[Application of multi-state Markov model in studying transition of number of chronic complications and influencing factors in type 2 diabetes mellitus patients]

Objective: To establish a multi-state Markov model of type 2 diabetes mellitus (T2DM) patients and explore the transition rule between the cumulative number of different chronic complications, estimate the transition probability and intensity between status, and explore the possible factors affecting the transition between status. Methods: A retrospective cohort study of 33 575 patients with T2DM was conducted. According to the baseline and the cumulative number of chronic complications during the follow-up period, the patients were classified based on five status: T2DM, one complication, two complications, three complications, four and above complication, indicated by S0, S1, S2, S3 and S4, respectively. A time-continuous and state-discrete multi-state irreversible Markov model was used for statistical analysis. Results: The study included 33 575 T2DM patients, and their average age was 60 years old, the median of follow-up length was 8 years. In these patients, 32 653 had no baseline complications. At the end of follow-up, the transition probabilities of S0→S1, S1→S2, S2→S3 and S3→S4 were 16.4%, 32.4%, 45.6% and 25.9%, respectively. The results of multivariate analysis showed that being female (HR=0.919), less than 60 years old (HR=0.929), higher fasting plasma glucose (HR=1.601), lower high-density lipoprotein (HR=1.087), higher total cholesterol (HR=1.090),weekly exercise (HR=0.897), vegetarian diet (HR=0.852) and heavy diet (HR=1.887) were the risk factors for S0 to S1. And being female (HR=0.768), less than 60 years old (HR=0.859) and lower high-density lipoprotein (HR=1.160) were the risk factors for S1 to S2. Conclusions: The probability of multiple complications in T2DM patients increased over time, the transition intensity of S2→S3 was largest, followed by S1→S2. Therefore, we need to conduct both early and long-term indicators monitoring and disease prevention, strengthen the health education to improve patients' daily living habits at early stage of the illness, encourage patients to have moderate exercise and balanced diet, strengthen the monitoring of fasting blood- glucose, cholesterol and high-density lipoprotein levels to prevent the deterioration of the illness.

[Expression of nicotinamide-N-methyltransferase in gastric cancer and its biological and clinicopathological significance]

OBJECTIVE

To investigate the expression of nicotinamide-N-methyltransferase (NNMT) in gastric cancer (GC) and explore its biological and clinicopathological significance.

OBJECTIVE

We screened the candidate genes associated with the classification and prognosis of gastric cancer by analyzing GEO, Oncomine and TCGA datasets. The molecular pathways and protein interaction network involving these candidate genes were analyzed using STRING, GSEA, David and Cytoscape software. The expressions of the candidate genes in 28 pairs of gastric cancer and adjacent tissues were detected with qRTPCR, and CCK-8 assay, clone formation assay, wound healing assay and Transwell assay were carried out to analyze the effects of modulation of NNMT expression on proliferation, invasion and migration of different gastric cancer cell lines.

OBJECTIVE

NNMT was highly expressed in gastric cancer tissues and was negatively correlated with the prognosis of patients with gastric cancer. Pathway analysis showed that the high expression of NNMT was associated with adhesion-related pathway molecules such as extracellular matrix receptors, cell adhesion molecules, and cytokine receptors, while its low expression was associated with base mismatch repair and riboflavin metabolism. Protein interaction analysis showed that NNMT interacted with 16 differentially expressed proteins such as AURKA and was co-expressed with TAGLN, PTRF, AKAP12 and IGF2BP2. In clinical tissue specimens, qRT-PCR results showed that the expression of NNMT mRNA was significantly higher in gastric cancer tissues than in the adjacent tissues (P < 0.05). In gastric cancer cell lines, overexpression of NNMT was found to significantly promote cell proliferation, invasion and migration, while NNMT knockdown produced obvious inhibitory effects on cell proliferation, invasion and migration.

OBJECTIVE

NNMT is highly expressed in gastric cancer and negatively correlated with the prognosis of gastric cancer patients. The high expression of NNMT promotes the proliferation, invasion and metastasis of gastric cancer cells, suggesting the potential of NNMT as prognostic marker of gastric cancer.

