Association Between First-Time Neurologic Events and Metronidazole Treatment: A Case-Time Control Study

PURPOSE

Metronidazole, a widely used antimicrobial medication, has been linked to neurologic adverse drug reactions. This study investigates the association between metronidazole use and first-time neurologic events.

METHODS

We conducted a case-time-control study using data from the Danish National Patient Register and the National Prescription Register in years 2013 to 2021. Patients with a first-time diagnosis of encephalopathy, cerebellar dysfunction, or peripheral neuropathy were included. Conditional logistic regression analyses were performed to estimate the risk of neurologic events associated with metronidazole use.

FINDINGS

Out of 476,066 first-time metronidazole prescriptions, the 100-day cumulative incidence of peripheral neuropathy was 0.016%, and 0.002% for cerebellar dysfunction or encephalopathy. In the case-time control study, we identified 17,667 persons with a first-time neurologic event and were included for the analysis. The estimated odds ratio for the combined neurologic events was 0.98 (95% CI, 0.59-1.64, P = 0.95) with no statistically significant association across different subgroups and time windows.

IMPLICATIONS

Our findings suggest that metronidazole-induced neurologic events may be rarer than previously described, and we did not find any consistent or statistically significant association between metronidazole exposure. Nonetheless, clinicians should remain vigilant to potential neurologic risks in patients receiving metronidazole, to ensure its safe and effective use.

[A panel study on the effect of atmospheric PM2.5 exposure on the gut microbiome in healthy elderly people aged 60-69 years old]

Objective: To analyze the short-term effect of individual atmospheric PM_2.5 exposure on the diversity, enterotype, and community structure of gut microbiome in healthy elderly people in Jinan, Shandong province. Methods: The present panel study recruited 76 healthy elderly people aged 60-69 years old in Dianliu Street, Lixia District, Jinan, Shandong Province, and followed them up five times from September 2018 to January 2019. The relevant information was collected by questionnaire, physical examination, precise monitoring of individual PM_2.5 exposure, fecal sample collection and gut microbiome 16S rDNA sequencing. The Dirichlet multinomial mixtures (DMM) model was used to analyze the enterotype. Linear mixed effect model and generalized linear mixed effect model were used to analyze the effect of PM_2.5 exposure on gut microbiome α diversity indices (Shannon, Simpson, Chao1, and ACE indices), enterotype and abundance of core species. Results: Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 352 person-visits. The age of 76 subjects was (65.0±2.8) years old with BMI (25.0±2.4) kg/m². There were 38 males accounting for 50% of the subjects. People with an educational level of primary school or below accounted for 10.5% of the 76 subjects, and those with secondary school and junior college or above accounting for 71.1% and 18.4%. The individual PM2.5 exposure concentration of 76 subjects during the study period was (58.7±53.7) μg/m³. DMM model showed that the subjects could be divided into four enterotypes, which were mainly driven by Bacteroides, Faecalibacterium, Lachnospiraceae, Prevotellaceae, and Ruminococcaceae. Linear mixed effects model showed that different lag periods of PM_2.5 exposure were significantly associated with a lower gut α diversity index (P<0.05 after correction). Further analysis showed that PM_2.5 exposure was significantly associated with changes in the abundances of Firmicutes (Megamonas, Blautia, Streptococcus, etc.) and Bacteroidetes (Alistipes) (P<0.05 after correction). Conclusion: Short-term PM_2.5 exposure is significantly associated with a decrease in gut microbiome diversity and changes in the abundance of several species of Firmicutes and Bacteroidetes in the elderly. It is necessary to further explore the underlying mechanisms between PM_2.5 exposure and the gut microbiome, so as to provide a scientific basis for promoting the intestinal health of the elderly.

Whole-cycle analysis of echocardiographic tissue Doppler velocities as a marker of biological age

Purpose

Tissue Doppler imaging (TDI) is a sensitive marker of impaired cardiac function and different phases of the TDI curve carry different prognostic information. It is not known how continuous TDI curves change with age in normal subjects, and whether these changes differ from changes seen in individuals at risk of future cardiac events.

Methods

A total of 1,763 individuals from the general population were examined with color TDI at the septal and lateral mitral sites. A low-risk group was defined as without cardiac risk factors (hypertension, diabetes or ischemic heart disease) at baseline and without any cardiac events (cardiovascular death or admission due to either heart failure or acute myocardial infarction) during 10-years follow-up. All TDI curves were corrected for heart rate, and whole-cycle analysis of age-related changes to TDI velocities was performed in both low-risk (n = 881) and high-risk individuals (n = 882).

Results

In the low-risk population, four phases where myocardial velocity differed most (p < 10^-10) according to age were identified [in a standardized cardiac cycle of 1 second (s)]: Systolic peak (0.09-0.13 s), systolic plateau (0.18-0.27 s), early diastole (0.43-0.54 s) and late diastole (0.88-0.95 s). With increasing age, systolic velocities decreased, early diastolic velocities decreased and had delayed peak, and late diastolic velocities increased until age 70 and then stopped increasing. In the high-risk population, comparison to corresponding age groups of the low-risk population showed: Lower early diastolic velocities in 20-40-year-olds; higher late diastolic velocities and lower peak systolic velocities in 40-60-year-olds; further decreased systolic velocities including the systolic plateau and decreased late diastolic velocities in 60-year-olds. The time segments around the systolic peak (p = 0.002) and early diastole (p < 0.001) differed significantly between the high-risk and low-risk population, thus making it possible to use the individual age gap between a TDI-derived biological age and the real chronological age as a tool to discriminate high-risk individuals from low-risk individuals.

Conclusion

We found that individuals with cardiac risk factors display findings compatible with an accelerated aging of the heart and thus propose TDI-derived biological age as a tool to identify high-risk patients.

Long-term use of Lacticaseibacillus paracasei N1115 from early life alleviates high-fat-diet-induced obesity and dysmetabolism in mice

Obesity has become one of the most serious public health problems worldwide, and an increasing number of studies indicate that the gut microbiota can affect host metabolism. Therefore, the present study was conducted to evaluate whether long-term use of probiotics can alleviate host obesity and metabolism by altering gut microbiota. The high-fat diet (HFD) starting from weaned period led to higher levels of visceral fat and a significantly heavier liver in male mice. Moreover, HFD resulted in disorders of glucose and lipid metabolism, changes in insulin-resistance indices (IR), and an increase in serum insulin and leptin in mice. Of note, 15 weeks use of Lacticaseibacillus paracasei N1115 decreased visceral fat, liver weight, serum levels of insulin and leptin, and IR and alleviated lipid dysmetabolism. HFD resulted in a significant increase in the relative abundance of Bilophila, Lachnoclostridium, and Blautia and may decrease the faecal short-chain fatty acid (SCFA) levels in mice; in turn, treatment with the potential probiotic strain L. paracasei N1115 protected mice from these negative effects. HFD significant impaired the physiology of the host especially in male mice and dramatically changed the composition of host gut microbiota. However, the use of potential probiotic strain, such as L. paracasei N1115, may prevent these impairments due to HFD via effecting the host gut microbiota and SCFA.

[One case of rhabdomyolysis caused by acute phoxim poisoning]

Patients with organophosphate poisoning usually die from respiratory depression and respiratory failure. The incidence of rhabdomyolysis is relatively low, but the mortality rate is extremely high once it occurs. In this paper, the treatment of a patient with acute phoxim poisoning was analyzed. The patient developed severe rhabdomyolysis syndrome on the 3rd day of treatment, the creatine kinase exceeded the normal value by more than 300 times (up to 103510.65 U/L) , and renal failure occurred. Clinical treatment included active detoxification, blood purification, organ support, and internal environment maintenance. The patient's rhabdomyolysis continued, and the condition worsened. Finally, the family gave up the treatment and the patient died. It is suggested that attention should be paid to the occurrence of rhabdomyolysis syndrome during the treatment of organophosphorus poisoning, and timely blood purification technology may be the key to treatment.

