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21.
Summary Oral MPA 1.5 g/day leads to plasma concentrations between 1 and 12 g/ml, with a broad intra-and interindividual variance. The plateau state is reached in between 4 and 16 days. Plasma concentrations in the plateau state are very sensitive to dose modifications. After cessation of administration, the decline in plasma levels seems to proceed in two phases, with half-times of about 20 h and 4 days. Extraction procedures reveal no benefit in discriminating between MPA and its metabolites.  相似文献   
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The antiarrhythmic and acute toxic actions of quinidine (Q) and dihydroquinidine (DHQ) were investigated in experiments in rats. 1. No significant difference was found between Q and DHQ with regard to the doses necessary to suppress electrically induced ventricular fibrillation in the heart (p greater than 0.05). 2. On oral administration, pure DHQ was slightly less toxic than pure Q. This difference is significant (p less than 0.05). It may be explained by a lower absorption rate of DHQ in the rat. Addition of 15 or 30% DHQ to Q did not produce any significant difference in the acute toxic doses (LD50) in comparison with pure Q (p greater than 0.05). 4. The results of a published clinical study showed that the antiarrhythmic actions of pure Q and "commercial" Q are the same with regard to quality, potency and duration. The frequency of side-effects after adminstration of the two alkaloids also did not differ. 5. Limitation or reduction of the DHQ content of pharmaceutical quality quinidine below a technically practicable level does not seem to be justified from a medical point of view from the results of the animal experiments presented and from the clinical study mentioned.  相似文献   
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Knowledge regarding human bladder smooth muscle cell (SMC) physiology is very limited. Only a few specific medical therapies for bladder disorders have therefore been established. The objective of this study was to develop a model for videomicroscopy of bladder SMC contractions. Cells were isolated from human cystoprostatectomy specimens and cultured in a modified EMEM medium. These cells were identified as SMCs by means of immunohistochemistry. For videomicroscopy, the culture flasks were coated with a viscous agent to allow cell contraction. Contractions were visualized by means of a cell culture microscope with a time-lapse videosystem. For cholinergic stimulation of the cells, acetylcholine, in concentrations ranging from 100 μM to 10 mM, was applied. The percentage of contracting cells within the observation field was evaluated for quantitative analysis. In control experiments without contractile stimulant 6% of the cells were observed to contract. Stimulation with acetylcholine induced a significant dose-dependent increase to 47% in contracting cells. These results demonstrated that videomicroscopy is an appropriate tool to investigate the contraction mechanisms of bladder SMCs. This model offers the possibility of studying drug effects on the human detrusor in vitro. Received: 16 September 1999 / Accepted: 1 May 2000  相似文献   
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Polymorphisms of genes coding for DNA repair can affect lung cancer risk. A common single nucleotide (-4) G-to-A polymorphism was identified previously in the 5' untranslated region of the XPA gene. In a case-control study in European Caucasians, the influence of this polymorphism on primary lung cancer risk overall and according to histologic subtypes was investigated. Four hundred sixty-three lung cancer cases (including 204 adenocarcinoma and 212 squamous cell carcinoma) and 460 tumor-free hospital controls were investigated using PCR amplification and melting point analysis of sequence-specific hybridization probes. Odds ratios (OR) were calculated by multiple logistic regression analysis adjusting for age, gender, smoking habits, and occupational exposure and showed a slightly enhanced risk for all lung cancer cases as well as for squamous cell carcinoma and adenocarcinoma cases. Gene-environment interactions were analyzed with respect to smoking and occupational exposure. A nearly 3-fold increased risk for adenocarcinoma associated with the XPA AA genotype was observed for occupationally exposed individuals (OR, 2.95; 95% confidence interval, 1.42-6.14) and for heavy smokers (OR, 2.52; 95% confidence interval, 1.17-5.42). No genotype-dependent increase in OR was found for nonexposed individuals or those smoking <20 pack-years. The significant effect of the XPA polymorphism in heavy smokers and occupationally exposed individuals suggests an important gene-environment interaction for the XPA gene. The underlying mechanisms as to why AA homozygotes are predisposed to lung adenocarcinoma and which specific carcinogens are involved remains to be determined.  相似文献   
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The aim of this study was to evaluate the fatty acids, tocopherols, squalene, sterols and phenolic antioxidants in three types of argan oil (Moroccan food, Moroccan aesthetic and a French commercial variety) along with a basic comparison with extra virgin olive and sunflower oil. The fatty acid profiles in the argan oils were very similar, with oleic acid (43%) and linoleic acid (36%) and their respective monoacylglycerols predominating. The major vitamer identified was -tocopherol with a mean of 483+/-11 mg/kg, in contrast to -tocopherol, which is the major vitamer in olive (190+/-1 mg/kg) and sunflower oil (532+/-6 mg/kg). The squalene content of the argan oils was very similar with a mean of 313+/-4 mg/100 g, which is lower than that of the olive oil (499 mg/100 g) but significantly higher than in the sunflower oil (6 mg/100 g). In contrast to olive and sunflower oils in which -sitosterol is predominant, the major sterols detected in the argan oils were schottenol (mean 147+/-10 mg/kg) and spinasterol (mean 122+/-10 mg/kg). The only phenolic compounds other than the tocopherol vitamers which could be readily detected and quantitated were vanillic, syringic and ferulic (probably conjugated to glucose) acids along with tyrosol. In contrast to the extra virgin olive oil (793 mg/kg), the concentration of total phenolic compounds is extremely low (<5.0 mg/kg). Nevertheless, argan oil with its high content of the vitamer -tocopherol, squalene and oleic acid is likely to enhance the cancer prevention effects of the Moroccan diet.  相似文献   
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PURPOSE: Various chemotherapeutic regimens have been applied for treatment of mucosa-associated lymphoid tissue (MALT) lymphoma, but no standard regimen has been identified to date. In view of the activity of oxaliplatin (L-OHP) in various types of lymphoma, we performed a phase II study to evaluate the activity of L-OHP for treatment of MALT lymphoma. The primary objective of this study was to determine the objective response rate according to WHO standard criteria. PATIENTS AND METHODS: A total of 16 patients with MALT lymphoma of various sites of origin (four of the ocular adnexa, five of the salivary glands, three of the stomach, two of the lung, and one of the colon and the breast) were administered L-OHP at a dose of 130 mg/m2 infused during 2 hours every 3 weeks. Restaging was performed every two cycles; treatment was continued until complete remission (CR) or for a maximum of six cycles in responders. RESULTS: Sixty-five cycles were administered (median, four; range, two to six); toxicity consisted of transient sensory neuropathy in eight patients and nausea/emesis WHO grade 2 in two patients, whereas hematologic adverse effects (thrombocytopenia and leukocytopenia grade 2) occurred in only one patient each. Fifteen patients responded to chemotherapy, with nine achieving CR (56%), six (37.5%) achieving partial response, and one achieving stable disease; the median time to response was 4 months (range; 2 to 4 months). CONCLUSION: These data suggest L-OHP is a highly active agent for treatment of MALT lymphoma. However, a longer follow-up is needed to judge whether these remissions are durable.  相似文献   
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