Nevin Manimala

J Neurosci Methods. 2023 Aug 18:109950. doi: 10.1016/j.jneumeth.2023.109950. Online ahead of print.

ABSTRACT

BACKGROUND: Consistent noise variance across data points (i.e. homoscedasticity) is required to ensure the validity of statistical analyses of MRI data conducted using linear regression methods. However, head motion leads to degradation of image quality, introducing noise heteroscedasticity into ordinary-least square analyses.

NEW METHOD: The recently introduced QUIQI method restores noise homoscedasticity by means of weighted least square analyses in which the weights, specific for each dataset of an analysis, are computed from an index of motion-induced image quality degradation. QUIQI was first demonstrated in the context of brain maps of the MRI parameter R2*, which were computed from a single set of images with variable echo time. Here, we extend this framework to quantitative maps of the MRI parameters R1, R2*, and MTsat, computed from multiple sets of images.

RESULTS: QUIQI restores homoscedasticity in analyses of quantitative MRI data computed from multiple scans. QUIQI allows for optimization of the noise model by using metrics quantifying heteroscedasticity and free energy.

COMPARISON WITH EXISTING METHODS: QUIQI restores homoscedasticity more effectively than insertion of an image quality index in the analysis design and yields higher sensitivity than simply removing the datasets most corrupted by head motion from the analysis.

CONCLUSION: QUIQI provides an optimal approach to group-wise analyses of a range of quantitative MRI parameter maps that is robust to inherent homoscedasticity.

PMID:37598941 | DOI:10.1016/j.jneumeth.2023.109950

Am J Med. 2023 Aug 18:S0002-9343(23)00489-8. doi: 10.1016/j.amjmed.2023.07.020. Online ahead of print.

ABSTRACT

BACKGROUND: Pulmonary fibrosis is associated with significant morbidity. Data are scarce on the link between COVID-19 and pulmonary fibrosis. We aimed to assess the association between COVID-19 with pulmonary fibrosis.

METHODS: We conducted a nested case-control study in a cohort of 2,894,801 adults without a diagnosis of pulmonary fibrosis. The underlying cohort consisted of members of the largest healthcare provider in Israel aged 18 years or older as of May 1, 2020. Subjects were followed up from cohort entry until June 30, 2022 for the occurrence of pulmonary fibrosis. Ten randomly selected controls were matched to each case of pulmonary fibrosis on age, sex and calendar time. To account for surveillance bias a lag-time of 60 days was used for ascertainment of prior COVID-19 and COVID-severity.

RESULTS: During follow-up 1,284 patients were newly diagnosed with pulmonary fibrosis and matched with 12,840 controls. Multivariable conditional logistic-regression models showed that the OR for pulmonary fibrosis was 1.80 (95% CI, 1.47-2.19) in patients with COVID-19 compared to no COVID-19. The multivariable OR for pulmonary fibrosis was 1.33 (1.06-1.68), 2.98 (1.16-7.65), and 9.30 (5.77-14.98) for mild, moderate, and severe COVID-19, respectively, compared to no COVID-19. The magnitude of the association was attenuated but remained statistically significant for severe disease when the lag-time was extended to 180 days; 1.08 (0.78-1.49), 2.37 (0.75-7.46), and 5.34 (2.75-10.36) for mild, moderate, and severe COVID-19, respectively.

CONCLUSIONS: COVID-19 appears to be associated with an increased risk of pulmonary fibrosis and the magnitude of the association increases with COVID-19 severity.

PMID:37598922 | DOI:10.1016/j.amjmed.2023.07.020

Am J Obstet Gynecol MFM. 2023 Aug 18:101136. doi: 10.1016/j.ajogmf.2023.101136. Online ahead of print.

ABSTRACT

BACKGROUND: Placenta previa diagnosed on midtrimester ultrasound often resolves by the third trimester. Multiparity and prior cesarean delivery have been associated with persistence of placenta previa at delivery. Risk factors for persistent placenta previa in nulliparas are not well characterized.

