RESUMEN
One distinctive trait of kendo, the Japanese martial art of fencing, is the execution of sustained, high-effort vocalizations during actions. The purpose of this study was to determine the effect of these vocalizations on respiratory functions. First, the intensity of 3 kendo exercises was quantified by measuring oxygen uptake (VÌO2) and comparing it with VÌO2max measured during treadmill tests of 8 university kendo athletes. Respiratory variables of these 8 athletes were then analyzed using a portable breath gas analyzer during the most intensive kendo exercise, kakari-keiko, with and without vocalization. Breathing frequency (fB) increased regardless of vocalization, but in trials with vocalization, fB and ventilation were significantly lower, and expiration time was significantly longer. Components of expired gases were also affected by vocalization. Although there was no significant difference in oxygen uptake, vocalization yielded a reduction in carbon dioxide output (VÌCO2) and an increase in fraction of end-tidal carbon dioxide (FetCO2). We thus conclude that these vocalizations greatly affect expiration breathing patterns in kendo. Moreover, repetition of kakari-keiko caused a reduction in VÌCO2 and an increase in FetCO2 and CO2 storage. We consider the possibility that the sustained high-effort vocalizations of kendo also increase cerebral blood flow.
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Dióxido de Carbono/metabolismo , Ejercicio Físico/fisiología , Artes Marciales/fisiología , Voz/fisiología , Adolescente , Pruebas Respiratorias/métodos , Prueba de Esfuerzo , Humanos , Masculino , Oxígeno/metabolismo , Respiración , Adulto JovenRESUMEN
OBJECTIVE: The authors evaluated the effectiveness and safety of "neo-metoro" or 'mini-metoro" metreurynters plus oxytocin for labor induction and assessed differences in parturition outcomes, according to the metreurynter used at induction initiation. MATERIALS AND METHODS: The authors retrospectively reviewed 146 consecutive women with live singleton pregnancies, and who underwent induction. Parturition outcomes were vaginal delivery achieved within the planned schedule (VDPS), vaginal delivery finally achieved (VDF), and induction-to-delivery interval (IDI). Women were divided into neo-metoro, mini-metoro, and without metreurynter groups based on metreurynter use at induction initiation. The authors examined the relationships of metreurynter groups with factors, parturition outcomes, and adverse events. In 113 women who underwent two-day induction, the authors calculated IDI and adjusted odds ratio (AOR) for achieving delivery per unit time. RESULTS: VDPS rates were 65% in nulliparous and 81% in multiparous women. VDF rates were 78% in nulliparous and 96% in multiparous women. AORs for VDPS were 0.30 in nulliparous women and 0.18 in Bishop score (BS) 1-3 class. AORs for VDF were 0.04 in BS1-3 class and 0.14 in BS4-5 class. In 113 women undergoing two-day induction, AORs for achieving delivery per unit time were 0.45 in nulliparous women, 0.46 in obese women, and 0.48 in BS1-3 class. Neo-metoro use at induction initiation tended to reduce IDI. CONCLUSIONS: Labor induction using these metreurynters plus oxytocin is safe and effective. The advantages of neo-metoro over mini-metoro use at induction initiation remain unclear; neo-metoro use at induction initiation may reduce IDI.
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Catéteres , Trabajo de Parto Inducido/métodos , Oxitócicos/administración & dosificación , Oxitocina/administración & dosificación , Administración Intravaginal , Adulto , Terapia Combinada , Diseño de Equipo , Femenino , Rotura Prematura de Membranas Fetales/terapia , Humanos , Japón , Paridad , Embarazo , Resultado del Embarazo , Modelos de Riesgos Proporcionales , Estudios RetrospectivosRESUMEN
Bovine mercaptalbumin (BMA) has 17 disulfide bonds and one SH group at Cys-34 which catalyzes the intramolecular SH, S-S exchange reaction (N-A isomerization, molecular aging) in the alkaline region at low ionic strength, resulting in the formation of the aged form (A-form). The aging reaction was completely reversible and strongly affected by environmental factors, such as pH, temperature, ionic strength, Ca2+, nonbranched short-chain fatty acids, etc. Disulfide configuration (or pairing of disulfide bonds) was affected by the environmental factors. Obtained results might support the concept of Klotz (1966) that protein conformation (or three-dimensional structure) is dependent upon (i) the primary structure and (ii) constituents of the solvent.
