Targeted gene disruption of murine CD7

CD7 is a 40 kDa type I transmembrane glycoprotein member of the Ig superfamily. CD7 is a marker of mature human T cells and NK cells, and is expressed early in their development. Cross-linking CD7 positively modulates T cell and NK cell activity as measured by calcium fluxes, expression of adhesion molecules, cytokine secretion and proliferation. CD7 associates directly with phosphoinositol 3'-kinase, and CD7 ligation induces production of D-3 phosphoinositides and tyrosine phosphorylation. Severe combined immunodeficiency has been associated with a lack of lymphocyte surface CD7. The CD7 ligand is unknown. The murine CD7 homolog is encoded by a single gene on chromosome 11. In order to characterize the role of CD7 in lymphocyte development and function we have eliminated the CD7 gene by targeted disruption. CD7- deficient mice display normal histology of thymus and spleen, normal lymphocyte populations in primary and secondary lymphoid tissues, and normal serum Ig levels. Specific antibody responses after immunization with T-dependent and T-independent antigens are equivalent in wild-type and CD7 knockout mice. CD7-deficient lymphocytes respond normally to T cell mitogenic and allogeneic stimuli, and display normal NK cell cytotoxicity.      

SA/hIL21双功能融合蛋白的表达、纯化及生物学活性检测

目的 制备链亲和素(SA)标记的人白细胞介素21融合蛋白(SA-hIL-21),检测其生物学活性.方法 构建hIL21-SA-pET21及pET24a-SA-hIL21质粒,利用大肠杆菌BL21(DE3)表达两种双功能融合蛋白,并利用镍金属螯合层析柱(Ni-NTA)纯化,之后透析复性,Western blotting进行鉴定,最后利用MTT法检测hIL21-SA及SA-hIL21融合蛋白与抗CD3单克隆抗体(anti-CD3)共刺激人外周血淋巴细胞的增殖活性,流式细胞仪分析两种融合蛋白对生物素化的MB49肿瘤细胞的锚定修饰效率.结果 hIL21-SA及SA-hIL21重组融合蛋白在大肠杆菌中实现了高效表达,约占菌体蛋白的30%,经复性后hIL21-SA及SA-hlL21具有了双重活性,即不仅可以与抗CD3单抗共刺激淋巴细胞的增殖,而且具有了SA介导的高效结合已生物素化的MB49肿瘤细胞表面的功能(表面修饰效率95.18%,96.91%).结论 本实验成功研制了具有双重活性的hIL21-SA及SA-hlL21融合蛋白,两种融合蛋白的双功能活性无显著性差异,该项研究为SA/hIL21双功能融合蛋白应用于肿瘤疫苗以及肿瘤局部治疗奠定了基础.     

南京医科大学七年制临床医学专业人才培养效果评价

通过对毕业生及其培养或用人单位的问卷调查,本文分析了南京医科大学七年制临床医学专业人才培养的成效,以及江苏省医疗卫生事业发展对高层次医学人才的需求.结果 显示,临床实践能力和科研创新能力是医疗卫生事业发展所需要的高层次医学人才的重要能力;在三级甲等医院工作,具有硕士/博士学位、在专业技术岗位的被调查者更加看重医学生的科研创新能力;而在1年通识教育、4年医学专业教育(含1年临床课程及见习、1年临床通科实习)、2年二级学科轮转模式下培养的七年制临床医学专业毕业生的临床实践能力较强,但是科研创新能力不足,且学业负担偏重.因此,应当加强对七年制临床医学专业学生科研创新能力的培养和临床实践能力的通科训练.

