Major lipids and lipoprotein levels and risk of blood pressure elevation: a Mendelian Randomisation study.

BACKGROUND: Quantitative nuclear magnetic resonance (NMR) metabolomics techniques provide detailed measurements of lipoprotein particle concentration. Metabolic dysfunction often represents a cluster of conditions, including dyslipidaemia, hypertension, and diabetes, that increase the risk of cardiovascular diseases (CVDs). However, the causal relationship between lipid profiles and blood pressure (BP) remains unclear. We performed a Mendelian Randomisation (MR) study to disentangle and prioritize the potential causal effects of major lipids, lipoprotein particles, and circulating metabolites on BP and pulse pressure (PP). METHODS: We employed single-nucleotide polymorphisms (SNPs) associated with major lipids, lipoprotein particles, and other metabolites from the UK Biobank as instrumental variables. Summary-level data for BP and PP were obtained from the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. Two-sample MR and MR Bayesian model averaging approaches (MR-BMA) were conducted to analyse and rank causal associations. FINDINGS: Genetically predicted TG was the most likely causal exposure among the major lipids to increase systolic blood pressure (SBP) and diastolic blood pressure (DBP), with marginal inclusion probabilities (MIPs) of 0.993 and 0.847, respectively. Among the majority of lipoproteins and their containing lipids, including major lipids, genetically elevated TG in small high-density lipoproteins (S_HDL_TG) had the strongest association with the increase of SBP and DBP, with MIPs of 0.416 and 0.397, respectively. HDL cholesterol (HDL_C) and low-density lipoprotein cholesterol (LDL_C) were potential causal factors for PP elevation among the major lipids (MIP = 0.927 for HDL_C and MIP = 0.718 for LDL_C). Within the sub-lipoproteins, genetically predicted atherogenic lipoprotein particles (i.e., sub-very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and LDL particles) had the most likely causal impact on increasing PP. INTERPRETATION: This study provides genetic evidence for the causality of lipids on BP indicators. However, the effect size on SBP, DBP, and PP varies depending on the lipids' components and sizes. Understanding this potential relationship may inform the potential benefits of comprehensive management of lipid profiles for BP control. FUNDING: Key Research and Development Program of Hubei Province, Science and Technology Innovation Project of Huanggang Central Hospital of Yangtze University, the Hubei Industrial Technology Research Institute of Heart-Brain Diseases, and the Hubei Provincial Engineering Research Centre of Comprehensive Care for Heart-Brain Diseases.

Prevalence and trend of atrial fibrillation and its associated risk factors among the population from nationwide health check-up centers in China, 2012-2017.

Background: Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, which poses huge disease burdens in China. A study was conducted to systematically analyze the recent prevalence trend of AF and age-related disparities in AF risk among the nationwide healthy check-up population. Method: We conducted a nationwide cross-sectional study involving 3,049,178 individuals ≥35 years from health check-up centers to explore the prevalence and trend of AF by age, sex, and region from 2012 to 2017. Additionally, we analyzed risk factors associated with AF among the overall population and different age groups via the Boruta algorithm, the LASSO regression, and the Logistic regression. Result: The age-, sex-. and regional-standardized prevalence of AF kept stable between 0.4%-0.45% among national physical examination individuals from 2012 to 2017. However, the prevalence of AF showed an undesirable upward trend in the 35-44-year age group (annual percentage changes (APC): 15.16 [95%CI: 6.42,24.62]). With increasing age, the risk of AF associated with the overweight or obesity gradually exceeds that associated with diabetes and hypertension. In addition to traditional leading risk factors such as age≥65 and coronary heart disease, elevated uric acid and impaired renal function were tightly correlated with AF in the population. Conclusion: The significant rise in the prevalence of AF in the 35-44 age group reminds us that in addition to the elderly (the high-risk group), younger people seem to be in more urgent need of attention. Age-related disparities in AF risk also exist. This updated information may provide references for the national prevention and control of AF.

The global disease burden attributable to a diet low in fibre in 204 countries and territories from 1990 to 2019.

