scholarly journals Pathology of Bioabsorbable Implants in Preclinical Studies

2019 ◽  
Vol 47 (3) ◽  
pp. 358-378 ◽  
Author(s):  
Serge D. Rousselle ◽  
Yuval Ramot ◽  
Abraham Nyska ◽  
Nicolette D. Jackson
Keyword(s):  
Tissue Repair ◽  
Animal Studies ◽  
Structural Strength ◽  
Cellular Responses ◽  
Study Data ◽  
Gradual Decline ◽  
Bioabsorbable Implants ◽  
Drug Elution ◽  
Different Types ◽  
Pathology Data

Bioabsorbable implants can be advantageous for certain surgical tissue bioengineering applications and implant-assisted tissue repair. They offer the obvious benefits of nonpermanence and eventual restoration of the native tissue’s biomechanical and immunological properties, while providing a structural scaffold for healing and a route for additional therapies (i.e., drug elution). They present unique developmental, imaging, and histopathological challenges in the conduct of preclinical animal studies and in interpretation of pathology data. The bioabsorption process is typically associated with a gradual decline (over months to years) in structural strength and integrity and may also be associated with cellular responses such as phagocytosis that may confound interpretation of efficacy and safety end points. Additionally, as these implants bioabsorb, they become increasingly difficult to isolate histologically and thus imaging modalities such as microCT become very valuable to determine the original location of the implants and to assess the remodeling response in tandem with histopathology. In this article, we will review different types of bioabsorbable implants and commonly used bioabsorbable materials; additionally, we will address some of the most common challenges and pitfalls confronting histologists and pathologists in collecting, handling, imaging, preparing tissues through histology, evaluating, and interpreting study data associated with bioabsorbable implants.

Are Improvements in Assessment Center Construct-Related Validity Paralleled by Improvements in Criterion-Related Validity?

2014 ◽  
Vol 13 (4) ◽  
pp. 184-193 ◽  
Author(s):  
Andreja Wirz ◽  
Klaus G. Melchers ◽  
Stefan Schultheiss ◽  
Martin Kleinmann
Keyword(s):  
Convergent Validity ◽  
Study Data ◽  
Assessment Center ◽  
Beneficial Effects ◽  
Single Study ◽  
Different Types

Previous studies have found that factors that improved assessment center (AC) construct-related validity also had beneficial effects on criterion-related validity. However, some factors might have diverging effects on construct- and criterion-related validity. Accordingly, we followed recent calls to evaluate construct- and criterion-related validity of ACs simultaneously by examining the effects of exercise similarity on both aspects of validity within a single study. Data were collected in an AC (N = 92) that consisted of two different types of exercises. Convergent validity was better for similar exercises than it was for dissimilar exercises. However, regarding criterion-related validity, we did not find differences between similar and dissimilar exercises. Hence, this study revealed that improvements in AC construct-related validity are not necessarily paralleled by improvements in criterion-related validity.

scholarly journals Effects of Polyphenols in Tea (Camellia sinensis sp.) on the Modulation of Gut Microbiota in Human Trials and Animal Studies

2021 ◽  
Vol 12 (2) ◽  
pp. 202-216
Author(s):  
Mus Azza Suhana Khairudin ◽  
Abbe Maleyki Mhd Jalil ◽  
Napisah Hussin
Keyword(s):  
Gut Microbiota ◽  
Beta Diversity ◽  
Animal Studies ◽  
Tea Polyphenols ◽  
Microbiota Composition ◽  
Polyphenol Compounds ◽  
Human Trials ◽  
Diet Induced Obesity ◽  
Different Types ◽  
Meta Analyses

