Human platelet phenol sulphotransferase: Assay procedure, substrate and tissue correlations

Procedures for the precise assay of human platelet phenol sulphotransferase activity were determined. The coefficient of variation of the assay was 5.8% when the enzyme activity was expressed per 10⁸ platelets, and was 9.4% when it was expressed per mg soluble platelet protein. Mean platelet phenol sulphotransferase (PST) activity in samples from 102 randomly selected adults was 1.2 ± 0.4 units/10⁸ platelets (mean ± S.D.), with a range from 0.2 to 2.9. The mean activity for umbilical cord blood platelet PST was 0.93 ± 0.3 units/10⁸ platelets (mean ± S.D., N = 27). The substrate used routinely for the assay was 3-methoxy-4-hydroxyphenylglycol (MHPG). There was a significant correlation between the formation of MHPG sulfate by individual platelet preparations and the formation of sulfated product with each of the following substrates: tyramine (r = 0.92, n = 21); dopamine (r = 0.82, n = 16); 5-hydroxytryptamine (r = 0.94, n = 20); acetaminophen (r = 0.77, n = 17); and alphamethyldopa (r = 0.77, n = 17) (p < 0.001 for each). Platelet PST activity correlated significantly with human renal cortex PST activity (r = 0.54, n = 20, p < 0.02). The correlation coefficient between platelet PST activity and jejunal mucosal enzyme activity in eight patients was 0.67. These results raise the possibility that human platelet PST activity measured with MHPG as substrate might reflect the enzyme activity in other tissues and the degree of sulfate conjugation of a variety of substrates.     

Comparison of cyclosporin A measurement in whole blood by six different methods

In a multicentre trial, we analyzed and compared the cyclosporin concentrations in whole blood specimens (trough values) from renal and bone marrow transplant patients using six different methods: high-performance liquid chromatography (n-butyl reversed-phase column) as reference, and 5 immunoassay procedures using monoclonal specific or non-specific antibodies, or polyclonal antibodies, for measuring cyclosporin with and without its cross-reacting metabolites. Results obtained by the 2 specific RIAs show good correlations (r-values of 0.945 and 0.921) versus the HPLC method, with average assay ratios of: 1.52 for 3H-RIA/HPLC and 1.26 for 125I-RIA/HPLC. In contrast, ratios for non-specific immunoassay/HPLC show multiple-fold overestimations of cyclosporin with very wide variations: 4.58 for 3H-RIA/HPLC, 3.97 for 125I-RIA/HPLC and 3.87 for fluorescence polarization immunoassay (FPIA)/HPLC. These findings indicate 1) that the 'specific' 3H- and 125I-RIAs can be used for cyclosporin measurements in whole blood using normal therapeutic ranges established by HPLC, 2) that the important disparity and variable overestimations by 'non-specific' RIA or fluorescence polarization immunoassay, compared with HPLC, require adjustments in therapeutic ranges, and 3) that the available 'specific' and 'non-specific' immunoassays should enable establishment of within-house reference 'therapeutic/toxic' ranges for cyclosporin in individual centres, based on these 'specific' versus 'non-specific' assays.     

Influence of tissue pressure on central venous pressure/peripheral venous pressure correlation: An experimental report

BACKGROUND: Peripheral venous pressure (PVP) has been shown to correlate with central venous pressure (CVP) in a number of reports. Few studies, however, have explored the relationship between tissue pressure (TP) and PVP/CVP correlation.METHODS: PVP and CVP were simultaneously recorded in a bench-top model of the venous circulation of the upper limb and in a single human volunteer after undergoing graded manipulation of tissue pressure surrounding the intervening venous conduit. Measures of correlation were determined below and above a point wherein absolute CVP exceeded TP.RESULTS: Greater correlation was observed between PVP and CVP when CVP exceeded TP in both models. Linear regression slope was 0.975 (95% CI: 0.959-0.990); r² 0.998 above tissue pressure 10 cmH₂O vs. 0.393 (95% CI: 0.360-0.426); and r² 0.972 below 10 cmH₂O at a flow rate of 2000 mL/h in the in vitro model. Linear regression slope was 0.839 (95% CI: 0.754-0.925); r² 0.933 above tissue pressure 10 mmHg vs. slope 0.238 (95% CI: -0.052-0.528); and r²0.276 in the en vivo model.CONCLUSION: PVP more accurately reflects CVP when absolute CVP values exceed tissue pressure.     

