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1.
ScientificWorldJournal ; 2014: 639246, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24723819

RESUMO

Botrytis gray mold (BGM) caused by Botrytis cinerea Pers. Ex. Fr. is an extremely devastating disease of chickpea (Cicer arietinum L.) and has a regional as well as an international perspective. Unfortunately, nonchemical methods for its control are weak and ineffective. In order to identify an effective control measure, six fungicides with different modes of action were evaluated on a BGM susceptible chickpea variety BARIchhola-1 at a high BGM incidence location (Madaripur) in Bangladesh for three years (2008, 2009, and 2010). Among the six fungicides tested, one was protectant [Vondozeb 42SC, a.i. mancozeb (0.2%)], two systemic [Bavistin 50 WP, a.i. carbendazim (0.2%), and Protaf 250EC, propiconazole (0.05%)], and three combination formulations [Acrobat MZ690, dimethomorph 9% + mancozeb 60%, (0.2%); Secure 600 WG, phenomadone + mancozeb (0.2%); and Companion, mancozeb 63% + carbendazim 12% (0.2%)]. The results showed superiority of combination formulations involving both protectant and systemic fungicides over the sole application of either fungicide separately. Among the combination fungicides, Companion was most effective, resulting in the lowest disease severity (3.33 score on 1-9 scale) and the highest increase (38%) of grain yield in chickpea. Therefore, this product could be preferred over the sole application of either solo protectant or systemic fungicides to reduce yield losses and avoid fungicide resistance.


Assuntos
Botrytis/patogenicidade , Cicer/microbiologia , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Botrytis/efeitos dos fármacos , Doenças das Plantas/prevenção & controle
2.
ScientificWorldJournal ; 2014: 709614, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25140344

RESUMO

An experiment was conducted in Field Laboratory, Department of Entomology at Bangladesh Agricultural University, Mymensingh, during 2013 to manage the mango hopper, Idioscopus clypealis L, using three chemical insecticides, Imidacloprid (0.3%), Endosulfan (0.5%), and Cypermethrin (0.4%), and natural Neem oil (3%) with three replications of each. All the treatments were significantly effective in managing mango hopper in comparison to the control. Imidacloprid showed the highest efficacy in percentage of reduction of hopper population (92.50 ± 9.02) at 72 hours after treatment in case of 2nd spray. It also showed the highest overall percentage of reduction (88.59 ± 8.64) of hopper population and less toxicity to natural enemies including green ant, spider, and lacewing of mango hopper. In case of biopesticide, azadirachtin based Neem oil was found effective against mango hopper as 48.35, 60.15, and 56.54% reduction after 24, 72, and 168 hours of spraying, respectively, which was comparable with Cypermethrin as there was no statistically significant difference after 168 hours of spray. Natural enemies were also higher after 1st and 2nd spray in case of Neem oil.


Assuntos
Glicerídeos , Hemípteros , Inseticidas , Controle de Pragas/métodos , Terpenos , Animais , Endossulfano , Imidazóis , Neonicotinoides , Nitrocompostos , Piretrinas
4.
Neurochem Int ; 51(6-7): 370-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17513015

RESUMO

Mild to severe cognitive impairments are frequently observed symptoms in chronic alcoholics. Decline of cognitive function significantly affects patients' recovery process and prognosis. The hippocampal region is sensitive to the effects of alcohol and it has been suggested that alcohol-induced hippocampal damage and/or changes in neuronal circuitry play an important role in generating these symptoms. Although various hypotheses have been proposed, molecular mechanisms underlying these alterations in the hippocampus are largely unknown. In the present study, we employed a 2DE-based proteomics approach to compare the protein expression profiles of the hippocampus in human alcoholic and healthy control brains. In the alcoholic hippocampus, 20 protein spots were found to be differentially regulated, 2 increased and 18 decreased. Seventeen proteins were identified using mass spectroscopy and were subcategorized into three energy metabolic proteins, six protein metabolic proteins, four signalling proteins, two oxidative stress-related proteins, one vesicle trafficking protein and one cytoskeletal protein. Some of these proteins have been previously implicated in alcohol-induced brain pathology. Based upon the results, several hypotheses were generated to explain the mechanisms underlying possible functional and/or structural alterations induced by chronic alcohol use in this brain region.


