低剂量超声预辐照对高强度聚焦超声消融兔肝VX2瘤的增效研究

目的探讨低剂量超声预辐照对高强度聚焦超声(High-intensity Focused Ultrasound,HIFU)消融兔肝VX2瘤的增效作用及其对残留肿瘤生长的影响.方法52只荷瘤免于接种后20天按随机数字表法分为低剂量超声预辐照组(A组)22只,单纯HIFU组(B组)20只,对照组(C组)10只.A组首先接受声...     

Effect of bromocriptine on the "prolactin-like cell" of Nectophrynoides occidentalis (Amphibia, viviparous Anura): optical and electronic microscopical studies]

Bromocriptin has an effect on prolactin-like cells of Nectophryno?des occidentalis. 16 days after delivery, these cells are fully active in normal animals. Retention of secretory granules and myelinic formations have been observed in the prolactin-like cells of females treated by CB 154.     

参附动员内皮祖细胞改善肝移植大鼠缺血再灌注损伤

目的 观察参附注射液对发生肝移植缺血再灌注损伤(IRI)的大鼠外周血中内源性内皮祖细胞(EPCs)的作用以及此作用对其肝脏功能的影响.方法 100只雌性SD大鼠随机分为3组:原位肝移植(0LT)+参附(SF)组,OLT对照组,假手术组.3组均于术后第1、4、7天取血液标本流式细胞术检测外周血内皮祖细胞数量及生化分析仪检测肝功能,观察胆汁分泌量,并取肝组织标本进行HE染色形态学观察肝脏损伤.结果 OLT+ SF组外周血中的EPCs在术后1天开始增加,第4天达到高峰并持续至第7天;并且在3个时间点上,OLT+ SF组的外周血EPCs数量较其它两组明显增加,具有统计学意义(p ＜0.01);OLT+ SF组在用药后IRI有所改善,较对照组有统计学差异(p＜0.05).结论 参附注射液能显著动员大鼠骨髓中的内源性EPCs进入外周血,修复损伤的肝血窦,改善微循环,进而改善肝移植术后的缺血再灌注损伤.     

In vivo effect of sodium valproate on mouse liver

The in vivo effect of sodium valproate (SV) on the activity of uridine diphosphate glucuronosyltransferase (UDP-GT) and hepatotoxicity in the mouse liver was studied. Mice were injected intraperitoneally (IP) with SV at doses varying from 50 to 800 mg/kg per day, for six consecutive days (dose-response group) or at a standard dose of 300 mg/g per day for 2-10 days (time-response group), whereas the controls were injected with normal saline. Valproic acid levels had a positive correlation to the dose (P < 0.001) and duration of drug administration (P = 0.006). A gradual increase in UDP-GT activity was observed in doses of up to approximately 400 mg/kg per day, whereas in higher doses the enzyme activity gradually decreased. The time course of UDP-GT activity at the standard dose of 300 mg/kg per day increased progressively, with a maximum up to the sixth day and then had a gradual reduction. Hepatic necrosis (which was unrelated to the dose or the duration of drug administration) was found in 13% of the SV-treated animals and in none of the controls. We conclude that at an optimal dose (300-400 mg/kg per day) and at a time course of 6 days, SV causes liver UDP-GT induction, whereas in higher doses and longer duration of administration, UDP-GT activity is gradually reduced. SV also causes hepatotoxicity unrelated to dose and time course.     

Reversible impairment of hepatobiliary function induced by streptozotocin in the rat

The effect of streptozotocin (SZ) on hepatobiliary function was studied in rats on the 1st, 7th and 15th days of treatment. Serum glucose increased significantly on the 1st day, and then remained high. Bile flow, bile acids output and BSP biliary excretion were significantly decreased on the 1st day of treatment, whereas serum sorbitol dehydrogenase was increased. All the parameters tested apart from serum glucose tended to normalize with time. The results suggested a transient toxic effect of SZ on the hepatocyte.     

