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1.
Biochim Biophys Acta ; 1438(2): 204-12, 1999 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-10320803

RESUMO

The increased production of oxygen-derived free radicals (OFR) and lipid peroxidation may contribute to vascular complications in diabetes. Some lipid peroxidation products have already been reported to be formed via glucose-induced oxidative stress. We have identified 9-hydroxy linoleic acid (9-OH-C18:2) in the red cell membrane phospholipid of diabetic subjects. We hypothesized that 9-OH-C18:2 would be formed in hydroxyl radical reactions to linoleic acid (C18:2) during glucose-induced oxidative stress, and confirmed that the formation of 9-OH-C18:2 was induced by ultraviolet (UV)-C irradiation to the synthetic C18:2. UV-C light generates highly reactive hydroxy radicals. C18:2 is confirmed to be the precursor of 9-OH-C18:2. To estimate the degree of oxidative damage to red cell membrane phospholipids, we developed a selective ion monitoring gas chromatography-mass spectrometric measurement for C18:2 and 9-OH-C18:2, following methanolysis of red cell membrane phospholipids. The relative peak height ratio of C18:2 to 9-OH-C18:2 (9-OH-C18:2/C18:2) was measured in phospholipid extracts of red cell membranes from healthy (n=29, 3.1+/-1.9%) and diabetic (n=27, 20. 9+/-16.1%) subjects. It was confirmed that 9-OH-C18:2/C18:2 is significantly (P<0.001) elevated in patients with diabetes. The measurement of 9-OH-C18:2/C18:2 in red cell membranes should be useful for assessing oxidative damage to membrane phospholipids in diabetes.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Membrana Eritrocítica/metabolismo , Ácidos Linoleicos Conjugados , Ácidos Linoleicos/biossíntese , Biomarcadores/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Oxirredução , Fosfolipídeos/metabolismo
2.
Gene ; 199(1-2): 211-7, 1997 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9358058

RESUMO

Selenoprotein P-like protein, similar to selenoprotein P, uses multiple TGAs for incorporation of selenocysteines but not as stop codons. It is also characterized by having a His-Pro-rich domain and a regionally differential expression pattern. Hence, in addition to selenium metabolism, this protein is considered to have a developmental function. In the present study, the structure of the selenoprotein P-like protein gene was analyzed. The gene consisted of five exons, and the 5'-flanking region contained a TATA box, TCF-1-CS, bHLH-CS, gamma-IRE-CS, c-Myb-CS, C/EBP-CS, HNF-5-CS, MRE2-CS, etc. The presence of motifs like TCF-1-CS, c-Myb-CS, etc. supports the suggestion that this protein is involved in cellular maturation. Since the presence of MRE2-CS suggests that this protein is related to the antidote effect of selenium against heavy metal intoxication, the availability of this motif was examined using bovine kidney cell lines, CKT-1 and MDBK. Metallothionein mRNA markedly increased 6 h after administration of 10(-6) M CdCl2 and ZnCl2 in both cell lines. No significant alteration was observed in selenoprotein P-like protein mRNA, whereas its basal expression was high, indicating that this protein is constitutively expressed. Thus, it is still possible that this protein acts as an antidote, even though it is not inducible by heavy metals.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Metais Pesados/farmacologia , Regiões Promotoras Genéticas/genética , Proteínas/genética , Animais , Sequência de Bases , Cloreto de Cádmio/farmacologia , Bovinos , Linhagem Celular , Cloretos/farmacologia , DNA Complementar/genética , Rim , Cloreto de Mercúrio/farmacologia , Metalotioneína/genética , Dados de Sequência Molecular , Especificidade de Órgãos , RNA Mensageiro/biossíntese , Mapeamento por Restrição , Selenoproteína P , Selenoproteínas , Análise de Sequência de DNA , Compostos de Zinco/farmacologia
3.
Neurology ; 48(5): 1266-70, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9153454

