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71.
Berner Bret Wilson Donald R. Guy Richard H. Mazzenga Gerard C. Clarke Frank H. Maibach Howard I. 《Pharmaceutical research》1988,5(10):660-663
The relationship between pK
a and skin irritation in man is studied for a homologous series of benzoic acid derivatives, which permeate through human skin at comparable rates (15–88 µg/cm2/hr). Skin irritation and pK
a are correlated for pK
a 4. Laser Doppler velocimetric assessment of skin blood flow, color meter readings, erythema, edema, and the primary irritation index are all linearly correlated and related to pK
a, erythema at 24 hr appears to be the most sensitive parameter to variation in pK
a when pK
a 4. 相似文献
72.
Mohammad Nasri-Sebdani Flavien Traoré Christian Cognard Daniel Potreau Jean -Pierre Poindessault Guy Raymond 《Pflügers Archiv : European journal of physiology》1990,416(1-2):106-112
The effects of tetracaine (10–50 M) and ryanodine (0.1–10 M) were tested on the slow outward K+ current (I
so) and the mechanical tension of isolated frog muscle fibres in a voltage-clamp device (double mannitol-gap) connected to a mechanoelectric transducer. In the concentration range tested, both drugs induced a simultaneous inhibition of tension and current. In all cases the effect on tension was twice that on current. The tetracaine-induced current and tension blocks were fully reversible and dose-dependent. In contrast the ryanodine effects on current and tension were not reversible and did not exhibit a dose dependence except for the delay before the onset of the response, which was shortened when the concentration was raised. Linear regression analysis of the time-dependent and dose-dependent effects of both drugs indicated a strong correlation between the decreases in tension and current. It is concluded that the slow outward current is partly under the control of the Ca2+ release from sarcoplasmic reticulum during contraction. 相似文献
73.
J M Guy M Lamaud C Segura T Berthaud B Duranton H Verneyre 《Annales de cardiologie et d'angeiologie》1989,38(4):215-218
The diagnosis of amyloid cardiomyopathy was only based, until the last few years, on the results of invasive techniques. It seems presently that the combined contribution of cardiac sonography and scintigraphy using technetium 99m pyrophosphate, makes, most of the time, this diagnosis possible without need for additional examinations. This notion is illustrated by a typical case-report and data from the literature. Demonstration on the cardiac sonogram of a thickening of the walls-while the context and especially the electrocardiogram are not in favor of a left ventricular hypertrophy--associated with a very particular "hyperechoing" aspect and an abnormal fixation on the scintigram, may be considered specific of this disease. 相似文献
74.
Guy G. Chabot Marie-Christine Bissery Alain Gouyette 《Cancer chemotherapy and pharmacology》1989,24(5):273-276
Summary Flavone acetic acid (FAA; LM 975; NSC 347512) is a new anticancer agent with unprecedented, broad antitumor activity in murine models. Although FAA is very effective in vivo against solid tumors, including colon 38 adenocarcinoma, it was not cytotoxic in vitro against colon 38 cells and human colon adenocarcinoma cells HCT116 at pharmacologically achievable concentrations and exposure times. For example, a concentration of 300 g/ml for a 10-day exposure time was required to obtain <1log cell kill. After the administration of an effective FAA dose (180 mg/kg, i.v.) to mice, plasma cytotoxicity against HCT116 cells attained a 2 log cell kill between 0.5 and 2 h, which decreased to 1 log cell kill at 4 h. No cytotoxicity was observed 6, 12 or 21 h after drug administration. The controls used comprised mouse plasma containing FAA concentrations similar to those assayed in the above plasma samples from in-vivo-dosed mice. These apiked plasma were not cytotoxic, indicating that other cytotoxic species, formed in vivo, were responsible for the increased cytotoxicity. Mouse hepatocytes co-cultured with HCT116 cells increased FAA cytotoxicity to 1 log cell kill at 30–100 g/ml. The addition of phenobarbital-induced mouse liver supernatant S-9000xg also markedly increased FAA cytotoxicity to a 2 log cell kill at 300 g/ml. We conclude that FAA can be activated both in vivo and in vitro to cytotoxic species that are more active than the parent compound.Part of this work has been published in abstract form in: Proc Am Assoc Cancer Res 29: 484, 1988 相似文献
75.
