RESUMEN
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.
Asunto(s)
Botrytis/patogenicidad , Cicer/microbiología , Fungicidas Industriales/farmacología , Enfermedades de las Plantas/microbiología , Botrytis/efectos de los fármacos , Enfermedades de las Plantas/prevención & controlRESUMEN
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.
Asunto(s)
Glicéridos , Hemípteros , Insecticidas , Control de Plagas/métodos , Terpenos , Animales , Endosulfano , Imidazoles , Neonicotinoides , Nitrocompuestos , PiretrinasRESUMEN
Optimization of pyrazinoindolone inhibitors of MAPKAP-K2 (MK2) provides a reasonable balance of cellular potency and physicochemical properties. Mechanistic studies support the inhibition of MK2 which is responsible for the sub-micromolar cellular efficacy.
Asunto(s)
Técnicas Químicas Combinatorias , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Indoles/síntesis química , Indoles/farmacología , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirazoles/síntesis química , Pirazoles/farmacología , Inhibidores Enzimáticos/química , Indoles/química , Concentración 50 Inhibidora , Estructura Molecular , Pirazoles/química , Relación Estructura-ActividadRESUMEN
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.
Asunto(s)
Trastornos del Sistema Nervioso Inducidos por Alcohol/metabolismo , Alcoholismo/complicaciones , Daño Encefálico Crónico/inducido químicamente , Etanol/efectos adversos , Hipocampo/efectos de los fármacos , Proteínas del Tejido Nervioso/efectos de los fármacos , Adulto , Anciano , Anciano de 80 o más Años , Trastornos del Sistema Nervioso Inducidos por Alcohol/fisiopatología , Alcoholismo/fisiopatología , Daño Encefálico Crónico/metabolismo , Daño Encefálico Crónico/fisiopatología , Depresores del Sistema Nervioso Central/efectos adversos , Electroforesis en Gel Bidimensional , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Hipocampo/metabolismo , Hipocampo/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Degeneración Nerviosa/inducido químicamente , Degeneración Nerviosa/metabolismo , Degeneración Nerviosa/fisiopatología , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Transporte de Proteínas/efectos de los fármacos , Transporte de Proteínas/fisiología , Proteómica , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
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.
Asunto(s)
Ácido Graso Sintasas/metabolismo , Hígado/enzimología , Animales , Pollos , Reactivos de Enlaces Cruzados , Activación Enzimática , Cinética , Luz , Concentración Osmolar , Dispersión de Radiación , Relación Estructura-Actividad , TemperaturaRESUMEN
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.
Asunto(s)
Monóxido de Carbono/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Corteza Suprarrenal/enzimología , Animales , Bovinos , Colesterol/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Mitocondrias/enzimología , Oxidación-Reducción , Unión Proteica , Análisis EspectralRESUMEN
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.
Asunto(s)
Antagonistas Adrenérgicos alfa/uso terapéutico , Inhibidores Enzimáticos/uso terapéutico , Finasterida/uso terapéutico , Prazosina/análogos & derivados , Hiperplasia Prostática/tratamiento farmacológico , Anciano , Bangladesh , Humanos , Masculino , Persona de Mediana Edad , Prazosina/uso terapéutico , Hiperplasia Prostática/orina , Resultado del TratamientoRESUMEN
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.
Asunto(s)
Antiasmáticos/uso terapéutico , Asma/tratamiento farmacológico , Carbamatos/uso terapéutico , Mastocitos/enzimología , Pentanos/uso terapéutico , Serina Endopeptidasas/metabolismo , Alérgenos , Animales , Antiasmáticos/farmacología , Bronquios/efectos de los fármacos , Bronquios/fisiología , Carbamatos/farmacología , Quimasas , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Femenino , Cobayas , Masculino , Mastocitos/efectos de los fármacos , Pentanos/farmacología , Pruebas de Función Respiratoria , Hipersensibilidad Respiratoria/inducido químicamente , Hipersensibilidad Respiratoria/tratamiento farmacológico , Serina Endopeptidasas/efectos de los fármacos , Ovinos , TriptasasRESUMEN
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.
