常用筛查方法在地中海贫血诊断中的临床应用

目的探讨常用地中海贫血(简称地贫)筛查方法红细胞平均体积(MCV)、红细胞脆性试验(一管定量法)、血红蛋白(Hb)电泳分析等单项或联合检测在地贫诊断中的应用。方法研究对象来自肇庆市第一人民医院产检、婚检及健康体检者,经基因确诊为地贫200例,非地贫80例,分析其MCV、红细胞脆性试验、Hb电泳分析等不同检测方法单项或联合检测诊断地贫的灵敏度和特异度。结果 MCV、红细胞脆性试验、Hb电泳分析等3种方法单项检测对地贫诊断的灵敏度分别为97.5%、86.0%和82.0%,特异度分别为76.3%、88.8%和93.8%,MCV与红细胞脆性试验联合检测的灵敏度和特异度分别为80.5%、90.0%,红细胞脆性与Hb电泳分析的灵敏度和特异度分别为75.5%和95.0%,MCV与红细胞脆性及Hb电泳3项联合检测的灵敏度和特异度为72.0%、100%。结论用MCV筛查地贫灵敏度较高,可作为筛查的首选方法 ,MCV、红细胞脆性试验及Hb电泳联合检测能大大提高诊断特异度。但这些方法对α地贫,尤其是轻型及静止型α地贫漏诊率较高。     

针刺临床研究中常用的Rs-fMRI分析方法:10年概况

Rs-fMRI是一种用于针刺临床中研究脑部活动的一种科学放法，Rs-fMRI分析方法可以辅助研究者得出研究结论，从而反馈于临床实践中。Rs-fMRI分析方法在近十年针刺临床研究中常用的有3种:局部一致性（ReHo）、低频振幅分析（ALFF）、功能连接性分析（FC）。ReHo在针刺研究中可用于研究某穴位激活或抑制，某个脑区或某几个脑区，从而得出该穴位的靶效应脑区，为研究“穴位-脑-疾病”打下基础；ALFF可直接反映局部神经元自发同步化神经活动的强度，在一定程度上反映各相关脑区间的相互作用和神经网络连接；FC可以得出脑区之间的功能连接，即脑区间的“高速路”，其简单易懂，结果直接。运用不同的分析方法可以显示针刺不同穴位的脑部活动，如局部神经活动的同步性、相邻脑区之间的连接性及大脑的自发波动及功能活动等。本文将阐述ReHo、ALFF、FC 3种分析方法在针刺研究中的适用研究方向。      

Impairment of coagulation by commonly used resuscitation fluids in human volunteers

Background

This study compared the effects of two commonly used resuscitation fluids on whole blood coagulation.

Methods

1000 ml of two resuscitation fluids each (saline and Gelofusine) were given to eight volunteers in a crossover design with a 2‐week washout period. The effect on whole blood coagulation was assessed using the Sonoclot analyzer, a conventional coagulation screen and coagulation markers.

Results

No significant effect was found on whole blood coagulation by giving saline (time to peak clot increased by a mean of 106 s; (95% confidence interval (CI) –140 to 354), whereas Gelofusine delayed the time to peak by a mean of 845 s (95% CI 435 to 1255). By contrast, there was no change in the conventional coagulation screen with either fluid.

Conclusion

It was concluded that some resuscitation fluids have an effect on clot formation that is not shown by the conventional coagulation screen, but is disclosed only if the whole coagulation process is studied.There is an ongoing controversy about the relative merits of different types of resuscitation fluid.¹ In this discussion, the effects of different fluids on coagulation is rarely mentioned, despite coagulopathy often being a problem after large‐volume fluid resuscitation. The origin of this coagulopathy is multifactorial,² and it is usually assumed that resuscitation fluids contribute by cooling the patient and diluting clotting factors. However, there may also be a direct effect owing to an interaction between resuscitation fluid molecules and the coagulation system.Using whole blood coagulation analysis, we have already found a wide variation in the in vitro effects of resuscitation fluids on coagulation, with no simple crystalloid or colloid difference.³ We know that in vitro 0.9% saline has a procoagulant effect at lower dilutions and an anticoagulant effect at higher dilutions, and that Gelofusine has a marked anticoagulant effect.⁴ If this direct effect of a resuscitation fluid on coagulation was also present in vivo, it would influence the choice of fluid given to the bleeding patient in emergency care. This study compares the effects of saline and Gelofusine on whole blood coagulation in human volunteers.     

