[Association of lifestyle and apolipoprotein E gene with risk for cognitive frailty in elderly population in China]

Objective: To investigate the impact of lifestyle, apolipoprotein E (ApoE) gene, and their interaction on the risk for cognitive frailty in the elderly population in China. Methods: The study participants were from the Chinese Longitudinal Healthy Longevity Survey. The information about their lifestyles were collected by questionnaire survey, and a weighted lifestyle score was constructed based on β coefficients associated with specific lifestyles to assess the combined lifestyle. ApoE genotypes were assessed by rs429358 and rs7412 single nucleotide polymorphisms. Cognitive frailty was assessed based on cognitive function and physical frailty. Cox proportional hazards regression model was used to analyze the association of lifestyle and ApoE gene with the risk for cognitive frailty and evaluate the multiplicative and additive interactions between lifestyle and ApoE gene. Results: A total of 5 676 elderly persons, with median age [M (Q1, Q3)] of 76 (68, 85) years, were included, in whom 615 had cognitive frailty. The analysis by Cox proportional hazards regression model indicated that moderate and high levels of dietary diversity could reduce the risk for cognitive frailty by 18% [hazard ratio (HR)=0.82, 95%CI: 0.68-1.00] and 28% (HR=0.72, 95%CI: 0.57-0.91), respectively; moderate and high levels of physical activity could reduce the risk by 31% (HR=0.69, 95%CI: 0.56-0.85) and 23% (HR=0.77, 95%CI: 0.64-0.93), respectively. Healthy lifestyle was associated with a 40% reduced risk for cognitive frailty (HR=0.60, 95%CI: 0.46-0.78). ApoE ε4 allele was associated with a 26% increased risk for cognitive frailty (HR=1.26, 95%CI: 1.02-1.56). No multiplicative or additive interactions were found between lifestyle and ApoE gene. Conclusions: Dietary diversity and regular physical activity have protective effects against cognitive frailty in elderly population. Healthy lifestyle can reduce the risk for cognitive frailty in elderly population regardless of ApoE ε4 allele carriage status.

Neck management of pathological N1 oral squamous cell carcinoma: a retrospective study

This study was performed to compare the effects of neck dissection procedures on the prognosis of patients with pathological N1 (pN1) oral squamous cell carcinoma (OSCC), analyse factors affecting the prognosis, and provide a neck management strategy for clinical N1 (cN1) oral cancer. The study patients were divided into two groups according to the neck dissection: a selective neck dissection (SND) group (n = 85) and a radical or modified radical neck dissection (RND/MRND) group (n = 22). There was no statistically significant difference in recurrence rates at local, regional, and distant sites between the SND and RND/MRND groups. The 5-year overall survival was 68.3% for SND and 65.2% for RND/MRND patients (P = 0.590), while the 5-year disease-specific survival was 70.4% for SND and 75.7% for RND/MRND patients (P = 0.715). Histological grade and postoperative radiotherapy were independent predictors of the outcome for SND patients. For histological grade II/III cases, 5-year overall survival (P = 0.004) and disease-specific survival (P = 0.002) outcomes differed significantly between patients treated with and without postoperative radiotherapy, with worse survival for patients not treated with radiotherapy. Therefore, SND appears appropriate for cN1 OSCC patients, and postoperative radiotherapy is recommended for those with histological grade II or III tumours.

Suvemcitug as second-line treatment of advanced or metastatic solid tumors and with FOLFIRI for pretreated metastatic colorectal cancer: phase Ia/Ib open label, dose-escalation trials

BACKGROUND

Suvemcitug (BD0801), a novel humanized rabbit monoclonal antibody against vascular endothelial growth factor, has demonstrated promising antitumor activities in preclinical studies.

PATIENTS AND METHODS

The phase Ia/b trials investigated the safety and tolerability and antitumor activities of suvemcitug for pretreated advanced solid tumors and in combination with FOLFIRI (leucovorin and fluorouracil plus irinotecan) in second-line treatment of metastatic colorectal cancer using a 3 + 3 dose-escalation design. Patients received escalating doses of suvemcitug (phase Ia: 2, 4, 5, 6, and 7.5 mg/kg; phase Ib: 1, 2, 3, 4, and 5 mg/kg plus FOLFIRI). The primary endpoint was safety and tolerability in both trials.

RESULTS

All patients in the phase Ia trial had at least one adverse event (AE). Dose-limiting toxicities included grade 3 hyperbilirubinemia (one patient), hypertension and proteinuria (one patient), and proteinuria (one patient). The maximum tolerated dose was 5 mg/kg. The most common grade 3 and above AEs were proteinuria (9/25, 36%) and hypertension (8/25, 32%). Forty-eight patients (85.7%) in phase Ib had grade 3 and above AEs, including neutropenia (25/56, 44.6%), reduced leucocyte count (12/56, 21.4%), proteinuria (10/56, 17.9%), and elevated blood pressure (9/56, 16.1%). Only 1 patient in the phase Ia trial showed partial response, [objective response rate 4.0%, 95% confidence interval (CI) 0.1% to 20.4%] whereas 18/53 patients in the phase Ib trial exhibited partial response (objective response rate 34.0%, 95% CI 21.5% to 48.3%). The median progression-free survival was 7.2 months (95% CI 5.1-8.7 months).

CONCLUSIONS

Suvemcitug has an acceptable toxicity profile and exhibits antitumor activities in pretreated patients with advanced solid tumors or metastatic colorectal cancer.

[Association of sleep duration and risk of frailty among the elderly over 80 years old in China: a prospective cohort study]

Objective: To explore the association between sleep duration and the risk of frailty among the elderly over 80 years old in China. Methods: Using the data from five surveys of the China Elderly Health Influencing Factors Follow-up Survey (CLHLS) (2005, 2008-2009, 2011-2012, 2014, and 2017-2018), 7 024 elderly people aged 80 years and above were selected as the study subjects. Questionnaires and physical examinations were used to collect information on sleep time, general demographic characteristics, functional status, physical signs, and illness. The frailty state was evaluated based on a frailty index that included 39 variables. The Cox proportional risk regression model was used to analyze the correlation between sleep time and the risk of frailty occurrence. A restricted cubic spline function was used to analyze the dose-response relationship between sleep time and the risk of frailty occurrence. The likelihood ratio test was used to analyze the interaction between age, gender, sleep quality, cognitive impairment, and sleep duration. Results: The age M (Q₁, Q₃) of 7 024 subjects was 87 (82, 92) years old, with a total of 3 435 (48.9%) patients experiencing frailty. The results of restricted cubic spline function analysis showed that there was an approximate U-shaped relationship between sleep time and the risk of frailty. When sleep time was 6.5-8.5 hours, the elderly had the lowest risk of frailty; Multivariate Cox proportional risk regression model analysis showed that compared to 6.5-8.5 hours of sleep, long sleep duration (>8.5 hours) increased the risk of frailty by 13% (HR: 1.13; 95%CI: 1.04-1.22). Conclusion: There is a nonlinear association between sleep time and the risk of frailty in the elderly.

