Soluble ST2 for predicting heart failure, atrial fibrillation and death in patients with coronary heart disease with or without renal insufficiency

Background

This study aimed to investigate the relationship between baseline soluble suppression of tumorigenesis-2 (sST2) concentration and the outcomes of heart failure (HF), atrial fibrillation (AF) or death in patients with coronary heart disease (CHD) with or without renal insufficiency (RI).

Methods

Between March 2011 and December 2015, 3454 patients with CHD from the Chinese PLA General Hospital were enrolled in this cohort study. The patients were followed up until October 2021. AF, HF, and death events were recorded. Associations between baseline sST2 concentrations and clinical outcomes were assessed using Kaplan-Meier (K-M) curves, and Cox regression and generalised additive models. Subgroup analysis were carried out between RI and non-RI groups.

Results

Among the patients with CHD (61.5 ± 11.8 years; 78.6 % men), 415 (12.02 %) had RI. During a median follow-up of 8.37 years, HF and AF were reported in 216 (6.25 %) and 174 (5.04 %) patients, respectively, and 297 (8.60 %) died. The K-M curves indicated that patients in the higher quartiles of sST2 concentrations were correlated with a poor survival rate of HF, AF, or death (all Ps < 0.001). Generalised additive model (GAM) demonstrated a nonlinear positive association between sST2 concentration and the risk of HF, AF, and death in CHD patients. The cut-off value of sST2 for predicting HF, AF and death were 32.1, 25.4 and 28.6 ng/mL, respectively. CHD patients with sST2 higher than the cut-off value had higher risks of HF (HR: 3.02, 95%CI: 2.24-4.05), AF (HR: 2.86; 95%CI: 2.10-3.90), and death (HR:2.11, 95%CI: 1.67-2.67). Furthermore, in patients with RI (12.02 %, n = 415), the prognostic value of sST2 over the cut-off value for HF and death remained unchanged (HR: 3.21 and 2.35; P < 0.05). In patients with CHD with or without RI, sST2 improved the area under the curve (AUC) of traditional risk models for predicting clinical endpoint events.

Conclusions

The biomarker sST2 may be useful for predicting HF, AF, and death in patients with CHD. The predicted value was not affected by renal function.

Prognostic value of growth differentiation factor-15 in heart failure among whole ejection fraction phenotypes

AIMS

The utility of growth differentiation factor-15 (GDF-15) in predicting long-term adverse outcomes in heart failure (HF) patients is not well established. This study explored the relationship between GDF-15 levels and adverse outcomes in HF patients across various ejection fraction (EF) phenotypes associated with coronary heart disease (CHD) and evaluated the added prognostic value of incorporating GDF-15 into the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score-based model.

METHODS AND RESULTS

This single-centre cohort study included 823 HF patients, categorized into 230 (27.9%) reduced EF (HFrEF), 271 (32.9%) mid-range EF (HFmrEF), and 322 (39.1%) preserved EF (HFpEF) groups. The median age was 68.0 years (range: 56.0-77.0), and 245 (29.8%) were females. Compared with the HFrEF and HFmrEF groups, the HFpEF group had a higher GDF-15 concentration (P = 0.002) and a higher MAGGIC risk score (P < 0.001). We examined the associations between GDF-15 levels and the risks of all-cause mortality and HF rehospitalization using Cox regression models. The C-index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) metrics were employed to assess the incremental prognostic value. During the 9.4 year follow-up period, 425 patients died, and 484 were rehospitalized due to HF. Multivariate Cox regression analysis revealed that elevated GDF-15 levels were significantly associated with an increased risk of all-cause mortality [hazard ratio (HR) = 1.36, 95% confidence interval (CI): 1.20-1.54; P < 0.001] and HF rehospitalization (HR = 1.75, 95% CI: 1.57-1.95; P < 0.001) across all HF phenotypes. This association remained significant when GDF-15 was treated as a categorical variable (high GDF-15 group: all-cause death: HR = 1.73, 95% CI: 1.40-2.14; P < 0.001; HF rehospitalization: HR = 3.37, 95% CI: 2.73-4.15; P < 0.001). Inclusion of GDF-15 in the MAGGIC risk score-based model provided additional prognostic value for all HF patients (Δ C-index = 0.021, 95% CI: 0.002-0.041; IDI = 0.011, 95% CI: 0.001-0.025; continuous NRI = 0.489, 95% CI: 0.174-0.629) and HF rehospitalization (Δ C-index = 0.034, 95% CI: 0.005-0.063; IDI = 0.021, 95% CI: 0.007-0.032; continuous NRI = 0.307, 95% CI: 0.147-0.548), particularly in the HFpEF subgroup.

CONCLUSIONS

GDF-15 is identified as an independent risk factor for adverse outcomes in HF patients across the entire EF spectrum in the context of CHD. Integrating GDF-15 into the MAGGIC risk score-based model enhances its prognostic capability for adverse outcomes in the general HF population. This incremental prognostic effect was observed specifically in the HFpEF subgroup and not in other subgroups.

Serum albumin and cardiovascular disease: a Mendelian randomization study

BACKGROUND

An increasing body of evidence suggests that serum albumin levels play a role in cardiovascular diseases. However, the specific causal relationship between serum albumin levels and cardiovascular disease remains partially unknown.

METHODS

Mendelian randomization (MR) was employed in this study to examine potential causal relationships between instrumental variables and cardiovascular diseases. Specifically, we utilized genetic variants of serum albumin levels within the reference range as our instrumental variables. To acquire data on genetic associations with cardiovascular diseases, we sourced information from renowned genome-wide association studies such as UK BioBank, EMBL-EBI, and FinnGen. Notably, our study leveraged summary statistics from large cohorts that have been previously described.

RESULTS

We explored the association between serum albumin levels and various conditions, including heart failure (HF), venous thromboembolism (VTE), stroke, atrial fibrillation (AF), coronary artery disease (CAD), type 2 diabetes (T2DM), and pulmonary heart disease (PHD). Genetically predicted serum albumin levels were associated with PHD (odds ratio = 0.737, 95% CI = 0.622 - 0.874, P < 0.001), AF (odds ratio = 0.922, 95% CI = 0.870 - 0.977, P = 0.006), VTE (odds ratio = 0.993, 95% CI = 0.991 - 0.995, P < 0.001), and Stroke (odds ratio = 0.997, 95% CI = 0.995 - 0.999, P = 0.002). However, genetically predicted serum albumin level traits were not associated with HF, CAD and T2DM.

CONCLUSION

Our study demonstrates a significant association between serum albumin levels and cardiovascular disease, underscoring the crucial role of low serum albumin as a predictive factor in patients with cardiovascular disease.

The relationship between triglyceride-glucose index and prospective key clinical outcomes in patients hospitalised for coronary artery disease

BACKGROUND

The triglyceride-glucose (TyG) index is regarded as a dependable alternative for assessing insulin resistance (IR), given its simplicity, cost-effectiveness, and strong correlation with IR. The relationship between the TyG index and adverse outcomes in patients with coronary heart disease (CHD) is not well established. This study examines the association of the TyG index with long-term adverse outcomes in hospitalized CHD patients.