早期营养不良对SD大鼠海马AchE和ChAT表达的影响

目的探讨生命早期营养不良对21天雄性sD大鼠中枢AchE和ChAT的影响。方法从妊娠晚期到哺乳期末给予母鼠半量饲料,造成子鼠营养不良,取哺乳期末雄性子鼠脑海马组织进行测量。结果免疫组化结果示：实验组海马CA3区ChAT光密度低于对照组（P〈0．05）,在CA!区无差异（P〉0．05）;而两纽间CAl和CA3区AchE光密度均无差异（P〉0．05）;RT—PCR示：实验组海马ChAT、AchEmRNA少于对照组（P〈0．05）。结论早期营养不良能导致子鼠海马及中枢胆碱能系统发育障碍,可能会影响成年后大鼠学习记忆能力。     

Alopecia induced in young mice by exposure to excess dietary zinc

Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

Blood histamine and response of spleen cells to phytohemagglutinins during moderate magnesium deficiency in the rat]

Blood histamine and spleen cell stimulation index by PHA were determined in either magnesium deficient or control Rats. Between the 10th and 17th days of diet (hyperemia and dermatosis period), histaminemia was significantly higher in deficient animals (485 ng/ml) than in control ones (112 ng/ml), but at the 32nd day it came back to normal values. The mean spleen cell stimulation index by PHA was depressed in deficient animals mainly between the 10th and 17th day of the deficiency; 33% of control mean value. A negative correlation is found between histamine level and stimulation index.     

Alopecia induced in young mice by exposure to excess dietary zinc

Summary Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

早期母子隔离应激对大鼠学习记忆能力的影响

目的探讨早期母子隔离应激对幼鼠学习记忆能力的影响。方法30只SD新生大鼠用于实验,实验随机分成3组,正常对照纽、母子隔离15分钟纽、母子隔离3小时纽。在生后40天,三组大鼠进行Morris水迷宫及记录海马脑片长时程增强电位（LTP）实验。结果Morris水迷宫测试,与正常组比较母子隔离3h组大鼠寻找平台需要的潜伏期延长（P〈0．05）,而母子隔离15分钟组大鼠寻找平台需要的潜伏期与正常组比较则无明显变化（P〉0．05）;海马脑片长时程增强电位提示：正常对照组条件刺激（CS）前后fEPSP斜率变化率为：64．7±22．9％;母子隔离3h组为：35．3±14．2％,低于正常组（P〈0．01）;母子隔离15min组为：66．3±29．7％,与正常组比较无显著性意义（P〉0．05）。结论幼鼠生后早期过度的应激导致大鼠的学习记忆能力减弱。     

Regulation of estrogen "receptors" in mammary tumors: action of prolactin in vivo

The effect of prolactin on estradiol receptors was determined in cytosol of estrogen-dependent mammary tumors of Sprague Dawley rats. Tumors were induced with 20 mg dimethylbenzanthracene, rats were ovariectomized, and the rats showing regression in tumor weight were given 1 mg sheep or rat prolactin for 5 days. Receptors were separated by dextran-charcoal and analyzed by sucrose gradient. Prolactin, milk proteins, serum proteins, and 1-alpha-feto-proteins were excluded immunologically. The estradiol receptors resembled uterine receptors in affinity, specificity, sedimentation, and nuclear transfer under estradiol influence. Castration diminished receptor content exponentially 170 f moles to 16 f moles/mg protein within 10 days; prolactin increased the number of receptors to 87 f moles compared with 15 in controls. Affinity, cellular location, and uterine receptor content were unaffected. Sheep and rat prolactin acted similarly. These results justify hypophysectomy as therapy for certain estrogen-dependent breast tumors.     

Lack of effect of antioxidant therapy during renal ischemia and reperfusion in dogs