Low expression of lncRNA TUBA4B promotes proliferation and inhibits apoptosis of colorectal cancer cells via regulating P15 and P16 expressions

OBJECTIVE

To explore the expression, function, and regulation mechanism of the long non-coding ribonucleic acid (lncRNA) tubulin alpha 4b (TUBA4B) in colorectal cancer (CRC) tissues and cells.

PATIENTS AND METHODS

Cancer and adjacent tissues were collected from 60 CRC patients. CRC cell lines SW480, SW620, HCT116, Caco-2, DLD-1 and HT29, and colonic epithelial cell line CCD841 were also enrolled. Then, the expression of TUBA4B in CRC tissues and cell lines was detected via quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). In vitro assays [cell counting kit-8 (CCK-8) assay, clone formation assay, and flow cytometry] were performed to study the biological function of TUBA4B in CRC. Additionally, the downstream regulatory targets of TUBA4B were investigated through Western blotting analysis and qRT-PCR assay.

RESULTS

The results of qRT-PCR revealed that compared with adjacent tissues, the expression of TUBA4B was down-regulated in 47/60 CRC tissues (47/60, 78.3%). According to in vitro assays (CCK-8 assay, clone formation assay, and flow cytometry), over-expression of TUBA4B inhibited the proliferation and promoted the apoptosis of CRC cells. TUBA4B remarkably regulated mRNA and protein levels of p15 and p16.

CONCLUSIONS

LncRNA TUBA4B is down-regulated expression in CRC tissues and cells, which facilitates CRC cell proliferation and suppresses apoptosis by regulating the expressions of p15 and p16.

Maize transcription factor ZmBES1/BZR1-5 positively regulates kernel size

The BES1/BZR1 transcription factors regulate the expression of genes responsive to brassinosteroids and play pivotal roles in plant development, but their role in regulating kernel development in maize remains unclear. In this study, we found that ZmBES1/BZR1-5 positively regulates kernel size. Association analysis of candidate genes in 513 diverse maize inbred lines indicated that three SNPs related to ZmBES1/BZR1-5 were significantly associated with kernel width and whilst four SNPs were related to 100-kernel weight. Overexpression of ZmBES1/BZR1-5 in Arabidopsis and rice both significantly increased seed size and weight, and smaller kernels were produced in maize Mu transposon insertion and EMS mutants. The ZmBES1/BZR1-5 protein locates in the nucleus, contains bHLH and BAM domains, and shows no transcriptional activity as a monomer but forms a homodimer through the BAM domain. ChIP-sequencing analysis, and yeast one-hybrid and dual-luciferase assays demonstrated that the protein binds to the promoters of AP2/EREBP genes (Zm00001d010676 and Zm00001d032077) and inhibits their transcription. cDNA library screening showed that ZmBES1/BZR1-5 interacts with casein kinase II subunit β4 (ZmCKIIβ4) and ferredoxin 2 (ZmFdx2) in vitro and in vivo, respectively. Taken together, our study suggests that ZmBES1/BZR1-5 positively regulates kernel size, and provides new insights into understanding the mechanisms of kernel development in maize.

MiRNA-411 attenuates inflammatory damage and apoptosis following spinal cord injury

OBJECTIVE

To investigate the role and regulate the target of miRNA-411 on spinal cord injury.

MATERIALS AND METHODS

The microglia cultured in vitro was activated by lipopolysaccharide (LPS) to express the inflammatory phenotype. The inflammatory response through miRNA-411 transfection in microglia was measured to certain whether increased miRNA-411 suppressed interleukin-18 (IL-18) level to attenuate the inflammation amplification via downregulating JNK pathway. Furthermore, we established spinal cord injury (SCI) model in SD rats and further explored the glial inflammatory degree and neurological recovery following miRNA-411 treatment. Lastly, we estimated the hindlimbs function of SCI rats with miRNA-411 administration or not within four weeks at post-SCI.

RESULTS

In vitro, miRNA-411 inhibited IL-18 expression and downregulated JNK pathway, along with that inflammatory microglia were declined. In SCI rats, we detected the decreased amounts of inflammatory microglia and reduction of the inflammatory factors after miRNA-411 treatment. IL-18 and JNK pathway was also restrained resulted from increased miRNA-411. In addition, apoptosis degree in injury site reduced and survived axons were relatively multiple in the miRNA-411 group compared with the SCI group. The Basso-Beattie-Bresnahan (BBB) locomotor scores of miRNA-411 treated rats were superior to those in rats with no treatment.