METHODS

In this single-center prospective cohort study, 3321 patients hospitalized with CHD were included. Multivariate Cox regression models were employed to assess the associations between the TyG index and the incidence of all-cause mortality and major adverse cardiovascular events (MACEs). To examine potential nonlinear associations, restricted cubic splines and threshold analysis were utilized.

RESULTS

During a follow-up period of 9.4 years, 759 patients (22.9%) succumbed to mortality, while 1291 (38.9%) experienced MACEs. Threshold analysis demonstrated a significant "U"-shaped nonlinear relationship with MACEs, with different hazard ratios observed below and above a TyG index of 8.62 (below: HR 0.71, 95% CI 0.50-0.99; above: HR 1.28, 95% CI 1.10-1.48). Notably, an increased risk of all-cause mortality was observed only when the TyG index exceeded 8.77 (HR 1.53, 95% CI 1.19-1.96).

CONCLUSIONS

This study reveals a nonlinear association between the TyG index and both all-cause mortality and MACEs in hospitalized CHD patients with CHD. Assessing the TyG index, particularly focusing on individuals with extremely low or high TyG index values, may enhance risk stratification for adverse outcomes in this patient population.

[Investigation and analysis of airborne allergenic pollen in 4 districts and 5 counties of Hohhot City]

Objective: To investigate the species, concentration and seasonal trends of main airborne allergenic pollen in 4 districts and 5 counties of Hohhot City. Methods: The Department of allergy, Beijing Shijitan Hospital Affiliated to Capital Medical University conducted a cross-sectional study about monitoring the airborne allergenic pollen from August 1, 2021 to July 31, 2022 by the gravitational method in 4 districts and 5 counties of Hohhot City, which include Yuquan District, Xincheng District, Huimin District, Saihan District, Tuoketuo County, Helingeer County, Tumotezuoqi County, Wuchuan County and Qingshuihe County. Daily pollens were counted and identified by optical microscopy, and the data were analyzed. Results: The airborne allergenic pollen was collected every month all year round in 4 districts and 5 counties of Hohhot city. Through the whole year of the total quantity of pollens ranged from 24 850 to 50 154 grains per 1 000 mm2 and two peaks of pollen concentration in air were observed,which happened in spring (from March to May) and in summer and autumn (from July to September). In spring, the main pollens were tree pollens, which principally distributed in Populus pollen (18.29%), Ulmus pollen (8.36%), Pinus pollen (6.20%), Cupressaceae pollen (5.23%), Betulaceae pollen (2.73%), Salix pollen (1.80%) and Quercus pollen (1.16%). In summer and autumn, the main pollens were weed pollens, which mainly included Artemisia pollen (42.73%), Chenopodiaceae pollen or Amaranthaceae pollen (7.46%), Poaceae pollen (2.26%), Humulus pollen or Cannabis pollen (0.60%). Conclusion: There were two peaks of main airborne allergenic pollen in 4 districts and 5 counties of Hohhot City. In the spring peak of pollen, the main airborne pollens were tree pollens. In the summer and autumn peak of pollen, the main airborne pollens were weed pollens. The Artemisia pollen was the most major airborne pollen in this area.

Association between allostatic load and adverse outcomes among older patients with heart failure with preserved ejection fraction

BACKGROUND

The allostatic load (AL) refers to the cumulative weakening of multiple physiological systems caused by repeated adaptation of the body to stressors There are still no studies have focused on the association between AL and the prognosis of patients with heart failure with preserved ejection fraction (HFpEF). The present study aimed to investigate the association between AL and adverse outcomes, including mortality and HF admission, among elderly male patients with HFpEF.

METHODS

We conducted a prospective cohort study of 1111 elderly male patients with HFpEF, diagnosed between 2015 and 2019 and followed up through 2021. We constructed an AL measure using a combination of 12 biomarkers. The diagnosis of HFpEF was made according to the 2021 European Society of Cardiology guidelines. A Cox proportional hazards model was used to determine the associations between AL and adverse outcomes.

RESULTS

In multivariate analysis, AL was significantly associated with increased risk of all-cause mortality (medium AL: adjusted hazard ratio [HR] = 2.53; 95% confidence interval [CI] 1.37-4.68; high AL: HR = 4.21; 95% CI 2.27-7.83; per-score increase: HR = 1.31; 95% CI 1.18-1.46), cardiovascular mortality (medium AL: HR = 2.67; 95% CI 1.07-6.68; high AL: HR = 3.13; 95% CI 1.23-7.97; per-score increase: HR = 1.20; 95% CI 1.03-1.40), non-cardiovascular mortality (medium AL: HR = 2.45; 95% CI 1.06-5.63; high AL: HR = 5.81; 95% CI 2.55-10.28; per-score increase: HR = 1.46; 95% CI 1.26-1.69), and HF admission (medium AL: HR = 2.68; 95% CI 1.43-5.01; high AL: HR = 3.24; 95% CI 1.69-6.23; per-score increase: HR = 1.24; 95% CI 1.11-1.39). Consistent results were found in multiple subgroup analyses.

CONCLUSIONS

A higher AL was associated with poor prognosis in elderly men with HFpEF. AL relies on information that is easily obtained in physical examinations and laboratory parameters and can be assessed in various care and clinical settings to help risk stratification of HFpEF patients.

A comparison of three approaches to measuring frailty to determine adverse health outcomes in critically ill patients

BACKGROUND

studies comparing different frailty measures in intensive care unit settings are lacking. We aimed to compare the frailty index based on physiological and laboratory tests (FI-Lab), modified frailty index (MFI) and hospital frailty risk score (HFRS) to predict short-term outcomes for critically ill patients.

METHODS

we conducted a secondary analysis of data from the Medical Information Mart for Intensive Care IV database. Outcomes of interest included in-hospital mortality and discharge with need for nursing care.

RESULTS

the primary analysis was conducted with 21,421 eligible critically ill patients. After adjusting for confounding variables, frailty as diagnosed by all three frailty measures was found to be significantly associated with increased in-hospital mortality. In addition, frail patients were more likely to receive further nursing care after being discharged. All three frailty scores could improve the discrimination ability of the initial model generated by baseline characteristics for adverse outcomes. The FI-Lab had the best predictive ability for in-hospital mortality, whereas the HFRS had the best predictive performance for discharge with need for nursing care amongst the three frailty measures. A combination of the FI-Lab with either the HFRS or MFI improved the identification of critically ill patients at increased risk of in-hospital mortality.

CONCLUSIONS

frailty, as assessed by the HFRS, MFI and FI-Lab, was associated with short-term survival and discharge with need for nursing care amongst critically ill patients. The FI-Lab was a better predictor of in-hospital mortality than the HFRS and MFI. Future studies focusing on FI-Lab are warranted.

Association between Frailty Assessed Using Two Electronic Medical Record-Based Frailty Assessment Tools and Long-Term Adverse Prognosis in Older Critically Ill Survivors

OBJECTIVES

Frailty has become an independent risk factor for adverse outcomes in critically ill patients. This study aimed to explore the predictive ability of two electronic medical record-based frailty assessment tools, the Hospital Frailty Risk Score (HFRS) and Frailty Index based on physiological and laboratory tests (FI-lab), for long-term adverse prognosis in older critically ill survivors.

