Determination of paracetamol at a graphite-polyurethane composite electrode as an amperometric flow detector

A bare graphite-polyurethane composite was evaluated as an amperometric flow injection detector in the determination of paracetamol (APAP) in pharmaceutical formulations. A linear analytical curve was observed in the 5.00 x 10-5 to 5.00 x 10-3 mol L-1 range with a minimum detectable net concentration of 18.9 µmol L-1 and 180 determinations h-1, after optimization of parameters such as the detection potential, sample loop volume, and carrier solution flow rate. Interference of ascorbic acid was observed, however, it was possible overcome the interference, reaching results that agreed with HPLC within 95% confidence level. These results showed that the graphite-polyurethane composite can be used as an amperometric detector for flow analysis in the determination of APAP.

Determinação de ácido acéttico em amostra de vinagre adulterada com ácido clorídrico - um experimento integrado de titulação potenciométrica e condutométrica

The determination of acetic acid in vinegar adulterated sample using simultaneous potentiometric and condutometric titrations was used as an example of integrated experiment in instrumental analysis. An Excel® spreadsheet, which allows the entry of simultaneous data and the construction of the superimposed experimental curves (condutometric, potentiometric, first and second derivative potentiometric curve and, distribution diagrama of the acetic species as function of pH), was used as powerful tool to discuss the fundamental concepts involved in each technique and choose the best of them to quantify, without mutual interference, H3CCOOH and HCl in vinegar adulterated sample.

Development and validation of a simple and rapid capillary zone electrophoresis method for determination of nnrti nevirapine in pharmaceutical formulations

A simple and fast capillary zone electrophoresis (CZE) method has been developed and validated for quantification of a non-nucleoside reverse transcriptase inhibitor (NNRTI) nevirapine, in pharmaceuticals. The analysis was optimized using 10 mmol L-1 sodium phosphate buffer pH 2.5, +25 kV applied voltage, hydrodynamic injection 0.5 psi for 5 s and direct UV detection at 200 µm. Diazepam (50.0 µg mL-1) was used as internal standard. Under these conditions, nevirapine was analyzed in approximately less than 2.5 min. The analytical curve presented a coefficient of correlation of 0.9994. Limits of detection and quantification were 1.4 µg mL-1 and 4.3 µg mL-1, respectively. Intra- and inter-day precision expressed as relative standard deviations were 1.4% and 1.3%, respectively and the mean recovery was 100.81%. The active pharmaceutical ingredient was subjected to hydrolysis (acid, basic and neutral) and oxidative stress conditions. No interference of degradation products and tablet excipients were observed. This method showed to be rapid, simple, precise, accurate and economical for determination of nevirapine in pharmaceuticals and it is suitable for routine quality control analysis since CE offers benefits in terms of quicker method development and significantly reduced operating costs.

Determinação espectrofotométrica do bromidrato de fenoterol em preparações farmacêuticas

Um método espectrofotométrico simples foi desenvolvido para a determinação do bromidrato de fenoterol (BF) em comprimidos, gotas e xarope, como princípio ativo único e associado ao ibuprofeno. O método se baseia na reação de acoplamento oxidativo do BF com o 3-metil-2-benzotiazolinona hidrazona (MBTH), na presença de sulfato cérico, como agente oxidante. A mistura de BF, MBTH e sulfato cérico, em meio ácido, produz um composto colorido (vermelho castanho) com máximo de absorção a 475 nm. A curva de calibração foi linear num intervalo de concentração de 3,0 a 12,0 µg/mL, com coeficiente de correlação linear de 0,9998. Os parâmetros experimentais que afetam o desenvolvimento e a estabilidade do produto colorido foram cuidadosamente estudados e otimizados. O método foi aplicado em amostras comerciais e simuladas, obtendo-se coeficientes de variação entre 0,25 % a 0,82 % e médias de recuperação do padrão que variaram de 98 % a 102 %. O método proposto mostrou-se exato, preciso, linear e não é passível de interferência de excipientes, para as formas farmacêuticas comprimidos e gotas. Não houve interferência do ibuprofeno que consta de uma das formulações analisadas, associado ao BF. Quanto ao xarope, houve interferência do veículo sugerindo reações de seus componentes com o MBTH.

