Synthesis of 1H-benzoxazine-2,4-diones from heterocyclic anhydrides: evaluation of antioxidant and antimicrobial activities

A facile one-step synthesis of 1H-benzoxazine-2,4-diones from heterocyclic anhydrides and TMSA was described. This paper determines their antimicrobial activity against nine human bacterial pathogens by the broth microdilution method; antioxidant activity by DPPH• inactivation and a ferric-reducing power assay; and toxicity by a brine shrimp, Artemia salina, assay. The 1H-benzoxazine-2,4-dione yields were in the range of 57 to 98%. The novel compound 1H-pyrazino[2,3-][1,3]oxazine-2,4-dione 4c showed the highest antioxidant capacity (DPPH 35.4% and FRAP 0.063 µmol TEs/µmol).

Potentiometric determination of Nickel (II) ion using 2-hydroxy-1-naphthylidene-N-cyanoacetohydrazone as electroactive material

A potentiometric Nickel sensor was prepared using 2-hydroxy-1-naphthylidene-N-cyanoacetohydrazone as electro-active material and epoxy resin as a binding material. A membrane composed of 40% Schiff's base and 60% epoxy resin exhibited the best performance. The membrane showed excellent response in the concentration range of 0.15 ppm to 0.1 mol L- 1 Ni+2 ions with non-Nernstian slope of 22.0 mV/decade, had a rapid response time (less than 10 s), and can be used for three months without any considerable loss of potential. The sensor was useful within the pH range of 1.3 to 9.6, and was able to discriminate between Ni2+ and a large number of alkaline earth and transition metal ions. The practical utility of the sensor has been demonstrated by using it successfully as an indicator electrode in the potentiometric titration of Ni2+ with EDTA and oxalic acid.

UTILIZAÇÃO DO COMPÓSITO NANOESTRUTURADO SIO2/TIO2NA FOTODEGRADAÇÃO DE CORANTES TÊXTEIS COM LUZ SOLAR NATURAL

SiO2/TiO2 nanostructured composites with three different ratios of Si:Ti were prepared using the sol-gel method. These materials were characterized using energy dispersive X-ray fluorescence, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence, Raman with Fourier transform infrared spectroscopy, and the specific surface area. The band gaps of materials were determined by diffuse reflectance spectra, and the values of 3.20 ± 0.01, 2.92 ± 0.02, and 2.85 ± 0.01 eV were obtained as a result of the proportional increases in the amount of Ti within the composite. The materials exhibit only the anatase (TiO2) crystalline phase and have crystalline domains ranging from 4 to 5 nm. The photodegradation process of methylene blue, royal blue GRL, and golden yellow GL dyes were studied with respect to their contact times, pH variations within the solution, and the variations in the dye concentration of the solution in response to only sunlight. The maximum amount of time for the mineralization of dyes was 90 min. The kinetics of the process follows an apparently first order model, in which the obtained rate constant values were 5.72 × 10-2 min-1 for methylene blue, 6.44 × 10-2min-1 for royal blue GRL, and 1.07 × 10-1min-1 for golden yellow.

Biosynthesis of Yersinia enterocolitica serotype O:3 lipopolysaccharide outer core

