基础医学教师课堂教学质量评价

为了了解本科教师的教学质量和教学效果 ,教学专家和学生评价了 14 7位基础医学教师。结果显示 ,讲师以上职称教师的教学质量明显好于初级职称教师 (P<0 .0 5 ) ,高级职称教师教学的科学性、艺术性和思想性明显好于讲师和助教 (P<0 .0 5 )。文章还对教学中存在的问题和对策进行了讨论。     

湘西自治州1995～2002年男性劳教人员法定性病监测报告

目的 了解湘西自治州重点人群性病患消长趋势，为性病防治工作提供科学依据。方法 从1995年起，采用统一的表格，每年对湘西州劳教所新入教人员进行一次法定性病监测。结果 三种法定性病平均患病率为14．64％(4．96～26．7％)，以1995年最低，1997年最高，8年未发现HIV／AIDS，患病率以20～39岁的性跃期人群为最高，汉族患病率高于其它民族；化程度越高，患病率越低。结论 男性劳教人员作为性病患病的高危人群，是哨点监测理想的目标人群。     

振动对急性缺氧小鼠肺损伤的影响

本文观察了频率为20Hz、振幅为0．67mm和作用时间为40min的振动预处理对急性缺氧小鼠肺损伤的影响。结果发现实验组的肺组织匀浆脂质过氧化物LghdPeroxde（LPO）、支气管肺泡灌洗液（BALF）中蛋白含量和白细胞数明显低于对照组（P＜0．05）。这表明在特定率数的振动作用下能明显减轻急性缺氧小鼠肺的损伤。     

A promising technique for transplantation of bone marrow-derived endothelial progenitor cells into rat heart.

OBJECTIVE: To investigate the feasibility of intracoronary application of endothelial progenitor cells and the subsequent distribution within the heart. METHODS: Endothelial progenitors cells (EPCs) cultured from rat bone marrow were identified by double-positive staining with Dil-Ac-LDL and BS1-lectin. Twenty-four hours before cell transplantation, EPCs were labeled with 5-bromo-2'-deoxyuridine (BrdU). Cells (5 x 10(5) in 250-microl medium) were injected into healthy rats, either as intracoronary application (n=11) or as intramyocardial injection (n = 6). At 15 min or 3 days posttransplantation, hearts as well as other organs (lung, liver, kidney, and spleen) were collected and processed for subsequent BrdU immunohistochemistry. The number of BrdU-positive cells per tissue area was counted. RESULTS: Compared to intramyocardial injection, intracoronary administration resulted in more than twice as much positive cells in the heart (P < .05), with no local differences within the heart. Whereas after 15 min, EPCs were equally distributed in all examined organs (except for the spleen), cells that were still present after 3 days, approximately 10%, were selectively restricted to the heart. CONCLUSIONS: Our data indicate that the intracoronary application provides a promising technique for EPC transplantation in the rat heart.     

Decreased prefrontal 5-HT2A receptor binding in subjects at enhanced risk for schizophrenia

The brain serotonin-2A receptor (5-HT_2AR) has been implicated in both the pathology of schizophrenia and the therapeutic action of atypical antipsychotics. However, little is known about the 5-HT_2AR status before the onset of schizophrenia and before the exposure to antipsychotics. We used [¹⁸F] altanserin and positron emission tomography (PET) in a pilot study of 6 individuals suspected to be at elevated risk for schizophrenia and seven age-matched controls to test the hypothesis that regional 5-HT_2AR binding is altered in the prodromal stages of schizophrenia. Distribution volume ratios (DVRs) as a proxy for 5-HT_2AR availability were significantly reduced in prefrontal cortex regions of at-risk subjects, implicating early abnormalities of serotonergic neurotransmission that antecede the onset of schizophrenia.     

