Confounding Research Articles

Evaluation of the Feasibility of 2D-SWE to Measure Liver Stiffness in Healthy Dogs and Analysis of Possible Confounding Factors.

(1) Background: Two-dimensional shear wave elastography (2D-SWE) is a non-invasive method widely used in human medicine to assess the extent of liver fibrosis but only rarely applied to veterinary medicine. This study aimed to measure liver stiffness in healthy dogs and investigate the factors that impacted 2D-SWE measurement. (2) Methods: In total, 55 healthy dogs were enrolled and subjected to 2D-SWE measurements before and after anesthesia administration. Post-anesthesia 2D-SWE measurements and computerized tomography (CT) scans were obtained. (3) Results: The liver stiffness range in healthy dogs was 3.96 ± 0.53 kPa. In a stratified analysis based on confounding factors, liver stiffness was influenced by measurement site and anesthesia, but not by sex. No correlation was observed between liver stiffness and weight or liver CT attenuation. (4) Conclusions: 2D-SWE is feasible for liver stiffness measurement in dogs. Anesthesia and measurement site are sources of variability. Therefore, these factors should be considered while recording 2D-SWE measurements. Our data on liver stiffness in healthy dogs can serve as the basis for future studies on 2D-SWE to assess pathological conditions in dogs.

Hypoglycemia and Cardiovascular Disease: Exploring the Connections.

It has long been known that administering insulin or insulin secretagogues to treat diabetes has the unfavorable side effect of hypoglycemia. Because hypoglycemia can disrupt normal brain function, it can have a profound impact on people's lives. Studies have shown a connection between hypoglycemia and a higher risk of death and cardiovascular disease. Through experimental studies, numerous potential reasons for the start of cardiovascular events have been discovered. In addition, studies on people have demonstrated that hypoglycemia can result in ventricular arrhythmias. According to recent studies, a number of factors may affect the relationship between hypoglycemia, cardiovascular events, and mortality. Confounding factors may explain the apparent correlation, at least in part. People with comorbidities may experience more hypoglycemia, increasing their risk of mortality. Those who have type 1 or type 2 diabetes, however, seem to be more susceptible to the negative effects of hypoglycemia on the cardiovascular system. When choosing appropriate glucose-lowering treatments and setting glycemic objectives with patients, clinicians should be aware of this risk.

Psychosocial and sociodemographic factors associated with gestational blood glucose levels in women attending public hospitals: Results from baseline of MAASTHI cohort.

Understanding psychosocial environment is important for improving maternal and fetal health outcomes during pregnancy. We aimed to identify the association between gestational blood glucose levels and psychosocial and demographic factors in pregnant women. In the MAASTHI pregnancy cohort in Bengaluru, we assessed depressive symptoms, and social support using validated scales at baseline in first trimester. A 2-hour 75 g oral glucose tolerance test (OGTT) was administered between 24-36 weeks of gestation. We examined the relation between psychosocial factors assessed at baseline and gestational blood glucose levels in second/third trimester using multivariate linear regression and explored association between serum cortisol and gestational blood glucose levels in subgroup samples. We found that 9% of pregnant women had depressive symptoms and 14.3% had Gestational Diabetes Mellitus (GDM). Psychosocial factors, including depressive symptoms, have a significant correlation with gestational fasting(β = 0.12, p-value<0.05) and postprandial blood sugar level(β = 0.23, p-value<0.05) and poor social support were found to have a significant association with gestational fasting blood glucose levels(β = 1.45, p-value <0.05) and postprandial blood sugar levels(β = 2.60, p-value <0.05). The sociodemographic factors such as respondent education, occupation, social and economic status were associated with gestational blood sugar after adjusting for potential confounder variables. Depressive symptoms and poor social support earlier in pregnancy were significantly associated with increased gestational blood glucose levels. Early detection and recognition of modifiable psychosocial risk factors can reduce glucose intolerance during pregnancy. Evaluating the benefits of screening for psychosocial factors and timely management of gestational diabetes mellitus can be helpful in India.

Prevalence of Age-Related Sensorineural Hearing Loss and Related Factors in Elderly Patients Attending Tertiary Hospital in Tanzania.

