Prevalence, risk and protective factors for mild cognitive impairment in a population-based study of Singaporean elderly.

The prevalence of dementia has been widely reported, and its potential risk and protective factors are well-characterized. However, there is a scarcity of related information regarding mild cognitive impairment (MCI). Thus this population-based study aimed to determine the prevalences of MCI and its subtypes, as well as to identify the risk and protective factors for MCI in the Chinese elderly population of Singapore. Results showed that the overall prevalence of MCI was 12.5%, while the gender-adjusted prevalence of MCI was 12.3%. Gender was found to be significantly associated with the subtypes of MCI, with males more likely to have amnestic MCI and females more likely to have non-amnestic MCI. Older age, lower educational levels, lower social activity levels, depression, hypertension, hyperlipidemia, diabetes and stroke were found to be risk factors for MCI in univariate analysis. However, multivariable analysis showed that only hypertension and stroke were the significant risk factors for MCI. Higher educational levels and active social engagements were significant protective factors for MCI in multivariable analysis. Age and depression had boundary significant associations with the prevalence of MCI. After adjusting for gender, the influence of hypertension, stroke, social engagement, age and depression on MCI remained unchanged, except that education became a boundary significant lower risk factor of MCI development. In conclusion, this study presented the prevalence, risk and protective factors for MCI among Singaporean Chinese older adults, which facilitates the screening of vulnerable groups for MCI.

Inactive bowel movement and stroke are associated with increased risks of mild cognitive impairment among community-living Singapore elderly.

Mild cognitive impairment (MCI), as a preclinical phase of dementia, provides an invaluable time window for intervention. Besides several proposed modifiable risk factors, the associations of MCI with dietary habits and bowel movement are not well clarified. We thus conducted a cross-sectional study of community-living Singapore elderly and focused on the relationship of clinically diagnosed MCI with dietary habits and bowel movement frequencies. The multiple logistic regression results showed that frequent (≥4 days per week) fruit consumption (P = 0.004), active (≥4 days per week) bowel movement within 10 minutes (P = 0.027), and years of schooling were negatively associated with MCI occurrence. In contrast, medical comorbidities including hypertension, stroke, and cataract/glaucoma were found to be risk factors. Furthermore, a Bayesian network model of causal inference detected five hypothesized causal-association paths leading to MCI, namely bowel movement, stroke, years of schooling via fruit consumption, hypertension via stroke and hypertension via cataract/glaucoma. The combination of the two direct factors (inactive bowel movement and stroke) reached a maximum conditional probability of 60.00% for MCI occurrence. Taken together, this study was the first to link bowel movement with MCI occurrence. In addition, it suggested five modifiable hypothesized causal-association paths to MCI.

[MIPPO and ORIF for the treatment of elderly proximal humerus fractures of type Neer II:a case control study].

OBJECTIVE: To compare the clinical efficacy of minimally invasive percutaneous plate osteosynthesis(MIPPO)and open reduction and internal fixation (ORIF) in treating senile NEER IIproximal humerus fractures. METHODS: From March 2014 to March 2016, 46 elderly patients with Neer II proximal humerus fractures were retrospectively reviewed. Among them, 20 patients in MIPPO group included 9 males and 11 females with an average age of (70.4±4.4) years old; while 26 patients in ORIF group included 11 males and 15 females with an average age of (70.9±4.0) years old. The length of hospital stay, times of fluoroscopy, beginning time of function rehabilitation, healing time of fracture, Constant Murley score of the shoulder joint at 3, 6, 12 months after operation and complications were observed and compared. RESULTS: All patients were followed up for 12 to 24 months with an average of 16.8±3.7. The healing time of fracture, beginning time of function rehabilitation in MIPPO group were(13.0±0.8) weeks, (3.0±0.9) days respectively and shorter than those in ORIF group which were (13.8±1.4) weeks and(6.8±1.3) days. The times of fluoroscopy in MIPPO group was 19.2±3.7 and more than that in ORIF group which was 12.1±3.4. At 3 and 6 months after operation, Constant Murley score in MIPPO group were 81.3±3.9, 86.6±5.4 and more than that in ORIF group which were 69.5±6.6, 80.5±6.7. There were no differences between two groups in the length of hospital stay, Constant Murley score at 12 months after operation and grading at the final follow-up. There was one fracture redisplacement in each group. And 1 case of axillary nerve injury in MIPPO group, 2 cases of delayed union in ORIF group. No incision infection, screw loosening or plate break was found. CONCLUSIONS: MIPPO and ORIF are both effective in treating Neer II proximal humeral fractures. MIPPO technique has the advantages of faster recovery, earlier rehabilitative exercise and better shoulder function. The disadvantages are more exposure to radiationd and the possibility of axillary nerve injure.

