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1.
Zhonghua Yi Xue Za Zhi ; 101(35): 2792-2797, 2021 Sep 21.
Artigo em Chinês | MEDLINE | ID: mdl-34551496

RESUMO

Objective: To study the relationship between emotional apathy and motor symptoms, sleep, and cognitive function in patients with early Parkinson's disease (PD). Methods: One hundred and twenty-nine early PD patients who were treated in the Second Affiliated Hospital of Soochow University from June to October 2020 were included, including 82 male and 47 female patients. The emotional apathy was assessed by modified apathy rating scale (MAES). The above 129 patients were divided into 67 patients in the PD with emotional apathy group (MAES>14 points) and 62 patients in the PD without emotional apathy group (MAES≤ 14 points). Age, gender, course of disease and levodopa equivalent dose were also collected. Hoehn-Yahr stage and unified Parkinson's disease rating scale PartⅢ(UPDRS-Ⅲ), Pittsburgh Sleep Quality Index (PSQI), polysomnography, and Montreal Cognitive Assessment Scale (MoCA) were used to evaluate the motor symptoms, sleep and cognitive functions of patients with early PD, and the clinical characteristics of patients with early PD with apathywere determined. Results: Compared with PD patients without apathy, those with apathy had longer disease duration [M(Q1,Q3)][5.0 (3.0, 7.0) years vs 3.0 (2.0, 5.0) years, P=0.006] and severer motor symptoms [20.0 (10.0, 28.0) vs 14.0 (8.5, 23.0), P=0.047]. There was no significant difference in PSQI score between the two groups. Among the 33 patients who completed polysomnography, compared with PD patients without apathy (n=16), those with apathy (n=17) had a longer rapid eye movement (REM) sleep latency [150 (124, 184) min vs 87 (57, 133) min, P=0.035)] and more frequent periodic limb movements in the REM phase(P=0.042).The REM sleep ratio (r=0.373, P=0.042), apnea-hypopena index (AHI)(r=0.374, P=0.046) and oxygen deficit index (r=0.409, P=0.025) were positively correlated with the degree of apathy in PD patients. PD patients with apathy had relatively poorer performance in cognition assessment than those without apathy and total MoCA score was inversely correlated with the degree of apathy (r=-0.231, P=0.017). Conclusion: Early PD patients with apathy have objective sleep disorders dominated by REM sleep disorders, which can have a negative impact on cognitive function.


Assuntos
Apatia , Doença de Parkinson , Transtorno do Comportamento do Sono REM , Cognição , Feminino , Humanos , Masculino , Doença de Parkinson/complicações , Sono
2.
Environ Technol ; 33(1-3): 173-81, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22519101

RESUMO

Municipal solid waste used for landfill becomes stabilized, or aged, some years after placement, and can be safely excavated; the term 'mineralized refuse' is used in this study. The adsorptions of phosphorus, and the nitrification of the mineralized refuse and clay, were investigated by batch incubation. The variation of phosphorus adsorption in the mineralized refuse was fitted to the Freundlich adsorption isotherm equation, giving a maximum phosphorus adsorption capacity of 2310 mg kg(-1). Based on the Langmuir isotherm equation, maximum phosphorus adsorption capacity was calculated to be 1976 mg kg(-1), almost twice that of the clay. The equations for both the mineralized refuse and clay were fitted to zero-order kinetics (R2 > 0.98, P < 0.01, n = 11), giving concentrations of phosphorus as phosphates less than 250 mg L(-1). The K value for the mineralized refuse was about 3.5 times higher than for the clay. The production of nitrogen as nitrates in both the mineralized refuse and the clay after 120 h incubation yielded a first-order reaction kinetics value of 100 mg kg(-1) NH4(+)-N from the initial concentration. The calculated net nitrification as nitrates for the mineralized refuse was 6.3 times higher than for the clay. Domestic wastewater was then treated in a mineralized refuse-based bioreactor for 30 days. The removal rates of COD(cr), total nitrogen and total phosphorus were 73.77 +/- 8.10%, 61.01 +/- 6.75%, and 69.14 +/- 9.25%, respectively. Large accumulations of nitrates occurred in the mineralized refuse-based bioreactor. For the full-scale design, a high column of mineralized refuse is recommended for the denitrification.