OBJECTIVES: To identify risk factors for persistent placenta previa in the nulliparous population, as well as evaluate differences in outcomes between persistent and resolved placenta previa.

STUDY DESIGN: This was a secondary analysis of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b), a prospective cohort study that followed 10,037 nulliparous individuals throughout pregnancy. Nulliparas diagnosed with placenta previa on midtrimester ultrasound were included in this analysis. Baseline characteristics and delivery outcomes of nulliparas with persistent placenta previa were compared to those with resolved placenta previa. Multivariate logistic regression with stepwise model selection was used for adjusted analyses.

RESULTS: A total of 171 nulliparas (1.7%) in the nuMoM2b study were diagnosed with placenta previa on midtrimester ultrasound, of whom 17% (n=29) had persistent placenta previa at delivery. When compared to those with resolved placenta previa, nulliparas with persistent placenta previa were more likely to be older (median 32 years (IQR 30-37) vs. 29 years (IQR 25-31), p<0.01), have a prior pregnancy <20 weeks (48.3% vs. 22.5%, p=0.01), have a prior dilation and curettage/evacuation procedure (27.6% vs. 10.6%, p=0.03), or have a pregnancy that resulted from assisted reproductive technology (31% vs. 4.9%, p=0.01). After adjusting for potential confounders, maternal age (aOR 1.11, 95% CI 1.02-1.21), in vitro fertilization (aOR 9.00, 95% CI 1.97-41.14), and prior pregnancy <20 weeks (aOR 2.77, 95% CI 1.10-6.95) remained statistically significant risk factors for persistent placenta previa. Persistent placenta previa also had a higher likelihood of antepartum admission (10.3% vs. 0%, p<0.01), preterm delivery (34.5% vs. 12%, p<0.01), lower neonatal birthweight (median 2847 grams, IQR 2655-3310, vs 3263 grams, IQR 2855-3560) and cesarean delivery (100% vs. 20.4%, p<0.001), but there were no differences in overall pregnancy or neonatal outcomes.

CONCLUSION: In nulliparous individuals diagnosed with placenta previa on midtrimester ultrasound, older maternal age, prior pregnancy <20 weeks, and in vitro fertilization are associated with persistent placenta previa at delivery.

PMID:37598887 | DOI:10.1016/j.ajogmf.2023.101136

Am J Obstet Gynecol MFM. 2023 Aug 18:101134. doi: 10.1016/j.ajogmf.2023.101134. Online ahead of print.

ABSTRACT

BACKGROUND: Umbilical cord gases are often use to assess the impact of labor and delivery on the fetus. However, no large series exists which reflects contemporary obstetric practice or analyses blood gas ranges by route of delivery. Baseline, pre-labor acid-base status in the human fetus is also poorly defined, rendering assessment of blood gas changes during labor difficult.

OBJECTIVE: To define normal umbilical cord gas and lactate values stratified by mode of delivery in a large contemporary series in which universal cord gas collection was dictated by protocol.

STUDY DESIGN: Retrospective cohort study. We analyzed umbilical cord gas and lactate data from an unselected population of infants born between March 2012 and April 2022 at a large teaching hospital. These values were then analyzed by mode of delivery and, for cesarean deliveries, by indication for cesarean and type of anesthesia. Cord gas values from infants delivered by elective cesarean under general anesthesia without labor were considered representative of baseline, pre-labor values.

RESULTS: Data was available for 45,475 infants. Median arterial pH values and interquartile ranges for vaginal births, elective cesarean births without labor and cesarean births performed for fetal heart rate concerns were 7.27 (0.09), 7.27 (0.06) and 7.25 (0.09), respectively. Arterial lactate values for these same 3 groups were 4.1 (2.5), 2.5 (1.2) and 4.0 (2.8) mmoles/l. Due to the very large sample size, most comparisons yielded differences which were statistically significant, but clinically irrelevant. Of all infants, 14% had an arterial pH < 7.20; a pH value of 7.1 represents 2 standard deviations from the mean.

