Tag: pubmed

Theor Biol Med Model. 2021 Mar 9;18(1):10. doi: 10.1186/s12976-021-00140-3.

ABSTRACT

BACKGROUND: The COVID-19 pandemic poses a serious threat to global health, and pathogenic mutations are a major challenge to disease control. We developed a statistical framework to explore the association between molecular-level mutation activity of SARS-CoV-2 and population-level disease transmissibility of COVID-19.

METHODS: We estimated the instantaneous transmissibility of COVID-19 by using the time-varying reproduction number (R_t). The mutation activity in SARS-CoV-2 is quantified empirically depending on (i) the prevalence of emerged amino acid substitutions and (ii) the frequency of these substitutions in the whole sequence. Using the likelihood-based approach, a statistical framework is developed to examine the association between mutation activity and R_t. We adopted the COVID-19 surveillance data in California as an example for demonstration.

RESULTS: We found a significant positive association between population-level COVID-19 transmissibility and the D614G substitution on the SARS-CoV-2 spike protein. We estimate that a per 0.01 increase in the prevalence of glycine (G) on codon 614 is positively associated with a 0.49% (95% CI: 0.39 to 0.59) increase in R_t, which explains 61% of the R_t variation after accounting for the control measures. We remark that the modeling framework can be extended to study other infectious pathogens.

CONCLUSIONS: Our findings show a link between the molecular-level mutation activity of SARS-CoV-2 and population-level transmission of COVID-19 to provide further evidence for a positive association between the D614G substitution and R_t. Future studies exploring the mechanism between SARS-CoV-2 mutations and COVID-19 infectivity are warranted.

PMID:33750399 | DOI:10.1186/s12976-021-00140-3

BMC Med Imaging. 2021 Mar 9;21(1):45. doi: 10.1186/s12880-021-00578-4.

ABSTRACT

OBJECTIVE: To investigate left atrial shape differences on CT scans of atrial fibrillation (AF) patients with (AF+) versus without (AF-) post-ablation recurrence and whether these shape differences predict AF recurrence.

METHODS: This retrospective study included 68 AF patients who had pre-catheter ablation cardiac CT scans with contrast. AF recurrence was defined at 1 year, excluding a 3-month post-ablation blanking period. After creating atlases of atrial models from segmented AF+ and AF- CT images, an atlas-based implicit shape differentiation method was used to identify surface of interest (SOI). After registering the SOI to each patient model, statistics of the deformation on the SOI were used to create shape descriptors. The performance in predicting AF recurrence using shape features at and outside the SOI and eight clinical factors (age, sex, left atrial volume, left ventricular ejection fraction, body mass index, sinus rhythm, and AF type [persistent vs paroxysmal], catheter-ablation type [Cryoablation vs Irrigated RF]) were compared using 100 runs of fivefold cross validation.

RESULTS: Differences in atrial shape were found surrounding the pulmonary vein ostia and the base of the left atrial appendage. In the prediction of AF recurrence, the area under the receiver-operating characteristics curve (AUC) was 0.67 for shape features from the SOI, 0.58 for shape features outside the SOI, 0.71 for the clinical parameters, and 0.78 combining shape and clinical features.

CONCLUSION: Differences in left atrial shape were identified between AF recurrent and non-recurrent patients using pre-procedure CT scans. New radiomic features corresponding to the differences in shape were found to predict post-ablation AF recurrence.

PMID:33750343 | DOI:10.1186/s12880-021-00578-4

BMC Ophthalmol. 2021 Mar 9;21(1):131. doi: 10.1186/s12886-021-01889-4.

ABSTRACT

BACKGROUND: Conjunctival autograft transplantation from superior conjunctiva is often chosen to lower the postoperative recurrence rate for pterygium treatment. However, inferior conjunctival autograft (ICA) might be taken as an alternative surgery method, especially under certain conditions. Consequently, we designed this research to estimate and contrast the result of inferior conjunctival autograft and superior conjunctival autograft (SCA) on the postoperative recurrence rate.

METHODS: We searched through network database (PubMed, Embase and Cochrane Central Register of Controlled Trials) to choose suitable randomized controlled trials (RCTs). Based on Cochrane review methods, we evaluated eligibility and risk of bias of included studies. The primary measures included postoperative recurrence rate. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were assessed. RevMan 5.3 software was utilized to conduct statistical analysis.

