Síntese de trans-resveratrol e controle de podridão em maçãs com uso de elicitores em pós-colheita

O objetivo deste trabalho foi avaliar o efeito da aplicação de elicitores abióticos na biossíntese de resveratrol e na indução de resistência à podridão póscolheita de maçãs 'Gala' e 'Fuji'. Foram realizados os tratamentos: radiação ultravioleta, fosfito e acibenzolar-Smetil - aplicados antes do armazenamento - e ozônio - aplicado intermitente durante o armazenamento. As condições de armazenamento foram: 'Gala', 1,5 kPa de O2 e 2,5 kPa de CO2, a 0,5±0,1ºC, por oito meses, e 'Fuji', 1,0 kPa de O2 e <0,5 kPa de CO2, a 0,5±0,1ºC, por sete meses. O delineamento experimental foi inteiramente ao acaso, com oito repetições de 25 frutos. Na casca dos frutos, determinou-se: trans-resveratrol, polifenóis totais, antocianinas totais e diâmetro de lesão, após inoculação de Penicillium sp. no ferimento. Analisou-se na polpa: firmeza de polpa, acidez titulável, sólidos solúveis totais, açúcares redutores e nãoredutores. Os elicitores não alteram a concentração de polifenóis totais e antocianinas, com exceção do acibenzolar-Smetil que reduz o conteúdo de antocianinas na maçã 'Gala'. Os elicitores induzem, na 'Fuji', mas não na maçã 'Gala', a síntese de trans-resveratrol na seqüência: acibenzolar-Smetil> fosfito> irradiação UV-C> ozônio. Na maçã 'Gala', o fosfito reduz a ocorrência de podridão, porém, em ambas as cultivares, não há correlação entre síntese de trans-resveratrol e controle de podridão.

Isomerismo cis-trans: de Werner aos nossos dias

In coordination chemistry the study of geometrical isomerization and reactivity of specific isomers is a topic of major importance. The preparation of specific isomers often requires considerable complexity, and it is important to acquire a sense of what is involved in studying isomerism in laboratory. If it is difficult sometimes to prepare pure isomers, it is not easier to understand the mechanisms of isomerization reactions since studies on this subject have shown conflicting results and diferent interpretations on the same system have been reported in the literature. Although cis-trans isomerism in octahedral metal complexes is a common occurrence, there are relatively few studies reporting how these isomerizations occur. This paper gives an overview on cis-trans isomerization processes and identification of these species.

Efecto de solvente sobre la descomposición térmica de trans-3,6-dimetil-3,6-difenil-1,2,4,5-tetraoxaciclohexano en solución

The thermal decomposition reaction of trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetraoxacyclohexane (acetophenone cyclic diperoxide, DPAF), in different solvents (methanol, 1,4-dioxane, acetonitrile and 2-propanol/benzene mixtures) in the initial concentration and temperature ranges of (4.2-10.5) x 10-3 M and 140.0 to 185.0 ºC, respectively, follows a pseudo first order kinetic law up to at least 70% DPAF conversion. An important solvent effect on the rate constant values, activation parameters (DH# and DS#) and reaction products obtained in different solvents is detected, showing that the reaction is accelerated in alcohols.

Estudos Cinéticos da aquação do trans-[Co(en)2Cl2]Cl

The trans-dichlorobis(ethylenediamine)cobalt(III) chloride was synthesized in an undergraduate laboratory and its aquation reaction was carried out at different temperatures. This reaction follows pseudo-first-order kinetics and the rate constants, determined at 25, 35, 45, 55 and 70 º C, are 1.44 x 10-3; 5.14 x 10-3; 1.48 x 10-2; 4.21 x 10-2 and 2.21 x 10-1 s-1, respectively. The activation energy is 93.99 ± 2.88 kJ mol-1.

Interesterificação química: alternativa para obtenção de gorduras zero trans

The function of lipids in human nutrition has been intensively debated in the last decade.This context reinforces the concern about controlling the trans fat ingestion, due to its negative implications on health. Interesterification provides an important alternative to modify the consistency of oils and fats without causing formation of trans isomers. This article reports research done towards production of zero trans fats by chemical interesterification, for different industrial purposes. Aspects related to the effect of trans fats on diet, their impact on health and modifications in Brazilian legislation are also covered.