Lipopolysacharide (LPS) present on the outer leaflet of Gram-negative bacteria is important for the adaptation of the bacteria to the environment. Structurally, LPS can be divided into three parts: lipid A, core and O-polysaccharide (OPS). OPS is the outermost and also the most diverse moiety. When OPS is composed of identical sugar residues it is called homopolymeric and when it is composed of repeating units of oligosaccharides it is called heteropolymeric. Bacteria synthesize LPS at the inner membrane via two separate pathways, Lipid A-core via one and OPS via the other. These are ligated together in the periplasmic space and the completed LPS molecule is translocated to the surface of the bacteria. The genes directing the OPS biosynthesis are often clustered and the clusters directing the biosynthesis of heteropolymeric OPS often contain genes for i) the biosynthesis of required NDP-sugar precursors, ii) glycosyltransferases needed to build up the repeating unit, iii) translocation of the completed O-unit to the periplasmic side of the inner membrane (flippase) and iv) polymerization of the repeating units to complete OPS. The aim of this thesis was to characterize the biosynthesis of the outer core (OC) of Yersinia enterocolitica serotype O:3 (YeO3). Y. enterocolitica is a member of the Gram-negative Yersinia genus and it causes diarrhea followed sometimes by reactive arthritis. The chemical structure of the OC and the nucleotide sequence of the gene cluster directing its biosynthesis were already known; however, no experimental evidence had been provided for the predicted functions of the gene products. The hypothesis was that the OC biosynthesis would follow the pathway described for heteropolymeric OPS, i.e. a Wzy-dependent pathway. In this work the biochemical activities of two enzymes involved in the NDP-sugar biosynthesis was established. Gne was determined to be a UDP-N-acetylglucosamine-4-epimerase catalyzing the conversion of UDP-GlcNAc to UDP-GalNAc and WbcP was shown to be a UDP-GlcNAc- 4,6-dehydratase catalyzing the reaction that converts UDP-GlcNAc to a rare UDP-2-acetamido- 2,6-dideoxy-d-xylo-hex-4-ulopyranose (UDP-Sugp). In this work, the linkage specificities and the order in which the different glycosyltransferases build up the OC onto the lipid carrier were also investigated. In addition, by using a site-directed mutagenesis approach the catalytically important amino acids of Gne and two of the characterized glycosyltranferases were identified. Also evidence to show the enzymes involved in the ligations of OC and OPS to the lipid A inner core was provided. The importance of the OC to the physiology of Y. enterocolitica O:3 was defined by determining the minimum requirements for the OC to be recognized by a bacteriophage, bacteriocin and monoclonal antibody. The biological importance of the rare keto sugar (Sugp) was also shown. As a conclusion this work provides an extensive overview of the biosynthesis of YeO3 OC as it provides a substantial amount of information of the stepwise and coordinated synthesis of the Ye O:3 OC hexasaccharide and detailed information of its properties as a receptor.

Indicadores de Prognóstico em Câncer de Mama com Axila Negativa: Receptor de Estrógeno e Expressão de P53 e de c-erbB-2

Objetivo: avaliar o valor prognóstico do receptor de estrógeno e da expressão das proteínas p53 e c-erbB-2 no câncer de mama com axila negativa. Métodos: foi realizado estudo imuno-histoquímico em material incluido em parafina, do arquivo do Instituto de Pesquisas Cito-Oncológicas (IPCO) da Fundação Faculdade Federal de Ciências Médicas de Porto Alegre (FFFCMPA), de 50 casos de câncer de mama sem comprometimento dos linfonodos axilares, em mulheres menopausadas, tratadas na Irmandade da Santa Casa de Porto Alegre (ISCMPA) e no Hospital Santa Rita de Porto Alegre (HSR) de janeiro 1990 a dezembro de 1994. Para análise estatística foram utilizados os testes de c² com correção de Yates, teste exato de Fisher e curvas de sobrevida pelo método de Kaplan-Meier comparados pelo teste log rank. O seguimento médio das pacientes foi de 3,6 anos (3,1-4,5). Dos 50 casos, 14 apresentaram recidiva no período observado. Resultados: a média de idade foi 61 anos (variação de 46 a 78 anos). A mastectomia radical modificada (MRM) foi realizada em 35 pacientes (70%) e 15 (30%) foram submetidas a setorectomia com esvaziamento axilar e posterior radioterapia. Metade das pacientes que apresentaram recidiva apresentaram-na nos três primeiros anos após o diagnóstico. O tamanho médio do tumor foi 2,8 cm (1,98-3,13) e o tipo histológico mais freqüente foi o carcinoma ductal infiltrante de tipo histológico não-especial (92%), conforme a graduação histológica de Bloom e Richardson, sendo 3 grau I (6,6%), 35 grau II (76%) e 8 grau III (17,4%); nos tumores que recidivaram não houve nenhum grau I, 9 (25,7%) eram grau II e 3 (37,5%) eram grau III. Em relação ao prognóstico, a taxa de intervalo livre de doença foi menor quando da associação de tumor pouco diferenciado (grau III) com receptor de estrógeno negativo (p = 0,006), p53 positivo (p = 0,006) e c-erbB-2 positivo (p = 0,001). Conclusão: mulheres menopausadas com câncer de mama sem comprometimento dos linfonodos axilares tem pior prognóstico, em relação ao intervalo livre de doença, quando apresentam associação de tumor pouco diferenciado com RE negativo, p53 positivo e c-erbB-2 positivo.

