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1.
Transpl Infect Dis ; 17(4): 544-50, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26041667

RESUMEN

BACKGROUND: Varicella zoster virus (VZV) reactivation following hematopoietic stem cell transplantation (SCT) is common. To help reduce its incidence and to identify predictive factors for VZV reactivation after autologous SCT (auto-SCT), we conducted a retrospective analysis in patients with hematologic malignancy at our hospital. METHODS: We conducted a single-hospital observational trial with a retrospective case-control analysis of post-auto-SCT VZV reactivation in patients with malignant lymphoma (ML) and multiple myeloma (MM) between January 2001 and December 2010, in the Department of Hematology at our hospital. First, we analyzed the cumulative incidence of VZV reactivation during the post-SCT period. Second, we conducted a case-control analysis to identify the risk factors for VZV reactivation within 1 year after SCT. Univariate analyses were performed using Fisher's exact test for categorical variables. A multivariable model and logistic regression were used to assess the risk factors for VZV reactivation. RESULTS: We included 97 patients in this study. The median duration of follow-up was 1027 days. Forty-two patients experienced VZV reactivation after SCT, while 29 (69.0%) experienced reactivation within 1 year after SCT. The cumulative incidence was 30.7% at 1 year and 51.2% for the total observation period. Multivariate analysis showed that engraftment after day 10 was an independent risk factor for VZV reactivation (P = 0.03). CONCLUSIONS: Our study showed a high incidence of VZV reactivation in the first year after auto-SCT in ML and MM patients. Patients with delayed engraftment are at high risk for VZV reactivation and should be considered for prolonged VZV prophylaxis.


Asunto(s)
Herpes Zóster/etiología , Herpesvirus Humano 3/fisiología , Linfoma/terapia , Mieloma Múltiple/terapia , Trasplante de Células Madre de Sangre Periférica , Activación Viral , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Herpes Zóster/diagnóstico , Herpes Zóster/epidemiología , Herpes Zóster/virología , Humanos , Incidencia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Trasplante Autólogo
2.
Opt Express ; 21(2): 2171-84, 2013 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-23389198

RESUMEN

In order to determine if the mesa geometry might affect the properties of the coherent terahertz (THz) radiation emitted from the intrinsic Josephson junctions in mesas constructed from single crystals of the high-temperature superconductor, Bi2Sr2CaCu2O8+δ, we studied triangular mesas. For equilateral triangular mesas, the observed emission was found to be limited to the single mesa TM(1,0) mode. However, tunable radiation over the range from 0.495 to 0.934 THz was found to arise from an acute isosceles triangular mesa. This 47% tunability is the widest yet observed from the outer current-voltage characteristic branch of such mesas of any geometry. Although the radiation at a few of the frequencies in the tunable range appear to have been enhanced by cavity resonances, most frequencies are far from such resonance frequencies, and can only be attributed to the ac-Josephson effect.


Asunto(s)
Cerámica/química , Iluminación/instrumentación , Semiconductores , Radiación Terahertz , Cerámica/efectos de la radiación , Diseño de Equipo , Análisis de Falla de Equipo
3.
Braz J Med Biol Res ; 55: e12376, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36629525

RESUMEN

The aim of our study was to validate the use of the standardized Radiological Society of North America (RSNA) reporting system in individuals with known lung cancer who presented to the emergency department with suspected COVID-19. We included patients aged 18 years or older from the Cancer Institute of the State of São Paulo (ICESP) with a confirmed diagnosis of lung cancer, admitted to the emergency department and undergoing chest computed tomography (CT) for suspicion of COVID-19. Comparison between SARS-CoV2 RT-PCR across RSNA categories was performed in all patients and further stratified by diagnosis of lung cancer progression. Among 58 individuals included in the analysis (65±9 years, 43% men), 20 had positive RT-PCR. Less than a half (43%) had no new lung findings in the CT. Positive RT-PCR was present in 75% of those with typical findings according to RSNA and in only 9% when these findings were classified as atypical or negative (P<0.001). Diagnostic accuracy was even higher when stratified by the presence or absence of progressive disease (PD). Extent of pulmonary inflammatory changes was strongly associated with higher mortality, reaching a lethality of 83% in patients with >25% of lung involvement and 100% when there was >50% of lung involvement. The lung involvement score was also highly predictive of prognosis in this population as was reported for non-lung cancer individuals. Collectively, our results demonstrated that diagnostic and prognostic values of chest CT findings in COVID-19 are robust to the presence of lung abnormalities related to lung cancer.


