The effect of grip strength on geriatric syndromes in elderly inpatients / 中华老年医学杂志

Objective:To investigate the occurrence of geriatric syndromes in elderly inpatients with different grip strength levels and the effect of grip strength on geriatric syndromes and thus to provide insight for the management of geriatric syndromes in elderly inpatients.Methods:A total of 225 elderly inpatients who had received comprehensive geriatric assessment at the geriatrics department of our hospital were selected retrospectively, and their general and geriatric syndrome data were collected.With grip strength of 28 kg for men and 18 kg for women as the cut-offs, the patients were divided into the normal grip strength group(114 cases)and the decreased grip strength group(111 cases). Based on demographic characteristics including age, gender, type of work, income, educational background and social support, 1∶1 propensity score matching(PSM)for the two groups was conducted, successfully resulting in a total of 77 pairs.Differences in geriatric syndromes between the two groups were compared, and the relationship between grip strength and geriatric syndromes was analyzed in these elderly inpatients.Results:After adjustment for the general demographic characteristics by PSM, the decreased grip strength group showed higher rates than the normal grip strength group of frailty/pre-frailty(87.0% vs.55.8%), disability(53.2% vs.27.3%), malnutrition/malnutrition risk(57.1% vs.22.1%), cognitive impairment(35.1% vs.9.1%), constipation(44.2% vs.20.8%), falls(32.5% vs.13.0%)and number of geriatric syndromes(4, range: 2-5 vs.2, range: 0-4)and higher Carlson comorbidity index(CCI)scores(6, range: 5-8 vs.5range: 4-6)and higher body mass index scores[(25±3)kg/m 2vs.(23±4)kg/m 2](all P<0.05). There was no significant difference in the incidence of pain, sleep disorders, depression, anxiety or polypharmacy, or in short physical performance scores between the two groups(all P>0.05). Spearman correlation analysis showed that decreased grip strength was positively correlated with the incidence of frailty/pre-frailty( r= 0.345), disability( r= 0.265), malnutrition/malnutrition risk( r= 0.358), cognitive impairment( r=0.313), constipation( r= 0.250), falls( r= 0.232)and number of geriatric syndromes( r=0.370)(all P<0.05). There was no significant correlation between grip strength and the incidence of pain, sleep disorder, depression or anxiety(all P> 0.05). Multivariate logistic regression analysis showed that, compared with the normal grip strength group, the decreased grip strength group had a higher risk of developing geriatric syndromes such as frailty/pre-frailty( OR=10.906), disability( OR=4.025), malnutrition/ malnutrition risk( OR=2.699), cognitive impairment( OR=6.620), constipation( OR=2.848)and falls( OR=4.145, all P<0.05). Conclusions:Decreased grip strength is an independent risk factor for many common geriatric syndromes such as frailty/pre-frailty, disability, malnutrition/ malnutrition risk, cognitive impairment, constipation and falls.Elderly patients with decreased grip strength should be a key population group when screening for geriatric syndromes.

Low-dose β-glycerophosphate induced differentiation of dental pulp stem cells into odontoblasts and expressions of relevant factors / 中国组织工程研究

BACKGROUND:The induced concentration for osteoblasts is often introduced as reference to induce odontoblast differentiation. However, there are no reports on other concentrations. OBJECTIVE: To observe the expression of dentin matrix protein-1, dentin sialoprotein and matrix extracelular phosphoglycoprotein during low-dose β-glycerophosphate-induced differentiation of dental pulp stem cels into odontoblasts. METHODS:Human dental pulp stem cels were isolated and cultured, and then induced by different concentrations of inducing solution to differentiate into adipocytes and osteoblasts, which could verify the multi-directional differentiation ability of human dental pulp stem cels. Under 5 mmol/L β-glycerophosphate, dental pulp stem cels differentiated into odontoblasts. At 7, 14, 21, 28 days of culture, RNA samples were extracted from dental pulp stem cels in each group, and reverse-transcription PCR was used to detect the expression of dentin matrix protein-1, dentin sialoprotein and matrix extracelular phosphoglycoprotein. Mineralized nodules were detected by alizarin red S staining to show the successfuly osteogenesis induction. RESULTS AND CONCLUSION: Human dental pulp stem cels could be induced to adipocytes and osteoblasts. The results of reverse-transcription PCR showed that the dental pulp stem cels under 5 mmol/L β-glycerophosphate could increase the expression of dentin matrix protein-1 and dentin sialoprotein, but downregulate the expression of matrix extracelular phosphoglycoprotein at 7, 14, 21 days. At 28 days of culture, dental pulp stem cels were al successfuly mineralized detected by alizarin red S. There were some red mineralized nodules. These findings indicate that the 5 mmol/L β-glycerophosphate can induce the differentiation of dental pulp stem cels into odontoblasts successfuly, up-regulate the mRNA expression of dentin sialoprotein and dentin matrix protein-1, and meanwhile down-regulate the mRNA expression of matrix extracelular phosphoglycoprotein.

