Induction of radioprotective peroxiredoxin-I by ionizing irradiation

Results of this study indicate a radioprotective effect of peroxiredoxin-I. Peroxiredoxin-I is an antioxidant that scavenges hydroperoxides, whereas reactive oxygen species are the main mediators of ionizing radiation toxicity. We hypothesized that peroxiredoxin-I might be induced by cellular exposure to radiation and act to protect them against its cytotoxic effects. Western blot and Northern blot analyses were used to assess peroxiredoxin-I protein and mRNA expression. Rat C6 glioma cells were engineered to overexpress sense or antisense human peroxiredoxin-I using retroviral vectors. Clonogenic cell survival was used to assess radiosensitivities of the engineered cells. Ionizing radiation induced peroxiredoxin-I protein and mRNA expression in human HT29 colon cancer and rat C6 glioma cells in a dose- and time-dependent manner over a 24 hr period. To determine the effect of peroxiredoxin-I on radiation responses, C6 glioma cells were engineered to overexpress sense or antisense human peroxiredoxin-I. In clonogenic assays, cells overexpressing peroxiredoxin-I were more radioresistant. Cells transduced with antisense peroxiredoxin-I were marginally more sensitive to radiation toxicity. Irradiation can induce peroxiredoxin-I expression, and the increased peroxiredoxin-I may protect cells from further radiation damage. These results suggest that protection by peroxiredoxin-I may play an important role in the survival of glioma and colon cancer cells in patients undergoing radiation therapy.     

A modified live Mycoplasma gallisepticum vaccine to protect chickens from respiratory disease

The aim of this study was to assess the efficacy of a modified live Mycoplasma gallisepticum vaccine (GT5) for the protection of chickens against infection and respiratory disease. GT5 was constructed by the reconstitution of the avirulent high passage R (R(high)) strain with the gene encoding the major cytadhesin GapA. GT5 expressed GapA on its surface yet retained the phenotypic characteristics of the parental R(high) strain. Birds vaccinated with GT5 were protected upon challenge with the virulent low passage R (R(low)) strain as evidenced by a complete absence of tracheal lesions 2 and 4 weeks post-challenge, in contrast to sham immunized/challenged control birds. Modest amounts of IgG, and little, if any secretory IgA or IgM anti-M. gallisepticum were found in tracheal washings following vaccination. However, copious amounts of specific IgA were found following challenge, especially in sham immunized birds. This suggests that the tracheal IgG elicited by GT5 vaccination may have been responsible for blocking the initial colonization of R(low), thereby resulting in protection.     

Inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters by tea and curcumin

Tea is one of the most popular beverages consumed in the world. Curcumin, the major yellow pigment in turmeric, is used widely as a spice and food-coloring agent. In this study, we studied the effects of tea and curcumin on 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinogenesis in hamsters. DMBA solution (0.5% in mineral oil, 0.1 ml) was applied topically to the left cheek pouch of male Syrian golden hamsters 3 times/week for 6 weeks. Two days after the last treatment of DMBA, the animals received green tea (6 mg tea solids/ml) as drinking fluid, or 10 mmol curcumin applied topically 3 times/week, or the combination of green tea and curcumin treatment, or no treatment for 18 weeks. The combination of tea and curcumin significantly decreased the oral visible tumor incidence from 92.3% (24/26) to 69.2% (18/26) and the squamous cell carcinoma (SCC) incidence from 76.9% (20/26) to 42.3% (11/26). The combination of tea and curcumin also decreased the number of visible tumors and the tumor volume by 52.4 and 69.8%, as well as the numbers of SCC, dysplasic lesions and papillomas by 62.0, 37.5 and 48.7%, respectively. Green tea or curcumin treatment decreased the number of visible tumors by 35.1 or 39.6%, the tumor volume by 41.6 or 61.3% and the number of SCC by 53.3 or 51.3%, respectively. Green tea also decreased the number of dysplasic lesions. Curcumin also significantly decreased the SCC incidence. Tea and curcumin, singly or in combination, decreased the proliferation index in hyperplasia, dysplasia and papillomas. Only the combination treatment decreased the proliferation index in SCC. Tea alone and in combination with curcumin significantly increased the apoptotic index in dysplasia and SCC. Curcumin, alone and in combination with tea, significantly inhibited the angiogenesis in papilloma and SCC. The results suggested that green tea and curcumin had inhibitory effects against oral carcinogenesis at the post-initiation stage and such inhibition may be related to the suppression of cell proliferation, induction of apoptosis and inhibition of angiogenesis.     