OBJECTIVE: The relationship of a diet low in fibre with mortality has not been evaluated. This study aims to assess the burden of non-communicable chronic diseases (NCD) attributable to a diet low in fibre globally from 1990 to 2019. DESIGN: All data were from the Global Burden of Disease (GBD) Study 2019, in which the mortality, disability-adjusted life-years (DALY) and years lived with disability (YLD) were estimated with Bayesian geospatial regression using data at global, regional and country level acquired from an extensively systematic review. SETTING: All data sourced from the GBD Study 2019. PARTICIPANTS: All age groups for both sexes. RESULTS: The age-standardised mortality rates (ASMR) declined in most GBD regions; however, in Southern sub-Saharan Africa, the ASMR increased from 4·07 (95 % uncertainty interval (UI) (2·08, 6·34)) to 4·60 (95 % UI (2·59, 6·90)), and in Central sub-Saharan Africa, the ASMR increased from 7·46 (95 % UI (3·64, 11·90)) to 9·34 (95 % UI (4·69, 15·25)). Uptrends were observed in the age-standardised YLD rates attributable to a diet low in fibre in a number of GBD regions. The burden caused by diabetes mellitus increased in Central Asia, Southern sub-Saharan Africa and Eastern Europe. CONCLUSIONS: The burdens of disease attributable to a diet low in fibre in Southern sub-Saharan Africa and Central sub-Saharan Africa and the age-standardised YLD rates in a number of GBD regions increased from 1990 to 2019. Therefore, greater efforts are needed to reduce the disease burden caused by a diet low in fibre.

Neoadjuvant Chemoimmunotherapy for the Treatment of Locally Advanced Head and Neck Squamous Cell Carcinoma: A Single-Arm Phase 2 Clinical Trial.

PURPOSE: This study aimed to assess the antitumor activity and safety of neoadjuvant chemotherapy combined with PD-1 inhibitor camrelizumab in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: In this single-center, single-arm, phase 2 trial, patients with resectable stage III-IVB HNSCC received chemotherapy [albumin-bound paclitaxel 260 mg/m2 (or docetaxel 75 mg/m2) plus cisplatin 75 mg/m2] and camrelizumab 200 mg on day 1 of each 21-day cycle for three cycles, followed by surgery, and adjuvant radiotherapy. Co-primary end points were pathological complete response (pCR) rate and safety. RESULTS: Thirty patients were enrolled and completed the neoadjuvant therapy, with an objective response rate (ORR) of 96.7% (29/30). Twenty-seven patients underwent surgery without delay, with an R0 resection rate of 92.6% (25/27). The clinical to pathological downstaging rate was 100% (27/27). The pCR rate was 37.0% [95% confidence interval (CI), 19.4%-57.6%], and the major pathological response (MPR) rate was 74.1% (95% CI, 53.7%-88.9%). The median follow-up duration was 16.1 months (range, 8.3-28.5), and the disease-free survival rate at 12 months was 95.8% (95% CI, 73.9%-99.4%). Grade 3 neoadjuvant therapy-related adverse events included rash (1; 3.3%), pruritis (1; 3.3%), and thrombocytopenia (1; 3.3%), and no grade 4 or 5 treatment-related events occurred. The most common surgical complication was delayed wound healing (5; 18.5%). CONCLUSIONS: Neoadjuvant chemotherapy plus camrelizumab for locally advanced HNSCC showed high ORR, pCR, and MPR rates, with an acceptable safety profile. These data support further evaluation of neoadjuvant chemoimmunotherapy for the treatment of locally advanced HNSCC.

A Bidirectional Relationship Between Hyperuricemia and Metabolic Dysfunction-Associated Fatty Liver Disease.