Ultrasonic propagation properties of excised human skin

Eight human skin samples were excised postmortem from the upper and lower back, chest and abdomen from two cadavers. The acoustical speed, attenuation and backscatter were measured as a function of frequency (20 to 30 MHz) at 100 positions on a uniform grid over a cross-sectional slice through each sample with the sound incident in a direction parallel to the skin surface. Measurements were made at 24 ± 0.5°C. Samples were then frozen, cut and stained for histological examination and quantification of fibrous proteins and fat content. The mean attenuation coefficients obtained for whole skin agreed well with previously published results. Employing the model = ₁ƒⁿ where is the attenuation coefficient in decibels per centimeter, ₁ is the value of the attenuation coefficient at 1 MHz and ƒ is frequency raised to the power n, mean values (±1 standard deviation) for epidermis were ₁ = 0.44 ± 0.26 and N = 1.55 ± 0.12, and for dermis ₁ = 0.264 ± 0.17 dB cm⁻¹ and N = 1.69 ± 0.084. Using a similar model the mean backscatter coefficient was defined by μ₁ = (5.01 ± 25.76) × 10⁻⁸Sr⁻¹ cm⁻¹, n = 3.77 ± 1.5 for the epidermis, and μ₁ = (1.79 ± 19.5) × 10⁻⁶ and n = 2.76 ± 1.4 for the dermis. The speed of sound values fell within the range to be found in the literature with a mean value in the epidermis of 1645 m s⁻¹ and in the dermis of 1595 m s⁻¹. Significant, strong correlation existed between the spatially averaged fibrous protein content in the epidermis and dermis and the spatially averaged integrated attenuation measurements. Likewise, strong correlation existed between integrated backscatter and fibrous protein content in the epidermis but not in the dermis. Further research is required to confirm these preliminary findings and to evaluate the role of collagen fibre orientation as a source of variation in the backscattering coefficient of dermis.     

New developments in the standardization of total prostate-specific antigen

Objective: Analytical evaluation of the calibration of three recently launched assays for the measurement of total prostate-specific antigen, i.e., IMx Total PSA (Abbott), Elecsys PSA (Roche), and IMMULITE 3rd Generation PSA (DPC).

Design and methods: For accuracy assessment two reference materials were applied namely, Stanford 90:10 PSA Calibrator and Certified Reference Material 613 Prostate-Specific Antigen. Dilutions of these preparations were analyzed with all assays. In addition, clinical specimens from known prostate cancer or benign prostate hyperplasia patients and samples taken from an ongoing prostate cancer screening study were used for comparison.

Results: Application of the Stanford Calibrator revealed results well within 10% of the calculated values for all assays. Regarding the CRM Calibrator only the IMx Total PSA proved to approach the line of identity. The IMMULITE results differed about 40% and the Elecsys about 18% from the calculated values. The comparison with clinical specimens showed statistically different results for the combination IMMULITE-IMx and for IMMULITE-Elecsys. The regression lines for both collections were: y(IMx)=0.86×(IMMULITE)+0.12 (n = 104, r = 0.970, S_y/x = 0.883 μg/L) and y(Elecsys)=0.98×(IMMULITE)+0.38 (n = 97, r = 0.976, S_y/x = 0.733 μg/L). In the lower measuring range (PSA < 5.0 μg/L) as measured with the screening samples (n = 43), these differences were less pronounced.

Conclusion: In analytical sense a difference was found for both reference preparations in the assays studied. Clinically, despite improvements in methodology, results for total prostate-specific antigen are still not interchangeable. The possible consequences need to be elaborated.     