RESULTS: Four RCTs composed of a total of 438 eyes were included in this meta-analysis, with 234 eyes in the inferior conjunctival autograft group and 204 eyes in the superior conjunctival autograft group. Statistical meta-analysis revealed that the postoperative recurrence rate was similar between the two groups (RR = 0.77, 95% CI: 0.36 to 1.62, P = 0.49). Only two RCTs applied the postoperative pain scale and one of them did not provided adequate numbers.

CONCLUSIONS: Our meta-analysis indicated that inferior autograft transplantation and superior autograft transplantation had a similar effect on postoperative recurrence rate. The inferior autograft group might have a less postoperative pain. Subsequent RCTs which have more patients participated and more outcomes are needed to confirm our conclusions in years to come.

PMID:33750344 | DOI:10.1186/s12886-021-01889-4

BMC Infect Dis. 2021 Mar 9;21(1):249. doi: 10.1186/s12879-021-05849-7.

ABSTRACT

BACKGROUND: Presymptomatic COVID-19 patients have been identified as a major stumbling block in efforts to break the chain of transmission. Studies on temporal dynamics of its shedding suggests it peaks 1-2 days prior to any symptom onset. Therefore, a large proportion of patients are actively spreading the disease unknowingly whilst undetected. However, lengthy lockdowns and isolation leads to a host of socioeconomic issues and are impractical. Conversely, there exists no study describing this group and their clinical significance despite their key role in disease transmission.

METHODS: As a result, we devised a retrospective study to look at the prevalence of presymptomatic patients with COVID-19 from data sourced via our medical records office. Subsequently, we identify early indicators of infection through demographic information, biochemical and radiological abnormalities which would allow early diagnosis and isolation. In addition, we will look into the clinical significance of this group and their outcome; if it differs from asymptomatic or symptomatic patients. Descriptive statistics were used in addition to tabulating the variables and corresponding values for reference. Variables are compared between the presymptomatic group and others via Chi-square testing and Fisher’s exact test, accepting a p value of < 0.05 as significant.

RESULTS: Our analysis shows a higher proportion of presymptomatic patients with atypical symptoms like chest pain while symptomatic patients commonly present with respiratory symptoms like cough and shortness of breath. Besides that, there were more females presenting as presymptomatic patients compared to males (p = 0.019) and these group of patients were likely to receive treatment (p < 0.001). Otherwise, we were not able to identify other statistically significant markers suggesting a patient is presymptomatic.

CONCLUSION: As we have little means of identifying these silent spreaders, it highlights further the importance of general measures implemented to stop COVID-19 transmission like social distancing, face mask, and widespread testing.

PMID:33750347 | DOI:10.1186/s12879-021-05849-7

BMC Womens Health. 2021 Mar 9;21(1):101. doi: 10.1186/s12905-021-01249-w.

ABSTRACT

BACKGROUND: Post-fistula-repair incontinence (PFRI) is a common complication of vesicovaginal fistula (VVF) surgeries. It entails continuous leakage of urine after successful VVF closure. Pelvic Floor Muscle Training (PFMT) plays a vital role in the management of PFRI, however, an evolving exercise approach is the Paula Exercise Method (PEM) which has shown a promising effect in stopping urinary incontinence, but there is no data on its effect on PFRI. This study therefore, proposes to primarily investigate the effect of PEM on urine leakage and secondarily, pelvic floor strength (PFS), quality of life (QoL), sexual function (SF), and mental health (MH) in women with PFRI.

METHODS: This is a study protocol for a randomized controlled trial. A total of 182 participants are expected to participate in the study after satisfying the inclusion criteria. The participants will be randomized into either PEM or PFMT study groups. The demographic data of all the participants will be recorded. Each participant will be assessed for urine leakage, PFS, QoL, SF, and MH at baseline and subsequently, at four, eight and 12 weeks of intervention. Demographic parameters will be summarized using descriptive statistics. Continuous data will be computed for differences using inferential statistic of Analysis of variance, t-test and Man Whitney U as appropriate. All analyses will be performed using SPSS version 22.0 with probability set at 0.05 alpha level.

DISCUSSION: It is hoped that the outcome of this study will determine the effect of the Paula exercise method on urine leakage, pelvic floor strength, quality of life, sexual function, and mental health among women with post-fistula-repair incontinence and also provide evidence for the use of the Paula method in urinary incontinence.

TRIAL REGISTRATION: Pan African Clinical Trials Registry ( www.pactr.org ), identifier PACTR201906515532827.

