Human Tissue Processing Research Articles

Smart Bandaid Integrated with Fully Textile OECT for Uric Acid Real-Time Monitoring in Wound Exudate

Hard-to-heal wounds (i.e., severe and/or chronic) are typically associated with particular pathologies or afflictions such as diabetes, immunodeficiencies, compression traumas in bedridden people, skin grafts, or third-degree burns. In this situation, it is critical to constantly monitor the healing stages and the overall wound conditions to allow for better-targeted therapies and faster patient recovery. At the moment, this operation is performed by removing the bandages and visually inspecting the wound, putting the patient at risk of infection and disturbing the healing stages. Recently, new devices have been developed to address these issues by monitoring important biomarkers related to the wound health status, such as pH, moisture, etc. In this contribution, we present a novel textile chemical sensor exploiting an organic electrochemical transistor (OECT) configuration based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) for uric acid (UA)-selective monitoring in wound exudate. The combination of special medical-grade textile materials provides a passive sampling system that enables the real-time and non-invasive analysis of wound fluid: UA was detected as a benchmark analyte to monitor the health status of wounds since it represents a relevant biomarker associated with infections or necrotization processes in human tissues. The sensors proved to reliably and reversibly detect UA concentration in synthetic wound exudate in the biologically relevant range of 220-750 μM, operating in flow conditions for better mimicking the real wound bed. This forerunner device paves the way for smart bandages integrated with real-time monitoring OECT-based sensors for wound-healing evaluation.

Vitamin D Deficiency-Associated Comorbidities: A Protein Network Dynamics Perspective

Vitamin D deficiency has been linked to numerous comorbid diseases. Despite this recognition, the effectiveness of vitamin D supplementation in improving clinical outcomes remains uncertain. To shed light on the underlying cause-effect relationships and molecular mechanisms involved, we analyzed effects of over 4000 diseases on information transfers between biological processes in human tissues. Spectral clustering of the data generated identified relationships between disease phenotypes and perturbations of protein network-network interactions mediating information transfers in tissues. Examination of these relationships discovered an integrated regulatory scheme involving interactions between 188 proteins responsive to vitamin D (vitamin D interactome). Functional analysis established a central role of fifteen proteins (core vitamin D interactome) in vitamin D pharmacology and their involvement in multiple reciprocal feedback loops. Identification of functions affected by this core regulatory framework provides new insights into relationships between vitamin D deficiency-associated comorbidities, epigenetic regulation of vitamin D pharmacology, and impact of mutations on disease. Recognition of these functional relationships suggests that vitamin D associated comorbidities may not be fully treatable by vitamin D supplementation alone. Further examination of consequences of perturbations of protein interactions within the core vitamin D interactome identified 590 morbidities exhibiting physical changes co-expressed in vitamin D deficiency. Further analysis revealed that these comorbidities can be differentiated based on cause-effect relationships defined by characteristic patterns of physical abnormalities and effects on protein network interactions. These findings demonstrate the utility of systems biology-based cause-effect analyses to unravel complex relationships involving multiple diseases and multiple biological processes; thereby providing a more comprehensive understanding of comorbidities and the impact of vitamin D deficiency on health. Article Details How to Cite

Longitudinal and Transverse Relaxivity Analysis of Native Ferritin and Magnetoferritin at 7 T MRI.

Magnetite mineralization in human tissue is associated with various pathological processes, especially neurodegenerative disorders. Ferritin’s mineral core is believed to be a precursor of magnetite mineralization. Magnetoferritin (MF) was prepared with different iron loading factors (LFs) as a model system for pathological ferritin to analyze its MRI relaxivity properties compared to those of native ferritin (NF). The results revealed that MF differs statistically significantly from NF, with the same LF, for all studied relaxation parameters at 7 T: r1, r2, r2*, r2/r1, r2*/r1. Distinguishability of MF from NF may be useful in non-invasive MRI diagnosis of pathological processes associated with iron accumulation and magnetite mineralization (e.g., neurodegenerative disorders, cancer, and diseases of the heart, lung and liver). In addition, it was found that MF samples possess very strong correlation and MF’s relaxivity is linearly dependent on the LF, and the transverse and longitudinal ratios r2/r1 and r2*/r1 possess complementary information. This is useful in eliminating false-positive hypointensive artefacts and diagnosis of the different stages of pathology. These findings could contribute to the exploitation of MRI techniques in the non-invasive diagnosis of iron-related pathological processes in human tissue.