Assuntos
Transtornos do Sistema Nervoso Induzidos por Álcool/metabolismo , Alcoolismo/complicações , Dano Encefálico Crônico/induzido quimicamente , Etanol/efeitos adversos , Hipocampo/efeitos dos fármacos , Proteínas do Tecido Nervoso/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos do Sistema Nervoso Induzidos por Álcool/fisiopatologia , Alcoolismo/fisiopatologia , Dano Encefálico Crônico/metabolismo , Dano Encefálico Crônico/fisiopatologia , Depressores do Sistema Nervoso Central/efeitos adversos , Eletroforese em Gel Bidimensional , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Degeneração Neural/induzido quimicamente , Degeneração Neural/metabolismo , Degeneração Neural/fisiopatologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/fisiologia , Proteômica , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
5.
Biochim Biophys Acta ; 956(1): 39-48, 1988 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-3408738

RESUMO

The relationships between the aggregation state and the enzymatic activities of chicken liver fatty acid synthase have been explored by monitoring the changes in light scattering, fluorescence, and the overall, beta-ketoacyl synthase, beta-ketoacyl reductase and enoyl reductase activities during dissociation and reassociation of the enzyme. The data obtained indicate that the enzyme dissociates at low temperature in both 0.1 M potassium phosphate (pH 7.0), 1 mM EDTA, and 5 mM Tris(hydroxymethyl)aminomethane, 35 mM glycine (pH 8.3) and 1 mM EDTA, but the extent of dissociation is less in the phosphate buffer. The assay conditions influence the assessment of the degree of dissociation and association: high temperatures, phosphate (high salt), NADPH and acetoacetyl-coenzyme A promote association of the monomeric enzyme, whereas dilution in the Tris-glycine buffer (low salt) and low temperature promote dissociation. Both the rate and extent of association and dissociation are altered by substrates. The monomeric enzyme does not possess beta-ketoacyl synthase and beta-ketoacyl reductase activities. Results obtained with the 1,3-dibromo-2-propanone cross-linked enzyme, which lacks beta-ketoacyl synthase activity, indicate that the NADPH-binding site of beta-ketoacyl reductase is disrupted at low ionic strength. In contrast, changes in ionic strength have little effect on the enoyl reductase activity. The dimer is stabilized by both electrostatic and hydrophobic interactions, with the former being of special importance for maintenance of the beta-ketoacyl reductase active site. site.


Assuntos
Ácido Graxo Sintases/metabolismo , Fígado/enzimologia , Animais , Galinhas , Reagentes de Ligações Cruzadas , Ativação Enzimática , Cinética , Luz , Concentração Osmolar , Espalhamento de Radiação , Relação Estrutura-Atividade , Temperatura
6.
Biochim Biophys Acta ; 911(2): 162-7, 1987 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-3801491

RESUMO

Carbon monoxide binding with both cholesterol-free (low-spin) and cholesterol-bound (high-spin) reduced forms of purified cytochrome P-450scc has been investigated by rapid-scan and stopped-flow spectrometry. CO binding occurs within 150 ms at 25 degrees C for both forms of P-450scc, with a typical absorption maximum at 450 nm. Isosbestic points occur at the following wavelengths: between reduced-CO and reduced cholesterol-free P-450scc at 434 and 471 nm; between reduced-CO and reduced cholesterol-bound P-450scc at 433 and 469 nm. Both the 'on' (k1) and 'off' rate constants (k-1) are found to be independent of pH between pH 5 and 9. The mean values of k1 for cholesterol-free (1.8 +/- 0.2) X 10(5) M-1 X s-1) and cholesterol-bound [1.9 +/- 0.1) X 10(5) M-1 X s-1) P-450scc are almost identical, while the mean value of k-1 for the former [2.3 +/- 0.3) X 10 s-1) is about double that of the latter [1.2 +/- 0.1) X 10 s-1). This suggests the instability of the reduced-CO complex in the absence of cholesterol.


