RESUMO
Rikkunshi-to (TJ-43), a gastroprotective herbal medicine, has been used for the symptomatic relief of adult patients with dyspepsia. However, its mechanism has yet to be fully elucidated. The aim of this study is to evaluate the effect of TJ-43 on the gastric myoelectric activity in post-operative dyspeptic patients, whose symptoms persisted for over 1 year after gastrointestinal surgery. Electrogastrography (EGG) recordings were performed to calculate the biomechanical parameters on the dominant peak frequency (DPF). Eight pediatric patients with dyspeptic symptoms after gastrointestinal surgery were examined and six age-matched children without any dyspeptic symptoms were used as controls, and they were compared with nine age-matched children without any dyspeptic symptoms after gastrointestinal surgery as subcontrols. All patients exhibited symptomatic relief after the administration of TJ-43, and the mean symptom score decreased significantly after the treatment of TJ-43 over a 1-month period ( P<0.0001). The variability index (VI) and the percentage of normal waves (PNW) were calculated as irregularity parameters of DPF. The power ratio (PR) was calculated as a parameter of the gastric contractile activity. There were no significant differences in the VI and PNW between the controls and patients during the postprandial state after therapy, even though significant differences existed regarding those parameters between the controls and patients before the therapy. There were no significant differences in the DPF, VI, and PNW between the controls and subcontrols. Furthermore, PR exhibited a significant increase after therapy ( P<0.05). However, there was a significant difference in the PR between the controls and subcontrols ( P<0.05). Postprandial dip was observed in all control subjects, eight patients in the subcontrols, and two patients after administration of TJ-43, respectively. An abnormal gastric electrical activity therefore seems to be an important factor in the pathophysiology of post-operative dyspeptic children. The coordinating and stimulating effect of TJ-43 on the gastric myoelectric activity therefore seems to play an important role in the reduction of dyspeptic symptoms.
Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Medicamentos de Ervas Chinesas/farmacologia , Dispepsia/tratamento farmacológico , Fármacos Gastrointestinais/farmacologia , Complexo Mioelétrico Migratório/efeitos dos fármacos , Adolescente , Criança , Pré-Escolar , Medicamentos de Ervas Chinesas/uso terapêutico , Dispepsia/etiologia , Fármacos Gastrointestinais/uso terapêutico , Gastroenteropatias/cirurgia , Humanos , Complexo Mioelétrico Migratório/fisiologia , Resultado do TratamentoRESUMO
BACKGROUND/PURPOSE: The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery. METHODS: Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum. RESULTS: A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically. CONCLUSIONS: Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.
Assuntos
Transfusão de Sangue Autóloga , Anormalidades Congênitas/cirurgia , Sangue Fetal , Assistência Perioperatória , Preservação de Sangue , Humanos , Recém-Nascido , Diagnóstico Pré-Natal , Coleta de Tecidos e Órgãos/métodos , Resultado do TratamentoRESUMO
In order to identify genes that are temporally and spatially regulated during wound response, a cDNA population in mechanically wounded tobacco leaves was screened by the fluorescence differential display method. Of 28 clones initially identified to have altered levels of transcripts within 3 h of wounding, eight were characterized. Although each clone showed a unique pattern of transcript accumulation, one distinct clone was further characterized because of its immediate-early response. Its transcripts began to accumulate 10 min after wounding, reached a maximum level within 1 h and disappeared after 2 h. The response, which occurred repeatably and systemically, was observed by the treatment with propionic acid or erythrosin B, indicating that cytosolic acidification could be one of the signals for immediate-early response of this gene. The cDNA encodes a polypeptide of 513 amino acids with a relative molecular mass of 60,952. The putative polypeptide is rich in lysine (K), glutamic acid (E) and aspartic acid (D), which constitute up to 70% of total amino acids, and was therefore designated as KED. The KED polypeptide is composed of a highly hydrophilic N-terminal region and a relatively hydrophobic C-terminal region, suggesting that KED may function through electrostatic interactions with cellular components.