Unravelling the Role of MAPKs (ERK1/2) in Venous Reflux in Patients with Chronic Venous Disorder

Chronic venous disorder (CVeD), is a disorder in which there is a modification in the conditions of blood return to the heart. The disorder may arise from incompetent valves and the resultant venous reflux (chronic venous insufficiency, CVI). The economic burden of CVeD on health systems is high, and research efforts have sought to elucidate the mechanisms involved as possible therapeutic targets. The mitogen-activated protein kinase (MAPK) enzymes mediate a wide array of physiopathological processes in human tissues. In this family of proteins, extracellular signal-regulated kinase (ERK)1/2 plays a direct role in the cell homeostasis that determines the viability of mammalian tissues. This study sought to examine whether ERK1/2 plays a role in venous reflux. This was a prospective study performed on 56 participants including 11 healthy controls. Of the CVeD patients, 23 had venous reflux with CVI (CVI-R) and 22 had no reflux (NR). Distribution by age was: controls <50 years (n = 4) and ≥50 years (n = 7); NR <50 years (n = 9) and ≥50 years (n = 13); CVI-R <50 years (n = 11) and ≥50 years (n = 12). Great saphenous vein specimens were subjected to gene (real-time polymerase chain reaction, RT-qPCR) and protein (immunohistochemistry, IHC) expression techniques to identify ERK1/2. Data was compared between groups using the Mann Whitney U test. Patients with CVI showed significant gene activation of ERK1/2 protein, and, in those with venous reflux, the expression of this gene was significantly greater. The CVI-R group <50 years showed significantly greater ERK1/2 gene expression than their age-matched controls. Expression patterns were consistent with IHC findings. Our studies suggest that ERK1/2 expression is involved in venous vascular disease.

IL-13–induced intestinal secretory epithelial cell antigen passages are required for IgE-mediated food-induced anaphylaxis

Food-induced anaphylaxis (FIA) is an IgE-dependent immune response that can affect multiple organs and lead to life-threatening complications. The processes by which food allergens cross the mucosal surface and are delivered to the subepithelial immune compartment to promote the clinical manifestations associated with food-triggered anaphylaxis are largely unexplored. We sought to define the processes involved in the translocation of food allergens across the mucosal epithelial surface to the subepithelial immune compartment in FIA. Two-photon confocal and immunofluorescence microscopy was used to visualize and trace food allergen passage in a murine model of FIA. Ahuman colon cancer cell line, RNA silencing, and pharmacologic approaches were used to identify the molecular regulation of intestinal epithelial allergen uptake and translocation. Human intestinal organoid transplants were used to demonstrate the conservation of these molecular processes in human tissues. Food allergens are sampled by using small intestine (SI) epithelial secretory cells (termed secretory antigen passages [SAPs]) that are localized to the SI villous and crypt region. SAPs channel food allergens to lamina propria mucosal mast cells through an IL-13-CD38-cyclic adenosine diphosphate ribose (cADPR)-dependent process. Blockade of IL-13-induced CD38/cADPR-dependent SAP antigen passaging in mice inhibited induction of clinical manifestations of FIA. IL-13-CD38-cADPR-dependent SAP sampling of food allergens was conserved in human intestinal organoids. We identify that SAPs are a mechanism by which food allergens are channeled across the SI epithelium mediated by the IL-13/CD38/cADPR pathway, regulate the onset of FIA reactions, and are conserved in human intestine.

Comparison of different human tissue processing methods for maximization of bacterial recovery

Tissues are valuable microbiological samples that have proved superiority over swabs. Culture of tissue samples is used in the diagnosis of a variety of infections. However, as well as factors such as the site of obtaining the sample, the number of samples, and previous antibiotic use, the method of tissue processing may have an important effect on sensitivity. Data from the literature comparing different tissue processing methods is very limited. This study aimed to compare different mechanical and chemical methods of tissue processing in terms of efficacy and retaining the viability of the bacteria in the tissues. Standard suspensions of Staphylococcus aureus and Escherichia coli were prepared and treated differently to test the effect of that treatment on bacterial viability. Artificially inoculated pork tissue and known infected human tissue samples were then processed by different methods prior to culture, and results were compared. Percentages of reduction in the number of viable bacteria compared to the control by homogenization was similar to 5-min dithiothreitol treatment but significantly lower than bead beating. Bacterial recovery from homogenized human tissues was significantly higher than from any other method of treatment. Although bead beating could be the most efficient method in obtaining a homogeneous tissue product, it significantly reduces the number of viable bacteria within tissues. Homogenization offers the most effective easily controllable retrieval of bacteria from tissue and retains their viability. Guidelines for diagnosing infections using tissue samples should include a standardized processing method.