The validity of oxygen content calculations

Blood oxygen content calculated from haemoglobin concentration, measured haemoglobin oxygen saturation and measured oxygen tension was compared with three other methods of estimating oxygen content. These other methods were those of Van Slyke and Zander, which are direct methods, and a method using Kelman's equation to estimate the saturation from meassured oxygen tension and hence content. The coefficients of correlation (corr coeff) (r) were 0.9050 (n = 22), 0.9919 (n = 24) and 0.9862 (n = 25) for the respective methods when compared with oxygen content calculated using measured saturation. The Van Slyke method proved to be imprecise in our hands. The direct measurement using the oxygen cuvette of Zander gave oxygen content values similar to those estimated from measured saturation. The oxygen content calculated from pO₂ alone when compared to that derived from measured saturation had a corr coeff (r) of 0.9862 (n = 25), but the high residual standard deviation (So) of 6.939 ml/l indicates that the practice of calculating oxygen content from oxygen tension alone is imprecise. We conclude that oxygen content may be satisfactorily estimated by the Zander method when it becomes generally available, but until then the measurement of oxygen saturation is a necessary prerequisite to the estimation of blood oxygen content.     

Central venous pressure, pulmonary artery occlusion pressure, intrathoracic blood volume, and right ventricular end-diastolic volume as indicators of cardiac preload

Central venous pressure (CVP), pulmonary artery occlusion pressure (PAOP) and right ventricular end-diastolic volume (RVEDV) are often regarded as indicators of both circulating blood volume and cardiac preload. To evaluate these relationships, the response of each variable to induced volume shifts was tested. The relationships between these variables and cardiac index (CI) and stroke volume index (SVI) was also recorded to assess the utility of each variable as an indicator of cardiac preload. The responses of the new variable intrathoracic blood volume (ITBV) to the same maneuvers was also tested. To examine the effects of changes in cardiac output alone on ITBV, the effects of infusing dobutamine were studied.

Ten anesthetized piglets were studied during conditions of normovolemia, hypovolemia, and hypervolemia. The effects of an infusion of dobutamine were examined under normovolemia and hypovolemia. Cardiac output was measured by thermodilution, and ITBV was measured by double-indicator dilution.

CI was correlated to CVP with r² = .42 (P ≤ .01), to PAOP with r² = .43 (P ≤ 5.01), to RVEDV index with r² = .21 (P ≤ .01), and to ITBV with r² = .78 (P ≤ .01) (pooled absolute values). Bias (mean difference of the percent changes with NORMOVOLEMIA = 100%) ± 1 SD; for SVI - ITBV index was 1 ± 22%, for SVI — CVP it was −128 ± 214%; for SVI — PAOP it was −36 ± 46%; and for SVI -RVEDV index it was 1 ± 29%. Dobutamine infusion increased heart rate (to about 190 × min⁻¹) and CI by 30% in normovolemia and hypovolemia, while ITBV remained basically unchanged.

Under the experimental conditions choosen neither CVP, PAOP, nor RVEDV reliably indicated changes in circulating blood volume, nor were they linearly and tightly correlated to the resulting changes in SVI. ITBV reflected both changes in volume status and the resulting alteration in cardiac output. The possibility that ITBV might be cardiac output-dependent was not supported. ITBV, therefore, shows potential as a clinically useful indicator of overall cardiac preload.     

Serum levels of tetranectin, intercellular adhesion molecule-1 and interleukin-10 in B-chronic lymphocytic leukemia

Background and objective: The fibrinolytic regulator tetranectin (TN), in association with the circulating intercellular adhesive molecule-1 (cICAM-1) and interleukin -10 (IL-10), may be involved in the metastatic cascade of B-chronic lymphocytic leukemia (B-CLL). Our aim was to investigate the potential usefulness of these molecules as prognostic markers in B-CLL.

