RESUMEN
Multilayer diffraction gratings are designed to improve the detection limit and sensitivity of soft x-ray flat-field spectrographs in the region of 300-1000 eV, placing emphasis on Fe-L (705 eV), Cu-L (930 eV), and Zn-L (1012 eV) emissions. For this purpose, spectral flux was used as the performance index, which is proportional to the amount of optical flux incident into a detector and correlated with detection sensitivity. A super-mirror-type W/B4C multilayer coating [Koike et al., Rev.Sci. Instrum. 94, 045109 (2023)] was employed to improve diffraction efficiency in a wide energy region. The unique feature of the multilayer structure is that the average refractive index and the period length of W/B4C layer pairs are increased from the bottom to top layers. In addition, the incidence angle was reduced to 86.03° from 88.65° and the nominal groove density was increased to 3200 lines/mm from 2400 lines/mm of our previous design, to improve spectral flux while maintaining dispersion and spectral resolution. A holographic varied-line-spacing spherical grating and a soft x-ray flat-field spectrograph were designed, using the aspherical-wavefront-recording method, assuming the nominal grating constant and incident angle described above. The numerical simulation results showed that the spectrograph employing the newly designed grating with the W/B4C multilayer indicated 3.2-8.2 times higher spectral flux compared with those using the previously designed grating while keeping the same spectral resolution.
RESUMEN
Laminar-type spherical diffraction gratings overcoated with carbon-based materials were designed, fabricated, and evaluated for the purpose of enhancing the analytical sensitivity of the flat-field spectrograph in a vacuum ultraviolet region of 35-110 eV. As the design benchmark for numerical calculations, diffraction efficiency (DE) and spectral flux, which are defined by the product of the DE and numerical aperture and correlate with the analytical sensitivity of the spectrograph, were used. To simplify the feasibility study on the overcoating effects, we assumed a laminar-type grating having a grating constant of 1/1000 mm and coated with a Au layer of 30.0 nm thickness and an incidence angle of 84.0°. The optimized groove depth and duty ratio were 30.0 nm and 0.3, respectively. In addition, the optimum thicknesses of the overcoating layer were 44, 46, 24, and 30 nm for B4C, C, diamond-like-carbon, and SiC, respectively. Based on these results, we have fabricated a varied-line-spacing holographic grating overcoated with B4C with a thickness of 47 nm. For the experimental evaluation, we used the light source of Mg-L and Al-L emissions excited by the electron beam generated from an electron microscope, an objective flat-field spectrograph, and a CCD imaging detector. The experimental results showed that the spectrograph employing a new grating overcoated with the B4C layer indicated almost the same spectral resolution and 2.9-4.2 times higher analytical sensitivity compared with those obtained with a previously designed Au-coated grating having a grating constant of 1/1200 mm and used at an incidence of 86.0°.
RESUMEN
OBJECTIVES: Modelling the apoptotic process is essential for simulating and understanding tumour growth, as most tumour tissues carry mutations in apoptotic signalling pathways. Thus here, we have aimed to construct a mathematical model of colonic crypts that explicitly incorporates the apoptotic mechanism. METHODS: A murine colonic crypt was described as being a two-dimensional rectangular surface model. In this system, three types of cells with different proliferating and differentiating potentials migrate. Apoptosis was described as a process activated by irradiation that progresses in a stepwise manner. Parameter values in the model were determined to be consistent with experimental data for changes in the apoptotic cell ratio within murine transverse colonic crypts following irradiation. RESULTS: First, we constructed a model reproducing cell proliferation dynamics in normal murine colonic crypts; next, we applied the apoptotic mechanism to this model. As a result, we succeeded in simultaneous reproduction of both spatial and temporal changes in distribution of apoptotic cells in murine colonic crypts by determining parameter values in numerical simulations. Through this adjustment process, we were able to predict that stem cells and transit amplifying (TA) cells in each generation must react distinctly from each other, to apoptosis-inducing stimuli. CONCLUSIONS: We constructed a mathematical model with which we could quantitatively describe cell proliferative and apoptotic dynamics in a murine colonic crypt. Using this model, we were able to make novel predictions that sensitivity to apoptosis-inducing stimuli is dependent on cell type.