Assuntos
Ácido Egtázico/análogos & derivados , Regulação da Expressão Gênica de Plantas , Genes Precoces , Proteínas Imediatamente Precoces/genética , Nicotiana/fisiologia , Proteínas de Plantas/genética , Plantas Tóxicas , Transcrição Gênica , Sequência de Aminoácidos , Cicloeximida/farmacologia , Citosol/fisiologia , DNA Complementar , Ácido Egtázico/farmacologia , Eritrosina/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas Imediatamente Precoces/química , Cinética , Dados de Sequência Molecular , Peso Molecular , Ácido Okadáico/farmacologia , Proteínas de Plantas/química , Propionatos/farmacologia , Homologia de Sequência de Aminoácidos , Estaurosporina/farmacologia , Fatores de Tempo , Nicotiana/genéticaRESUMO
An immediate-early, transiently activated wound-responsive gene was identified in tobacco by fluorescent differential display screening. The full-length cDNA encodes a polypeptide of 356 amino acids with a relative molecular mass of 39,082 Da. The deduced amino acid sequence shows two characteristic features; a leucine-zipper motif found in the more N-terminal region and a WRKY domain containing a zinc-finger motif located in the central region. The gene was designated as wizz (wound-induced leucine zipper zinc finger). Northern analysis showed that upon wounding wizz transcripts were locally and systemically accumulated within 10 min, reached a maximum level by 30 min, and decreased thereafter to the basal level. Analyses of a WIZZ-GFP fusion protein clearly indicated that WIZZ is a nuclear factor. WIZZ specifically binds to sequences containing two TTGAC core motifs that are separated by a spacer of appropriate length. The binding activity was dependent on bivalent cations, most probably zinc. In transient reporter assays, however, WIZZ did not show transactivation activity in tobacco suspension cells, suggesting that it functions together with other components. The results indicate that WIZZ is a new transcription factor which participates in early stages of the wound response.
Assuntos
Nicotiana/genética , Nicotiana/metabolismo , Proteínas Nucleares , Proteínas de Plantas/genética , Plantas Tóxicas , Fatores de Transcrição/genética , Sequência de Aminoácidos , Sequência de Bases , Núcleo Celular/metabolismo , Primers do DNA/genética , DNA Complementar/genética , DNA de Plantas/genética , Genes Precoces , Genes de Plantas , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Transcrição Gênica , Dedos de Zinco/genéticaRESUMO
Sixty-eight neonates with functional ileus were reviewed. Twelve required laparotomy; in seven, histological studies revealed decreased ganglia and ganglion cells of the myenteric plexus (MP) (Group A), and in five, MP was normal (Group B). In the remaining 56 cases, obstructive symptoms were relieved following conservative therapy (Group C). All Group A cases except one had normal birth weight, while Group B and C cases showed significantly lower birth weights. A marked caliber change of the small intestine and/or small-caliber distal intestine with meconium stagnation in the proximal intestine was commonly demonstrated at operation in Group A and B, or on contrast enema in Group C. Four Group A cases died of enteritis, and three survivors suffered from prolonged obstructive symptoms. The grade of histological abnormality of MP correlated with the clinical outcome. In Group B, three died of sepsis shortly after surgery, but two survivors have been free from symptoms. Group A can be categorized as Hirschsprung's disease-allied disorders (HAD). Group B and C can be categorized as meconium-related ileus (MRI). The similarity of the macroscopic findings of HAD and MRI, and the occurrence of MRI exclusively in low birth weight neonates, strongly suggest that functional immaturity of MP plays a role in the etiology of MRI.
