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1.
J Gen Virol ; 100(8): 1171-1186, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31237530

RESUMO

Rabies virus causes an invariably fatal encephalitis following the onset of clinical disease. Despite the availability of safe and effective vaccines, the clinical stages of rabies encephalitis remain untreatable, with few survivors being documented. A principal obstacle to the treatment of rabies is the neurotropic nature of the virus, with the blood-brain barrier size exclusion limit rendering the delivery of antiviral drugs and molecules to the central nervous system inherently problematic. This review focuses on efforts to try and overcome barriers to molecule delivery to treat clinical rabies and overviews current progress in the development of experimental live rabies virus vaccines that may have future applications in the treatment of clinical rabies, including the attenuation of rabies virus vectors through either the duplication or mutation of existing genes or the incorporation of non-viral elements within the genome. Rabies post-infection treatment (PIT) remains the holy grail of rabies research.

2.
Mol Genet Genomic Med ; 7(6): e697, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31033252

RESUMO

BACKGROUND: Trichilemmal cysts (TCs) are common intradermal or subcutaneous cysts, which are commonly sporadic and rarely autosomal dominantly inherited. However, little is known about the disease-determining genes in families with TCs exhibiting Mendelian inheritance. OBJECTIVE: The aim of this study was to identify the causative gene in a family with TCs. METHODS: Whole-exome sequencing was performed on a TCs family to identify the candidate gene. Sanger sequencing was conducted to validate the candidate variants and familial segregation. RESULTS: We identified the heterozygous variant c.3G>C (p.Met1?) within the BPIFC gene. Sanger sequencing confirmed the cosegregation of this variant with the TCs phenotype in the family by demonstrating the presence of the heterozygous variant in all the 12 affected and absence in all the seven unaffected individuals. This variant was found to be absent in dbSNP141, 1,000 Genomes database and 500 ethnicity matched controls. CONCLUSION: Our results imply that BPIFC is a causative gene in this Chinese family with hereditary TCs. Further studies should be performed to validate the role of BPIFC in the pathogenesis of this disease.

3.
J Gen Virol ; 99(12): 1590-1599, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29745870

RESUMO

The lyssaviruses are an important group of viruses that cause a fatal encephalitis termed rabies. The prototypic lyssavirus, rabies virus, is predicted to cause more than 60 000 human fatalities annually. The burden of disease for the other lyssaviruses is undefined. The original reports for the recently described highly divergent Lleida bat lyssavirus were based on the detection of virus sequence alone. The successful isolation of live Lleida bat lyssavirus from the carcass of the original bat and in vitro characterization of this novel lyssavirus are described here. In addition, the ability of a human rabies vaccine to confer protective immunity following challenge with this divergent lyssavirus was assessed. Two different doses of Lleida bat lyssavirus were used to challenge vaccinated or naïve mice: a high dose of 100 focus-forming units (f.f.u.) 30 µl-1 and a 100-fold dilution of this dose, 1 f.f.u. 30 µl-1. Although all naïve control mice succumbed to the 100 f.f.u. 30 µl-1 challenge, 42 % (n=5/12) of those infected intracerebrally with 1 f.f.u. 30 µl-1 survived the challenge. In the high-challenge-dose group, 42 % of the vaccinated mice survived the challenge (n=5/12), whilst at the lower challenge dose, 33 % (n=4/12) survived to the end of the experiment. Interestingly, a high proportion of mice demonstrated a measurable virus-neutralizing antibody response, demonstrating that neutralizing antibody titres do not necessarily correlate with the outcome of infection via the intracerebral route. Assessing the ability of existing rabies vaccines to protect against novel divergent lyssaviruses is important for the development of future public health strategies.

