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1.
Mymensingh Med J ; 32(2): 430-436, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37002754

RESUMO

Pancreatic exocrine insufficiency occurs as a clinical consequence of chronic pancreatitis leading to fat maldigestion, malabsorption and malnutrition. Fecal elastase-1 is a laboratory-based test used for the diagnosis or exclusion of pancreatic exocrine insufficiency. The aim of the study was to observe the value of fecal elastase-1 in children with pancreatitis as an indicator of pancreatic exocrine insufficiency. This was a cross-sectional descriptive study conducted from January 2017 through June 2018. Thirty children with pain abdomen as control and 36 patients with pancreatitis as cases were included. An ELISA technique which recognizes human pancreatic elastase-1 from spot stool sample was employed for the test. Fecal elastase-1 activity in spot stool samples in acute pancreatitis (AP) ranged from 198.2-500µg/g with a mean of 342.1±136.4µg/g, acute recurrent pancreatitis (ARP) ranged from 15-500µg/g with a mean of 332.8±194.5µg/g and chronic pancreatitis (CP) ranged from 15-492.8µg/g with a mean of 222.2±197.1µg/g was obtained. In controls, fecal elastase-1 ranged from 28.4-500µg/g with a mean of 398.8±114.9µg/g. Disease severity was classified as mild to moderate pancreatic insufficiency (fecal elastase-1 100 to 200µg/g stool) was found in AP (14.3%) and CP (6.7%) cases. The severe pancreatic insufficiency (fecal elastase-1<100µg/g stool) was observed in ARP (28.6%) and CP (46.7%) cases. Malnutrition was observed in severe pancreatic insufficiency cases. This study result showed that fecal elastase-1 can be used as a measure of pancreatic exocrine function in children with pancreatitis.


Assuntos
Insuficiência Pancreática Exócrina , Desnutrição , Pancreatite Crônica , Humanos , Criança , Estudos Transversais , Doença Aguda , Elastase Pancreática/análise , Fezes , Pancreatite Crônica/complicações , Pancreatite Crônica/diagnóstico , Insuficiência Pancreática Exócrina/diagnóstico , Insuficiência Pancreática Exócrina/etiologia
2.
Mymensingh Med J ; 32(1): 10-17, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36594293

RESUMO

Asthma is a major noncommunicable disease (NCD), affecting both children and adults, and is the most common chronic disease among children. It is common in all ages and the prevalence is increasing in most countries, especially among children as because of urbanization. Multiple therapeutic modalities are available for management of acute asthma. The commonly used formulation is Racemic Salbutamol which contains equal amounts of both R and S isomers. Levosalbutamol contains only R isomer. The aim of the study was to compare the efficacy of levosalbutamol and racemic salbutamol for the treatment of acute exacerbation of asthma in children (5 to 15 years). A randomized double blind clinical trial was conducted in the Department of Paediatrics, Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh from October 2013 to March 2014. In this study randomization was done in two groups. Group A received nebulized levosalbutamol (LEV) and Group B received nebulized racemic salbutamol (RAC). The study parameters were respiratory rate (RR), heart rate (HR), oxygen saturation in room air (SpO2), PEFR, asthma score and serum K+ level. The results of treatment outcome were compared between two groups. After treatment the respiratory rate was 24.4±5.6 per minute versus 27.6±5.3 per minute (p<0.05); heart rate was 115.5±16.4 per minute versus 124.5±12.0 per minute (p<0.05); SpO2 was 97.2±1.8% vs 95.0±1.6% (p<0.05); PEFR was found 159.6±30.7L/min versus 143.8±27.1L/min (p<0.05) in the LEV and RAC group respectively. LEV is more effective than RAC in respect to significant improvement of asthma score. Regarding adverse events racemic salbutamol causes significant tachycardia. The study concluded that nebulized levosalbutamol is superior to racemic salbutamol in children in the treatment of acute exacerbation of asthma.