Polarizabilidades e primeira hiperpolarizabilidades elétricas dipolares de ésteres E-4-amino-trans-1,3-butadienil-(1',2'-di-hidroxibenzeno) de boro, alumínio e gálio

Static electric dipole polarizabilities and first hyperpolarizabilites have been calculated for the title molecules and their 3' and 4'-nitro derivatives at ab-initio Hartree- Fock/6-31G(d, p) level. The influence of the pivotal p vacant 3A elements (B, Al or Ga) substitution on the electrical properties of these molecules is detailed. The axial vector components of the first hyperpolarizabilities β(0) of the push-pull 4'-nitro derivatives, -18.2×10-32 esu (B), -21.1×10-32 esu (Al) and -20.8×10-32 esu (Ga) are calculated to be as much as fourfold larger then that calculated for the p-nitroaniline, a reference organic molecule for comparison for this type of molecular property.

Optimization of a HPLC procedure for simultaneous determination of cisplatin and the complex cis,cis,trans-diamminedichlorodihydroxoplatinum(IV) in aqueous solutions

A RP-HPLC procedure for the simultaneous determination of cisplatin and the complex cis,cis,trans-diamminedichlorodihydroxo-platinum(IV), was development. The developed procedure was validated in terms of linearity, accuracy, precision, limits of detection (LOD), limits of quantification (LOQ) and specificity. The limits of detection (LOD) were 0.47 x 10-4 and 0.53 x 10-4 mol L-1 and the limits of quantification (LOQ) were 1.57 x 10-4 and 1.75 x 10-4 mol L-1, for cisplatin and cis,cis,trans-diamminedichlorodihydroxopla-tinum(IV), respectively. The average recoveries of cisplatin and cis,cis,trans-diamminedichlorodihydroxoplatinum(IV) was 100.6% ± 1.4 and 101.2% ± 1.1, respectively. Intermediate (inter-day) precision, repeatability and specificity of the procedure for hydrolysis products of cisplatin were studied. The results of the study showed that the proposed RP-HPLC procedure is simple, rapid, precise, accurate and specific.

Extração de ácido trans-trans mucônico urinário com polímeros de impressão molecular e análise por cromatografia gasosa: espectrometria de massas

This paper describes selective molecularly imprinted solid-phase extraction of ttMA from urine samples followed by derivatization and analysis by gas chromatography/mass spectrometry (GC/MS). The analytical calibration curve ranged from 0.3 to 7.0 mg L-1 (r = 0.999) and the limit of quantitation (LOQ) was 0.3 mg L-1. The method was applied for the determination of ttMA in urine samples from smokers and concentrations detected ranged from < LOQ to 1.64 mg L-1. Thus, the proposed method proved adequate for the determination of urinary ttMA in the biomonitoring of occupational exposure to low levels of benzene.

Exploración estocástica de las superficies de energía potencial de dímeros cis-trans y trans-trans del ácido fórmico

Potential energy surface (PES) of cis-trans and trans-trans formic acid dimers were sampled using a stochastic method, and the geometries, energies, and vibrational frequencies were computed at B3LYP/6-311++G(3df,2p) level of theory. The results show that molar free energy of dimerization deviated up to 108.4% when basis set superposition error (BSSE) and zero-point energy (ZPE) were not considered. For cis-trans dimers, C=O and O - H bond weakened, whereas C - O bonds strengthened due to dimerization. Also, trans-trans FA dimers did not show a trend regarding strengthening or weakening of the C=O, O - H and C - O bonds.