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Disulfuros/metabolismo , Albúmina Sérica Bovina/metabolismo , Albúmina Sérica/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Animales , Bovinos , Ácidos Grasos/farmacología , Calor , Isomerismo , Concentración Osmolar , Albúmina Sérica/efectos de los fármacos , Albúmina Sérica Bovina/efectos de los fármacosRESUMEN
We have applied the transition state theory of Eyring et al. (The Theory of Rate Processes, McGraw-Hill, 1941) to water transport across cell membranes. We have then evaluated free energy (Delta F(not equal)), enthalpy (Delta H(not equal)) and entropy (Delta S(not equal)) of activation for water permeation across membranes, such as Arbacia eggs, Xenopus oocytes with or without aquaporin water channels, mammalian erythrocytes, aquaporin proteoliposomes, liposomes and collodion membrane. Delta H(not equal) was found to be correlated with Delta S(not equal). This is so-called Delta H(not equal) and Delta S(not equal) compensation over the ranges of Delta H(not equal) and Delta S(not equal) from 2 to 22 kcal/mol and from -26 to 45 e.u., respectively, indicating that low Delta H(not equal) values correspond to negative Delta S(not equal). Large positive Delta S(not equal) and high Delta H(not equal) values might be accompanied by reversible breakage of secondary bonds in the membrane, presumably in membrane lipid bilayer. Largely negative Delta S(not equal) and low Delta H(not equal) values for aquaporin water channels, aquaporin proteoliposomes and porous collodion membrane could be explained by the immobilization of permeating water molecules in the membrane, i.e., the partial loss of rotational and/or translational freedoms of water molecules in water channels.
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Membrana Celular/metabolismo , Agua/metabolismo , Animales , Permeabilidad de la Membrana Celular , Colodión , Modelos Teóricos , Presión Osmótica , Erizos de Mar , TermodinámicaRESUMEN
Human serum albumin (HSA) is the mixture of human mercaptalbumin (HMA, reduced form) and human nonmercaptalbumin (HNA, oxidized form). We developed a rapid and concise HPLC system to obtain the clear resolution of HSA into HMA and HNA, using an Asahipak GS-520H column. The mean value of the fraction of HMA (f(HMA)) for healthy young male subjects was 0.76 +/- 0.04 (n = 54). However, the f(HMA, 60-90) value for healthy elderly subjects (where the numbers in brackets indicate the range of ages) was 0.48 +/- 0.06 (n = 183). In healthy elderly subjects, f(HMA) was significantly lower than in healthy young male subjects, indicating that HSA in the elderly becomes more oxidized than in the young subjects. Consequently, we suggest that one of the important functions of serum albumin could be to participate in the maintenance of a constant redox potential in the extracellular fluids, thus securing a certain redox buffer capacity. f(HMA) on HSA might reflect this redox buffer capacity with age.
Asunto(s)
Envejecimiento , Albúmina Sérica/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Cromatografía Líquida de Alta Presión , Humanos , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Albúmina Sérica HumanaRESUMEN
In order to provide new insight into the molecular mechanism of perforating trauma-induced cataract formation in an 8-week-old ddY mouse lens, we performed an in situ investigation into changes in the water-protein and/or protein-protein interactions by using 500 MHz (1)H-NMR spectroscopy, and into structural alterations in lens proteins by using Raman spectroscopy. Cross-relaxation times of water protons in the perforated opaque lens were considerably shorter than those in the intact transparent lens, whereas there was no significant difference in water content, suggesting a drastic change in water-protein and protein-protein interactions in the perforated lens. In addition, there was no significant difference in the intensity ratios of several key Raman bands between intact and perforated lenses, indicating that no significant local and overall conformational changes in lens protein itself occur in the perforated lens. The present (1)H-NMR and Raman results lead us to the conclusion that changes leading to lens opacification in the perforating trauma-induced cataract appear to involve the rapid formation of immobile large lens protein aggregates without formation of intra- and intermolecular disulfide linkages, and rapid increase in a fraction of bound water associated with large protein aggregates.
