氧化低密度脂蛋白、低氧和5-HT对血管平滑肌细胞5-HT2A受体及胞内游离钙的影响

目的　为探讨粥样硬化病变动脉对 5 - HT收缩反应增加的机制 ,观察与粥样硬化有关因子氧化低密度脂蛋白 (ox L DL)、低氧、5 - HT对血管平滑肌细胞 5 - HT2 A受体及其基因表达 ,以及细胞 [Ca2 ]i的效应。方法　分别将大鼠主动脉平滑肌细胞单独以 5 0 μg/ m l ox L DL 培养 8h,2 %低氧处理 2 4和 48h,10 μm ol/ L 5 - HT处理30 min,放射配基结合分析测定 5 - HT2 A受体 ;RT- PCR和 Southern杂交检测受体基因的 m RNA;激光共聚焦扫描显微镜测单个细胞 [Ca2 ]i。结果　经 ox L DL、低氧、 5 - HT处理 ,血管平滑肌细胞 5 - HT2 A受体显著上调 (P<0 .0 1) ;ox L DL及低氧处理的受体基因的 m RNA表达增加 ;ox L DL、低氧处理后 ,5 - HT刺激的血管平滑肌细胞[Ca2 ]i升高幅度显著加大 (P<0 .0 5及 P<0 .0 1)。结论　 ox L DL、低氧、5 - HT引起血管平滑肌细胞 5 - HT2 A受体上调及细胞 [Ca2 ]i增加 ,可能是粥样硬化动脉对 5 - HT收缩反应增强的部分原因。     

增生性瘢痕和瘢痕疙瘩组织中Ⅰ、Ⅲ型前胶原及TGF-β_1 mRNA的表达

目的：探讨增生性瘢痕（Ｈ）和瘢痕疙瘩（Ｋ）组织中Ⅰ、Ⅲ型前胶原及ＴＧＦ－β１基因表达改变的相互关系及临床意义。方法：总ＲＮＡ抽提试剂盒抽提总ＲＮＡ,斑点杂交检测Ⅰ、Ⅲ型前胶原及ＴＧＦ－β１ｍＲＮＡ稳态水平的改变。结果：Ｈ和Ｋ组织中ＴＧＦ－β１ｍＲＮＡ（１．１９７±０．２３７,１．２０４±０．２４３）表达均高于正常瘢痕和正常皮肤（０．３２７±０．０８１,０．３３１±０．０７８）,Ｐ＜０．０１;Ｋ选择性地Ⅰ型前胶原ｍＲＮＡ表达增强,而Ｈ组织中Ⅰ、Ⅲ前胶原ｍＲＮＡ表达均增强,导致ＫⅠ、Ⅲ前胶原ｍＲＮＡ比值明显高于Ｈ（８．１６４±０．３００,１．６６６±０．２０１,Ｐ＜０．０１）。结论：Ｋ和Ｈ组织中胶原蛋白基因表达类型及强度不同,提示在Ｋ和Ｈ发生发展中具有不同的分子机理：ＴＧＦ－β１在增生性瘢痕疙瘩的发病机理中具有不同的分子机理;ＴＧＦ－β１在增生性瘢痕和瘢痕疙瘩的发病机理中具有一定作用。     

1,25-二羟维生素D_3抑制报导载体pGL_2荧光素酶表达的研究

通过磷酸钙沉淀法将载体DNA转染Caco－2细胞。Caeo－2细胞经不同浓度1,25一二羟维生素D3处理后,测定表达的荧光素酶活性。结果;当pSG5－VDR表达载体共转染时1,25一二羟维生素D3显著地抑制Caco－2细胞荧光素酶的表达;而未使用pSG5－VDR表达载体共转染时,则无抑制作用。说明1,25一二羟维生素D3能抑制报导载体pGL2荧光素酶的表达。类似于人类PTH基因中的潜在抑制性VDRE存在于报导载体pGL2。     

Morphological and functional demonstration of rat dura mater mast cell-neuron interactions in vitro and in vivo

