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1.
J Med Virol ; 93(8): 4840-4845, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33543795

RESUMO

Conjunctivitis is a frequent ocular disorder caused by human adenoviruses (HAdVs). Only a few of the 45 HAdV-D species are associated with epidemic keratoconjunctivitis, including HAdV-D8. Nosocomial outbreaks due to HAdV-D8 have been rarely described, because keratoconjunctivitis cases are clinically diagnosed and treated without having to characterize the causative agent. Moreover, molecular typing is tedious when using classical techniques. In this study, a hospital outbreak of conjunctivitis caused by HAdV-D8 was characterized using the recently developed whole-genome sequencing (WGS) method. Of the 363 patients attending the Ophthalmology Department between July 13 and August 13, 2018, 36 may have acquired intrahospital conjunctivitis. Also, 11 of 22 samples sent to the Virology section were selected for WGS analysis. The WGS results revealed that 10 out of 11 HAdV-D8 strains were closely related. The remaining strain (Case 28) was more similar to a strain from an outbreak in Germany obtained from a public sequence database. WGS results showed that outbreak HAdV-D8 strains had a minimum percentage of identity of 94.3%. WGS is useful in a clinical setting, because it avoids carrying out viral culture or specific polymerase chain reaction sequencing. The public availability of sequence reads makes it easier to compare clusters in circulation. In conclusion, WGS can play an important role in standard routines to describe viral outbreaks.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/genética , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Genoma Viral/genética , Ceratoconjuntivite/epidemiologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecção Hospitalar/virologia , DNA Viral/genética , Feminino , Humanos , Ceratoconjuntivite/virologia , Masculino , Pessoa de Meia-Idade , Filogenia , Espanha/epidemiologia , Centros de Atenção Terciária , Sequenciamento Completo do Genoma
2.
Euro Surveill ; 21(13)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27055477

RESUMO

Colistin resistance was detected in 53 of 10,011 Escherichia coli (0.5%) by prospective phenotypic testing of consecutive clinical isolates in a single hospital in Barcelona, Spain (2012-15). The mcr-1 gene was retrospectively identified by PCR and sequencing in 15 of 50 available isolates. Each isolate had a unique PFGE pattern except for two. This clonal diversity supports the hypothesis of horizontal dissemination of the mcr-1 gene in the local study population.


Assuntos
Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Eletroforese em Gel de Campo Pulsado , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Estudos Prospectivos , Espanha/epidemiologia , Adulto Jovem
3.
J Antimicrob Chemother ; 69(4): 947-54, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24216765

RESUMO

OBJECTIVES: Ethambutol resistance has mostly been related to mutations in the embB gene. The objective of the present study was to characterize the embB gene in a collection of ethambutol-resistant and ethambutol-susceptible isolates of Mycobacterium tuberculosis complex (MTBC) from Barcelona, and to develop a DNA microarray for the rapid detection of embB mutations in our area. METHODS: Fifty-three ethambutol-resistant and 702 ethambutol-susceptible isolates of MTBC were sequenced in internal 982-1495 bp fragments of the embB gene. In addition, a low-cost, low-density array was designed to include the embB codons identified as being most frequently mutated in our area (LD-EMB array). RESULTS: The global prevalence of embB mutations found among the ethambutol-resistant isolates was 77.4% (41/53). Substitutions in embB306 were the most common [53.7% (22/41)], followed by substitutions in embB406 [26.8% (11/41)]. The presence of mutations in embB406 was related to higher levels of ethambutol resistance and to multidrug resistance. Among unrelated isolates (from 24-locus MIRU-VNTR genotyping), the percentage of embB-mutated isolates was 72.9% (27/37)--59.3% (16/27) in embB306 and 25.9% (7/27) in embB406. None of the ethambutol-susceptible isolates studied showed a mutation in codon 306 or 406. The LD-EMB array showed 100% sensitivity and specificity in identifying the main embB substitutions in our area. CONCLUSIONS: Mutations at codons 306 and 406 of embB have a relevant role in resistance to ethambutol in our area. The LD-EMB array developed in this study would appear to be a good molecular test for rapid detection of ethambutol resistance.