Assuntos
Monóxido de Carbono/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Córtex Suprarrenal/enzimologia , Animais , Bovinos , Colesterol/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Mitocôndrias/enzimologia , Oxirredução , Ligação Proteica , Análise Espectral
7.
Bangladesh Med Res Counc Bull ; 31(2): 54-61, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16967810

RESUMO

Medical treatment for symptomatic Benign Prostatic Hyperplasia (BPH) has become popular for the last few years. This study was designed to find out and compare the efficacy of terazosin, a alpha1 adrenoceptor blocker and finasteride, a 5alpha-reductase inhibitor in symptomatic BPH. A total of 60 patients (30 in terazosin group and 30 finasteride group) of symptomatic BPH were selected. Terazosin group received 1 mg daily at bedtime for 3 days, 2 mg at bedtime for 7 days, thereafter 5 mg at bedtime daily for 6 months. Finasteride group received 5 mg once daily. In terazosin treated patients, improvement after 3 months were as follows, IPSS 3.93 +/- .74 points reduction, Qmax 2.13 +/- .68 ml/s increase, post-voided residual urine volume (PVR) 20.67 +/- 10.56 ml reduction (significant, p<0.001) and prostate volume 0.57 +/- 1.54 ml reduction (not significant). Similar statistical differences were observed at 6 months follow up. In finasteride treated patients, improvements after 3 months were as follows, International Prostate Symptom Score (IPSS) 1.38 +/- .63 points reduction, Qmax 0.55 +/- 0.78 ml/s increase, PVR 5.93 +/- 7.64 ml reduction (significant, p<0.001) and prostate volume 0.17 +/- 5.6 ml reduction (non-significant). At 6 month follow up statistical differences were significant in all parameters including prostate volume 4.57 +/- 5.30 ml reduction (p<0.001). In comparison, statistically significant superiority of terazosin over finasteride was found in improving IPSS, Qmax and PVR in both follow up visits. But terazosin had nonsignificant effect in reducing prostate volume; in contrast, finasteride had significant effect in second visit. It can be concluded from this study that terazosin 5mg once daily is effective in mild to moderate cases of symptomatic BPH. On the other hand, finasteride 5mg once daily may be useful in large prostate and to be given for at least 6 months.


Assuntos
Antagonistas Adrenérgicos alfa/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Finasterida/uso terapêutico , Prazosina/análogos & derivados , Hiperplasia Prostática/tratamento farmacológico , Idoso , Bangladesh , Humanos , Masculino , Pessoa de Meia-Idade , Prazosina/uso terapêutico , Hiperplasia Prostática/urina , Resultado do Tratamento
8.
Biochem Pharmacol ; 58(12): 1989-96, 1999 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-10591155

RESUMO

Emerging evidence suggests that mast cell tryptase is a therapeutic target for the treatment of asthma. The effects of this serine protease are associated with both pathophysiologic pulmonary responses and pathologic changes of the asthmatic airway. In this study, the tryptase inhibitor 1,5-bis-[4-[(3-carbamimidoyl-benzenesulfonylamino)-methyl]-p henoxy]-pentane (AMG-126737) was evaluated for its pharmacologic effects against allergen-induced airway responses. AMG-126737 is a potent inhibitor of human lung mast cell tryptase (Ki = 90 nM), with greater than 10- to 200-fold selectivity versus other serine proteases. Intratracheal administration of AMG-126737 inhibited the development of airway hyperresponsiveness in allergen-challenged guinea pigs with an ED50 of 0.015 mg/kg. In addition, the compound exhibited oral activity in the guinea pig model. The in vivo activity of AMG-126737 was confirmed in a sheep model of allergen-induced airway responses, where the compound inhibited early and late phase bronchoconstriction responses and the development of airway hyperresponsiveness. These results support the proposed role of tryptase in the pathology of asthma and suggest that AMG-126737 has potential therapeutic utility in this pulmonary disorder.


Assuntos
Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Carbamatos/uso terapêutico , Mastócitos/enzimologia , Pentanos/uso terapêutico , Serina Endopeptidases/metabolismo , Alérgenos , Animais , Antiasmáticos/farmacologia , Brônquios/efeitos dos fármacos , Brônquios/fisiologia , Carbamatos/farmacologia , Quimases , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Feminino , Cobaias , Masculino , Mastócitos/efeitos dos fármacos , Pentanos/farmacologia , Testes de Função Respiratória , Hipersensibilidade Respiratória/induzido quimicamente , Hipersensibilidade Respiratória/tratamento farmacológico , Serina Endopeptidases/efeitos dos fármacos , Ovinos , Triptases
9.
J Thorac Cardiovasc Surg ; 115(6): 1367-73, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9628680