DESIGN

Retrospective observational study.

SETTING AND PARTICIPANTS

9,082 critically ill survivors aged ≥ 65 years.

MEASUREMENTS

The HFRS and the 33-item FI-lab were constructed based on the published literature. Cox and logistic regression models assessed the association between frailty and 1-year mortality and post-discharge care needs.

RESULTS

2,586 patients died within 1 year of follow-up. In fully adjusted models, frailty assessed using both the HFRS (per point, hazard ratio [HR] 1.06, 95% confidential interval [CI] 1.05-1.06; intermediate frailty risk, HR 2.00, 95% CI 1.78-2.25; high frailty risk, HR 3.06, 95% CI 2.68-3.50) and FI-lab (per 0.01 points, HR 1.03, 95% CI 1.03-1.03; intermediate frailty risk, HR 1.59, 95% CI 1.44-1.76; high frailty risk, HR 2.30, 95% CI 2.06-2.57) was associated with mortality. Addition of frailty indicators improved the predictive validity of the Sequential Organ Failure Assessment score for mortality (HFRS alone ∆ C-index 0.034; FI-lab alone ∆ C-index 0.016; HFRS and FI-lab combined ∆ C-index 0.042). The HFRS but not the FI-lab was associated with higher probability of post-discharge care needs.

CONCLUSION

Both the HFRS and FI-lab could independently predict 1-year mortality in older critically ill survivors. Adding the HFRS to the SOFA score model improved it more than adding the FI-lab. The greatest improvement was achieved when both frailty indicators were used together. These findings suggest that electronic medical record-based frailty assessment methods can be useful tools for predicting long-term outcomes in older critically ill patients.

Association between frailty and short- and long-term mortality in patients with critical acute myocardial infarction: Results from MIMIC-IV

Background

Frailty has been recognized as an important prognostic indicator in patients with acute myocardial infarction (AMI). However, no study has focused on critical AMI patients. We aimed to determine the impact of frailty on short- and long-term mortality risk in critical AMI patients.

Methods

Data from the Medical Information Mart for Intensive Care (MIMIC)-IV database was used. Frailty was assessed using the Hospital Frailty Risk Score (HFRS). Outcomes were in-hospital mortality and 1-year mortality. Logistic regression and Cox proportional-hazards models were used to investigate the association between frailty and outcomes.

Results

Among 5,003 critical AMI patients, 2,176 were non-frail (43.5%), 2,355 were pre-frail (47.1%), and 472 were frail (9.4%). The in-hospital mortality rate was 13.8%, and the 1-year mortality rate was 29.5%. In our multivariable model, frailty was significantly associated with in-hospital mortality [odds ratio (OR) = 1.30, 95% confidence interval (CI): 1.20-1.41] and 1-year mortality [hazard ratio (HR) = 1.29, 95% CI: 1.24-1.35] as a continuous variable (per five-score increase). When assessed as categorical variables, pre-frailty and frailty were both associated with in-hospital mortality (OR = 2.80, 95% CI: 2.19-3.59 and OR = 2.69, 95% CI: 1.93-3.73, respectively) and 1-year mortality (HR = 2.32, 95% CI: 2.00-2.69 and HR = 2.81, 95% CI: 2.33-3.39, respectively) after adjustment for confounders. Subgroup analysis showed that frailty was only associated with in-hospital mortality in critically ill patients with non-ST-segment elevation myocardial infarction (STEMI) but not STEMI (p for interaction = 0.012). In addition, frailty was associated with 1-year mortality in both STEMI and non-STEMI patients (p for interaction = 0.447). The addition of frailty produced the incremental value over the initial model generated by baseline characteristics for both in-hospital and 1-year mortality.

Conclusion

Frailty, as assessed by the HFRS, was associated with both in-hospital and 1-year mortality in critical AMI patients. Frailty improves the prediction of short- and long-term mortality in critical AMI patients and may have potential clinical applications.

Frailty index based on laboratory tests improves prediction of short-and long-term mortality in patients with critical acute myocardial infarction

Background

Previous studies have shown that the frailty index based on laboratory tests (FI-Lab) can identify older adults at increased risk of adverse health outcomes. This study aimed to determine whether the FI-Lab is associated with mortality risk and can provide incremental improvements in risk stratification of patients with critical acute myocardial infarction (AMI).

Materials and methods

We conducted a secondary analysis of data from the Medical Information Mart for Intensive Care (MIMIC)-IV database. A 33-item FI-Lab was constructed. Outcomes of interest were in-hospital and 1-year mortality. Logistic regression models were used to investigate the association between the FI-Lab and outcomes. For the assessment of the incremental predictive value, the FI-Lab was added to several risk stratification scoring systems for critically ill patients, and the following indices were calculated: Δ C-statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI).

Results

Out of 2,159 patients, 477 died in hospital (22.1%), and 898 died during the 1-year follow-up period. After adjustment for confounders, the FI-Lab was associated with increased in-hospital mortality [odds ratio (OR) = 1.06, 95% confidence interval (CI): 1.05-1.07] and 1-year mortality (OR = 1.05, 95% CI: 1.04-1.06) when assessed as a continuous variable (per 0.01-score increase). When assessed as a categorical variable, the FI-Lab was associated with in-hospital mortality (2nd Quartile: OR = 1.89, 95% CI: 1.18-3.03; 3rd Quartile: OR = 3.46, 95% CI: 2.20-5.46; and 4th Quartile: OR = 5.79, 95% CI: 3.61-9.28 compared to 1st Quartile) as well as 1-year mortality (2nd Quartile: OR = 1.66, 95% CI: 1.23-2.24; 3rd Quartile: OR = 2.40, 95% CI: 1.76-3.26; and 4th Quartile: OR = 3.76, 95% CI: 2.66-5.30 compared to 1st Quartile) after adjustment for confounders. The addition of the FI-Lab to all disease severity scores improved discrimination and significantly reclassified in-hospital and 1-year mortality risk.

Conclusion

The FI-Lab was a strong predictor of short- and long-term mortality in patients with critical AMI. The FI-Lab improved the ability to predict mortality in patients with critical AMI and therefore might be useful in the clinical decision-making process.

Characteristics of oral microbiota in plateau and plain youth‐positive correlations between blood lipid level, metabolism and specific microflora in the plateau group

Objectives

To analyze the characteristics of oral microbiota in plateau and plain youth and the possible function of the microbiome.

Materials and methods

A total of 120 healthy young males (80 on the plateau, 40 on the plain) completed this cross-sectional study. Oral microflora samples were collected from all participants. The bacterial 16S rDNA was amplified using PCR and sequenced using Illumina MiSeq high-throughput sequencing. The data were analyzed to determine the microbial distribution and community structure of the oral microflora from the two groups. Metastats was used to test differences in relative species abundance between the groups. The correlation between the abundance of specific bacteria and blood indicators was also analyzed.