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana , Etambutol/farmacologia , Mutação de Sentido Incorreto , Mycobacterium tuberculosis/genética , Pentosiltransferases/genética , Códon , Genótipo , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Análise de Sequência com Séries de Oligonucleotídeos , Análise de Sequência de DNA , Espanha
4.
Chem Sci ; 15(1): 55-76, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38131070

RESUMO

Hydroxyapatite-based materials have been widely used in countless applications, such as bone regeneration, catalysis, air and water purification or protein separation. Recently, much interest has been given to controlling the aspect ratio of hydroxyapatite crystals from bulk samples. The ability to exert control over the aspect ratio may revolutionize the applications of these materials towards new functional materials. Controlling the shape, size and orientation of HA crystals allows obtaining high aspect ratio structures, improving several key properties of HA materials such as molecule adsorption, ion exchange, catalytic reactions, and even overcoming the well-known brittleness of ceramic materials. Regulating the morphogenesis of HA crystals to form elongated oriented fibres has led to flexible inorganic synthetic sponges, aerogels, membranes, papers, among others, with applications in sustainability, energy and catalysis, and especially in the biomedical field.

5.
Enferm Infecc Microbiol Clin ; 30(1): 3-10, 2012 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-21924798

RESUMO

INTRODUCTION: The aim of the present work was to demonstrate the utility of a non-tuberculous mycobacteria (NTM) identification algorithm, which integrates different PCR-based techniques and basic phenotypic features. Moreover, the algorithm for pattern restriction analysis of hsp65 (hsp65 PRA) interpretation has been updated. METHODS: The workflow chosen consisted of the identification by a DNA hybridization probe method, followed by PCR-restriction enzyme analysis of hsp65 (hsp65 PRA) in those isolates that cannot be identified by hybridization probes. If necessary, 16S rRNA gene and hsp65 gene sequencing were used for speciation. RESULTS: A total of 236 NTM were collected, in which 102 (43.2%) isolates were identified by DNA specific probes and 76 (32.2%) isolates were identified with hsp65 PRA. Partial sequencing of the 16S rRNA gene was used for species identification of the remaining 58 (24.5%) isolates. Fifty-three (22.4%) were identified using this method. Five isolates (2.1%) were submitted for partial sequencing of hsp65 gene and one isolate was identified with this method. Four strains (1.7%) could not be identified at species level. Three new PRA patterns were found. Seven isolates tested positive with the AccuProbe Mycobacterium avium complex identification test but did not test positive with the M. avium or Mycobacterium intracellulare specific probes. Five and two of these isolates were identified as M. intracellulare and Mycobacterium colombiense, respectively. CONCLUSION: This approach allowed us to identify almost all NTM isolates found in this study, including some recently described species.


Assuntos
Algoritmos , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , DNA Bacteriano/análise , Humanos
6.
Enferm Infecc Microbiol Clin ; 30(3): 143-6, 2012 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-22284133

RESUMO

INTRODUCTION: Description of an outbreak of Listeria monocytogenes in a neonatal intensive care unit. METHODS: A questionnaire, environmental investigation and molecular study were performed. RESULTS: We identified a nosocomial outbreak of L. monocytogenes, confirmed by the genetic study, in a neonatal intensive care unit. Three infants were affected. Although the transmission mechanism could not be elucidated, cross-infection was strongly suggested. CONCLUSION: Adherence to universal hygiene standards is necessary to avoid nosocomial outbreaks.


Assuntos
Infecção Hospitalar/epidemiologia , Surtos de Doenças , Doenças do Prematuro/epidemiologia , Unidades de Terapia Intensiva Neonatal , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Contaminação de Equipamentos , Feminino , Mãos/microbiologia , Humanos , Higiene , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/microbiologia , Transmissão de Doença Infecciosa do Profissional para o Paciente/prevenção & controle , Listeria monocytogenes/genética , Listeriose/microbiologia , Listeriose/prevenção & controle , Listeriose/transmissão , Masculino , Meningite por Listeria/líquido cefalorraquidiano , Meningite por Listeria/epidemiologia , Meningite por Listeria/microbiologia , Meningite por Listeria/transmissão , Placenta/microbiologia , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Sabões , Espanha/epidemiologia , Inquéritos e Questionários
7.
J Tissue Eng ; 13: 20417314221119895, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36199978