Anxiolytic-like effects of 4-phenyl-2-trichloromethyl-3H-1,5-benzodiazepine hydrogen sulfate in mice

The pharmacological effects of 4-phenyl-2-trichloromethyl-3H-1,5-benzodiazepine hydrogen sulfate (PTMB), a novel synthetic benzodiazepine, were examined in mice. In the elevated plus-maze test of anxiety, 0.3-1 mg/kg diazepam ip (F(3,53) = 3.78; P<0.05) and 1-10 mg/kg PTMB ip increased (F(5,98) = 3.26; P<0.01), whereas 2 mg/kg picrotoxin ip decreased (F(3,59) = 8.32; P<0.001) the proportion of time spent in the open arms, consistent with an anxiolytic action of both benzodiazepines, and an anxiogenic role for picrotoxin. In the holeboard, 1.0 mg/kg diazepam ip increased (F(3,54) = 2.78; P<0.05) and 2 mg/kg picrotoxin ip decreased (F(3,59) = 4.69; P<0.01) locomotor activity. Rotarod assessment revealed that 1 mg/kg diazepam ip and 3, 10 and 30 mg/kg PTMB ip produced significant motor incoordination compared to vehicle control (F(4,70) = 7.6; P<0.001). These data suggest that the recently synthesized PTMB compound possesses anxiolytic activity and produces motor incoordination similar to those observed with diazepam.

Gliclazide and bedtime insulin are more efficient than insulin alone for type 2 diabetic patients with sulfonylurea secondary failure

To determine the effects of combined therapy of gliclazide and bedtime insulin on glycemic control and C-peptide secretion, we studied 25 patients with type 2 diabetes and sulfonylurea secondary failure, aged 56.8 ± 8.3 years, with a duration of diabetes of 10.6 ± 6.6 years, fasting plasma glucose of 277.3 ± 64.6 mg/dl and a body mass index of 27.4 ± 4.8 kg/m². Patients were submitted to three therapeutic regimens lasting 2 months each: 320 mg gliclazide (phase 1), 320 mg gliclazide and bedtime NPH insulin (phase 2), and insulin (phase 3). At the end of each period, glycemic and C-peptide curves in response to a mixed meal were determined. During combined therapy, there was a decrease in all glycemic curve values (P<0.01). Twelve patients (48%) reached fasting plasma glucose <140 mg/dl with a significant weight gain of 64.8 kg (43.1-98.8) vs 66.7 kg (42.8-101.4) (P<0.05), with no increase in C-peptide secretion or decrease in HbA1. C-Peptide glucose score (C-peptide/glucose x 100) increased from 0.9 (0.2-2.1) to 1.3 (0.2-4.7) during combined therapy (P<0.01). Despite a 50% increase in insulin doses in phase 3 (12 U (9-30) vs 18 U (11-60); P<0.01) only 3 patients who responded to combined therapy maintained fasting plasma glucose <140 mg/dl (P<0.02). A tendency to a higher absolute increase in C-peptide (0.99 (0.15-2.5) vs 0.6 (0-2.15); P = 0.08) and C-peptide incremental area (2.47 (0.22-6.2) vs 1.2 (0-3.35); P = 0.07) was observed among responders. We conclude that combined therapy resulted in a better glucose response to a mixed meal than insulin alone and should be tried in type 2 diabetic patients before starting insulin monotherapy, despite difficulties in predicting the response.