PMID:33750376 | DOI:10.1186/s12905-021-01249-w

BMC Med Res Methodol. 2021 Mar 9;21(1):46. doi: 10.1186/s12874-021-01238-5.

ABSTRACT

BACKGROUND: This study investigated the ArmA-TH sub-scale measurement properties based on item response theory using the Rasch model.

METHODS: Patients with upper limb hemiplegia resulting from cerebrovascular and other brain disorders were asked to complete the ArmA-TH questionnaire. Rasch analysis was performed to test how well the ArmA-TH passive and active function sub-scales fit the Rasch model by investigating unidimensionality, response category functioning, reliability of person and item, and differential item functioning (DIF) for age, sex, and education.

RESULTS: Participants had stroke or other acquired brain injury (n = 185), and the majority were men (126, 68.1 %), with a mean age of 55 (SD 22). Most patients (91, 49.2 %) had graduated from elementary/primary school. For the ArmA-TH passive function scale, all items had acceptable fit statistics. The scale’s unidimensionality and local independence were supported. The reliability was acceptable. A disordered threshold was found for five items, and none indicated DIF. For the ArmA-TH active function scale, one item was misfit and three were locally dependent. The reliability was good. No items showed DIF. All items had disordered thresholds, and the data fitted the Rasch model better after rescoring.

CONCLUSIONS: Both sub-scales of ArmA-TH fitted the Rasch model and were valid and reliable. The disordered thresholds should be further investigated.

PMID:33750313 | DOI:10.1186/s12874-021-01238-5

BMC Geriatr. 2021 Mar 9;21(1):171. doi: 10.1186/s12877-021-02123-y.

ABSTRACT

BACKGROUND: Although previous studies have evaluated risk factors for the incidence of severe infection in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), the relationship between body mass index (BMI) and severe infection in AAV has not been elucidated. We hypothesized that older adults with AAV and a low BMI would be at a higher risk of infection. We therefore investigated the association between underweight status at AAV diagnosis and subsequent occurrence of severe infection in older adults with AAV.

METHODS: This single-center retrospective cohort study included 93 consecutive older adults with microscopic polyangiitis (MPA) treated at the Aichi Medical University Hospital in Japan between 2004 and 2018. The relationships between BMI at diagnosis and subsequent first severe infection were assessed using multivariate Cox proportional hazards models. The cumulative probability of the development of the first severe infection was calculated using the Kaplan-Meier method and the log-rank test. The level of statistical significance was set at P < 0.05.

RESULTS: During the median follow-up period of 19 (6-53) months, 29 (31.2%) patients developed at least one severe infection. Older age (adjusted hazard ratio [HR] = 2.02, 95% confidence interval [CI]: 1.14-3.52, per 10 years; P = 0.016), low BMI (< 18.5 kg/m² compared with normal BMI [18.5-23.0 kg/m²], adjusted HR = 2.63, 95% CI: 1.11-6.19; P = 0.027), and use of methylprednisolone pulse therapy (adjusted HR = 2.48, 95% CI: 1.07-5.76; P = 0.034) were found to be significant predictors of severe infection.

CONCLUSIONS: Low BMI was associated with a higher risk of severe infection in older adults with MPA, suggesting that careful management may be required to prevent this complication in this vulnerable group. Further studies are needed to elucidate the optimal treatment strategy for these patients.

PMID:33750328 | DOI:10.1186/s12877-021-02123-y

BMC Neurol. 2021 Mar 9;21(1):107. doi: 10.1186/s12883-021-02143-6.

ABSTRACT

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is usually a benign, yet underdiagnosed clinical condition associated with subacute to acute neurological manifestations primarily affecting white matter. PRES is reversible when recognized promptly and treated early by removal of the insulting factor; however, can lead to irreversible and life-threatening complications such as cerebral hemorrhage, cerebellar herniation, and refractory status epilepticus.

METHODS: We utilized the National Inpatient Sample database provided by the Healthcare Cost and Utilization Project (HCUP-NIS) 2017 to investigate the demographic variables (age, sex, and race) for patients with PRES, concomitant comorbidities and conditions, inpatient complications, inpatient mortality, length of stay (LOS), and disposition.

