RESUMO
We investigated the effects of the antiparasitic drug ivermectin on the dung beetles Copris acutidens Motschulsky, Onthophagus bivertex Heyden, O. lenzii Harold and Phelotrupes auratus auratus Motschulsky in Japan. Ivermectin was detected in cattle dung from 1 to 3 or 7 days post-treatment, with a peak at 3 days post-treatment in two pour-on administrations (500 µg kg-1). In C. acutidens, adult survivals and numbers of brood balls were significantly reduced in dung collected at 3 and 7 days post-treatment, and adult emergence rates were significantly decreased in dung collected at 7 and 14 days post-treatment. Feeding activity of C. acutidens was inhibited in dung collected at 3 days post-treatment, but was not significantly different from that seen in control dung at 7 and 14 days post-treatment. In O. bivertex and O. lenzii, there were no effects of ivermectin on adult survival or feeding activities, but the numbers of brood balls of O. bivertex constructed in dung collected at 3 and 7 days post-treatment were significantly lower than observed with control dung. The adult emergence rates of O. bivertex and O. lenzii were significantly reduced in dung collected at 1 to 3 and 1 to 7 days post-treatment, respectively. In P. auratus, there were no effects of ivermectin on adult survival, oviposition, feeding activity, or larval survival (until the third instar) in dung at 3 days post-treatment. The environmental risks affecting the populations of dung beetles in Japan are discussed.
Assuntos
Antiparasitários/toxicidade , Besouros/efeitos dos fármacos , Ivermectina/toxicidade , Animais , Antiparasitários/análise , Fezes/química , Comportamento Alimentar/efeitos dos fármacos , Feminino , Ivermectina/análise , Masculino , Reprodução/efeitos dos fármacos , Testes de Toxicidade SubcrônicaRESUMO
Effects of the antiparasitic drug eprinomectin were studied on the dung beetles, Onthophagus lenzii Harold and the rare species, Copris ochus Motschulsky by pour-on administrations (500 µg kg-1) in Japan. Eprinomectin was detected in cattle dung from 1 to 7 or 14 days after treatment, with a peak at 1 day after treatment in two experiments. In O. lenzii, adult survivals and numbers of brood balls constructed were significantly reduced in dung from eprinomectin-treated cattle at 1 and 3 days post-treatment in experiment 1, and adult emergence rates were extremely reduced in dung at 1, 3, and 7 days post-treatment. In C. ochus, adult survivals were significantly reduced in dung at 3 days post-treatment (experiment 1), and equivalent levels to the control were restored in dung at 7 and 14 days post-treatment (experiment 2). Numbers of brood balls of C. ochus were nil in dung at 3 days (experiment 1), and significantly reduced in dung at 7 days (experiment 2) post-treatment compared with control. Adult emergence rates of C. ochus were 100 and 71.6% in dung from control cattle in experiments 1 and 2, respectively. However, no oviposition was observed in dung at 3 days post-treatment, and all offspring died at egg or the first instar larval stage in dung from 7 and 14 days post-treatment. Feeding activities of O. lenzii and C. ochus were significantly inhibited in dung from treated cattle at 1-3 days and 3 days post-treatment, respectively, returning to levels of the control at 7 days post-treatment.
Assuntos
Anti-Helmínticos/toxicidade , Besouros , Ivermectina/análogos & derivados , Animais , Comportamento Alimentar/efeitos dos fármacos , Feminino , Ivermectina/toxicidade , Masculino , Reprodução/efeitos dos fármacos , Testes de ToxicidadeRESUMO
Focal dystonia is regarded as a characteristic feature of blepharospasm. However, patients do not always present with motor symptoms. To clarify the clinical features of blepharospasm in Japan, we conducted a retrospective observational study involving a large population of patients from a single institution. Common symptoms included difficulty opening the eyes, photophobia, and ocular pain/irritation. Initial symptoms often occurred following the long-term use of psychotropics such as etizoram, benzodiazepines, and zolpidem (32% of patients). Our findings demonstrated that the clinical presentation of blepharospasm is heterogenous, and that understanding regarding sensory-dominant forms of the disease may be poor among practitioners in Japan.
