Hereditary hypouricemia may result from mutations in the renal tubular uric acid transporter URAT1. Whether mutation of other uric acid transporters produces a similar phenotype is unknown. We studied two families who had severe hereditary hypouricemia and did not have a URAT1 defect. We performed a genome-wide homozygosity screen and linkage analysis and identified the candidate gene SLC2A9, which encodes the glucose transporter 9 (GLUT9). Both families had homozygous SLC2A9 mutations: A missense mutation (L75R) in six affected members of one family and a 36-kb deletion, resulting in a truncated protein, in the other. In vitro, the L75R mutation dramatically impaired transport of uric acid. The mean concentration of serum uric acid of seven homozygous individuals was 0.17 Ϯ 0.2 mg/dl, and all had a fractional excretion of uric acid Ͼ150%. Three individuals had nephrolithiasis, and three had a history of exercise-induced acute renal failure. In conclusion, homozygous loss-of-function mutations of GLUT9 cause a total defect of uric acid absorption, leading to severe renal hypouricemia complicated by nephrolithiasis and exercise-induced acute renal failure. In addition to clarifying renal handling of uric acid, our findings may provide a better understanding of the pathophysiology of acute renal failure, nephrolithiasis, hyperuricemia, and gout. 21: 64 -72, 201021: 64 -72, . doi: 10.1681 In most mammals, uric acid (UA) is oxidized by the hepatic enzyme uricase to highly soluble allantoin. In humans, however, this enzyme is inactive as a result of mutational silencing, 1 making UA the end product of purine metabolism. Serum UA concentration depends on both UA production and UA removal by the kidneys and intestinal tract and is high in humans compared with other mammals. Elevation of serum UA levels has been associated with various diseases, including gout, hypertension, and cardiovascular and renal disease. 2 Conversely, it has been suggested that UA has a beneficial role as a natural antioxidant, and low serum UA levels have been linked to several neurologic diseases. 2 Studies of renal handling of UA in humans have J Am Soc Nephrol

ACTRN12615000231549.

Impairments in cervical kinematics are common in patients with neck pain. A virtual reality (VR) device has potential to be effective in the management of these impairments. The objective of this study was to investigate the effect of kinematic training (KT) with and without the use of an interactive VR device. In this assessorblinded, allocation-concealed pilot clinical trial, 32 participants with chronic neck pain were randomised into the KT or kinematic plus VR training (KTVR) group. Both groups completed four to six training sessions comprising of similar KT activities such as active and quick head movements and fine head movement control and stability over five weeks. Only the KTVR group used the VR device. The primary outcome measures were neck disability index (NDI), cervical range of motion (ROM), head movement velocity and accuracy. Kinematic measures were collected using the VR system that was also used for training. Secondary measures included pain intensity, TAMPA scale of kinesiophobia, static and dynamic balance, global perceived effect and participant satisfaction. The results demonstrated significant (p<0.05) improvements in NDI, ROM (rotation), velocity, and the step test in both groups post-intervention. At 3-month post-intervention, these improvements were mostly sustained; however there was no control group, which limits the interpretation of this. Between-group analysis showed a few specific differences including global perceived change that was greater in the KTVR group.This pilot study has provided directions and justification for future research exploring training using kinematic training and VR for those with neck pain in a larger cohort.  The results demonstrated significant improvements in NDI, ROM, velocity, and the step test in both groups, with a few specific between-group differences including global perceived change that was greater in the VR group. This pilot study has provided directions and justification for future research exploring training using kinematic training and VR for those with neck pain.

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Interactive cervical motion kinematics: sensitivity, specificity and clinically significant values for identifying kinematic impairments in patients with chronic neck pain. AbstractChronic neck pain has been consistently shown to be associated with impaired kinematic control including reduced range, velocity and smoothness of cervical motion, that seem relevant to daily function as in quick neck motion in response to surrounding stimuli. The objectives of this study were: to compare interactive cervical kinematics in patients with neck pain and controls; to explore the new measures of cervical motion accuracy; and to find the sensitivity, specificity, and optimal cutoff values for defining impaired kinematics in those with neck pain.In this cross-section study, 33 patients with chronic neck pain and 22 asymptomatic controls were assessed for their cervical kinematic control using interactive virtual reality hardware and customized software utilizing a head mounted display with built-in head tracking.Outcome measures included peak and mean velocity, smoothness (NVP), symmetry (TTPP), and accuracy of cervical motion.Results demonstrated significant and strong effect-size differences in peak and mean velocities, NVP and TTPP in all directions excluding TTPP in left rotation, and good effect-size group differences in 5/8 accuracy measures.Regression results emphasized the high clinical value of neck motion velocity, with very high sensitivity and specificity (85%-100%), followed by motion smoothness, symmetry and accuracy. These finding suggest cervical kinematics should be evaluated clinically, and screened by the provided cut off values for identification of relevant impairments in those with neck pain. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPTSuch identification of presence or absence of kinematic impairments may direct treatment strategies and additional evaluation when needed.

BACKGROUND: Flight-associated neck pain (FANP) is a serious problem in fighter pilots. Despite the high impact of FANP there is little evidence for effective management. However, self-kinematic training showed a positive effect in the general population. The purpose of this study was to investigate the effectiveness of a self-kinematic training program using virtual reality in improving neck pain in fighter pilots.METHODS: There were 45 pilots with FANP who were randomized to a control group (N 23) or a training group (N 22). Training participants were instructed to exercise using a personalized self-training program, for 20 min/wk, for 4 wk. Primary outcome measures were neck disability (NDI%) and mean velocity ( s1), and secondary were pain, health status, accuracy, and isometric strength. Assessments were conducted by a blinded assessor and intention-to-treat analysis by a blinded statistician.RESULTS: There were 40 pilots who completed the postintervention assessments, and 35 completed the 6-mo follow-up. Baseline measurements showed mild pain and disability (mean VAS 43 22.73, NDI 17.76 9.59%) and high kinematic performance. Compliance with self-training was poor. No differences were observed in self-reported measures and strength. Exercise duration was correlated with NDI% improvement.DISCUSSION: This self-kinematic training promoted kinematic performance, but was ineffective in engaging the pilots to exercise, and consequently did not improve pain and disability. Poor compliance was previously reported in self-training for FANP, suggesting further studies should prioritize supervised training. Considering the high baseline kinematic performance, kinematics does not seem to be a key factor in FANP, and future exercise research should aim for intense strengthening to increase endurance to the high Gz pilots experience.Sarig Bahat H, German D, Palomo G, Gold H, Frankel Nir Y. Self-kinematic training for flight-associated neck pain: a randomized controlled trial. Aerosp Med Hum Perform. 2020; 91(10):790797.

The results suggest high reliability for peak and mean velocity as measured by the interactive Neck VR assessment of neck motion kinematics. VR appears to provide a reliable and more ecologically valid method of cervical motion evaluation than previous conventional methodologies.