Publications by authors named "R D Mehta"

2,904 Publications

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Mind over body: A neuroergonomic approach to assessing motor performance under stress in older adults.

Appl Ergon 2022 Jan 24;101:103691. Epub 2022 Jan 24.

Wm. Michael Barnes '64 Department of Industrial and Systems Engineering, Texas A&M University, College Station, TX, 77843, USA; J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, 77843, USA. Electronic address:

Stress impairs motor performance, which is exacerbated with age. Stress also impairs brain activity in the prefrontal cortex, which communicates with the motor areas of the brain to regulate exercise and motor performance. To develop ergogenic strategies for the aging workforce, mind (brain)-body mechanisms behind the effect of stress on neuromuscular performance need to be well understood. This study investigated the influence of social stress on motor performance and information flow between the frontal and motor regions of the brain during intermittent handgrip contractions among older adults. Thirty older adults, balanced by gender, performed intermittent handgrip contractions at 30% of maximum strength before and after being subjected to a social stressor. Force steadiness, strength loss, root mean square electromyogram (EMG) activity, activation of the brain regions, and functional and effective connectivity between the frontal and motor brain regions were computed for pre- and post-stressor handgrip contractions. Older men exhibited improved motor performance after the stressor and concomitant reduction in functional connectivity between the frontal-motor brain regions ipsilateral to the contracting hand. Additionally, while both sexes exhibited significant causal information flow, i.e., effective connectivity, from the frontal to the motor regions of the brain, irrespective of the stressor, older women exhibited a bidirectional effective connectivity between the frontal-motor brain regions after the stressor. Stress had a facilitative effect on the motor performance of older men through compensatory brain network reorganization. Older women exhibited comparable motor performance pre/post stress, despite showing an increase in bidirectional information flow between the frontal-motor areas. Employing brain hemodynamics can facilitate better understanding of the impact of stress on neuromuscular performance and its differential impacts on brain network reorganization between the sexes.
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http://dx.doi.org/10.1016/j.apergo.2022.103691DOI Listing
January 2022

Clinicopathological Profile and Outcome of a Large Cohort of Patients with Nonalcoholic Fatty Liver Disease from South Asia: Interim Results of the Indian Consortium on Nonalcoholic Fatty Liver Disease.

Metab Syndr Relat Disord 2022 Jan 25. Epub 2022 Jan 25.

Division of Gastroenterology, Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, USA.

Previous data from South Asia and India had shown that patients with nonalcoholic fatty liver disease (NAFLD) have mild liver disease severity. There are no data regarding long-term clinical outcomes in patients with NAFLD from South Asia. The aim of the study was to evaluate the clinicopathological profile, severity of NAFLD, and clinical outcomes in a large cohort of patients with NAFLD from South Asia. In an ongoing real-life study [Indian Consortium on nonalcoholic fatty liver disease (ICON-D)], interim data captured across 23 centers in India over 18 months was analyzed for clinicopathological profile, severity of NAFLD, and hepatic/extrahepatic events on follow-up. Of 4313 patients (mean age 45 ± 12.2 years, males 52%), data on metabolic risk factors in 3553 (82.3%) patients revealed that 378 (10.6%) were lean, 575 (16.2%) overweight, 2584 (72.7%) obese; metabolic syndrome in 1518 (42.7%) and at least one metabolic risk factor in 3292 (92.6%) patients. Evidence of significant or advanced fibrosis assessed with [aspartate transaminase to platelet ratio index (APRI),  = 3196 (74%)], [fibrosis-4 (FIB-4),  = 3554 (82.4%)], [NAFLD fibrosis score (NFS),  = 1924 (44.6%)], [Fibroscan,  = 2475, (57.3%)], and histology [ = 267 (6.2%)] was present in 682 (21.3%), 676 (19%), 397 (20.6%), 715 (29%), and 41 (15.4%) patients, respectively; 246 (10%) patients on Fibroscan and 22 (8.2%) on histology had evidence of cirrhosis. On a mean follow-up 43.5 months, hepatic and extrahepatic events recorded in 1353 (31.3%) patients showed that patients with compensated cirrhosis [71 (5.2%)] had more hepatic [26 (36.7%)] and extrahepatic events [8 (11.3%)] in comparison with those without cirrhosis ( < 0.0001). Around one fifth of patients with NAFLD in South Asia have significant liver disease. Both hepatic and extrahepatic events on follow-up are observed more commonly in patients with nonalcoholic steatohepatitis-related compensated cirrhosis.
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http://dx.doi.org/10.1089/met.2021.0104DOI Listing
January 2022

Grass-roots entrepreneurship complements traditional top-down innovation in lung and breast cancer.