Design and methods: Therefore, TN, cICAM-1, and IL-10 were assessed (ELISA) in the serum of 53 B-CLL patients, classified in Binet A, B, and C stages in comparison with those in 45 healthy subjects (HS).

Results: TN was significantly lower in B-CLL patients than in HS (9.63 [8.75–11.51] mg/L, 13.75 [12.56–14.64] ng/mL, respectively, p < 10⁻⁵), being lower (p = 0.05) in B and C stage patients (subgroup B+C) than in A stage ones (subgroup A). cICAM-1 levels were significantly higher in B-CLL patients than in HS (475.86 [355.86–593.79] ng/mL vs. 225.62 [118.49–312.83] ng/mL, respectively, p < 10⁻⁵) with a tendency for higher levels in subgroup B+C than in subgroup A. A significant correlation of cICAM-1 with lactate dehydrogenase (LDH) (r_s = 0.532, p = 0.049), and a significant increase in cICAM-1 in B-CLL with diffuse bone marrow infiltration (BMI) compared to that in B-CLL with nondiffuse BMI (624.48 [557.24–726.55] ng/mL vs. 480.34 [368.96–590.34] ng/mL, respectively, p = 0.0172) were found. A significant negative correlation between TN and cICAM-1 (r_s = −0.5017, p = 0.0001) was observed. IL-10 was detected in all B-CLL patients and in no HS (7.37 [5.30–10.55] pg/mL), being higher (p = 0.0153) in C than in A stage patients. A significant correlation of IL-10 with TN and cICAM-1 in subgroup B+C (r_s = −0.659 [p = 0.014] and r_s = 0.679 [p = 0.011], respectively) was found.

Conclusions: The abovementioned findings and good performance characteristics of TN and cICAM-1 in B-CLL suggest the potential usefulness of these adhesive/recognition molecules as prognostic markers in B-CLL. The implication of these molecules along with IL-10 in the disease process deserves further study.     

婴幼儿时期血管瘤患儿特异性生活质量现状及影响因素分析

目的 了解婴幼儿时期血管瘤患儿特异性生活质量现状,并分析其影响因素。方法 采用便利抽样法,选取2021年1月-2022年1月在笔者所在医院住院的126例血管瘤患儿及其父母为研究对象,采用一般资料问卷、中文版婴儿血管瘤特异性生活质量问卷、家庭复原力评定量表以及社会支持量表对其进行调查。结果 血管瘤患儿特异性生活质量问卷得分为(54.69±6.85)分,与家庭复原力以及社会支持均呈负相关(r=-0.681,P=0.001;r=-0.754,P=0.001)。多元线性回归分析结果显示,是否为独生子女、父母文化程度、家庭复原力以及社会支持水平是血管瘤患儿特异性生活质量的独立影响因素(R²=0.736,_△R²=0.695,F=15.241,P＜0.001)。结论 血管瘤患儿特异性生活质量处于中等水平,有待进一步提高,医护人员要着重关注非独生子女、父母文化程度低、家庭复原力以及社会支持水平低的血管瘤患儿及其父母,从个人、家庭以及社会不同层面对患儿及其父母提供支持,提升其特异性生活质量。     

Measurement of cyclosporine by liquid chromatography and three immunoassays in blood from liver, cardiac, and renal transplant recipients.

In an effort to replace HPLC for whole-blood determination of cyclosporine (CsA), we compared HPLC with radioimmunoassay (RIA; INCSTAR, Cyclo-Trac SP assay), fluorescence polarization immunoassay (FPIA; Abbott TDx), and in-house modified enzyme-multiplied immunoassay technique (EMIT; Syva Co.). For blood samples from 200 various transplant recipients, RIA = 1.262 (HPLC) - 8.16, r = 0.983; FPIA = 1.200 (HPLC) + 19.90, r = 0.981; and EMIT = 1.038 (HPLC) + 11.28, r = 0.985. For segregation by transplant type, RIA, FPIA, and EMIT demonstrated positive biases of 27%, 12%, and 3%, respectively, for liver transplant recipients (n = 50) when compared with HPLC. Heart transplant recipients (n = 50) gave positive bias values of 23%, 14%, and 4% for RIA, FPIA, and EMIT, respectively. Adult renal transplant recipients (n = 50) demonstrated positive bias values of 30%, 31%, and 0% for RIA, FPIA, and EMIT, respectively. For pediatric renal transplant recipients (n = 50), positive biases of 40%, 31%, and 9% were obtained for RIA, FPIA, and EMIT, respectively. We conclude that the modified EMIT represents the best replacement for HPLC.     