RESULTS: A total of 635 admissions for patients aged 18 years or older with PRES were identified. The mean age was 57.2 ± 0.6 years old with most encounters for female patients (71.7%, n = 455) and white as the most prevalent race. Half the patients in our study presented with seizures (50.1%, n = 318), sixty-three patients (9.9%) presented with vision loss, and sixty-four patients (10.1%) had speech difficulty. In addition, 45.5% of patients had hypertensive crisis (n = 289). 2.2% of hospitalizations had death as the outcome (n = 14). The mean LOS was 8.2 (±0.3) days, and the mean total charges were $92,503 (±$5758). Inpatient mortality differed between males and females (1.7% vs. 2.4%) and by race (3.6% in black vs. 1.8% in white) but was ultimately determined to be not statistically significant. Most patients who present with vision disturbance have a high risk of intracranial hemorrhage. Furthermore, end-stage renal disease, atrial fibrillation, and malignancy seemed to be linked with a very high risk of mortality.

CONCLUSION: PRES, formerly known as reversible posterior leukoencephalopathy, is a neurological disorder with variable presenting symptoms. Although it is generally a reversible condition, some patients suffer significant morbidity and even mortality. To the best of our knowledge, this is the largest retrospective cohort of PRES admissions that raises clinician awareness of clinical characteristics and outcomes of this syndrome.

PMID:33750332 | DOI:10.1186/s12883-021-02143-6

BMC Gastroenterol. 2021 Mar 9;21(1):117. doi: 10.1186/s12876-021-01701-z.

ABSTRACT

BACKGROUND: A colorectal cancer screening programme (CCSP) was implemented from 2012 to 2017 in Tianjin, China. Residents with a positive faecal immunochemical test (FIT) or positive self-reported symptom questionnaire (SRSQ) were recommended to undergo colonoscopy. The objective was to investigate the potential factors associated with nonadherence to colonoscopy among a risk-increased population.

METHODS: Data were obtained from the CCSP database, and 199,522 residents with positive FIT or positive SRSQ during two screening rounds (2012-2017) were included in the analysis. Logistic regression analysis was performed to assess the association between nonadherence to colonoscopy and potential predictors.

RESULTS: A total of 152,870 (76.6%) individuals did not undergo colonoscopy after positive FIT or positive SRSQ. Residents with positive SRSQ but without positive FIT were more likely not to undergo colonoscopy (negative FIT: OR, 2.35; 95% CI, 2.29-2.41, no FIT: OR, 1.27; 95% CI, 1.24-1.31). Patients without a cancer history were less likely to undergo colonoscopy even if they received risk-increased reports based on the SRSQ.

CONCLUSION: In the CCSP, seventy-seven percent of the risk-increased population did not undergo colonoscopy. FIT should be recommended since positive FIT results are related to improved adherence to colonoscopy. Residents with negative FIT but positive SRSQ should be informed of the potential cancer risk to ensure adherence to colonoscopy.

PMID:33750307 | DOI:10.1186/s12876-021-01701-z

Quintessence Int. 2021 Mar 22;0(0):0. doi: 10.3290/j.qi.b1098315. Online ahead of print.

ABSTRACT

OBJECTIVES: The goal of the study was to determine the effects of software updates on the trueness and precision of digital impressions obtained with a variety of intraoral scanner (IOS) systems.

METHOD AND MATERIALS: Seven IOS systems were investigated. Each system was tested using two versions of software, with the second version being the latest at the time of conducting the study. Scans were performed on a custom mandibular typodont model with natural teeth that were either unrestored or restored with amalgam, composite, lithium disilicate, zirconia, and gold. Eight scans were obtained for each software version on any of the tested IOS systems. Experimental IOS scans were compared against an industry-standard master scan of the typodont obtained with an ATOS Capsule scanner proven to have a trueness of 3 µm and a precision of 2 µm. Isolation of each substrate material on the digital experimental and master scans was achieved using the Geomagic metrology software for subsequent analysis of the substrate influence on accuracy. A generalized linear mixed model was used to determine the influence of the software version on the trueness and precision of the impression scan.

RESULTS: For some IOS systems, scans made with older software versions differ in accuracy compared with those obtained with the most recent software versions. Trueness was improved for most scanners following the software update, although the Element2 IOS performance deteriorated. Software updates had lesser effects on precision and showed variable trends among different systems. Software updates also influence different substrate materials scans’ accuracy, although the results show variability among IOS systems. When comparisons were done among IOS systems updated with the latest software version, best performers for complete arch trueness were the Emerald S, Trios 3, and Primescan systems.

CONCLUSION: Software updates have a statistically significant effect on the trueness and precision of different IOS systems. These updates can have both positive and negative effects on scan accuracy, although it appears that these variations are within the clinical acceptability levels.

PMID:33749223 | DOI:10.3290/j.qi.b1098315