Pathophysiological Alterations Research Articles

Edaravone Improved Behavioral Abnormalities, Alleviated Oxidative Stress Inflammation, and Metabolic Homeostasis Pathways in Depression

Depression is one of the main factors affecting our daily performance. Among many putative compounds with effect on behavioral and pathophysiological alterations in depression, edaravone (EDV) demonstrates antioxidant and free radical scavenging properties. To investigate possible antidepressive and anxiolytic-like effects of EDV, Wistar rats were randomly divided into six groups: (1) control; (2) EDV (6 mg/kg); (3) post weaning social isolation (PWSI); (4) PWSI+EDV (1.5 mg/kg); (5) PWSI+EDV (3 mg/kg); and (6) PWSI+EDV (6 mg/kg). After the series of behavioral tests, animals were sacrificed, and their hippocampi were dissected for further biochemical and gene expression assays. Our results showed that treatment with 3 and 6 mg/kg EDV after social isolation would improve anxiety, depressive and anhedonic-like behavior in OFT, EPM, FST, and splash tests. In addition, treatment at the aforementioned doses achieved to recover total cellular antioxidant and GSH level. These effects were accompanied with the suppressive effect of EDV on MDA and PCO levels. EDV treatment also modulated the expression of AMPK, Tlr-4, BDNF, nNOS, and iNOS genes. The treatment with 3 and 6 mg/kg EDV would lead to the recovery of behavioral impairments, cellular free radical surge that could be in correlation with the effect of this substance on immune system response, improved energy production system, and more efficacy in the recovery of neural tissue. In conclusion, EDV ameliorates depressive-like disorder by modulating neuroinflammation, energy production, and neural tissue recovery.

Dengyinnaotong attenuates atherosclerotic lesions, gut dysbiosis and intestinal epithelial barrier impairment in the high fat diet-fed ApoE−/− mice

Ethnopharmacological relevanceDengyinnaotong (DYNT) is a traditional Chinese medicine-based patent drug officially approved for the treatment of ischemic stroke primarily based on its indigenous application for the treatment of cardiovascular and cerebrovascular diseases in Southwest China. Atherosclerosis is the principal pathology underlying the pathogenesis of ischemic stroke and coronary artery disease. However, whether DYNT is effective at mitigating atherosclerosis remains unknown. Aims of the studyThe purpose of the current study is to evaluate the potential impact of DYNT treatment on the atherosclerotic lesions and associated pathological mechanisms. Materials and methodsHistological, immunohistochemical, molecular biological approaches were adopted to investigate the pharmacological impact of DYNT treatment on atherosclerosis and associated pathophysiological alterations in the high fat diet (HFD)-fed ApoE gene deficient (ApoE−/−) mice. ResultsDYNT treatment reduced the size of the atherosclerotic plaques, alleviated the necrotic core, lowered the lipid retention, mitigated the macrophagic burden and decreased the expression of proatherogenic chemokine Ccl2 in the atherosclerotic lesions. DYNT treatment also offered partial protection against atherogenic dyslipidemia and mitigated hepatic lipid content as well as fatty liver pathologies in the HFD-fed ApoE−/− mice. Furthermore, DYNT treatment protected against atherosclerosis-associated gut dysbiosis and impairment in the intestinal epithelial barrier. ConclusionsOur work provides novel preclinical evidence that underpins the multifaceted effects of DYNT in the control of atherosclerosis.

