Renin-Angiotensin System Blockade Associated with Statin Improves Endothelial Function in Diabetics / Bloqueio do Sistema Renina-Angiotensina Associado a Estatina Melhora a Função Endotelial em Diabéticos

Abstract Background: Studies suggest that statins have pleiotropic effects, such as reduction in blood pressure, and improvement in endothelial function and vascular stiffness. Objective: To analyze if prior statin use influences the effect of renin-angiotensin-aldosterone system inhibitors on blood pressure, endothelial function, and vascular stiffness. Methods: Patients with diabetes and hypertension with office systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 80 mmHg had their antihypertensive medications replaced by amlodipine during 6 weeks. They were then randomized to either benazepril or losartan for 12 additional weeks while continuing on amlodipine. Blood pressure (assessed with ambulatory blood pressure monitoring), endothelial function (brachial artery flow-mediated dilation), and vascular stiffness (pulse wave velocity) were evaluated before and after the combined treatment. In this study, a post hoc analysis was performed to compare patients who were or were not on statins (SU and NSU groups, respectively). Results: The SU group presented a greater reduction in the 24-hour systolic blood pressure (from 134 to 122 mmHg, p = 0.007), and in the brachial artery flow-mediated dilation (from 6.5 to 10.9%, p = 0.003) when compared with the NSU group (from 137 to 128 mmHg, p = 0.362, and from 7.5 to 8.3%, p = 0.820). There was no statistically significant difference in pulse wave velocity (SU group: from 9.95 to 9.90 m/s, p = 0.650; NSU group: from 10.65 to 11.05 m/s, p = 0.586). Conclusion: Combined use of statins, amlodipine, and renin-angiotensin-aldosterone system inhibitors improves the antihypertensive response and endothelial function in patients with hypertension and diabetes.

Resumo Fundamentos: Estudos sugerem que as estatinas possuem efeitos pleotrópicos, como melhora da função endotelial, da rigidez vascular e redução da pressão arterial. Objetivo: Analisar se o uso prévio de estatina influenciou o efeito sobre a pressão arterial, a função endotelial e a rigidez vascular de drogas inibidoras do sistema renina-angiotensina-aldosterona. Métodos: Pacientes hipertensos e diabéticos com pressão arterial de consultório sistólica ≥ 130 mmHg e/ou diastólica ≥ 80 mmHg tiveram suas medicações anti-hipertensivas substituídas por anlodipino durante 6 semanas. Em seguida, foram randomizados para associação de benazepril ou losartana por mais 12 semanas. Pressão arterial (através da monitorização ambulatorial da pressão arterial), função endotelial (dilatação mediada por fluxo da artéria braquial) e rigidez vascular (velocidade da onda de pulso) foram avaliados antes e após o tratamento combinado. Neste trabalho, uma análise post-hoc foi realizada para comparar pacientes que vinham (grupo CE) ou não (grupo SE) em uso de estatina. Resultados: O grupo CE apresentou maior redução na pressão arterial sistólica nas 24 horas (134 para 122 mmHg, p = 0,007) e na dilatação mediada por fluxo da artéria braquial (6,5 para 10,9%, p = 0,003) quando comparado com o grupo SE (137 para 128 mmHg, p = 0,362, e 7,5 para 8,3%, p = 0,820). Não houve diferença estatisticamente significante na velocidade de onda de pulso (grupo CE 9,95 para 9,90 m/s, p = 0,650 e grupo SE 10,65 para 11,05 m/s, p = 0,586). Conclusão: O uso combinado de estatinas, anlodipino e inibidores do sistema renina-angiotensina-aldosterona melhora a resposta anti-hipertensiva e a função endotelial em pacientes hipertensos e diabéticos.