NPJ Digit Med 2022 Jan 21;5(1):10. Epub 2022 Jan 21.

Hacking Medicine, Massachusetts Institute of Technology, Cambridge, MA, USA.

The majority of biomedical research is funded by public, governmental, and philanthropic grants. These initiatives often shape the avenues and scope of research across disease areas. However, the prioritization of disease-specific funding is not always reflective of the health and social burden of each disease. We identify a prioritization disparity between lung and breast cancers, whereby lung cancer contributes to a substantially higher socioeconomic cost on society yet receives significantly less funding than breast cancer. Using search engine results and natural language processing (NLP) of Twitter tweets, we show that this disparity correlates with enhanced public awareness and positive sentiment for breast cancer. Interestingly, disease-specific venture activity does not correlate with funding or public opinion. We use outcomes from recent early-stage innovation events focused on lung cancer to highlight the complementary mechanism by which bottom-up "grass-roots" initiatives can identify and tackle under-prioritized conditions.
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http://dx.doi.org/10.1038/s41746-021-00545-xDOI Listing
January 2022

Comparison of clinical features of pregnant and non-pregnant females with primary hyperoxaluria.

J Nephrol 2022 Jan 18. Epub 2022 Jan 18.

Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.

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http://dx.doi.org/10.1007/s40620-022-01253-9DOI Listing
January 2022

Shortening dome osteotomy for correction of severe cubitus varus secondary to malunited supracondylar fractures in children.

Arch Orthop Trauma Surg 2022 Jan 18. Epub 2022 Jan 18.

Department of Orthopaedic Surgery, Maulana Azad Medical College and Associated Lok Nayak Hospital, Bahadur Shah Zafar Marg, New Delhi, 110002, India.

The results of conventional corrective procedures remain suboptimal for severe cubitus varus deformities (> 30) in children. We present the results of shortening dome osteotomy for the correction of such deformities.

Patients And Methods: We present retrospective review of prospectively collected data of 18 patients (11 boys and 7 girls) who underwent shortening dome osteotomy between January 2011 and December 2019 for severe cubitus varus deformities (> 30) secondary to malunited supracondylar fracture. The procedure involved the removal of convexo-concave bone (5-8 mm wide) between the two domes. Humero-ulnar angles, lateral condylar prominence index (LCPI), and elbow range of movements were recorded preoperatively and postoperatively.

Results: Mean age was 7.5 years (range 5 years-11 years). Indication for surgery was poor cosmesis in all the patients and tardy ulnar nerve symptoms in three patients. Mean preoperative humero-ulnar angle was 26.1 varus (range 22-34), while it was 7.1 valgus (range 0-12) for contralateral normal elbow. They were followed for a mean duration of 2.2 years (range 12 months-5.8 years). The mean postoperative valgus angle achieved was 7.3 (range 2-12) as total angular correction achieved was 34.4 (range 30-44) (p < 0.001). Radiological healing was observed in all the patients at mean duration of 7.1 weeks (range 5 weeks-9 weeks). Mean preoperative and postoperative LCPI were - 2.4 (range +4.7 to - 10.5) and - 1.7 (range +4.5 to - 5.1), respectively (p = 0.595). Three patients had pin tract infections and two of them responded to aseptic dressings and oral antibiotics, while another required early pin removal and additional protection in splint. All patients regained preoperative arc of motion within 6 months after the procedure.

Conclusion: Shortening dome osteotomy is a safe and effective method for correcting severe cubitus varus deformities (> 30) secondary to malunited supracondylar fracture in children.
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http://dx.doi.org/10.1007/s00402-021-04288-yDOI Listing
January 2022
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