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1.
RSC Adv ; 13(23): 15947-15959, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37260570

RESUMO

Graphene oxide (GO) has attracted increasing interest for biomedical applications owing to its outstanding properties such as high specific surface area, ability to bind functional molecules for therapeutic purposes and solubility, together with mechanical resistance and good thermal conductivity. The combination of GO with other biomaterials, such as calcium phosphate (CaP) and biodegradable polymers, presents a promising strategy for bone tissue engineering. Presently, the development of these advanced biomaterials benefits from the use of additive manufacturing techniques, such as 3D printing. In this study, we develop a 3D printed PLA:CaP:GO scaffold for bone tissue engineering. First, GO was characterised alone by XPS to determine its main bond contributions and C : O ratio. Secondly, we determined the GO dose which ensures the absence of toxicity, directly exposed in vitro (human osteoblast-like cells MG-63) and in vivo (zebrafish model). In addition, GO was microinjected in the zebrafish to evaluate its effect on immune cells, quantifying the genetic expression of the main markers. Results indicated that the GO tested (C : O of 2.14, 49.50% oxidised, main bonds: C-OH, C-O-C) in a dose ≤0.25 mg mL-1 promoted MG63 cells viability percentages above 70%, and in a dose ≤0.10 mg mL-1 resulted in the absence of toxicity in zebrafish embryos. The immune response evaluation reinforced this result. Finally, the optimised GO dose (0.10 mg mL-1) was combined with polylactic acid (PLA) and CaP to obtain a 3D printed PLA:CaP:GO scaffold. Physicochemical characterisation (SEM/EDS, XRD, FT-Raman, nano-indentation) was performed and in vivo tests confirmed its biocompatibility, enabling a novel approach for bone tissue-related applications.

2.
Biomed Phys Eng Express ; 8(6)2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36206662

RESUMO

Pulsed laser deposition (PLD) represents a promising bottom-up methodology for the synthesis and transference of nanoparticles to the surface of a biomedical device. Silver (Ag) nanoparticles directly incorporated on the metallic implant emerge as an alternative strategy for local action against prosthetic joint-associated infections. In the present research, a dual sequential PLD process is proposed to obtain a bilayer coating with (1) a bio-derived calcium phosphate (CaP) layer, to provide osteointegrative properties and (2) the controlled growth of the Ag nanoparticles over it, ranging the number of laser pulses from 100 to 500. The characterization by SEM, EDS, TEM, XPS and AFM revealed the uniform deposit of Ag rounded nanoparticles, with a narrow mean size distribution, in the original non-oxidized metallic state. Moreover, given the evidences from XPS and AFM techniques, the occurrence of a coalescence phenomenon from 400 pulses onwards was proposed together with the expected positive linear relation between the number of pulses and Ag contribution with a deposition rate of 0.05 at. % of Ag per pulse. Conversely, the decrease in roughness as the Ag content increased was also verified. Finally, the expected bacteriostatic activity for these PLD deposited metallic state Ag nanoparticles against the bacterial strainStaphylococcus aureuswas confirmed. Moreover, the evaluation of the osteoblast-like MG-63 cells viability on the Ag(100-500)-CaP coatings revealed a significant increased proliferation (p > 0.05) on the Ag100-CaP coating compared to the control (Ag0-CaP). When same coating was evaluated againstS. aureusthe effect was not significant. The possibility of modulating the amount of nanoparticles in the bilayer coating to obtain a greater or lesser effect in combination with CaP was revealed.


Assuntos
Nanopartículas Metálicas , Prata , Materiais Revestidos Biocompatíveis , Fosfatos de Cálcio , Lasers
3.
Cancers (Basel) ; 11(4)2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30925758

