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Nevin Manimala Statistics

Two-Compartment Perfusion MR IVIM Model to Investigate Normal and Pathological Placental Tissue

J Magn Reson Imaging. 2023 Jun 17. doi: 10.1002/jmri.28858. Online ahead of print.

ABSTRACT

BACKGROUND: Perfusion and diffusion coexist in the placenta and can be altered by pathologies. The two-perfusion model, where f1 and, f2 are the perfusion-fraction of the fastest and slowest perfusion compartment, respectively, and D is the diffusion coefficient, may help differentiate between normal and impaired placentas.

PURPOSE: Investigate the potential of the two-perfusion IVIM model in differentiating between normal and abnormal placentas.

STUDY-TYPE: Retrospective, case-control.

POPULATION: 43 normal pregnancy, 9 fetal-growth-restriction (FGR), 6 small-for-gestational-age (SGA), 4 accreta, 1 increta and 2 percreta placentas.

FIELD STRENGTH/SEQUENCE: Diffusion-weighted-echo planar imaging sequence at 1.5 T.

ASSESSMENT: Voxel-wise signal-correction and fitting-controls were used to avoid overfitting obtaining that two-perfusion model fitted the observed data better than the IVIM model (Akaike weight: 0.94). The two-perfusion parametric-maps were quantified from ROIs in the fetal and maternal placenta and in the accretion zone of accreta placentas. The diffusion coefficient D was evaluated using a b ≥ 200 sec/mm2 -mono-exponential decay fit. IVIM metrics were quantified to fix f1 + f2 = fIVIM .

STATISTICAL-TESTS: ANOVA with Dunn-Sidák’s post-hoc correction and Cohen’s d test were used to compare parameters between groups. Spearman’s coefficient was evaluated to study the correlation between variables. A P-value<0.05 indicated a statistically significant difference.

RESULTS: There was a significant difference in f1 between FGR and SGA, and significant differences in f2 and fIVIM between normal and FGR. The percreta + increta group showed the highest f1 values (Cohen’s d = -2.66). The f2 between normal and percreta + increta groups showed Cohen’s d = 1.12. Conversely, fIVIM had a small effective size (Cohen’s d = 0.32). In the accretion zone, a significant correlation was found between f2 and GA (ρ = 0.90) whereas a significant negative correlation was found between fIVIM and D (ρ = -0.37 in fetal and ρ = -0.56 in maternal side) and f2 and D (ρ = -0.38 in fetal and ρ = -0.51 in maternal side) in normal placentas.

CONCLUSION: The two-perfusion model provides complementary information to IVIM parameters that may be useful in identifying placenta impairment.

LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 1.

PMID:37329218 | DOI:10.1002/jmri.28858

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Nevin Manimala Statistics

The histamine system and cognitive function: An in vivo H3 receptor PET imaging study in healthy volunteers and patients with schizophrenia

J Psychopharmacol. 2023 Jun 16:2698811231177287. doi: 10.1177/02698811231177287. Online ahead of print.

ABSTRACT

BACKGROUND: The histamine-3 receptor (H3R) is an auto- and heteroreceptor that inhibits the release of histamine and other neurotransmitters. Post-mortem evidence has found altered H3R expression in patients with psychotic disorders, which may underlie cognitive impairment associated with schizophrenia (CIAS).

AIMS: We used positron emission tomography (PET) imaging to compare brain uptake of an H3R selective tracer between patients with schizophrenia and matched controls (healthy individuals). Regions of interest included the dorsolateral prefrontal cortex (DLPFC) and striatum. We explored correlations between tracer uptake and symptoms, including cognitive domains.

METHODS: A total of 12 patients and 12 matched controls were recruited to the study and were assessed with psychiatric and cognitive rating scales. They received a PET scan using the H3R-specific radioligand [11C]MK-8278 to determine H3R availability.

RESULTS: There was no statistically significant difference in tracer uptake between patients and controls in the DLPFC (t19 = 0.79, p = 0.44) or striatum (t21 = 1.18, p = 0.25). An exploratory analysis found evidence for lower volume of distribution in the left cuneus (pFWE-corrected = 0.01). DLPFC tracer uptake was strongly correlated with cognition in controls (trail making test (TMT) A: r = 0.77, p = 0.006; TMT B: rho = 0.74, p = 0.01), but not in patients (TMT A: r = -0.18, p = 0.62; TMT B: rho = -0.06, p = 0.81).