Acute ischemic renal failure is of great clinical importance because of its frequent occurrence and the high mortality it causes. Recent observations indicate that reperfusion has its own dangers because of oxygenderived free radicals. To study this problem, ischemia was evoked in dogs in one kidney, by clamping the left renal artery for 45 min. This was followed by a 90-min period of reperfusion when diuresis, GFR, PAH clearance and sodium and potassium excretion were studied. Besides a control group (n=6), the following treatment groups were investigated. Allopurinol (n=7): 50 mg/kg for two days p.o. and 50 mg/kg in physiological saline infusion during the experiment; a small dose of SOD (n=6): 0.5 mg/kg in infusion, started 1 min before reperfusion and given continuously for 10 min; and a high dose of SOD (n=7): 5 mg/kg as above. In the first 15 min following reperfusion, the renal functions significantly worsened in all groups. Later on, the renal functions gradually improved and in the last period after reperfusion, GFR in the ischemic kidney was 64%, cPAH 59%, diuresis 60% and sodium and potassium excretion were 65% and 76%, respectively, of the basal values in the control group.Treatment with free radical scavengers did not cause any considerable changes in the renal functions. In some respects, the worst results were observed with low-level SOD treatment (cPAH, diuresis, as well as sodium and potassium excretion).At the end of reperfusion, there was a significant drop in sodium excretion by the right (intact circulation) kidney of the treated animals.     

1Alpha,25-dihydroxyvitamin D3 inhibits hepatic chromosomal aberrations, DNA strand breaks and specific DNA adducts during rat hepatocarcinogenesis

The possible promoting effect of streptozotocin (STZ; 65 mg/kg body weight, intraperitoneal)-induced diabetes during 2-acetylaminofluorene (2-AAF; 0.04% in basal diet)-initiated hepatocarcinogenesis and modulatory effect of 1α,25-dihydroxyvitamin D₃ (VD₃; 0.3 μg/0.1 ml in propylene glycol, per os) were investigated by monitoring chromosomal aberrations (CAs), DNA strand breaks and specific DNA adducts in rat liver. VD₃ treatment (twice a week) was started 4 weeks before the 2-AAF regimen and continued throughout the study. Aberrant metaphase chromosomes were counted from the regenerating hepatocytes 15, 30 or 45 weeks after STZ injection, while DNA strand break and adduct assays were performed 45 days post-STZ treatment. Dietary exposure to 2-AAF elicited a substantial increase in CAs and elevated the extent of DNA strand breaks and formation of N-(deoxyguanosin-8-yl)-2-aminofluorene. A promoting effect of STZ was evident from CAs coupled with DNA strand break analysis. VD₃ treatment substantially reducted 2-AAF+STZ-induced CAs as well as DNA strand breaks and adducts. Thus, VD₃ appears to be effective in suppressing liver-specific early chromosomal as well as DNA damage during the process of rat hepatocarcinogenesis initiated with 2-AAF and promoted by STZ contributing to its promise as a cancer chemotherapeutic agent. Received 27 April 2001; accepted 22 May 2001     

Glutamine aminotransferase and glutamine aminohydrolase ratio as a possible test for antitumour compounds.

Three known antitumour drugs have been tested for their effect on the GAT/GNase ratio of Ehrlich Ascites cells and host plasma. It was observed that all these drugs had changed the ratio of the 2 types of glutaminases from below 1.0 to the normal value of 1.0, this was accompanied with an increase in the survival time of the tumour-bearing animals. There was, however, no effect on the plasma GAT/GNase ratio of normal animals in the presence of the 3 antitumour compounds tested.     

Reversible impairment of hepatobiliary function induced by streptozotocin in the rat

Summary The effect of streptozotocin (SZ) on hepatobiliary function was studied in rats on the 1st, 7th and 15th days of treatment. Serum glucose increased significantly on the 1st day, and then remained high. Bile flow, bile acids output and BSP biliary excretion were significantly decreased on the 1st day of treatment, whereas serum sorbitol dehydrogenase was increased. All the parameters tested apart from serum glucose tended to normalize with time. The results suggested a transient toxic effect of SZ on the hepatocyte.Acknowledgment. This study was supported by a Research Grant from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), República Argentina. Joaquín V. Rodriguez is gratefully acknowledged for doing the chromatographic analyses of sulfobromophthalein, José M. Pellegrino for performing bile acids determination, and Mr. Raúl A. Trbojevich for surgical assistance.     

Influence of sex on radioinduced changes in longevity: comparative sensitivity of 2 strains of Drosophila melanogaster]

Two strains of Drosophila were irradiated with 25 to 75 Krads of 60Co gamma rays at a dose rate of 1 000 rad/mm, on the fourth day of imaginal life. A radiosensitivity difference between the strains was observed. However, the influence of sex was similar in the two strains, the females being more sensitive than the males.     