Asunto(s)
Apoptosis/efectos de la radiación , Colon/citología , Colon/efectos de la radiación , Simulación por Computador , Modelos Biológicos , Animales , Movimiento Celular/efectos de la radiación , Proliferación Celular/efectos de la radiación , Colon/patología , RatonesRESUMEN
OBJECTIVE: Adipose tissue is closely associated with angiogenesis, but the mechanisms are not fully understood. Some of the adipocyte-derived cytokines are hypothesized to play an important role in angiogenesis. We evaluated tube formation of human umbilical vascular endothelial cells (HUVECs) cultured in type I collagen gel when overlaid with the supernatant of 3T3-L1 cell culture, and expression of tube-forming factor(s) in 3T3-L1 cells with or without pioglitazone. We also studied plasma growth factor levels in patients with type 2 diabetes mellitus treated with pioglitazone. RESULTS AND METHODS: The supernatant of 3T3-L1 cells increased tube formation of HUVECs by 9.03-fold of control. Reverse transcription-polymerase chain reaction showed that hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) mRNA were expressed in 3T3-L1 cells. Western blot analysis also demonstrated HGF and VEGF protein expression. When 3T3-L1 cells were treated with 100 nM small interfering RNAs (siRNAs) for HGF, the HGF mRNA and protein were suppressed. The VEGF mRNA and protein in the cells were also suppressed by siRNA for VEGF. The supernatant of 3T3-L1 cells treated with HGF siRNA suppressed tube formation of HUVECs by 61% compared with the supernatant of cells treated with control siRNA. Addition of VEGF siRNA resulted in no significant changes. The supernatant conditioned with pioglitazone further promoted the tube formation. Pioglitazone enhanced HGF mRNA expression in 3T3-L1 cells. After 12 weeks of pioglitazone treatment, the changes of plasma HGF levels in patients treated with pioglitazone were significantly higher than those in control. CONCLUSION: These results suggest that HGF secreted from 3T3-L1 cells may be the major factor regulating the tube formation, and agents that enhance the differentiation of adipocytes may promote tube formation of HUVECs mediated by HGF secreted by adipocytes.
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Adipocitos/metabolismo , Células Endoteliales/fisiología , Factor de Crecimiento de Hepatocito/fisiología , Neovascularización Fisiológica/fisiología , Células 3T3 , Animales , Células Cultivadas , Medios de Cultivo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Células Endoteliales/efectos de los fármacos , Femenino , Factor de Crecimiento de Hepatocito/metabolismo , Humanos , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Masculino , Ratones , Persona de Mediana Edad , Neovascularización Fisiológica/efectos de los fármacos , Pioglitazona , ARN Mensajero/análisis , ARN Interferente Pequeño/farmacología , Tiazolidinedionas/farmacología , Tiazolidinedionas/uso terapéutico , Factor A de Crecimiento Endotelial Vascular/análisisRESUMEN
We report on a patient who developed acute rhabdomyolysis after taking cerivastatin. A 74-year-old hypercholestrerolaemic woman taking cerivastatin (0.15 mg/day) for 22 days complained of general muscle weakness and muscle pain. Her serum creatinine phosphokinase level was 19,190 IU/L. Serum myoglobin was over 3000 ng/mL. Serum concentration of cerivastatin at 6 h after taking the last dose (0.15 mg) was 8062.5 ng/L, which was almost 5.7 times higher than that of normal persons. The serum concentration of cerivastatin showed that the half-life of cerivastatin in this patient was 22.4 h, compared with 2.4 h for normal controls. Cerivastatin is catabolized by cytochrome P450, 3A4 and 2C8 to M-1, and by 2C8 to M-23. The ratio of M-23 to M-1 in her serum was much lower than that of control persons (0.64 vs. 2.08). She had previously taken simvastatin which is metabolized by CYP3A4, without any sign and symptoms of rhabdomyolysis. These results suggest that the slowed clearance of cerivastatin in this patient might have been compounded by cytochrome P450, 2C8 dysfunction.
