scholarly journals Bone remodelling patterns around orthodontic mini-implants migrating in bone: an experimental study in rat vertebrae

2021 ◽  
Author(s):  
Kathrin Becker ◽  
Nicole Rauch ◽  
Giulia Brunello ◽  
Sarah Azimi ◽  
Mathias Beller ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Remodelling ◽  
Micro Computed Tomography ◽  
Bone Apposition ◽  
Implant Migration ◽  
Mini Implants ◽  
Quantitative Analyses ◽  
Bone To Implant Contact ◽  
Laser Capture ◽  
Complementary Analysis

Summary Background Orthodontic implant migration has been clinically observed in presence of continuous loading forces. Recent studies indicate that osteocytes play a crucial role in this phenomenon. Objectives Aim of this study was to investigate local osteocytic gene expression, protein expression, and bone micro-structure in peri-implant regions of pressure and tension. Material and methods The present work reports a complementary analysis to a previous micro-computed tomography study. Two customized mini-implants were placed in one caudal rat vertebra and connected by a nickel–titanium contraction spring generating different forces (i.e. 0, 0.5, 1.0, and 1.5 N). Either at 2 or 8 weeks, the vertebrae were harvested and utilized for 1. osteocytic gene expression using laser capture micro-dissection on frozen sections coupled with qPCR, 2. haematoxylin–eosin staining for qualitative and quantitative analyses, 3. immunofluorescence staining and analysis, and 4. bone-to-implant contact on undecalcified samples. Results At the two time points for all the performed analyses no significant differences were observed with respect to the applied force magnitudes and cell harvesting localization. However, descriptive histological analysis revealed remarkable bone remodelling at 2 weeks of loading. At 8 weeks the implants were osseointegrated and, especially in 1.0 and 1.5 N groups, newly formed bone presented a characteristic load bearing architecture with trabecula oriented in the direction of the loading. Conclusions The present study confirmed that stress-induced bone remodelling is the biological mechanism of orthodontic implant migration. Bone apposition was found at ‘tension’ and ‘pressure’ sites thus limiting implant migration over time.

scholarly journals Mechanical and Histological Effects of Resorbable Blasting Media Surface Treatment on the Initial Stability of Orthodontic Mini-Implants

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Odontuya Gansukh ◽  
Jong-Wha Jeong ◽  
Jong-Wan Kim ◽  
Jong-Ho Lee ◽  
Tae-Woo Kim
Keyword(s):  
Bone Resorption ◽  
Surface Treatment ◽  
Histological Study ◽  
Machined Surface ◽  
Bone Apposition ◽  
Mini Implants ◽  
Initial Stability ◽  
Significant Difference ◽  
Mechanical Study ◽  
Bone To Implant Contact

Introduction. This study aimed to evaluate the effects of resorbable blasting media (RBM) treatment on early stability of orthodontic mini-implants by mechanical, histomorphometric, and histological analyses.Methods. Ninety-six (64 for mechanical study and 32 for histological study and histomorphometric analysis) titanium orthodontic mini-implants (OMIs) with machined (machined group) or RBM-treated (CaP) surface (RBM group) were implanted in the tibiae of 24 rabbits. Maximum initial torque (MIT) was measured during insertion, and maximum removal torque (MRT) and removal angular momentum (RAM) were measured at 2 and 4 weeks after implantation. Bone-to-implant contact (BIC) and bone area (BA) were analyzed at 4 weeks after implantation.Results. RBM group exhibited significantly lower MIT and significantly higher MRT and RAM at 2 weeks than machined group. No significant difference in MRT, RAM, and BIC between the two groups was noted at 4 weeks, although BA was significantly higher in RBM group than in machined group. RBM group showed little bone resorption, whereas machined group showed new bone formation after bone resorption.Conclusions. RBM surface treatment can provide early stability of OMIs around 2 weeks after insertion, whereas stability of machined surface OMIs may decrease in early stages because of bone resorption, although it can subsequently recover by new bone apposition.

scholarly journals Gene expression profiles in anatomically and functionally distinct regions of the normal aged human brain

2007 ◽  
Vol 28 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Winnie S. Liang ◽  
Travis Dunckley ◽  
Thomas G. Beach ◽  
Andrew Grover ◽  
Diego Mastroeni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Neurofibrillary Tangle ◽  
Gene Expression Profiles ◽  
Posterior Cingulate Cortex ◽  
Neuritic Plaque ◽  
Reference Information ◽  
Plaque Pathology ◽  
Human Brains ◽  
Laser Capture

In this article, we have characterized and compared gene expression profiles from laser capture microdissected neurons in six functionally and anatomically distinct regions from clinically and histopathologically normal aged human brains. These regions, which are also known to be differentially vulnerable to the histopathological and metabolic features of Alzheimer’s disease (AD), include the entorhinal cortex and hippocampus (limbic and paralimbic areas vulnerable to early neurofibrillary tangle pathology in AD), posterior cingulate cortex (a paralimbic area vulnerable to early metabolic abnormalities in AD), temporal and prefrontal cortex (unimodal and heteromodal sensory association areas vulnerable to early neuritic plaque pathology in AD), and primary visual cortex (a primary sensory area relatively spared in early AD). These neuronal profiles will provide valuable reference information for future studies of the brain, in normal aging, AD and other neurological and psychiatric disorders.