Serologisch-hämatologische und immunologische Untersuchungen an winterschlafenden Fledermäusen (Myotis myotis S.)

Summary Antibody deficiency in hibernating bats (Myotis myotis S.) was shown by precipitin reaction. The-globulins in serum of hibernating bats decreased to one half of the normal value. There is significant leukopenia, lymphopenia and eosinopenia. Injected bovine albumin was completely removed within 9 days in active animals, in torpid animals only 1/25 was absorbed from the 6th to the 23rd day.     

NSA2在激光诱导的小鼠脉络膜新生血管模型中表达的时相性和定位研究

目的探讨NSA2在激光诱导的小鼠脉络膜新生血管（choroidal neovascularization，CNV）模型眼组织中的表达及其意义。方法532nm激光诱导C57BI/6J小鼠CNV模型。用CD31抗体标记血管内皮细胞的方法对CNV模型进行鉴定，采用RT-PCR和Western blotting方法检测正常对照组和光凝后1d、3d、5d、7d和14d组小鼠CNV中NSA2mRNA和蛋白表达的时间变化规律。取光凝后7d组小鼠眼做眼球冰冻切片，用免疫荧光染色方法对NSA2蛋白在CNV中的表达进行定位研究。结果NSA2在正常小鼠的视网膜脉络膜组织中弱表达。视网膜光凝后，NSA2mRNA和蛋白在CNV模型眼组织中的表达有明显的时间变化规律，光凝后l～3d逐渐增强，3d达高峰，之后逐渐减弱，14d时仍稍高于正常水平。同时发现NSA2在CNV区域表达较强。结论NSA2在CNV形成早期表达上调，具有明显的时间变化规律，且在CNV区域有较强的表达，因此我们推断NSA2可能在CNV形成这一病理过程中起着重要作用。     

Action of diphenylhydantoin on chromosomes

The effect of diphenyl hydantoin, (DPH) a nonbarbituate anticonvulsant drug, on chromosomes and fertility was tested in cultured human lymphocytes, mouse fertility, and rat maternal marrow chromosomes and fetal development. Whole human blood from 5 male and 5 female subjects was cultured for 68 hours with phytohemagglutinin, then incubated for 2 hours in isotonic salts with .05-.3 mg per ml DPH, .02 mcg per ml colchicine, or .4 mg per ml sodium diethylbarbiturate. The mean number of metaphases per 1000 stimulated cells was 10.0 in controls, 40.3 with colchicine, 27.9 with diethylbarbiturate, and 30.5 with .25 mg DPH per ml. Both diphenylbarbiturate and DPH produced linear dose effect curves. These results were demonstrated not to be due to urea, since there were no differences in urea content, with a 2 hour urease micromethod. Mouse fertility was totally inhibited in 6 virgin mice given .1mg DPH daily for 10 days compared to 41 pups both of 6 control mice. In 6 pregnant rats given 25 mg DPH per 100 gm/orally 4 times daily for 2 days on gestation Days 7 and 8, there were 5 rats with all fetuses resorbed and 1 rat with 3 living and several resorptions. 6 controls had 6-14 normal fetuses each. 50 metaphase plates from each rat's femoral marrow and each fetus were examined 2 hous after injecting .3 mg colchicine per 100 gm. 30% of the metaphase cells from treated females and fetuses showed strongly contracted chromosomes and reduced number os "pulverized" chromosomes. These phenomena may have been due to inhibition by DPH of folic acid metabolism which is involved in purine synthesis.     

The effects in vivo of some sex hormones on the growth of tibias of normal and chondrodystrophic (Creeper) chick embryos]

Various sex hormones (testosterone, oestradiol, dehydroepiandrosterone), in the form of suspensions in oil, are injected into the allantois of normal and chondrodystrophic (Creeper) chick embryos of 6 days 1/2 incubation. Observations made on each of the phenotypes on the 12th day of incubation show that oil injected alone causes a significant decrease in the dry weight of the tibiae. This inhibitory effect is partially abolished when the oil is injected together with the sex hormones, testosterone being the most effective.