BACKGROUND AND AIMS: Metabolic dysfunction-associated fatty liver disease (MAFLD) is a newly emerged term that is suggested to better reflect the pathogenesis of nonalcoholic fatty liver disease (NAFLD); however, the association between hyperuricemia and MAFLD has not been explored in the Chinese population. Meantime, this study also examined the temporal relationship between the two entities in a longitudinal cohort. METHODS: We conducted a retrospective cross-sectional study including 1,587,962 individuals from 19 health check-up centers in China from 2009-2017 and a longitudinal study with 16,112 individuals. A logistic regression model was applied to determine the association between hyperuricemia and MAFLD in a cross-sectional study. The Cox regression model was used to explore the association between hyperuricemia at baseline and subsequent onset of MAFLD or the association between the presence of MAFLD at baseline and the subsequent incidence of hyperuricemia. The cross-lagged analysis was applied to exam the temporal relationship between hyperuricemia and MAFLD. RESULTS: In the cross-sectional study, hyperuricemia showed a strong positive association with MAFLD after controlled potential confounders. In the longitudinal cohorts, hyperuricemia at baseline was associated with the new-onset of MAFLD, with a hazard ratio (HR) of 1.765 (95% CI: 1.512, 2.060). Interestingly, baseline MAFLD was also associated with the subsequent incidence of hyperuricemia, with an HR of 1.245 (95% CI: 1.106, 1.400). The cross-lagged path analysis revealed a bidirectional relationship between hyperuricemia and MAFLD. CONCLUSIONS: The results suggested that hyperuricemia and MAFLD form a vicious cycle, resulting in more deterioration of metabolic status.

Global death burden and attributable risk factors of peripheral artery disease by age, sex, SDI regions, and countries from 1990 to 2030: Results from the Global Burden of Disease study 2019.

BACKGROUND AND AIMS: Peripheral artery disease (PAD) is a prevalent cardiovascular disease. Understanding current and future disease burden of PAD and its attributable risk factors is critical for developing prevention measures targeting PAD and associated complications. METHODS: We analyzed the death burden of PAD and the trends of six risk factors from 1990 to 2019 using the updated 2019 Global Burden of Disease study database, and projected the next decade death burden using a Bayesian age-period-cohort (BAPC) model. RESULTS: The global age-standardized mortality rate (ASMR) of PAD has a modest downward trend from 1990 to 2019. Regionally, ASMRs in higher-sociodemographic index (SDI) areas remained more remarkable than in lower-SDI areas by 2019, while the rate of increase in death burden in the lower-SDI regions increased rapidly over time. ASMR in males was greater than in females. In the population aged older than 40 years, the sex difference in PAD-associated mortality decreased with age. High fasting plasma glucose (FPG) became the primary risk factor for PAD-related death. The contributions of risk factors to PAD-related death varied by age group. Kidney dysfunction was the primary contributor to PAD-related death in people aged 40-59 years, particularly in women. CONCLUSIONS: The global death burden of PAD has not substantially decreased over the three decades. There are large variations in the trend of PAD mortality and its attributable risk factors by SDI regions, sex, and age group. Targeted and effective strategies are needed for the management of PAD-related mortality in specific subgroups.

High Remnant Cholesterol Level Potentiates the Development of Hypertension.

Background: Emerging evidence suggests an association between remnant cholesterol (RC) and vascular damage and hypertension. However, this association has not been explored in a large-scale population in China, and a temporal relationship between RC and hypertension also needs to be investigated. Methods: We conducted a retrospective cross-sectional study in 2,199,366 individuals and a longitudinal study in 24,252 individuals with repeated measurements of lipid profile and blood pressure in at least a 3-year follow-up. The logistic model was used to explore the association between lipid components and hypertension in the cross-sectional analysis. The Cox model was used to analyze the association between high RC (HRC) at baseline and the subsequent incidence of hypertension or the association between hypertension at baseline and incidence of HRC. The cross-lagged panel model was applied to analyze the temporal relationship between RC and hypertension. Results: RC level as a continuous variable had the highest correlation with hypertension among lipid profiles, including RC, low-density lipoprotein cholesterol, total cholesterol, non-high-density lipoprotein cholesterol, and triglycerides, with an odds ratio of 1.59 (95% confidence interval: 1.58-1.59). In the longitudinal cohort, HRC at baseline was associated with incident hypertension. We further explored the temporal relationship between RC and hypertension using the cross-lagged analysis, and the results showed that RC increase preceded the development of hypertension, rather than vice versa. Conclusions: RC had an unexpected high correlation with the prevalence and incidence of hypertension. Moreover, RC increase might precede the development of hypertension, suggesting the potential role of RC in the development of hypertension.