RESUMO

Although alginate is widely used as a matrix in the formulation of cell-laden inks, this polymer often requires laborious processing strategies due to its lack of cell adhesion moieties. The main objective of the present work was to explore the incorporation of microspheres into alginate-based bioinks as a simple and tuneable way to solve the cell adhesion problems, while adding extra biological functionality and improving their mechanical properties. To this end, three types of microspheres with different mineral contents (i.e. gelatine with 0% of hydroxyapatite, gelatine with 25 wt% of hydroxyapatite nanoparticles and 100 wt% of calcium -deficient hydroxyapatite) were synthesised and incorporated into the formulation of cell-laden inks. The results showed that the addition of microspheres generally improved the rheological properties of the ink, favoured cell proliferation and positively affected osteogenic cell differentiation. Furthermore, this differentiation was found to be influenced by the type of microsphere and the ability of the cells to migrate towards them, which was highly dependent on the stiffness of the bioink. In this regard, Ca2+ supplementation in the cell culture medium had a pronounced effect on the relaxation of the stiffness of these cell-loaded inks, influencing the overall cell performance. In conclusion, we have developed a powerful and tuneable strategy for the fabrication of alginate-based bioinks with enhanced biological characteristics by incorporating microspheres into the initial ink formulation.

8.
Biomater Adv ; 136: 212797, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35929296

RESUMO

Since the discovery that nanostructured surfaces were able to kill bacteria, many works have been published focusing on the design of nanopatterned surfaces with antimicrobial properties. Synthetic bone grafts, based on calcium phosphate (CaP) formulations, can greatly benefit from this discovery if adequate nanotopographies can be developed. However, CaP are reactive materials and experience ionic exchanges when placed into aqueous solutions which may in turn affect cell behaviour and complicate the interpretation of the bactericidal results. The present study explores the bactericidal potential of two nanopillared CaP prepared by hydrolysis of two different sizes of α-tricalcium phosphate (α-TCP) powders under biomimetic or hydrothermal conditions. A more lethal bactericidal response toward Pseudomonas aeruginosa (~75% killing efficiency of adhered bacteria) was obtained from the hydrothermally treated CaP which consisted in a more irregular topography in terms of pillar size (radius: 20-60 nm), interpillar distances (100-1500 nm) and pillar distribution (pillar groups forming bouquets) than the biomimetically treated one (radius: 20-40 nm and interpillar distances: 50-200 nm with a homogeneous pillar distribution). The material reactivity was greatly influenced by the type of medium (nutrient-rich versus nutrient-free) and the presence or not of bacteria. A lower reactivity and superior bacterial attachment were observed in the nutrient-free medium while a lower attachment was observed for the nutrient rich medium which was explained by a superior reactivity of the material paired with the lower tendency of planktonic bacteria to adhere on surfaces in the presence of nutrients. Importantly, the ionic exchanges produced by the presence of materials were not toxic to planktonic cells. Thus, we can conclude that topography was the main contributor to mortality in the bacterial adhesion tests.


Assuntos
Biomimética , Nanoestruturas , Antibacterianos/farmacologia , Aderência Bacteriana , Fosfatos de Cálcio/farmacologia
9.
Biomech Model Mechanobiol ; 21(4): 1099-1115, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35511308

RESUMO

Scaffolds are microporous biocompatible structures that serve as material support for cells to proliferate, differentiate and form functional tissue. In particular, in the field of bone regeneration, insertion of scaffolds in a proper physiological environment is known to favour bone formation by releasing calcium ions, among others, triggering differentiation of mesenchymal cells into osteoblasts. Computational simulation of molecular distributions through scaffolds is a potential tool to study the scaffolds' performance or optimal designs, to analyse their impact on cell differentiation, and also to move towards reduction in animal experimentation. Unfortunately, the required numerical models are often highly complex and computationally too costly to develop parametric studies. In this context, we propose a computational parametric reduced-order model to obtain the distribution of calcium ions in the interstitial fluid flowing through scaffolds, depending on several physical parameters. We use the well-known Proper Orthogonal Decomposition (POD) with two different variations: local POD and POD with quadratic approximations. Computations are performed using two realistic geometries based on a foamed and a 3D-printed scaffolds. The location of regions with high concentration of calcium in the numerical simulations is in fair agreement with regions of bone formation shown in experimental observations reported in the literature. Besides, reduced-order solutions accurately approximate the reference finite element solutions, with a significant decrease in the number of degrees of freedom, thus avoiding computationally expensive simulations, especially when performing a parametric analysis. The proposed reduced-order model is a competitive tool to assist the design of scaffolds in osteoinduction research.