Asunto(s)
COVID-19 , Neoplasias Pulmonares , Masculino , Humanos , Femenino , COVID-19/diagnóstico por imagen , SARS-CoV-2 , ARN Viral , Brasil , Tomografía Computarizada por Rayos X/métodos , Neoplasias Pulmonares/diagnóstico por imagen , América del Norte/epidemiología , Estudios Retrospectivos
4.
Int J Tuberc Lung Dis ; 26(7): 629-635, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35768931

RESUMEN

BACKGROUND: The prevalence of persistent respiratory symptoms tends to be low in patients with a longer recovery time after COVID-19. However, some patients may present persistent pulmonary abnormalities.OBJECTIVE: To evaluate the prevalence of tomographic abnormalities 90 days after symptom onset in patients with COVID-19 and compare two chest high-resolution computed tomography (HRCT) analysis techniques.METHODS: A multicentre study of patients hospitalised with COVID-19 having oxygen saturation <93% on room air at hospital admission were evaluated using pulmonary function and HRCT scans 90 days after symptom onset. The images were evaluated by two thoracic radiologists, and were assessed using software that automatically quantified the extent of pulmonary abnormalities.RESULTS: Of the 91 patients included, 81% had at least one pulmonary lobe with abnormalities 90 days after discharge (84% were identified using the automated algorithm). Ground-glass opacities (76%) and parenchymal bands (65%) were the predominant abnormalities. Both chest HRCT technical assessments presented high sensitivity (95.9%) and positive predictive value (92%), with a statistically significant correlation at baseline (R = 0.80) and after 90 days (R = 0.36).CONCLUSION: The prevalence of pulmonary abnormalities on chest HRCT 90 days after symptom onset due to COVID-19 was high; both technical assessments can be used to analyse the images.


Asunto(s)
COVID-19 , Enfermedades Pulmonares , Humanos , Pulmón/diagnóstico por imagen , Prevalencia , Tomografía Computarizada por Rayos X/métodos
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 3427-3430, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34891976

RESUMEN

Computer-aided detection algorithms applied to CT lung imaging have the potential to objectively quantify pulmonary pathology. We aim to develop an automatic classification method based on textural features able to classify healthy and pathological patterns on CT lung images and to quantify the extent of each disease pattern in a group of patients with chronic hypersensitivity pneumonitis (cHP), in comparison to pulmonary function tests (PFTs).27 cHP patients were scanned via high resolution CT (HRCT) at full-inspiration. Regions of interest (ROIs) were extracted and labeled as normal (NOR), ground glass opacity (GGO), reticulation (RET), consolidation (C), honeycombing (HB) and air trapping (AT). For each ROI, statistical, morphological and fractal parameters were computed. For automatic classification, we compared two classification methods (Bayesian and Support Vector Machine) and three ROI sizes. The classifier was therefore applied to the overall CT images and the extent of each class was calculated and compared to PFTs. Better classification accuracy was found for the Bayesian classifier and the 16x16 ROI size: 92.1±2.7%. The extent of GGO, HB and NOR significantly correlated with forced vital capacity (FVC) and the extent of NOR with carbon monoxide diffusing capacity (DLCO).Clinical Relevance- Texture analysis can differentiate and objectively quantify pathological classes in the lung parenchyma and may represent a quantitative diagnostic tool in cHP.