Abstract：

An evaluation of 7-year medical education program in Nanjing Medical University was performed via questionnaire survey to the graduates and the staff of hospitals in which the graduates work,and the demand for advanced quality of medical graduates in the field of medical health care in Jiangsu Province is further analyzed. The results showed that the capacity for clinical practice and the capacity for research and innovation are the most important, which can meet the demands of health service development for high-level medical talents. The staff working in advanced hospitals, possessing master or doctor degree,or working as medical experts put more emphasis on the ability of the graduates to do innovative scientific research. Through the completed procedure of the 7-year program includes college general education for 1 year, medical education for 4 years ( containing senior clinical clerkship for 1 year and internship for 1 year) and alternation for medical and surgery subspecialties for 2 years, the graduates showed higher ability to do clinical practice, but not showed the growth of capacity for research and innovation. The most staff investigated proposed an enhancement in training for the capacity for innovative research and general clinical practice.     

Identification of clone-9 antigenic protein of Theileria uilenbergi and evaluation of its application for serodiagnosis

The pathogenic protozoan parasite Theileria uilenbergi is one of the causative agents of theileriosis in small ruminants in China. The infection results in great economical losses in the northwest part of China. Efforts are underway to establish an enzyme-linked immunosorbent assay (ELISA) based on a T. uilenbergi immunodominant recombinantly expressed protein using different approaches in order to perform epidemiological studies in the area. In this study, we describe the possible use of the clone-9 protein for this purpose, which was identified as a potential immunogenic piroplasm protein by random sequencing of cDNA library clones followed by bioinformatic analyses. The clone-9 gene was partially recombinantly expressed and used for the development of an indirect ELISA for the detection of circulating antibodies in sera of T. uilenbergi-infected sheep. No cross-reactivity was observed in serum from animals infected with Theileria lestoquardi. The cut-off was calculated at 48.6% positivity using 25 serum samples from uninfected animals. A total of 101 field samples collected from an endemic area in China were used to evaluate the clone-9 ELISA for its use in the field.     

GABA uptake regulates cortical excitability via cell type-specific tonic inhibition

GABA(A) receptors can mediate both 'phasic' synaptic inhibition and a persistent 'tonic' form of signaling. We show that, in the presence of intact GABA uptake, guinea pig hippocampal interneurons, but not pyramidal cells, express a tonic GABA(A) receptor-mediated conductance. This conductance was pharmacologically distinct from spontaneous inhibitory postsynaptic currents (IPSCs). Inhibiting GABA uptake resulted in the expression of a comparable GABA(A) receptor-mediated tonic conductance in pyramidal cells. Reducing the tonic conductance in interneurons enhanced their excitability and the inhibitory drive to pyramidal cells. These results point to a role for cell type-dependent tonic inhibition in regulating cortical excitability.     

Dendritic Ca2+ responses in neonatal lateral superior olive neurons elicited by glycinergic/GABAergic synapses and action potentials

During development, GABA/glycinergic connections from the medial nucleus of the trapezoid body (MNTB) to the lateral superior olive (LSO) gradually change from being depolarizing to being hyperpolarizing. Previous studies have shown that depolarizing MNTB-LSO synapses can trigger action potentials and increase the concentration of intracellular calcium. In the present study we used confocal calcium imaging combined with whole-cell patch clamp recordings to investigate how depolarizing MNTB inputs in neonatal rats and mice increase the calcium concentration in the dendrites of LSO neurons. Our results show that subthreshold synaptic responses can elicit local dendritic calcium responses while suprathreshold responses reliably generate global calcium responses that are observed in all dendritic processes. The amplitude of global dendritic calcium responses increased with distance from the soma. Global calcium responses were blocked by tetrodotoxin and could not be recovered by somatic injection of action potential waveforms indicating that global calcium responses are generated by back-propagating sodium action potentials.     

美国脂质协会他汀药物肝脏安全性评估简介

最近．美国国家脂质协会（National Lipid Association, NLA）邀请致力于非酒精性脂肪性肝病（nonalcoholic fatty liver disease, NAFLD）,脂质代谢紊乱和药物性肝损害研究方面的肝脏病学专家加盟他汀安全性工作组．旨在对他汀肝脏安全性问题进行一次全面的、严格的、学术的、最新的以及无偏见的评估。本文主要介绍NLA与肝病专家委员之间的对话。     

Relative picrotoxin insensitivity distinguishes ionotropic GABA receptor-mediated IPSCs in hippocampal interneurons

