等渗透剂量的7.5%高渗盐水和20%甘露醇治疗颅内高压疗效的对比研究

目的:比较等渗透剂量的7.5%高渗盐水(hypertonic saline,HTS)和20%甘露醇治疗颅高压的疗效。方法:当患者的颅内压(intracranial pressure,ICP)超过20 mm Hg时,一组患者接受了4 m L/kg 7.5%HTS(HTS组,n=27),另外一组患者接受了0.5 g/kg 20%甘露醇(甘露醇组,n=31)的降颅压治疗,两种药物均经深静脉在30 min内快速滴注完成。用药期间,连续监测患者ICP,平均动脉压(mean arterial pressure,MAP)、脑灌注压(cerebral perfusion pressure,CPP)及中心静脉压(central venous pressure,CVP)。记录有效降颅压持续时间、ICP最大降幅及其时间,用药前及用药后1 h、3 h、6 h抽血查电解质和血浆渗透压等。结果:静脉快速滴注7.5%HTS和20%甘露醇后,两者均可有效降低ICP(P0.05)。两组在控制颅高压的有效率、起效时间及ICP降幅无统计学差异(P0.05),但HTS组的作用持续时间要明显长于甘露醇组(P0.05)。两组渗透压较用药前相比均有显著上升(P0.05)。用药前后,两组MAP、CPP和CVP变化无统计学差异(P0.05)。结论:等渗透剂量的7.5%HTS与20%甘露醇均可有效降低患者的ICP,两者降颅压效果相当,均可作为治疗颅内高压的一线治疗药物。     

无创颅内压监测在创伤性急性弥漫性脑肿胀治疗中的临床应用研究

目的:探讨无创颅内压监测(Intracranial pressure,ICP)监测对救治创伤性急性弥漫性脑肿胀(Posttraumatic acute diffuse brains welling,PADBS)患者的辅助作用,为无创ICP检测的临床应用提供参考依据。方法:收集2011年1月至2016年1月我院神经外科收治的114例PADBS患者的临床资料进行回顾性分析,依据纳入与排除标准共取得病例组53例,对照组61例,分别给予采用无创颅内压监测和有创颅内压监测,根据患者资料进行组间比较及生存分析。结果:病例组与对照组不同分型颅内压检测值比较无统计学差异(P0.05);患者48h内进行大骨瓣开颅手术时间的生存分析,病例组中位手术时间为35.6个月,对照组中位DFS为33.5个月,两组患者检测进行手术时间的生存曲线无统计学差异(P0.05);有创ICP检测患者继发性出血率为3.2%,脑脊液感染病况为7.9%;两组患者预后情况差异并无统计学意义(P0.05)。无创ICP检测患者住院天数短于有创ICP检测患者(P0.05)。结论:无创ICP应用于PADBS治疗的临床价值与有创ICP相当,但无创ICP更便捷、创伤小,有利于对患者进行持续性检测。     

CT灌注成像技术用于重型颅脑损伤患者脑室型颅内压探头植入的临床价值评估

目的:探讨CT灌注成像技术用于重型颅脑损伤患者脑室型颅内压(Intracranial Pressure, ICP)探头植入的临床价值。方法:选取60例重型颅脑损伤患者,均行患侧开颅去骨瓣减压和颅内压监测探头置入术。其中,行普通型颅内压监测探头置入术28例,脑室型颅内压监测探头置入术32例。比较两组术后甘露醇应用剂量和应用时间,术后局部脑血流参数区域脑血流量(regional Cerebral Blood Flow, r CBF)、相对脑血容量(relative Cerebral Blood Volume, r CBV)、平均通过时间(Mean Transit Time, MTT)、对比剂达峰时间(time to peak, TTP)恢复情况。结果:脑室型颅内压监测组患者术后应用甘露醇的剂量和天数较普通颅内压监测组明显缩短(P0.05),术后3个月随访提示脑室型ICP监测组预后良好比例较普通型ICP组显著增加(P0.05)。并且螺旋CT灌注成像结果提示脑室型颅内压监测组患者术后局部脑血流参数r CBF、r CBV、MTT、TTP恢复情况明显优于普通型颅内压监测组(P0.05)。结论:重型颅脑损伤患者应用脑室型颅内监测探头改变了脱水剂在临床应用中的治疗模式,通过螺旋CT灌注成像检测患者损伤部位的r CBF、r CBV、MTT和TTP可评估脑损伤的程度以及预后,对重型颅脑损伤的临床治疗和改善患者预后具有重要意义。     

