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1.
(E)-[2-(4-(Dimethylamino)phenyl)vinyl]benzenes bearing a nitrile or carboxyl group in the 2', 3', or 4' position were synthesized and tested for substrate activity with purified pig liver flavin-containing monooxygenase (FMO1). Although the nitrile derivatives were too insoluble to saturate the catalytic site at pH 7.4, they appeared to be substrates with K(m)'s somewhat above their maximum solubility (approximately equal to 0.1 mM) in the assay medium. Of the three carboxylic acid analogs, (E)-4-[2-(4(dimethylamino)phenyl)vinyl]benzoic acid had no detectable water solubility at pH 7.4, and measurements were restricted to (E)-3-[2-(4-(dimethylamino)phenyl)vinyl]benzoic acid (DS3CO) and (E)-2-[2-(4-(dimethylamino)phenyl)vinyl]benzoic acid (DS2CO). While DS3CO and DS2CO were substrates, they also inhibited FMO1 turnover. DS3CO was the more effective inhibitor, and at 2 mM it inhibited FMO1 and microsomal-catalyzed oxidation of methimazole (N-methyl-2-mercaptoimidazole) by 80-90%. Kinetic studies indicated that the aminostilbene carboxylates were noncompetitive with both the xenobiotic substrate, methimazole, and NADPH. However, inhibition constants calculated from double reciprocal plots of velocity vs NADPH were K(i)(comp) 130 and 150 microM for DS3CO and DS2CO, respectively, whereas the uncompetitive Ki's were 10-15 times higher, which suggests that inhibition of NADPH binding may be primarily responsible for inhibition of FMO1 by the aminostilbene carboxylates. This model is also consistent with inhibition of cyclohexanone monooxygenase, a bacterial analog of FMO. DS3CO and DS2CO were again noncompetitive with methimazole but primarily competitive with NADPH. The aminostilbene carboxylates had no detectable effects on activity of pig or rat liver NADPH-cytochrome P450 reductase, which suggests that they are not nonspecific flavoprotein antagonists.  相似文献   
2.
In order to be faster and more precise than any numerical technique for the computation of the photo-induced plasma in semiconductor, an analytical solution has to be developed. In this paper, the Hankel transform is used to simplify the solution of the differential equation of second order with nonconstant coefficient, known as the diffusion equation. The resulting expression of the three-dimensional (3-D) carrier density includes all the physical parameters of the substrate and the laser beam as well. A parametric study was also feasible using the developed expressions.  相似文献   
3.
Oligomerization of ethylene oxide during the functionalization of poly(butadienyl)lithium in benzene and cyclohexane at 25 °C has been investigated by MALDI-TOF MS and 1H NMR. Chemically significant amounts of oligomer were found using 4 equiv. of ethylene oxide ([EO]/[PLi]) after 12 h in both benzene and cyclohexane. No oligomer was observed when the reaction time was minimized.  相似文献   
4.
BACKGROUND: Ganglioneuroblastoma is commonly observed in children but rarely in adults. Therapy and prognosis are not well defined in adults. CASE REPORT: We report the case of a female adult who developed a ganglioneuroblastoma of the left adrenal gland with liver metastasis. Surgical treatment combined with radio and chemotherapy led to complete remission. DISCUSSION: The outcome in our patient and data reported in the literature suggest that a multidisciplinary approach is necessary and that initial surgical resection should be performed whenever possible. Adjuvant radiotherapy or chemotherapy have been shown to be somewhat effective in children but their true impact in adults remains to be ascertained. Follow-up after resection should include physical examination, assay of adrenal derivatives in plasma and urine and imaging.  相似文献   
5.
Anti-CD3 MoAb treatment is widely used as an immunosuppressive therapy. In the present study we examined the in vitro T cell response in mice having received 24 h before a single i.v. injection of 10 microgram of anti-CD3 MoAb. We found that splenocytes from these mice displayed a dramatically decreased proliferative response to the T cell mitogens concanavalin A (Con A), anti-CD3, phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) + calcium ionophore, while the effect of lipopolysaccharide (LPS) was not impaired. T cell suppression persisted for about 10 days after anti-CD3 injection, returning to normal within 15 days. The F(ab')2 fragment of anti-CD3 had no such effect, indicating the requirement for in vivo activation. At the dose used, anti-CD3 resulted neither in T cell depletion nor in down-modulation of the CD3/T cell receptor (TCR) complex. The low proliferation was also not explained by apoptosis, following secondary challenge with Con A. Splenocytes from anti-CD3-injected mice were highly responsive to IL-2, but generated little or no IL-2, IL-3, IL-4 and interferon-gamma (IFN-gamma) when exposed to Con A. Normal cytokine production could not be restored by the addition of optimal doses of IL-2 during Con A stimulation. Transforming growth factor-beta (TGF-beta) was the only cytokine whose mRNA expression was not modified in stimulated splenocytes from anti-CD3-injected mice. Furthermore, anti-TGF-beta antibodies increased Con A-induced T cell proliferation, but not cytokine production.  相似文献   
6.
The Institute of Scientific information has edited an index to evaluate the diffusion of scientific articles. It is based on the fact that the more an article is cited as a reference in other articles, the more it is considered to be important, and the higher the coefficient attributed to the journal in which it was originally published. The impact factor takes into account the average number of times which a journal is mentioned for recent articles published in a given year. This index is an attempt to quantify the notoriety of scientific journal for all scientific medical specialties.  相似文献   
7.
Titanium and its alloys are base materials used in the dental and orthopaedic fields owing to suitable intrinsic properties: good biocompatibility, high corrosion resistance and excellent mechanical properties. However, the bonding between titanium and bone tissue is not always strong enough and can become a critical problem. In this context, the two main objectives of this paper are the increase of the corrosion resistance and the improvement of the hydroxyapatite (HAp) growth. The surface modification considered here is achieved in three main steps and consists in the elaboration of different inorganic and organic coatings. The first step is the elaboration of electrodeposition of tantalum on the titanium oxide film of a titanium substrate. The second step is the modification of the tantalum oxide coating with organophosphonic acids. The last step is the nucleation and growth of HAP on the outermost layer of the system by immersion in a simulated body fluid. The hybrid coating tantalum oxide/organophosphonic acids/molecular layer is shown to be promising for orthopaedic implants.  相似文献   
8.
9.
Main geological reserves of sands and gravels, in France, are fossil and not renewable. An official in ventory of resources began in 1971 on public funds. The author examines all the studies made up to mid september 1983 mainly financed by a “Tax on aggregates”. He reviews the various scales of the inventories: general (1/200.000–1/50.000); intermediate (1/25.000); detailed. Then the methods used: documentation, photogeology, field survey, geophysics, borings, sampling, tests on specimen, hydrogeological study, economical study, checking of environemental constraints. The results are given. The growing importance of freezing of resources due to constraints is emphasized, showing the necessity of a policy of preservation of the resources.  相似文献   
10.
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