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Chronic inflammation promotes pancreatic β-cell decompensation to insulin resistance because of local accumulation of supraphysiologic interleukin 1β (IL-1β) levels. However, the underlying molecular mechanisms remain elusive. We show that miR-503-5p is exclusively upregulated in islets from humans with type 2 diabetes and diabetic rodents because of its promoter hypomethylation and increased local IL-1β levels. β-Cell–specific miR-503 transgenic mice display mild or severe diabetes in a time- and expression-dependent manner. By contrast, deletion of the miR-503 cluster protects mice from high-fat diet–induced insulin resistance and glucose intolerance. Mechanistically, miR-503-5p represses c-Jun N-terminal kinase–interacting protein 2 (JIP2) translation to activate mitogen-activated protein kinase signaling cascades, thus inhibiting glucose-stimulated insulin secretion (GSIS) and compensatory β-cell proliferation. In addition, β-cell miR-503-5p is packaged in nanovesicles to dampen insulin signaling transduction in liver and adipose tissues by targeting insulin receptors. Notably, specifically blocking the miR-503 cluster in β-cells effectively remits aging-associated diabetes through recovery of GSIS capacity and insulin sensitivity. Our findings demonstrate that β-cell miR-503-5p is required for the development of insulin resistance and β-cell decompensation, providing a potential therapeutic target against diabetes. Article Highlights: Promoter hypomethylation during natural aging permits miR-503-5p overexpression in islets under inflammation conditions, conserving from rodents to humans. Impaired β-cells release nanovesicular miR-503-5p to accumulate in liver and adipose tissue, leading to their insulin resistance via the miR-503-5p/insulin receptor/phosphorylated AKT axis. Accumulated miR-503-5p in β-cells impairs glucose-stimulated insulin secretion via the JIP2-coordinated mitogen-activated protein kinase signaling cascades. Specific blockage of β-cell miR-503-5p improves β-cell function and glucose tolerance in aging mice. [ABSTRACT FROM AUTHOR]

Identifying saline soils is of great importance for protecting land resources and for the sustainable development of agriculture. Total soil salinity (TSS) is the most commonly used indicator for determining soil salinization, but the application of soil geochemical data is rarely reported. In general, there is a significant relationship between TSS and the content of soil-soluble Na, which can be estimated by the difference between the bulk-soil Na2O content and its background value. In this study, the partial least squares regression (PLSR) method was employed to calculate the Na2O background value via a regression model between Na2O and SiO2, Al2O3, TFe2O3, Cr, Nb, and P in a 1:250,000 scale regional geochemical data set of soils in Jilin Province, NE China. We defined δNa as the difference between the bulk-soil Na2O value and the regression background value, which can be used as a geochemical indicator to identify saline soils. One hundred and five samples with known TSS contents in the study area were selected to test the capability of the indicator δNa. The result shows that the identification accuracy can be up to 75%, indicating that the indicator can provide a new means for saline soil identification. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the MR features of the traumatic injury of the triangular fibrocartilage complex (TFCC) by using high-resolution 3-T magnetic resonance imaging (MRI) and to refine the Palmer classification system.Materials and Methods: From November 2015 to May 2019, sixty-seven patients met the including and excluding criteria and were enrolled into this retrospective study. All subjects had high-resolution 3-T MRI scan of the wrist and eleven had indirect MR arthrography of the wrist. All the MRI were read by two experienced musculoskeletal radiologists. Diagnostic sensitivity, specificity, and accuracy of MRI were calculated by using the arthroscopy and surgery as the standard of reference. A P value less than 0.05 was considered statistically significant. The interobserver agreement was assessed by kappa analysis.Results: There were 49 cases of TFCC injuries proven by the arthroscopy or surgery. The TFCC injuries in the other 18 patients were proved by the combination of clinical follow-up examination and follow-up MRI. Among the arthroscopy- or surgery-confirmed cases, there were 32 patients with original Palmer injuries (IA = 10, IB = 19, ID = 3), 5 with capsular detachment, 4 with bucket-handle tear of the TFCC that have rarely been reported, and 8 with complex injuries that involved the listed classifications above. The sensitivities and specificities of MRI for diagnosing IA, IB, ID, complex injuries, and bucket-handle tear were 67-100% and 90-100%, and overall good to perfect interobserver agreements (kappa, 0.64-1.00). The diagnostic performance for the capsular detachment was lower (kappa, 0.38).Conclusion: With high-resolution 3-T MRI, more detailed injury patterns were found including capsular injuries, the horizontal tear of the articular disk, and the bucket-handle tear. It is necessary to refine the classic Palmer classification of TFCC injuries. [ABSTRACT FROM AUTHOR]

Objectives: To investigate if using high-resolution 3-T MRI can identify additional injuries of the triangular fibrocartilage complex (TFCC) beyond the Palmer classification.Materials and Methods: Eighty-six patients with surgically proven TFCC injury were included in this study. All patients underwent high-resolution 3-T MRI of the injured wrist. The MR imaging features of TFCC were analyzed according to the Palmer classification.Results: According to the Palmer classification, 69 patients could be classified as having Palmer injuries (52 had traumatic tears and 17 had degenerative tears). There were 17 patients whose injuries could not be classified according to the Palmer classification: 13 had volar or dorsal capsular TFC detachment and 4 had a horizontal tear of the articular disk.Conclusion: Using high-resolution 3-T MRI, we have not only found all the TFCC injuries described in the Palmer classification, additional injury types were found in this study, including horizontal tear of the TFC and capsular TFC detachment. We propose the modified Palmer classification and add the injury types that were not included in the original Palmer classification. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study is to assess the functional connectivity of the motor cortical network in patients with brachial plexus avulsion injury (BPAI) after contralateral C7 nerve transfer, using resting-state functional magnetic resonance imaging (RS-fMRI). Methods: Twelve patients with total brachial plexus root avulsion underwent RS-fMRI after contralateral C7 nerve transfer. Seventeen healthy volunteers were also included in this fMRI study as controls. The hand motor seed regions were defined as region of interests in the bilateral hemispheres. The seed-based functional connectivity was calculated in all the subjects. Differences in functional connectivity of the motor cortical network between patients and healthy controls were compared. Results: The inter-hemispheric functional connectivity of the M1 areas was increased in patients with BPAI compared with the controls. The inter-hemispheric functional connectivity between the supplementary motor areas was reduced bilaterally. Conclusions: The resting-state inter-hemispheric functional connectivity of the bilateral M1 areas is altered in patients after contralateral C7 nerve transfer, suggesting a functional reorganization of cerebral cortex. [ABSTRACT FROM AUTHOR]