Asunto(s)
Alveolitis Alérgica Extrínseca , Enfermedades Pulmonares , Alveolitis Alérgica Extrínseca/diagnóstico por imagen , Teorema de Bayes , Humanos , Pruebas de Función Respiratoria , Tomografía Computarizada por Rayos X
6.
Science ; 291(5510): 1944-7, 2001 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-11239150

RESUMEN

The low solubility of fullerenes in aqueous solution limits their applications in biology. By appropriate substitution, the fullerenes can be transformed into stabilized anions that are water soluble and can form large aggregated structures. A laser light scattering study of the association behavior of the potassium salt of pentaphenyl fullerene (Ph5C60K) in water revealed that the hydrocarbon anions Ph5C60- associate into bilayers, forming stable spherical vesicles with an average hydrodynamic radius and a radius of gyration of about 17 nanometers at a very low critical aggregation concentration of less than 10(-7) moles per liter. The average aggregation number of associated particles in these large spherical vesicles is about 1.2 x 10(4).

7.
Braz. j. med. biol. res ; 55: e12376, 2022. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1420744

RESUMEN

The aim of our study was to validate the use of the standardized Radiological Society of North America (RSNA) reporting system in individuals with known lung cancer who presented to the emergency department with suspected COVID-19. We included patients aged 18 years or older from the Cancer Institute of the State of São Paulo (ICESP) with a confirmed diagnosis of lung cancer, admitted to the emergency department and undergoing chest computed tomography (CT) for suspicion of COVID-19. Comparison between SARS-CoV2 RT-PCR across RSNA categories was performed in all patients and further stratified by diagnosis of lung cancer progression. Among 58 individuals included in the analysis (65±9 years, 43% men), 20 had positive RT-PCR. Less than a half (43%) had no new lung findings in the CT. Positive RT-PCR was present in 75% of those with typical findings according to RSNA and in only 9% when these findings were classified as atypical or negative (P<0.001). Diagnostic accuracy was even higher when stratified by the presence or absence of progressive disease (PD). Extent of pulmonary inflammatory changes was strongly associated with higher mortality, reaching a lethality of 83% in patients with >25% of lung involvement and 100% when there was >50% of lung involvement. The lung involvement score was also highly predictive of prognosis in this population as was reported for non-lung cancer individuals. Collectively, our results demonstrated that diagnostic and prognostic values of chest CT findings in COVID-19 are robust to the presence of lung abnormalities related to lung cancer.

8.
Cancer Res ; 38(6): 1782-4, 1978 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-348304

RESUMEN

An antitumor antibiotic aclacinomycin A, was nonmutagenic in a Salmonella test, but its derivative, N-demethylaclacinomycin A, was mutagenic. Similarly, 1-deoxypyrromycin, a hydrolysis product of aclacinomycin A, was nonmutagenic, but N-demethyl-1-deoxypyrromycin was mutagenic. Daunomycin was highly mutagenic, but N-methyldaunomycin showed only weak mutagenicity, and N-dimethyldaunomycin was nonmutagenic. The aglycones of aclacinomycin A and daunomycin were not mutagenic. Thus, the amino moiety of anthracycline glycosides is concluded to be essential for mutagenesis.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Daunorrubicina/análogos & derivados , Mutágenos , Naftacenos/farmacología , Salmonella typhimurium/efectos de los fármacos , Aclarubicina/análogos & derivados , Daunorrubicina/farmacología , Glicósidos/farmacología , Mutación/efectos de los fármacos , Relación Estructura-Actividad
9.
Cancer Res ; 39(9): 3780-2, 1979 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-383289