RESUMO
This report presents a simple model that describes the motion of a single Dictyostelium discoideum cell exposed to a traveling wave of cyclic adenosine monophosphate (cAMP). The model incorporates two types of responses to stimulation by cAMP: the changes in the polarity and motility of the cell. The periodic change in motility is assumed to be induced by periodic cAMP stimulation on the basis of previous experimental studies. Consequently, the net migration of the cell occurs in a particular direction with respect to wave propagation, which explains the migration of D. discoideum cells in aggregation. The wave period and the difference between the two response times are important parameters that determine the direction of migration. The theoretical prediction compared with experiments presented in another study. The transition from the single-cell state of the population of D. discoideum cells to the aggregation state is understood to be a specific example of spontaneous breakage of symmetry in biology.
Assuntos
Quimiotaxia , AMP Cíclico/metabolismo , Dictyostelium/fisiologia , Dictyostelium/citologia , Modelos BiológicosRESUMO
In the present study, an analysis of the DNA homology of the pericentric chromosomal regions and pericentric heterochromatin in distantly related species of wood mice (species from the Apodemus genus, as well as from the Apodemus and Sylvaemus genera) was conducted by fluorescent in situ hybridization (FISH) with microdissected DNA probes obtained from the corresponding chromosomal regions of these species. Cross-hybridization of microdissected DNA probes obtained from pericentric C-positive blocks of chromosomes of Sylvaemus species with chromosomes of Apodemus species, as well as DNA probes from pericentric C-positive blocks of chromosomes of Apodemus species with chromosomes of Apodemus and Sylvaemus species, showed that DNA repeats homologous to the pericentric regions in other species represented. dispersed repeats in C-negative chromosomal regions, as well as in several regions bordering pericentric C-positive and C-negative regions in heterochromosomes and autosomes and in distal regions in the long arms of several autosomes. The results indicate that the level of DNA homology in pericentric chromosomal regions decreases with an increase in the differentiation level and a decrease in the kinship between the compared forms and species of wood mice. Most likely, degeneration of the DNA repeats is accompanied by a gradual destruction of repeat clusters and their replacement by new, nonhomologous repeats in almost all pericentric regions (some old repetitive sequences might be "extruded" into interstitial or telomeric regions of chromosomes). These processes, which are observed in some species from Sylvaemus genus in distantly related species of Sylvaemus and Apodemus genera, have almost achieved the final stages.
Assuntos
Cromossomos de Mamíferos/genética , Heterocromatina/genética , Murinae/genética , Telômero/genética , Animais , Feminino , Masculino , Especificidade da EspécieRESUMO
Korean field mice (Apodemus peninsulae) are widely distributed throughout northeastern Asia, including the Russian Far East, northern China, the Korean peninsula, Sakhalin, and Hokkaido. This mouse species is characterized by a high frequency of animals with B chromosomes differing in their number, morphology, and DNA composition in different geographical regions. For the first time a comparative analysis of DNA probes from B chromosomes with metaphase chromosomes of mice from Transbaikalia, the Far East (including the Russian Far East), Japan, and South Korea was conducted by in situ hybridization. B chromosomes in mice from the Russian Far East were shown to exhibit low variability in DNA content; however, the DNA composition of B chromosomes in species from Transbaikalia and Japan were highly variable. B chromosomes in A. peninsulae from the South Korean population demonstrate minor differences from those from the Russian Far East. We discuss the origin of B chromosomes in the studied region in comparison with previously obtained data for mice from Siberia and the Baikal region, as well as the dispersal routes of the Korean field mouse.
Assuntos
Cromossomos de Mamíferos/genética , Variação Genética , Murinae/genética , Filogenia , Animais , Hibridização in Situ Fluorescente , SibériaRESUMO
Previously, many studies have revealed the presence of B chromosomes in wild mouse taxa of the genus Apodemus (Rodentia, Muridae). In one of the Apodemus species, A. argenteus, which is endemic to Japan, it is known that B chromosomes were confirmed only in individuals (2n = 46 + B chromosome) from Hokkaido, Japan. There is no report of the presence of B chromosomes from other localities in the Japanese Islands. In this study, we analyzed the chromosomal constitutions of 43 individuals of A. argenteus from three localities in Honshu, Japan. A total of three individuals from central Honshu showed 2n = 47, and each individual carrieda dot-like B chromosome. In addition, these B chromosome features were analyzed by differential staining methods, and the C- and QM-banding patterns of the B chromosomes were identical to those of the X chromosomal heterochromatic region showing the delayed-fluorescent response. Thus, it is considered that these B chromosomes would be derived from the heterochromatin of the X chromosomes, as reported in previously published papers.