First-in-human, phase I study of AK109, an anti-VEGFR2 antibody in patients with advanced or metastatic solid tumors

BACKGROUND

Vascular endothelial growth factor receptor 2 (VEGFR2) plays a key role in antiangiogenesis which has been an essential strategy for cancer treatment. We report the first-in-human study of AK109, a novel anti-VEGFR2 monoclonal antibody, to characterize the safety profile and pharmacokinetics/pharmacodynamics (PK/PD) properties, and explore the preliminary antitumor efficacy in patients with solid tumors.

PATIENTS AND METHODS

This was a multicenter, open-label, phase I study, including dose escalation and dose expansion (NCT04547205). Patients with advanced cancers were treated 2 and 3 weekly with escalating doses of AK109. A 3 + 3 design was used to determine the maximum tolerated dose. Blood was sampled for PK/PD analysis. The primary endpoint was safety and recommended phase II dose (RP2D).

RESULTS

A total of 40 patients were enrolled. No dose-limiting toxicity was observed. However, 38 patients reported treatment-related adverse events (TRAEs); grade ≥3 TRAEs occurred in 10 patients. The most common TRAEs were proteinuria (n = 24, 60%), hypertension (n = 13, 32.5%), increased aspartate transaminase (n = 11, 27.5%), thrombopenia (n = 10, 25%), and anemia (n = 10, 25%). A total of 28 patients (70%) reported adverse events of special interest (AESIs). The most common AESIs were proteinuria (60%), hypertension (32.5%), and hemorrhage (32.5%), mainly including gum bleeding and urethrorrhagia. AK109 exhibited an approximately linear PK exposure with dose escalation at 2-12 mg/kg. PD analyses showed rapid target engagement. Among the 40 patients, 4 achieved partial response and 21 achieved stable disease with an objective response rate of 10% and a disease control rate of 62.5%. Based on the safety profile, the PK/PD profile, and preliminary antitumor activities, 12 mg/kg Q2W and 15 mg/kg Q3W were selected as RP2D.

CONCLUSIONS

AK109 showed manageable safety profile and promising antitumor activity, supporting further clinical development in a large population.

UCHL1 Impairs Periodontal Ligament Stem Cell Osteogenesis in Periodontitis

Periodontitis comprises a series of inflammatory responses resulting in alveolar bone loss. The suppression of osteogenesis of periodontal ligament stem cells (PDLSCs) by inflammation is responsible for impaired alveolar bone regeneration, which remains an ongoing challenge for periodontitis therapy. Ubiquitin C-terminal hydrolase L1 (UCHL1) belongs to the family of deubiquitinating enzymes, which was found to play roles in inflammation previously. In this study, the upregulation of UCHL1 was identified in inflamed PDLSCs isolated from periodontitis patients and in healthy PDLSCs treated with tumor necrosis factor-α or interleukin-1β, and the higher expression level of UCHL1 was accompanied with the impaired osteogenesis of PDLSCs. Then UCHL1 was inhibited in PDLSCs using the lentivirus or inhibitor, and the osteogenesis of PDLSCs suppressed by inflammation was rescued by UCHL1 inhibition. Mechanistically, the negative effect of UCHL1 on the osteogenesis of PDLSCs was attributable to its negative regulation of mitophagy-dependent bone morphogenetic protein 2/Smad signaling pathway in periodontitis-associated inflammation. Furthermore, a ligature-induced murine periodontitis model was established, and the specific inhibitor of UCHL1 was administrated to periodontitis mice. The histological results showed increased active osteoblasts on alveolar bone surface and enhanced alveolar bone regeneration when UCHL1 was inhibited in periodontitis mice. Besides, the therapeutic effects of UCHL1 inhibition on ameliorating periodontitis were verified, as indicated by less bone loss and reduced inflammation. Altogether, our study proved UCHL1 to be a key negative regulator of the osteogenesis of PDLSCs in periodontitis and suggested that UCHL1 inhibition holds promise for alveolar bone regeneration in periodontitis treatment.

Site-specific therapy in cancers of unknown primary site: a systematic review and meta-analysis

Background

Cancer of unknown primary site (CUP) is a term applied to characterize pathologically confirmed metastatic cancer with unknown primary tumor origin. It remains uncertain whether patients with CUP benefit from site-specific therapy guided by molecular profiling.

Patients and methods

A systematic search in PubMed, Web of Science, Embase, Cochrane Library, and ClinicalTrials.gov, and of conference abstracts from January 1976 to January 2021 was performed to identify studies investigating the efficacy of site-specific therapy on patients with CUP. The quality of included studies was evaluated using the Cochrane risk of bias tool and Newcastle–Ottawa scale. Eligible studies were weighted and pooled for meta-analysis. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were assessed to compare the efficacy of site-specific therapy with empiric therapy in patients with CUP. In addition, subgroup analyses were conducted.

Results

Five studies comprising 1114 patients were identified, of which 454 patients received site-specific therapy, and 660 patients received empiric therapy. Our meta-analysis revealed that site-specific therapy was not significantly associated with improved PFS [HR 0.93, 95% confidence interval (CI) 0.74-1.17, P = 0.534] and OS (HR 0.75, 95% CI 0.55-1.03, P = 0.069), compared with empiric therapy. However, during subgroup analysis significantly improved OS was associated with site-specific therapy in the high-accuracy predictive assay subgroup (HR 0.46, 95% CI 0.26-0.81, P = 0.008) compared with the low accuracy predictive assay subgroup (HR 0.93, 95% CI 0.75-1.15, P = 0.509). Furthermore, compared with patients with less responsive tumor types, more survival benefit from site-specific therapy was found in patients with more responsive tumors (HR 0.67, 95% CI 0.46-0.97, P = 0.037).