Serum interleukin-17 levels are associated with nephritis in childhood-onset systemic lupus erythematosus

OBJECTIVES: To determine the serum interleukin-17 (IL-17) levels in childhood-onset systemic lupus erythematosus patients and to evaluate the association between IL-17 and clinical manifestations, disease activity, laboratory findings and treatment. METHODS: We included 67 consecutive childhood-onset systemic lupus erythematosus patients [61 women; median age 18 years (range 11-31)], 55 first-degree relatives [50 women; median age 40 years (range 29-52)] and 47 age- and sex-matched healthy controls [42 women; median age 19 years (range 6-30)]. The childhood-onset systemic lupus erythematosus patients were assessed for clinical and laboratory systemic lupus erythematosus manifestations, disease activity [Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)], cumulative damage [Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index] and current drug use. Serum IL-17 levels were measured by an enzyme-linked immunosorbent assay using commercial kits. RESULTS: The median serum IL-17 level was 36.3 (range 17.36-105.92) pg/mL in childhood-onset systemic lupus erythematosus patients and 29.47 (15.16-62.17) pg/mL in healthy controls (p=0.009). We observed an association between serum IL-17 levels and active nephritis (p=0.01) and migraines (p=0.03). Serum IL-17 levels were not associated with disease activity (p=0.32), cumulative damage (p=0.34), or medication use (p=0.63). CONCLUSION: IL-17 is increased in childhood-onset systemic lupus erythematosus and may play a role in the pathogenesis of neuropsychiatric and renal manifestations. Longitudinal studies are necessary to determine the role of IL-17 in childhood-onset systemic lupus erythematosus. .

Influência da L-glutamina sobre aspectos imunomodulatórios de células tronco mesenquimais medulares em situação de desnutrição proteico-energética / The influence of L-glutamine on imunumodulatory aspects of bone marrow mesenchymal stem cells under protein-energy malnutrition

A desnutrição proteico-energética (DPE) altera a hemopoese e, portanto, a geração de células imunológicas, bem como compromete o sistema imune. Desta forma, indivíduos desnutridos apresentam maior susceptibilidade a infecções. As células tronco mesenquimais (CTMs) possuem propriedades imunomodulatórias e são importantes na formação do estroma medular que sustenta a hemopoese. Visto que a L-glutamina (GLUT) é o aminoácido condicionalmente essencial mais consumido por CTMs, e que também apresenta capacidade imunomoduladora, investigou-se, neste trabalho, se a GLUT exerceria efeito sobre aspectos imunomodulatórios das CTMs em um modelo experimental de DPE. Para tanto, utilizou-se camundongos da linhagem BALB/c, os quais receberam rações normoproteica ou hipoproteica isocalóricas contendo, respectivamente, 12% e 2% de proteína por um período de 5 semanas. Após o isolamento e a caracterização de CTMs provenientes dos grupos controle (CTMct) e desnutrido (CTMdesn), cultivou-se essas células em 0, 0,6, 2 e 10mM GLUT, a fim de determinar a influência deste aminoácido sobre a expressão de fatores de transcrição e produção de citocinas por CTMct e CTMdesn. Adicionalmente, avaliou-se o efeito dos sobrenadantes das culturas de CTMct e CTMdesn sobre a proliferação e produção de citocinas por macrófagos e linfócitos esplênicos. Os animais desnutridos apresentaram anemia, leucopenia, hipoplasia medular e diminuição na concentração de proteínas séricas, albumina e préa-lbumina. A DPE não modificou a morfologia e o fenótipo das CTMs, bem como não alterou a expressão de proteínas reguladoras do ciclo celular. Por outro lado, a expressão de NFkB e STAT-3 e a produção de IL-1ß, IL-6, IL-10 e TGF-ß por CTMs foram alteradas pela DPE e variaram de acordo com as concentrações de GLUT testadas. O aumento na concentração de GLUT diminuiu a expressão de NFkB e induziu a expressão de STAT-3 por CTMs obtidas de ambos os grupos. Quanto a produção de citocinas por essas células, observou-se uma diminuição nos níveis de IL-ß e IL-6 e uma elevação nos níveis de IL-10 e TGF-ß com o aumento na concentração de GLUT. Variações na concentração desse aminoácido não alteraram a produção de IL-17 ou IFN-γ por CTMct e CTMdesn. Ademais, a concentração de GLUT alterou, de forma diretamente proporcional, a taxa de proliferação das CTMs. Os meios condicionados de CTMct e CTMdesn diminuíram a proliferação de macrófagos e linfócitos esplênicos estimulados com LPS, induziram aumento na produção da citocina antiinflamatória IL-10 por ambos os tipos celulares e diminuíram a produção das citocinas pró-inflamatórias IL-12 e TNF-α por macrófagos e IL-17 por linfócitos. Portanto, conclui-se que a GLUT possui efeito sobre a proliferação das CTMs, bem como a capacidade de imunomodular estas células

