Significant Difference In Peak Velocity Research Articles

Tocotrienol-Rich Vitamin E (Tocovid) Improved Nerve Conduction Velocity in Type 2 Diabetes Mellitus Patients in a Phase II Double-Blind, Randomized Controlled Clinical Trial

Diabetic peripheral neuropathy (DPN) is the most common microvascular complication of diabetes that affects approximately half of the diabetic population. Up to 53% of DPN patients experience neuropathic pain, which leads to a reduction in the quality of life and work productivity. Tocotrienols have been shown to possess antioxidant, anti-inflammatory, and neuroprotective properties in preclinical and clinical studies. This study aimed to investigate the effects of tocotrienol-rich vitamin E (Tocovid SuprabioTM) on nerve conduction parameters and serum biomarkers among patients with type 2 diabetes mellitus (T2DM). A total of 88 patients were randomized to receive 200 mg of Tocovid twice daily, or a matching placebo for 12 months. Fasting blood samples were collected for measurements of HbA1c, renal profile, lipid profile, and biomarkers. A nerve conduction study (NCS) was performed on all patients at baseline and subsequently at 2, 6, 12 months. Patients were reassessed after 6 months of washout. After 12 months of supplementation, patients in the Tocovid group exhibited highly significant improvements in conduction velocity (CV) of both median and sural sensory nerves as compared to those in the placebo group. The between-intervention-group differences (treatment effects) in CV were 1.60 m/s (95% CI: 0.70, 2.40) for the median nerve and 2.10 m/s (95% CI: 1.50, 2.90) for the sural nerve. A significant difference in peak velocity (PV) was also observed in the sural nerve (2.10 m/s; 95% CI: 1.00, 3.20) after 12 months. Significant improvements in CV were only observed up to 6 months in the tibial motor nerve, 1.30 m/s (95% CI: 0.60, 2.20). There were no significant changes in serum biomarkers, transforming growth factor beta-1 (TGFβ-1), or vascular endothelial growth factor A (VEGF-A). After 6 months of washout, there were no significant differences from baseline between groups in nerve conduction parameters of all three nerves. Tocovid at 400 mg/day significantly improve tibial motor nerve CV up to 6 months, but median and sural sensory nerve CV in up to 12 months of supplementation. All improvements diminished after 6 months of washout.

Magnetic Resonance Imaging Cerebrospinal Fluid Hydrodynamics in Patients with Meningitis.

Objective:The objective of the study was to evaluate the cerebrospinal fluid (CSF) flow alterations in meningitis using phase-contrast magnetic resonance imaging (PCMRI).Materials and Methods:Fifty patients with clinically confirmed or strongly suspected infectious meningitis and 20 controls were evaluated with MRI. Quantitative CSF analysis was performed at the level of cerebral aqueduct using cardiac-gated PCMRI. Velocity encoding (Venc) was kept at 20 cm/s. Patients were subdivided into Group I (patients with hydrocephalus [n = 21]) and Group II (patients without hydrocephalus [n = 29]).Results:The mean peak velocity and stroke volume in controls were 2.49 ± 0.86 cm/s and 13.23 ± 6.84 µl and in patients were 2.85 ± 2.90 cm/s and 16.30 ± 20.02 µl, respectively. A wide variation of flow parameters was noted in meningitis irrespective of the degree of ventricular dilatation. A significant difference in peak velocity and stroke volume was noted in Group II as compared to controls. Viral meningitis showed milder alteration of CSF flow dynamics as compared to bacterial and tuberculous etiologies. At a cutoff value of 3.57 cm/s in peak CSF velocity, the specificity was 100% and sensitivity was 22.7% to differentiate between viral and non-viral meningitis.Conclusion:Alteration of CSF flow dynamics on PCMRI can improve segregation of patients into viral and non- viral etiologies, especially in those in whom contrast is contraindicated or not recommended. This may aid in institution of appropriate clinical treatment.