RESUMO

BACKGROUND: Natural killer (NK) and CD8+ T cells are involved in the immune response against melanoma. C-Type lectin-like NK cell receptors are located in the Natural Killer Complex (NKC) region 12p13.2-p12.3 and play a critical role in regulating the activity of NK and CD8+ T cells. An association between polymorphisms in the NKC region, including the NKG2D gene and NKG2A promoter, and the risk of cancer has been previously described. The aim of this study was to analyze the association of polymorphisms in the NKC region with cutaneous melanoma in patients from southeastern Spain. METHODS: Seven single-nucleotide polymorphisms (SNPs) in the NKG2D gene (NKC3,4,7,9,10,11,12), and one SNP in the NKG2A promoter (NKC17) were genotyped by a TaqMan 5' Nuclease Assay in 233 melanoma patients and 200 matched healthy controls. RESULTS: A linkage disequilibrium analysis of the SNPs performed in the NKC region revealed two blocks of haplotypes (Hb-1 and Hb-2) with 14 and seven different haplotype subtypes, respectively. The third most frequent haplotype from the block Hb-2-NK3 (CAT haplotype)-was significantly more frequent on melanoma patients than on healthy controls (p = 0.00009, Pc = 0.0006). No further associations were found when NKC SNPs were considered independently. CONCLUSIONS: Our results suggest an association between NKG2D polymorphisms and the risk of cutaneous malignant melanoma.

4.
Vet Microbiol ; 204: 15-19, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28532794

RESUMO

Streptococcus equi subsp. equi (S. equi) is the causative agent of strangles, one of the most frequently diagnosed infectious diseases of horses worldwide. Phospholipase A2 toxins (PLA2) cleave phospholipid molecules at position sn-2 contributing to the production of leukotrienes that are important inflammatory mediators. Two homologous phospholipases, SlaA and SlaB are encoded by the S. equi genome suggesting that PLA2 toxins may contribute to its pathogenicity. Here we report the immunogenicity and role of PLA2 toxins during natural and experimental infection of horses with S. equi. The levels of anti-PLA2 specific antibodies in serum from horses naturally exposed to S. equi or without exposure were measured by indirect ELISA. Furthermore, the importance of PLA2 was determined during experimental infection of Welsh Mountain ponies with a mutant strain of S. equi lacking slaA and slaB. Our results show that PLA2 toxins are immunogenic, which supports their production during natural S. equi infection, but that these toxins are not essential for the development of strangles in a susceptible natural host.


Assuntos
Anticorpos Antibacterianos/sangue , Doenças dos Cavalos/microbiologia , Fosfolipases A2/imunologia , Streptococcus equi/metabolismo , Streptococcus equi/patogenicidade , Animais , Doenças dos Cavalos/imunologia , Cavalos , Fosfolipases A2/metabolismo , Virulência
6.
Biomed Mater ; 12(1): 015028, 2017 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-28102173

RESUMO

Selenium is an essential trace element present in 25 selenoenzymes, playing critical roles in a variety of physiological processes, such as anti-oxidative defense and the modulation of cell proliferation and differentiation. This paper characterizes selenium-doped calcium phosphate coatings and evaluates their effects on the osteogenic activity, the proliferation of osteosarcoma cells and biofilm formation. To do so, the structure and elemental composition of the obtained coatings were analyzed, in addition to their thicknesses, and they were compared to pure calcium phosphate coatings. Moreover, the dose-effect ratio of two coatings with the lower (0.6 at%) and the higher (2.7 at%) selenium content was studied in terms of osteogenic, anti-biofilm and cancerous anti-proliferative properties. The results showed the incorporation of selenium in the form of selenite groups into the hydroxyapatite structure, with a similar crystalline pattern to the latter and increased roughness of the coatings. The calcium phosphate coatings with 2.7 at% of selenium resulted in significant osteogenic activity (p < 0.01) of healthy pre-osteoblasts (MC3T3-E1) over long periods of incubation, a significant anti-proliferative effect (p < 0.01) on cancerous osteoblasts (MG63) in a preliminary study, and anti-biofilm properties (p < 0.01) against Staphylococcus epidermidis and Staphylococcus aureus bacterial strains, which are responsible for most infections after orthopedic surgeries.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Osteogênese/efeitos dos fármacos , Selênio/química , Selênio/farmacologia , Células 3T3 , Animais , Biofilmes/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Teste de Materiais , Camundongos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Espectroscopia Fotoeletrônica , Selênio/administração & dosagem , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos
7.
Genome Med ; 8(1): 99, 2016 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-27686127