Assuntos
Reatores Biológicos , Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação , Purificação da Água/métodos , Adsorção , Silicatos de Alumínio , Argila , Nitrificação , Compostos de Amônio Quaternário/química , Poluentes Químicos da Água/isolamento & purificação
3.
Eur J Gastroenterol Hepatol ; 13(11): 1341-5, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11692061

RESUMO

OBJECTIVE: Hepatocellular carcinoma is the most common malignancy in Taiwan, and spinal metastasis is a serious complication in cancer patients. In this study, we aimed to delineate the clinical features, evaluate the radiotherapy response and analyse the prognostic features in hepatocellular carcinoma subjects with spinal metastasis. METHODS: From 1981 to 1997, 102 patients with spinal metastasis were enrolled, taken from the 5887 documented hepatocellular carcinoma patients treated at Taipei Veterans General Hospital. All the clinical and laboratory data were recorded, including: age; gender; liver biochemistry; tumour characteristics; Child-Pugh's score; performance status; number and location of vertebral metastasis; motor capacity; neurological symptoms and signs; response to radiotherapy of the spinal lesion; and survival. Prognostic factors in hepatocellular carcinoma patients with spinal metastasis were analysed using Cox's regression model. RESULTS: The most common symptoms in hepatocellular carcinoma patients with spinal metastasis were lower back pain (74.5%), thoracic numbness (52.9%) and lower limb weakness (51.0%). Of the 102 patients, 84 received palliative radiotherapy using 3000 cGy for spinal lesions. Of these 84 patients, 32.1% showed a complete response, 26.2% a partial response and 41.7% a non-response to the radiotherapy. Multivariate Cox's regression analysis revealed that responsive radiotherapy (complete response + partial response) and good performance status (score

Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Neoplasias da Coluna Vertebral/secundário , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/fisiopatologia , Carcinoma Hepatocelular/terapia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias da Coluna Vertebral/mortalidade , Neoplasias da Coluna Vertebral/fisiopatologia , Neoplasias da Coluna Vertebral/terapia
4.
Meat Sci ; 59(4): 343-51, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22062958

RESUMO

Microbiological and physicochemical characteristics of reduced-fat (approximately 22%) Chinese-style sausages containing 0.1% chitosan (in 1% lactic acid solution) with three different molecular weights [low molecular weight chitosan (CHL), MW= 150 kDa; medium molecular weight chitosan (CHM), MW=600 kDa; high molecular weight chitosan (CHH), MW=1250 kDa] were demonstrated. Sausages were also subject to oven heating or deep-fat frying for sensory evaluation. Treatments containing chitosan were lower in pH at any storage periods than the control (CONT). Generally speaking, total plate counts and lactic acid bacteria counts of all treatments slightly increased, with CHL being the lowest. However, all bacterial counts were lower than 7 [log colony forming unit (CFU)/g] at the end of storage. Results from sensory evaluation showed that deep-fat fried sausages from treatments CHL and CHM were higher in overall acceptability. This study demonstrated that the addition of chitosan to reduced-fat Chinese-style sausage resulted in no detrimental effect on textural properties.

