunto(s)
Ajo/uso terapéutico , Infecciones por Helicobacter/complicaciones , Helicobacter pylori , Fitoterapia , Plantas Medicinales , Lesiones Precancerosas/prevención & control , Neoplasias Gástricas/prevención & control , Adulto , Anticuerpos Antibacterianos/análisis , China/epidemiología , Ensayo de Inmunoadsorción Enzimática , Femenino , Gastroscopía , Infecciones por Helicobacter/terapia , Helicobacter pylori/inmunología , Humanos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/epidemiología , Lesiones Precancerosas/etiología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Población Rural , Neoplasias Gástricas/epidemiología , Neoplasias Gástricas/etiología , Encuestas y CuestionariosRESUMEN
To examine whether dietary fiber modifies breast cancer risk, a case-control study involving 351 newly diagnosed patients with breast cancer and 356 hospitalized controls was conducted in Uruguay. Dietary patterns were assessed in detail by use of a food frequency questionnaire on 64 items, which allowed the calculation of total energy intake. Nutrient residuals were calculated through regression analysis. After adjustment for potential confounders (which included age, residence, family history of breast cancer, prior history of benign breast disease, parity, total energy, red meat, lutein/zeaxanthin and quercetin intake, and menopausal status), dietary fiber and total nonstarch polysaccharides were associated with a strong reduction in risk of breast cancer (odds ratio for uppermost quartile of total dietary fiber = 0.51, 95% confidence limit = 0.31-0.82). Also the dose-response pattern was highly significant (p < 0.001). The inverse association was observed in pre- and post-menopausal women and was similar for soluble and insoluble fiber. Furthermore, dietary fiber displayed a strong joint effect with fat, quercetin, and lutein/zeaxanthin.
Asunto(s)
Neoplasias de la Mama/prevención & control , Fibras de la Dieta/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Grasas de la Dieta/administración & dosificación , Fibras de la Dieta/administración & dosificación , Femenino , Frutas , Humanos , Luteína/administración & dosificación , Persona de Mediana Edad , Quercetina/administración & dosificación , Factores de Riesgo , Uruguay , Verduras , Xantófilas , Zeaxantinas , beta Caroteno/administración & dosificación , beta Caroteno/análogos & derivadosRESUMEN
Helicobacter pylori infection is a known risk factor for gastric cancer. We hypothesized that H. pylori infection would lead to the sustained production of the reactive nitrogen species nitric oxide and peroxynitrite as part of the host immune response. We further hypothesized that H. pylori infection would lead to increased apoptosis of gastric epithelial cells, possibly in response to free radical-mediated DNA damage. Using immunohistochemistry, we stained and scored gastric antral biopsies from 84 Colombian patients with nonatrophic gastritis before and after treatment for H. pylori infection. We examined expression of inducible nitric oxide synthase (iNOS); nitrotyrosine, a marker for peroxynitrite; and DNA fragmentation, a marker for apoptosis. Patients were treated with triple therapy (amoxicillin, 500 mg three times a day for 2 weeks; metronidazole, 400 mg three times a day for 2 weeks; and bismuth subsalicylate, 262 mg four times a day for 2 weeks, followed by 262 mg every day for 4-12 months). Eradication of H. pylori infection resulted in a significant reduction in iNOS and nitrotyrosine staining and a marginally significant reduction in apoptosis. Dietary supplementation with beta-carotene (30 mg every day for 4-12 months) resulted in a significant decrease in iNOS staining. Supplementation with ascorbic acid (1 g twice a day for 4-12 months) led to a significant reduction in nitrotyrosine staining. In patients supplemented with either ascorbic acid or beta-carotene, there was a trend toward a reduction in apoptosis, but this was not statistically significant. We conclude that H. pylori infection is accompanied by the formation of endogenous reactive nitrogen intermediates, which may contribute to DNA damage and apoptosis. In addition to antimicrobial therapy, dietary supplementation with beta-carotene and ascorbic acid may prevent the formation of these potential carcinogens.
Asunto(s)
Apoptosis , Gastritis/metabolismo , Infecciones por Helicobacter/metabolismo , Óxido Nítrico Sintasa/biosíntesis , Tirosina/análogos & derivados , Antibacterianos/uso terapéutico , Biomarcadores , Biopsia , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Humanos , Técnicas para InmunoenzimasRESUMEN
The effect of canthaxanthin (CX), a nonprovitamin A carotenoid, on gastric epithelial proliferation was studied in ferrets colonized with Helicobacter mustelae, which causes a chronic gastritis and an increased gastric epithelial cell proliferation. Seven spayed female ferrets were dosed by gavage with CX beadlets (50 mg/kg body wt, 5 d/wk) over 2 y, whereas seven control animals were given placebo beadlets. At the end of the 2-y-period, ferrets were killed, and gastric tissues were obtained from the antrum and body regions. A cell-proliferating biomarker, proliferating cell nuclear antigen (PCNA), was assayed by immunohistochemistry. The PCNA positivity was measured by a computer-based image analysis system. Serum concentrations of carotenoids, retinoids and tocopherols were analyzed by HPLC. Serum antioxidant status was measured by the oxygen radical absorbance capacity (ORAC) assay. The PCNA positivity in both antrum and body regions was not significantly different between CX-fed ferrets and controls. Serum CX concentrations were significantly higher in CX-fed ferrets vs. controls (P < 0.001), whereas levels of other carotenoids, retinoids and tocopherols were not significantly different. The ORAC values were not significant different between groups. This study does not suggest inhibitory effects of CX on gastric epithelial cell proliferation in H. mustelae infected ferrets.