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Catarata/metabolismo , Cristalinas/metabolismo , Cristalino/metabolismo , Animales , Catarata/etiología , Cristalinas/química , Espectroscopía de Resonancia Magnética , Ratones , Espectrometría Raman , Heridas y LesionesRESUMEN
The physical state of water in mouse lenses (2-, 4- or 8-wk-old) and soft contact lenses (SCLs, water content from 18.4 to 79.2%) were studied by measuring spin-lattice relaxation times (T1) and apparent intermolecular cross-relaxation times (TIS) from irradiated protein or polymer protons to water protons, using 360 MHz 1H-NMR spectrometer at 25 degrees C. (1) 1/T1 values of SCLs increased gradually with increasing dry weight (W(%)). 1/TIS values of SCLs were approximately zero at W of 20.8 and 26.8%, increased gradually from 26.8% and then steeply above approximately 50%. (2) A plot of 1/T1 vs. W(%) of mouse lenses was almost equal to that of SCLs. However, a plot of 1/TIS vs. W(%) was an approximately straight line with the intercept at W of 23% and with the slope which is almost equal to that of SCLs above W of approximately 50%. The plot of 1/TIS vs. W(%) of mouse lenses might indicate the significant change in the physical state of water and/or protein-water interactions above W of 23%.
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Lentes de Contacto Hidrofílicos , Cristalino/química , Agua/química , Factores de Edad , Animales , Fenómenos Químicos , Química Física , Cristalinas/química , Humanos , Sustancias Macromoleculares , Espectroscopía de Resonancia Magnética , Ratones , Modelos Químicos , Polímeros/química , ProtonesRESUMEN
Whereas bovine beta-lactoglobulin is a predominantly beta-sheet protein, it has a marked alpha-helical preference and can be considered to be a useful model of the alpha-->beta transition, a key issue for understanding the folding and biological function of a number of proteins. In order to understand the mechanism of the alpha-->beta transition, the backbone structures of the recombinant bovine beta-lactoglobulin A in the native state and in the highly helical state induced by 2,2,2-trifluoroethanol were characterized by 1H, 13C and 15N multidimensional NMR spectroscopy. Overall, the secondary structures in the native state were similar to those of the crystal structure. On the other hand, beta-lactoglobulin in the 2,2,2-trifluoroethanol state was composed of many alpha-helical segments. The presence of the persistent alpha-helices in the helical state and the core beta-sheet in the native state suggested that during folding native-like core beta-sheet and several non-native helices are formed first and the remaining beta-sheet is subsequently "induced" through interaction with the pre-existing beta-sheet.
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Lactoglobulinas/química , Animales , Bovinos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Pliegue de Proteína , Estructura Secundaria de Proteína , Trifluoroetanol/farmacologíaRESUMEN
AIM: This randomized controlled study was designed to examine the effects of reduced coenzyme Q10 (ubiquinol; CoQ10) supplementation on blood pressure (BP) and exercise-induced muscle damage in kendo athletes during a 4-day kendo training camp. METHODS: In a double-blinded manner, 32 young kendo athletes were randomly assigned to supplement with either placebo or CoQ10 (600 mg) daily for 11 days from 1 week prior to camp to end of camp. BP was measured every morning after waking up during the training camp. Blood samples were taken at 3 time points; 1 week and 1 day prior and upon completion of training camp at 17:30. Statistical analysis was performed by repeated-measures analysis of variance followed by Bonferroni/Dunn post-hoc tests. RESULTS: Before the training camp started, there were no differences in diastolic BP between these groups. However, after kendo training started, diastolic BP in the CoQ10 group was significantly lower than that in the placebo group (P<0.05). Plasma creatine kinase (CK) and myoglobin (Mb) concentrations were significantly increased in both groups during the camp (P<0.05), whereas there were no significant differences in CK and Mb between CoQ10 and placebo groups (CK: P=0.82, Mb: P=0.69). CONCLUSION: Oral supplementation with reduced form of CoQ10 (ubiquinol; Kaneka QHTM) showed a significant hypotensive effect in young male kendo athletes during a 4-day kendo training camp, although it did not significantly ameliorate kendo exercise-induced muscle damage.