CONCLUSIONS: These findings indicate H3R in the DLPFC might play a role in executive function and this is disrupted in schizophrenia in the absence of major alterations in H3R availability as assessed using a selective radiotracer for H3R. This provides further evidence for the role of H3R in CIAS.

PMID:37329185 | DOI:10.1177/02698811231177287

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Nevin Manimala Statistics

Effects of a lymphedema prevention program based on the theory of knowledge-attitude-practice on postoperative breast cancer patients: A randomized clinical trial

Cancer Med. 2023 Jun 17. doi: 10.1002/cam4.6171. Online ahead of print.

ABSTRACT

BACKGROUND: Breast cancer-related lymphedema (BCRL) is one of the common postoperative complications that severely affects the functions of the arm and quality of life. Since lymphedema is difficult to treat and prone to recurrence, early prevention of lymphedema is crucial.

METHODS: Patient diagnosed with breast cancer (N = 108) were randomized to the intervention (n = 52) or control group (n = 56). In the intervention group, patients were provided the lymphedema prevention program based on the theory of knowledge-attitude-practice during the perioperative period and the first three chemotherapy sessions (mainly includes health education, seminars, knowledge manuals, sports guidance, peer education, and WeChat group).The limb volume, handgrip strength, arm function, and quality of life were measured in all patients at the baseline, 9 weeks (T1), and 18 weeks (T2) after surgery.

RESULTS: The incidence of lymphedema in the Intervention group was numerically lower than in the control group after implementing the lymphedema prevention program, but the difference was not statistically significant (T1: 1.9% vs. 3.8%, p = 1.000; T2: 3.6% vs. 7.1%, p = 0.744). However, compared with the control group, the intervention group showed there was less deterioration in handgrip strength (T1 [t = -2.512, p < 0.05] and T2 [t = -2.538, p < 0.05]), improved postoperative upper limb dysfunction (T1 [t = 3.087, p < 0.05] and T2 [t = 5.399, p < 0.05]) and less deterioration in quality of life (T1 [p < 0.05] and T2 [p < 0.05]).

CONCLUSION: Although the investigated lymphedema prevention program improved arm function and quality of life, it did not reduce the incidence of lymphedema in postoperative breast cancer patients.

PMID:37329176 | DOI:10.1002/cam4.6171

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Nevin Manimala Statistics

14th Annual University of Pennsylvania Conference on statistical issues in clinical trials/subgroup analysis in clinical trials: Opportunities and challenges (morning panel discussion)

Clin Trials. 2023 Jun 16:17407745231175078. doi: 10.1177/17407745231175078. Online ahead of print.

NO ABSTRACT

PMID:37329159 | DOI:10.1177/17407745231175078

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Nevin Manimala Statistics

Rookery through rehabilitation: Microbial community assembly in newborn harbour seals after maternal separation

Environ Microbiol. 2023 Jun 16. doi: 10.1111/1462-2920.16444. Online ahead of print.

ABSTRACT

Microbial community assembly remains largely unexplored in marine mammals, despite its potential importance for conservation and management. Here, neonatal microbiota assembly was studied in harbour seals (Phoca vitulina richardii) at a rehabilitation facility soon after maternal separation, through weaning, to the time of release back to their native environment. We found that the gingival and rectal communities of rehabilitated harbour seals were distinct from the microbiotas of formula and pool water, and became increasingly diverse and dissimilar over time, ultimately resembling the gingival and rectal communities of local wild harbour seals. Harbour seal microbiota assembly was compared to that of human infants, revealing the rapid emergence of host specificity and evidence of phylosymbiosis even though these harbour seals had been raised by humans. Early life prophylactic antibiotics were associated with changes in the composition of the harbour seal gingival and rectal communities and surprisingly, with transient increases in alpha diversity, perhaps because of microbiota sharing during close cohabitation with other harbour seals. Antibiotic-associated effects dissipated over time. These results suggest that while early life maternal contact may provide seeding for microbial assembly, co-housing of conspecifics during rehabilitation may help neonatal mammals achieve a healthy host-specific microbiota with features of resilience.

