低强度脉冲电磁场对大鼠骨质疏松的影响

目的：观察低强度脉冲电磁场（pulsed electromagnetic fields，PEMFs）对去卵巢诱导骨质疏松症的大鼠生化指标和骨应力的影响。方法：雌性SD大鼠30只，随机等分为3组（n=10），分别为假手术组（Sham）、骨质疏松模型组（Model）、脉冲电磁场照射组（PEMFs）。经适应4wk后，在25mg·Kg^-1戊巴比妥钠腹腔麻醉下，Model组和PEMFs组摘除双侧卵巢．Sham组找到但不切除卵巢。各实验组均在相同环境下饲养，模型制备4wk后开始治疗，由GZY型低强度低频率脉冲电磁场发生仪产生低频脉冲磁场，根据实验要求，我们使用亥姆霍兹线圈形成均匀磁场，PEMFs组经照射刺激治疗，频率14．3Hz，场强2Gs．日照8h。Model组和Sham组正常饲养。治疗8wk后，对各组大鼠血清、尿液中ALP和Ca以及骨应力进行检测。结果：（1）ALP、Ca检测结果：与Model组相比，PEMFs组ALP值、Ca值差异均有统计学意义（P〈0．05）。其中，血清中ALP值，Model组为（275．16±228，57），PEMFs组为（179．30±87．68）；Ca值，Model组为（2，66±0，13），PEMFs组为（2．52±0．05）。（2）骨应力检测结果：Model组为（923．60±34．15Pa），PEMFs组为（1152．85±118，20Pa），组间差异有统计学意义（P〈0．05）。结论：研究发现，PEMFs对于促进骨重建、提高Ca吸收和骨应力恢复具有积极作用。     

Effect of biphenyl dimethyl dicarboxylate on the humoral immunosuppression by ethanol

The present study was undertaken to investigate the effect of biphenyl dimethyl dicarboxylate (PMC) on the humoral immunosuppression by ethanol (EtOH) in ICR mice. PMC at a dose of 6 mg/kg was orally administered to mice daily for 28 consecutive days, and the control mice were given vehicle. Mice treated with EtOH were given freely with 20% EtOH instead of water. The results of this study are summarized as follows; a gain of body weight and the relative weights of spleen and liver were significantly increased by combination of PMC and EtOH, as compared with those in mice treated with EtOH alone. Splenic plaque forming cells (PFC) and hemagglutination (HA) titers to sheep red blood cells (SRBC), and the secondary IgG antibody response to bovine serum albumin (BSA) were decreased by the treatment of EtOH alone, then restored to normal level by PMC treatment. The elevations of serum glutamic-pyruvic transaminase (S-GPT) and total protein levels caused by EtOH were reduced to normal level by the combination of PMC and EtOH. In addition, lower serum albumin and A/G ratio were also increased to normal level. These findings indicate that PMC has a protective effect against EtOH-induced humoral immunosuppression.     

Chitinases and chitinase-like proteins in T(H)2 inflammation and asthma

Chitin is the second most abundant biopolymer in nature, where it protects crustaceans, parasites, fungi, and other pathogens from the adverse effects of their environments, hosts, or both. Because chitin does not exist in mammals, it had been assumed that the chitinases that degrade it are also restricted to lower life forms. However, chitinases and chitinase-like proteins have recently been noted in mice and human subjects. The prototypic chitinase, acidic mammalian chitinase, was also noted to be induced during T(H)2 inflammation through an IL-13-dependent mechanism. It was also shown to play an important role in the pathogenesis of T(H)2 inflammation and IL-13 effector pathway activation and demonstrated to be expressed in an exaggerated fashion in human asthmatic tissues. The finding that chitinases contribute to host anti-parasite responses and asthmatic T(H)2 inflammation support the concept that asthma might be a parasite-independent anti-parasite response.     

Age-dependent DNA methylation changes in the ITGAL (CD11a) promoter

DNA methylation patterns change with age in a complex fashion, typically with an overall decrease in genomic deoxymethylcytosine (d(m)C) content, but with local increases in some promoters that contain GC-rich sequences known as CpG islands. While the consequences of age-dependent CpG island methylation have recently been studied in organs such as the colon, less is known about the functional significance of the progressive hypomethylation of promoters lacking CpG islands, and the significance of age-dependent changes in T cell DNA methylation is completely unexplored. We asked if age-dependent DNA hypomethylation might contribute to overexpression of the T cell ITGAL gene, which encodes CD11a, a subunit of LFA-1. CD11a mRNA increased with age as well as with experimentally induced DNA hypomethylation. This increase correlated with hypomethylation of sequences flanking the ITGAL promoter in vitro and in aging. 'Patch' methylation of the region suppressed promoter function. DNA methyltransferases 1 and 3a also decreased with aging. These results indicate that hypomethylation of regions flanking the ITGAL promoter may increase CD11a expression, and suggest that age-dependent hypomethylation of promoters lacking CpG islands, perhaps due to decreased DNA methyltransferase expression, may be one mechanism contributing to increased T cell gene expression with aging.     

