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1.
Phys Med ; 123: 103394, 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38852364

ABSTRACT

PURPOSE: To present the results of the first multi-centre real-world validation of autoplanning for whole breast irradiation after breast-sparing surgery, encompassing high complexity cases (e.g. with a boost or regional lymph nodes) and a wide range of clinical practices. METHODS: The 24 participating centers each included 10 IMRT/VMAT/Tomotherapy patients, previously treated with a manually generated plan ('manplan'). There were no restrictions regarding case complexity, planning aims, plan evaluation parameters and criteria, fractionation, treatment planning system or treatment machine/technique. In addition to dosimetric comparisons of autoplans with manplans, blinded plan scoring/ranking was conducted by a clinician from the treating center. Autoplanning was performed using a single configuration for all patients in all centres. Deliverability was verified through measurements at delivery units. RESULTS: Target dosimetry showed comparability, while reductions in OAR dose parameters were 21.4 % for heart Dmean, 16.7 % for ipsilateral lung Dmean, and 101.9 %, 45.5 %, and 35.7 % for contralateral breast D0.03cc, D5% and Dmean, respectively (all p < 0.001). Among the 240 patients included, the clinicians preferred the autoplan for 119 patients, with manplans preferred for 96 cases (p = 0.01). Per centre there were on average 5.0 ± 2.9 (1SD) patients with a preferred autoplan (range [0-10]), compared to 4.0 ± 2.7 with a preferred manplan ([0,9]). No differences were observed regarding deliverability. CONCLUSION: The automation significantly reduced the hands-on planning workload compared to manual planning, while also achieving an overall superiority. However, fine-tuning of the autoplanning configuration prior to clinical implementation may be necessary in some centres to enhance clinicians' satisfaction with the generated autoplans.

2.
Biomater Adv ; 160: 213849, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38599041

ABSTRACT

Spheroids derived from human mesenchymal stem cells (hMSCs) are of limited use for cartilage regeneration, as the viability of the cells progressively decreases during the period required for chondrogenic differentiation (21 days). In this work, spheroids based on hMSCs and a lactose-modified chitosan (CTL) were formed by seeding cells onto an air-dried coating of CTL. The polymer coating can inhibit cell adhesion and it is simultaneously incorporated into spheroid structure. CTL-spheroids were characterized from a morphological and biological perspective, and their properties were compared with those of spheroids obtained by seeding the cells onto a non-adherent surface (agar gel). Compared to the latter, smaller and more viable spheroids form in the presence of CTL as early as 4 days of culture. At this time point, analysis of stem cells differentiation in spheroids showed a remarkable increase in collagen type-2 (COL2A1) gene expression (~700-fold compared to day 0), whereas only a 2-fold increase was observed in the control spheroids at day 21. These results were confirmed by histological and transmission electron microscopy (TEM) analyses, which showed that in CTL-spheroids an early deposition of collagen with a banding structure already occurred at day 7. Overall, these results support the use of CTL-spheroids as a novel system for cartilage regeneration, characterized by increased cell viability and differentiation capacity within a short time-frame. This will pave the way for approaches aimed at increasing the success rate of procedures and reducing the time required for tissue regeneration.


Subject(s)
Cell Differentiation , Chitosan , Chondrogenesis , Lactose , Mesenchymal Stem Cells , Spheroids, Cellular , Chitosan/pharmacology , Chitosan/chemistry , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/cytology , Humans , Cell Differentiation/drug effects , Chondrogenesis/drug effects , Spheroids, Cellular/drug effects , Spheroids, Cellular/cytology , Lactose/pharmacology , Lactose/chemistry , Cell Survival/drug effects , Cells, Cultured , Collagen Type II/metabolism , Collagen Type II/genetics
3.
Phys Med ; 113: 102657, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37567068

ABSTRACT

PURPOSE: Different methods are available to identify haematopoietically active bone marrow (ActBM). However, their use can be challenging for radiotherapy routine treatments, since they require specific equipment and dedicated time. A machine learning (ML) approach, based on radiomic features as inputs to three different classifiers, was applied to computed tomography (CT) images to identify haematopoietically active bone marrow in anal cancer patients. METHODS: A total of 40 patients was assigned to the construction set (training set + test set). Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET) images were used to detect the active part of the pelvic bone marrow (ActPBM) and stored as ground-truth for three subregions: iliac, lower pelvis and lumbosacral bone marrow (ActIBM, ActLPBM, ActLSBM). Three parameters were used for the correspondence analyses between 18FDG-PET and ML classifiers: DICE index, Precision and Recall. RESULTS: For the 40-patient cohort, median values [min; max] of the Dice index were 0.69 [0.20; 0.84], 0.76 [0.25; 0.89], and 0.36 [0.15; 0.67] for ActIBM, ActLSBM, and ActLPBM, respectively. The Precision/Recall (P/R) ratio median value for the ActLPBM structure was 0.59 [0.20; 1.84] (over segmentation), while for the other two subregions the P/R ratio median has values of 1.249 [0.43; 4.15] for ActIBM and 1.093 [0.24; 1.91] for ActLSBM (under segmentation). CONCLUSION: A satisfactory degree of overlap compared to 18FDG-PET was found for 2 out of the 3 subregions within pelvic bones. Further optimization and generalization of the process is required before clinical implementation.