Age-related sensorineural hearing loss (SNHL), is a progressive, usually bilateral hearing loss that occurs in elderly. It is correctable using rehabilitative hearing devices, which can vastly improve the older person's quality of life. This study aimed to find out the prevalence and related factors of age-related sensorineural hearing loss among elderly patients in Tanzania. A total of 380 elderly patients who received Otorhinolaryngology (ORL) services at Muhimbili tertiary hospital were enrolled. Participants were screened for hearing loss and interviewed by the structured questionnaire followed by otoscopic examination and Pure tone Audiometry (PTA). This study included 182(47.9%) males, and 198 (52.1%) females. The prevalence of SNHL was 27.6%, males were mostly affected 57(31.3%) p = 0.574. Bilateral SNHL was found 90 (85.7%) p = 0.026, and the severity of age-related SNHL was found to increase as age increases. Sensorineural hearing loss among the elderly was prevalent, mostly bilateral, and the severity increases with age. Confounding factors such as hypertension, diabetes mellitus (DM), cigarette smoking, and ototoxic medication may have contributed. Elderly should be screened for hearing loss especially on the individuals with other co-morbidities for early diagnosis and management in order to improve the quality of life of the elderly.

Association between remnant cholesterol, metabolic syndrome, and cardiovascular disease: post hoc analysis of a prospective national cohort study

BackgroundEpidemiologic evidence suggested that remnant cholesterol (RC) is associated with the occurrence of cardiovascular disease (CVD). In recent years, RC has been connected with different types of cardiometabolic disorders. We aim to clarify the relationship among RC, metabolic syndrome (MetS) and subsequent CVD.MethodsWe enrolled 7471 individuals into our study from China Health and Nutrition Survey in 2009 and followed participants till 2015. RC was calculated as total cholesterol minus low-density lipoprotein cholesterol minus high-density lipoprotein cholesterol. CVD was defined as myocardial infarction and stroke. Multivariate logistic regression and Cox regression models were used to evaluate the association between RC and MetS as well as CVD. We further investigated whether the association between RC and CVD was mediated by MetS.ResultsOf all subjects, 24.73% were diagnosed with MetS and 2.74% developed CVD. Multivariate logistic regression analysis elucidated that per-tertile-increase in RC was associated with MetS after adjusting all the confounder factors, (odds ratio: 3.49, 95% confidence interval CI 3.21–3.79, P for trend < 0.001). And per-tertile-increase RC had a significant increased risk of CVD (hazard ratio: 1.26, 95% CI 1.06–1.50, P for trend = 0.008). Meanwhile, we found that RC level is associated with the prevalence of all the components of MetS. Significant indirect effects of RC between MetS and CVD were found, with the index mediated at 48.46% of the association.ConclusionsOur study provides the evidence that RC level is independently associated with the prevalence of MetS and each component of MetS. MetS partially mediated the association between RC level and CVD risk.

Impact of possible errors in natural language processing-derived data on downstream epidemiologic analysis.

To assess the impact of potential errors in natural language processing (NLP) on the results of epidemiologic studies. We utilized data from three outcomes research studies where the primary predictor variable was generated using NLP. For each of these studies, Monte Carlo simulations were applied to generate datasets simulating potential errors in NLP-derived variables. We subsequently fit the original regression models to these partially simulated datasets and compared the distribution of coefficient estimates to the original study results. Among the four models evaluated, the mean change in the point estimate of the relationship between the predictor variable and the outcome ranged from -21.9% to 4.12%. In three of the four models, significance of this relationship was not eliminated in a single of the 500 simulations, and in one model it was eliminated in 12% of simulations. Mean changes in the estimates for confounder variables ranged from 0.27% to 2.27% and significance of the relationship was eliminated between 0% and 9.25% of the time. No variables underwent a shift in the direction of its interpretation. Impact of simulated NLP errors on the results of epidemiologic studies was modest, with only small changes in effect estimates and no changes in the interpretation of the findings (direction and significance of association with the outcome) for either the NLP-generated variables or other variables in the models. NLP errors are unlikely to affect the results of studies that use NLP as the source of data.