Risk factors for COVID-19 progression and mortality in hospitalized patients without pre-existing comorbidities.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pandemic continues to escalate intensively worldwide. Massive studies on general populations with SARS-CoV-2 infection have revealed that pre-existing comorbidities were a major risk factor for the poor prognosis of COVID-19. Notably, 49-75% of COVID-19 patients had no comorbidities, but this cohort would also progress to severe COVID-19 or even death. However, risk factors contributing to disease progression and death in patients without chronic comorbidities are largely unknown; thus, specific clinical interventions for those patients are challenging. METHODS: A multicenter, retrospective study based on 4806 COVID-19 patients without chronic comorbidities was performed to identify potential risk factors contributing to COVID-19 progression and death using LASSO and a stepwise logistic regression model. RESULTS: Among 4806 patients without pre-existing comorbidities, the proportions with severe progression and mortality were 34.29% and 2.10%, respectively. The median age was 47.00 years [interquartile range, 36.00-56.00], and 2162 (44.99%) were men. Among 51 clinical parameters on admission, age ≥ 47, oxygen saturation < 95%, increased lactate dehydrogenase, neutrophil count, direct bilirubin, creatine phosphokinase, blood urea nitrogen levels, dyspnea, increased blood glucose and prothrombin time levels were associated with COVID-19 mortality in the entire cohort. Of the 3647 patients diagnosed with non-severe COVID-19 on admission, 489(13.41%) progressed to severe disease. The risk factors associated with COVID-19 progression from non-severe to severe illness were increased procalcitonin levels, SpO2 < 95%, age ≥ 47, increased LDH, activated partial thromboplastin time levels, decreased high-density lipoprotein cholesterol levels, dyspnea and increased D-dimer levels. CONCLUSIONS: COVID-19 patients without pre-existing chronic comorbidities have specific traits and disease patterns. COVID-19 accompanied by severe bacterial infections, as indicated by increased procalcitonin levels, was highly associated with disease progression from non-severe to severe. Aging, impaired respiratory function, coagulation dysfunction, tissue injury, and lipid metabolism dysregulation were also associated with disease progression. Once factors for multi-organ damage were elevated and glucose increased at admission, these findings indicated a higher risk for mortality. This study provides information that helps to predict COVID-19 prognosis specifically in patients without chronic comorbidities.

A risk score based on baseline risk factors for predicting mortality in COVID-19 patients.

BACKGROUND: To develop a sensitive and clinically applicable risk assessment tool identifying coronavirus disease 2019 (COVID-19) patients with a high risk of mortality at hospital admission. This model would assist frontline clinicians in optimizing medical treatment with limited resources. METHODS: 6415 patients from seven hospitals in Wuhan city were assigned to the training and testing cohorts. A total of 6351 patients from another three hospitals in Wuhan, 2169 patients from outside of Wuhan, and 553 patients from Milan, Italy were assigned to three independent validation cohorts. A total of 64 candidate clinical variables at hospital admission were analyzed by random forest and least absolute shrinkage and selection operator (LASSO) analyses. RESULTS: Eight factors, namely, Oxygen saturation, blood Urea nitrogen, Respiratory rate, admission before the date the national Maximum number of daily new cases was reached, Age, Procalcitonin, C-reactive protein (CRP), and absolute Neutrophil counts, were identified as having significant associations with mortality in COVID-19 patients. A composite score based on these eight risk factors, termed the OURMAPCN-score, predicted the risk of mortality among the COVID-19 patients, with a C-statistic of 0.92 (95% confidence interval [CI] 0.90-0.93). The hazard ratio for all-cause mortality between patients with OURMAPCN-score >11 compared with those with scores ≤ 11 was 18.18 (95% CI 13.93-23.71; p < .0001). The predictive performance, specificity, and sensitivity of the score were validated in three independent cohorts. CONCLUSIONS: The OURMAPCN score is a risk assessment tool to determine the mortality rate in COVID-19 patients based on a limited number of baseline parameters. This tool can assist physicians in optimizing the clinical management of COVID-19 patients with limited hospital resources.

Kidney Function Indicators Predict Adverse Outcomes of COVID-19.