Conclusions

Our results suggest that site-specific therapy is not significantly associated with improved survival outcomes; however, it might benefit patients with CUP with responsive tumor types.

•

Studies evaluating the role of site-specific therapy guided by molecular profiling in CUP provided contradictory results.

•

Site-specific therapy is not significantly associated with improved survival outcomes in the overall CUP population.

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Molecularly defined site-specific therapy may improve OS only when high-accuracy assays assign CUP to responsive tumor types.

[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.

[Association between sleep duration and activity of daily living in the elderly aged 65 years and older in China]

Objective: To investigate the association between sleep duration and activity of daily living (ADL) in the elderly aged 65 years and older in China. Methods: A total of 11 247 subjects aged 65 and above were included in the Chinese Elderly Health Factors Tracking Survey from March 29, 2005 to April 8, 2019. Self-made questionnaire was used to collect the data of population sociological characteristics, health status and disease status. ADL status was assessed by basic activities of daily living. The association between sleep duration and ADL impairment was assessed by Cox proportional risk regression model. The dose-response relationship between sleep duration and ADL impairment was analyzed using restricted cubic spline function. Results: The age of the subjects was (79±10) years, including 5 793(51.5%) females. The incidence of ADL impairment was 33.3% (3 747/11 247). Subjects were divided into short, medium, and long sleep groups according to sleep duration of fewer than seven hours, seven to eight hours, or more than eight hours. The number of short, medium and long sleepers was 2 974 (26.4%), 4 922 (43.8%) and 3 351(29.8%), respectively. The intermediate sleep group had the lowest incidence of impaired ADL (4.98/100 person-years). Cox proportional risk regression model analysis showed that: taking the intermediate sleep group as reference, after adjustment of gender, age, marital status, educational level, place of residence, living with family, smoking, drinking, exercise, frequency of fruit consumption, vegetable intake frequency, sleep quality, factors such as hypertension, diabetes, heart disease and cerebrovascular disease, the long sleep time increased the risk of impaired ADL [HR (95%CI): 1.148 (1.062-1.241)]. Subgroup analysis showed a weak positive multiplicative interaction between sleep duration and age [HR (95%CI): 1.004 (1.000-1.009)], but no multiplicative interaction between sleep duration and sex [HR(95%CI): 0.948 (0.870-1.034)]. Longer sleep duration increased the risk of ADL impairment in women [HR (95%CI): 1.195 (1.074-1.329)], but not in men [HR (95%CI): 1.084 (0.966-1.217)]. Longer sleep duration increased the risk of ADL impairment in people aged 80 years and older [HR (95%CI): 1.185 (1.076-1.305)], but not in people younger than 80 years [HR (95%CI): 1.020 (0.890-1.169)]. There was a non-linear dose-response relationship between sleep duration and ADL damage (P=0.007), and the risk of ADL damage was lowest when sleep duration was 7.5 h. Conclusion: Sleep duration was positively correlated with the risk of ADL impairment in the elderly in a nonlinear dose-response relationship.

[Sensitivity and specificity of nucleic acid testing in close contacts of COVID-19 cases in Guangzhou]

Objective: To analyze the sensitivity and specificity of SARS-CoV-2 nucleic acid testing in 20 348 close contacts of COVID-19 cases in different prevention and control stages in Guangzhou and to provide scientific evidence for optimizing epidemic response strategies. Methods: A total of 20 348 close contacts of COVID-19 cases in Guangzhou were traced between February 21 and September 22,2020. All the close contacts were tested for the nucleic acid of SARS-CoV-2. The sensitivity and specificity of nucleic acid testing and diagnosis in the different prevention and control stages were compared. Results: In 20 348 close contacts, 12 462 were males (61.24%), the median (P₂₅,P₇₅) of age of them was 31.0 years (23.0,43.0), the median number (P₂₅,P₇₅) of nucleic acid testing for them was 2.0 (1.0,3.0), and the median (P₂₅,P₇₅) of their quarantine days was 12.0 (8.0,13.0) days, respectively. A total of 256 COVID-19 cases were confirmed in the close contacts after seven nucleic acid tests. In the 1^st, 2^nd, 3^rd and 7^th nucleic acid testing, the sensitivity and specificity were 69.14% and 99.99% (177 cases confirmed), 89.84% and 99.99% (230 cases confirmed), 97.27% and 99.99% (249 cases confirmed), and 100.00% and 99.98%, respectively. In the three stages of COVID-19 prevention and control in China: domestic case stage, imported case stage, and imported case associated local epidemic stage, the sensitivity of the 1^st nucleic acid testing was 70.68%, 68.00% and 67.35%, and the specificity was 99.98%, 100.00% and 100.00%, respectively. Conclusions: The sensitivity of nucleic acid testing in the close contacts at the different stages were consistent with slight decrease, which might be related to the increased proportion of asymptomatic infections in the late stage of epidemic prevention and control with COVID-19 in Guangzhou. It is suggested to give three nucleic acid tests to improve the sensitivity and reduce false negative risk.

[Trend analysis and prediction of colorectal cancer morbidity and mortality of residents in urban areas of Guangzhou from 1972 to 2015]

Objective: To analyze the trend of mortality and incidence of colorectal cancer among urban residents in Guangzhou from 1972 to 2015 and to predict the mortality of colorectal cancer from 2016 to 2025. Methods: The mortality data of colorectal cancer among urban residents in Guangzhou were collected from the death registration of malignant tumors of Guangzhou Health Statistics Bureau (1972-1979), Guangzhou Health Statistics (1980-2001), Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence of colorectal cancer was collected from Guangzhou Cancer Registration Annual Report (2002-2009) and China Cancer Registration Annual Report (2010-2015). The incidence and mortality data of colorectal cancer coded as C18-C21 in 10th Edition of International Classification of Diseases (ICD-10) were obtained from the above data, and the demographic data were from the Guangzhou Municipal Bureau of Statistics. Joinpoint model was used to calculate the annual change percentage (APC) and average annual change percentage (AAPC) of colorectal cancer mortality and incidence among urban residents in Guangzhou from 1972 to 2015 and from 2002 to 2015. ARIMA model was used to predict colorectal cancer mortality from 2016 to 2025. Results: There were 19 309 colorectal cancer deaths among urban residents in Guangzhou from 1972 to 2015. The crude mortality rate of colorectal cancer increased from 4.33/100 000 to 24.89/100 000 (AAPC=4.2%, P<0.001). A total of 24 033 new cases of colorectal cancer were reported in Guangzhou from 2002 to 2015. The crude incidence rate of colorectal cancer increased from 22.95/100 000 to 52.81/100 000 (AAPC=6.6%, P<0.001). The mortality rate of colorectal cancer among urban residents of Guangzhou would continuously increase from 2016 to 2025 and reach 29.53/100 000 in 2025. Conclusion: The mortality rate of colorectal cancer among urban residents of Guangzhou from 1972 to 2015 and the incidence rate of colorectal cancer from 2002 to 2015 both show an upward trend. The mortality rate will increase from 2016 to 2025.

