Background:Late-onset depression(LOD)and early-onset depression(EOD)exhibit different pathological mechanisms and clinical phenotypes,including different extents of olfactory dysfunction.However,the brain abnormalitie...Background:Late-onset depression(LOD)and early-onset depression(EOD)exhibit different pathological mechanisms and clinical phenotypes,including different extents of olfactory dysfunction.However,the brain abnormalities underlying the differences in ol-factory dysfunction between EOD and LOD remain unclear.Objective:The aim of this study was to compare the functional connectivity(FC)patterns of olfactory regions between EOD patients and LOD patients and examine their relationship with cognitive function.Methods:One hundred and five patients with EOD,101 patients with LOD and 160 normal controls(NCs)were recruited for the present study.Participants underwent clinical assessment,olfactory testing,cognitive assessments,and magnetic resonance imaging.Eight regions of the primary and secondary olfactory regions were selected to investigate olfactory FC.Results:Patients with LOD exhibited decreased odor identification(OI)compared with patients with EOD and NCs.The LOD group exhibited decreased FC compared with the EOD and NC groups when primary and secondary olfactory regions were selected as the regions of interest(the piriform cortex,lateral entorhinal cortex,and orbital-frontal cortex).Additionally,these abnormal olfactory FCs were associated with decreased cognitive function scores and OI,and the FC between the left orbital-frontal cortex and left amygdala was a partial mediator of the relationship between global cognitive scores and OI.Conclusion:Overall,patients with LOD exhibited decreased FC in both the primary and secondary olfactory cortices compared with patients with EOD,and abnormal olfactory FC was associated with OI dysfunction and cognitive impairment.The FC between the orbital-frontal cortex and amygdala mediated the relationship between global cognitive function and OI.展开更多
Dear Editor, Type 2 diabetes mellitus （T2DM） develops only in insulin-resistant subjects when pancreatic β-cell compensation fails （Matveyenko and Butler, 2006）. Decreased insulin secretory function and reduced ...Dear Editor, Type 2 diabetes mellitus （T2DM） develops only in insulin-resistant subjects when pancreatic β-cell compensation fails （Matveyenko and Butler, 2006）. Decreased insulin secretory function and reduced cell mass are traditionally viewed as major contributing factors in β-cell insufficiency. A recent study using a diabetic rodent model suggests that progressive β-cell de- differentiation is an important underlying mechanism in β-cell failure （Talchai et al., 2012）. β-cell dedifferentiation in diabetes refers to the loss by healthy β-cells of key components characteristic of the differen- tiated state （Dor and Glaser, 2013）, including insulin （for its secretory product）, Glut2 （for glucose intake）, and PDX-1 （for critical insulin transcription factor）, β-cell dedifferentiation may be largely respon- sible for not only β-cell secretory dysfunction but also impaired β-cell identity. In view of findings that bariatric surgery in a rodent T2DM model led to increased β-cell mass and improved islet morphology （Strader et al., 2009）, we investigated the effects of gastric bypass surgery on dedifferentiated β-cells.展开更多
Increasing evidence suggests that the gut may influence the host’s metabolism and ultimately change the outcomes of type 2 diabetes mellitus(T2DM).We review the evidence on the relationship between the gut and T2DM r...Increasing evidence suggests that the gut may influence the host’s metabolism and ultimately change the outcomes of type 2 diabetes mellitus(T2DM).We review the evidence on the relationship between the gut and T2DM remission after gastric bypass surgery,and discuss the potential mechanisms underlying the above relationship:gut anatomical rearrangement,microbial composition changes,altered gut cells,and gut hormone modulation.However,the exact changes and their relative importance in the metabolic improvements after gastric bypass surgery remain to be further clarified.Elucidating the precise metabolic mechanisms of T2DM resolution after bypass surgery will help to reveal the molecular mechanisms of pathogenesis,and facilitate the development of novel diagnoses and preventative interventions for this common disease.展开更多
基金supported by a grant from the National Natu-ral Science Foundation of China (nos 82171533,82101508)Medical Scientific Technology Research Foundation of Guangdong Province of China (no.A2020446)the Key Laboratory for Innovation Platform Plan,the Science and Technology Program of Guangzhou,China,the Science and Technology Plan Project of Guangdong Province (no.2019B030316001).