5.
Chest ; 118(3): 744-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10988197

RESUMO

BACKGROUND AND STUDY OBJECTIVES: Cardiac tamponade is a life-threatening complication of non-small cell lung cancer (NSCLC). Malignant pericardial effusion signifies advanced disease, but the significance of a negative pericardial fluid cytology in patients with advanced lung cancer is still controversial. The differential diagnosis of cytology-negative pericardial effusion is difficult and sometimes impossible. The purpose of this study is to determine the prognostic role of pericardial fluid cytology in patients with NSCLC and cardiac tamponade. DESIGN: Retrospective review of patients with concurrent NSCLC and cardiac tamponade over a 10-year period. METHODS AND RESULTS: Eighty-two patients were included in this study. Pericardial fluid cytology was positive in 60 patients and negative in 22 patients. The overall median survival was 74.5 days, and 1-year survival was 7.3%, with no survival difference between the two groups (p = 0.2506). However, there was a significant survival difference after different treatment strategies. Patients receiving systemic chemotherapy survived longer than those receiving local therapy (p<0.001), and these patients, in turn, survived longer than those receiving supportive treatment (p<0.001). CONCLUSIONS: When patients have concurrent advanced NSCLC and cardiac tamponade, the most likely cause of the pericardial effusion is the cancer itself, regardless of the results of the cytologic examination. Our results suggest that systemic chemotherapy might prolong survival in such patients, but further prospective, randomized study is necessary.


Assuntos
Líquidos Corporais/citologia , Carcinoma Pulmonar de Células não Pequenas/complicações , Tamponamento Cardíaco/patologia , Neoplasias Pulmonares/complicações , Derrame Pericárdico/patologia , Idoso , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Tamponamento Cardíaco/etiologia , Tamponamento Cardíaco/mortalidade , Tamponamento Cardíaco/cirurgia , Terapia Combinada , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Derrame Pericárdico/complicações , Derrame Pericárdico/mortalidade , Derrame Pericárdico/cirurgia , Pericardiocentese , Prognóstico , Taxa de Sobrevida
6.
Zhonghua Yi Xue Za Zhi (Taipei) ; 63(6): 459-66, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10925536

RESUMO

BACKGROUND: It has been reported that combination chemotherapy and radiotherapy prolongs locally advanced stage IIIB non-small-cell lung cancer (NSCLC) patient survival and cisplatin-based chemotherapy prolongs survival in stage IV disease. This study was aimed at investigating whether this conclusion also applies to Chinese patients. METHODS: We retrospectively reviewed the medical records of NSCLC patients diagnosed at the Taipei Veterans General Hospital covering a period from 1990 to 1996 to examine the effect of treatment regimen on survival. RESULTS: There were 3,925 cases of NSCLC diagnosed during this period. The stage at diagnosis was stage III or IV in the majority (76.6%) of cases. Surgery followed by chemotherapy with or without radiotherapy conferred a survival benefit of more than two years in stage IIIA patients. For stage IIIB patients, chemotherapy in combination with radiotherapy yielded a median survival of 13 months, compared to only seven months for radiotherapy alone. For stage IV patients, cisplatin-based chemotherapy prolonged median survival for more than two months compared with palliative radiotherapy alone or supportive care only. Survival was improved in stage IV patients who received chemotherapy during 1990 to 1996 compared with those who received chemotherapy during 1985 to 1989. This improvement was most likely due to improvements in supportive care because the treatment regimen was constant during the study period. CONCLUSIONS: Cisplatin-based chemotherapy prolonged survival of Chinese patients with metastatic NSCLC. Combination chemotherapy and radiotherapy also prolonged survival of Chinese patients with locally advanced NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Terapia Combinada , Hospitais de Ensino , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Taxa de Sobrevida
7.
Int J Lepr Other Mycobact Dis ; 68(1): 57-62, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10834070