Immediate Effect of Training at the Onset of Reaching in Preterm Infants: Randomized Clinical Trial

ABSTRACTThe authors' aim was to investigate the immediate effect of a single specific training session (serial varied practice), of short duration on the kinematic parameters of reaching, in the period of the emergence of the skill in preterm and low birth weight infants. The study included 16 infants of both sexes, born at a mean gestational age of 32.13 (±1.36) weeks and mean birth weight of 1720.94 (±358.46) g. The infants were randomly divided into 2 groups: experimental and control. The experimental group was given a 5-min training session in reaching, while the control group received no training. The results showed significant differences in peak velocity in the intra (Z = –2.10, p = .036) and intergroup (U = 9.00, p = .016) evaluations, which decreased in the experimental group after training. Cohen's d test for clinical relevance suggested that the specific, short duration training proved effective in promoting slower reaches, with greater adjustment and lower number of units of movement. These results are positive for preterm infants given that these parameters more closely resemble the typical development of mature reaching behaviors in term infants, which suggests that this protocol of reaching training (serial varied practice) could be used as an evidence-based intervention strategy.

Do Force–Time and Power–Time Measures in a Loaded Jump Squat Differentiate between Speed Performance and Playing Level in Elite and Elite Junior Rugby Union Players?

The purpose of this study was to investigate the discriminative ability of rebound jump squat force-time and power-time measures in differentiating speed performance and competition level in elite and elite junior rugby union players. Forty professional rugby union players performed 3 rebound jump squats with an external load of 40 kg from which a number of force-time and power-time variables were acquired and analyzed. Additionally, players performed 3 sprints over 30 m with timing gates at 5, 10, and 30 m. Significant differences (p < 0.05) between the fastest 20 and slowest 20 athletes, and elite (n = 25) and elite junior (n = 15) players in speed and force-time and power-time variables were determined using independent sample t-tests. The fastest and slowest sprinters over 10 m differed in peak power (PP) expressed relative to body weight. Over 30 m, there were significant differences in peak velocity and relative PP and rate of power development. There was no significant difference in speed over any distance between elite and elite junior rugby union players; however, a number of force and power variables including peak force, PP, force at 100 milliseconds from minimum force, and force and impulse 200 milliseconds from minimum force were significantly (p < 0.05) different between playing levels. Although only power values expressed relative to body weight were able to differentiate speed performance, both absolute and relative force and power values differentiated playing levels in professional rugby union players. For speed development in rugby union players, training strategies should aim to optimize the athlete's power to weight ratio, and lower body resistance training should focus on movement velocity. For player development to transition elite junior players to elite status, adding lean mass is likely to be most beneficial.

Effects of Auditory Feedback on Movement Time in a Fitts Task

ABSTRACT The purpose of the present experiment was to investigate the role of auditory feedback and its impact on movement time in a standard Fitts task. Feedback was given at the moment of target acquisition. A 2-way analysis of variance found significant differences between feedback groups at all three indexes of difficulty (F(2, 40) = 156.02, p < .001). Results from a mixed-model multivariate analysis of variance for kinematic factors show significant differences in peak velocity and the location of peak velocity when comparing feedback groups. In general, the addition of auditory feedback decreased the task ID by .5.

