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排序方式: 共有707条查询结果,搜索用时 200 毫秒
141.
Detection of DNA adducts of acetaldehyde in peripheral white blood cells of alcohol abusers 总被引:20,自引:8,他引:12
The effect of alcohol drinking on the formation of DNA adducts of
acetaldehyde, the primary oxidative metabolite of ethanol, was investigated
in humans. DNA was isolated from granulocytes and lymphocytes from 24
alcoholic patients and 12 control subjects. DNA adduct levels were measured
by 32P-postlabelling using reversed-phase HPLC with on-line detection of
radioactivity. A large interindividual variation in adduct levels was
observed. The average adduct levels in granulocyte and lymphocyte DNA from
alcoholic patients were 3.4 +/- 3.8 and 2.1 +/- 0.8 adducts/10(7)
nucleotides (n = 24), respectively. These levels were 13- and 7-fold higher
than the corresponding levels in control subjects (P<0.001). The average
adduct level in granulocyte DNA from alcoholic patients was 60% higher than
in lymphocyte DNA (P<0.01). Our results, in conjunction with the
genotoxicity of acetaldehyde, thus suggest the formation of DNA adducts of
acetaldehyde as a plausible mechanism explaining the involvement of alcohol
drinking in carcinogenesis.
相似文献
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大环内酯类抗生素麦迪霉素的电化学特性 总被引:3,自引:0,他引:3
在K2HPO4,NH4Cl+NH3和NaOH的10%(v/v)乙醇水溶液中,除0.01mol·L-1以上NaOH液作为支持电解质外,麦迪霉素的伏安波皆为两个峰。峰A相当于它的甲醛基还原波,峰B为催化吸附氢波。溶液pH对两峰有强烈的影响。实验表明伏安波有吸附特性,且不可逆。两峰的ip与麦迪霉素的浓度成正比,线性范围分别为3×10-6~3×10-5mol·L-1和1×10-7~4×10-5mol·L-1,检测限为:1×10-6mol·L-1和5×10-8mol·L-1。可应用于麦迪霉素的定量测定。研究了两峰的特性和电极机理,测定了有关的物理常数。 相似文献
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KA Waters F Everett D Sillence E Fagan CE Sullivan 《Archives of disease in childhood》1993,69(2):191-196
Overnight sleep studies were performed in 20 subjects with achondroplasia to document further the respiratory abnormalities present in this group. Somatosensory evoked potentials (SEPs) were recorded in 19 of the subjects to screen for the presence of brainstem abnormalities, which are one of the potential aetiological mechanisms. Fifteen children aged 1 to 14 years, and five young adults, aged 20 to 31 years were included. All had upper airway obstruction and 15 (75%) had a pathological apnoea index (greater than five per hour). Other sleep associated respiratory abnormalities, including partial obstruction, central apnoea, and abnormal electromyographic activity of accessory muscles of respiration, also showed a high prevalence. SEPs were abnormal in eight (42%), but there was no correlation between abnormal SEPs and apnoea during sleep, either qualitatively or quantitatively. A high prevalence of both sleep related respiratory abnormalities and abnormal SEPs in young subjects with achondroplasia was demonstrated. However, the sleep related respiratory abnormalities do not always result in significant blood gas disturbances or correlate with abnormal SEPs in this group. 相似文献
146.
Femoral head avascular necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings 总被引:39,自引:0,他引:39
Mitchell DG; Rao VM; Dalinka MK; Spritzer CE; Alavi A; Steinberg ME; Fallon M; Kressel HY 《Radiology》1987,162(3):709-715
To better correlate the appearance of avascular necrosis (AVN) of the femoral head on magnetic resonance (MR) images with the stage of disease, MR images of 56 proved AVN lesions were compared with staging from corresponding radiographs (n = 56), Tc-99m scans (n = 41), and grade of symptoms (n = 28). Fractures complicating AVN were seen in 28 (50%) of 56 radiographs (radiographic stages III-V). With long repetition (TR) and echo delay (TE) times, a characteristic "double line sign" consisting of high signal intensity inside a low-intensity peripheral rim was seen in 45 lesions (80%). The central region within the rim was isointense with marrow fat on both short and long TR and TE images in 20 (71%) of 28 lesions uncomplicated by fracture (stages I-II) but in only four (14%) of 28 stage III-V lesions (P less than .001). Symptoms were least severe in lesions isointense with fat and most severe in lesions with low-signal central regions at short and long TRs and TEs. The peripheral double line sign on long TR/TE images may add specificity to the diagnosis of AVN by MR imaging. A chronologic pattern of central MR signal features is presented which may allow staging of AVN by MR imaging. 相似文献
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PA Kowacs EJ Piovesan CE Tatsui MC Lange LC Ribas LC Werneck 《Cephalalgia : an international journal of headache》1999,19(4):241-242
The case of a 42-year-old woman with prolonged migraine visual aura without headache, whose long-lasting episodes of visual aura were successfully controlled by oral sumatriptan, is reported. Effectiveness of sumatriptan was unequivocal, since, after taking sumatriptan, duration of aura would drop from 1.5 h to approximately 20 min. This case suggests that sumatriptan may cross the blood-brain barrier and block spreading depression. 相似文献