Ensemble method employing quantitative biomarkers and deep learning approach from structural magnetic resonance imaging to diagnose Alzheimer’s disease

Abstract Introduction: Alzheimer’s disease (AD) is a neurodegenerative condition that impairs activities of daily living and sharply declines gross cognitive ability. Over 152 million individuals worldwide will live with the dreaded consequence of a longer lifespan by the year 2050, making it a pressing public health issue. Magnetic resonance imaging (MRI) provides excellent soft tissue contrast and helps image the brain in vivo, non-invasively. Aims and Objectives: To summarize AD’s anatomical, physiological, and pathophysiological changes and derivation of quantifiable biomarkers from MRI to develop artificial intelligence (AI) based computer-aided detection (CAD) system to classify subjects among AD, mild cognitive impairment (MCI), and cognitively normal (CN). Materials and Methods: This retrospective study uses clinical and standardized, pre-processed, quality-controlled, and quality-checked—structural MRI imaging (diagnosed/labeled) data of 1069 subjects, age, gender, and class matched, taken from Alzheimer’s disease neuroimaging initiative. A pipeline is developed to get quantified biomarkers from the assessment of (1) cortical thickness, (2) volumetric segmentation for whole brain volumes, and (3) region of interest (ROI) areas most affected in AD. A gradient boosting method is used to predict class labels. The second approach implements a convolution neural network (CNN) model comprising 3D ROI. Results: Implemented CAD system using an ensemble gradient boosting approach has demonstrated good receiver operating characteristics characteristic and yielded balanced accuracy (BA) of 82.31%, 78.52%, and 72.73%, and the CNN approach has given better results 88.44%, 82.96%, and 74.34% for classification task AD versus CN, AD versus MCI, and MCI versus CN, respectively. Conclusion: This study has used a substantially large dataset of 1069 subjects. The deep learning-based efficient and optimal CNN model has used significantly large ROI-based 3-Dimentional volume, resulting in impressive performance improvements over comparable methods. The CNN model had given higher accuracy (6.13% for AD vs. CN, 4.44% for AD vs. MCI and 1.61% for MCI vs. CN) over gradient boosting, as the model uses significantly large ROI-based 3D brain volume and an inherent capability of it in learning most discriminative features automatically. However, quantitative biomarkers derived from brain morphometry, which accesses structural changes, yield reasonable estimates over pathophysiological alterations across the brain and augment a clinician with insightful and a holistic view, resulting in higher confidence over predicated class label by CNN and is a step closer to explainable AI. Accuracy for MCI versus CN drops as these classes share similar features and characteristics and can be improved by integrating biomarkers from other MRI modalities.

ASSOCIATION BETWEEN SLEEP QUALITY AND GERIATRIC SYNDROMES IN NURSING HOME RESIDENTS

Background: With aging, an increase is observed in some geriatric syndromes as well as sleep disorders. Objective: The aim of this study is to investigate the relationship between sleep quality and geriatric syndromes (dementia, depression, sarcopenia, malnutrition, and frailty) in nursing home residents. Methods: The participants’ demographic characteristics, comorbid diseases, number of drugs, cognitive performance, mood and nutritional states, sarcopenia and fraility screening tests and sleep quality test were evaluated by two geriatricians. The participants were divided into two groups as good sleep quality and poor sleep quality. Correlation analysis of sleep quality and geriatric and mental functionality tests was performed with Spearman correlation analysis. Results: A total of 104 nursing home residents (34 females, 74 males, aged 61-98) participated in the study. Sleep quality was found to be worse in the elderly between the ages of 75-84, with a higher number of children, using assistive devices, and taking selective serotonin reuptake inhibitors. In addition, in participants with poor sleep quality, SARC-f (strength, assistance with walking, rising from a chair, climbing stairs, and falls) and geriatric depression scale scores were significantly higher. The Pittsburgh Sleep Quality Index global score was negatively associated with total sleep time and positively associated with geriatric depression scale score and SARC-f score. Conclusion: Findings from the present study in relation between poor sleep quality and some geriatric evaluation parameters suggests that there may be a common pathophysiological alteration with aging.

