51 research outputs found

    Effect of growth factors on the osteoinductive potential of Hydroxyapatite β-Tricalcium Phosphate (HA-TCP).

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    The replacement of missing teeth by osseointegrated dental implants is a commonly utilised treatment option in dentistry. However, successful treatment outcomes are dependent on sufficient bone quantity in the proposed surgical site for implant placement (Buser et al., 2004). Surgical augmentation of bone defects is commonly performed prior to or during implant placement. Bone augmentation procedures of the maxillary sinus or guided bone regeneration (GBR) procedures of alveolar ridge defects have utilised a variety of bone graft materials in block or particulate form, either alone or in combination with resorbable or non-resorbable barrier membranes. Objective: The aim of this study was to determine whether Hydroxyapatite β-Tricalcium Phosphate (HA-TCP) either alone or combined with Enamel Matrix Derivative (EMD) or recombinant human Platelet Derived Growth Factor-BB (rhPDGF-BB) is osteoinductive when implanted into a nonosseous site. Methods: Twenty CD-1 adult male mice underwent intramuscular implantation into both hindlimbs of an empty gelatine capsule or a gelatine capsule containing one of the following: 10 mg of uncoated particulate HA-TCP, (Straumann Bone Ceramic®, HA-TCP), EMD coated HA-TCP, (Emdogain®, HATCP + EMD) or rhPDGF-BB coated HA-TCP (HA-TCP + PDGF). Ten animals were sacrificed at four and eight weeks with five specimens from each group retrieved at each time point. The area of graft placement was radiographed and after graft retrieval, a semi-quantitative histological examination was performed with the aim of assessing the inflammatory changes, reparative processes and osteoinduction within the graft site. Results: At both 4 and 8 weeks, histological analysis failed to demonstrate any osteoinductive activity in any of the specimens from the three experimental groups. A minimal chronic inflammatory response and foreign body reaction was seen in the experimental groups which reduced over time. The particles were embedded within fibrous connective tissue and were encapsulated by a dense cellular layer consisting of active fibroblasts and occasional macrophages with the thickness of this layer decreasing over time. At 4 weeks, a greater density of the fibrous connective tissue was demonstrated in the HA-TCP + EMD group (P<0.001) while a greater thickness in the capsule thickness was seen in the HA-TCP group (P=0.022) although no differences were seen after 8 weeks. Greater neovascularisation was seen in the HA-TCP + PDGF group after 8 weeks (P=0.043) while greater amounts of adipose tissue surrounding the particles were detected in the HA-TCP + PDGF group at 4 weeks (P=0.002) and in the HA-TCP + EMD group at eight weeks (P=0.002). Conclusions: The results of this study suggest that the use of commercially available HA-TCP alone or in combination with EMD or rhPDGF-BB is biocompatible but not osteoinductive in the murine model.Thesis (D.Clin.Dent.) -- University of Adelaide, School of Dentistry, 201

    The impact of compassion from others and self-compassion on psychological distress, flourishing, and meaning in life among university students

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    Objectives: Research shows that compassion from others and from the self may enable university students to face, overcome, and bounce back from adversity and generate a greater sense of thriving and meaning in life. However, the underlying processes are largely unknown. The present study aimed to examine the associations of compassion with psychological distress, flourishing, and meaning in life among university students and explore the mechanisms underlying these associations. Methods: A total of 536 Hong Kong university students completed questionnaires measuring their experiences of compassion from others, self-compassion, resilience, psychological distress, flourishing, and meaning in life. Results: Serial mediation analyses showed that compassion from others was associated positively with self-compassion, which was, in turn, linked to greater resilience and consequently lower levels of psychological distress and higher levels of flourishing and meaning in life. Conclusions: Our findings reveal the associations of compassion from others and self-compassion with the well-being and life meaning of university students. The findings highlight the importance of being open and receptive to love and kindness from others. The findings also point to the importance of developing a caring attitude toward oneself

    Modulation of microglia by Wolfberry on the survival of retinal ganglion cells in a rat ocular hypertension model