远端蒂腓肠神经营养血管皮瓣与肌皮瓣的临床应用与改进

目的:报道应用远端蒂腓肠神经营养血管皮瓣,肌皮瓣修复小腿下段及足踝部软组织缺损的可行性安全性和临床效果。方法:对42例以远端蒂腓肠神经营养血管(肌)皮瓣修复小腿下段及足踝部不同原因所致软组织缺损病例进行总结分析。本组男36例,女6例;年龄最大75岁、最小6岁;皮瓣最大面积17.0cm×15.0cm,最小6.0cm×5.0cm,其中12例皮瓣面积在10.0cm×10.0cm以上;6例设计为肌皮瓣(腓肠肌外侧头),肌瓣最大为10.0cm×7.0cm×2.0cm,最小为6.0cm×5.0cm×1.0cm。结果:所有病例术后皆出现不同程度的皮瓣肿胀,暗道较明道者明显。2例大皮瓣经行小隐静脉远端结扎仍出现肿胀、色暗,皮瓣近侧1/3坏死。皮瓣边缘坏死3例,换药治愈。部分坏死需行植皮者3例。36例术后伤口I期愈合,骨外露软件组织缺损覆盖修复满意,6例II期愈合,其中糖尿病,地中海贫血各一例。结论:(1)远端蒂腓肠神经营养血管皮瓣转位修复小腿下1/3及足踝部缺损创面,极有临床实用价值;(2)设计切取腓肠神经营养血管肌皮瓣修复小腿及足踝填充感染创腔是可行的;(3)但对其皮瓣及所携带的肌瓣究竟切取多大面积是安全的、肌瓣的血运机理以及远端蒂筋膜皮瓣中小隐静脉干是否结扎,何处结扎等问题仍有待进一步研究。     

A rat model for radiation-induced proctitis

Radiation proctitis is a frequent acute complication encountered with pelvic irradiation. This study was aimed at establishing the optimal radiation dose for radiation-induced proctitis in rats. Female Wistar rats were used. The rectal specimens were examined morphologically at 5th and 10th day following 10-30 Gy irradiation in single fraction. With increasing dose, mucosal damage became worse, and there was a prominent reaction after > or =15 Gy. We selected 17.5 Gy as an optimal dose for radiation proctitis and examined specimens at day 1-14 and at week 4, 6, 8, and 12 after 17.5 Gy. The rectal mucosa revealed characteristic histological changes with time. An edema in lamina propria started as early as 1-2 days after irradiation and progressed into acute inflammation. On day 7 and 8, regeneration was observed with or without ulcer. Four weeks later, all regeneration processes have been completed with end result of either fibrosis or normal appearing mucosa. This study showed that the radiation injury of the rectum in rat develops in dose-dependent manner as it has reported in previous studies and suggested that 17.5 Gy in single fraction is the optimum dose to evaluate the protective effect of various medications for radiation proctitis in face of the clinical situation.     

慢性乙肝患者杀伤性免疫细胞功能的研究

通过对４４例病毒性肝炎患者Ｔ细胞亚群，ＮＫ细胞活性与ＬＡＫ细胞活性的观察，探讨了在慢性乙型肝炎病毒复制与非复制状态下的杀伤性细胞活性。结果表明：在乙肝病毒的高复制状态下，ＣＤ８＾＋细胞数增加，ＣＤ４＾＋／ＣＤ８＾＋比例显著下降；ＮＫ细胞活性与ＬＡＫ细胞活性也明显低下，且在ＨＢｅＡｇ与ＨＢＶＤＮＡ阳性组中，ＮＫ活性与ＬＡＫ活性的改变与ＨＢｅＡｇ的Ｐ／Ｎ值变化呈显著负相关，而ＮＫ活性与ＬＡＫ活性变化则     

Negative pressure effects during the isothermal crystallization of isotactic poly(propylene) studied by light and atomic force microscopy

The formation of holes during the late stage of the isothermal crystallization in thin films of isotactic poly(propylene) between two cover glasses was observed by light microscopy and atomic force microscopy. This behavior can be described consistently by the well-known negative pressure effect. Light microscopy reveals the simultaneous and sudden occurrence of a large number of small holes at the liquid-solid interface after the liquid in front of the spherulites is completely confined by other spherulites for a certain time interval. In exceptional cases only a few holes appear and finally large cavities are formed. Atomic force microscopy measurements carried out in the height mode are able to prove the hole formation in front of the spherulites. Furthermore, a substantial thinning of the two-dimensional spherulites in thin films can be observed prior to the hole formation.