CONCLUSIONS

MiRNA-411 increase ameliorates the inflammatory microglia-induced neurological lesion and promotes neural recovery by JNK pathway inhibition via negative targeting IL-18 in SCI.

[Introduction to COSMOS-E: Guidance on conducting systematic reviews and Meta-analyses on etiology of observational studies]

This paper introduces the conducting systematic reviews and Meta-analyses of observational studies of etiology (COSMOS-E) and illustrates the critical issues of COSMOS-E with a published systematic review. This document provides researchers with guidance on all steps in systematic reviews of observational studies of etiology, from shaping the research question, defining exposure and outcomes, to assessing the risk of bias and statistical analysis.

Multimorbidity in Community-Dwelling Older Adults in Beijing: Prevalence and Trends, 2004-2017

OBJECTIVES

The burden of multimorbidity is increasing worldwide; however, little is known about trends in multimorbidity prevalence among Chinese older adults. We aimed to estimate the prevalence and trends of multimorbidity in community-dwelling older adults in Beijing.

DESIGN

Longitudinal.

SETTING AND PARTICIPANTS

Residents of Beijing aged ≥60 years.

MEASUREMENTS

Data were derived from the Beijing Longitudinal Study of Aging, using cluster, stratification, and random sampling. A total of 1842, 2914, and 1837 participants were included in the 2004, 2011, and 2017 sample, respectively. Multimorbidity was defined as the presence of two or more chronic conditions. Trends in multimorbidity were examined by age, sex, and geographical area.

RESULTS

The prevalence of multimorbidity was 32.5%, 52.9%, and 53.2% in 2004, 2011, and 2017, respectively, following an upward trend over time (P =0.003). A similar multimorbidity increase trend was present in age-, sex-, and region-stratified analysis for the 2004-2017 period (all P<0.05). The most common chronic diseases in 2004 were hypertension (34.3%), cataract (18.2%), coronary heart disease (CHD) (15.6%), stroke (14.3%), and chronic obstructive pulmonary disease (7.9%); in 2011, these were hypertension (49.6%), arthritis (30.9%), CHD (22.3%), stroke (21.9%), and diabetes (15.1%); in 2017, these were hypertension (54.4%), arthritis (26.3%), stroke (22.6%), cataract (20.5%), and CHD (20.1%). The proportion of older adults diagnosed with ≥3 chronic diseases significantly increased from 13.4% in 2004 to 73.1% in 2011 and 69.5% in 2017.

CONCLUSIONS

Multimorbidity is common and the overall and age-, sex-, and region-specific multimorbidity prevalence has been increasing over the past 13 years. Public health policies should account for the more complex care needs and growing costs associated with increasing prevalence of chronic disease and multimorbidity in Chinese older adults.

[Current status and enlightenment of teaching models in evidence-based medicine at home and abroad: a qualitative systematic review]

Objective: To summarize the different teaching models and their effects in evidence-based medicine at home and abroad by qualitative method and systematic review. Methods: We searched the following databases (from inception to 13 May, 2019): PubMed, Embase, Proquest, Cochrane, Web of Science database and the Chinese databases (CNKI, Wanfang, SinoMed and VIP). To assess data strength and validity, risk of bias assessments were undertaken. Results: A total of 52 literatures were included in this study, including 21 Chinese-language literature and 31 English-language literature. PBL teaching model, mixed teaching model and workshop teaching model were the three teaching models with the largest number of studies in 20 teaching models. Conclusion: The evidence-based medicine teaching effect was closely related to the teaching models, so it is necessary to explore more suitable teaching models for the evidence-based medicine to improve the teaching effects.

PCAT1 promotes the proliferative and migratory potentials of ovarian cancer via targeting NEK2

OBJECTIVE

The aim of this study was to clarify the potential role of PCAT1 in the occurrence and development of ovarian cancer (OC).