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    The active component of Wolfberry (Lycium barbarum), lycium barbarum polysaccharides (LBP), has been shown to be neuroprotective to retinal ganglion cells (RGCs) against ocular hypertension (OH). Aiming to study whether this neuroprotection is mediated via modulating immune cells in the retina, we used multiphoton confocal microscopy to investigate morphological changes of microglia in whole-mounted retinas. Retinas under OH displayed slightly activated microglia. One to 100 mg/kg LBP exerted the best neuroprotection and elicited moderately activated microglia in the inner retina with ramified appearance but thicker and focally enlarged processes. Intravitreous injection of lipopolysaccharide decreased the survival of RGCs at 4 weeks, and the activated microglia exhibited amoeboid appearance as fully activated phenotype. When activation of microglia was attenuated by intravitreous injection of macrophage/microglia inhibitory factor, protective effect of 10 mg/kg LBP was attenuated. The results implicated that neuroprotective effects of LBP were partly due to modulating the activation of microglia

    Meta-analysis Followed by Replication Identifies Loci in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as Associated with Systemic Lupus Erythematosus in Asians

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    Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic involvement and ethnic differences. Susceptibility genes identified so far only explain a small portion of the genetic heritability of SLE, suggesting that many more loci are yet to be uncovered for this disease. In this study, we performed a meta-analysis of genome-wide association studies on SLE in Chinese Han populations and followed up the findings by replication in four additional Asian cohorts with a total of 5,365 cases and 10,054 corresponding controls. We identified genetic variants in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with the disease. These findings point to potential roles of cell-cycle regulation, autophagy, and DNA demethylation in SLE pathogenesis. For the region involving TET3 and that involving CDKN1B, multiple independent SNPs were identified, highlighting a phenomenon that might partially explain the missing heritability of complex diseases

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Viruses and periodontal disease

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    Bacterial species within the subginigival plaque biofilm are considered the aetiological agents of host mediated periodontal tissue destruction. However, not all individuals are equally susceptible to periodontitis with environmental and genetic factors contributing to disease development and progression. Over the last decade, viral infection has also been suggested to play a role in the aetiopathogenesis of periodontal disease alongside these traditional risk factors. (author abstract)Chan, Rhttp://search.informit.com.au/search;rs=1;rec=1;action=showCompleteRe

    Bereavement of spouses of cancer patients

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    published_or_final_versionabstracttocClinical PsychologyMasterMaster of Social Science

    The co-occurrence of multidimensional loneliness with depression, social anxiety and paranoia in non-clinical young adults: A latent profile analysis

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    IntroductionLoneliness is a negative experience arising from a mismatch between perceived and actual social relationships. Several dimensions of loneliness have been suggested, namely intimate, relational and collective loneliness. Loneliness has been linked to poorer mental health, with its co-occurrence with depression, social anxiety, and paranoia most widely reported. While expressions of these symptoms are heterogeneous across individuals in the non-clinical population, it remains unclear how these symptoms co-occur with one another and with various dimensions of loneliness. It is also of interest how trait factors such as core schemas about self/others may moderate these relationships between loneliness and co-occurring symptoms. MethodsA demographically diverse sample of young adults was recruited from multiple sources. The validated sample consisted of 2,089 participants (68.4% female), who completed an online survey consisting of questionnaires assessing levels of multidimensional loneliness, depression, social anxiety, paranoia, core schemas, and demographic characteristics. Latent profile analysis (LPA) was used to identify distinct profiles of loneliness and the three symptoms. Positive and negative core schemas about self and others were modeled as predictors of these profiles. ResultsFive distinct profiles were identified. Profile 1 had low levels across all symptoms and dimensions of loneliness (n = 1,273, 60.9%). Profiles 2-5 were elevated on dimensions of loneliness, and were heightened in depression (n = 189, 9.0%), social anxiety (n = 206, 9.9%), paranoia (n = 198, 9.5%), and all symptoms (n = 223, 10.7%), respectively. Relative to Profile 1, the other four profiles scored higher on negative-self (adjusted ORs = 1.36-1.49, ps < 0.001) and negative-other schemas (adjusted ORs = 1.24-1.44, ps < 0.001), and lower on positive-self (adjusted ORs = 0.82-0.85, ps < 0.001) and positive-other schemas (adjusted ORs = 0.81-0.90, ps < 0.001). ConclusionMore marked intimate, relational and collective loneliness were evident across profiles that had heightened depression, social anxiety and/or paranoia, suggesting that loneliness may serve as a general risk factor for these psychopathologies. Our findings shed light on the heterogeneity of the co-occurrence of loneliness and various mental health difficulties in non-clinical young adults. Core schemas are suggested to be putative psychological mechanisms underlying their co-occurrence and even development
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