Surgical resection of clinically benign tumours in the maxillomandibular deep lobe of the parotid gland via sternocleidomastoid muscle-parotid space approach

This article reports the surgical resection of clinically benign tumours in the maxillomandibular deep lobe of the parotid gland via sternocleidomastoid muscle-parotid space (SPS) approach. The use of maxillary-mandibular planes to subdivide the deep lobe of the parotid gland in order to establish the tumour location and accessibility is introduced. This approach, which does not raise a skin flap, may preserve the superficial lobe. Ten patients with clinically benign tumours in the maxillomandibular deep lobe of the parotid gland were treated via the SPS approach. The patients were followed up for 3-5 years and the surgical outcomes were analysed. All tumours were completely enucleated via the SPS approach with an optimal aesthetic outcome. No permanent facial weakness or tumour recurrence was identified during the 3-5 years of follow-up. The SPS approach to surgical resection is an ideal option for clinically benign tumours in the maxillomandibular deep lobe of the parotid gland and demonstrates good results.

[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.

[The relationship between resting heart rate and all-cause mortality among the Chinese oldest-old aged more than 80: a prospective cohort study]

Objective: To explore the association between resting heart rate(RHR) and all-cause mortality among the Chinese oldest-old aged more than 80. Methods: Using a total of seven surveys or follow-ups data (1998, 2000, 2002, 2005, 2008, 2011 and 2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 17 886 elderly over 80 years old were selected as subjects, their resting heart rate were measured though baseline survey and the survival outcome and death time of the subjects were followed up. The subjects were divided into 6 groups according to their resting heart rate. Cox regression model was used to estimate the effect of resting heart rate on mortality risk. The interaction of age, gender and resting heart rate was also analyzed by likelihood ratio test. Results: The age of subjects M (P₂₅, P₇₅) was 92 (86, 100) years old, including 10 531 females (58.9%) and there were 13 598 participants died, the mortality rate was 195.5 per 1 000 person-years. Multivariate Cox regression analysis showed that compared to the control group (60-69 pbm/min), the hazard ratio of the elderly are 1.06 (95%CI: 1.02, 1.11), 1.09 (95%CI: 1.04, 1.15), 1.23 (95%CI: 1.14, 1.34), 1.25 (95%CI: 1.08, 1.44) in the group of RHR between 70-79, 80-89, 90-99 and ≥100 pbm/min and P values are all less than 0.05. Likelihood ratio test showed that RHR and age had an interaction effect. (P for interaction=0.011). Conclusion: The risk of all-cause death increased with the increase of resting heart rate and this relationship was stronger between the 80-89 years old people.

Immunogenicity and protective ability of RpoE against Streptococcus suis serotype 2

AIMS

RpoE is quite immunogenic and can be used as a candidate vaccine for Streptococcus suis infection via immunoproteomics as reported in our previous studies. In this study, we aimed to verify the immunogenicity of recombinant RpoE and its protective effect against of S. suis.

METHODS AND RESULTS

The RpoE protein was successfully expressed in Escherichia coli, and the purified recombinant protein was mixed with ISA206 to prepare an S. suis subunit vaccine. Mice were immunized with the RpoE subunit vaccine and then infected with the virulent S. suis strain ZY05719. Subunit vaccine-immunized mice achieved 50% protection, less pathological damage and less bacterial distribution in each organ compared with the control mice. Furthermore, in vitro culture, showed that mouse antisera significantly (P ＜ 0·001) inhibited the growth of S. suis, and qRT-PCR results showed that RpoE successfully induced the up-regulation of IL-6 and TNF-α cytokines.

CONCLUSIONS

RpoE mice were vaccinated to obtain immune protection, which may be candidates for S. suis subunit vaccine.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study will provide new ideas for the development of safe and effective recombinant subunits vaccines for S. suis.

Does the Brown classification of maxillectomy defects have prognostic prediction for patients with oral cavity squamous cell carcinoma involving the maxilla?

The aim of this study was to investigate the correlation between the maxillectomy defect, T stage, and prognosis of patients with maxillary squamous cell carcinoma (SCC). The Brown classification system was used to appraise the maxillectomy defects due to maxillary SCC. The clinical data of 137 patients with maxillary SCC during the period 2000-2010 were reviewed; 105 patients were followed up. Preoperative T stage and postoperative maxillectomy class were recorded. The relationship between the maxillectomy defect class and T stage of maxillary SCC was analysed. Correlations between the maxillectomy defect class, local recurrence rate, and survival rate were assessed using IBM SPSS Statistics v19.0. The most common maxillectomy defect class was IIb (54.7%, 75/137). The maxillectomy defect class was significantly associated with the T stage (P < 0.001). Both T stage and the maxillectomy defect class were significantly associated with the survival rate of patients with maxillary SCC (both P< 0.001). In conclusion, the class of the maxillectomy defect was found to be associated with the T stage. Both of these were prognostic factors for patients with maxillary SCC. The class of the maxillectomy defect is suitable for clinical application in predicting the prognosis compared with T stage.

[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.

[Historical perspective of progress and achievement on epidemiology in the past 70 years in China]

Epidemiology is a discipline developed in the practice of preventing diseases and promoting health and is the key of public health and preventive medicine. Since the founding of the People's Republic of China, with the changing of disease pattern in populations, the applications of epidemiology now have expanded from infectious diseases to chronic non-communicable diseases, injuries and health related events. The discipline has made remarkable achievements in the field of disease prevention and control, scientific research and teaching, institution building and academic journals. In this paper we briefly review the history and achievements of epidemiology in China in the past 70 years, and explore the future development of the discipline, which may leave a trace of history for the development of epidemiology in China.