Effect of high hydrostatic pressure on the barrier properties of polyamide-6 films

Little is known about the barrier properties of polymer films during high pressure processing of prepackaged foods. In order to learn more about this, we examined the influence of high hydrostatic pressure on the permeation of raspberry ketone (dissolved in ethanol/water) through polyamide-6 films at temperatures between 20 and 60ºC. Permeation was lowered by increasing pressure at all temperatures. At 23°C, the increasing pressure sequence 0.1, 50, 100, 150, and 200 MPa correlated with the decreasing permeation coefficients P/(10(9) cm² s-1) of 6.2, 3.8, 3.0, 2.2, and 1.6. Analysis of the permeation kinetics indicated that this effect was due to a reduced diffusion coefficient. Pressure and temperature acted antagonistically to each other. The decrease in permeation at 200 MPa was compensated for by a temperature increase of 20ºC. After release of pressure, the former permeation coefficients were recovered, which suggests that this `pressure effect' is reversible. Taken together, our data revealed no detrimental effects of high hydrostatic pressure on the barrier properties of polymer films.

Vascular complications of black patients with type 2 diabetes mellitus in Southern Brazil

Ethnicity has been shown to be associated with micro- and macrovascular complications of diabetes in European and North American populations. We analyzed the contribution of ethnicity to the prevalence of micro- and macrovascular complications in Brazilian subjects with type 2 diabetes attending the national public health system. Data from 1810 subjects with type 2 diabetes (1512 whites and 298 blacks) were analyzed cross-sectionally. The rates of ischemic heart disease, peripheral vascular disease, stroke, distal sensory neuropathy, and diabetic retinopathy were assessed according to self-reported ethnicity using multiple logistic regression models. Compared to whites, black subjects [odds ratio = 1.72 (95%CI = 1.14-2.6)] were more likely to have ischemic heart disease when data were adjusted for age, sex, fasting plasma glucose, HDL cholesterol, hypertension, smoking habit, and serum creatinine. Blacks were also more likely to have end-stage renal disease [3.2 (1.7-6.0)] and proliferative diabetic retinopathy [1.9 (1.1-3.2)] compared to whites when data were adjusted for age, sex, fasting plasma glucose, HDL cholesterol, hypertension, and smoking habit. The rates of peripheral vascular disease, stroke and distal sensory neuropathy did not differ between groups. The higher rates of ischemic heart disease, end-stage renal disease and proliferative diabetic retinopathy in black rather than in white Brazilians were not explained by differences in conventional risk factors. Identifying which aspects of ethnicity confer a higher risk for these complications in black patients is crucial in order to understand why such differences exist and to develop more effective strategies to reduce the onset and progression of these complications.

Fish oil ingestion reduces the number of aberrant crypt foci and adenoma in 1,2-dimethylhydrazine-induced colon cancer in rats

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18% by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (± SEM) number of aberrant crypt foci compared to SO (113.55 ± 6.97 vs 214.60 ± 18.61; P < 0.05) and the incidence of adenoma (FO: 20% vs SO: 100%), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total ω-3 (FO: 8.18 ± 0.97 vs SO: 1.71 ± 0.54%) and total ω-6 (FO: 3.83 ± 0.59 vs SO: 10.43 ± 1.28%). The same occurred in the liver (P < 0.05): total ω-3 (FO: 34.41 ± 2.6 vs SO: 6.46 ± 0.59%) and total ω-6 (FO: 8.73 ± 1.37 vs SO: 42.12 ± 2.33%). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.