Dexmedetomidine protects against learning and memory impairments caused by electroconvulsive shock in depressed rats: Involvement of the NMDA receptor subunit 2B (NR2B)-ERK signaling pathway.

Cognitive impairment is a common adverse effect of electroconvulsive therapy (ECT) during treatment for severe depression. Dexmedetomidine (DEX), a sedative-anesthetic drug, is used to treat post-ECT agitation. However, it is not known if DEX can protect against ECT-induced cognitive impairments. To address this, we used chronic unpredictable mild stress (CUMS) to establish a model of depression for ECT treatment. Our Morris water maze and sucrose preference test results suggest that DEX alleviates ECT-induced learning and memory impairments without altering the antidepressant efficacy of ECT. To further investigate the underlying mechanisms of DEX, hippocampal expression of NR2B, p-ERK/ERK, p-CREB/CREB, and BDNF were quantified by western blotting. These results show that DEX suppresses over-activation of NR2B and enhances phosphorylation of ERK1/2 in the hippocampus of ECT-treated depressed rats. Furthermore, DEX had no significant effect on ECT-induced increases in p-CREB and BDNF. Overall, our findings suggest that DEX ameliorates ECT-induced learning and memory impairments in depressed rats via the NR2B-ERK signaling cascade. Moreover, CREB/BDNF seems not appear to participate in the cognitive protective mechanisms of DEX during ECT treatment.

[Etiology and treatment of postoperative spinal cord injury for patients undergoing laminectomy for fluorosis thoracic canal stenosis].

OBJECTIVE: To elucidate the etiology of postoperative spinal cord injury (PSCI) for patients undergoing laminectomy for fluorosis thoracic canal stenosis (FTCS) and summarize the methods of diagnosis and treatment. METHODS: From 2006 to 2009, a total of 192 FTCS cases underwent laminectomy. Among them, 16 cases with gradual postoperative neural deterioration were finally diagnosed as PSCI on MRI.One case of intraoperative spinal cord injury was excluded so that only 15 cases were included. RESULTS: All cases were treated immediately with incision cite puncture and dehydration.Neural function recovered after secondary operation as JOA score improved from 3.00 ± 1.14 to 7.72 ± 1.41 at 12 months follow-up.Statistical analysis demonstrated a linear correlation between the diagnosis time and the improvement of JOA score. CONCLUSION: Hematoma and fluid leakage are the common reasons of PSCI for FTCS patients. Meticulous hemostasis, usage of artificial dura matter and partial negative pressure drainage are valuable preventive measures.

[Damage of blood brain barrier of spinal cord in rats with chronic fluorosis].