Assuntos
Albuterol , Asma , Adulto , Humanos , Criança , Albuterol/uso terapêutico , Albuterol/efeitos adversos , Bangladesh , Asma/tratamento farmacológico , Levalbuterol/uso terapêutico , Administração por Inalação , Método Duplo-Cego , Broncodilatadores/uso terapêutico , Doença Aguda
3.
Kathmandu Univ Med J (KUMJ) ; 20(77): 107-110, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36273302

RESUMO

Osteopetrosis (Marble bone disease) is a very rare congenital genetic disease of skeleton, resulting from defective bone resorption, due to functionally defective osteoclast, leading to accumulation of excessive bone mass. Malignant infantile osteopetrosis (MIO) is one of the varieties of osteopetrosis, which is fatal and is diagnosed in early infancy. Malignant infantile osteopetrosis is present with abnormal bone remodeling, hematological abnormities, features of extramedullary hematopoiesis. Radiology is the key of diagnosis. In this case, we present a 5-monthold male infant diagnosed as malignant infantile osteopetrosis, who presented with bronchopneumonia, anemia, thrombocytopenia, hepatosplenomegaly, failure to thrive (FTT).


Assuntos
Anemia , Osteopetrose , Lactente , Humanos , Masculino , Pré-Escolar , Osteopetrose/diagnóstico , Osteopetrose/diagnóstico por imagem , Medula Óssea , Esplenomegalia/diagnóstico por imagem , Esplenomegalia/etiologia , Radiografia
4.
Chemosphere ; 306: 135631, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35810869

RESUMO

The catalyst recovery is the major concern in commercialization of photocatalysts for the industrial effluent treatment process. To overcome this major issue, Fe2O3 based magnetic photocatalytic heterostructure É£-Fe2O3/FeTiO3 nanocomposite was synthesized by hydrothermal method. Fe2O3 is the cheapest visible active magnetic photocatalytic material, but it has the limitation of fast e-/h + recombination. Titanium (Ti) was loaded on γ-Fe2O3 to overcome this issue. The loaded Ti has grown as FeTiO3 on the surface of É£-Fe2O3 nanocrystals and emerged as heterostructure É£- Fe2O3/FeTiO3 nanocomposites, which was confirmed by XRD and TEM results. The loading concentration of Ti on γ-Fe2O3 was optimized to achieve the maximum photocatalytic efficiency without compromising the magnetic property of γ-Fe2O3 to facilitate the magnetic separation. DRS-UV spectra revealed the strong visible light response of γ- Fe2O3/FeTiO3 nanocomposite. The photocatalytic efficiencies of the synthesized materials were evaluated using methylene blue (MB) as a model pollutant under sunlight. The built-in electric field between p-n junction between FeTiO3 and Fe2O3 and type II charge transfer mechanism extended the lifetime of the charge carriers at the heterojunction of γ- Fe2O3/FeTiO3, which was confirmed by PL spectra. The vibrating sample magnetometer (VSM) study revealed the decreasing magnetization, coercivity (Hc), and retentivity (Mr) of γ-Fe2O3 with increasing concentration of Ti. 92% of the used-up 20 wt% Ti loaded γ-Fe2O3/FeTiO3 magnetic nanocomposite was recovered from the treated wastewater using an electromagnet. Both magnetic properties and efficiency of the nanocomposite increased up to 20 wt% of Ti loading, beyond that decreased due to the increasing composition of antiferromagnetic FeTiO3 and the increasing number of defect sites as recombination centers. Hence, 20 wt% loading of Ti was concluded as the optimum to enhance the efficiency and to retain the magnetic properties. This work aims the commercialization of magnetic photocatalytic materials for the industrial effluent treatment.

5.
Mater Sci Eng C Mater Biol Appl ; 118: 111409, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33255012

RESUMO

One of the significant problems associated with islet encapsulation for type 1 diabetes treatment is the loss of islet functionality or cell death after transplantation because of the unfavorable environment for the cells. In this work, we propose a simple strategy to fabricate electrospun membranes that will provide a favorable environment for proper islet function and also a desirable pore size to cease cellular infiltration, protecting the encapsulated islet from immune cells. By electrospinning the wettability of three different biocompatible polymers: cellulose acetate (CA), polyethersulfone (PES), and polytetrafluoroethylene (PTFE) was greatly modified. The contact angle of electrospun CA, PES, and PTFE increased to 136°, 126°, and 155° as compared to 55°, 71°, and 128° respectively as a thin film, making the electrospun membranes hydrophobic. Commercial porous membranes of PES and PTFE show a contact angle of 30° and 118°, respectively, confirming the hydrophobicity of electrospun membranes is due to the surface morphology induced by electrospinning. In- vivo results confirm that the induced hydrophobicity and surface morphology of electrospun membranes impede cell attachment, which would help in maintaining the 3D circular morphology of islet cell. More importantly, the pore size of 0.3-0.6 µm obtained due to the densely packed structure of nanofibers, will be able to restrict immune cells but would allow free movement of molecules like insulin and glucose. Therefore, electrospun polymer fibrous membranes as fabricated in this work, with hydrophobic and porous properties, make a strong case for successful islet encapsulation.