Effect Of Load On Bar, Body And System Power Output In The Power Clean

Various methods of calculation can affect power output values in the power clean. This may be due to analysis of the bar, body and system using different kinetic and kinematic variables. The purpose of this study was to utilize the combination of a force plate and videography to determine power output of the bar, the body, and the system independent of one another. Seven college-aged males (height = 175.29 ± 5.47 cm, weight = 80.84 ± 7.18 kg, age = 24.7 ± 2.06 yr, 1RM = 97.14 ± 6.36 kg) with at least one year experience in the power clean performed two sets of one repetition each at 30, 40, 50, 60, 70, 80, and 90% of their 1 repetition maximum (1RM) in a randomized order. Force, power, and velocity were obtained for the bar, body and system independently. Peak power (PP) of the bar was found to be at 90% of 1RM (2308 ± 229.1 W), PP of the body at 90% of 1RM (1077 ± 538.7 W) and PP of the system at 80% of 1RM (1768 ± 470.7 W). Significant differences (p ≤ 0.05) in PP were found between the bar and body at 40%, 50%, 60%, and 70% of 1RM, while 60% of 1RM also showed significant differences between the system and body. Significant differences between the bar, body and system occurred at 80% and 90% of 1RM for PP. Peak velocity (PV) occurred for the bar, body and system at 30% of 1RM (Bar PV 30% = 2.38 ± 0.15 m/s), 30% of 1RM (Body PV 30% = 0.79 ± 0.21 m/s) and 60% of 1RM (System PV 60% = 0.90 ± 0.16 m/s), respectively. Every load displayed significant differences in PV between the bar and body and between the bar and system, except for 60% of 1RM, where a significant difference occurred between the bar, body, and system. Peak force (PF) was highest at 90% of 1RM for the bar (1291 ± 72.9 N), while both the body and system PF occurred at 80% of 1RM (Body PF 80% = 1505 ± 270.1 N, System PF 80% = 2797 ± 618.2 N). Significant differences in peak force were found between the bar, body and system at every load, except 90% of 1RM where significant differences were between the bar and body and between the bar and system. In conclusion, bar, body, and system values for PP, PV, and PF are influenced differently across the loading spectrum. Proper training loads for the power clean maybe influenced by whether PP of the bar, body or system is desired.

Accelerated phase‐contrast MR imaging: Comparison of k‐t BLAST with SENSE and doppler ultrasound for velocity and flow measurements in the aorta

To evaluate differences in velocity and flow measurements in the aorta between accelerated phase-contrast (PC) magnetic resonance imaging (MRI) using SENSE and k-t BLAST and in peak velocity to Doppler ultrasound. Two-dimensional PC-MRI perpendicular to the ascending and descending aorta was performed in 11 volunteers using SENSE (R = 2) and k-t BLAST (2-, 4-, 6-, and 8-fold). Peak velocity, mean velocity, and stroke volume of the accelerated PC-MRI experiments were correlated. Peak velocities were compared to Doppler ultrasound. All acceleration techniques showed significant correlations for peak velocity with Doppler ultrasound. However, k-t BLAST 6 and 8 showed a significant underestimation. Strong correlations between SENSE and k-t BLAST were found for all three parameters. Significant differences in peak velocity were found between SENSE and all k-t BLAST experiments, but not for 2-fold k-t BLAST in the ascending aorta, and 2- and 4-fold k-t BLAST in the descending aorta. For mean velocity no significant differences were found. Stroke volume showed significant differences for all k-t BLAST experiments in the ascending and for 6- and 8-fold k-t BLAST in the descending aorta. Peak velocity of accelerated PC-MRI correlated with CW Doppler measurements, but high k-t BLAST acceleration factors lead to a significant underestimation. SENSE with R = 2 and 2-fold k-t BLAST are most highly correlated in phase-contrast flow measurements.

MR flow measurements for assessment of the pulmonary, systemic and bronchosystemic circulation: Impact of different ECG gating methods and breathing schema