RESUMO

OBJECTIVE: To study the epidemiology of leprosy in children in Taiwan. SETTING: Taiwan, with a population increase from 3.3 to 21.7 million, several tides of immigration and national leprosy control programs, from 1910 to 1997. DESIGN: To collect and analyze the documents of Taiwan leprosy surveys and charts of the National Leprosy Control Center. PATIENTS AND MEASUREMENTS: Cumulative and new number of all-age and pediatric-age patients, prevalence rates, new case detection rates, and results of skin bacterial smears. RESULTS AND CONCLUSIONS: The prevalence rates of all-age leprosy ranged between 1.54 and 3.22 per 10,000 population. The proportion of children among all-age patients reached the highest of 4.93% in 1966, dropping to 0% in 1984 and thereafter, until 1988 and 1991 when two and one pediatric-age patients appeared, respectively, following the influx of immigrants from leprosy-endemic countries. The rise and fall of new patients younger than 15 years and 15 years or older were slightly correlated (r = 0.935, p < 0.001). Detection and confirmation of leprosy in children are usually belated. Physicians should still be acquainted with the clinical diagnosis of leprosy since sporadic cases of leprosy can reappear, particularly among children coming from endemic countries.


Assuntos
Hanseníase/epidemiologia , Mycobacterium leprae/isolamento & purificação , Adolescente , Criança , Estudos de Coortes , Emigração e Imigração , Humanos , Indonésia/etnologia , Mianmar/etnologia , Prevalência , Estudos Retrospectivos , Pele/microbiologia , Taiwan/epidemiologia
8.
Zhonghua Yi Xue Za Zhi (Taipei) ; 63(3): 220-5, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10746418

RESUMO

BACKGROUND: Ovarian cancer is a well-known disease with a poor prognosis. Due to the relatively small number of cases in Taiwan, the outcome and prognostic factors of patients with primary epithelial ovarian carcinoma are unknown. METHODS: We retrospectively studied patients with proven surgical and pathologic (Federation Internationale de Gynecologie et d'Obstetrique) FIGO IIIC primary epithelial ovarian carcinoma. All patients underwent standard staging surgery, including washing cytology, total abdominal hysterectomy, bilateral salpingo-oophorectomy, retroperitoneal lymphadenectomy, infracolic omentectomy and excisional biopsy of all suspicious lesions followed by adjuvant chemotherapy with four to 12 courses of cyclophosphamide, epirubicin and cisplatin (CEP) or cyclophosphamide, adriamycin and cisplatin (CAP) intravenously, every three weeks. To avoid the coeffects of chemotherapy and surgical procedures upon the outcome, patients who received paclitaxel-based regimens or underwent incomplete surgery were excluded. Ninety-eight patients from 1990 to 1996 were identified. RESULTS: The mean follow-up time was 28.7 months, ranging from 5.4 months to 105.9 months. The cumulative five-year disease-free survival rate for all patients was 31.6%. Optimal debulking surgery was completed in 41.8% of patients, which contributed to long-term patient survival (54% vs 16%, p < 0.0001), compared to patients without optimal debulking surgery. Optimal debulking surgery was the only statistically significant independent prognostic factor for five-year disease-free survival using multivariate analysis. CONCLUSIONS: To improve survival of patients with FIGO stage IIIC epithelial ovarian carcinoma, optimal debulking surgery should be performed as the initial form of surgical intervention.


Assuntos
Neoplasias Epiteliais e Glandulares/cirurgia , Neoplasias Ovarianas/cirurgia , Antígeno Ca-125/sangue , Feminino , Humanos , Estadiamento de Neoplasias , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Prognóstico , Estudos Retrospectivos
9.
Chest ; 117(2): 354-7, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10669674