Assuntos
Nanofibras , Interações Hidrofóbicas e Hidrofílicas , Polímeros , Têxteis , Molhabilidade
6.
J Am Chem Soc ; 142(4): 1975-1986, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31895979

RESUMO

The biological activity of chitosans depends on their degree of polymerization (DP) and degree of acetylation (DA). However, information could also be carried by the pattern of acetylation (PA): the sequence of ß-1,4-linked glucosamine (deacetylated/D) and N-acetylglucosamine (acetylated/A) units. To address this hypothesis, we prepared partially acetylated chitosan oligosaccharides from a chitosan polymer (DA = 35%, DPw = 905) using recombinant chitosan hydrolases with distinct substrate and cleavage specificities. The mixtures were separated into fractions DP4-DP12, which were tested for elicitor and priming activities in rice cells. We confirmed that both activities were influenced by DP, but also observed apparent DA-dependent priming activity, with the ADDD+DADD fraction proving remarkably effective. We then compared all four monoacetylated tetramers prepared using different chitin deacetylases and observed significant differences in priming activity. This demonstrates for the first time that PA influences the biological activity of chitosans, which can now be recognized as bona fide information-carrying molecules.


Assuntos
Biopolímeros/metabolismo , Quitosana/metabolismo , Acetilação , Acetilglucosamina/metabolismo , Amidoidrolases/metabolismo , Glucosamina/metabolismo , Oryza/metabolismo , Polimerização , Especificidade por Substrato
7.
Regen Med ; 14(7): 647-661, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31347456

RESUMO

Aim: We investigated the role of induced endothelial cells (iECs) in mesenchymal stem cells (MSCs)/iECs co-culture and assessed their osteogenic ability on silk fibroin nanofiber scaffolds. Methods: The osteogenic differentiation was assessed by the ALP assay, calcium assay and gene expression studies. Results: The osteogenic differentiation of the iECs co-cultures was found to be higher than the MSCs group and proximal to endothelial cells (ECs) co-cultures. Furthermore, the usage of isogenic iECs for co-culture increased the osteogenic and endothelial gene expression. Conclusion: These findings suggest that iECs mimic endothelial cells when co-cultured with MSCs and that one MSCs source can be used to give rise to both MSCs and iECs. The isogenic MSCs/iECs co-culture provides a new option for bone tissue engineering applications.


Assuntos
Diferenciação Celular , Células Endoteliais/metabolismo , Fibroínas/química , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Alicerces Teciduais/química , Técnicas de Cocultura , Células Endoteliais/citologia , Regulação da Expressão Gênica , Humanos , Células-Tronco Mesenquimais/citologia
8.
J Tissue Eng Regen Med ; 13(6): 908-924, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30866145

RESUMO

In spite of being a new field, three-dimensional (3D) bioprinting has undergone rapid growth in the recent years. Bioprinting methods offer a unique opportunity for stem cell distribution, positioning, and differentiation at the microscale to make the differentiated architecture of any tissue while maintaining precision and control over the cellular microenvironment. Bioprinting introduces a wide array of approaches to modify stem cell fate. This review discusses these methodologies of 3D bioprinting stem cells. Fabricating a fully operational tissue or organ construct with a long life will be the most significant challenge of 3D bioprinting. Once this is achieved, a whole human organ can be fabricated for the defect place at the site of surgery.


Assuntos
Bioimpressão/tendências , Impressão Tridimensional/tendências , Células-Tronco/citologia , Animais , Diferenciação Celular , Humanos , Engenharia Tecidual , Alicerces Teciduais/química
9.
Mater Sci Eng C Mater Biol Appl ; 94: 703-712, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30423757

RESUMO

2D cell culture has been widely developed with various micropatterning and microfabrication techniques over the past few decades for creating and controlling cellular microenvironments including cell-matrix interactions, cell-cell interactions, and bio-mimicking the in-vivo tissue hierarchy and functions. However, the drawbacks of 2D culture have currently paved the way to 3D cell culture which is considered clinically and biologically more relevant. Here we report a 3D double strategy for osteodifferentiation of MSC spheroids on nano- and micro-patterned PLGA/Collagen/nHAp electrospun fiber mats. A comparison of cell alignment, proliferation and differentiation of 2D and 3D MSCs on patterned and non-patterned substrate was done. The study demonstrates the synergistic effect of geometric cues and 3D culture on differentiation of MSC spheroids into osteogenic lineage even in absence of osteoinduction medium.