Neuroprotective effects of ginseng total saponin and ginsenosides Rb1 and Rg1 on spinal cord neurons in vitro

Spinal cord injury is a major cause of disability and results in many serious physical, psychological, and social difficulties. Numerous studies have shown that traumatic spinal cord injuries (SCI) lead to neuronal loss and axonal degeneration in and around the injury site that cause partial disability or complete paralysis. An important strategy in the treatment of SCI is to promote neuron survival and axon outgrowth, making possible the recovery of neural connections. Using an in vitro survival assay, we have identified ginsenosides Rb1 and Rg1, extracted from ginseng root (Panax ginseng C. A. Meyer), as efficient neuroprotective agents for spinal cord neurons. These compounds protect spinal neurons from excitotoxicity induced by glutamate and kainic acid, as well as oxidative stress induced by H(2)O(2). The neuroprotective effects are dose-dependent. The optimal doses are 20-40 microM for ginsenosides Rb1 and Rg1. The effects are specific for Rb1 and Rg1, since a third ginsenoside, Re, did not exhibit any activity. Ginseng has been used for thousands of years in the treatment of neurological disorders and other diseases in Asia. Ginsenosides Rb1 and Rg1 represent potentially effective therapeutic agents for spinal cord injuries.     

Granuloma gluteale adultorum associated with use of topical benzocaine preparations: case report and literature review

Background: Granuloma gluteale infantum is a skin disorder of controversial etiology manifested clinically by oval reddish-purple granulomatous nodules on the gluteal surfaces and groin areas of infants. Similar granulomas are noted in adults and the elderly and are referred to as granuloma gluteale adultorum and diaper area granuloma of the aged, respectively. Occlusion from diapers, paper napkins, plastic pants, detergents, starch, powder, halogenated steroids, candidal infection, and urine and feces are postulated as possible etiologies. Objective: We report a case of a 40-year-old woman presenting with a 3-year history of multiple, painful, closely set, red-purple, oval, smooth, firm papules and nodules in the genitocrural area. The development of the lesions was associated with prolonged use of topical benzocaine. Histology of the lesions was consistent with granuloma gluteale infantum. Gram stain and culture of representative tissue did not demonstrate bacterial or fungal organisms. The lesions significantly improved with discontinuation of topical benzocaine. Patch testing of skin to determine allergic contact hypersensitivity to benzocaine was negative. Conclusion: We propose that topical benzocaine preparations may play a role in the pathogenesis of granuloma gluteale adultorum, independent of contact sensitization to benzocaine.     

Topical applications of caffeine or (-)-epigallocatechin gallate (EGCG) inhibit carcinogenesis and selectively increase apoptosis in UVB-induced skin tumors in mice

SKH-1 hairless mice were irradiated with ultraviolet B (UVB) twice weekly for 20 weeks. These tumor-free mice, which had a high risk of developing skin tumors during the next several months, were then treated topically with caffeine (6.2 micromol) or (-)-epigallocatechin gallate (EGCG; 6.5 micromol) once a day 5 days a week for 18 weeks in the absence of further treatment with UVB. Topical applications of caffeine to these mice decreased the number of nonmalignant and malignant skin tumors per mouse by 44% and 72%, respectively. Topical applications of EGCG decreased the number of nonmalignant and malignant tumors per mouse by 55% and 66%, respectively. Immunohistochemical analysis showed that topical applications of caffeine or EGCG increased apoptosis as measured by the number of caspase 3-positive cells in nonmalignant skin tumors by 87% or 72%, respectively, and in squamous cell carcinomas by 92% or 56%, respectively, but there was no effect on apoptosis in nontumor areas of the epidermis. Topical applications of caffeine or EGCG had a small inhibitory effect on proliferation in nonmalignant tumors as measured by BrdUrd labeling (16-22%), and there was also a similar, but nonsignificant, inhibitory effect on proliferation in malignant tumors. The results suggest a need for further studies to determine whether topical applications of caffeine or EGCG can inhibit sunlight-induced skin cancer in humans.     