Olfaction unraveled: Anatomy, dysfunctions and implications for health and sensory perception

This review addresses the fundamental role of smell in human life, including its function in detecting odors, influencing personal preferences, and social behaviors. The article discusses the anatomy of the olfactory system, covering the structures involved in olfactory detection and processing. The evaluation of olfactory function is explored using different approaches, such as standardized tests, clinical examinations, and imaging techniques, which allow an accurate assessment of olfactory capacity and assist in the diagnosis of olfactory-related disorders. Additionally, conditions such as anosmia and dysosmia are addressed, investigating their causes, impacts, and diagnostic methods. Anosmia may be due to lesions in the olfactory structures or underlying medical conditions, while dysosmias involve qualitative alterations in the perception of smell. The article also discusses the prevalence of olfactory alterations in different contexts, including the COVID-19 pandemic, which has shown association with temporary or persistent loss of smell. Finally, the importance of advancing research in this area for a thorough understanding of the pathophysiology of olfactory alterations is emphasized. This understanding is critical for the development of personalized and effective therapeutic strategies. Collaboration between researchers and healthcare professionals is essential to drive scientific and clinical advances related to this topic. It is hoped that this review will provide a comprehensive overview of olfaction, contributing to a better understanding of olfactory mechanisms and supporting more effective clinical approaches to the diagnosis and treatment of olfactory disorders.

A physiologically based pharmacokinetic model of cefepime to predict its pharmacokinetics in healthy, pediatric and disease populations

The physiologically based pharmacokinetic modeling (PBPK) approach can predict drug pharmacokinetics (PK) by combining changes in blood flow and pathophysiological alterations for developing drug-disease models. Cefepime hydrochloride is a parenteral cephalosporin that is used to treat pneumonia, sepsis, and febrile neutropenia, among other things. The current study sought to identify the factors that impact cefepime pharmacokinetics (PK) following dosing in healthy, diseased (CKD and obese), and pediatric populations. For model construction and simulation, the modeling tool PK-SIM was utilized. Estimating cefepime PK following intravenous (IV) application in healthy subjects served as the primary step in the model-building procedure. The prediction of cefepime PK in chronic kidney disease (CKD) and obese populations were performed after the integration of the relevant pathophysiological changes. Visual predictive checks and a comparison of the observed and predicted values of the PK parameters were used to verify the developed model. The results of the PK parameters were consistent with the reported clinical data in healthy subjects. The developed PBPK model successfully predicted cefepime PK as observed from the ratio of the observed and predicted PK parameters as they were within a two-fold error range.

Cognitive dysfunction in diabetes: abnormal glucose metabolic regulation in the brain.

Cognitive dysfunction is increasingly recognized as a complication and comorbidity of diabetes, supported by evidence of abnormal brain structure and function. Although few mechanistic metabolic studies have shown clear pathophysiological links between diabetes and cognitive dysfunction, there are several plausible ways in which this connection may occur. Since, brain functions require a constant supply of glucose as an energy source, the brain may be more susceptible to abnormalities in glucose metabolism. Glucose metabolic abnormalities under diabetic conditions may play an important role in cognitive dysfunction by affecting glucose transport and reducing glucose metabolism. These changes, along with oxidative stress, inflammation, mitochondrial dysfunction, and other factors, can affect synaptic transmission, neural plasticity, and ultimately lead to impaired neuronal and cognitive function. Insulin signal triggers intracellular signal transduction that regulates glucose transport and metabolism. Insulin resistance, one hallmark of diabetes, has also been linked with impaired cerebral glucose metabolism in the brain. In this review, we conclude that glucose metabolic abnormalities play a critical role in the pathophysiological alterations underlying diabetic cognitive dysfunction (DCD), which is associated with multiple pathogenic factors such as oxidative stress, mitochondrial dysfunction, inflammation, and others. Brain insulin resistance is highly emphasized and characterized as an important pathogenic mechanism in the DCD.

Pursuing the Real Vancomycin Clearance during Continuous Renal Replacement Therapy in Intensive Care Unit Patients: Is There Adequate Target Attainment?