Impact of baseline luteinizing hormone (LH) level and anti-Müllerian hormone (AMH) on pregnancy outcomes in polycystic ovary syndrome (PCOS) patients undergoing IVF/ICSI cycle in antagonist protocol

Introduction: Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder often associated with infertility. There are several factors that could impair the pregnancy outcomes of PCOS patients. The latter endocrine profile along with high baseline luteinizing hormone (LH), high LH/follicle-stimulating hormone ratio, as well as high anti-Müllerian hormone (AMH) levels appear detrimental for patients undergoing In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). The objective of this study is to evaluate the impact of baseline LH and AMH levels on pregnancy outcomes in PCOS patients performing IVF/ICSI cycles in an antagonist protocol. Materials and methods: The current investigation is a retrospective cohort study conducted at IVF Tiziri Center in Algiers on PCOS patients undergoing IVF/ICSI from January 2017 to March 2021. According to the Rotterdam criteria, patients aged between 23 and 42 years were divided into 2 groups: group 1 (G1) =91 patients; group 2 (G2) =100 all patients had an LH level &gt;10 IU/L. Both groups had AMH levels &gt;5 ng/mL. Controlled ovarian stimulation was done with a fixed antagonist protocol, as for the ovulation it was triggered with human chorionic gonadotropin or gonadotropin-releasing hormone agonist. Fresh and frozen embryo transfers were, thereafter, evaluated. Concerning the statistical analysis, it was done with SPSS software. Results: The mean LH level was 15.16±7.08 for G1 versus 5.7±1.86 for G2 (P=10−6), mean LH/follicle-stimulating hormone ratio 2.71±1.36 in G1 versus 1.05±0.44 (P=10−6) and mean AMH level was 9.27±3.90 for G1 versus 7.53±2.76 for G2 with (P&lt;10−3). The mean follicles over 11 mm in diameter, estradiol (E2) level, and progesterone level on the trigger day did not differ significantly between G1 and G2. Also, the mean of oocytes and metaphase II oocytes retrieved fertilization, and blastulation rate were similar for both groups. The pregnancy rate for G1 was 40.6% versus 54% (P&gt;0.05); the ongoing pregnancy rate (OPR) was 28.6% in G1 versus 47% in G2 (P=0.078); and the miscarriage rate was 32.4% for G1 versus 12.9 for G2 (P=0.072). A univariate analysis was performed with all confounder factors supposed to impact pregnancy outcomes: AMH level did not impact pregnancy outcomes, whereas LH level &lt;11 IU/L has been determined as a threshold impacting positively on OPR with odds ratio=2.01 (95% CI: 1.05–3.87). After a multivariate logistic regression including con-founders, 3 factors significantly influence OPR: LH, E2, and infertility with known etiology. Conclusion: The high baseline LH level impairs pregnancy outcomes in PCOs patients undergoing an antagonist protocol IVF/ICSI cycle. The identification of PCOS patients by their endocrine profile enables the establishment of a prognosis for council patients and a plan for an individualized therapeutic strategy.

Predictive Model for Reintervention in Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: Osteoarthritis (OA) of the tibiotalar joint is associated with a high degree of morbidity, being comparable with final stages of renal and heart failure. The incidence of OA of the tibiotalar joint is as high as 47.7 per 100,000 habitants, of whom most of them will need a surgical intervention to improve their quality of life. Up to date evidence supports the use of the total ankle arthroplasty for its management. A great effort has been made to elucidate the factors associated with failure of the total ankle prothesis, until now no attempt has been made to look for factors associated with the need of surgical reintervention, beyond revision of the prothesis. Methods: Prospective cohort study in patients with tibiotalar OA operated between 2015 and 2022, with a minimum follow-up of 12 months, excluding revision prothesis and lost to follow-up. Reintervention was considered as any complication, related to the prothesis, that needed a surgical intervention that was not planned. We performed a multivariate logistic regression model with 13 variables (diabetes, hypertension, tabaquism, age, etiology, hind foot alignment, subtalar OA, talonavicular OA, calcaneocuboid OA, pes planus, cavo varus, previous subtalar arthrodesis and surgical time). Confounding effect was assessed with the change of the odds ratio of the principal independent variable, by adding or subtracting potentially confounder variables into the model. The variables that were statistically non-significant and those variables that do not cause confusion effect, were discarded. Goodness of fit was evaluated using the Hosmer-Lemeshow test and the discrimination of the model with the ROC curve. The Kaplan-Meier curve was used for survival analysis. Results: 105 total ankle arthoplasties were included, the statistically significant variables were: take-down etiology OR = 171.73 (CI: 6.87 - 4294.95, p &lt; 0.01), post-traumatic etiology OR = 14.56 (CI: 1.98 - 107.04, p &lt; 0.01) and surgical time OR = 0.96 (CI: 0.92 - 0.99, p = 0.04), while age OR = 1.02 (CI: 0.96 - 1.09, p = 0.57) and cavo varus OR = 4.75 (CI: 0.71 - 31.93, p = 0.11), wereincluded in the model because of its confounding effect. Goodness of fit demonstrates that the data fit the model adequately (p = 0.84). The ROC curve demonstrates 89.03% discriminatory power. The survival rate at 8 years was 80.39%, median of survival rate was not determined, because longer follow-up was needed. Conclusion: The take-down and post-traumatic etiology can be considered as important risk factors for requiring a surgical reintervention. Patients with a take-down etiology that have a cavo varus deformity and higher age, have a higher risk to require a surgical reintervention. Longer surgical time can be considered as a protective factor for needing a surgical reintervention. At 8 years 20.61% of patients will need a surgical reintervention, related to their Total Ankle Arthroplasty.