Structural insight into substrate specificity of human intestinal maltase-glucoamylase

Human maltase-glucoamylase (MGAM) hydrolyzes linear alpha-1,4-linked oligosaccharide substrates, playing a crucial role in the production of glucose in the human lumen and acting as an efficient drug target for type 2 diabetes and obesity. The amino- and carboxyl-terminal portions of MGAM (MGAM-N and MGAM-C) carry out the same catalytic reaction but have different substrate specificities. In this study, we report crystal structures of MGAM-C alone at a resolution of 3.1 Å, and in complex with its inhibitor acarbose at a resolution of 2.9 Å. Structural studies, combined with biochemical analysis, revealed that a segment of 21 amino acids in the active site of MGAM-C forms additional sugar subsites (+ 2 and + 3 subsites), accounting for the preference for longer substrates of MAGM-C compared with that of MGAM-N. Moreover, we discovered that a single mutation of Trp1251 to tyrosine in MGAM-C imparts a novel catalytic ability to digest branched alpha-1,6-linked oligosaccharides. These results provide important information for understanding the substrate specificity of alpha-glucosidases during the process of terminal starch digestion, and for designing more efficient drugs to control type 2 diabetes or obesity.

Location and fine structure of melanocytes in human fetal scalp hair follicles / 中华皮肤科杂志

Objective To investigate the location,fine structure of melanocytes in human fetal scalp hair follicles.Methods The scalp with hair follicles was obtained from a dead fetus of 6 months of age,and divided into two parts.One part was embedded in paraffin,tissue sections were prepared with a width of 7 μm and stained with NKI/beteb,monoclonal antibodies to HMB-45,tyrosinase and tyrosinase-related protein 1(TRP1),respectively.The other part with hair follicles was treated with collagenase type Ⅱ 0.1 g/L and trypsin,then,cell suspension was collected and cultured.After 14-day culture,follicle melanocyte cells (FMC)were separated from keratinocytes by differential trypsinization,and fibroblasts were removed with geneticin.Following three times of pure passage,FMC were seeded and fixed on mica for scanning electron microscopy(SEM)and atomic force microscope(AFM)scanning.Results Histopathological examination showed that NKI/beteb positive cells located at the outer root sheath of human hair follicles,and these cells stained negatively for HMB-45,tyrosinase and TRP1 antibodies.However,in the hair bulb,lots of cells expressed HMB-45,tyrosinase and TRP1 antigens.After fibroblasts and keratinocytes were removed,two kinds of melanocytes remained in the culture:one was small in number and showed abundant melanin,which was lost after subsequent passage;the othgr was large in number and had no melanin initially,but proliferated very rapidly.After three passages,almost all the melanocytes were positive for NKI/beteb.As SEM and AFM showed,most cultured melanocytes appeared fusiform with two(rarely three)dendrites,and the cell body was round or oval with a few melanosomes scattered in but no clear secondary branches on the dendrites.Conclusions The melanocytes in outer root sheath of hair follicles from the fetal scalp are presumed as melanocyte stem cells or their progenies.In vitro,these cells proliferate very rapidly during early phases,but the morphology and function of them still remain immature,which is unfavorable for melanosome transport.