OBJECTIVE: To explore the impairment mechanisms of blood brain barrier in spinal cord and observe the changes of matrix metalloproteinase-9 (MMP-9) and functional improvement in rats with chronic fluorosis. METHODS: A total of 120 Wistar rats were divided randomly into 4 groups, high fluoride (fed by water with a high concentration of sodium fluoride at 200 mg/L), high fluoride control (fed by distilled water), defluorination (fed by water with a high concentration of sodium fluoride at 200 mg/L for 12 weeks and then distilled water for 12 weeks) and defluorination control (n = 30 each). The urinary contents of fluoride were detect for 4 groups at Weeks 4, 8 and 12. The high fluoride and control groups were sacrificed at Week 12 while the defluorination and defluorination control groups at Week 24. Their cervical spinal cords were collected for electron microscope examinations. The expression of MMP-9 protein in thoracic cord was detected by immunohistochemistry and Western blot. Quantitative analysis of function of blood brain cord barrier was performed by the technique of Evans blue. The comparison of measurement data was performed with F test and correlation analysis. The cytological changes of neurons in thoracic spinal cord were detected after chronic fluorosis. RESULTS: Under electron microscope, the pathological manifestations of chronic damage in blood brain barrier could be found. As compared with the high fluoride control group, the content of Evans blue increased markedly in spinal cord of the high fluoride group (29.2 ± 0.1 vs 0.7 ± 0.1 mg/L, P < 0.01). It was higher in the defluorination group than that in the defluorination control group. But there was no significant difference with the high fluoride group (29.2 ± 0.1 vs 28.9 ± 0.2 mg/L, P > 0.01). And the expression of MMP-9 increased in spinal cord of the fluorosis and defluorination groups in comparison with those in the control group. But no difference existed among them. CONCLUSION: The damage of blood brain barrier of spinal cord occurs probably as a result of a higher expression of MMP-9 in rats with chronic fluorosis. Defluorination for a short time may not recover.

Monoclonal antibody based inhibition ELISA as a new tool for the analysis of melamine in milk and pet food samples.

Stories of recent cases about melamine misuse to raise the false impression of a high protein content of milk in China emerged in September of 2008, have become an international health event. To meet the need for rapid and reliable monitoring of melamine in milk samples, a monoclonal antibody (mAb) was produced and an inhibition enzyme-linked immunosorbent assay (ELISA) was developed based on the mAb. The standard curve was linear in the range from 0.03 to 9 ng mL(-1) with a detection limit (LOD) of 0.01 ng mL(-1). The sensitivity of the assay was 0.35 ng mL(-1). The average recovery values of melamine in the liquid milk, powder milk, dog food and cat food were 99%, 96%, 9% and 98%, respectively and the coefficient of variation (CV) values of all samples were less than 10%. The obtained results showed a potential method as a tool for the rapid and reliable monitoring of melamine in liquid milk and milk powder samples (158 words).

Influence of hinge position on the effectiveness of open-door expansive laminoplasty for cervical spondylotic myelopathy.

OBJECTIVE: To assess the influence of different hinge positions on clinical results of expansive open-door laminoplasty (EOLP) for cervical spondylotic myelopathy (CSM). METHODS: A total of 102 CSM patients who underwent EOLP from February 2006 to February 2007 were enrolled in this randomized controlled trial. Using a random digits table, 57 patients with the hinge located at the inner margin of the lateral mass were classified as wide-open group, while 45 patients with the hinge positioned at the lamina margin served as narrow-open group. All patients were observed over 24 months, and the clinical and radiological results were analyzed statistically. RESULTS: There were no significant differences in operation duration, intraoperative bleeding volume, Japanese Orthopaedic Association (JOA) scores, cervical curvature index, range of motion and neural function recovery rate. The neural functions were satisfactorily improved after surgery in both groups, while the severity of axial symptoms was significantly lower in the narrow-open group than in the wide-open group (P equal to 0.003). The incidence of C(5) palsy in the wide-open group was higher than that in the narrow-open group (5.3% vs 0), even though the difference did not reach statistical significance (one tailed Fisher's exact test, P equal to 0.17). CONCLUSIONS: Proper inward shift of the hinge can ensure effectiveness of surgical decompression, avoid an excessive backward shift of the spinal cord, decrease the incidence of C(5) palsy and alleviate the severity of axial symptoms.

[Relationship between expression of MMP-9 and presyrinx state of experimental syringomyelia of rabbits].