[Associations between personal fine particulate matter and blood lipid profiles: A panel study in Chinese people aged 60-69 years]

Objective: To explore the association between short-term exposures to fine particulate matter (PM_2.5) on blood lipids in the elderly. Methods: In this panel study, five repeated measurements were performed on 76 people aged 60-69 in Jinan city. Each participant had a PM_2.5 monitor for 72 hours before each health examination, including a questionnaire survey, physical examination, and biological sample collection. Serum triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were examined, and non-HDL-C concentrations were calculated by subtracting HDL-C from TC. The generalized linear mixed-effects model was used to quantify the association of personal PM_2.5 exposure at different lag with blood lipids and dyslipidemia. Results: The age of 70 participants was (65.0±2.8) years, of which 48.6% (34/70) were males. The BMI of participants was (25.0±2.5) kg/m². Their TC, TG, LDL-C, HDL-C, and non-HDL-C concentrations were (5.75±1.32), (1.55±0.53), (3.27±0.94), (1.78±0.52), and (3.97±1.06) mmol/L, respectively. Generalized linear mixed-effects model showed that after adjusting for confounding factors, at lag 72 hours, each 10 μg/m³ increase in PM_2.5 was associated with the percentage change in TC, LDL-C, HDL-C and non-HDL-C about 1.77% (95%CI: 1.22%-2.32%), 1.90% (95%CI: 1.18%-2.63%), 1.99% (95%CI: 1.37%-2.60%) and 1.74% (95%CI: 1.11%-2.37%), and the OR values (95%CI) of hypercholesterolemia, hypertriglyceridemia and hyperbetalipoproteinemia were 1.11 (1.01-1.22), 1.33 (1.03-1.71) and 1.15 (1.01-1.31), respectively. Conclusion: There is a significant association of short-term PM_2.5 exposure with the concentration of blood lipids and the risk of dyslipidemia in the elderly.

[Role of pyroptosis pathway related molecules in acute lung injury induced by gas explosion in rats]

Objective: To explore the role and significance of pyroptosis in gas explosion-induced acute lung injury (ALI) in rats. Methods: In February 2018, 126 SPF male SD rats were selected and randomly divided into blank control group (18 rats) and experimental group (40 m, 80 m, 120 m, 160 m, 200 m and 240 m, 18 per group) . The experimental group carried out gas explosion in the roadway to build the ALI model, the control group did not carry out gas explosion, and other conditions were consistent with the experimental group. Respiratory function indexes such as respiratory frequency (f) , tidal volume (TV) , minute ventilation (MV) and airway stenosis index (Penh) were measured 24 hours after the explosion. 5 rats in each group were sacrificed after anesthesia, Hematoxylin-Eosin (HE) staining was used to observe the pathological morphology of lung tissue. Immunohistochemistry was used to detect the content of Caspase-1. Western blotting was used to detect the content of cell pyroptosis including nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) , Caspase-1, interleukin-1β (IL-1β) and interleukin-18 (IL-18) in lung tissue related protein expression. Results: The f and MV of rats in the experimental group were higher than those in the control group (P<0.05) . Except for the 40 m and 80 m groups, the TV of rats in the other experimental groups were higher than those in the control group (P<0.05) . Except for the 40 m group, the Penh of rats in the experimental groups were lower than those in the control group (P<0.05) . HE staining showed that the lung tissue of the experimental groups at different distance points showed obvious edema of the pulmonary interstitium and alveoli, a large number of red blood cells and inflammatory cells exuded in the alveolar space, thickening of the pulmonary interstitium, and increased lung injury score (P<0.05) . The results of immunohistochemistry showed that the positive expression of Caspase-1 in each experimental group was higher than that in the control group (P<0.05) . Western blotting results showed that the expression of pyroptosis-related proteins in each experimental group was higher than that in the control group (P<0.05) . Conclusion: Pyroptosis is involved in the pathophysiological process of gas explosion-induced ALI in rats.

Exosome-mediated delivery of SCD-1 siRNA promoted the death of anaplastic thyroid carcinoma cells via regulating ROS level

PURPOSE

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive cancers in the world. Stearoyl-CoA desaturase-1 (SCD-1) is one of major enzymes in the de novo synthesis of fatty acids and is related to cancer aggressiveness and poor patient prognosis. The study aimed to construct exosomes loaded SCD-1 interference, investigate its effects and mechanisms on the cell proliferation and apoptosis of ATC cells.

METHODS

The expressions of SCD-1 in normal thyroid cell line and ATC cell lines were determined by qRT-PCR and western blotting, respectively. Exosomes were prepared and purification then loaded with SCD-1 siRNA by electroporation and observed by transmission electron microscopy. Higher SCD-1 mRNA and protein levels were found in ATC cell lines compared than normal thyroid cell line (P < 0.05), and both Hth-7 and FRO cells could uptake PKH67-labeled exosomes. The effects of exosomes loaded SCD-1 siRNA on ATC cells were measured by CCK8 assay and apoptosis detection kit.

RESULTS

When compared with control group, the cell viability significantly decreased in both two ATC cell lines taken up exosomes loaded SCD-1 siRNA (P < 0.001), and apoptotic and necrotic cells obviously increased (P < 0.05). In order to explore the mechanism of exosomes loaded SCD-1 on ATC, the ROS level was detected by fluorescence reagent. It was found that exosomes loaded SCD-1 siRNA significantly increased intracellular ROS level of ATC cells (P < 0.05).

CONCLUSIONS

Exosomes loaded SCD-1 siRNA inhibited ATC cellular proliferation and promoted cellular apoptosis, and the mechanisms involved maybe the regulation of fatty acids metabolism and ROS level. Our study provides a promising therapeutic strategy for ATC.

[Prediction of 6-year risk of activities of daily living disability in elderly aged 65 years and older in China]

Objective: To construct an easy-to-use risk prediction tool for 6-year risk of activities of daily living(ADL) disability among Chinese elderly aged 65 and above. Methods: A total of 34 349 elderly aged 65 and above were recruited from the Chinese Longitudinal Healthy Longevity Survey. Demographic characteristics, lifestyle and chronic diseases of the elderly were collected through face-to-face interviews. The functional status of the elderly was evaluated by the instrumental activities of daily living(IADL) scale. The mental health status of the elderly was evaluated by the Mini-Mental State Examination. The height, weight, blood pressure and other information of the subjects were obtained through physical examination and body mass index(BMI) was calculated. The ADL status was evaluated by Katz Scale at baseline and follow-up surveys. Taking ADL status as the dependent variable and the key predictors were selected from Lasso regression as the independent variables, a Cox proportional risk regression model was constructed and visualized by the nomogram tool. Area under the receiver operating characteristic curve(AUC) and calibration curve were used to evaluate the discrimination and calibration of the model. A total of 200 bootstrap resamples were used for internal validation of the model. Sensitivity analysis was used to evaluate the robustness of the model. Results: The M(Q₁, Q₃) of subjects' age as 86(75, 94) years old, of which 9 774(46.0%) were males. A total of 112 606 person-years were followed up, 4 578 cases of ADL disability occurred and the incidence density was 40.7/1 000 person-years. Cox proportional risk regression model analysis showed that older age, higher BMI, female, hypertension and history of cerebrovascular disease were associated with higher risk of ADL disability [HR(95%CI) were 1.06(1.05-1.06), 1.05(1.04-1.06), 1.17(1.10-1.25),1.07(1.01-1.13) and 1.41(1.23-1.62), respectively.]; Ethnic minorities, walking 1 km continuously, taking public transportation alone and doing housework almost every day were associated with lower risk of ADL disability [HR(95%CI): 0.71(0.62-0.80), 0.72(0.65-0.80), 0.74(0.68-0.82) and 0.69(0.64-0.74), respectively]. The AUC value of the model was 0.853, and the calibration curve showed that the predicted probability was highly consistent with the observed probability. After excluding non-intervening factors(age, sex and ethnicity), the AUC value of the model for predicting the risk of ADL disability was 0.779. The AUC values of 65-74 years old and 75 years old and above were 0.634 and 0.765, respectively. The AUC values of the model based on walking 1 km continuous and taking public transport alone in IADL and the model based on comprehensive score of IADL were 0.853 and 0.851, respectively. Conclusion: The risk prediction model of ADL disability established in this study has good performance and robustness.