Efeito de medicamentos indicados para a prevenção da mastite bovina no período seco sobre a função fagocítica in vitro de leucócitos do leite de caprinos

O uso de medicamentos antimamíticos específicos para vacas no período seco é indicado para prevenção de infecções na lactação seguinte. Não obstante, a ação das células envolvidas no período de secagem tem fundamental importância para a involução da glândula mamária e seu restabelecimento para a lactação subseqüente. A indisponibilidade de tais medicamentos para uso em cabras tem resultado na extrapolação do uso de produtos recomendados para vacas sem que se considerem as particularidades e diferenças anátomo-fisiológicas entre as espécies bovina e caprina. O presente estudo teve por objetivo avaliar a influência de cinco antimamíticos específicos para vacas secas sobre a função dos fagócitos provenientes de leite caprino. Para tal, fez-se o isolamento de células somáticas de 20 amostras de leite provenientes de 10 cabras lactantes, sem antecedentes de tratamento de mamite nos últimos 30 dias, sob condições higiênico-sanitárias de colheita e com resultados negativos ao cultivo microbiológico do leite. As células aderidas a lamínulas de vidro foram confrontadas com formulações contendo princípios ativos disponíveis no mercado como Gentamicina (M1), Cefalônio Anidro (M2), Ampicilina (M3), Cloxacilina Benzatínica (M4) e Cefapirina Benzatínica (M5). Avaliou-se, por microscopia, a fagocitose de partículas de Zymosan. As médias dos índices de fagocitose das células submetidas ao tratamento com M2 (15,12% ± 16,22), M3 (6,02% ± 7,96), M4 (4,54% ± 5,45) e M5 (2,47% ± 4,64) foram menores (p<0,001) que a média dos índices de fagocitose do grupo controle (40,67% ± 19,68). A média dos índices de fagocitose das células submetidas ao tratamento com M2 foi maior (p<0,05) que as médias dos tratamentos com M3, M4 e M5 enquanto estas foram estatisticamente iguais entre si. As amostras celulares submetidas ao medicamento M1 exibiram adesão insuficiente ou ausente às lamínulas, inviabilizando a avaliação da fagocitose por meio da técnica utilizada. Os resultados obtidos permitem concluir que os medicamentos estudados exerceram influência negativa sobre os fagócitos do leite, porém, esta interferência sobre as funções das células somáticas não pode por si só determinar o insucesso da terapia proposta para o período seco, pois deve ser considerada, outrossim, a eficácia do princípio ativo sobre o patógeno causador do processo infeccioso.

Digestible lysine and organic zinc for male broiler from 1 to 11 days of age: performance and body composition

This study evaluated levels of digestible lysine and organic zinc for male Ross strain broilers from 1 to 11 days of age. It was used 1,050 chicks distributed in randomized block design, in 5 × 2 factorial scheme, with seven repetitions of 15 birds per experimental unit. The dietary concentrations of digestible lysine were 0.90; 1.00; 1.10; 1.20; and 1.40% combined with 43 and 253 ppm zinc chelate. The diets contained 2,965 ± 18 kcal/kg of apparent metabolizable energy (AME) and 21.48 ± 0.18% of CP. It was determined chemical composition, protein, lipid, mineral and water depositions on carcass and empty body. There was no interaction among the factors digestible lysine and organic zinc. Effect of zinc concentration increase was observed on greatest deposition of body fat, indicating that there is interference in lipid metabolism of the birds in the studied phase. The most pronounced effects resulted from the dietary inclusion of lysine. There was a linear effect on reconstituted body weight as a response to the increase of dietary lysine, which suggests equal or superior requirement to the greatest studied level. However, the deposition of water and protein on the carcass had a quadratic increase, characterizing higher muscle mass accumulation up to the levels 1.25 and 1.27 of this amino acid in the diet. Considering the studied strain, broiler chickens from the first to the 11th days of age require 1.28 ± 0.01% of digestible lysine, according to the deposition of muscle mass.