PATIENTS AND METHODS

Expression levels of PCAT1 and NEK2 in OC tissues and cell lines were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). Correlation between PCAT1 expression with tumor stage and prognosis of OC patients was analyzed. Knockdown or over-expression of PCAT1 and NEK2 were achieved by siRNA or lentivirus transfection, respectively. Subsequently, cell viability, apoptosis, cell cycle progression and migration were determined by cell counting kit-8 (CCK-8), flow cytometry and transwell assay, respectively. Furthermore, the protein levels of relative genes in Wnt pathway were detected by Western blot.

RESULTS

PCAT1 was highly expressed in OC tissues and cell lines, especially in tumor tissues with stage III-IV compared with stage I-II. The prognosis of OC patients with higher expression of PCAT1 was significantly worse than those with lower expression. In vitro experiments confirmed that PCAT1 knockdown obviously inhibited proliferative and migratory potentials, whereas induced apoptosis of OC cells. No significant changes were observed in cell cycle progression of OC cells after knockdown or overexpression of PCAT1. Meanwhile, overexpression of PCAT1 remarkably upregulated the expression level of NEK2, which was the target gene of PCAT1. Interestingly, NEK2 knockdown could obviously suppress cell migration. Furthermore, Western blot results elucidated that PCAT1 knockdown could inhibit the protein levels of relative genes in Wnt pathway in OC cells.

CONCLUSIONS

PCAT1 was highly expressed in OC tissues than adjacent normal tissues. PCAT1 overexpression significantly promoted proliferative and migratory potentials, whereas inhibited apoptosis of OC cells through upregulating NEK2 expression via Wnt pathway.

[Epidemiological characteristics of COVID-19 in Wuchang district of Wuhan]

Objective: To analyzes epidemiological characteristics of COVID-19 and provide evidence for adjustment for COVID-19 prevention and control strategies. Methods: The data of COVID-19 cases in Wuchang district reported as of 19 March, 2020 were obtained from National Notifiable Disease Report System of Chinese Disease Prevention and Control Information System. The software's of Excel 2010, SPSSS 22.0, Arc GIS10.2 and Joinpoint regression program 4.8.0.0 were used for statistical analysis. Results: A total of 7547 COVID-19 cases had been reported as of 19 March, 2020 in Wuchang district, including 5 448 confirmed cases (72.19%), 2009 clinical diagnosed cases (26.62%) and 90 asymptomatic cases case (1.19%). The age of the cases was (56.65±16.25) years and age ranged from 2 days to 105 years among confirmed cases, 2634 were males (48.35%) and 2814 were females (51.65%), 2 492 were retirees (45.74%). A total of 545 health workers were infected with SARS-CoV-2 (7.22% of all cases) including 365 confirmed cases and 5 cases have died. A total of 430 cases of death were reported with case fatality rate of 7.89% (430/5 448), case fatality rate of males (10.9%, 266/2 634) was higher than that of females (5.82%, 164/2 814). The first phase of epidemic peak was from January 24 to January 26, the second phase of epidemic peak was from February 1 to February 5 and there was no one of new confirmed case in one day for the first time on March 18. The first four Streets with the highest incidence rates of confirmed cases were Huanghelou Street (1 043.77/100 000), Ziyang Street (627.97/100 000), Yangyuan Street (503.67/100 000) and Shuiguohu Street (486.02/100 000). Compared with females, aged ≤50 years and mild cases of clinical classification respectively, males (RR=0.690, 95%CI: 0.322-1.478), aged >50 years (RR=11.745, 95%CI: 6.878-20.058), severe cases (RR=2.317, 95%CI: 1.789-3.000) and critical cases of clinical classification (RR=10.794, 95%CI: 7.997-14.569), and gender time-dependent covariate (RR=1.392, 95%CI: 1.053-1.840) were major influencing factors of prognosis of COVID-19 confirmed cases. Conclusions: The gender, ages and occupation of distribution were wide among COVID-19 cases in Wuchang district. Males, aged >50 years, severe cases and critical cases of clinical classification were influencing factors of prognosis of COVID-19 confirmed cases. The standardized management of discharged cases, asymptomatic infected cases and close contact persons were main measures to reduce incidence rates of COVID-19 cases.

MicroRNA-488 regulates diabetic nephropathy via TGF-β1 pathway

OBJECTIVE

The aim of this study was to clarify the biological roles of microRNA-488 and transforming growth factor β1 (TGF-β1) pathway in the occurrence and progression of diabetic nephropathy (DN).