CONCLUSION: This large, population-based study of cord gas/lactate levels in an unselected population stratified by delivery mode represents a previously unavailable benchmark for evaluation of umbilical cord gases. Arterial cord pH values for infants delivered by elective caesarean without labor (median pH 7.28) reflect a lower pre-labor fetal pH baseline than that previously assumed. This finding, coupled with our determination of a 2 standard deviation lower pH limit of 7.1 rather than the historic arbitrary pH 7.2 threshold of normal helps explain the poor positive predictive value of electronic fetal heart rate monitoring, a test designed to detect arterial pH levels which have fallen from an assumed baseline near pH 7.4 to an assumed potentially injurious pH level < 7.2. Uncomplicated labor, even when prolonged, does not generally result in a clinically significant cumulative hypoxic stress to the human fetus. These findings, along with our determination of no difference in acid-base status among infants delivered by cesarean for fetal heart rate concerns, help explain the failure of current approaches to labor and delivery management in reducing the rates of neonatal hypoxic-ischemic encephalopathy and cerebral palsy, condition which almost always reflect developmental events rather than the effects of labor on the fetus.

PMID:37598886 | DOI:10.1016/j.ajogmf.2023.101134

Biol Psychol. 2023 Aug 18:108661. doi: 10.1016/j.biopsycho.2023.108661. Online ahead of print.

ABSTRACT

OBJECTIVE: To investigate the effects of sustained mental activity on perceptions of mental fatigue, cognitive performance, and autonomic response in patients with clinical burnout as compared to a healthy control group.

METHODS: Patients with clinical burnout (n = 30) and healthy control participants (n = 30) completed a 3-hour test session, in which they were administered a set of cognitive tests before and after an effortful cognitive task with concurrent sound exposure. Perceptions of mental fatigue and task demands (mental effort and concentration difficulties) were assessed repeatedly over the course of the test session. Heart rate variability was recorded to index autonomic response.

RESULTS: In comparison with controls, perceived mental fatigue increased earlier in the session for the clinical burnout group and did not recover following a short rest period. Throughout the session, patients rated the tasks as more demanding and showed less improvement on measures of attention and processing speed, inhibition and working memory. While autonomic responses were initially comparable, there was a unique decrease in high-frequency heart rate variability in the clinical burnout group after extended testing and exposure.

CONCLUSION: Patients with clinical burnout are affected differently than healthy controls by sustained mental activity, as reflected by ratings of perceived mental fatigue, aspects of cognitive performance and autonomic response. Further investigation into the role of autonomic regulation in relation to cognitive symptoms in clinical burnout is warranted.

PMID:37598882 | DOI:10.1016/j.biopsycho.2023.108661

Biochim Biophys Acta Biomembr. 2023 Aug 18:184216. doi: 10.1016/j.bbamem.2023.184216. Online ahead of print.

ABSTRACT

Boosted by the indiscriminate use of antibiotics, multidrug-resistance (MDR) demands new strategies to combat bacterial infections, such as photothermal therapy (PTT) based on plasmonic nanostructures. PTT efficiency relies on photoinduced damage caused to the bacterial machinery, for which nanostructure incorporation into the cell envelope is key. Herein, we shall unveil the binding and photochemical mechanisms of gold shell-isolated nanorods (AuSHINRs) on bioinspired bacterial membranes assembled as Langmuir and LS monolayers of DOPE, Lysyl-PG, DOPG and CL. AuSHINRs incorporation expanded the isotherms, with stronger effect on the anionic DOPG and CL. Indeed, FTIR of LS films revealed more modifications for DOPG and CL owing to stronger attractive electrostatic interactions between anionic phosphates and the positively charged AuSHINRs, while electrostatic repulsions with the cationic ethanolamine (DOPE) and lysyl (Lysyl-PG) polar groups might have weakened their interactions with AuSHINRs. No statistical difference was observed in the surface area of irradiated DOPE and Lysyl-PG monolayers on AuSHINRs, which is evidence of the restricted nanostructures insertion. In contrast, irradiated DOPG monolayer on AuSHINRs decreased 4.0 % in surface area, while irradiated CL monolayer increased 3.7 %. Such results agree with oxidative reactions prompted by ROS generated by AuSHINRs photoactivation. The deepest AuSHINRs insertion into DOPG may have favored chain cleavage while hydroperoxidation is the mostly like outcome in CL, where AuSHINRs are surrounding the polar groups. Furthermore, preliminary experiments on Escherichia coli culture demonstrated that the electrostatic interactions with AuSHINRs do not inhibit bacterial growth, but the photoinduced effects are highly toxic, resulting in microbial inactivation.

