Decreased mitochondrial gene expression in isolated islets of rats injected neonatally with streptozotocin

Summary The aim of the present study was to evaluate the possible role of the expression of the mitochondrial genome for the regulation of insulin production in the pancreatic Beta cell. For this purpose, islets of Langerhans were isolated from adult control rats and rats injected neonatally with streptozotocin and the islet contents of specific mitochondrial DNAs and RNAs together with nuclear-encoded RNAs were determined. The contents of mitochondrial cytochrome b mRNA, the mitochondrial 12 S rRNA and insulin mRNA were all 30–40% lower in islets isolated from the streptozotocin-treated rats as compared to islets from control rats. In contrast, the nuclear mRNA coding for the mitochondrial adenine nucleotide translocator was not decreased in the streptozotocin-treated rats. Contents of mitochondrial DNA, as assessed by the Southern blotting technique, were markedly decreased in the streptozotocin islets. Sequence analysis of mitochondrial DNA from streptozotocin islets and control islets however, did not reveal any differences in nucleotide sequences. In control islets the contents of mitochondrial cytochrome b mRNA increased in response to a high glucose concentration during a 4-h incubation period. Serum deprivation or the addition of theophylline or 4-phorbol 12-myristate 13-acetate failed to affect the cytochrome b mRNA contents in vitro. It is concluded that islets of streptozotocin-treated rats contain low contents of mitochondrial DNA and RNA. Since a lower mitochondrial RNA content may result in a diminished oxidative capacity, it is conceivable that a deficiency of this messenger may contribute to the development of insulin deficiency.     

精子DNA检测评价我国寒冷地区男性的精子质量

目的：探讨长期低温作业是否能造成精子DNA的损伤。方法：对长期工作在寒冷地区的部队官兵进行现况调查及自身对照，通过精液标本进行单细胞凝胶电泳和染色质结构分析，检测精子DNA单双链的损伤情况。结果：调查组单细胞凝胶电泳Ⅰ级彗星率平均4．4％，对照组仅1．9％；染色质结构分析中COMPαt平均22．9％，对照组为19．3％，两组相差显著。半年后重复检测调查组，各项检测指标明显下降。结论：长期工作在寒冷地区的部队官兵精子DNA单双链损伤是可逆的。提示低温作业不影响男性生殖力，但加强寒冷地区作业人员的男性生殖健康预防保健工作仍然十分重要。     

CK、CK-MB、TnT对再通后急性心肌梗死患者梗死面积的估测

目的:探讨急性心肌梗死(AMI)直接经皮介入干预(direct PCI)后血清磷酸肌酸激酶(CK)及其同工酶(CK-MB)、心肌肌钙蛋白T(cTnT)的估测梗死(MI)面积的可行性.方法:对直接PCI成功的60例AMI患者入院后连续抽静脉血测定血清CK、CK-MB及TnT水平,入院10-30d内做核素心肌显像测定心肌梗死面积指数(infarct size index,ISI).以测定的生化指标拟合释放曲线,分别以其峰值、所测定总值及术后16小时内曲线下面积与ISI做相关性比较.结果:直接PCI术后即刻血清CK、CK-MB以及TnT浓度迅速升高,与术前有显著性差异(P均小于0.05).CK、CK-MB及TnT在发病24小时内释放曲线基本呈现出单峰特征.所测血清CK、CK-MB及TnT的峰值、累积值及释放曲线下面积与ISI都有相关性.多元回归分析发现TnT释放曲线下面积与ISI相关性最好(r=0.58;P=0.0012).TnT释放曲线下面积与ISI的线性回归方程为:Y=1.39 × 10-4X 0.20.以ISI=30%为界限将患者分为两组,两组间TnT释放曲线下面积做t检验,发现有显著性差异(P＜0.01).直接PCI术后16小时内TnT释放曲线下面积对ISI的临床估测价值为85.2%、特异度为84%、敏感度为100%.ISI小于30%的占88.46%(以ECT=30%,TnT-Area=688 g·h/L为界限).结论:直接PCI治疗后TnT 16小时内曲线下面积可以用来估测心肌MI面积.     

Comparison of Injection Materials for the Elevation of Gastric Mucosa Prior to Endoscopic Mucosal Resection

Endoscopic mucosal resection (EMR), namely strip biopsy, to eradicate gastric mucosal lesions requires certain special techniques, including submucosal injection of appropriate agents. This experimental study using dogs was conducted to compare, with regard to the degree of duration of mucosal elevation and subsequent histologic changes of the gastric wall, three injection materials; physiological saline, hypertonic saline with epinephrine (HSE) and 10% soybean oil. The duration of mucosal elevation which should be sufficient for the EMR procedure did not differ between the three agents. The post-injection histologic changes included vessel dilatation in the peri-muscularis mucosae, dilatation of the lymphatic channels and vessel congestion. These changes appeared in all injection material groups, and the vessel congestion was found to be more conspicuous in the HSE group. All EMRs in this series were performed by single snare cutting, which was also evaluated. The margin of the stripped material was well limited to the submucosal layer in all cases, but the depth of the ulcers formed varied. The healing process of the ulcer for the first 4 weeks was delayed in the soybean oil group. Although there were few cases of perforation in this experiment and some subjects had adhesion between the gastric serosa and adjacent organs, the single snare method could be applicable for clinical use by skilled hands.     