Introduction: Vancomycin is used in intensive care unit (ICU) patients for the treatment of infections caused by gram-positive bacteria. The vancomycin pharmacokinetic/pharmacodynamic index is a ratio of the area under the concentration to the minimum inhibitory concentration ≥400–600 h*mg/L. This target can generally be achieved by a plasma concentration of 20–25 mg/L. Together with the pathophysiological alterations and pharmacokinetic variability associated with critical illness, the use of continuous renal replacement therapy (CRRT) may complicate the attainment of adequate vancomycin concentrations. The primary objective was the prevalence of attainment of vancomycin concentrations 20–25 mg/L after 24 h in adult ICU patients receiving CRRT. Secondary outcomes were to evaluate target attainment at days 2 and 3 and to calculate vancomycin clearance (CL) by CRRT and residual diuresis. Methods: We performed a prospective observational study in adult ICU patients on CRRT, which received at least 24 h continuous infusion of vancomycin. Between May 2020 and February 2021, daily vancomycin residual blood gas and dialysate samples were collected from 20 patients, every 6 h and if possible vancomycin urine samples. Vancomycin was analysed with an immunoassay method. The CL by CRRT was calculated by a different approach correcting for the downtime and providing insight into the degree of filter patency. Results: The proportion of patients with vancomycin concentrations <20 mg/L was 50% 24 h after starting vancomycin (n = 10). No differences were observed in patient characteristics. The target vancomycin concentration 20–25 mg/L was only achieved in 30% of the patients. On days 2 and 3, despite the use of TDM and albeit in lower percentages, sub- and supratherapeutic levels were still observed. Taking downtime and filter patency into account resulted in lower vancomycin CL. Conclusions: 50% of the studied ICU patients on CRRT showed subtherapeutic vancomycin concentrations 24 h after starting therapy. The results reveal that optimization of vancomycin dosage during CRRT therapy is needed.

The Stria Vascularis in Mice and Humans Is an Early Site of Age-Related Cochlear Degeneration, Macrophage Dysfunction, and Inflammation.

Age-related hearing loss, or presbyacusis, is a common degenerative disorder affecting communication and quality of life for millions of older adults. Multiple pathophysiologic manifestations, along with many cellular and molecular alterations, have been linked to presbyacusis; however, the initial events and causal factors have not been clearly established. Comparisons of the transcriptome in the lateral wall (LW) with other cochlear regions in a mouse model (of both sexes) of "normal" age-related hearing loss revealed that early pathophysiological alterations in the stria vascularis (SV) are associated with increased macrophage activation and a molecular signature indicative of inflammaging, a common form of immune dysfunction. Structure-function correlation analyses in mice across the lifespan showed that the age-dependent increase in macrophage activation in the stria vascularis is associated with a decline in auditory sensitivity. High-resolution imaging analysis of macrophage activation in middle-aged and aged mouse and human cochleas, along with transcriptomic analysis of age-dependent changes in mouse cochlear macrophage gene expression, support the hypothesis that aberrant macrophage activity is an important contributor to age-dependent strial dysfunction, cochlear pathology, and hearing loss. Thus, this study highlights the SV as a primary site of age-related cochlear degeneration and aberrant macrophage activity and dysregulation of the immune system as early indicators of age-related cochlear pathology and hearing loss. Importantly, novel new imaging methods described here now provide a means to analyze human temporal bones in a way that had not previously been feasible and thereby represent a significant new tool for otopathological evaluation.SIGNIFICANCE STATEMENT Age-related hearing loss is a common neurodegenerative disorder affecting communication and quality of life. Current interventions (primarily hearing aids and cochlear implants) offer imperfect and often unsuccessful therapeutic outcomes. Identification of early pathology and causal factors is crucial for the development of new treatments and early diagnostic tests. Here, we find that the SV, a nonsensory component of the cochlea, is an early site of structural and functional pathology in mice and humans that is characterized by aberrant immune cell activity. We also establish a new technique for evaluating cochleas from human temporal bones, an important but understudied area of research because of a lack of well-preserved human specimens and difficult tissue preparation and processing approaches.