RESUMEN

The aglycone methylazoxymethanol of the naturally occurring carcinogenic glucoside, cycasin, has previously been shown to be mutagenic, but cycasin per se has not. In this work, cycasin was demonstrated to be mutagenic using a modification of the Ames Salmonella test in which it was preincubated with beta-glucosidase and the tester strain in liquid medium. The mutagenicity of cycasin to six histine-depedent Salmonella strains varied considerably with strain HisG46 being the most susceptible. Methylazoxymethyl-beta-D-glucosiduronic acid, which also is nonmutagenic per se, similarly became mutagenic when preincubated with beta-glucuronidase. Methylazoxymethyl acetate, which is slightly mutagenic by the Ames standard pour plate method, became highly mutagenic on preincubation. The mutagenicity of free methylazoxymethanol was confirmed, and a linear dose-response relationship was observed. The common conditions required for activation of nonmutagenic methylazoxymethanol conjugates, the glucoside cycasin and methylazoxymethyl-beta-D-glucosiduronic acid, are 90-min preincubation at 30 degrees, pH 6.5, with an appropriate hydrolase and Salmonella typhimurium HisG46.


Asunto(s)
Compuestos Azo/farmacología , Cicasina/farmacología , Glucuronidasa/farmacología , Acetato de Metilazoximetanol/farmacología , Mutágenos , Salmonella typhimurium/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Especificidad de la Especie
10.
Cancer Res ; 40(7): 2539-42, 1980 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7388809

RESUMEN

The inhibitory effects of protease inhibitors on blood-borne metastasis in male Donryu rat lung were studied. Injection i.v. of 10(6) Yoshida ascites hepatoma AH7974 cells induced about 118 +/- 92 (S.D.) metastatic foci in rat lung after 3 weeks. Leupeptin (50 mg/kg body weight twice a day), injected i.p. from 2 days before to 4 days after the inoculation of tumor cells, reduced the number of metastatic foci to about 49 +/- 45 (p less than 0.005). Leupeptin also suppressed the formation of metastatic foci of Yoshida ascites hepatoma AH100B cells (p less than 0.001). Elastatinal (100 mg/kg body weight twice a day) and chymostatin (100 mg/kg body weight once a day) did not inhibit formation of metastatic foci of AH7974 cells. Injection i.v. of 10(6) AH7974 cells induced pulmonary thrombi within 1 hr. Leupeptin (50 mg/kg body weight twice a day) reduced the number of thrombi from 1298 +/- 395 to 646 +/- 218, when injected i.p. for 2 days before the inoculation of the cells (p less than 0.005). Chymostatin and elastatinal did not significantly change the number of pulmonary thrombi. These results indicate that leupeptin inhibited metastasis formation and suggest that this effect may be due to the inhibition of thrombus formation after the arrest of circulating tumor cells.


Asunto(s)
Neoplasias Pulmonares/secundario , Células Neoplásicas Circulantes , Inhibidores de Proteasas/farmacología , Animales , Leupeptinas/farmacología , Neoplasias Hepáticas Experimentales/patología , Masculino , Metástasis de la Neoplasia , Trasplante de Neoplasias , Embolia Pulmonar/prevención & control , Ratas
11.
Cancer Res ; 48(21): 6234-7, 1988 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-2971435

RESUMEN

We investigated the ultrastructure of myeloma cells obtained from four cases of common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma. Clinically, the disease was aggressive and our patients died with a median survival after diagnosis of only 62 days. By light microscopic criteria of Greipp et al., their disease was classified as plasmablastic, immature (two cases), and intermediate. In contrast, the myeloma cells of all four cases were judged to be immature and abnormal on the basis of the electron microscopic observation. Characteristic features were sparse heterochromatin, high to moderate nucleocytoplasmic ratio, nuclear bodies, thin and short rough endoplasmic reticula, scattered pattern of mitochondria, and polysomes consisting of five to six ribosomes, along with irregular nuclear membrane, poorly developed organella, and abnormalities in cytoplasmic structures such as dense bodies, vacuoli, buddings, single-sac loop-like structures, multilamellar bodies, and abnormal inclusion bodies. While overlapping each other, it is suggested that the CALLA-positive and the plasmablastic myelomas should be classified separately. Thus, the electron microscopic study, like the immunological marker analysis, provides a useful means for better assessment regarding immaturity and abnormality of myeloma cells.