针灸联合生物反馈治疗直肠癌保肛术后排便失禁的效果

目的 探讨针灸联合生物反馈治疗直肠癌保肛术后排便失禁的效果。方法 2016年1月1日至2018年6月30日,本院收治的直肠癌保肛根治术后患者226例,筛选出排便失禁者120例,随机分为对照组(n = 40)、针灸组(n = 40)和观察组(n = 40)。术后1个月,三组均接受提肛锻炼,另外,针灸组接受针灸治疗,观察组接受针灸联合生物反馈治疗,共3个月。治疗前,治疗1、2、3个月分别检测各组大便失禁克利夫兰评分(CCF-FIS)、肛门直肠压力、盆底表面肌电和生活质量评分。结果 治疗前,三组CCF-FIS、肛门直肠压力、盆底表面肌电和生活质量评分均无显著性差异(F < 2.943, P> 0.05)。治疗后,三组CCF-FIS均下降,肛门直肠压力、盆底表面肌电和生活质量评分均明显改善(F > 5.235, P< 0.01);不同时间点,针灸组和观察组各指标均优于对照组(P< 0.05),观察组优于针灸组(P<0.05)。观察组治疗1个月疗效与肿瘤位置高低有关(χ² = 5.230, P< 0.05),治疗后各时间点疗效与术中是否行盆腔自主神经保存术(χ² > 5.657, P< 0.05)、术后是否增加放疗(χ² > 4.329, P< 0.05)有关。治疗结束后3个月随访时,观察组复发率(8.6%)低于针灸组(35.7%)和对照组(35.0%) (χ²> 5.976, P< 0.05),三组均未发生并发症。结论 针灸联合生物反馈治疗可改善直肠癌保肛患者术后排便失禁症状,促进肛门功能康复。     

改良式手-膝位分娩对初产妇分娩结局和舒适度的影响

目的评价第二产程中采用改良式手-膝位分娩对初产妇分娩结局和舒适度的影响。方法选取2019年10月1日—2020年3月31日在西安市某三级甲等医院产房中心分娩的290名初产妇为研究对象,采用随机数字表法分为试验组(n=145)和对照组(n=145),试验组在第二产程采用改良式手-膝位分娩,对照组采用屈膝半卧位分娩,比较两组分娩结局和舒适度的差异。结果试验组自然分娩率高于对照组(χ²=12.590)、会阴侧切率低于对照组(χ²=48.019)、第二产程时间短于对照组(t=-2.579)、产时及产后2 h出血量少于对照组(t=-2.134)、分娩舒适度问卷得分高于对照组(t=-10.775),差异具有统计学意义(均P<0.05);两组新生儿窒息率比较,差异无统计学意义(χ²=0.344,P=0.995)。结论改良式手-膝位分娩可提高产妇自然分娩率,缩短第二产程时间,降低会阴侧切率,减少产后出血,提高产妇分娩舒适度。     

A sensitive colorimetric assay for polyamines in erythrocytes using oat seedling polyamine oxidase

