Purification and characterization of the carbonic anhydrase enzyme from Black Sea trout (Salmo trutta Labrax Coruhensis) kidney and inhibition effects of some metal ions on enzyme activity

In this study, the carbonic anhydrase (CA) enzyme was purified from Black Sea trout (Salmo trutta Labrax Coruhensis) kidney with a specific activity of 603.77 EU/mg and a yield of 35.5% using Sepharose-4B-l-tyrosine- sulphanilamide affinity column chromatography. For determining the enzyme purity and subunit molecular mass, sodiumdodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was performed and single band was observed. The molecular mass of subunit was found approximately 29.71 kDa. The optimum temperature, activation energy (E_a), activation enthalpy (ΔH) and Q₁₀ values were obtained from Arrhenius plot. K_m and V_max values for p-nitrophenyl acetate of the purified enzyme were calculated from Lineweaver-Burk graphs. In addition, the inhibitory effects of different heavy metal ions (Fe²⁺, Pb²⁺, Co²⁺, Ag⁺ and Cu²⁺) on Black Sea trout kidney tissue CA enzyme activities were investigated by using esterase method under in vitro conditions. The heavy metal concentrations inhibiting 50% of enzyme activity (IC₅₀) were obtained. Finally K_i values and inhibition types were calculated from Lineweaver-Burk graphs.     

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.     

含有黄嘌呤衍生物的N-杂环卡宾金属配合物的生物活性研究进展

N-杂环卡宾(NHC)是一类多功能的配体,能够与过渡金属形成稳定的配位化合物,在催化、药学和材料科学等领域有着广泛的应用。黄嘌呤衍生物具有抗肿瘤转移和抗血管生成等生物活性,且结构易于修饰。将黄嘌呤衍生的NHC配体与过渡金属相结合有望得到具有全新生物活性的金属配合物。综述黄嘌呤衍生物的生物活性,以及黄嘌呤衍生的NHC金属配合物的结构特点和生物活性,并对黄嘌呤NHC金属配合物的研究进行了总结和展望,以期为进一步的研究提供参考。     

几种常用金属对大肠埃希菌杀灭作用观察

采用悬液定量浸泡杀菌试验和电镜技术,在实验室进行了常用金属对细菌的杀灭作用及其作用机理观察。结果,将不同金属置于含菌悬液内浸泡作用不同时间,金属铜对大肠埃希菌作用 30min,平均杀灭率为 97%;金属银和金作用 30min,平均杀灭率分别为 35. 6%和 30. 3%;不锈钢,金属铝、铁和锡等对细菌作用很弱。透射电镜观察发现,经金属铜作用 30min的大肠埃希菌,其细胞壁出现凹凸不平,局部细胞膜有分离现象,细胞质明显减少甚至消失,细胞核质浓缩呈块状。结论,常用金属中以金属铜、银对细菌作用明显,作用后的细胞结构有改变,其他常用金属对细菌作用不明显。     

Development of a Device for Removing a Partial Denture in a Patient with Scleroderma

Scleroderma is a chronic disease that has been associated with immune dysfunction. One of the oral manifestations is microsomia, a result of collagen deposition in the perioral tissues. The complexity of treating these patients includes limited mouth opening ability, and difficulty inserting and removing dentures due to finger deformity. This article will describe an appliance specially designed especially for scleroderma patients, which facilitates treatment of the patient with removable partial dentures (RPD).     

金属换热器传热过程的数学模型及应用

应用蒙特卡洛法仿真辐射式金属换热器内的辐射传热过程，建立了换热器综合传热的数学模型，利用概率论原理，把辐射能迁移过程仿真为一定累积概率分面下的随机过程，该模型能较好地反映换热器内传热过程的真实情况，可以计算出换热器内烟气、筒壁、空气的温度和壁面热流分布，以及研究烟气进口温度、换热器筒径和狭逢宽度对换热效果的影响。     

放射性NiTi合金血管内支架可行性及安全性的实验观察

目的：观察2．3μCi的放射性NiTi合金血管内支架植入正常兔腹主动脉后的安全性及可行性。方法：将16只兔随机分为放射性支架组(n＝8)及非放射性支架组(n＝8)，分别于腹主动脉内植入放射性NiTi合金血管内支架和不具有放射性的NiTi合金血管内支架。于3个月后处死两组动物，肉眼观察支架局部有无血栓形成，光镜及透射电镜观察支架局部血管的结构改变；生化法测定肝功、肾功；骨穿涂片观察骨髓象。结果：放射性支架组新生血管内膜厚度明显低于非放射性支架组，新生血管内膜平滑肌细胞(SMCs)明显减少，中膜的厚度和SMCs与非放射组无显著性差异，两组新生血管内膜均完全内皮化，无血栓形成；两组的谷丙转氨酶、谷草转氨酶和尿素氮、肌酐均无显著性差异；两组动物的骨髓增生均正常。结论：2．3μCi的放射性NiTi合金血管内支架可减少血管新生内膜增生，对血管中膜、邻近重要脏器及骨髓造血无影响，可安全应用。     

Intracranial Angioplasty and Stenting in the Awake Patient

BACKGROUND AND PURPOSE: Endovascular treatment for intracranial atherosclerosis is evolving, but complications remain an issue. Most interventions are performed under general anesthesia, preventing intraprocedural clinical evaluations. We describe our approach to intracranial angioplasty and stenting, using local rather than general anesthesia, and intraprocedural neurological assessment. METHODS: We prospectively collected procedural and outcome information on all patients undergoing intracranial angioplasty and stenting. Patients underwent interventions under local anesthesia with mild intravenous sedation or analgesia only if needed. Intraoperative neurological evaluations were performed, and symptomatology was used to guide the interventional technique. RESULTS: Forty-eight arteries in 40 patients with a mean age of 65.2 years were treated. Thirty-two anterior and 16 posterior circulation segments were treated. Technical success was achieved in 100% of patients with reduction of the mean pretreatment stenosis from 85 +/- 8.6% to 7 +/- 10.1%. Stents were deployed in 40 segments; five patients were treated with drug-eluting stents. The cobalt-chromium coronary stents were the easiest to deliver. Thirty-seven patients were treated under local anesthesia and, of those, 61.4% experienced intraprocedural symptoms that led to some alteration of the interventional technique. Headache was the most common symptom, and, when persistent, it heralded the occurrence of subarachnoid hemorrhage. There were seven total neurological complications, but only five (10.5%) led to permanent morbidity (4 strokes) or mortality (1 death). CONCLUSIONS: Intracranial angioplasty and stenting can be successfully performed using coronary techniques and equipment including drug-eluting stents. Local anesthesia permits neurological evaluations and often leads to the adjustment of the interventional technique, potentially making the procedure safer.     

Covered metal stent for tumor obstruction of efferent loop recurrence after gastrectomy

Reports the case of a 60-year-old woman who underwent R2 total gastrectomy, and subsequent palliation of painful symptom recurrence via a membrane-covered metal stent. Received: 13 June 1996/Accepted: 31 July 1996