Protein-energy malnutrition (PEM) alters hemopoiesis and, therefore, the generation of immune cells, and compromises the immune system. In this way, malnourished individuals are more susceptible to infections. Mesenchymal stem cells (MSCs) have immunomodulatory properties and are important in the formation of bone marrow stroma that supports hemopoiesis. Since L-glutamine (GLUT) is a conditionally essential amino acid, which is most consumed by MSCs, and present immunomodulatory capacity, this work investigated whether GLUT would have an effect on immunomodulatory aspects of MSCs in a PEM experimental model. For this purpose, BALB/c mice were used, which received isocaloric normoproteic or hypoproteic diets, containing respectively, 12% and 2% of protein for a period of 5 weeks. After isolation and characterization of MSCs from control (MSCct) and malnourished (MSCmaln) groups, these cells were cultured with 0, 0.6, 2 and GLUT 10mM in order to determine the influence of this amino acid on the expression of transcription factors and cytokine production by MSCct and MSCmaln. Besides that, the effect of MSCct and MSCmaln culture supernatants on proliferation and cytokine production by macrophages and splenic lymphocytes was evaluated. Malnourished animals presented anemia, leucopenia, marrow hypoplasia and decreased concentration of serum proteins, albumin and prealbumin. PEM did not change morphology and phenotype of MSCs or altered the expression of cell cycle regulatory proteins. On the other hand, the expression of NFkB and STAT-3 and the production of IL-1ß, IL-6, IL-10 and TGF-ß by MSCs were modified by PEM and varied according to the tested GLUT concentrations. An increase in GLUT concentration decreased NFkB expression and induced STAT-3 expression by MSCs obtained from both groups. Regarding the production of cytokines by these cells, an increase in GLUT concentration resulted in decreased IL-1ß and IL-6 levels and increased IL- 10 and TGF-ß levels. Changes in the concentration of this aminoacid did not alter IL- 17 or IFN-γ production by MSCct and MSCmaln. Furthermore, the concentration of GLUT changed, in direct proportion, the proliferation of MSCs. The conditioned media MSCct and MSCmaln decreased the proliferation of macrophages and splenic lymphocytes stimulated with LPS, induced an increase in the production of the antiinflammatory cytokine IL-10 by both cell types, and decreased the production of proinflammatory cytokines IL-12 and TNF-α by macrophages and IL-17 by lymphocytes. Therefore, it can be concluded that GLUT has an effect on the proliferation of MSCs and it has the capacity to immunomodulate these cells

Assessment of somatic embryogenesis potency in Indian soybean [Glycine max (L.) Merr.] cultivars.

Majority of the Indian soybean cultivars are recalcitrant to tissue culture regeneration. The present communication reports the development of somatic embryogenesis in a liquid culture medium from immature cotyledons of G. max. Following induction with 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthalene acetic acid (NAA), the number of somatic embryos and percentage of explants that responded were higher with 45.24 µM 2,4-D. The proliferation of somatic embryos for three successive cycles was achieved in 22.62 µM 2,4-D. Histodifferentiation of somatic embryos under NAA (10.74 µM) indicated that better embryo development and maturation was achieved without any growth regulator. The amino acids such as L-glutamine favoured the somatic embryo induction and histodifferentiation at 20 and 30 mM respectively, where as L-asparagine at 10 mM concentration enhanced the somatic embryo proliferation. In addition, somatic embryos that were desiccated (air-drying method) for 5 days showed better germination (40.88%). The Indian soybean cultivars also showed strict genotypic influence and cv. Pusa 16 was emerged as a best responding cultivar for somatic embryo induction with 74.42% of response.

Protective effect of some amino acids synthesized derivatives and their chelates on Escherichia coli under X-ray irradiation.