Background: Most of the polyamines circulating in blood are spermidine (Spd) and spermine (Spm) with only trace amounts of putrescine (Put), and they are mainly localized in erythrocytes. We developed a simple and sensitive colorimetric assay for polyamines in erythrocytes using oat seedling polyamine oxidase (OSPO). The method is based on the unique substrate specificity of OSPO, which is active toward Spd and Spm, but not toward diamines such as Put and cadaverine and monoamines such as histamine. Methods: The polyamines, which were purified from packed erythrocytes by weak cation-exchange chromatography, were incubated with OSPO at 37 °C for 15 min. In the presence of the H₂O₂ produced by this polyamine oxidase reaction and a new chromogen, N-(carboxymethylaminocarbonyl)-4,4′-bis(dimethylamino)-diphenylamine sodium salt (DA-64), peroxidase (POD) catalyzes the formation of N-[4-[[4-(dimethylamino)phenyl]imino]-2,5-cyclohexadien-1-ylidene]-N-methylmethanaminium chloride (Bindschedler's Green) having an absorption maximum at 727 nm. Results: The detection limit was 0.2 μmol/l for packed erythrocytes. The within-run and between-run precisions (coefficient of variation, CVs) were 5.6–15.2% and 6.5–16.4%, respectively. Analytical recoveries were 93.3–97.4%. Polyamine values obtained by this assay correlated well with those obtained by an HPLC (y=0.948x+1.912; r=0.944; n=46). Conclusions: This colorimetric assay is simple and highly sensitive and practical for clinical use.     

老年女性肌少症与平衡功能的相关性

目的 探讨老年女性肌少症与平衡功能之间的相关性。方法 2017年9月至11月,招募60~70岁老年女性224例,根据肌容量、握力和6米步速分为正常组(n = 198)和肌少症组(n = 26)。比较两组闭眼单足站立时间和5次坐立试验时间;闭眼单足站立时间和5次坐立试验时间分别与肌容量、握力和6米步速行Pearson相关分析。结果 老年女性肌容量、握力、6米步速单个指标异常率分别为20.5%、14.3%和2.2%,肌少症发生率11.6%。肌少症组闭眼单足站立时间显著短于正常组(t = 4.072, P < 0.001),5次坐立试验时间显著长于正常组( t = -5.461, P < 0.001);正常组闭眼单足站立时间与6米步速明显正相关( r = 0.675, P < 0.01);肌少症组闭眼单足站立时间与6米步速( r = 0.492)和握力(r = 0.286)均显著正相关(P < 0.001);两组5次坐立时间均与握力( r = 0.351, r = 0.462)、肌容量(r = 0.258, r = 0.321)、6米步速(r = 0.337, r = 0.396)显著正相关(P < 0.001)。 结论 相对肌肉质量和力量而言,老年女性增龄过程中肌肉功能保持相对较好。患肌少症的老年女性动静态平衡功能均下降。静态平衡主要与肌肉功能关系较大,动态平衡与肌肉质量、力量和功能均有关联。     

The effect of auto-positive end-expiratory pressure on the arterial-end-tidal carbon dioxide pressure gradient and expired carbon dioxide slope in critically ill patients during total ventilatory support