Assuntos
Cromossomos de Mamíferos/genética , Heterocromatina/genética , Murinae/genética , Cromossomo X/genética , Animais , JapãoRESUMO
A rare non-sex mosaic abnormality represented by genitalia-like appendages on the ventral surface of abdominal segment 8 of a male black fly collected in Hokkaido, Japan, is reported. The appendages consist of a pair of style-like projections each arising from a coxite-like base, inverted-Y shaped ventral plate-like structure, and isolated round structure. This male was morphologically and molecularly identified as an abnormal form of S. (S.) iwatense (Shiraki), the only species in the Simulium (Simulium) ornatum species-group in Japan, although certain morphological characteristics of this male including the reduced number of uppereye (large) facets and elongate cerci are different from those of S. (S.) iwatense.
Assuntos
Simuliidae , Animais , Genitália , Japão , Larva , Masculino , Simuliidae/anatomia & histologia , Simuliidae/classificaçãoRESUMO
Retinol-binding protein 4 (RBP4) is a recently identified adipokine that is elevated in the blood in several insulin-resistant states. We investigated the association between plasma RBP4 and histological and biochemical characteristics of chronic hepatitis C (CHC), as well as changes in RBP4 levels following interferon therapy. Eighty-one patients with CHC infected with genotype 1 received treatment with peginterferon plus ribavirin. Histological data were available for 41 out of 81 patients before treatment, and the degree of fibrosis, inflammation and steatosis was assessed. Plasma levels of RBP4 were determined in serial samples (before, at the end of treatment, and at 6 months post-treatment). RBP4 levels were lower in CHC patients than in control subjects (34.6 +/- 12.3 microg/mL vs 46.2 +/- 10.5 microg/mL; P Assuntos
Antivirais/uso terapêutico
, Hepatite C Crônica/tratamento farmacológico
, Interferon-alfa/uso terapêutico
, Polietilenoglicóis/uso terapêutico
, Proteínas Plasmáticas de Ligação ao Retinol/análise
, Idoso
, Fígado Gorduroso/patologia
, Feminino
, Genótipo
, Hepacivirus/classificação
, Hepacivirus/isolamento & purificação
, Hepatite C Crônica/patologia
, Humanos
, Interferon alfa-2
, Fígado/patologia
, Cirrose Hepática/patologia
, Masculino
, Pessoa de Meia-Idade
, Plasma/química
, Proteínas Recombinantes
, Ribavirina/uso terapêutico
, Índice de Gravidade de Doença
, Carga Viral
RESUMO
8-Hydroxydeoxyguanosine (8-OHdG) is a promutagenic DNA lesion produced by hydroxyl radicals and is recognized as a useful marker in estimating DNA damage induced by oxidative stress. The aim of this study was to clarify the clinical significance of hepatic 8-OHdG levels in patients with chronic viral hepatitis. Hepatic 8-OHdG accumulation was investigated in patients with chronic hepatitis C (CH-C) (n = 77) and chronic hepatitis B (CH-B) (n = 34) by immunohistochemical staining of liver biopsy samples. 8-OHdG positive hepatocytes were significantly higher in patients with CH-C compared to CH-B (median 55.0 vs 18.8 cells/10(5) mum(2), P < 0.0001). The number of positive hepatocytes significantly increased with the elevation of serum aminotransferase levels, especially in CH-C patients (8-OHdG vs alanine aminotransferase (ALT)/aspartate aminotrasferase (AST) were r = 0.738/0.720 in CH-C and 0.506/0.515 in CH-B). 8-OHdG reactivity was strongly correlated with body and hepatic iron storage markers in CH-C (vs serum ferritin, r = 0.615; vs hepatic total iron score, r = 0.520; vs hepatic hepcidin mRNA levels, r = 0.571), although it was related to serum HBV-DNA titers (r = 0.540) and age of patients (r = -0.559) in CH-B. These results indicate that hepatic oxidative DNA damage is common in chronic viral hepatitis, in particular chronic HCV-infected patients, suggesting a possible link between chronic hepatic inflammation and hepatocarcinogenesis. The strong positive correlation between hepatic DNA damage and iron overload suggests that iron content is one of the most likely mediators of hepatic oxidative stress and iron reduction may be beneficial to reduce the incidence of hepatic cancer in CH-C patients.