[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.

[The relationship between hazard ratio and median survival time]

The hazard ratio and median survival time are the routine indicators in survival analysis. We briefly introduced the relationship between hazard ratio and median survival time and the role of proportional hazard assumption. We compared 110 pairs of hazard ratio and median survival time ratio in 58 articles and demonstrated the reasons for the difference by examples. The results showed that the hazard ratio estimated by the Cox regression model is unreasonable and not equivalent to median survival time ratio when the proportional hazard assumption is not met. Therefore, before performing the Cox regression model, the proportional hazard assumption should be tested first. If proportional hazard assumption is met, Cox regression model can be used; if proportional hazard assumption is not met, restricted mean survival times is suggested.

Two sphingomyelin synthase homologues regulate body weight and sphingomyelin synthesis in female brown planthopper, N. lugens (Stål)

Although sphingomyelins known to be are lipid constituents of the plasma membrane in vertebrates, much remains obscure about the metabolism of sphingomyelins in insects. With ultra performance liquid chromatography-time-of-flight-tandem mass spectrometry analysis, we revealed for the first time that sphingomyelins are abundant in Nilaparvata lugens (Stål), the brown planthopper (BPH), and their biosynthesis is carried out by sphingomyelin synthase-like protein 2 (SMSL2), which is homologous to sphingomyelin synthase-related protein (SMSr). Unlike other insect species, high concentrations of sphingomyelins rather than ceramide phosphoethanolamines exist in the BPH. Two putative genes, which are homologous to SMSr, are named Nilaparvata lugens SMS-like 1 (NlSMSL1) and 2 (NlSMSL2). Knockdowns of both NlSMSL2 and NlSMSL1 were conducted but only the first decreased concentrations of sphingomyelins in the BPH, indicating that NlSMSL2 plays a role in the biosynthesis of sphingomyelins. Real-time quantitative PCR analysis revealed both NlSMSL1 and NlSMSL2 are highly expressed in BPH adults, with NlSMSL1 specifically highly expressed in reproductive organs (ovaries and testes) whereas NlSMSL2 was highly expressed in the malpighian tubules. The knockdown of NlSMSL1 or NlSMSL2 increased BPH female body weight but not that of males, suggesting sex-specific roles for SMSLs in influencing BPH body weight. The results suggest that NlSMSL2 catalyses the synthesis of sphingomyelins and maintains female BPH body weight through alteration of sphingolipid content.

[The Correlation Analysis of Turnover Intention,Moral Distress and Stressor in Nurses]

Objective: To explore the turnover intention of nurses in Quzhou and its influential factors. Methods: From July to August in 2017 cross-sectional study and self-filled questionnaire are used to investigate 980 nurses from 7 hospitals in Quzhou, including two third-level hospitals and five second-level ones. T-test, F-test, Pearson and linear regression are used in data with the method of statistical analysis. Results: The total score of turnover intention of nurses was (14.95±3.17) points, and the index value was 62.27%, of which the turnover intention was above 78%. The analysis of Single factor showed that age (F=4.895) , Department (F=2.971) , title, nursing age (F=5.863) , self-assessment of physical conditions (F=4.092) were closely related to nurses' turnover intention(P<0.05). According to Person's correlation analysis, there are positive correlations between turnover intention and source of stressor, and moral distress (P<0.05) . Multiple linear regression showed that the nurses' turnover intention was age, Department, health selfevaluation, stressor and moral distress. Conclusion: The turnover intention of nurses is high, which is related to age, Department, self-evaluation of health, stressor and moral distress.

Comparison of the subjective satisfaction of the donor site morbidity: Free radial forearm flap versus anterolateral thigh flap for reconstruction in tongue cancer patients

BACKGROUND

The purpose of the study was to compare the differences of the subjective satisfaction of the donor site morbidity between the free radial forearm flap (FRFF) and anterolateral thigh flap (ALTF) for tongue reconstruction.

MATERIAL AND METHODS

One hundred and nineteen patients underwent FRFF or ALTF reconstruction were retrospectively evaluated by a standardized self-established donor site morbidity questionnaire which included 5 domains, sensibility, movement disabilities, cosmetics, social activities and general impacts on the quality of life.

RESULTS

The Cronbach's coefficient alpha of the questionnaire was 0.707. The exploratory factor analysis revealed that the 5 items of the questionnaire might load onto two distinct subscales. Patients with ALTF had higher scores in the sensibility, cosmetics and the composite score (P < 0.05). No significant differences were found in the movement disabilities, social activities and general impacts on the quality of life between the two groups (P > 0.05).

CONCLUSIONS

ALTF has the advantage of better results of donor site morbidity, such as sensibility and cosmetics, over FRFF.

[Multimodal image fusion technology for diagnosis and treatment of the skull base-infratemporal tumors]

OBJECTIVE

To explore the value of incorporated multimodal image fusion technology with computer-aided design of the skull base-infratemporal tumor treatment.

METHODS

A retrospective study was carried out to enroll seventeen patients with skull base-infratemporal tumors treated at Peking University Hospital of Stomatology from February 2011 to September 2018. Plain CT, enhanced CT and MRI data were imported into the iPlan 3.0 software (BrainLab navigation system), and the image fusion was performed for each patient preoperatively. Then the three-dimensional images of the tumor, vital vessels and craniofacial bones were reconstructed to prepare virtual operation design. We evaluated the application of multimodal image fusion technology that had been incorporated with computer-aided planning during the navigation-guided biopsy or surgery, through the analysis of the biopsy and operation data and regular follow-up postoperatively.