Results

As demonstrated by alpha and beta diversity, the plateau group had lower microbial richness and a less even distribution of oral microbiota than the plain group. All predominant phyla and genera were qualitatively similar between the two groups, but their relative abundances differed. The relative abundance of bacteria in the phylum Firmicutes was significantly higher in the plateau group than in the plain group. At the genus level, Streptococcus spp. and Gemella spp. were also more abundant in the plateau group. The functional prediction indicated vigorous microbial metabolism in the oral bacterial community. We also found that the relative abundance of Streptococcus spp., the dominant genus, was positively correlated with triglyceride levels in the plateau group.

Conclusions

With increasing altitude, the diversity of oral microbiota and the relative proportion of predominant bacteria were altered. The distribution and related function of Streptococcus spp. were prominent in plateau samples. This comprehensive study of the relationship between oral microecology and elevation provides a point of reference for studying the human body’s adaptability or inadaptability to high altitude.

Impact of the CYP2D6 Genotype on Metoprolol Tolerance and Adverse Events in Elderly Chinese Patients With Cardiovascular Diseases

The latest consensus has changed CYP2D6 genotyping among Chinese population, while its impact on metoprolol tolerance and adverse events in elderly Chinese patients with cardiovascular diseases remains unclear. In this study, we prospectively included elderly patients who started metoprolol treatment for cardiovascular indications. According to the latest consensus on CYP2D6 genotype-to-phenotype translation, the patients were categorized as normal, intermediate, or poor metabolizers (NMs, IMs, or PMs, respectively) by detecting the presence of the CYP2D6*1, *2, *5, *10, and *14. Logistic regression model was used to analyze the correlation between the CYP2D6 phenotype and incidence of adverse events, which were assessed over a 12-week period. In this study, there were 651 (62.7%) NMs, 385 (37.1%) IMs, and 3 (0.3%) PMs. After 12 weeks of follow-up, compared with NMs, IMs had the lower maintenance dose [50.0 (25.0–50.0) mg/day vs. 25.0 (25.0–50.0) mg/day, p < 0.001] and lower weight-adjusted maintenance doses (0.52 ± 0.25 mg/day/kg vs. 0.42 ± 0.22 mg/day/kg, p < 0.001), and had higher incidence of postural hypotension (6.0% vs. 10.9%, p = 0.006), bradycardia (21.5% vs. 28.6%, p = 0.011), asystole (0.8% vs. 3.1%, p = 0.009) and syncope (2.0% vs. 6.2%, p = 0.001). In logistic regression model, the overall incidence of adverse events was 1.37-fold larger in IMs than in NMs (odds ratio = 1.37, 95% confidence interval = 1.05–1.79, p = 0.021). We conclude that IMs have lower tolerance and higher incidence of metoprolol-related adverse events than NMs in elderly Chinese patients with cardiovascular diseases. CYP2D6 genotyping is justifiable in elderly patients to minimize the risk of adverse events and ensure the benefits of metoprolol.

[Investigation of contamination of SARS-CoV-2 in imported frozen seafood from a foreign cargo ship and risk factors for infection in stevedores in Qingdao]

Objective: To investigate the contamination status of SARS-CoV-2 in imported frozen seafood from a Russia cargo ship in Qingdao and to analyze the risk factors for infection in local stevedores. Methods: The method of "two-stage, full coverage and mixed sampling" was used to collect the seafood packaging samples for the nucleic acid detection of SARS-CoV-2 by real-time fluorescent quantitative RT-PCR. A unified questionnaire was designed to investigate 71 stevedores in two shifts through telephone interview. The stevedores were divided into two groups, with 23 in the shit with two infections was group A and 48 in the shift without infection was group B. Software Epi Info7.2 was used to identify the risk factors for SARS-CoV-2 infections in the stevedores. Results: In the frozen seafood from a Russia cargo ship, the total positive rate of SARS-CoV-2 nucleic acid in the frozen seafood was 11.53% (106/919). The positive rate of SARS-CoV-2 nucleic acid in the frozen seafood unloaded by group A (14.29%,70/490) was significantly higher than that in the frozen seafood unloaded by group B (8.39%,36/429)(χ²=7.79,P=0.01) and the viral loads detected in the frozen seafood unloaded by group A were higher than those detected in the frozen seafood unloaded by group B. The scores of personal protection and behaviors in the stevedores in group A were significantly lower than those in group B (P<0.05), and toilet use, smoking and improper hand washing before meals were the risk factors for the infection. Conclusions: The imported frozen seafood was contaminated by SARS-CoV-2 and the contamination distribution was uneven. Supervision and management of personal occupational protection and behaviors of workers engaged in imported frozen food transportation should be strengthened. It is suggested that a closed-loop monitoring and management system for the whole process of "fishing-transport- loading/unloading" should be established by marine fishery authority.

Associations of falls and severe falls with blood pressure and frailty among Chinese community-dwelling oldest olds: The Chinese Longitudinal Health and Longevity Study

INTRODUCTION

Falls are a leading cause of death among Chinese oldest olds. However, studies on Chinese community-dwelling older adults are lacking. We aimed to identify the associations of falls and severe falls with blood pressure and frailty among Chinese community-dwelling oldest olds.

METHODS

Cross-sectional analyses were conducted with 6,595 community-dwelling oldest olds (aged ≥80 years) from 22 Chinese provinces from the Chinese Longitudinal Health and Longevity Study (CLHLS). Systolic BP (SBP) and diastolic BP (DBP) were measured twice at participants' homes, and a 38-item frailty index was used to assess the frailty status of participants. Falls and severe falls were confirmed through face-to-face interviews. Multivariate logistic regression was used to investigate the associations of BP and frailty with falls and severe falls.

RESULTS

The mean participant age was 91.0 years, and 56.1% were female. In total, 24.2% participants had a history of fall and 8.3% had a history of severe falls. The multivariate-adjusted odds ratio (OR) for falls among the oldest old with SBP ≥140 mm Hg compared to those with an SBP of 120-129 mm Hg was 1.20 (95% confidence interval [CI], 1.01-1.44). The adjusted OR for falls among frail participants compared to robust participants was 1.39 (95% CI, 1.02-1.89). DBP and pre-frailty were not associated with falls after multivariate adjustment. SBP, DBP, and frailty status were not associated with severe falls after multivariate adjustment.

CONCLUSIONS

SBP and frailty but not DBP and pre-frailty are associated with increased odds of falls among Chinese community-dwelling oldest olds.

Waist to height ratio is associated with an increased risk of mortality in Chinese patients with heart failure with preserved ejection fraction

Background

Abdominal obesity as a predominant comorbidity has played a key role in the incidence and worsening of heart failure with preserved ejection fraction (HFpEF), and waist-to-height ratio (WHtR) behaves better than waist circumference or body mass index in evaluating abdominal obesity. While the association between WHtR and all-cause death in Chinese patients with HFpEF remains unclear.

Methods

Patients with stable HFpEF (N = 2041) who presented to our hospital from January 2008 to July 2019 were divided into low-WHtR (< 0.5, N = 378) and high-WHtR (≥ 0.5, N = 1663). Multivariable Cox proportional-hazard models were used to examine the association of WHtR with all-cause death.