Assuntos
Dano ao DNA , Desoxiguanosina/análogos & derivados , Hepatite B Crônica/metabolismo , Hepatite C Crônica/metabolismo , Sobrecarga de Ferro/metabolismo , Estresse Oxidativo , 8-Hidroxi-2'-Desoxiguanosina , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Desoxiguanosina/metabolismo , Feminino , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/genética , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Pessoa de Meia-IdadeAssuntos
Neoplasias Duodenais/complicações , Lipoma/complicações , Abscesso Hepático/etiologia , Neoplasias Duodenais/diagnóstico por imagem , Feminino , Humanos , Lipoma/diagnóstico por imagem , Abscesso Hepático/diagnóstico , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios XRESUMO
Here, we present two cases in which larvae of the family Piophilidae were detected in human cadavers. Both cases were found in Tochigi Prefecture, which is located in the middle of Honshu Island, Japan. Case 1: A corpse was found hanging in the sun lounge of a house. Dipteran larvae were collected from inside the spinal canal, despite no visible breach on the skin. The adults derived from these larvae were identified as Piophila casei (Linnaeus, 1758) and Liopiophila varipes (Meigen, 1830). Case 2: Skeletal human remains were found in a mountainous forest. Dipteran larvae were detected in the bone marrow cavity of a tibial section during autopsy. One adult fly derived from the larvae was identified as Protopiophila contecta (Walker, 1860). This is the first report of the identification of L. varipes and P. contecta in human cadavers.
Assuntos
Dípteros , Comportamento Alimentar , Mudanças Depois da Morte , Adulto , Animais , Entomologia , Antropologia Forense , Patologia Legal , Humanos , Japão , Larva , MasculinoRESUMO
BACKGROUND: Alcohol consumption is a major cause of liver injury but the mechanisms are not completely understood. Protein S (PS) is an anticoagulant glycoprotein with multiple functions. The role of PS in liver injury is unknown. OBJECTIVES: This study investigated the role of PS in acute alcoholic hepatitis. METHODS: A mouse overexpressing human PS (hPS-TG) was generated in which acute hepatitis was induced by intraperitoneal injection of ethanol. RESULTS: The levels of serum liver enzymes and liver tissue inflammatory cytokines and the degree of hepatic steatosis were significantly increased in hPS-TG mice treated with ethanol compared with ethanol-treated wild type (WT) mice. Cell expansion, activation and inhibition of apoptosis were significantly augmented in natural killer T (NKT) cells from hPS-TG mice compared with WT mice. Liver mononuclear cells from hPS-TG mice express higher levels of inflammatory cytokines than those from WT mice after stimulation with a specific stimulant of NKT cells in vitro. In a co-culture system of hepatocytes and NKT cells, the effects of PS on ethanol-mediated cell injury were suppressed by a CD1d neutralizing antibody. Alcoholic liver injury was significantly improved in mice pre-treated with PS siRNA and anti-protein S antibody compared with control mice. Patients with alcoholic hepatitis showed significantly increased plasma PS levels and enhanced liver expression of PS and CD1d compared with controls. CONCLUSIONS: The results of this study suggest that PS exacerbates acute alcoholic hepatitis by inhibiting apoptosis of activated NKT cells.
Assuntos
Proteínas Sanguíneas/metabolismo , Hepatite Alcoólica/metabolismo , Hepatócitos/metabolismo , Fígado/metabolismo , Ativação Linfocitária , Células T Matadoras Naturais/metabolismo , Proteína S/metabolismo , Animais , Anticorpos Neutralizantes/farmacologia , Antígenos CD1d/imunologia , Antígenos CD1d/metabolismo , Apoptose , Proteínas Sanguíneas/genética , Estudos de Casos e Controles , Células Cultivadas , Técnicas de Cocultura , Modelos Animais de Doenças , Etanol , Fígado Gorduroso Alcoólico/imunologia , Fígado Gorduroso Alcoólico/metabolismo , Fígado Gorduroso Alcoólico/patologia , Hepatite Alcoólica/genética , Hepatite Alcoólica/imunologia , Hepatite Alcoólica/patologia , Hepatite Alcoólica/prevenção & controle , Hepatócitos/imunologia , Hepatócitos/patologia , Humanos , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Fígado/imunologia , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células T Matadoras Naturais/imunologia , Proteína S/genética , Terapêutica com RNAi , Índice de Gravidade de Doença , Transdução de Sinais , Regulação para CimaRESUMO
In the present study we sought to determine the presence of myoglobin in human thyroid tissue. When reacted with antihuman myoglobin antibody on the Ouchterlony plate, homogenates of human thyroid tissue formed a precipitation line. When the human thyroid extract was included in human myoglobin RIA, the dilution curve of thyroid extract was parallel to the standard curve of myoglobin. When the myoglobin immunoreactivity in thyroid extract was fractionated with Sephadex G 75 column, the immunoreactivity was eluted in a peak identical with authentic myoglobin. The position of the peak was different from that of thyroglobulin. Myoglobin concentration in thyroid tissue was estimated to be 0.7-110 mg/g wet wt, being about 1/6000 to 1/40 of that in skeletal muscle. Histochemical studies demonstrated the presence of myoglobin immunoreactivity in thyroid tissue, especially in the apical border of thyroid epithelial cells, implying a functional role in iodinating process or exocytotic-endocytotic process.
