Follow-up testing of borderline SARS-CoV-2 patients by rRT-PCR allows early diagnosis of COVID-19.

Detection of SARS-CoV-2 RNA in nasopharyngeal samples using the real-time reverse transcription polymerase chain reaction (rRT-PCR) is the gold standard for diagnosing COVID-19. Determination of SARS-CoV-2 RNA by rRT-PCR sometimes results in an inconclusive test result due to a high cycle threshold-value. We retrospectively analyzed 30,851 SARS-CoV-2 rRT-PCR test results.

By the Skin of Your Teeth: A Subcutaneous Mouse Model to Study Pulp Regeneration.

Exiting developments in tissue engineering and new insights in stem cell biology have led to new possible strategies for the regeneration of damaged tissues in the oral cavity. The regeneration of the pulp-dentin complex regeneration in particular, has drawn the attention of many researchers because of the high clinical needs. While it is still important to perform in vitro research using a wide variety of cells, scaffolds and growth factors, it is also critical to have a reliable animal model for preclinical trials.

Dental Tissue and Stem Cells Revisited: New Insights From the Expression of Fibroblast Activation Protein-Alpha.

Fibroblast activation protein-α (FAPα) is a membrane protein with dipeptidyl-peptidase and type I collagenase activity and is expressed during fetal growth. At the age of adolescence, FAPα expression is greatly reduced, only emerging in pathologies associated with extracellular matrix remodeling. We determined whether FAPα is expressed in human dental tissue involved in root maturation i.

Regenerative Endodontic Procedures Posttrauma: Immunohistologic Analysis of a Retrospective Series of Failed Cases.

Introduction: Regenerative endodontic procedures (REP) are a novel treatment modality to restore the function of necrotic pulp tissue via stimulation or transplantation of stem cells into the root canal. This study aimed to investigate the immunohistologic outcome of 3 extracted teeth because of sequelae of trauma and unsatisfactory REP outcomes.

Methods: Three immature permanent maxillary central incisors of 3 female patients (6-9 years) were extracted 5.

Is Hypoxia Related to External Cervical Resorption? A Case Report.

Despite the fact that external cervical resorption (ECR) is a well-known and rather frequently met condition, the driving force of this phenomenon still remains unclear. Recently, hypoxia has been linked to ECR. Thus, the aim of this work was to investigate the existence of hypoxia in ECR and hypothesize on its role at the time of extraction.

Angiogenic Properties of 'Leukocyte- and Platelet-Rich Fibrin'.

Leukocyte- and Platelet-Rich Fibrin (L-PRF) is an autologous platelet concentrate, consisting of a fibrin matrix enriched with platelets, leukocytes and a plethora of cytokines and growth factors. Since L-PRF is produced bedside from whole blood without the use of an anti-coagulant, it is becoming a popular adjuvant in regenerative medicine. While other types of platelet concentrates have been described to stimulate blood vessel formation, little is known about the angiogenic capacities of L-PRF.

Dermal Interstitial Alterations in Patients With Heart Failure and Reduced Ejection Fraction: A Potential Contributor to Fluid Accumulation?

Background: Large networks of interstitial glycosaminoglycans help to regulate water and electrolyte homeostasis. The relation between dermal interstitial alterations and occurrence of edema in heart failure patients with reduced ejection fraction (HFrEF) is unknown. We hypothesize that in HFrEF patients (1) interstitial glycosaminoglycan density is increased, (2) changes in the interstitial glycosaminoglycan network are associated with interstitial fluid accumulation, and (3) there is a link between the interstitial glycosaminoglycan network and the renin-angiotensin-aldosterone system.

Stem Cells for Cartilage Repair: Preclinical Studies and Insights in Translational Animal Models and Outcome Measures.

Due to the restricted intrinsic capacity of resident chondrocytes to regenerate the lost cartilage postinjury, stem cell-based therapies have been proposed as a novel therapeutic approach for cartilage repair. Moreover, stem cell-based therapies using mesenchymal stem cells (MSCs) or induced pluripotent stem cells (iPSCs) have been used successfully in preclinical and clinical settings. Despite these promising reports, the exact mechanisms underlying stem cell-mediated cartilage repair remain uncertain.

The Angiogenic Potential of DPSCs and SCAPs in an Model of Dental Pulp Regeneration.

Adequate vascularization, a restricting factor for the survival of engineered tissues, is often promoted by the addition of stem cells or the appropriate angiogenic growth factors. In this study, human dental pulp stem cells (DPSCs) and stem cells from the apical papilla (SCAPs) were applied in an model of dental pulp regeneration in order to compare their regenerative potential and confirm their previously demonstrated paracrine angiogenic properties. 3D-printed hydroxyapatite scaffolds containing DPSCs and/or SCAPs were subcutaneously transplanted into immunocompromised mice.

Dental Pulp Stem Cells: Their Potential in Reinnervation and Angiogenesis by Using Scaffolds.