Asunto(s)
Antígenos de Diferenciación/análisis , Antígenos de Neoplasias/análisis , Mieloma Múltiple/ultraestructura , Adulto , Anciano , Anciano de 80 o más Años , Retículo Endoplásmico/ultraestructura , Femenino , Humanos , Masculino , Mitocondrias/ultraestructura , Mieloma Múltiple/inmunología , Neprilisina , Células Tumorales Cultivadas
12.
Chem Biol ; 2(8): 517-25, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9383455

RESUMEN

BACKGROUND: (-)-Depudecin is a fungal metabolite that reverts the rounded phenotype of NIH3T3 fibroblasts transformed with v-ras and v-src oncogenes to the flat phenotype of the nontransformed parental cells. The mechanism of action of this detransformation agent is unknown. Although depudecin appears to be an excellent molecule for probing signaling pathways that regulate changes in the cytoskeletal architecture, reagents based on depudecin are not available as it has not yet been successfully synthesized. We therefore set out to synthesize (-)-depudecin. RESULTS: An asymmetric synthesis of (-)-depudecin has been developed. A cell staining assay has been used to reveal the ability of synthetic depudecin, but not several structural variants, to induce a flattened morphology in v-Ha-ras-transformed NIH3T3 cells. This assay also shows that depudecin induces an intricate network of actin stress fibers in these cells and in MG63 osteosarcoma cells and reveals the essential role of the epoxide and hydroxyl moieties in depudecin. Cycloheximide and actinomycin D inhibited the ability of depudecin to induce a morphological change, suggesting that both mRNA synthesis and de novo protein synthesis are required for depudecin-mediated suppression of the transformed phenotypes in ras-transformed cells. CONCLUSIONS: The synthetic procedure provides access to (-)-depudecin and could be readily modified to produce depudecin-related reagents for the identification of depudecin's cellular target(s). This target appears to be involved in the regulation of the assembly of the actin microfilament component of the cytoskeleton in mammalian cells.


Asunto(s)
Alcadienos/síntesis química , Alcadienos/farmacología , Transformación Celular Neoplásica/efectos de los fármacos , Compuestos Epoxi/síntesis química , Compuestos Epoxi/farmacología , Alcoholes Grasos/síntesis química , Alcoholes Grasos/farmacología , Células 3T3/efectos de los fármacos , Actinas/química , Actinas/efectos de los fármacos , Animales , Neoplasias Óseas/química , Núcleo Celular/efectos de los fármacos , Núcleo Celular/ultraestructura , Cicloheximida/farmacología , Citoesqueleto/efectos de los fármacos , Dactinomicina/farmacología , Genes ras/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Ratones , Osteosarcoma/química , Inhibidores de la Síntesis de la Proteína/farmacología , Transducción de Señal/efectos de los fármacos , Espectrofotometría Infrarroja , Estereoisomerismo , Células Tumorales Cultivadas
13.
Am J Cardiol ; 58(9): 733-8, 1986 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-2945420

RESUMEN

Nicorandil therapy was compared with placebo therapy in 11 patients with chronic stable angina pectoris. A computer-assisted treadmill exercise test was performed after administration of either 10 or 30 mg of nicorandil. Analysis of variance showed a significant difference among placebo and nicorandil treatments (p less than 0.01). Ten milligrams of nicorandil prolonged time to onset of ischemia 36% (p less than 0.05) but increased the exercise duration only 15%. Thirty milligrams of nicorandil prolonged time to onset of ischemia 82% (p less than 0.01) and exercise duration 45% (p less than 0.01). Both time to onset of ischemia and exercise duration increased progressively from the 10-mg to the 30-mg dose (p less than 0.05). Heart rate at rest was significantly higher and systolic pressure at rest significantly lower with 30 mg of nicorandil than with placebo. After administration of 30 mg of nicorandil there was a significant reduction in ST depression associated with a slight decrease in the double product at the end of Bruce stage 2 exercise. The peak double product was greater after administration of 30 mg of nicorandil than after placebo, indicating an increased myocardial oxygen supply to the ischemic area. The plasma concentration of nicorandil averaged 78 +/- 83 ng/ml with the 10 mg and 313 +/- 142 ng/ml with 30 mg. There was an increase in exercise duration of more than 1 minute in 8 of 9 patients who had plasma nicorandil concentrations greater than 100 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Angina de Pecho/tratamiento farmacológico , Niacinamida/análogos & derivados , Adulto , Anciano , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Niacinamida/administración & dosificación , Niacinamida/uso terapéutico , Nicorandil
14.
Leuk Res ; 25(9): 749-55, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11489468