Association of CCNG1 and FDXR Gene Expression during Radiotherapy with Disease - And Therapy-Related Confounding Factors in Breast Cancer Patients

The objective of this study is to investigate the changes in CCNG1 and FDXR gene expression during RT in breast cancer patients and associate the observed changes with disease- and therapy-related confounding factors through a nonrandomized, controlled, open-trial clinical study of 57 breast cancer patients.

Physical Confounding Factors Affecting Gas Sensors Response: A Review on Effects and Compensation Strategies for Electronic Nose Applications

Electronic noses (e-noses) are devices based on combining different gas sensors’ responses to a given sample for identifying specific odor fingerprints. In recent years, this technology has been considered a promising novel tool in several fields of application, but several issues still hamper its widespread use. This review paper describes how some physical confounding factors, such as temperature, humidity, and gas flow, in terms of flow direction and flow rate, can drastically influence gas sensors’ responses and, consequently, e-nose results. Among the software and hardware approaches adopted to address such issues, different hardware compensation strategies proposed in the literature were critically analyzed. Solutions related to e-nose sensors’ modification, design and readout, sampling system and/or chamber geometry design were investigated. A trade-off between the loss of volatile compounds of interest, the decrease of sensors’ sensitivity, and the lack of fast responses need to be pointed out. The existing body of knowledge suggests that the e-nose design needs to be highly tailored to the target application to exploit the technology potentialities fully and highlights the need for further studies comparing the several solutions proposed as a starting point for the application-driven design of e-nose-based systems.

Comments on: Effect of physical activity on long COVID fatigue.

This correspondence discusses a published article on the effects of physical activity on Long COVID fatigue. Confounding factors are possible and should be acknowledged. When managing Long COVID-19 fatigue, you need to worry about other possible causes of the problem.

Anorexia Nervosa in vivo cytokine production: a systematic review

IntroductionThe underlying psychobiology that contributes to Anorexia Nervosa (AN) onset and disease progression remains unclear. New research is emerging suggesting a possible link between inflammation and a variety of mental illnesses. Alterations of cytokines may play a role in the pathogenesis of AN. Some studies have found differences in the cytokine profile of those with AN compared to healthy controls, but results are heterogeneous. The aim of this work was to systematically review existing studies investigating in-vivo cytokine production in those with AN before and after weight restoration compared to controls. MethodsA comprehensive literature search of four electronic databases (PubMed, PsychInfo, EMBASE and CINAH) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify human in-vivo studies investigating the relationship between AN and cytokine production. Data extracted from included studies related to population characteristics (e.g. age, gender, mean mBMI/%IBW), cytokine measurement and relevant findings. Confounding factors (e.g. smoking status, co-morbid mental illness, menstruation status) were also collected. Results36 studies were eligible for this systematic review of which the majority were conducted in Europe (77.8%) and involved female subjects (97.2%). Those with AN ranged in age from 13 to 47 years and had an illness duration of 3 months to 24 years. 15 candidate cytokines and 3 receptors were identified (TNF-alpha, IL-6, IL-1B, CRP, IL-2, IL-7, IL-10, IFN-γ, TNF-R2, IL-1 α, IL-15, TNF-R1, IL-17, IL-18, TGF-B1, IL-12, IL-6R and TGF-B2) exploring in-vivo levels in patients with AN and comparing to controls. TNF-alpha and IL-6 were the most extensively studied with IL-6 being significantly elevated in 4 out of 8 (50%) of longitudinal studies when comparing AN patients at baseline compared to post weight restoration. Following weight restoration, there was no difference in IL-6 levels when comparing to HC in 7 of 8 (87.5%) longitudinal studies examined. ConclusionsThe most promising cytokine potentially involved in the pathogenesis of AN appears to be IL-6, and possibly TNF-alpha pathways. The heterogeneity of clinical and methodology factors impedes the generalizability of results. Future studies may wish to address these methodological shortcomings as alterations in cytokine levels in AN could act as therapeutic targets assisting with weight restoration and psychopathology and may offer diagnostic potential.