BACKGROUND: The coronavirus disease 2019 (COVID-19) is a recently emerged respiratory infectious disease with kidney injury as a part of the clinical complications. However, the dynamic change of kidney function and its association with COVID-19 prognosis are largely unknown. METHODS: In this multicenter retrospective cohort study, we analyzed clinical characteristics, medical history, laboratory tests, and treatment data of 12,413 COVID-19 patients. The patient cohort was stratified according to the severity of the outcome into three groups: non-severe, severe, and death. FINDINGS: The prevalence of elevated blood urea nitrogen (BUN), elevated serum creatinine (Scr), and decreased blood uric acid (BUA) at admission was 6.29%, 5.22%, and 11.66%, respectively. The trajectories showed the elevation in BUN and Scr levels, as well as a reduction in BUA level for 28 days after admission in death cases. Increased all-cause mortality risk was associated with elevated baseline levels of BUN and Scr and decreased levels of BUA. CONCLUSIONS: The dynamic changes of the three kidney function markers were associated with different severity and poor prognosis of COVID-19 patients. BUN showed a close association with and high potential for predicting adverse outcomes in COVID-19 patients for severity stratification and triage. FUNDING: This study was supported by grants from the National Key R&D Program of China (2016YFF0101504), the National Science Foundation of China (81630011, 81970364, 81970070, 81970011, 81870171, and 81700356), the Major Research Plan of the National Natural Science Foundation of China (91639304), the Hubei Science and Technology Support Project (2019BFC582, 2018BEC473, and 2017BEC001), and the Medical Flight Plan of Wuhan University.

Longitudinal Association Between Markers of Liver Injury and Mortality in COVID-19 in China.

BACKGROUND AND AIMS: Coronavirus disease 2019 (COVID-19) is a new infectious disease. To reveal the hepatic injury related to this disease and its clinical significance, we conducted a multicenter retrospective cohort study that included 5,771 adult patients with COVID-19 pneumonia in Hubei Province. APPROACH AND RESULTS: We reported the distributional and temporal patterns of liver injury indicators in these patients and determined their associated factors and death risk. Longitudinal liver function tests were retrospectively analyzed and correlated with the risk factors and death. Liver injury dynamic patterns differed in alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin (TBIL). AST elevated first, followed by ALT, in severe patients. ALP modestly increased during hospitalization and largely remained in the normal range. The fluctuation in TBIL levels was mild in the non-severe and the severe groups. AST abnormality was associated with the highest mortality risk compared with the other indicators of liver injury during hospitalization. Common factors associated with elevated liver injury indicators were lymphocyte count decrease, neutrophil count increase, and male gender. CONCLUSION: The dynamic patterns of liver injury indicators and their potential risk factors may provide an important explanation for the COVID-19-associated liver injury. Because elevated liver injury indicators, particularly AST, are strongly associated with the mortality risk, our study indicates that these parameters should be monitored during hospitalization.

A sensitive fluorescent sensor based on the photoinduced electron transfer mechanism for cefixime and ctDNA.

Cefixime is a third generation orally administered cephalosporin that is frequently used as a broad spectrum antibiotic against various gram-negative and gram-positive bacteria. In this study, a simple and sensitive fluorescent sensor for the determination of the cefixime and ctDNA was established based on the CdTe:Zn2+ quantum dots (QDs). The fluorescence of CdTe:Zn2+ QDs can be effectively quenched by cefixime in virtue of the surface binding of cefixime on CdTe:Zn2+ QDs and the subsequent photoinduced electron transfer process from CdTe:Zn2+ QDs to cefixime, in particular, the high sensitivity of QDs fluorescence emission to cefixime at the micromole per liter level, which render the cefixime-CdTe:Zn2+ QDs system into fluorescence "OFF" status, then turn on in the presence of ctDNA. Furthermore, the Fourier transform infrared (FTIR) spectra of characteristic bands of C-N and N-H groups of cefixime endow evidence for the interaction of cefixime with CdTe:Zn2+ QDs. The relative electrochemical behavior of the affinity of CdTe:Zn2+ QDs for cefixime and ctDNA reveals the potential molecular binding mechanism.

Probing the interaction of cephalosporin with bovine serum albumin: A structural and comparative perspective.

