The effect of unilateral nephrectomy on the subsequent radiation response of the pig kidney.

The left kidney of 14 Large White female pigs, approximately 14 weeks of age, was surgically removed. Thirty weeks after unilateral nephrectomy (UN) the remaining kidney was irradiated with a single dose of between 11.9 and 15.6 Gy of 60Co gamma-rays; three pigs received sham irradiation. Following irradiation glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and haematocrit (Hct) were determined for up to 48 weeks after irradiation. Irradiation resulted in a dose-dependent decline in GFR, evident 8 weeks after irradiation. This was followed by a gradual improvement in GFR, although after doses of 14.0 Gy GFR remained below control values throughout the study. A similar pattern of response was seen in terms of ERPF, but this was not dose-related. Doses of greater than or equal to 14.0 Gy also caused a significant reduction (p less than 0.001) in Hct within 4-8 weeks. Minimal levels were evident 16 weeks after irradiation; Hct then increased, but remained below preirradiation values. Dose-effect curves were obtained by determining the percentage of irradiated kidneys which showed a greater than or equal to 50% reduction in GFR and ERPF, fitted by probit analysis, and ED50 values (+/- SE) were calculated for each parameter. The ED50 values for GFR and ERPF were 14.49 +/- 0.27 Gy and 12.56 +/- 0.98 Gy, respectively. These values were not significantly different from those obtained from intact age-matched pigs in which the right kidney alone was irradiated; UN did not compromise or alter the radiation response of the kidney to irradiation. However, the ED50 values obtained for the UN pigs were significantly greater (p less than 0.001) than the values of 9.76 +/- 0.17 Gy and 6.19 +/- 0.93 Gy, seen for GFR and ERPF in intact age-matched pigs in which both kidneys were irradiated. Thus although both experimental situations involved irradiating the entire renal tissue, the relative radiosensitivity of the kidneys varied considerably. These findings show that the radiosensitivity of the pig kidney can vary markedly, depending on the physiological status of the kidney at the time of irradiation.     

封闭负压引流对猪皮肤软组织爆炸伤感染创面肉芽组织生成的影响

目的　观察封闭负压引流技术 (VAC)对猪皮肤软组织爆炸伤感染创面肉芽组织生成的影响。方法　用电雷管在 4只 15～2 0kg的小白家猪双侧肩胛及双侧臀部造成 16个爆炸伤创面 ,随机分为对照组和治疗组。各组创面伤后 72h内不做任何处理 ,以造成创面感染。伤后第 3天起 ,对照组油纱布换药 ,治疗组用 - 15kPa的VAC治疗。于治疗前和治疗后 1、3、6、9、14、19、2 4天测量创面深度 ,并取创面中心的活组织进行HE染色和免疫组化染色 ,观察血管内皮细胞和增殖细胞的数目 ,计算增殖指数。结果　治疗后 1～ 19天 ,治疗组创面深度较对照组浅 (P <0 0 1) ;治疗后 1～ 6天 ,治疗组创面中血管内皮细胞数较对照组显著增高 (P <0 0 1) ;治疗后 1～ 3天 ,治疗组创面的增殖指数较对照组高 (P <0 0 1)。结论　与常规治疗相比 ,VAC能快速启动猪皮肤软组织爆炸伤感染创面肉芽组织生成 ,缩短肉芽组织填平伤口的时间。     

The effect of paclitaxel on the radiosensitivity of gynecological tumor cells

Background

Paclitaxel, a natural product from Taxus brevifolia, is a microtubule stabilizing agent, which has been shown to block different cells in the G2/M phase of the cell cycle and consequently, to modulate their radioresponsiveness. Our aim was to test the cytotoxic and radiosensitizing potential of paclitaxel, with respect to different gynecological tumors with varying radiosensitivities.

Material and Method

We performed clonogenic assays and flow cytometry on 2 cell lines, MCF-7 (breast) and CaSki (cervix) cells, and on 2 primary ovarian tumor samples (OC-I and OC-II). The cells were irradiated with 200 kV X-rays, radiation doses of up to 8 Gy were applied either as single doses or in 2 Gy fractions. Paclitaxel concentrations varied from 0.07 to 700 nM, incubation times varied from 3 to 120 h.

Results

Paclitaxel alone changed the cell cycle distribution of the cells tested and was cytotoxic in a time and concentration dependent manner. When combined with radiation, most schedules resulted in additive effects of the combined treatments. However, for MCF-7 cells, when 7 nM paclitaxel, applied 24 h before irradiation, were combined with fractionated irradiation a supra-additive effect with a SER of 1.2 was found. For CaSki cells, under comparable conditions the SER was 1.13 but the effects were not statistically significant.

Conclusion

Under specific conditions, paclitaxel exerted a weak radiosensitizing effect on breast and cervical carcinoma cells. A therapeutic gain may be possible on the basis of an optimal paclitaxel/radiation scheduling.     

