葛根对小白鼠免疫功能的影响

从免疫学方面探讨中药葛根的强身健体作用。方法 :用 10 0 %葛根水浸出液定期给小鼠灌胃 ,然后检测小鼠抗体产生能力、淋巴细胞转化率、巨噬细胞吞噬的功能。结果 :用药组小白鼠以上免疫学指标均有显著增强作用 ,与对照组相比有非常显著性差异 (P <0 .0 1)。未见有副作用。结论 :口服葛根可明显增强机体免疫功能。     

慢性氟中毒对小鼠切牙胚内釉上皮TGF-beta1表达的影响

目的 :观察慢性氟中毒对小鼠切牙胚内釉上皮表达 TGF- beta1的影响 ,探讨TGF- beta1在氟牙症发生机制中的作用。方法 :给小鼠分别喂以含 0、5 0、1 0 0 ppm Na F的饮水 ,6周后免疫组化观察结果。结果 :图像分析显示加氟组 TGF- beta1的表达水平低于空白组。结论 :氟可能通过抑制 TGF- beta1的表达干扰内釉上皮的分化和基质分泌 ,导致氟牙症的发生。     

In vitro determination of lung airway compliance in small animals

An in vitro method for obtaining pressure/volume curves from the lungs of small animals is described. The excised lungs were inflated and deflated with saline or air by a motor-driven syringe controlled by a microcomputer. The computer was programmed to display the curves in real time, correcting when necessary for the compressibility of air in the system. Volume compliance (K=dV/dP×1/V) was calculated by differentiating a polynomial fitted to the measured pressure/volume points. Repeatable curves were obtained from mice aged 24h (body weight 1·3±0·14g (SD), residual lung volume 8·43±1·5 μl (SD). A nonlinear decrease in differential compliance (K=dV/dP×1/V) with increasing strain was observed while the ratio K_saline/K_air increased from 2·5 to 10 over the range of strains investigated (ε=1–5). The relative surface tension (calculated from the difference between the pressures required to inflate the air and saline-filled organs to a given volume) increased exponentially with increasing volume. We conclude that it is now possible to obtain reproducible pressure/volume curves for lungs with a residual volume of less than 10 μl, from animals weighing approximately 1·5 g and, from these curves, estimate airway compliance and surface tension.     

Activity of the hypothalamic-pituitary-adrenal axis in mice selected for left- or right-handedness

Asymmetry in brain modulation of the immune system has been previously described. In mice, paw preference has been shown to be associated with immune reactivity but the mechanisms involved in such an association are not yet known. The autonomic nervous system and the neuroendocrine system are considered as major candidates for neural influences on the immune system. In the present study, the activity of the hypothalamic-pituitary-adrenal (HPA) axis of adult female mice selected for paw preference (left-handers vs. right-handers) was assessed by measuring both adrenocorticotropic hormone (ACTH) and corticosterone plasma levels, as well as the in vitro responses of hypothalamus and adrenocortical cells to various hormone releasing stimuli. The results reported here showed no difference in the activity of the HPA axis between left- and right-handed mice, suggesting that this neuroendocrine axis is not implicated in the association between functional brain asymmetry and immune reactivity. However, our results do not exclude the possibility that the HPA axis could play a role in such an association under other circumstances, such as during development or stressful situations.     

Behavioral dissociation of anterodorsal and posteroventral hippocampus by subseizure stimulation in mice

BALB/c mice were bilaterally implanted with bipolar electrodes either in anterodorsal (ADH) or posteroventral hippocampus (PVH) in order to compare the effects of postsession electrical stimulation on memory processes. For each experiment, 30 s after the end of the first session, the animals were stimulated during 80 s. For both hippocampal regions, the stimulation intensity was half of the afterdischarge threshold value. Control groups were naive, ADH and PVH implanted non-stimulated animals. Different appetitive and aversive tasks were used. Subseizure stimulation never created a deficit. Depending on the region of the hippocampus stimulated and on the learning task, a retention enhancement was eventually observed. These data are in agreement with the involvement of hippocampus in initial stages of memory consolidation. Further, the subseizure stimulation permitted a functional dissociation between the two hippocampal regions. Both regions seemed involved in the integration of information, but the anterodorsal part would be rather related to behavioral inhibition, while the posteroventral part would have the capacity to induce an arousal state allowing behavioral flexibility.     

