Disease Subjects Research Articles

A voxel-level approach to brain age prediction: A method to assess regional brain aging

Brain aging is a regional phenomenon, a facet that remains relatively under-explored within the realm of brain age prediction research using machine learning methods. Voxel-level predictions can provide localized brain age estimates that can provide granular insights into the regional aging processes. This is essential to understand the differences in aging trajectories in healthy versus diseased subjects. In this work, a deep learning-based multitask model is proposed for voxel-level brain age prediction from T1-weighted magnetic resonance images. The proposed model outperforms the models existing in the literature and yields valuable clinical insights when applied to both healthy and diseased populations. Regional analysis is performed on the voxel-level brain age predictions to understand aging trajectories of known anatomical regions in the brain and show that there exist disparities in regional aging trajectories of healthy subjects compared to ones with underlying neurological disorders such as Dementia and more specifically, Alzheimer’s disease. Our code is available at <a href='https://github.com/nehagianchandani/Voxel-level-brain-age-prediction'>https://github.com/nehagianchandani/Voxel-level-brain-age-prediction</a>

Estimating the serological underrecognition of patients with weak or partial RHD variants.

For patients with weak or discrepant RhD RBC phenotypes, RHD genotyping is employed to determine need for RhD-negative management. However, many RHD variants are type D-negative or D-positive. Serological recognition rates (RRs) of weak and partial RHD variants are poorly characterized. Four US studies employing RHD genotyping for weak or discrepant RhD phenotypes provided data for race/ethnicity-specific serological recognition. Three studies used microplate, and 1 used gel and tube; 2 had anti-D data. We obtained White and Hispanic/Latino allele frequencies (AFs) of weak D types 1, 2, and 3 single-nucleotide variants (SNVs) from the Genome Aggregation Database (gnomAD, v4.0.0) and devised Hardy-Weinberg-based formulas to correct for gnomAD's overcount of hemizygous RHD SNVs as homozygous. We compiled common partial RHD AF from genotyped cohorts of US Black or sickle cell disease subjects. From variant AF, we calculated hemizygous-plus-homozygous genetic prevalences. Serological prevalence: genetic prevalence ratios yielded serological RRs. Overall RRs of weak D types 1-3 were 17% (95% confidence interval 12%-24%) in Whites and 12% (5%-27%) in Hispanics/Latinos. For eight partial RHD variants in Blacks, overall RR was 11% (8%-14%). However, DAR RR was 80% (38%-156%). Compared to microplate, gel-tube recognition was higher for type 2 and DAU5 and lower for type 4.0. Anti-D was present in 6% of recognized partial RHD cases, but only in 0.7% of estimated total genetic cases. Based on AF, >80% of patients with weak or partial RHD variants were unrecognized serologically. Although overall anti-D rates were low, better detection of partial RHD variants is desirable.

Dynamic cerebral autoregulation is governed by two time constants: Arterial transit time and feedback time constant.

Dynamic cerebral autoregulation (dCA) is the mechanism that describes how the brain maintains cerebral blood flow approximately constant in response to short-term changes in arterial blood pressure. This is known to be impaired in many different pathological conditions, including ischaemic and haemorrhagic stroke, dementia and traumatic brain injury. Many different approaches have thus been used both to analyse and to quantify this mechanism in a range of healthy and diseased subjects, including data-driven models (in both the time and the frequency domain) and biophysical models. However, despite the substantial body of work on both biophysical models and data-driven models of dCA, there remains little work that links the two together. One of the reasons for this is proposed to be the discrepancies between the time constants that govern dCA in models and in experimental data. In this study, the processes that govern dCA are examined and it is proposed that the application of biophysical models remains limited due to a lack of understanding about the physical processes that are being modelled, partly due to the specific model formulation that has been most widely used (the equivalent electrical circuit). Based on the analysis presented here, it is proposed that the two most important time constants are arterial transit time and feedback time constant. It is therefore time to revisit equivalent electrical circuit models of dCA and to develop a more physiologically realistic alternative, one that can more easily be related to experimental data. KEY POINTS: Dynamic cerebral autoregulation is governed by two time constants. The first time constant is the arterial transit time, rather than the traditional 'RC' time constant widely used in previous models. This arterial transit time is approximately 1s in the brain. The second time constant is the feedback time constant, which is less accurately known, although it is somewhat larger than the arterial transit time. The equivalent electrical circuit model of dynamic cerebral autoregulation should be replaced with a more physiologically representative model.