The protective effects of novel synthesized derivatives of some amino acids — nicotinyl-L-tyrosinate and nicotinyl-L-tryptophanate schiff bases and their Cu(II) and Mn(II) chelates on growth, survival and membrane-associated ATPase activity of E. coli under X-ray irradiation were investigated. The specific growth rate and survival of E. coli were decreased at 10, 20 and 30 Gy doses. However, as 30 Gy was found to be the most effective irradiation dose, it was chosen for studying the radio-protective properties of different compounds. These compounds could increase the bacterial cell protection against X-ray irradiation in concentration-dependent manner. They had a role in stimulation of synthesis or regulation of activity of metal-dependent enzymes, required for reversing the X-ray irradiation damage. The study may prove useful for further estimation of the effectiveness of different compounds as radio-protectors on bacteria and other cells, especially mammalian cells under X-ray irradiation.

Suplementação proteica não aumenta a concentração plasmática de óxido nítrico em homens saudáveis / Protein supplementation does not increase nitric oxide plasmatic concentration in healthy men

Suplementos nutricionais, supostamente, capazes de potencializar a produção endógena de óxido nítrico (NO) têm experimentado crescente popularidade entre os indivíduos fisicamente ativos. Diante da carência de informações sobre o assunto, o objetivo do presente estudo foi avaliar o efeito de um suplemento comercial à base de proteínas e aminoácidos sobre a produção endógena de NO. MÉTODOS: A amostra foi constituída de 12 homens sedentários, mas sem fatores de risco para doenças cardiovasculares. O protocolo de suplementação foi conduzido conforme o arranjo experimental duplo-cego cruzado. Os participantes receberam, aleatoriamente, placebo (PLA) ou suplemento proteico (SP), em dois momentos diferentes, separados por uma semana. Com o intuito de determinar a concentração plasmática de NO, amostras de sangue foram coletadas antes (24h e imediatamente antes) e depois (30 e 60 minutos) do consumo da substância PLA ou do SP. RESULTADOS: Não foi observada alteração na concentração plasmática de NO após a ingestão do SP em comparação com o PLA (pós- suplementação 30min - PLA: 19,3 ± 4,7µmol.L- 1 vs. SP: 18,9 ± 4,4µmol.L-1 e pós-suplementação 60min - PLA: 21,3 ± 6,5µmol.L-1 vs. SP: 20,3 ± 4,9µmol.L-1). Também não foi verificada alteração da pressão arterial. CONCLUSÃO: O suplemento nutricional à base de proteínas e aminoácidos, testado no presente estudo, não potencializou a produção endógena de NO.

Nutritional supplements, theoretically able to increase endogenous nitric oxide (NO) production have experienced great popularity among physically active individuals. AIM: scientific evidence available regarding this issue is scarce. Therefore, the purpose of this study was to evaluate the effect of a dietary supplement commercialized as a nitric oxide booster. MATERIALS AND METHODS: twelve sedentary men with no risk factors for cardiovascular diseases were supplemented with placebo or protein in two different occasions. The present study was conducted in a cross double-blind design. In order to assess plasmatic NO concentration, blood samples were obtained before (24hs and immediately before) and after (30 and 60 minutes) consumption of placebo (PLA) or protein supplement (SP). RESULTS: there was no difference in plasmatic nitric oxide concentration between both trails (Post-supplementation 30 min - PLA: 19.3±4.7 µmol.L-1 vs. SP: 18.9±4.4 µmol.L-1 and Post-supplementation 60 min - PLA: 21.3±6.5 µmol.L-1 vs. SP: 20.3±4.9 µmol.L-1). In addition, no difference was detected for arterial blood pressure. CONCLUSION: the dietary supplement analyzed in the present study failed to increase nitric oxide endogenous production.

Reversible male sterility in transgenic tobacco carrying a dominant-negative mutated glutamine synthetase gene under the control of microspore-specific promoter.