A diet high in polyphenols is associated with a diversified gut microbiome. Tea is the second most consumed beverage in the world, after water. The health benefits of tea might be attributed to the presence of polyphenol compounds such as flavonoids (e.g., catechins and epicatechins), theaflavins, and tannins. Although many studies have been conducted on tea, little is known of its effects on the trillions of gut microbiota. Hence, this review aimed to systematically study the effect of tea polyphenols on the stimulation or suppression of gut microbiota in humans and animals. It was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Articles were retrieved from PubMed and Scopus databases, and data were extracted from 6 human trials and 15 animal studies. Overall, large variations were observed in terms of microbiota composition between humans and animals. A more consistent pattern of diversified microbiota was observed in animal studies. Tea alleviated the gut microbiota imbalance caused by high-fat diet-induced obesity, diabetes, and ultraviolet-induced damage. The overall changes in microbiota composition measured by beta diversity analysis showed that tea had shifted the microbiota from the pattern seen in animals that received tea-free intervention. In humans, a prebiotic-like effect was observed toward the gut microbiota, but these results appeared in lower-quality studies. The beta diversity in human microbiota remains intact despite tea intervention; supplementation with different teas affects different types of bacterial taxa in the gut. These studies suggest that tea polyphenols may have a prebiotic effect in disease-induced animals and in a limited number of human interventions. Further intervention is needed to identify the mechanisms of action underlying the effects of tea on gut microbiota.

scholarly journals Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

2020 ◽  
Author(s):  
Peter Everts ◽  
Kentaro Onishi ◽  
Prathap Jayaram ◽  
José Fábio Lana ◽  
and Kenneth Mautner
Keyword(s):  
Tissue Repair ◽  
Animal Studies ◽  
Platelet Rich Plasma ◽  
Unmet Need ◽  
Treatment Protocols ◽  
Rehabilitation Protocols ◽  
Recent Developments ◽  
Treatment Plans ◽  
New Research

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

scholarly journals Pathology Study Design, Conduct, and Reporting to Achieve Rigor and Reproducibility in Translational Research Using Animal Models

ILAR Journal ◽  
2018 ◽  
Vol 59 (1) ◽  
pp. 4-12 ◽  
Author(s):  
Jeffrey I Everitt ◽  
Piper M Treuting ◽  
Cheryl Scudamore ◽  
Rani Sellers ◽  
Patricia V Turner ◽  
...  
Keyword(s):  
Animal Models ◽  
Best Practices ◽  
Translational Research ◽  
Safety Assessment ◽  
Animal Studies ◽  
Animal Experiments ◽  
Study Data ◽  
Track Record ◽  
Preclinical Animal Models

AbstractIn translational research, animal models are an important tool to aid in decision-making when taking potential therapies into human clinical trials. Recently, there have been a number of papers that have suggested limited concordance of preclinical animal experiments with subsequent human clinical experience. Assessments of preclinical animal studies have led to concerns about the reproducibility of data and have highlighted the need for an emphasis on rigor and quality in the planning, conduct, analysis, and reporting of such studies. The incorporation of a wider role for the comparative pathologist using pathology best practices in the planning and conduct of animal model-based research is one way to increase the quality and reproducibility of data. The use of optimal design and planning of tissue collection, incorporation of pathology methods into written protocols, conduct of pathology procedures using accepted best practices, and the use of optimal pathology analysis and reporting methods enhance the quality of the data acquired from many types of preclinical animal models and studies. Many of these pathology practices are well established in the discipline of toxicologic pathology and have a proven and useful track record in enhancing the data from animal-based studies used in safety assessment of human therapeutics. Some of this experience can be adopted by the wider community of preclinical investigators to increase the reproducibility of animal study data.

scholarly journals Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020

2020 ◽  
Vol 21 (20) ◽  
pp. 7794
Author(s):  
Peter Everts ◽  
Kentaro Onishi ◽  
Prathap Jayaram ◽  
José Fábio Lana ◽  
Kenneth Mautner
Keyword(s):  
Tissue Repair ◽  
Animal Studies ◽  
Platelet Rich Plasma ◽  
Unmet Need ◽  
Treatment Protocols ◽  
Rehabilitation Protocols ◽  
Recent Developments ◽  
Treatment Plans ◽  
New Research