Asunto(s)
Tasa de Depuración Metabólica/efectos de los fármacos , Piridinas/efectos adversos , Piridinas/sangre , Rabdomiólisis/inducido químicamente , Enfermedad Aguda , Anciano , Hidrocarburo de Aril Hidroxilasas/efectos de los fármacos , Hidrocarburo de Aril Hidroxilasas/genética , Hidrocarburo de Aril Hidroxilasas/metabolismo , Creatinina/sangre , Citocromo P-450 CYP2C8 , Citocromo P-450 CYP3A , Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Esquema de Medicación , Femenino , Semivida , Humanos , Hipercolesterolemia/complicaciones , Hipercolesterolemia/diagnóstico , Hipercolesterolemia/tratamiento farmacológico , Tasa de Depuración Metabólica/genética , Mioglobina/sangre , Mioglobinuria/inducido químicamente , Piridinas/administración & dosificación , Rabdomiólisis/complicaciones , Simvastatina/administración & dosificación , Factores de TiempoRESUMEN
UNLABELLED: Two independent severe hypertriglyceridemic infants with transiently impaired lipoprotein lipase (LPL) activity were observed and the causes were explored. Both infants were female, born prematurely with low birth weight and developed hypertriglyceridemia (Fredrickson type V hyperlipidemia: high VLDL and low LDL/HDL) a few months after birth. While mass levels of their post-heparin plasma LPL and apoprotein C-II (apo C-II), a physiological activator of LPL, were normal, their post-heparin plasma LPL activities were remarkably impaired. Both of their mothers' post-heparin plasma LPL activities were slightly or moderately impaired as well, without a decrease in the LPL mass level. No mutations in the genes for LPL and apo C-II were detected in either patient. In an in vitro study with their serum at onset, we could not detect any distinct circulating inhibitors for LPL. There was no data supporting infection or autoimmune diseases, which might have an impact on LPL activity, during the follow-up period. Levels of their plasma triglyceride (TG) and total cholesterol (TC) were decreased quickly by a dietary intervention with medium-chain triglyceride (MCT) milk and kept normal even after stopping the intervention at around age 1 year. However, their low post-heparin LPL activity persisted and returned to normal at around age 2 years. Their low HDL cholesterol levels persisted even after recovery of the TG and TC levels, although lecithin:cholesterol acyltransferase (LCAT) and cholesterol-ester-transfer protein (CETP), two key enzymes of HDL metabolism, were normal throughout the course. The exact reasons why their post-heparin LPL activities were impaired for a certain period and why their HDL cholesterol levels have remained low are still unclear. CONCLUSION: Transiently impaired LPL activity with no defect in LPL enzyme induced severe hypertriglyceridemia in infants. The transient occurrence of inhibitor(s) for LPL was proposed.
Asunto(s)
Hiperlipoproteinemia Tipo V/fisiopatología , Lipoproteína Lipasa/antagonistas & inhibidores , Niño , Preescolar , HDL-Colesterol/sangre , Femenino , Humanos , Hiperlipoproteinemia Tipo V/sangre , Hiperlipoproteinemia Tipo V/diagnóstico , Hiperlipoproteinemia Tipo V/genética , Lipoproteína Lipasa/genética , Lipoproteína Lipasa/metabolismoRESUMEN
Water extract from commercial English tea has a potent inhibitory activity against human placenta aldose reductase (NADPH oxidoreductase, E.C.1.1.1.21.). Inhibitory activity was separated into five major fractions by one-step chromatography with a C-18 reverse phase column. The most active fraction was further subjected to reverse phase column chromatography. As a result, a well-known flavone-glycoside, isoquercitrin, was isolated as the most potent chemical. The inhibitory character of isoquercitrin for aldose reductase was a mix of uncompetitive and noncompetitive inhibitions, and its IC50 was 1 x 10(-6) M. In rat sciatic nerve tissue preparations, sorbitol accumulation in the presence of high concentrations of glucose (30 mM) was inhibited by 38% at 5 x 10(-4) M of isoquercitrin. The flavone-glycoside isoquercitrin is the active inhibitor of aldose reductase inhibitor present in English tea. Given the ability of aldose reductase inhibitors to prevent diabetic complications, an epidemiological study of the effect of tea consumption on the pathogenesis and progression of diabetic complications would be interesting.
