大鼠血管性痴呆模型动物中海马神经元凋亡和蛋白表达的研究

目的:观察不同时点分别结扎左、右颈总动脉建立大鼠血管性痴呆模型中海马CA1区神经元凋亡和Bcl-2及Bax蛋白表达的影响,探讨其在血管性痴呆发病过程中的作用。方法:采取间隔3 d分2次结扎双侧颈总动脉建立血管性痴呆模型,术后4周用TUNEL法检测海马CA1区神经元凋亡,用免疫组织化学法检测其Bcl-2及Bax蛋白表达。结果:模型组大鼠海马CA1区可见大量凋亡神经元;模型组Bcl-2及Bax蛋白表达明显增加,与假手术组比较差异均有显著意义(P<0.05)。结论:此血管性痴呆模型大鼠中海马CA1区神经元大量凋亡丢失,可能是导致血管性痴呆的病理基础。     

Co-administration of Cisplatin and Furosemide Causes Rapid and Massive Loss of Cochlear Hair Cells in Mice

The expanding arsenal of transgenic mice has created a powerful tool for investigating the biological mechanisms involved in ototoxicity. However, cisplatin ototoxicity is difficult to investigate in mice because of their small size and vulnerability to death by nephrotoxicity. To overcome this problem, we developed a strategy for promoting cisplatin-induced ototoxicity by coadministration of furosemide a loop diuretic. A dose–response study identified 200 mg/kg of furosemide as the optimal dose for disrupting the stria vascularis and opening the blood–ear barrier. Our analysis of stria pathology indicated that the optimal period for administering cisplatin was 1 h after furosemide treatment. Combined treatment with 0.5 mg/kg of cisplatin and 200 mg/kg furosemide resulted in only moderate loss of outer hair cells in the basal 20% of the cochlea, only mild threshold shifts and minimal loss of distortion product otoacoustic emission (DPOAE). In contrast, 1 mg/kg of cisplatin plus 200 mg/kg of furosemide resulted in a permanent 40–50 dB elevation of auditory brainstem response thresholds, almost complete elimination of DPOAE, and nearly total loss of outer hair cells. The widespread outer hair cell lesions that develop in mice treated with cisplatin plus furosemide could serve as extremely useful murine model for investigating techniques for regenerating outer hair cells, studying the mechanisms of cisplatin and furosemide ototoxicity and assessing the perceptual and electrophysiological consequences of outer hair cell loss on central auditory plasticity.     

肠道菌鉴定培养基的研究进展

目前,细菌学的分类和鉴定技术有了很大的发展,但是,临床上肠道菌鉴定主要还以生化反应为主.单管多用的显色培养基筛选微生物是一种较新的技术,其操作简便、特异性强,能提高微生物细菌鉴定在临床上的地位,单管多用的显色培养基的开发、应用是今后的发展趋势.     

低温对兔睾丸生精作用的影响

采用低温对兔睾丸生精功能进行实验研究。结果表明：低温作用后，既可对兔睾丸精子的发生产生快速影响，又可破坏附睾中的成熟精子。关于低温作用是否有可逆性，取决于低温的强度和作用时间；本实验在－１０℃作用下，对精原细胞和支持细胞均无影响，从而进一步推测低温抑制精子形成是可逆的。     

Genetic background effects on age-related hearing loss associated with Cdh23 variants in mice

Inbred strain variants of the Cdh23 gene have been shown to influence the onset and progression of age-related hearing loss (AHL) in mice. In linkage backcrosses, the recessive Cdh23 allele (ahl) of the C57BL/6J strain, when homozygous, confers increased susceptibility to AHL, while the dominant allele (Ahl+) of the CBA/CaJ strain confers resistance. To determine the isolated effects of these alleles on different strain backgrounds, we produced the reciprocal congenic strains B6.CBACa-Cdh23^Ahl+ and CBACa.B6-Cdh23^ahl and tested 15-30 mice from each for hearing loss progression. ABR thresholds for 8 kHz, 16 kHz, and 32 kHz pure-tone stimuli were measured at 3, 6, 9, 12, 15 and 18 months of age and compared with age-matched mice of the C57BL/6J and CBA/CaJ parental strains. Mice of the C57BL/6N strain, which is the source of embryonic stem cells for the large International Knockout Mouse Consortium, were also tested for comparisons with C57BL/6J mice. Mice of the C57BL/6J and C57BL/6N strains exhibited identical hearing loss profiles: their 32 kHz ABR thresholds were significantly higher than those of CBA/CaJ and congenic strain mice by 6 months of age, and their 16 kHz thresholds were significantly higher by 12 months. Thresholds of the CBA/CaJ, the B6.CBACa-Cdh23^Ahl+, and the CBACa.B6-Cdh23^ahl strain mice differed little from one another and only slightly increased throughout the 18-month test period. Hearing loss, which corresponded well with cochlear hair cell loss, was most profound in the C57BL/6J and C57BL/6NJ strains. These results indicate that the CBA/CaJ-derived Cdh23^Ahl+ allele dramatically lessens hearing loss and hair cell death in an otherwise C57BL/6J genetic background, but that the C57BL/6J-derived Cdh23^ahl allele has little effect on hearing loss in an otherwise CBA/CaJ background. We conclude that although Cdh23^ahl homozygosity is necessary, it is not by itself sufficient to account for the accelerated hearing loss of C57BL/6J mice.     