淋巴细胞/单核细胞比值对急性脑梗死患者预后的预测价值研究

目的:探讨淋巴细胞/单核细胞比值(LMR)对急性脑梗死预后的预测价值。方法:回顾性分析急性脑梗死患者242例的临床资料,根据发病90天改良m RS评分分为预后良好组(163例,m RS 0-2分)和预后不良组(79例,m RS 3-6分),比较其入院时一般人口学资料、美国国立卫生研究院卒中量表评分(NIHSS评分)、血常规、血生化、C反应蛋白(CRP)等资料,根据入院时淋巴细胞与单核细胞计数计算出LMR值,采用logistics回归分析评估LMR与急性脑梗死预后的关系。采用受试者工作特征(ROC)曲线评价入院时LMR水平对急性脑梗预后的预测价值。结果:与预后良好组相比,预后不良组年龄、入院时NIHSS评分、伴随房颤、尿素氮、白细胞、CRP较高,而LMR水平较低,组间差异具有统计学意义(P0.05)。预后不良组LMR水平较预后良好组明显降低(3.48±2.23 vs. 4.39±1.84,P0.05),入院时NIHSS评分增高与低水平LMR是预后不良的独立危险因素(OR值分别为2.066、0.835,95%可信区间为1.668-2.559、0.759-0.946,P0.05)。入院时LMR水平ROC曲线下面积为0.762(95%CI 0.692-0.832),Youden法计算出LMR低于2.633(最佳临界值)预示预后不良,敏感性为86.9%,特异性为47%。结论:入院时LMR水平与急性脑梗死预后不良负相关,低水平LMR对预测急性脑梗死患者预后不良具有一定的参考价值。     

亚低温治疗对重型颅脑损伤患者颅内压、脑血流及氧代谢的影响

目的:探讨亚低温治疗对重症颅脑损伤(sTBI)患者颅内压(ICP)、脑血流及氧代谢的影响。方法:收集50例sTBI患者随机分为实验组和对照组,每组25例,均给予常规治疗,观察组在常规治疗基础上给予亚低温辅助治疗,检测患者治疗前、治疗第3、5、7天ICP动态变化以及治疗前和治疗7天后脑血流和氧代谢等指标变化。结果:治疗第3、5、7天ICP组间差异均具有统计学意义(P0.05),随着治疗时间增加两组ICP均逐渐降低,差异具有统计学意义(P0.05);治疗前Qmean、Vmean、Wv、DR等组间差异无统计学意义(P0.05),治疗7天后Qmean、Vmean均升高,Wv、DR均降低,差异具有统计学意义(P0.05);治疗前SjvO_2、CjvO_2、CaO_2、CERO_2组间差异无统计学意义(P0.05),治疗7天后SjvO_2、CjvO_2、CERO_2均升高,CaO_2降低,差异具有统计学意义(P0.05)。结论:亚低温治疗可以显著降低患者颅内压,改善脑血流和氧代谢水平。     