Matted Lymph Nodes on MRI in Nasopharyngeal Carcinoma: Prognostic Factor and Potential Indication for Induction Chemotherapy Benefits.

Lymph node characteristics markedly affect nasopharyngeal carcinoma (NPC) prognosis. Matted node (MN), an important characteristic for lymph node, lacks explored MRI-based prognostic implications. Investigate MRI-determined MNs' prognostic value in NPC, including 5-year overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), progression-free survival (PFS), and its role in induction chemotherapy (IC). Retrospective cohort survival study. Seven hundred ninety-two patients with non-metastatic NPC (female: 27.3%, >45-year old: 50.1%) confirmed by biopsy. 5-T/3.0-T, T1-, T2- and post-contrast T1-weighted fast spin echo sequences acquired. MNs were defined as ≥3 nodes abutting with intervening fat plane replaced by extracapsular nodal spread (ENS). Patients were observed every 3 months for 2 years and every 6 months for 5 years using MRI. Follow-up extended from treatment initiation to death or final follow-up. MNs were evaluated by three radiologists with inter-reader reliability calculated. A 1:1 matched-pair method compared survival differences between MN-positive patients with or without IC. Primary endpoints (OS, DMFS, LRFS, PFS) were calculated from therapy initiation to respective event. Kappa values assessed inter-reader reliability. Correlation between MN, ENS, and LNN was studied through Spearman's correlation coefficient. Clinical characteristics were calculated via Fisher's exact, Chi-squared, and Student's t-test. Kaplan-Meier curves and log-rank tests analyzed all time-to-event data. Confounding factors were included in Multivariable Cox proportional hazard models to identify independent prognostic factors. P-values <0.05 were considered statistically significant. MNs incidence was 24.6%. MNs independently associated with decreased 5-year OS, DMFS, and PFS; not LRFS (P = 0.252). MN-positive patients gained significant survival benefit from IC in 5-year OS (88.4% vs. 66.0%) and PFS (76.4% vs. 53.5%), but not DMFS (83.1% vs. 69.9%, P = 0.145) or LRFS (89.9% vs. 77.8%, P = 0.140). MNs may independently stratify NPC risk and offer survival benefit from IC. 3 TECHNICAL EFFICACY: Stage 2.

Interaction of dietary patterns with rs28362491 on severity of coronary artery stenosis in patients undergoing coronary angiography

Coronary artery disease (CAD) is one of the most important cardiovascular diseases. Lifestyle and genetic factors play important roles in the development of CAD. The aim of the study is to examine the interaction of dietary patterns and genes on the likelihood of abnormal lipid profile and coronary artery stenosis in Iranians undergoing coronary angiography. This cross-sectional study was performed on 440 patients who underwent coronary angiography. The factor analysis method was used to extract dietary patterns. Commercial kits have been used to assess biochemical parameters. The detection of the rs28362491 genotype was carried out by the method of restriction fragment length polymorphism. Traditional (TDP) and western dietary pattern (WDP) were extracted. We observed an interaction of adherence to TDP and rs28362491 on the odds of having a high Gensini score. These interactions indicated that higher adherence to TDP was associated with higher odds of having a high Gensini score for patients with DD genotype than for those with II genotype. (OR 2.33, 95%CI 1.00–5.44; P = 0.05). These interactions remained statistically significant even after confounder variables. We observed an interaction between higher adherence to TDP and rs28362491 variants on the odds of high low-density lipoprotein cholesterol levels (P = 0.04) in the unadjusted model. We found a significant interaction of this polymorphism and higher adherence to WDP on the odds of having a high Gensini score in the unadjusted model (P = 0.04). This study provides a basis for future research on NF-KB1 gene and diet interaction. More large-scale longitudinal studies are needed to validate these findings.