RESUMO

Spinal muscular atrophy (SMA) is characterized by degeneration of spinal cord anterior horn cells and muscular atrophy and has three phenotypes based on clinical severity and age of onset. One of the responsible genes for SMA is the survival motor neuron (SMN) gene, which is homozygously absent or interrupted in more than 90% of SMA patients. The cBCD541 (BCD) gene is a highly homologous copy of the SMN gene, which has a single synonymous transition in the coding region and may compensate for the loss of the SMN gene. To evaluate the effects of the BCD gene expression on the phenotypes of SMA, we examined lymphocyte mRNA from 9 SMA patients lacking the SMN gene, 10 asymptomatic parents, and 15 control subjects. We amplified mRNA fragments containing exon 7 of the SMN or BCD genes using reverse transcription-polymerase chain reaction since the transcript lacking exon 7 encodes a putative protein with a different C-terminal end. We used glyceraldehyde-3-phosphate dehydrogenase (GAPDH) transcript as an internal control, and the relative expression level of the SMN or BCD gene was shown as the ratio of SMN or BCD transcript to GAPDH transcript (S/G ratio). The mean S/G ratios of the patients were significantly lower than that of the parents and controls. However, among the patients examined in this study, there was no relationship between the S/G ratios and phenotypes of SMA. The results showed that the BCD gene expression was not related to the phenotypes of SMA. Furthermore, there was an overlap between the S/G ratios in patients and controls. As our discrimination study showed that the S/G ratio reflected the expression of the BCD transcripts in patients and the SMN transcripts in controls, this finding suggested that the BCD gene expression per se does not compensate for the loss of the SMN gene.


Assuntos
Expressão Gênica , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/fisiopatologia , RNA Mensageiro/metabolismo , Atrofias Musculares Espinais da Infância/genética , Atrofias Musculares Espinais da Infância/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , DNA/genética , Feminino , Genoma , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Humanos , Linfócitos/metabolismo , Masculino , Fenótipo , Reação em Cadeia da Polimerase , Valores de Referência , Transcrição Gênica
4.
Atherosclerosis ; 148(1): 197-202, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10580186

RESUMO

Increased urinary excretion of dicarboxylic acids (DAs) has been well known in patients with diabetic ketoacidosis (DKA). It was known that small amounts of such DAs were also detected in urine from healthy humans. Upon chemical, radiation-induced or enzymatic oxidation, cis-polyunsaturated fatty acids (PUFA) have previously been shown to generate saturated short- and medium-chain length DAs. In diabetes, it was confirmed that the imbalance between the generation of free radicals and antioxidant defense systems increases oxidative stress and leads to the damage of lipid, which contains PUFA. Some peroxidation products of PUFA, such as malondialdehyde and conjugated diene, are generally known to be elevated in patients with diabetes. The present study was undertaken to determine if urinary excretion of DAs is elevated in diabetic patients without DKA. Urine samples from ten non-ketoacidotic patients with type 2 diabetes and ten healthy subjects were examined for DAs by combined gas chromatography and mass spectrometry with selected ion monitoring. The diabetic subjects had significantly (Psebacic acid. Being stable and easily detectable compounds, DAs may be considered potential markers of oxidative attack on PUFA in diabetes.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Ácidos Dicarboxílicos/urina , Ácidos Graxos/metabolismo , Peróxidos/metabolismo , Adulto , Idoso , Biomarcadores/urina , Diabetes Mellitus Tipo 2/urina , Estabilidade de Medicamentos , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Environ Health Perspect ; 59: 129-35, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3921355