The effect of hypertension on the apparent diffusion coefficient values of kidneys

PURPOSE: The purpose of this study was to diagnose hypertension- induced renal microvascular dysfunction using renal diffusion magnetic resonance imaging (MRI) and to identify any correlation between blood pressure level and apparent diffusion coefficient (ADC) values. MATERIALS AND METHODS: The study included 77 consecutive patients (41 women and 36 men). The patients were divided into 4 groups according to their blood pressure level. Group 1 consisted of normotensive control patients; group 2, pre-hypertensive patients; group 3, stage 1 hypertensive patients; and group 4, stage 2 hypertensive patients. All patients underwent transverse diffusion-weighted multi-section echo-planar MRI. In the transverse ADC maps, rectangular regions of interest were placed in the cortex at 3 sites (upper, middle, and lower pole) of each kidney. The ADCs of the kidneys were calculated separately for low, average, and high b values to enable the differentiation of the relative influence of the perfusion fraction and true diffusion. In addition, a multi-slab balanced turbo field-echo magnetic resonance angiographic technique (without the use of a contrast agent) was used to exclude renal artery stenosis. RESULTS: There was no statistically significant difference between the groups in age, and no significant correlation between the ADC values of both kidneys and blood pressure level in each group (P > 0.05). In addition, the ADC values of patients with microalbuminuria did not differ from those of the other patients (P > 0.05). CONCLUSION Despite the end-organ damage caused by hypertension, renal microvascular functions were preserved and hypertension did not affect ADC values.     

葛根芩连汤对糖尿病肾病大鼠肾组织的保护作用

目的 探讨葛根芩连汤（Gegen Qinlian decoction,GQD）对糖尿病肾病大鼠肾组织的保护作用及机制。 方法 利用SD大鼠进行糖尿病肾病模型的制备,30只SD大鼠随机分为对照组（灌胃生理盐水）、模型组[高脂饲料喂养+链尿佐菌素 (streptozotocin,STZ)腹腔注射+灌胃生理盐水]、GQD组（高脂饲料喂养+STZ腹腔注射+灌胃GQD）。实验结束后取血液,检测血清炎症因子白细胞介素-6、肿瘤坏死因子-α的水平;检测血糖、血清胰岛素、血肌酐和尿素氮及24 h尿蛋白水平;取肾脏,测定脏器指数,制作石蜡切片,检测细胞凋亡;检测信号通路相关蛋白磷酸肌醇3激酶（phosphatidylinositol-4,5-bisphosphate 3-kinase,PI3K）、蛋白激酶B（protein kinase B,PKB/AKT）、磷酸化PI3K（phosphorylation-PI3K,p-PI3K）、磷酸化AKT（phosphorylation-AKT,p-AKT） mRNA和蛋白水平。 结果 与对照组比较,模型组大鼠血清炎症因子水平明显升高（P<0.05）;血糖、血清胰岛素、血肌酐和尿素氮及24 h尿蛋白水平升高（P<0.05）;细胞凋亡水平明显升高（P<0.05）;PI3K/AKT通路相关指标（PI3K、AKT）蛋白磷酸化水平减弱（P<0.05）; 而GQD处理显著改善上述异常。 结论 GQD能够改善糖尿病肾病大鼠的肾脏损伤,增强肾脏功能,抑制血清炎症因子的释放,其机制可能是通过增强PI3K/AKT信号通路实现的。     

复合抗氧化剂对局部荷瘤大鼠放疗肾脏损伤的保护作用

目的　探讨荷瘤大鼠6 0 Coγ射线局部辐射引起的肾脏氧化损伤以及复合抗氧化剂的保护作用。方法　采用Walker 2 5 6肿瘤细胞株接种大鼠皮下 ,得到实体瘤 ,摘除实体瘤分割成小块植入大鼠的右后腿皮下 ,制成大鼠荷瘤模型 ,将荷瘤大鼠随机分成 3组 ,分别为肿瘤模型组、单纯放疗组和抗氧化剂保护组 ,同时选取正常大鼠作为阴性对照组。抗氧化剂保护组每日给予复合抗氧化剂灌胃 ,分次对单纯放疗组和抗氧化剂保护组的荷瘤大鼠进行6 0 Coγ射线局部照射 4次 ,每次间隔 1周 ,累计剂量为 4 7Gy ,最后一次照射后 7d ,解剖大鼠 ,取肾脏制成组织匀浆 ,分别检测丙二醛(MDA)、总超氧化物歧化酶 (SOD)和总抗氧化力 (TAC)。结果　与阴性组相比单纯放疗组的MDA含量显著升高 (P <0 0 1,P <0 0 1) ,抗氧化剂保护组MDA较单纯放疗组显著降低 (P <0 0 5 )。单纯放疗组SOD活性和TAC显著低于非照射组 (P <0 0 1,P <0 0 1) ,而抗氧化剂保护组SOD和TAC显著高于单纯放疗组 (P <0 0 1,P <0 0 1)。结论　6 0 Coγ射线局部放疗可以引起肾脏的氧化损伤 ,高效的复合抗氧化剂可以起到有效的保护作用。