磁共振成像弥散张量成像参数联合血清NSE、Lp-PLA2在脑梗死患者的诊断和预后不良风险评估中的应用价值

摘要 目的：探讨磁共振成像（MRI）弥散张量成像（DTI）参数联合血清神经元特异性烯醇化酶（NSE）、脂蛋白相关磷脂酶A2（Lp-PLA2）在脑梗死患者的诊断和预后不良风险评估中的应用价值。方法：选择2021年3月至2022年9月吉林大学中日联谊医院收治的106例脑梗死患者作为脑梗死组，另选同期62例体检健康志愿者作为对照组，比较两组DTI参数，血清NSE和Lp-PLA2水平。脑梗死组出院90d后，采用改良Rankin量表（mRS）进行预后评估，分为预后良好组与预后不良组，并比较两组上述指标水平。受试者工作特征（ROC）曲线分析DTI参数联合血清NSE、Lp-PLA2诊断脑梗死和预测脑梗死患者预后的价值。结果：脑梗死组表观弥散系数（ADC）值、部分各向异性指数（FA）值低于对照组（P＜0.05），血清NSE、Lp-PLA2水平高于对照组（P＜0.05）。预后不良组FA值、ADC值低于预后良好组（P＜0.05），血清NSE、Lp-PLA2水平高于预后良好组（P＜0.05）。联合FA值、ADC值、NSE和Lp-PLA2诊断脑梗死以及预测脑梗死患者预后不良的曲线下面积（AUC）分别为0.852、0.874，均高于各因素单独诊断和预测。结论：脑梗死DTI参数FA值、ADC值降低，血清NSE、Lp-PLA2水平增高，联合DTI参数和血清NSE、Lp-PLA2检测在脑梗死诊断和预后预测中具有较高价值。     

低浓度高渗盐水治疗重型颅脑损伤术后颅内高压的临床效果分析

目的:探讨低浓度的高渗盐水对重型颅脑损伤患者手术后颅内高压的治疗效果。方法:选取2014年8月至2017年8月本院收治的104例行去骨瓣减压术后出现颅内高压的重型颅脑损伤患者为研究对象,按照随机数表法将其分为实验组、观察组,每组各52例。在持续监测颅内压(ICP)的情况下,实验组、观察组分别给予233.3 m L的3%HS、29.9 m L的23.4%HS,比较两组治疗前后的ICP、平均动脉压(MAP)、中心静脉压(CVP)、血钠(Na+)、钾(K+)、渗透压、肌酐(Cr)、尿素氮(BUN)水平的变化及半年的预后情况。结果:两组治疗后30 min时ICP显著低于治疗前,而MAP明显高于治疗前(P 0.05);实验组治疗后240 min、300 min时ICP显著低于观察组,120 min、240 min、300 min、360 min时MAP均显著高于观察组(P 0.05);两组治疗前后的CVP比较差异无统计学意义(P0.05)。两组治疗后3 d、6 d血Na+均显著高于治疗前,治疗后1 d、3 d、6 d的渗透压均显著高于治疗前(P 0.05),两组治疗前后的血K+、Cr、BUN比较差异无统计学意义(P0.05);两组治疗前后的同期各血生化指标比较差异无统计学意义(P0.05)。实验组治疗半年后死亡6例(11.5%),预后不良14例(26.9%),预后良好32例(61.5%),观察组死亡8例(15.4%),预后不良20例(38.5%),预后良好24例(46.2%),两组比较差异无统计学意义(P0.05)。结论:3%和23.4%两种浓度的HS均能安全迅速降低重型颅脑损伤患者的ICP,且均有明显的扩容效果,但低浓度HS作用持续时间更长。     

腰大池持续引流术对老年重型颅脑损伤患者颅内压和并发症及预后的影响

目的:探讨腰大池持续引流术对老年重型颅脑损伤患者颅内压、并发症和预后的影响。方法:选取2014年8月～2018年8月期间成都医学院第一附属医院收治的老年重型颅脑损伤患者60例为研究对象。根据随机数字表法将患者分为对照组(n=30)与研究组(n=30),其中对照组术后给予常规的脱水对症治疗,研究组则在此基础上给予腰大池持续引流术。比较两组术后临床疗效以及并发症,术后3d、5d、7d颅内压,随访半年,观察两组患者预后。结果:研究组治疗后总有效率为90.00%,显著高于对照组患者的66.67%(P0.05)。两组患者术后3d、5d、7d颅内压均较术前降低,且研究组低于对照组(P0.05)。研究组脑梗死、脑水肿、硬膜下积液、癫痫、纵裂积液等并发症发生率均低于对照组(P0.05),而颅内感染比较差异无统计学意义(P0.05)。研究组良好例数高于对照组,而重残以及死亡例数均低于对照组,差异有统计学意义(P0.05);而两组轻残、植物生存例数比较差异无统计学意义(P0.05)。结论:腰大池持续引流术治疗老年重型颅脑损伤患者,疗效满意,可显著改善患者颅内压,减少并发症发生率,改善患者预后,适于临床推广。     