RESUMO

Mercapto-, methylthio-, methylsulfinyl- and methysulfonyl metabolites of PCBs 2,5,2',5'-tetrachlorobiphenyl, 1,3,5-trichlorobenzene and some other chlorobenzenes were identified in adipose tissues of mice, rats and guinea pigs by using GC/MS/COM systems. By means of administration of CD3-methionine, it was confirmed that the methyl group in methylthio metabolites was derived from the methionine. Moreover, after pretreatment with either esterification of urinary metabolites in guinea pigs with 1,3,5-trichlorobenzene and 1,3-dichlorobenzene or N-acetylation after esterification, it was confirmed that cysteinylglycine, cysteine, N-acetylcysteine, cysteamine, mercaptopyruvate, mercaptolactate, mercaptacetate, thiol and disulfide conjugates were detected as a serial modified derivatives of glutathione moiety. These results are summarized as a metabolic proposed pathway of halogenated aromatic compounds. Three routes in pathway correspond to oxygenation (initial route), glutathione thioether disposition (intermediate route) and sulfoxydation (final route) in connection with both reactive intermediates of epoxide and thiol. Methylation of the thiol by S-adenosylmethionine may be important in inhibiting covalent binding of reactive intermediates with biocomponents, similar to the glutathione conjugation for the detoxification of epoxide.


Assuntos
Carcinógenos , Hidrocarbonetos Halogenados/metabolismo , Sulfonas/biossíntese , Animais , Biotransformação , Fenômenos Químicos , Química , Cisteína/metabolismo , Dimetil Sulfóxido , Fígado/metabolismo , Metionina/metabolismo , Camundongos , Bifenilos Policlorados/metabolismo , Ratos , Sulfonas/metabolismo
6.
Brain Res Mol Brain Res ; 30(2): 301-11, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7637580

RESUMO

When cDNA containing proteins enriched in the bovine cerebellar cortex were cloned, a clone which seemed to encode a selenoprotein P-like protein was isolated. The coding nucleotide sequence of its cDNA insert displayed high homology to rat and human selenoprotein P cDNA but contained 12 rather than 10 TGAs (12 rather than 10 selenocysteines in deduced amino acids), a tandem repeat of one CACTCC (His-Ser) and seven CATCCCs (His-Pro), and a 3' untranslated region approximately 890 bases shorter than that of rat liver selenoprotein P. RT-PCR using a set of primers flanking to the repeat displayed the existence of mRNA without the repeat. The tandem repeat and its adjacent region consisted of a similar motif of CAC/TCC/AC/T. Thus, these proteins included a (His-Pro) rich domain with a slightly negative free energy change irrespective of having the tandem repeat or not. Such His-Pro repeats reportedly exist in the segmentation gene paired or homeobox protein Om(1D) of Drosophila. Moreover, both this selenoprotein P-like protein mRNA and selenoprotein P mRNA were expressed in all the areas of the brain but most prominently in the cerebellar cortex, hippocampus, and olfactory bulb. These findings suggest the possibility that these selenoproteins are major selenium carriers in the brain and play a role in the morphological response of nerve or glial cells.


Assuntos
Proteínas/genética , Selênio/metabolismo , Selenocisteína/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Cerebelo/metabolismo , Clonagem Molecular , DNA Complementar/genética , Expressão Gênica , Hibridização In Situ , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Ratos , Selenoproteína P , Selenoproteínas
7.
Metabolism ; 48(2): 205-9, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10024083

RESUMO

In diabetes, glycation and subsequent browning (or glycoxidation) reactions are enhanced by elevated glucose concentrations. It is unclear whether the diabetic state per se also induces an increase in the generation of oxygen-derived free radicals (OFRs). However, there is some evidence that glycation itself may induce the formation of OFRs. OFRs cause oxidative damage to endogenous molecules, including cholesterol. 7-Oxocholesterol is known to be one of the major products of cholesterol oxidation. The level of cholesterol peroxidation products was assessed in erythrocyte membrane lipid by monitoring the peak height ratio of 7-oxocholesterol, one of the products of cholesterol peroxidation, to cholesterol with gas chromatography/mass spectrometry (GC/MS). The peak height ratio of 7-oxocholesterol to cholesterol was used as a biomarker of lipid peroxidation. The hemoglobin A1c (HbA1c) value, an index of glycemic stress, was measured by high-performance liquid chromatography. We examined the relationship between the levels of cholesterol peroxidation products and HbA1c in erythrocytes of diabetic and healthy subjects. There was a significantly increased ratio of 7-oxocholesterol to cholesterol in diabetic erythrocytes compared with control erythrocytes. The ratio of 7-oxocholesterol to cholesterol was significantly correlated with the level of HbA1c. This suggests that glycation of hemoglobin via chronic hyperglycemia is linked to cholesterol peroxidation in erythrocytes of both diabetic and healthy subjects.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Eritrócitos/metabolismo , Hemoglobinas Glicadas/metabolismo , Peroxidação de Lipídeos , Colesterol/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Cetocolesteróis/sangue , Masculino , Pessoa de Meia-Idade
8.
J Neurol ; 248(10): 856-60, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11697521