Dental pulp is a highly vascularized and innervated tissue containing a heterogeneous stem cell population with multilineage differentiation potential. Current endodontic treatments focus on the preservation of the pulp tissue and the regeneration of dental pulp after pathological insults. Human dental pulp stem cells (hDPSCs) are currently investigated as stem cell-based therapy for pulp regeneration and for peripheral nerve injury in which neurons and Schwann cells display limited regenerative capacity.

Angiogenic Capacity of Periodontal Ligament Stem Cells Pretreated with Deferoxamine and/or Fibroblast Growth Factor-2.

Periodontal ligament stem cells (PDLSCs) represent a good source of multipotent cells for cell-based therapies in regenerative medicine. The success rate of these treatments is severely dependent on the establishment of adequate vasculature in order to provide oxygen and nutrients to the transplanted cells. Pharmacological preconditioning of stem cells has been proposed as a promising method to augment their therapeutic efficacy.

Cryopreservation and Banking of Dental Stem Cells.

Over the past decade, dental tissues have become an attractive source of mesenchymal stem cells (MSCs). Dental stem cells (DSCs) are not only able to differentiate into adipogenic, chondrogenic and osteogenic lineanges, but an increasing amount of research also pointed out their potential applicability in numerous clinical disorders, such as myocardial infarction, neurodegenerative diseases and diabetes. Together with their multilineage differentiation capacity, their easy availability from extracted third molars makes these stem cells a suitable alternative for bone marrow-derived MSCs.

Stem Cell-Based Therapies for Ischemic Stroke: Preclinical Results and the Potential of Imaging-Assisted Evaluation of Donor Cell Fate and Mechanisms of Brain Regeneration.

Stroke is the second most common cause of death and is a major cause of permanent disability. Given the current demographic trend of an ageing population and associated increased risk, the prevalence of and socioeconomic burden caused by stroke will continue to rise. Current therapies are unable to sufficiently ameliorate the disease outcome and are not applicable to all patients.

The Neurovascular Properties of Dental Stem Cells and Their Importance in Dental Tissue Engineering.

Within the field of tissue engineering, natural tissues are reconstructed by combining growth factors, stem cells, and different biomaterials to serve as a scaffold for novel tissue growth. As adequate vascularization and innervation are essential components for the viability of regenerated tissues, there is a high need for easily accessible stem cells that are capable of supporting these functions. Within the human tooth and its surrounding tissues, different stem cell populations can be distinguished, such as dental pulp stem cells, stem cells from human deciduous teeth, stem cells from the apical papilla, dental follicle stem cells, and periodontal ligament stem cells.

Regenerative endodontic procedure of an infected immature permanent human tooth: an immunohistological study.

Objectives: An immunohistological study of an infected immature permanent human tooth after a regenerative endodontic procedure (REP) was conducted in order to determine the histologic outcome of this procedure. Besides observed signs of angiogenesis and neurogenesis, repair and/or regeneration of the pulp-dentin complex was also investigated.

Materials And Methods: A REP was performed on tooth 45 of a 10-year-old girl.

Dental Stem Cells in Pulp Regeneration: Near Future or Long Road Ahead?

Although regenerative endodontic procedures have yielded an impressive body of favorable outcomes, the treatment of necrotic immature permanent teeth in particular remains to be a challenge. Recent advances in dental stem cell (DSC) research have gained increasing insight in their regenerative potential and prospective use in the formation of viable dental tissues. Numerous studies have already reported successful dental pulp regeneration following application of dental pulp stem cells, stem cells from the apical papilla, or dental follicle precursor cells in different in vivo models.

Neurogenic maturation of human dental pulp stem cells following neurosphere generation induces morphological and electrophysiological characteristics of functional neurons.

Cell-based therapies are emerging as an alternative treatment option to promote functional recovery in patients suffering from neurological disorders, which are the major cause of death and permanent disability. The present study aimed to differentiate human dental pulp stem cells (hDPSCs) toward functionally active neuronal cells in vitro. hDPSCs were subjected to a two-step protocol.

Mesenchymal stem/stromal cells as a pharmacological and therapeutic approach to accelerate angiogenesis.

Mesenchymal stem cells or multipotent stromal cells (MSCs) have initially captured attention in the scientific world because of their differentiation potential into osteoblasts, chondroblasts and adipocytes and possible transdifferentiation into neurons, glial cells and endothelial cells. This broad plasticity was originally hypothesized as the key mechanism of their demonstrated efficacy in numerous animal models of disease as well as in clinical settings. However, there is accumulating evidence suggesting that the beneficial effects of MSCs are predominantly caused by the multitude of bioactive molecules secreted by these remarkable cells.

Angiogenic properties of human dental pulp stem cells.

Angiogenesis, the formation of capillaries from pre-existing blood vessels, is a key process in tissue engineering. If blood supply cannot be established rapidly, there is insufficient oxygen and nutrient transport and necrosis of the implanted tissue will occur. Recent studies indicate that the human dental pulp contains precursor cells, named dental pulp stem cells (hDPSC) that show self-renewal and multilineage differentiation capacity.