ObjectiveTo observe the influence of mitochondrial cytochrome c oxidase(COX) decrease on cholinergic and dopaminergic system in brain of model rats.MethodsRats were administrated with 1mg/kg/h or 2mg/kg/h subcutaneously via an Alzet minipump for 30 days. Choline-acetyl-transfertase(ChAT) and acetylcholinesterase(AChE) activity in hippocampus and cortex of rats were measured by radiochemical method and hydroxylamine colorimetry separately. The contents of Norepinephrine(NE), dopamine, 5-hydroxytryptamine(5-HT) and their metabolic products in striatum were measured by HPLC.ResultsChAT activity was significantly inhibited in hippocampus and cortex of model rats, however, the activity of AChE increased in hippocampus and was not affected at the cortex. Therefore, the ratio of ChAT/AChE decreased in model rats. The content of NE, dopamine, 5-HT and their metabolic products in striatum were not different among all groups.ConclusionsCOX deficiency can induce abnormality of ChAT and AChE activity in model rats. Dysfunction of neurotransmitter-acetylcholine would be account for learning-memory deficiency. Model rats indicated cholinergic system deficit without any dopaminergic system abnormality, so chronic infusion of sodium azide via minipump may specially serve as a tool for developing the experimental model of Alzheimer's disease.

Objective To investigate the effect of dexmedetomidine combined with fentanil on postoperative sleep quality and cognitive function in elderly patients with patient-controlled intravenous analgesia (PCIA). Methods Forty elderly patients underwent thoracic surgery were randomly divided into control group (fentanil group, n = 20) and experimental group C (fentanil plus dexmedetomidine group, n = 20), The control group was mixed 15 μg/kg fentanil and 5 mg tropisetron into100 mL of normal saline in patient-controlled intravenous analgesia pump, and experimental group contained 15 μg/kg fentanil, 1. 0 μg/kg dexmedetomidine and 5 mg tropisetron in 100 mL of normal saline. The pump was withdrawn after 48 h. The total steep time, sleep quality were recorded at 1 d before surgery and on the day of surgery, and at 3 d after surgery. The Mini-Mental Status Examination (MMSE) were recorded at 1 d before surgery and 1, 3, 7 d after surgery, and the incidence of postoperative cognitive dysfunction was observed. Results Compared with control group, the sleep time of experimental group on the surgery day and at 2 d after surgery was longer (P ＜ 0. 05); the sleep quality were significantly higher (P ＜ 0. 05); the MMSE scores of experimental group on the first and third postoperative day were higher (P ＜ 0. 05), and the incidence of POPD was lower than that in the control group (P ＜ 0. 05). Conclusion Dexmedetomidine combined with fentanil administered for postoperative analgesia in elderly patients shows better efficacy in improvement of sleep status, and improve the postoperative cognitive function.

Objective To investigate the effect of dexmedetomidine combined with fentanil on postoperative sleep quality and cognitive function in elderly patients with patient-controlled intravenous analgesia (PCIA). Methods Forty elderly patients underwent thoracic surgery were randomly divided into control group (fentanil group, n = 20) and experimental group C (fentanil plus dexmedetomidine group, n = 20), The control group was mixed 15 μg/kg fentanil and 5 mg tropisetron into100 mL of normal saline in patient-controlled intravenous analgesia pump, and experimental group contained 15 μg/kg fentanil, 1. 0 μg/kg dexmedetomidine and 5 mg tropisetron in 100 mL of normal saline. The pump was withdrawn after 48 h. The total steep time, sleep quality were recorded at 1 d before surgery and on the day of surgery, and at 3 d after surgery. The Mini-Mental Status Examination (MMSE) were recorded at 1 d before surgery and 1, 3, 7 d after surgery, and the incidence of postoperative cognitive dysfunction was observed. Results Compared with control group, the sleep time of experimental group on the surgery day and at 2 d after surgery was longer (P ＜ 0. 05); the sleep quality were significantly higher (P ＜ 0. 05); the MMSE scores of experimental group on the first and third postoperative day were higher (P ＜ 0. 05), and the incidence of POPD was lower than that in the control group (P ＜ 0. 05). Conclusion Dexmedetomidine combined with fentanil administered for postoperative analgesia in elderly patients shows better efficacy in improvement of sleep status, and improve the postoperative cognitive function.

BACKGROUNDN-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) are excellent biomarkers for detecting heart failure and subclinical myocardial injury. However, it remains unclear whether subclinical myocardial injury is associated with NT-proBNP elevation in a community based population.

METHODSIn a community based study, levels of hs-cTnT and of NT-proBNP were determined in 1 497 participants older than 45 years. The lower detection limit of the hs-cTnT assay used in the present study was 0.003 ng/ml. The association of hs-cTnT levels and NT-proBNP levels was analyzed.

RESULTSWhen the subjects with undetectable (<0.003 ng/ml), intermediate (0.003-0.014 ng/ml), and elevated (≥0.014 ng/ml) levels of hs-cTnT were compared (r = 0.175, P < 0.001), a strong association between the hs-cTnT levels and NT-proBNP levels was observed (β = -0.206, P < 0.001; β = -0.118, P < 0.001, respectively). In multivariable analyses, older age and hs-cTnT were positively and independently associated with NT-proBNP levels (β = 0.341, P < 0.001; β = 0.143, P < 0.001, respectively), and male gender and the levels of eGFR were inversely and independently associated with NT-proBNP levels. When the subjects with normal or elevated NT-proBNP were analyzed separately, the hs-cTnT level was not an independent predictor for the NT-proBNP level in the normal NT-proBNP group, whereas the hs-cTnT level was the only independent predictor for NT-proBNP level in the elevated NT-proBNP group (β = 0.399, P < 0.01).

CONCLUSIONSIn this community based population, NT-proBNP elevation was common. In addition to female gender and older age, subclinical myocardial injury indicated by the hs-cTnT level was another important factor in NT-proBNP elevation.

Biomarkers ; analysis ; Female ; Humans ; Male ; Middle Aged ; Natriuretic Peptide, Brain ; blood ; Peptide Fragments ; blood ; Troponin T ; blood