Association study of the estrogen receptor polymorphisms with tardive dyskinesia in schizophrenia

Tardive dyskinesia (TD) is an involuntary movement disorder induced by long-term antipsychotic treatments. Estrogen is suggested to modulate dopamine receptors in the central nervous system and may decrease the incidence and/or relieve the symptoms of TD. In this study, 118 schizophrenia patients with antipsychotic-induced TD and 128 sex- and age-matched non-TD schizophrenia patients were recruited. All patients were assessed by the Abnormal Involuntary Movement Scale and genotyped for the polymorphisms of estrogen receptor-alpha gene (ESR 1). There was a marginal association of the genotypes determined by PVU II between TD and non-TD patients (p = 0.057), but not of the genotypes determined by XBA I (p = 0.896). However, further studies on other polymorphisms of ESR 1 or other estrogen receptors are necessary to clarify the role of estrogen in the pathogenesis of TD.     

标准化脐血筛选方法在脐血库中的应用

目的对广州脐血库脐血筛选结果进行回顾性分析,建立脐血筛选的标准化方法和探讨其在脐血库建立中的意义。方法对脐血供者从产妇或其旁系亲属医学病史到新生儿随访实行四步筛选程序,筛选内容包括遗传、血液病等病史、脐血采集量、总有核细胞数、细胞活率、凝块和病原学感染等。结果1998年6月至2004年12月共分娩27404例、采集脐血8350份,占总分娩量比率为30.47%。合格4085份,合格率为48.92%;废弃脐血4265份(占51.08%),废弃的主要原因依次为脐血采集量<60ml、血凝块、总有核细胞数、活率低。检疫期共废弃脐血46份(占1.11%);其中检出细菌阳性19例(占41.30%),巨细胞病毒抗体(CMV-lgM)阳性20例(占43.48%)。新生儿随访共发现15例异常,占0.37%。4085份脐血总有核细胞数平均为1.21×109,根据脐血有核细胞输入量3.7×107/kg体重计算,平均能适合32.7kg的受者移植;而按2.0×107/kg体重计算平均能适合60.5kg的受者移植。104例脐血移植中72例获得植入(69.2%)。结论脐血供者的标准化筛选方法可以排除可能存在的血液性、遗传性和传染性等疾病,确保移植用脐血的安全;并能为脐血库的建立节约采集、处理、冻存等费用,提高库存脐血的有效利用率。     

腹腔镜在地中海贫血微创脾切除术中的应用

目的探讨腹腔镜在地中海贫血微创脾切除术中的应用。方法应用腹腔镜对中间型α地贫(HbH病)13例,重型β地贫3例,β地贫+异常HbEl例共17例进行微创脾切除术,占同期地贫脾切除术的28.33%。结果均取得较好的手术效果。结论与传统脾切除手术比较,腹腔镜微创脾切除术创口小,损伤轻,出血少,恢复快,住院时间短。     

间歇性张应力对牙周膜成纤维细胞蛋白合成功能的影响

目的:利用四点弯曲细胞力学加载仪对人牙周膜成纤维细胞(humanPeriodontalFibroblastCells,hP DLFs)施加间歇性机械张力,观察细胞内蛋白合成总量的变化,为深入研究机械力介导的牙周组织改建过程奠定一 定的实验基础。方法:体外培养hPDLFs。取第4～7代细胞,分别设计3个加力组,各时间点均增多设计对照组,经 过2,4,6h后收集细胞。考马斯亮蓝微板法测定细胞内蛋白总量。结果:各加力组细胞蛋白合成均增加,增幅与 力值呈相反关系(P<0.01),达峰值后迅速回落。结论:蛋白合成对机械力变化有一较宽的适应范围,提示除细胞 周期影响外,可能还有多种机制参与调控细胞内蛋白合成,同时也反应了蛋白定量只是反应细胞功能的粗略指标。