RESUMEN

We studied tumor cell invasions of bone marrow and peripheral blood in patients with various types of advanced non-Hodgkin's lymphoma by amplifying complementarity determining region III using the polymerase chain reaction (PCR) method and developing patient-specific probes. After molecular engineering, we could detect tumor cells in bone marrow from seven of 11 cases and in peripheral blood from six of 11 cases, despite negative results in four cases studied morphologically. Indolent cases were more likely to yield positive results than aggressive cases. The reason may be different biological behaviors among the histological types.


Asunto(s)
Neoplasias de la Médula Ósea/secundario , Regiones Determinantes de Complementariedad/genética , ADN de Neoplasias/análisis , Linfoma/patología , Neoplasias de la Médula Ósea/genética , Humanos , Leucocitos Mononucleares/patología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/secundario , Linfoma/clasificación , Linfoma/diagnóstico , Linfoma/genética , Invasividad Neoplásica , Hibridación de Ácido Nucleico/métodos , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Neoplasias del Bazo/genética , Neoplasias del Bazo/secundario
15.
Am J Hypertens ; 12(11 Pt 1): 1098-104, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10604486

RESUMEN

To evaluate the effects of nongenetic factors, aging, and salt-loading on the quantitative trait loci (QTLs) for blood pressure (BP), we conducted a genome-wide linkage analysis using multiple sets of BP measurements in 125 male F2 generation cross derived from stroke-prone spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. The experiment was arranged in two stages. In the first stage, corresponding to the developing period of the rats, BP was measured repeatedly without loading of salt; this continued until the rats were 5 months of age. In the second stage, after the baseline BP leveled off, 1% salt water was given to the rats and BP was monitored for the subsequent 7 months. Genome scanning was performed using 201 markers. In the developing period, three QTLs were identified on chromosomes 1, 3, and 4 (logarithmic odds [LOD] scores of 5.6, 3.1, and 3.2, respectively), which had peaks at 8 or 10 weeks of age. In the latter salt-loading stage, QTLs for BP were detected on chromosomes 1 and 10 (LOD scores 4.6 and 4.5, respectively). When the BP increase during salt-loading was analyzed as a phenotype, however, only the region on chromosome 10 showed linkage at a suggestive level (LOD score 3.2). The present study provides experimental evidence that QTLs for BP could be modulated by nongenetic factors, such as aging and salt-loading.


Asunto(s)
Envejecimiento , Presión Sanguínea , Hipertensión/genética , Cloruro de Sodio/administración & dosificación , Animales , Mapeo Cromosómico , Cromosomas/genética , ADN/análisis , Femenino , Ligamiento Genético , Hipertensión/sangre , Masculino , Reacción en Cadena de la Polimerasa , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY
16.
J Biochem ; 122(3): 647-54, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9348097