Macrophage-enriched novel functional long noncoding RNAs LRRC75A-AS1 and GAPLINC regulate polarization and innate immune responses.

Macrophages (Mφs) are functionally dynamic immune cells that bridge innate and adaptive immune responses; however, the underlying epigenetic mechanisms that control Mφ plasticity and innate immune functions are not well elucidated. To identify novel functions of macrophage-enriched lncRNAs in regulating polarization and innate immune responses. Total RNA isolated from differentiating monocyte-derived M1 and M2 Mφs was profiled for lncRNAs expression using RNAseq. Impact of LRRC75A-AS1, GAPLINC and AL139099.5 knockdown was examined on macrophage differentiation,polarization markers, phagocytosis, and antigen processing by flow cytometry and florescence microscopy. Cytokine profiles were examined by multiplex bead array and cytoskeletal signaling pathway genes were quantified by PCR-based array. Gingival biopsies were collected from periodontally healthy and diseased subjects to examine lncRNAs,M1/M2marker expression. Transcriptome profiling of M1 and M2 Mφs identified thousands of differentially expressed known and novel lncRNAs. We characterized three Mφ-enriched lncRNAs LRRC75A-AS1, GAPLINC and AL139099.5 in polarization and innate immunity. Knockdown of LRRC75A-AS1 and GAPLINC downregulated the Mφ differentiation markers and skewed Mφ polarization by decreasing M1 markers without a significant impact on M2 markers. LRRC75A-AS1 and GAPLINC knockdown also attenuated bacterial phagocytosis, antigen processing and inflammatory cytokine secretion in Mφs, supporting their functional role in potentiating innate immune functions. Mechanistically, LRRC75A-AS1 and GAPLINC knockdown impaired Mφ migration by downregulating the expression of multiple cytoskeletal signaling pathways suggesting their critical role in regulating Mφ migration. Finally, we showed that LRRC75A-AS1 and GAPLINC were upregulated in periodontitis and their expression correlates with higher M1 markers suggesting their role in macrophage polarizationin vivo. Our results show that polarized Mφs acquire a unique lncRNA repertoire and identified many previously unknown lncRNA sequences. LRRC75A-AS1 and GAPLINC, which are induced in periodontitis, regulate Mφ polarization and innate immune functions supporting their critical role in inflammation.

Clinical Utility of Tectal Plate Measurements on Magnetic Resonance Imaging in Progressive Supranuclear Palsy.

Midbrain atrophy is a characteristic feature of progressive supranuclear palsy (PSP), observed in PSP-Richardson's syndrome (PSP-RS) and to a lesser extent PSP-parkinsonism (PSP-P). Our aim was to critically evaluate the utility of manual magnetic resonance imaging measurements of the midbrain tectal plate as a diagnostic biomarker in PSP. Length of the tectal plate and width of the superior and inferior colliculi were measured in 40 PSP (20 PSP-RS and 20 PSP-P) patients and compared with 20 Parkinson's disease and 20 healthy control subjects. Tectal plate length was reduced in both PSP groups compared with Parkinson's disease and control subjects and was most abnormal in PSP-RS followed by PSP-P. Reduced tectal plate length was associated with worse PSP Rating Scale scores. Simple manual measurements of tectal plate length show utility as a diagnostic biomarker in PSP, particularly for PSP-RS.

Prevalence, tropism, and activity of cutavirus in circulating blood lymphocytes, stool, and skin biopsy specimens of patients with cutaneous T-cell lymphoma and parapsoriasis en plaques.

A significant association has been established between a newly emerging human parvovirus, cutavirus (CuV), and cutaneous T-cell lymphoma/mycosis fungoides (CTCL/MF) and its precursor parapsoriasis en plaques (PP). CTCL is a heterogeneous group of skin malignancies of T cells, the cause of which remains unknown. This study aimed to determine the activity, spread, and cell tropism of the skin-persistent CuV. CuV DNA was detected in both skin biopsies (6/20, 30%) and peripheral blood mononuclear cells (PBMCs) (4/29, 13.8%) from 49 CTCL/MF or PP patients, while none from 33 patients with any other type of skin disease or healthy subjects harbored CuV DNA. CuV DNA persisted in the skin or PBMCs for up to 15 years, despite circulating CuV-specific IgG. Spliced CuV mRNA was expressed in skin, indicating viral activity. Also, both of two available stool samples contained encapsidated CuV genomes, suggesting that the patients excrete infectious virus into the environment. Finally, CuV was observed to target circulating and skin-resident CD4 + T cells and some skin keratinocytes and macrophages. This is especially intriguing as malignant T cells in CTCL develop from CD4 + T cells. Hence, CuV should be further investigated for the overall role it plays in the complex tumor microenvironment of CTCL/MF.