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Aldehído Reductasa/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Quercetina/farmacología , Té/química , Aldehído Reductasa/metabolismo , Animales , Sitios de Unión , Inhibidores Enzimáticos/aislamiento & purificación , Inhibidores Enzimáticos/metabolismo , Femenino , Humanos , Técnicas In Vitro , Placenta/enzimología , Extractos Vegetales/metabolismo , Extractos Vegetales/farmacología , Quercetina/análogos & derivados , Quercetina/aislamiento & purificación , Ratas , Nervio Ciático/metabolismo , Sorbitol/metabolismoRESUMEN
To clarify the clinical implication of preheparin serum lipoprotein lipase mass (preheparin LpL mass), we studied the relationships between preheparin LpL mass and serum lipids, including midband lipoproteins, which migrate between very low density lipoproteins and low density lipoproteins on polyacrylamide gel disc electrophoresis, in hyperlipidemias. And we also studied the changes of preheparin LpL mass in hypertriglyceridemic patients during bezafibrate administration, which is known to enhance LpL activity in postheparin plasma. Preheparin LpL mass correlated positively with high-density lipoprotein-cholesterol (HDL-C) (r=0.418, P<0.01) and negatively with triglyceride (TG) (r=-0.256, P<0.01), but did not correlate with total cholesterol (TC) in 64 hyperlipidemic (type IIa, IIb and IV) patients. The midband lipoproteins were observed in 80% of hypertriglyceridemic patients (32/40). Preheparin LpL mass in midband lipoprotein-positive subjects was lower significantly than that in midband-negative subjects. When bezafibrate (400 mg/day) was administrated to 40 hypertriglyceridemic patients for 4 months, TG level significantly decreased (-49+/-7%, P<0.01), TC levels decreased (-11+/-4%, not significant), and HDL-C levels increased (+27+/-4%, P<0.01). The midband lipoproteins disappeared in 95% of patients. Preheparin LpL mass significantly increased (+25+/-6%, P<0. 0005). In nine patients who stopped bezafibrate, TG levels significantly increased (+49+/-7%, P<0.01) and HDL-C levels decreased (-27+/-4%, P<0.01). Preheparin LPL mass significantly decreased (-25+/-6%, P<0.0005). These results suggested that bezafibrate administration enhanced preheparin LpL mass. And it might be implicated that enhanced LpL production by bezafibrate could reflect an increase of preheparin LpL mass.
Asunto(s)
Bezafibrato/uso terapéutico , Hiperlipidemias/sangre , Hiperlipidemias/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Lipoproteína Lipasa/sangre , Bezafibrato/administración & dosificación , Esquema de Medicación , Electroforesis en Gel Bidimensional , Ensayo de Inmunoadsorción Enzimática , Humanos , Hipertrigliceridemia/sangre , Hipertrigliceridemia/tratamiento farmacológico , Hipolipemiantes/administración & dosificación , Lípidos/sangre , Lipoproteínas/sangre , Lipoproteínas/químicaRESUMEN
Lipoprotein lipase mass exists in preheparin serum, even though the activity is scarcely found. The implication of this is unclear. We studied the effect of an insulin sensitizer, troglitazone, on this preheparin serum lipoprotein lipase mass (preheparin LPL mass) in non-insulin-dependent diabetes mellitus (NIDDM) patients as well as on serum lipid levels and low density lipoproteins (LDL) particle size. Thirty-one NIDDM patients with poor control were administered troglitazone 400 mg/day. Hemoglobin A1c had significantly decreased (13%, P < 0.001) 2 months later. Preheparin LPL mass had gradually increased and a 69% increase (P<0.01) was observed 4 months later. Triglyceride significantly decreased (23%, P < 0.01) and high density lipoprotein-cholesterol increased (10%, P < 0.01), whereas total cholesterol and LDL levels did not change 4 months later. The size of LDL increased significantly (P < 0.01). These results were consistent with the idea that preheparin LPL mass might be relating to the insulin sensitivity enhanced by troglitazone, as well as LDL particle size.
