Experimental Regeneration of The Periodontium

The biologic possibility of regenerating periodontal tissues,especially bone, lost due to chronic inflammatory periodontal disease has fascinated researchers for over 100 years. During the past 15 years, an explosion of new knowledge in the area of periodontal physiology coupled with the application of novel techniques in cellular and molecular biology has shed new light on the biologic possibilities of regenerating periodontal tissues. Along with the breakthroughs, we have generated more challenging questions and controversies. Wound healing in general has been described in the biomedical literature using a timescale compartmentalization (for review, see Clark1). Wound healing in the periodontium may best be considered as unusual combinations of biologic phenomena, typically inconsistent and incompletely understood. This article reviews the current knowledge in the area of wound repair and regeneration of periodontal tissues that have been lost due to chronic inflammatory disease

Inner speech and clarity of self-concept in thought disorder and auditory-verbal hallucinations

Eighty patients and thirty controls were interviewed using one interview that promoted personal disclosure and another about everyday topics. Speech was scored using the Thought, Language and Communication scale (TLC). All participants completed the Self-Concept Clarity Scale (SCCS) and the Varieties of Inner Speech Questionnaire (VISQ). Patients scored lower than comparisons on the SCCS. Low scores were associated the disorganized dimension of TD. Patients also scored significantly higher on condensed and other people in inner speech, but not on dialogical or evaluative inner speech. The poverty of speech dimension of TD was associated with less dialogical inner speech, other people in inner speech, and less evaluative inner speech. Hallucinations were significantly associated with more other people in inner speech and evaluative inner speech. Clarity of self-concept and qualities of inner speech are differentially associated with dimensions of TD. The findings also support inner speech models of hallucinations

Temporal dystrophic remodeling within the intrinsic cardiac nervous system of the streptozotocin-induced diabetic rat model

INTRODUCTION: The pathogenesis of heart failure (HF) in diabetic individuals, called “diabetic cardiomyopathy”, is only partially understood. Alterations in the cardiac autonomic nervous system due to oxidative stress have been implicated. The intrinsic cardiac nervous system (ICNS) is an important regulatory pathway of cardiac autonomic function, however, little is known about the alterations that occur in the ICNS in diabetes. We sought to characterize morphologic changes and the role of oxidative stress within the ICNS of diabetic hearts. Cultured ICNS neuronal cells from the hearts of 3- and 6-month old type 1 diabetic streptozotocin (STZ)-induced diabetic Sprague-Dawley rats and age-matched controls were examined. Confocal microscopy analysis for protein gene product 9.5 (PGP 9.5) and amino acid adducts of (E)-4-hydroxy-2-nonenal (4-HNE) using immunofluorescence was undertaken. Cell morphology was then analyzed in a blinded fashion for features of neuronal dystrophy and the presence of 4-HNE adducts. RESULTS: At 3-months, diabetic ICNS neuronal cells exhibited 30% more neurite swellings per area (p = 0.01), and had a higher proportion with dystrophic appearance (88.1% vs. 50.5%; p = <0.0001), as compared to control neurons. At 6-months, diabetic ICNS neurons exhibited more features of dystrophy as compared to controls (74.3% vs. 62.2%; p = 0.0448), with 50% more neurite branching (p = 0.0015) and 50% less neurite outgrowth (p = <0.001). Analysis of 4-HNE adducts in ICNS neurons of 6-month diabetic rats demonstrated twice the amount of reactive oxygen species (ROS) as compared to controls (p = <0.001). CONCLUSION: Neuronal dystrophy occurs in the ICNS neurons of STZ-induced diabetic rats, and accumulates temporally within the disease process. In addition, findings implicate an increase in ROS within the neuronal processes of ICNS neurons of diabetic rats suggesting an association between oxidative stress and the development of dystrophy in cardiac autonomic neurons

Obesity, Metabolic Syndrome, and Adipocytes

Obesity and metabolic syndromes are examples whereby excess energy consumption and energy flux disruptions are causative agents of increased fatness. Because other, as yet elucidated, cellular factors may be involved and because potential treatments of these metabolic problems involve systemic agents that are not adipose depot-specific in their actions, should we be thinking of adipose depot-specific (cellular) treatments for these problems? For sure, whether treating obesity or metabolic syndrome, the characteristics of all adipose depot-specific adipocytes and stromal vascular cells should be considered. The focus of this paper is to begin to align metabolic dysfunctions with specific characteristics of adipocytes

Review: Animal model and the current understanding of molecule dynamics of adipogenesis

Among several potential animal models that can be used for adipogenic studies, Wagyu cattle is the one that presents unique molecular mechanisms underlying the deposit of substantial amounts of intramuscular fat. As such, this review is focused on current knowledge of such mechanisms related to adipose tissue deposition using Wagyu cattle as model. So abundant is the lipid accumulation in the skeletal muscles of these animals that in many cases, the muscle cross-sectional area appears more white (adipose tissue) than red (muscle fibers). This enhanced marbling accumulation is morphologically similar to that seen in numerous skeletal muscle dysfunctions, disease states and myopathies; this might indicate cross-similar mechanisms between such dysfunctions and fat deposition in Wagyu breed. Animal models can be used not only for a better understanding of fat deposition in livestock, but also as models to an increased comprehension on molecular mechanisms behind human conditions. This revision underlies some of the complex molecular processes of fat deposition in animals

Minimally Invasive Periodontal Treatment Using the Er,Cr: YSGG Laser. A 2-year Retrospective Preliminary Clinical Study