Cephalosporins belong the largest class of antibiotics used in the treatment of a wide range of infectious diseases caused by susceptible organisms. In the present study, we chose two typical antibiotics cefalexin/cefixime based on their structure, and investigated the interaction of cephalexin/cefixime with bovine serum albumin (BSA) using UV-vis absorption spectra, fluorescence spectroscopy, circular dichroism (CD) spectroscopy and molecular modeling approaches. Spectroscopic experiments revealed the formation of a BSA - cefalexin/cefixime complex. The binding parameters calculated using a modified Stern - Volmer method and the Scatchard method reached 103 -104  L·mol-1 . Thermodynamic parameter studies revealed that binding characteristics by negative enthalpy and positive entropy changes, and electrostatic interactions play a major role. Site marker competitive displacement experiments and molecular modeling approaches demonstrated that cefalexin and cefixime bind with appropriate affinity to site I (subdomain IIA) of BSA. Furthermore, synchronous fluorescence spectra, CD spectra and molecular modeling results indicated that the secondary structure of BSA was changed in the presence of cefalexin and cefixime. Additionally, the effects of metal ions on the BSA - cefalexin/cefixime system were also assessed.

One-pot synthesis and characterization CdTe:Zn2+ quantum dots and its molecular interaction with calf thymus DNA.

Tremendous research efforts have been dedicated to fabricating high-quality Zn-doped CdTe quantum dots (QDs) for any potential biomedical applications. In particular, the correlation of issues regarding how QDs interact with DNA is of greatest importance. Herein, a pH-responsive study of the interactions between CdTe:Zn2+ quantum dots with 4 different sizes and calf thymus DNA (ctDNA) was conducted using multispectroscopic techniques and electrochemical investigation. Fluorescence studies revealed that this interaction process is predominantly a static process and groove binding was the main binding mode for CdTe:Zn2+ QDs to ctDNA. The calculated negative values of enthalpy (-45.06 kJ mol-1 ) and entropy (-133.62 J mol-1  K-1 ) with temperature changes indicated that the hydrogen bonds and van der Waals interactions played major roles in the reaction. Furthermore, circular dichroism spectroscopy and Fourier transform infrared spectrometry analyses indicate that the normal conformation of ctDNA is discombobulated by CdTe:Zn2+ QDs. In addition, the electrochemical behavior of the affinity of CdTe:Zn2+ QDs for ctDNA agreed well with the results obtained from fluorescence experiments. This study might be meaningful for understanding the molecular binding mechanism of QDs for DNA and provides a basis for QD-labeled systems.

Experimental study on the optimization of general conditions for a free-flow electrophoresis device with a thermoelectric cooler.

With a given free-flow electrophoresis device, reasonable conditions (electric field strength, carrier buffer conductivity, and flow rate) are crucial for an optimized separation. However, there has been no experimental study on how to choose reasonable general conditions for a free-flow electrophoresis device with a thermoelectric cooler in view of Joule heat generation. Herein, comparative experiments were carried out to propose the selection procedure of general conditions in this study. The experimental results demonstrated that appropriate conditions were (i) <67 V/cm electric field strength; (ii) lower than 1.3 mS/cm carrier buffer conductivity (Tris-HCl: 20 mM Tris was titrated by HCl to pH 8.0); and (iii) higher than 3.6 mL/min carrier buffer flow rate. Furthermore, under inappropriate conditions (e.g. 400 V voltage and 40 mM Tris-HCl carrier buffer), the free-flow electrophoresis separation would be destroyed by bubbles caused by more Joule heating. Additionally, a series of applications under the appropriate conditions were performed with samples of model dyes, proteins (bovine serum albumin, myoglobin, and cytochrome c), and cells (Escherichia coli, Streptococcus thermophilus, and Saccharomyces cerevisiae). The separation results showed that under the appropriate conditions, separation efficiency was obviously better than that in the previous experiments with randomly or empirically selected conditions.

Negative-pressure-induced collector for a self-balance free-flow electrophoresis device.

Uneven flow in free-flow electrophoresis (FFE) with a gravity-induced fraction collector caused by air bubbles in outlets and/or imbalance of the surface tension of collecting tubes would result in a poor separation. To solve these issues, this work describes a novel collector for FFE. The collector is composed of a self-balance unit, multisoft pipe flow controller, fraction collector, and vacuum pump. A negative pressure induced continuous air flow rapidly flowed through the self-balance unit, taking the background electrolyte and samples into the fraction collector. The developed collector has the following advantages: (i) supplying a stable and harmonious hydrodynamic environment in the separation chamber for FFE separation, (ii) effectively preventing background electrolyte and sample flow-back at the outlet of the chamber and improving the resolution, (iii) increasing the preparative scale of the separation, and (iv) simplifying the operation. In addition, the cost of the FFE device was reduced without using a multichannel peristaltic pump for sample collection. Finally, comparative FFE experiments on dyes, proteins, and cells were carried out. It is evident that the new developed collector could overcome the problems inherent in the previous gravity-induced self-balance collector.