Assuntos
Células-Tronco Mesenquimais , Alicerces Teciduais , Animais , Regeneração Óssea , Cálcio , Osteogênese , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais/química
10.
Microorganisms ; 10(3)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35336167

RESUMO

There is a growing interest in echovirus 30 (E30), an enterovirus responsible for neurological disease and hospitalization. There are multiple studies of outbreaks, but few that study the epidemiology over long periods of time. Our study aims to describe the clinical, epidemiological and microbiological characteristics of a series of E30 infections detected over 26 years. Data were retrospectively collected from a database of all enterovirus infections identified in our laboratory. They were detected by viral isolation or nucleic acid detection in patients presenting with respiratory or neurological infections, rash, sepsis-like syndrome, or gastroenteritis. Enterovirus genotyping was performed by amplification of the VP1 gene using RT-nested PCR, followed by sequencing and BLAST analysis. Of the 2402 enterovirus infections detected, 1619 were linked to at least one genotype and 173 were caused by E30. Clinical information was available for 158 (91.3%) patients. E30 was associated with neurological infection in 107 (67.8%) cases and it was detected almost every year. Phylogenetic analysis was performed with 67 sequences. We observed that E30 strains circulating in Catalonia from 1996 to 2016 belong to two lineages (E and F), although the majority cluster was in F. In 2018, lineage I emerged as the dominant lineage.

11.
Biomater Adv ; 142: 213148, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36274359

RESUMO

Hydroxyapatite nanoparticles are popular tools in bone regeneration, but they have also been used for gene delivery and as anticancer drugs. Understanding their mechanism of action, particularly for the latter application, is crucial to predict their toxicity. To this end, we aimed to elucidate the importance of nanoparticle membrane interactions in the cytotoxicity of MG-63 cells using two different types of nanoparticles. In addition, conventional techniques for studying nanoparticle internalisation were evaluated and compared with newer and less exploited approaches. Hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles were used as suspensions or compacted as specular discs. Comparison between cells seeded on the discs and those supplemented with the nanoparticles allowed direct interaction of the cell membrane with the material to be ruled out as the main mechanism of toxicity. In addition, standard techniques such as flow cytometry were inconclusive when used to assess nanoparticles toxicity. Interestingly, the use of intracellular calcium fluorescent probes revealed the presence of a high number of calcium-rich vesicles after nanoparticle supplementation in cell culture. These structures could not be detected by transmission electron microscopy due to their liquid content. However, by using cryo-soft X-ray imaging, which was used to visualise the cellular ultrastructure without further treatment other than vitrification and to quantify the linear absorption coefficient of each organelle, it was possible to identify them as multivesicular bodies, potentially acting as calcium stores. In the study, an advanced state of degradation of the hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles within MG-63 cells was observed. Overall, we demonstrate that the combination of fluorescent calcium probes together with cryo-SXT is an excellent approach to investigate intracellular calcium, especially when found in its soluble form.


Assuntos
Durapatita , Nanopartículas , Durapatita/química , Magnésio , Nanopartículas/toxicidade , Regeneração Óssea , Microscopia Eletrônica de Transmissão
12.
J Antimicrob Chemother ; 66(10): 2277-80, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21791442