MATERIALS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expressions of microRNA-488, fibrinogen factors coII, coIIV, and fibronectin (FN) in Human mesangial cells (HMCs) with high-glucose or low-glucose treatment. After transfection of microRNA-488 mimics or inhibitor, expression levels of coII, coIIV, and FN in HMCs were determined by qRT-PCR and Western blot. Their expressions in HMC cells treated with different doses of TGF-β1 at different time points were also detected. Finally, we evaluated the potential influence of microRNA-488 on TGF-β1-induced fibrosis of HMC cells by qRT-PCR.

RESULTS

Compared with low-glucose treatment, the expression of microRNA-488 markedly increased in HMCs treated with high-glucose, as well as coII, coIIV, and FN. Overexpression of microRNA-488 remarkably upregulated mRNA and protein levels of coII, coIIV, and FN, whereas microRNA-488 knockdown downregulated their levels. Expression levels of microRNA-488, coII, coIIV, and FN gradually upregulated with the increase of TGF-β1 dose and treatment duration.

CONCLUSIONS

MicroRNA-488 regulates the development of diabetic nephropathy-induced fibrosis by TGF-β1 pathway.

[Current global development of screening guidelines for hepatocellular carcinoma: a systematic review]

Objective: The objective of the study was systematically summarized the current status of the hepatocellular carcinoma (HCC) screening guidelines, and evaluated the HCC screening guidelines according to the authoritative framework of cancer screening guidelines of authoritative institutions, which provided important value for the formulation of HCC screening evidence-based guidelines. Methods: Literature search was conducted in multiple databases from their inception dates to January 3, 2019. In addition, we sought relevant websites further was searched to identify potentially eligible studies. Two reviewers independently screened literature and extracted data. Qualitative description of the basic information, recommendations of HCC screening, source of evidence and update progress of the HCC screening guidelines was conducted. Results: At present, there were no independent HCC screening guidelines worldwide. There were only 17 clinical practice HCC guidelines briefly provided the recommendation of HCC screening. Current HCC screening guidelines only recommended screening for high-risk groups of HCC. All guidelines have identified patients with chronic hepatitis B, hepatitis C and cirrhosis as high-risk groups for HCC. Most of guidelines recommended screening intervals was 6 months. The latest guidelines in Europe and the United States recommended ultrasound for screening HCC. The combination of ultrasound and AFP was recommended in the Asian guidelines. Currently, HCC screening guidelines mainly recommended screening strategies based on factors such as risk of HCC, accuracy of screening modality, screening cost, etc.. The key factors such as screening efficacy and safety have not yet been considered comprehensively. Conclusions: There were no independent HCC screening guidelines worldwide. Only some clinical practice HCC guidelines briefly mentioned HCC screening. Currently, the guidelines only recommend screening for high-risk groups of HCC, with a screening interval of 6 months. There are differences in screening modalities recommended by European, American and Asian guidelines for screening HCC. It is suggested that the relevant institutions should formulate the evidence-based HCC screening guidelines by referring to the theoretical framework of other authoritative other cancer screening guidelines.

Tear inflammatory cytokines and ocular surface changes in patients with active thyroid eye disease treated with high-dose intravenous glucocorticoids

PURPOSE

To evaluate high-dose intravenous glucocorticoid treatment on tear inflammatory cytokines and ocular surface parameters in patients with active TED. Correlations between tear inflammatory cytokines and clinical parameters were also investigated.

METHODS

This prospective pilot study included 15 moderate-to-severe and active TED patients. Control group consist of 15 sex and age-matched healthy subjects. All TED patients were treated with high-dose intravenous methylprednisolone with cumulative dose of 4.5 g during the therapy subdivided into 12 weekly infusions. Tear concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17A, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) were measured by multiplex bead analysis in TED patients at baseline and 12 weeks after treatment. Ocular surface disease index (OSDI), tear break-up time (TBUT), corneal fluorescent staining, and Schirmer's test were obtained from TED and controls.

RESULTS

All baseline cytokine levels except for IL-17A were significantly elevated in active TED patients compared with controls. Concentrations of IL-1β, IL-6, IL-8, TNF-α, and VEGF were significantly decreased at 12 weeks compared with baseline. OSDI and TBUT showed significant improvement at 6 and 12 weeks. There were significant positive correlations between IL-6, IL-8, and CAS, and negative correlation was found between IL-6 level and TED duration before methylprednisolone treatment. The reduction of IL-6, IL-8, and VEGF were positive correlated with the reduction in CAS at 12 weeks.