RESUMO

OBJECTIVE: A simple and reproducible large animal model of dilated cardiomyopathy has yet to be developed. This study was performed to establish a canine model of dilated cardiomyopathy. METHODS: Six closed-chest pure-bred beagles weighing 8 to 12 kg (10 +/- 1.9 kg) underwent intracoronary infusion of doxorubicin (Adriamycin). Low-dose (0.7 mg/kg) doxorubicin was infused into the left main coronary artery through a 5F Judkins catheter. Infusions were repeated weekly for 5 weeks. We evaluated the effects on cardiac hemodynamics, chamber size, the neuroendocrine system, and cardiac ultrastructure before and 1 and 3 months after five intracoronary infusions of doxorubicin. RESULTS: Three months after treatment, fractional shortening (mean +/- standard error of the mean) had decreased from 36.5% +/- 0.8% to 21.7% +/- 1.4% (p = 0.0003), and left ventricular ejection fraction had decreased from 71.0% +/- 3.3% to 36.3% +/- 5.5% (p = 0.001). The left ventricular diastolic dimension had increased from 27.8 +/- 0.9 to 35.5 +/- 0.6 mm (p = 0.003), and the left ventricular end-diastolic volume had increased from 27.5 +/- 1.8 to 38.3 +/- 1.9 ml (p = 0.015). Left ventricular end-diastolic pressure had increased from 8.5 +/- 0.9 to 14.5 +/- 1.1 mm Hg (p = 0.01), and the stroke volume had decreased from 16.7 +/- 0.9 to 11.5 +/- 0.4 ml (p = 0.001). During the same period, the plasma norepinephrine concentration also increased from 114 +/- 27.4 to 423 +/- 88.9 pg/ml (p = 0.024), and plasma atrial natriuretic peptide levels increased from 33.8 +/- 7.0 to 76.5 +/- 14.8 pg/ml (p = 0.012). Histologic changes such as myofiber atrophy and cytoplasmic vacuolation, accompanied with interstitial fibrosis, were found predominantly in the left ventricle. CONCLUSION: Repeated intracoronary infusions of doxorubicin represent a simple and reliable technique to produce dilated cardiomyopathy in the dog. This model can be used to evaluate the effects of new therapies, especially surgical treatments such as dynamic cardiomyoplasty and reduction ventriculoplasty, on dilated cardiomyopathy.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Cardiomiopatia Dilatada/induzido quimicamente , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Animais , Antibióticos Antineoplásicos/administração & dosagem , Atrofia/patologia , Cateterismo Cardíaco , Cardiomiopatia Dilatada/sangue , Cardiomiopatia Dilatada/fisiopatologia , Catecolaminas/sangue , Angiografia Coronária , Vasos Coronários , Cães , Doxorrubicina/administração & dosagem , Ecocardiografia , Fibrose/patologia , Seguimentos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/ultraestrutura , Infusões Intra-Arteriais , Miofibrilas/patologia , Volume Sistólico , Função Ventricular Esquerda/efeitos dos fármacos , Pressão Ventricular
10.
J Thorac Cardiovasc Surg ; 108(4): 609-15, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7934092

RESUMO

The usefulness of dynamic cardiomyoplasty has been demonstrated repeatedly, both experimentally and clinically. Although clinical applications of dynamic cardiomyoplasty to ischemic heart disease have been reported, its effect on the coronary blood flow has never been discussed. Therefore, we tested the hypothesis that dynamic cardiomyoplasty might adversely affect coronary arterial blood flow through compression of the coronary arteries during systolic skeletal muscular contraction and incomplete relaxation of the skeletal muscle flap during diastole. Dynamic cardiomyoplasty was performed in seven mongrel dogs with the use of a left latissimus dorsi-muscle flap, paced synchronously with the R wave of the electrocardiogram. A 3F Doppler catheter was placed in the left main trunk of the coronary artery to assess the instantaneous changes of coronary flow velocity by fast Fourier transformation analysis, We compared systolic and diastolic properties during assisted versus unassisted cardiac cycles by calculating the peak velocity and the time-velocity integral. During assisted cardiac cycles, a significant enhancement of coronary arterial blood flow velocity was demonstrated by significant increases in both systolic and diastolic peak velocity (26.9% +/- 6.5%, p < 0.005; 4.0% +/- 1.6%, p < 0.05, respectively) and time-velocity integral (20.9% +/- 4.8%, p < 0.05; 10.0% +/- 4.6%, p < 0.05, respectively). Enhancement of coronary arterial blood flow velocity was associated with an increase in mean aortic pressure (16.4% +/- 1.3%, p < 0.005) and descending aortic flow (67.5% +/- 5.3%, p < 0.005). Also, the improved systolic coronary arterial blood flow velocity was consistent with an increase in systolic aortic pressure (15.8% +/- 1.5%, p < 0.005), and enhancement of diastolic coronary arterial blood flow velocity was associated with an increase in diastolic aortic pressure (8.6% +/- 2.3%, p < 0.01). We concluded that coronary arterial blood flow velocity was increased by the enhancement of cardiac function as a result of dynamic cardiomyoplasty, leading to an increase of coronary perfusion pressure and cardiac output.