Esofagectomia trans-hiatal no tratamento do megaesôfago chagásico avançado

OBJETIVO: Avaliar os resultados da esofagectomia trans-hiatal no tratamento do megaesôfago chagásico avançado. MÉTODO: Foram estudados retrospectivamente 28 pacientes portadores de megaesôfago chagásico avançado (MCA), graus III e IV, segundo a classificação radiológica de Rezende (adotada pela Organização Mundial de Saúde), e que foram submetidos à esofagectomia subtotal trans-hiatal no Serviço de Clínica Cirúrgica do Hospital Universitário Prof. Alberto Antunes (HUPAA) da Universidade Federal de Alagoas, entre 1982 e 2000. Foram analisadas, as seguintes variáveis: A) Queixas clínicas pré-operatórias versus as pós-operatórias (disfagia, regurgitação, pirose, diarréia, dumping, plenitude pós-prandial, pneumonia e o estado ponderal). B) avaliação radiológica pós-operatória da boca anastomótica esofagogástrica cervical e do estômago transposto. C) avaliação endoscópica pós-operatória do coto esofágico e da boca anastomótica. RESULTADOS: O seguimento variou de 4 a 192 meses, média de 58,18 meses. Dezesseis pacientes eram do sexo feminino e 12 masculinos. Idade mínima de 16 e máxima de 67 anos, média de 36,5 anos. Não houve mortalidade nesta série. Houve resolução plena da disfagia na maioria dos pacientes (20/28 - 71,4%), um (3,6%) referiu disfagia leve que não necessitou tratamento e 7/28 (25%) necessitaram de uma ou mais sessões de dilatação. Nenhum necessitou de dilatação permanente. A pirose foi o sintoma mais importante no seguimento tardio (35,7%), seguida da regurgitação (25%), diarréia (14,3%), plenitude pós-prandial (10,7%) e dumping (3,6%). Houve ganho ponderal em 87,5% dos pacientes avaliados. A esofagite no coto esofágico foi o achado endoscópico mais significativo (46,4%). O esôfago de Barrett no coto remanescente foi encontrada em 10,7% dos casos. A maioria dos achados radiológicos foi normal, embora três doentes (10,7%) tenham apresentado estase gástrica. CONCLUSÃO: A esofagectomia trans-hiatal mostrou-se eficaz para o tratamento da disfagia no megaesôfago chagásico avançado, embora com morbidade elevada, porém com mortalidade nula.

Esofagectomia trans-hiatal versus transtorácica: experiência do Instituto Nacional do Câncer (INCA)

OBJETIVO: Analisar comparativamente a morbimortalidade e sobrevida após esofagectomia trans-hiatal (TH) ou transtorácica (TT). METODOS: Estudo retrospectivo não randomizado de 68 pacientes com neoplasia de esôfago operados no INCA entre 1997 e 2005, divididos em dois grupos: 1 - TH (33 pacientes); e 2 - TT (35 pacientes). RESULTADOS: A idade média foi 40,7 anos (25 - 74 anos), sendo 73,5% homens. Tumores do 1/3 médio predominaram no Grupo 2 (48,6% versus 21,2%, p = 0,02). A média de linfonodos dissecados foi maior no Grupo 2 (21,6 versus 17,8 linfonodos, p = 0,04), porém sem diferença no número de linfonodos metastáticos (4,1 versus 3,9 linfonodos, p = 0,85). O tempo cirúrgico médio foi maior no Grupo 2 (410 versus 270 minutos, p = 0,001). O tempo médio de internação também foi maior no Grupo 2 (19 versus 14 dias, p = 0,001). A morbidade operatória foi 50%, sem diferença significativa (42,4% versus 57,1%, p = 0,23). Fístula esofágica ocorreu em 13,2%, sem diferença significativa (9,1% versus 17,1%, p = 0,23). A mortalidade foi 5,8% (04 pacientes), sem diferença significativa (1,4% versus 4,4%, p = 0,83). CONCLUSÃO: Neste estudo, a morbimortalidade não apresentou diferença em relação à via de acesso para a esofagectomia, apesar do maior tempo cirúrgico e de permanência hospitalar na via TT. A sobrevida global em 3 e 5 anos também foi maior na TT, possivelmente devido a maior freqüência de estágios iniciais em pacientes submetidos à transtorácica.