Asunto(s)
Antioxidantes/farmacología , Cantaxantina/farmacología , Infecciones por Helicobacter/patología , Estómago/citología , Estómago/microbiología , Animales , Cantaxantina/sangre , División Celular/efectos de los fármacos , División Celular/fisiología , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Células Epiteliales , Epitelio/química , Epitelio/microbiología , Femenino , Hurones , Helicobacter/aislamiento & purificación , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Oxígeno/sangre , Antígeno Nuclear de Célula en Proliferación/análisis , Estómago/química , Factores de TiempoRESUMEN
Conflicting reports of the effects of beta-carotene supplementation on serum alpha-tocopherol concentration led us to evaluated serum alpha-tocopherol in subjects with and without beta-carotene (30 mg/day) supplementation for up to 2 years duration in an ongoing chemoprevention trial. No adverse effect has been observed at any of the time periods examined.
Asunto(s)
Antineoplásicos/uso terapéutico , Carotenoides/uso terapéutico , Neoplasias Gástricas/prevención & control , Vitamina E/sangre , Adulto , Anciano , Dieta , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias Gástricas/sangre , beta CarotenoRESUMEN
Clinical observations in patients with X-linked hypophosphataemic rickets, that bone changes can be corrected during puberty, suggest that androgen can participate actively in the process of bone mineralization. In the present study we investigated the role of testosterone on the bone mineralization of male rats placed on a low phosphorus and vitamin D diet and kept in complete darkness after weaning. After 15 days the animals presented hypophosphataemia, rickets and osteomalacia, as assessed by histomorphometry of the tibia and seventh caudal vertebra calcification fronts respectively. Testosterone propionate administration for five days, while the animals were kept on the same rachitogenic diet, induced an improvement in the bone mineralization process of the hypophosphataemic rat independently of serum phosphate levels. Testosterone-treated rats were cured of rickets but not of osteomalacia, despite the reduction in osteoid seam area.
Asunto(s)
Calcificación Fisiológica/efectos de los fármacos , Fosfatos/sangre , Fósforo/deficiencia , Testosterona/farmacología , Animales , Desarrollo Óseo , Huesos/patología , Cartílago/patología , Oscuridad , Dieta , Placa de Crecimiento/patología , Hipofosfatemia Familiar/fisiopatología , Masculino , Osteomalacia/etiología , Osteomalacia/patología , Ratas , Ratas Endogámicas , Raquitismo/etiología , Raquitismo/patología , Raquitismo/fisiopatología , Deficiencia de Vitamina DRESUMEN
A case-control study of bladder cancer involving interviews with 111 incident cases and 222 controls was carried out in Montevideo, Uruguay. The analysis was conducted separately for each sex. Point estimates of relative risk associated with smoking variables, ingestion of infusions of the herb Ilex paraguariensis (maté), and selected dietary items were obtained by stratified and logistic regression analysis. Among men, smokers of black tobacco showed a relative risk (RR) 2.7 higher than blond tobacco smokers and maté exposure showed a significant dose-response, after adjustment for age, residence, social class, hospital, type of tobacco, smoking intensity, smoking duration, and vegetable consumption, with a seven-fold increase in risk for heavy consumers. Joint exposure to type of tobacco and maté consumption showed a multiplicative effect. Women showed a similar increase in risk with maté consumption. The results suggest that the high mortality rates of bladder cancer observed in Uruguay could be explained by the combined effect of black tobacco smoking and maté ingestion.
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Fumar/efectos adversos , Té/efectos adversos , Neoplasias de la Vejiga Urinaria/etiología , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Factores de Riesgo , Tasa de Supervivencia , Neoplasias de la Vejiga Urinaria/epidemiología , Neoplasias de la Vejiga Urinaria/mortalidad , Uruguay/epidemiologíaAsunto(s)
Fabaceae/toxicidad , Metilnitronitrosoguanidina/toxicidad , Plantas Medicinales , Sodio en la Dieta/farmacología , Cocarcinogénesis , Neoplasias Gastrointestinales/inducido químicamente , Humanos , Pruebas de Mutagenicidad , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Sodio en la Dieta/efectos adversosRESUMEN
New studies continue to examine the puzzle of pancreatic cancer, and the results to date have provided us with clues but no clear answers other than the detrimental effects of tobacco. Many of those clues, however, are promising, particularly with regard to diet. It is hoped that in the future better dietary assessment methods will help sort out the complicated, but important, contribution of diet.
Asunto(s)
Neoplasias Pancreáticas/epidemiología , Alcoholismo/complicaciones , Café/efectos adversos , Estudios de Cohortes , Dieta/efectos adversos , Exposición a Riesgos Ambientales , Humanos , Enfermedades Profesionales , Neoplasias Pancreáticas/etiología , Factores de Riesgo , Fumar/efectos adversos , Té/efectos adversos , Estados UnidosRESUMEN
The work reported here examined the effects of smoking cigarettes made predominantly of dark tobacco, alcohol consumption, and coffee drinking upon the risk of developing cancers of the bladder, larynx, lung, and oral cavity/hypopharynx in Medellín, Colombia. For this purpose 439 subjects with newly diagnosed cancers at the indicated sites were selected. Each subject was then matched by age, sex, and socioeconomic status with at least one control. Data from interviews with the selected subjects, upon analysis, showed both the intensity and duration of cigarette smoking to be statistically significant predictors of cancer at all four sites. In addition, heavy alcohol consumption and coffee drinking in excess of seven cups daily were associated with some elevation of cancer risk at most of the sites studied. Multivariate analyses of cigarette smoking, alcohol consumption, and coffee drinking showed that adjustment for coffee and alcohol consumption did not change the observed associations between elevated cancer risks and cigarette smoking. However, adjustment of the coffee and alcohol consumption data for cigarette smoking reduced most of the observed relative risks of coffee and alcohol consumption and eliminated the statistical significance of certain associations.