Analyzing key elements of breathing patterns, deriving remaining variables, and identifying cutoff values in individuals with chronic respiratory disease and healthy subjects

BackgroundPulmonary physiology encompasses intricate breathing patterns (BPs), characterized by breathing frequency (Bf), volumes, and flows. The complexities intensify in the presence of interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD), especially during exercise. This study seeks to identify pivotal factors driving changes among these variables and establish cutoff values, comparing their efficacy in differentiating BPs to traditional methods, specifically a breathing reserve (BR) of 30% and a Bf of 50 bpm. MethodsScreening 267 subjects revealed 23 with ILD, 126 with COPD, 33 healthy individuals, and the exclusion of 85 subjects. Lung function tests and ramp-pattern cardiopulmonary exercise testing (CPET) were conducted, identifying crucial BP elements. Changes were compared between groups at peak exercise. The area under the receiver operating characteristic curve (AUC) analysis determined cutoff values. ResultsInspiratory time (TI) remained constant at peak exercise for all subjects (two-group comparisons, all p=NS). Given known differences in expiratory time (TE) and tidal volume (VT) among ILD, COPD, and healthy states, constant TI could infer patterns for Bf, total breathing cycle time (TTOT=60/Bf), I:E ratio, inspiratory duty cycle (IDC, TI/TTOT), rapid shallow breathing index (Bf/VT), tidal inspiratory and expiratory flows (VT/TI and VT/TE), and minute ventilation (V̇E=Bf×VT) across conditions. These inferences aligned with measurements, with potential type II errors causing inconsistencies. RSBI of 23 bpm/L and VT/TI of 104 L/min may differentiate ILD from control, while V̇E of 54 L/min, BR of 30%, and VT/TE of 108 may differentiate COPD from control. BR of 21%, TE of 0.99 s, and IDC of .45 may differentiate ILD from COPD. The algorithm outperformed traditional methods (AUC 0.84–0.91 versus 0.59–0.90). ConclusionThe quasi-fixed TI, in conjunction with TE and VT, proves effective in inferring time-related variables of BPs. The findings have the potential to significantly enhance medical education in interpreting cardiopulmonary exercise testing. Moreover, the study introduces a novel algorithm for distinguishing BPs among individuals with ILD, COPD, and those who are healthy.

Plasma Concentrations of High Mobility Group Box 1 Proteins and Soluble Receptors for Advanced Glycation End-Products Are Relevant Biomarkers of Cognitive Impairment in Alcohol Use Disorder: A Pilot Study.

Alcohol use disorder (AUD) is a major component in the etiology of cognitive decline and dementia. Underlying mechanisms by which long-term alcohol abuse causes cognitive dysfunction include excessive oxidative stress and inflammation in the brain, activated by increased reactive oxygen/nitrogen species (ROS/RNS), advanced glycation end-products (AGEs) and high-mobility group box 1 protein (HMGB1). In a pilot study, we examine the potential clinical value of circulating biomarkers of oxidative stress including ROS/RNS, HMGB1, the soluble receptor for AGE (sRAGE), the brain biomarker of aging apolipoprotein D (ApoD), and the antioxidant regulator nuclear factor erythroid 2-related factor 2 (NRF2) as predictive indices for cognitive impairment (CI) in abstinent patients with AUD (n = 25) compared to patients with established Alzheimer's disease (AD, n = 26) and control subjects (n = 25). Plasma concentrations of sRAGE were evaluated with immunoblotting; ROS/RNS with a fluorometric kit; and HMGB1, ApoD, and NRF2 by ELISA. Abstinent AUD patients had higher sRAGE, ROS/RNS (p < 0.05), and ApoD (p < 0.01) concentrations, similar to those of AD patients, and lower NRF2 (p < 0.01) concentrations, compared to controls. These changes were remarkable in AUD patients with CI. HMGB1, and sRAGE correlated positively with duration of alcohol use (rho = 0.398, p = 0.022; rho = 0.404, p = 0.018), whereas sRAGE correlated negatively with periods of alcohol abstinence (rho = -0.340, p = 0.045). A predictive model including ROS/RNS, HMGB1, sRAGE, alcohol use duration, and alcohol abstinence periods was able to differentiate AUD patients with CI (92.3% of correct predictions, ROC-AUC= 0.90) from those without CI. In conclusion, we propose ROS/RNS, HMGB1, and sRAGE as stress biomarkers capable of predicting cognitive impairment in AUD patients.

