The Inhibitory Effect of Radix Salviae Miltiorrhizae on Hypoxic Structural Remodeling of Intra－acinarPulmonary Arteries

(席思川)(车东媛)(张婉蓉)ＴｈｅＩｎｈｉｂｉｔｏｒｙＥｆｆｅｃｔｏｆＲａｄｉｘＳａｌｖｉａｅＭｉｌｔｉｏｒｒｈｉｚａｅｏｎＨｙｐｏｘｉｃＳｔｒｕｃｔｕｒａｌＲｅｍｏｄｅｌｉｎｇｏｆＩｎｔｒａ－ａｃｉｎａｒＰｕｌｍｏｎａｒｙＡｒｔｅｒｉｅｓ￥ＸＩＳｉ－ｃ...     

CO作用后大鼠肺血管细胞增殖和凋亡状况的研究

目的：通过研究CO和低氧作用后大鼠肺血管细胞增殖和凋亡状况，探讨低氧肺动脉高压的发病机制及防治措施。方法：应用免疫组织化学，原位末端标记及Western杂交等方法检测常压低氧大鼠肺血管壁细胞增殖，凋亡及c-myc基因的表达状况。结果：正常组，低氧和锡原卟啉组，低浓度CO和血晶素组大鼠肺动脉均存在增殖和凋亡的阳性细胞，两类细胞在肺内呈不均匀散在分布，低氧和锡原卟啉组大鼠肺血管增殖细胞数显著升高而凋亡细胞数显著减少，细胞增殖凋亡比值分别为对照组的5倍或4倍，而低浓度CO和血晶素组肺血管增殖细胞和凋亡细胞系数均显著增加，细胞增殖凋亡比值均为1．2，c-myc在低氧和锡原卟啉组大鼠肺内表达显著增加，在低浓度CO和血晶素组大鼠肺内表达减少。结论：增殖和凋亡现象共存在于正常和处理大鼠的肺血管细胞中，也许c-myc等基因的异常表达导致了细胞增殖和凋亡的失衡，进而调节了慢性低氧肺血管结构的改建。     

Architectural alterations in rat cerebral microvessels after hypobaric hypoxia

We performed 3-dimensional studies of vascular casts of the microvasculature of the cerebral cortex of rats that were exposed to three weeks of hypobaric hypoxia and of control rats. Scanning electron microscopy of the casts gave the qualitative impression of increased vascularity of the cerebral cortex, particularly the deeper layers, in hypoxic rats. Quantitative analysis of capillary segment lengths revealed a significant shift in the frequency distribution to longer lengths (from 77 ± 8 to 90 ± 14 μm) in the deep, but not in the superficial, layers of the cerebral cortex of hypoxic rats. These findings agree with previous results reporting increased capillary density in the brain after exposure to prolonged hypobaric hypoxia and suggest that capillary segment elongation plays a role in the increased capillary density in the deeper layers of the cerebral cortex.     

In vitro radiation sensitivity of the lncap prostatic tumor cell line

Because there is extremely limited information on the intrinsic radiosensitivity of human prostatic cancer cells, we have investigated the in vitro radiation response of exponentially growing LNCaP cells. Due to the very poor colony-forming potential of the LNCaP cells, radiation survival was investigated using the dose-dependent (0-6 Gy) changes seen after X-irradiation in the shapes of regrowth curves. Survival was described using both the single-hit, multitarget (SHMT) equation and the linear-quadratic (LQ) equation. The values and 95% confidence limits of the extrapolation number (n), quasi-threshold dose (D_q), and mean lethal dose (D_o) in SHMT terminology were respectively: 0.9 (0.7-1.0), 0.0 Gy, and 1.39 (0.11) Gy. The LQ alpha and beta parameters were respectively 6.80 (1.13) and -0.53 (2.89). The X-ray dose response of the LNCaP line is, therefore, purely exponential. The mean survival at the clinically relevant dose of 2 Gy (S₂) was 51.2% for the LNCaP line. Comparison of the S₂ value for the LNCaP line with previous investigations with other human prostatic cancer cell lines (DU145 and PC-3) indicates a mean S₂ value of 47.6%, which suggests that human prostate cancer cells might lie toward the resistant side of the spectrum for various classes of human neoplasms. © 1994 Wiey-Liss, Inc.     

振动对急性缺氧小鼠肺损伤的影响

本文观察了频率为20Hz、振幅为0．67mm和作用时间为40min的振动预处理对急性缺氧小鼠肺损伤的影响。结果发现实验组的肺组织匀浆脂质过氧化物LghdPeroxde（LPO）、支气管肺泡灌洗液（BALF）中蛋白含量和白细胞数明显低于对照组（P＜0．05）。这表明在特定率数的振动作用下能明显减轻急性缺氧小鼠肺的损伤。     

Relationship between cellular ATP content and cellular functions of primary cultured rat hepatocytes in hypoxia

The importance of oxygen in maintaining the functional integrity of hepatocytes has been well established in a variety of experimental models, such as in vivo , perfused liver and isolated hepatocytes. However, one of the shortcomings of these systems is their short life span. Therefore, we have examined the effects of long-term hypoxia on cellular adenine nucleotide content and cellular functions, such as albumin production, urea production and DNA synthesis, in adult rat hepatocytes in primary culture. Hepatocytes were cultured at a density of 11 × 10⁴ and 5 × 10⁴ cells/0.18 mL per cm² for the study of albumin and urea production and DNA synthesis, respectively, at various oxygen tensions (20, 12, 8 and 5%) for 24 h. Cellular ATP content in cultured hepatocytes in hypoxia gradually declined, corresponding to the decrease in oxygen tension, and the cellular ATP level at 5% oxygen was approximately 20% of that at 20% oxygen. Albumin production also decreased in parallel with the decrease in cellular ATP content in cultured hepatocytes in hypoxia. However, even when cellular ATP content gradually declined corresponding with the decrease in oxygen tension in cultured hepatocytes in hypoxia, such as at 8 or 5% oxygen, urea production remained at a high level; in contrast, DNA synthesis was completely suppressed. These results suggest that the cellular ATP content decreases in cultured hepatocytes during long-term hypoxia in relation to oxygen tension and that the relationship between decreased ATP levels and liver function in cultured hepatocytes during hypoxia differs for albumin production, urea production and DNA synthesis.     

Could Chronic Mesenteric Originated Hypoxia Insult Produce Opposite Pathologic Features： Hypoplasia and Hyperplasia of the Intestine

Chronic ischemia produces corresponding tissue hypoplasia. However, here we report a distinctive hypertrophy of the intestine due to chronic mesenteric insufficiency, which was confirmed by angiography in two patients with opposite characteristic pathologic presentation of intestine. During surgery of the first patient, an approximately 60cm long ileum with sausage consistency and cyanosis color was identified proximal to the caecum; wall-attached thromboembolism material and the hypertrophied segment of ileum were removed. In the other patient, the intestine wall was paper thin; after aorto-mesenteric bypass the intestine wall grew thicker. Post operative recovery of both patients was uneventful. The commonly observed situation after a long-standing hypoxic insult in a setting of chronic mesenteric ischemia is that the target tissue will at least develop a slight hypoplasia. However, the cases we present here had either pronounced hyperplasia or severe hypoplasia. We thus report it, expecting to identify a special mechanism to explain this paradox.