Novel signals and polygenic score for height are associated with pubertal growth traits in Southwestern American Indians.

Most genetic variants associated with adult height have been identified through large genome-wide association studies (GWASs) in European-ancestry cohorts. However, it is unclear how these variants influence linear growth during adolescence. This study uses anthropometric and genotypic data from a longitudinal study conducted in an American Indian community in Arizona between 1965-2007. Growth parameters (i.e. height, velocity, and timing of growth spurt) were derived from the Preece-Baines growth model, a parametric growth curve fitted to longitudinal height data, in 787 participants with height measurements spanning the whole period of growth. Heritability estimates suggested that genetic factors could explain 25% to 71% of the variance of pubertal growth traits. We performed a GWAS of growth parameters, testing their associations with 5 077 595 imputed or directly genotyped variants. Six variants associated with height at peak velocity (P < 5 × 10-8, adjusted for sex, birth year and principal components). Implicated genes include NUDT3, previously associated with adult height, and PACSIN1. Two novel variants associated with duration of growth spurt (P < 5 × 10-8) in LOC105375344, an uncharacterized gene with unknown function. We finally examined the association of growth parameters with a polygenic score for height derived from 9557 single nucleotide polymorphisms (SNPs) identified in the GIANT meta-analysis for which genotypic data were available for the American Indian study population. Height polygenic score was correlated with the magnitude and velocity of height growth that occurred before and at the peak of the adolescent growth spurt, indicating overlapping genetic architecture, with no influence on the timing of adolescent growth.

Application of arbitrary and individualized load quantification strategies over the weekly microcycle in professional soccer players.

The aims of this study were to: (a) determine the differences in external load quantification between arbitrary and individual speed thresholds over the weekly microcycle in professional soccer players, and (b) analyse the association between internal load and different external load quantification strategies (ELQSs). Ten professional outfield players were monitored during training sessions and official matches using 10 Hz GPS devices over a 6-week in-season period. The absolute and relative ("R" before the distance category) distances covered were calculated for the following external load variables: medium-intensity running distance (MIR), high-intensity running (HIR), sprint distance (SD), and very high-intensity running (VHIR). Individualized thresholds were determined based on maximal sprinting speed (MSS) and the last speed achieved during the 30-15 Intermittent Fitness Test (VIFT) of each player. In terms of match-day workload, significant differences (p < 0.05) were observed between arbitrary and individualized strategies (i.e., MSS and VIFT) for the distance covered in MIR, HIR, SD, VHIR, RHIR, RSD, and RVHIR. The MSS strategy compared to arbitrary thresholds revealed significant differences (p < 0.05) for distance covered in HIR, RHIR, and VHIR during all training sessions. The present results showed that arbitrary thresholds lead to underestimation of external load absolute and relative metrics compared to the MSS strategy throughout the microcycle. The VIFT strategy mainly revealed differences in external load quantification regarding MD compared to arbitrary thresholds. Individualized speed threshold strategies did not achieve better associations with internal load measures in comparison with arbitrary thresholds in professional soccer players.

The effect of mobility-related anxiety on walking across the lifespan: a virtual reality simulation study.

Older adults who report a fear of falling are more likely to subsequently fall, yet, some gait anxiety-related alterations may protect balance. We examined the effect of age on walking in anxiety-inducing virtual reality (VR) settings. We predicted a high elevation-related postural threat would impair gait in older age, and differences in cognitive and physical function would relate to the observed effects. Altogether, 24 adults (age (y) = 49.2 (18.7), 13 women) walked on a 2.2-m walkway at self-selected and fast speeds at low (ground) and high (15 m) VR elevation. Self-reported cognitive and somatic anxiety and mental effort were greater at high elevations (all p < 0.001), but age- and speed-related effects were not observed. At high VR elevations, participants walked slower, took shorter steps, and reduced turning speed (all p < 0.001). Significant interactions with age in gait speed and step length showed that relatively older adults walked slower (ß = - 0.05, p = 0.024) and took shorter steps (ß = - 0.05, p = 0.001) at self-selected speeds at high compared to low elevation settings. The effect of Age on gait speed and step length disappeared between self-selected and fast speeds and at high elevation. At self-selected speeds, older adults took shorter and slower steps at high elevation without changing step width, suggesting that in threatening settings relatively older people change gait parameters to promote stability. At fast speeds, older adults walked like relatively younger adults (or young adults walked like older adults) supporting the notion that people opt to walk faster in a way that still protects balance and stability in threatening settings.