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Presión Sanguínea/efectos de los fármacos , Artes Marciales/fisiología , Músculo Esquelético/efectos de los fármacos , Ubiquinona/análogos & derivados , Biomarcadores/sangre , Creatina Quinasa/sangre , Suplementos Dietéticos , Método Doble Ciego , Humanos , Masculino , Mioglobina/sangre , Educación y Entrenamiento Físico , Ubiquinona/administración & dosificación , Adulto JovenRESUMEN
The E2 ubiquitin conjugating enzyme Ubc13 and the E3 ubiquitin ligases Rad18 and Rnf8 promote homologous recombination (HR)-mediated double-strand break (DSB) repair by enhancing polymerization of the Rad51 recombinase at γ-ray-induced DSB sites. To analyze functional interactions between the three enzymes, we created RAD18(-/-), RNF8(-/-), RAD18(-/-)/RNF8(-/-) and UBC13(-/-)clones in chicken DT40 cells. To assess the capability of HR, we measured the cellular sensitivity to camptothecin (topoisomerase I poison) and olaparib (poly(ADP ribose)polymerase inhibitor) because these chemotherapeutic agents induce DSBs during DNA replication, which are repaired exclusively by HR. RAD18(-/-), RNF8(-/-) and RAD18(-/-)/RNF8(-/-) clones showed very similar levels of hypersensitivity, indicating that Rad18 and Rnf8 operate in the same pathway in the promotion of HR. Although these three mutants show less prominent defects in the formation of Rad51 foci than UBC13(-/-)cells, they are more sensitive to camptothecin and olaparib than UBC13(-/-)cells. Thus, Rad18 and Rnf8 promote HR-dependent repair in a manner distinct from Ubc13. Remarkably, deletion of Ku70, a protein essential for nonhomologous end joining (NHEJ) significantly restored tolerance of RAD18(-/-) and RNF8(-/-) cells to camptothecin and olaparib without affecting Rad51 focus formation. Thus, in cellular tolerance to the chemotherapeutic agents, the two enzymes collaboratively promote DSB repair by HR by suppressing the toxic effect of NHEJ on HR rather than enhancing Rad51 focus formation. In contrast, following exposure to γ-rays, RAD18(-/-), RNF8(-/-), RAD18(-/-)/RNF8(-/-) and UBC13(-/-)cells showed close correlation between cellular survival and Rad51 focus formation at DSB sites. In summary, the current study reveals that Rad18 and Rnf8 facilitate HR by two distinct mechanisms: suppression of the toxic effect of NHEJ on HR during DNA replication and the promotion of Rad51 focus formation at radiotherapy-induced DSB sites.
Asunto(s)
Reparación del ADN por Unión de Extremidades/genética , Proteínas de Unión al ADN/genética , Recombinación Homóloga/genética , Recombinasa Rad51/genética , Antígenos Nucleares/genética , Línea Celular Tumoral , Reparación del ADN/genética , Replicación del ADN/genética , Células HCT116 , Humanos , Autoantígeno Ku , Enzimas Ubiquitina-Conjugadoras/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación/genéticaRESUMEN
Using heteronuclear NMR spectroscopy, we studied the solution structure and dynamics of bovine beta-lactoglobulin A at pH 2.0 and 45 degrees C, where the protein exists as a monomeric native state. The monomeric NMR structure, comprising an eight-stranded continuous antiparallel beta-barrel and one major alpha-helix, is similar to the X-ray dimeric structure obtained at pH 6.2, including betaI-strand that forms the dimer interface and loop EF that serves as a lid of the interior hydrophobic hole. [1H]-15N NOE revealed that betaF, betaG, and betaH strands buried under the major alpha-helix are rigid on a pico- to nanosecond time scale and also emphasized rapid fluctuations of loops and the N- and C-terminal regions.