Subject(s)
Anus Neoplasms , Bone Marrow , Humans , Bone Marrow/diagnostic imaging , Fluorodeoxyglucose F18 , Positron-Emission Tomography/methods , Tomography, X-Ray Computed , Anus Neoplasms/diagnostic imaging , Anus Neoplasms/therapy , Machine Learning , Positron Emission Tomography Computed Tomography/methods , Radiopharmaceuticals , Retrospective Studies
4.
BMJ Open ; 11(9): e049858, 2021 09 28.
Article in English | MEDLINE | ID: mdl-34588252

ABSTRACT

INTRODUCTION: There is currently only one approved medication effective at improving walking distance in people with intermittent claudication. Preclinical data suggest that the ß3-adrenergic receptor agonist (mirabegron) could be repurposed to treat intermittent claudication associated with peripheral artery disease. The aim of the Stimulating ß3-Adrenergic Receptors for Peripheral Artery Disease (STAR-PAD) trial is to test whether mirabegron improves walking distance in people with intermittent claudication. METHODS AND ANALYSIS: The STAR-PAD trial is a Phase II, multicentre, double-blind, randomised, placebo-controlled trial of mirabegron versus placebo on walking distance in patients with PAD. A total of 120 patients aged ≥40 years with stable PAD and intermittent claudication will be randomly assigned (1:1 ratio) to receive either mirabegron (50 mg orally once a day) or matched placebo, for 12 weeks. The primary endpoint is change in peak walking distance as assessed by a graded treadmill test. Secondary endpoints will include: (i) initial claudication distance; (ii) average daily step count and total step count and (iii) functional status and quality of life assessment. Mechanistic substudies will examine potential effects of mirabegron on vascular function, including brachial artery flow-mediate dilatation; MRI assessment of lower limb blood flow, tissue perfusion and arterial stiffness and numbers and angiogenesis potential of endothelial progenitor cells. Given that mirabegron is safe and clinically available for alternative purposes, a positive study is positioned to immediately impact patient care. ETHICS AND DISSEMINATION: The STAR-PAD trial is approved by the Northern Sydney Local Health District Human Research Ethics Committee (HREC/18/HAWKE/50). The study results will be published in peer-reviewed medical or scientific journals and presented at scientific meetings, regardless of the study outcomes. TRIAL REGISTRATION NUMBER: ACTRN12619000423112; Results.


Subject(s)
Peripheral Arterial Disease , Receptors, Adrenergic, beta-3 , Acetanilides , Clinical Trials, Phase II as Topic , Double-Blind Method , Humans , Multicenter Studies as Topic , Peripheral Arterial Disease/drug therapy , Physical Functional Performance , Quality of Life , Randomized Controlled Trials as Topic , Thiazoles , Walking
5.
Eur Cell Mater ; 41: 108-120, 2021 01 27.
Article in English | MEDLINE | ID: mdl-33501637

ABSTRACT

Human dental pulp stem cell (DPSC) differentiation toward the osteoblastic phenotype is enhanced when culture media are supplemented with differentiating factors, i.e. ascorbic acid, ß-glycerophosphate and dexamethasone. Liposomes, spherical vesicles formed by a phospholipid bilayer, are frequently used as carriers for drugs, growth factors and hydrophobic molecules. The aim of this work was to speed up DPSC commitment to the osteogenic lineage by embedding differentiating factors within liposomes. Firstly, liposomes were prepared by rehydrating a phospholipidic thin film and characterised in terms of dimensions. Secondly, liposome-exposed DPSCs were characterised by their immunophenotypic profile. Levels of CD90 were significantly decreased in the presence of liposomes filled with ascorbic acid, ß-glycerophosphate and dexamethasone (Lipo-Mix) with respect to normal differentiation medium (DM), while CD73 and CD29 expression were enhanced, suggesting osteogenic commitment. Additionally, an appreciable extracellular matrix deposition is detected. Thirdly, the Lipo-Mix formulation better increases alkaline phosphatase activity and levels of Collagen I secretion with respect to DM. In parallel, the new liposome formulation is capable of decreasing the release of H2O2 and of triggering a precocious antioxidant cell response, redressing the redox balance required upon mesenchymal stem cell commitment to osteogenesis. It can be therefore hypothesised that Lipo-Mix could represent a suitable tool for clinical regenerative purposes in the field of tissue engineering by speeding up DPSC osteogenic commitment, mineralised matrix deposition and remodelling.