RESUMO

Killer cell immunoglobulin-like receptors (KIRs), expressed on natural killer cells and T cells, have considerable biomedical relevance playing significant roles in immunity, pregnancy and transplantation. The KIR locus is one of the most complex and polymorphic regions of the human genome. Extensive sequence homology and copy number variation makes KIRs technically laborious and expensive to type. To aid the investigation of KIRs in human disease we developed a high-throughput, multiplex real-time polymerase chain reaction method to determine gene copy number for each KIR locus. We used reference DNA samples to validate the accuracy and a cohort of 1698 individuals to evaluate capability for precise copy number discrimination. The method provides improved information and identifies KIR haplotype alterations that were not previously visible using other approaches.

8.
Biomed Mater ; 11(3): 035011, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27271863

RESUMO

Autologous bone is considered to be the gold standard for bone tissue regeneration, providing more highly efficient functional responses compared to synthetic materials, and avoiding the rejection risks of allogenic grafts. However, it presents limitations for certain types of surgery due to its high resorption levels and donor site morbidity. Different biphasic synthetic composites, based onnon-apatitic calcium phosphates enriched with apatitic phases-such as hydroxyapatite, and bioderived bone grafts of bovine and porcine origin-are proposed as lower resorption materials due to their higher crystalline structure. The present work proposes two new sources of bioapatites for bone filler applications obtained from the dentine and enameloid of shark teeth, respectively. These bioapatites each present a characteristic apatite-based composition and additional enrichments of specific trace elements, such as magnesium and fluorine, with proven roles in bone metabolism. Their processing and physicochemical characterization (SEM, FT-Raman and XRD) is presented, together with an in vitro evaluation of osteogenic activity compared to a commercial bovine mineralized matrix and synthetic HA/ß TCP grafts. The results proved the globular morphology (0.5-1.5 µm) and porosity (~50 µm and ~0.5-1 µm) of shark dentine bioapatites with biphasic composition: apatitic (hydroxyapatite and apatite-(CaF)), non-apatitic (whitlockite), and an apatitic phase (fluorapatite), organized in oriented crystals in enameloid bioapatites. An evaluation of the pre-osteoblast MC3T3-E1 morphology revealed the colonization of pores in dentine bioapatites and an aligned cell growth in the oriented enameloid crystals. A higher proliferation (p < 0.01) was detected at up to 21 d in both the shark bioapatites and synthetic biphasic graft with respect to the bovine mineralized matrix. Finally, the great potential of porous biphasic dentine bioapatites enriched with Mg and the aligned fluorapatite crystals of enameloid bioapatites in promoting greater osteogenic activity was confirmed with a significantly increased ALP synthesis (p < 0.01) compared to the commercial grafts.


Assuntos
Apatitas/química , Materiais Biocompatíveis/química , Transplante Ósseo/métodos , Tubarões , Células 3T3 , Animais , Regeneração Óssea , Substitutos Ósseos/química , Fosfatos de Cálcio/química , Bovinos , Proliferação de Células , Teste de Materiais , Camundongos , Microscopia Eletrônica de Varredura , Osteogênese , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Suínos , Dente , Difração de Raios X
9.
Immunogenetics ; 68(9): 743-7, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27333811

RESUMO

Leukocyte immunoglobulin-like receptors (LILR) are expressed mostly on myelomonocytic cells where they are mediators of immunological tolerance. Two LILR genes, LILRA3 and LILRA6, exhibit marked copy number variation. We assessed the contribution of these genes to atopic dermatitis (AD) by analysing transmission in 378 AD families. The data indicated that copies of LILRA6 were over-transmitted to affected patients. They are consistent with a contribution of LILR genes to AD. They could affect the equilibrium between activating and inhibitory signals in the immune response.