RESUMO

STUDY OBJECTIVE: A cancer registry was analyzed to determine if the clinicopathologic characteristics, treatment modalities, and prognosis of non-small cell lung cancer (NSCLC) patients < 40 years of age at diagnosis differed from patients > 80 years of age at diagnosis. DESIGN: Retrospective review of patients with NSCLC diagnosed between 1987 and 1996. SETTING: General teaching hospital in Taiwan. PATIENTS: There were 6,048 cases of NSCLC diagnosed during this period. Among them, 127 patients were < 40 years old and 184 patients were > 80 years old. These patients were selected for our study. MEASUREMENTS: Data regarding demographics, presentation symptoms, histology, tumor staging, treatment modality, and survival were obtained from all patients. Pearson's chi(2) test and the Kaplan-Meier method with a log-rank test were used for statistical analysis. RESULTS: We found significantly more female patients (p < 0.001) and adenocarcinoma (p < 0.001) in the younger group, when compared with the older patients. Cough was the most frequent presenting symptom in both age groups, followed by dyspnea, chest pain, and hemoptysis. There was no statistical difference in the severity of the disease in terms of staging between the two age groups. Young patients received surgical intervention more frequently than the aged (p = 0.025). The older patients received only supportive care more frequently (p = 0.011) than the younger patients. Survival was better in young patients, when compared with other patients or aged patients (p < 0.001). CONCLUSIONS: The female sex and adenocarcinoma were predominant in young NSCLC patients, when compared with the older patients. Young NSCLC patients tended to receive more aggressive treatment and had better survival.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/mortalidade , Neoplasias Pulmonares/mortalidade , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Sistema de Registros/estatística & dados numéricos , Estudos Retrospectivos , Análise de Sobrevida , Taiwan , Resultado do Tratamento
10.
Jpn J Clin Oncol ; 26(5): 322-7, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8895672

RESUMO

It has been reported that the incidence of lung cancer is higher in patients with pulmonary tuberculosis (TB). However, there is little information on the survival and clinical characteristics of these patients. We retrospectively reviewed the medical records of patients with coexisting pulmonary TB and lung cancer covering a period from 1988 to 1994. There were 31 such patients among a total of 3928 lung cancers diagnosed. Lung cancer patients had an increased risk of active pulmonary TB in comparison with the general population in Taiwan. Diabetes mellitus (DM) was found in 37.5% of patients who were diagnosed as having active pulmonary TB within 2 years before, or concurrent with, the diagnosis of lung cancer. However, none of the patients who had developed lung cancer before TB had a history of DM. Epidermoid carcinoma accounted for 64.5% of these cases. The patients who had developed active pulmonary TB before, or concurrently with, the diagnosis of lung cancer survived shorter than those who did not have pulmonary TB at diagnosis of lung cancer (P=0.007). Survival from diagnosis of pulmonary TB was longer in patients who developed the disease earlier than lung cancer (P=0.046). Survival from the time of diagnosis of lung cancer was significantly longer in patients who developed cancer earlier than active pulmonary TB (P=0.0048), those without DM (P=0.0132), those with an early tumor stage (P=0.002), and those given specific cancer treatment (P=0.0001). It is concluded that survival is shorter in lung cancer patients who present initially with active TB than in those who do not have TB.


Assuntos
Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/mortalidade , Tuberculose Pulmonar/complicações , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/mortalidade , Complicações do Diabetes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Tempo
11.
J Clin Oncol ; 13(10): 2620-8, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7595716

RESUMO

PURPOSE: To evaluate prospectively the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the reduction of chemotherapy-induced oral mucositis. PATIENTS AND METHODS: Twenty patients with stage IV squamous cell carcinoma of head and neck were studied. Two-cycles (periods) of identical doses of cisplatin, fluorouracil (5-FU), and leucovorin (PFL) chemotherapy with cisplatin 20 mg/m2/d, 5-FU 800 mg/m2/d, leucovorin 90 mg/m2/d by 96-hour continuous intravenous infusion every 3 weeks were given to each patient. After PFL chemotherapy, GM-CSF 4 micrograms/kg subcutaneously from days 5 to 14 or no therapy was given by a randomized self-controlled crossover study design. Oral mucositis was graded with modified Radiation Therapy Oncology Group criteria. RESULTS: In the first cycle of PFL chemotherapy, GM-CSF significantly reduced the incidence, mean duration, and mean area under the curve (AUC) of severe oral gross mucositis (grade > or = 3) compared with no therapy. These beneficial effects continued into the second cycle of PFL chemotherapy after crossover to no GM-CSF. The incidence of severe mucositis was reduced when GM-CSF was given in the second cycle of PFL. Analysis of variance indicated significant direct GM-CSF treatment effects on the mean AUC of gross/functional scores and duration of moderate gross mucositis (grade > or = 2) over both periods. There was a significant period effect in favor of giving GM-CSF in the first cycle of chemotherapy. CONCLUSION: GM-CSF can significantly reduce the severity and duration of chemotherapy-induced oral mucositis after PFL chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carcinoma de Células Escamosas/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Mucosa Bucal/efeitos dos fármacos , Estomatite/prevenção & controle , Adulto , Idoso , Análise de Variância , Cisplatino/administração & dosagem , Estudos Cross-Over , Feminino , Fluoruracila/administração & dosagem , Doenças Hematológicas/induzido quimicamente , Humanos , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estomatite/induzido quimicamente
12.
Anal Biochem ; 140(2): 548-52, 1984 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-6486439