Robotic versus laparoscopic hepatectomy: A single-center, propensity score- matched study.

Although the effectiveness of robotic hepatectomy (RH) has been evaluated in several studies, the superiority of RH over other approaches has not been definitely established. Therefore, in the present propensity score-matched cohort study, we compared RH and laparoscopic hepatectomy (LH) in terms of perioperative and oncologic outcomes. This retrospective study included patients who underwent RH or LH for benign and malignant liver lesions at a single center in Taiwan at any time between 2014 and 2020. Confounding factors, specifically age, sex, body mass index, American Society of Anesthesiologists score, IWATE criteria, and Charlson comorbidity index, were adjusted through propensity score matching (PSM). A total of 329 patients were finally included in this study. Two homogeneous groups (RH and LH; n, 72 each) were formed using PSM. The RH group had a longer operative time (median: 231 vs.180min, respectively; P=.001) and lower conversion (to open surgery) rate (9.7% vs.0.0%, respectively; P=.013) than did the LH group. However, the two groups did not differ in terms of other perioperative outcomes, specifically blood loss, hospital stay, intensive care unit admission, mortality, morbidity, or tumor margin status. The rate of conversion to open surgery is lower in RH than in LH. Although operative time is longer in RH than in LH, RH is feasible and safe for patients with benign or malignant liver lesion. Our study also demonstrated comparable oncological results in patients with hepatocellular carcinoma between LH and RH group.

How Do Active and Passive Cigarette Smokers in Iran Evaluate Their Health? A Sex-Specific Analysis on the Full-Spectrum of Quality of Life.

This study aimed to determine the sex-specific effects of active and passive cigarette smoking on the full spectrum of health-related quality of life (HRQoL) among a sizeable adult population. This study was conducted within the Tehran Lipid and Glucose Study (TLGS) framework. Participants included 7478 adults in the last examination of the TLGS. We used a quantile regression model to compare sex-specific HRQoL distributions among non-, current, and passive smokers. Two-step cluster analysis was used to consider the synergic effects of confounder variables. In men, current smoking was negatively associated with only mental HRQoL in all percentiles of its distribution with a decrease in absolute estimation values from the lowest (5th: β = -6.59, p < .001) to the highest (90th: β=-0.93, p = .027). Also, passive smoking was negatively associated with men's physical HRQoL in the upper percentiles of its distribution (75th: β = -1.12, p = .010; 90th: β = -1.26, p = .016). In women, the current (β = -4.17 to -4.45 for 25th to 90th percentiles) and passive smokers (β = -2.05 to -4.25 for 10th to 90th percentiles) had lower mental HRQoL in the mentioned percentiles. Also, the current smoking had a negative association with the 5th percentile (β = -2.04, p = .008), and a positive association with the 50th (β = 1.94, p < .008) and 75th percentile of physical HRQoL (β = 2.25, p = .004). The present study showed the harmful effect of smoking on mental HRQol in all participants. In contrast, the physical effect of smoking was only observed in female active smokers and at the extreme levels of the physical HRQoL spectrum. According to the harmful effect of smoking on HRQoL, understanding active and passive smokers' perceptions of how smoking impacts their health is critical for tobacco control programs. Since most previous studies of smoking and HRQoL have mainly focused on the extreme parts or central values of the HRQoL distribution, the use of a multiple regression approach enables the evaluation of other parts of the conditional distribution of the outcome variable. This study demonstrated the prominent effect of smoking on the mental HRQoL as well as the more serious public health burden of passive smoking in women.