Assuntos
Variações do Número de Cópias de DNA/genética , DNA/genética , Dermatite Atópica/genética , Dermatite Atópica/patologia , Suscetibilidade a Doenças , Receptores Imunológicos/genética , Criança , DNA/análise , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase
10.
Eur J Clin Microbiol Infect Dis ; 34(8): 1657-65, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26017665

RESUMO

Streptococcus bovis group and Enterococcus spp. share phenotypic characteristics and intestinal habitat. Both have been associated with endocarditis and colorectal neoplasm (CRN). We studied all cases of endocarditis diagnosed between 1988 and 2014 in our centre and caused by S. bovis (109, 48.8 % of the bacteremia) and by Enterococcus spp. (36, 3.4 % of the bacteremia). Patients were seen until death or during a long-term follow-up, in order to rule out a concomitant CRN. The 109 cases of S. bovis endocarditis (SbIE) compared with the 36 caused by enterococci showed: a higher proportion of males (91 % vs. 72 %, p=0.005), more multivalvular involvement (28 % vs. 6 %, p=0.004), embolic complications (44 vs. 22 %, p=0.02) and colorectal neoplasm (64 % vs. 25 %, p=0.001). SbIE showed fewer co-morbidities (32 vs. 58 %, p=0.005), and less frequently urinary infection source (0 vs. 25 %, p=0.001) and healthcare-related infection (2 vs. 44 %, p=0.001). A total of 123 patients were followed up for an extended period (mean: 65.9 ± 57.5 months). During the follow-up, 6 of 28 (21 %) cases with enterococcal endocarditis and 43 of 95 (45.2 %, p=0.01) cases with SbIE developed a new CRN. These neoplasiae appeared a mean of 60.4 months later (range 12-181 months). Among the 43 cases with SbIE and CRN, 12 had had a previously normal colonoscopy and 31 had had a previous CRN and developed a second neoplasm. Cases of SbIE present important differences with those caused by Enterococcus spp. Colonoscopy must be mandatory both in the initial evaluation of SbIE, as during the follow-up period.


Assuntos
Neoplasias Colorretais/complicações , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/patologia , Enterococcus/isolamento & purificação , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/patologia , Streptococcus bovis/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Endocardite Bacteriana/epidemiologia , Feminino , Seguimentos , Infecções por Bactérias Gram-Positivas/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
J Infect ; 71(3): 317-25, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25982024

RESUMO

OBJECTIVES: To determine the incidence of Streptococcus bovis (Sb) biotypes causing bacteraemia and associated malignancies. METHODS: This is a retrospective analysis of patients with Sb bacteraemia, pulled out from a prospective surveillance protocol of bacteraemia cases, in three areas of Spain (1990-2013): a cattle area (Lugo), a fishing area (Ferrol) and an urban area (Barcelona). Colonoscopy and Sb biotypes (Sb-I and Sb-II) were determined in most cases. RESULTS: 506 patients with Sb bacteraemia; mean age 68.1 (±14.1) years, and 66.2% were males. The cattle area, compared with the fishing and urban areas, had higher incidence of bacteraemia by SbI (40.29 vs 9.38 vs 6.15 cases/10(6) person-years, P < 0.001) and bacteraemia by Sb-II (29.07 vs 9.84 vs 13.37 cases/10(6) person-years, P < 0.001). The Sb-I cases (n = 224), compared with Sb-II cases (n = 270), had greater rates of endocarditis (77.6% vs 9.6%, P < 0.001) and colorectal neoplasm (CRN) (50.9% vs 16.6%, P < 0.001), and smaller rates of biliary tract infection (2.2% vs 29.6%, P < 0.001) and non-colorectal malignancy (8.9% vs 31.4%, P < 0.001). CONCLUSION: There was a link between the cattle area and higher incidence of Sb bacteraemia. Sb-I differed from Sb-II cases in clinical findings and associated malignancies. Colonoscopy is mandatory in cases of endocarditis or bacteraemia caused by Sb-I.