Fidedignidade de rótulos de alimentos comercializados no município de São Paulo, SP

OBJETIVO: Avaliar a fidedignidade das informações sobre dados nutricionais declarados em rótulos de alimentos comercializados. MÉTODOS: Foram avaliados 153 alimentos industrializados habitualmente consumidos por crianças e adolescentes, comercializados no município de São Paulo (SP) entre os anos de 2001 e 2005. Os teores de nutrientes informados pelos rótulos foram confrontados com os resultados obtidos por métodos analíticos (físico-químicos) oficiais, considerando a variabilidade de 20% tolerada pela legislação vigente, para aprovar ou condenar as amostras. Foram calculadas médias, desvios-padrão e intervalos com 95% de confiança para os nutrientes analisados, assim como a distribuição da freqüência percentual de amostras condenadas. RESULTADOS: Todos os produtos salgados analisados apresentaram inconformidades relativamente ao conteúdo de fibra alimentar, sódio ou de gorduras saturadas. Os produtos doces apresentaram variação de zero a 36% de condenação relativamente ao teor de fibra alimentar. Mais da metade (52%) dos biscoitos recheados foram condenados quanto à quantidade de gorduras saturadas. Os nutrientes implicados com a obesidade e suas complicações para a saúde foram aqueles que apresentaram maiores proporções de inconformidade. A falta de fidedignidade das informações de rótulos nas amostras analisadas viola as disposições da Resolução da Diretoria Colegiada 360/03 da ANVISA e os direitos garantidos pela lei de Segurança Alimentar e Nutricional e pelo Código de Defesa do Consumidor. CONCLUSÕES: Foram encontrados altos índices de não conformidade dos dados nutricionais nos rótulos de alimentos destinados ao público adolescente e infantil, indicando a urgência de ações de fiscalização e de outras medidas de rotulagem nutricional

Interferências do ruído do tráfego urbano na qualidade de vida: zona residencial de Brasília, DF

Objetivo: avaliar o ruído de trânsito e seus possíveis efeitos na qualidade de vida e na saúde em área residencial de Brasília. Métodos: foram feitas medições de ruído em vários andares dos prédios, com janela aberta e fechada. Aplicou-se um questionário para identificar a sensibilidade e os efeitos relacionados à exposição ao ruído. Resultados: entre os resultados identificaram-se: a área de estudo é afetada pela poluição sonora; o nível de ruído incomoda as pessoas que moram na área e interfere na realização de atividades diárias, sendo que pessoas do sexo feminino e os mais jovens se mostraram mais sensíveis ao ruído e declararam sentir, com maior intensidade, seus efeitos negativos.

Immediate reconstruction following breast-conserving surgery: management of the positive surgical margins and influence on secondary reconstruction

The efficacy of breast-conserving surgery for the local control of early breast cancer has been repeatedly evidenced. Although immediate reconstruction following breast-conserving surgery has been described, little information is available regarding surgical management in reoperative settings due to positive margins. We studied the influence of intraoperatively assessed and postoperatively controlled surgical margin status on the type of breast-conserving surgery and report our results regarding complications in a reoperative breast reconstruction scenario. All patients were seen by a multidisciplinary team who recommended breast-conserving surgery. According to the breast volume, ptosis and tumor size/location, the patients were also evaluated by a plastic surgeon, who recommended reconstruction with the appropriate technique. Intraoperative assessment of surgical margins was determined by histological examination of frozen sections. The mean follow-up time was 48months. Two hundred and eighteen patients (88.5 per cent ) underwent breast-conserving surgery and immediate reconstruction. Twelve (5.5 per cent ) patients had a positive tumor margin after review of the permanent section. All patients underwent re-exploration. In 1.3 per cent , a second reconstructive technique was indicated and in 2.2 per cent a skin-sparing mastectomy with total reconstruction was performed. Our findings support the important role of the intraoperative assessment of surgical margins and its interference in the selection of reconstruction techniques and negative margins; however, it will not guarantee complete excision of the tumor. Success depends on coordinated planning with the oncologic surgeon and careful intraoperative management