[Changes and significance of autophagy in rat lung injury induced by gas explosion]

Objective: To explore the changes and significance of autophagy in acute lung injury (ALI) induced by gas explosion in rats. Methods: In February 2018, the gas explosion in underground coal mine was simulated by large tunnel explosion experiment system, SD rats were randomly divided into control group and 6 distance groups (40 m, 80 m, 120 m, 160 m, 200 m, 240 m) with 18 rats in each group. The respiratory function of rats 24 h before and after explosion was detected. Post-explosion rats were anesthetized and sacrificed, histopathological changes of lung were observed by HE staining. Immunohistochemistry was performed to detect the in situ expression of autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3B) . The expression levels of autophagy related gene 12 (Atg12) , LC3B, P62, lysosomal associated membrane protein 2 (Lamp2) , B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl2 interaction protein (Beclin-1) were detected by Western blot. Results: After gas explosion, the rats in 80 m distance point group had the hightest mortality (n=13, 72.22%) and the most severe lung injury degree, and the histopathological scores was (4.00±0.00) point. After gas explosion, the minute ventilation volume (MVb) , maximum inspiratory flow rate (PIFb) and maximum expiratory flow rate (PEFb) of rats were lower than before the gas explosion (P<0.05) . The respiratory frequency of rats in 80 m, 200 m, and 240 m distance point groups were significantly higher than that in the control group (P<0.05) . The expression levels of LC3B in 40 m, 80 m, 120 m, 160 m, and 200 m distance point groups were higher than that in the control group (P<0.05) . The relative expression levels of Atg12 and LC3BⅡ/Ⅰ in lung tissues of rats in different distance point groups were higher than those in the control group (P<0.05) . The relative expression levels of Beclin1 in 40 m, 80 m, 120 m, and 160 m distance point groups were significantly higher than that in the control group (P<0.05) . The relative expression levels of P62 in 80 m, 160 m and 200 m distance point groups were lower than that in the control group (P<0.05) . The relative expression levels of Lamp2 and Bcl-2 in lung tissues of rats in all distance groups except 240 m distance group were lower than those in the control group (P<0.05) . Conclusion: Gas explosion could induce increased autophagy in lung tissues of ALI rats. Autophagy-related signaling pathway could be involved in the pathophysiological process of ALI in rats caused by gas explosion, then the autophagy and the severity of the lesion showed a significant positive correlation.

Elevated Serum FGG Levels Prognosticate and Promote the Disease Progression in Prostate Cancer

Castration-resistant prostate cancer (CRPC) threatens the health of men in general and no effective therapeutics currently exists for the treatment of CRPC. It is therefore of great importance to find a novel molecule that can be a biomarker and a therapeutic target for CRPC. First, we found that the serum fibrinogen gamma (FGG) levels in patients with CRPC were significantly higher than those with localized prostate cancer (PCa) through iTRAQ proteomics and ELISA experiments. Immunohistochemistry, quantitative real-time polymerase chain reaction and western blot also showed an increase of FGG expression in CRPC tissues and cells. Then we proved the proliferation, invasion and migration ability of CRPC cells were significantly reduced after FGG knockdown. The number of apoptotic cells increased at least sixfold after FGG silencing, and was observed in conjunction with an upregulation of p53, caspase 3, clea-caspase 3, and Bax, and a downregulation of Bcl2 and survivin. FGG knockdown in DU145 cells resulted in smaller xenografts than control cells in a mouse model. and we established that FGG is modulated by IL-6 which was increased in CRPC patients via phosphorylation of STAT3. The data suggests that FGG may be a potential therapeutic target and prognostic marker for CRPC.

[Effects of oxygen saturation on all-cause mortality among the elderly over 65 years old in 9 longevity areas of China]

Objective: To investigate the association between oxygen saturation (SpO₂) and risk of 3-year all-cause mortality among Chinese older adults aged 65 or over. Methods: The participants were enrolled from Healthy Aging and Biomarkers Cohort Study in year of 2012 to 2014 in 9 longevity areas in China. In this prospective cohort study, 2 287 participants aged 65 or over were enrolled. Data on SpO₂ and body measurements were collected at baseline in 2012, and data on survival outcome and time of mortality were collected at the follow-up in 2014. Participants were divided into two groups according to whether SpO₂ was abnormal (SpO₂<94% was defined as abnormal). Results: The 2 287 participants were (86.5±12.2) years old, 1 006 were males (44.0%), and 315 (13.8%) were abnormal in SpO₂. During follow-up in 2014, 452 were died, 1 434 were survived, and 401 were lost to follow-up. The all-cause mortality rate was 19.8%, and the follow-up rate was 82.5%. The mortality rate of SpO₂ in normal group was 21.1%, and that of abnormal group was 41.6% (P<0.001). After adjusting for confounding factors, compared to participants with normal SpO₂, participants with abnormal SpO₂ had increased risk of all-cause mortality with HR (95%CI) of 1.62 (1.31-2.02); HR (95 % CI) was 1.49 (0.98-2.26) for males and 1.71 (1.30-2.26) for females in abnormal SpO₂ group, respectively; HR (95%CI) was 2.70 (0.98-7.44) for aged 65-79 years old, 1.22 (0.63-2.38) for aged 80-89 years old, and 1.72 (1.35-2.19) for aged over 90 years old in abnormal SpO₂ group, respectively. Conclusion: Abnormal SpO₂ was responsible for increased risk of 3-year all-cause mortality among Chinese elderly adults.

[Health management of breast cancer patients outside the hospital during the outbreak of 2019 novel coronavirus disease]

The outbreak of 2019 novel coronavirus disease (COVID-19) is spreading rapidly. In order to prevent cluster outbreaks, the government strengthened the management and control of personnel mobility, which had a great impact on the examination and treatment of breast cancer patients. This paper discusses how to realize scientific health management of breast cancer patients outside the hospital based on the existing epidemic situation, characteristics of breast cancer patients and public health safety factors. The breast cancer patients should synthetically consider the epidemic prevention situation of inhabitance, the disease stage and previous therapeutic schedule to decide the next therapeutic schedule. If necessary, after professional discussion and communication between doctors and patients online or offline, the hospital visiting time should be delayed through seeking alternative treatment schemes, and psychological counseling for patients should be paid attention to at the same time.