CONCLUSIONS

High-dose glucocorticoids treatment improved ocular surface symptom, increased the tear film stability, and decreased tear inflammatory cytokines in active TED. The reduction of the inflammatory cytokines is consistent with the improvement of clinical parameters.

[Safety of biological valves for aortic valve replacement: A systematic review and meta-analysis]

OBJECTIVE

To provide a comprehensive and contemporary overview of the long-term safety outcomes after aortic valve replacements (AVR) with conventional biological heart valve (stented or stentless).

METHODS

English databases (Medline, Embase, Web of Science, CENTRAL, and ClinicalTrial.gov) and Chinese databases (CNKI, VIP, WanFang, and SinoMed) were searched systemically from January 1, 2000 to January 26, 2019. Eligible randomized controlled trials, non-randomized clinical trials, cohort studies (retrospective or prospective), and unselected case series were included. Strict screening of the obtained literature was conducted to extract relevant data by two reviewers. Other inclusion criteria were studied reporting on outcomes of AVR with biological valves (stented or stentless), with or without coronary artery bypass grafting (CABG) or valve repair procedure, with mean follow-up length equal to or longer than 5 years. We excluded studies that reported only a specific patient group (e.g., patients with renal failure, or pregnancy), without the report of biological valve type, or with study population size less than 100. The meta-analysis was performed using Stata 14.0 software.

RESULTS

In this study, 53 papers (in total 57 study groups) involving 47 803 patients were included. (1) The all-cause mortality was 6.33/100 patient-years (95%CI: 5.85-6.84). Subgroup analysis showed that the mortality rates of porcine and bovine valve prostheses were 5.69/100 patient-years (95%CI: 5.05-6.41) and 7.29/100 patient-years (95%CI: 6.53-8.13), respectively. The all-cause mortality rates for stented and stentless valve were 6.69/100 patient-years (95%CI: 6.12-7.30) and 5.21/100 patient-years (95%CI: 4.43-6.14), respectively. (2) The incidence rate of thromboembolism was 1.16/100 patient-years (95%CI: 0.96-1.40), the incidence rate of permanent pacemaker (PPM) implantation was 1.08/100 patient-years (95%CI: 0.75-1.54), the incidence rate of stroke was 0.74/100 patient-years (95%CI: 0.51-1.06), the incidence rate of structural valve dysfunction (SVD) was 0.73/100 patient-years (95%CI: 0.59-0.91), the incidence rate of major bleeding was 0.52/100 patient-years (95%CI: 0.41-0.65), the incidence rate of endocarditis was 0.38/100 patient-years (95%CI: 0.33-0.44), and the incidence rate of non-structural valve dysfunction (NSVD) was 0.20/100 patient-years (95%CI: 0.13-0.31). The total reoperation rate for biological aortic valve was 0.77/100 patient-years (95%CI: 0.65-0.91), and the SVD related reoperation rate was 0.46/100 patient-years (95%CI: 0.36-0.58).

CONCLUSION

The all-cause mortality for conventional biological AVR was 6.33/100 patient-years. Thromboembolism, PPM implantation, reoperation, stroke, and SVD were major long term complications.

Ultrafast quasiparticle dynamics and coherent phonon in nodal line topological material LaBi

We use an ultrafast optical pump-probe spectroscopy to study quasiparticle (QP) dynamics in a topological insulator LaBi. Temperature-dependent optical measurements have been carried out, by which we observed nearly constant fast component (with a lifetime of 0.15 ps) and slow component (with a lifetime of 1.5 ps) for the whole range from 10 K to 295 K. The laser fluence dependence result shows that there is no saturation for the QP dynamics up to 3.3 mJ /cm². Moreover, an Eg mode transverse optical (TO) coherent phonon has also been observed, with a frequency of 2.8 THz. Our results provide for the first time the ultrafast dynamics information of both the QPs and coherent phonons in a nodal line topological material.