The Effects of the Thoracoabdominal Aortic Metabolism on the Endovascular Procedures Outcomes

Aortic metabolism is a merge of complex processes. Atherosclerotic infiltration of the aortic wall is a crucial factor when choosing an appropriate endovascular treatment modality for anatomically suitable patients. Due to the rise of endovascular treatments and placement of endovascular devices in younger patients, many physicians are starting to take a more considerable interest in this complex process. Many experimental animal models are used for elucidation of individual aspects in this area. This led to an in-depth explanation of many metabolic processes of the aortic wall. However, only a few papers are reporting on the assessment of these pathological processes in human tissues. This paper outlines some of the crucial aspects of the thoracoabdominal aortic metabolism. Final results of endovascular treatments are believed to be significantly affected by the quality of the aortic wall and the ability to predict its further changes. This includes the pathological changes and their effects on the symbiotic metabolic changes. “Patient-tailored” endovascular aortic treatments based on the aortic metabolic assessment may be able to optimise the cases outcomes. Due to the rise of endovascular treatments and placement of endovascular devices in younger patients, further research is needed to understand better aortic metabolic processes in various patient groups, including groups of patients suffering from chronic metabolic diseases. Aortic wall metabolism should be assessed with the aim to optimise the endovascular treatment outcomes.

New material for orthopedic implants: Electrochemical study of nickel free P558 stainless steel in minimum essential medium

Nickel, a component of stainless steels (SS) applied in orthopedic implants may cause allergic processes in human tissues. P558 nickel free SS was studied to verify its viability as a substitute for stainless steel containing nickel. Its performance is compared to ISO 5832-9 and F138 most used nowadays grades in implants fabrications, in minimum essential medium, MEM, at 37 °C. Potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and “in vitro” cytotoxicity were used as techniques. From the electrochemical point of view P558 SS is comparable to ISO 5832-9 SS in MEM. It remains passivated until the transpassivation potential, above which generalized corrosion occurs. F138 presents pitting corrosion at 370 mV/SCE. The cytotoxicity results showed that P558, ISO 5832-9 and F138 do not present cytotoxic character. Therefore, these results suggest that P558 SS can be applied in orthopedic implants.

Cell-Bound IL-8 Increases in Bronchial Epithelial Cells after Arylsulfatase B Silencing due to Sequestration with Chondroitin-4-Sulfate

The chemokine IL-8 is critically important in inflammatory processes in human tissues, and IL-8 interactions with sulfated glycosaminoglycans have been implicated in modification of inflammatory responses in bronchial epithelium. To determine the role of chondroitin-4-sulfate (C4S) in mediating effects of IL-8, we silenced the enzyme N-acetylgalactosamine-4-sulfatase (arylsulfatase B [ASB]) that removes the 4-sulfate group from C4S, in the IB3-1 and C38 bronchial epithelial cell lines and in normal primary bronchial epithelial cells. When ASB was silenced and IL-8 production stimulated by exposure to TNF-alpha, ASB activity declined by roughly 75%, cellular C4S content increased by over 7.5 microg/mg protein, cell-bound IL-8 increased by over 530 pg/mg protein, and secreted IL-8 declined by over 520 pg/mg protein in all cell lines (P < 0.001). When cell lysates were immunoprecipitated with C4S antibody after ASB silencing and TNF-alpha, the IL-8 content of the immunoprecipitate was approximately 500 pg/mg protein, indicating that most of the cell-bound IL-8 was associated with C4S. Cell fractionation demonstrated that the IL-8 content associated with the cell membranes was about twice that of the cytosolic fraction. Also, ASB appeared to localize in the cell membrane, as well as in lysosomes. Neutrophil attraction to the cell lysates increased after ASB silencing, consistent with increased attraction to the cell-bound IL-8. These findings provide evidence for the influential role of ASB and C4S in the regulation of IL-8 secretion, and suggest that changes in ASB activity and C4S content may have a significant impact on IL-8-mediated inflammatory responses.

Oligonucleotide microarray expression profiling: Human skeletal muscle phenotype and aerobic exercise training

Regular aerobic exercise reduces risk of cardiovascular disease far more effectively than any pharmaceutical agent. The precise mechanisms contributing to these health benefits are unknown. Currently, much of our knowledge regarding the molecular regulators of skeletal muscle phenotype remodeling in response to muscle activity is derived from rodent models. Over the past five years large scale gene analysis has emerged as a promising research strategy for studying complex processes in human tissue. This review will principally discuss the application of large scale gene expression profiling to study the molecular responses to longitudinal aerobic exercise training studies in humans. The focus is largely on the Affymetrix technology platform, as this can be most easily compared, in a quantitative manner, across laboratories. Indeed, there are compelling reasons to adopt a common standard to obtain maximum synergy across complex, expensive and invasive human studies. Direct comparisons between array data sets can be made, and these should be considered novel 'experiments', often providing great insight into disease mechanisms. Weaknesses in existing human studies are identified and future objectives are discussed.

Processing of human tissue to establish primary cultures in vitro

Processing of human tissue to establish primary cultures in vitro