[Association of sleep with anxiety in the elderly aged 60 years and older in China]

Objective: To investigate the relationship of sleep duration and sleep quality with anxiety in the elderly aged 60 years and older in China. Methods: The elderly aged 60 years and older were selected from the China Short-term Health Effects of Air Pollution Study conducted between July 18, 2017 and February 7, 2018. Multivariate logistic regression models were used to analyze the association of sleep duration and sleep quality with anxiety. Results: A total of 3 897 elderly aged 60 years and older were included in the study. The age of the elderly was (73.4±8.0) years old. Among the elderly surveyed, 6.5% were defined with anxiety, and 18.7% reported poor sleep quality. Multivariate logistic regression models showed shorter sleep duration was the risk factor for anxiety in the elderly that after adjusting for factors such as general demographics, socioeconomic factors, lifestyle, health status, social support and ambient fine particulates exposure. Compared with the elderly with 7 hours of sleep duration daily, the OR (95%CI) of anxiety for those with sleep duration ≤ 6 hours was 2.09 (1.49-2.93). Compared with those with good sleep quality, the OR (95%CI) of anxiety for those with poor sleep quality was 5.12 (3.88-6.77). We also found statistically significant correlations of the scores of subscales of Pittsburgh sleep quality index with anxiety, in which the effects of sleep disturbance, subjective sleep quality and daytime dysfunction scores were most obvious, the ORs (95%CI) were 4.63 (3.55-6.04), 2.75 (2.33-3.23) and 2.50 (2.19-2.86), respectively. Subgroup analysis showed that the association of sleep duration and sleep quality with anxiety was more obvious in males and in those aged <80 years. Conclusion: Shorter sleep duration and poor sleep quality are associated with anxiety in the elderly in China.

[Prediction of 6-year incidence risk of chronic kidney disease in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To establish a prediction model for 6-year incidence risk of chronic kidney disease (CKD) in the elderly aged 65 years and older in China. Methods: In this prospective cohort study, we used the data of 3 742 participants collected during 2008/2009-2014 and during 2012-2017/2018 from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey. Two follow up surveys for renal function were successfully conducted for 1 055 participants without CKD in baseline survey. Lasso method was used for the selection of risk factors. The risk prediction model of CKD was established by using Cox proportional hazards regression models and visualized through nomogram tool. Bootstrap method (1 000 resample) was used for internal validation, and the performance of the model was assessed by C-index and calibration curve. Results: The mean age of participants was (80.8±11.4) years. In 4 797 person years of follow up, CKD was found in 262 participants (24.8%). Age, BMI, sex, education level, marital status, having retirement pension or insurance, hypertension prevalence, blood uric acid, blood urea nitrogen and total cholesterol levels and estimated glomerular filtration rate in baseline survey were used in the model to predict the 6-year incidence risk of CKD in the elderly. The corrected C-index was 0.766, the calibration curve showed good consistence between predicted probability and observed probability in high risk group, but relatively poor consistence in low risk group. Conclusion: The incidence risk prediction model of CKD established in this study has a good performance, and the nomogram can be used as visualization tool to predict the 6-year risk of CKD in the elderly aged 65 years and older in China.

[Effects of estimated glomerular filtration rate on all-cause mortality in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To investigate the association between estimated glomerular filtration rate (eGFR) and all-cause mortality in the elderly aged 65 years and older in longevity areas in China. Methods: Data used in this study were obtained from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey, 1 802 elderly adults were collected in the study during 2012-2017/2018. In this study, the elderly were classified into 4 groups, moderate-to-severe group [<45 ml·min(-1)·(1.73 m(2))(-1)], mild-to-moderate group [45- ml·min(-1)·(1.73 m(2))(-1)], mild group [60- ml·min(-1)·(1.73 m(2))(-1)] and normal group [≥90 ml·min(-1)·(1.73 m(2))(-1)] according to their eGFR levels. Results: After 6 years of follow-up, 852 participants died, with a mortality rate of 47.3%. Multivariate Cox regression analysis showed that the levels of eGFR were negatively correlated with all-cause mortality risk in the elderly (the HR of elderly was 0.993 and the 95%CI was 0.989-0.997 for every unit of eGFR increased, P=0.001), while compared with the group with normal eGFR, the HRs (95%CI) of the elderly in the moderate-to-severe group, mild-to-moderate group, and mild group were 1.690 (1.224-2.332, P=0.001), 1.312 (0.978-1.758, P=0.070), 1.349 (1.047-1.737, P=0.020) respectively [trend test P<0.001]. Conclusion: The decrease in eGFR was associated with higher mortality risk among the elderly in longevity areas in China.

[Influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To analyze influencing factors for depressive symptoms in the elderly aged 65 years and older in 8 longevity areas in China. Methods: We recruited 2 180 participants aged 65 years and older in 8 longevity areas from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey in 2017. Multivariate logistic regression analysis was performed to evaluate the relationships of socio-demographic characteristics, behavioral lifestyle, chronic disease prevalence, functional status, family and social support with depressive symptoms in the elderly. Results: The detection rate of depression symptoms was 15.0% in the elderly aged 65 years and older in 8 longevity areas of China, and the detection rate of depression symptoms was 11.5% in men and 18.5% in women. Multivariate logistic regression analysis results showed that the detection rate of depressive symptoms was lower in the elderly who had regular physical exercises (OR=0.44, 95%CI: 0.26-0.74), frequent fish intakes (OR=0.57, 95%CI: 0.39-0.83), recreational activities (OR=0.65, 95%CI: 0.44-0.96), social activities (OR=0.28, 95%CI: 0.11-0.73) and community services (OR=0.68, 95%CI: 0.50-0.93). The elderly who were lack of sleep (OR=2.04, 95%CI: 1.49-2.80), had visual impairment (OR=1.54, 95%CI: 1.08-2.18), had gastrointestinal ulcer (OR=2.97, 95%CI: 1.53-5.77), had arthritis (OR=2.63, 95%CI: 1.61-4.32), had higher family expenditure than income (OR=1.80, 95%CI: 1.17-2.78) and were in poor economic condition (OR=4.58, 95%CI: 2.48-8.47) had higher detection rate of depressive symptoms. Conclusion: The status of doing physical exercise, fish intake in diet, social activity participation, sleep quality or vision, and the prevalence of gastrointestinal ulcers and arthritis were associated with the detection rate of depressive symptoms in the elderly.

[Diagnosis and treatment of strabismus caused by nasal endoscopic surgery]

Objective: Strabismus with diplopia is the main orbital complication of functional endoscopic sinus surgery (FESS). This study was to analyze clinical findings, treatment and outcomes of such cases. Methods: Retrospective case series. Twenty-three cases were divided into 3 groups based on the disease severity: group A, partial transection of the medial rectus muscle, group B, complete transection of the medical rectus, group C, transection of the medial rectus combined with the other orbital injuries. Complete ophthalmology examinations, including eye alignment, eye motility, force duction test, force generation test, general eye exam, and medical imaging (orbital CT or MRI), were performed for each case. The treatment included botulinum toxin (Botox) injection to the lateral rectus muscle, transposition of the vertical rectus muscle, and orbital surgery if needed. Results: In group A with Botox injection, all the cases achieved single vision in primary position, but still remained some adduction weakness. In group B treated by vertical transposition surgery combined with Botox, 22% of the cases got single vision in primary gaze. In group C, even with more efforts of treatment, the cases with orbital injury can only get cosmetic improvement, and diplopia and adduction dysfunction were found in most cases. Conclusions: Due to the variety of the complications of FESS, force duction test is a crucial exam to detect the direction and severity of synechia in the orbit, which will give solid information to surgery approach as well as prognosis. Botox injection at early stage will minimize the contraction of antagonist lateral rectus, helping to postpone the transposition surgery which may cause anterior segment ischemia when performed right after the medial rectus transection injury. Botox may even reduce the synechia by minimizing the scarring process. Partial vertical rectus transposition combined with muscle resection may effectively correct the eye misalignment in primary gaze and improve eye motility. The prognosis of FESS induced orbital complications is quite related with the severity of the injury. Botox combined with surgery may help medial rectus transection cases to achieve single vision in primary gaze, but when there is any other orbital injury, treatment may only improve cosmetic appearance. (Chin J Ophthalmol, 2017, 53: 917-923).