降钙素原联合SOFA评分对老年脓毒症患者预后的评估价值

目的:探讨降钙素原(procalcitonin,PCT)联合SOFA评分(sequential organ failure assessment,SOFA)对老年脓毒症患者预后的评估价值。方法:选择首都医科大学宣武医院急诊抢救室收治的105例老年脓毒症患者,入院后给予血常规、血清PCT水平、血气分析及生化全项等检查,并进行急性生理及慢性健康状况评分(acute physiology and chronic health evaluation,APACHEⅡ)和SOFA评分。根据预后将患者分成死亡组27例和存活组78例,比较两组组患者血清PCT水平、白细胞(WBC)、SOFA评分和APACHEⅡ评分,同时比较和分析APACHEⅡ评分、血清PCT水平、SOFA评分、PCT和SOFA评分联合预测患者死亡的受试者工作特征曲线(Receiver operating characteristic curve,ROC)下面积。结果:死亡组患者血清PCT水平、SOFA评分和APACHEⅡ评分均明显高于存活组(P0.05),两组WBC比较无统计学差异(P=0.132);PCT预测患者死亡的ROC曲线下面积为0.694(P=0.001),SOFA预测患者死亡的ROC曲线下面积为0.660(P=0.012),APACHE II评分预测患者死亡的ROC曲线下面积为0.852(P=0.001),大于PCT和SOFA评分(P0.05),PCT和SOFA评分联合预测患者死亡的ROC曲线下面积0.761(P=0.001),与APACHE II评分比较无统计学差异(P=0.139)。结论:血清PCT水平联合SOFA评分预测老年脓毒症患者预后的临床价值与APACHE II评分相当,均明显优于血清PCT水平和SOFA评分单项检测。     

脂蛋白相关磷脂酶A2对急性前循环脑梗死患者颈动脉斑块易损性的预测价值

目的:探讨脂蛋白相关磷脂酶A2(Lp-PLA2)对急性前循环脑梗死患者颈动脉斑块易损性的预测价值。方法:选取2015年9月至2017年3月我院收治的急性前循环脑梗死患者150例作为研究组,另选同期我院体检健康者100例作为对照组,检测两组血清Lp-PLA2、超敏C反应蛋白(hs-CRP)水平,并应用彩色多普勒超声检查研究组患者颈动脉粥样硬化情况,分析不同颈动脉粥样硬化情况以及不同病情患者血清Lp-PLA2、hs-CRP、颈动脉内膜-中层厚度(IMT),并分析血清Lp-PLA2对颈动脉斑块易损性的预测价值。结果:研究组血清Lp-PLA2、hs-CRP和IMT均显著高于对照组(P0.05)。易损斑块组、稳定斑块组、内膜增厚组血清Lp-PLA2、hs-CRP和IMT均显著高于内膜正常组,易损斑块组、稳定斑块组血清Lp-PLA2、hs-CRP和IMT均显著高于内膜增厚组(P0.05),易损斑块组血清Lp-PLA2、hs-CRP显著高于稳定斑块组(P0.05),而IMT比较无统计学差异(P0.05)。重度组、中度组脑梗死患者血清Lp-PLA2、hs-CRP和IMT均显著高于轻度组,重度组脑梗死患者血清Lp-PLA2、hs-CRP和IMT显著高于中度组(P0.05)。ROC曲线显示血清Lp-PLA2、hs-CRP对脑梗死患者颈动脉斑块易损性预测的曲线下面积(AUC)分别为0.809(95%CI:0.739-0.883)、0.598(95%CI:0.495-0.694),血清Lp-PLA2对脑梗死患者颈动脉斑块易损性的预测价值显著高于hs-CRP(P0.05)。结论:急性前循环脑梗死患者血清Lp-PLA2出现异常升高,其水平可以反映颈动脉斑块易损性,可为脑梗死诊断提供依据。     

Diurnal changes in xylem pressure and mesophyll cell turgor pressure of the lianaTetrastigma voinierianum — the role of cell turgor in long-distance water transport: a reply

Summary From equilibrium thermodynamics an equation is given to show that in a liquid negative pressures (tensions) are physical reality and may reliably be recorded from any point of the aqueous phase within the xylem conduit by the xylem pressure probe introduced by Balling et al. (Naturwissenschaften 75: 409–411, 1988).     