Healthcare use according to deprivation among French Alzheimer's Disease and Related Diseases subjects: a national cross-sectional descriptive study based on the FRA-DEM cohort.

Pluriprofessional and coordinated healthcare use is recommended for Alzheimer's Disease and Related Diseases (ADRD). Despite a protective health system, France is characterized by persistent and significant social inequalities in health. Although social health inequalities are well documented, less is known about social disparities in healthcare use in ADRD, especially in France. Therefore, this study aimed to describe healthcare use according to socioeconomic deprivation among ADRD subjects and the possible potentiating role of deprivation by age. We studied subjects identified with incident ADRD in 2017 in the French health insurance database (SNDS). We described a large extent of their healthcare use during the year following their ADRD identification. Deprivation was assessed through French deprivation index (Fdep), measured at the municipality level, and categorized into quintiles. We compared healthcare use according to the Fdep quintiles through chi-square tests. We stratified the description of certain healthcare uses by age groups (40-64 years, 65-74 years, 75-84 years, 85 years, and older), number of comorbidities (0, 1, 2-3, 4 comorbidities and more), or the presence of psychiatric comorbidity. In total, 124,441 subjects were included. The most deprived subjects had less use of physiotherapy (28.56% vs. 38.24%), ambulatory specialists (27.24% vs. 34.07%), ambulatory speech therapy (6.35% vs. 16.64%), preventive consultations (62.34% vs. 69.65%), and were less institutionalized (28.09% vs. 31.33%) than the less deprived ones. Conversely, they were more exposed to antipsychotics (11.16% vs. 8.43%), benzodiazepines (24.34% vs. 19.07%), hospital emergency care (63.84% vs. 57.57%), and potentially avoidable hospitalizations (12.04% vs. 10.95%) than the less deprived ones. The healthcare use of subjects with ADRD in France differed according to the deprivation index, suggesting potential health renunciation as in other diseases. These social inequalities may be driven by financial barriers and lower education levels, which contribute to health literacy (especially for preventive care). Further studies may explore them.

Efficacy of Antimicrobial Photodynamic Therapy as an adjunct periodontal intervention in periodontally diseased subjects undergoing orthodontic therapy

Photodynamic therapy in fixed orthodontic patients with gingival disease might be beneficial, being non-invasive and having accessibility to difficulty to reach areas like, interdental region with the presence of wires and brackets. This systematic review was designed to analyze the available evidence on the efficacy of antimicrobial photodynamic therapy as an adjunct to scaling in reduction of gingival inflammation in periodontally diseased subjects undergoing fixed orthodontic treatment. Comprehensive search was conducted in electronic databases like PubMed, Scopus and Google scholar along with hand search in relevant journals. Five studies satisfied the criteria and were included in qualitative synthesis of the systematic review. The results of the primary outcome showed adjunctive aPDT did not result in any difference in reduction of gingival inflammation (BOP) compared to scaling alone in fixed orthodontic patients. Only one study showed a significant reduction of gingival inflammation with aPDT, whereas it was better in the scaling group (one study) or no significant difference (3 study) in the other studies. However, aPDT resulted in significant reduction of most of the bacterial species count and proinflammatory cytokine levels in GCF compared to scaling alone. Within the limitations of this systematic review, there is no clear evidence that aPDT adjunctive to scaling has a better effect in reducing gingival inflammation in fixed orthodontic patients. Future studies addressing this area should focus on well planned standardized, long term RCTs that will aid clinicians in making a more evidence - based decision.

Handling missing disease information due to death in diseases that need two visits to diagnose.