[Association of plasma albumin and hypersensitive C-reactive protein with 5-year all-cause mortality among Chinese older adults aged 65 and older from 8 longevity areas in China]

Objective: To investigate the relationship of plasma albumin and hypersensitive C-reactive protein (Hs-CRP) with 5-year all-cause mortality among Chinese older adults aged 65 and older. Method: Data was collected in 8 longevity areas of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) study conducted by Chinese Center for Disease Control and Prevention and Peking University at baseline survey in 2012 and 2014, the participants enrolled in 2012 was followed-up in 2014 and 2017, the participants enrolled in 2014 was followed-up in 2017 only. Finally, 3 118 older adults aged 65 and older with complete information on albumin, Hs-CRP and body mass index (BMI) were included in this study. Plasma samples of older adults were collected for the detection of albumin and Hs-CRP at baseline survey. Survival status and follow-up time was recorded for all participants. All older adults were divided into 4 groups according to the levels of plasma albumin and Hs-CRP, and Cox proportional hazard models were constructed to assess their influence on the risk of all-cause mortality. Results: Among 3 118 older adults included, the prevalence of hypoalbuminemia was 10.1% (316/3 118), and was 22.8% (711/3 118) for elevated Hs-CRP. During 10 132 person-years of follow-up, 1 212 participants died. Participants with hypoalbuminemia had increased risk of all-cause mortality, with an hazard ratio (HR) and 95% confidential interval (CI) of 1.18 (1.01-1.38), compared to participants with normal plasma albuminemia; participants with elevated Hs-CRP had increased risk of all-cause mortality, with an HR (95%CI) of 1.18 (1.04-1.35), compared to participants with normal plasma Hs-CRP. Participants with normal plasma albumin and elevated Hs-CRP, with hypoalbuminemia and normal Hs-CRP, with hypoalbuminemia and elevated Hs-CRP also had increased risk of all-cause mortality when compared to those with normal plasma albumin and normal Hs-CRP, the HR (95%CI) were 1.16 (1.01-1.34), 1.11 (0.91-1.37) and 1.43 (1.11-1.83), respectively. Conclusion: Hypoalbuminemia and elevated Hs-CRP were responsible for increased risk of 5-year all-cause mortality among Chinese older adults from 8 longevity areas.

[Feasibility and toxicity of EC-T dose-dense adjuvant chemotherapy: A real world study in Chinese early-stage breast cancer patients with high recurrence risk]

Objective: We aimed to examine the feasibility and toxicity of EC-T dose-dense regimen and to demonstrate the suitable dose of epirubicin in a Chinese early-stage breast cancer population with high recurrence risk. Methods: 370 patients with early-stage breast cancer at high risk of recurrence were treated with EC-T dose-dense adjuvant chemotherapy and prophylactic administration of recombinant human granulocyte stimulating factor (G-CSF). The incidence of delayed chemotherapy, drug reduction and adverse reactions were retrospectively analyzed. Results: 370 patients completed the planned eight cycles of chemotherapy, 50 patients experienced chemotherapy delay, and 90 had chemotherapy dose reductions. Overall, 61.1% of the patients experienced grade 3 or 4 hematology toxicities, 4.1% of the patients experienced grade 3 gastrointestinal toxicity, 16.3% experienced grade 3 or 4 liver malfunction, and 1.9% experienced grade 3 alopecia. In the multivariate analysis, pretreatment epirubicin levels were associated with comprehensive and hematology toxicity risk (OR=1.268, P=0.046; OR=1.244, P=0.036). With G-CSF support, the probability of grade 3-4 dose limiting toxicity, i. e. neutropenia, abnormal liver function, and gastrointestinal adverse effects did not increase as the epirubicin dose level increased(P>0.05). However, there were no statistically significant associations between epirubicin grade and treatment delay (P=0.814) or dose reduction (P=0.282). Conclusions: EC-T dose-dense chemotherapy shows tolerable toxicity. High dose level is not a limiting factor for this regimen. With G-CSF support, epirubicin 85-90 mg/m(2) is appropriate tolerance dose for Chinese early breast cancer patients with high recurrence risk.

[Influence of low dose perfluorooctanoate acid exposure to the cell proliferation, migration and invasion of the human muscle rhabdomyosarcoma cell line]

Objective: This study aimed to explore the effect of perfluorooctanoate acid (PFOA) on the proliferation, migration and invasion of the human muscle rhabdomyosarcoma RD cell line and its related mechanisms. Methods: RD cells were cultured and exposed to PFOA of different concentrations with 6-72 hours. The cell viability was assessed by cell counting kit-8 (CCK-8) assay. Wound healing and transwell filter assay were used to evaluated the migration and invasion ability of the RD cells respectively. The cell cycles were detected by Flow cytometry. Quantitative real-time PCR and Western blot were used to quantify the mRNA and protein expression difference of related genes, respectively. Results: CCK-8 assay showed that, after treated the RD cell with different dose of PFOA for 72 h, low dose PFOA (1,10,50, 100 μmol/L) promotes the proliferation of RD cells while high dose PFOA (250, 500 mol/L) inhibits the proliferation (P<0.001). Flow cytometry showed that compared with the control group, there was no significant difference in G0/G1 phase, while cells in S phase deceased and G2/M phase cells increased after treated with PFOA (50 μmol/L) for 72 h. The relative proportions of S and G2/M were significantly different between the two groups (P<0.01). The results of qPCR showed that the mRNA relative expression of CDK2 of the control group and the PFOA (50 μmol/L) group were 0.97±0.07 and 2.64±0.11 respectively, and there was a significant difference (t=12.60, P<0.001); The mRNA relative expression of cyclin E2 of the control group and the PFOA (50 μmol/L) group were 1.33±0.17 and 3.35±0.22 respectively, and there was a significant difference (t=7.42, P<0.001); The results of Western blot showed that the protein relative expression of CDK2 of the control group and the PFOA (50 μmol/L) group were 0.35±0.01 and 0.84±0.03 respectively, and there was a significant difference (t=14.60, P<0.001); The protein relative expression of cyclin E2 of the control group and the PFOA (50 μmol/L) group were 0.67±0.04 and 0.86±0.01 respectively, and there was a significant difference (t=4.88, P<0.01); There was no significant difference in the mRNA and protein expression of p21 and p53 between the PFOA and control group (P>0.05). The wound healing rate of the PFOA (50 μmol/L) group was faster than that of the control group, and the relative migration area of the PFOA group was larger accordingly (P<0.001). After PFOA (50 μmol/L) treated, the number of the cell through the membranes was much more than the control group (t=54.40, P<0.001), which means PFOA significantly stimulated the invasion ability of the RD cells. The results of qPCR showed that the mRNA relative expression of vimentin of the control group and the PFOA (50 μmol/L) group were 0.71±0.03 and 2.53±0.16 respectively, and there was a significant difference (t=11.00, P<0.001); The mRNA relative expression of MMP2 of the control group and the PFOA (50 μmol/L) group were 1.09±0.04 and 10.73±1.20 respectively, and there was a significant difference (t=8.04, P<0.001). The results of Western blot showed that the protein relative expression of vimentin of the control group and the PFOA (50 μmol/L) group were 0.55±0.06 and 0.81±0.01 respectively, and there was a significant difference (t=4.50, P<0.05). The protein relative expression of cyclin E2 of the control group and the PFOA (50 μmol/L) group were 0.64±0.04 and 1.03±0.13 respectively, and there was a significant difference (t=2.94, P<0.05). Conclusions: Low dose PFOA (50 μmol/L) exposure promotes cell proliferation, migration and invasion in the human muscle rhabdomyosarcoma cell line through inducing the expressions of MMP2, vimentin and cell cycle related genes.

