Tag: pubmed

Biomed Phys Eng Express. 2022 Jan 17. doi: 10.1088/2057-1976/ac4c2a. Online ahead of print.

ABSTRACT

By using the statistical techniques of ANOVA: mean test and regression, it was found that the N_KRcalibration factor of Standard Imaging (SI) model HDR 1000 plus chambers presents a quadratic dependence with the reference air kerma rateK_R(from 6.9 mGy h^-1to 43.9 mGy h^-1). In order to understand and correct this dependency one model is presented for total recombination:k_s=I₃₀₀/I₁₅₀=1+k_ini+ k_d+k_volI₃₀₀+k_screenI₃₀₀², wherek_iniis the initial recombination,k_dthe thermal diffusion recombination,k_volthe volumetric recombination andk_screenthe screening for the currents/charges collected at the potential differences of 300 and 150 V. In conclusion, the total recombinationk_sis composed by onek_iniwith a constant contribution of 0.019%, onek_dcontribution of 0.017%, onek_volI₃₀₀contribution from 0.022% to 0.138%, and thek_screenI₃₀₀²effects from 0.002% to 0.09% in the range ofK_Rrate above. However, when this model fork_sis applied to try to correct the quadratic dependence of theN_KRvs K_R, explicitly there is no improvement in the variation range of 0.5% of theN_KRvs K_R.Nonetheless, it allows to obtainN_KRvalues consistent with a u_c≤ 0.7 %, which is less than 1.25% reported in the literature by ADCL or SSDL.

PMID:35039465 | DOI:10.1088/2057-1976/ac4c2a

J Am Board Fam Med. 2022 Jan-Feb;35(1):140-151. doi: 10.3122/jabfm.2022.01.210273.

ABSTRACT

PURPOSE: Hyperuricemia is associated with increased cardiovascular risk. Because patients with asymptomatic hyperuricemia (AH) experience no immediate discomfort and there are possible side effects of urate-lowering drugs, treatment for AH is controversial. We aimed to perform a network meta-analysis (NMA) to investigate the effects of different urate-lowering therapies (ULTs) on serum uric acid level, renal function, blood pressure (BP), and safety in AH patients.

METHODS: This NMA focused on AH patients. The intervention group (patients receiving urate-lowering drugs) was compared with others using other types of drugs, placebo, or usual care. We undertook a NMA under the frequentist framework by R.

RESULTS: Thirteen eligible trials were identified. The interventions included allopurinol, febuxostat, and benzbromarone, which are not approved in the United States. Benzbromarone and allopurinol had the best efficacy on lowering serum uric acid level in short-term and long-term follow-up (mean difference [MD] = -3.05; 95% CI, -5.19 to -0.91 vs MD = -3.17; 95% CI, -5.19 to -1.15). Patients using allopurinol had significantly higher eGFR than using placebo in both short-term and long-term follow-up (MD = 3.07; 95% CI, 0.18 to 5.95 vs MD = 4.10; 95% CI, 2.66 to 5.54). No difference in BP was found between groups, except for febuxostat to diastolic BP after long-term treatment (MD = -1.47; 95% CI, -2.91 to -0.04). No statistically increased odds of safety events were found with the use of ULT.

CONCLUSIONS: Our result showed that in AH patients, allopurinol has a renoprotective effect. Febuxostat has a significant impact in lowering diastolic BP. ULT does not result in a higher risk of safety events.

PMID:35039419 | DOI:10.3122/jabfm.2022.01.210273

J Neurointerv Surg. 2022 Jan 17:neurintsurg-2021-018353. doi: 10.1136/neurintsurg-2021-018353. Online ahead of print.

ABSTRACT

BACKGROUND: Stent sizing remains a challenging task for flow diverter implantation because of stent foreshortening. In this study, we aimed to quantify the change in length after implantation and assess the error in length prediction using AneuGuide^TM software.

METHODS: In a retrospective cohort of 101 patients with 102 aneurysms undergoing treatment with a pipeline embolization device (PED; Covidien, Irvine, California, USA), we used AneuGuide^TM software to obtain measured lengths (ML) and calculated lengths (CL) after stent implantation. Stent elongation was defined as the ratio of ML-LL to the labeled length (LL). Simulation error was defined as the ratio of the absolute value of CL-ML to ML. The correlation and consistency between ML and LL and between ML and CL were analyzed using Pearson’s correlation test and the Bland-Altman plot. Statistical significance was set at p<0.05.