Assuntos
Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Neoplasias Colorretais/epidemiologia , Endocardite Bacteriana/epidemiologia , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus bovis/classificação , Idoso , Animais , Técnicas de Tipagem Bacteriana , Bovinos , Colonoscopia , Neoplasias Colorretais/etiologia , Endocardite Bacteriana/microbiologia , Feminino , Geografia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Espanha/epidemiologia , Infecções Estreptocócicas/complicações , Fatores de Tempo
12.
Eur J Clin Microbiol Infect Dis ; 34(4): 719-25, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25416160

RESUMO

The Streptococcus bovis group (SBG) comprises several microorganisms associated with human infections. They have been associated with bacteremia, endocarditis, biliary tract infection, meningitis, and colorectal cancer, but their role as urinary pathogens is not well known. The objective of this investigation was to discover the incidence and clinical significance of the bacteriuria associated with this complex. A retrospective analysis of all adult patients with bacteriuria caused by SBG during the period 1995-2012 was carried out. During the study period, SBG was isolated in 153 adult patients, who had a mean age of 67 years, most of them being women (80%). Most of our patients (65%) had some underlying disease, with urologic disease being the most common (37%), followed by diabetes mellitus (27%) and neurologic disease (25%). Among the 88 patients in whom we were able to correctly assess symptoms, 45% had asymptomatic bacteriuria, 35% had lower urinary tract infection, and 20% had upper urinary tract infection. In 14 cases (9%), SBG was also isolated in blood cultures. Most of the isolates of SBG (72%) were S. gallolyticus subsp. pasteurianus. All isolates were susceptible to penicillin, 98% to nitrofurantoin, and 77% to fosfomycin. Although SBG bacteriuria is uncommon, it should not always be taken as a contaminant, mainly when S. pasteurianus is isolated, because it may cause urinary tract infections and, occasionally, sepsis, whereas when S. gallolyticus is isolated from urine, it may be a marker of underlying endocarditis and colorectal cancer.


Assuntos
Infecções Estreptocócicas/microbiologia , Streptococcus bovis/isolamento & purificação , Infecções Urinárias/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Feminino , Humanos , Incidência , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Estreptocócicas/epidemiologia , Streptococcus bovis/efeitos dos fármacos , Infecções Urinárias/epidemiologia , Adulto Jovem
13.
Eur J Clin Microbiol Infect Dis ; 33(2): 171-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23934596

RESUMO

The association of colorectal neoplasia (CRN) with Streptococcus bovis biotype I (SBI) infection is well recognized. However, this is not the case for Streptococcus bovis biotype II (SBII). We conducted this study in order to analyze the relationship between SBII and CRN. We analyzed all cases of bacteremia due to SBI (n = 99) and SBII (n = 36) diagnosed in our hospital (during the period 1988-2011) that were followed up with colonoscopy. In addition, we reviewed the literature (during the period 1982-2011) to select all cases of infection of SB that had undergone colonoscopy or other adequate form of colorectal examination. A multivariate analysis was performed to detect CRN risk factors in patients infected with SB. From the 223 cases of SB infection included in the analysis (135 from our institution and 88 from the literature review), 159 were due to SBI and 64 were caused by SBII. As compared with SBI, the SBII cases had a lower frequency of CRN (27 % vs. 67 %, p <0.001), advanced adenomas (8 % vs. 29 %, p <0.01), and carcinomas (6 % vs. 21 %, p <0.01). In a multivariate analysis, and after adjusting for age, sex, type of infection, and biotype, SBII infection was not associated with CRN: odds ratio (OR) = 0.17; 95 % confidence interval (CI) = 0.09 to 0.33. The only factor independently associated with CRN was SBI infection: OR = 5.7; 95 % CI = 3.0 to 10.9. The prevalence of CRN in patients infected with SBII is significantly lower than patients with SBI and does not appear to be higher than the CRN prevalence among the general population.


Assuntos
Bacteriemia/complicações , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Infecções Estreptocócicas/complicações , Streptococcus bovis/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Neoplasias Colorretais/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Medição de Risco , Infecções Estreptocócicas/microbiologia , Streptococcus bovis/classificação
14.
Clin Microbiol Infect ; 20(5): 405-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24033711