Results

The average age was 76.63 ± 11.44 years, and the mean follow-up was 4.53 years. During follow-up, 185 patients (9.06%) reached the primary outcome of all-cause death. As for the secondary outcome, 79 patients (3.87%) experienced cardiovascular death, 106 (5.19%) had non-cardiovascular death, and 94 (4.61%) had heart failure rehospitalization. After multivariable adjustment, a higher WHtR was significantly associated with the increased risks of all-cause death [adjusted hazard ratios (HR) 1.91, 95% confidence interval (CI) 1.06–3.45, p = 0.032], cardiovascular death (adjusted HR 2.58; 95% CI 1.01–6.67, p = 0.048), and HF rehospitalization (adjusted HR 3.04; 95% CI 1.26–7.31, p = 0.013).

Conclusions

Higher WHtR is an independent risk factor for all-cause death in Chinese patients with HFpEF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02080-9.

Prognostic value of soluble suppression of tumorigenesis-2 (sST2) for cardiovascular events in coronary artery disease patients with and without diabetes mellitus

Background

Soluble suppression of tumorigenesis-2 (sST2) is implicated in myocardial overload and has long been recognized as an inflammatory marker related to heart failure and acute coronary syndrome, but data on the prognostic value of sST2 in patients with coronary artery disease (CAD) remain limited. This study sought to investigate the prognostic value of sST2 in patients with established CAD and its predictive value in CAD patients with and without type 2 diabetes mellitus (T2DM).

Methods

A total of 3641 consecutive patients were included in this prospective cohort study. The primary end point was major adverse cardiovascular events (MACEs). The secondary end point was all-cause death. The association between sST2 and outcomes was investigated using multivariable Cox regression.

Results

During a median follow-up of 6.4 years, MACEs occurred in 775 patients, and 275 patients died. Multiple Cox regression models showed that a higher level of sST2 was an independent predictor of MACEs development (HR = 1.36, 95% CI 1.17–1.56, p < 0.001) and all-cause death (HR = 2.01, 95% CI 1.56–2.59, p < 0.001). The addition of sST2 to established risk factors significantly improved risk prediction of the composite outcome of MACEs and all-cause death (C-index, net reclassification index, and integrated discrimination improvement, all p < 0.05). In subgroup analysis depending on diabetes status, the diabetes group had a significantly higher level of sST2, which remained a significant predictor of MACEs and all-cause death in patients with and without T2DM in multivariable models. The area under the curve (AUC) of CAD patients with diabetes mellitus was significantly higher than that of those without T2DM. For MACEs, the AUC was 0.737 (patients with T2DM) vs 0.620 (patients without T2DM). For all-cause death, the AUC was 0.923 (patients with T2DM) vs 0.789 (patients without T2DM).

Conclusions

A higher level of sST2 is significantly associated with long-term MACEs and all-cause death in CAD patients with and without T2DM. sST2 has strong predictive value for cardiovascular adverse events in CAD patients with T2DM, and these results provide new evidence for the role of sST2.

Impulse Control and ERP Characteristics of Patients with Mental Disorder Caused by Traumatic Brain Injury

Abstract

Objective To explore the impulse control and event-related potential （ERP） characteristics of patients with mental disorders caused by traumatic brain injury （TBI） in forensic psychiatry identification and to provide objective auxiliary indicators for forensic psychiatry identification. Methods Thirty patients （TBI group） with mental disorders caused by traumatic brain injury, who were identified as mild psychiatric impairment by judicial psychiatry, including 24 males and 6 females, as well as the thirty people in the control group participated in the study. All the participants completed Barratt Impulsiveness Scale-11 （BIS-11） and ERP induced by Go/NoGo tasks. BIS-11 and ERP data were collected and analyzed. Results The results of the BIS-11 showed that the total score and subscale scores of the TBI group were higher compared to the control group （P<0.05）. Moreover, the TBI group exhibited significantly lower NoGo-N2 amplitude and lower NoGo-P3 amplitude than the control group. The NoGo-N2 amplitude was larger than the Go-N2 amplitude, and the NoGo-P3 amplitude was larger than the Go-P3 amplitude in both groups （P<0.05）. Conclusion Traumatic brain injury could impair impulse control of mild psychiatric impairment patients, and the amplitudes of NoGo-N2 and NoGo-P3 could be important parameters to evaluate the impulse control of patients with mental disorders caused by traumatic brain injury.

FBXW7 regulates DISC1 stability via the ubiquitin-proteosome system

Disrupted in schizophrenia 1 (DISC1) is a multi-functional scaffolding protein that has been associated with neuropsychiatric disease. The role of DISC1 is to assemble protein complexes that promote neural development and signaling, hence tight control of the concentration of cellular DISC1 in neurons is vital to brain function. Using structural and biochemical techniques, we show for we believe the first time that not only is DISC1 turnover elicited by the ubiquitin proteasome system (UPS) but that it is orchestrated by the F-Box protein, FBXW7. We present the structure of FBXW7 bound to the DISC1 phosphodegron motif and exploit this information to prove that disruption of the FBXW7-DISC1 complex results in a stabilization of DISC1. This action can counteract DISC1 deficiencies observed in neural progenitor cells derived from induced pluripotent stem cells from schizophrenia patients with a DISC1 frameshift mutation. Thus manipulation of DISC1 levels via the UPS may provide a novel method to explore DISC1 function.

[Correlation between Genetic Variants and Polymorphism of Caveolin and Sudden Unexplained Death]

OBJECTIVES

To explore the genetic variation sites of caveolin （CAV） and their correlation with sudden unexplained death （SUD）.

METHODS

The blood samples were collected from SUD group （71 cases）, coronary artery disease （CAD） group （62 cases） and control group （60 cases）, respectively. The genome DNA were extracted and sequencing was performed directly by amplifying gene coding region and exon-intron splicing region of CAV1 and CAV3 using PCR. The type of heritable variation of CVA was confirmed and statistical analysis was performed.

RESULTS

A total of 4 variation sites that maybe significative were identified in SUD group, and two were newfound which were CAV1： c.45C>T （T15T） and CAV1：c.512G>A （R171H）, and two were SNP loci which were CAV1：c.246C>T （rs35242077） and CAV3：c.99C>T （rs1008642） and had significant difference （P<0.05） in allele and genotype frequencies between SUD and control groups. Forementioned variation sites were not found in CAD group.

CONCLUSIONS

The variants of CAV1 and CAV3 may be correlated with a part of SUD group.

[Research Progress of the Correlation between Caveolin and Unexpected Sudden Cardiac Death]

Due to the negative autopsy and without cardiac structural abnormalities, unexpected sudden cardiac death （USCD） is always a tough issue for forensic pathological expertise. USCD may be associated with parts of fatal arrhythmic diseases. These arrhythmic diseases may be caused by disorders of cardiac ion channels or channel-related proteins. Caveolin can combine with multiple myocardial ion channel proteins through its scaffolding regions and plays an important role in maintaining the depolarization and repolarization of cardiac action potential. When the structure and function of caveolin are affected by gene mutations or abnormal protein expression, the functions of the regulated ion channels are correspondingly impaired, which leads to the occurrence of multiple channelopathies, arrhythmia or even sudden cardiac death. It is important to study the effects of caveolin on the functions of ion channels for exploring the mechanisms of malignant arrhythmia and sudden cardiac death.