Automated 4D flow cardiac MRI pipeline to derive peak mitral inflow diastolic velocities using short-axis cine stack: two centre validation study against echocardiographic pulse-wave doppler.

BACKGROUND: Measurement of peak velocities is important in the evaluation of heart failure. This study compared the performance of automated 4D flow cardiac MRI (CMR) with traditional transthoracic Doppler echocardiography (TTE) for the measurement of mitral inflow peak diastolic velocities. METHODS: Patients with Doppler echocardiography and 4D flow cardiac magnetic resonance data were included retrospectively. An established automated technique was used to segment the left ventricular transvalvular flow using short-axis cine stack of images. Peak mitral E-wave and peak mitral A-wave velocities were automatically derived using in-plane velocity maps of transvalvular flow. Additionally, we checked the agreement between peak mitral E-wave velocity derived by 4D flow CMR and Doppler echocardiography in patients with sinus rhythm and atrial fibrillation (AF) separately. RESULTS: Forty-eight patients were included (median age 69 years, IQR 63 to 76; 46% female). Data were split into three groups according to heart rhythm. The median peak E-wave mitral inflow velocity by automated 4D flow CMR was comparable with Doppler echocardiography in all patients (0.90 ± 0.43 m/s vs 0.94 ± 0.48 m/s, P = 0.132), sinus rhythm-only group (0.88 ± 0.35 m/s vs 0.86 ± 0.38 m/s, P = 0.54) and in AF-only group (1.33 ± 0.56 m/s vs 1.18 ± 0.47 m/s, P = 0.06). Peak A-wave mitral inflow velocity results had no significant difference between Doppler TTE and automated 4D flow CMR (0.81 ± 0.44 m/s vs 0.81 ± 0.53 m/s, P = 0.09) in all patients and sinus rhythm-only groups. Automated 4D flow CMR showed a significant correlation with TTE for measurement of peak E-wave in all patients group (r = 0.73, P < 0.001) and peak A-wave velocities (r = 0.88, P < 0.001). Moreover, there was a significant correlation between automated 4D flow CMR and TTE for peak-E wave velocity in sinus rhythm-only patients (r = 0.68, P < 0.001) and AF-only patients (r = 0.81, P = 0.014). Excellent intra-and inter-observer variability was demonstrated for both parameters. CONCLUSION: Automated dynamic peak mitral inflow diastolic velocity tracing using 4D flow CMR is comparable to Doppler echocardiography and has excellent repeatability for clinical use. However, 4D flow CMR can potentially underestimate peak velocity in patients with AF.

Current Commonly Used Dynamic Parameters and Monitoring Systems for Perioperative Goal-Directed Fluid Therapy: A Review.

Goal-directed fluid therapy (GDFT) is usually recommended in patients undergoing major surgery and is essential in enhanced recovery after surgery (ERAS) protocols. This fluid regimen is usually guided by dynamic hemodynamic parameters and aims to optimize patients' cardiac output to maximize oxygen delivery to their vital organs. While many studies have shown that GDFT benefits patients perioperatively and can decrease postoperative complications, there is no consensus on which dynamic hemodynamic parameters to guide GDFT with. Furthermore, there are many commercialized hemodynamic monitoring systems to measure these dynamic hemodynamic parameters, and each has its pros and cons. This review will discuss and review the commonly used GDFT dynamic hemodynamic parameters and hemodynamic monitoring systems.

Valvular regurgitation flow jet assessment using in vitro 4D flow MRI: Implication for mitral regurgitation.

