Cultivation of compound ability of postgraduates with medical professional degree: the importance of double tutor system.

As we all know, medical postgraduate education is very important for training high-quality clinicians, and can have a long-term impact on the promotion of the global health service system. In recent years, following the example of developed countries in Europe and America, the Chinese government has reformed the training mode of medical postgraduates and implemented the double tutor system. Although this system will bring many positive effects in theory, the difficulties encountered in implementing this system are real and need the joint efforts of schools, tutors and students to solve them. This article closely follows the background of the current era, compares the differences between Chinese and foreign graduate training modes, and emphatically discusses the significance and problems of the double tutor system in the postgraduate education reform in China.

Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: This is the first randomised controlled trial for assessment of the immunogenicity and safety of a candidate non-replicating adenovirus type-5 (Ad5)-vectored COVID-19 vaccine, aiming to determine an appropriate dose of the candidate vaccine for an efficacy study. METHODS: This randomised, double-blind, placebo-controlled, phase 2 trial of the Ad5-vectored COVID-19 vaccine was done in a single centre in Wuhan, China. Healthy adults aged 18 years or older, who were HIV-negative and previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-free, were eligible to participate and were randomly assigned to receive the vaccine at a dose of 1 × 1011 viral particles per mL or 5 × 1010 viral particles per mL, or placebo. Investigators allocated participants at a ratio of 2:1:1 to receive a single injection intramuscularly in the arm. The randomisation list (block size 4) was generated by an independent statistician. Participants, investigators, and staff undertaking laboratory analyses were masked to group allocation. The primary endpoints for immunogenicity were the geometric mean titres (GMTs) of specific ELISA antibody responses to the receptor binding domain (RBD) and neutralising antibody responses at day 28. The primary endpoint for safety evaluation was the incidence of adverse reactions within 14 days. All recruited participants who received at least one dose were included in the primary and safety analyses. This study is registered with ClinicalTrials.gov, NCT04341389. FINDINGS: 603 volunteers were recruited and screened for eligibility between April 11 and 16, 2020. 508 eligible participants (50% male; mean age 39·7 years, SD 12·5) consented to participate in the trial and were randomly assigned to receive the vaccine (1 × 1011 viral particles n=253; 5 × 1010 viral particles n=129) or placebo (n=126). In the 1 × 1011 and 5 × 1010 viral particles dose groups, the RBD-specific ELISA antibodies peaked at 656·5 (95% CI 575·2-749·2) and 571·0 (467·6-697·3), with seroconversion rates at 96% (95% CI 93-98) and 97% (92-99), respectively, at day 28. Both doses of the vaccine induced significant neutralising antibody responses to live SARS-CoV-2, with GMTs of 19·5 (95% CI 16·8-22·7) and 18·3 (14·4-23·3) in participants receiving 1 × 1011 and 5 × 1010 viral particles, respectively. Specific interferon γ enzyme-linked immunospot assay responses post vaccination were observed in 227 (90%, 95% CI 85-93) of 253 and 113 (88%, 81-92) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Solicited adverse reactions were reported by 183 (72%) of 253 and 96 (74%) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Severe adverse reactions were reported by 24 (9%) participants in the 1 × 1011 viral particles dose group and one (1%) participant in the 5 × 1010 viral particles dose group. No serious adverse reactions were documented. INTERPRETATION: The Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles is safe, and induced significant immune responses in the majority of recipients after a single immunisation. FUNDING: National Key R&D Programme of China, National Science and Technology Major Project, and CanSino Biologics.

Metagenomic and 14 C tracing evidence for autotrophic microbial CO2 fixation in paddy soils.

Autotrophic carbon dioxide (CO2 ) fixation by microbes is ubiquitous in the environment and potentially contributes to the soil organic carbon (SOC) pool. However, the multiple autotrophic pathways of microbial carbon assimilation and fixation in paddy soils remain poorly characterized. In this study, we combine metagenomic analysis with 14 C-labelling to investigate all known autotrophic pathways and CO2 assimilation mechanisms in five typical paddy soils from southern China. Marker genes of six autotrophic pathways are detected in all soil samples, which are dominated by the cbbL genes (67%-82%) coding the ribulose-bisphosphate carboxylase large chain in the Calvin cycle. These marker genes are associated with a broad range of phototrophic and chemotrophic genera. Significant amounts of 14 C-CO2 are assimilated into SOC (74.3-175.8 mg 14 C kg-1 ) and microbial biomass (5.2-24.1 mg 14 C kg-1 ) after 45 days incubation, where more than 70% of 14 C-SOC was concentrated in the relatively stable humin fractions. These results show that paddy soil microbes contain the genetic potential for autotrophic carbon fixation spreading over broad taxonomic ranges, and can incorporate atmospheric carbon into organic components, which ultimately contribute to the stable SOC pool.