Biosynthesis of natural and novel C-glycosylflavones utilising recombinant Oryza sativa C-glycosyltransferase (OsCGT) and Desmodium incanum root proteins

The rice C-glycosyltransferase (OsCGT) is one of only a small number of characterised plant C-glycosyltransferases (CGT) known. The enzyme C-glucosylates a 2-hydroxyflavanone substrate with UDP-glucose as the sugar donor to produce C-glucosyl-2-hydroxyflavanones. We tested substrate specificity of the enzyme, using synthetic 2-hydroxyflavanones, and showed it has the potential to generate known natural CGFs that have been isolated from rice and also other plants. In addition, we synthesised novel, unnatural 2-hydroxyflavanone substrates to test the B-ring chemical space of substrate accepted by the OsCGT and demonstrated the OsCGT capacity as a synthetic reagent to generate significant quantities of known and novel CGFs. Many B-ring analogues are tolerated within a confined steric limit. Finally the OsCGT was used to generate novel mono-C-glucosyl-2-hydroxyflavanones as putative biosynthetic intermediates to examine the potential of Desmodium incanum biosynthetic CGTs to produce novel di-C-glycosylflavones, compounds implicated in the allelopathic biological activity of Desmodium against parasitic weeds from the Striga genus.

Isolation and identification of Desmodium root exudates from drought tolerant species used as intercrops against Striga hermonthica

Plants from the genus Desmodium, in particular D. uncinatum, are used on sub-Saharan small-holder farms as intercrops to inhibit parasitism of cereal crops by Striga hermonthica and Striga asiatica via an allelopathic mechanism. The search for Desmodium species which are adapted to more arid conditions, and which show resilience to increased drought stress, previously identified D. intortum, D. incanum and D. ramosissimum as potential drought tolerant intercrops. Their potential as intercrops was assessed for resource poor areas of rain-fed cereal production where drought conditions can persist through normal meteorological activity, or where drought may have increasing impact through climate change. The chemical composition of the root exudates were characterised and the whole exudate biological activity was shown to be active in pot experiments for inhibition of Striga parasitism on maize. Furthermore, rain fed plot experiments showed the drought tolerant Desmodium intercrops to be effective for Striga inhibition. This work demonstrates the allelopathic nature of the new drought tolerant intercrops through activity of root exudates and the major compounds seen in the exudates are characterised as being C-glycosylflavonoid. In young plants, the exudates show large qualitative differences but as the plants mature, there is a high degree of convergence of the C-glycosylflavonoid exudate chemical profile amongst active Desmodium intercrops that confers biological activity. This defines the material for examining the mechanism for Striga inhibition.

Epidemiology and molecular characterization of bacteremia due to carbapenem-resistant Klebsiella pneumoniae in transplant recipients

We conducted a retrospective study of 17 transplant recipients with carbapenem-resistant Klebsiella pneumoniae bacteremia, and described epidemiology, clinical characteristics and strain genotypes. Eighty-eight percent (15/17) of patients were liver or intestinal transplant recipients. Outcomes were death due to septic shock (18%), cure (24%) and persistent (>7 days) or recurrent bacteremia (29% each). Thirty- and 90-day mortality was 18% and 47%, respectively. Patients who were cured received at least one active antimicrobial agent and underwent source control interventions. Forty-one percent (7/17) of patients had intra-abdominal infections; all except one developed persistent/recurrent bacteremia despite drainage. Two patients tolerated persistent bacteremia for >300 days. All patients except one were infected with sequence type 258 (ST258), K. pneumoniae carbapenemase (KPC)-2-producing strains harboring a mutant ompK35 porin gene; the exception was infected with an ST37, KPC-3-producing strain. Seventy-one percent (12/17) of patients were infected with ST258 ompK36 mutant strains. In two patients, persistent bacteremia was caused by two strains with different ompK36 genotypes. Three ompK36 mutations were associated with significantly higher carbapenem minimum inhibitory concentrations than wild-type ompK36. Pulse-field gel electrophoresis identified a single ST258 lineage; serial strains from individual patients were indistinguishable. In conclusion, KPC-K. pneumoniae bacteremia exhibited highly diverse clinical courses following transplantation, and was caused by clonal ST258 strains with different ompK36 genotypes.

Screening of genes expressed in vivo after infection by Vibrio anguillarum M3

AIMS

Genes uniquely expressed in vivo may contribute to the overall pathogenicity of an organism and are likely to serve as potential targets for the development of new vaccine. This study aims to screen the genes expressed in vivo after Vibrio anguillarum infection by in vivo-induced antigen technology (IVIAT).

METHODS AND RESULTS

The convalescent-phase sera were obtained from turbot (Scophthalmus maximus) survived after infection by the virulent V. anguillarum M3. The pooled sera were thoroughly adsorbed with M3 cells and Escherichia coli BL21 (DE3) cells. A genomic expression library of M3 was constructed and screened for the identification of immunogenic proteins by colony immunoblot analysis with the adsorbed sera. After three rounds of screening, 19 putative in vivo-induced (ivi) genes were obtained. These ivi genes were catalogued into four functional groups: regulator/signalling, metabolism, biological process and hypothetical proteins. Three ivi genes were insertion-mutated, and the growth and 50% lethal dose (LD(50) ) of these mutants were evaluated.

CONCLUSIONS

The identification of ivi genes in V. anguillarum M3 sheds light on understanding the bacterial pathogenesis and provides novel targets for the development of new vaccines and diagnostic reagents.

SIGNIFICANCE AND IMPACT OF THE STUDY

To the best of our knowledge, this is the first report describing in vivo-expressed genes of V. anguillarum using IVIAT. The screened ivi genes in this study could be new virulent factors and targets for the development of vaccine, which may have implications for the development of diagnostic regents.

Bicyclol for chronic hepatitis B

BACKGROUND

Bicyclol is a novel synthetic 'anti-hepatitis' drug, used in China for chronic hepatitis B. Until now, systematic reviews of bicyclol therapy have not been performed.

OBJECTIVES

To study the benefits and harms of bicyclol for patients with chronic hepatitis B.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (July 2005), The Cochrane Central Register of Controlled Trials in The Cochrane Library (Issue 2, 2005), MEDLINE (1950 to July 2005), EMBASE (1980 to July 2005), Science Citation Index Expanded (1945 to July 2005), The Chinese Biomedical Database (1994 to August 2005), VIP Chinese Science and Technique Journals Database (1994 to August 2005), and China National Infrastructure (CNKI)(1994 to August 2005). We also contacted manufacturers and researchers in the field.

SELECTION CRITERIA

Randomised clinical trials with bicyclol versus no intervention, placebo, or other interventions were included, irrespective of blinding, publication status, or language.

DATA COLLECTION AND ANALYSIS

The primary outcome measures were mortality (total and liver-related) and liver-related morbidity (eg, cirrhosis and carcinoma). Secondary outcome measures were viral response and liver histology.