RESUMO

Streptococcus bovis is a well-known cause of endocarditis, but its role in other infections has not been well described. We analysed prospectively all patients with biliary tract infections caused by S. bovis group during the period 1988-2011. We selected those cases associated with cholangitis and cholecystitis, defined according to Tokyo guidelines. Identification of the strains was performed using the API 20 Strep and the GP card of the Vitek 2 system, and was confirmed by molecular methods. Our series included 51 cases (30 cholangitis and 21 cholecystitis). The associated microorganisms were: Streptococcus infantarius (biotype II/1) 29 cases (57%), Streptococcus gallolyticus subsp. pasteurianus (biotype II/2) 20 cases (39%) and Streptococcus gallolyticus subsp. gallolyticus (biotype I) two cases (4%). The only difference found between S. infantarius and S. gallolyticus subsp. pasteurianus was a greater association of the first with malignant strictures of the bile ducts: 48% (14/29) versus 5% (1/20), p <0.001. Thirty-seven of the cases also had bacteraemia, causing 20% (37/185) of all S. bovis bacteraemia, with differences between S. gallolyticus subsp. gallolyticus (2/112; 2%) and the other two microorganisms: S. infantarius and S. gallolyticus subsp. pasteurianus (35/73; 48%; p <0.001). The vast majority of biliary tract infections due to S. bovis group are caused by S. infantarius and S. gallolyticus subsp. pasteurianus (S. bovis biotype II), and nearly half of the bacteraemia due to these two species has a biliary source (43% of the S. infantarius and 56% of S. gallolyticus subsp. pasteurianus).


Assuntos
Bacteriemia/microbiologia , Ductos Biliares/microbiologia , Colangite/microbiologia , Colecistite/microbiologia , Neoplasias do Sistema Digestório/complicações , Infecções Estreptocócicas , Streptococcus bovis/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Coledocolitíase/complicações , Colestase/etiologia , Constrição Patológica/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/terapia
15.
Biomed Mater ; 8(5): 055006, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24057755

RESUMO

Polyetheretherketone (PEEK) is currently being used in implants as an alternative to titanium, due to its mechanical properties, cytocompatibility and inertness. Several studies have demonstrated that certain patterning on the implants promotes the oriented cell growth of osteoblasts, favouring the formation of bone tissue. This patterning improves the implant's osteointegration in the bone and its mechanical stability. Therefore, the objective of this work is to micro-structure PEEK by laser radiation and to carry out an exhaustive study of the orientation of pre-osteoblast cells that grow on this material. Parallel microgrooves were obtained using an ArF excimer laser coupled with a mask projection unit with distances of 25, 50, 75 and 100 µm between grooves. The cell growth on these PEEK surfaces was studied, in order to compare the effect of different distances between grooves on the biological response of MC3T3-E1 pre-osteoblastic cells. Preferential cell orientation was observed for all studied distances, which was more pronounced in the 25 and 50 µm ones.


Assuntos
Materiais Biocompatíveis/química , Cetonas/química , Lasers , Osteoblastos/citologia , Polietilenoglicóis/química , Células 3T3 , Animais , Benzofenonas , Adesão Celular , Desenho de Equipamento , Interferometria , Camundongos , Osteoblastos/efeitos dos fármacos , Polímeros , Análise Espectral Raman , Propriedades de Superfície , Raios Ultravioleta
16.
Immunogenetics ; 65(5): 333-43, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23370861

RESUMO

Natural killer and CD8(+) T cells are believed to be involved in the immune protection against melanoma. Their function may be regulated by a group of receptors defined as killer immunoglobulin-like receptors (KIRs) and their cognate HLA class I ligands. In this study, we analyzed the influence of KIR genes and KIR/HLA-I combinations on melanoma susceptibility and/or prognosis in a Spanish Caucasian population. For this purpose, KIR genotyping by PCR-SSP and HLA-C genotyping by reverse PCR-SSO were performed in 187 melanoma patients and 200 matched controls. We found a significantly low frequency of KIR2DL3 in nodular melanoma (NM) patients (P = 0.001) and in ulcerated melanoma patients (P < 0.0001). Similarly, the KIR2DL3/C1 combination was significantly decreased in melanoma patients (Pc = 0.008) and in patients with sentinel lymph node (SLN) melanoma metastasis (Pc = 0.002). Multivariate logistic regression models showed that KIR2DL3 behaves as a protective marker for NM and ulcerated melanoma (P = 0.02, odds ratio (OR) = 0.14 and P = 0.04, OR = 0.28, respectively), whereas the KIR2DL3/C1 pair acts as a protective marker for melanoma (P = 0.017, OR = 0.54), particularly superficial spreading melanoma (P = 0.02, OR = 0.52), and SLN metastasis (P = 0.0004, OR = 0.14). In contrast, the KIR2DL3(-)/C1C2 genotype seems to be correlated with NM and ulceration. We also report that the KIR2DL1(+)/S1(-)/C2C2 genotype is associated with susceptibility to melanoma and SLN metastasis. Altogether, the study of KIR2D genes and HLA-C ligands may help in assessing cutaneous melanoma risk and prognosis.