RESULTS: The mean elongation of ML was 32.6% (range 26.3-109.2%). Moderate consistency was observed between LL and ML (ρ=0.74, p<0.001). With the AneuGuide^TM software, the mean simulation error was 6.6% (range 0.32-21.2%). Pearson’s correlation test and the Bland-Altman plot showed a high correlation and consistency between ML and CL (ρ=0.96, p<0.001).

CONCLUSION: Labeled length provides only a low reference value for predicting the actual length of the flow diverter after implantation. The high consistency between ML and CL obtained from AneuGuide^TM software shows its great potential for the optimization of the flow diverter sizing process.

PMID:35039401 | DOI:10.1136/neurintsurg-2021-018353

BMJ Open. 2022 Jan 17;12(1):e057156. doi: 10.1136/bmjopen-2021-057156.

ABSTRACT

INTRODUCTION: Hand osteoarthritis (OA) is a common joint disorder in the adult population. No cure for hand OA is known yet, but treatment aims to reduce symptoms. Non-surgical and non-pharmacological therapy interventions can include splinting, patient education, and strengthening and range of movement exercises. However, it is still unclear which treatment is most beneficial for which patient. This study aims to identify subgroups of patients with hand OA that benefit most from the different non-surgical and non-pharmacological treatments.

METHODS AND ANALYSIS: We will conduct an individual patient data (IPD) meta-analysis by extracting IPD of eligible published randomised controlled trials (RCTs). A systematic literature search through Embase, Medline and Cochrane was performed on 8 February 2021. The primary outcome will be hand pain, and our secondary outcomes are objective and subjective hand physical functions. Subgroups include age, sex, body mass index, hypermobility and other comorbidities, pain medication, occupation, baseline pain, erosive OA, type and the number of hand joints involved, radiological severity of OA, and duration of symptoms. IPD of RCTs with homogeneous treatment interventions will be pooled and analysed using a two-stage approach to evaluate treatment effect on different subgroups.

ETHICS AND DISSEMINATION: No new data will be collected, so research ethical or governance approval is exempt. Findings will be disseminated via national and international conferences, publications in peer-reviewed journals, and summaries posted on websites accessed by the public and clinicians.

PMID:35039303 | DOI:10.1136/bmjopen-2021-057156

BMJ Open. 2022 Jan 17;12(1):e052278. doi: 10.1136/bmjopen-2021-052278.

ABSTRACT

OBJECTIVES: Our study aimed to compare the quality of life (QoL) between Chinese developmental dyslexia (DD) and healthy children.

DESIGN: A cross-sectional study.

SETTING: The participants were recruited from grades 3-6 in six primary schools in Tianmen, a city of Hubei Province, China.

PARTICIPANTS: A total of 5679 students were recruited. After excluding children with visual and auditory dysfunction or psychiatric diseases or with a response rate on the scales or questionnaires of less than 90%, 5352 children were finally included in the analysis. DD children were diagnosed according to their clinical symptoms, which were mainly assessed by the Dyslexia Checklist for Chinese Children and the Pupil Rating Scale Revised Screening for Learning Disabilities.

OUTCOME MEASURES: The QoL for DD and healthy children was appraised by the Quality of Life Scale for Children and Adolescents (QLSCA). Outcome measures included its four domain scores (psychosocial function, physiological and mental health, living environment and satisfaction with QoL) and total score.

RESULTS: A total of 186 children were diagnosed with DD. The distribution of DD children in five levels of QoL was statistically different from that of healthy children (χ²=57.63, p<0.001). Compared with healthy children, the proportion of poor or worse QoL in DD was higher, and the proportion of moderate, better or good QoL was lower. The total QLSCA score in DD children was 3.475 lower than that in healthy children (B=-3.475, p=0.006). Psychosocial function, physiological and mental health, living environment and satisfaction with QoL of DD children were also inferior to those of healthy children.

CONCLUSION: The QoL of DD was significantly lower than that of healthy children, prompting more public efforts to improve DD QoL.

PMID:35039286 | DOI:10.1136/bmjopen-2021-052278

BMJ Open. 2022 Jan 17;12(1):e052376. doi: 10.1136/bmjopen-2021-052376.