PMID:37329141 | DOI:10.1111/1462-2920.16444

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Nevin Manimala Statistics

Highly Active Middle School Athletes Demonstrate Poor Motor Skill Proficiency

Sports Health. 2023 Jun 16:19417381231178822. doi: 10.1177/19417381231178822. Online ahead of print.

ABSTRACT

BACKGROUND: Fundamental movement skills (FMS) are critical components to lifelong participation in sports and physical activity. With the rise in early sports specialization, mastery of motor skills may be limited in youth athletes. The purpose of this study was to assess FMS proficiency in highly active middle school athletes and determine whether proficiency differed between specialization levels and sex.

HYPOTHESIS: (1) Most athletes would fail to achieve proficiency in all domains of the Test of Gross Motor Development (TGMD-2), (2) highly specialized athletes would demonstrate lower proficiency in all domains of the TGMD-2, and (3) male athletes would demonstrate higher proficiency than female athletes.

STUDY DESIGN: Cross-sectional.

LEVEL OF EVIDENCE: Level 4.

METHODS: A total of 91 athletes were recruited (44 male, 12.6 ± 0.9 years). Activity level was quantified using the Hospital for Special Surgery (HSS) Pediatric Functional Activity Brief Scale (Pedi-FABS), specialization level was determined using the Jayanthi Specialization Scale, and the TGMD-2 was used to assess FMS proficiency. Descriptive statistics were used to describe gross motor, locomotor, and object control percentile rank. A 1-way analysis of variance (ANOVA) was used to assess differences in percentile rank between low, moderate, and high specialization groups and independent samples t tests were used to compare sexes (α < 0.05).

RESULTS: Mean Pedi-FABS score was 23.6 ± 4.9. In total, 24.2%, 38.5%, and 37.4% of athletes classified as low, moderate, and highly specialized, respectively. Mean percentile ranks were 56.2%, 64.7%, and 62.6% for locomotor, object control, and gross motor domains, respectively. No athlete achieved a percentile rank >99% in any domain of the TGMD-2, and there was no significant difference between specialization groups or sex.

CONCLUSION: Despite high activity levels, no athlete demonstrated proficiency in any domain of the TGMD-2, and there was no difference in proficiency between specialization levels or by sex.

CLINICAL RELEVANCE: Sport participation, regardless of level, does not ensure adequate mastery of FMS.

PMID:37329118 | DOI:10.1177/19417381231178822

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Nevin Manimala Statistics

Drug-Coated Balloon vs. Drug-Eluting Stent in Acute Myocardial Infarction: A Systematic Review and Updated Meta-Analysis

Anatol J Cardiol. 2023 Jun 15. doi: 10.14744/AnatolJCardiol.2023.2953. Online ahead of print.

ABSTRACT

BACKGROUND: This study aimed to systematically review the evidence of drug-coated balloon used in the treatment of acute myocardial infarction and compared with using drug-eluting stent in terms of clinical and angiographic outcomes for a relatively long follow-up period.

METHODS: Electronic databases including PubMed, Embase, and the Cochrane Library were used to search for the information of each study. A total of 8 studies involving 1310 patients were included in this meta-analysis.

RESULTS: During a median follow-up duration of 12 months (range 3-24 months), there were no statistical differences between the drug-coated balloon and drug-eluting stent group in terms of a major adverse cardiovascular event (odds ratio = 1.07; P =.75; 95% CI: 0.72-1.57), all-cause death (odds ratio = 1.01; P =.98; 95% CI = 0.56-1.82), cardiac death (odds ratio = 0.85, P =.65; 95% CI = 0.42-1.72), target lesion revascularization (odds ratio = 1.72; P =.09; 95% CI: 0.93-3.19), recurrent myocardial infarction (odds ratio = 0.89, P =.76; 95% CI: 0.44-1.83), and thrombotic event (odds ratio = 1.10; P =.90; 95% CI: 0.24-5.02). Drug-coated balloon was not linked with risk of late lumen loss compared with drug-eluting stent (mean difference = -0.06 mm; P =.42; 95% CI: -0.22-0.09 mm). However, there was a higher incidence of target vessel revascularization noted in the drug-coated balloon group compared with the drug-eluting stent group (odds ratio = 1.88; P =.02; 95% CI: 1.10-3.22). The subgroup analysis stratified by different study types and ethnicities showed there were no significant differences between the 2 groups.