PURPOSE: The purpose of this study was to evaluate the accuracy of four-dimensional (4D) flow MRI for direct assessment of peak velocity, flow volume, and momentum of a mitral regurgitation (MR) flow jets using an in vitro pulsatile jet flow phantom. We systematically investigated the impact of spatial resolution and quantification location along the jet on flow quantities with Doppler ultrasound as a reference for peak velocity. METHODS: Four-dimensional flow MRI data of a pulsatile jet through a circular, elliptical, and 3D-printed patient-specific MR orifice model was acquired with varying spatial resolution (1.5-5 mm isotropic voxel). Flow rate and momentum of the jet were quantified at various axial distances (x = 0-50 mm) and integrated over time to calculate Voljet and MTIjet . In vivo assessment of Voljet and MTIjet was performed on 3 MR patients. RESULTS: Peak velocities were comparable to Doppler ultrasound (3% error, 1.5 mm voxel), but underestimated with decreasing spatial resolution (-40% error, 5 mm voxel). Voljet was similar to regurgitant volume (RVol) within 5 mm, and then increased linearly with the axial distance (19%/cm) because of flow entrainment. MTIjet remained steady throughout the jet (2%/cm) as theoretically predicted. Four and 9 voxels across the jet were required to measure flow volume and momentum-time-integral within 10% error, respectively. CONCLUSION: Four-dimensional flow MRI detected accurate peak velocity, flow rate, and momentum for in vitro MR-mimicking flow jets. Spatial resolution significantly impacted flow quantitation, which otherwise followed predictions of flow entrainment and momentum conservation. This study provides important preliminary information for accurate in vivo MR assessment using 4D flow MRI.

Corrected flow time and respirophasic variation in blood flow peak velocity of radial artery predict fluid responsiveness in gynecological surgical patients with mechanical ventilation.

BACKGROUND: Recent evidence suggests that ultrasound measurements of carotid and brachial artery corrected flow time (FTc) and respirophasic variation in blood flow peak velocity (ΔVpeak) are valuable for predicting fluid responsiveness in mechanical ventilated patients. We performed the study to reveal the performance of ultrasonic measurements of radial artery FTc and ΔVpeak for predicting fluid responsiveness in mechanical ventilated patients undergoing gynecological surgery. METHODS: A total of eighty mechanical ventilated patients were enrolled. Radial artery FTc and ΔVpeak, and non-invasive pulse pressure variation (PPV) were measured before and after fluid challenge. Fluid responsiveness was defined as an increase in stroke volume index (SVI) of 15% or more after the fluid challenge. Multivariate logistic regression analyses and receiver operating characteristic (ROC) curve were used to screen multivariate predictors of fluid responsiveness and identify the predictive abilitie of non-invasive PPV, ΔVpeak and FTc on fluid responsiveness. RESULTS: Forty-four (55%) patients were fluid responders. Multivariate logistic regression analysis showed that radial artery FTc, ΔVpeak, and non-invasive PPV were the independent predictors of fluid responsiveness, with odds ratios of 1.152 [95% confidence interval (CI) 1.045 to 1.270], 0.581 (95% CI 0.403 to 0.839), and 0.361 (95% CI, 0.193 to 0.676), respectively. The area under the ROC curve of fluid responsiveness predicted by FTC was 0.802 (95% CI, 0.706-0.898), and ΔVpeak was 0.812 (95% CI, 0.091-0.286), which were comparable with non-invasive PPV (0.846, 95%CI, 0.070-0.238). The optimal cut-off values of FTc for fluid responsiveness was 336.6 ms (sensitivity of 75.3%; specificity of 75.9%), ΔVpeak was 14.2% (sensitivity of 88.2%; specificity of 67.9%). The grey zone for FTc was 313.5-336.6 ms and included 40 (50%) of the patients, ΔVpeak was 12.2-16.5% and included 37(46%) of the patients. CONCLUSIONS: Ultrasound measurement of radial artery FTc and ΔVpeak are the feasible and reliable methods for predicting fluid responsiveness in mechanically ventilated patients. TRIAL REGISTRATION: The trial was registered at the Chinese Clinical Trial Registry (ChiCTR)(www.chictr.org), registration number ChiCTR2000040941.

Impact of Thickened Liquids on Laryngeal Movement Velocity in Patients with Dysphagia.

