Subthreshold depression is common in the elderly. It is also one of the neuropsychiatric symptoms that frequently affect patients with mild cognitive impairment (MCI). MCI patients with subthreshold depression may suffer from more severe cognitive impairment and an increased risk of dementia. In recent years, more attention has been paid to the relationship between subthreshold depression and cognitive impairment. This article reviews the research progress on the epidemiology and neuroimaging of subthreshold depression in the elderly with MCI.

Subthreshold depression is common in the elderly. It is also one of the neuropsychiatric symptoms that frequently affect patients with mild cognitive impairment (MCI). MCI patients with subthreshold depression may suffer from more severe cognitive impairment and an increased risk of dementia. In recent years, more attention has been paid to the relationship between subthreshold depression and cognitive impairment. This article reviews the research progress on the epidemiology and neuroimaging of subthreshold depression in the elderly with MCI.

Objective:To find the better imaging method for the diagnosis of sialolithiasis by comparing the 3 different imaging methods.Methods:32 cases of salivary calculus were examined by sonography,X-ray and cone beam computed tomography(CBCT),the sensitivity,specificity,positive predictive value,negative predictive value were compared among the 3 methods.Results:The sensitivity and negative predictive value of cone beam computed tomography(95.8％ and 80％) was significantly higher than those of sonography(83.3％,50.0％) and X-ray(58.3％,20％)(P ＜ 0.05).Of three imaging methods there was no statistical difference in specificity and positive predictive value.Conclusion:CBCT is more sensitive than sonography or X-ray in the diagnosis of sialolithiasis.

Objective To investigate the effects of exogenous IGF- Ⅰon apoptosis, bax,bcl-2 and caspase-3 gene mRNA transcription in intestinal mucosal epithelial cell of SAP rats. Method Seventy-two male Wistar rats were randomly divided into sham operation group (SO),SAP group(SAP) and IGF-Ⅰ treatment (SAP + IGF-Ⅰ) group.Every group was randomly divided into 3 time units (6,12,24 h),8 rats as each time unit. SAP was induced in the rats by injecting adversely 5.0 % sodium taurocholate into biliary-pancreafic duct. The SO rats were infused with NS by the same way. The rats in IGF-Ⅰgroup were injected with IGF-Ⅰ by subcutano at half an hour before operation and three hours after operation,respectively. Animals in each group were killed separately at 6,12 and 24 hours after operation.The apoptosis in mucesal cells of small intestine was detected by TUNEL, and histo pathological changes of the small intestine was observed. The expressions of bax and bcl-2 and caspase-3 mR-NA gene in small intestine were measured by reverse transcription polymerase chain reaction(RT-PCR). Results Compared with the SAP group,the serum amylase were lower in IGF-Ⅰ group,and there existed significant at 12 h and24 h (P < 0.05).The pathological score of small intestinal was significantly reduced in IGF-Ⅰ group com-pared with SAP group,and there were statistical differences at 12 h and 24 h.ln IGFo-Ⅰ group,the apoptosis index of intestinal epithelial decreased significantly compared with SAP group[6 h: (13.88±1.73) vs. (19.00±2.78) ;12h:(10.13±1.55) vs. (17.63±.60);24 h:(9.50±1.07) vs. (17.25±2.76)] (P <0.05); the histopathdogical changes were more improved compared wit SAP group under the electronic microscope; the expres-sion of bax mRNA [6 h:(1.35±0.18) vs.(0.85±0.12);12 h:(1.21±0.21) vs. (0.86±0.24);24 h:(1.14±0.24) vs. (0.95±0.22)] and caspese-3 mRNA[6 h:(0.78±0.01) vs. (0.55±0.04);12 h:(0.79±0.04) vs. (0.57±0.05) ;24 h: (0.81±0.06) vs. (0.55±0.01) (P < 0.01)] were higher in three time units in SAP group than those in SO group (P < 0.01) ,and in IGF-1 group it was weakened significantly compared with the SAP group at each time point (P <0.05). bcl-2 mRNA expression was weak and have no difference between the SO group and SAP group (P > 0.05), but increased signifycantly in the IGF-± group at each time point [6 h:(0.65±0.07) vs. (0.54±0.04) vs. (0.57±0.06);12 h:(0.69±0.04) vs. (0.56±0.05) vs. (0.53±0.05);24h:(0.72±0.05) vs. (0.54±0.07) vs. (0.58±0.08)] (P <0.05). Conclusions Exogenous IGF-Ⅰ could rivalry SAP induced apoptosis to mucosal cells of small intestine , then could alleviate SAP induced injury to intestinal mucosal, It may be associated with the mechanisms that IGF-Ⅰ could improve the expression of bcl-2 mRNA and inhibit the expression of bax,caspase-3 mRNA.