RESUMO

OBJECTIVES: We analysed the ability of Mycobacterium tuberculosis clinical isolates to penetrate and grow inside murine macrophages as a surrogate of fitness. METHODS: Thirty-five drug-resistant and 10 drug-susceptible M. tuberculosis isolates were studied in a murine macrophage model from the J774.2 cell line in a 6 day protocol, performing semi-quantitative counts in Middlebrook 7H11 medium. The mycobacterial penetration index (MPI) after infection and the mycobacterial growth ratio (MGR) inside the macrophages were determined to evaluate the fitness of isolates. RESULTS: Isolates with the katG S315T mutation and multidrug-resistant (MDR) isolates had a significantly lower MGR compared with drug-susceptible isolates. The MPI of the isolates with the katG S315T mutation showed a significant decrease compared with the MPI of those without this mutation. A trend to significantly lower values was also observed on comparing the MPI of the MDR isolates with that of the drug-susceptible isolates and the isolates resistant to isoniazid. CONCLUSIONS: The isoniazid-resistant and MDR isolates with mutations in the katG gene showed decreased multiplication inside murine macrophages, suggesting a lower fitness of M. tuberculosis with these resistance patterns.


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Macrófagos/microbiologia , Mycobacterium tuberculosis/crescimento & desenvolvimento , Animais , Proteínas de Bactérias/genética , Catalase/genética , Linhagem Celular , RNA Polimerases Dirigidas por DNA , Humanos , Isoniazida/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Oxirredutases/genética
13.
Acta Biomater ; 134: 744-759, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34358699

RESUMO

Porosity plays a key role on the osteogenic performance of bone scaffolds. Direct Ink Writing (DIW) allows the design of customized synthetic bone grafts with patient-specific architecture and controlled macroporosity. Being an extrusion-based technique, the scaffolds obtained are formed by arrays of cylindrical filaments, and therefore have convex surfaces. This may represent a serious limitation, as the role of surface curvature and more specifically the stimulating role of concave surfaces in osteoinduction and bone growth has been recently highlighted. Hence the need to design strategies that allow the introduction of concave pores in DIW scaffolds. In the current study, we propose to add gelatin microspheres as a sacrificial material in a self-setting calcium phosphate ink. Neither the phase transformation responsible for the hardening of the scaffold nor the formation of characteristic network of needle-like hydroxyapatite crystals was affected by the addition of gelatin microspheres. The partial dissolution of the gelatin resulted in the creation of spherical pores throughout the filaments and exposed on the surface, increasing filament porosity from 0.2 % to 67.9 %. Moreover, the presence of retained gelatin proved to have a significant effect on the mechanical properties, reducing the strength but simultaneously giving the scaffolds an elastic behavior, despite the high content of ceramic as a continuous phase. Notwithstanding the inherent difficulty of in vitro cultures with this highly reactive material an enhancement of MG-63 cell proliferation, as well as better spreading of hMSCs was recorded on the developed scaffolds. STATEMENT OF SIGNIFICANCE: Recent studies have stressed the role that concave surfaces play in tissue regeneration and, more specifically, in osteoinduction and osteogenesis. Direct ink writing enables the production of patient-specific bone grafts with controlled architecture. However, besides many advantages, it has the serious limitation that the surfaces obtained are convex. In this article, for the first time we develop a strategy to introduce concave pores in the printed filaments of biomimetic hydroxyapatite by incorporation and partial dissolution of gelatin microspheres. The retention of part of the gelatin results in a more elastic behavior compared to the brittleness of hydroxyapatite scaffolds, while the needle-shaped nanostructure of biomimetic hydroxyapatite is maintained and gelatin-coated concave pores on the surface of the filaments enhance cell spreading.


Assuntos
Biomimética , Durapatita , Humanos , Porosidade , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais
14.
Acta Biomater ; 135: 671-688, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34496283

