Progress of researches on Blastocystis hominis infection among patients with inflammatory bowel disease and irritable bowel syndrome / 中国血吸虫病防治杂志

Blastocystis is a common unicellular intestinal protozoa in humans and animals, and the most common clinical manifestations of infections include abdominal pain and diarrhea. Based on the sequence of the small-subunit ribosomal RNA (SSU rRNA) gene, 28 subtypes of B. hominis (ST1 to ST17, ST21 and ST23 to ST32) have been characterized. Previous studies have demonstrated that B. hominis infection is strongly associated with inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and other intestinal diseases, which threatens the health and quality of life among patients with B. hominis infection and is considered as an important public health problem. This review summarizes the progress of researches on B. hominis infection among IBD and IBS patients during the past 20 years, so as to provide insights into management of blastocystosis in China.

Tractostorm 2: Optimizing tractography dissection reproducibility with segmentation protocol dissemination.

The segmentation of brain structures is a key component of many neuroimaging studies. Consistent anatomical definitions are crucial to ensure consensus on the position and shape of brain structures, but segmentations are prone to variation in their interpretation and execution. White-matter (WM) pathways are global structures of the brain defined by local landmarks, which leads to anatomical definitions being difficult to convey, learn, or teach. Moreover, the complex shape of WM pathways and their representation using tractography (streamlines) make the design and evaluation of dissection protocols difficult and time-consuming. The first iteration of Tractostorm quantified the variability of a pyramidal tract dissection protocol and compared results between experts in neuroanatomy and nonexperts. Despite virtual dissection being used for decades, in-depth investigations of how learning or practicing such protocols impact dissection results are nonexistent. To begin to fill the gap, we evaluate an online educational tractography course and investigate the impact learning and practicing a dissection protocol has on interrater (groupwise) reproducibility. To generate the required data to quantify reproducibility across raters and time, 20 independent raters performed dissections of three bundles of interest on five Human Connectome Project subjects, each with four timepoints. Our investigation shows that the dissection protocol in conjunction with an online course achieves a high level of reproducibility (between 0.85 and 0.90 for the voxel-based Dice score) for the three bundles of interest and remains stable over time (repetition of the protocol). Suggesting that once raters are familiar with the software and tasks at hand, their interpretation and execution at the group level do not drastically vary. When compared to previous work that used a different method of communication for the protocol, our results show that incorporating a virtual educational session increased reproducibility. Insights from this work may be used to improve the future design of WM pathway dissection protocols and to further inform neuroanatomical definitions.

Changing patterns in Australian and New Zealand: vascular surgery during COVID-19.

BACKGROUND: Early government-mandated restrictions in Australia and New Zealand contributed to a successful public health outcome during the COVID-19 pandemic, including an unprecedented temporary cancellation of all non-urgent elective surgical procedures. This study describes the change in vascular surgery services across Australia and New Zealand before and during the COVID-19 restrictions. METHODS: De-identified data from the Australia and New Zealand Society for Vascular Surgery Australasian Vascular Audit from January 2015 to September 2020 was obtained. Vascular surgery procedure numbers from January to September of 2020 (study period) was compared to the corresponding months between 2015 and 2019 (pre-study period). The volume of procedures, both elective and emergency, were compared. Subgroup analyses included procedures categorized by operation type and location. RESULTS: There was a 11% decrease in total vascular procedures, 22% decrease in elective procedures, and a 14% increase in emergency procedures, comparing the study and pre-study periods. There was a large increase in all revascularization procedures for critical limb ischemia and no change in acute limb ischemia interventions, without a concomitant rise in major or minor all-cause amputation. There was a decrease in interventions for abdominal aortic aneurysm and carotid artery disease, driven by a fall in elective procedures, while volume for dialysis access remained the same. Change in procedural volume varied by state with the largest decrease noted in NSW and Victoria. CONCLUSIONS: The COVID-19 pandemic reduced vascular surgery procedures across Australia and New Zealand with a decrease in elective operations and an increase in emergency operations.

SARS-CoV-2 spike protein gene variants with N501T and G142D mutation dominated infections in minks in the US

Large number of minks were infected with SARS-CoV-2 virus containing the spike protein Y453F mutation in Europe, causing zoonosis concerns. To evaluate the genetic characteristics of the US and Canadian mink-derived SARS-CoV-2 sequences, we analyzed all animal-derived (977), all Canadian (19,529) and US (173,277) SARS-CoV-2 sequences deposited in GISAID from December 2019 to March 12, 2021, and identified 2 dominant novel variants, the N501T-G142D variant and N501T-G142D-F486L variant, in the US mink-derived SARS-CoV-2 sequences. These variants were not found in minks from Canada or other countries. The Y453F mutation was not identified in the mink-derive sequences in the US and Canada. The N501T mutation occurred two months earlier in the human than in the minks in the US, and the novel N501T-G142D variant and N501T-G142D-F486L variant were found in human prior to minks. The result of this study indicates that the novel variants may have evolved during human infection and then transmitted to mink populations in the US.