Subject(s)
Mesenchymal Stem Cells , Osteogenesis , Cell Differentiation , Cell Proliferation , Cells, Cultured , Dental Pulp , Humans , Hydrogen Peroxide , Liposomes
6.
J Phys Chem A ; 124(37): 7416-7426, 2020 Sep 17.
Article in English | MEDLINE | ID: mdl-32816480

ABSTRACT

Furans are promising second generation biofuels with comparable energy densities to conventional fossil fuels. Combustion of furans is initiated and controlled to a large part by reactions with OH radicals, the kinetics of which are critical to understand the processes occurring under conditions relevant to low-temperature combustion. The reactions of OH radicals with furan (OH + F, R1), 2-methyl furan (OH + 2-MF, R2), and 2,5-dimethyl furan (OH + 2,5-DMF, R3) have been studied in this work over the temperature range 294-668 K at pressures between 5 mbar and 10 bar using laser flash photolysis coupled with laser-induced fluorescence (LIF) spectroscopy to generate and monitor OH radicals under pseudo-first-order conditions. Measurements at p ≤ 200 mbar were made in N2, using H2O2 or (CH3)3COOH radical precursors, while those at p ≥ 2 bar were made in He, using HNO3 as the radical precursor. The kinetics of reactions R1-R3 were observed to display a negative dependence on temperature over the range investigated, indicating the dominance of addition reactions under such conditions, with no significant dependence on pressure observed. Master equation calculations are in good agreement with the observed kinetics, and a combined parametrization of addition channels and abstraction channels for R1-R3 is provided on the basis of this work and previous shock tube measurements at higher temperatures. This work significantly extends the temperature range previously investigated for R1 and represents the first temperature-dependent measurements of R2 and R3 at temperatures relevant for atmospheric chemistry and low-temperature combustion.

7.
Br J Cancer ; 123(7): 1101-1113, 2020 09.
Article in English | MEDLINE | ID: mdl-32684628

ABSTRACT

BACKGROUND: Epithelioid inflammatory myofibroblastic sarcoma (eIMS) is characterised by perinuclear ALK localisation, CD30 expression and early relapse despite crizotinib treatment. We aimed to identify therapies to prevent and/or treat ALK inhibitor resistance. METHODS: Malignant ascites, from an eIMS patient at diagnosis and following multiple relapses, were used to generate matched diagnosis and relapse xenografts. RESULTS: Xenografts were validated by confirmation of RANBP2-ALK rearrangement, perinuclear ALK localisation and CD30 expression. Although brentuximab-vedotin (BV) demonstrated single-agent activity, tumours regrew during BV therapy. BV resistance was associated with reduced CD30 expression and induction of ABCB1. BV resistance was reversed in vitro by tariquidar, but combination BV and tariquidar treatment only briefly slowed xenograft growth compared with BV alone. Combining BV with either crizotinib or ceritinib resulted in marked tumour shrinkage in both xenograft models, and resulted in prolonged tumour-free survival in the diagnosis compared with the relapse xenograft. CONCLUSIONS: CD30 is a therapeutic target in eIMS. BV efficacy is limited by the rapid emergence of resistance. Prolonged survival with combination ALK and CD30-targeted-therapy in the diagnosis model provides the rationale to trial this combination in eIMS patients at diagnosis. This combination could also be considered for other CD30-positive, ALK-rearranged malignancies.


Subject(s)
Anaplastic Lymphoma Kinase/antagonists & inhibitors , Anaplastic Lymphoma Kinase/genetics , Gene Rearrangement , Ki-1 Antigen/antagonists & inhibitors , Molecular Chaperones/genetics , Myofibroblasts/pathology , Nuclear Pore Complex Proteins/genetics , Sarcoma/drug therapy , ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors , Aged, 80 and over , Animals , Brentuximab Vedotin/therapeutic use , Drug Resistance, Neoplasm , Humans , Inflammation , Male , Mice , Sarcoma/genetics , Xenograft Model Antitumor Assays
8.
Phys Chem Chem Phys ; 22(17): 9448-9459, 2020 May 07.
Article in English | MEDLINE | ID: mdl-32314758

ABSTRACT

The UV absorption cross-sections of the Criegee intermediate CH2OO, and kinetics of the CH2OO self-reaction and the reaction of CH2OO with I are reported as a function of pressure at 298 K. Measurements were made using pulsed laser flash photolysis of CH2I2/O2/N2 gas mixtures coupled with time-resolved broadband UV absorption spectroscopy at pressures between 6 and 300 Torr. Results give a peak absorption cross-section of (1.37 ± 0.29) × 10-17 cm2 at ∼340 nm and a rate coefficient for the CH2OO self-reaction of (8.0 ± 1.1) × 10-11 cm3 s-1, with no significant pressure dependence of the absorption cross-sections or the self-reaction kinetics over the range investigated. The rate coefficient for the reaction between CH2OO and I demonstrates pressure dependence over the range investigated, with a Lindemann fit giving k0 = (4.4 ± 1.0) × 10-29 cm6 s-1 and k∞ = (6.7 ± 0.6) × 10-11 cm3 s-1. The origins of IO in the system have been investigated, the implications of which are discussed.