Assuntos
Cardiomioplastia , Vasos Coronários/fisiologia , Contração Miocárdica/fisiologia , Animais , Circulação Assistida , Velocidade do Fluxo Sanguíneo , Débito Cardíaco , Cães , Feminino , Hemodinâmica , Masculino
11.
Ann Thorac Surg ; 65(6): 1676-9, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9647080

RESUMO

BACKGROUND: Although cardiomyoplasty (CMP) is thought to improve ventricular systolic function, its effects on ventricular diastolic function are not clear. Especially the effects on right ventricular diastolic filling have not been fully investigated. Because pericardial influences are more pronounced in the right ventricle than in the left ventricle, CMP with its external constraint may substantially impair right ventricular diastolic filling. METHODS: Fourteen purebred adult beagles were used in this study. Seven underwent left posterior CMP, and 7 underwent a sham operation with a pericardiotomy and served as controls. Four weeks later, the hemodynamic effects of CMP were evaluated by heart catheterization before and after volume loading (central venous infusion of 10 mg/kg of 4.5% albumin solution for 5 minutes). RESULTS: In the CMP group, mean right atrial pressure and right ventricular end-diastolic pressure increased significantly from 3.1 +/- 1.2 mm Hg to 6.1 +/- 2.0 mm Hg (p < 0.001) and from 4.0 +/- 1.8 mm Hg to 9.6 +/- 2.5 mm Hg (p < 0.001), respectively. Volume loading in the control group did not significantly increase either variable. Right ventricular end-diastolic volume and stroke volume did not change significantly (from 53 +/- 9.3 mL to 60 +/- 9.0 mL and from 20 +/- 2.3 mL to 21 +/- 3.2 mL, respectively) in the CMP group. In the control group, however, right ventricular end-diastolic volume and stroke volume increased significantly from 45 +/- 7.7 mL to 63 +/- 14 mL (p < 0.05) and from 18 +/- 4.3 mL to 22 +/- 4.2 mL (p < 0.05), respectively. CONCLUSIONS: These results suggest that CMP may reduce right ventricular compliance and restrict right ventricular diastolic filling in response to rapid volume loading because of its external constraint.


Assuntos
Débito Cardíaco/fisiologia , Cardiomioplastia , Função Ventricular Direita/fisiologia , Albuminas , Animais , Função do Átrio Direito/fisiologia , Pressão Sanguínea/fisiologia , Cateterismo Cardíaco , Volume Cardíaco/fisiologia , Cateterismo Venoso Central , Diástole/fisiologia , Cães , Frequência Cardíaca/fisiologia , Infusões Intravenosas , Contração Miocárdica/fisiologia , Pericardiectomia , Artéria Pulmonar/fisiologia , Volume Sistólico/fisiologia , Pressão Ventricular/fisiologia
12.
Life Sci ; 63(26): 2295-303, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9877219

RESUMO

Hyperresponsiveness of airway smooth muscle to allergens and environmental factors has long been associated with the pathophysiology of asthma. Tryptase, a serine protease of lung mast cells, has been implicated as one of the mediators involved in the induction of hyperresponsiveness. As a consequence, tryptase inhibitors have become the subject of study as potential novel therapeutic agents for asthma. Secretory leukocyte protease inhibitor (SLPI) is a naturally occurring protein of human airways which exhibits anti-tryptase activity. To assess the potential therapeutic utility of SLPI in asthma, its effects were evaluated using in vitro and ex vivo models of airway hyperresponsiveness and compared with the effects of the small molecule tryptase inhibitor APC-366. Our results demonstrate that SLPI inhibits tryptase-mediated hyperresponsiveness in vitro and attenuates the hyperresponsiveness observed in airway smooth muscle from antigen-sensitized animals subjected to antigen exposure. The small molecule tryptase inhibitor APC-366 has a similar inhibitory effect. Thus, tryptase appears to be a significant contributor to the development of hyperresponsiveness in these models. To the extent that tryptase contributes to the development and progression of asthma, SLPI may possess therapeutic potential in this disease setting.