The acute effects of varying strength exercises bouts on 5km running

This study investigated if there were acute interference effects of strength exercises on subsequent continuous and intermittent 5Km aerobic exercises. Eleven physically active males (23.1 +/- 3.1 yrs, 1.75 +/- 0.07 m, 70.5 +/- 8.8 kg, and 58.2 +/- 8.3 VO(2)max) performed the following experimental sessions: A) 5 sets of 5 RM on the leg press followed by a 5km run performed continuously (average velocity of the first and second ventilatory thresholds, nu Delta 50), B) 5 sets of 5 RM on the leg press followed by a 5km run performed intermittently (1 min run at the nu VO(2)max : 1 min of rest); C) 2 sets of 15 RM on the leg press followed by a 5km continuous run; and D) 2 sets of 15 RM on the leg press followed by a 5km intermittent run. Heart rate, blood lactate concentration, rate of perceived exertion, and VO(2) at the first and the fifth km were considered for statistical purposes. There were no significant effects of both strength bouts on any of the variables associated with endurance performance (p > 0.05). It seems that both maximum and strength endurance bouts do not acutely impair aerobic performance.

Possible states in the flow around two circular cylinders in tandem with separations in the vicinity of the drag inversion spacing

The possible states in the flow around two identical circular cylinders in tandem arrangements are investigated for configurations in the vicinity of the drag inversion separation. By means of numerical simulations, the hysteresis in the transition between the shedding regimes is studied and the relationship between (three-dimensional) secondary instabilities and shedding regime determination is addressed. The differences observed in the behavior of two- and three-dimensional flows are analyzed, and the regions of bistable flow are delimited. Very good agreement is found between the proposed scenario and results available in the literature. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3420111]

Bee communities (Hymenoptera: Anthophila) of the "Cerrado" ecosystem in Sao Paulo State, Brazil

Five surveys of the bee communities in four "Cerrado" ecosystem reserves in Sao Paulo State were compared for species richness and similarity. These areas are fragment vegetation reser-reserves located in the Cerrado Corumbata Reserve (Corumbata), Jata Ecological Park (Luiz Antonio), Cajuru (Cajuru), and Vassununga State Park - ""Gleba de Cerrado de Pe-de-Gigante"" (Santa Rita do Passa Quatro). The methodology consisted of capturing bees foraging on flowers along transects, though with small differences between surveys. These ""cerrado"" areas have a large number of species of native bees, which are important pollinators in several Brazilian ecosystems. The community of bees varied among these different fragments. Based on 500 individuals (standardized by rarefaction), Cajuru, Corumbata 1 and Corumbata 2 were the areas with highest species richness, and Jata and Pe-de-Gigante had the lowest species richness in the bee communities. The bee faunas of Corumbata 2 and Pe-de-Gigante had the highest similarity, forming a group with the bee fauna of Cajuru. The bee faunas of Corumbata 1 and Jata were isolated from this group. We found that the bee species richness and similarity found in these ""cerrado"" areas cannot be explained by general factors such as the size of the fragment, the species richness of plants and the distance between the areas. Therefore, we suppose that local factors that differ among areas, such as interactions between populations, and competition and interference from surrounding areas influence and determine bee species richness and similarity in these reserves.