RESUMO

A liquid chromatographic-fluorometric assay has been developed to study the role of dihydrofolate reductase in adult rat brain since low levels of the enzyme preclude measurement by current spectrophotometric procedures. This method involves in vitro incubation of desalted, cell-free brain extracts with 7,8-dihydrobiopterin, NADPH, and an NADPH-regenerating system. The tetrahydrobiopterin formed is quantitatively converted to pterin using alkaline iodine oxidation, and the pterin formed is separated by liquid chromatography and detected fluorometrically. The method is linear from 100 fmol to greater than or equal to 1 nmol of product, and the sensitivity is at least 100 times greater than that of existing spectrophotometric assays. Enzyme activity of desalted brain extracts is linear with both time (to 100 min) and protein (from 50 to 620 micrograms). The enzyme shows an absolute requirement for NADPH, does not use NADH, and is completely inhibited by 10 nM methotrexate. The Km of the enzyme for NADPH was found to be 7.5 microM, while the Km for 7,8-dihydrobiopterin was 88 microM. Since brain dihydrobiopterin reductase has the same properties as dihydrofolate reductase, this fluorometric procedure can serve as a sensitive assay for dihydrofolate reductase.


Assuntos
Biopterinas/metabolismo , Encéfalo/enzimologia , Pteridinas/metabolismo , Tetra-Hidrofolato Desidrogenase/análise , Animais , Biopterinas/análogos & derivados , Cromatografia Líquida de Alta Pressão , Cinética , Ratos , Espectrometria de Fluorescência
14.
Proc Natl Acad Sci U S A ; 80(6): 1546-50, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6572916

RESUMO

Mammalian cells and tissues were found to have two pathways for the biosynthesis of tetrahydrobiopterin (BH4): (i) the conversion of GTP to BH4 by a methotrexate-insensitive de novo pathway, and (ii) the conversion of sepiapterin to BH4 by a pterin salvage pathway dependent on dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) activity. In a Chinese hamster ovary cell mutant lacking dihydrofolate reductase (DUKX-B11), endogenous formation of BH4 proceeds normally but, unlike the parent cells, these cells or extracts of them do not convert sepiapterin or 7,8-dihydrobiopterin to BH4. KB cells, which do not contain detectable levels of GTP cyclohydrolase or BH4 but do contain dihydrofolate reductase, readily convert sepiapterin to BH4 and this conversion is completely prevented by methotrexate. In supernatant fractions of bovine adrenal medulla, the conversion of sepiapterin to BH4 is completely inhibited by methotrexate. Similarly, this conversion in rat brain in vivo is methotrexate-sensitive. Sepiapterin and 7,8-dihydrobiopterin apparently do not enter the de novo pathway of BH4 biosynthesis and may be derived from labile intermediates which have not yet been characterized.


Assuntos
Medula Suprarrenal/metabolismo , Biopterinas/biossíntese , Encéfalo/metabolismo , Pteridinas/biossíntese , Pterinas , Animais , Biopterinas/análogos & derivados , Bovinos , Células Cultivadas , Cricetinae , Guanosina Trifosfato/metabolismo , Metotrexato/farmacologia , Camundongos , Pteridinas/metabolismo , Ratos
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