The earliest unequivocally modern humans in southern China.

The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ∼45,000 years that can be unequivocally attributed to Homo sapiens are lacking. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this sample supports its unequivocal assignment to H. sapiens. The Daoxian sample is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000-70,000 years earlier than in the Levant and Europe. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals' extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ∼80,000 years ago, there is no evidence that they entered Europe before ∼45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started.

Management of Sonographically Suspicious Thyroid Nodules 1 cm or Smaller and Candidacy for Active Surveillance: Experience of a Tertiary Center in China.

OBJECTIVE: Our objective was to investigate the management of patients with asymptomatic suspicious thyroid nodules ≤1 cm. METHODS: We retrospectively reviewed medical records of patients with sonographically suspicious thyroid nodules ≤1 cm and without distant metastases, suspicious lymph node metastasis (LNM), or extrathyroidal extension (ETE). RESULTS: Of the 386 enrolled patients, 174 (45.1%) had immediate surgery (IS), while 212 (54.9%) underwent active surveillance (AS). In the IS group, 166 (95.4%) patients were confirmed as having papillary thyroid microcarcinoma. LNM and ETE were observed in 24.7% and 2.4% cases, respectively. In the AS group, nodule size increased by ≥3 mm in 11 (5.2%) patients and 39 (18.4%) had a >50% increase in nodule volume after a median follow-up of 12 months. Nodules with smaller volume at diagnosis were more likely to increase in volume later. Newly suspicious LNM was detected in 23 (10.8%) patients. Delayed surgery (DS) was performed in 101 patients, with 27 showing disease progression. ETE and LNM were detected in 3% and 36%, respectively, of patients with papillary thyroid microcarcinoma. Compared with IS, tumors in the DS group more frequently showed lateral LNM and capsular invasion (P < .05). No patient had recurrence or died of thyroid cancer during postoperative follow-up (median 26 [4-60] months). CONCLUSIONS: IS or DS of patients with asymptomatic suspicious thyroid nodules ≤1 cm was relatively high in China. The inertia of low-risk nodules and the effectiveness of DS for those that progressed make AS a feasible strategy.

Heparin versus 0.9% saline solution to maintain patency of totally implanted venous access ports in cancer patients: A systematic review and meta-analysis.

AIM: The use of heparin and 0.9% saline solution is always controversial for central venous catheters. However, there is no systematic review or guideline about whether saline solution can replace heparin solution in adult cancer patients with totally implantable venous access ports (TIVAPs). The purpose of this review is to evaluate whether saline solution can replace heparin saline to lock TIVAPs. METHODS: The following databases were searched: PubMed, the Cochrane Library, Web of Science, Embase, CINAHL and Ovid (January 1, 1982, and February 21, 2020). All statistical analyses of the meta-analysis were completed using the Review Manager 5.3. RESULTS: A total of 201 studies were identified from these databases after initial review, and four studies met inclusion criteria, including 2652 cases. There was little heterogeneity among the included studies (I2 < 30%), and all analyses were conducted by the fixed-effects model. The total complications, catheter occlusions, catheter-related bloodstream infections and other complication rates in the heparin solution group were higher than in the saline solution group. In the subgroup analysis of heparin concentration, total complication rates in the saline solution group were higher than with 50 U of heparin and lower than with 100 U of heparin. However, the differences in these complications were small, and no significant difference was observed (all P > 0.05). CONCLUSIONS: Based on existing clinical studies, we recommend that saline solution can replace 50 or 100 U/ml of heparin as a safe and effective flush solution for TIVAPs.

CD5+MYC+ predicts worse prognosis in diffuse large B-cell lymphoma.

The dual expression of CD5 and MYC protein (DECM) on B-lymphocytes may arise at a specific stage of de novo diffuse large B-cell lymphoma (DLBCL). This study retrospectively reviewed 210 patients with de novo DLBCL at the Affiliated Hospital of Jiangnan University between 2006 and 2017. DECM was significantly correlated with a worse prognosis than that in either the CD5+ or MYC+ or CD5-MYC- patients. Furthermore, patients with DECM showed a similar outcome to MYC+BCL2+ lymphoma patients who have extremely poor survival rates. Multivariate analysis demonstrated that DECM was a significant independent predictor for overall survival (P < .0001) and progression-free survival (P < .0001) in DLBCL. DLBCL patients with DECM showed significantly inferior clinical outcomes compared to the CD5+, MYC+ or CD5-MYC- patients. Combinational therapeutic modalities might be a candidate approach to improve the prognosis of these patients.