Assuntos
Regeneração Óssea/fisiologia , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Osteogênese , Esferoides Celulares/citologia , Engenharia Tecidual/métodos , Fosfatase Alcalina/metabolismo , Proliferação de Células , Sobrevivência Celular , Citoesqueleto/metabolismo , Humanos , Células-Tronco Mesenquimais/enzimologia , Coloração e Rotulagem
10.
J Nanosci Nanotechnol ; 18(2): 925-935, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29448516

RESUMO

Gallium doped mesoporous TiO2 with different weight percentages were synthesized by sol-gel method using Pluronic P123 as the structure directing template. The physico-chemical properties of all the synthesized catalysts were determined by XRD, TEM, SEM-EDAX, N2 adsorption-desorption studies, XPS, UV-vis DRS, FT-IR and photoluminescence spectroscopy. 1.0 wt% Ga-TiO2 exhibited the highest photocatalytic efficiency among all the synthesized materials under visible light due to the high surface area, reduced band gap and suppressed electron-hole recombination. Ga3+ ions substitutions for Ti4+ ions in TiO2 lattice created oxygen vacancies in TiO2 lattice, which created a defect energy level below the conduction band of TiO2 and hence the band gap was reduced. The oxygen vacancy defects was playing significant role to improve the adsorption of oxygen molecules, hydroxide ions and cationic rhodamine B (RhB) on TiO2 surface in an aqueous medium. The lifetime of the charge carriers was also enhanced by trapping the photogenerated electrons in oxygen vacancies and transferring them to the adsorbed O2 to produce superoxide anion radicals (O-. 2 ). The photo-induced holes at valence band reduced the adsorbed OH- ions and produced a large number of .OH radicals, which subsequently degraded the RhB. Hence oxygen vacancies created by gallium doping on TiO2 enhanced the photocatalytic efficiency for the degradation of RhB under visible light.

11.
J Tissue Eng Regen Med ; 12(4): e2073-e2084, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29327436

RESUMO

Considering the complex hierarchical structure of bone, biomimicking the micro and nano level features should be an integral part of scaffold fabrication for successful bone regeneration. We aim to biomimic the microstructure and nanostructure of bone and study the effect of physical cues on cell alignment, proliferation, and differentiation. To achieve this, we have divided the scaffolds into groups: electrospun SU-8 nanofibers, electrospun SU-8 nanofibers with UV treatment, and micropatterned (20 µm sized ridges and grooves) SU-8 nanofibers by photolithography with UV treatment. Two types of culture conditions were applied: with and without osteoinduction medium. In vitro cell proliferation assays, protein estimation, alkaline phosphatase osteodifferentiation assay, live dead assay, and cell alignment studies were performed on these micropatterned nanofiber domains. Our findings show that patterned surface induced an early osteodifferentiation of mesenchymal stem cells even in absence of osteoinduction medium. An interesting similarity with the helicoidal plywood model of the bone was observed. The cells showed layering and rotation along the patterns with time. This resembles the in vivo anisotropic multilamellar bone tissue architecture thus, closely mimicking the subcellular features of bone. This might serve as a smart biomaterial surface for mesenchymal stem cell differentiation in therapeutics where the addition of external chemical factors is a challenge.


Assuntos
Materiais Biomiméticos/química , Osso e Ossos/metabolismo , Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Nanofibras/química , Osteogênese , Osso e Ossos/citologia , Humanos , Células-Tronco Mesenquimais/citologia , Engenharia Tecidual
12.
J Tissue Eng Regen Med ; 12(1): e604-e619, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-27686061