9.
J Neurosci ; 38(41): 8831-8844, 2018 10 10.
Article in English | MEDLINE | ID: mdl-30120206

ABSTRACT

Transforming a brief sensory event into a persistent neural response represents a mechanism for linking temporally disparate stimuli together to support learning. The cerebellum requires this type of persistent input during trace conditioning to engage associative plasticity and acquire adaptively timed conditioned responses (CRs). An initial step toward identifying the sites and mechanisms generating and transmitting persistent signals to the cerebellum is to identify the input pathway. The medial auditory thalamic nuclei (MATN) are the necessary and sufficient source of auditory input to the cerebellum for delay conditioning in rodents and a possible input to forebrain sites generating persistent signals. Using pharmacological and computational approaches, we test (1) whether the necessity of MATN during auditory eyelid conditioning is conserved across species, (2) whether the MATN are necessary for the expression of trace eyelid CRs, and if so, (3)whether this relates to the generation of persistent signals. We find that contralateral inactivation of MATN with muscimol largely abolished trace and delay CRs in male rabbits. Residual CRs were decreased in amplitude, but CR timing was unaffected. Results from large-scale cerebellar simulations are consistent with previous experimental demonstrations that silencing only CS-duration inputs does not abolish trace CRs, and instead affects their timing. Together, these results suggest that the MATN are a necessary component of both the direct auditory stimulus pathway to the cerebellum and the pathway generating task-essential persistent signals.SIGNIFICANCE STATEMENT Persistent activity is required for working memory-dependent tasks, such as trace conditioning, and represents a mechanism by which sensory information can be used over time for learning and cognition. This neuronal response entails the transformation of a discrete sensory-evoked response into a signal that extends beyond the stimulus event. Understanding the generation and transmission of this stimulus transformation requires identifying the input sources necessary for task-essential persistent signals. We report that the medial auditory thalamic nuclei are required for the expression of auditory trace conditioning and suggest that these nuclei are a component of the pathway-generating persistent signals. Our study provides a foundation for testing circuit-level mechanisms underlying persistent activity in a cerebellar learning model with identified inputs and well defined behavioral outputs.


Subject(s)
Cerebellum/physiology , Conditioning, Eyelid/physiology , Mediodorsal Thalamic Nucleus/physiology , Memory, Short-Term/physiology , Acoustic Stimulation , Animals , Auditory Pathways/physiology , Male , Models, Neurological , Neural Networks, Computer , Rabbits
10.
Cureus ; 9(9): e1713, 2017 Sep 25.
Article in English | MEDLINE | ID: mdl-29188157

ABSTRACT

Objective To predict changes in the quality of life scores of hemodialysis patients for the coming month and the development of an early warning system using machine learning Methods It was a prospective cohort study (one-month duration) at the dialysis center of a tertiary care hospital in Pakistan. The study started on 1st October 2016. About 78 patients have been enrolled till now. Bachelor of Medicine and Bachelor of Surgery (MBBS) qualified doctors administered a proforma with demographics and the validated Urdu version of World Health Organization Quality Of Life-BREF (WHOQOL-BREF). It was to be repeated after one month to the same patient by the same investigator. Simple statistics were computed using SPSS version 24 (IBM Corp., Armonk, NY) while machine learning was performed using R (version 3.0) and Orange (version 3.1). Results Using machine learning algorithms, two models (classification tree and Naïve Bayes) were generated to predict an increase or decrease of 5% in a patient's WHOQOL-BREF score over one month. The classification tree was selected as the most accurate model with an area under curve (AUC) of 83.3% (accuracy: 81.9%) for the prediction of 5% increase in QOL and an AUC of 76.2% (accuracy: 81.8%) for the prediction of 5% decrease in QOL over the coming month. The factors associated with an increase of QOL by 5% or more over the next month included younger age (<19 years) and higher iron sucrose doses (>278mg/month). Drops in psychological, physical, and social domain scores lead to a decrease of 5% or more in QOL scores over the following month. Conclusion An early warning system, dialysis data interpretation for algorithmic-prediction on quality of life (DIAL) was built for the early detection of deteriorating QOL scores in the hemodialysis population using machine learning algorithms. The model pointed out that working on psychological and environmental domains, in particular, may prevent the drop in QOL scores from occurring. DIAL, if implemented on a larger scale, is expected to help patients in terms of ensuring a better QOL and in reducing the financial burden in the long term.