In studies that assess disease status periodically, time of disease onset is interval censored between visits. Participants who die between two visits may have unknown disease status after their last visit. In this work, we consider an additional scenario where diagnosis requires two consecutive positive tests, such that disease status can also be unknown at the last visit preceding death. We show that this impacts the choice of censoring time for those who die without an observed disease diagnosis. We investigate two classes of models that quantify the effect of risk factors on disease outcome: a Cox proportional hazards model with death as a competing risk and an illness death model that treats disease as a possible intermediate state. We also consider four censoring strategies: participants without observed disease are censored at death (Cox model only), the last visit, the last visit with a negative test, or the second last visit. We evaluate the performance of model and censoring strategy combinations on simulated data with a binary risk factor and illustrate with a real data application. We find that the illness death model with censoring at the second last visit shows the best performance in all simulation settings. Other combinations show bias that varies in magnitude and direction depending on the differential mortality between diseased and disease-free subjects, the gap between visits, and the choice of the censoring time.

VARIATIONS IN SERUM CONCENTRATIONS OF Hs-CRP IN PERIODONTITIS AND HEALTHY SUBJECTS

CRP is a plasma protein that measures the acute phase response to systemic inflammation and is one of the markers of choice in monitoring numerous chronic diseases. Patients with periodontitis have specific haematological variations, such as higher C-reactive protein (CRP) levels and elevated pro-inflammatory mediator levels. This study aims to quantify Hs-CRP levels in periodontally healthy and diseased subjects and evaluate the relationship between periodontitis and Hs-CRP levels. This Case-control study recruited 120 patients from two study groups—60 cases of chronic periodontitis (moderate to severe) and 60 controls. Periodontitis is assessed by three different index scores, namely: Community periodontal index score (CPI), Clinical attachment level (CAL) and periodontal probing depth (PPD). The Hs-CRP is measured due to its high sensitivity to assess systemic inflammation, making it more effective than conventional CRP tests. Our study results indicate that Hs-CRP levels increase subsequently with the severity of the periodontal disease. Moreover, Clinical attachment level (CAL) is the most significant indicator of Periodontitis that correlates with systemic inflammation in the body. Hence, concluding that periodontitis, being an oral condition, can have a massive impact on general systemic health, and elevated Hs-CRP levels, considered a biomarker of chronic systemic inflammation, can be a future risk to several fatal systemic diseases.

Favorable subgingival plaque microbiome shifts are associated with clinical treatment for peri-implant diseases

We performed a longitudinal shotgun metagenomic investigation of the plaque microbiome associated with peri-implant diseases in a cohort of 91 subjects with 320 quality-controlled metagenomes. Through recently improved taxonomic profiling methods, we identified the most discriminative species between healthy and diseased subjects at baseline, evaluated their change over time, and provided evidence that clinical treatment had a positive effect on plaque microbiome composition in patients affected by mucositis and peri-implantitis.

Intracerebellar injection of monocytic immature myeloid cells prevents the adverse effects caused by stereotactic surgery in a model of cerebellar neurodegeneration

BackgroundMyeloid-derived suppressor cells (MDSCs) constitute a recently discovered bone-marrow-derived cell type useful for dealing with neuroinflammatory disorders. However, these cells are only formed during inflammatory conditions from immature myeloid cells (IMCs) that acquire immunosuppressive activity, thus being commonly gathered from diseased animals. Then, to obtain a more clinically feasible source, we characterized IMCs directly derived from healthy bone marrow and proved their potential immunosuppressive activity under pathological conditions in vitro. We then explored their neuroprotective potential in a model of human cerebellar ataxia, the Purkinje Cell Degeneration (PCD) mouse, as it displays a well-defined neurodegenerative and neuroinflammatory process that can be also aggravated by invasive surgeries.MethodsIMCs were obtained from healthy bone marrow and co-cultured with activated T cells. The proliferation and apoptotic rate of the later were analyzed with Tag-it Violet. For in vivo studies, IMCs were transplanted by stereotactic surgery into the cerebellum of PCD mice. We also used sham-operated animals as controls of the surgical effects, as well as their untreated counterparts. Motor behavior of mice was assessed by rotarod test. The Purkinje cell density was measured by immunohistochemistry and cell death assessed with the TUNEL technique. We also analyzed the microglial phenotype by immunofluorescence and the expression pattern of inflammation-related genes by qPCR. Parametric tests were applied depending on the specific experiment: one or two way ANOVA and Student’s T test.ResultsIMCs were proven to effectively acquire immunosuppressive activity under pathological conditions in vitro, thus acting as MDSCs. Concerning in vivo studios, sham-operated PCD mice suffered detrimental effects in motor coordination, Purkinje cell survival and microglial activation. After intracranial administration of IMCs into the cerebellum of PCD mice, no special benefits were detected in the transplanted animals when compared to untreated mice. Nonetheless, this transplant almost completely prevented the impairments caused by the surgery in PCD mice, probably by the modulation of the inflammatory patterns.ConclusionsOur work comprise two main translational findings: (1) IMCs can be directly used as they behave as MDSCs under pathological conditions, thus avoiding their gathering from diseased subjects; (2) IMCs are promising adjuvants when performing neurosurgery.