Rapid Isothermal Amplification and Portable Detection System for SARS-CoV-2

The COVID-19 pandemic provides an urgent example where a gap exists between availability of state-of-the-art diagnostics and current needs. As assay details and primer sequences become widely known, many laboratories could perform diagnostic tests using methods such as RT-PCR or isothermal RT-LAMP amplification. A key advantage of RT-LAMP based approaches compared to RT-PCR is that RT-LAMP is known to be robust in detecting targets from unprocessed samples. In addition, RT-LAMP assays are performed at a constant temperature enabling speed, simplicity, and point-of-use testing. Here, we provide the details of an RT-LAMP isothermal assay for the detection of SARS-CoV-2 virus with performance comparable to currently approved tests using RT-PCR. We characterize the assay by introducing swabs in virus spiked synthetic nasal fluids, moving the swab to viral transport medium (VTM), and using a volume of that VTM for performing the amplification without an RNA extraction kit. The assay has a Limit-of-Detection (LOD) of 50 RNA copies/μL in the VTM solution within 20 minutes, and LOD of 5000 RNA copies/μL in the nasal solution. Additionally, we show the utility of this assay for real-time point-of-use testing by demonstrating detection of SARS-CoV-2 virus in less than 40 minutes using an additively manufactured cartridge and a smartphone-based reader. Finally, we explore the speed and cost advantages by comparing the required resources and workflows with RT-PCR. This work could accelerate the development and availability of SARS-CoV-2 diagnostics by proving alternatives to conventional laboratory benchtop tests.

Cardiovascular mortality and morbidity following radical radiotherapy for lung cancer: Is cardiovascular death under-reported?

BACKGROUND

Lung cancer is the most common malignancy worldwide. Radical radiotherapy is an essential treatment in the management of early and locally advanced lung cancer. Cardiac events are known to occur following radical radiotherapy for lung cancer. This study examines the burden of cardiac events post radiotherapy, and estimates the accuracy of death certification in patients who received radical radiotherapy for lung cancer.

METHODS

We conducted a retrospective observational cohort study for all patients receiving radical radiotherapy for non-small cell lung cancer (NSCLC) at a large cancer centre between 01/01/2010 to 31/12/2016. Baseline cardiovascular disease and cancer status and treatment data were collected, along with hospital admission data and documented cause of death from the national registry for a median follow-up period of 34 months.

RESULTS

Of 1224 patients included in the analysis, 378 (30.9%) patients had cardiovascular disease at baseline, including 140 (11.4%) with prior myocardial infarction. In the 846 patients without known cardiovascular disease, 451 (53.3%) had a QRISK2 predicted 10-year cardiovascular risk >20% over 10 years. During follow-up, 215 hospitalisations occurred (Incidence rate 6.2 per hundred patient years) which were classified as primarily cardiac, and 622 patients died (18 per 100 patient-years). However, death certificates stated a primary cardiac cause of death in only 33 cases (5.3% of deaths). Notably, 29% of patients dying out of hospital and certified as cancer death did not have documented cancer relapse prior to death, and 61% had no community palliative care input prior to death, implying these events may have been sudden and unexpected.

CONCLUSION

There is a high prevalence of baseline cardiovascular disease in people undergoing radiotherapy for NSCLC, accompanied by significant rates of post-radiotherapy cardiovascular hospitalisation. However, only a small proportion of deaths are attributed to cardiovascular disease, together with the large amount of sudden deaths observed, this suggests that cardiovascular death is greatly under-reported in official statistics.

[Introduction of the Prediction model Risk Of Bias ASsessment Tool: a tool to assess risk of bias and applicability of prediction model studies]

This paper introduceds the tool named as "Prediction model Risk Of Bias ASsessment Tool" (PROBAST) to assess the risk of bias and applicability in prediction model studies and the relevant items and steps of assessment. PROBAST is organized into four domains including participants, predictors, outcome and analysis. These domains contain a total of 20 signaling questions to facilitate structured judgment of risk of bias occurring in study design, conduct or analysis. Through comprehensive judgment, the risk of bias and applicability of original study is categorized as high, low or unclear. PROBAST enables a focused and transparent approach to assessing the risk of bias of studies that develop, validate, or update prediction models for individualized predictions. Although PROBAST was designed for systematic reviews, it can be also used more generally in critical appraisal of prediction model studies.