Assuntos
Doença de Hirschsprung/patologia , Obstrução Intestinal/patologia , Plexo Mientérico/patologia , Gânglios/patologia , Doença de Hirschsprung/metabolismo , Doença de Hirschsprung/terapia , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Obstrução Intestinal/metabolismo , Obstrução Intestinal/terapia , MecônioAssuntos
Anestesia por Inalação , Anestésicos Inalatórios/administração & dosagem , Xenônio/administração & dosagem , Adulto , Anestesia com Circuito Fechado , Anestésicos Inalatórios/efeitos adversos , Eletroencefalografia/efeitos dos fármacos , Eletromiografia/efeitos dos fármacos , Feminino , Humanos , Riso , Masculino , Óxido Nitroso/efeitos adversos , Volume de Ventilação PulmonarRESUMO
Because selenium is seldom added to formulations for enteral nutrition (EN), postoperative patients who are supported with EN are at risk for selenium deficiency. This report describes four cases of suspected selenium deficiency in long-term EN. Two patients underwent pancreaticoduodenectomy, one underwent total gastro-pancreatectomy, and one underwent esophageal resection and reconstruction with jejunal autotransplantation. They all developed malabsorption syndrome within 2 yr after operation. Enteral nutritional support with an elemental diet was provided continuously for 7-11 yr. Over the past 1-2 yr they experienced increasing bilateral muscular pain and weakness in the legs, gait disturbance, palpitation, and shortness of breath. Investigation for possible trace element deficiency revealed very low levels of selenium in the blood. After 10-20 d of supplementation with daily intravenous administration of selenious acid 0.16 mg/d (100 micrograms/d of selenium), their blood levels of selenium rose and their symptoms resolved. They were then continued on a maintenance regimen of oral sodium selenite 0.13 mg/d (60 micrograms/d of selenium).
Assuntos
Nutrição Enteral/efeitos adversos , Complicações Pós-Operatórias , Selênio/deficiência , Idoso , Ampola Hepatopancreática , Neoplasias do Ducto Colédoco/cirurgia , Duodeno/cirurgia , Neoplasias Esofágicas/cirurgia , Gastrectomia , Humanos , Jejuno/transplante , Masculino , Pancreatectomia , Neoplasias Gástricas/cirurgia , Fatores de TempoRESUMO
In a screening series of bioactive components in edible and medicinal plants, we found that Calumbae Radix (Colombo root, 1% powdered feed, for 5 d) and its component, columbin (20-40 mg/kg/d, for 5 d, orally), shortened the sleeping time induced by a urethane and alpha-chloralose mixture and prolonged the sleeping time induced by hexobarbital in mice.
Assuntos
Diterpenos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Lactonas/farmacologia , Sono/efeitos dos fármacos , Anestesia , Animais , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Hexobarbital/farmacologia , Lactonas/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos , Extratos Vegetais/farmacologia , Fatores de Tempo , Uretana/farmacologiaRESUMO
Vascular invasion and intrahepatic metastasis by hepatocellular carcinoma are important factors predisposing to tumor recurrence. Recurrences of this malignancy occur frequently in residual liver, and its prevention is one of the most important factors in obtaining better surgical survival. Fifty patients who underwent hepatectomy for invasive hepatocellular carcinoma with vascular invasion and/or intrahepatic metastases were studied to evaluate the effect of adjuvant bolus hepatic arterial infusion of iodized poppyseed oil (Lipiodol) containing anticancer drugs in preventing recurrence and in prolonging survival. Patients were assigned to two treatment groups. Twenty-three of the fifty patients received adjuvant bolus infusion of Lipiodol containing doxorubicin and mitomycin C, whereas 27 patients received no therapy. The disease-free survival rate for the patients who received adjuvant therapy was significantly better (p < 0.05) than that for those who did not when measured at 172, 516, 688 and 860 days after hepatectomy, and the disease-free survival curve for patients with adjuvant therapy was significantly (p = 0.0237) better than that without adjuvant therapy. The cumulative survival rates and curves were not significantly different between the two groups. While adjuvant hepatic arterial infusion of Lipiodol containing anticancer drugs was effective in improving disease-free survival, the effect was not satisfactory. Further trials of adjuvant chemotherapy are required to improve the surgical survival of hepatocellular carcinoma patients.