4.
Vaccine ; 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29523449

RESUMO

Rabies causes more than 60,000 human deaths annually in areas where the virus is endemic. Importantly, rabies is one of the few pathogens for which there is no treatment following the onset of clinical disease with the outcome of infection being death in almost 100% of cases. Whilst vaccination, and the combination of vaccine and rabies immunoglobulin treatment for post-exposure administration are available, no tools have been identified that can reduce or prevent rabies virus replication once clinical disease has initiated. The search for effective antiviral molecules to treat those that have already developed clinical disease associated with rabies virus infection is considered one of the most important goals in rabies research. The current study assesses a single chain antibody molecule (ScFv) based on a monoclonal antibody that potently neutralises rabies in vitro as a potential therapeutic candidate. The recombinant ScFv was generated in Nicotiana benthamiana by transient expression, and was chemically conjugated (ScFv/RVG) to a 29 amino acid peptide, specific for nicotinic acetylcholine receptor (nAchR) binding in the CNS. This conjugated molecule was able to bind nAchR in vitro and enter neuronal cells more efficiently than ScFv. The ability of the ScFv/RVG to neutralise virus in vivo was assessed using a staggered administration where the molecule was inoculated either four hours before, two days after or four days after infection. The ScFv/RVG conjugate was evaluated in direct comparison with HRIG and a potential antiviral molecule, Favipiravir (also known as T-705) to indicate whether there was greater bioavailability of the ScFv in the brains of treated mice. The study indicated that the approach taken with the ScFv/RVG conjugate may have utility in the design and implementation of novel tools targetting rabies virus infection in the brain.

5.
Viruses ; 10(3)2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29543715

RESUMO

Lyssaviruses constitute a diverse range of viruses with the ability to cause fatal encephalitis known as rabies. Existing human rabies vaccines and post exposure prophylaxes (PEP) are based on inactivated preparations of, and neutralising antibody preparations directed against, classical rabies viruses, respectively. Whilst these prophylaxes are highly efficient at neutralising and preventing a productive infection with rabies virus, their ability to neutralise other lyssaviruses is thought to be limited. The remaining 15 virus species within the lyssavirus genus have been divided into at least three phylogroups that generally predict vaccine protection. Existing rabies vaccines afford protection against phylogroup I viruses but offer little to no protection against phylogroup II and III viruses. As such, work involving sharps with phylogroup II and III must be considered of high risk as no PEP is thought to have any effect on the prevention of a productive infection with these lyssaviruses. Whilst rabies virus itself has been characterised in a number of different animal models, data on the remaining lyssaviruses are scarce. As the lyssavirus glycoprotein is considered to be the sole target of neutralising antibodies we generated a vaccine strain of rabies using reverse genetics expressing highly divergent glycoproteins of West Caucasian Bat lyssavirus and Ikoma lyssavirus. Using these recombinants, we propose that recombinant vaccine strain derived lyssaviruses containing heterologous glycoproteins may be a suitable surrogate for wildtype viruses when assessing vaccine protection for the lyssaviruses.


Assuntos
Lyssavirus/genética , Lyssavirus/imunologia , Infecções por Rhabdoviridae/imunologia , Infecções por Rhabdoviridae/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Quirópteros/virologia , Camundongos , Raiva/imunologia , Raiva/prevenção & controle , Vacinas Antirrábicas/imunologia , Vírus da Raiva/genética , Vírus da Raiva/imunologia
6.
Artif Organs ; 42(9): 891-898, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27925225

RESUMO

Effective anticoagulation regimens are needed to reduce risks of thrombosis and bleeding in animal models of ventricular assist device to verify its hemocompatibility, biologic safety and reliability. This study is to develop a validated anticoagulation procedure for a sheep model to test the newly developed CH-VAD. CH-VAD models were established in six healthy sheep by constructing blood bypass of left ventricle → ventricular assist device → descending aorta. Heparin infusion was used during operation and in the prior 4 days to maintain activated clotting time 1.5-2.0 times the baseline. From the third day, proper dosage of warfarin was used orally to maintain international normalized ratio values within the range of 1.2-2.0. After termination, we examined whether there was thrombosis in the blood pump, grafts, and anastomotic stoma. Macroscopic and histopathologic examinations were performed in major organs to check for congestion and infarction. Bleeding complications were not found in any animals throughout the experiments. Activated clotting time values were 326 ± 33 s intraoperatively and 157 ± 28 s in the prior 4 days postoperatively. Activated partial thromboplastin time values increased slowly and reached the lower limit of the target range on the fourth day. Only in one of six cases was thrombus or fibrosis tissue found in the blood flow channel of the pump. Pathologic analysis showed no thrombosis, necrosis and microembolus in end-stage organs. Under the anticoagulation regimens, coagulation system could be well controlled to avoid thrombosis and bleeding complications in sheep models for CH-VAD.