Assuntos
Biomarcadores Tumorais/genética , Predisposição Genética para Doença , Variação Genética/genética , Antígenos HLA-C/genética , Melanoma/genética , Receptores KIR2DL3/genética , Neoplasias Cutâneas/genética , Feminino , Genótipo , Humanos , Metástase Linfática , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Prognóstico , Neoplasias Cutâneas/secundário
17.
J Biomed Mater Res A ; 101(3): 853-61, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22968925

RESUMO

Nowadays there is a short-term need of investigating in orthopedic implants with a greater functionality, including an improved osseointegration and also antibacterial properties. The coating of metallic implants with hydroxyapatite (HA) remains to be the main proposal, but superior quality HA coatings with compositions closer to natural bone apatites, including carbonates, trace elements are required. Selenium is an essential nutrient in biological tissues and, at the same time, it also presents antibacterial properties. A pioneering study on the fabrication of selenium-doped carbonated hydroxyapatite (iHA:Se) coatings by Pulsed Laser Deposition (PLD) is presented. Different proportions of selenium were incorporated to obtain the iHA:Se coatings. Their physicochemical characterization, performed by SEM/EDS, FTIR, FT-Raman, Interferometric Profilometry and XPS, revealed typical columnar growth of HA in globular aggregates and the efficient incorporation of selenium into the HA coatings by the, most probably, substitution of SeO(3)(2-) groups in the CO(3)(2-) sites. Biological evaluation illustrated the absence of cytotoxicity when an amount of 0.6 at.% of Se was added to the iHA:Se coatings and excellent proliferation of the MC3T3-E1 preosteoblasts. Antibacterial properties were also proved with the inhibition of P. aeruginosa and S. aureus from establishing bacterial biofilms.


Assuntos
Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Durapatita/química , Osteoblastos/metabolismo , Próteses e Implantes , Pseudomonas aeruginosa/crescimento & desenvolvimento , Selênio/química , Animais , Linhagem Celular , Teste de Materiais , Camundongos , Osteoblastos/citologia , Propriedades de Superfície
18.
Hum Immunol ; 74(3): 318-24, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23247208

RESUMO

Cardiac allograft vasculopathy (CAV) is the single most important long-term limitation to heart transplantation. This study aimed to assess the value of monitoring soluble human leukocyte antigen-G (sHLA-G) during the first year post-transplantation to predict the severity of CAV, in 21 out of 77 heart recipients assessed by intravascular ultrasound (IVUS). Serum sHLA-G concentration increased after transplant in recipients free of severe CAV, but decreased in recipients suffering from severe CAV, significant differences between these two groups were found 6 to 12 months post-transplantation. The optimal value of the change in post-transplant sHLA-G for identifying severe CAV was ≥0.062%, which maximized sensitivity (80%) and specificity (100%). Importantly, increases in post-transplant sHLA-G were inversely associated with severe CAV, but directly associated with human cytomegalovirus reactivation. In addition, recipients presenting non-severe CAV or an increased sHLA-G post-transplantation, showed higher numbers of CD8(+)CD28(-) T cells and a down-modulation of CD28 on CD4(+) lymphocytes, which typically identifies CD8(+) regulatory T cells and anergic/tolerogenic T helper cells, respectively. In conclusion, quantification of sHLA-G might offer a complementary non-invasive method for identifying recipients at risk of more severe CAV and who might benefit from earlier preventive therapies, although these results need to be confirmed in larger series.