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica , Óleo Iodado/administração & dosagem , Neoplasias Hepáticas/terapia , Idoso , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Terapia Combinada , Doxorrubicina/administração & dosagem , Feminino , Hepatectomia , Artéria Hepática , Humanos , Infusões Intra-Arteriais , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Invasividade Neoplásica , Metástase Neoplásica , Recidiva Local de Neoplasia/prevenção & controle , Estudos Prospectivos , Taxa de SobrevidaRESUMO
The serum 4-O-methylpyridoxine (MPN) levels in a 21 months-old patient with gin-nan food poisoning were determined by HPLC. The blood of the patient was taken at 8.5 and 15.5 h after taking about 50 ginkgo albumens. After deproteinization of the serum, the supernatant was pretreated with Sep-pak C18 cartridge and was applied to HPLC. HPLC was performed with a Hibar LiChrosorb RP-18 (4.0 mm i.d. x 250 mm, 7 microns) using a fluorescence detector (wave length of excitation and fluorescence; 290 and 400 nm, respectively). The serum MPN level was determined by the absolute calibration method. The determination limit of MPN in the serum was 0.05 micrograms/ml. The serum MPN concentration was 0.09 micrograms/ml at 8.5 h after taking ginkgo seeds, and was less than the determination limit of MPN (0.05 micrograms/ml) at 15.5 h. MPN, isolated from the seed of Ginkgo biloba L., is responsible for "gin-nan food poisoning," and its cardinal symptoms are mainly tonic and/or clonic convulsions and loss of consciousness. Infants are particularly vulnerable. This method may be available for proving the gin-nan food poisoning, chemically.
Assuntos
Intoxicação por Plantas/sangue , Plantas Comestíveis , Piridoxina/análogos & derivados , Convulsões/etiologia , Cromatografia Líquida de Alta Pressão , Humanos , Lactente , Piridoxina/sangueRESUMO
Based on the idea of transsphincteric approach by Peña, we applied anterior sagittal anorectoplasty (ASARP) as a redo operation in 10 patients, who present moderate to severe fecal incontinence postoperatively. Those patients exhibited anal opening located anteriorly to the center of contraction of external sphincter muscles. Operation is begun with making a circumferential skin incision in the mucocutaneous junction around the anal opening, extending posteriorly along the median line to the center of the external sphincter muscles. Upon confirming the vertical muscle and the external sphincter muscles, the rectal tube, being dissected free, is mobilized backward to be placed at the center of the vertical muscles and enclosed by the muscle. After the operation, an improvement was noted in either clinical symptoms or scores, being particularly marked for incontinence and staining scores. Anorectal manometry and barium enema studies also showed a significant improvement. These results provide ample justification of ASARP as a redo operation for imperforate anus being worthwhile trying in properly selected patients with poor anorectal function following the primary operation.
Assuntos
Anus Imperfurado/cirurgia , Incontinência Fecal/cirurgia , Complicações Pós-Operatórias/cirurgia , Anus Imperfurado/diagnóstico , Sulfato de Bário , Criança , Pré-Escolar , Enema , Incontinência Fecal/diagnóstico , Feminino , Humanos , Masculino , Manometria , Complicações Pós-Operatórias/diagnóstico , Reoperação , Procedimentos Cirúrgicos Operatórios/métodosRESUMO
The leaves of Ginkgo biloba L. and aqueous extract from them shortened the sleeping time induced in mice by anesthetics (hexobarbital, alpha-chloralose and urethane, i.p.). Two characteristic terpenoids in G. biloba, bilobalide and ginkgolide A, significantly shortened the sleeping time induced by anesthetics. A toxic substance, 4-O-methylpyridoxine (MPN), responsible for "gin-nan food poisoning" isolated from the seed of G. biloba, was not detected from the extract of the leaves of G. biloba. Therefore, the Ginkgo biloba extract has no toxicities for MPN.