RESUMO

In X-linked recessive disorders, a few female gene carriers become symptomatic. Recent evidence implicates skewed X-chromosome inactivation in such female carriers. We studied the clinical features of eight female gene carriers of X-linked recessive spinal and bulbar muscular atrophy (SBMA), and evaluated the relationship between phenotype and genotype from the viewpoint of X-chromosome inactivation. Seven of eight cases were symptomatic, showing mild muscle weakness, frequent muscle cramps, slight elevation of the serum creatinine kinase level, or neurogenic changes on the electromyogram. Only one carrier was asymptomatic clinically. For the estimation of X-chromosome inactivation, the methylation status of the androgen receptor (AR) gene was determined by polymerase chain reaction-based assay. Highly skewed inactivation of the affected AR gene was found in the asymptomatic carrier, while symptomatic carriers had a random or lower inactivation pattern of the affected AR gene. These findings suggest that most female carriers of SBMA show some clinical abnormalities, and highly skewed inactivation of the affected X-chromosome seems to closely relate with escape of the manifestation in female carriers of SBMA.


Assuntos
Mecanismo Genético de Compensação de Dose , Atrofia Muscular Espinal/genética , Cromossomo X/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Desoxirribonuclease HpaII/genética , Eletromiografia , Feminino , Genes Recessivos , Ligação Genética , Heterozigoto , Humanos , Pessoa de Meia-Idade , Atrofia Muscular Espinal/fisiopatologia , Receptores Androgênicos/genética , Sequências Repetitivas de Ácido Nucleico , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
J Neurol ; 246(1): 48-52, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9987714

RESUMO

Most spinal muscular atrophy (SMA) patients lack the survival motor neuron gene (SMN). However, the patients retain at least one copy of the cBCD541 gene (BCD), which is highly homologous with SMN. Here, we determined the SMN/BCD copy number ratios (the S/B ratios) of 12 parents of Japanese SMA patients with a homozygous SMN deletion, using competitive oligonucleotide priming polymerase chain reaction. We identified an S/B ratio of 2 in 25% of the parents examined, whereas less than 2% of parents of SMA patients in Western populations have an S/B ratio of 2. The high incidence of an S/B ratio of 2 in Japanese parents of SMA patients may reflect the characteristic genetic background of SMA in Japan.


Assuntos
Atrofia Muscular Espinal/genética , Proteínas do Tecido Nervoso/genética , Proteínas Proto-Oncogênicas/genética , Transativadores , Feminino , Marcadores Genéticos , Humanos , Japão/etnologia , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like , Masculino , Atrofia Muscular Espinal/etnologia , Linhagem , Proteínas de Ligação a RNA
10.
Clin Biochem ; 33(7): 541-7, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11124339