Asunto(s)
Antibióticos Antineoplásicos/toxicidad , Cardiomiopatía Dilatada/inducido químicamente , Modelos Animales de Enfermedad , Doxorrubicina/toxicidad , Animales , Antibióticos Antineoplásicos/administración & dosificación , Atrofia/patología , Cateterismo Cardíaco , Cardiomiopatía Dilatada/sangre , Cardiomiopatía Dilatada/fisiopatología , Catecolaminas/sangre , Angiografía Coronaria , Vasos Coronarios , Perros , Doxorrubicina/administración & dosificación , Ecocardiografía , Fibrosis/patología , Estudios de Seguimiento , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/fisiopatología , Ventrículos Cardíacos/ultraestructura , Infusiones Intraarteriales , Miofibrillas/patología , Volumen Sistólico , Función Ventricular Izquierda/efectos de los fármacos , Presión VentricularRESUMEN
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.
Asunto(s)
Cardiomioplastia , Vasos Coronarios/fisiología , Contracción Miocárdica/fisiología , Animales , Circulación Asistida , Velocidad del Flujo Sanguíneo , Gasto Cardíaco , Perros , Femenino , Hemodinámica , MasculinoRESUMEN
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.
Asunto(s)
Gasto Cardíaco/fisiología , Cardiomioplastia , Función Ventricular Derecha/fisiología , Albúminas , Animales , Función del Atrio Derecho/fisiología , Presión Sanguínea/fisiología , Cateterismo Cardíaco , Volumen Cardíaco/fisiología , Cateterismo Venoso Central , Diástole/fisiología , Perros , Frecuencia Cardíaca/fisiología , Infusiones Intravenosas , Contracción Miocárdica/fisiología , Pericardiectomía , Arteria Pulmonar/fisiología , Volumen Sistólico/fisiología , Presión Ventricular/fisiologíaRESUMEN
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.
Asunto(s)
Hiperreactividad Bronquial/etiología , Serina Endopeptidasas/fisiología , Animales , Quimasas , Dipéptidos/farmacología , Relación Dosis-Respuesta a Droga , Cobayas , Histamina/farmacología , Humanos , Técnicas In Vitro , Masculino , Proteínas Inhibidoras de Proteinasas Secretoras , Proteínas/farmacología , Inhibidor Secretorio de Peptidasas Leucocitarias , TriptasasRESUMEN
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.
Asunto(s)
Fucosa/química , Oligosacáridos/síntesis química , Ácidos Siálicos/química , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Estructura Molecular , Ácido N-AcetilneuramínicoRESUMEN
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.
Asunto(s)
Fucosiltransferasas , Leche Humana/enzimología , Oligosacáridos/síntesis química , Antígeno CA-19-9 , Secuencia de Carbohidratos , Datos de Secuencia Molecular , Estructura Molecular , Oxidación-Reducción , Antígeno Sialil Lewis XRESUMEN
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.
Asunto(s)
Negro o Afroamericano , Monitoreo Ambulatorio de la Presión Arterial , Presión Sanguínea , Endotelio Vascular/fisiopatología , Hipertensión/diagnóstico , Músculo Liso Vascular/fisiopatología , Biomarcadores/sangre , Arteria Braquial/fisiopatología , Micropartículas Derivadas de Células/metabolismo , Selectina E/sangre , Endotelio Vascular/metabolismo , Femenino , Humanos , Hipertensión/sangre , Hipertensión/etnología , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Músculo Liso Vascular/metabolismo , Nitroglicerina , Philadelphia/epidemiología , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/sangre , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Valor Predictivo de las Pruebas , Factores de Tiempo , Vasodilatación , VasodilatadoresAsunto(s)
Epítopos/química , Fucosa , Oligosacáridos/química , Oligosacáridos/síntesis química , Ácidos Siálicos , Animales , Secuencia de Carbohidratos , Indicadores y Reactivos , Hígado/enzimología , Datos de Secuencia Molecular , Ácido N-Acetilneuramínico , Oligosacáridos/biosíntesis , Ratas , Sialiltransferasas/metabolismo , beta-D-Galactósido alfa 2-6-SialiltransferasaRESUMEN
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.
Asunto(s)
Corteza Suprarrenal/enzimología , Sistema Enzimático del Citocromo P-450/metabolismo , Animales , Bovinos , Colesterol/metabolismo , Sistema Enzimático del Citocromo P-450/aislamiento & purificación , Concentración de Iones de Hidrógeno , Cinética , Mitocondrias/enzimología , Consumo de Oxígeno , Proteínas/metabolismo , Espectrofotometría UltravioletaRESUMEN
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.
Asunto(s)
Peroxidasa de Rábano Silvestre/metabolismo , NAD/metabolismo , Peroxidasas/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Matemática , Oxidación-ReducciónRESUMEN
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.