RESUMEN

The biosynthesis of cholesterol is regulated mainly by HMG-CoA reductase, however, recent studies indicated the pivotal role of another enzyme in cholesterol homeostasis. A previous report showed a marked decrease in the activity of mevalonate pyrophosphate decarboxylase (MPD) in stroke-prone spontaneously hypertensive rats and its possible involvement in the pathogenesis of the disorder. In this study, we purified liver MPD from rats fed a diet containing cholestyramine and pravastatin (CP diet) using conventional chromatographic techniques. We obtained two electrophoretically homogeneous enzyme preparations; 45 and 37 kDa proteins with specific activities of 8.0 and 7.4 micromol/min/mg, respectively. The enzymes showed similar molecular weights of 90 kDa, as judged on gel permeation chromatography. A kinetic study indicated apparent Km values for mevalonate pyrophosphate and ATP of 22.7 microM and 0.71 mM, respectively, for the 45 kDa MPD, and 20.0 microM and 0.80 mM, respectively, for the 37 kDa MPD. Half maximum activities were observed at 1.5 mM and 1.1 mM Mg2+ for the 45 and 37 kDa MPDs, respectively. Both enzymes required ATP as a phosphate acceptor, and in addition Mg2+, Mn2+, and Co2+ were effective as divalent cations. The optimum pH for both enzymes was 7.0. The isoelectric points for the 45 and 37 kDa MPDs were 5.6 and 5.4, respectively. Polyclonal antiserum raised against the 45 kDa enzyme detected both the 45 and 37 kDa bands on immunoblots with CP diet-induced liver crude extract as an antigen. However, non-induced liver contained the 45 kDa protein but not the 37 kDa protein. These results indicated that the CP diet induced a new species, 37 kDa, of MPD which is characteristically and immunologically very similar to the well-known 45 kDa MPD.


Asunto(s)
Carboxiliasas/aislamiento & purificación , Carboxiliasas/metabolismo , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismo , Hígado/enzimología , Animales , Anticolesterolemiantes/farmacología , Carboxiliasas/química , Colesterol/biosíntesis , Resina de Colestiramina/farmacología , Inducción Enzimática , Glicosilación , Concentración de Iones de Hidrógeno , Immunoblotting , Inmunohistoquímica , Punto Isoeléctrico , Isoenzimas/química , Cinética , Hígado/efectos de los fármacos , Masculino , Peso Molecular , Oligosacáridos/análisis , Oligosacáridos/metabolismo , Pravastatina/farmacología , Ratas , Ratas Endogámicas WKY
17.
J Biochem ; 124(1): 40-4, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9644243

RESUMEN

Spontaneously hypertensive rat (stroke-prone) (SHRSP) has a low serum cholesterol level as compared with the normotensive Wistar Kyoto rat (WKY). We previously indicated that the lower activity of mevalonate pyrophosphate decarboxylase (MPD) was responsible for the reduced cholesterol biosynthesis in the liver of SHRSP [Sawamura et al. (1992) J. Biol. Chem. 267, 6051-6055]. To elucidate the mechanism of the reduced activity, we purified liver MPD from SHRSP treated with cholestyramine and pravastatin in this study. We compared its enzymatic properties with those of the enzyme from WKY, and also measured the amounts of MPD in the crude extract of various tissues in WKY and SHRSP by Western blot analysis. Results indicated that (i) MPD of SHRSP has essentially the same properties as MPD of WKY, except for a difference in the dependency on divalent cations. (ii) The amount, as well as the activity, of MPD in the crude extract of brain and liver was reduced in SHRSP. (iii) There was no difference between SHRSP and WKY, in the ratio of the enzyme activity to the amount of MPD in the crude extract. These data led us to conclude that the lower activity of MPD was caused by the reduced amount of this enzyme in SHRSP.


Asunto(s)
Carboxiliasas/metabolismo , Trastornos Cerebrovasculares/enzimología , Hipertensión/enzimología , Animales , Western Blotting , Encéfalo/enzimología , Hígado/enzimología , Masculino , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Especificidad de la Especie
18.
Leuk Lymphoma ; 21(1-2): 31-6, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8907266