PMID:37598878 | DOI:10.1016/j.bbamem.2023.184216

Kidney Int. 2023 Aug 18:S0085-2538(23)00563-X. doi: 10.1016/j.kint.2023.07.025. Online ahead of print.

ABSTRACT

Systematic screening for BKPyV-DNAemia has been advocated to aid prevention and treatment of polyomavirus associated nephropathy (PyVAN), an important cause of kidney graft failure. The added value of performing a biopsy at time of BKPyV-DNAemia, to distinguish presumptive PyVAN (negative SV40 immunohistochemistry) and proven PyVAN (positive SV40) has not been established. Therefore, we studied an unselected cohort of 950 transplantations, performed between 2008-2017. BKPyV-DNAemia was detected in 250 (26.3%) transplant recipients, and positive SV40 in 91 cases (9.6%). Among 209 patients with a concurrent biopsy at time of first BKPyV-DNAemia, 60 (28.7%) biopsies were SV40 positive. Plasma viral load showed high diagnostic value for concurrent SV40 positivity (ROC-AUC 0.950, 95% confidence interval 0.916-0.978) and the semiquantitatively scored percentage of tubules with evidence of polyomavirus replication (pvl score) (0.979, 0.968-0.988). SV40 positivity was highly unlikely when plasma viral load is below 4 log₁₀ copies/ml (negative predictive value 0.989, 0.979-0.994). In SV40 positive patients, higher plasma BKPyV-DNA load and higher pvl scores were associated with slower viral clearance from the blood (hazard ratio 0.712, 95% confidence interval 0.604-0.839, and 0.327, 0.161-0.668, respectively), whereas the dichotomy positivity/negativity of SV40 immunohistochemistry did not predict viral clearance. Although the pvl score offers some prognostic value for viral clearance on top of plasma viral load, the latter provided good guidance for when a biopsy was unnecessary to exclude PyVAN. Thus, the distinction between presumptive and proven PyVAN, based on SV40 immunohistochemistry, has limited clinical value. Hence, management of BKPyV-DNAemia and immunosuppression reduction should be weighed against the risk of occurrence of rejection, or exacerbation of rejection observed concomitantly.

PMID:37598855 | DOI:10.1016/j.kint.2023.07.025

Environ Res. 2023 Aug 18:116921. doi: 10.1016/j.envres.2023.116921. Online ahead of print.