OBJECTIVE: To investigate the relationship between the expression of MMP-9 and the formation of spinal cord edema in presyrinx state of experimental syringomyelia in rabbits and evaluate the inhibitory function of doxycycline in the formation of spinal cord edema in presyrinx state. METHODS: A total of 96 Chinese white rabbits were divided randomly into four groups:kaolin group (n = 24), doxycycline treatment group (n = 24), physiological saline group (n = 24) and control group (n = 24). Under ketamine anesthesia, 0.6 ml of 25% kaolin solution was injected into the cisterna magna in all rabbits of kaolin and doxycycline groups while 0.6 ml of 37°C physiological saline into the cistern in those of saline group; doxycycline (25 mg × kg(-1) × d(-1)) was applied post-operatively for doxycycline group. At Days 1, 3, 7 and 14 after kaolin injection, 6 rabbits of all four groups were selected randomly for sacrificing. Water content of spinal cord could be obtained. The expression of MMP-9 activity was measured by Western blot and immunohistochemistry. RESULTS: At any time point, the water content of spinal cord and the expression of MMP-9 in kaolin group improved obviously more than those of saline and control groups (P < 0.01). At Day 1, there was no marked difference in the water content of spinal cord and the expression of MMP-9 between doxycycline and kaolin groups (P > 0.05). At other time points, the water content of spinal cord and the expression of MMP-9 in doxycycline group markedly decreased than those of kaolin group (P < 0.01). CONCLUSION: In the model of experimental syringomyelia, MMP-9 plays an important role in causing edema in presyrinx state. Thus doxycycline may be used to prevent and treat syringomyelia.

Development of a novel antibody probe useful for domoic acid detection.

The generation of monoclonal antibody (mAb) against marine toxins can serve as a valuable probe to detect this kind of compounds by immunological methods. However, traditional approaches to mAb generation usually need a comparative large quantity of standard substance (more than 400 microg mouse(-1)), and a comparative long immunization period (more than 6 weeks). Here we report a simple, inexpensive and fast protocol for the generation of monoclonal antibody probe specific for domoic acid (DA). In the method, lymph node cells were harvested from the Balb/C mice of hind footpad injection and fused with murine myeloma cells SP2/0 for hybridoma generation. This method for the preparation of mAb for DA has two main advantages: (a) there is no need for large-scale expensive antigen (only 70 microg antigen for one mouse); (b) immunization protocol can be accomplished within 16 days. Some characteristics of the mAb were studied and a direct competitive ELISA for the detection of DA using the mAb as a probe was developed. The detection limit was 0.41 ng well(-1) in phosphate buffered saline (PBS) and 0.53 ng well(-1) in blue mussel Mytilus edulis. The recoveries of DA from mussel and PBS buffer were from 94.8% to 105.1% and from 96.2% to 103.7%, respectively. Thus, the newly developed direct competitive ELISA using the mAb appears to be a reliable and useful method for monitoring of DA in shellfish (228 words).

Radiographic predictors of residual low back pain after laminectomy for lumbar canal stenosis: a minimum of 6-year follow-up.

OBJECTIVE: To identify radiographic predictors of residual low back pain (LBP) after laminectomy for lumbar canal stenosis (LCS). METHODS: Clinical results and radiographic findings in 69 patients who underwent single level laminectomy for LCS were retrospectively reviewed. Patients who had an improvement in LBP scores evaluated by Japanese Orthopaedic Association (JOA) scoring system during the follow-up periods were classified as the recovery group, and others were classified as the non-recovery group. Patients'clinical data and radiographic parameters like lordosis angle, range of motion and intervertebral rotational angle were analyzed using binary logistic regression analysis to detect factors significantly related with the occurrence of residual LBP. RESULTS: The average preoperative JOA score of 14.8+/-5.05 improved to 21.59+/-5.51 at the final follow-up. Binary logistic regression analysis revealed that significant predictors of residual LBP were preoperative lumbar lordosis angle and range of motion. CONCLUSIONS: Our results suggest that patients with flat back and limited lumbar mobility before surgery tend to have poor results in terms of LBP. Therefore, these sagittal radiographic parameters should be taken into account when choosing laminectomy as the surgical option for LCS.