RESUMO

OBJECTIVES: To reveal increased lipid peroxidation in diabetics by quantification of cholesterol oxidation products (COPs) not only in plasma, but also in erythrocytes. DESIGN AND METHODS: We quantified 7-ketocholesterol (7-kCho) by gas chromatography-mass spectrometry as a surrogate measure for COPs. These assays were performed on both plasma and erythrocytes in 20 control subjects and 20 treated patients with relatively poorly controlled Type 2 diabetes. RESULTS: Both plasma and erythrocyte 7-kCho levels in diabetics were significantly higher than those in control subjects. Although neither plasma nor erythrocyte 7-kCho levels were associated with markers for glucose tolerance in diabetics, a negative correlation of serum HDL-cholesterol levels with erythrocyte, but not plasma, 7-kCho levels was found. CONCLUSION: Increased oxidative stress in diabetics affects oxidation of cholesterol. Assays of COPs not only in plasma, but also in erythrocytes, may yield complementary information in lipid peroxidation.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Eritrócitos/metabolismo , Cetocolesteróis/sangue , Estresse Oxidativo , Plasma/metabolismo , Idoso , Calibragem , Estudos de Casos e Controles , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/metabolismo , Fatores de Risco , Fatores Sexuais , Fatores de Tempo
11.
Clin Chim Acta ; 170(2-3): 305-14, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3436064

RESUMO

A new method for extraction and quantification of plasma o,p'-DDD (2,2-(2-chlorophenyl,4'-chlorophenyl)1,1-dichloroethane) and its metabolites has been developed. When plasma (0.1 ml) adsorbed to and dried on a filter paper was heated with 5% hydrogen chloride in methanol (1 ml) in a boiling water bath, o,p'-DDD and its metabolites were liberated from the serum protein and were able to be easily extracted with benzene. The recovery rate was raised compared with conventional methods. In addition, this procedure also carried out the simultaneous methylation of o,p'-DDA, one of the metabolites. Mass numbers of 199, 210, 235 and 246 were selected from the mass spectra of o,p'-DDD and its related substances, and they were monitored. Identification was performed on the basis of the retention time and the mass peak intensity ratio. Quantitative determination was performed using the internal standard technique. It was learned that o,p'-DDA is present in the plasma at a concentration about 10 times higher than the levels of o,p'-DDD and o,p'-DDE.


Assuntos
Mitotano/análogos & derivados , Mitotano/sangue , Ritmo Circadiano , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos
12.
Clin Chim Acta ; 295(1-2): 155-68, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10767401

RESUMO

We established a method to quantify 7-ketocholesterol (7-KC) in low density lipoprotein by using the heparin-citrate method and gas chromatography-mass spectrometry. We examined the concentration of 7-ketocholesterol in LDL using this method to assess the pathological conditions in uremic patients with hemodialysis and healthy controls. We also examined the fatty acid composition in erythrocyte membranes to estimate the modification of biological membranes. We showed that the concentrations of 7-KC/cholesterol in LDL were significantly increased in hemodialysis patients compared to healthy controls (3.68+/-0.45 vs. 2.41+/-0.19, P<0.05) and the ratio of polyunsaturated fatty acids to saturated fatty acids in erythrocyte membranes was significantly decreased in hemodialysis patients compared to healthy controls (0.499+/-0.014 vs. 0.655+/-0. 017, P<0.001). There was no significant difference in 7-KC concentration in LDL or fatty acid composition in erythrocyte membranes between pre- and post-intervention of hemodialysis. We concluded that hemodialysis patients are under oxidative stress, which modifies LDL and erythrocyte membranes and we speculated these modifications may participate in the process of atherosclerosis. We believe that the method to quantify 7-KC in this study is concise and reliable and may be used to investigate various diseases.


Assuntos
Membrana Eritrocítica/metabolismo , Ácidos Graxos/sangue , Cetocolesteróis/sangue , Lipoproteínas LDL/sangue , Diálise Renal , Estudos de Casos e Controles , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Uremia/etiologia , Uremia/terapia
13.
Clin Chim Acta ; 252(2): 137-45, 1996 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-8853561