Parameters modulating the maximum insertion pressure of proteins and peptides in lipid monolayers

The lipid monolayer model membrane is useful for studying the parameters responsible for protein and peptide membrane binding. Different approaches have been used to determine the extent of protein and peptide binding to lipid monolayers. This review focuses on the use of the “maximum insertion pressure” (MIP) to estimate the extent of protein and peptide penetration in lipid monolayers. The MIP data obtained with different proteins and peptides have been reviewed and discussed which allowed to draw conclusions on the parameters modulating the monolayer binding of proteins and peptides. In particular, secondary structure components such as amphipathic α-helices of proteins and peptides as well as electrostatic interactions play important roles in monolayer binding. The MIPs have been compared to the estimated lateral pressure of biomembranes which allowed to evaluate the possible association between proteins or peptides with natural membranes. For example, the MIP of a membrane-anchored protein with a glycosylphosphatidylinositol (GPI) was found to be far below the estimated lateral pressure of biomembranes. This allowed us to conclude that this protein is probably unable to penetrate the membrane and should thus be hanged at the membrane surface by use of its GPI lipid anchor. Moreover, the values of MIP obtained with myristoylated and non-myristoylated forms of calcineurin suggest that the myristoyl group does not contribute to monolayer binding. However, the acylation of a peptide resulted in a large increase of MIP. Finally, the physical state of lipid monolayers can have a strong effect on the values of MIP such that it is preferable to perform measurements with lipids showing a single physical state. Altogether the data show that the measurement of the maximum insertion pressure provides very useful information on the membrane binding properties of proteins and peptides although uncertainties must be provided to make sure the observed differences are significant.     

Diurnal changes in xylem pressure and mesophyll cell turgor pressure of the lianaTetrastigma voinierianum — the role of cell turgor in long-distance water transport: a comment

Summary The calculation of absolute-pressure values on the basis of measurements with differential-gauge pressure sensors, as described by Thürmer et al. (Protoplasma 206: 152–162, 1999), leads to discrepancies with the definition of absolute pressure when negative values are reached. From previous experiments with the xylem pressure probe we can conclude that the recorded pressure signal belongs not only to the xylem pressure, as stated by the authors, but also to the capillary pressure.     

Meta-Analysis of the Relationship between Normal Tension Glaucoma,Open-Angle Glaucoma,and Fractional Pressure Reserve

Aim: To investigate the relationship between glaucoma and intraocular pressure (IOP), intracranial pressure (ICP), trans-laminar cribrosa pressure difference (TLCPD), and the newly proposed fractional pressure reserve (FPR). Methods: Ten articles were analyzed by meta-analysis, and subgroup analysis of three factors was conducted. Results: The patients with normal tension glaucoma (NTG) and open-angle glaucoma (OAG) have higher TLCPD and lower ICP than healthy subjects, with obvious heterogeneity. The greater heterogeneity may arise from different ICP measurements and from different countries or regions. FPR performs better than TLCPD in some ways. Conclusion: Both FPR and TLCPD can be used as indicators of NTG and OAG, and FPR is more effective than TLCPD in comparisons between different experiments or individuals.     

Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non‐invasive,online monitoring leaf patch clamp pressure probe

Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so‐called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P_p that is highly correlated with the turgor pressure. Real‐time recording of P_p values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic‐based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P_p values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non‐invasive turgor pressure sensor system for elucidating the dynamics of short‐ and long‐distance water transport in higher plants.     