子宫内膜异位症在位内膜神经纤维分布与疼痛关系的研究

目的:检测子宫内膜异位症(EMT)在位内膜中的神经纤维蛋白基因产物9.5(PGP9.5)、P物质(SP)和神经生长因子(NGF)的分布,探讨其与疼痛的关系。方法:选择EMT患者45例,按视觉模拟评分(VAS)法将患者分为EMT疼痛组(24例)和EMT无痛组(21例),其中轻度疼痛者4例,中度疼痛者7例,重度疼痛者13例;另选择同期患子宫肌瘤住院的患者25例作为对照组。应用免疫组化SP方法分别检测子宫内膜的PGP9.5标记的神经纤维密度(条/mm2)和SP、NGF的平均光密度(OD)值,并与VAS评分进行相关性分析。结果:EMT疼痛组中PGP9.5的密度和SP、NGF的OD值均高于EMT无痛组和对照组(P<0.05)。EMT重度疼痛组中PGP9.5的密度和SP、NGF的OD值明显高于轻度和中度疼痛组(P<0.05)。同时,EMT疼痛组中PGP9.5的密度和SP、NGF的OD值与患者的VAS疼痛评分呈正相关(r=0.745,0.624,0.628;P<0.05)。结论:EMT患者在位内膜存在神经纤维的异常分布。EMT中神经纤维的表达与疼痛的严重程度有关,神经纤维的异常高表达可能是EMT患者疼痛的原因之一。     

实验动物前庭感觉毛细胞的定量观察

目的 测量常用实验动物内耳前庭感觉区的实际面积和量化分析前庭各个感觉区的毛细胞总数或密度。方法 ①制作CBA/CaJ小鼠、裸鼠、SD大鼠、豚鼠、南美栗鼠、新西兰白兔和非洲黑长尾猴的球囊斑铺片和椭圆囊斑铺片及壶腹嵴铺片,所有铺片样品来自每种受试动物的6个颞骨,在放大100倍的光学显微镜下拍摄2个囊斑铺片的整体照片;②应用Image J软件的图像测量程序,测量了上述7种常用实验动物球囊斑和椭圆囊斑的实际面积;③用网格将球囊斑铺片和椭圆囊斑铺片照片上的前庭感觉区划分为一个个方块区域。在放大400倍的光学显微镜下准确计数每个方格内的毛细胞数量,然后将每个方格的毛细胞计数结果相加以获得每种受试动物球囊斑和椭圆囊斑上的毛细胞总数;④应用前庭小视野定量观察技术计算出前庭各个感觉区小视野范围内的毛细胞密度。结果 ①从小鼠、裸鼠、大鼠、豚鼠、南美栗鼠、白兔到猴的球囊斑面积依次为(0.193±0.009)、(0.216±0.008)、(0.323±0.010)、(0.528±0.035)、(0.687±0.065)、(1.237±0.075)、(1.371±0.032)mm²;椭圆囊斑的面积依次为(0.193±0.020)、(0.208±0.013)、(0.321±0.011)、(0.526±0.034)、(0.795±0.017)、(1.224±0.082)、(1.388±0.048)mm²;②从小鼠、裸鼠、大鼠、豚鼠、南美栗鼠、白兔到猴的球囊斑毛细胞的总数依次为(2476.3±64.4)、(2389.8±47.8)、(3135.3±191.6)、(4882.2±208.7)、(6128.5±242.9)、(10572.2±464.4)、(10992.7±397.4)个;椭圆囊斑毛细胞的总数依次为(2491.4±54.8)、(2368.0±46.1)、(3218.8±82.9)、(4925.3±271.1)、(7794.0±386.1)、(11347.4±435.7)、(11114.5±410.6)个;③从小鼠、大鼠、豚鼠、南美栗鼠、白兔和猴的球囊斑微纹区和周边区的毛细胞密度(毛细胞数量/0.007mm²)依次为101.0±5.79(微纹区)/120.8±4.15(周边区),95.5±3.91(微纹区)/109.2±5.26(周边区),78.4±6.54(微纹区)/94.8±4.38(周边区),60.0±4.74(微纹区)/84.6±2.61(周边区),57.2±3.83(微纹区)/80.0±3.54(周边区),53.8±4.21(微纹区)/68.0±4.18(周边区)。从小鼠、大鼠、豚鼠、南美栗鼠、白兔和猴的椭圆囊斑微纹区和周边区的毛细胞密度(毛细胞数量/0.007mm²)依次为103.8±5.02(微纹区)/119.2±3.70(周边区),91.2±2.49(微纹区)/106.4±4.16(周边区),74.1±3.54(微纹区)/90.8±3.56(周边区),60.4±4.98(微纹区)/81.6±2.07(周边区),57.8±1.92(微纹区)/77.8±3.70(周边区),54.0±2.74(微纹区)/66.4±2.51(周边区)。从小鼠、大鼠、豚鼠、南美栗鼠、白兔和猴的壶腹嵴毛细胞密度(毛细胞数量/0.007mm²)依次为112.4±6.38,105.5±3.51,95.2±3.42,84.0±7.16,78.2±2.86,70.8±2.39。可见由于体型较小动物毛细胞的细胞体比体型较大动物毛细胞的细胞体小,因而体型较小动物的前庭毛细胞密度高于体型较大动物的前庭毛细胞密度。另外,每种实验动物球囊斑和椭圆囊斑微纹区的毛细胞密度相似,周边区的毛细胞密度也大致相同,但是同种实验动物囊斑微纹区的毛细胞密度却低于周边区的毛细胞密度。此外,壶腹嵴毛细胞的密度与球囊斑和椭圆囊斑周边区的毛细胞密度几乎相同。鉴于某些损害因素往往具有选择性破坏囊斑微纹区毛细胞的表现,因此囊斑微纹区的毛细胞密度应该与囊斑周边区的毛细胞密度区分开来进行统计,必要时甚至需要把Ⅰ型毛细胞和Ⅱ型毛细胞也区分开来分别予以病理学改变的定量评估。结论 本研究采用的前庭测量方法和获得的前庭各个感觉区的测量数据和毛细胞总数及毛细胞密度,为前庭病理学研究的定量分析提供了有益的参考经验和必要的参考数据。     