Assuntos
Anestésicos/farmacologia , Ciclopentanos/farmacologia , Diterpenos , Furanos/farmacologia , Lactonas/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Sono/efeitos dos fármacos , Animais , Cloralose , Ciclopentanos/isolamento & purificação , Furanos/isolamento & purificação , Ginkgolídeos , Hexobarbital , Lactonas/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos , Fatores de Tempo , UretanaRESUMO
Twenty-four patients with acute low-tone sensorineural hearing loss (ALHL) were examined using electrocochleography. The negative summating potential (SP) amplitude and the summating potential/action potential (AP) ratio were significantly greater in the ALHL patients than in normals. The SP/AP ratio was smaller in the ALHL patients than in patients with known Meniere's disease and moderate hearing loss, although the SP amplitude was somewhat greater in the former. An abnormal increase in the SP amplitude following click stimuli was found in 54% of the ALHL patients, while the SP/AP ratio was increased abnormally in 63% of these patients. These findings suggest that the pathophysiology of ALHL may be similar to that for endolymphatic hydrops.
Assuntos
Audiometria de Resposta Evocada , Perda Auditiva Neurossensorial/fisiopatologia , Estimulação Acústica , Potenciais de Ação , Doença Aguda , Adulto , Cóclea/fisiopatologia , Feminino , Humanos , Masculino , Doença de Meniere/fisiopatologia , Pessoa de Meia-IdadeRESUMO
Effects of seven limonoids, obakunone (1), 7 alpha-obakunol (2), 7 beta-obakunol (3), limonin (4), 7 alpha-limonol (5), 7 beta-limonol (6) and nomilin (7), on the sleeping time induced in mice by anesthetics were assayed. All the limonoids, except for 2, shortened the sleeping time induced by alpha-chloralose and urethane. 7 gave the highest reduction rate of sleeping time, and the order of the reduction rate of sleeping time was as follows; 7 > 1 and 3 > 4, 5 and 6. As the chemical structures of these compounds are similar to each other, the relationship between the structure and the effects of limonoids on sleeping time was discussed.
Assuntos
Extratos Vegetais/farmacologia , Sono/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Cloralose/farmacologia , Interpretação Estatística de Dados , Masculino , Camundongos , Extratos Vegetais/química , Triterpenos/química , Uretana/farmacologiaRESUMO
Postoperative adjuvant locoregional chemotherapy was performed on patients who underwent hepatic resection for hepatocellular carcinoma with permeation of tumor into portal vein and/or into hepatic vein and/or intrahepatic metastasis to prevent recurrence. Twenty patients received intra-hepato-arterial infusion of chemotherapeutic drugs or Lipiodol, or transcatheter arterial embolization as adjuvant therapy, and 25 patients did not receive the therapy. There was no significant difference in the recurrence rate between the two groups, and disease-free-survival would not be improved significantly by adjuvant therapy. But the disease-free-survival was improved in patients who underwent relative noncurative hepatectomies. Median duration from the hepatic resection to the recurrence was prolonged by adjuvant therapy, but no significant difference was noted between the two groups. Serious hepatic injury was a side effect of adjuvant therapy in one patient. Therefore great care was necessary when performing the therapy. Further study on choice of the drugs and methods was considered necessary to obtain more effective therapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma Hepatocelular/prevenção & controle , Quimioembolização Terapêutica , Hepatectomia , Neoplasias Hepáticas/prevenção & controle , Recidiva Local de Neoplasia/prevenção & controle , Carcinoma Hepatocelular/cirurgia , Cisplatino/administração & dosagem , Doxorrubicina/administração & dosagem , Humanos , Infusões Intra-Arteriais , Óleo Iodado/administração & dosagem , Neoplasias Hepáticas/cirurgia , Mitomicina/administração & dosagem , Cuidados Pós-OperatóriosRESUMO
The hearing ability and histological characteristics of the cochlea of a strain of new-mutant mice were analyzed. This new mutant arose as a spontaneous mutation in the C3H/He stock. The genetic mode is autosomal recessive and the animals show abnormal behavior such as circling, head-tossing and hyperactivity. The audiological findings exhibited no recordable auditory brain stem response (ABR) in any homozygotes at ages ranging from 11 days to 117 days. For morphological examination, we used 36 homozygote with ages ranging from 10 days to 18 months. The primary morphological abnormalities were observed in the organ of Corti. The stereocilia of the outer hair cells showed disarray throughout the whole cochlea, although outer hair cell cytoplasm became fully developed, including the nerve terminals. Age-dependent degeneration of the outer hair cells subsequently occurred from the basal to the apical part of the cochlea. The earliest change demonstrated in the outer hair cells was cuticular degeneration. Although the abnormalities of the inner hair cells occurred late, a complete loss of inner and outer hair cells was demonstrated. The stria vascularis was well preserved at a later age as were spiral ganglion cells. These histological findings confirm that this mouse is classified as a neuroepithelial-type mutant. As this animal was expected to have a single gene abnormality, molecular genetic studies on this animal can provide important information on the nature of histological changes of the hair cell from a mode of gene action.