Inhibition of matrix metalloproteinases by chemically modified tetracyclines in sepsis

Sepsis precipitates a systemic inflammatory stimulus that causes systemic release of cytokines and sequestration of polymorphonuclear neutrophils, resulting in degranulation of matrix metalloproteinases (MMPs), which causes extracellular matrix basement membrane degradation. One of the important anti-inflammatory properties of tetracyclines is their ability to inhibit MMPs. In this study, we focused on the regulation of MMPs in sepsis and their reduction by treatment with nonantimicrobial chemically modified tetracyclines (CMTs), which retain their anti-inflammatory activity. Sepsis was induced by cecal ligation and puncture (CLP) method. At 24 h and 1 h before CLP, some rats received CMT-3 (25 mg/kg), another group of rats received hydroxamate (H; an inhibitor of MMP; 25 mg/kg), and untreated rats received saline by gavage. At 0 h, 0.5 h, 1.5 h, and 24 h after CLP, blood and liver samples were collected. Plasma and liver MMP-9 by zymography and Western immunoblotting, plasma nitric oxide by measuring nitrate level, plasma glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) by enzymatic method, and liver gelatinase by radiolabeled gelatin lysis assay and 24 h mortality were determined. Plasma MMP-9 (92 kDa), nitrate, and GOT and GPT levels were elevated compared with the time 0 level and reached peak at 1.5 h CLP and remained high for 24 h. Both CMT-3 and H treatment reduced GOT,GPT, 92-kDa gelatinase, and nitrate levels throughout the 24 h. CMT-3 and H are equally effective in sepsis treatment. The 24-h mortality for CLP rats was 30%, whereas pretreatment with CMT-3 and H resulted in 0% mortality. Hepatic MMP-9 and gelatinase activity increased significantly after CLP, and pretreatment with CMT-3 and H inhibited these expressions. These results indicate the beneficial effect of CMT-3 in preventing the increase in GOT, GPT, NO, MMP-9, gelatinase activity, and the ensuing septic shock.     

Relative transmissivity of ultrasound coupling agents commonly used by therapists in the UK

Coupling agents are required when using therapeutic ultrasound (US) to maximize acoustic contact between the transducer and the insonated tissue. US beam power is attenuated to varying extents by different couplants and this may influence treatment efficacy, since therapeutic effects are dose-dependent. It is therefore important to know how well different couplants transmit US. In this study, the transmission characteristics of a range of gel couplants were measured using a radiation force balance. Data were collected for gels commonly used by UK therapists and at the powers and frequencies advocated for low-intensity therapeutic practice. Transmissivities of standard couplants relative to degassed water varied between 95% and 108% (nominal 95% confidence intervals between 0% and 11%). The spread and ranking of transmissivities changed when the US frequency was varied. For clinical purposes, however, there was no significant difference between transmissivities of the gels under test.     

北京某医院临床医师常用医学检索软件与工具的调查

目的了解不同级别临床医师常用医学检索软件和工具的使用情况。 方法设计调查问卷,分别对北京市某医院高年级见习医师、住院医师、主治医师、副主任/主任医师（≤45岁、>45岁各50名）各100名进行问卷调查。 结果高年级见习医师检索软件首选百度（50%）、检索工具首选手机（65%）;住院医师检索软件首选临床指南（60%）,检索工具首选手机（63%）;主治医师检索软件首选临床指南（58%）,检索工具首选手机（55%）;副主任/主任医师≤45岁者检索软件首选PubMed（46%）、检索工具首选台式机（44%）,而>45岁者检索软件首选百度（44%）,检索工具首选台式机（72%）。 结论不同级别临床医师首选医学检索软件和工具不同,可能与年龄、教育环境、个人习惯等有关。     