Assuntos
Hiper-Reatividade Brônquica/etiologia , Serina Endopeptidases/fisiologia , Animais , Quimases , Dipeptídeos/farmacologia , Relação Dose-Resposta a Droga , Cobaias , Histamina/farmacologia , Humanos , Técnicas In Vitro , Masculino , Proteínas Secretadas Inibidoras de Proteinases , Proteínas/farmacologia , Inibidor Secretado de Peptidases Leucocitárias , Triptases
13.
Carbohydr Res ; 250(1): 129-44, 1993 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-8143287

RESUMO

Several sialylated and fucosylated oligosaccharides, based upon the N-acetyllactosaminyl core structure, have been synthesized from a single trisaccharide glycoside, beta-D-GlcNAc-(1-->3)-beta-D-Gal-(1-->4)-beta-D-GlcNAc-OCH2(CH2)++ +7CO2CH3, by the sequential use of several glycosyltransferases and one sialidase. In these chemoenzymic syntheses, selective internal monofucosylation of a dimeric N-acetyl-lactosaminyl tetrasaccharide is achieved via two routes. It is demonstrated that the pentasaccharide beta-D-Gal-(1-->4)-beta-D-GlcNAc-(1-->3)-beta-D-Gal-(1-->4)-[alpha- L-Fuc-(1-->3)]-beta-D-GlcNAc-OCH2(CH2)7-CO2CH3 is an acceptor for the rat liver beta-D-Gal-(1-->3/4)-D-Glc-NAc alpha 2,3- and beta-D-Gal-(1-->4)-D-GlcNAc alpha 2,6-sialyltransferases. Among the structures obtained is the terminal hexasaccharide of the CD-65/VIM-2 epitope.


Assuntos
Fucose/química , Oligossacarídeos/síntese química , Ácidos Siálicos/química , Sequência de Carboidratos , Dados de Sequência Molecular , Estrutura Molecular , Ácido N-Acetilneuramínico
14.
Carbohydr Res ; 250(1): 145-60, 1993 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-8143288

RESUMO

Two series of trisaccharides, having the formulas alpha-Neu5Ac-(2-->3)-beta-D-Gal-(1-->4)-beta-D-GlcZ-OR and alpha-Neu5Ac-(2-->3)-beta-D-Gal-(1-->3)-beta-D-GlcZ-OR [R = (CH2)8CO2CH3] respectively, in which the 2-deoxy substituent Z is azido, amino, propionamido, or acetamido, were prepared by chemical synthesis. Both types of modified trisaccharides are acceptors for a fucosyltransferase preparation obtained from human milk. Preparative fucosylations using this enzyme provided analogues of the sialyl Lewis(x) and sialyl Lewis(a) tetrasaccharide structures, which have been proposed to be ligands for cell-adhesion molecules. These syntheses further demonstrate the utility of glycosyltransferases in the preparation of oligosaccharide analogues.


Assuntos
Fucosiltransferases , Leite Humano/enzimologia , Oligossacarídeos/síntese química , Antígeno CA-19-9 , Sequência de Carboidratos , Dados de Sequência Molecular , Estrutura Molecular , Oxirredução , Antígeno Sialil Lewis X
15.
J Hum Hypertens ; 27(11): 671-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23615389

RESUMO

The purpose of this study was to investigate the association of visit-to-visit and 24-h blood pressure (BP) variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking and free of cardiovascular (CV) and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles (EMPs). Significantly lower CD31+CD42- EMPs were found in participants with high visit-to-visit systolic blood pressure (SBP) variability or high 24-h diastolic blood pressure (DBP) variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ EMPs; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, body mass index and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of CV disease, in part, through influences on vascular health.


