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1.
The purpose of this research was to study the effects of nicotine and ethanol, alone and in combination, on cardiac membrane potentials (MP). Rat atrial preparations driven at 5 Hz were superfused with Tyrode's solution (37 degrees C) while recording MP with intracellular microelectrodes. Nicotine concentrations below and including 6.2 x 10(-5) M did not affect MP. Within 15 s, nicotine 3.1 x 10(-3) M shortened the action potential duration (APD) and depressed the overshoot of the action potential (OS). This action was blocked by atropine. After 3 min, nicotine prolonged the APD and depressed Vmax of phase O, OS and the amplitude of the action potential (AAP), without affecting the resting membrane potential (RMP). Nifedipine blocked the depression of the OS while tetraethylammonium chloride blocked the prolongation of the APD. Acute exposure to ethanol depressed OS and AAP and shortened APD, but it did not affect RMP or Vmax of phase O. When nicotine and ethanol were administered simultaneously, the APD-prolonging effects of nicotine prevailed. The influence of chronic ethanol ingestion on the acute action of nicotine and/or ethanol was studied in rats pair-fed a liquid diet with (ER) or without (NR) ethanol (35% of total caloric intake) for 24 weeks. Chronic ethanol ingestion accentuated the depressant effect of nicotine 3.1 x 10(-3) M on OS and AAP, but it did not modify the APD-prolonging action of nicotine. The same results were observed when ER and NR were exposed to nicotine and ethanol simultaneously. 相似文献
2.
G Lallement P Carpentier I Pernot-Marino D Baubichon A Collet G Blanchet 《Neurotoxicology》1991,12(4):655-664
Glutamate (GLU)-receptor subtypes, (quisqualate (QA)-, kainate (KA)-, N- methyl-D-aspartate (NMDA)-receptors) and the phencyclidine sites localized in the ion-channel associated to the NMDA-receptors, were studied by autoradiography in the hippocampus of rats subjected to a convulsive dose of the acetylcholinesterase inhibitor soman (0-, 1,2,2-trimethylpropyl methylphosphonofluoridate). In intoxicated rats, a significant increase in L-[3H]-GLU binding occurred within the first 40 min of seizures in the hippocampal CA3 and CA1 areas. Whereas binding to KA- and NMDA-receptors remained unchanged, L-[3H]-GLU binding to CA3 QA-receptors increased by 31 and 50% respectively after 10 and 40 min of seizures. In CA1, the change in QA-receptors was delayed (+30% after 40 min) and accompanied by an increase in the phencyclidine site binding capacity, reflecting the probable concomitant opening of NMDA ion-channels. These findings confirmed the previously suspected involvement of GLU in the earliest stages of soman-induced seizures, and suggested that, in hippocampus, the primary activation of QA-receptors in the CA3 region could lead to the secondary recruitment of combined non-NMDA (QA) and NMDA mechanisms in CA1. 相似文献
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4.
1%线状透明颤菌面霜在中国女性敏感性皮肤的功效与耐受性评价 总被引:1,自引:0,他引:1
目的评价温泉浮游生物纯提取物(pureextractthermalplankton,PETP)即线状透明颤菌(Vitreoscillafiliformis,VF)提取物用于中国女性敏感性皮肤的功效与耐受性。方法经临床检查和乳酸刺激实验筛选出伴有敏感性皮肤的健康女性36例。早晚清洁面部后,均匀涂抹1%VF面霜,每日2次,连续使用3周。分别于实验前后由同一个皮肤科医师观察受试者的皮肤乳酸刺激分数,以及皮肤的临床表现(干燥、红斑、鳞屑、弹性、光滑度)。同时,检测皮肤颜色及皮肤角质层水合度等皮肤生物学参数。结果受试者的乳酸刺激分数显著降低,使用前后差异显著(P<0.0001)。干燥、红斑、鳞屑、光滑度均有不同程度改善。受试者对VF面霜耐受良好。结论伴有敏感性皮肤的中国女性,在皮肤日常护理中,使用含有VF提取物的护肤品有助于改善皮肤的敏感状态和皮肤保健。 相似文献
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6.
Summary This paper describes a new technique for the division of syndactyly. The commissure is reconstructed by a dorsal trilobed flap and a zig zag incision which produces triangular flaps for the side of the digits. This technique does not require use of a skin graft. Seventeen syndactylies in fourteen children, nine incomplete (six congenital and three secondary to burn) and eight complete syndactylies were treated by this technique. The results after a maximum of twelve months follow-up and the advantages of the technique are discussed.[/ab] 相似文献
7.
Silber SJ; Nagy Z; Devroey P; Tournaye H; Van Steirteghem AC 《Human reproduction (Oxford, England)》1997,12(11):2422-2428
The aim of the study was to determine whether a prior diagnostic testicle
biopsy can predict success or failure of testicular sperm extraction (TESE)
with intracytoplasmic sperm injection (ICSI) in patients with
non-obstructive azoospermia caused by testicular failure, and what is the
minimum threshold of sperm production in the testis which must be surpassed
for spermatozoa to reach the ejaculate. Forty- five patients with
non-obstructive azoospermia caused by testicular failure underwent
diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure.
The diagnostic testicle biopsy was analysed quantitatively, and correlated
with the quantitative findings of spermatogenesis in patients with normal
spermatogenesis, as well as with the results of subsequent attempts at
TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure
had a mean of 0-6 mature spermatids/seminiferous tubule seen on a
diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in
men with normal spermatogenesis and obstructive azoospermia. These findings
were the same for all types of testicular failure whether Sertoli cell
only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia.
Twenty-two of 26 men with mature spermatids found in the prior testis
biopsy had successful retrieval of spermatozoa for ICSI, 12 of their
partners became pregnant, and are either ongoing or delivered. The study
suggests that 4-6 mature spermatids/tubule must be present in the testis
biopsy for any spermatozoa to reach the ejaculate. More than half of
azoospermic patients with germinal failure have minute foci of
spermatogenesis which are insufficient to produce spermatozoa in the
ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for
the presence of mature spermatids) can predict subsequent success or
failure with TESE-ICSI. Incomplete testicular failure may involve a sparse
multi-focal distribution of spermatogenesis throughout the entire testicle,
rather than a regional distribution. Therefore, it is possible that massive
testicular sampling from many different regions of the testes may not be
necessary for successful TESE-ICSI.
相似文献
8.
β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis. 相似文献
9.
S Plawecki E Carpentier P Lascombes J Prevot J E Robb 《Journal of pediatric orthopedics》1990,10(6):786-790
Three cases of congenital pseudarthrosis were treated by the Ilizarov method. Consolidation was obtained by 3.5 months in three patients who had undergone several previous surgical procedures. Although the length of follow-up was short (maximum 3.5 years), consolidation occurred more quickly than by traditional methods. This technique also permitted both simultaneous correction of axial malalignment and leg lengthening. We think that this method has a place as a salvage procedure except where the distal fragment is very thin or dystrophic. 相似文献
10.