黄芪植入可控降解胶原支架控释促血管生成的效应

目的：将中药黄芪载入胶原支架内,通过对胶原支架进行修饰,观察黄芪能否代替生长因子起到促进血管生成疗效,并了解黄芪与生长因子是否有协同作用. 方法：实验于2004-07-01/2006-07-01在德国亚琛工业大学生化研究所及江苏省中医院中心实验室进行.首先通过不同的EDC/NHS与肝素钠比例来交链修饰Ⅰ型胶原（EDC与NHS质量比固定为1∶0.6,EDC与肝素钠比例为0.2～4）,然后将1 mL黄芪注射液（相当于3 mg生药黄芪）载入修饰后的胶原内.体外通过甲苯胺蓝法测定修饰后胶原内肝素含量,胶原酶降解法测量胶原体外降解率,同时对胶原的亲水性及自由氨基团进行测定.体内通过鸡胚绒毛尿囊膜模型进行血管计数及血红蛋白测定. 结果：①体外实验结果：通过对胶原的修饰程度,可以控制胶原内的肝素含量、体外降解率、自由氨基团含量、亲水性大小.②体内实验结果：黄芪注射液1 mL载入修饰后的胶原较载入未修饰的胶原,可以明显促进鸡胚绒毛尿囊膜内微血管生成,提高胶原内血红蛋白含量（P＜0.01）,其疗效与重组人体血管内皮生长因子载入修饰后的胶原内相当,且与血管内皮生长因子有协同作用的趋势. 结论：通过对胶原的修饰来控制胶原的体外降解,载入黄芪后,使黄芪促血管生成疗效增强,达到与血管内皮生长因子载入后的疗效相当,其作用机制有待进一步研究.     

Inhibition of breast cancer cell extracellular matrix degradative activity by chemically modified tetracyclines

BACKGROUND: Inhibition of tumour cell proliferation, invasion and metastasis by chemically modified tetracyclines has been ascribed to inhibition of matrix metalloproteinase (MMP) activity. METHODS: Exposure of the human breast carcinoma cell line MDA-MB-231 or its MMP-9-overproducing transfected clone (E-10) to 6-demethyl, 6-deoxy, 4-de [dimethylamino]-tetracycline (CMT-3), a chemically modified non-antimicrobial tetracycline followed by analysis using gelatinase activity assay, zymography, degradation of radiolabelled extracellular matrix (ECM), Western blotting, TNF-alpha ELISA and cell viability assays. RESULTS: CMT-3 treatment results in diminution in extracellular MMP-9 protein levels as well as inhibition of gelatinase activity. This prevents cell-mediated ECM degradation without inducing general cytostasis or cytotoxicity. Culturing E-10 cells in 10 or 20 microM CMT-3 diminished secreted MMP-9 levels by 45% or 60%, respectively, but did not affect levels of most other secreted proteins, including tissue inhibitor of Metalloproteinases (TIMP-1). ECM degradation by E-10 cells or their conditioned medium was inhibited by approximately 20%-30% in the presence of 20 microM CMT-3, reflecting inhibition of MMP-9 activity in addition to diminution of released MMP-9 levels. TNF-alpha levels were also diminished in E-10 conditioned medium in the presence of CMT-3, but cell viability, measured by MTS reduction and cytosolic LDH retention, was unaffected. CONCLUSIONS: It is proposed that the reduction in ECM-degradative activity reflects diminished levels of expression as well as inhibition of enzymatic activity of MMPs released by cells in the presence of CMT-3. These multiple effects of CMT-3 may offer promise for use in suppressing tumour invasion, and if used in conjunction with other chemotherapy agents, may lead to more successful treatment of cancer.     

Inhibition of breast cancer cell extracellular matrix degradative activity by chemically modified tetracyclines

BACKGROUND. Inhibition of tumour cell proliferation, invasion and metastasis by chemically modified tetracyclines has been ascribed to inhibition of matrix metalloproteinase (MMP) activity.

METHODS. Exposure of the human breast carcinoma cell line MDA‐MB‐231 or its MMP‐9‐overproducing transfected clone (E‐10) to 6‐demethyl, 6‐deoxy, 4‐de [dimethylamino]‐tetracycline (CMT‐3), a chemically modified non‐antimicrobial tetracycline followed by analysis using gelatinase activity assay, zymography, degradation of radiolabelled extracellular matrix (ECM), Western blotting, TNF‐α ELISA and cell viability assays.