In-tube solid-phase microextraction with a hybrid monolithic column for the preconcentration of ultra-trace metals prior to simultaneous determination by ICP-MS.

The preparation of an amino-functionalized hybrid monolithic column (TEOS-co-AEAPTES) via one-pot co-condensation of tetraethoxysilane (TEOS) and N-(ß-aminoethyl)-γ-aminopropyltriethoxysilane (AEAPTES) in a capillary is descibed. It was used as solid-phase microextraction (SPME) matrix followed by inductively coupled plasma-mass spectrometry (ICP-MS) for determination of trace metals. Under optimum conditions, the amino-functionalized SPME material can simultaneously retain Cu(II), Zn(II), Au(III), and Pb(II) with adsorption capacities of 148, 60, 81, and 64 µg m-1, respectively. Subsequently, these four metal ions can be quantitatively eluted using 1 mol L-1 HNO3 containing 1% thiourea. The retention mechanism of Cu(II), Zn(II), Au(III), and Pb(II) on the amino-functionalized hybrid monolith was explained as the combination of electrostatic and coordination interactions. With a 10-fold enrichment factor, the calibration curves were established in the range 0.5-100 µg L-1 with linear correlation coefficients above 0.9943 and the limits of quantitation were 0.05 µg L-1 for four target analytes. The limits of detection were 0.006, 0.012, 0.004, and 0.007 µg L-1 for Cu(II), Zn(II), Au(III), and Pb(II), respectively. The protocol was validated by analyzing Certified Reference Materials including standard sediment, soil, and nickel ore, and the results were in good agreement with their certified values. The relative standard deviations of the method were in the range 0.22-17.6%. The recoveries of the four metal ions in spiked samples were in the range 88.0-113.8%. Compared to direct ICP-MS determination, the proposed in-tube SPME procedure can effectively eliminate the interference from complex matrix, especially from those ores with very high content of main metal to improve the accuracy of analysis. Therefore the method is suitable for the simultaneous determination of ultra-trace Cu(II), Zn(II), Au(III), and Pb(II) in environmental and mineral samples. Graphical abstract The preparation of the TEOS-co-AEAPTES monolithic column and the SPME procedure of Cu(II), Zn(II), Au(III), and Pb(II).

Classification of Chinese vinegar varieties using electronic nose and fuzzy Foley-Sammon transformation.

Due to the difference of raw materials and brewing technology, the quality and flavours of vinegar are different. Different kinds of vinegar have different functions and effects. Therefore, it is important to classify the vinegar varieties correctly. This work presented a new fuzzy feature extraction algorithm, called fuzzy Foley-Sammon transformation (FFST), and designed the electronic nose (E-nose) system for classifying vinegar varieties successfully. Principal component analysis (PCA) and standard normal variate (SNV) were used as the data preprocessing algorithms for the E-nose system. FFST, Foley-Sammon transformation (FST) and linear discriminant analysis (LDA) were used to extract discriminant information from E-nose data, respectively. Then, K nearest neighbor (KNN) served as a classifier for the classification of vinegar varieties. The highest identification accuracy rate was 96.92% by using the FFST and KNN. Therefore, the E-nose system combined with the FFST was an effective method to identify Chinese vinegar varieties and this method has wide application prospects.

Prognostic significance of serum aspartic transaminase in diffuse large B-cell lymphoma.

BACKGROUND: Liver function is routinely assessed in clinical practice as liver function tests provide sensitive indicators of hepatocellular injury. However, the prognostic value of enzymes that indicate hepatic injury has never been systematically investigated in lymphoma, including diffuse large B-cell lymphoma (DLBCL). METHODS: This study examined the prognostic value of baseline aspartic transaminase (AST) in DLBCL patients. The association between AST and clinical features was analyzed in 179 DLBCL patients treated from 2006 to 2016. All enrolled patients were treated with R-CHOP or R-CHOP-like chemotherapy. Log-rank test, univariable analysis, and subgroup analysis were performed to evaluate the impact of AST on survival. RESULTS: AST 33.3 U/L was considered to be the optimal threshold value for predicting prognosis. A higher AST level was associated with advanced stage (P = 0.001), poorer performance status (P = 0.014), elevated lactate dehydrogenase level (P <  0.0001), presence of B symptoms (P = 0.001), high-risk International Prognostic Index (IPI, IPI 3-5) (P = 0.002), non-germinal center B-cell subtypes (P = 0.038), hepatitis B virus surface antigen positivity (P = 0.045) and more extra nodal involvement (ENI, ENI ≥ 2) (P = 0.027). Patients with a higher AST level had a shorter overall survival (OS) (2-year OS rate, 53.6% vs. 83.6%, P <  0.001). Subgroup analysis indicated that higher AST levels have poorer prognostic values in patients without B symptoms and LDH positive groups. CONCLUSION: A pretreatment AST level is associated with OS in DLBCL patients treated with R-CHOP or similar chemotherapy regimens. A high pretreatment AST level might be a reliable prognostic factor for predicting a dismal outcome in DLBCL patients. Serum AST levels may be investigated for use as an easily determinable, inexpensive biomarker for risk assessment in patients with DLBCL.