7.
Tex Heart Inst J ; 44(5): 312-319, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29259500

RESUMO

Understanding plaque formation in patients at risk for coronary artery disease-the leading cause of morbidity and death in the world-enables physicians to better determine whether and how to treat these individuals. We used computed tomographic angiography to quantitatively evaluate the progression of nonculprit coronary plaques along the full length of the right coronary artery in 21 patients with acute coronary syndrome. Each right coronary artery was analyzed in sequential, 3-mm-long segments, and the minimum luminal area, plaque burden, and plaque volume within each segment were evaluated at baseline and at 12-month follow-up. Serial remodeling of the right coronary artery was also evaluated. In total, 625 arterial segments were analyzed. At 12-month follow-up, the plaque burden had increased slightly by 0.34% (interquartile range [IQR], -4.32% to 6.35%; P=0.02), and the plaque volume was not significantly changed (0.33 mm3; IQR, -3.05 to 3.54; P=0.213). The minimum luminal area decreased 0.05 mm2 (IQR, -1.33 to 0.87 mm2; P=0.012), and this was accompanied by vessel reduction, as evidenced by negative remodeling in 43% of the 625 segments. We conclude that serial computed tomographic angiography can be used to quantitatively evaluate the morphologic progression of coronary plaques.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Angiografia Coronária , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/métodos , Placa Aterosclerótica/diagnóstico , Doença da Artéria Coronariana , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco
8.
Vaccine ; 2017 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-29132993

RESUMO

There is no antiviral treatment available once clinical disease following rabies virus infection has initiated. Considered a neglected tropical disease, >60,000 human rabies deaths are estimated each year despite the availability of pre- and post-exposure prophylaxis for pre-immunisation or administration following a potential exposure before the onset of clinical disease. Such post-exposure treatments include administration of rabies immunoglobulin (RIG) and vaccination at a distant site to prime a humoral immune response. However, current therapeutic options are limited. Regardless there is a need for molecules that target virus infection following the onset of clinical disease where the outcome of infection is invariably fatal. Numerous molecules have been assessed as potential antivirals against rabies virus (RABV) but with little promise. Favipiravir (T-705) is a broad-spectrum RNA polymerase inhibitor, which has been shown to have antiviral activity against a range of RNA viruses including some against RABV. In the present study, the utility of T-705 has been reassessed in vitro as well as in vivo in a murine model using intraperitoneal administration to investigate any immune protective effect of the molecule. In vitro T-705 effectively reduces RABV replication. However, in vivo, following assessment of various applications of the molecule in both pre- and post-exposure scenarios, the effect was limited. T-705 treatment delayed the onset of clinical signs when virus was delivered intramuscularly at a higher dose (106.8 TCID50/ml) and reduced the number of mice that developed clinical signs when virus was delivered at a lower dose (105.8 TCID50/ml) during the observation period. The day at which treatment commenced did not appear to have a statistically significant effect on the results in either experiment. The use of T-705 as a single biological entity may be limited, however, further work is required to assess the synergistic effect of T-705 as a component of a multi-drug therapy for treating human rabies infections.

9.
Comput Assist Surg (Abingdon) ; 22(sup1): 286-294, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29032716

RESUMO

OBJECTIVES: Coronary atherosclerotic plaques progress in a highly individual manner. Accurately predicting plaque progression will promote clinical management of atherosclerosis. The purpose of this study was to investigate the role of local biomechanics factors and vascular characteristics in coronary plaque progression and arterial remodeling. METHODS: Computed tomography angiography-based three-dimensional reconstruction of the native right coronary artery was performed in vivo in twelve patients with acute coronary syndrome at baseline and 12-month follow-up. The reconstructed arteries were divided into sequential 3-mm-long segments. Wall shear stress (WSS) and von Mises stress (VMS) were computed in all segments at baseline by applying fluid-structure interaction simulations. RESULTS: In total, 365 segments 3-mm long were analyzed. The decrease in minimal lumen area was independently predicted by low baseline VMS (-0.73 ± 0.13 mm2), increase in plaque burden was independently predicted by small minimal lumen area and low baseline WSS (6.28 ± 0.96%), and decrease in plaque volume was independently predicted by low baseline VMS (-0.99 ± 0.49 mm3). Negative remodeling was more likely to occur in low- (55%) and moderate-VMS (40%) segments, but expansive remodeling was more likely to occur in high-VMS (44%) segments. CONCLUSIONS: Local von Mises stress, wall shear stress, minimal lumen area, and plaque burden provide independent and additive prediction in identifying coronary plaque progression and arterial remodeling.