The dependence of twitch relaxation on sodium ions and on internal Ca2+ stores in voltage clamped frog atrial fibres

Frog heart relaxation was analyzed under voltage clamp conditions as the tension decay observed after the membrane potential had been returned to its resting value. The tension decayed exponentially with a time constant of 188±3.8 ms SEM. The relaxation rate decreased with the external Na concentration. It fell to about one tenth in a Na-free solution. Increasing the intracellular Na-content by an application of veratrine also decreased the relaxation rate. Thus relaxation seems dependent on the Na gradient. The relaxation rate decreased within one second upon switching from a high to a low Na-containing solution. The relaxation rate reached a minimum before rising slightly to a new steady state value. This rebound may reflect the partial recovery of the Na gradient since a fast variation in [Na]_i follows alteration of [Na]_o. Mn and La ions also slowed relaxation. In a Na-free solution, adrenaline accelerated tension decay, an effect not noticeable in frog heart contained in Ringer solution. Other cAMP-promoting agents, such as dibutyryl-cAMP and aminophylline, also increased relaxation rate.It is concluded that in frog myocardium, part of the decrease of the intracellular Ca²⁺-concentration which occurs during each cardiac cycle could be dependent on a Na–Ca exchange mechanism. The relative importance of this mechanism, versus internal Ca sequestration, in the relaxation of tension may well be greater in contractile tissues whose cells have a large surface/volume ratio.     

An extended association screen in multiple sclerosis using 202 microsatellite markers targeting apoptosis-related genes does not reveal new predisposing factors

Apoptosis, the programmed death of cells, plays a distinct role in the etiopathogenesis of Multiple sclerosis (MS), a common disease of the central nervous system with complex genetic background. Yet, it is not clear whether the impact of apoptosis is due to altered apoptotic behaviour caused by variations of apoptosis-related genes. Instead, apoptosis in MS may also represent a secondary response to cellular stress during acute inflammation in the central nervous system. Here, we screened 202 apoptosis-related genes for association by genotyping 202 microsatellite markers in initially 160 MS patients and 160 controls, both divided in 4 sets of pooled DNA samples, respectively. When applying Bonferroni correction, no significant differences in allele frequencies were detected between MS patients and controls. Nevertheless, we chose 7 markers for retyping in individual DNA samples, thereby eliminating 6 markers from the list of candidates. The remaining candidate, the ERBB3 gene microsatellite, was genotyped in additional 245 MS patients and controls. No association of the ERBB3 marker with the disease was detected in these additional cohorts. In consequence, we did not find further evidence for apoptosis-related genes as predisposition factors in MS.     

Co-administration of a DNA vaccine encoding the prostate specific membrane antigen and CpG oligodeoxynucleotides suppresses tumor growth

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a well characterized prostate-specific tumor associated antigen. Its expression is elevated in prostate carcinoma, particularly in metastatic and recurrent lesions. These observations suggest that PSMA can be used as immune target to induce tumor cell-specific recognition by the host and, consequently tumor rejection. We utilized a DNA-based vaccine to specifically enhance PSMA expression. An immune modulator, such as CpG oligodeoxynucleotides which promote Th1-type immune responses was combined to increase the efficacy of tumor recognition and elimination. METHODS: A eukaryotic expression plasmid pCDNA3.1-PSMA encoding full-length PSMA was constructed. C57BL/6 mice were immunized with endotoxin-free pCDNA3.1-PSMA alone or in combination with CpG oligodeoxynucleotides by intramuscular injection. After 4 immunizations, PSMA specific antibodies and cytotoxic T lymphocyte reactivity were measured. Immunized C57BL/6 mice were also challenged subcutaneously with B16 cells transfected with PSMA to evaluate suppression of tumor growth. RESULTS: Vaccine-specific cytotoxic T lymphocytes reactive with B16 cells expressing PSMA could be induced with this treatment schedule. Immune protection was observed in vaccinated mice as indicated by increased tumor growth in the control group (100%) compared with the groups vaccinated with DNA alone (66.7%) or DNA plus CpG oligodeoxynucleotides (50%) respectively. Average tumor volume was smaller in vaccinated groups and tumor-free survival time was prolonged by the vaccination. CONCLUSION: The current findings suggest that specific anti-tumor immune response can be induced by DNA vaccines expressing PSMA. In addition, the suppression of in vivo growth of tumor cells expressing PSMA was augmented by CpG oligodeoxynucleotides. This strategy may provide a new venue for the treatment of carcinoma of prostate after failure of standard therapy.