Metabolic engineering was used to disrupt glutamine metabolism in microspores in order to block pollen development. We used a dominant-negative mutant (DNM) approach of cytosolic glutamine synthetase (GS1) gene under the microspore-specific promoter NTM19 to block glutamine synthesis in developing pollen grains. We observed partial male sterility in primary transgenic plants by using light microscopy, FDA, DAPI and in vitro pollen germination test. Microspores started to die in the early unicellular microspore stage, pollen viability in all primary transgenic lines ranged from 40-50%. All primary transgenics produced seeds like control plants, hence the inserted gene did not affect the sporophyte and was inherited through the female germline. We regenerated plants by in vitro microspore embryogenesis from 4 individual lines, pollen viability of progeny ranged from 12 to 20%, but some of them also showed 100% male sterility. After foliage spray with glutamine, 100% male-sterile plants were produced viable pollen and seed set was also observed. These results suggested that mutated GS1 activity on microspores had a significant effect on normal pollen development. Back-cross progenies (T2) of DH 100% male-sterile plants showed normal seed set like primary transgenics and control plants.

Studies on L-asparaginase enzyme of actinomycetes isolated from estuarine fishes.

Actinomycetes were isolated from different organs viz. skin, gills and gut contents of three species of fishes viz. Mugil cephalus (Linnaeus, 1758), Chanos chanos (Forskal, 1775) and Etroplus suratensis (Bloch, 1780) using three different media from the Vellar estuary, situated along the southeast coast of India. Among the three fishes, M. cephalus harboured highest number of actinomycetes population in all the three body parts examined followed by C. chanos and E. suratensis. Out of the three body parts of all fishes, gut contents had highest actinomycetes population followed by gills and skin. Among the three media used for isolation of actinomycetes, Kuster's agar medium was found to be suitable than the starch casein agar and glucose asparagine agar media. Out of the 40 strains isolated, only six strains (LA-2, LA-8, LA-15, LA-20, LA-29 and LA-35) showed significant L-asparagianse activity and were taken up for further studies. Impact of various physical and chemical factors such as pH, temperature, sodium chloride concentration, carbon sources and amino acids on the growth of actinomycetes and L-asparaginase activity was also studied. Optimum growth and enzyme activity was noticed under pH 7 to 8, temperature 37 degrees C, 1-2% sodium chloride concentration, sucrose as carbon source and without any amino acids. Analysis of the cell components of the isolated strains has revealed the wall type-I (the wall type-I is typical for the genus Streptomyces) and the strains were micromorphologically similar to the genus Streptomyces. Hence, the morphological, physiological and biochemical along with the micromorphological results obtained for the L-asparaginase producing strains were compared and the strains were tentatively identified as Streptomyces aureofasciculus (LA-2), S. chattanoogenesis (LA-8), S. hawaiiensis (LA-15), S. orientalis (LA-20), S. canus (LA-29) and S. olivoviridis (LA-35).

The effect of some osmolytes on the activity and stability of mushroom tyrosinase.

The thermodynamical stability and remained activity of mushroom tyrosinase (MT) from Agaricus bisporus in 10 mM phosphate buffer, pH 6.8, stored at two temperatures of 4 and 40 degrees C were investigated in the presence of three different amino acids (His, Phe and Asp) and also trehalose as osmolytes, for comparing with the results obtained in the absence of any additive. Kinetics of inactivation obey the first order law. Inactivation rate constant (kinact) value is the best parameter describing effect of osmolytes on kinetic stability of the enzyme. Trehalose and His have the smallest value of kinact (0.7x10(-4) s-1) in comparison with their absence (2.5x10(-4) s-1). Moreover, to obtain effect of these four osmolytes on thermodynamical stability of the enzyme, protein denaturation by dodecyl trimethylammonium bromide (DTAB) and thermal scanning was investigated. Sigmoidal denaturation curves were analysed according to the two states model of Pace theory to find the Gibbs free energy change of denaturation process in aqueous solution at room temperature, as a very good thermodynamic criterion indicating stability of the protein. Although His, Phe and Asp induced constriction of MT tertiary structure, its secondary structure had not any change and the result was a chemical and thermal stabilization of MT. The enzyme shows a proper coincidence of thermodynamic and structural changes with the presence of trehalose. Thus, among the four osmolytes, trehalose is an exceptional protein stabilizer.