Purpose Different ECG gating techniques are available for MR phase-contrast (PC) flow measurements. Until now no study has reported the impact of different ECG gating techniques on quantitative flow parameters. The goal was to evaluate the impact of the gating method and the breathing schema on the pulmonary, systemic and bronchosystemic circulation. Material and methods Twenty volunteers were examined (1.5 T) with free breathing phase-contrast flow (PC-flow) measurements with prospective ( free- prospective) and retrospective ( free- retrospective) ECG gating. Additionally, expiratory breath-hold retrospective ECG gated measurements ( bh- retrospective) were performed. Blood flow per minute; peak velocity and time to peak velocity were compared. The clinically important difference between the systemic and pulmonary circulation (bronchosystemic shunt) was calculated. Results Blood flow per minute was lowest for free- prospective (6 l/min, pulmonary trunc) and highest for bh- retrospective measurements (6.9 l/min, pulmonary trunc). No clinically significant difference in peak velocity was assessed (82–83 cm/s pulmonary trunc, 109–113 cm/s aorta). Time to peak velocity was shorter for retro-gated free- retrospective and bh- retrospective than for pro-gated free- prospective. The difference between systemic and pulmonary measurements was least for the free- retrospective technique. Conclusion The type of gating has a significant impact on flow measurements. Therefore, it is important to use the same ECG gating method, especially for follow-up examinations. Retrospective ECG gated free breathing measurements allow for the most precise assessment of the bronchosystemic blood flow and should be used in clinical routine.

Left ventricular diastolic filling in young persons with type 1 diabetes mellitus.

The purpose of this study was to evaluate the influence of diabetes mellitus on left ventricular function. Using Doppler echocardiography we examined a group of 49 young (20-32 years old) persons with type 1 diabetes mellitus and a group of healthy age-matched men and evaluated the parameters of diastolic filling of the left ventricle (LV). We found significant differences in peak velocity of early filling of the left ventricle ((70.07+/-10.84 vers. 78.2+/-10.59 cm.s(-1), p+/-0. 01), peak velocity of late diastolic filling of LV (A = 47.74+/-11.6 vers. 43.15+/-7.48 cm.s(-1), p < or = 0.027), ratio E/A (1.53+/-0.4 vers. 1.84+/-0.33), time velocity integral of peak E (TVIE = 0.083+/-0.014 vers. 0.1+/-0.022 m, p < or = 0.001), time velocity integral of peak A (TVIA = 0.039+/-0.011 vers. 0.037+/-0.012 m, p < or = 0.3), ratio TVIE/TVIA (2.3+/-0.73 vers. 2.9+/-0.9, p < or = 0.001), time E (204.4+/-31.59 vers. 198.4+/-19.09 ms, p < or = 0.27), time A (126.9 < or = 23.0 vers. 113.5+/-15.59 ms, p < or = 0.002), time E/time A (1.64+/-0.3 vers. 1.76+/-0.22, p < or = 0.039) and duration of isovolumic relaxation period (IVRT = 88.2+/-10.8 vers. 71.13+/-8.4 ms, p < or = 0.0001). Despite significant differences all the results were in the range of values for the healthy population. However in detailed analysis we found that the values measured in young (20-32 years old) persons with type 1 diabetes mellitus corresponded with diastolic parameters of healthy men of the age of 50 years and more. Thus, diabetes mellitus can influence the relaxation properties of the left ventricle.

Color Doppler assessment of folliculogenesis in in vitro fertilization patients

To characterize hemodynamics of human ovarian follicles in the course of their development and to compare the results in relation to the age of patients, pregnancy, location of the ovary, and the quality of the oocytes. Serial measurements of peak velocity and resistance index by color Doppler imaging. The In Vitro Fertilization Clinic, Success Through Assisted Reproductive Technologies, Inc., Toronto, Ontario, Canada. Fifty-two women undergoing hormonal stimulation for IVF. The perifollicular peak velocity and resistance index values. The perifollicular peak velocity values were gradually increasing with the increasing size of the follicles. Highly significant elevation of the peak velocity was observed especially after hCG injection. Such rapid rise of blood velocity was greater in the right ovary than in the left in the younger patients (mean age, 34 years) whereas in older patients (mean age, 41 years), the greater values were observed in the left ovary. There was no significant difference in peak velocity or resistance index between pregnant and nonpregnant patients. There is a strong, positive correlation between the size of ovarian follicles and their peak velocity, which suggests an increase of blood flow around developing follicles in the course of the follicular phase. Human chorionic gonadotropin plays an important role in inducing influx of blood within follicles; however, the significance of this event remains obscure. It appears that the resistance index is not a useful parameter for characterization of the intrafollicular flow. Changes in peak velocity did not correlate with oocyte quality and may have no predictive value for IVF outcome.