ABSTRACT

OBJECTIVES: Colorectal cancer (CRC) is the second-leading cause of cancer deaths globally, with low-income and middle-income countries (LMICs) disproportionately affected. Estimates of CRC rates in LMIC are scarce. We aimed to (1) estimate sex-specific incidence of CRC, (2) estimate temporal trend and (3) determine regional variations of CRC rates on the African continent.

DESIGN: Systematic review and meta-analysis METHODS: PubMed (MEDLINE), OVID (MEDLINE), Scopus and Cochrane Library databases were systematically searched from inception to 12 December 2020. We included population-based studies that reported the incidence or prevalence estimates of CRC in Africa. Studies not conducted in humans or did not directly report the rates of CRC were excluded. Random effects model was used to pool the estimates. The methodological quality of studies was assessed with the Newcastle-Ottawa Scale.

OUTCOME MEASURES: Overall and sex-specific annual age-standardised incidence rates (ASIR) of CRC per 100 000 population.

RESULTS: The meta-analysis included 14 studies consisting of 3365 individuals with CRC (mean age, 58 years, 53% male). The overall ASIR of CRC in Africa per 100 000 population was 5.25 (95% CI 4.08 to 6.75). The rates were slightly higher in males (4.76) than in females (4.18), but not significantly different. Subgroup analysis indicated greater point estimates in North Africa (8.66) compared with sub-Saharan Africa (5.91); and higher estimates in Eastern (8.29) and Northern (8.66) Africa compared with Western (3.55) and Southern (3.57) Africa, but not statistically significant. The overall trend in ASIR has remained constant at nearly 5 per 100 000 population for the last 6 decades.

CONCLUSION: CRC estimates in Africa are heterogeneous and could be underestimated. High-quality data collection systems such as population-based cancer registries may facilitate accurate estimation of country-specific rates and provide critical information which would be lucrative to the consideration of resources needed for screening, early detection, treatment and improving overall patient outcomes.

PMID:35039287 | DOI:10.1136/bmjopen-2021-052376

Mol Biol Evol. 2022 Jan 17:msac013. doi: 10.1093/molbev/msac013. Online ahead of print.

ABSTRACT

The ongoing SARS-CoV-2 pandemic has seen an unprecedented amount of rapidly generated genome data. These data have revealed the emergence of lineages with mutations associated to transmissibility and antigenicity, known as variants of concern (VOCs). A striking aspect of VOCs is that many of them involve an unusually large number of defining mutations. Current phylogenetic estimates of the substitution rate of SARS-CoV-2 suggest that its genome accrues around 2 mutations per month. However, VOCs can have 15 or more defining mutations and it is hypothesized that they emerged over the course of a few months, implying that they must have evolved faster for a period of time. We analysed genome sequence data from the GISAID database to assess whether the emergence of VOCs can be attributed to changes in the substitution rate of the virus and whether this pattern can be detected at a phylogenetic level using genome data. We fit a range of molecular clock models and assessed their statistical performance. Our analyses indicate that the emergence of VOCs is driven by an episodic increase in the substitution rate of around 4-fold the background phylogenetic rate estimate that may have lasted several weeks or months. These results underscore the importance of monitoring the molecular evolution of the virus as a means of understanding the circumstances under which VOCs may emerge.

PMID:35038741 | DOI:10.1093/molbev/msac013

Phys Med Biol. 2022 Jan 17. doi: 10.1088/1361-6560/ac4c2d. Online ahead of print.