突发性感音神经性聋的rCBF显像研究

目的探讨局部脑血流（ｒＣＢＦ）断层显像对突发性感音神经性聋（简称突聋）的临床价值。方法对１０例正常志愿者，１９例传音性耳聋（简称传聋）及３１例突聋患者治疗前行ｒＣＢＦ显像，并与同期ＣＴ对照；随访突聋病例６～１２个月，并复查ｒＣＢＦ显像。结果①突聋的病灶（位于颞横回）与正常脑组织的放射性比值（Ｔ／ＮＴ）明显低于传聋和正常组；②ｒＣＢＦ显像诊断突聋的灵敏度（８０６％）和准确率（８８３％）明显高于ＣＴ（３２％和５０％）；③突聋的Ｔ／ＮＴ值与耳聋程度有较高的相关性；④ｒＣＢＦ显像无异常的突聋患者预后较好；⑤ｒＣＢＦ显像与临床预后观察有较高的一致性（８４６％）。结论ｒＣＢＦ显像对突聋的诊断明显优于ＣＴ。     

Recombinant single‐chain antibodies against s‐Triazines

Recombinant antibody (RAb) technology is expected to play an essential role in future food and environmental immunoanalysis. The RAb approach is not yet, however, considered as a standard method, mainly due to technical reasons. In order to establish a feasible protocol for the production of hapten specific RAbs, the essential steps of the procedure are considered in detail, especially the polymerase chain reaction amplification of antibody coding genes and the utilization of immunomagnetic selection of phages displaying selective RAbs. The synthesis of functional recombinant single‐chain Fv against s‐triazine herbicides is used as an example. Expressed RAbs are characterized by immunoassay. Although RAb‐based calibration curves were shifted toward higher concentrations by one order of magnitude, the cross‐reactivity pattern of RAbs corresponded to the original monoclonal antibodies. Sequences of different RAb clones derived from the same hybridoma line only differed in a single silent mutation. This confirms the reliability of the RAb procedure.     

Ictal HMPAO-Single Photon Emission Computed Tomography Findings in Reading Epilepsy in a Japanese Boy

Summary: Reading epilepsy is rare. We report a 14-year-old right-handed Japanese boy who had had jaw jerking only while reading since age 12 years. The episodes occurred every time he read an English textbook and some-times during prolonged reading of a Japanese textbook. The jaw jerking evolved to generalized tonic-clonic seizures (GTCS) on only two occasions during prolonged reading aloud. Routine EEGs showed no abnormality. After a few minutes of reading, however, the EEG showed bilateral 2-Hz, 150-μ V spike-wave complexes with left frontotemporal accentuation, accompanied by jaw jerking. Ictal single photon emission computed tomography (SPECT) with [^99mTc]hexamethylpropylene amine oxime (HMPAO) showed focal hyperperfusion of the frontal lobes bilaterally and of the left temporal area. Interictal SPECT and magnetic resonance imaging (MRI) were normal. The combination of valproate (VPA) and clonazepam (CZP) almost eliminated his symptoms. Ictal SPECT is a useful technique for seizure localization in reading epilepsy.     

Sequential check and computer analysis of a cloned DNA fragment specific for Plasmodium vivax

A cloned DNA fragment specific for Plasmodium vivax was cleaved from theplasmid pVA1 and ligated into phage M13mp18.The nucleotides of the insert were se-quenced by the dideoxy-chain termination procedure.The fragment was composed of 261base pairs and 3 Hinf Ⅰ sites but no tandem repeat sequences.Computer retrieval andanalysis show that the nucleotide sequence of the cloned DNA fragment is unique,forthere has not been any significant homologue with that of other Plasmodium genes pub-lished as yet.     

Transverse fusion of the renal pelves and single ureter

We present a case of a rare renal anomaly in which the 2 kidneys (separate or fused across the midline) are drained by a common renal pelvis and ureter. Previously reported cases have been reviewed and are classified in 3 groups according to their anatomical features. The lesion is associated with some frequency with imperforate anus, sacral and other vertebral defects, neurogenic bladder, vesicoureteral reflux, upper tract dilatation, and urinary tract infections.