Considering that thickened liquids are frequently used for patients with dysphagia, elucidating their impact on laryngeal dynamics is important. Although studies have investigated the impact of thickened liquids on laryngeal movement velocity among healthy young adults, no study has examined the same among patients with dysphagia. We aimed to elucidate the influence of bolus consistency on laryngeal movement velocity and surface electromyographic activity of the suprahyoid muscles in patients with dysphagia. Participants included 18 male, poststroke patients with dysphagia, whereas patients with true bulbar paralysis, head and neck cancer, neuromuscular disease, or recurrent nerve paralysis were excluded. A video fluoroscopic swallowing study (VFSS) was performed while swallowing 3 mL of moderately thick and thin liquids. Quantitative VFSS analysis, including factors such as laryngeal peak velocity, laryngeal mean velocity, laryngeal movement distance, duration of the laryngeal elevation movement, and the temporal location of laryngeal vestibule closure within the laryngeal elevation movement was performed. Muscle activity was evaluated using integrated muscles activity values obtained from electromyography (iEMG) of the suprahyoid muscle during swallowing. VFSS analysis showed that laryngeal peak velocity and laryngeal mean velocity were significantly faster while swallowing moderately thick than while swallowing thin liquids. Laryngeal movement distance was significantly greater while swallowing moderately thick than while swallowing thin liquids. iEMG was significantly higher while swallowing moderately thick liquids than while swallowing thin liquids. Compared to thin liquids, moderately thick induced an increase in laryngeal movement velocity and in suprahyoid muscle activity among patients with dysphagia, a finding consistent with that of a previous study among healthy adults.

Severe aortic stenosis echocardiographic thresholds revisited.

BACKGROUND: In view of inconsistencies in threshold values of severe aortic stenosis (AS) hemodynamic indices, it is unclear what is the relative contribution of each variable in a binary classification of AS based on aortic valve replacement (AVR) indication. We aimed to assess relative discriminative value and optimal threshold of each constituent hemodynamic parameter for this classification and confirm additional prognostic value. METHODS: Echocardiography studies of 168 patients with ≥ moderate AS were included. AS types were dichotomized into Group-A, comprising moderate and Normal-Flow Low-Gradient (NFLG), and Group-B, comprising High-Gradient(HG), Low Ejection Fraction Low-Flow Low-Gradient(Low EF-LFLG), and Paradoxical Low-Flow Low-Gradient(PLFLG) AS. Aortic valve area (AVA), Doppler velocity index (DVI), peak aortic velocity, mean gradient, stroke volume index and transaortic flow rate(TFR) were assessed for A/B Group discrimination value and optimal thresholds were determined. Dichotomized values were assessed for predictive value for AVR or death. RESULTS: C-statistic values for binary AS classification was .74-.9 for the tested variables. AVA and DVI featured the highest score, and SVI the lowest one. AVA≤.81 cm2 and DVI≤.249 had 87.6% and 86% respective sensitivity for Group B patients, and a similar specificity of 80.9%. During a mean follow-up of 9.1±10.1 months, each of the tested dichotomized variables except for SVI predicted AVR or death on multivariate analysis. CONCLUSION: An AVA value ≤.81 cm2 or a DVI ≤ .249 threshold carry the highest discriminative value for severe AS in patients with aortic stenosis, translating into an independent prognostic value, and can be helpful in making clinical decisions.

Accuracy and diagnostic performance of doppler echocardiography to estimate mean pulmonary artery pressure in heart failure.

BACKGROUND: Multiple echocardiographic algorithms have been proposed to estimate mean pulmonary artery pressure (PAPM ) and assess pulmonary hypertension (PH) likelihood. We assessed the accuracy of four echocardiographic approaches to estimate PAPM in heart failure (HF) patients undergoing near-simultaneous right heart catheterization (RHC), and compared diagnostic performance to identify PH with recommendation-advised tricuspid regurgitation peak velocity (TRVmax ). METHODS: We employed four validated echocardiographic algorithms incorporating tricuspid regurgitation peak or mean gradient, pulmonary regurgitation peak gradient, and right ventricular outflow tract acceleration time to estimate PAPM . Echocardiographic estimates of right atrial pressure were incorporated in all algorithms but one. Association and agreement with invasive PAPM were assessed. Diagnostic performance of all algorithms to identify PH was evaluated and compared with the recommended TRVmax cut-off. RESULTS: In 112 HF patients, all echocardiographic algorithms demonstrated reasonable association (r = .41-.65; p < 0.001) and good agreement with invasive PAPM , with relatively lower mean bias and higher precision observed in algorithms that incorporated tricuspid regurgitation peak or mean gradient. All methods demonstrated strong ability to identify PH (AUC = .70-.80; p < 0.001) but did not outperform TRVmax (AUC = .84; p < 0.001). Echocardiographic estimates of right atrial pressure were falsely elevated in 30% of patients. CONCLUSIONS: Echocardiographic estimates demonstrate reasonable association with invasive PAPM and strong ability to identify PH in HF. However, none of the algorithms outperformed recommendation-advised TRVmax . The incremental value of echocardiographic estimates of right atrial pressure may need to be re-evaluated.

