Hypothalamic neuropeptides play essential roles in regulating energy and body weight balance. Energy imbalance and obesity have been linked to hypothalamic signaling defects in regulating neuropeptide genes; however, it is unknown whether dysregulation of neuropeptide exocytosis could be critically involved. This study discovered that synaptotagmin-4, an atypical modulator of synaptic exocytosis, is expressed most abundantly in oxytocin neurons of the hypothalamus. Synaptotagmin-4 negatively regulates oxytocin exocytosis, and dietary obesity is associated with increased vesicle binding of synaptotagmin-4 and thus enhanced negative regulation of oxytocin release. Overexpressing synaptotagmin-4 in hypothalamic oxytocin neurons and centrally antagonizing oxytocin in mice are similarly obesogenic. Synaptotagmin-4 inhibition prevents against dietary obesity by normalizing oxytocin release and energy balance under chronic nutritional excess. In conclusion, the negative regulation of synaptotagmin-4 on oxytocin release represents a hypothalamic basis of neuropeptide exocytosis in controlling obesity and related diseases.
Retinal screening contributes to early detection of diabetic retinopathy and timely treatment. To facilitate the screening process, we develop a deep learning system, named DeepDR, that can detect early-to-late stages of diabetic retinopathy. DeepDR is trained for real-time image quality assessment, lesion detection and grading using 466,247 fundus images from 121,342 patients with diabetes. Evaluation is performed on a local dataset with 200,136 fundus images from 52,004 patients and three external datasets with a total of 209,322 images. The area under the receiver operating characteristic curves for detecting microaneurysms, cotton-wool spots, hard exudates and hemorrhages are 0.901, 0.941, 0.954 and 0.967, respectively. The grading of diabetic retinopathy as mild, moderate, severe and proliferative achieves area under the curves of 0.943, 0.955, 0.960 and 0.972, respectively. In external validations, the area under the curves for grading range from 0.916 to 0.970, which further supports the system is efficient for diabetic retinopathy grading.
Study design: A systematic review. Background: The number of traumatic spinal cord injury (TSCI) reports grows annually, especially in China and Korea. The epidemiological characteristics of TSCI in Asia differ from those in other countries. Thus, we compiled epidemiological factors from Asia to compare with those from other countries. Method: We searched articles published in any language between January 1980 to December 2011 using the terms "spinal cord injury", "traumatic spinal cord injury", "epidemiology", and "Asia". The articles were reviewed for information regarding TSCI incidence, total cases, case criteria, case source, causes of injury, male/female ratio, mean age, prospective or retrospective, neurological level of injury, extent of injury, and America Spinal Injury Association Impairment Scale (AIS)/grade. Results: Epidemiological data were extracted from 39 reports in the published literature that met the inclusion criteria. Only two studies reported prevalence rates. Incidence rates ranged from 12.06 to 61.6 per million. The average age ranged from 26.8 to 56.6 years old. Men were at higher risk than women. Motor vehicle collisions (MVCs) and falls were the main causes of TSCI. However, several countries reported war wounds as the major cause. The neurological level and extent of injury were mixed, and most patients were categorized as AIS/Frankel grade A. Conclusion: TSCI is an important public health problem and a major cause of paralysis. We must understand the epidemiology to implement appropriate preventative measures. Asian epidemiology is different from that in other regions, so intervention measures must be established according to population-specific characteristics.
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