Molecular-guided therapy for the treatment of patients with relapsed and refractory childhood cancers: a Beat Childhood Cancer Research Consortium trial

BackgroundChildren with relapsed central nervous system (CNS tumors), neuroblastoma, sarcomas, and other rare solid tumors face poor outcomes. This prospective clinical trial examined the feasibility of combining genomic and transcriptomic profiling of tumor samples with a molecular tumor board (MTB) approach to make real‑time treatment decisions for children with relapsed/refractory solid tumors.MethodsSubjects were divided into three strata: stratum 1—relapsed/refractory neuroblastoma; stratum 2—relapsed/refractory CNS tumors; and stratum 3—relapsed/refractory rare solid tumors. Tumor samples were sent for tumor/normal whole-exome (WES) and tumor whole-transcriptome (WTS) sequencing, and the genomic data were used in a multi-institutional MTB to make real‑time treatment decisions. The MTB recommended plan allowed for a combination of up to 4 agents. Feasibility was measured by time to completion of genomic sequencing, MTB review and initiation of treatment. Response was assessed after every two cycles using Response Evaluation Criteria in Solid Tumors (RECIST). Patient clinical benefit was calculated by the sum of the CR, PR, SD, and NED subjects divided by the sum of complete response (CR), partial response (PR), stable disease (SD), no evidence of disease (NED), and progressive disease (PD) subjects. Grade 3 and higher related and unexpected adverse events (AEs) were tabulated for safety evaluation.ResultsA total of 186 eligible patients were enrolled with 144 evaluable for safety and 124 evaluable for response. The average number of days from biopsy to initiation of the MTB-recommended combination therapy was 38 days. Patient benefit was exhibited in 65% of all subjects, 67% of neuroblastoma subjects, 73% of CNS tumor subjects, and 60% of rare tumor subjects. There was little associated toxicity above that expected for the MGT drugs used during this trial, suggestive of the safety of utilizing this method of selecting combination targeted therapy.ConclusionsThis trial demonstrated the feasibility, safety, and efficacy of a comprehensive sequencing model to guide personalized therapy for patients with any relapsed/refractory solid malignancy. Personalized therapy was well tolerated, and the clinical benefit rate of 65% in these heavily pretreated populations suggests that this treatment strategy could be an effective option for relapsed and refractory pediatric cancers.Trial registrationClinicalTrials.gov, NCT02162732. Prospectively registered on June 11, 2014.

The relationship between fermented and nonfermented dairy products consumption and hypertension among premature coronary artery disease patients: Iran premature coronary artery disease study.

Dairy products may affect hypertension (HTN) risk. The aim of this study was to examine the association between fermented and nonfermented dairy foods and HTN in a sample of premature coronary artery disease (PCAD) subjects. This cross-sectional study was performed on 1854 PCAD patients. A 110-item food frequency questionnaire was used to assess dietary intakes. HTN was considered if systolic blood pressure was 140 mmHg and higher and/or diastolic blood pressure was 90 mmHg and higher. The odds ratio of HTN across the quartiles of different types of dairy products was evaluated by binary logistic regression. The mean (SD) of dairy products consumption was 339.8 (223.5) g/day, of which 285.4 g/day was fermented dairy products. In the crude model, participants in the fourth quartile of fermented dairy products had lesser risk of HTN compared to the bottom quartile (OR = 0.70, 95% CI: 0.52, 0.96; p for trend = .058). However, after considering the possible confounders, the significance disappeared. Subjects in the top quartile of high-fat fermented dairy products had 34% lower risk for HTN compared to the bottom quartile (95% CI: 0.49, 0.88; p for trend < .001). Adjustment for potential risk factors weakened the association but remained significant (OR = 0.73, 95% CI: 0.53, 1.01; p for trend = .001). Nonsignificant relation was detected between low-fat fermented, low-fat nonfermented, and high-fat nonfermented dairy products and HTN. Moderate consumption of high-fat fermented dairy products, in a population with low consumption of dairy foods, might relate to reduced likelihood of HTN.