Minimally invasive surgery (MIS) using the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser (Waterlase MD, Biolase, Irvine, CA) to treat moderate to advanced periodontal disease is presented as an alternative to conventional therapies. To date, there are few short- or long-term studies to demonstrate the effects of this laser in treating and maintaining periodontal health. Electronic clinical records from 16 patients – total of 126 teeth, with pocket depths ranging from 4 mm to 9 mm – were treated with the same protocol using the Er,Cr:YSGG laser. The mean baseline probing depths (PD) were 5 mm and clinical attachment levels (CAL) were 5 mm in the 4 - 6 mm pretreated laser group. The mean baseline probing depths were 7.5 and 7.6 mm for PD and CAL respectfully in the 7 – 9 mm pretreatment laser group. At the 2 year mark, the average PD was 3.2 ± 1.1 mm for the 4-6 mm pocket group and the 7-9 mm pocket group had a mean PD of 3.7 ± 1.2 mm. mean CAL was 3.1 ± 1.1 mm for the 4-6 mm group and 3.6 ± 1.2 for the 7-9 mm group with an overall reduction of 1.9 mm and 4.0 mm respectively. At one and two years, both groups remained stable with PD comparable to the three-month gains. The CAL measurements at one and two years were also comparable to the three-month gains

Instrumented fusion of thoracolumbar fracture with type I mineralized collagen matrix combined with autogenous bone marrow as a bone graft substitute: a four-case report

In order to avoid the morbidity from autogenous bone harvesting, bone graft substitutes are being used more frequently in spinal surgery. There is indirect radiological evidence that bone graft substitutes are efficacious in humans. The purpose of this four-case study was to visually, manually, and histologically assess the quality of a fusion mass produced by a collagen hydroxyapatite scaffold impregnated with autologous bone marrow aspirate for posterolateral fusion. Four patients sustained an acute thoracolumbar fracture and were treated by short posterior segment fusion using the AO fixateur interne. Autologous bone marrow (iliac crest) impregnated hydroxyapatite-collagen scaffold was laid on the decorticated posterior elements. Routine implant removal was performed after a mean of 15.3 months (12–20). During this second surgery, fusion mass was assessed visually and manually. A bone biopsy was sent for histological analysis of all four cases. Fusion was confirmed in all four patients intraoperatively and sagittal stress testing confirmed mechanical adequacy of the fusion mass. Three out of the four (cases 2–4) had their implants removed between 12 and 15 months after the index surgery. All their histological cuts showed evidence of newly formed bone and presence of active membranous and/or enchondral ossification foci. The last patient (case 1) underwent implant removal at 20 months and his histological cuts showed mature bone, but no active ossification foci. This four-case report suggests that the fusion mass produced by a mineralized collagen matrix graft soaked in aspirated bone marrow is histologically and mechanically adequate in a thoracolumbar fracture model. A larger patient series and/or randomized controlled studies are warranted to confirm these initial results

Verbal thinking and inner speech use in autism spectrum disorder

The extent to which cognition is verbally mediated in neurotypical individuals is the subject of debate in cognitive neuropsychology, as well as philosophy and psychology. Studying “verbal thinking” in developmental/neuropsychological disorders provides a valuable opportunity to inform theory building, as well as clinical practice. In this paper, we provide a comprehensive, critical review of such studies among individuals with autism spectrum disorder (ASD). ASD involves severe social-communication deficits and limitations in cognitive/behavioural flexibility. The prevailing view in the field is that neither cognition nor behaviour is mediated verbally in ASD, and that this contributes to diagnostic features. However, our review suggests that, on the contrary, most studies to date actually find that among people with ASD cognitive task performance is either a) mediated verbally in a typical fashion, or b) not mediated verbally, but at no obvious cost to overall task performance. Overall though, these studies have methodological limitations and thus clear-cut conclusions are not possible at this stage. The aim of the review is to take stock of existing empirical findings, as well as to help develop the directions for future research that will resolve the many outstanding issues in this field

Mesenchymal Stem Cell Responses to Bone-Mimetic Electrospun Matrices Composed of Polycaprolactone, Collagen I and Nanoparticulate Hydroxyapatite

The performance of biomaterials designed for bone repair depends, in part, on the ability of the material to support the adhesion and survival of mesenchymal stem cells (MSCs). In this study, a nanofibrous bone-mimicking scaffold was electrospun from a mixture of polycaprolactone (PCL), collagen I, and hydroxyapatite (HA) nanoparticles with a dry weight ratio of 50/30/20 respectively (PCL/col/HA). The cytocompatibility of this tri-component scaffold was compared with three other scaffold formulations: 100% PCL (PCL), 100% collagen I (col), and a bi-component scaffold containing 80% PCL/20% HA (PCL/HA). Scanning electron microscopy, fluorescent live cell imaging, and MTS assays showed that MSCs adhered to the PCL, PCL/HA and PCL/col/HA scaffolds, however more rapid cell spreading and significantly greater cell proliferation was observed for MSCs on the tri-component bone-mimetic scaffolds. In contrast, the col scaffolds did not support cell spreading or survival, possibly due to the low tensile modulus of this material. PCL/col/HA scaffolds adsorbed a substantially greater quantity of the adhesive proteins, fibronectin and vitronectin, than PCL or PCL/HA following in vitro exposure to serum, or placement into rat tibiae, which may have contributed to the favorable cell responses to the tri-component substrates. In addition, cells seeded onto PCL/col/HA scaffolds showed markedly increased levels of phosphorylated FAK, a marker of integrin activation and a signaling molecule known to be important for directing cell survival and osteoblastic differentiation. Collectively these results suggest that electrospun bone-mimetic matrices serve as promising degradable substrates for bone regenerative applications