Assuntos
Aberrações Cromossômicas/veterinária , Cóclea/anormalidades , Genes Recessivos , Células Ciliadas Auditivas/anormalidades , Camundongos Mutantes Neurológicos/genética , Estimulação Acústica , Animais , Audiometria de Resposta Evocada , Transtornos Cromossômicos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Genótipo , Camundongos , Microscopia Eletrônica , Microscopia Eletrônica de VarreduraAssuntos
Benzopiranos/isolamento & purificação , Benzoxepinas/isolamento & purificação , Medicamentos de Ervas Chinesas/análise , Limoninas , Sono/efeitos dos fármacos , Triterpenos/isolamento & purificação , Animais , Benzopiranos/farmacologia , Benzoxepinas/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Camundongos , Fatores de Tempo , Triterpenos/farmacologiaRESUMO
PTT.119 is a new synthetic compound under assessment as a chemotherapeutic agent against neoplasia. Exposure of three diverse tumor cell lines, L1210 leukemia, MJY-alpha mammary tumor, and B16 melanoma to 1 to 50 micrograms PTT.119/ml for 15, 30 or 60 minutes significantly reduced cell survivals. Each tumor model was differentially susceptible to PTT.119 activity in the extent and kinetics of cell cytolysis. Pathological changes unique to each tumor cell type were also observed and included nuclear fragmentation and lobulation, formation of multinucleated cells, mitotic asynchrony and vacuolization of both nuclear and cytosol compartments. The data demonstrate the necessity of using more than one tumor system for the evaluation of compounds and suggest that PTT.119 exerted its cancericidal activity by more than one mechanism.
Assuntos
Alquilantes/farmacologia , Antineoplásicos , Compostos de Mostarda Nitrogenada/farmacologia , Alquilantes/uso terapêutico , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Leucemia L1210/tratamento farmacológico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Melanoma/tratamento farmacológico , Camundongos , Camundongos EndogâmicosRESUMO
Tryptophan-p-1 (trp-p-1) and p-2, which have high mutagenic and carcinogenic potential, are oxidized by catalase- and horseradish peroxidase (HRP)-H2O2 intermediates with optimum pH 5.9 (0.2 M-acetate) in catalase and pH 5.0 (0.2 M-acetate), 8.0 (0.01 M-phosphate) in HRP. The rate constants (k4) of the oxidation in the catalase at pH 5.9 (0.2 M-acetate) were 2965 M-1 x sec-1 for trp-p-1 and 576 M-1 x sec-1 for trp-p-2. In the case of HRP, 1894 M-1 x sec-1, (pH 5.0, 0.2 M-acetate) for trp-p-1 and 705 M-1 x sec-1 (pH 8.0, 0.001 M-phosphate) for trp-p-2 under each optimum condition. The oxidation products of trp-p-1 and p-2 by catalase or HRP lost completely their mutagenic potential in the mutation assay.