Triglycerides Stabilize Water/Organic Interfaces of Changing Area via Conformational Flexibility.

The role of triglycerides (TGs) in both natural and synthetic biological membranes has long been the subject of study, involving metabolism, disease, and colloidal synthesis. TGs have been found to be critical components for successful liposomal encapsulation via a water/oil/water double emulsion, which this work endeavors to explain. TGs can occupy multiple positions in biological membranes. The glycerol backbone can reside at the water/organic interface, adjacent to phospholipid headgroups ("m" conformation), typically with relatively low (<3%) solubility. The glycerol backbone can also occupy hydrophobic regions, where it is isolated from water ("h" or "oil" conformation). This can occur in either midmembrane positions or phospholipid-coated lipid droplets (LDs). These conformations can be distinguished using 13C-nuclear magnetic resonance spectroscopy (NMR), which determines the degree of hydration of the TG backbone. Using this method, it was revealed that TGs transition from "m" to "h" conformation as the organic solvent is removed via evaporation. A new transitional TG backbone position has been identified with a level of hydration between "m" and "h". These results suggest that TGs can temporarily coat and stabilize the large water/organic interfaces present after emulsification. As the organic solvent is removed and interfaces shrink, the TGs recede into midmembrane spaces or bud off into LDs, which are confirmed via transmission electron microscopy (TEM) and can be removed via centrifugation. Encapsulation efficiency is found to be inversely related to both the saturation and length of the TG acyl chains, indicating that membrane fluidization is a key property arising from the presence of TGs. Beyond clarification of a mechanism for high-efficiency liposomal encapsulation, these results implicate TGs as components that are able to stabilize biological membrane transitions involving a changing interfacial area and curvature. This role for TGs may be of use in the formulation of drug delivery systems as well as in the investigation of membrane transitions in life sciences.

WESTERN DIET DEPLETES SMALL INTESTINAL INTRAEPITHELIAL LYMPHOCYTES VIA FXR-INTERFERON PATHWAY

Abstract BACKGROUND The prevalence of obesity has continued to increase over the past several decades. Understanding how diet-induced obesity modulates mucosal immunity is of clinical relevance. We previously showed that consumption of a high fat, high sugar “Western” diet (WD) reduces the density and function of small intestinal Paneth cells, a small intestinal epithelial cell type with innate immune function. We hypothesized that obesity could also result in repressed adaptive immunity. METHODS Small intestine samples from non-inflammatory bowel disease (IBD) subjects who underwent resection were used for CD3 immunohistochemistry (IHC), and the CD3+ intraepithelial lymphocytes (IEL) densities were correlated with the patients’ body mass index (BMI). Mice were fed with either standard diet (SD) or WD for various durations, and IELs were isolated for flow cytometry analysis. RESULTS In non-IBD subjects, high BMI correlated with reduced IEL density. We recapitulated this in wild type (WT) mice fed with WD. A 4-week WD consumption was able to deplete IEL (including major subsets CD4+, CD8+, CD8α+8β-CD4+, and γδCD8+ T cells) but not splenic lymphocytes, and the effect was reversible after another 4 weeks of SD washout. ob/ob mice that spontaneously developed obesity while fed with SD did not show IEL depletion, suggesting that the quality, not the quantity of the diet is key to this phenotype. Importantly, WD-associated IEL depletion was not dependent on the presence of gut microbiota, as WD-fed germ-free mice also showed IEL depletion. We previously showed that a key molecular pathway activated by WD in the ileum is the FXR pathway. Phagocyte-specific Fxr conditional knockout (cKO) mice were protected from WD-mediated IEL depletion, suggesting that FXR activation in the phagocytes is critical in mediating this phenotype. Activated FXR signaling stimulated phagocytes to secrete type I interferon (IFN), and inhibition of type I IFN signaling within the phagocytes (type I IFN monoclonal antibody treatment and Stat1 cKO mice) prevented WD-mediated IEL loss. CONCLUSION WD consumption depletes IEL by a FXR-IFN pathway mediated by gut phagocytes. These findings have significant clinical implications in understanding the pathogenesis of gut inflammatory disorders such as IBD.