RESUMEN

Multiple myeloma is a B-cell malignancy characterized by the accumulation of a clonal population of plasma cells in the bone marrow that secrete a monoclonal immunoglobulin protein. It has been regarded as a tumor arising at the B, pre-B lymphocyte, or even stem cell level. Precursor cells are presumed to proliferate and differentiate, giving rise to clonal expansion in plasma cells. Peripheral blood mononuclear cells (PBMC) from 36 patients with multiple myeloma, 12 with monoclonal gammopathy of undetermined significance (MGUS), and 21 healthy controls were cultured in vitro in the presence of tumor necrosis factor-alpha (TNF-alpha) and interleukin 4 (IL-4). We have demonstrated that monoclonal plasma cells can be induced in different proportions from PBMC obtained from myeloma patients when exposed in vitro to TNF-alpha and IL-4. Although myeloma cell precursors cannot be distinguished from other cells by morphology, a high number of monoclonal plasma cells was detected in our culture system on day 4 even when plasma cells accounted for less than 0.2% of the cells seeded on day 0. In 16 of the 36 patients with myeloma, monoclonal plasma cells appeared after 4 days. These changes were not observed in PBMC from patients with MGUS or from controls. These findings thus suggest that circulating myeloma cell precursors differentiate into plasma cells in the presence of TNF-alpha and IL-4, and the variation in the number of myeloma cell precursors in peripheral blood could therefore be used as a prognostic parameter in response to chemotherapy in myeloma patients.


Asunto(s)
Interleucina-4/farmacología , Interleucina-4/fisiología , Mieloma Múltiple/patología , Células Madre Neoplásicas/patología , Factor de Necrosis Tumoral alfa/farmacología , Factor de Necrosis Tumoral alfa/fisiología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Humanos , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/efectos de los fármacos , Mieloma Múltiple/sangre , Mieloma Múltiple/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos
19.
Toxicol Lett ; 8(1-2): 17-22, 1981 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7245236

RESUMEN

Betel quid, a masticatory widely used in Sri Lanka, consists of Jaffna tobacco, the nuts and leaves of betel plants and calcium hydroxide. An ethyl acetate extract of Jaffna tobacco induced morphological transformation of hamster embryo cells. The extract also induced sister chromatid exchanges inn virally transformed and phytohaemagglutinin (PHA)-stimulated human lymphocytes. The induction of sister chromatid exchanges was potentiated by addition of rat liver homogenate. The extract did not induce ouabain-resistant mutation of V79 cells. Extracts of betel nuts and leaves gave negative results in assay of morphological transformation, sister chromatid exchange and mutagenesis.


Asunto(s)
Areca , Transformación Celular Neoplásica , Intercambio Genético/efectos de los fármacos , Mutágenos/toxicidad , Plantas Medicinales , Intercambio de Cromátides Hermanas/efectos de los fármacos , Técnicas In Vitro , Pruebas de Mutagenicidad , Extractos Vegetales/toxicidad
20.
J Agric Food Chem ; 48(12): 6227-9, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11312796

RESUMEN

Lactose, a reducing disaccharide abundant in milk, reacts extensively with the amino groups of protein through the Maillard reaction. The Maillard reaction products showed 3'-[1-[(phenylamino)carbonyl]-3,4-tetrazolium]bis(4-methoxy-6-nitro)benzensulfonic acid hydrate (XTT) reducibility. The objective of this study was to clarify the Maillard reaction products responsible for the XTT reducibility. When lactose and butylamine were heated at 100 degrees C, the characteristic UV maximum at 320 nm was recognized and the relationship between the XTT reducibility and the compound with absorption maximum at 320 nm was investigated. The time course and the dependence on the heating temperature of the formation of the compound with absorption maximum at 320 nm were similar to those of the XTT reducibility. Their relationship showed a significant correlation (r = 0.967, n = 19). Furthermore, the spectrum change of the heated model solution by the addition of XTT suggested that the compound with absorption maximum at 320 nm would be involved in the reduction of XTT. Because the compound with absorption maximum at 320 nm was identified as an aminoreductone, 1-(butylamino)-1,2-dehydro-1,4-dideoxy-3-hexulose, by NMR analysis, it can be concluded that this was the main XTT-reducing substance.


Asunto(s)
Reacción de Maillard , Leche/química , Sales de Tetrazolio/análisis , Animales , Lactosa , Espectroscopía de Resonancia Magnética , Oxidación-Reducción , Temperatura
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