10.
J Virol Methods ; 243: 109-112, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28174074

RESUMO

Rabies virus is a notifiable pathogen that must be handled in high containment facilities where national and international guidelines apply. For the effective inactivation of rabies virus, a number of reagents were tested. Virkon S (1%) solution caused more than 4log reduction of rabies virus in culture medium supplemented with 10% foetal calf serum within 1min. Isopropyl alcohol (70%) treatment resulted in >3log reduction of rabies virus within 20s when applied at a ratio of 19:1, making it a suitable agent for surface decontamination whereas 70% ethanol was ineffective. Rabies virus (from 102.33 to 103ffu/ml) was also inactivated when cell cultures were fixed with 3% or 4% paraformaldehyde for 30min. Regardless of inactivation procedure, when taking inactivated virus preparations out of a biological containment envelope, proof of inocuity must be demonstrated to cover any possible error/deviation from procedure.


Assuntos
Desinfetantes/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Vírus da Raiva/efeitos dos fármacos , Vírus da Raiva/fisiologia , Inativação de Vírus
11.
J Antimicrob Chemother ; 71(5): 1178-82, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26803720

RESUMO

OBJECTIVES: This study aimed to compare ESBL-producing Escherichia coli causing infections in humans with infecting or commensal isolates from animals and isolates from food of animal origin in terms of the strain types, the ESBL gene present and the plasmids that carry the respective ESBL genes. METHODS: A collection of 353 ESBL-positive E. coli isolates from the UK, the Netherlands and Germany were studied by MLST and ESBL genes were identified. Characterization of ESBL gene-carrying plasmids was performed using PCR-based replicon typing. Moreover, IncI1-Iγ and IncN plasmids were characterized by plasmid MLST. RESULTS: The ESBL-producing E. coli represented 158 different STs with ST131, ST10 and ST88 being the most common. Overall, blaCTX-M-1 was the most frequently detected ESBL gene, followed by blaCTX-M-15, which was the most common ESBL gene in the human isolates. The most common plasmid replicon type overall was IncI1-Iγ followed by multiple IncF replicons. CONCLUSIONS: ESBL genes were present in a wide variety of E. coli STs. IncI1-Iγ plasmids that carried the blaCTX-M-1 gene were widely disseminated amongst STs in isolates from animals and humans, whereas other plasmids and STs appeared to be more restricted to isolates from specific hosts.


Assuntos
Toxinas Bacterianas/genética , Enterotoxinas/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Microbiologia de Alimentos , Plasmídeos/análise , beta-Lactamases/genética , Animais , Escherichia coli/classificação , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Alemanha , Humanos , Tipagem de Sequências Multilocus , Países Baixos , Reação em Cadeia da Polimerase , Reino Unido
12.
Biomed Res Int ; 2015: 148579, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26539463

RESUMO

The aim of the study was to use the ovine model to evaluate the hemocompatibility and end-organ effects of a newly developed magnetic suspension centrifugal left ventricular assist device (LVAD) by CH Biomedical Inc., Jiangsu, China. The LVADs were implanted in 6 healthy sheep, where inflow was inserted into the left ventricular apex and outflow was anastomosed to the descending aorta. All sheep received anticoagulation and antiaggregation therapy during the study. Hematologic and biochemical tests were performed to evaluate anemia, hepatorenal function, and the extent of hemolysis. The experiments lasted for up to 30 days on the beating hearts. All sheep were humanely killed at the termination of the experiments, and the end-organs were examined macroscopically and histopathologically. Autopsy was performed in all animals and there was no thrombus formation observed inside the pump. The pump's inflow and outflow conduits were also free of thrombus. Hematologic and biochemical test results were within normal limits during the study period. Postmortem examination of the explanted organs revealed no evidence of ischemia or infarction. Based on the in vivo study, this LVAD is suitable for implantation and can provide efficient support with good biocompatibility. The encouraging results in this study suggest that it is feasible to evaluate the device's long-term durability and stability.