ABSTRACT

Objective:Mammogram image quality in Europe is defined by threshold gold thickness (T) assessment of the CDMAM contrast-detail phantom. Several limitations of the phantom exist including expense, number of images required and inter-phantom manufacturing variability. Two alternative approaches to image quality assessment for routine quality control are examined and compared to the CDMAM technique: (i) A detectability index (d’) based on a non-prewhitened model observer with an eye filter and (ii) A statistical estimate of contrast based on image noise levels (C_STAT).Approach:The d’ calculation follows previously published methodology based on the NNPS and contrast, both measured from an image of 5cm of PMMA containing a 0.2mm Al target, as well as the MTF measured under standard conditions. For the statistical method, pixels in the centre of the same NNPS image were re-binned into a range of equivalent CDMAM target areas. For any area, the minimum contrast necessary to distinguish a signal from the background, C_STAT, is 3.29σ at a 95% level of confidence, where σ is the standard deviation of the background pixels. Theoretical analysis predicts simple relationships between C_STAT, T and d’. Measured values of C_STATwere compared to T and d’ as a function of air kerma at the detector for ten mammography systems from three manufacturers.Main Results:Theoretical relationships between C_STAT, d’ and T were demonstrated. Minimum acceptable image quality performance for 0.10 and 0.25 mm diameter discs, defined by the European Guidelines in terms of T, are equivalent to d’ values of 0.85 and 5.36 and threshold C_STATvalues of 0.055 and 0.022.Significance:Strong correlations between log(T), log(d’) and log(C_STAT) suggest that either alternative approach produces information corresponding to that obtained using the CDMAM. C_STATshould be considered as a simple, objective and cost-effective alternative to routine image quality assessment in mammography.

PMID:35038692 | DOI:10.1088/1361-6560/ac4c2d

Mol Immunol. 2022 Jan 14;143:50-57. doi: 10.1016/j.molimm.2022.01.005. Online ahead of print.

ABSTRACT

Asthma is a disease with complicated network of inflammatory responses of cytokines and ImmunoglobulinE (IgE). The aim of this study was to explore the clinical characteristics, cytokine profile and plasma IgE in the Malaysian population. This is a cross-sectional study involving physician-diagnosed asthma patients (n = 287) recruited from the Chest Clinic, University of Malaya Medical Centre (UMMC). Blood (8 mL) was taken after consent was obtained. The peripheral blood leucocytes (PBL) were cultured in presence of a mitogen for 72 h to quantify cytokines [Interleukin-5(IL-5), Interleukin-9 (IL-9), Interleukin-12 Beta (IL-12ꞵ) and granulocyte-macrophage colony-stimulating factor (GM-CSF)] and plasma was used to quantify IgE levels with commercial ELISA kits. Results were compared against the same biomarkers in healthy subjects (n = 203). In addition, the amount of the biomarkers in the asthma patients were compared with their disease severity and clinical characteristics. Statistical tests in the SPSS software (Mann-Whitney U test and the Kruskal Wallis) were used to compare cytokine production and plasma IgE levels. The mean plasma IgE level was markedly higher (p < 0.0001) in asthmatics compared to controls. There were higher levels of IL-5, IL-9, IL-12ꞵ and GM-CSF (p < 0.0001) produced by cultured PBL from asthma patients compared to controls. However, our results did not expose a significant association between these cytokine levels and severity and clinical symptoms of asthma. However, there was a marked association between asthma severity and blood lymphocyte count [ꭓ²(2) = 6.745, p < 0.05]. These findings support the roles played by cytokines and IgE in the airway inflammation in asthma. The findings of this study provide new information about inflammatory cytokines in Malaysian asthma patients.

PMID:35038659 | DOI:10.1016/j.molimm.2022.01.005

J Environ Manage. 2022 Jan 14;306:114495. doi: 10.1016/j.jenvman.2022.114495. Online ahead of print.

ABSTRACT

Accelerating the development of renewable energy is seen as an effective way for achieving the goals of carbon peak and carbon neutrality. The polices of Renewable Electricity Standard (RES) and Renewable Energy Certificates (REC) play increasing and important roles in developing renewable energy. In this paper, we develop an analytical model to analyze the impacts of the interaction of RES and REC polices on the renewable energy investment levels of an electricity generation firm and the carbon emissions. Our analysis reveals several interesting insights. First, we find that the green tags price under REC policy has a non-monotonic effect on the renewable energy investment, which highly depends on the quota (i.e., the required percentage of renewable electricity consumption on total electricity consumption) under the RES policy. Specifically, when the quota in RES policy is set too high, an increase in the green tags price will increase renewable energy investment; otherwise it will reduce the electricity generation firm’s incentive to invest in renewable energy. Second, we show that the green tags price also has a non-monotonic effect on the carbon emissions. Specifically, when the quota in RES policy is set small enough, an increase in the green tags price will decrease the carbon emission. However, when the quota in RES policy is high enough, an increase in the green tags price will increase the carbon emission.

PMID:35038670 | DOI:10.1016/j.jenvman.2022.114495