CONCLUSIONS: Using drug-coated balloon might serve as a potential alternative strategy for patients with acute myocardial infarction because of the similar clinical and angiographic outcomes compared with using drug-eluting stent; nevertheless, the issue of target vessel revascularization should be more focused on. Larger and more representative studies are needed in the future.

PMID:37329115 | DOI:10.14744/AnatolJCardiol.2023.2953

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Nevin Manimala Statistics

Simple rose model of water in constant electric field

Phys Rev E. 2023 May;107(5-1):054801. doi: 10.1103/PhysRevE.107.054801.

ABSTRACT

A simple two-dimensional statistical mechanical water model, called the rose model, was used in this work. We studied how a homogeneous constant electric field affects the properties of water. The rose model is a very simple model that helps explain the anomalous properties of water. Rose water molecules are represented as two-dimensional Lennard-Jones disks with potentials for orientation-dependent pairwise interactions mimicking formations of hydrogen bonds. The original model is modified by addition of charges for interaction with the electric field. We studied what kind of influence the electric field strength has on the model’s properties. To determine the structure and thermodynamics of the rose model under the influence of the electric field we used Monte Carlo simulations. Under the influence of a weak electric field the anomalous properties and phase transitions of the water do not change. On the other hand, the strong fields shift the phase transition points as well as the position of the density maximum.

PMID:37329104 | DOI:10.1103/PhysRevE.107.054801

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Nevin Manimala Statistics

Stable recursive auxiliary field quantum Monte Carlo algorithm in the canonical ensemble: Applications to thermometry and the Hubbard model

Phys Rev E. 2023 May;107(5-2):055302. doi: 10.1103/PhysRevE.107.055302.

ABSTRACT

Many experimentally accessible, finite-sized interacting quantum systems are most appropriately described by the canonical ensemble of statistical mechanics. Conventional numerical simulation methods either approximate them as being coupled to a particle bath or use projective algorithms which may suffer from nonoptimal scaling with system size or large algorithmic prefactors. In this paper, we introduce a highly stable, recursive auxiliary field quantum Monte Carlo approach that can directly simulate systems in the canonical ensemble. We apply the method to the fermion Hubbard model in one and two spatial dimensions in a regime known to exhibit a significant “sign” problem and find improved performance over existing approaches including rapid convergence to ground-state expectation values. The effects of excitations above the ground state are quantified using an estimator-agnostic approach including studying the temperature dependence of the purity and overlap fidelity of the canonical and grand canonical density matrices. As an important application, we show that thermometry approaches often exploited in ultracold atoms that employ an analysis of the velocity distribution in the grand canonical ensemble may be subject to errors leading to an underestimation of extracted temperatures with respect to the Fermi temperature.

PMID:37329093 | DOI:10.1103/PhysRevE.107.055302

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Nevin Manimala Statistics

Topological and nontopological mechanisms of loop formation in chromosomes: Effects on the contact probability

Phys Rev E. 2023 May;107(5-1):054135. doi: 10.1103/PhysRevE.107.054135.

ABSTRACT

Chromosomes are crumpled polymer chains further folded into a sequence of stochastic loops via loop extrusion. While extrusion has been verified experimentally, the particular means by which the extruding complexes bind DNA polymer remains controversial. Here we analyze the behavior of the contact probability function for a crumpled polymer with loops for the two possible modes of cohesin binding, topological and nontopological mechanisms. As we show, in the nontopological model the chain with loops resembles a comb-like polymer that can be solved analytically using the quenched disorder approach. In contrast, in the topological binding case the loop constraints are statistically coupled due to long-range correlations present in a nonideal chain, which can be described by the perturbation theory in the limit of small loop densities. As we show, the quantitative effect of loops on a crumpled chain in the case of topological binding should be stronger, which is translated into a larger amplitude of the log-derivative of the contact probability. Our results highlight a physically different organization of a crumpled chain with loops by the two mechanisms of loop formation.

PMID:37329090 | DOI:10.1103/PhysRevE.107.054135