Effects and mechanism of fibroblast growth factor 21 on rat vascular smooth muscle cells calcification / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the effect and mechanism of fibroblast growth factor 21 (FGF21) on rat vascular smooth muscle cells (VSMCs) calcification in vitro.</p><p><b>METHODS</b>VSMCs was treated with calcification medium containing calcium chloride and β-glycerophosphate to induce rat VSMCs calcification in vitro. VSMCs were divided into 5 groups: the control group (cultured in normal medium), the calcification group (incubated in calcified medium), the FGF21 group (cultured in calcified medium and FGF21), the PD166866 group (cultured in calcified medium and FGF21 and PD166866, inhibitor of fibroblast growth factor receptor-1 (FGFR1)), the GW9662 group (cultured in calcified medium and FGF21 and GW9662, inhibitor of peroxisome proliferators activated receptor-γ (PPAR-γ)). The calcification of VSMCs was detected by calcium content, alkaline phosphatase activity and alizarin red staining. The protein and mRNA expression of FGFR1, β-Klotho, osteocalcin and smooth muscle 22α (SM22α) were determined by western blot analysis and realtime-PCR, respectively.</p><p><b>RESULTS</b>(1) The mRNA (P < 0.01) and protein expressions of β-Klotho and FGFR1 were significantly downregulated in calcification group compared with control group (P < 0.05 or 0.01). (2) The protein levels and mRNA expression of calcium content, alkaline phosphatase activity and osteocalcin were significantly downregulated, while the protein levels and mRNA of SM22α were significantly increased in FGF21 group compared with calcification group (all P < 0.05). Moreover, alizarin red staining verified positive red nodules on calcified VSMCs was significantly reduced in FGF21 group than in calcification group. (3) Calcium content, alkaline phosphatase activity and alizarin red staining were similar between PD166866 group and calcification group (all P > 0.05). (4) Calcium content, alkaline phosphatase activity and alizarin red staining were similar between GW9662 group and calcification group (all P > 0.05).</p><p><b>CONCLUSION</b>The inhibition of VSMCs calcification by FGF21 is mediated by further downregulating FGFR1 and β-Klotho while activating PPAR-γ pathways.</p>

Special considerations for patients aged 80 years or over receiving pacemaker implantation / 中华老年医学杂志

Objective To investigate indications,pacing modes,pacing parameters and postoperative complications of pacemaker implantation for patients aged 80 years or over.Methods Patients were recruited on a continuous basis and were assigned into two groups,with 112 patients in the very elderly (80-90 years old) group and 484 patients in the elderly (60-79 years old) group,which served as the control.Follow-up observations with the two groups were conducted concerning indications,mode selection,pacing parameters and postoperative complications.Results Compared with the control group,the very elderly group showed:1) a higher rate of coronary heart disease (58cases vs.163 cases or 51.8％ vs.33.7％ ; x2 =12.78,P＜0.01) ; 2) more single-chamber pacemaker implantations (63 cases vs.217 cases or 56.3％ vs.44.8％; x2=4.76,P＜0.05) and fewer dual-or multi-chamber pacemaker implantations (49 cases vs.267 cases or 43.8％ vs.55.2％ ; x2 =4.76,P＜0.05) ; 3) a higher rate of double bundles branch block (19 cases vs.31 cases or 17.0％ vs.6.4％ ; x2=13.20,P＜0.01); 4) a higher rate of postoperative acute cerebral infarction (x2 =8.34,P＜0.01) ; and 5) increased ventricular [(0.78±0.24)V vs.(0.55±0.16)V,P＜0.05]and atrial [(1.07±0.22)V vs.(0.84±0.28)V,P＜0.05]pacing thresholds.Conclusions Special considerations should be made when pacemaker implantation is planned for patients aged 80 or over.Pacemaker selection decisions ought to be based on a comprehensive evaluation of relevant clinical situations so that clinical benefits can be maximized.