11.
Eur J Histochem ; 59(1): 2455, 2015 Feb 03.
Article in English | MEDLINE | ID: mdl-25820558

ABSTRACT

Osteonecrosis of the jaw (ONJ) is a chronic complication affecting long-term bisphosphonate-treated subjects, recognized by non-healing exposed bone in the maxillofacial region. The pathophysiological mechanism underlying ONJ has not been fully elucidated. The aim of the present study was to investigate the role of RANK/RANKL/OPG signaling pathway and, in parallel, to evaluate angiogenic and matrix mineralization processes in jaw bone necrotic samples obtained from bisphosphonate-treated subjects with established ONJ. Necrotic bone samples and native bone samples were processed for Light and Field Emission in Lens Scanning Electron Microscope (FEISEM) analyses, for Real-Time RT-PCR to evaluate the gene expression of TNFRSF11A (RANK), TNFSF11 (RANKL), and TNFSF11B (OPG) and for immunohistochemical analyses of VEGF and BSP expression. Morphological analyses performed by Light microscope and FEISEM show empty osteocytic lacunae and alteration of lamellar organization with degradation of the mineralized bone matrix in necrotic bone samples. A significant increase in TNFRSF11A, TNFSF11, TRAF6 and NFAT2 gene expression, and a reduction of TNFSF11B gene transcription level compared is also showed in necrotic bone compared to control samples. No significant difference of VEGF expression is evidenced, while lower BSP expression in necrotic bone compared to healthy samples is found. Even if the pathogenesis of bisphosphonate-associated ONJ remains unknown, a link between oral pathogens and its development seems to exist. We suppose lipopolysaccharide produced by bacteria colonizing and infecting necrotic bone and the surrounding viable area could trigger RANK/RANKL/OPG signaling pathway and, in this context, osteoclasts activation could be considered as a protective strategy carried out by the host bone tissue to delimitate the necrotic area and to counteract infection.


Subject(s)
Bisphosphonate-Associated Osteonecrosis of the Jaw/physiopathology , RANK Ligand/physiology , Signal Transduction , Adult , Aged , Humans , Immunohistochemistry , Middle Aged , Polymerase Chain Reaction , RANK Ligand/genetics
12.
Int Endod J ; 48(9): 839-49, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25231818

ABSTRACT

AIM: To evaluate the effect of TEGDMA on human gingival fibroblasts (HGFs) in vitro co-cultured with Streptococcus mitis, focusing on the signalling pathways underlying cell tissue remodelling and inflammatory response processes. METHODOLOGY: ß1 integrin expression was evaluated by means of imaging flow cytometry. The Western blot technique was used to investigate the expression of protein kinase C (PKC), extracellular signal-regulated kinase (ERK), matrix metalloproteinase 9 (MMP9) and 3 (MMP3). RT-PCR was performed to quantify nuclear factor-kb subunits (Nf-kb1, ReLa), IkB kinase ß (IkBkB), cyclooxygenase II (COX-2) and tumour necrosis factor-α (TNF-α) mRNA levels. Statistical analysis was performed using the analysis of variance (anova). RESULTS: When HGFs are co-cultured with S. mitis, ß1 integrin intensity, phosphorylated PKC (p-PKC), activated ERK (p-ERK), IkBkB mRNA level and MMP9 expression increased (for all molecules P < 0.05 HGFs versus HGFs co-cultured with S. mitis). A higher level of MMP3 in HGFs treated with TEGDMA was recorded (P < 0.05 HGFs versus HGFs exposed to TEGDMA). COX-2 inflammatory factor mRNA level appeared higher in HGFs exposed to 1 mmol L(-1) TEGDMA (P < 0.01 HGFs versus HGFs exposed to TEGDMA), whereas TNF-α gene expression was higher in HGFs co-cultured with S. mitis (P < 0.05 HGFs versus HGFs co-cultured with S. mitis). CONCLUSIONS: ß1 integrin triggered the signalling pathway, transduced by p-PKCα and involving ERK 1 and 2 and MMPs. This pathway resulted in an unbalanced equilibrium in tissue remodelling process, along with inflammatory response when HGFs are exposed to bacteria or biomaterial alone. On the contrary, the TEGDMA/S. mitis combination restored the balance between extracellular matrix deposition and degradation and prevented an inflammatory response.