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Cromanos/farmacología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/farmacología , Lipoproteína Lipasa/sangre , Tiazoles/farmacología , Tiazolidinedionas , Adulto , Anciano , Colesterol/sangre , HDL-Colesterol/sangre , Diabetes Mellitus Tipo 2/dietoterapia , Dieta para Diabéticos , Femenino , Hemoglobina Glucada/metabolismo , Heparina , Humanos , Insulina/fisiología , Masculino , Persona de Mediana Edad , Compuestos de Sulfonilurea/uso terapéutico , TroglitazonaRESUMEN
To clarify the factors regulating preheparin serum lipoprotein lipase mass (preheparin LPL mass), the correlations between preheparin LPL mass and age, gender and types of hyperlipidemias were investigated in 377 persons who underwent annual health examinations. Preheparin LPL mass level did not significantly differ in individuals from 19 to 70 years old, for both men and women. Preheparin LPL mass level correlated negatively with triglyceride (TG), positively with high density lipoprotein-cholesterol (HDL-C), and not at all with total cholesterol (TC) or low density lipoprotein-cholesterol (LDL-C). Preheparin LPL mass levels were apparently higher in women than in men, but when serum lipid levels were adjusted, preheparin LPL mass levels were identical. In type IV and IIb hyperlipidemia, preheparin LPL mass levels were lower than in type IIa patients and in normals. Remnant positive individuals had lower levels of preheparin LPL mass than the negative individuals. In conclusion, preheparin LPL mass levels were not affected by aging and gender, but were lower in the conditions in which TG catabolism was disturbed, indicating that preheparin LPL mass might reflect somewhat the amount of LPL working in the body.
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Heparina/farmacología , Hiperlipidemias/enzimología , Lipoproteína Lipasa/sangre , Adulto , Factores de Edad , Anciano , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Femenino , Humanos , Hiperlipidemias/sangre , Masculino , Persona de Mediana Edad , Factores Sexuales , Triglicéridos/sangreRESUMEN
A series of alpha,alpha-difluorobenzylphosphonic acids having a hydrophobic functional group were prepared via the Stille coupling reaction from halogenated alpha,alpha-difluorobenzylphosphonates. Evaluation of inhibitory activity toward protein tyrosine phosphatase (PTP 1B) revealed that the ethynyl, phenylethynyl and (E)-styryl groups on the benzene nuclei increased the inhibitory activity of alpha,alpha-difluorobenzylphosphonic acid. Inhibitory activities significantly increased upon introducing both (E)-styryl and bis-methylsulfonamide functional groups onto the benzene nuclei of alpha,alpha-difluorobenzylphosphonic acid.
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Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Organofosfonatos/química , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Estructura Molecular , Organofosfonatos/síntesis química , Organofosfonatos/farmacologíaRESUMEN
Apolipoprotein E (apoE), which is reported to recognize the low density lipoprotein receptor and remnant receptor, mediates the delivery of cholesterol and other lipids to the cells all over the body. There are several phenotypes such as apoE2, apoE3 and apoE4. Recently, it is reported that apoE plays an important role in neurite outgrowth. To determine whether apoE phenotype is concerned in diabetic peripheral neuropathy, we investigated the incidence of apoE phenotypes in diabetic patients with peripheral neuropathy. The occurrence of retinopathy and nephropathy were not different in apoE2, apoE3 and apoE4. However, the frequency of diabetic neuropathy was higher in apoE4 than apoE2 and apoE3 (p < 0.05). Furthermore, as the stage of diabetic neuropathy advanced, the incidence of apoE4 increased. From these results we conclude that apoE phenotype influences the progress of diabetic peripheral neuropathy and that apoE4 contributes to the deterioration of diabetic peripheral neuropathy.
