定量组织速度成像对家兔肺动脉栓塞模型的动态观察

目的 评价定量组织速度成像技术对检测家兔肺动脉栓塞模型右室功能的应用价值。方法 家兔22只, 经耳缘静脉注入栓子制成急性肺动脉栓塞模型。分别于造模前、造模后即刻、造模后1周及3周观察家兔右心室动态变化情况。存储心尖四腔心切面定量组织速度成像(QTVI)图像并进行脱机分析。结果 造模后即刻, 右室游离壁基底段, 中间段的收缩期峰值速度(V_P)均较造模前明显减低, 达峰时间(T_Vp)延长, 三尖瓣口舒张早期峰值血流速度/舒张晚期峰值血流速度(Ve/Va)大于1。差别具有显著性意义(P<0.05)。造模后1周, 右室游离壁基底段, 中间段的收缩期峰值速度(V_P)均较造模前减低, 达峰时间(T_Vp)延长, 较造模后即刻组差别无显著性意义, 但Ve/Va小于1。造模后3周, 右室游离壁基底段, 中间段的收缩期峰值速度(V_P)较造模前仍减低, Ve/Va比值小于1。较造模后1周组差别具有显著性意义(P<0.05)。组内比较收缩期峰值速度, 右室游离壁基底段均较中间段增大, 差别具有显著性意义。但收缩期达峰时间, 两者差别无显著性意义。结论 定量组织速度成像能够直观反映家兔右室舒张及收缩功能状况,是评价动物肺动脉栓塞模型右室功能的重要手段。     

Boric acid reduces axonal and myelin damage in experimental sciatic nerve injury

hTe aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I) , and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI atfer injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA.In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were signiifcantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were signiifcantly greater in group BAI than in group I. Moreover, myelin injury was signiifcantly milder and the intensity of nuclear factor kappa B immunostaining was signiifcantly weaker in group BAI than in group I. hTe results of this study show that administration of boric acid at 100 mg/kg atfer sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions.     

Umbilical artery blood flows among pregnancies with single umbilical artery: a prospective case-control study

Objectives: To evaluate peak systolic velocity (PSV) in the umbilical artery (UA) among patients with single umbilical artery (SUA) as compared with patients with three vessel cords.

Methods: A prospective case-control study was performed. UA blood flow velocimetry was obtained from fetuses with SUA and from a control group with three vessel cord. PSV and pulsatility index (PI) were measured. Patients’ characteristics were compared for statistical differences and a linear regression model was constructed for the different groups.

Results: UA Doppler velocimetry measurements were obtained from 29 patients with SUA and from 29 controls matched for gestational age. The differences between UA PI with and without SUA were significant (F?=?3.471; p?=?0.0379) showing a lower PI in the SUA group. However, no significant statistical difference was found in PSV between these two groups (F?=?0.149; p?=?0.86).

Conclusions: While the impedance in the UA of patients with a SUA was lower compared with patients with a normal umbilical cord, the PSV did not differ.     

Differentiating early Parkinson's disease and multiple system atrophy with parkinsonism by saccade velocity profiles

ObjectivePatients with Parkinson's disease (PD) and multiple system atrophy both present predominantly with parkinsonism at early stages, whereas cerebellar symptoms are largely masked in multiple system atrophy with parkinsonism (MSAP). We sought to determine whether the velocity profiles of saccades could be used to differentiate between these two disorders, revealing the underlying basal ganglia and/or cerebellar dysfunction and brainstem pathology in these disorders.MethodsSixteen MSA-P patients, 63 PD patients, and 36 age-matched normal subjects performed the visually guided (VGS) and memory-guided saccade (MGS) tasks. Targets were presented at eccentricities of 5, 10, 20, and 30 degrees. The amplitude, peak velocity, and duration of saccades were compared among subject groups. Duration was further subdivided into acceleration and deceleration periods, corresponding to the times before and after peak velocity. These parameters correlated with the severity of Parkinsonism as assessed by the UPDRS motor score.ResultsHypometria predominated in both PD and MSAP patients, whereas hypermetria, frequently noted in cerebellar ataxia, was rarely observed. Saccades in MSAP were characterized both by prolonged acceleration and deceleration periods with reduced peak velocity. In contrast, the velocity profile of PD patients was characterized mainly by the prolonged deceleration period. The changes observed in velocity profiles of MGS deteriorated with advancing severity of parkinsonism in MSAP and PD patients.ConclusionSaccade profiles provide useful information for differentiating between PD and MSAP at early stages. While the changes in velocity profiles may be explained by the cerebellar and brainstem pathology in MSAP, the changes in velocity profile in both PD and MSAP correlated significantly with increasing severity of Parkinsonism in both disorders, suggesting a link with striatonigral pathology.SignificanceThe differential changes in saccade velocity profiles of MSAP and PD may be used as a measure indexing the progression of cerebellar and basal ganglia dysfunction as well as for assessing the functional improvement when clinical treatment becomes available.     