RESUMO

Biomimetic scaffolds mimicking the natural hierarchical structure of tissues have recently attracted the interest of researchers and provide a promising strategy to resemble the nonhomogeneous property of tissues. This review provides an overview of the various hierarchical length scales in the native tissues of the musculoskeletal system. It further focuses on electrospinning as a technique to mimic the tissue structures with specific emphasis on bone. The effect of cellular alignment, infiltration, vascularisation, and differentiation in these nanostructures has also been discussed. An outline of the various additive manufacturing techniques in combination with electrospinning has been elaborated. The review concludes with the challenges and future directions to understand the intricacies of bottom-up approach to engineer the systems at a macroscale. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Biomimética , Sistema Musculoesquelético/metabolismo , Nanofibras/química , Regeneração , Engenharia Tecidual/métodos , Animais , Humanos , Sistema Musculoesquelético/anatomia & histologia , Neovascularização Fisiológica
13.
Biotechnol J ; 12(12)2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28980771

RESUMO

Electrospinning is a popular technique used to mimic the natural sub-micron features of the native tissue. The ultra-fine fibers provide a favorable extracellular matrix-like environment for regulation of cellular functions. This article summarizes and reviews the current advances in electrospun fiber application and focuses on the novel strategies applied for tissue regeneration and repair. It explores the different factors affecting the attachment and proliferation of mesenchymal stem cells (MSCs) on the electrospun substrates. The influence of different features of electrospun fibers in the differentiation of MSCs into specific lineages (bone, cartilage, tendon/ligament, and nerves) has been elaborated. In addition, the different techniques to mimic the hierarchical features of tissues and its effect on cellular functions are reviewed. Additionally, the new developments like three-dimensional (3D) electrospinning, 3D spheroid double strategy and the comparative analysis of dynamic and static culture on electrospun scaffolds are discussed. With the intricate understanding of the interaction between the cells and the electrospun fiber matrix we can aim to combine the newer strategies to overcome the existing challenges and improve the potential application of electrospun fibers in the field of tissue regeneration and repair.


Assuntos
Diferenciação Celular , Técnicas Eletroquímicas , Nanofibras , Medicina Regenerativa , Células-Tronco , Animais , Microambiente Celular , Humanos , Camundongos , Engenharia Tecidual , Alicerces Teciduais
14.
ACS Biomater Sci Eng ; 3(8): 1730-1737, 2017 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-33429654

RESUMO

Alginate-based hydrogels are extensively used matrices for cell encapsulation, but they need to be modified to recapitulate chemical, microstructural, and mechanical properties of the native extracellular matrix. Like other cell types, mesenchymal stem cells exhibit rounded and clustered morphologies when they are embedded in alginate hydrogels. In this study, we use covalently cross-linked oxidized alginate-gelatin hydrogels to encapsulate human adipose-derived stem cells in order to investigate cell growth, viability, and morphology during osteogenic differentiation taking advantage of the different physicochemical properties of this modified alginate-based hydrogel in comparison to those of the pristine alginate hydrogel. We investigate the effect of hydrogel compositions on stem cell behavior in 3D. Higher viability and the spreading morphology of encapsulated cells with interconnected networks were observed in high gelatin containing compositions. More filopodial protrusions from multicellular nodules were noticed during osteogenic differentiation in the hydrogels having a high amount of gelatin, confirming their suitability for cell encapsulation and bone tissue engineering applications.

15.
J Tissue Eng Regen Med ; 10(10): E497-E509, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-24357645

RESUMO

Mesenchymal stem cells can be isolated from a variety of different sources, each having their own peculiar merits and drawbacks. Although a number of studies have been conducted comparing these stem cells for their osteo-differentiation ability, these are mostly done in culture plastics. We have selected stem cells from either adipose tissue (ADSCs) or bone marrow (BMSCs) and studied their differentiation ability in highly porous three-dimensional (3D) 45S5 Bioglass®-based scaffolds. Equal numbers of cells were seeded onto 5 × 5 × 4 mm3 scaffolds and cultured in vitro, with or without osteo-induction medium. After 2 and 4 weeks, the cell-scaffold constructs were analysed for cell number, cell spreading, viability, alkaline phosphatase activity and osteogenic gene expression. The scaffolds with ADSCs displayed osteo-differentiation even without osteo-induction medium; however, with osteo-induction medium osteogenic differentiation was further increased. In contrast, the scaffolds with BMSCs showed no osteo-differentiation without osteo-induction medium; after application of osteo-induction medium, osteo-differentiation was confirmed, although lower than in scaffolds with ADSCs. In general, stem cells in 3D bioactive glass scaffolds differentiated better than cells in culture plastics with respect to their ALP content and osteogenic gene expression. In summary, 45S5 Bioglass-based scaffolds seeded with ADSCs are well-suited for possible bone tissue-engineering applications. Induction of osteogenic differentiation appears unnecessary prior to implantation in this specific setting. Copyright © 2013 John Wiley & Sons, Ltd.