RESULTS

The mean age of 17 patients (7 males and 10 females) was 46 years. Primary tumors occurred in 11 cases, and recurrent tumors in 6 cases. The size of the 17 tumors ranged from 2.9 cm to 9 cm, and the mean size was 4.35 cm. There were 7 cases with skull base bone destruction and/or intracranial extension, and 10 cases with tumors adjacent to the skull base. High-quality multimodal fused images were obtained in all the 17 cases. The spatial-position relationships of the tumors, adjacent craniomaxillofacial bones and vital vessels labeled with different colors were displayed well on the generated fusion images. The multimodal image fusion technology that incorporated with computer-aided three-dimensional reconstruction and then applied in navigation-guided biopsy or surgery showed that, preoperative analysis and virtual operation design functioned with good results, especially in cases with small tumor size, recurrence or illdefined borders in the skull base-infratemporal region. Operation was carried out in 16 cases after preoperative diagnosis and assessment, and 1 case was performed by navigation-guided biopsy only. The proportions of navigation-guided surgery and biopsy were 70.6% (12/17) and 17.6% (3/17) individually. The positive rate of pathologic diagnosis using navigation-guided biopsy was 100% (3/3). All the navigation-guided biopsies or operations were carried out successfully. Complications included 1 case of cerebrospinal fluid leak from a recurred meningioma patient postoperatively, and 1 case of facial paralysis resulting from parotid-gland deep lobe tumor. Most (14/15) tumors got complete removal with safe boundary through intra-operative navigation verification and post-operative imaging confirmation, except for one case of subtotal resection to avoid the injury of cavernous sinus. The pathological results of the tumors could be classified to mesenchymal (10), adenogenous (3), neurogenic (3) or epithelial (1) resources. The follow-up time ranged from 3 to 94 months, with the median follow-up time of 9 months.

CONCLUSION

Taking full advantages of individualized multimodal images, could help analyze the three-dimensional spatial position relationship of tumors, vital vessels and craniofacial bones properly, and then complete the virtual operation design well. The incorporated multimodal image fusion technology with navigation technology may improve the accuracy and safety of core needle biopsy and surgical treatment of skull base-infratemporal tumors.

Are antithrombotic agents necessary for head and neck microvascular surgery?

The aim of this prospective study was to determine the effect of antithrombotic agents in preventing thrombosis after head and neck reconstructive surgery. A randomized clinical trial of referred patients undergoing free flap surgery between February 2015 and July 2017 was conducted. Four hundred and fifty-four patients were randomly assigned to group A (n=153), administered aspirin and low molecular weight dextran; group B (n=150), administered low molecular weight heparin; and group C (n=151), not administered any antithrombotic agent. Patient demographic characteristics, donor site, thrombosis, haematoma, and flap failure were recorded. Coagulation values including platelet count, prothrombin time, and activated partial thromboplastin time were measured during the perioperative period. Repeated-measures ANOVA and the χ² test were used for data comparisons. No significant inter-group differences were observed for postoperative microvascular thrombosis (P=0.536) or flap failure (P=0.615) among the three groups. There were more postoperative haematoma revisions in group B than in groups A and C (P=0.032). It is concluded that postoperative antithrombotic agents neither provide a significant improvement in the free flap success rate nor decrease the risk of thrombosis and may increase the risk of haematoma.

Biochemical and histological alterations in adult zebrafish（Danio rerio）ovary following exposure to the tetronic acid insecticide spirotetramat

As a new tetronic acid derivative insecticide, spirotetramat has been reported to be toxic to an array of aquatic organisms. However, the toxic effects of spirotetramat on zebrafish especially at ovary are still obscure. Hereby, the acute toxicity of spirotetramat towards zebrafish（Danio rerio），as well as the changes on biochemical and histological traits of ovary were investigated. The acute toxicity test results showed that the median lethal concentration (LC₅₀) value of spirotetramat were 9.61 mg/L and 7.21 mg/L at 72 h and 96 h, respectively, suggesting spirotetramat has moderate toxicity to zebrafish. In the following sub-lethal toxicity test, the gene expression of superoxide dismutase (SOD), catalase (CAT), and gonadotropic hormone receptor (FSHR and LHR) together with the content of malondialdehyde (MDA) in ovary were measured at 14, 21, and 28 days after exposure to 36, 360 and 720 μg/L. Under high concentration treatment (360 and 720 μg/L), MDA content, the relative transcription CAT and SOD gene level increased significantly in ovary (p < 0.05). That indicated sub-lethal doses spirotetramat caused oxidative stress and lipid peroxidation in zebrafish ovary during the entire experimental period. Under the exposure to spirotetramat at 720 μg/L after 14 days, the relative transcript FSHR gene level was down regulated, and the relative transcript LHR gene level was up regulated. Moreover, spirotetramat affected the oocyte development especially on the diameter size and maturation during the ovary tissue biopsies at 28 days. Taken together, these findings revealed the adverse effects of spirotetramat on fish from the biochemical and histological aspects.

Capturing intracellular oncogenic microRNAs with self-assembled DNA nanostructures for microRNA-based cancer therapy

Aberrantly overexpressed oncogenic microRNAs (miRNAs, miRs) are excellent targets for therapeutic interventions.

Aberrantly overexpressed oncogenic microRNAs (miRNAs, miRs) are excellent targets for therapeutic interventions. Nevertheless, thus far, little progress has been made in developing miRNA-based drugs and techniques for clinical applications, especially for overexpressed miRNAs. In this study, we demonstrate that self-assembled DNA nanostructures bearing multiple DNA sequences that are complementary to a target miRNA can effectively capture the overexpressed oncogenic miRNA and subsequently inhibit cancer cell proliferation. Specifically, a DNA nanotube structure that carries functional DNA segments (single-stranded, duplex and hairpin forms) was designed and synthesized to capture two well-known overexpressed miRNAs, miR-21 and miR-155. It was found that all three DNA nanotubes significantly reduced both miRNA levels and inhibited cancer cell growth. Moreover, the capture efficiency was highly concentration dependent and was associated with the structural design of the DNA nanotube. These results demonstrate that through careful design, programmable DNA nanostructures can hijack the natural cellular machinery and can serve as nucleic acid drugs themselves. The concept of using self-assembled DNA nanostructures to disrupt the intracellular machinery for therapeutic purposes opens a new paradigm for exploiting self-assembled DNA nanostructures for miRNA-based anticancer therapy.