ABSTRACT

Mobile communication technology has evolved rapidly over the last ten years with a drastic increase in wireless data traffic and the deployment of new telecommunication technologies. The aim of this study was to evaluate the ambient radiofrequency electromagnetic field (RF-EMF) levels and temporal changes in various microenvironments in Switzerland in 2014 and 2021. We measured the ambient RF-EMF levels in V/m in the same 49 outdoor areas and in public transport in 2014 and 2021 using portable RF-EMF exposure meters carried in a backpack. The areas were selected to represent some typical types of microenvironments (e.g. urban city centres, suburban and rural areas). We calculated the summary statistics (mean, percentiles) in mW/m² and converted back to V/m for each microenvironment. We evaluated the distribution and the variability of the ambient RF-EMF levels per microenvironment types in 2021. Finally, we compared the ambient RF-EMF mean levels in 2014 and 2021 using multilevel regression modelling. In outdoor areas, the average ambient RF-EMF mean levels per microenvironment in 2021 ranged from 0.19 V/m in rural areas to 0.43 V/m in industrial areas (overall mean: 0.27 V/m). In public transports, the mean levels were 0.27 V/m in buses, 0.33 V/m in trains and 0.36 V/m in trams. In 2021, mean levels across all outdoor areas were -0.022 V/m lower (95% confidence interval: 0.072, 0.030) than in 2014. Results from our comprehensive measurement study across Switzerland suggest that RF-EMF levels in public places have not significantly changed between 2014 and 2021 despite an 18-fold increase in mobile data transmission during that period. The absence of temporal changes may be owed to the shift to newer mobile communication technologies, which are more efficient.

PMID:37598840 | DOI:10.1016/j.envres.2023.116921

J Ren Nutr. 2023 Aug 18:S1051-2276(23)00129-2. doi: 10.1053/j.jrn.2023.08.007. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the effects of supplementation with whey protein combined with vitamins C and E on inflammatory markers in hemodialysis (HD) patients.

DESIGN AND METHODS: This was a pioneer, randomized and double-blinded study. Patients were randomised into two groups and stratified by HD frequency. The supplementation group received 20 g of whey protein, 250 mg of vitamin C, and 600 IU of vitamin E; the placebo group, 20 g of rice flour, and microcrystalline cellulose capsules. The interventions were given after HD, 3 times a week, for 8 weeks. The inflammatory markers were assessed: interleukin (IL) IL-12p70, IL-10, IL-6, IL-8, and tumor necrosis factor alpha. For statistical analysis, the χ2 test, Student’s t-test, Mann – Whitney test, analysis of variance for repeated two-way measurements, paired t test, and Wilcoxon test were performed. P < 0.05.

RESULTS: Twenty-three patients completed the study. No significant differences were found in inflammatory markers when comparing the groups post-intervention. In the intragroup was a decrease in IL-10 in the supplementation group after 8 weeks (p=0.0382). IL-6 tended to decrease by 810.95% in the supplementation group and increased by 732.8% (non-significant) in the placebo group.

CONCLUSION: The supplementation with whey protein combined with vitamins C and E could be beneficial to reduce inflammatory markers in HD patients. Future studies are suggested with a larger sample size, different supplementation doses, and longer interventions.

PMID:37598813 | DOI:10.1053/j.jrn.2023.08.007

J Pharmacol Toxicol Methods. 2023 Aug 18:107469. doi: 10.1016/j.vascn.2023.107469. Online ahead of print.

ABSTRACT

The aim of the recent study was to collect data on the genotype characteristics of the Hungarian self-bred Pannon minipigs by adapting a standardized infarct model procedure. Closed chest AMI was induced by balloon occlusion for 90 min in the left anterior descendent coronary artery (LAD) in 24 adult intact female minipigs followed by reperfusion. To assess the left ventricular (LV) function, serial cardiac magnetic resonance imaging (cMRI) was performed prior to the experimental procedure, on day 3 post-AMI (72 ± 12 h), and at 1 month follow-up (Day 30 ± 2 days). Compared to baseline cMRI scans the end-diastolic volume (EDV) was increased on days 3 and 30 On day 3 the left ventricular ejection fraction (LVEF) decreased significantly but there was no statistical difference between the baseline and day 30 measurements. Cardiac output, stroke volume, and end-systolic volume significantly were increased compared to baseline on day 30 A high percentage (54%) of malignant arrhythmias occurred during the AMI procedure, with a 25% mortality rate. The compensatory capacity of the Pannon minipig heart is excellent therefore the use of different cardiac parameters and invasive measurements is advisable in chronic pharmacological experiments to complement cMRI data.

PMID:37598810 | DOI:10.1016/j.vascn.2023.107469