Inhibitory GABAergic signalling in the hippocampus plays an important role in synchronizing principal cells and regulating the excitability of this seizure-prone structure. Distinct mechanisms modulate release from GABAergic terminals in the hippocampus, depending on whether the postsynaptic partner is an interneuron or a principal cell. Here, we report that postsynaptic ionotropic GABA receptors in principal cells and interneurons also show a striking pharmacological difference. The broad-spectrum antagonist picrotoxin (PTX) was less potent at blocking IPSCs evoked in stratum radiatum interneurons than in pyramidal neurons in the CA1 region. GABA-evoked currents in membrane patches from interneurons showed a smaller mean unitary conductance than in patches from pyramidal neurons. Because retinal GABA(C) receptors show decreased picrotoxin sensitivity and conductance, we examined the effect of the GABA(C) receptor agonist cis-aminocrotonic acid (CACA). Although this agent evoked picrotoxin-resistant currents in interneurons, these were enhanced by the GABA(A) allosteric modulator pentobarbital. Moreover, both picrotoxin-resistant IPSCs and CACA-evoked currents were blocked by the GABA(A) receptor-selective antagonist bicuculline. The presence of relatively picrotoxin-resistant GABA(A) receptors in interneurons provides a potential target for agents to modulate the activity of sub-populations of hippocampal neurons.     

Current view of rehabilitation

The study selects some changing and developing aspects of the contemporary considerations of rehabilitation and relates them closely to neurological rehabilitation. Functional diagnostics aims at the assessment of impairments and functioning. Several internationally recognized methods of neurological rehabilitation have already been adapted in Hungary. Author emphasises the use of International classification of functioning, disability and health, officially accepted by the Assembly of the World Health Organization in 2001. Its use for functional diagnostics is also possible. The everyday practice of teamwork is still problematic. Its implementation in rehabilitation is inevitable. The neurological rehabilitation is a special field where the cooperation of many teammembers is needed. The attitude to human beings in rehabilitation is different from medicine at large. It considers man not only as biological but also as social beings with own life history, thus helping to achieve compliance and increasing autonomy. The author mentions the possibility for the cooperation with organizers of the independent living movement. The separation of quality of life and health status assessments is suggested. Attention is called to the requirements of the adaptation of assessment methods and an initial account of own experiences is given.     

Outcome of ventilatory support for acute respiratory failure in motor neurone disease

OBJECTIVES: To review the outcome of acute ventilatory support in patients presenting acutely with respiratory failure, either with an established diagnosis of motor neurone disease (MND) or with a clinical event where the diagnosis of MND has not yet been established. METHODS: Outcome was reviewed in 24 patients with respiratory failure due to MND who received endotracheal intubation and intermittent positive pressure ventilation either at presentation or as a result of the unexpected development of respiratory failure. Patients presenting to local hospitals with acute respiratory insufficiency and requiring tracheal intubation, ventilatory support, and admission to an intensive therapy unit (ITU) before transfer to a regional respiratory care unit were selected. Clinical features of presentation, management, and outcome were studied. RESULTS: 24 patients with MND were identified, all being intubated and ventilated acutely within hours of presentation. 17 patients (71%) were admitted in respiratory failure before the diagnosis of MND had been made; the remaining seven patients (29%) were already known to have MND but deteriorated rapidly such that intubation and ventilation were initiated acutely. Seven patients (29%) died on ITU (between seven and 54 days after admission). 17 patients (71%) were discharged from ITU. 16 patients (67%) received long term respiratory support and one patient required no respiratory support following tracheal extubation. The daily duration of support that was required increased gradually with time. CONCLUSION: When a patient with MND is ventilated acutely, with or without an established diagnosis, independence from the ventilator is rarely achieved. Almost all of these patients need long term ventilatory support and the degree of respiratory support increases with time as the disease progresses. The aim of management should be weaning the patient to the minimum support compatible with symptomatic relief and comfort. Respiratory failure should be anticipated in patients with MND when the diagnosis has been established.