Non-vascularised fibular bone graft after vascular crisis: compensation for the failure of vascularised fibular free flaps

After reconstruction of a segmental mandibular defect with a fibular free flap, a vascular crisis can be detected clinically and a "no-flow" phenomenon found during re-exploration. Traditional methods used to solve this include removal of the failed flap and delayed mandibular reconstruction, or restoration of the defect with a functional reconstruction plate or contralateral fibular free flap. Our aim therefore was to investigate under what circumstances it is feasible to use a non-vascularised fibular bone graft (NVFB) as a free bone graft after the failure of a vascularised fibular free flap. From 1 January 2010-31 December 2014, 10 patients who had NVFB after failure of a fibular free flap were included in the study. All patients were treated at the Peking University School and Hospital of Stomatology. NVFB were preserved successfully without infection in all 10 cases, and follow-up imaging showed that it had incorporated well with the residual mandible, the basic function and facial aesthetics of which were maintained. In conclusion we have identified that by precise selection of patients, detailed preoperative planning, and meticulous postoperative care, NVFB can be used as a "rescue" technique after failure of a fibular free flap, and can successfully restore the segmental mandibular defect and facial contour.

[Comorbidity in oral squamous cell carcinoma patients: an initial research in Beijing area]

Objective: To make a preliminery research of comobidity in oral squamous cell carcinoma (OSCC) patients who resides in Beijing area and investigate whether comorbidity affect the surviving rate independently. Compare the similarities and differences between Chinese and foreign OSCC patients. Methods: The medical records of 313 patients who undertaken operation in Peking University Stomatology School from January 2007 to Delember 2009 were retrospectively reviewed. Adult comorbidity evaluation-27 Chinese edition index was used to estimate the comorbidity severity. COX proportional hazards model was used to analyze whether the TNM stage, comobidity, age and gender affected 5-year survival rate. Results: TNM stage and comorbidity have a significant impact on survival rate, the postoperative survival rate decreased significantly with the increasing level of TNM staging and the complexity of comorbidity disease. In this study, the proportion of patients with none, mild, moderate and severe comorbidity diseases was 24%, 48%, 18% and 10%. The five-year survival rates of patients with moderate and severe comorbidity disease were 50% (29/58) and 13% (4/30) respectively. Conclusions: The comorbidity disease information can help assess the overall health of OSCC patients, and it is recommended to improve the clinical staging and overall evaluation of oral cancer patients with comorbidity disease information.

[Clinical analysis of cervical lymph node metastasis of cN0 maxillary malignant tumor]

OBJECTIVE

To investigate the cervical lymphatic metastasis rates of clinically negative neck lymph node (cN0) maxillary malignant tumors, to compare the cervical lymphatic metastasis rates of the various pathological types, and to provide the reference for the treatment of the neck of the patients with cN0 maxillary malignant tumor.

METHODS

The clinical data of 277 cases with cN0 maxillary malignant tumor, treated in the department of oral and maxillofacial surgery of Peking University School and Hospital of Stomatology from 1990 to 2010, were reviewed. The cervical lymph node metastasis and the related clinical information were recorded. The clinical information including histopathology type of the tumors, tumor grade, primary site and TNM staging, as well as other demographic and clinical data, were retrieved from the electronic medical record system (EMRS) of the hospital. The pathogenesis of cervical lymph node metastasis in maxillary malignant tumors of different histopathological types, and the factors related to lymph node metastasis of upper cervical malignancy were analyzed by SPSS 19.0 statistical software.

RESULTS

The overall cervical lymph node metastasis rate of the 277 patients with cN0 maxillary malignant tumor was 15.5% (43/277). Maxillary squamous cell carcinoma (SCC) had a strong cervical lymph node metastasis tendency and the rate was 33.0%. The overall metastatic rate of adenocarcinoma was 7.6% lower than that of SCC, and the occurrence of cervical lymph node metastasis time was relatively late, but the metastasis rate of highly malignant grade salivary gland carcinoma was significantly higher than that of intermediate and low grade carcinoma (P=0.037). The metastatic rates of some highly malignant cN0 salivary gland carcinomas including adenocarcinoma, not other specified, high-grade mucoepidermoid carcinoma (MEC), and salivary duct carcinoma were exceeded 15%, while the metastasis rates of adenoid cystic carcinoma and myoepithelial carcinoma were lower. The metastasis rate of the sarcomas was very low with the rate of 4.9%.

CONCLUSION

Selective neck dissection (SND) is recommended for cN0 maxillary SCC and feasible for some highly malignant cN0 salivary gland carcinomas including adenocarcinoma, not other specified, high-grade MEC, salivary duct carcinoma. The neck can be closely observed for the patients with maxillary sarcoma.

[The use and pitfalls of large randomized controlled trials]

Modern epidemiology is the art and science of investigating quantitatively regularities or general laws regarding applied healthcare issues. The validity of epidemiological studies is primarily determined by the study design and the precision by the sample size. Large randomized controlled trial (RCT) is thus the most rigorous and most precise epidemiological study design. Due to ethical concerns, RCTs can however be used only to evaluate medical interventions. Rigorousness of study design and sample size required for a study are inversely related to the anticipated size of effect to be evaluated: the smaller the effect, the more rigorous the study design and larger the sample size are required. Thus, large RCTs are necessary and called upon when and only when the effectiveness to be proved is relatively small; large effectiveness can be verified with small or medium-sized RCTs or even observational studies. In the stages of scientific research, large RCTs are confirmatory rather than original investigations on new hypotheses, whereas the value of a study is ultimately determined by the importance and novelty of the research question rather than methodology and the P value. Overemphasis on large RCTs has been causing: 1) overemphasis on interventions of small or moderate effect; 2) overemphasis on confirmatory studies and on size of study and funding and weakening original creative work; 3) increasing the risk of research resources, medical activities, and patients' well-being being hijacked by pharmaceutical companies.

Identification and characterization of Laodelphax striatellus (Insecta: Hemiptera: Delphacidae) neutral sphingomyelinase

The neutral sphingomyelinase (nSMase) 1 homologue gene LsSMase was cloned from Laodelphax striatellus, a direct sap-sucker and virus vector of gramineous plants, and expressed via a Bac to Bac baculovirus expression system. The LsSMase-enhanced green fluorescent protein fusion protein was located in the endoplasmic reticulum in a similar manner to mammalian nSMase 1. The biochemical properties of LsSMase were determined in detail. The optimal pH and temperature for recombinant LsSMase were 8 and 37 °C, respectively. LsSMase was an Mg²⁺ or Mn²⁺ dependent enzyme, but different concentration of each were needed. The activity of LsSMase was significantly stimulated by Ethylene glycol bis(2-aminoethyl ether)tetraacetic acid (EGTA), whereas it was inhibited by ethylenediaminetetraacetic acid. Millimolar concentrations of Zn²⁺ completely inhibited LsSMase. The reducing agents dithiothreitol and β-mercaptoethanol varied in their effects on activity. Phospholipids were not found to stimulate LsSMase.

