Nitrite infusions to prevent delayed cerebral vasospasm in a primate model of subarachnoid hemorrhage

Context  Delayed cerebral vasospasm causes permanent neurological deficits or death in at least 15% of patients following otherwise successful treatment for ruptured intracranial aneurysm. Decreased bioavailability of nitric oxide has been associated with the development of cerebral vasospasm. Objective  To determine whether infusions of nitrite will prevent delayed cerebral vasospasm. Design, Setting, and Subjects  A total of 14 anesthetized cynomolgus monkeys had an autologous blood clot placed around the right middle cerebral artery. Cerebral arteriography was performed before clot placement and on days 7 and 14 to assess vasospasm. The study was conducted from August 2003 to February 2004. Interventions  A 90-mg sodium nitrite intravenous solution infused over 24 hours plus a 45-mg sodium nitrite bolus daily (n = 3); a 180-mg sodium nitrite intravenous solution infused over 24 hours (n = 3); or a control saline solution infusion (n = 8). Each was infused continuously for 14 days. Main Outcome Measures  Nitrite, S-nitrosothiol, and methemoglobin levels in blood and cerebrospinal fluid and degree of arteriographic vasospasm. Results  In control monkeys, mean (SD) cerebrospinal fluid nitrite levels decreased from 3.1 (1.5) µmol/L to 0.4 (0.1) µmol/L at day 7 and to 0.4 (0.4) µmol/L at day 14 (P = .03). All 8 control monkeys developed significant vasospasm of the right middle cerebral artery, which was complicated by stroke and death in 1 animal. Sodium nitrite infusions increased the nitrite and methemoglobin levels (<2.1% of total hemoglobin) in the blood and cerebrospinal fluid without evoking systemic hypotension. Nitrite infusion prevented development of vasospasm (no animals developed significant vasospasm; mean [SD] reduction in right middle cerebral artery area on day 7 after subarachnoid hemorrhage of 8% [9%] in nitrite-treated monkeys vs 47% [5%] in saline-treated controls; P<.001). There was a negative correlation between the concentration of nitrite in cerebrospinal fluid and the degree of cerebral vasospasm (P<.001). Pharmacological effects of nitrite infusion were also associated with the formation of S-nitrosothiol in cerebrospinal fluid. There was no clinical or pathological evidence of nitrite toxicity. Conclusion  Subacute sodium nitrite infusions prevented delayed cerebral vasospasm in a primate model of subarachnoid hemorrhage.      

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.     

Selective opening of the blood-tumor barrier by a nitric oxide donor and long-term survival in rats with C6 gliomas

OBJECT: The response of brain tumors to systemic chemotherapy is limited by the blood-tumor barrier (BTB). Nitric oxide (NO) has been implicated in the regulation of vascular permeability and blood flow. The authors evaluated the effects of exogenous NO, which was released from a short-acting NO donor (Proli/NO), and those of NO metabolites on the capillary permeability of tumors and normal brain tissue by using quantitative autoradiography in a C6 glioma model in rats. METHODS: The Proli/NO was infused at a wide dose range (10(-2) to 10(-12) M) either intravenously or into the internal carotid artery (ICA) and demonstrated substantial tumor-selective increases in blood-brain barrier (BBB) permeability in response to various-sized tracers ([14C]aminoisobutyric acid, [14C]sucrose, [14C]dextran). Internal carotid artery or intravenous administration of sodium nitrite had a comparable effect on BTB permeability. The NO effect on microvascular permeability could be obtained without causing hemodynamic side effects. The effect of NO on the efficacy of carboplatin chemotherapy was investigated in intracerebral C6 gliomas. Simultaneous intravenous infusions of Proli/NO (10(-6) M) and carboplatin (20 mg/kg) led to long-term survival in 40% of rats harboring intracerebral C6 gliomas compared with control animals receiving ICA or intravenous infusions of carboplatin, Proli/NO, or vehicle alone. No residual tumor was demonstrated on histological or magnetic resonance imaging studies performed in rats treated with Proli/NO and carboplatin, and no toxicity was observed. CONCLUSIONS: This new approach demonstrated the in vivo efficacy and safety of NO and nitrite in enhancing the delivery of systemically delivered radiolabeled tracers and carboplatin into rat gliomas. The NO-induced tumor-selective BBB disruption and intravenous carboplatin chemotherapy may be more efficacious than current chemotherapy strategies against brain tumors.     