Asunto(s)
Lactoglobulinas/química , Secuencia de Aminoácidos , Animales , Bovinos , Variación Genética , Concentración de Iones de Hidrógeno , Lactoglobulinas/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Estructura Secundaria de Proteína , SolucionesRESUMEN
Conformational changes in cystine disulfide bridges of bovine serum albumin during acid-induced isomerization (N --> F and F --> E transitions) have been studied with Raman spectroscopy. In an X-ray crystallographic study of human serum albumin, Carter and Ho reported that all disulfide bridges of the albumin molecule are in the gauche-gauche-gauche conformation [1]. On the other hand, the solution structure of bovine serum albumin examined by Raman spectroscopy differs from its crystal structure in the conformation of some of the disulfide bridges. Two Raman bands were detected at 520 and 505 cm(-1) in the disulfide stretching mode region, suggesting that the 17 disulfide bridges in the N-form of bovine serum albumin solution take both the gauche-gauche-gauche and gauche-gauche-trans conformations. The ratio of the peak intensities at 520 and 505 cm(-1) (I505/I520) is increased from 1.6 to 2.1 and from 2.1 to 6.3 on going from the N- to the F-form and from the F- to the E-form, respectively, indicating that the gauche-gauche-trans conformation of the disulfide bridges is converted to a gauche-gauche-gauche one which is the most energetically stable form during the acid-induced isomerization. However, small amounts of gauche-gauche-trans conformation still remain even in the E-form.
Asunto(s)
Cistina , Disulfuros , Conformación Proteica , Albúmina Sérica Bovina/química , Animales , Bovinos , Cristalografía por Rayos X , Humanos , Albúmina Sérica/química , Espectrometría RamanRESUMEN
From summer to mid-autumn for four consecutive years (1974 to 1977), a 50-year-old woman barber experienced cough and exertional dyspnea with sputum production. Rales were audible at the posterior lung bases bilaterally. Her chest x-ray film showed diffuse nodular shadows, and pulmonary function studies revealed markedly decreased DCO. Open chest lung biopsy was performed and granulomatous lesions with multinucleated giant cells without central necrosis were observed. Having experienced multiple episodes for four years, she ceased to show symptoms after demolishing and reorganizing her house. This case is thought to represent the typical summer-type hypersensitivity pneumonitis, which we have subsequently found to be the most prevalent form of hypersensitivity pneumonitis in Japan.
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Alveolitis Alérgica Extrínseca/patología , Femenino , Humanos , Pulmón/patología , Persona de Mediana Edad , Recurrencia , Estaciones del AñoRESUMEN
The effect of exercise training on the antilipolytic action of insulin was studied in rat adipocytes. Exercise training enhanced lipolysis induced by norepinephrine. Insulin dose dependently inhibited norepinephrine- (1 microM) stimulated lipolysis in both groups. Its inhibition rate was significantly greater in the trained than in the control group. Thus, exercise training enhanced the antilipolytic action of insulin. In the control group, insulin (1,000 microU/ml) reduced the displacement rate of [3H]CGP-12177 binding to adipocytes by low concentrations of (-)-norepinephrine. The slope factor without insulin was 0.76, whereas that with insulin was 0.95. In the trained group, insulin did not affect the competition binding of (-)-norepinephrine for [3H]CGP-12177. The displacement rate of [3H]CGP-12177 binding from adipocytes by low concentrations of (-)-norepinephrine was significantly greater in the trained than in the control group. The number of surface beta-adrenergic receptors per adipocyte was smaller in the trained than in the control group. Cilostamide, which blocks the antilipolytic action of insulin, restored lipolysis in both groups. The recovery rate was significantly greater in the trained than in the control group. These findings suggest that the enhanced antilipolytic action by insulin in the trained group occurs at a site distal to the binding of norepinephrine to beta-adrenergic receptors and that it is due to the increased activity of particulate low-Michaelis constant phosphodiesterase.