An adaptive synchronous extraction (ASE) method for estimating intensity and footprint of surface urban heat islands: A case study of 254 North American cities

The urban heat island (UHI) effect has attracted great attention due to its potential impacts on rapidly growing urban areas. Using remotely sensed estimates of land surface temperature (LST), a large number of studies have focused on the surface UHI (SUHI) effect, which can be characterized by its two fundamental properties: intensity and footprint. The SUHI intensity reflects the LST difference between the urban area and the background reference area (BRA), and the SUHI footprint indicates the spatial extent influenced by the heat island. Currently, numerous methods have been developed to estimate the SUHI intensity and footprint, but are still greatly challenged by three main issues. Namely, the discrepancy in BRA selection criterion brings great uncertainty to the estimated SUHI intensity, the estimation of SUHI footprint is largely constrained by the predefined models, and the quantification of SUHI effect is potentially influenced by several confounding factors. Here, we proposed an adaptive synchronous extraction (ASE) method, which is capable of adaptively selecting the most optimal BRA while removing the influence of confounding factors, and achieving synchronous estimation of SUHI intensity and footprint. We applied the ASE method to 254 North American cities and conducted an in-depth comparative analysis to discuss its applicability and benefits. The main results include: (1) The ASE method avoids the limitations of existing methods in BRA selection and model presetting, and shows resilience to parameter variations. This makes the ASE method highly applicable to quantify the SUHI intensity and footprint in cities with various thermal characteristics. (2) The ASE method can better highlight the spatial, seasonal and day-night contrasts in the estimated SUHI intensity. This superiority is particularly evident when comparing it to methods based on the equal-area buffer or the simplified urban-extent algorithm. (3) Confounding factors pose non-negligible impacts on the quantification of the SUHI effect. Typically, ignoring the influence of topographic relief or missing LST data can lead to an overall overestimation of the SUHI intensity, while not removing surrounding urban areas will cause some underestimation of the SUHI intensity. Overall, the proposed ASE method provides a new generalizable tool for quantifying the SUHI effect, which has great potentials for future studies and urban climate assessments.

Association of CYP2C9*2 Allele with Sulphonylurea-Induced Hypoglycaemia in Type 2 Diabetes Mellitus Patients: A Pharmacogenetic Study in Pakistani Pashtun Population.

Polymorphism in cytochrome P450 (CYP) 2C9 enzyme is known to cause significant inter-individual differences in drug response and occurrence of adverse drug reactions. Different alleles of the CYP2C9 gene have been identified, but the notable alleles responsible for reduced enzyme activity are CYP2C9*2 and CYP2C9*3. No pharmacogenetic data are available on CYP2C9*2 and CYP2C9*3 alleles in the Pakistani population. In Pakistan, pharmacogenetics, which examines the relationship between genetic factors and drug response, are in the early stages of development. We, for the first time, investigated the association between the CYP2C9 variant alleles CYP2C9*2 and CYP2C9*3 and the incidence of hypoglycaemia in patients with Type 2 diabetes mellitus (T2DM) receiving sulphonylurea medications. A total of n = 400 individuals of Pashtun ethnicity were recruited from 10 different districts of Khyber Pakhtunkhwa, Pakistan to participate in the study. The study participants were divided into two distinct groups: the case group (n = 200) and the control group (n = 200). The case group consisted of individuals with T2DM who were receiving sulphonylurea medications and experienced hypoglycaemia with it, whereas the control group included individuals with T2DM who were receiving sulphonylurea medication but did not experience sulphonylurea-induced hypoglycaemia (SIH). Blood samples were obtained from study participants following informed consent. DNA was isolated from whole blood samples using a Wiz-Prep DNA extraction kit. Following DNA isolation, CYP2C9 alleles were genotyped using MassARRAY sequencing platform at the Centre of Genomics at the Rehman Medical Institute (RMI). The frequency of CYP2C9*2 (low-activity allele) was more frequent in the diabetic patients with SIH compared to the control group (17.5% vs. 6.0%, p = 0.021). The frequency of its corresponding genotype CYP2C9*1/*2 was higher in cases compared to the control group (10% vs. 6% with p = 0.036); the same was true for genotype CYP2C9*2/*2 (7% vs. 3.5% with p = 0.028). Logistic regression analysis evidenced potential association of CYP2C9*2 allele and its genotypes with SIH. When adjusted for confounding factors such as age, weight, sex, mean daily dose of sulphonylurea, and triglyceride level, the association between the CYP2C9*2 allele and hypoglycaemia remained consistent. Confounding factors played no role in SIH (insignificant p-value) because both groups (cases and controls) were closely matched in term of age, weight, sex, mean daily dose of sulphonylurea, and triglyceride levels. Our study suggests that genetic information about a patient's CYP2C9 gene/enzyme can potentially assist physicians in prescribing the most suitable and safest drug, based on their genetic make-up.