The synthesis and antibacterial activity of 3-alkyl derivatives of some pyrimido[4,5-d] pyrimidine

The synthesis of 4,5-diamino derivatives of pyrimidine and pyrimido[4,5-d]pyrimidines is presented. The antibacterial and antifungal activity of the compounds was investigated on nine selected bacterial species, comparing the changes in the chemical structure with increase in the bioactive properties. The investigations have shown that the obtained derivatives of pyrimido[4,5-d]pyrimidines and especially the compounds reveal interesting antibacterial 6e and antifungal 6d activity.     

肾康片质量标准的研究

目的：研究肾康片的质量标准并控制该制剂的质量。方法：用薄层色谱法鉴别了肾康片中的黄芪,山茱萸,桑寄生及丹参,用薄层色谱法限量检查屯该制剂中的乌头碱,用双波长薄层扫描法测定了该制剂中黄芪甲苷的含量。结果：乌头碱限量符合中国药典测定,黄芪甲苷的平均回收率为９７．５％,其ＲＳＤ为１．４３％。结论：本文的结果显示出这些方法可用于控制该制剂的质量,方法灵敏,简便,专属,准确。     

Radioimmunoassay of serum SP 1 and HPL in normal and abnormal pregnancies.

Serum concentrations of the pregnancy-specific beta 1-glycoprotein (SP 1) and human placental lactogen (HPL) were measured by radioimmunoassay in 372 blood samples obtained from 40 women in the second half of a normal singleton pregnancy. The mean level of SP 1 steadily increased from 40 micrograms/ml in the 22nd week of pregnancy to 168 micrograms/ml in the 36th week of gestation and thereafter reached a plateau. The half-life of SP 1 during the first week after delivery was about 39 h. The clinical value of SP 1 in comparison to HPL estimations was assessed in a prospective study of a few high risk pregnancies. There were no significant differences between serum SP 1 and HPL levels in pregnancies complicated by preeclampsia with or without intrauterine growth retardation and in twin pregnancies. Serum HPL and SP 1 levels were equally effective in predicting placental insufficiency with fetal growth retardation.     

虚拟现实技术在运动康复中的应用

目的:介绍虚拟现实技术在运动功能障碍的康复性训练领域的应用和新发展,讨论虚拟现实技术应用于运动康复的优势和前景。资料来源:应用计算机检索外文期刊PsycINFO和PubMed数据库1996/2006与虚拟现实技术在康复训练中应用相关的文章,检索语种为“English”,检索词为“motor rehabilitation,virtual reality”。检索中文期刊CNKI数据库1996/2006相关的文献,检索语种为中文,检索词为“康复,虚拟现实”。资料选择:根据摘要和关键词对资料进行初选,选择全面介绍虚拟现实技术的文章,以及近几年将虚拟现实技术应用于空间感知障碍和运动功能受损患者康复训练的实验研究报告。资料提炼:在上述3个数据库中分别检索到相关英文文献121篇,以及中文文献21篇,按上述标准纳入18篇,再继续搜索已有文献引用和被引用的参考文献,最后得到相关的中英文文献30篇。资料综合:30篇文献中,4篇文章详细介绍了虚拟现实技术在运动康复领域的应用,26篇实验报告了应用虚拟现实对受损的运动功能进行康复性训练的成效。按照运动康复的种类将研究报告分为4类:平衡和姿态训练、行走训练、上下肢康复训练和日常生活技能训练。通过模仿练习,感知运动受损的患者可以在虚拟环境中完成针对性训练任务,学会运动技能。在虚拟环境中习得的运动技能可以迁移到现实世界的真实任务中。结论:与传统康复训练方法相比,虚拟现实具有更安全、更有趣、针对性强、康复速度快、疗效好等优势。作为一种有效的运动康复技术手段,虚拟现实技术有很好的发展前景。