P.064 Enhancing the neuroprotective properties of edaravone using glutathione nanogel as a promising carrier for brain drug delivery in transient global ischemia in a rodent model

Background: Edaravone (EDV) is an antioxidant that scavengs ROS, which is known to associate with pathophysiology of ischemic stroke. Low stability and bioavailability are major EDV drawbacks. Decorating nanogel surface with glutathione to target brain tissue was performed to optimize drug delivery. Methods: Nano vehicle characterization was assessed with FT-IR and HNMR. Images from the surface of nano vehicle was captured by AFM and TEM instruments. After development of mPEG-b-PLGA EDV nano particles, their effect on biochemical factors including malondialdehyde and protein carbonyl level was measured on Wistar rats under global ischemia. The level of GSH and FRAP were also measured. Results: The Size (199 nm, hydrodynamic diameter) and zeta potential (-25 mV) of optimum formulation was assessed and the calibration curve in deionized water was created at 244 nm. In-vitro drug release profile depicted a sustained release process. EDV and glutathione presence in one vehicle simultaneously, resulted in elevated spatial memory and learning along with cognitive function. In addition, significantly lower MDA and PCO, and higher level of neural GSH and FRAP were observed. Conclusions: The developed mPEG-b-PLGA EDV nanogel can be a suited vehicle for brain drug delivery of EDV, while managing to minimize the biochemical and pathophysiological alterations in ischemic-like disorder.

THE RELATIONSHIP BETWEEN ARTERIAL STIFFNESS, SUBCLINICAL HEART FAILURE, CARDIAC FIBROSIS AND RENAL FUNCTION IN CHRONIC KIDNEY DISEASE, IGA NEPHROPATHY

Objective: IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide. Arterial stiffness may predict cardiovascular (CV) mortality and morbidity in chronic kidney disease (CKD). Heart failure is very common in advanced CKD stages. Onset of myocardial fibrosis may be a pathophysiological alteration in CKD patients with heart failure. Design and method: In our cross-sectional study, we examined 90 patients who cared for IgAN in our clinic. Arterial stiffness was determined by measuring carotis-femoral pulse wave velocity (cfPWV) using the ShygmoCor device. N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and carboxy-terminal telopeptide of collagen type I (CITP) were measured using ELISA kits. Renal function was detected by the estimated glomerular filtration rate (eGFR-CKD-EPI). Furthermore, a routine echocardiography examination was performed. Results: Of the 90 patients included in the study, 50 were male, with a mean age of 54.9 ± 14.4 years. Patients were divided into two groups based on eGFR (CKD 1-2 and CKD 3-5). There were significantly higher NT-proBNP (p = 0.035), cfPWV (p = 0.004), and central aortic systolic pressure (p = 0.037), but not CITP, in the CKD 3-5 group. The number of patients with combined biomarker positivity (NT-proBNP and CITP) was also significantly higher in the CKD3-5 group (p = 0.035) compared to the CKD 1-2 group. The central aortic systolic pressure was significantly higher in the diastolic dysfunction group (p = 0.034), but the systolic blood pressure was not. eGFR and hemoglobin level showed a strong negative correlation, while left ventricular mass index (LVMI), aortic pulse pressure, central aortic systolic pressure, and cfPWV showed a positive correlation with NT-proBNP. cfPWV, aortic pulse pressure, and LVMI showed a strong positive correlation with CITP by Spearman's correlation. Only eGFR was an independent predictor of NT-proBNP by linear regression analysis. Conclusions: A possible mechanism for the development of heart failure in CKD patients may be an elevation of central aortic systolic pressure. NT-proBNP and CITP biomarkers may help to identify IgAN patients at high risk for subclinical heart failure and further atherosclerotic disease.