Use of transcranial Doppler sonography to predict development of a delayed ischemic deficit after subarachnoid hemorrhage

Blood flow velocity was recorded from the middle or anterior cerebral and extracranial internal carotid arteries using transcranial Doppler sonography (TCD) in 121 unselected consecutive patients with acute aneurysmal subarachnoid hemorrhage (SAH). Recordings were made daily or every 2nd day after SAH for a 14-day period. The highest recorded velocity was greater in the 47 patients who developed a delayed ischemic neurological deficit (186 +/- 6 cm sec-1; mean +/- standard error of the mean) than in the 74 patients who did not develop a neurological deficit (149 +/- 5 cm sec-1) (p < 0.001, Mann-Whitney test). Peak velocity recordings can thus assist in the diagnosis of delayed ischemic neurological deficit; however, peak velocity was often recorded only after the onset of neurological deficit. When only those readings made before the onset of neurological deficit were considered, there was no significant difference in peak velocity between the groups (157 +/- 8 cm sec-1 vs. 149 +/- 5 cm sec-1, respectively). Alternative TCD parameters for predicting delayed neurological deficit were therefore sought. The rate of increase in TCD velocity, recorded during the first few days after SAH, was significantly higher in the patients who later developed a neurological deficit. A maximum velocity increase of 65 +/- 5 cm sec-1 per 24-hour period was recorded in patients who later developed a neurological deficit, compared to 47 +/- 3 cm sec-1 24 hrs-1 in patients who did not develop a delayed neurological deficit (p = 0.003). A rise of more than 50 cm sec-1 24 hrs-1 identifies those patients who are most likely to develop a delayed ischemic neurological deficit after SAH. This can be applied prospectively to individual cases. Serial TCD studies in the early period after SAH are thus of value to identify patients who can be selected for prophylactic therapy, which may prevent or ameliorate development of delayed ischemic neurological deficits.

Comparison of Doppler echocardiographic and hemodynamic indexes of left ventricular diastolic properties in coronary artery disease

Transmitral flow velocity was measured by Doppler echocardiography in 15 patients with coronary artery disease simultaneously with high-fidelity recording of left ventricular pressure. Doppler echocardiographic recordings were also performed in 14 age- and heart rate-matched normal subjects. Statistically significant differences (p < 0.05) in acceleration half-time (55.3 ± 8.2 vs 70.4 ± 14.9 ms), deceleration half-time (83.1 ± 17.9 vs 109.5 ± 18.1 ms), deceleration rate (4.9 ± 0.9 vs 3.1 ±0.9 m/s 2), peak velocity of early diastolic left ventricular inflow (E wave) (0.78 ± 0.13 vs 0.61 ± 0.13 m/s) and A E ratio (0.74 ± 0.20 vs 0.98 ±0.31) between normal subjects and patients were noted. There was no significant difference in peak velocity of atrial systolic flow (A wave) between normal subjects and patients. Correlation between transmitral flow indexes and hemodynamic indexes of left ventricular diastolic properties were poor, with r values ranging from 0.02 to 0.65. Significant correlations between deceleration rate versus maximal isovolumic left ventricular pressure decrease (maximum − dP dt ) and A wave versus maximum − dP dt (p < 0.05) were found (0.53 and 0.65, respectively). Deceleration rate was the most sensitive index of isovolumic relaxation assessed by hemodynamic methods, whereas the A E ratio was a poor indicator of hemodynamic measurements of isovolumic relaxation. An abnormal deceleration rate had 100% specificity for detecting abnormal maximum − dP dt , while abnormal acceleration half-time, deceleration half-time and A E ratio had 80% specificity for detecting abnormal time constant. The deceleration rate, acceleration half-time, deceleration half-time and A E ratio had a predictive value of 60 to 100% for the detection of abnormal maximum − dP dt and time constant.