Assuntos
Tecido Adiposo/metabolismo , Células da Medula Óssea/metabolismo , Diferenciação Celular , Vidro/química , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Alicerces Teciduais/química , Tecido Adiposo/citologia , Células da Medula Óssea/citologia , Humanos , Células-Tronco Mesenquimais/citologia
16.
J Conserv Dent ; 18(1): 15-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25657520

RESUMO

AIM: The purpose of this study was to evaluate the effects of three electronic apex locators (EAL), electric pulp tester (EPT) and diathermy on pacemaker function in vitro. MATERIALS AND METHODS: Three EALs: Root ZX (J. Morita Co., Tustin, CA, U.S.A.), Propex (Dentsply), Mini Apex locator (SybronEndo, Anaheim, CA, USA), EPT (Parkell pulp vitality tester Farmingdale, NY, USA) and Diathermy (Neomed 250 B) were tested for any interference with one pacemaker (A medtronic kappa KVDD901-serial number: PLE734632S). Directly connecting the pacemaker lead with the EAL/EPT/diathermy operating on a flat bench top, the telemetry wand was held directly over the pacemaker to monitor the pacing pattern for a period of 30 s. Pacemaker activity was continuously recorded on the telemetric programmer and electro gram (EGM) readings examined for pacer inhibition, noise reversion or inappropriate pacemaker pulses. RESULTS: All the three apex locators showed no pacing interference or background noise during its function or at rest. The EGM readings of EPT showed varying levels of background noise in between pacing however, this did not affect the normal pacing pattern and the pacing interval remained constant. EGM readings of diathermy showed an increase in the pacing interval (irregular pacing pattern) followed by complete inhibition of the pacing system. CONCLUSION: The tested EALs do not interfere with cardiac pacemaker function. The tested EPT showed varying levels of background noise but does not interfere with cardiac pacemaker function. Use of Diathermy interfered with the normal pacing, leading to complete inhibition of the pacing system.

17.
PLoS One ; 9(12): e113319, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25470000

RESUMO

Bioactive glass (BG) scaffolds are being investigated for bone tissue engineering applications because of their osteoconductive and angiogenic nature. However, to increase the in vivo performance of the scaffold, including enhancing the angiogenetic growth into the scaffolds, some researchers use different modifications of the scaffold including addition of inorganic ionic components to the basic BG composition. In this study, we investigated the in vitro biocompatibility and bioactivity of Cu2+-doped BG derived scaffolds in either BMSC (bone-marrow derived mesenchymal stem cells)-only culture or co-culture of BMSC and human dermal microvascular endothelial cells (HDMEC). In BMSC-only culture, cells were seeded either directly on the scaffolds (3D or direct culture) or were exposed to ionic dissolution products of the BG scaffolds, kept in permeable cell culture inserts (2D or indirect culture). Though we did not observe any direct osteoinduction of BMSCs by alkaline phosphatase (ALP) assay or by PCR, there was increased vascular endothelial growth factor (VEGF) expression, observed by PCR and ELISA assays. Additionally, the scaffolds showed no toxicity to BMSCs and there were healthy live cells found throughout the scaffold. To analyze further the reasons behind the increased VEGF expression and to exploit the benefits of the finding, we used the indirect method with HDMECs in culture plastic and Cu2+-doped BG scaffolds with or without BMSCs in cell culture inserts. There was clear observation of increased endothelial markers by both FACS analysis and acetylated LDL (acLDL) uptake assay. Only in presence of Cu2+-doped BG scaffolds with BMSCs, a high VEGF secretion was demonstrated by ELISA; and typical tubular structures were observed in culture plastics. We conclude that Cu2+-doped BG scaffolds release Cu2+, which in turn act on BMSCs to secrete VEGF. This result is of significance for the application of BG scaffolds in bone tissue engineering approaches.