Black Seed Oil Improves Beef Fat-induced Blood-biochemical Abnormalities in Swiss Albino Mice

Background: The high saturated fatty acid content of beef has been linked to obesity and cardiovascular diseases. The study investigated the impact of black seed oil (BSO) on beef fat-altered hemato-biochemical and pathophysiological alterations in albino mice. Methods: Twenty four Swiss Albino mice (Mus musculus) of 25-28 days old were equally divided into three groups (n=8) namely A, B and C. Mice of group A was designated as the untreated control group. Groups B and C were fed pellets containing 10% beef fat and 10% BSO, respectively for 9 weeks. Result: The results revealed that beef fat-fed mice gained weight and BSO normalized the weight gain. The hematological values of beef fat supplemented mice improved after being supplemented with 10% BSO. LDL-c, Triglycerides and total cholesterol levels were all significantly lower in mice fed BSO plus beef fat. HDL-c levels were significantly higher in BSO plus beef fat-fed mice. Spleens in BSO plus beef fat-fed mice were slightly enlarged without gross abnormalities. 10% beef fat caused minor changes in the histostructures of the kidney, heart and liver. There were significant changes in cardiac muscle and massive fatty changes in kidney tissue. This study concluded that BSO has beneficial effects on the body and can prevent beef fat-induced abnormalities.

Adipocyte Na, K-ATPase Signaling Attenuates Experimental Uremic Cardiomyopathy.

Oxidative stress has been shown to cause an alteration of intracellular signaling in adipocytes that may lead to various comorbidities of obesity and cardiovascular complications. Evidence suggests that dysregulation of Na, K-ATPase signaling can contribute to systemic inflammation and redox signaling that leads to various metabolic disturbances. Hence the present study aims to explore the specific role of adipocyte Na, K-ATPase signaling in the amelioration of pathophysiological alterations of experimental uremic cardiomyopathy. Experimental uremic cardiomyopathy was induced by partial nephrectomy (PNx), and adipocyte-specific expression of NaKtide, a peptide that inhibits Na, K-ATPase signaling, was achieved using a lentivirus construct with NaKtide expression driven by an adiponectin promoter. Cardiomyopathy and anemia induced in partial nephrectomy mice were accompanied by an altered molecular phenotype of adipocytes, increased systemic inflammatory cytokines and oxidant stress within 4 weeks. These changes were significantly worsened by the addition of a Western diet (enriched in fat and fructose contents) but were prevented with specific expression of NaKtide in adipocytes. The skeletal muscle-specific expression of NaKtide did not ameliorate the disease phenotype. Adipocyte dysfunction and uremic cardiomyopathy developed in PNx mice, both were significantly ameliorated by the adipocyte-specific expression of NaKtide. These findings suggest that oxidative milieu in the adipocyte has a pivotal role in the development and progression of uremic cardiomyopathy in mice subjected to partial nephrectomy. If confirmed in humans, this may be a lead for future research to explore novel therapeutic targets in chronic renal failure.

Recognition and management of hemorrhaging in combination with emerging enterogenic sepsis during a hepatectomy: a case report

BackgroundPatients with hemorrhagic shock may develop emerging enterogenic sepsis due to damage to the intestinal mucosal barrier and translocation of intestinal bacteria and endotoxins caused by ischemic injury. Because of the dual effects of anesthesia state and hemorrhagic shock, perioperative emerging enterogenic sepsis is even more rare and insidious.Case presentationWe reported a case of 56-year-old man who underwent right hepatectomy for intrahepatic bile duct stones. Severe hemorrhage occurred during the procedure and the hemodynamics neither improved nor worsened after rehydration therapy and vasoactive drug administration. Based on the patient’s history and clinical presentation, a possible enterogenic sepsis was considered. After anti-infective treatment and hormone supplementation, the patient’s circulation improved significantly and he had an uneventful recovery.ConclusionThe possibility of emerging enterogenic sepsis in hemorrhagic shock must always be taken into consideration. Familiarity with the risk factors and pathophysiological alterations of enterogenic sepsis is a prerequisite for early recognition and sound clinical decision making.

Role of Sodium and Sodium Restriction in Heart Failure.