Postmortem Study Exploring Distribution and Patterns of Intracranial Artery Calcification.

Background and Purpose- Intracranial artery calcification detected by computed tomography is associated with ischemic stroke as an indicator of intracranial atherosclerosis. However, little is known about its histopathology. This study aimed to explore the intracranial calcification patterns and their associations with atherosclerotic plaques. Methods- We recruited 32 adult autopsy cases to assess the calcification patterns and distributions in the middle cerebral artery, vertebral artery, and basilar artery. The relationships of calcification patterns with plaque phenotype and luminal stenosis were evaluated. The calcification patterns on computed tomography were correlated with that on histology. Results- Visible calcifications were detected within 37 (39%) segments, including 25 segments with intimal calcification, 6 segments with internal elastic lamina calcification, 3 segments with adventitial calcification, and 3 segments with concurrent calcification. Calcification occurred more often in the vertebral artery (51%), followed by the middle cerebral artery (35%) and basilar artery (14%; P<0.01 for vertebral artery versus basilar artery). Internal elastic lamina calcification was predominantly detected in the vertebral artery (7/8, 88%). All of the 27 (100%) intimal calcifications were present in the progressive atherosclerotic lesions ( P<0.001), whereas only 3/8 (38%) internal elastic lamina calcifications and 4/6 (67%) adventitial calcifications were associated with progressive plaques. Arteries with intimal calcification had more severe luminal stenosis than those without (46% versus 21%; P<0.001). Conclusions- Our histological findings indicate that the presence of intracranial artery calcification has 3 patterns, including intimal, internal elastic lamina, and adventitial calcifications. But only intimal calcification is related with progressive atherosclerotic lesions, indicative of a proxy for intracranial atherosclerosis.

Inflammation marker ESR is effective in predicting outcome of diffuse large B-cell lymphoma.

BACKGROUND: Systemic inflammation has been implicated in cancer development and progression. This study examined the best cutoff value of erythrocyte sedimentation rate (ESR) in diffuse large B-cell lymphoma (DLBCL) patients. METHODS: The relationship between ESR and clinical characteristics was analyzed in 182 DLBCL patients from 2006 to 2017. The log-rank test, univariate analysis, and Cox regression analysis were applied to evaluate the relationship between ESR and survival. An ESR of more than 37.5 mm/hour was found to be the optimal threshold value for predicting prognosis. RESULTS: ESR was associated with more frequent advanced Ann Arbor stage, poorer performance status, elevated lactate dehydrogenase level, the presence of B symptoms, high-risk International Prognostic Index (IPI 3-5), more extranodal involvement (ENI ≥2), non-germinal-center B-cell (non-GCB) subtypes, and more frequent Myc protein positivity. Shorter overall survival (OS) and progression-free survival (PFS) were found for patients with higher ESRs. Multivariate analysis demonstrated that ESR level is an independent prognostic factor of both OS and PFS. In addition, dynamic changes in ESR are valuable in assessing curative effect and predicting disease recurrence. CONCLUSION: High ESR in DLBCL patients indicated unfavorable prognosis that may require alternative treatment regimens.

High Extent of Intracranial Carotid Artery Calcification Is Associated with Downstream Microemboli in Stroke Patients.