Esofagectomia trans-hiatal com esternotomia parcial

A esofagectomia trans-hiatal oferece a vantagem de não necessitar da toracotomia ou toracoscopia. Apresenta a desvantagem de ter que ser realizada, pelo menos em parte, com dissecação romba, às cegas, ocorrendo com frequência lesão pleural, maior sangramento, entre outras complicações. A associação da transecção mediana do diafragma com a esternotomia parcial permite o isolamento do esôfago totalmente sob visão direta. Os autores apresentam a técnica da esofagectomia trans-hiatal com esternotomia parcial.

Cardiovascular responses to microinjection of trans-(±)-ACPD into the NTS were similar in conscious and chloralose-anesthetized rats

The changes in mean arterial pressure (MAP) and heart rate (HR) in response to the activation of metabotropic receptors in the nucleus tractus solitarii (NTS) with trans-(±)-1-amino-1,3-cyclopentanedicarboxylic acid (trans-(±)-ACPD) were evaluated in conscious and anesthetized Wistar, male rats weighing 240-260 g (N = 8). The responses obtained with trans-(±)-ACPD were compared with the responses to L-glutamate (1 nmol/100 nl), since in a previous study we showed that anesthesia converted a pressor response to L-glutamate microinjected into the NTS of conscious rats to a depressor response in the same rats under urethane or chloralose anesthesia. Microinjection of 3 doses of trans-(±)-ACPD (100, 500 and 1000 pmol/100 nl) produced a dose-dependent fall in MAP (range, -20 to -50 mmHg) and HR (range, -30 to -170 bpm) under both conscious and chloralose anesthesia conditions. These data indicate that the cardiovascular responses to the activation of metabotropic receptors by trans-(±)-ACPD are not affected by chloralose anesthesia while the cardiovascular responses to the activation of excitatory amino acid (EAA) receptors by L-glutamate are significantly altered

Effect of all-trans retinoic acid on newly diagnosed acute promyelocytic leukemia patients: results of a Brazilian center

Thirty-seven patients with acute promyelocytic leukemia (APL) were treated with all-trans retinoic acid (ATRA). Patients received 45 mg m-2 day-1 po of ATRA until complete remission (CR) was achieved, defined as: a) presence of less than 5% blasts in the bone marrow, with b) white blood cells >103/mm3, c) platelets >105/mm3 and d) hemoglobin concentration >8 g/dl, with no blood or platelet transfusions. Thirty-one (83.7%) patients achieved CR by day 50, and 75% of these before day 30. Correction of the coagulopathy, achieved between days 2 and 10 (mean, 3 days), was the first evidence of response to treatment. Only one patient had been previously treated with chemotherapy and three had the microgranular variant M3 form. Dryness of skin and mucosae was the most common side effect observed in 82% of the patients. Thrombosis, hepatotoxicity and retinoid acid syndrome (RAS) were observed in 7 (19%), 6 (16%) and 4 (11%) patients, respectively. Thirteen (35%) patients had to be submitted to chemotherapy due to hyperleukocytosis (above 40 x 103/mm3) and six of these presented with new signs of coagulopathy after chemotherapy. Four (11%) patients died secondarily to intracerebral hemorrhage (IH) and two (5.4%) dropped out of the protocol due to severe ATRA side effects (one RAS and one hepatotoxicity). RAS and IH were related strictly to hyperleukocytosis. The reduced use of platelets and fresh frozen plasma probably lowered the total cost of treatment. We conclude that ATRA is an effective agent for inducing complete remission in APL patients.

Trans-sialidase delivered as a naked DNA vaccine elicits an immunological response similar to a Trypanosoma cruzi infection

Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, does not synthesize sialic acid, but expresses a trans-sialidase (TS) that catalyzes the transfer of sialic acid from host glycoconjugates to the parasite surface. Here, we review studies that characterize the immune response to the catalytic domain of the enzyme in humans during Chagas' disease or in mice following immunization with the TS gene. In both cases, there are antibodies that strongly inhibit the enzymatic activity and generation of interferon-g-producing T cells.