Assuntos
Antígenos HLA-G/imunologia , Transplante de Coração/imunologia , Túnica Íntima/imunologia , Adulto , Idoso , Antígenos CD28/imunologia , Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Citomegalovirus/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Antígenos HLA-G/sangue , Antígenos HLA-G/metabolismo , Transplante de Coração/efeitos adversos , Transplante de Coração/métodos , Humanos , Hiperplasia/sangue , Hiperplasia/etiologia , Hiperplasia/imunologia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Índice de Gravidade de Doença , Solubilidade , Fatores de Tempo , Transplante Homólogo , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia , Ultrassonografia de Intervenção , Ativação Viral/imunologia
19.
Clin Infect Dis ; 55(4): 491-6, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22563018

RESUMO

BACKGROUND: The association between bacteremia by Streptococcus gallolyticus subsp. gallolyticus (SGG) and colorectal neoplasia (CRN) is well established but the frequency of the association varies widely in different studies. We conducted a case-control study to assess the association between SGG bacteremia and CRN. METHODS: An analysis of all SGG bacteremias was performed during the period 1988-2011. The frequency of CRN in patients with SGG bacteremia was compared with the frequency of CRN in a symptomatic control group of patients matched at a 1:2 ratio for gender and age (±3 years) without S. bovis bacteremia and personal history of CRN and with increased risk of CRN (by the presence of symptoms, signs, or test suspicious of colonic pathology or by family history of CRN). RESULTS: One hundred nine cases of SGG bacteremia were detected (mean age, 66 years; 87% male). Colonoscopy was performed in 98 cases, diagnosing 69 cases of CRN: 57 adenomas (39 advanced adenomas) and 12 invasive carcinomas. Only 4 cases had suspected CRN before the blood culture. The prevalence of CRN was higher in patients with SGG bacteremia than in the 196 control patients (70% vs 32%; odds ratio [OR], 5.1; 95% confidence interval [CI], 3.0-8.6). This difference was not significant when comparing nonadvanced adenomas (19% vs 12%), but we found significant differences in advanced adenomas (40% vs 16%; OR, 3.5; 95% CI, 2.0-6.1) and invasive carcinomas (12% vs 5%; OR, 2.9; 95% CI, 1.2-6.9). CONCLUSIONS: The frequency of CRN among SGG infected patients is significantly increased compared with symptomatic age-matched controls, indicating that SGG infection is a strong indicator for underlying occult malignancy.


Assuntos
Bacteriemia/patologia , Neoplasias Colorretais/microbiologia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/patologia , Streptococcus bovis/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Hum Immunol ; 72(10): 841-8, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21742001

RESUMO

Viral infections and cellular acute rejection (AR) condition immunosuppressive therapy and compromise the evolution of allografts. Immune monitoring can be useful for ascertaining rejection and for differentiating allo-reaction from activation induced by infections. This work analyzes the usefulness of monitoring the expression of CD28 and KIR2D receptors in peripheral blood T lymphocytes by flow cytometry, to ascertain the immune response in heart and liver transplant recipients. In both types of transplant, the up-regulation of CD28 in CD4(+) lymphocytes in the periods of greatest AR frequency indicates an effective allo-response, whereas the post-transplantation emergence of circulating CD8(+)CD28(-) and CD8(+)CD28(-)KIR2D(+) T cells correlates with better early clinical results. Cytomegalovirus (CMV) infection, but not hepatitis C virus (HCV) or other infections, abrogated both CD28 up-regulation and CD8(+)CD28(-)KIR2D(+) T-cell expansion. Our results show that monitoring the expression of CD28 and KIR2D receptors on T lymphocytes might be considered as sensors of the immune status of heart and liver recipients.


Assuntos
Antígenos CD28/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Terapia de Imunossupressão/efeitos adversos , Transplante de Fígado/imunologia , Receptores KIR/imunologia , Biomarcadores/sangue , Antígenos CD28/sangue , Antígenos CD28/genética , Linfócitos T CD8-Positivos/citologia , Citomegalovirus/imunologia , Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/virologia , Feminino , Citometria de Fluxo , Rejeição de Enxerto/sangue , Transplante de Coração/patologia , Humanos , Transplante de Fígado/patologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Receptores KIR/sangue , Receptores KIR/genética , Espanha , Transplante Homólogo , Regulação para Cima
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