Functional recognition of the neuronal tyrosine hydroxylase cAMP regulatory element in different cell types.

Transient transfection of pLB2CAT constructs bearing short synthetic oligonucleotides derived either from the tyrosine hydroxylase (TH) promoter or other sources was used to examine functional cAMP regulatory element (CRE) activity in a variety of cell lines. The region containing only the putative TH CRE was found to be as or more effective in conferring cAMP responsiveness onto pLB2CAT (which employs the TK promoter) than the immediate 272 bp region of the TH promoter. Increases in CAT activity of 10- to 20-fold were observed in JEG-3 cells with a single insert of the TH CRE region (-31 to -54) in pLB2CAT, and the presence of a second insert generated only a modest further increase. This construct also responded to cAMP in 4 other cell lines tested but the degree of increase was less dramatic. Inserts containing the consensus 8 bp CRE motif embedded in other natural or artificial contexts served generally as weak functional CREs in all cell lines tested. In vitro analysis revealed that a specific protein-DNA complex apparently containing a single protein with a MW of 45-50 kDa was formed equally well with JEG-3 cell nuclear extract and CRE-bearing-TH and other fragments which produced dramatically different cAMP effects in vivo. These results suggest specificity in the effects of cAMP on different CREs which are dictated by contextual differences.     

选择性环氧化酶—2抑制剂的研究现状及应用评价

选择性环氧化酶（COX）-2抑制剂可有效地治疗炎症，同时避免或减轻由于抑制COX-1而导致的毒副作用。有乐观的临床应用前景，但其不良反应亦不容忽视，寻找临床评价好的选择性COX-2抑制剂是当前非甾体类抗类药物研究的重点。     

CT扫描及超声内镜术前评价进展期食管癌

目的比较胸部螺旋CT增强扫描及微探头超声内镜 (MPS)检查在评价进展期食管癌中的价值。方法 :32例进展期食管癌术前行CT扫描和MPS检查并与术后病理学比较。结果 :CT扫描能发现 84 .4 %的食管癌病灶 ,但不能准确诊断癌肿浸润深度 ,诊断纵隔结构受侵准确率 75 % ,发现区域淋巴结转移的敏感性90 .9% ,特异性 81.8% ,对纵隔内远处淋巴结转移诊断准确率 80 %。MPS检查能检出所有病例的进展期食管癌病灶 ,癌肿浸润深度诊断准确率 81.3% ,诊断纵隔结构受侵准确率 5 0 % ,诊断区域淋巴结转移敏感性81.8% ,特异性 72 .7% ,而对纵隔内远处转移的淋巴结均未能探及。结论 :CT扫描在评价进展期食管癌纵隔内结构受侵及远处淋巴结转移的意义较大。而MPS检查在判断癌肿管腔浸润深度的准确率较高。     

烯烃的热力学性质的拓扑研究

目的：寻找一种性能优良的拓扑指数，方法：根据分子图的邻接矩阵和距离矩阵提出一种新的拓扑指数P1^*,P2^*,P3^*,p^4*。结果，拓扑指数P1^*,P2^*,P3^*,p^4*与烯烃的热力学函数－△Hf(g),S(g),△Gf(g)均有相关性，其复相关系数均在99．6％以上。结论：拓扑指数P1^*,P2^*,P3^*,p^4*与烯烃的热力学函的多种物理化学性质均有良好的相关性。     

神经干细胞静脉移植治疗脊髓损伤的实验研究

[目的]观察神经干细胞静脉移植对损伤大鼠脊髓功能的治疗作用。[方法]取孕14—16dSD胎鼠的脑室下区组织，体外培养后鉴定细胞。制作脊髓全切模型，伤后1周将Brdu标记好的神经干细胞通过尾静脉注射移植到大鼠体内，移植后及8周行皮层体感诱发电位（CSEP）检测和BBB功能评分，并留损伤脊髓处作病理切片及免疫组化染色。[结果]（1）移植后8周BBB评分损伤组、移植组都有所恢复，但都未达到正常水平，移植组恢复较好；（2）模型制作后，CSEP波均消失，细胞移植后8周移植组的波形有不同程度的恢复，但潜伏期延长；（3）移植组大鼠脊髓损伤处存在大量Brdu染色阳性细胞，表明移植的细胞在体内可到达损伤脊髓处并能存活；脊髓损伤部位NF-200及GFAP染色阳性的细胞表明移植的细胞可以分化为具有神经元和胶质细胞特性的细胞。[结论]静脉移植的神经干细胞能到达损伤区代替受损的神经元及神经胶质细胞，使损伤的脊髓功能得到一定程度的恢复。     

Transvaginal sonography in the assessment of distal ureteral calculi.