Sodium plays an essential role in the regulation of extracellular volume. The current review discusses the physiologic handling of sodium in the body, underscores pathophysiologic alterations in sodium handling in heart failure and assesses the evidence and rational for sodium restriction in heart failure. Recent trials such as the SODIUM-HF trial have failed to demonstrate a benefit of sodium restriction in heart failure. The current review re-evaluates physiologic elements in sodium handling and discusses how the intrinsic renal sodium avidity, which drives the renal propensity towards retaining sodium, differs amongst patients. The sodium intake in heart failure patients is often above the threshold set by guidelines. This review gives an overview of the pathophysiology of sodium retention in heart failure and the rational for sodium restriction and potential of individualizing sodium restriction recommendations based on renal sodium avidity profiles.

Regulatory role of the programmed cell death 1 signaling pathway in sepsis induced immunosuppression.

Sepsis is a multiple organ dysfunction syndrome caused by the host's immune response to infection, with extremely high incidence and mortality. Immunosuppression is an essential pathophysiological alteration that influences the clinical treatment and prognosis of sepsis. Recent studies have suggested that the programmed cell death 1 signaling pathway is involved in the formation of immunosuppression in sepsis. In this review, we systematically present the mechanisms of immune dysregulation in sepsis and elucidate the expression and regulatory effects of the programmed cell death 1 signaling pathway on immune cells associated with sepsis. We then specify current research developments and prospects for the application of the programmed cell death 1 signaling pathway in immunomodulatory therapy for sepsis. Several open questions and future research are discussed at the end.

Pipeline for precise insoluble matrisome coverage in tissue extracellular matrices.

The extracellular matrix (ECM) is assembled by hundreds of proteins orchestrating tissue patterning and surrounding cell fates via the mechanical-biochemical feedback loop. Aberrant ECM protein production or assembly usually creates pathological niches eliciting lesions that mainly involve fibrogenesis and carcinogenesis. Yet, our current knowledge about the pathophysiological ECM compositions and alterations in healthy or diseased tissues is limited since the methodology for precise insoluble matrisome coverage in the ECM is a "bottleneck." Our current study proposes an enhanced sodium dodecyl sulfonate (E-SDS) workflow for thorough tissue decellularization and an intact pipeline for the accurate identification and quantification of highly insoluble ECM matrisome proteins. We tested this pipeline in nine mouse organs and highlighted the full landscape of insoluble matrisome proteins in the decellularized ECM (dECM) scaffolds. Typical experimental validations and mass spectrometry (MS) analysis confirmed very little contamination of cellular debris remaining in the dECM scaffolds. Our current study will provide a low-cost, simple, reliable, and effective pipeline for tissue insoluble matrisome analysis in the quest to comprehend ECM discovery proteomic studies.

Pathophysiological mechanisms of reduced physical activity: Insights from the human step reduction model and animal analogues.

Physical inactivity represents a heavy burden for modern societies and is spreading worldwide, it is a recognised pandemic and is the fourth cause of global mortality. Not surprisingly, there is an increasing interest in longitudinal studies on the impact of reduced physical activity on different physiological systems. This narrative review focuses on the pathophysiological mechanisms of step reduction (SR), an experimental paradigm that involves a sudden decrease in participants' habitual daily steps to a lower level, mimicking the effects of a sedentary lifestyle. Analogous animal models of reduced physical activity, namely, the "wheel-lock" and the "cage reduction" models, which can provide the foundation for human studies, are also discussed. The empirical evidence obtained thus far shows that even brief periods of reduced physical activity can lead to substantial alterations in skeletal muscle health and metabolic function. In particular, decrements in lean/muscle mass, muscle function, muscle protein synthesis, cardiorespiratory fitness, endothelial function and insulin sensitivity, together with an increased fat mass and inflammation, have been observed. Exercise interventions seem particularly effective for counteracting these pathophysiological alterations induced by periods of reduced physical activity. A direct comparison of SR with other human models of unloading, such as bed rest and lower limb suspension/immobilisation, is presented. In addition, we propose a conceptual framework aiming to unravel the mechanisms of muscle atrophy and insulin resistance in the specific context of reduced ambulatory activity. Finally, methodological considerations, knowledge gaps and future directions for both animal and human models are also discussed in the review.