Subject(s)
Fibroblasts/drug effects , Gingiva/drug effects , Polyethylene Glycols/pharmacology , Polymethacrylic Acids/pharmacology , Streptococcus mitis/drug effects , Coculture Techniques , Fibroblasts/cytology , Fibroblasts/enzymology , Gingiva/cytology , Gingiva/enzymology , Humans , Inflammation/metabolism , Integrin beta1/metabolism , Protein Kinase C-alpha/metabolism , Signal Transduction , Streptococcus mitis/physiology , Tumor Necrosis Factor-alpha/metabolism
13.
J Org Chem ; 78(22): 11172-83, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24050840

ABSTRACT

Peptoids are an increasingly important class of peptidomimetic foldamers comprised of N-alkylglycine units that have been successfully developed as antimicrobial agents, lung surfactant replacements, enzyme inhibitors, and catalysts, among many other applications. Since peptoid secondary structures can be crucial to their desired functions, significant efforts have been devoted to developing means of modularly controlling peptoid backbone amide cis-trans isomerism using side chains. Strategic engineering of interactions between side chain aromatic rings and backbone cis-amides (n→π*(Ar) interactions) is an attractive strategy for stabilizing helical structures in N-a-chiral aromatic peptoids, which are among the most utilized classes of structured peptoids. Herein, we report the first detailed computational and experimental study of n→π*(Ar) interactions in models of peptoids containing backbone thioamides, which we term "thiopeptoids". Our work has revealed that these interactions significantly affect amide rotamerism in both peptoid and thiopeptoid models via a newly characterized "bridged" mode of interaction mediated by the N-α-C-H σ orbitals. Overall, this work elucidates new strategies for controlling both peptoid and thiopeptoid folding and suggests that thiopeptoids will be highly structured and therefore potentially useful as therapeutics, biological probes, and nanostructural engineering elements.


Subject(s)
Peptoids/chemistry , Thioamides/chemistry , Models, Molecular , Molecular Structure , Quantum Theory , Stereoisomerism
14.
Adv Exp Med Biol ; 788: 59-64, 2013.
Article in English | MEDLINE | ID: mdl-23835959

ABSTRACT

The aim of the present study was to evaluate the presence of Neuroglobin (Ngb) and Cytoglobin (Cygb) in the solitary tract nucleus (STN) and in the carotid body of human subjects. Transverse serial sections of formalin-fixed, paraffin-embedded brainstems, taken from six subjects, were investigated. Ngb and Cygb are expressed in both the structures. Differences in expression of Ngb and Cygb among dorsal and ventral area of the STN may be related to their different functions and different metabolic demands. Because the STN plays an important role in the processing of cardiovascular and respiratory reflex inputs, Ngb and Cygb may play an integrative central modulatory action for the two systems.


Subject(s)
Brain Stem/metabolism , Carotid Body/metabolism , Gene Expression Regulation , Globins/metabolism , Nerve Tissue Proteins/metabolism , Solitary Nucleus/metabolism , Cytoglobin , Densitometry , Humans , Image Processing, Computer-Assisted , Immunohistochemistry , Neuroglobin , Neurotransmitter Agents/metabolism , Tissue Distribution
15.
Int Endod J ; 46(12): 1164-72, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23611114

ABSTRACT

AIM: To investigate in coculture of human gingival fibroblasts (HGFs) and Streptococcus mitis, the molecular mechanisms driving the response to 2-hydroxyethyl methacrylate (HEMA) in terms of eukaryotic/prokaryotic cell adhesion, signal transduction and apoptosis. METHODOLOGY: The clinical strain S. mitis DS12, cultured in Trypticase soy broth was added to HGFs, obtained from fragments of healthy marginal gingival tissue and cultured in DMEM, treated with 3 mmol L(-1) 2-hydroxyethyl methacrylate (HEMA) for 48 h and processed for microscopic, western blotting and flow cytometric analyses. RESULTS: 2-hydroxyethyl methacrylate (HEMA) treatment increased the adhesion between S. mitis and HGFs, which seemed to be mediated by the PKC α/integrin ß 1 signalling system, improved by the presence of saliva. It also reduced the viability and the adhesion of HGFs to polypropylene substrate in terms of procollagen I and MMP3 expression. The presence of saliva and S. mitis reduced the number of necrotic HGFs and upregulated the expression of both procollagen I and MMP3. CONCLUSIONS: These results shed more light on the biological and molecular events occurring in vitro in a coculture model that mimics the environment of the oral cavity with HEMA treatment. The key role played by oral bacteria and saliva in preventing inflammatory and toxic processes that occur in vivo in human gingival fibroblasts upon the release of dental material monomers is confirmed.