14例永久性心脏起搏在儿童病例中应用的体会

目的观察永久心脏起搏器在儿童病例中的应用及疗效.方法1981年9月～2000年5月,对14例儿童进行了永久起搏器的植入,其中男性10例,女性4例,年龄2.5～12.0岁,平均(8.4±4.0)岁.12例因心脏手术和2例因非心脏手术致完全性房室阻滞.经右颈内静脉切开植入电极导线7例、经右锁骨下静脉穿刺3例、经头静脉切开3例,直视手术下1例.结果14例患儿植入永久性心脏起搏器后,心功能恢复良好.结论儿童永久性心脏起搏器植入是安全可靠的,但对婴幼儿在导线径路方面,静脉切开的方法较穿刺方法更为安全.10岁左右儿童可采取自头静脉插入导线,与成人比较无差别.起搏器选择、植入途径和导线在心房内长度的处理是起搏器成功治疗的关键.     

镁与氟相互作用的研究近况

近年氟与微量元素关系日前受到关注,特别是氟与钙的关系报道较多,但镁、氟相互作用研究较少。笔者 就近期有关镁、 氟相互作用在骨组织系统、酶系统、胶原和细胞遗传毒性几个方面的拮抗作用做了 初步综全,以期对氯致病机理和对其拮抗作用从理论上进一步加深理解。通过本文说明对高氟人群健康保护,降低机体对氟毒性作用的敏感性,有些重要的因素,如环境镁水平、机体镁的适宜水平、饮食镁的必需摄 入量等在促进机体 氟的排泄和缓减氟毒性作用 方面占有重要的地位。本文引用的部分研究结果和某些观点,对指导高氟人群免受或少受氟损害以及制订防治对策或许有参考价值。     

肝癌荷瘤大鼠立体定向放射治疗的实验研究

目的探讨立体定向放射治疗对肝癌的治疗作用.方法通过CBRH-3肝癌细胞株建立大鼠肝癌模型,采用立体定向放射技术,对皮下癌结节取不同的放射剂量一次性照射,观察照射前后肿瘤大小,流式细胞仪检测BCL-2、凋亡率、细胞周期.结果立体定向放射治疗24小时后,肿瘤体积缩小,并与放射剂量呈正相关,随照射剂量的增大凋亡发生率、BCL-2表达率增加,流式细胞仪检测结果显示肿瘤细胞G2期受阻滞.结论立体定向放射治疗肝癌疗效确切,疗效与剂量呈正相关.