电位滴定法的计算原理及Excel软件应用

阐述了电位滴定法的计算原理以及Excel软件在电位滴定数据处理中的应用。     

经迷路进路听神经瘤术后脑脊液漏的预防及处理

目的　探讨经迷路进路听神经瘤切除术后脑脊液漏发生的影响因素及处理方法。方法1999年以来采用迷路进路或扩大迷路进路听神经瘤切除术 85例 ,前 4 1例采用传统关闭术腔技术 ,后4 4例对关闭技术进行改良 ,分析其脑脊液漏的发生率。发生脑脊液漏者行保守或手术治疗。结果传统关闭技术组中脑脊液漏的发生率为 19 5 % ( 8 4 1) ,改良关闭技术组中脑脊液漏的发生率为 2 3%( 1 4 4 ) ,两组差异有显著性意义 (P =0 0 13)。传统关闭技术组中脑脊液漏多数发生在大型听神经瘤中 ,其发生率随肿瘤增大有上升的趋势。 9例脑脊液漏的患者中 ,3例经保守治疗 ;6例经手术修补成功 ,其中 5例 1次修补成功。结论　改良关闭术腔技术可显著降低经迷路进路听神经瘤切除术后脑脊液漏的发生率 ,手术修补为终止脑脊液漏的有效措施     

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration /= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.     

Hypospadias trends in two US surveillance systems

OBJECTIVE: Hypospadias is a common congenital anomaly, the cause of which is unknown. Unexplained increases in the rates of hypospadias occurred in five European countries in the 1970s and 1980s. We examined data from two birth defects surveillance systems in the United States for evidence of similar trends. METHODOLOGY: The Metropolitan Atlanta Congenital Defects Program (MACDP) provided birth prevalence rates from 1968 to 1993. The nationwide Birth Defects Monitoring Program (BDMP) provided rates from 1970 to 1993. MACDP data are population-based and could be categorized by the severity of the hypospadias. BDMP data allowed analysis of rate trends for the four census regions of the United States. RESULTS: Data from both surveillance systems showed an approximate doubling of hypospadias rates in the 1970s and 1980s. MACDP data showed that the rate of severe cases increased while the ratio of mild to severe cases decreased. BDMP data showed that hypospadias rates increased markedly in all four regions of the United States. CONCLUSIONS: The observed increases are unlikely to be attributable to increased sensitivity of the surveillance systems or the identification of more mild cases by physicians over time, because either trend would have increased rather than decreased the ratio of mild to severe cases. If real, these trends represent the largest number of cases and the first report of an increase in hypospadias rates outside of Europe. Additional investigation of a possible increase in hypospadias rates is warranted.     

Marked enhancement of anti-allodynic effect by combined intrathecal administration of the adenosine A1-receptor agonist R-phenylisopropyladenosine and morphine in a rat model of central pain

BACKGROUND: There is often no satisfactory treatment for chronic pain after spinal cord injury. We have previously reported that intrathecal (i.t.) administration of the adenosine A1-receptor agonist R-phenylisopropyl-adenosine (R-PIA) or the opioid morphine has anti-allodynic effects in a model of presumed chronic central pain after photochemically induced spinal cord injury in rats. In the present study, we set out to investigate the possible interaction between i.t. R-PIA and morphine in spinally injured rats. METHODS: Sprague-Dawley rats displaying allodynia-like behaviors to mechanical and cold stimuli after photochemically induced spinal cord injury with minor motor deficits were used. R-PIA and morphine, either alone or in combination, were administered i.t. through an implanted catheter to lumbar spinal cord. RESULTS: Cumulative doses of R-PIA or morphine dose-dependently reduced the mechanical allodynia-like behavior, with a threshold of 1 nmol and 1.5 nmol, respectively. When co-administrated, R-PIA and morphine produced marked suppression of mechanical allodynia at doses of 5 pmol and 7.5 pmol, respectively. The effect of i.t. co-administration of R-PIA and morphine on cold allodynia was comparable to i.t. R-PIA alone. The combination of R-PIA and morphine did not increase adverse effects such as motor deficits in comparison to either drug alone. CONCLUSION: These results demonstrate a supra-additive interaction between the adenosine A1-receptor agonist R-PIA and morphine to reduce mechanical allodynia-like behavior in rats with chronic spinal cord injury. The combination of R-PIA and morphine administered spinally may be superior to R-PIA or morphine alone for treating such pain.     

