外周神经动作电位记录中刺激伪迹的消除方法

<正> 记录外周神经动作电位的实验中往往有难以克服的刺激伪迹。特别所记录的外周神经比较短时,此问题更为突出。一般常用的消除刺激伪迹方法亦不易奏效。通过摸索,我们找到一种简单的消除方法。现介绍如下:     

乳腺囊性增生病癌变过程中部分因素变化的意义

检测乳腺囊性增生病（ＦＣＤ）经不典型增生到癌变部分因素的变化。结果提示：从因明显ＦＣＤ症状活检至癌变为２～１０年；从Ⅱ级以上不典型增生到临床癌变需２～７年；癌变率为３．１％。ＦＣＤ患者存在性激素分泌调控失常，血浆雌激素和催乳素含量增加，导致上皮细胞增生。乳腺一般性增生细胞的ＤＮＡ含量和超微结构与正常乳腺上皮细胞相似；无肿瘤相关抗原及异常基因产物表达。而发生在一般性增生基础上的不典型增生则呈现细胞基因物质ＤＮＡ含量增加，部分为超４Ｃ的多倍体细胞；同时出现细胞膜和细胞核超微结构异常；雌激素受体含量增加，对性激素的依赖性和敏感性增强；部分不典型增生细胞出现胚胎性肿瘤相关抗原和异常基因产物表达。随不典型增生程度加重至乳腺癌，上述诸因素的变化趋势具有明显规律性。提示ＦＣＤ上皮细胞从一般性增生经不典型增生至乳腺癌为细胞生物学连续逐渐变化的过程。部分不典型增生细胞中具有癌倾向的细胞生物学行为异常和表型变化与乳腺癌发生密切相关。细胞核ＤＮＡ含量等异常变化及程度可作为乳腺癌前病变发展程度的客观标志     

骨髓腔静脉造影在特发性股骨头坏死诊断中的应用

本文介绍17例（34髋）特发性股骨头坏死、4例（4髋）正常人骨髓腔静脉造影所见。发现25髋有异常改变,并经病理证实。作者认为:①骨干返流;②2支或2支以上静脉不显影;③多条静脉明显变细;④干骺端瘀积是股骨头坏死的造影表现,前二者是可靠的诊断依据。造影结果提示髓腔静脉造影是一种安全而敏感的诊断技术。     

181例外伤性脾破裂的诊断和治疗

本文报导181例外伤性脾破裂，其中包括21例延迟性脾破裂的诊断和治疗。术中脾损伤的临床分度有助于治疗方法的选择。及时．有效的止血和治疗以及重视对合并伤的防治是降低死亡率的关键。     

颈外动脉栓塞在耳鼻咽喉科的应用

在耳鼻咽喉科手术中应用颈外动脉栓塞法１０例，形成栓塞组，并把单纯颈外动脉结扎１０例作为对照组。结果表明：栓塞组较对照组术中出血量显著减少，有利于病灶彻底清除，因而有提高治愈率减少复发率的作用。掌握栓塞位置、栓塞剂用量和注射速度是防止并发症的关键。     

Evaluation of peripheral blood involvement of mantle cell lymphoma by fluorescence in situ hybridization in comparison with immunophenotypic and morphologic findings.

Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease.     

Molecular epidemiology and control of nosocomial methicillin-resistant Staphylococcus aureus infection in a teaching hospital.

BACKGROUND AND PURPOSE: Nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection is difficult to control. Due to a dramatic increase in the nosocomial MRSA infection rate at our hospital from 2000 to 2001, this study was conducted to identify the source of these infections and the effectiveness of control measures. METHODS: 179 healthcare workers (HCWs) were screened for carriage of MRSA. Starting in April 2001, all patients with MRSA infection or colonization were put in strict contact and cohort isolation. The bacterial isolates of HCW carriers and patients with MRSA infection from April 2001 to September 2001 were subjected to antimicrobial susceptibility testing by disk-diffusion method and molecular typing by pulsed-field gel electrophoresis (PFGE). RESULTS: Fifteen HCWs were found to be carriers of MRSA. They were all given topical mupirocin treatment. After these interventions, the nosocomial MRSA infection rate decreased from 1.23 to 0.53 per 1000 patient-days. All 61 MRSA isolates available for antimicrobial susceptibility testing and molecular typing were multidrug resistant. PFGE study revealed 2 predominant types, type C and type Y, comprising 36 and 12 isolates, respectively. CONCLUSIONS: The current study demonstrates the importance of measures to control nosocomial MRSA infections in hospitals that already have a high incidence of endemic MRSA infection. Elimination of carriage by healthcare workers, and strict contact and cohort isolation are the main effective measures.     

Absence of relaxation to lactate in human placental vessels of pregnancies with severe preeclampsia

OBJECTIVE: Our objective was to determine whether the observed relaxation to lactate and other agents in placental vessels of normal pregnancies is altered in severe preeclampsia.STUDY DESIGN: Isolated placental arteries and veins from women with severe preeclampsia and uncomplicated term pregnancies were precontracted with prostaglandin F_2α under 5% oxygen and 5% carbon dioxide with the balance nitrogen (Po₂ 35 to 38 torr) and then exposed to lactate (1 to 10 mmol/L, pH 7.4, n = 8 to 15), arachidonic acid (0.01 to 10 μmol/L, n = 6 to 13), nitroglycerin (1 nmol to 1 μmol/L, n = 4 to 12), or forskolin (0.01 to 10 μmol/L, n = 6 to 9). The response to lactate was also examined in placental vessels from appropriate-for-gestational-age preterm deliveries (n = 8) for comparison with a similar group with severe preeclampsia (n = 8). The t test and analysis of variance statistics were used.RESULTS: Relaxation to lactate was markedly inhibited in both placental arteries and veins of women with severe preeclampsia compared with vessels from uncomplicated term or preterm pregnancies. Responses to the other relaxing agents were not altered in the severely preeclampsia vessels.CONCLUSIONS: In severe preeclampsia absence of lactate-induced dilatation of placental vessels may contribute to the fetal complications associated with impaired blood flow and vasospasm.     

Use of epr oximetry with india ink to measure the po2 in the liver in vivo in mice

The partial pressure of oxygen (pO₂) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO₂ below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO₂ measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO₂ decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI₄)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI₄-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI₄-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO₂ of the liver in vivo and that the pO₂ in the Kupffer cells is decreased when the liver is damaged by CCI₄.