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排序方式: 共有4766条查询结果,搜索用时 15 毫秒
41.
42.
Summary A new double sucrose gap chamber using electrodes of high stability and low resistance is described. The size of each sucrose gap and the central node can be modified independently so that this chamber is suitable for research on multicellular or unicellular excitable preparation under voltage clamp conditions. The shape of the central channel is made so as to reduce the series resistance between the preparation and the recording electrode to a minimum. A window made in the floor of the chamber allows to observe the preparation under a microscope.This work was performed under the I.N.S.E.R.M. grant no. 17.75.40. 相似文献
43.
A high quality of cytogenetic preparations is important for maintaining a high standard in the cytogenetic laboratory. In the past, quality has been assessed by visual counting or estimation of the number of bands on chromosomes. In this paper we have counted bands automatically during karyotyping by using the Magiscan chromosome analysis system. A high correlation between automatic and visual counting was found, the automatic counting was reproducible and count figures were comparable when the karyotyping machines were operated by different technicians. The automatic counting procedure has now been included in our routine for 1 year. The highest numbers of bands were counted on slides from peripheral blood, with fewer bands for amniotic fluid and the lowest number for cells from chorionic villi. All three cell types showed significant variations in band number over time, which may be due to changes in weather conditions and/or the reagents used for cell culture, harvest and staining. It is concluded that the automatic counting procedure may be used to monitor the quality of metaphases over time and to set limits for band number on routine preparations acceptale for analysis. 相似文献
44.
An isolated case of Duchenne muscular dystrophy (DMD) in a female who has a deletion of the DMD locus is described. This patient was a 26-year-old woman born to unrelated, healthy parents. She was initially examined at age 6 because of a waddling gait. At age 15, pseudohypertrophy of calves and pes equinus were observed along with proximal muscular weakness and wasting. Her serum creatine kinase level was high and histological evidence of muscular dystrophy was apparent on muscle biopsy. The patient was ambulant at age 15 and progression of motor disability has been slow. Chromosomal studies revealed a normal karyotype, and mental retardation is moderate. DNA analysis at age 26 revealed that she has a deletion of DMD cDNA 8 mapped within Xp21 and is heterozygous for the deletion. Since diagnosis of DMD is now dependent on the evidence of mutation or deletion at Xp21, this patient is thought to have a form of DMD. Expression of the DMD gene in the heterozygous state might be due to random but unequal lyonization. 相似文献
45.
犬陈旧性心肌梗死时连接蛋白43的分布 总被引:5,自引:0,他引:5
目的:探讨陈旧性心肌梗死时心肌缝隙连接蛋白43(connexin 43,Cx43)的分布特征。方法:结扎犬冠状动脉造成心肌梗死,术后恢复40-50d,用改良的免疫细胞化学法显示心肌梗死区,边缘带及非缺血区Cx43的分布,半定量分析不同部位Cx43的分布密度。结果:与正常心肌相比,梗死病灶及其邻近区域Cx43的分布出现明显紊乱:梗死中心区Cx43完全消失;边缘带Cx43呈现不均匀消失,少量Cx43分布于岛状或半岛状尚存活的心肌;心肌细胞端-端相接处的Cx43严重消失,而细胞侧-侧相接处的Cx43仍有部分存在。非缺血区Cx43的密度和分布与正常心肌相比无明显改变。结论:陈旧性心肌梗死时Cx43的数量和分布呈现高度不均一性,尤其在边缘带Cx43的分布特点是形成局部传导阻滞和折返性心律失常的结构基础。 相似文献
46.
根据薄膜理论基础,分析了受抑全内反射(FTIR)的理论机制,并导出相应的光线透过率及反射率公式,绘制出透射率、反射率随棱镜相对间隙d/λ、入射角θ。的变化曲线。并建立了一套FTIR组合测试原理实验装置,得到了透过及发射光脉冲曲线,通过实验地其特性进行了具体分析。 相似文献
47.