Subject(s)
Bacterial Adhesion/drug effects , Gingiva/enzymology , Integrin beta1/metabolism , Methacrylates/pharmacology , Protein Kinase C-alpha/metabolism , Streptococcus mitis/physiology , Coculture Techniques , Gingiva/cytology , Gingiva/metabolism , Gingiva/microbiology , Humans
16.
Eur J Histochem ; 57(1): e10, 2013 Feb 27.
Article in English | MEDLINE | ID: mdl-23549459

ABSTRACT

Autologous bone is considered the gold standard for bone regeneration, even if different heterologous bone substitutes have been proposed to overcome the limits related to its use. The aim of this study was to analyze and to compare the molecular events switched on by autologous or heterologous bone graft insertion, focusing on TGFß1 expression and OPG/RANKL ratio, to analyze resorption process, and estimating graft vascularization, new bone tissue deposition and its mineralization, through VEGF, BSP and SPARC expression evaluation, respectively. Patients needing pre-prosthetic rehabilitation of the posterior maxilla were treated using an equine-derived biomaterial (Group 1) or calvaria autologous bone (Group 2), according to the morphology of the bone defect. Bone graft integration was evaluated on bone samples obtained from the treated areas at the moment of dental implant insertion, by morphological and immunohistochemical analyses for TGFß1, OPG, RANKL, VEGF, BSP, and SPARC expression. Morphological analysis shows the presence of biomaterial residual granules in Group 1, in parallel to a good integration between graft and host tissue. Moderate TGFß1 expression is seen in both Group 1 and Group 2. OPG/RANKL ratio appear higher in Group 1; VEGF expression appears very strong in Group 1 and strong in Group 2, while BSP and SPARC expression results weak in Group 1 and moderate in Group 2. Results reveal the good integration between both types of graft and the host tissue, even though autologous graft seems to produce a faster regenerative process, as evidenced by the different expression of the investigated molecules. According to these observations, the clinical use of heterologous particulate equine-derived biomaterial may ensure long-term predictability of implant-prosthetic rehabilitation, comparable to that obtained with autologous bone graft.


Subject(s)
Bone Substitutes/administration & dosage , Gene Expression Regulation , Horses , Maxilla , Osteoprotegerin/biosynthesis , RANK Ligand/biosynthesis , Skull/chemistry , Animals , Bone Substitutes/chemistry , Female , Humans , Male , Maxilla/abnormalities , Maxilla/metabolism , Maxilla/pathology , Maxilla/surgery , Middle Aged , Transforming Growth Factor beta1/biosynthesis , Transplantation, Autologous , Transplantation, Heterologous
17.
Histol Histopathol ; 28(7): 903-11, 2013 07.
Article in English | MEDLINE | ID: mdl-23319379

ABSTRACT

AIMS: The carotid body (CB) represents the prime site for detecting and responding to hypoxia. Since the role of heroin in respiratory depression with consequent hypoxia is known, the authors were able to investigate morphological and molecular modifications occurring in the CB of heroin addicted subjects compared to subjects who died because of trauma. METHODS AND RESULTS: CB sampled from six 27 year old subjects, slides were treated with Mallory Trichrome staining or used for immunohistochemical analysis to detect Neuroglobin (NGB), Hypoxia Inducible Factor-1 (HIF-1α), Vascular Endothelial Growth Factor (VEGF), Inducible Nitric Oxide Synthase (i-NOS), Bax and cleaved Caspase-3 proteins. Mallory Trichrome staining shows an increase in the connective tissue in heroin subjects compared to controls and a parallel reduction in parenchymal area. Immunohistochemical analyses in heroin subjects found a decrease in NGB and an increase in HIF-1α and VEGF compared to controls; i-NOS expression was not statistically significant. Bax and cleaved caspase-3 were positive only in the heroin subjects. CONCLUSIONS: These results could confirm the typical hypoxic condition occurring in heroin addicts. Since NGB may function as a reactive oxygen or nitrogen species scavenger and as apoptotic cell death protector, the decrease in its expression may suggest a key role of this globin in human CB impairment due to heroin addiction.


Subject(s)
Carotid Body/metabolism , Globins/metabolism , Heroin Dependence/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Nerve Tissue Proteins/metabolism , Vascular Endothelial Growth Factor A/metabolism , Adult , Autopsy , Carotid Arteries/pathology , Caspase 3/metabolism , Humans , Hypoxia , Immunohistochemistry , Male , Neuroglobin , Nitric Oxide Synthase Type II/metabolism , Nitrogen/chemistry , Reactive Oxygen Species , bcl-2-Associated X Protein/metabolism
18.
Adv Exp Med Biol ; 756: 223-8, 2013.
Article in English | MEDLINE | ID: mdl-22836639