Emerging autologous cellular therapies that utilize platelet-rich plasma (PRP) applications have the potential to play adjunctive roles in a variety of regenerative medicine treatment plans. There is a global unmet need for tissue repair strategies to treat musculoskeletal (MSK) and spinal disorders, osteoarthritis (OA), and patients with chronic complex and recalcitrant wounds. PRP therapy is based on the fact that platelet growth factors (PGFs) support the three phases of wound healing and repair cascade (inflammation, proliferation, remodeling). Many different PRP formulations have been evaluated, originating from human, in vitro, and animal studies. However, recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, progress has been made in understanding PRP technology and the concepts for bioformulation, and new research directives and new indications have been suggested. In this review, we will discuss recent developments regarding PRP preparation and composition regarding platelet dosing, leukocyte activities concerning innate and adaptive immunomodulation, serotonin (5-HT) effects, and pain killing. Furthermore, we discuss PRP mechanisms related to inflammation and angiogenesis in tissue repair and regenerative processes. Lastly, we will review the effect of certain drugs on PRP activity, and the combination of PRP and rehabilitation protocols.

scholarly journals Cellular Responses to Proteasome Inhibition: Molecular Mechanisms and Beyond

2019 ◽  
Vol 20 (14) ◽  
pp. 3379 ◽  
Author(s):  
Nicolas Albornoz ◽  
Hianara Bustamante ◽  
Andrea Soza ◽  
Patricia Burgos
Keyword(s):  
Side Effects ◽  
Inclusion Bodies ◽  
Molecular Mechanisms ◽  
Proteasome Inhibitors ◽  
Proteasome Inhibition ◽  
Cellular Responses ◽  
Cell Responses ◽  
Different Types ◽  
Inflammatory Processes

Proteasome inhibitors have been actively tested as potential anticancer drugs and in the treatment of inflammatory and autoimmune diseases. Unfortunately, cells adapt to survive in the presence of proteasome inhibitors activating a variety of cell responses that explain why these therapies have not fulfilled their expected results. In addition, all proteasome inhibitors tested and approved by the FDA have caused a variety of side effects in humans. Here, we describe the different types of proteasome complexes found within cells and the variety of regulators proteins that can modulate their activities, including those that are upregulated in the context of inflammatory processes. We also summarize the adaptive cellular responses activated during proteasome inhibition with special emphasis on the activation of the Autophagic-Lysosomal Pathway (ALP), proteaphagy, p62/SQSTM1 enriched-inclusion bodies, and proteasome biogenesis dependent on Nrf1 and Nrf2 transcription factors. Moreover, we discuss the role of IRE1 and PERK sensors in ALP activation during ER stress and the involvement of two deubiquitinases, Rpn11 and USP14, in these processes. Finally, we discuss the aspects that should be currently considered in the development of novel strategies that use proteasome activity as a therapeutic target for the treatment of human diseases.

The morphological and functional development of the stria vascularis in miniature pigs

2017 ◽  
Vol 29 (3) ◽  
pp. 585 ◽  
Author(s):  
Weiwei Guo ◽  
Haijin Yi ◽  
Zhang Yan ◽  
Lili Ren ◽  
Lei Chen ◽  
...  
Keyword(s):  
Animal Studies ◽  
Stria Vascularis ◽  
Organ Of Corti ◽  
Lateral Wall ◽  
Cell Types ◽  
Endocochlear Potential ◽  
Miniature Pigs ◽  
Functional Development ◽  
Transmission Electron ◽  
Different Types

The purpose of this study was to examine the morphological and functional development of the lateral wall of the scala media of the cochlea in miniature pigs; light and transmission electron microscopy and electrophysiology were used for this purpose. We showed that the lateral wall of the scala media of the cochlea appears at embryonic Day 21 (E21) when the cochlear duct begins to form. From E28 to E49, the lateral wall can be distinguished according to its position along the cochlea. At E56, cells in the lateral wall begin to differentiate into three different types. At E70, three cell types, marginal, intermediate and basal, can be clearly distinguished. At E91, the stria vascularis is adult-like and the organ of Corti is also morphologically mature. The average endocochlear potential measured from the second turn of the cochlea (at E98, postnatal Day 1 (P1), P13 and P30) was 71.4 ± 2.5 (n = 7), 78.8 ± 1.5 (n = 10), 77.3 ± 2.3 (n = 10) and 78.0 ± 2.1 mV (n = 10), respectively. Our results suggest that in miniature pigs the stria vascularis develops during the embryonic period, concurrent with maturation of the organ of Corti. The magnitude of the endocochlear potential reached its mature level when the stria vascularis was morphologically adult-like at E98. These findings provide a morphological and functional basis for future animal studies using the miniature pig model concerning the pathogenesis of various inner-ear diseases.