To probe age-related changes in skin barrier function, transepidermal water loss (TEWL) rates have been measured in young (19–42 years) and old (69–85 years) subjects. TEWL was determined at ventral forearm skin sites, which had been occluded for 24 hr with polypropylene chambers. Baseline TEWL rates (J
, which showed no dependence on age, were measured for each subject before and after the experiment. Following removal of the occlusive chamber, TEWL was monitored continuously from t = 0.5 min until its return to the baseline (preocclusion) level, which was typically in the range of 2–7 g/m2/hr. Initial TEWL rates (mean ± SD) were found to differ significantly between young (28.6 ± 7.5 g/m2/hr; n = 26) and old (36.9 ± 10.5 g/m2/hr; n = 18) subjects (P < 0.01). Relaxation of TEWL to J
was significantly slower in the aged cohort, such that the characteristic time for diffusion of water in the stratum corneum was estimated to be (mean ± SD) 176 ± 59 min for the young subjects, compared to 360 ± 76 min for the old (P < 0.001.). Thus, the initial TEWL value following removal of occlusion is significantly greater, and the excessive stratum corneum hydration produced by occlusion is dissipated more slowly, in old skin than in young. A hypothesis to explain the slower relaxation of perturbed TEWL in old skin is proposed. 相似文献
76.
Rachid Haraoubia Chantal Bonnans-Plaisance Guy Levesque 《Macromolecular chemistry and physics.》1981,182(9):2409-2419
The syntheses and free-radical polymerizations of methyl and carboxymethyl 4-vinyldithiobenzoates are described as well as various copolymers. Copolymerisation parameters were determined for the copolymerizations of the methyl dithioester with styrene and with methyl methacrylate. 相似文献
77.
When Marburg virus (MBGV) nucleoprotein (NP) is expressed in insect cells, it binds to cellular RNA and forms NP-RNA complexes such as insect cell-expressed nucleoproteins from other nonsegmented negative-strand RNA viruses. Recombinant MBGV NP-RNA forms loose coils that resemble rabies virus N-RNA. MBGV NP monomers are rods that are spaced along the coil similar to the nucleoprotein monomers of the rabies virus N-RNA. High salt treatment induces tight coiling of the MBGV NP-RNA, again a characteristic observed for other nonsegmented negative-strand virus N-RNAs. Electron microscopy of fixed Marburg virus particles shows that the viral nucleocapsid has a smaller diameter than the free, recombinant NP-RNA. This difference in helical parameters could be caused by the interaction of other viral proteins with the NP-RNA. A similar but opposite phenomenon is observed for rhabdovirus nucleocapsids that are condensed by the viral matrix protein upon which they acquire a larger diameter. Finally, there appears to be an extensive and regular protein scaffold between the viral nucleocapsid and the membrane that seems not to exist in the other negative-strand RNA viruses. 相似文献
78.
Analysis of the butyrylcholinesterase gene and nearby chromosome 3 markers in Alzheimer disease 总被引:3,自引:0,他引:3
Brindle N; Song Y; Rogaeva E; Premkumar S; Levesque G; Yu G; Ikeda M; Nishimura M; Paterson A; Sorbi S; Duara R; Farrer L; St George-Hyslop P 《Human molecular genetics》1998,7(5):933-935
The K-variant of butyrylcholinesterase (BCHE-K) recently has been reported
to be associated with Alzheimer disease (AD) in carriers of the epsilon4
allele of the apolipoprotein E (APOE) gene. We have re- examined the
frequency of the BCHE-K allele in a large data set of both sporadic and
familial cases of AD disease, and we have also examined the segregation of
three genetic markers on chromosome 3 near BCHE . Our data neither support
an association of BCHE-K with sporadic or familial AD, nor do they suggest
the existence of another gene nearby on chromosome 3 as a common cause of
familial AD.
相似文献
79.
80.
Guy RJ Breschkin AM Keenan CM Catton MG Enriquez AM Hellard ME 《Journal of acquired immune deficiency syndromes (1999)》2005,38(4):495-499
Between 1999 and 2000, new diagnoses of HIV in Victoria (Australia) rose by 41%, from 140 to 197. In this time period, sera from new HIV diagnoses were tested using the Organon Teknika "detuned" enzyme immunoassay (EIA). We compared the results of the detuned EIA with incident infections defined by surveillance (on the basis of a previous negative or indeterminate HIV test and/or a seroconversion illness within the 12 months preceding HIV diagnosis). Of 317 specimens, 97 (31%) incident infections and 114 (36%) recent infections were detected using surveillance and detuned EIA, respectively. The detuned assay misclassified 11 cases with AIDS and 2 cases with CD4 counts < or = 200 micro3 (probable long-standing infections) as recent infections and was unable to identify 31 (32%) of 97 cases previously classified as incident cases by surveillance. The assay detected an extra 35 recent infections that were previously classified as nonincident by surveillance. By combining the detuned assay and surveillance, 132 (42%) incident infections were identified from 317 specimens, 36% more than surveillance alone. We recommend that a detuned assay or similar test become part of the routine strategy to identify incident infections in Victoria. Incident infections provide important information for targeting prevention strategies and the opportunity to interrupt ongoing viral transmission. 相似文献