BACKGROUND: Intracranial arterial calcification (ICAC) is frequently detected on head computed tomography and has been found to be associated with ischemic stroke by recent clinical studies. AIMS: Based on a hospital-based study, we aimed to compare the occurrence of cerebral microembolic signals (MES) among stroke patients with different degrees of ICAC, which may indicate the potential mechanisms linking ICAC and ischemic stroke in intracranial atherosclerosis patients. METHODS: This is a post-hoc analysis of our previous clinical study in 2005-2007, recruiting consecutive ischemic stroke patients with middle cerebral artery territory infarctions and good temporal window for MES monitoring. The degrees of ICAC in the Circle of Willis, especially calcification in the ipsilateral intracranial internal carotid artery (iICA), were evaluated both qualitatively and quantitatively on unenhanced head computed tomography. RESULTS: Among the 68 recruited patients, MES was detected in 26 patients (38.24%). The overall degree of ICAC in the Circle of Willis was similar between patients with and without MES. For calcification in ipsilateral iICA, the presence of MES was more frequent in the high extent group (widest arc of calcification ≥90°) than in the low extent group (54.2% versus 29.5%, P = .046). Logistic regression found that a high extent ipsilateral iICA calcification was an independent risk factor of MES (odds ratio: 3.134; 95% confidence interval, 1.029-9.543; P = .044). CONCLUSIONS: MES is frequently detected in patients with a high extent of ipsilateral iICA calcification, which suggests that a high extent of iICA calcification indicates artery vulnerability and accounts for the occurrence of microemboli in the corresponding artery.

Tangeretin inhibits neurodegeneration and attenuates inflammatory responses and behavioural deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease dementia in rats.

Our aim was to investigate whether tangeretin, a citrus flavonoid, was able to prevent neuroinflammation and improve dementia in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced rodent model of Parkinson's disease (PD). MPTP-HCl was infused into the substantia nigra pars compacta of male Sprague-Dawley rats. Tangeretin (50, 100 or 200 mg/kg body weight) was administered orally starting 3 days prior to MPTP injection and was continued for 20 days following injection. MPTP-lesioned rats revealed motor dysfunction in bar test and rota rod tests. Deficits in working memory and object recognition function were also observed following MPTP induction. Tangeretin treatment significantly attenuated the memory deficits and improved motor functions and cognition. Immunohistochemical analysis reveals the protective effects of tangeretin against MPTP lesion-induced dopaminergic degeneration and hippocampal neuronal loss. Tangeretin reduced expression of inflammatory mediators-COX-2, iNOS-as well reduced the levels of cytokines-interleukins (IL)-IL-1ß, IL-6 and IL-2. The experimental data suggest tangeretin as an effective candidate drug with potential for prevention and treatment of neuroinflammation and dementia associated with PD.

[Epidemiological characteristics of imported malaria in Sichuan Province in 2015].

Objective: To analyze the epidemiological characteristics of imported malaria in Sichuan Province in 2015 in the aim of providing scientific basis for malaria control. Methods: The epidemiological data of malaria in Sichuan Province reported through the Infectious Disease Reporting and Management System of China Information System for Disease Control and Prevention in 2015 were collected and analyzed. Results: In 2015,290 malaria cases were reported in Sichuan Provinc, consisting of 158 falciparum malaria cases (54.5%),107 vivax malaria cases (36.9%),14 ovale malaria cases (4.8%), one quartan malaria case(0.3%), and 10 mixed infections of vivax malaria and falciparum malaria (3.5%). Five cases of falciparum malaria died. The reported cases were all imported, with a major source of Africa (271, 93.4%), in which Ethiopia (83) and Angola (49) were two major sources. The cases were reported continuously from January to December, with the majority(139, 47.9%) being reported in December, August, June and July. The cases distributed mainly in Guangan, Chengdu, Nanchong, Mianyang, Deyang, Luzhou and Suining(243, 83.8%). Among the 209 cases who first visited medical units after onset, 118 cases were diagnosed as malaria, the misdiagnosis rate at first visit was 43.5%(91/209). Conclusion: The malaria cases reported in Sichuan Province in 2015 are all imported from overseas, mainly infected with P. falciparum and P. vivax, and imported mostly from Africa. There is a high rate of misdiagnosis in medical units in Sichuan Province.

Downregulation of SATB1 increases the invasiveness of Jurkat cell via activation of the WNT/ß-catenin signaling pathway in vitro.

Special AT-rich sequence-binding protein-1 (SATB1) is critical for genome organizer that reprograms chromatin organization and transcription profiles, and associated with tumor growth and metastasis in several cancer types. Many studies suggest that SATB1 overexpression is an indicator of poor prognosis in various cancers, such as breast cancer, malignant cutaneous melanoma, and liver cancer. However, their expression patterns and function values for adult T cell leukemia (ATL) are still largely unknown. The aim of this study is to examine the levels of SATB1 in ATL and to explore its function and mechanisms in Jurkat cell line. Here, we reported that SATB1 expressions were decreased in ATL cells (p < 0.001) compared with normal controls. Knockdown of SATB1 expression significantly enhanced invasion of Jurkat cell in vitro. Furthermore, knockdown of SATB1 gene enhances ß-catenin nuclear accumulation and transcriptional activity and thus may increase the invasiveness of Jurkat cell through the activation of Wnt/ß-catenin signaling pathway in vitro.