Assuntos
Mioglobina/análise , Glândula Tireoide/análise , Adolescente , Adulto , Idoso , Anticorpos/imunologia , Cromatografia em Gel , Epitélio/análise , Feminino , Histocitoquímica , Humanos , Masculino , Métodos , Pessoa de Meia-Idade , Mioglobina/imunologia , Radioimunoensaio , Extratos de Tecidos/análiseRESUMO
We constructed a common-AB diploid strain of Coprinus cinereus and mated this to a compatible haploid strain to construct a diploid-haploid dikaryon. We examined the positions of the diploid and haploid nuclei in the apical and subapical cells of the dikaryon by fluorescence microscopy and microfluorometry. In 60% of apical cells the leading nucleus (the nucleus proximal to the hyphal apex) was diploid and the second nucleus (the nucleus distal to the apex) was haploid, whereas in the remaining 40% of apical cells the order of the two nuclei was reversed. It was also observed that in 97% of hyphae examined the order of the diploid and haploid nuclei was reversed between the apical cell and the subapical cell. Based on these observations, we conclude that the two nuclei alternate in taking the leading and second positions in the apical cell at almost every conjugate division in the dikaryon. Copyright 1998 Academic Press.
RESUMO
BACKGROUND AND PURPOSE: T1-weighted MR images show high signal intensity in the pallidum of many patients with liver cirrhosis. The purpose of this study was to evaluate quantitative changes in MR signals in patients with liver cirrhosis by using the magnetization transfer technique. METHODS: Magnetization transfer ratios were measured in seven different regions of the brain in 37 patients with liver cirrhosis and in 37 healthy volunteers. RESULTS: The magnetization transfer ratios in patients with liver cirrhosis were significantly lower than those in control subjects in the globus pallidus, putamen, thalamus, corona radiata, and subcortical white matter. CONCLUSION: Abnormal magnetization transfer ratios may be found in otherwise normal-appearing cerebral regions.
Assuntos
Encéfalo/patologia , Cirrose Hepática/patologia , Imageamento por Ressonância Magnética/métodos , Estudos de Casos e Controles , Feminino , Globo Pálido/patologia , Hepatite B/patologia , Hepatite C/patologia , Hipocampo/patologia , Humanos , Cirrose Hepática/virologia , Cirrose Hepática Alcoólica/patologia , Masculino , Pessoa de Meia-Idade , Lobo Parietal/patologia , Putamen/patologia , Núcleos Talâmicos/patologia , Tálamo/patologiaRESUMO
Nucleotides and nucleosides have effects on improving energy metabolism and enhancing immune function. Under a surgical stress, requirement of nucleotides are increased as well as nitrogen. A well-balanced nucleoside solution (OG-VI) was developed for parenteral administration and its effect was examined in animals. The OG-VI solution contained 3.11% of nucleosides which was composed of inosine, guanosine monophosphate, cytidine, uridine and thymidine of 4:4:4:3:1 in molar ratio. The whole body protein turnover increased significantly in rats received total parenteral nutrition (TPN) with OG-VI after 70% hepatectomy and enhanced the fractional protein synthesis rates of the muscle and liver. Also myocardial contractility (%segment shortening, %SS) in dogs after occlusion of left anterior descending artery (LAD) was recovered to 70% after reperfusion in the OG-VI group. The creatine phosphate (PCr) / inorganic phosphate (Pi) was maintained the baseline level and did not decrease after hypoxia in the OG-VI group while PCr/ Pi was decreased after hypoxia in normal rat. These data suggested that the nucleoside-nucleotide (OG-VI) improved nitrogen metabolism and might stimulate synthesis of high-energy phosphate in recovery after severe surgical stress.