Matricaria chamomilla (Chamomile) Ameliorates Muscle Atrophy in Mice by Targeting Protein Catalytic Pathways, Myogenesis, and Mitochondrial Dysfunction

2021 ◽  
pp. 1-22
Author(s):  
Sang Hee Park ◽  
Dong Seon Kim ◽  
Jieun Oh ◽  
Jeong-Ho Geum ◽  
Jung-Eun Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Atrophy ◽  
Muscle Wasting ◽  
Mrna Level ◽  
Herbal Medicines ◽  
Ethanol Extract ◽  
C2c12 Cells ◽  
Matricaria Chamomilla ◽  
Micro Computed Tomography ◽  
Active Components

Muscle atrophy, or loss of skeletal muscle, is caused by aging, malnutrition, immobility through injury, or diseases such as cancer. Chamomile (Matricaria chamomilla L.) contains various active components, including flavonoids, sesquiterpenes, polyacetylenes, and coumarins, and is used in various herbal medicines in the European Pharmacopoeia. In this study, we investigated the effects of ethanol extract of chamomile [Formula: see text](MC) on muscle wasting and its mechanism of action. Mice with dexamethasone (DEX)-induced muscle atrophy were orally administered MC (100, 200, and 300 mg/kg) for 4 weeks. Micro-computed tomography analysis showed that MC (200 and 300 mg/kg) significantly recovered DEX-induced loss of muscle volume, density, and weight and MC-treated DEX-induced mice also showed increased moving distance and grip strength. MC suppressed the mRNA level of muscle RING finger 1 (MuRF1) while increasing the expression of mitochondrial transcription factor A (TFAM), MyoD, and Myogenin-1. We found 25 peaks in MC samples through HPLC analysis and identified 6 peaks by comparison with a profile of standard compounds: chlorogenic acid (CGA), luteolin-7-O-glucoside (L7G), patulitrin, apigenin-7-O-glucoside (A7G), herniarin, and (E)-tonghaosu. Of these components, the gene expression of MyoD was significantly augmented by patulitrin, herniarin, CGA, and L7G in C2C12 cells, while Myogenin-1 gene expression was increased by A7G, patulitrin, herniarin, CGA, and L7G. Moreover, TFAM gene expression and phosphorylation of AKT were increased by all six ingredients. Based on our results, we suggest MC for use as a supplement or remedy for muscle wasting, including cachexia and sarcopenia.

scholarly journals Global transcriptome analysis of rat hypothalamic arcuate nucleus demonstrates reversal of hypothalamic gliosis following surgically and diet induced weight loss

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pernille Barkholt ◽  
Kristoffer T. G. Rigbolt ◽  
Mechthilde Falkenhahn ◽  
Thomas Hübschle ◽  
Uwe Schwahn ◽  
...  
Keyword(s):  
Gene Expression ◽  
Weight Loss ◽  
Molecular Mechanisms ◽  
Arcuate Nucleus ◽  
Gene Expression Signature ◽  
Global Gene Expression ◽  
Metabolic Effects ◽  
Expression Of Genes ◽  
Hypothalamic Arcuate Nucleus ◽  
Laser Capture

Abstract The central mechanisms underlying the marked beneficial metabolic effects of bariatric surgery are unclear. Here, we characterized global gene expression in the hypothalamic arcuate nucleus (Arc) in diet-induced obese (DIO) rats following Roux-en-Y gastric bypass (RYGB). 60 days post-RYGB, the Arc was isolated by laser-capture microdissection and global gene expression was assessed by RNA sequencing. RYGB lowered body weight and adiposity as compared to sham-operated DIO rats. Discrete transcriptome changes were observed in the Arc following RYGB, including differential expression of genes associated with inflammation and neuropeptide signaling. RYGB reduced gene expression of glial cell markers, including Gfap, Aif1 and Timp1, confirmed by a lower number of GFAP immunopositive astrocyte profiles in the Arc. Sham-operated weight-matched rats demonstrated a similar glial gene expression signature, suggesting that RYGB and dietary restriction have common effects on hypothalamic gliosis. Considering that RYGB surgery also led to increased orexigenic and decreased anorexigenic gene expression, this may signify increased hunger-associated signaling at the level of the Arc. Hence, induction of counterregulatory molecular mechanisms downstream from the Arc may play an important role in RYGB-induced weight loss.

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