RESUMO

Hydrothermal (H) processes accelerate the hydrolysis reaction of α-tricalcium phosphate (α-TCP) compared to the long-established biomimetic (B) treatments. They are of special interest for patient-specific 3D-printed bone graft substitutes, where the manufacturing time represents a critical constraint. Altering the reaction conditions has implications for the physicochemical properties of the reaction product. However, the impact of the changes produced by the hydrothermal reaction on the in vivo performance was hitherto unknown. The present study compares the bone regeneration potential of 3D-printed α-TCP scaffolds hardened using these two treatments in rabbit condyle monocortical defects. Although both consolidation processes resulted in biocompatible scaffolds with osseointegrative and osteoconductive properties, the amount of newly formed bone increased by one third in the hydrothermal vs the biomimetic samples. B and H scaffolds consisted mostly of high specific surface area calcium-deficient hydroxyapatite (38 and 27 m2 g-1, respectively), with H samples containing also 10 wt.% ß-tricalcium phosphate (ß-TCP). The shrinkage produced during the consolidation process was shown to be very small in both cases, below 3%, and smaller for H than for B samples. The differences in the in vivo performance were mainly attributed to the distinct crystallisation nanostructures, which proved to have a major impact on permeability and protein adsorption capacity, using BSA as a model protein, with B samples being highly impermeable. Given the crucial role that soluble proteins play in osteogenesis, this is proposed to be a relevant factor behind the distinct in vivo performances observed for the two materials. STATEMENT OF SIGNIFICANCE: The possibility to accelerate the consolidation of self-setting calcium phosphate inks through hydrothermal treatments has aroused great interest due to the associated advantages for the development of 3D-printed personalised bone scaffolds. Understanding the implications of this approach on the in vivo performance of the scaffolds is of paramount importance. This study compares, for the first time, this treatment to the long-established biomimetic setting strategy in terms of osteogenic potential in vivo in a rabbit model, and relates the results obtained to the physicochemical properties of the 3D-printed scaffolds (composition, crystallinity, nanostructure, nanoporosity) and their interaction with soluble proteins.


Assuntos
Biomimética , Osteogênese , Animais , Regeneração Óssea , Fosfatos de Cálcio , Humanos , Impressão Tridimensional , Coelhos , Alicerces Teciduais
16.
J Clin Microbiol ; 47(1): 198-204, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19020067

RESUMO

The aim of this study was to analyze the factors associated with conventional contact tracing (CCT) and molecular epidemiology (ME) methods in assessing tuberculosis (TB) transmission, comparing the populations studied and the epidemiological links established by both methods. Data were obtained from TB case and CCT registries, and ME was performed using IS6110-based restriction fragment length polymorphism (RFLP) analysis and mycobacterial interspersed repetitive unit 12 (MIRU12) typing as a secondary typing method. During two years (2003 and 2004), 892 cases of TB were reported, of which 687 (77%) were confirmed by culture. RFLP analysis was performed with 463 (67.4%) of the 687 isolated strains, and MIRU12 types in 75 strains were evaluated; 280 strains (60.5%) had a unique RFLP pattern, and 183 (39.5%) shared patterns, grouping into 65 clusters. CCT of 613 (68.7%) of 892 cases detected 44 clusters involving 101 patients. The results of both CCT and ME methods yielded 96 clusters involving 255 patients. The household link was the one most frequently identified by CCT (corresponding to 80.7% of the cases clustered by this method), whereas nonhousehold and unknown links were associated with 94.1% of the strains clustered by ME. When both methods were used in 351 cases (39.3%), they showed the same results in 214 cases (61%). Of the remainder, 106 (30.2%) were clustered only by ME, 19 (5.5%) were clustered only by CCT, and 12 (3.4%) were clustered by both methods but into different clusters. Patients with factors potentially associated with social problems were less frequently studied by CCT (P = 0.002), whereas patients of <15 years of age, most with negative cultures, were less frequently studied by ME (P = 0.005). Significant differences in the populations studied by ME versus CCT were observed, possibly explaining the scarce correlation found between the results of these methods. Moreover, ME allowed the detection of nonhousehold contact relationships, whereas CCT was more useful for tracing transmission chains involving patients of <15 years of age. In conclusion, the two methods are complementary, suggesting the need to improve the methodology of contact study protocols.