Assuntos
Substitutos Ósseos/farmacologia , Cobre/farmacologia , Células Endoteliais/metabolismo , Células-Tronco Mesenquimais/metabolismo , Alicerces Teciduais/química , Substitutos Ósseos/química , Diferenciação Celular , Técnicas de Cocultura , Cobre/química , Células Endoteliais/citologia , Vidro/química , Humanos , Células-Tronco Mesenquimais/citologia , Microvasos/citologia , Osteogênese , Engenharia Tecidual/métodos , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
Materials (Basel) ; 7(3): 1957-1974, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-28788549

RESUMO

In addition to good mechanical properties needed for three-dimensional tissue engineering, the combination of alginate dialdehyde, gelatin and nano-scaled bioactive glass (45S5) is supposed to combine excellent cellular adhesion, proliferation and differentiation properties, good biocompatibility and predictable degradation rates. The goal of this study was to evaluate the in vitro and in vivo biocompatibility as a first step on the way to its use as a scaffold in bone tissue engineering. In vitro evaluation showed good cell adherence and proliferation of bone marrow derived mesenchymal stem cells seeded on covalently crosslinked alginate dialdehyde-gelatin (ADA-GEL) hydrogel films with and without 0.1% nano-Bioglass® (nBG). Lactate dehydrogenase (LDH)- and mitochondrial activity significantly increased in both ADA-GEL and ADA-GEL-nBG groups compared to alginate. However, addition of 0.1% nBG seemed to have slight cytotoxic effect compared to ADA-GEL. In vivo implantation did not produce a significant inflammatory reaction, and ongoing degradation could be seen after four weeks. Ongoing vascularization was detected after four weeks. The good biocompatibility encourages future studies using ADA-GEL and nBG for bone tissue engineering application.

19.
J Endod ; 39(10): 1261-4, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24041388

RESUMO

BACKGROUND: The aim of this investigation was to compare the effectiveness of 3% sodium hypochlorite (NaOCl), 2% chlorhexidine, 1% peracetic acid, and 10% povidone-iodine in the rapid disinfection of Resilon (Pentron Clinical Technologies, LLC, Wallingford, CT) and gutta-percha cones contaminated with Enterococcus faecalis and Bacillus subtilis. METHODS: Two hundred fifty-six samples consisting of 128 gutta-percha cones and 128 Resilon cones were used in this study. The materials were tested for disinfection according to the type of solution (3% NaOCl, 2% chlorhexidine, 1% peracetic acid, or 10% povidone-iodine), the time of exposure to each solution (1 or 5 minutes), and the type of microorganisms (E. faecalis or B. subtilis). Subsequent to the disinfection, samples were placed in test tubes containing 10 mL Mueller-Hinton broth and incubated at 37°C for 7 days. All test tubes were observed at 24-hour intervals and visually checked for turbidity, signifying microbial growth. RESULTS: In this study, 1% peracetic acid showed the best results for both 1 minute and 5 minutes of disinfection, 2% chlorhexidine showed the second best results although it was statistically at par with peracetic acid, and 3% hypochlorite ranked third in disinfection; this was statistically significant when compared with peracetic acid and chlorhexidine. Disinfection by povidone-iodine was the least within all the groups for both contact times although disinfection for 5 minutes showed better results than disinfection for 1 minute for gutta-percha. CONCLUSIONS: The outcome of this study confirmed the efficacy of 1% peracetic acid and 2% chlorhexidine in the rapid disinfection of both Resilon and gutta-percha.


Assuntos
Clorexidina/farmacologia , Desinfetantes/farmacologia , Guta-Percha/química , Ácido Peracético/farmacologia , Povidona-Iodo/farmacologia , Materiais Restauradores do Canal Radicular/química , Hipoclorito de Sódio/farmacologia , Bacillus subtilis/efeitos dos fármacos , Desinfecção/métodos , Contaminação de Medicamentos/prevenção & controle , Enterococcus faecalis/efeitos dos fármacos , Humanos , Teste de Materiais , Nefelometria e Turbidimetria , Propriedades de Superfície , Temperatura , Fatores de Tempo
20.
J Conserv Dent ; 16(3): 272-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23833466

RESUMO

Aberrations in the root canal system can pose a considerable challenge to the endodontist during root canal treatment. These anatomical variations are more commonly seen in maxillary molars and mandibular teeth, but only a few cases have been reported with alteration in the internal canal anatomy of maxillary canine. The present report describes the diagnosis of bilateral occurrence of two root canals in maxillary canines with single root and the endodontic management of the right maxillary canine with the aid of spiral computed tomography (CT). The CT images revealed the presence of Vertucci's type-III canal configuration in the right maxillary canine. The same canal pattern was found in the contra-lateral canine, which was absolutely healthy; and also all the mandibular anterior teeth and first premolars showed bifid canal pattern.

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