The effects of changes in temperature on primary and secondary endings of isolated cat muscle spindles were investigated under ramp-and-hold stretches and different degrees of pre-stretch. Temperature-induced alterations of the discharge frequency were compared over a temperature range of 25–35°C. Both primary and secondary endings responded to warming with increasing discharge frequencies when the spindle was pre-stretched by 5–10% of its in situ length. The following differences between the temperature effects on primary and secondary endings were observed: (1) The temperature coefficients (Q₁₀) obtained from the discharge frequencies during the dynamic and static phase of a stretch were similar for endings of the same type, but they were larger in primary endings (range of Q₁₀: 2.3–3.3; mean: 2.9) than in secondary endings (range of Q₁₀: 1.6–2.2; mean: 2.0); (2) With primary endings, but not with secondary endings, the temperature sensitivity (imp s⁻¹ °C⁻¹) was larger during the dynamic phase than during the static phase of a stretch; (3) In primary endings, the fast and slow adaptive components occurring in the discharge frequency during the static phase of a stretch clearly increased with warming while in secondary endings, the slow decay was less affected, and the fast decay showed no change; (4) In relaxed spindles, the excitatory effect of warming was overlaid by a strong inhibitory effect as soon as the temperature exceeded about 30°C, resulting in an abrupt cessation of the background activity in most secondary endings, but not usually in primary endings. In general, warming induced an enhanced stretch sensitivity in both types of ending, and additionally an inhibitory effect that is obvious only in secondary endings of relaxed spindles. The different effects of temperature on the discharge frequency of primary and secondary afferents are assumed to be caused by different properties of their sensory membranes.     

An analysis of an air-ambulance program for children

Air-ambulance services are extremely expensive to operate and maintain. The value of their existence has been questioned in this era of rationalization and downsizing. We examined the cost, safety, flight crew composition, types of trauma, and effectiveness of our air-ambulance program at the Children's Hospital of Eastern Ontario (CHEO) over a 3-year period, 1994-1997. During this time, 392 children were aeroevacuated to CHEO, 113 surgical (29%), 136 medical (35%), and 143 neonates (36%). Of the surgical cases, 43% were transferred for orthopaedic trauma, the commonest being fractured femur, 23% for general surgical cases, most common being thoracoabdominal trauma, and 22% for neurosurgical reasons, most commonly basilar skull fractures. The average response time (time from which the call was received to the time when the helicopter reached the patient site) for all of the cases was 46 min. The average travel time (time from departure of patient site to arrival at CHEO) for these same cases was 25.59 min. The air-ambulance program for children in the Ottawa-Carleton Eastern Ontario areas, was found to be safe, effective, and allowed earlier specialized medical care to be provided.     

维生素D_3对报告载体荧光素酶表达的作用

目的：　研究１,２５－二羟维生素Ｄ３ 对结肠癌细胞系Ｃａｃｏ－２ 细胞中报告基因表达的作用,并探讨在报告载体ｐＧＬ２ 序列中存在潜在的抑制性维生素Ｄ应答元件（ＶＤＲＥ）的可能性。方法：　采用磷酸钙沉淀法将报告载体转染入Ｃａｃｏ－２ 细胞。Ｃａｃｏ－２细胞经不同浓度１,２５－二羟维生素Ｄ３ 处理后测定细胞裂解液中表达的荧光素酶活性。结果：　应用ｐＧＬ２ 报告载体时,当用ｐＳＧ５－ＶＤＲ表达载体共转染后,１,２５－二羟维生素Ｄ３显著地抑制Ｃａｃｏ－２ 细胞荧光素酶的表达（Ｐ＜ ０．０５）;而未使用该表达载体共转染则无抑制作用（Ｐ＞ ０．０５）。应用ｐＧＬ３ 报告载体时,不同浓度的１,２５－二羟维生素Ｄ３ 对ｐＬＧ３转染后Ｃａｃｏ－２ 细胞表达的荧光素酶活性均无显著抑制作用（Ｐ＞ ０．０５）,该作用不依赖是否存在有ｐＳＧ５－ＶＤＲ表达载体共转染。结论：１,２５－二羟维生素Ｄ３ 对报告载体ＰＧＬ２ 荧光素酶表达具有抑制作用,而对ｐＧＬ３ 则否;类似人类ＰＴＨ基因中的潜在抑制性ＶＤＲＥ存在于报告载体ｐＧＬ２,在ｐＧＬ３ 中该ＶＤＲＥ业已改变。     

健康寿命年——一个新的测量疾病负担的指标

介绍一种新的测量疾病负担的指标——健康寿命率（ＨｅａＬＹ）。我们用此指标对１９９０～１９９３年北京ＭＯＮＩＣＡ资料进行了重新估算和分析,并将其与几年前ＷＨＯ和世界银行提出的另一个测量疾病负担的指标ＤＡＬＹ进行了比较。     

放射状角膜切开手术中微穿孔对角膜内皮的影响

目的：评价放射状角膜切开术（ＲＫ）中微穿孔对术后１年内角膜内皮的影响。方法：应用角膜内皮镜及角膜内皮分析仪研究４８例ＲＫ术中微穿孔和未穿孔眼的角膜内皮形态学变化,分别在术前及术后１、３、６、１２个月行角膜内皮检查及分析。结果：比较手术前后角膜内皮的数量、平均面积、最大面积和最小面积,穿孔眼及未穿孔眼差异无显著性,但内皮细胞面积两组都有扩大的趋势。结论：ＲＫ术后一年内无论微穿孔还是未穿孔眼的角膜内皮