Methylation-Based Age Estimation Model Construction and Its Effectiveness Evaluation

OBJECTIVES

To screen the DNA methylation loci associated with the age of Han males in northern China and to construct an age estimation model.

METHODS

Twenty-one candidate methylation loci were screened. The DNA methylation levels of 476 blood samples from Chinese Han males were detected for 21 amplicons using EpiTYPER technology platform, and data on 153 DNA methylation loci were obtained.

RESULTS

After correlation analysis, 8 age-related DNA methylation loci were finally screened. CpG1, CpG2, CpG4, CpG7, CpG8 were located on TRIM59, RASSF5, Clorf132, CSNK1D, ELOVL2,CpG5, CpG6 on PDE4C, and CpG3 on chr17:21452808. Based on the 8 loci, 352 samples were used for model construction. A multivariate linear regression age estimation model was constructed （R²=0.93）, with mean absolute deviation （MAD） of 2.69 years old. When 109 samples were used for model validation, the MAD was 3.80 years old. The test was repeated 3 times in 15 new samples, with MADs of 4.08, 4.68 and 3.93 years old, respectively.

CONCLUSIONS

The age estimation model on Han males in northern China constructed in this study can be used to estimate the age of victims and suspects and to narrow the scope of investigation, and therefore has practical application value.

[Expression of anaplastic lymphoma kinase fusion gene in patients with lung sarcomatoid carcinoma and treatment analysis]

Objective: To investigate the expression status of anaplastic lymphoma kinase (ALK) fusion gene in lung sarcomatoid carcinoma (LSC) and the role of ALK inhibitors for treatment. Methods: Total of 84 cases of LSC confirmed by histopathology were detected for ALK fusion gene from January 2011 to December 2014 in the Cancer Hospital of Chinese Academy of Medical Science&Peking Union Medical College and Shandong Zibo Wanjie Cancer Hospital. All patients were primarily treated by the multi-disciplinary mode in combination with chemotherapy or targeted therapy based on surgery. Postoperative adjuvant chemotherapy was given on platinum based two-drug combination regimen. In ALK fusion gene (+ ) patients with recurrence or metastasis, crizotinib target therapy was prefered. Chi-square test was applied for the comparison of 1, 3, 5-year survival rates between the two groups. Results: Eighty-two cases completed the follow-up. ALK fusion gene was found in 9(10.7%) patients. After application of crizotinib, 1 case was evaluated as complete remission, 6 cases as partial response, 2 cases as stable disease; the 1, 3, 5-year survival rate was 100% (9/9), 100% (9/9) and 88.9% (8/9) for the patients with ALK fusion gene, and it was 65.8% (48/73), 15.1% (11/73) and 6.8% (5/73) respectively for patients without ALK fusion gene. There was significant difference in the survival rate between the two groups (χ(2)=1.56, 1.56, 0.83, all P<0.05). Conclusion: ALK fusion gene maybe expressed in LSC patients. Compared with conventional chemotherapy, crizotinib can significantly prolong the survival time of patients with ALK fusion gene.

[Clinical significance of S100A6 and Notch1 in multiple myeloma patients]

目的

探讨S100A6、Notch1在多发性骨髓瘤（MM）患者中的表达及其临床意义。

方法

以28例MM患者为研究对象，以20例白细胞、血小板略低但骨髓检查未见异常者为对照，采用real time PCR法检测骨髓单个核细胞S100A6、Notch1的表达；采用免疫组化染色法检测S100A6、Notch1蛋白在MM患者骨髓和髓外浸润组织活检病理切片中的表达；采用real time PCR法和Western blot法检测siRNA沉默骨髓瘤U266细胞S100A6基因后对Notch1 mRNA和蛋白水平的影响。并结合临床进行相关分析。

结果

①S100A6、Notch1 mRNA表达水平：初发MM患者组分别为2.19±1.25、2.98±0.64，均高于对照组（0.71±0.20、0.58±0.39）和稳定期患者组（0.85±0.26、0.72±0.40）（P值均<0.05）；伴髓外转移组（8例）分别为3.36±1.23、5.71±3.96，均高于无髓外转移组（20例）（1.40±0.25、1.16±1.00）。②S100A6与Notch1 mRNA表达呈正相关（r=0.505，P=0.007）。③MM患者骨髓和髓外浸润组织活检病理切片均可见浆细胞S100A6、Notch1阳性表达。④siRNA转染U266细胞48 h后S100A6基因表达沉默，Notch1 mRNA及蛋白水平明显下降。

结论

S100A6、Notch1表达与MM疾病发生、进展、髓外转移相关，二者具有显著相关性，可作为MM诊断及预后的指标。

[Advances in epidemiology and serum markers for the noninvasive diagnosis of nonalcoholic fatty liver disease]

The global prevalence rate of nonalcoholic fatty liver disease (NAFLD) has increased year by year, and it has become the number one cause for chronic liver disease in China. In addition, the trend of NAFLD has become more pronounced and evident in female gender and younger age group. The long-term persistence of fatty liver disease may cause serious consequences. There are no accepted diagnostic criteria for diagnosing noninvasive diagnosis of NAFLD. Alpha-ketoglutarate is a newly discovered serological marker of high diagnostic value and considered the most valuable potential biomarker along with cytokeratine-18 (CK-18).

[Association between air pollution and cognitive function in the elderly]

Cognition disorders is one of the most important factors affecting the elderly. Impaired cognitive function caused by the elderly daily self-care ability decreased, the elderly in China cause serious social, psychological and economic burden. The purpose of this review is to summarize the current evidence on main air pollutants(SO(2), NO(2), CO, PM(2.5) and PM(10), black carbon)and cognitive function in elderly. The study found that exposure to air pollution, especially particulate matter, is associated with cognitive disorders n in the elderly. However, the existence of such correlations requires reasonable physiological mechanisms. Future studies also require a large number of longitudinal cohorts to investigate air pollution in association with cognitive impairment . There is a need for parallel toxicological and epidemiological studies to elucidate mechanisms and pathways of action.

[Occupational mental health and job satisfaction in university teachers in Shenyang, China]

Objective: To investigate the current status of occupational mental health and job satisfaction in university teachers in Shenyang, China and related influencing factors. Methods: A total of 1500 teachers from 6 universities in Shenyang were randomly selected as study subjects from November 2013 to January 2014. Self-administered questionnaires were used to investigate mental health, including effort-reward imbalance questionnaire, Minnesota Satisfaction Questionnaire, Center for Epidemiological Survey-Depression Scale, and Psychological Capital Questionnaire. Results: Of all teachers, 58.9% had depressive symptoms. Depressive symptoms in university teachers were negatively correlated with the scores of psychological capital, supervisory commitment, and perceived organizational support (r=-0.461, -0.306, and -0.366, all P<0.01) and were positively correlated with the score of occupational stress (r=0.414, P<0.01) . Job satisfaction was positively correlated with psychological capital, perceived organizational support, and supervisory commitment (r=0.650, 0.715, and 0.636, all P<0.01) and negatively correlated with occupational stress (r=-0.475, P<0.01) . The direct effects of occupational stress, perceived organizational support, and supervisory commitment on job satisfaction were -0.30, 0.26, and 0.14, respectively, and their indirect effects were -0.0176, 0.0656, and 0.0368, respectively. The direct effects of occupational stress, perceived organizational support, and supervisory commitment on depressive symptoms were 0.20, -0.08, and -0.05, respectively, and their indirect effects was 0.033, -0.123, and -0.069, respectively. Conclusion: Occupational mental health is closely associated with job satisfaction in university teachers in Shenyang, and psychological capital has a mediating effect on perceived organizational support, supervisory commitment, occupational stress, job satisfaction, and depressive symptoms.