Changes in the cochlear and retrocochlear parts of the auditory system in 19-39 and 40-60 years old patients with type 1 diabetes mellitus.

Pathophysiological alterations in the cochlea and functional tests of the auditory pathway support that in diabetes both vasculopathy and neural changes could be present. The aim of our research was to study the differential effect of type 1 diabetes mellitus (T1DM) on two different age groups. Audiological investigation was carried out in 42 patients and 25 controls at the same age groups. Investigation of the conductive and sensorineural part of the hearing system by pure tone audiometry, distortion product otoacoustic emission measurement and acoustically evoked brainstem response registration were evaluated. Among the 19-39-year-old people the incidence of hearing impairment was not different in the diabetes and control groups. Among the 40-60-year-old people hearing impairment was more common in the diabetes group (75%) than in the control group (15,4%). Among patients with type 1 diabetes, the mean threshold values were higher in both age groups at all frequencies although significant difference was in 19-39 years old group: 500-4000Hz right ear, 4000Hz left ear, in 40-60 years old group: 4000-8000 Hz both ears. In the 19-39 years old diabetes group only at 8000 Hertz on the left side was a significant (p<0,05) difference in otoacoustic emissions. In the 40-60 years old diabetes group significantly less otoacoustic emissions at 8000 Hz on the right side (p<0,01) and at 4000-6000-8000 Hertz on the left side, (p<0,05, p<0,01, p<0,05 respectively) was present compared to the control group. According to ABR (auditory brainstem response) latencies and wave morphologies, a possible retrocochlear lesion arose in 15% of the 19-39 years old and 25% of the 40-60 years old diabetes group. According to our results, T1DM affects negatively the cochlear function and the neural part of the hearing system. The alterations are more and more detectable with aging.

P274 LEFT ATRIAL STRAIN RESPONSE TO HEART RATE IN PATIENTS AFFECTED OR NOT BY CHRONIC HEART FAILURE: CLINICAL CORRELATES

Abstract Background and aim of the study. Left atrium (LA) is poorly understood in many pathological conditions and it is often considered a passive bystander of these pathophysiologic alterations. In the setting of impaired heart rate related LV response, the LA function could play a relevant role. The relevance of LA has been also recently demonstrated by studies which have evaluated its function by using new echocardiographic techniques such as two–dimensional speckle tracking evaluation (2D–STE). The aim of this study was to evaluate the relationship between changes in LV and LA function, assessed by 2D–STE, in response to the increase of heart rate (HR) in a group of patients carrying a pacemaker (PM) or an implantable cardioverter defibrillator (ICD). Methods We enrolled 45 patients. Among them, 38 were evaluated with LA strain. 31 patients were affected by CHF, among whom 18 with implanted cardioverter defibrillator (ICD), 13 with ICD and cardiac resynchronization therapy (ICD–CRT) and 7 without CHF who had a PM implanted. All were in clinically stable conditions for at least 30 days and in conventional medical therapy. Starting from basal values, HR was increased by 10 beats/min programming the implantable devices at higher atrial stimulation frequencies to max 90 beats/min. At each HR, echocardiography was performed and for left atrium the strain of reservoir (LAr), strain of conduit (LAcd) and contraction (LAct) were calculated (figure 1). Changes in left ventricle global longitudinal strain (LVGLS) were also calculated. Results The LAr shows a significant reduction from baseline at a heart rate of 90 bpm in conjunction with a significant change in the LAcd. No variation in LAct was observed at the various frequencies. Among the 38 patients, 29 showed a worsening of LVGLS and 9 no worsening with increasing heart rate. We demonstrated a close relationship between LV and LA function assessed by longitudinal strain measures (figure 2). A significant decrease in LAr was observed in patients with worsening LV–GLS that was not evident in patients with no or improvement. Conclusions Our study demonstrates that, in chronic HF outpatients, HR increase has different and heterogeneous effects on the LA function, assessed by STI and this response is more frequent among patients with LV systolic dysfunction. These results could be useful for guiding the optimal heart rate responsiveness of the implanted devices.