Assuntos
Negro ou Afro-Americano , Monitorização Ambulatorial da Pressão Arterial , Pressão Sanguínea , Endotélio Vascular/fisiopatologia , Hipertensão/diagnóstico , Músculo Liso Vascular/fisiopatologia , Biomarcadores/sangue , Artéria Braquial/fisiopatologia , Micropartículas Derivadas de Células/metabolismo , Selectina E/sangue , Endotélio Vascular/metabolismo , Feminino , Humanos , Hipertensão/sangue , Hipertensão/etnologia , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/metabolismo , Nitroglicerina , Philadelphia/epidemiologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/sangue , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Valor Preditivo dos Testes , Fatores de Tempo , Vasodilatação , Vasodilatadores
18.
Biochem Cell Biol ; 65(5): 486-92, 1987 May.
Artigo em Inglês | MEDLINE | ID: mdl-3620163

RESUMO

The formation and spontaneous decay of the oxyferrous complex of purified beef adrenocortical cholesterol-bound (high spin) cytochrome P-450scc have been studied by means of rapid-scan spectrometry in the Soret region at 4 degrees C. The oxyferrous complex, the formation of which occurs within 40 ms with a Soret absorption peak at 422 nm, is unstable and decays spontaneously to the ferric cholesterol-bound cytochrome P-450scc. The rapid-scan spectra for both processes were recorded. Isosbestic points occur at the following wavelengths: between ferrous and oxyferrous complex at 418 nm, between oxyferrous complex and ferric cytochrome P-450scc at 411 nm. The kinetics of oxygen binding and spontaneous decay of the oxyferrous complex have also been studied at 4 degrees C by means of stopped-flow experiments in the pH range 5.1-8.8. The rate constant for oxygen binding is constant at 5.8 X 10(5) +/- 0.8 X 10(5) M-1 X S-1 over the pH range of the study. On the other hand, the decay process exhibited pH-dependent monophasic first-order kinetics. The rate constant for the decay appears to be influenced by an acid group with a pKa of 7.1 on the oxyferrous complex of cholesterol-bound cytochrome P-450.


Assuntos
Córtex Suprarrenal/enzimologia , Sistema Enzimático do Citocromo P-450/metabolismo , Animais , Bovinos , Colesterol/metabolismo , Sistema Enzimático do Citocromo P-450/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Mitocôndrias/enzimologia , Consumo de Oxigênio , Proteínas/metabolismo , Espectrofotometria Ultravioleta
19.
Biochem Cell Biol ; 64(4): 323-7, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3718706

RESUMO

The transient state kinetics of the oxidation of reduced nicotinamide adenine dinucleotide (NADH) by horseradish peroxidase compound I and II (HRP-I and HRP-II) was investigated as a function of pH at 25.0 degrees C in aqueous solutions of ionic strength 0.11 using both a stopped-flow apparatus and a conventional spectrophotometer. In agreement with studies using many other substrates, the pH dependence of the HRP-I-NADH reaction can be explained in terms of a single ionization of pKa = 4.7 +/- 0.5 at the active site of HRP-I. Contrary to studies with other substrates, the pH dependence of the HRP-II-NADH reaction can be interpreted in terms of a single ionization with pKa of 4.2 +/- 1.4 at the active site of HRP-II. An apparent reversibility of the HRP-II-NADH reaction was observed. Over the pH range of 4-10 the rate constant for the reaction of HRP-I with NADH varied from 2.6 X 10(5) to 5.6 X 10(2) M-1 s-1 and of HRP-II with NADH varied from 4.4 X 10(4) to 4.1 M-1 s-1. These rate constants must be taken into consideration to explain quantitatively the oxidase reaction of horseradish peroxidase with NADH.


Assuntos
Peroxidase do Rábano Silvestre/metabolismo , NAD/metabolismo , Peroxidases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Matemática , Oxirredução
20.
Biochem Biophys Res Commun ; 145(1): 563-8, 1987 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-3593351

RESUMO

Transient state, burst and steady state kinetics of reactions of the blue copper nitrite reductase (NIR) and blue copper protein from Achromobacter cycloclastes are investigated. The two copper-containing species are reacted with each other and where possible with dithionite, ascorbate and nitrite. Both copper proteins are fully reduced by dithionite with both S2O4(2-) and SO2-. species active. NIR is only partially reduced by ascorbate in an unusual biphasic reaction consistent with complete reduction of type-one copper followed by partial reduction of type-two copper. The rate of reduction of the type-one copper is accelerated using phenazine methosulfate as mediator. Nitrite can oxidize dithionite-reduced NIR but cannot reduce oxidized NIR. Rate constants were determined for all observed reactions.


Assuntos
Alcaligenes/enzimologia , Proteínas de Bactérias , Metaloproteínas/metabolismo , NADH NADPH Oxirredutases/metabolismo , Nitrito Redutases/metabolismo , Ácido Ascórbico/farmacologia , Ditionita/farmacologia , Cinética
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