文摘Background:Late-onset depression(LOD)and early-onset depression(EOD)exhibit different pathological mechanisms and clinical phenotypes,including different extents of olfactory dysfunction.However,the brain abnormalities underlying the differences in ol-factory dysfunction between EOD and LOD remain unclear.Objective:The aim of this study was to compare the functional connectivity(FC)patterns of olfactory regions between EOD patients and LOD patients and examine their relationship with cognitive function.Methods:One hundred and five patients with EOD,101 patients with LOD and 160 normal controls(NCs)were recruited for the present study.Participants underwent clinical assessment,olfactory testing,cognitive assessments,and magnetic resonance imaging.Eight regions of the primary and secondary olfactory regions were selected to investigate olfactory FC.Results:Patients with LOD exhibited decreased odor identification(OI)compared with patients with EOD and NCs.The LOD group exhibited decreased FC compared with the EOD and NC groups when primary and secondary olfactory regions were selected as the regions of interest(the piriform cortex,lateral entorhinal cortex,and orbital-frontal cortex).Additionally,these abnormal olfactory FCs were associated with decreased cognitive function scores and OI,and the FC between the left orbital-frontal cortex and left amygdala was a partial mediator of the relationship between global cognitive scores and OI.Conclusion:Overall,patients with LOD exhibited decreased FC in both the primary and secondary olfactory cortices compared with patients with EOD,and abnormal olfactory FC was associated with OI dysfunction and cognitive impairment.The FC between the orbital-frontal cortex and amygdala mediated the relationship between global cognitive function and OI.
文摘Dear Editor, Type 2 diabetes mellitus （T2DM） develops only in insulin-resistant subjects when pancreatic β-cell compensation fails （Matveyenko and Butler, 2006）. Decreased insulin secretory function and reduced cell mass are traditionally viewed as major contributing factors in β-cell insufficiency. A recent study using a diabetic rodent model suggests that progressive β-cell de- differentiation is an important underlying mechanism in β-cell failure （Talchai et al., 2012）. β-cell dedifferentiation in diabetes refers to the loss by healthy β-cells of key components characteristic of the differen- tiated state （Dor and Glaser, 2013）, including insulin （for its secretory product）, Glut2 （for glucose intake）, and PDX-1 （for critical insulin transcription factor）, β-cell dedifferentiation may be largely respon- sible for not only β-cell secretory dysfunction but also impaired β-cell identity. In view of findings that bariatric surgery in a rodent T2DM model led to increased β-cell mass and improved islet morphology （Strader et al., 2009）, we investigated the effects of gastric bypass surgery on dedifferentiated β-cells.
基金supported by grants from the National Basic Research Program of China(973 Program,2011CB504003 to H.Z.)the National Natural Science Foundation of China(Grant No.61134013 to H.Z.,No.81070657 to H.Z.)NN-CAS Research Foundation(NNCAS-2009-1 to H.Z.).
文摘Increasing evidence suggests that the gut may influence the host’s metabolism and ultimately change the outcomes of type 2 diabetes mellitus(T2DM).We review the evidence on the relationship between the gut and T2DM remission after gastric bypass surgery,and discuss the potential mechanisms underlying the above relationship:gut anatomical rearrangement,microbial composition changes,altered gut cells,and gut hormone modulation.However,the exact changes and their relative importance in the metabolic improvements after gastric bypass surgery remain to be further clarified.Elucidating the precise metabolic mechanisms of T2DM resolution after bypass surgery will help to reveal the molecular mechanisms of pathogenesis,and facilitate the development of novel diagnoses and preventative interventions for this common disease.