COVID-19 Excess Deaths in Peru's 25 States in 2020: Nationwide Trends, Confounding Factors, and Correlations With the Extent of Ivermectin Treatment by State.

Introduction In 2020, nations hastened to contain an emerging COVID-19 pandemic by deploying diverse public health approaches, but conclusive appraisals of the efficacy of these approaches are elusive in most cases. One of the medicines deployed, ivermectin (IVM), a macrocyclic lactone having biochemical activity against SARS-CoV-2 through competitive binding to its spike protein, has yielded mixed results in randomized clinical trials (RCTs) for COVID-19 treatments. In Peru, an opportunity to track the efficacy of IVM with a close consideration of confounding factors was provided through data for excess deaths as correlated with IVM use in 2020, under semi-autonomous policies in its 25 states. Methods To evaluate possible IVM treatment effects, excess deaths as determined from Peruvian national health data were analyzed by state for ages ≥60 in Peru's 25 states. These data were compared with monthly summary data for excess deaths in Peru for the period 2020-2021 as published by the WHO in 2022. To identify potential confounding factors, Google mobility data, population densities, SARS-CoV-2 genetic variations, and seropositivity rates were also examined. Results Reductions in excess deaths over a period of 30 days after peak deaths averaged 74% in the 10 states with the most intensive IVM use. As determined across all 25 states, these reductions in excess deaths correlated closely with the extent of IVM use (p<0.002). During four months of IVM use in 2020, before a new president of Peru restricted its use, there was a 14-fold reduction in nationwide excess deaths and then a 13-fold increase in the two months following the restriction of IVM use. Notably, these trends in nationwide excess deaths align with WHO summary data for the same period in Peru. Conclusions The natural experiment that was put into motion with the authorization of IVM use for COVID-19 in Peru in May 2020, as analyzed using data on excess deaths by locality and by state from Peruvian national health sources, resulted in strong evidence for the drug's effectiveness. Several potential confounding factors, including effects of a social isolation mandate imposed in May 2020, variations in the genetic makeup of the SARS-CoV-2 virus, and differences in seropositivity rates and population densities across the 25 states, were considered but did not appear to have significantly influenced these outcomes.

Gender Disparities in Complications, Costs, and Mortality After Emergency Gastrointestinal Surgery in Kenya

IntroductionLittle is known about the impact of gender on emergency surgery within Kenya. Therefore, we aimed to investigate the association of gender on outcomes of postoperative complications, health care costs, and mortality. MethodsWe evaluated an established cohort of patients undergoing emergency gastrointestinal surgery in rural Kenya between January 1st, 2016 and June 30th, 2019. Utilizing logistic regression, we examined the association between self-reported patient gender and the outcomes of postoperative complications and mortality. A generalized linear model was created for total hospital costs, inflation-adjusted in international dollars purchasing power parity, to examine the impact of gender. Confounding factors were controlled by Africa Surgical Outcomes Study Surgical Risk Score. ResultsAmong 484 patients reviewed, 149 (30.8%) were women. 165 (34.1%) patients developed complications, with women experiencing more than men (40.9% versus 31.0%; P = 0.03) and longer hospital stays (median 6 days (4-9) versus 5 (4-7); P = 0.02). After controlling for Africa Surgical Outcomes Study Surgical Risk Score, odds of developing complications for women were 1.67 (95% confidence interval: 1.09-2.55; P = 0.019) times higher than men, and the odds of death were 2.38 (95% confidence interval: 1.12-5.09; P = 0.025) times greater for women than men, despite similar failure-to-rescue rates and intensive care unit utilization. Total hospital costs were increased for women by 531 international dollars purchasing power parity (117-946; P = 0.012) when compared to men, attributed to longer lengths of stay. ConclusionsThese findings demonstrate that a discrepancy exists between men and women undergoing emergency gastrointestinal surgery in our setting. Further exploration of the underlying causes of this inequity is necessary for quality improvement for women in rural Kenya.