Asunto(s)
Apolipoproteínas E/genética , Neuropatías Diabéticas/genética , Anciano , Apolipoproteínas E/metabolismo , Apolipoproteínas E/fisiología , Neuropatías Diabéticas/epidemiología , Retinopatía Diabética/epidemiología , Retinopatía Diabética/genética , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Crecimiento Nervioso/fisiología , FenotipoRESUMEN
To make diagnosis arteriosclerosis directly by biochemical markers is not easy, but to identify risk factors by biochemical markers is useful. Lipoprotein disorder is one such risk factor. Low density lipoproteins (LDL), remnants and small LDL were high risks of coronary disease in Japanese. Moreover, those incidences were significantly higher in diabetes mellitus, especially with nephropathy, and latter two lipoproteins frequently coexisted. Oxidizability of small LDL was the highest among LDLs, indicating that small LDL promotes atherosclerosis by forming oxidized lipids, which enhance complicated lesion of atherosclerosis. The mechanism by which the remnant is retained remains unknown. We measured LPL mass in preheparin serum. Preheparin LPL mass was negatively correlated with triglyceride, and positively correlated with high density lipoprotein cholesterol. Further more, preheparin LPL mass was lower in remnant-positive persons, indicating that preheparin LPL mass might be involved in remnant clearance. Understanding the role and catabolism of LPL itself requires further study.
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Arteriosclerosis/diagnóstico , Hiperlipidemias/sangre , LDL-Colesterol/sangre , Enfermedad Coronaria/sangre , Humanos , Lipoproteína Lipasa/metabolismo , Lipoproteínas LDL/sangre , Factores de RiesgoAsunto(s)
Codón de Terminación , Hiperlipoproteinemias/genética , Lipoproteína Lipasa/genética , Serina/genética , Adulto , Anciano , Femenino , Genotipo , Humanos , Hiperlipoproteinemias/sangre , Hipertrigliceridemia/sangre , Hipertrigliceridemia/genética , Japón , Lipoproteína Lipasa/sangre , Lipoproteínas/sangre , Lipoproteínas/metabolismo , Masculino , Persona de Mediana Edad , MutaciónRESUMEN
Activins, members of a family of proteins that includes transforming growth factor-beta (TGF-beta), are gonadal polypeptide hormones that stimulate secretion of follicle-stimulating hormone (FSH). During large-scale sequencing analysis of a 1.2-Mb fragment of human genomic DNA on 3p22-p21.3, we found the gene encoding activin receptor type IIB (hActR-IIB). Comparison of its reported cDNA sequence with this genomic sequence showed that the hActR-IIB gene consists of 11 exons and spans about 30 kb of genomic DNA.
Asunto(s)
Cromosomas Humanos Par 3/genética , Genes , Receptores de Factores de Crecimiento/genética , Receptores de Activinas Tipo II , Mapeo Cromosómico , Paseo de Cromosoma , ADN de Neoplasias/genética , Exones/genética , Humanos , Hibridación Fluorescente in Situ , Neoplasias Pulmonares/genética , Eliminación de SecuenciaRESUMEN
A decrease in smooth muscle cells is observed in advanced atherosclerotic lesion. To understand this mechanism, we selected oxysterols as candidates for toxic lipid, and examined their cytotoxicity on human cultured vascular smooth muscle cells, together with the manner of cell death. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol (50 mumol/L), the percentage of detached cells increased significantly with dose dependency, and an increase in detached cell number and DNA nick detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling study (TUNEL) preceded an increase in lactate dehydrogenase released into the medium. DNA extracted from smooth muscle cells incubated with 7-ketocholesterol or 7 beta-hydroxycholesterol showed a laddering pattern on agarose electrophoresis. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol, fragmented DNA quantified by the quantitative sandwich enzyme immunoassay was significantly increased. From these results, it is proposed that 7-ketocholesterol and 7 beta-hydroxycholesterol are toxic to smooth muscle cells, and that this cytotoxicity is mediated by apoptosis.