Specific nutrient supplementation of defined serum-free medium for the improvement of CHO cells growth and t-PA production

Recombinant CHO TF70R cells are able to grow and produce t-PA on serum-free medium BIOPRO1 (BioWhitaker Europe, Belgium). The purpose of the present study was to determine the effect of medium supplementation with vitamins, lipids, and specific amino acids on cell growth, t-PA production and biological functionality. Among vitamins, only biotin, folic acid, cobalamine and benzoic acid were required for improving growth and t-PA production. Lipid supplement allowed a significant increase cell concentration and t-PA specific activity and concentration, though its specific production rate decreased slightly. Medium supplementation with proline, serine and asparagine had also positive effects on cell growth. Besides, the addition of asparagine (even in the presence of glutamine) was essential for the production and biological quality of the t-PA. This systematic approach for media supplementation produced an increase in cell concentration around 100 percent and in t-PA production around 80 percent, with no detrimental effect on its biological activity. The effect of asparagine on t-PA production was unexpected and needs to be further studied. The above modifications of the production medium did not produce a significant effect on the metabolism of the main carbon and energy sources (glucose and glutamine) and the level of by-product formation (lactate and ammonia).

[Influence of some essential and non essential amino acids on plasma lipids and gamma glutamyl transferase [GGT] activity in rats]

Long-term administration of L-essential amino acids including isoleucine [Ile], leucine [leu] and valine [Val] to young rates for 70 consecutive days caused significant increase in plasma cholesterol triglycerides, LDL-cholesterol and total LDL and gammaGT activity, whereas Lysine [Lys] produced the same effects in these parameters but the plasma triglycerides were not changed. Administration of L-non-essential amino acids including arginine [Arg] cystine [Cys] and glycine [Gly] to another group of young rates did not affect cholesterol, triglycerides levels or [gamma GT] activity during the same period and under the same condition. Administration of glutamic acid [Glu] caused significant decreases in plasma cholesterol, LDL cholesterol and total LDL levels IIE, Leu, Val, Cys and Arg produced a significant decrease in HDL-cholesterol but Glu caused a significant increase. These results demonstrated that long-term feeding of pure L-essential amino acids caused a significant increase in plasma lipids along with plasma gamma GT activity of young rates. Furthermore, our result indicates that Glu causes reductions in plasma cholesterol levels, with its ability to protect the myocardium against insulting stimuli that precipitate ischemia and arrhythmias [31] may has therapeutic value in correcting hypercholesterolemia and improving cardiac performance

Complicaciones y sus factores asociados en la nutrición parenteral total en neonatos: Servicio de Neonatología Hospital Central de San Cristóbal julio-septiembre 2002 / Complications and associated factors in total parenteral nutrition in neonates: Department of Neonatology Hospital Central de San Cristóbal july-september 2002

La nutrición parenteral (NP) es una técnica adecuada, pero no fisiológica, que permite administrar macro y micronutrientes y calorías directamente a través de la circulación sistémica. Sin embargo, aunque la NPT sea un método adecuado de soporte nutricional, no está exento de complicaciones. Algunos autores, han descrito las complicaciones de tipo metabólicas e infecciosas como las más frecuentes en el período neonatal y otros estudios han destacado además diversas complicaciones de tipo mecánico, relacionadas con la colocación de los catéteres. Determinar las complicaciones que se presentan en los recién nacidos que ameritan nutrición parenteral, hospitalizados en la Unidad de Recién Nacidos y en la Unidad de Patología Neonatal del Hospital Central de San Cristóbal e identificar los factores de riesgo asociados. Se implementó un estudio prospectivo, longitudinal, descriptivo y observacional, con un intervalo de tres meses para selección de la muestra. Durante este tiempo, se obtuvieron muestras de 36 pacientes, de los cuales todos fueron estudidos. El criterio final de inclusión para cada paciente lo constituyó la indicación de la NPT. El tiempo promedio de administración fue de 8 días; 26 (72 por ciento) de los neonatos eran prematuros. En 26 por ciento (72 por ciento) se encontraron complicaciones y de ellas las más frecuentes fueron las metabólicas. No se encontró correlación significativa entre los factores de riesgo y la aparición de complicaciones por administración de NPT. No se encontró una asociación significativa entre los factores de riesgo y las complicaciones, aunque la mayor parte de neonatos complicados resultaron prematuros con indicación prolongada de NPT. Es necesaria mayor vigilancia en todos los procedimientos relacionados con la administración de NPT, en especial para pacientes prematuros y en los que se administre por tiempo prolongado.