MAIN RESULTS

The search identified one randomised clinical trial comparing bicyclol with bifendate (biphenyldicarboxylate) for patients with hepatitis B. The follow-up was three months. There was no evidence that bicyclol was superior to bifendate for loss of HBeAg (RR 1.38, 95% CI 0.95 to 2.00), seroconversion of HBeAg to HBeAb (RR 1.44, 95% CI 0.90 to 2.29), loss of HBV DNA (RR 1.19, 95%CI 0.93 to 1.53), or number of patients with normalised alanine aminotransferase and aspartate aminotransferase activity (RR 0.88, 95% CI 0.70 to 1.11 and RR 0.97, 95% CI 0.79 to 1.20, respectively).

AUTHORS' CONCLUSIONS

Only one randomised clinical trial has examined the potential benefit of bicyclol for patients with chronic hepatitis B. This small, short-term trial found no evidence to support or refute its use. Large, randomised double-blind clinical trials with long-term follow-up are needed to examine the possible benefits and harms associated with bicyclol. Bicyclol can only be recommended for use in randomised trials.

A novel T-77C polymorphism in DNA repair gene XRCC1 contributes to diminished promoter activity and increased risk of non-small cell lung cancer

X-ray repair cross-complementing 1 (XRCC1) plays a key role in DNA base excision repair and cells lacking its activity are hypersensitive to DNA damage. Recently, we reported a SNP (rs3213245, -77T>C) in the XRCC1 gene 5' untranslated region (UTR) was significantly associated with the risk of developing esophageal squamous-cell carcinoma. Computer analysis predicted that this SNP was in the core of Sp1-binding motif, which suggested its functional significance. Gel shift and super shift assays confirmed that -77T>C polymorphic site in the XRCC1 promoter was within the Sp1-binding motif and the T>C substitution greatly enhanced the binding affinity of Sp1 to this region. Luciferase assays indicated that the Sp1-high-affinity C-allelic XRCC1 promoter was associated with a reduced transcriptional activity. The association between -77T>C and three other amino-acid substitution-causing polymorphisms in XRCC1 and risk of lung cancer was examined in 1024 patients and 1118 controls and the results showed that only the -77T>C polymorphism was significantly associated with an increased risk of developing lung cancer. Multivariate logistic regression analysis found that an increased risk of lung cancer was associated with the variant XRCC1 -77 genotypes (TC and CC) compared with the TT genotype (OR=1.46, 95% CI=1.18-1.82; P=0.001) and the increased risk was more pronounced in smokers (OR=1.63, 95% CI=1.20-2.21) than in non-smokers (OR=1.28, 95% CI=0.94-1.76). Taken together, these results showed that the functional SNP -77T>C in XRCC1 5'UTR was associated with cancer development owing to the decreased transcriptional activity of C-allele-containing promoter with higher affinity to Sp1 binding.

Osteopontin regulation by protein kinase B (Akt) in HepG2 cells

AIM

The mechanism responsible for osteopontin regulation is not understood in HepG2 cells. The aim of this study was to investigate the relationship between protein kinase B (Akt), a key gene in PI3K signal transduction pathway, and osteopontin expression.

METHODS

HepG2 cells were transfected with constitutively active Akt and dominant negative Akt using lipofectin. The Akt transfection was confirmed by Western blot analysis. Osteopontin expression was detected by both Northern blot and Western blot.

RESULTS

Overexpression of exogenous Akt was detected in HepG2 cells by Western blot, indicating that HepG2 cells were successfully transfected with the Akt genes. In serum-free condition, the expression of osteopontin was either low or undetectable in HepG2 cells transfected with vector only, however, the expression increased after transfection of cells with constitutively active Akt. Osteopontin expression decreased when HepG2 cells were transfected with dominant negative Akt.

CONCLUSION

Protein kinase B (Akt) gene regulated osteopontin expression in RNA level and protein level, suggesting that osteopontin synthesis can be blocked by inactivation of the Akt gene. This leads to a potential means of intervention for the inhibition of metastases in liver cancer.

Linkage Disequilibrium and Haplotype Architecture for two ABC Transporter Genes (ABCC1 and ABCG2) in Chinese Population: Implications for Pharmacogenomic Association Studies

Information about linkage disequilibrium (LD) patterns and haplotype structures for candidate genes is instructive for the design and analysis of genetic association studies for complex diseases and drug response. ABCC1 and ABCG2 are genes coding for two multidrug resistance (MDR) associated transporters; they are also related to some pathophysiological traits. To pinpoint the LD profiles of these MDR genes in Chinese, we systemically screened 27 unrelated individuals for single nucleotide polymorphisms (SNPs) in the coding and regulatory regions of these genes, and thereby characterized their haplotype structures. Despite marked variations in haplotype diversity, LD pattern and intragenic recombination intensity between the two genes, both loci could be partitioned into several LD blocks, in which a modest number of haplotypes accounted for a high fraction of the sampled chromosomes. We concluded that each locus has its own genomic LD profile, but that they still share a common segmental LD architecture with low haplotype diversity. Our data will benefit genetic association studies of complex traits and drug response possibly related to these genes.

[Genetic polymorphism of eight STR loci in the Han population in Henan province]

OBJECTIVE

To investigate the allele frequencies of eight short tandem repeats(STR) loci: TH01, FES, D19S400, D7S820, D16S539, D20S161, D3S1545 and D5S818 in Han population in Henan province.

METHODS

DNA was extracted with phenol-chloroform from EDTA-blood samples of the unrelated individuals in Henan province and amplified with PCR technique. The PCR product was analyzed with the undenatured PAGE vertical electrophoresis and silver-stain.

RESULTS

The authors got the frequencies of the eight loci. The heterozygosities of the eight loci are 0.66, 0.67, 0.80, 0.76, 0.79, 0.79, 0.78 and 0.78; the discrimination powers are 0.83, 0.83, 0.94, 0.91, 0.93, 0.93, 0.92 and 0.92.

CONCLUSION

The heterozygosities of the eight loci are high and the frequencies are in good agreement with Hardy-Weinberg equilibrium, so the eight loci can be used in individual identification testing.

[Relationship between interleukin-2, interleukin-2 receptor and the non-and hypo-responsiveness to hepatitis B vaccine]

OBJECTIVE

To study the relationship between interleukin-2 (IL-2), soluble interleukin-2 receptor (sIL-2R) and the non-and-hypo-responsiveness to hepatitis B vaccine.

METHODS

Peripheral blood mononuclear cells (PBMC) isolated from 21 non-and -hypo-responders, 22 hyperresponders and 21 chronic HBsAg carriers were incubated in the presence of HBsAg and phytohaemagglutinin (PHA). The levels of IL-2 and sIL-2R in the supernatants of activated cells were measured by an enzyme-linked immunosorbent assay.

RESULTS

The average level of IL-2 in the non-and-hypo-responders was significantly lower than that in the hyperresponders (t=8.80, P<0.001), but was comparable to that in chronic HBsAg carriers (q=0.06, P>0.5). Between the hyperresponders and the non-and-hypo-responders, the average sIL-2R levels showed no noticeable difference.

CONCLUSION

The results suggest that low level of IL-2 may be one of the causes and mechanisms of non-and-hypo-responsiveness to hepatitis B vaccine.