[Analysis of treatment and prognosis in post-operative patients with urachal carcinoma]

OBJECTIVE

Urachal carcinoma is a kind of urogenital tract malignancy with a very low incidence. The objective of this study was to observe the clinical presentation, pathological condition, treatment method and outcome of patients with urachal carcinoma.

METHODS

A retrospective analysis of thirty-six cases of urachal carcinoma diagnosed over a period of 10 years from 2003 to 2013 was carried out. All pathologic specimens were reviewed by two separate pathologists. Clinical and histological features, treatment condition, patient follow-up and survival outcome was reviewed and calculated.

RESULTS

The mean age at diagnosis was 53 years. Of the thirty-six patients, twenty-five were male. All patients underwent partial cystectomy with bilateral pelvic lymph node dissection. All cases were adenocarcinoma, including 20 mucinous adenocarcinoma, 7 moderately differentiated adenocarcinoma, 5 poorly differentiated adenocarcinoma, 1 signet ring cell carcinoma, 3 hybrid adenocarcinoma. The Sheldon pathologic stage was stage Ⅱ in 11, Ⅲ in 16 and Ⅳa in 9 cases. All patients received medical oncological therapy. The median follow-up period was 27 months. The median overall survival was 36 months. One-year survival rate was 70% and five-year survival rate was 28%.

CONCLUSIONS

Urachal carcinomas are rare and usually at locally advanced stage at diagnosis with a high tendency of metastases. Surgery is a key method of primary treatment and medical oncological therapy may play a role in decreasing the chances of recurrence which still needs to be explained by prospective clinical trials.

Enhanced ultraviolet emission from Au/Ag-nanoparticles@MgO/ZnO heterostructure light-emitting diodes: A combined effect of exciton- and photon- localized surface plasmon couplings

Localized surface plasmon (LSP)-enhanced ultraviolet light-emitting diodes (LEDs) based on a Au/MgO/ZnO metal/insulator/semi- conductor heterostructure were fabricated by embedding Ag nanoparticles (Ag-NPs) into MgO dielectric layer. A ~6-fold electroluminescence (EL) enhancement was achieved from the Ag-NPs decorated device. Time-resolved spectroscopy studies, as well as analogue simulation and theoretical estimation based on experimental data, reveal that the internal quantum efficiency and light extraction efficiency of the heterojunction LED are increased ~3-fold and ~2-fold, respectively, as a result of the introduction of Ag LSPs. This result indicates that the observed EL enhancement originates from a combined effect of both exciton-LSP coupling and photon-LSP coupling.

Giant negative magnetoresistance in Manganese-substituted Zinc Oxide

We report a large negative magnetoresistance in Manganese-substituted Zinc Oxide thin films. This anomalous effect was found to appear in oxygen-deficient films and to increase with the concentration of Manganese. By combining magnetoresistive measurements with magneto-photoluminescence, we demonstrate that the effect can be explained as the result of a magnetically induced transition from hopping to band conduction where the activation energy is caused by the sp-d exchange interaction.

Strengthening of a Pd-free high gold dental alloy for porcelain bonding by a pre-firing heat treatment

OBJECTIVES

The purpose of the present investigation was to report a Pd-free high gold alloy for porcelain bonding based on the ternary system of Au-Pt-Zn with a nominal composition of 86Au-11Pt-1.5Zn-0.5In-0.7Rh-0.2Fe-0.1Ir (wt.%). Emphasis was put on the effect of a pre-firing heat treatment on the mechanical properties of the alloy.

METHODS

The strengthening effect of the pre-firing heat treatment was investigated by means of hardness measurement, tensile testing, X-ray diffraction, optical microscopy and scanning electron microscopy.

RESULTS

Experimental results showed that both the hardness and tensile strength of the alloy can be significantly improved after heat treatment at the temperature of 980 degrees C for 15 min. The strengthening could be attributed to homogenization of microstructure and alloying elements and precipitation of new fine particles.

SIGNIFICANCE

The cast framework of the present new Pd-free alloy could be heat treated before actual firing, and this would improve the processing properties of the alloy during firing.

Age-hardening behavior of a low-gold dental alloy

The age-hardening behaviors of a low gold dental alloy were studied by means of differential scanning calorimetry, hardness testing, X-ray diffraction, optical microscopy and transmission election microscopy. Two distinct hardening behaviors were found at two different aging temperatures. Age-hardening at 290 degrees C was attributed to the formation of the metastable AuCuI' ordered phase, and the gradual softening in the overaging stage resulted from the slow growth of this phase. The rapid increase in hardness in the early stage at 495 degrees C was due to the precipitation of the metastable AuCuI' or/and AuCuII' ordered phases, and the rapid decrease in hardness in the overaging stage was a consequence of the growth of these phases and the loss of the coherency strain at the interface between the spindal-like AuCuI platelets and the matrix.

Spectral dependence of spin photocurrent and current-induced spin polarization in an InGaAs/InAlAs two-dimensional electron gas

The converse effects of spin photocurrent and current induced spin polarization are experimentally demonstrated in a two-dimensional electron gas system with Rashba spin splitting. Their consistency with the strength of the Rashba coupling as measured for the same system from beating of the Shubnikov-de Haas oscillations reveals a unified picture for the spin photocurrent, current-induced spin-polarization, and spin-orbit coupling. In addition, the observed spectral inversion of the spin photocurrent indicates a system with dominating structure inversion asymmetry.

Effective dose evaluation for chest and abdomen X-ray tests

The radiation doses resulting from diagnostic X-ray examinations are routinely measured in terms of entrance skin exposure (ESE). In this study, for the purpose of radiation protection, the radiation doses received from chest and abdomen X-ray tests were evaluated in terms of equivalent dose and effective dose. The dose calculations were conducted by using the MCNP Monte Carlo code and an adult hermaphrodite mathematical phantom. The effects of both operating high voltage and projection geometry on the effective dose were investigated. The absolute values of the effective doses may be provided from the national average ESE.

Low energy electron irradiation induced deep level defects in 6H-SiC: the implication for the microstructure of the deep levels E1/E2

N-type 6H-SiC samples irradiated with electrons having energies of E(e)=0.2, 0.3, 0.5, and 1.7 were studied by deep level transient technique. No deep level was detected at below 0.2 MeV irradiation energy while for E(e)>/=0.3 MeV, deep levels ED1, E(1)/E(2), and E(i) appeared. By considering the minimum energy required to displace the C atom or the Si atom in the SiC lattice, it is concluded that generation of the deep levels E(1)/E(2), as well as ED1 and E(i), involves the displacement of the C atom in the SiC lattice.

Structural analysis of the epitopes on erbB2 interacted with inhibitory or non-inhibitory monoclonal antibodies

erbB2 oncogene encodes a growth factor receptor. The overexpression of erbB2 was correlated with more aggressive tumors and a poorer prognosis. Some antibodies directed to this molecule have an antitumor effect in vivo, but some antibodies do not. In an attempt to understand the molecular basis of the anti-erbB2 antibody interaction with erbB2 ectodomain (ECD), we analyzed binding epitopes on erbB2 for inhibitory and non-inhibitory antibodies, Herceptin and HF by computer-guided protein engineering and site-directed mutagenesis. Two different interaction domains were identified by molecular docking, computer graphics and distance geometry method and confirmed through studies on a series of mutants of erbB2 ECD. Non-inhibitory antibody HF only recognized N-terminal portion of erbB2 ECD, but inhibitory antibody Herceptin bound to C-terminal portion of it exclusively. The region interacted with inhibitory antibody Herceptin can be an important target for anticancer therapies.