scholarly journals Evacuation solutions for individuals with functional limitations in the built environment: a scoping review protocol

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Brad W. R. Roberts ◽  
Abdulrahman Al Bochi ◽  
Mark Weiler ◽  
Yashoda Sharma ◽  
Cesar Marquez-Chin ◽  
...  
Keyword(s):  
Built Environment ◽  
Scoping Review ◽  
Data Extraction ◽  
Functional Limitations ◽  
Open Science ◽  
Included Study ◽  
Study Data ◽  
Different Types ◽  
Review Protocol ◽  
Science Framework

Abstract Background Whether due to aging, disability, injury, or other circumstances, an increasing number of Canadians experience functional limitations that reduce their ability to participate in activities of daily life. While the built environment has become increasingly accessible, existing Canadian evacuation guidelines lack comprehensive strategies for evacuating individuals with functional limitations from buildings during emergencies. To inform guideline revisions, a map of existing solutions for evacuating such individuals is required. Therefore, this scoping review aims to provide an account of solutions that have been reported to safely evacuate individuals with functional limitations from the built environment. Methods We will conduct a scoping review using the Arksey and O’Malley methodological framework. To identify potentially relevant studies, comprehensive searches (from January 2002 onwards) of the CINAHL, Ei Compendex, Inspec, Embase, MEDLINE, KCI, RSCI, SciELO CI, Web of Science Collection, and Scopus databases will be performed. Using a set of inclusion and exclusion criteria, two reviewers will independently (1) classify identified studies as relevant, irrelevant, or maybe relevant by evaluating their titles and abstracts and (2) classify the relevant and maybe relevant studies as included or excluded by evaluating their full-text. From each included study, data on publication information, study purpose, methodological details, evacuation information, and outcomes will be extracted using a set of data extraction items. We will present a numerical summary of the key characteristics of the included studies. For each evacuation activity, reported evacuation solutions will be summarized, and citations provided for functional limitations that are targeted by a given evacuation solution. To inform Canadian evacuation guideline revisions, we will tabulate evacuation activities common to different types of buildings and emergencies. Discussion To our knowledge, this will be the first scoping review to identify the state and use of solutions for evacuating individuals with functional limitations from the built environment. Identifying solutions that enable all individuals to safely evacuate from different types of buildings will allow us to inform recommendations for the revision of evacuation guidelines in Canada and other jurisdictions. The findings of this scoping review will be published in a peer-reviewed journal, presented at relevant conferences, and made publicly available on the internet. Systematic review registration Open Science Framework: osf.io/jefgy

scholarly journals Advances in biomineralization-inspired materials for hard tissue repair

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Shuxian Tang ◽  
Zhiyun Dong ◽  
Xiang Ke ◽  
Jun Luo ◽  
Jianshu Li
Keyword(s):  
Tissue Repair ◽  
Bone Repair ◽  
Hierarchical Structures ◽  
Hard Tissue ◽  
Future Directions ◽  
Artificial Materials ◽  
Mineral Phases ◽  
Different Types ◽  
Mineralized Tissues ◽  
Underlying Mechanisms

AbstractBiomineralization is the process by which organisms form mineralized tissues with hierarchical structures and excellent properties, including the bones and teeth in vertebrates. The underlying mechanisms and pathways of biomineralization provide inspiration for designing and constructing materials to repair hard tissues. In particular, the formation processes of minerals can be partly replicated by utilizing bioinspired artificial materials to mimic the functions of biomolecules or stabilize intermediate mineral phases involved in biomineralization. Here, we review recent advances in biomineralization-inspired materials developed for hard tissue repair. Biomineralization-inspired materials are categorized into different types based on their specific applications, which include bone repair, dentin remineralization, and enamel remineralization. Finally, the advantages and limitations of these materials are summarized, and several perspectives on future directions are discussed.

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