Measurements of exhaled airflow velocity through human coughs using particle image velocimetry.

The sudden outbreak of coronavirus (COVID-19) has infected over 100 million people and led to over two million deaths (data in January 2021), posing a significant threat to global human health. As a potential carrier of the novel coronavirus, the exhaled airflow of infected individuals through coughs is significant in virus transmission. The research of detailed airflow characteristics and velocity distributions is insufficient because most previous studies utilize particle image velocimetry (PIV) with low frequency. This study measured the airflow velocity of human coughs in a chamber using PIV with high frequency (interval: 1/2986 s) to provide a detailed validation database for droplet propagation CFD simulation. Sixty cough cases for ten young healthy nonsmoking volunteers (five males and five females) were analyzed. Ensemble-average operations were conducted to eliminate individual variations. Vertical and horizontal velocity distributions were measured around the mouth area. Overall cough characteristics such as cough duration time (CDT), peak velocity time (PVT), maximum velocities, and cough spread angle were obtained. The CDT of the cough airflow was 520-560 m s, while PVT was 20 m s. The male/female averaged maximum velocities were 15.2/13.1 m/s. The average vertical/horizontal cough spread angle was 15.3°/13.3° for males and 15.6°/14.2° for females. In addition, the spatial and temporal distributions of ensemble-averaged velocity profiles were obtained in the vertical and horizontal directions. The experimental data can provide a detailed validation database the basis for further study on the influence of cough airflow on virus transmission using computational fluid dynamic simulations.

How can two biological variables have opposing secular trends, yet be positively related? A demonstration using timing of puberty and adult height.

Timing of puberty and adult height have opposing secular trends yet are positively associated in individuals. We demonstrate this using data from a single sample and discuss possible statistical and epidemiological reasons behind it. The sample comprised 365 females from Fels Longitudinal Study born 1929-1992. We used Super-Imposition by Translation and Rotation (SITAR) to estimate individual age at peak height velocity (PHV) and PHV from serial height data (8149 observations between 5 and 24 years). General linear regression was used to investigate the association between height and age at PHV, and secular trends in height, age at PHV and PHV. Although adult height increased 0.42 (95% CI: 0.08, 0.77) cm per decade, and age at PHV decreased 1.14 (-3.74, 1.45) weeks per decade, adult height increased by 2.44 (1.78, 3.10) cm per year higher age at PHV. We found tentative evidence of the positive association between age at PHV and adult height strengthened 0.25 (-0.09, 0.59) cm each decade. Secular trends in related variables may differ if the between-individual and between-cohort associations are different. To understand if a secular trend in one variable has contributed to a trend in another, each needs to be modelled over time, together with the changing association between them.

Global Positioning System Analysis of Physical Demands in Small and Large-Sided Games with Floaters and Official Matches in the Process of Return to Play in High Level Soccer Players.

The aim of this study was twofold: (i) to analyze the physical demands in the return to play (RTP) process of high-level soccer players in the role of floater in different soccer sided games (SGs) formats (i.e., 4vs4 + 2 and 8vs8 + 1); and (ii) to analyze the differences in physical demands encountered by regular and floater players among the SGs formats and official matches by means of global positioning system technology (GPS APEX pod, North Ireland) was used. Twenty-six highly trained, male soccer players (U16 years) participated in this investigation. Players were classified into two groups: 23 regular and 3 floater players, a total of eight SGs were analyzed, which involved the recording of 80 observations of regular and floater players. Match-play players showed most likely-probable differences in distance covered at high-intensity per minute (D > 14.4/min), at high-speed running per minute (D > 21/min), and peak velocity (Vpeak) in comparison to floaters in the 8vs8 + 1 LSG (large-side-games), and presented most likely differences in accelerations >2/min in comparison to match-play players. Therefore, the use of floaters during the last phase of the RTP (return to play) seems to be a useful strategy for progressive reintroduction into specific training (1) floater in the 4vs4 + 2 SSG; (2) floater in the 8vs8 + 1 LSG; (3) regular player in the 4vs4 + 2 SSG; and (4) regular player in the 8vs8 + 1 LSG before starting full trainings and returning to competition.