Age-dependent protection quantities for external neutron irradiation

Based on the recommendations issued by the International Commission on Radiological Protection (ICRP), equivalent doses and effective doses for different ages are obtained for external neutron sources. The calculations at 28 neutron energies from 1 x 10(-9) MeV to 20 MeV are carried out for six irradiation geometries: AP, PA, RLAT, LLAT, ROT and ISO. An age-dependent anthropomorphic mathematical phantom series of six age groups: newborn, 1, 5, 10, 15 years old and adult is used with the Monte Carlo computer code MCNP for the dose evaluations. The results for adults are compared with those in ICRP Publication 74 and are in good agreement. At low energies the effective doses increase as the phantom age increases, but at high energics they decrease with increasing age for the AP, PA, ROT and ISO irradiation geometries. In the whole energy region the effective doses decrease as the phantom age increases for the RLAT and LLAT irradiation geometries. The age-dependent equivalent doses behave similarly to the effective doses, with some exceptions caused by the influence of the organ position.

Validity of the updated pediatric risk of mortality score (PRISM III) in predicting the probability of mortality in a pediatric intensive care unit

This study assessed the validity of the PRISM III scoring system in accurately predicting the probability of mortality in a pediatric intensive care unit (PICU) in Taiwan. We collected data from consecutive patients admitted to our PICU during a one-year period from November 1999 through October 2000. Our PICU had 412 admissions including 385 patients (202 boys and 183 girls) with an average age of 53.9 +/- 58.2 months (range: 1 month to 18 years). The most common reason for admission was respiratory failure (26.2%). Almost 60% of the patients had at least one underlying chronic disease. The average duration of stay was 4.52 +/- 8.43 days (range 1 day to 81 days). The average PRISM III score was 5.06 +/- 6.95 (range 0-44). The overall mortality rate in the PICU was 8.17%. The mortality rate was not significantly different from the predicted rate (7.56%) (p=0.65). The efficiency of care was 32.5% and the standardized PICU length of stay ratio (SLOSR) was 1.33. The SLOSR ratio was significantly higher than the predicted rate (p value < 0.001). The PRISM III score was validfor assessing mortality risk of PICU patients in this hospital in Taiwan. However, the SLOSR ratio obtained in this study was higher than predicted. Differences in the patterns of practicing medicine may play an important role in observed PICU length of stay. Special caution is needed in adopting a severity of illness scoring system to assess performance of care, particularly in contexts different from the ones in which the instrument was originally developed. Further study including more pediatric intensive care units and other regions would enable greater generalization of the validity of this instrument.

Superconductivity in 4 angstrom single-walled carbon nanotubes

Investigation of the magnetic and transport properties of single-walled small-diameter carbon nanotubes embedded in a zeolite matrix revealed that at temperatures below 20 kelvin, 4 angstrom tubes exhibit superconducting behavior manifest as an anisotropic Meissner effect, with a superconducting gap and fluctuation supercurrent. The measured superconducting characteristics display smooth temperature variations owing to one-dimensional fluctuations, with a mean-field superconducting transition temperature of 15 kelvin. Statistical mechanic calculations based on the Ginzburg-Landau free-energy functional yield predictions that are in excellent agreement with the experiments.

Age-dependent protection quantities for external photon irradiation

The age-dependent conversion coefficients of the protection quantities, the equivalent dose and the effective dose defined by the International Commission on Radiological Protection (ICRP), are obtained. A Monte Carlo computer code and the age-dependent hermaphrodite mathematical phantoms of six age groups: newborn, 1, 5, 10, 15 years old and adult are used for the evaluation. Twenty-three photon source energies from 10 keV to 10 MeV and six kinds of irradiation geometries: AP, PA, RLAT, LLAT, ROT, and ISO are chosen in the calculation. The evaluated conversion coefficients for the adult are compared with those in ICRP Publication 74 with good agreement. The conversion coefficients of the equivalent dose and the effective dose increase while the age of the phantom decreases, but with some exceptions for the AP irradiation geometry under certain conditions.

[Analysis of ginsenosides by high performance liquid chromatography/mass spectrometry/mass spectrometry(LC/MS/MS)]

Ginseng, one of the most popular medicinal herbs used in traditional Chinese medicines, has been studied to have biological effects attributing to its main constituents such as ginsenosides. There are more than 30 kinds of ginsenosides and some of them have similar polarity and structure. Thus, it is difficult to separate those ginsenosides with isocratic mobile phase owing to their similar polarity. A reversed-phase high performance liquid chromatographic method with gradient elution has been developed in this work. Nine ginsenosides can be separated by this method. Among them, five ginsenosides with different molecular weights can be determined by means of their molecular weight gained through LC/MS with an ESI interface. Re and Rd have the same Mw but belonging to two different kinds of ginsenosides. They can be differentiated from each other through their MS/MS gained by CID(collision induced decomposition) at the second stage quadrapole. Rc and Rb3 having the same molecular weight and belonging to the same kind of ginsenoside can be distinguished through their negative ion spectra gotten from LC/MS. So 9 ginsenosides can be determined by LC/MS/MS. This method can also be used to determine the ginsenosides contained in commercially available samples.

Ectopic atrial tachycardia in children

BACKGROUND AND PURPOSE

Ectopic atrial tachycardia (EAT) is an unusual and potentially risky arrhythmia that can result in left ventricular dysfunction if not properly managed. In adults, EAT is mainly caused by diseased atrial myocardium and responds poorly to antiarrhythmic drugs. The characteristics of EAT in children might be different from those in adults because of their immature myocardium and the different electrophysiologic characteristics of their conduction tissue. We examined the natural history and treatment of EAT in children.

METHODS AND RESULTS

From June 1990 through June 1999, 24 children (8 girls and 16 boys; median age 4 mo [1 d-10 yr]) were admitted to our hospital with a diagnosis of EAT. Fifteen had healthy hearts, six had congenital heart disease, one had myocarditis, one had bronchopulmonary dysplasia with severe pulmonary hypertension, and one had hypertrophic cardiomyopathy. Thirteen patients presented with congestive heart failure. Only four patients had symptoms of prodromal airway infection. The maximum atrial rate was 244 +/- 66 beats per minute. Atrioventricular block was documented at least once during tachycardia in 10 patients. Warm-up or cool-down phenomenon was seen at the initiation or termination of tachycardia in thirteen patients. Primary pharmacologic treatment was attempted in all patients. EAT was initially controlled in all patients using digoxin plus propranolol (18 patients), propranolol only (4), or digoxin plus procainamide (2). EAT was controlled using medication in 22 patients. Fifteen patients had sinus rhythm but did not receive medication for 39 +/- 25 months. Two patients died of uncontrolled arrhythmia, and two of underlying disease. Recurrence was seen within 3 months after initial therapy in five patients. Surgery was performed to correct the underlying heart disease in three patients with frequently recurring EAT, all of whom remained tachycardia-free after surgery, without pharmacologic treatment. The spontaneous remission rate was 75% (18/24).

CONCLUSION

EAT in children without underlying heart disease can be effectively treated using antiarrhythmic drugs. Spontaneous resolution of EAT after medication in children was frequent (75%) in this series. The results of this study suggest that a step-wise approach using digoxin, a beta-blocker, and a class I antiarrhythmic drug may be the most effective treatment for EAT.

Dangerous impact--commotio cordis

Sudden death following blunt chest trauma is a frightening occurrence known as 'commotio cordis' or 'concussion of the heart'. It is speculated that commotio cordis could be caused by ventricular fibrillation secondary to an impact-induced energy that was transmitted via the chest wall to the myocardium during its vulnerable repolarization period. We describe a survivor of commotio cordis caused by a baseball. In this patient, an initial ventricular fibrillation was documented and converted by direct current defibrillation. Serial electrocardiographic changes (bifascicular conduction block and T wave inversion in precordial leads) were noticed in this patient. Our case suggested that coronary vasospasm might also play a role in commotio cordis.