Avaliação do estado energético de enxertos hepáticos após perfusão hipotérmica contínua ou conservação simples com solução universidade de wisconsin modificada / Effect on energy status of liver grafts preserved with modified UW solution by hypothermic continuous perfusion or simple storage

Racional - O transplante hepático representa, atualmente, o tratamento de escolha para doenças hepáticas crônicas irreversíveis, em estado terminal. Seu sucesso está ligado a diferentes fatores, dentre os quais se inclui uma eficiente conservação do enxerto hepático. A perfusão hipotérmica contínua do enxerto hepático demonstrou experimentalmente ampliar o período de conservação do fígado para além dos limites clinicamente atingidos. A resistência do fígado a períodos mais prolongados de conservação parece estar relacionada aos níveis energéticos das células. Objetivos - Verificar se melhores níveis energéticos de enxertos hepáticos são obtidos com o acréscimo dos aminoácidos glutamina, ácido glutâmico, cisteína, alanina e glicina à solução de conservação em perfusão hipotérmica contínua. Material e Método - Vinte porcos da raça Large-White foram operados após 12 horas de jejum. Seis dos fígados retirados foram preservados por 24 horas pelo método da conservação simples, três com a solução Universidade de Wisconsin, chamada BASE, e três com a mesma solução acrescida dos aminoácidos supracitados. Quatorze fígados foram conservados pelo método da perfusão hipotérmica contínua, metade deles com a solução BASE e outra metade com a solução acrescida de aminoácidos. A avaliação do estado emergético do fígado foi feita pela dosagem tecidual dos nucleotídeos adenílicos e glicogênio. O glutation foi também medido no tecido hepático tendo em vista sua importância como neutralizador de radicais livres de oxigênio. Resultados - O glicogênio hepático não se alterou com o uso de aminoácidos na solução ou com o método de preservação (CS ou PHC). O glutation, elevou sua concentração durante conservação simples com solução com aminoácidos,mas não se alterou com a perfusão contínua. O ATP manteve-se estável no tecido hepático, quando a perfusão contínua foi utilizada, mas reduziu-se rapidamente com a conservação simples. A perfusão contínua manteve estável a carga energética e a carga total em nucleotídeos adenílicos do enxerto, durante o período de conservação. Conclusão - O estudo demonstrou que a perfusão hipotérmica contínua foi capaz de manter os níveis energéticos iniciais do tecido hepático, independentemente da solução utilizada, enquanto que a conservação simples permitiu uma rápida queda nos níveis teciduais de trifosfato de adenosina.

Bone development of broiler chikens fed diets with different amino acid and calcium levels during the starter phase

Two experiments were conducted in order to evaluate the effects of different dietary amino acid and calcium profiles on the bone characteristics of two chicken strains (Avian Farms and Cobb) during the starter phase. At the end of each experiment, 2 chickens of each replicate were sacrificed and their tibiae were collected for analysis of following bone characteristics: bone measurements (weight, length and thickness of the compact and spongy layers) and bone density (bone densitometry). A total of 540 birds were used in each experiment, divided into fully randomized blocks with a 3 x 2 factorial schemes, i. e., 3 amino acid profiles (methionine, lysine and threonine ¡ 100 per cent, 125 per cent and 150 per cent of NRC recommendations, 1994) and 2 calcium levels (75 per cent and 100 per cent of NRC recommendations, 1994), with 30 birds per replicate. Birds of the Cobb strains fed 75 per cent of the recommended calcium allowance showed lower bone density. Calcium level significantly affected the weight and thickness of the spongy layer of the tibia. In birds of the Avian strain, bone density and measurements were not affected by any of the experimental treatments.