RESUMO

Lipids in erythrocyte membranes from 16 hemodialysis patients and 16 healthy volunteers were studied using gas chromatographic mass spectrometry. 7-keto cholestadiene was first reported in this study. The ratios of 7-keto cholestadiene to cholesterol, the ratios of arachidonate to cholesterol and the ratios of dochosahexanate to cholesterol in peak heights of chromatograms were measured in both groups as the markers of lipid peroxidation. Higher 7-keto cholestadiene/cholesterol ratios and lower arachidonate/cholesterol and dochosahexanate/cholesterol ratios were significantly observed in hemodialysis patients compared with healthy subjects. Our results are evidence that hemodialysis patients are exposed to much oxidative stress. It has been suggested that, during hemodialysis, leukocytes are activated by contract with non-physiological surfaces of the blood line tubing and produce oxygen free radicals. Oxygen free radicals attach cholesterol, arachidonate and dochosahexanate to produce lipid peroxides. In this study, this cell activation may be responsible for the increased lipid peroxidation of hemodialysis patients, 7-Keto cholestadiene, arachidonate and dochosahexanate can be used as markers of lipid peroxidation in hemodialysis patients.


Assuntos
Membrana Eritrocítica/metabolismo , Falência Renal Crônica/sangue , Lipídeos de Membrana/sangue , Adulto , Idoso , Biomarcadores , Ácidos Graxos Insaturados/sangue , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Falência Renal Crônica/terapia , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal
14.
Clin Chim Acta ; 285(1-2): 35-44, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10481921

RESUMO

Oxidative stress is postulated to be increased in patients with diabetes mellitus. Glycation enhanced by elevated glucose concentrations may induce the formation of oxygen-derived free radicals (OFRs). OFRs would cause oxidative damage to endogenous molecules, including cholesterol. Accumulating evidence suggests that oxidative cell injury caused by OFRs contributes to the development of both macroangiopathy and microangiopathy in diabetes. Our previous studies have shown that 7-keto cholestadien is one of the major products of cholesterol peroxidation in diabetic erythrocyte membrane and its levels correlate with hemoglobin Alc (HbAlc) values. We have newly identified 3-cholesten-6-one, one of the minor products of cholesterol peroxidation, in it. The aim of our study is to investigate whether 3-cholesten-6-one levels also correlate with HbAlc values. Levels of 3-cholesten-6-one were assessed in erythrocyte membrane lipid by monitoring peak areas of 3-cholesten-6-one to cholesterol with gas chromatography-mass spectrometry. The peak area ratio of 3-cholesten-6-one to cholesterol was used as a marker of cholesterol peroxidation. The HbAlc value, an index of both glycemic stress and glycation, was measured by high-performance liquid chromatography. In this study, we evaluated 33 diabetic and 29 healthy subjects, matched for age (59.3+/-14.5 vs. 57.3+/-13.7 years, mean+/-S.D.) and sex (15 males and 14 females vs. 16 males and 17 females). There were both significantly raised HbAlc levels (4.6+/-0.8 vs. 8.3+/-2.4%, P<0.001) and significantly increased ratios of 3-cholesten-6-one to cholesterol (0.2+/-0.4 vs. 21+/-1.8, P<0.001) in diabetic patients compared to control subjects. A good correlation between HbAlc levels and ratios of 3-cholesten-6-one to cholesterol was found in participants (r = 0.75, P<0.001, y = 0.46x-1.8). This suggests that an oxidative stress exists in diabetes and the link between glycation and lipoxidation is found in diabetic red blood cell.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Eritrócitos/metabolismo , Hemoglobinas Glicadas/metabolismo , Lipídeos/sangue , Estresse Oxidativo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade
15.
Clin Chim Acta ; 276(2): 163-72, 1998 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-9764734

RESUMO

In diabetes, the glycation and subsequent browning (or glycoxidation) reactions are enhanced by elevated glucose concentrations. It is unclear whether or not the diabetic state per se also induces an increase in the generation of oxygen-derived free radicals (OFRs). There is some evidence, however, that glycation itself may induce the formation of OFRs. OFRs could cause oxidative damage to endogenous molecules. We examined the relationship between the levels of lipid peroxidation and the levels of glycated hemoglobin A1c (GHbA1c) in erythrocytes of diabetic and healthy subjects. Lipid peroxidation was assessed in erythrocyte membrane lipids by monitoring peak height ratios of conjugated linoleic acid (CLA), one of the products of lipid peroxidation, to linoleic acid (LA) using gas chromatography-mass spectrometry (GC/MS). CLA is a collective term used to designate a mixture of positional and geometric isomers of LA in which the double bonds are conjugated. The peak height ratio of CLA to LA was used as a biomarker of lipid peroxidation. GHbA1c, an index of glycemic stress, was measured by high-performance liquid chromatography. There were significantly increased ratios of CLA to LA in diabetic erythrocytes compared with control erythrocytes. These ratios of CLA to LA were also significantly correlated with GHbA1c values. This suggests that glycation via chronic hyperglycemia links lipid peroxidation in the erythrocytes of both diabetic and healthy subjects.