Evaluation of WHO listed COVID-19 qPCR primers and probe in silico with 375 SERS-CoV-2 full genome sequences

Quantitative reverse-transcription PCR (qRT-PCR) assays remains the gold standard for detection of the SARS-CoV-2 virus because of its sensitivity and specificity. However, successful design of qRT-PCR assays requires accurate viral genome sequences. With mutations accumulating as the virus is transmitted globally, we sought to compare current assays recommended by the World Health Organization with available SARS-CoV-2 genomic sequences in silico. While most sequences were conserved, there were notable mismatches, particularly in assays developed using early sequences when compared to more recent isolates. We recommend that any assay being evaluated for diagnostic tests be compared with prevalent sequence data from the region of proposed testing and that continued publicly accessible sequence information continue to be provided by the research community.

Progress in research of relationship between heavy metal exposure and cardiovascular disease / 中华流行病学杂志

Heavy metal is one of pollutants existed widely in the environment, its relationship with cardiovascular disease has attracted more and more attention. In this review, the concentrations of heavy metals, including lead, cadium and asenic, in the body from several national surveillance networks and the epidemiological studies on the effects of the exposure of three heavy metals on cardiovascular system were summarized. It is suggested to strengthen nationwide surveillance for body concentrations of heavy metals in general population in order to provide baseline data for quantitative evaluation of the risk of heavy metal exposure on cardiovascular disease.

Association and interaction of pre-pregnant body mass index and gestational weight gain of women on neonatal birthweight / 中华流行病学杂志

Objective: To investigate the association between maternal pre-pregnant body mass index and gestational weight gain, as well as their interaction on neonatal birthweight. Methods: We built a cohort in Anqing Municipal Hospital from January 2014 to March 2015, enrolling pregnant women who decided to give birth in this hospital. All women were asked to fill a questionnaire for basic information collection. Medical information of both pregnant women and their newborns were obtained through electronic medical record. Chi-square analysis, multinomial logistic regression, multiplicative and additive interaction methods were used to analyze the association between pre-pregnant body mass index and gestational weight gain as well as their interactions on birth weight of the neonates. Results: A total of 2 881 pregnant women were included in this study. Of the 2 881 newborns, 359 (12.46%) were small for gestational age (SGA) and 273 (9.48%) were large for gestational age (LGA). After adjusting the possible confounding factors, results from the multinomial logistic regression showed that pre-pregnancy underweight women were more possible to deliver SGA (aRR=1.33, 95%CI: 1.02-1.73). If the gestational weight gain was below the recommended criteria, the risk of SGA (aRR=1.64, 95%CI: 1.23-2.19) might increase. Pre-pregnancy overweight/obese could increase the risk of being LGA (aRR=1.86, 95%CI: 1.33-2.60). Maternal gestational weight gain above the recommendation level was associated with higher rates of LGA (aRR=2.03, 95%CI: 1.49-2.78). Results from the interaction analysis showed that there appeared no significant interaction between pre-pregnancy BMI and gestational weight on birthweight. Conclusion: Pre-pregnancy body mass index and gestational weight gain were independently associated with neonatal birthweight while pre-pregnancy BMI and gestational weight gain did not present interaction on birthweight.

Exposure-preceding-outcome regarding time sequence among cohort studies in real world / 中华流行病学杂志

One of the commonly accepted merits of cohort studies (CSs) refers to the exposure precedes outcome superior to other observational designs. We use Directed Acyclic Graphs to construct a causal graph among research populations under CSs. We notice that the substitution of research population in place of a susceptible one can be used for effect estimation. Its correctness depends on the outcome-free status of the substituted population and the performance of both screening and diagnosis regarding the outcomes under study at baseline. The temporal precedence of exposure over outcome occurs theoretically, despite the opposite happens in realities. Correct effect estimate is affected by both the suitability of population substitution and the validities of outcome identification and exclusion.

A structural classification of strategies for confounding control in research design / 中华流行病学杂志

Confounding affects the causal relation among the population. Depending on whether the confounders are known, measurable or measured, they can be divided into four categories. Based on Directed Acyclic Graphs, the strategies for confounding control can be classified as (1) the broken-confounding-path method, which can be further divided into single and dual broken paths, corresponding to exposure complete intervention, restriction and stratification, (2) and the reserved-confounding-path method, which can be further divided into incomplete exposure intervention (in instrumental variable design and non-perfect random control test), mediator method and matching method. Among them, random control test, instrumental variable design or Mendelian randomized design, mediator method can meet the requirements for controlling all four types of confounders, while the restriction, stratification and matching methods are only applicable to known, measurable and measured confounders. Identifying the mechanisms of confounding control is a prerequisite for obtaining correct causal effect estimates, which will be helpful in research design.

Sampling methods and errors appearing in the China National Human Biomonitoring Program / 中华流行病学杂志

Objective: To explore the sampling method in China National Human Biomonitoring Program (HBP) and the related errors, so as to calculate and evaluate the study design in sampling. Methods: The sampling method of HBP is of multistage nature. Taking the results of sampling method from Guizhou province as an example, results related to sampling error and variation coefficient were calculated, using the multistage unequal probability sampling error method. Results: The HBP covered 152 monitoring sites in 31 provinces (autonomous regions and municipalities) and with 21 888 residents selected. The replacement rates at various stages were 5.26%, 6.35% and 40.6% respectively. The sampling error in Guizhou province was 3 207 594, and the coefficient of variation was 0.097. Conclusions: According to the multi-stage unequal probability sampling method, the sampling coefficient variability appeared small with high precision, in Guizhou province. However, this method did not consider the weight adjustment of non-sampling errors such as population missing rate and response rate. Methods related to the calculation on multi-stage sampling error among large-scale public health monitoring projects need to be further studied.