To examine the effect of auto-positive end-expiratory pressure (autoPEEP) on the estimation of arterial carbon dioxide pressure (PaCO₂) from end-tidal carbon dioxide pressure (PetCO₂) during changes in minute ventilation (MV), we studied 24 consecutive sedated and paralyzed patients under controlled mechanical ventilation for acute respiratory failure. The patients were grouped according to whether they had autoPEEP: group I (n = 11) comprised non-autoPEEP patients and group II (n = 13) comprised autoPEEP patients. Patients were randomly ventilated at three different levels of MV: normal MV (basal tidal volume), high MV (tidal volume 2.5 mL/kg above basal), and low MV (tidal volume 2.5 mL/ kg below basal). Respiratory rate and inspiration to expiration ratio were kept constant during the study. In each condition, we measured arterial blood gases, expiratory capnograms, airway pressure, and autoPEEP. We determined PaCO₂-PetCO₂ gradient, predicted PaCo₂ (Pa'CO₂) [Pa'CO₂ = PetCO₂ for each condition + (PaCO₂ PetCO₂ gradient at normal MV)], and expired CO₂ slope. The PaCO₂-PetCO₂ gradient only remained stable in group I (mean values for low, normal, and high MV were 3.3, 3.3, and 3.5 mm Hg, respectively), while group II showed a significant difference during low MV (12.2 mm Hg) when compared with normal MV (8.4 mm Hg; P < .01) and high MV (8.9 mm Hg; P < .05). PaCO₂ and PetCO₂ showed significant correlations in both groups (r = .92 in group I and .79 in group II). However, Pa'CO₂ could only be safely estimated in patients without autoPEEP when the difference between PaCO₂ and Pa'CO₂, ranged between 1.6 and −1.9 mm Hg. Slopes of expired CO₂ greater than 3 mm Hg/s identified patients with autoPEEP of 89% sensitivity, 93% specificity, 94% positive predictive power, and 95% accuracy. A significant correlation was found between autoPEEP and expired CO₂ slope (r = .70; P < .001), between autoPEEP and PaCO₂-PetCO₂ gradient (r = .46; P < .001), and between CO₂ expired slope and PaCO₂ PetCO₂ gradient (r = .74; P < .001). These results indicate that in patients with acute respiratory failure under controlled mechanical ventilation, the presence of autoPEEP is associated with inaccuracy in the calculation of predicted PacoZ from PetcoZ after changes in MV at fixed respiratory rates.     

Biomechanical characteristics of human trabecular bone

Objective. To evaluate the effect of strain rate (ġ3), apparent density (_a) and tissue density (_t) on Young's modulus (E), strength (σ_u) and ultimate strain (_u) on intervertebral bone from a Chinese population.

Methods. Testing was performed by uniaxial compression at five strain rates on 36 human trabecular bone specimens from three male T₁₂˜L₄ vertebrae.

Results. Apparent density ranged between 0.46 and 0.71 g/cm³. Tissue density ranged between 1.02 and 1.54 g/cm³. Non-linear regression analyses using strength, Young's modulus or ultimate strain as dependent variables (Y) and strain rate and apparent density or tissue density as independent variables were performed using the following equation: Y = a^bġ3^c. The exponent of apparent density and strain rate to Young's modulus were 1.88 and 0.07, separately (P = 0.0007). The variation of strength was explained only by apparent density with an exponent of 1.29 (P = 0.0107). The variation of Young's modulus was explained equally by the quadratic and cubic relationship to apparent density or tissue density (P < 0.01). Ultimate strain varied independently of apparent density or tissue density and strain rate.     

一次性气管切开集痰保湿防护罩在气管切开术后患者气道湿化中的应用效果

目的 评价一次性气管切开集痰保湿防护罩在气管切开术后非机械通气患者气道湿化中的应用效果.方法 选取气管切开术后非机械通气患者48例,随机将其分入传统组(n=16)、实验组(n=16)和对照组(n=16).传统组采用2层湿纱布覆盖气管切开导管口进行湿化,实验组使用防护罩湿化,对照组使用人工鼻湿化.比较3组患者呼吸功能、气...     