Assuntos
Diabetes Mellitus/sangue , Eritrócitos/metabolismo , Hemoglobinas Glicadas/metabolismo , Peróxidos Lipídicos/sangue , Adulto , Idoso , Membrana Eritrocítica/química , Feminino , Radicais Livres , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Ácidos Linoleicos/sangue , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Modelos Químicos
16.
Clin Chim Acta ; 159(1): 77-82, 1986 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-3757269

RESUMO

A new, simple method for the diagnosis of adrenoleukodystrophy (ALD) using a dried blood spot sample, is described. Fatty acid from the dried blood spot was extracted and methylated simultaneously with HCl-methanol. Fatty acid methyl esters were analyzed by gas chromatography-mass spectrometry. Fatty acid compositions of the blood spot from four patients with ALD and five healthy controls were determined from the mass chromatograms of the m/z 143 ion, [(CH2)6 COOCH3]+. The ratios of tetracosanoic acid to docosanoic acid (C24:0/C22:0) and hexacosanoic acid to docosanoic acid (C26:0/C22:0) were significantly greater in ALD patients than in the controls. The fatty acid composition of the dried blood spot did not change at room temperature within a week. Since the specimens can be sent by mail, this method could be applied to the screening of ALD.


Assuntos
Adrenoleucodistrofia/diagnóstico , Esclerose Cerebral Difusa de Schilder/diagnóstico , Adrenoleucodistrofia/sangue , Ácidos Graxos/sangue , Filtração/instrumentação , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Manejo de Espécimes , Temperatura
17.
J Neurosurg ; 72(4): 610-5, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1690792

RESUMO

Reduced glutathione (gamma-glutamylcysteinylglycine, GSH) plays an important role in the protection of cells against damage from free radicals and other electrophils and also influences cellular radiosensitivity, cellular response to hyperthermia, and cytotoxicity to some kinds of chemotherapeutic agents. The concentrations of GSH in 40 primary and metastatic brain tumors were quantitatively analyzed, and GSH was localized in these tumors by a novel o-phthalaldehyde histofluorescence method. The level of GSH was 195.2 +/- 57.1 micrograms/gm (mean +/- standard deviation) in glioblastomas multiforme, 444.1 +/- 105.1 micrograms/gm in normal brain tissues, and 614.4 +/- 237.4 micrograms/gm in meningiomas. The differences in GSH levels between glioblastomas and normal brain tissues and between glioblastomas and meningiomas were statistically significant (p less than 0.01). The mean GSH level in astrocytoma grades II and III was 321.9 +/- 11.8 micrograms/gm. The difference in the GSH level between glioblastomas and astrocytomas was statistically significant (p less than 0.05). Radiosensitive tumors, such as multiple myeloma, germinoma, and small-cell carcinoma, showed low GSH levels. These data suggest the possibility that the GSH may be a predictor for the efficacy of radiation therapy. The cytochemical study showed GSH localized in the cytoplasm; although it stained well in meningioma tissue, GSH was not well stained in sections of multiple myeloma. The endothelial proliferation did not stain well in glioblastoma, which seems to imply that this area is vulnerable to attack by free radicals from irradiation and/or chemotherapy.