Doppler evaluation of maternal vessels in normal gestation and threatened abortion in canines.

BACKGROUND: Ultrasonographic monitoring of the pregnant bitch is an established routine in many veterinary clinics. In order to better assess foetal health and avoid pregnancy losses, Doppler ultrasonographic evaluation of the pregnant uterus is the need of the day. Investigations on the dynamics of maternal and foetal blood flow using Doppler ultrasound have been conducted in multiple species recently and it is invisaged that it would be a reliable diagnostic tool in future in monitoring pregnancy. The present study was designed to compare Doppler parameters systolic peak velocity (SPV), end diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) of the uteroplacental (UPA) and umbilical arteries (UA) measured during 40 to 50 and 51 to 60 days in normal gestation and threatened abortion in canines. RESULTS: In total 40 pregnant bitches with known history of breeding; irrespective of age and parity belonging to different breeds were classified into normal gestation (NG) and threatened abortion (TA). Bitches with the history of greenish black discharge or expulsion of one foetus were included in the abortion group and bitches with no such symptoms were included in the normal gestation group. End diastolic velocity of uteroplacental vessels decreased while PI and RI increased significantly with decrease in body weight in threatened abortion cases during 40 to 50 and 51 to 60 days of gestation in canines. Systolic peak velocity and EDV of umbilical arteries increased while PI decreased significantly with decrease in body weight during 40 to 50 days of gestation in canine threatened abortions. CONCLUSIONS: Doppler evaluation of uteroplacental and umbilical arteries is recommended as a diagnostic tool to monitor high risk pregnancy during 40 to 50 and 51 to 60 days of gestation in canines.

Type and Size of Implanted Bioprosthetic Valve Rather Than Intraoperative Peak Transprosthetic Valvular Velocity Predict Postoperative Midterm Prosthesis-Patient Mismatch in Patients Undergoing Surgical Aortic Valve Replacement.

OBJECTIVES: High transprosthetic valvular peak velocity (PV) is indicative of prosthesis-patient mismatch (PPM), which exacerbates mortality and morbidity after surgical aortic valve replacement (AVR). During surgical AVR, a high intraoperative PV sometimes is detected, but whether it affects mortality and morbidity is unknown. The aims of this study were to determine whether intraoperative and postoperative PV were correlated and what factors predicted postoperative PPM. DESIGN: Retrospective, observational, cohort study. SETTING: Tertiary medical center. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The study comprised 556 patients who underwent AVR with a bioprosthetic valve. PV was measured intraoperatively, 1 month after surgery, and 1 year after surgery. The occurrence of PPM was defined as an effective orifice area index of less than 0.85 cm2/m2. The associations between PV values at the aforementioned 3 time points were analyzed using a multivariable nonlinear regression model. A multivariable logistic regression model was used to identify the predictors of PPM at 1 year. There was no significant association between intraoperative PV and PV at 1 month (p = 0.419) or 1 year (p = 0.115). The implanted valve type (p < 0.001) and size (p < 0.001), but not intraoperative PV (p = 0.503), were independent predictors of PPM. CONCLUSIONS: There was no significant association between intraoperative and postoperative PV values. Implanted valve type and size, but not intraoperative PV, predicted postoperative PPM.

Can testicular artery Doppler velocimetry values change according to the measured region in dogs?