低强度超短波对小鼠体质及智力的影响

本实验探讨了低强度超短波对小鼠连续三代辐射,对学习、记忆、拉力、运动耐力和周围血象的影响。用81MHz,10～12V/m 的超短波进行辐射,每天辐射2小时,每周6天。结果表明:经过超短波辐射的各代小鼠与对照组相比,学习能力、记忆能力、拉力及运动耐力有明显的降低,且运动耐力有进行性降低的趋势,而经过辐射的三代小鼠红细胞、血红蛋白含量及白细胞数均明显增高,每个红细胞的血红蛋白含量则低于对照组。     

钳夹法建立小鼠胆管缺血狭窄模型

目的 探讨建立小鼠胆管缺血狭窄模型的方法。方法 先探索昆明小白鼠胆管缺血最适时间点，尔后选取昆明小白鼠随机分为正常对照组和模型组，每组10只，模型组用2枚显微血管夹（宽0．1cm）夹闭一段长约0．4cm的胆总管90min，正常对照组仅暴露胆管未夹闭。术后21d两组小鼠均行胆道造影，下腔静脉取血，分离血清进行总胆红素及谷丙转氨酶含量测定，取胆总管和肝组织石蜡包埋，HE染色，观察病理改变。结果 模型组钳夹部位以上胆管明显扩张，胆管造影示胆管扩张，壁光滑，狭窄部位以下胆管未显影；正常对照组肝内胆管未显影，肝外胆管显影。血清总胆红素模型组高于正常对照组5倍以上，谷丙转氨酶模型组显著高于正常对照组6倍以上。病理示缺血胆管管腔变小或闭塞，胆管黏膜坏死脱落，管壁纤维化增厚；病变部位以上胆管管腔增大，管壁变薄。肝脏可见少量肝细胞坏死，炎性细胞浸润。结论 血管夹钳闭缺血法成功地建立了小鼠胆管缺血狭窄模型，为肝移植术后胆管缺血狭窄并发症发生机制的实验研究和临床研究提供可靠的实验方法。     

Pathological effects on mice by gambierol, possibly one of the ciguatera toxins

Gambierol was isolated from Gambierdiscus toxicus, which causes ciguatera fish poisoning. The acute toxicological effects induced in mice by synthesized gambierol were studied. The lethal doses were about 80 μg/kg by i.p. and i.v., and 150 μg/kg by p.o. The main injury by this toxin was observed in the lung, and secondary in the heart, resulting in systemic congestion. Another toxic effect was seen in the stomach, inducing hypersecretion and ulceration. With survival from the severe stage during the initial 3 h, recovery was favorable, especially after 4 days. Additional effects were not evident during 1-week post-administration observation.     

Maintenance of Androgen-, Glucocorticoid- or Estrogen-responsive Growth in Shionogi Carcinoma 115 Subline Sustained in Castrated Mice with High Dose of Estrogen for 30 Generations (3 Years)

Shionogi carcinoma 115 (SC115), an androgen-dependent mouse mammary tumor, rapidly loses its androgen responsiveness after androgen withdrawal. The growth of this tumor can also be stimulated by high doses of estrogen or glucocorticoid. In the present study, the maintenance of hormone-responsive growth of SC115 tumors with a high dose of estrogen was examined in castrated male mice using an SCI 15 subline obtained by serial transplantations of SCI 15 tumors in estrogen-treated castrated mice for 3 years (30 generations) (subline E₂). Seed tumors from both SC115 and subline E₂ could rapidly grow in castrated mice given daily injections of testosterone propionate (TP), 17β-estradiol (E₂), or dexamethasone (Dex) (100 μg/mouse/day) but not in those given vehicle alone. Although SCI 15 and subline-E₂ tumors grown with TP or Dex showed temporary regression after steroid withdrawal, the tumors grown with E₂ did not show such temporary regression. The TP-, E₂-, or Dex-induced growth of subline-E₂ tumors was almost the same as that of the original SCI 15 tumors. However, responsiveness to androgen, estrogen or glucocorticoid of both tumors disappeared within one passage in steroid-depleted castrated mice. The present findings demonstrate that the loss of responsiveness to androgen as well as to high doses of estrogen or glucocorticoid of SCI 15 tumors can be prevented in castrated mice not only with androgen but also with high doses of estrogen.     

Serotonin reduction in the mouse neostriatum during hyperthermia-induced convulsions studied by immunohistochemistry

Summary Changes occurring in serotonin neurons during hyperthermia-induced convulsions were examined by means of a modified immunohistochemical method. All mice (8–12 weeks of age) exposed to the temperature of 50°C had convulsions, showing a generalized tonic and/or clonic pattern. Immediately after the convulsions, the animals were perfused transcardially with a fixative. A significant reduction in serotonin immunoreactivity was observed in the neostratum (caudate-putamen complex) of the mice which had hyperthermia-induced seizures, while the serotonin immunoreactivity remained unchanged in the neocortex and paleostriatum. These results suggest that serotonin may be an important mediator in the mechanism of hyperthermia-induced convulsions or that the susceptibility of serotonin neurons to a convulsive state is greatest in the neostriatum.Supported in part by Grant No. 86-05 from the National Center for Nervous, Mental and Muscular Disorders (NCNMMD) of the Ministry of Health and Welfare and Grant No. 62770677 from the Ministry of Education, Science and Culture, Japan