Assuntos
Neoplasias Encefálicas/metabolismo , Glutationa/metabolismo , Neoplasias Encefálicas/ultraestrutura , Citoplasma/metabolismo , Histocitoquímica/métodos , Humanos , Microscopia de Fluorescência , Coloração e Rotulagem
18.
Toxicol In Vitro ; 1(4): 233-7, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-20702368

RESUMO

The effect of methylmercury (MeHg) chloride on the release of [(3)H]acetylcholine ([(3)H]ACh) was examined using guinea-pig striatal slices. When the Hg concentration in the striatal slices was less than 10 ppm, MeHg chloride had no effect on spontaneous [(3)H]ACh release. However, electrically evoked release of [(3)H]ACh was significantly increased when the tissue Hg concentration was between 0.08 and 3 ppm and was about 160% of the control value at around 0.7 ppm. The increase in evoked ACh release induced by MeHg chloride at low tissue concentrations was partly due to inhibition of the re-uptake of choline. These results suggest that MeHg chloride-induced hyperactivation of cholinergic transmission may be involved in some of the early signs of mercury intoxication.

19.
J Agric Food Chem ; 48(11): 5512-6, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11087511

RESUMO

Neochlorogenic acid (3-CQA) and cryptochlorogenic acid (4-CQA), isolated from prune (Prunus domestica L.), were identified by NMR and MS analyses. In addition, the quantity of chlorogenic acid isomers in prune were measured by HPLC. These isomers, 3-CQA, 4-CQA, and chlorogenic acid (5-CQA), were contained in the ratio 78.7:18. 4:3.9, respectively. 4-CQA was identified and quantified in prune for the first time, and relatively high amounts of this isomer were characteristic. Antioxidative activities of the chlorogenic acid isomers, such as scavenging activity on superoxide anion radicals and inhibitory effect against oxidation of methyl linoleate, were also evaluated. Each isomer showed antioxidative activities which were almost the same.


Assuntos
Antioxidantes/análise , Ácido Clorogênico/análogos & derivados , Ácido Clorogênico/análise , Conservação de Alimentos , Frutas/química , Antioxidantes/química , Antioxidantes/farmacologia , Ácido Clorogênico/química , Ácido Clorogênico/farmacologia , Sequestradores de Radicais Livres/análise , Sequestradores de Radicais Livres/farmacologia , Isomerismo , Modelos Moleculares , Conformação Molecular , Superóxidos/química
20.
Forensic Sci Int ; 51(1): 35-50, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1752593

RESUMO

The medical examiner system has been steadily abolished in Japan. Instead, medicolegal investigations are entrusted by the police to medical practitioners, who are not permitted to perform autopsies. The necessity for the medical examiner system was assessed through inquest records in Hyogo, one of the three prefectures which still have medical examiner systems. Standardized mortality ratios (SMRs) for accidents and suicides were negatively associated with population density, being high in rural areas with a large proportion of elderly citizens, while the SMR for natural deaths was high in urbanized areas and associated with the proportion of inquests to total resident deaths. The high proportion of inquests, however, did not always mean that inquest records were of good quality. Significant differences in the quality of medicolegal investigations seemed to exist between medical examiners and medical practitioners. That is, in order to certify the cause-of-death, medical examiners performed autopsies in about half of their cases, while only 2% of medical practitioner cases were subjected to autopsies. Medical practitioners, who certified the cause-of-death as "heart failure" without advising an autopsy, were regularly entrusted with inquests. It is likely that the causes-of-death for medicolegal cases may be questionable since more than 85% of all medicolegal deaths were investigated by medical practitioners, which may cause inaccuracy in at least 3-7% of mortality statistics. It is necessary to educate medical practitioners concerning the importance of mortality statistics and ICD and on the validity of autopsies, in order to obtain accurate mortality statistics from medicolegal cases.


Assuntos
Autopsia/estatística & dados numéricos , Causas de Morte , Médicos Legistas , Medicina Legal/organização & administração , Acidentes/estatística & dados numéricos , Atestado de Óbito , Medicina Legal/normas , Medicina Legal/estatística & dados numéricos , Humanos , Japão , Densidade Demográfica , População Rural , Suicídio/estatística & dados numéricos , População Urbana
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