[Study on statistical method of distribution for erythrocyte morphological features by computerized image processing]

This study sought to develop a new statistic method for the semiautomatic analysis and classification of erythrocyte morphology based on the morphological features and shape analysis of erythrocytes by computer image processing. Shape factor as the description of the erythrocyte morphological features was used for the shape classification of erythrocytes. And the models and algorithms of erythrocytes image segmentation, cell body shape recognition and measure can be implemented through the VC++. The present method can efficiently and semi-automatically provide the statistical analysis of erythrocyte morphology, and can give the distribution of erythrocyte morphological features. The result showed that there was a significant difference between the distribution curves of the normal erythrocyte morphology (one apex) and hemolytic anemia's (two apices). By this way, it can be obtained the proportion data of different cell bodies' shapes. This method could provide some information for the study and diagnosis of the diseases (e.g. hemolytic anemia, pre-leukemia) related to erythrocyte morphology.

[The influence of conception of time - space - orientation in pre - Qin society on traditional Chinese medicine theories]

The article discusses the views of the time - space - orientation of Wuxing (Five - Evolutive Phase), Yin - yang and Sifeng (Four - Wind), and its influence on traditional Chinese medical theories. It is shown that traditional Chinese medical theories are developed and established on the basis of the science and technology and social thought of the pre - Qin period, with some contents to be further discussed, and bias would be resulted if the issue is interpreted by concepts of post - Qin period.

New mechanistic insights from structural studies of the oxygen-sensing domain of Bradyrhizobium japonicum FixL

The FixL heme domain serves as the dioxygen switch in the FixL/FixJ two-component system of Rhizobia. Recent structural studies of the Bradyrhizobium japonicum FixL heme domain (BjFixLH) have suggested an allosteric mechanism that is distinct from the classical hemoglobin model. To gain further insight into the FixL sensing mechanism, structures of BjFixLH bound to dioxygen, imidazole, and nitric oxide have been determined. These structures, particularly the structure of BjFixLH bound to its physiological ligand, dioxygen, have helped to address a number of important issues relevant to the BjFixLH sensing mechanism. On the basis of the oxy-BjFixLH structure, a conserved arginine is found to stabilize the dioxygen ligand in a mode reminiscent of the distal histidine in classical myoglobins and hemoglobins. The structure of BjFixLH bound to imidazole elucidates the structural requirements for accommodating sterically bulky ligands. Finally, the structure of BjFixLH bound to nitric oxide provides evidence for a structural intermediate in the heme-driven conformational change.

Structural basis for the design of antibiotics targeting peptide deformylase

While protein synthesis in bacteria begins with a formylated methionine, the formyl group of the nascent polypeptide is removed by peptide deformylase. Since eukaryotic protein synthesis does not involve formylation and deformylation at the N-terminus, there has been increasing interest in peptide deformylase as a potential target for antibacterial chemotherapy. Toward this end and to aid in the design of effective antibiotics targeting peptide deformylase, the structures of the protein-inhibitor complexes of both the cobalt and the zinc containing Escherichia coli peptide deformylase bound to the transition-state analogue, (S)-2-O-(H-phosphonoxy)-L-caproyl-L-leucyl-p-nitroanilide (PCLNA), have been determined. The proteins for both deformylase-inhibitor complexes show basically the same fold as for the native enzyme. The PCLNA inhibitor adopts an extended conformation and fits nicely into a hydrophobic cavity located near the metal site. On the basis of these structures, guidelines for the design of high-affinity deformylase inhibitors are suggested. As our results show that the protein residues which interact with the PCLNA inhibitor are conserved over a wide variety of species, we suggest that antibiotics targeting deformylase could have wide applicability.

Structure of a biological oxygen sensor: a new mechanism for heme-driven signal transduction

The FixL proteins are biological oxygen sensors that restrict the expression of specific genes to hypoxic conditions. FixL's oxygen-detecting domain is a heme binding region that controls the activity of an attached histidine kinase. The FixL switch is regulated by binding of oxygen and other strong-field ligands. In the absence of bound ligand, the heme domain permits kinase activity. In the presence of bound ligand, this domain turns off kinase activity. Comparison of the structures of two forms of the Bradyrhizobium japonicum FixL heme domain, one in the "on" state without bound ligand and one in the "off" state with bound cyanide, reveals a mechanism of regulation by a heme that is distinct from the classical hemoglobin models. The close structural resemblance of the FixL heme domain to the photoactive yellow protein confirms the existence of a PAS structural motif but reveals the presence of an alternative regulatory gateway.

Crystal structure of the Escherichia coli peptide deformylase

Protein synthesis in bacteria involves the formylation and deformylation of the N-terminal methionine. As eukaryotic organisms differ in their protein biosynthetic mechanisms, peptide deformylase, the bacterial enzyme responsible for deformylation, represents a potential target for antibiotic studies. Here we report the crystallization and 2.9 A X-ray structure solution of the zinc containing Escherichia coli peptide deformylase. While the primary sequence, tertiary structure, and use of coordinated cysteine suggest that E. coli deformylase belongs to a new subfamily of metalloproteases, the environment around the metal appears to have strong geometric similarity to the active sites of the thermolysin family. This suggests a possible similarity in their hydrolytic mechanisms. Another important issue is the origin of the enzyme's specificity for N-formylated over N-acetylated substrates. Based on the structure, the specificity appears to result from hydrogen-bonding interactions which orient the substrate for cleavage, and steric factors which physically limit the size of the N-terminal carbonyl group.

[Isolation and determination of the seeds of Pachyrrhizus errosus protein by high performance gel filtration chromatography (GFC)]

From the seeds of Pachyrrhizus errosus, three protein constituents, namel PE1, PE2 and PE3, have been isolated and purified by extraction with 5mmol/L phosphate saline (0.9% NaCl) buffer (PB) at pH 7.2, and S-Sepharose Fast Flow Column (2.6cm x 15cm) chromatography which eluted with 5mmol/L phosphate buffer (pH 7.0) containing 1mmol/L NaCl. Three proteins were burther separated on two connected Protein-Pak 60+Protein-Pak 125 [7.5mm x 39cm, 10microm] columns with mobile phase of 0.2mol/L phosphate buffer (pH 6.5). The flow rate was kept constant at 0.8mL/min by YSB-2 type high press pump. The effluent was monitored at a wavelength of 280nm on photodiode array detector. These three proteins are proved to be homogeneous by SDS-PAGE, IEF and HPGFC experiments, and all present the typical absorption spectra in ultraviolet region. The moleculer weights of the three proteins are approxiamtely 33000D, 14500D and 14000D respectively by SDS-PAGE. But as using HPGFC analysis, the MW value of PE2 is 28000D. This indicates PE2 may be composed of two chains joined by disulfide bond, which is further proved from the latter amino acid composition analysis. The isoelectric points of three proteins are 4.5, 6.5 and 7.5 respectively by using IEF. The amion acids compositions of the three proteins were determined with OPA post-column derivatization/fluorescence detection.

Preliminary crystallographic studies of a protein from Pachyrrhizus erosus

Crystals of a protein extracted from the seeds of Pachyrrhizus erosus have been obtained by vapor-phase diffusion. The crystal belongs to the space group P4(1)2(1)2 or P4(3)2(1)2 with cell parameters a = b = 62.52, c = 147.42 A. There is one protein molecule of 33 kDa in an asymmetric unit. A data set at 3.1 A has been collected on an area detector.