H型高血压并发缺血性脑卒中患者MTHFR C677T基因多态性及血清Hcy水平的相关性研究

目的 探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性及血清同型半胱氨酸(Hcy)水平与H型高血压并发缺血性脑卒中的相关性。方法 首先采用病例-对照研究,随机选取491例研究对象,分为对照组(n=111)、缺血性脑卒中组(n=185)、H型高血压并发缺血性脑卒中组(n=195)。其次采用聚合酶链反应-芯片杂交法测定MTHFR基因型,采用循环酶法检测血清Hcy水平,最后通过统计学方法分析基因型在不同组间的分布情况,以及不同基因型患者的Hcy水平。结果各实验组和对照组相比,MTHFR基因型分布差异均具有统计学意义(χ2=7.45～10.748,均P<0.05)。等位基因T频率和对照组比较,差异均具有统计学意义(χ2=4.343～9.886,均P<0.05)。而H型高血压并发缺血性脑卒中组和缺血性脑卒中组比较,MTHFR基因型分布差异无统计学意义(χ2=2.668,P=0.263)。各实验组TT型Hcy水平明显高于CT型和CC型,差异具有统计学意义(F=8.503～10.659,均P<0.05)。缺血性脑卒中组及H型高血压并发缺血性脑卒中组的Hcy水平(16.87±9.04,21.63±14.09 μmol/L)均高于对照组Hcy水平(10.76±2.44 μmol/L),差异具有统计学意义(F=37.942,P<0.001)。H型高血压并发缺血性脑卒中组的Hcy水平(21.63±14.09 μmol/L)高于缺血性脑卒中组Hcy水平(16.87±9.04 μmol/L),差异具有统计学意义(F=37.942,P<0.001)。结论 MTHFR基因多态性和血清高Hcy水平均可能为缺血性脑卒中的危险因素。对于H型高血压患者,更应注意在降压同时补充叶酸,以降低H型高血压患者缺血性脑卒中的发生率。     

The inter-relationships between albuminuria, plasma albumin concentration and indices of glycaemic control in non-insulin-dependent diabetes mellitus

We studied the relationship between albuminuria (measured as albumin/creatinine ratio (alb/Cr) in a random urine sample) and measures of glycaemic control (fructosamine, HbA₁ and glucose) in 470 patients with non-insulin-dependent diabetes mellitus (NIDDM). Albumin excretion was in the microalbuminuric range (alb/Cr ratio > 5.4–40.3) in 112 (23.8%) and in the macroalbuminuric range (alb/Cr ratio > 40.3 mg/mmol) in 89 patients (18.9%). Fourteen percent (n = 67) of patients had a normal plasma HbA₁ (≤8.5%) while 27% (n = 127) had a normal plasma fructosamine concentration (≤ 2.2 mmol/l). Using stepwise multiple regression analysis, plasma fructosamine concentration was found to be independently and negatively associated with urine albumin/creatinine ratio (B = 0.24, P < 0.006) in the macroalbuminuric group. Further analysis of the relationship between plasma albumin concentration and indices of glycaemic control showed that plasma albumin concentration correlated negatively with random plasma glucose concentration in the normoalbuminuric patients (r = −0.16, P = 0.008) but not in microalbuminuric or macroalbuminuric groups. HbA₁ was not correlated with plasma albumin concentration. Our results indicate that albuminuria has an effect on the plasma fructosamine concentration which is independent of plasma albumin concentration.     

Relationships between contour and/or contour/area ratio at Doppler and left ventricular hypertrophy in patients with significant aortic stenosis

Planimetry of the stenotic flow areas using Doppler imaging of jet origin was performed, together with the measurement of their contour and a calculated contour/area (C/A) Doppler ratio, on 38 adult patients with significant aortic stenosis (0.27 to 0.85 cm²). Echo measurements of left ventricular hypertrophy (LVH) were also performed to study the differences in LVH according to the areas, contours or C/A ratios. There were 10 areas below, and 28 over 0.5 cm². The latter group was subdivided according to a C/A < 0.8 (n = 14), or 0.8 > (n = 14). There was a wide scatter in values for LVH vs. areas, even in case of smaller areas. This led to lower mean values of LVH (p < 0.001) in this group, and to a correlation coefficient at 0.18. The smallest areas were generally rounded and had a high C/A ratio. Contour was regular in half of areas over 0.5 cm². It increased less rapidly than areas increased, leading to a decreased C/A. The other half, of a similar range of sizes, had a markedly increased irregular contour, entailing a C/A > 0.8. The highest mean value in LVH was found in this subgroup. Correlation coefficients vs. LVH were 0.43 for contour, and 0.32 for C/A ratio. Diagnostic reliability of a C/A > 0.8 for an LVH > 150 g/ m² BSA ranged from 55 to 70%. In conclusion, the study suggests that contour length weighs on LVH development when stenoses are significant, and should be coupled with area measurements. Figures also suggest that other factors intervene, requiring further study.