Impact of a 2-year intervention program on cardiometabolic profile according to the number of goals achieved

We investigated the impact of lifestyle goal achievement on cardiovascular risk factors after a 2-year behavioral intervention program applied to 394 adults (113 with diabetes, mean age 60.2 ± 11.4 years, 56% women) and targeting four goals: ≥5% weight loss; ≥150 min/week physical activities; <10% saturated fat intake/day; ≥400 g fruit and vegetable intake/day. Baseline characteristics and changes in variables after intervention among the four categories of number of goals achieved (none, 1, 2, and ≥3) were compared by independent ANOVA or the Kruskal-Wallis test. Individuals without diabetes achieving a higher number of goals were more likely to be older (3 or 4 goals: 61.8 ± 12.6 years vs none: 53.3 ± 10.3 years, P < 0.05) and to have a lower mean BMI (3 or 4 goals: 21.7 ± 2.6 kg/m² vs none: 29.0 ± 4.8 kg/m², P < 0.05), diastolic blood pressure (3 or 4 goals: 77.3 ± 2.1 mmHg vs none: 85.4 ± 9.6 mmHg, P < 0.05), triglyceride (3 or 4 goals: 116.1 ± 95.1 mg/dL vs none: 144.8 ± 65.5 mg/dL, P < 0.05) and insulin levels (3 or 4 goals: 3.6 ± 2.4 μU/L vs none: 5.7 ± 4.0 μU/L, P < 0.05) than those achieving fewer goals. The absolute changes in cardiovascular risk factors tended to be more pronounced with increasing number of goals achieved in individuals without diabetes. The intervention had a beneficial impact on the cardiometabolic profile of individuals with normal or altered glucose metabolism. The number of goals achieved in this lifestyle intervention was associated with the magnitude of improvement of cardiovascular risk factors in individuals without diabetes. Participants with a better cardiometabolic profile seemed to be more likely to have a healthy lifestyle.

Effect of pH, dextrose and yeast extract on cadmium toxicity on Saccharomyces cerevisiae PE-2

The aim of this study was to evaluate the effects of pH, dextrose and yeast extract on the cadmium toxicity on Saccharomyces cerevisiae PE-2. In the first assay, the YED mediums with different pH (2, 3, 4, 5, 6, 7, and 8) containing 0.0 and 0.05 mmol Cd L-1 were inoculated with yeast suspension and incubated at 30 °C for 18 hours. During the anaerobic growth, the biomass concentration was determined. The yeast trehalose content, cell viability, and the growth rate were assessed at the beginning and at the end of the growth stages. In the second assay the YED mediums were diluted to the total, ½, and ¼ content of dextrose and yeast and 0.0 and 0.05 mmol Cd L-1 were added. The pH of the mediums was adjusted to 5. The culture mediums were inoculated and incubated at 30 °C for 18 hours. The yeast growth was not affected by cadmium at high pH, but at low pH the yeast becomes more sensitive to the toxic effect. The yeast susceptibility to cadmium was enhanced by the decrease of yeast extract strength and the increase of dextrose strength.

Chemometrics applied to the incorporation of omega-3 in tilapia fillet feed flaxseed flour

This study evaluated the effect of adding flaxseed flour to the diet of Nile tilapia on the fatty acid composition of fillets using chemometrics. A traditional and an experimental diet containing flaxseed flour were used to feed the fish for 60 days. An increase of 18:3 n-3 and 22:6 n-3 and a decrease of 18:2 n-6 were observed in the tilapia fillets fed the experimental diet. There was a reduction in the n-6:n-3 ratio. A period of 45 days of incorporation caused a significant change in tilapia chemical composition. Principal Component Analysis showed that the time periods of 45 and 60 days positively contributed to the total content of n-3, LNA, and DHA, highlighting the effect of omega-3 incorporation in the treatment containing flaxseed flour.