Multisite external validation of blood test for colorectal neoplasia screening in a majority average-risk screening cohort of 449 subjects.

66 Background: The FirstSight CRC screening blood test was previously shown to have sensitivities of 92.1% and 54.5% for CRC and AA at a specificity of 90.6% for 1,038 subjects from 18 clinical sites. In this report, we describe the independent external validation of the predefined FirstSight CRC screening blood test with new subjects from 16 sites dispersed across the US, 4 of which are new and did not participate in the previous study. Methods: The validation study included subjects from two sources: Average-risk, asymptomatic screening subjects from screening clinics supplemented with diseased-only subjects from surgical oncology centers. Blood was drawn before bowel prep for colonoscopy or treatment. External validation as well as Monte Carlo cross-validation (MCCV) methods were used to evaluate the performance of the pre-defined FirstSight assay, algorithm, and clinical thresholds in this independent external validation set. Results include sensitivity and specificity to detect CRC and AA and 95% confidence intervals. Results: The study cohort (55.2% female; mean age 56.9 yrs.) consisted of 449 subjects (White 61.7%; Black 14.5%; Hispanic 18%; AAPI and Middle Easterners 5.8%). The majority of them, 376 (84%), were asymptomatic, average-risk screening subjects (including 1 CRC, 53 AA, and all 322 negative subjects). An additional 73 (16%) diseased subjects (39 CRC and 34 AA) were enriched due to low disease prevalence. The FirstSight algorithm derives a test score from 0 to 100 as a quantitative measure of AA and CRC risk with a cutpoint to assign a binary low- or high-risk designation. The previously described cutpoint of 47.2 yielded a test specificity of 90.0%, and 90.0% and 52.9% sensitivity for the detection of CRC and AA, respectively. Here we report a higher cutpoint 50 with identical sensitivities but improved specificity to 90.7%. Point estimates of sensitivity and specificity, including CRC staging, and Clopper-Pearson exact 95% confidence intervals based on the external validation results are presented below. Conclusions: An external validation included 449 subjects from a multi-site, majority average-risk CRC screening study successfully validated the FirstSight Blood Test’s high performance as previously established with 1,038 subjects. The results bring forth confidence in the Test’s reproducibility in a large-scale clinical trial. Clinical trial information: NCT05127096 . [Table: see text]

Metal dyshomeostasis in the substantia nigra of patients with Parkinson's disease or multiple sclerosis.

Abnormal metal distribution in vulnerable brain regions is involved in the pathogenesis of most neurodegenerative diseases, suggesting common molecular mechanisms of metal dyshomeostasis. This study aimed to compare the intra- and extra-neuronal metal content and the expression of proteins related to metal homeostasis in the substantia nigra (SN) from patients with Parkinson's disease (PD), multiple sclerosis (MS), and control subjects. Metal quantification was performed via ion-beam micro-analysis in neuromelanin-positive neurons and the surrounding tissue. For proteomic analysis, SN tissue lysates were analyzed on a nanoflow chromatography system hyphenated to a hybrid triple-quadrupole time-of-flight mass spectrometer. We found increased amounts of iron in neuromelanin-positive neurons and surrounding tissue in patients with PD and MS compared to controls (4- to 5-fold higher) that, however, also showed large inter-individual variations. Copper content was systematically lower (-2.4-fold) in neuromelanin-positive neurons of PD patients compared with controls, whereas it remained unchanged in MS. Protein-protein interaction (PPI) network analyses revealed clusters related to Fe and Cu homeostasis among PD-deregulated proteins. An enrichment for the term "metal homeostasis" was observed for MS-deregulated proteins. Important deregulated hub proteins included hemopexin and transferrin in PD, and calreticulin and ferredoxin reductase in MS. Our findings show that PD and MS share commonalities in terms of iron accumulation in the SN. Concomitant proteomics experiments revealed PPI networks related to metal homeostasis, substantiating the results of metal quantification.