ABSTRACT

During development and aging, vascular remodeling represents a critical adaptive response to modifications in oxygen supply to tissues. Hypoxia inducible factor (HIF) has a crucial role and is modulated by oxygen levels, with an age-dependent response in neonates, adult, and aged people. ROS are generated under hypoxic conditions and the accumulation of free radicals during life reduces the ability of tissues to their removal. In this immunohistochemical study we investigated the presence and localization of VEGF and iNOS in human carotid bodies (CB) sampled at autopsy from three children (mean age - 2 years), four adult young subjects (mean age - 44.3 years), and four old subjects (mean age - 67.3 years). VEGF immunoreactivity was significantly enhanced in CB tissues from the children (7.2 ± 1.2%) and aged subjects (4.7 ± 1.7%) compared with the young adults (1.4 ± 0.7%). On the other hand, iNOS immunoreactivity was enhanced in CB tissues from the children (0.4 ± 0.04%) and young adult subjects (0.3 ± 0.02%) compared with the old subjects (0.2 ± 0.02%). Prevention of oxygen desaturation, reducing all causes of hypoxemia from neonatal life to aging would decrease the incidence of diseases in the elderly population with lifespan extension.


Subject(s)
Aging/physiology , Carotid Body/metabolism , Nitric Oxide Synthase Type II/metabolism , Oxygen/metabolism , Vascular Endothelial Growth Factor A/metabolism , Adult , Aged , Carotid Body/enzymology , Cell Differentiation , Child, Preschool , Humans , Hypoxia/metabolism , Young Adult
19.
Int Endod J ; 46(5): 466-76, 2013 May.
Article in English | MEDLINE | ID: mdl-23137186

ABSTRACT

AIM: To investigate the inflammatory response in human gingival fibroblasts (HGFs) treated with a relatively low 2-hydroxyethyl methacrylate (HEMA) concentration by studying reactive oxygen species (ROS) production, cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) gene expression, and prostaglandin E2 (PGE2) release. METHODOLOGY: Cultured HGFs were exposed to 3 mmol L⁻¹ HEMA for 0, 24 or 96 h. ROS production was investigated by flow cytometry; TNF-α and COX-2 gene expression was determined by RT-PCR, and prostaglandin E2 production was detected by an enzyme immunoassay. RESULTS: After 24- or 96-h HEMA incubation, ROS levels were approximately eightfold and elevenfold higher than controls, whilst COX-2 gene expression was approximately twofold or fourfold higher than controls, respectively. Twenty-four-hour exposure enhanced TNF-α mRNA levels by approximately 66%, whilst after 96-h incubation, TNF-α gene expression was fivefold higher than controls. Ninety-six-hour HEMA treatment increased PGE2 concentration in the culture medium by around 17% compared with controls. CONCLUSIONS: 2-Hydroxyethyl methacrylate treatment (3 mmol L⁻¹) induced an inflammatory response in HGFs modulated by ROS production, as well as by the increase in TNF-α and COX-2 gene expression and by PGE2 release.


Subject(s)
Dental Materials/pharmacology , Fibroblasts/drug effects , Gingiva/drug effects , Methacrylates/pharmacology , Acetylcysteine/pharmacology , Cell Culture Techniques , Cell Survival/drug effects , Cells, Cultured , Cyclooxygenase 2/drug effects , Dinoprostone/analysis , Free Radical Scavengers/pharmacology , Gingiva/cytology , Humans , Inflammation Mediators/pharmacology , Reactive Oxygen Species/analysis , Time Factors , Tumor Necrosis Factor-alpha/drug effects
20.
Adv Exp Med Biol ; 758: 265-71, 2012.
Article in English | MEDLINE | ID: mdl-23080171

ABSTRACT

Hypoxia inducible factor 1(HIF-1α) is the regulator of oxygen homeostasis in tissue correlated with neuroglobin (NGB) a member of the family of globins in vertebrates. The present study investigates, the expression and the location of NGB, HIF-1α in human carotid bodies, sampled at autopsy from children (mean age: 2 year ±), young (mean age: 27.5) and 4 old subjects (mean age: 73.5). The percentage of NGB positive area was higher in the old subjects (4.4 ±2.8%), as compared with the young ones (2.4 ±1.8%) and children (1.0 ±1.8%). Positive HIF-1α nuclei were detected in young and old subjects (1.0 ±0.14% vs 3.0 ±0.28%, respectively), whereas CB tissues from children did not show any HIF-1α reaction. The increase of NGB and HIF-1α expression suggests a possible role of the two oxygen sensors in the aging processes. Even though the physiological role of NGB is not well understood, it could be suggested that is act as a respiratory protein connected with HIF.


Subject(s)
Aging/physiology , Carotid Body/physiology , Globins/physiology , Hypoxia-Inducible Factor 1, alpha Subunit/physiology , Nerve Tissue Proteins/physiology , Adult , Aged , Child, Preschool , Globins/analysis , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/analysis , Immunohistochemistry , Nerve Tissue Proteins/analysis , Neuroglobin
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