Testicular tissue maintenance is performed by the testicular artery, and the hemodynamics of this artery can be evaluated using Doppler ultrasonography. The aim of this study was to characterize the peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) of five regions of the testicular artery in dogs, including two proposed regions and three that have been previously described. Twenty-two dogs were used, and the PSV, EDV, PI and RI of the testicular artery were measured in five regions: proximal, medial and distal supratesticular; marginal; and intratesticular. The median values for PSV (cm/s), EDV (cm/s), PI and RI in the five regions were as follows: proximal supratesticular (23.1, 3.7, 2.1 and 0.8); medial supratesticular (17.2, 4.5, 1.5, and 0.7); distal supratesticular (12.2, 5.7, 0.8, and 0.5); marginal (11.3, 6.5, 0.5, and 0.4); and intratesticular (5.7, 3.5, 0.5, and 0.4). There was a difference between the PSV of the medial and distal supratesticular regions. There were differences in the PSV, EDV, PI and RI among the distal supratesticular, marginal and intratesticular regions. Measurements of PSV, EDV, PI and RI of the testicular artery in dogs at the proposed regions showed different results due to the hemodynamic and morphological differences of the artery during its course in the spermatic cord and to the testicles. It is necessary to identify the region in testicular artery Doppler velocimetric evaluations of dogs, given that there is a difference according to the region measured.

Respiratory variation in peripheral arterial blood flow peak velocity to predict fluid responsiveness in mechanically ventilated patients: a systematic review and meta-analysis.

BACKGROUND: Fluid overloading is detrimental to organ function and results in a poor prognosis. It is necessary to evaluate fluid responsiveness before fluid loading. We performed a systematic meta-analysis to evaluate the diagnostic value of the respiratory variation in peripheral arterial blood flow peak velocity (△Vpeak PA) in predicting fluid responsiveness in mechanically ventilated patients. METHODS: PubMed, Embase and The Cochrane Library databases were searched for studies that used △Vpeak PA to predict fluid responsiveness in mechanically ventilated patients. We calculated the pooled values of sensitivity, specificity and the area of the summary receiver operating characteristic curve by Meta-Disc 14.0 software. RESULTS: Nine studies with a total of 402 patients were included. Two low quality studies were deleted in further analysis. Moreover, because of different locations of peripheral artery, the rest included studies were divided into brachial site group and carotid site group for meta-analysis individually. The pooled sensitivity, specificity and area under curve were 0.85 (95% confidence interval (CI) 0.77-0.92), 0.86 (95% CI 0.77-0.92) and 0.9268 in carotid site group. The pooled sensitivity, specificity and area under curve were 0.72 (95% CI 0.60-0.81), 0.85 (95% CI 0.74-0.93) and 0.8587 in brachial site group. CONCLUSIONS: △Vpeak of carotid and brachial artery had a diagnostic value in predicting fluid responsiveness respectively. Moreover, △Vpeak of carotid artery had more value than brachial artery in predicting fluid responsiveness. However, there was some clinical heterogeneity; therefore, further studies are needed to confirm diagnostic accuracy.

The oscillatory flow of the cerebrospinal fluid in the Sylvian aqueduct and the prepontine cistern measured with phase contrast MRI in children with hydrocephalus-a preliminary report.

INTRODUCTION: Recognizing patients with ventriculomegaly who are at risk of developing acute hydrocephalus presents a challenge for the clinician. The association between disturbed cerebrospinal fluid flow (CSF) and impaired brain compliance may play a role in the pathogenesis of hydrocephalus. Phase contrast MRI is a noninvasive technique which can be used to assess CSF parameters. The aim of the work is to evaluate the effectiveness of phase contrast MRI in recognizing patients at risk of acute hydrocephalus, based on measuring the pulsatile CSF flow parameters in the Sylvian aqueduct and prepontine cistern in children with ventriculomegaly. AIM: The aim of the work is to characterize the parameters of cerebrospinal fluid (CSF) flow in the Sylvian aqueduct and prepontine cistern in children with ventriculomegaly with regard to patient age and symptoms. We hypothesize that the relationship between CSF flow parameters in these two regions will vary according to analyzed factors and it will allow to recognize children at risk of hydrocephalus. MATERIALS AND METHODS: A group of 26 children with ventriculomegaly (five girls and 21 boys) underwent phase contrast MRI examinations (Philips 3T Achieva with Q-flow integral application). Amplitudes of average and peak velocities of the CSF flow through the Sylvian aqueduct and prepontine cistern were used to calculate ratios of oscillation and peak velocities, respectively. The relationship between the oscillation coefficient, the peak velocity coefficient, and stroke volume was then assessed in accordance with age and clinical symptoms. RESULTS: The peak velocity coefficient was significantly higher in patients with hyper-oscillating flow through the Sylvian aqueduct (3.04 ± 3.37 vs. 0.54 ± 0.28; p = 0.0094). Moreover, these patients tended to develop symptoms more often (p = 0.0612). No significant age-related changes were observed in CSF flow parameters. CONCLUSION: Phase contrast MRI is a useful tool for noninvasive assessment of CSF flow parameters. The application of coefficients instead of direct values seems to better represent hemodynamic conditions in the ventricular system. However, further studies are required to evaluate their clinical significance and normal limits.