兔蜗神经直接动作电位的特征

目的　探讨新西兰大白兔蜗神经直接动作电位 (directcochlearnerveactionpotential,DCNAP)的记录方法和特征 ,建立术中听觉监护动物模型。方法　纯种新西兰大白兔 6只 (12耳 ) ,乙状窦后进路暴露小脑、脑干及双侧桥脑小脑角区 ,插入针状电极于蜗神经 ,记录DCNAP ,并按常规方法记录听性脑干反应 (auditorybrainstemresponse ,ABR)。结果　用本方法记录的DCNAP具有振幅大、波形稳定、重复性好、记录时间短的特点 ,但个体差异较大。结论　在蜗神经桥脑小脑角区用针状电极可以可靠记录到DCNAP ,是术中听觉监护的可行方法     

螺旋CT三维重建在鼻骨骨折中的临床应用价值

目的：探讨螺旋CT三维成像对鼻骨骨折的诊断价值。方法：应用GE Lightspeed Plus多排螺旋机扫描仪，对46例鼻外伤患者进行鼻骨横断面扫描和三维重建成像，并对检查结果进行分析。结果：46例鼻外伤患者中，9例普通X线侧位平片未发现骨折(19．6％)；CT图像均能清晰显示骨折线，其中单纯鼻骨骨折32例(69.6％)，并发上颌骨额突骨折11例(23．9%)，上颌窦骨折1例，筛窦纸样板骨折3例，鼻中隔断裂1例。结论：螺旋CT三维成像对于诊断鼻骨骨折具有重要的诊断价值。     

彝族儿童幽门螺杆菌感染HLA-DQA1免疫遗传学特征分析

目的研究人类白细胞抗原(HLA)DQA1基因位点上是否存在H.pylori感染的易感基因或抵抗基因，探讨免疫遗传因素在H.pylori感染中的作用。方法用聚合酶链反应-序列特异性引物(PCR-SSP)技术对用血清学试验及^13C尿素呼气实验确诊的31例H．pylori感染的彝族儿童及39例无感染儿童进行HLA．DQA1基因分型。结果感染组HLA-DQA1*0102等位基因频率明显高于对照组(14．52％vs3．85％，P=0．025，Pc=0．35)，OR=4．245(95％CI：1．097～16．428)；感染组HLA-DQA1*0302等位基因频率低于对照组(0 vs12．82％，P=0．003，Pc=0．042)，OR=1．147(95％CI：1．053-1．249)。结论在HLA-DQA1位点上，H．pflori感染的彝族儿童与对照组儿童存在免疫遗传学差异，HLA-DQA1*0102基因可能是彝族H．pylori感染的易感基因，而HLA-DQA1*0302基因则可能是抵抗基因和具有免疫抵抗作用。     

儿童鞍区肿瘤的手术治疗

目的 探索儿童鞍区肿瘤的有效手术治疗方法。方法 回顾性分析53例儿童鞍区肿瘤患者的临床资料，其中颅咽管瘤29例，生殖细胞瘤7例，垂体瘤11例，表皮囊肿2例，星形细胞瘤1例，恶性畸胎瘤1例，神经鞘瘤1例，蛛网膜囊肿1例。29例患儿行经额下硬脑膜入路，13例经改良翼点入路，11例经蝶窦入路，16例行脑室一腹腔分流术。结果 肿瘤全切除32例；次全切除16例；大部切除5例。术中22例可见垂体柄，均予保留。术后出现多饮多尿27例，其中20例在术后2周内恢复正常；出现高钠血症7例，低钠血症7例，均在2周内恢复正常，术后死亡2例。随访30例，其中3例术后1年内复发而再次手术，2例行γ-刀治疗，25例患儿术后可参加正常学习。结论 选择合适的手术入路，并注意保护下丘脑结构，防止其供血动脉损伤，是儿童鞍区肿瘤手术治疗的原则和取得较好效果的关键。