RESULTS. CMT‐3 treatment results in diminution in extracellular MMP‐9 protein levels as well as inhibition of gelatinase activity. This prevents cell‐mediated ECM degradation without inducing general cytostasis or cytotoxicity. Culturing E‐10 cells in 10 or 20?µM CMT‐3 diminished secreted MMP‐9 levels by 45% or 60%, respectively, but did not affect levels of most other secreted proteins, including tissue inhibitor of Metalloproteinases (TIMP‐1). ECM degradation by E‐10 cells or their conditioned medium was inhibited by ～ 20%–30% in the presence of 20?µM CMT‐3, reflecting inhibition of MMP‐9 activity in addition to diminution of released MMP‐9 levels. TNF‐α levels were also diminished in E‐10 conditioned medium in the presence of CMT‐3, but cell viability, measured by MTS reduction and cytosolic LDH retention, was unaffected.

CONCLUSIONS. It is proposed that the reduction in ECM‐degradative activity reflects diminished levels of expression as well as inhibition of enzymatic activity of MMPs released by cells in the presence of CMT‐3. These multiple effects of CMT‐3 may offer promise for use in suppressing tumour invasion, and if used in conjunction with other chemotherapy agents, may lead to more successful treatment of cancer.     

Comparison of gluteal and hamstring activation during five commonly used plyometric exercises

Background

Anterior cruciate ligament injuries occur frequently in athletics, and anterior cruciate ligament injury prevention programs may decrease injury risk. However, previous prevention programs that include plyometrics use a variety of exercises with little justification of exercise inclusion. Because gluteal and hamstring activation is thought to be important for preventing knee injuries, the purpose of this study was to determine which commonly used plyometric exercises produce the greatest activation of the gluteals and hamstrings.

Methods

EMG (Electromyography) amplitudes of the hamstring and gluteal muscles during preparatory and loading phases of landing were recorded in 41 subjects during 5 commonly used plyometric exercises. Repeated measures ANOVAs (Analysis of Variance) were used on 36 subjects to examine differences in muscle activation.

Findings

Differences in hamstring (P < .01) and gluteal (P < .01) activities were identified across exercises during the preparatory and landing phases. The single-leg sagittal plane hurdle hops produced the greatest gluteal and hamstring activity in both phases. The 180° jumps did not produce significantly greater gluteal or hamstring activity than any other exercise.

Interpretation

Single-leg sagittal plane hurdle hops may be the most effective exercise to activate the gluteals and hamstrings and may be important to include in anterior cruciate ligament injury prevention programs, given the importance of these muscles for limiting valgus loading of the knee. Because 180° jumps do not produce greater gluteal and hamstring activation than other plyometric exercises, their removal from injury prevention programs may be warranted without affecting program efficacy.     

假肢常用材料与人体皮肤摩擦学及其生物相容性

背景:目前主要采用强度高,质量轻的高分子材料来制造假肢零部件,其中热塑性塑料板材、树脂基复合材料、低温热塑材料采用最广泛.目的:分析假肢常用高分子材料与人体皮肤的摩擦学及生物学相容性.方法:由作者检索1990/2008万方数据库有关假肢的常用材料及其与皮肤摩擦学和生物学相容性等方面的文献.结果与结论:聚乙烯、聚丙烯以及改性聚酯等热塑板材,低温热板材料,硅橡胶,钛合金等均与人体皮肤具有良好的生物相容性,但与人体皮肤摩擦学方面各有优缺点,今后应以分子生物学研究和毒理学研究为基础,不断改进假体材料的组织相容性,更进一步探讨假体材料在人体内生理环境下的摩擦行为,找到更为确实可靠的理论依据进行体外实验,以便更好的设计假体模型,达到仿生效果.     