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Tejido Adiposo/efectos de los fármacos , Insulina/farmacología , Lipólisis/efectos de los fármacos , Condicionamiento Físico Animal , 3',5'-AMP Cíclico Fosfodiesterasas/metabolismo , Tejido Adiposo/metabolismo , Antagonistas Adrenérgicos beta/metabolismo , Animales , Unión Competitiva , Técnicas In Vitro , Masculino , Norepinefrina/metabolismo , Norepinefrina/farmacología , Propanolaminas/metabolismo , Quinolonas/farmacología , Ratas , Ratas Wistar , Receptores Adrenérgicos beta/efectos de los fármacos , Receptores Adrenérgicos beta/metabolismoRESUMEN
The charge effect on the translational self-diffusion constant, D, of polyelectrolytes has been quantitatively analyzed based on dynamic light scattering experiments. Perfectly monodisperse bovine mercaptalbumin has been used at low pH as a positively charged polyelectrolyte sample. Completely linear plots of log(g2(t)-1) vs. time t have been obtained for uncharged states of the protein, for the correlation function of the scattered light intensity, g2(t). The plots deviate from linearity as polyions bear the charges. The D values for various ionic states, obtained from the initial slopes of the plots, have been analyzed using the simple theory of Imai and Mandel (N. Imai and M. Mandel, Macromolecules 15 (1982) 1562) derived based on the Onsager-Navier-Stokes equation for solvent flow with counterion distribution around a polyion. It has turned out that the experimental D values coincide well with the theory and that the characteristic nature of D can be elucidated principally from the charge effect.
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Albúmina Sérica Bovina , Albúmina Sérica , Difusión , Concentración de Iones de Hidrógeno , Cinética , MatemáticaRESUMEN
The charge effect on the translational self-diffusion constant, D, of polyelectrolytes has been quantitatively analyzed based on dynamic light scattering experiments. Perfectly monodisperse bovine mercaptalbumin has been used at low pH as a positively charged polyelectrolyte sample. Completely linear plots of log{g2(t)-1} vs. time t have been obtained for uncharged states of the protein, for the cor relation function of the scattered light intensity, g2(t). The plots deviate from linearity as polyions bear the charges. The D values for various ionic states, obtained from the initial slopes of the plots, have been analyzed using the simple theory of Imai and Mandel (N. Imai and M. Mandel, Macromolecules 15 (1982) 1562) derived based on the Onsager-Navier-Stokes equation for solvent flow with counterion distribution around a polyion. It has turned out that the experimental D values coincide well with the theory and that the characteristic nature of D can be elucidated principally from the charge effect.
RESUMEN
High-performance liquid chromatographic (HPLC) analysis of human serum albumin (HSA) on Asahipak GS-520H columns at neutral pH (6.87) showed a clear resolution of human mercaptalbumin (HMA) and nonmercaptalbumin (HNA), which are reduced and oxidized form of HSA, respectively. We studied the conversion of HMA to HNA (mercapt-nonmercapt conversion) as an index of oxidative change of the tissues and organs in 28 normal subjects and in a total of 47 patients with non-insulin dependent diabetes mellitus (NIDDM). Mean (+/- SD) values of the HMA fraction of HSA, f(HMA), [HMA/(HMA + HNA)], was significantly lower in NIDDM patients than in normal subjects (0.63 +/- 0.067 vs 0.75 +/- 0.028, P < 0.001). It was lower in poorly controlled NIDDM patients (0.63 +/- 0.058, n = 20) than in well controlled NIDDM patients (0.67 +/- 0.032, n = 9) (P < 0.05). Plasma glucose values sampled on occasions including overnight fasting and postprandial ones (r = -0.441, n = 47, P < 0.01), but not plasma glucose values sampled on overnight fasting (r = -0.345, n = 29) or postprandial (r = -0.467, n = 18) conditions and HbA1c (r = -0.211, n = 34), negatively correlated with the f(HMA) values, indicating that mercapt-nonmercapt conversion may not be due to cumulative hyperglycemia over a month, but due to short-term alteration in blood glucose level. The presence or absence of diabetic complications including nephropathy, retinopathy and neuropathy did not affect the f(HMA) values. In conclusion, decreased f(HMA) values in the diabetic patients suggested the presence of a rapidly altered oxidative change of albumin due to hyperglycemia.