Anti-tumor therapy with macroencapsulated endostatin producer cells

Background: Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Results: Mice were inoculated subcutaneously with melanoma (B16F10 cells) or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 10(7) recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. Conclusions: This study indicates that immunoisolation devices containing endostatin-expressing cells are effective for the inhibition of the growth of melanoma and Ehrlich tumors. Macroencapsulation of engineered cells is therefore a reliable platform for the refinement of innovative therapeutic strategies against tumors.

Abnormal collagen deposition in synovia after collagen type V immunization in rabbits

Sinovitis in Scleroderma (SSc) is rare, usually aggressive and fully resembles rheumatoid arthritis. Experimental models of SSc have been used in an attempt to understand its pathogenesis. Previous studies done in our laboratory had already revealed the presence of a synovial remodeling process in rabbits immunized with collagen V. To validate the importance of collagen type V and to explore the quantitative relationship between this factor and synovia remodeling as well as the relationship between collagen type V and other collagens, we studied the synovial tissue in immunized rabbits. Rabbits (N= 10) were immunized with collagen V plus Freund's adjuvant and compared with animals inoculated with adjuvant only (N= 10). Synovial tissues were submitted to histological analysis, immunolocalization to collagen I, III and V and biochemical analysis by eletrophoresis, immunoblot and densitometric method. The synovial tissue presented an intense remodeling process with deposits of collagen types I, III and V after 75 and 120 days of immunization, mainly distributed around the vessels and interstitium of synovial extracellular matrix. Densitometric analysis confirmed the increased synthesis of collagen I, III and V chains (407.69 +/- 80.31; 24.46 +/- 2.58; 70.51 +/- 7.66, respectively) in immunized rabbits when compared with animals from control group (164.91 +/- 15.67; 12.89 +/- 1.05; 32 +/- 3.57) (p<0.0001). We conclude that synovial remodeling observed in the experimental model can reflect the articular compromise present in patients with scleroderma. Certainly, this experimental model induced by collagen V immunization will bring new insights in to pathogenic mechanisms and allow the testing of new therapeutic strategies to ameliorate the prognosis for scleroderma patients.

Collagen V-induced nasal tolerance downregulates pulmonary collagen mRNA gene and TGF-beta expression in experimental systemic sclerosis

Background: The purpose of this study was to evaluate collagen deposition, mRNA collagen synthesis and TGFbeta expression in the lung tissue in an experimental model of scleroderma after collagen V-induced nasal tolerance. Methods: Female New Zealand rabbits (N = 12) were immunized with 1 mg/ml of collagen V in Freund's adjuvant (IM). After 150 days, six immunized animals were tolerated by nasal administration of collagen V ( 25 mu g/day) (IM-TOL) daily for 60 days. The collagen content was determined by morphometry, and mRNA expressions of types I, III and V collagen were determined by Real-time PCR. The TGF-beta expression was evaluated by immunostaining and quantified by point counting methods. To statistic analysis ANOVA with Bonferroni test were employed for multiple comparison when appropriate and the level of significance was determined to be p < 0.05. Results: IM-TOL, when compared to IM, showed significant reduction in total collagen content around the vessels (0.371 +/- 0.118 vs. 0.874 +/- 0.282, p < 0.001), bronchioles (0.294 +/- 0.139 vs. 0.646 +/- 0.172, p < 0.001) and in the septal interstitium (0.027 +/- 0.014 vs. 0.067 +/- 0.039, p = 0.026). The lung tissue of IM-TOL, when compared to IM, showed decreased immunostaining of types I, III and V collagen, reduced mRNA expression of types I (0.10 +/- 0.07 vs. 1.0 +/- 0.528, p = 0.002) and V (1.12 +/- 0.42 vs. 4.74 +/- 2.25, p = 0.009) collagen, in addition to decreased TGF-beta expression ( p < 0.0001). Conclusions: Collagen V-induced nasal tolerance in the experimental model of SSc regulated the pulmonary remodeling process, inhibiting collagen deposition and collagen I and V mRNA synthesis. Additionally, it decreased TGF-beta expression, suggesting a promising therapeutic option for scleroderma treatment.