Clinical and echocardiographic risk factors for extubation failure in infants with congenital diaphragmatic hernia.

INTRODUCTION: Infants after surgical correction of congenital diaphragmatic hernia are at high risk for extubation failure, but little is known about contributing factors. Therefore, our study aimed to analyze clinical and echocardiographic parameters. MATERIALS AND METHODS: Data of 34 infants with congenital diaphragmatic hernia treated at our department (July 2013-December 2015) were analyzed. Inclusion criteria were: presence of congenital diaphragmatic hernia and echocardiography performed within 48 hours before the first, and, in case of reintubation, the final extubation attempt. Infants were allocated to group A (extubation failure) and group B (extubation successful). RESULTS: Extubation failure occurred in 12/34 infants (35%). Infants in group A had a higher proportion of intrathoracic liver herniation (P = 0.001, OR 17 [2.8/104.5]) and lower rates of the lung-to-head ratio (P = 0.042, 95% CI [-0.4/20]), even as higher rates of extracorporeal membrane oxygenation (P = 0.001, 95% CI [2.7/80.9]). The oxygenation index and the PaO2 /FiO2 ratio differed significantly between both groups (both P = 0.000; 95% CI [-11/-4.1] and [79/215], respectively). The mean airway pressure and fraction of inspired oxygen prior to extubation was significantly higher in group A (P = 0.008; 95% CI [-3.9/-1.4]; P = 0.000; 95% CI [-0.6/-0.2], respectively). In addition, the respiratory severity score was higher in group A (P = 0.000; 95% CI [-7.3/-2.6]). In group A, administration of sildenafil and the vasoactive inotropic score were significantly higher (P = 0.037; OR 9 [0.9/88.6] and P = 0.013; 95% CI [-14/-1.8], respectively). More infants in group A had need for a surgical patch repair of the diaphragm (P = 0.017; OR 7.2 [1.3/41.1]) and showed higher rates of relevant pleural effusions prior the extubation (P = 0.021; OR 6 [1.2/29.5]). The total duration of the ventilation and the length of hospital stay were longer in group A (P = 0.004; 95% CI [-915/-190] and P = 0.000; 95% CI [-110/-39], respectively). The prevalence of pulmonary hypertension was more frequent in group A (P = 0.012; OR 12 [1.3/114]), the time to peak velocity in the main pulmonary artery was significantly lower in group A (P = 0.024; 95% CI [2/25.6]), and these infants suffered more often from cardiac dysfunction (P = 0.007; OR 10 [1.6/63.1]). CONCLUSION: Our results demonstrate that extubation failure in infants with a congenital diaphragmatic hernia is associated with several clinical and echocardiographic risk factors.

Optimal design for longitudinal studies to estimate pubertal height growth in individuals.

BACKGROUND: The SITAR model expresses individual pubertal height growth in terms of mean size, peak height velocity (PHV) and age at PHV. AIM: To use SITAR to identify the optimal time interval between measurements to summarise individual pubertal height growth. SUBJECTS AND METHODS: Heights in 3172 boys aged 9-19 years from Christ's Hospital School measured on 128 679 occasions (a median of 42 heights per boy) were analysed using the SITAR (SuperImposition by Translation And Rotation) mixed effects growth curve model, which estimates a mean curve and three subject-specific random effects. Separate models were fitted to sub-sets of the data with measurement intervals of 2, 3, 4, 6, 12 and 24 months, and the different models were compared. RESULTS: The models for intervals 2-12 months gave effectively identical results for the residual standard deviation (0.8 cm), mean spline curve (6 degrees of freedom) and random effects (correlations >0.9), showing there is no benefit in measuring height more often than annually. The model for 2-year intervals fitted slightly less well, but needed just four-to-five measurements per individual. CONCLUSIONS: Height during puberty needs to be measured only annually and, with slightly lower precision, just four biennial measurements can be sufficient.