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Diabetes Mellitus Tipo 2/sangre , Albúmina Sérica/análisis , Adulto , Biomarcadores/sangre , Glucemia/metabolismo , Cromatografía Líquida de Alta Presión , Neuropatías Diabéticas/sangre , Ingestión de Alimentos , Ayuno , Femenino , Hemoglobina Glucada/análisis , Humanos , Masculino , Persona de Mediana Edad , Oxidación-Reducción , Valores de Referencia , Albúmina Sérica HumanaRESUMEN
The clinical applicability of magnetization transfer (MT) technique in magnetic resonance imaging (MRI) for the estimation of the histological and constitutional feature of brain tumors was investigated. MT effect was evaluated by measuring the MT ratio (MTR). The parameters in 1.5-tesla MRI system were as follows: TR, 50 msec; TE, 5 msec; flip angle, 30 degree; offset frequency of off-resonance MT pulse, 1000 Hz. The sequence was performed in 20 normal volunteers and 45 patients with brain tumors which were characterized histologically and surgically. The MTR for brain tumors was significantly lower than that for normal brain tissue (p < 0.05). The MTR for meningioma was higher than that for the other brain tumors (p < 0.05). In the meningiomas, MTR for fibrous type was higher than that for meningothelial type, but there was no statistical significance. Regarding the physical consistency for the brain tumors, as classified by surgery, there was a statistically significant difference in MTR between the soft tumor group (0.22 +/- 0.03, n = 6) and the hard tumor group (0.36 +/- 0.04, n = 10) (p < 0.01). This study suggested that the MT technique for patients with brain tumor may be useful to understand the characteristics of the tumors presurgically, based on the degree of intermolecular interaction of macromolecule such as protein.
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Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Imagen por Resonancia Magnética/métodos , Meningioma/diagnóstico , Adenoma/diagnóstico , Encéfalo/patología , Diagnóstico Diferencial , Humanos , Infiltración Leucémica , Linfoma/diagnósticoRESUMEN
We investigated the clinical applicability of pulsed off-resonance magnetization transfer (MT) technique in magnetic resonance (MR) imaging for the estimation of the histological feature of brain tumor. The parameters were optimized using bovine serum albumin (BSA) solutions and gels in 1.5-tesla MR system as follows: TR, 50 msec; TE, 5 msec; flip angle, 30 degree; offset frequency, 1000 Hz. MT effect was evaluated by measuring the MT ratio (MTR) and reconstructing calculated MTR color image. The MTRs of the BSA solutions and gels increased with increasing concentrations of protein, while the MTRs of the gels were remarkably higher than those of the solutions. The optimized sequence was performed in 20 healthy volunteers and 30 patients with brain tumors. In normal brains, the MTRs were significantly higher in white matter than in gray matter (p < 0.05). The MTR in brain tumor was significantly lower than that in normal brain tissue (p < 0.05) and the calculated MTR image produced contrast between brain tumor and normal brain tissue. There was a statistically significant difference in MTR between benign (0.30 +/- 0.05, n = 17) and malignant (0.26 +/- 0.04, n = 13) tumors (p < 0.05). The optimized MT technique is quite sensitive for estimating the degree of intermolecular interaction between macromolecules and water within the central nervous system.
Asunto(s)
Neoplasias Encefálicas/diagnóstico , Imagen por Resonancia Magnética/métodos , Color , Humanos , Procesamiento de Imagen Asistido por Computador , Valores de Referencia , Albúmina Sérica BovinaRESUMEN
The purpose of this study is to estimate the clinical applicability of functional magnetic resonance imaging (f-MRI) combined with the activation study using single photon emission computerized tomography (SPECT) with special reference to identification of primary sensorimotor area. Five healthy volunteers and 5 patients with brain tumors located around the sensorimotor cortex were studied by both f-MRI with gradient echo and SPECT with 99mTc-ethyl cysteinate dimer using split-dose and subtraction method. In f-MRI study, the significant activation of the sensorimotor area was observed in all subjects. Various concurrent activation regions such as supplementary motor (2 volunteers vs. 4 patients), premotor (1 vs. 2) and ipsilateral sensorimotor area (1 vs. 2) were also observed. In the cases with the activation of neighboring regions of sensorimotor area, it was difficult to identify the area in f-MRI. In SPECT study, the sensorimotor area was depicted as the most increased area in regional cerebral blood flow in eight cases, the characteristics of which were helpful to diagnose the area, while significant activation of the area with edema could not be detected in two patients. Consequently, the sensorimotor area was cross-validated with both the modalities. This study demonstrated that it would be valuable to use both techniques for the clinical assessment of the sensorimotor area.