RESUMO
The catalytic subunit of cAMP-dependent protein kinase purified from bovine heart was significantly stabilized by non-ionic detergents. Freezing and thawing did not cause a significant decrease in the enzyme activity in the presence of 0.1% Tween 80. A very convenient method for purification and crystallization of the catalytic subunit was also described.
Assuntos
Miocárdio/enzimologia , Proteínas Quinases/isolamento & purificação , Animais , Bovinos , Cromatografia por Troca Iônica , Cristalização , Detergentes , Estabilidade Enzimática , Congelamento , Hidroxiapatitas , PolissorbatosRESUMO
To determine the regulatory mechanism for human tyrosine hydroxylase, we examined modulations of the activity of the enzyme from human pheochromocytoma by cyclic AMP-dependent protein kinase, calmodulin-dependent protein kinase II and polyanion. The most remarkable activation was observed when the enzyme was assayed at physiological pH (pH 7) after being subjected to phosphorylation by cyclic AMP-dependent protein kinase. Calmodulin-dependent protein kinase II and polyanion also modulated the enzyme activity. The results suggest that tyrosine hydroxylase may be regulated similarly in both human and rat.
Assuntos
Polímeros/farmacologia , Proteínas Quinases/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Sulfato de Dextrana , Dextranos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Feocromocitoma , Polieletrólitos , Ratos , Células Tumorais CultivadasRESUMO
Mucositis is a prominent dose-limiting toxicity associated with 5-FU-based chemotherapy. On the basis of preliminary data suggesting that the amino acid glutamine could alleviate this problem, the authors developed this trial. Patients scheduled to receive their first 5-FU-based chemotherapy regimen were selected for study. Following stratification, patients were randomized, in a double-blind manner, to receive oral glutamine or a placebo preparation in a prophylactic manner. Patients in both groups were given oral cryotherapy before chemotherapy and were evaluated for mucositis by standard physicians' evaluation and by a self-report instrument. Sixty-six patients were randomized to receive glutamine and 68 to receive the placebo preparation. There were no significant differences or substantial trends in the mucositis scores between the two study arms as measured by either the physicians or the patients. It was concluded that the dose and schedule of glutamine used in this clinical trial does not alleviate 5-FU-induced mucositis.
Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Fluoruracila/efeitos adversos , Glutamina/uso terapêutico , Estomatite/induzido quimicamente , Estomatite/prevenção & controle , Administração Oral , Administração Tópica , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Feminino , Fluoruracila/administração & dosagem , Glutamina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Antissépticos BucaisRESUMO
Abnormal function of fibrinogen was observed in a 25-year-old woman with no symptoms attributable to dysfibrinogenemia. Disturbed polymerization of fibrin monomer was identified, but the release of fibrinopeptide from the purified fibrinogen and the cross-linking by factor XIII were normal. Other abnormal findings included a high value of fibrinogen degradation products, rapid mobility on immunoelectrophoresis and abnormal spot of gamma-chain on two-dimensional polyacrylamide gel electrophoresis. Similar abnormalities were also observed among the patient's family members.