[Surgical reconstruction of maxillary defects using a computer-assisted techniques]

The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate diagnosis and treatment of maxillary tumor; (2) Maxillary reconstruction with free fibula flap used computer assisted techniques; (3) Computer assisted orbital floor reconstruction after maxillectomy. The results suggested that computer assisted techniques could significantly improve the clinical outcome of maxillary reconstruction.

Experiments of a monolithic radial transmission line

This paper presents the experimental results of a monolithic radial transmission line (MRTL) that may be used in pulsed power generators and microwave devices. The MRTL with a hyperbolic impedance profile is 508 mm in radius, corresponding to a one-way transit time of 15 ns for the electromagnetic wave. In the experiments, up to twenty identical voltage pulses, 10 ns in FWHM and 2 ns in rise-time, were fed into the MRTL through 20 input BNC connectors that are uniformly distributed along the outer circumference of the MRTL. It was found that the amplitude of the voltage from the output BNC connector located in the center of the MRTL is nearly proportional to the total number of the input branches. The effect of the failure modes on the output voltage was investigated. For the MRTL driven by 20 input branches, while the open-circuit or short-circuit even in one input branch considerably decreases the amplitude of the output voltage, the jitter shorter than 2 ns in 3 input branches makes no obvious effect on the output voltage.

Systematic review with meta-analysis: the gastrointestinal benefits of COX-2 selective inhibitors with concomitant use of low-dose aspirin

BACKGROUND

It is uncertain whether concurrent use of low-dose aspirin removes the gastrointestinal benefit displayed by COX-2 selective inhibitors (coxibs) when compared to traditional nonsteroidal anti-inflammatory drugs (NSAIDs).

AIM

To evaluate the gastrointestinal risks associated with coxibs and traditional NSAIDs and the interaction with concurrent use of low-dose aspirin.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library through April 2016 to identify randomised trials comparing the gastrointestinal risk between coxibs and traditional NSAIDs in patients taking or not taking low-dose aspirin. Results were combined using random effects meta-analysis. Subgroup analyses by concurrent use of aspirin were undertaken.

RESULTS

Eleven trials (84 150 participants) were included. The overall relative risk (RR) of coxibs vs. traditional NSAIDs for complicated gastrointestinal events was 0.54 (95% CI, confidence interval 0.32-0.92), with a significant subgroup difference (P = 0.04) according to concurrent use of aspirin (used: RR = 0.96, 95% CI 0.66-1.24; not used: RR = 0.33, 95% CI 0.14-0.83). The overall RR for clinical gastrointestinal events was 0.59 (95% CI 0.47-0.75), with a significant subgroup difference according to aspirin usage (P = 0.008; used: RR = 0.77, 95% CI 0.62-0.95; not used: RR = 0.50, 95% CI 0.39-0.64). Overall coxibs were associated with significantly lower risk of symptomatic ulcers (RR = 0.60, 95% CI 0.50-0.72) and endoscopic ulcers (RR = 0.29, 95% CI 0.16-0.53) than traditional NSAIDs; a significant subgroup difference was shown for endoscopic ulcers (P = 0.05) but not for symptomatic ulcers (P = 0.27).

CONCLUSION

Concomitant use of low-dose aspirin reduces but does not completely eliminate the gastrointestinal benefit of coxibs over traditional NSAIDs.

Systematic review with network meta-analysis: comparative effectiveness and safety of strategies for preventing NSAID-associated gastrointestinal toxicity

BACKGROUND

Many strategies are used to prevent nonsteroidal anti-inflammatory drug (NSAID)-associated gastrointestinal toxicity, but the comparative effectiveness remains unclear.

AIM

To evaluate the comparative effectiveness of clinical strategies for preventing gastrointestinal toxicity induced by NSAIDs.

METHODS

MEDLINE, EMBASE and the Cochrane Library (from their inception to May 2015) were searched for randomised controlled trials comparing the risk of gastrointestinal adverse events in patients taking nonselective NSAIDs, selective cyclooxygenase(COX)-2 inhibitors or nonselective NSAIDs/COX-2 inhibitors plus gastroprotective agents [proton pump inhibitors (PPIs), histamine-2 receptor antagonists, misoprostol]. Both pairwise meta-analysis and Bayesian network meta-analysis were performed.

RESULTS

Analyses were based on 82 trials including 125 053 participants. Network meta-analysis demonstrated that selective COX-2 inhibitors + PPIs [Risk ratio (RR), 95% Credible Interval (CrI): ulcer complications 0.07, 0.02-0.18], selective COX-2 inhibitors (RR, 95% CrI: ulcer complications 0.25, 0.15- 0.38; symptomatic ulcer 0.12, 0.04-0.30), nonselective NSAIDs + PPIs (RR, 95% CrI: ulcer complications 0.28, 0.18-0.41; symptomatic ulcer 0.11, 0.04-0.23), nonselective NSAIDs + misoprostol (RR, 95% CrI: ulcer complications 0.47, 0.24-0.81; symptomatic ulcer 0.41, 0.13-1.00) were associated with significantly lower risk of clinical gastrointestinal events compared with nonselective NSAIDs. For all effectiveness endpoints, selective COX-2 inhibitors + PPIs was associated with the lowest absolute event probability and the highest rank, followed by selective COX-2 inhibitors and thirdly by nonselective NSAIDs + PPIs.

CONCLUSION

The combination of selective COX-2 inhibitors plus PPIs provides the best gastrointestinal protection, followed by selective COX-2 inhibitors, and thirdly by nonselective NSAIDs plus PPIs.

Note: A novel method for generating multichannel quasi-square-wave pulses

A 21-channel quasi-square-wave nanosecond pulse generator was constructed. The generator consists of a high-voltage square-wave pulser and a channel divider. Using an electromagnetic relay as a switch and a 50-Ω polyethylene cable as a pulse forming line, the high-voltage pulser produces a 10-ns square-wave pulse of 1070 V. With a specially designed resistor-cable network, the channel divider divides the high-voltage square-wave pulse into 21 identical 10-ns quasi-square-wave pulses of 51 V, exactly equal to 1070 V/21. The generator can operate not only in a simultaneous mode but also in a delay mode if the cables in the channel divider are different in length.