OBJECTIVES: To explore the morphological and functional findings of transvaginal sonography (TVS) in the diagnosis and management of distal ureteral calculi. METHODS: We retrospectively reviewed the imaging studies in seven cases of distal ureteral calculi (study group) and 20 cases of female volunteers without urinary tract infection (control group). All 27 patients had undergone TVS for assessment of the lower urinary tract. The variables measured on ultrasound included the presence or absence of distal ureteral calculi, the size and location of a calculus if present, the presence or absence of the ureter jet phenomenon, morphological changes of the ureteral papilla and adjoining tissue, and the height of the ureteral papilla, as well as vascular changes seen on Doppler imaging. RESULTS: In the controls, 80% of the ureteral papillae were triangular and 20% trapezoidal. The average (+/-SD) height of the ureteral papillae was 3.5 +/- 0.7 mm on the right and 3.6 +/- 0.9 mm on the left. There was no statistically significant difference between the heights of the right and left papillae (P = 0.619). In the study group, echogenic stones were identified in all seven patients and a hypoechogenic tubular structure connected to the involved papilla was identified in 6/7 patients. The average height of the involved papilla was 6.7 +/- 1.6 mm. Ureteric jets were visible in all patients in both the study and control groups. CONCLUSION: In patients with distal ureteral calculi, TVS provides a rapid, non-invasive and repeatable means of assessing the morphology and function of the distal ureter.     

Serine hydroxymethyltransferase isoforms are differentially inhibited by leucovorin: characterization and comparison of recombinant zebrafish serine hydroxymethyltransferases.

Serine hydroxymethyltransferase (SHMT) provides activated one-carbon units required for the biosynthesis of nucleotides, protein, and methyl group by converting serine and tetrahydrofolate to glycine and N(5),N(10)-methylenetetrahydrofolate. It is postulated that SHMT activity is associated with the development of methotrexate resistance and the in vivo activity of SHMT is regulated by the binding of N(5)-CHO-THF, the rescue agent in high-dose methotrexate chemotherapy. The aim of this study is to advance our understanding of the folate-mediated one-carbon metabolism in zebrafish by characterizing zebrafish mitochondrial SHMT. The cDNA encoding zebrafish mitochondrial SHMT was cloned, overexpressed in Escherichia coli, and purified with a three-step purification protocol. Similarities in structural, physical, and kinetic properties were revealed between the recombinant zebrafish mitochondrial SHMT and its mammalian orthologs. Surprisingly, leucovorin significantly inhibits the aldol cleavage of serine catalyzed by zebrafish cytosolic SHMT but inhibits to a lesser extent the reaction catalyzed by the mitochondrial isozyme. This is, to our knowledge, the first report on zebrafish mitochondrial folate enzyme as well as the differential inhibition of leucovorin on these two SHMT isoforms. Western blot analysis revealed tissue-specific distribution with the highest enrichment present in liver for both cytosolic and mitochondrial SHMTs. Intracellular localization was confirmed by confocal microscopy for both mitochondrial and cytosolic SHMTs. Unexpectedly, the cytosolic isoform was observed in both nucleus and cytosol. Together with the previous report on zebrafish cytosolic SHMT, we suggest that zSHMTs can be used in in vitro assays for folate-related investigation and antifolate drug discovery.     

Changes in T .lymphocyte subsets after severe traumatic brain inJury

BACKGROUND： Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE： To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN： A comparative observation. SETTINGS： Department of Neurosurgery, Longgang District Buji People＇s Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS： All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People＇s Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score （GCS） was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group （GCS ranged 14- 15 points）, including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS： （1） The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. （2） The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES： Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS： Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. （1） Changes of T lymphocyte subsets： At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group （t =2.77 - 3.26, P 〈 0.01）, and began to recover at 7 days, which were significantly different from those in the control group （t = 2.06 - 2.24, P 〈 0.05）, and generally recovered to the normal levels at 14 days （P 〉 0.05）. （2） Conditions of pulmonary infections： At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% （22/30）, 0, x2=37.29, P 〈 0.01]. CONCLUSION： Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period （within 7 days）, and they are easily to be accompanied by pulmonary infections.