Asunto(s)
Apoptosis/efectos de los fármacos , Hidroxicolesteroles/toxicidad , Cetocolesteroles/toxicidad , Músculo Liso Vascular/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Recuento de Células/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colesterol/farmacología , Daño del ADN , Fragmentación del ADN , Humanos , L-Lactato Deshidrogenasa/metabolismo , Músculo Liso Vascular/metabolismoRESUMEN
Octa-heme peptide (CHP) obtained from Candida krusei cytochrome c was tested for suicidal activation of halogenomethanes. Under anaerobic conditions, CHP was kept in the reduced state in the presence of NADPH and NADPH-cytochrome P-450 reductase. Addition of CBrCl3 to the reduced CHP caused spectral changes such as rapid disappearance of alpha and beta bands and gradual decrease in the gamma-peak height, accompanied by oxidation of NADPH. Heme content of the reaction mixture, determined as pyridine hemochrome, also decreased NADPH dependently. CCl4 was less effective than CBrCl3, while CHCl3 had almost no effect. N-tert-butyl-alpha-phenylnitrone (PBN) suppressed the CBrCl3-induced heme damage, and resulted in the formation of radical adduct .PBN-CCl3 as evidenced by ESR spectroscopy. Radical formation was also observed with CCl4. The CHP damage induced by CBrCl3 was also accompanied by the release of Br- about 11-12-times molar excess of CHP, whereas the release of CHCl3 was about 20% that of Br-.FD-MS assay of the product of CHP reaction suggested that 10 trichloromethyl radicals bonded with CHP. Thus, CBrCl3 undergoes single-electron reduction in the presence of reduced CHP to trichloromethyl radicals, which covalently bind to CHP molecules. Heme peptide may be a useful tool in the study of mechanisms involved in the destruction of cytochrome P-450 by halogenomethanes.
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Bromotriclorometano/farmacología , Tetracloruro de Carbono/farmacología , Grupo Citocromo c/química , Hemo/química , Péptidos/química , Secuencia de Aminoácidos , Bromotriclorometano/metabolismo , Tetracloruro de Carbono/metabolismo , Grupo Citocromo c/efectos de los fármacos , Grupo Citocromo c/aislamiento & purificación , Modelos Moleculares , Datos de Secuencia Molecular , Piridinas/química , Análisis EspectralRESUMEN
In order to examine the immune response of chickens to different population levels of mites, a microscopic slide modification of the Ouchterlony double-gel diffusion technique was adopted for examination of circulating antibody against the extract of northern fowl mite, Ornithonyssus sylviarum. Precipitating antibodies were detected in all the chickens infested with the mite. One to three clearly defined precipitation lines appeared in almost all the serum samples of infested birds. Titers of antibody correlated with population levels of the mite on chickens, and no differences in antibody development of hens and roosters were distinguished. These results suggest that the titration of precipitating antibodies appears to be useful for the assessment of mite population levels on chickens.
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Anticuerpos/análisis , Pollos/parasitología , Infestaciones por Ácaros/veterinaria , Ácaros/inmunología , Enfermedades de las Aves de Corral/inmunología , Animales , Femenino , Inmunodifusión , Masculino , Infestaciones por Ácaros/inmunología , Ácaros/patogenicidad , Enfermedades de las Aves de Corral/parasitología , Factores de TiempoRESUMEN
Hepatotoxic action of CHCl3 was examined biochemically by comparing with those of CCl4 and other related halogenomethanes using normal and phenobarbital (PB)-pretreated animals. In the later stage (24 hr), in mice, PB pretreatment augmented CHCl3-induced liver damage as evidenced by an enhancement of elevation of plasma transaminase activities and a parallel rise in liver triglyceride content. In the earlier stage (1 hr), in normal rats, CCl4 (1.0 ml/kg, i.p.) decreased microsomal glucose-6-phosphatase (G-6-Pase) activity and cytochrome P-450 content, whereas no significant effect was observed with the same dose of CHCl3. PB pretreatment produced a significant loss of both enzymes by CHCl3, and enhanced the loss of cytochrome P-450 induced by CCl4, while G-6-Pase activity was little affected by CCl4 in PB-pretreated rats. Both hepatotoxins increased liver malondialdehyde (MDA) content. Some of these early changes in vivo were reproduced in the lipid peroxidation system in vitro. Diethyldithiocarbamate suppressed various toxic manifestations induced by CHCl3 in PB-pretreated rats, but did not protect against the loss of cytochrome P-450 induced by CHCl3 or CCl4. These results suggest that lipid peroxidation hypothesis proposed for CCl4 hepatotoxicity may be applied to the case of CHCl3 though there exist some qualitatively different characteristics between these hepatotoxins, and that the mechanisms of the loss of microsomal G-6-Pase and cytochrome P-450 by either of these hepatotoxins might be different.