假肢常用材料与人体皮肤摩擦学及其生物相容性

背景：目前主要采用强度高,质量轻的高分子材料来制造假肢零部件,其中热塑性塑料板材、树脂基复合材料、低温热塑材料采用最广泛。目的：分析假肢常用高分子材料与人体皮肤的摩擦学及生物学相容性。方法：由作者检索1990/2008万方数据库有关假肢的常用材料及其与皮肤摩擦学和生物学相容性等方面的文献。结果与结论：聚乙烯、聚丙烯以及改性聚酯等热塑板材,低温热板材料,硅橡胶,钛合金等均与人体皮肤具有良好的生物相容性,但与人体皮肤摩擦学方面各有优缺点,今后应以分子生物学研究和毒理学研究为基础,不断改进假体材料的组织相容性,更进一步探讨假体材料在人体内生理环境下的摩擦行为,找到更为确实可靠的理论依据进行体外实验,以便更好的设计假体模型,达到仿生效果。     

Contraindications and side effects of commonly used medications in coronary CT angiography

For certain clinical applications, coronary CT angiography (CCTA) has become a useful tool for the noninvasive evaluation of coronary artery atherosclerosis. To optimize image quality in CCTA, medications are often given prior to scanning to slow the heart rate or distend the arteries. These medications have side effects and are contraindicated in certain patient populations. Metoprolol is the ß-blocker of choice in CCTA, and it has been shown to be effective in achieving the goal heart rate of less than 65 beats per minute for CCTA and in minimizing variability of heart rate. It is contraindicated in patients with hypotension or high degree AV block, and it must be used with caution in patients with asthma or obstructive pulmonary disease, patients with decompensated heart failure, and those with vasospastic or vasoocclusive disease. Diltiazem, the calcium channel blocker of choice in CCTA, is a reasonable alternative for heart control, particularly in patients with asthma or bronchospastic disease, and patients with orthotopic heart transplants that have been sympathetically denervated. Sublingual nitroglycerin is especially useful in order to dilate distal arteries to improve stenosis visibility. However, it is contraindicated in patients on erectile dysfunction medications and those with severe anemia. It must be used cautiously in patients with aortic stenosis or other preload-dependant cardiac pathologies.     

Comparison between cardiac output measured by thermodilution technique and calculated by O2 and modified CO2 Fick methods using a new metabolic monitor

Objective: To calculate cardiac output from dual oximetry with carbon dioxide production (VCO₂) and oxygen consumption (VO₂) measured by a new metabolic monitor, and to compare these values with measurements made simultaneously using the thermodilution method during the steady state condition. Design: Prospective, comparative clinical study. Setting: The adult postsurgical intensive care unit (ICU) of a University Hospital. Patients: Twenty mechanically ventilated postsurgical patients (70.7 ± 7.8 years of age; range 50–84). Measurements and results: A new metabolic monitor (Puritan-Bennett 7250, Carlsbard, USA) connected to a ventilator (Puritan-Bennett 7200) was used to measure VCO₂ and VO₂. Measurements of arterial (SaO₂) and mixed venous (SvO₂) oxygen saturations were made using pulse and venous fiberoptic oximeters. Cardiac output starting from VCO₂ (CO_VCO2) was obtained according to Mahutte's formula: CO_VCO2 = VCO₂/[k (SaO₂− SvO₂)], where k represents a constant. The value for each patient was determined from the initial measurements of thermodilution cardiac output (COtd), VCO₂, SaO₂ and SvO₂. CO_VCO2 calculated from the previous equation was compared to the COtd. Cardiac output calculated from the traditional O₂ Fick equation (CO_VO2) was compared to the COtd. All patients were studied over a period of 120 min at 15-min intervals in reasonably stable conditions. CO_VCO2 was closely related to COtd (r = 0.94; SEE = 0.79; p = 0.0001; n = 180) with a bias of − 0.10 and a precision of 0.45 l/min. The mean percent difference between the two methods was − 2.2 ± 8.3 %. CO_VO2 was related to COtd (r = 0.77; SEE = 0.79; p = 0.0001; n = 180) with a bias of − 0.57 and precision of 0.86 l/min. The mean percent difference between the two methods was − 10.8 ± 16.0 %. Conclusions: In stable patients, cardiac output measurements obtained from dual oximetry with VO₂ and VCO₂ measured by this new metabolic monitor, show good correlation with measurements made using the thermodilution method. The values of cardiac output calculated from VCO₂ are more accurate and precise than values from VO₂. The validity of these measurements in hemodynamically unstable patients and during various modes of mechanical ventilation seems warranted. Received: 5 February 1997 Accepted: 16 June 1997