Plant availability of cadmium in presence of organic acids: an interactive aspect.

The present communication reports the effect of various carboxylic and amino acids on the uptake and translocation of root-absorbed Cd by maize (Zea mays). Statistically significant increases in Cd accumulation in various plant tissues with increasing supplementation of organic acids suggested the existence of Cd-organic acid interaction in soil-rhizosphere environment of the plant. The potentiality of phytochelators (organic acids) to form plant available organically bound Cd is discussed.

Effects of tryptophan depletion on anxiety induced by simulated public speaking

Several lines of evidence point to the participation of serotonin (5HT) in anxiety. Its specific role, however, remains obscure. The objective of the present study was to evaluate the effect of reducing 5HT-neurotransmission through an acute tryptophan depletion on anxiety induced by a simulated public speaking (SPS) test. Two groups of 14-15 subjects were submitted to a 24-h diet with a low or normal content of tryptophan and received an amino acid mixture without (TRY-) or with (TRY+) tryptophan under double-blind conditions. Five hours later they were submitted to the SPS test. The state-trait anxiety inventory (STAI) and the visual analogue mood scale (VAMS) were used to measure subjective anxiety. Both scales showed that SPS induced a significant increase in anxiety. Although no overall difference between groups was found, there was a trend (P = 0.078) to an interaction of group x gender x phases of the SPS, and a separate analysis of each gender showed an increase in anxiety measured by the STAI in females of the TRY- group. The results for the female TRY- group also suggested a greater arousing effect of the SPS test. In conclusion, the tryptophan depletion procedure employed in the present study did not induce a significant general change in subjective anxiety, but tended to induce anxiety in females. This suggests a greater sensitivity of the 5HT system to the effects of the procedure in this gender.

Thyroid peroxidase activity is inhibited by amino acids

Normal in vitro thyroid peroxidase (TPO) iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml) or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml). A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml) and some amino acids (cysteine, tryptophan and methionine, 50 µM each) also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml), and tyrosine, phenylalanine and histidine (50 µM each) inhibited the TPO reaction by 54 per cent or less. A pancreatic digest of gelatin (0.1 mg/ml) or any other amino acid (50 µM) tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino acids contain side chains with either sulfur atoms (cysteine and methionine) or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine). Among the amino acids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 µM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2) concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

Binding Study of Immunoglobulin G [IgG] to Some N-Propargyl Amino Acids

The study was conducted on immunoglobulin G [IgG] and N-propargyl amino acid anti cancer cells based upon ultraviolet spectroscopic technique using different concentration and temperatures [20°C, 30°C, 37°C, 40°C] in aqueous solution. The N-propargyl phenyl alanine showed positive value at enthalpy while N propargyl [Histidine, Clycine, Valine, Arginine] showed the reversed

Effect of amino acids on inhibition of lactate dehydrogenase-X by gossypol

Gossypol acetic acid (GAA) has been shown to have male antifertility effects, but there are pronounced differences among animal species. In the search of endogenous effector molecules, which interfere with the functions of GAA, we have studied the in vitro effect of various amino acids on the inhibition of the purified LDH-X by GAA. Histidine, cysteine and glycine were shown to block the effect of GAA. The effects of these amino acids were concentration dependent. Histidine and glycine protection was found to be complex type in which both the Km and Vmax were decreased compared to control. Arginine, glutamic acid, phenylalanine and valine were found to be ineffective against the inhibitory action of GAA.

Central modulation of formalin-induced acute peripheral inflammation & pain by some putative amino acid neurotransmitters in rats.

Possible central modulation of acute peripheral inflammation by putative amino acid neurotransmitters was investigated in rats by adopting formalin induced pedal inflammation as an experimental model. Out of five amino acids (GABA, glycine, DL-alanine, L-glutamic acid and L-aspartic acid) tested, intracerebroventricular (icv) administration of GABA and L-aspartic acid produced significant alteration in acute inflammation. GABA showed a significant attenuation of paw oedema and nociception whereas, L-aspartic acid produced significant increase in oedema volume along with marked hyperalgesia. In conclusion, the study confirms that CNS is capable of modulating peripheral inflammation.