Assuntos
Isquemia Miocárdica/fisiopatologia , Nucleosídeos/administração & dosagem , Nucleotídeos/administração & dosagem , Nutrição Parenteral Total , Proteínas/metabolismo , Animais , Cães , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Contração Miocárdica/efeitos dos fármacos , Contração Miocárdica/fisiologia , RatosRESUMO
Esophageal cancer is frequently found when it is already in the advanced stage and curative surgery for such cases is consequently difficult to perform. The new multi-disciplinary treatment for esophageal cancer presented here was, therefore, conceived to improve both the survival rate and quality of life of these patients. This combined treatment modality consists of limited surgery, external irradiation, intracavitary irradiation with remote-controlled after-loading system (RALS) and peri-operative chemotherapy. In the present series, 45 patients with esophageal cancer received esophagectomy and on another 11 patients bypass operation was performed. All patients were treated with this multi-disciplinary treatment after operation. A 3 cm-wide thin gastric tube was made from the greater curvature of the stomach of the patient using an autosuture apparatus (PLC55 or GIA). In the bypass operation, the jejunum was anastomosed to the original esophagus in the Roux-en Y fashion and jejunostomy was performed on the oral side of the Roux loop. A silastic tube of 9 mm inner diameter was inserted from the jejunostomy and placed into the original esophagus for the purpose of postoperative intracavitary irradiation with RALS. For the patients receiving esophagectomy, a similar silastic tube was also placed in the posterior mediastinum for intracavitary irradiation with RALS. The indication of the bypass operation was i) a tumor length longer than 9 cm on the X-ray film and/or ii) direct invasion to the aortic wall evident by CT or MRI examination. Two weeks after the operation, external irradiation to the mediastinum with Linac 10 MV X-ray, and to the bilateral cervical regions with Linac 15 MeV electron beam, was started. The irradiation doses were 30 Gy (2 Gy/day, 5 times/ week) and 48 Gy (4 Gy/day, 3 times/week), respectively. The intracavitary irradiation with RALS was started shortly before the end of the external irradiation period and was delivered from a 60Co source. The total dose was 24 Gy (6 Gy/day, once a week) for the esophagectomized cases, and 18 Gy for the bypassed cases. Two or three weeks after the termination of the radiotherapy, chemotherapy with cisplatinum and 5-fluorouracil was performed and repeated every 6 months for 2 years. All patients could eat normally and were discharged after finishing the first chemotherapy session. The overall 5-year survival rate was 49% for the esophagectomized cases and 11% for the bypassed cases. The longest survival time in the bypassed cases was 5 years and 4 months. Neither operative death nor severe complications were experienced during the treatment period. The results indicate that this newly developed multi-disciplinary treatment with RALS can improve the prognosis and the quality of life not only in the esophagectomized patients but also in the bypassed patients with advanced esophageal cancer.
Assuntos
Braquiterapia , Neoplasias Esofágicas/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bleomicina/administração & dosagem , Braquiterapia/métodos , Cisplatino/administração & dosagem , Terapia Combinada , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/cirurgia , Feminino , Fluoruracila/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia Torácica , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
To establish a paraquat-resistant Wistar rat strain, we carried out continuous sister-brother mating among rats that survived high-dose intraperitoneal administration of paraquat dichloride (360 mg/kg). The percentages of paraquat-resistant rats among wild rats and among the fifth-generations were 7.1% and 20.6%, respectively. After high-dose paraquat administration, the serum paraquat concentration in sensitive rats was much higher than that in paraquat-resistant rats. The cytosol fraction of liver from paraquat-resistant rats had higher paraquat- and diquat-metabolizing activities than that of liver from paraquat-sensitive rats. By contrast, microsomal fractions from livers of paraquat-resistant and paraquat-sensitive rats had no paraquat- or diquat-metabolizing activity. This paraquat/diquat-metabolizing enzyme was partially purified from paraquat-resistant rat liver cytosol using affinity chromatography for diquat. At the end of the purification procedure, rat liver diquat-metabolizing enzyme was purified 1154-fold to a final specific activity of 32.32 mol/h/mg protein, and an overall recovery of about 0.46% was obtained. This enzyme oxidized diquat to diquat-dipyridone during overnight incubation at 37 degrees C, but only metabolized traces of paraquat. The molecular mass of the enzyme was estimated as 190 kDa, and its isoelectric point of it was 4.6-4.7. Kinetic study revealed the values of K(m) and V(max) to be 35.0 micromol/l and 0.81 micromol/h/ml, respectively.