A simple and highly stable free-flow electrophoresis device with thermoelectric cooling system.

Complex assembly, inconvenient operations, poor control of Joule heating and leakage of solution are still fundamental issues greatly hindering application of free-flow electrophoresis (FFE) for preparative purpose in bio-separation. To address these issues, a novel FFE device was developed based on our previous work. Firstly, a new mechanical structure was designed for compact assembly of separation chamber, fast removal of air bubble, and good anti-leakage performance. Secondly, a highly efficient thermoelectric cooling system was used for dispersing Joule heating for the first time. The systemic experiments revealed the three merits: (i) 3min assembly without any liquid leakage, 80 times faster than pervious FFE device designed by us or commercial device (4h); (ii) 5s removing of air bubble in chamber, 1000-fold faster than a normal one (2h or more) and (iii) good control of Joule heating by the cooling system. These merits endowed the device high stable thermo- and hydro-dynamic flow for long-term separation even under high electric field of 63V/cm. Finally, the developed device was used for up to 8h continuous separation of 5mg/mL fuchsin acid and purification of three model proteins of phycocyanin, myoglobin and cytochrome C, demonstrating the applicability of FFE. The developed FFE device has evident significance to the studies on stem cell, cell or organelle proteomics, and protein complex as well as micro- or nano-particles.

[Expression of Th1/th2 transcription factors and cytokines in laryngeal squamous cell carcinoma and its clinical significance].

OBJECTIVE: To study the differentiation of Th1/Th2 on the levels of transcription factors and cytokines production in patients with laryngeal squamous cell carcinoma in peripheral blood mononuclear cells (PBMC). In addition, the relation of p53 and T-bet, GATA3 expression was discussed for understanding the role of T-bet and GATA3 in metastasis. METHOD: The gene expression of Th1/Th2 type transcription factors T-bet, GATA3 and cytokines IFN-gamma, IL-4 were determined by RT-PCR and realtime RT-PCR from 49 patients with laryngeal squamous cell carcinoma and 30 normal controls. The expression of p53 was analyzed by immunohistochemistry. RESULT: Predominant expression of Th2 type cytokines was detected in 49 laryngeal squamous cell carcinoma patients. The expression rates of T-bet, GATA3, IFN-gamma and IL-4 was 42.86% (21/49), 71.43% (35/49), 26.53% (13/49), 63.27% (33/49) respectively. The expression rates of T-bet and IFN-gamma in patients were lower than in control group (P < 0.05), but the results of GATA3 and IL-4 were opposite (P < 0.05). The similar results were obtained by realtime PCR. The expression of p53 in patients was accompanied with lower expression of T-betmRNA and higher expression of GATA3mRNA. CONCLUSION: There is predominant expression of Th2 type transcription factors and cytokines in PBMC of laryngeal squamous cell carcinoma patients. T-bet and GATA3 can be used as reference indicators for the metastasis of laryngeal squamous cell carcinoma.

[Utilization of functional surgery in benign parotid tumor of superficial lobe].

OBJECTIVE: To investigate the utilization of functional surgery in benign parotid tumor of superficial lobe. METHOD: Conventional parotidectomy were modified in the following aspects: incision, preservation of great auricular nerve, local facial nerve dissection, partial superficial parotidectomy and repairing of sunken deformity. The post-operative recurrence incidence, functional outcomes and complications of 21 patients with benign parotid tumor of superficial lobe undergoing functional surgery were analyzed retrospectively. RESULT: No recurrence of tumor was found in follow-ups. No obvious scar and sunken deformity was found. The area with abnormal sensory around the auricle was smaller compared with those whose great auricular nerve had not been preserved. Post-operative transient facial paralysis was observed in 4 cases and all recovered in 3 months. One case complained about Frey's syndrome. Salivary leakage was found on 1 case. CONCLUSION: Compared with conventional surgery, functional surgery for benign parotid tumor of superficial lobe may improve cosmetic, sensory, salivary function, facial nerve function and quality of life without raising post-operative recurrence.