Left Ventricular End-Diastolic Pressure Versus Urine Flow Rate–Guided Hydration in Preventing Contrast-Associated Acute Kidney Injury

ObjectivesThis study compared left ventricular end-diastolic pressure (LVEDP)–guided and urine flow rate (UFR)-guided hydration.BackgroundTailored hydration regimens improve the prevention of contrast-associated acute kidney injury (CA-AKI).MethodsBetween July 15, 2015, and June 6, 2019, patients at high risk for CA-AKI scheduled for coronary and peripheral procedures were randomized to 2 groups: 1) normal saline infusion rate adjusted according to the LVEDP (LVEDP-guided group); and 2) hydration controlled by the RenalGuard System in order to reach UFR ≥300 ml/h (UFR-guided group). The primary endpoint was the composite of CA-AKI (i.e., serum creatinine increase ≥25% or ≥0.5 mg/dl at 48 h) and acute pulmonary edema (PE). Major adverse events (all-cause death, renal failure requiring dialysis, PE, and sustained kidney injury) at 1 month were assessed.ResultsThe primary endpoint occurred in 20 of 351 (5.7%) patients in the UFR-guided group and in 36 of 351 (10.3%) patients in the LVEDP-guided group (relative risk [RR]: 0.560; 95% confidence interval [CI]: 0.390 to 0.790; p = 0.036). CA-AKI and PE rates in the UFR-guided group and LVEDP-guided group were 5.7% and 10.0% (RR: 0.570; 95% CI: 0.300 to 0.960; p = 0.048), and, respectively, 0.3% and 2.0% (RR: 0.070; 95% CI: 0.020 to 1.160; p = 0.069). Three patients in the UFR-guided group experienced complications related to the Foley catheter. Hypokalemia rate was 6.2% in the UFR-guided group and 2.3% in the LVEDP-guided group (p = 0.013). The 1-month major adverse events rate was 7.1% in the UFR-guided group and 12.0% in the LVEDP-guided group (p = 0.030).ConclusionsThe study demonstrates that UFR-guided hydration is superior to LVEDP-guided hydration to prevent the composite of CA-AKI and PE.     

Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self‐adhesive resin cement

Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s^?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water.     

MScanFit motor unit number estimation (MScan) and muscle velocity recovery cycle recordings in amyotrophic lateral sclerosis patients

ObjectiveMotor Unit Number Estimation (MUNE) methods, such as the recently developed MScanFit MUNE (MScan), may be valuable in tracking motor unit loss in ALS. Muscle Velocity Recovery Cycles (MVRCs) provide information about muscle membrane properties and can reveal disease-related changes.This study was undertaken to test the applicability of MScan to the anterior tibial muscle (TA) and to test whether the MVRCs could improve understanding of ALS pathophysiology.MethodsTwenty-six ALS patients and 25 healthy controls were evaluated by quantitative electromyography, nerve conduction study and the two novel methods: MScan and MVRC; all in the TA and peroneal nerve.ResultsThe estimated number of motor units for ALS patients (Median: 45, interquartile range: 28.5–76.5) was significantly lower than for the controls (117, 96.0–121.0) (P = 2.19 × 10⁻⁷). Unit size was increased only when amplitudes were expressed as percentage of CMAP. Of MVRC measurements, only relative refractory period was significantly abnormal in patients.ConclusionMScanFit MUNE gives a sensitive and quantitative measure of loss of TA motor units in ALS. Muscle fiber membrane properties are mostly unaffected, despite substantial denervation, presumably due to collateral reinnervation.SignificanceMScan is suitable for detecting motor unit loss in TA. MVRCs do not provide new insights in ALS.