Incorporation of colonization pressure into the propagule pressure-based global ballast water standard

Aim

In 2024, cargo vessels must meet the International Maritime Organization's global ballast water discharge standards (IMO D-2) that limit the concentration of living organisms. D-2 focuses on reducing invasion risk by reducing ‘community propagule pressure (CPP)’, though it does not consider colonization pressure (CP).

Location

Global.

Methods

We modelled risk differences in IMO D-2-compliant discharges (10 ind. m⁻³) for communities that had inverse patterns of CP and species' individual propagule pressures (IPP). Secondly, we determined the effect on risk of varying CPP and CP. As part of this, we tested whether the IMO D-2 standard for zooplankton-sized organisms of <10 individuals m⁻³ was an optimal choice. Risk was defined as probability of at least one species invading using four risk–release models.

Results

Risk differed strongly at the D-2 limit based on community composition. At low CPP (<25 ind. m⁻³), risk was strongly affected by CP for hyperbolic and linear risk–release models and weakly for exponential and logistic models, while CPP affected only the former two model types. Across a much wider range of CPP values, risk was affected by CP, CPP and by their interaction for all models.

Main Conclusion

The IMO D-2 standard for zooplankton-sized organisms requires very low CPP and even lower IPPs in mixed-species releases, which will impede successful colonization. Species-abundance theory predicts that discharges meeting the D-2 standard (low CPP) will also have low CP. Much more empirical data are required to determine whether vessels can consistently reduce CP as it lowers CPP in order to meet these requirements.     

Diurnal changes in xylem pressure and mesophyll cell turgor pressure of the lianaTetrastigma voinierianum: The role of cell turgor in long-distance water transport

Summary Long-term xylem pressure measurements were performed on the lianaTetrastigma voinierianum (grown in a tropical greenhouse) between heights of 1 m and 9.5 m during the summer and autumn seasons with the xylem pressure probe. Simultaneously, the light intensity, the temperature, and the relative humidity were recorded at the measuring points. Parallel to the xylem pressure measurements, the diurnal changes in the cell turgor and the osmotic pressure of leaf cells at heights of 1 m and 5 m (partly also at a height of 9.5 m) were recorded. The results showed that tensions (and height-varying tension gradients) developed during the day time in the vessels mainly due to an increase in the local light intensity (at a maximum 0.4 MPa). The decrease of the local xylem pressure from positive, subatmospheric or slightly above-atmospheric values (established during the night) to negative values after daybreak was associated with an almost 1 1 decrease in the cell turgor pressure of the mesophyll cells (on average from about 0.4 to 0.5 MPa down to 0.08 MPa). Similarly, in the afternoon the increase of the xylem pressure towards more positive values correlated with an increase in the cell turgor pressure (ratio of about 1 1). The cell osmotic pressure remained nearly constant during the day and was about 0.75–0.85 MPa between 1 m and 9.5 m (within the limits of accuracy). These findings indicate that the turgor pressure primarily determines the corresponding pressure in the vessels (and vice versa) due to the tight hydraulic connection and thus due to the water equilibrium between both compartments. An increase in the transpiration rate (due to an increase in light intensity) results in very rapid establishment of a new equilibrium state by an equivalent decrease in the xylem and cell turgor pressure. From the xylem, cell turgor, and cell osmotic pressure data the osmotic pressure (or more accurately the water activity) of the xylem sap was calculated to be about 0.35–0.45 MPa; this value was apparently not subject to diurnal changes. Considering that the xylem pressure is determined by the turgor pressure (and vice versa), the xylem pressure of the liana could not drop to — in agreement with the experimental results — less than -0.4 MPa, because this pressure corresponds to zero turgor pressure.     

Stress tolerance of pressure-shocked Saccharomyces cerevisiae

Pressure shock treatment induced synthesis of heat shock protein (hsp104) and tolerance against various stresses such as high temperature, high pressure and high concentration of ethanol in Saccharomyces cerevisiae. The optimum pressures that induced maximal tolerance against these stresses were in the range of 50–75 MPa and depended on the type of stress. However, pressure shock did not stimulate trehalose production in the cells. © Rapid Science Ltd. 1998