Assuntos
Busca de Comunicante , Mycobacterium tuberculosis/genética , Tuberculose/epidemiologia , Tuberculose/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , Impressões Digitais de DNA , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Mycobacterium tuberculosis/isolamento & purificação , Polimorfismo de Fragmento de Restrição , Espanha/epidemiologia
18.
J Tissue Eng Regen Med ; 13(7): 1217-1229, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31050382

RESUMO

The immobilization of natural molecules on synthetic bone grafts stands as a strategy to enhance their biological interactions. During the early stages of healing, immune cells and osteoclasts (OC) modulate the inflammatory response and resorb the biomaterial, respectively. In this study, heparin, a naturally occurring molecule in the bone extracellular matrix, was covalently immobilized on biomimetic calcium-deficient hydroxyapatite (CDHA). The effect of heparin-functionalized CDHA on inflammation and osteoclastogenesis was investigated using primary human cells and compared with pristine CDHA and beta-tricalcium phosphate (ß-TCP). Biomimetic substrates led to lower oxidative stresses by neutrophils and monocytes than sintered ß-TCP, even though no further reduction was induced by the presence of heparin. In contrast, heparinized CDHA fostered osteoclastogenesis. Optical images of stained TRAP positive cells showed an earlier and higher presence of multinucleated cells, compatible with OC at 14 days, while pristine CDHA and ß-TCP present OC at 21-28 days. Although no statistically significant differences were found in the OC activity, microscopy images evidenced early stages of degradation on heparinized CDHA, compatible with osteoclastic resorption. Overall, the results suggest that the functionalization with heparin fostered the formation and activity of OC, thus offering a promising strategy to integrate biomaterials in the bone remodelling cycle by increasing their OC-mediated resorption.


Assuntos
Substitutos Ósseos , Fosfatos de Cálcio , Diferenciação Celular/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Heparina , Osteoclastos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Células-Tronco Hematopoéticas/patologia , Heparina/química , Heparina/farmacologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Osteoclastos/citologia
19.
ACS Appl Mater Interfaces ; 11(9): 8818-8830, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30740968

RESUMO

Bone apatite consists of carbonated calcium-deficient hydroxyapatite (CDHA) nanocrystals. Biomimetic routes allow fabricating synthetic bone grafts that mimic biological apatite. In this work, we explored the role of two distinctive features of biomimetic apatites, namely, nanocrystal morphology (plate vs needle-like crystals) and carbonate content, on the bone regeneration potential of CDHA scaffolds in an in vivo canine model. Both ectopic bone formation and scaffold degradation were drastically affected by the nanocrystal morphology after intramuscular implantation. Fine-CDHA foams with needle-like nanocrystals, comparable in size to bone mineral, showed a markedly higher osteoinductive potential and a superior degradation than chemically identical coarse-CDHA foams with larger plate-shaped crystals. These findings correlated well with the superior bone-healing capacity showed by the fine-CDHA scaffolds when implanted intraosseously. Moreover, carbonate doping of CDHA, which resulted in small plate-shaped nanocrystals, accelerated both the intrinsic osteoinduction and the bone healing capacity, and significantly increased the cell-mediated resorption. These results suggest that tuning the chemical composition and the nanostructural features may allow the material to enter the physiological bone remodeling cycle, promoting a tight synchronization between scaffold degradation and bone formation.


Assuntos
Materiais Biomiméticos/química , Substitutos Ósseos/química , Nanopartículas/química , Animais , Materiais Biomiméticos/farmacologia , Regeneração Óssea , Substitutos Ósseos/farmacologia , Osso e Ossos/diagnóstico por imagem , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Cães , Durapatita/química , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Osteogênese/efeitos dos fármacos , Ratos , Alicerces Teciduais/química , Microtomografia por Raio-X
20.
EFORT Open Rev ; 3(5): 173-183, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29951254

RESUMO

Calcium phosphates have long been used as synthetic bone grafts. Recent studies have shown that the modulation of composition and textural properties, such as nano-, micro- and macro-porosity, is a powerful strategy to control and synchronize material resorption and bone formation.Biomimetic calcium phosphates, which closely mimic the composition and structure of bone mineral, can be produced using low-temperature processing routes, and offer the possibility to modulate the material properties to a larger extent than conventional high temperature sintering processes.Advanced technologies open up new possibilities in the design of bioceramics for bone regeneration; 3D-printing technologies, in combination with the development of hybrid materials with enhanced mechanical properties, supported by finite element modelling tools, are expected to enable the design and fabrication of mechanically competent patient-specific bone grafts.The association of ions, drugs and cells allows leveraging of the osteogenic potential of bioceramic scaffolds in compromised clinical situations, where the intrinsic bone regeneration potential is impaired. Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170056.

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