慢性扁桃体炎病儿细胞免疫功能的变化 总被引:5,自引:0,他引:5
1目的 探讨慢性扁桃体炎病儿细胞免疫功能的变化及临床意义。2方法 采用碱性磷酸酶抗碱性磷酸酶法及红细胞酵母菌花环法 ,检测了 40例慢性扁桃体炎病儿及 30例健康儿童红细胞 C3b受体花环率 (E- C3bRR )、红细胞免疫复合物花环率 (E- ICR)、T淋巴细胞亚群和可溶性白细胞介素 2受体 (s IL - 2 R)的变化。3结果慢性扁桃体炎病儿外周血 T淋巴细胞亚群 CD4阳性细胞及 CD4/ CD8比值较对照组降低 (t=2 .10 ,3.70 ,P <0 .0 1,0 .0 5 ) ,CD8阳性细胞较对照组升高 (t=6 .83,P<0 .0 1) ;E- C3b RR,E- ICR较对照组降低 (t=10 .47,3.35 ,P<0 .0 1) ;血清中 s IL- 2 R水平较对照组升高 (t=9.11,P<0 .0 1) ;CD4/ CD8比值与 s IL- 2 R水平呈显著负相关 (r=- 0 .8436 ,P<0 .0 1)。4结论 慢性扁桃体炎病儿细胞免疫功能低下且紊乱。 相似文献
48.
Constricting band penile injuries in children may be caused by inadvertent entrapment by a variety of agents including hair, thread, and circumcision dressings. Alternatively, the offending band may have been self-applied or applied by an attendant. Unrelieved, the band causes serious vascular occlusion, progressive tissue necrosis, and injury to the urethra and erectile tissue. We report a case of CBPI in a 12-year-old circumcised boy. The glans was attached to the penile shaft by a tenuous segment of tissue dorsally with complete transection of the urethra. A three-stage reconstruction using a delayed groin flap was successful. 相似文献
49.
Background: In the past 4 years we performed operations on 90 patients who suffered from morbid obesity. Five different operative
techniques were available, vertical banded gastroplasty (VBG), silastic ring vertical gastroplasty (SRVG), gastric banding
operation, adjustable silicone gastric banding (ASGB) and biliopancreatic diversion (BPD). Methods: Two of these operations
were mainly utilized. The ASGB was done routinely. The SRVG was used particularly for patients with hiatal hernia. Only one
patient, who had a deformed pylorus, underwent the BPD. Results: Eleven patients had to be reoperated due to complications
after the first operation of gastric restriction. They were divided into three groups depending on the type of complication:
reoperation due to lack of compliance, due to technical failure, or due to other complications. In the last group we observed
three patients with band perforation into the stomach without epigastric pain. This complication has, to our knowledge, only
been described in very few cases. Conclusion: In some patients it remained difficult to reach adequate compliance, although
we kept close contact with them after the operation. We do not yet know the reasons for the band perforation observed in three
patients. 相似文献
50.
《中华耳科学杂志(英文版)》2022,17(4):232-238
ObjectiveTo determine the circadian influence on sound sensitivity produced by temporal hearing deprivation in healthy normal human subjects.DesignParticipants underwent bilateral earplugging before completion of anthropometry, the author's developed questionnaire, the Hamilton Anxiety and Depression Inventory, pure tone audiometry (PTA), stapedial reflex thresholds (SRT), distortion products otoacoustic emissions input/output (DPOAE-I/O), and uncomfortable loudness levels (ULLs). Afterward, the participants were randomly divided into group A, starting at 8:00 a.m. and finishing at 8:00 p.m., and group B, starting at 4:00 p.m. and ending at 4:00 a.m. Serum cortisol levels and audiological test results were obtained at the beginning and end of the session and 24-h free urinary cortisol levels were measured.Study sampleThirty healthy volunteers.ResultsPTA was 2.68 and 3.33 dB HL in groups A and B, respectively, with no statistical difference between them. ULLs were significantly lower in group A compared to group B, with an average of 8.1 dB SPL in group A and 3.3 dB SPL in group B (p < 0.0001). A SRT shift was observed in group A, with no difference in group B, and a night shift in DPOAE-I/O in group B.ConclusionsReduced loudness tolerance is demonstrated during daytime hearing deprivation in contrast to nighttime; this may be due to increased central gain in the awake cortex. 相似文献