Research Progress in MRI of the Visual Pathway in Diabetic Retinopathy

With an increasing incidence,diabetic retinopathy is one of the most important complications of diabetes mellitus (DM)and is also known as one of the major reasons of adult acquired blindness.It is widely accepted that the visual impairment of diabetic patients results from retinal microvascular changes.However,recent clinical experimental and neuroimaging studies suggest that the visual impairment of diabetic patients is also related to the pathophysiological changes of different parts of the visual pathway in diabetic retinopathy.Therefore,the magnetic resonance imaging (MRI)techniques have been widely used for evaluating the microstructural changes,white matter integrity,metabolite changes,and the whole or partial functional and anatomic changes in the diabetic retinopathy patients'brains in order to fully understand the mechanism of vision loss of the diabetic retinopathy patients.This review focuses on the research progress in application of MRI of the visual pathway in diabetic retinopathy.

Hypertension Exacerbates Severity and Outcomes of COVID-19 in Elderly Patients:A Retrospective Observational Study

Objective To evaluate the impact of hypertension on the clinical outcome of COVID-19 patients aged 60 years old and older.Methods This single-center retrospective cohort study enrolled consecutive COVID-19 patients aged 60 years old and older,who were admitted to Liyuan Hospital from January 1,2020 to April 25,2020.All included patients were divided into two groups:hypertension and nonhypertension group.The baseline demographic characteristics,laboratory test results,chest computed tomography(CT)images and clinical outcomes were collected and analyzed.The prognostic value of hypertension was determined using binary logistic regression.Results Among the 232 patients included in the analysis,105(45.3%)patients had comorbid hypertension.Compared to the nonhypertension group,patients in the hypertension group had higher neutrophil-to-lymphocyte ratios,red cell distribution widths,lactate dehydrogenase,high-sensitivity C-reactive protein,D-dimer and severity of lung lesion,and lower lymphocyte counts(all P<0.05).Furthermore,the hypertension group had a higher proportion of intensive care unit admissions[24(22.9%)vs.14(11.0%),P=0.02]and deaths[16(15.2%)vs.3(2.4%),P<0.001]and a significantly lower probability of survival(P<0.001)than the nonhypertension group.Hypertension(OR:4.540,95%CI:1.203–17.129,P=0.026)was independently correlated with all-cause in-hospital death in elderly patients with COVID-19.Conclusion The elderly COVID-19 patients with hypertension tend to have worse conditions at baseline than those without hypertension.Hypertension may be an independent prognostic factor of poor clinical outcome in elderly COVID-19 patients.

Discovery of four gravitational lensing systems by clusters in the SDSS DR6

We report the discovery of 4 strong gravitational lensing systems by visual inspections of the Sloan Digital Sky Survey images of galaxy clusters in Data Release 6 （SDSS DR6）. Two of the four systems show Einstein rings while the others show tangen- tial giant arcs. These arcs or rings have large angular separations （〉 8″） from the bright central galaxies and show bluer color compared with the red cluster galaxies. In addition, we found 5 probable and 4 possible lenses by galaxy clusters.

Liraglutide Ameliorates Hyperhomocysteinemia-Induced Alzheimer-Like Pathology and Memory Deficits in Rats via Multi-molecular Targeting

Hyperhomocysteinemia(Hhcy)is an independent risk factor for Alzheimer's disease(AD),and insulinresistance is commonly seen in patients with Hhcy.Liraglutide(Lir),a glucagon-like peptide that increases the secretion and sensitivity of insulin,has a neurotrophic or neuroprotective effect.However,it is not known whether Lir ameliorates the AD-like pathology and memory deficit induced by Hhcy.By vena caudalis injection of homocysteine to produce the Hhcy model in rats,we found here that simultaneous administration of Lir for 2 weeks ameliorated the Hhcy-induced memory deficit,along with increased density of dendritic spines and up-regulation of synaptic proteins.Lir also attenuated the Hhcy-induced tau hyperphosphorylation and Aβ overproduction,and the molecular mechanisms involved the restoration of protein phosphatase-2 A activity and inhibition of β-and γ-secretases.Phosphorylated insulin receptor substrate-1 also decreased after treatment with Lir.Our data reveal that Lir improves the Hhcy-induced AD-like spatial memory deficit and the mechanisms involve the modulation of insulinresistance and the pathways generating abnormal tau and Aβ.