Assuntos
Aorta/fisiopatologia , Ventrículos do Coração/fisiopatologia , Coração Auxiliar , Disfunção Ventricular Esquerda/terapia , Animais , Coagulação Sanguínea , China , Modelos Animais de Doenças , Humanos , Ovinos , Disfunção Ventricular Esquerda/fisiopatologia
13.
Antimicrob Agents Chemother ; 59(9): 5357-65, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26100710

RESUMO

The aim of the study was to identify the plasmid-encoded factors contributing to the emergence and spread of epidemic IncI1-Iγ plasmids obtained from Escherichia coli and Salmonella enterica isolates from animal and human reservoirs. For this, 251 IncI1-Iγ plasmids carrying various extended-spectrum ß-lactamase (ESBL) or AmpC ß-lactamase genes were compared using plasmid multilocus sequence typing (pMLST). Thirty-two of these plasmids belonging to different pMLST types were sequenced using Roche 454 and Illumina platforms. Epidemic IncI1-Iγ plasmids could be assigned to various dominant clades, whereas rarely detected plasmids clustered together as a distinct clade. Similar phylogenetic trees were obtained using only the plasmid backbone sequences, showing that the differences observed between the plasmids belonging to distinct clades resulted mainly from differences between their backbone sequences. Plasmids belonging to the various clades differed particularly in the presence/absence of genes encoding partitioning and addiction systems, which contribute to stable inheritance during cell division and plasmid maintenance. Despite this, plasmids belonging to the various phylogenetic clades also showed marked resistance gene associations, indicating the circulation of successful plasmid-gene combinations. The variation in traY and excA genes found in IncI1-Iγ plasmids is conserved within pMLST sequence types and plays a role in incompatibility, although functional study is needed to elucidate the role of these genes in plasmid epidemiology.


Assuntos
Escherichia coli/genética , Plasmídeos/genética , Salmonella enterica/genética , Animais , Proteínas de Bactérias/genética , Humanos , Tipagem de Sequências Multilocus , Filogenia , beta-Lactamases/genética
14.
Int J Artif Organs ; 38(3): 138-45, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25837877

RESUMO

PURPOSE: The CH-VAD is an implantable, fully magnetically suspended ventricular assist device developed by the China Heart Biomedical Corporation (Suzhou, China) for full cardiac support. This study was performed to evaluate the reliability, hemocompatibility and end-organ effects of CH-VAD in a 35-day animal model trial. METHODS: The pump was implanted in 6 sheep. The pump inflow was inserted into the left ventricle and the outflow graft was anastomosed to the descending aorta. Data on pump function and the health condition of the animals, including hematologic and biochemical tests, were collected during the study period. When each study was determined to termination, the sheep were humanely euthanized and the end organs were examined macroscopically and histopathologically. Hemolysis was evaluated based on the amount of free hemoglobin in the plasma. RESULTS: Except for one device that stopped operation on postoperative day 25 because of thrombus formation, the devices functioned normally until the scheduled termination. Gross examination of the pump interiors, inflow and outflow, and of the arterial anastomosis sites showed no significant abnormalities. Hematologic and biochemical test results were within normal limits during the study period. Macroscopic and histopathologic examinations of the explanted organs revealed no evidence of ischemia or infarction associated with the device implantation, except for small foci of infarction in the kidneys of two sheep. The free hemoglobin level in plasma peaked at 9.5 mg/dl on postoperative day 5. CONCLUSIONS: The CH-VAD system demonstrated promising reliability and blood-handling characteristics without obvious damage to end organs during a 35-day implantation in sheep.


Assuntos
Coração Auxiliar , Animais , Fenômenos Magnéticos , Masculino , Desenho de Prótese , Reprodutibilidade dos Testes , Ovinos
15.
Chin Med J (Engl) ; 128(3): 342-7, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25635429

RESUMO

BACKGROUND: The thickness of the alveolar mucosa influences the probability of the occurrence of denture-induced irritations. Thick denture-supporting tissues offer relief from mucosal tenderness and ulcers; however, the uniformity of the thickness across the entire mandibular alveolar mucosa cannot be accurately determined in edentulous patients. This study aimed to assess the mucosal thickness of the denture-bearing area in the edentulous mandible. METHODS: Twenty-seven edentulous patients underwent cone-beam computed tomography scanning, wherein the patients wore a record base to retract soft tissues away from the alveolar mucosa. The measured regions were the central incisor (IC), lateral incisor (IL), canine (Ca), first premolar (P1), second premolar (P2), first molar (M1), and second molar (M2) regions. The thickness was measured in the alveolar ridge crest (T), buccal (B1-B4), and lingual (L1-L4) alveolar ridge mucosa. The average thickness of the mucosa at buccal sides (B) and lingual sides (L) were also assessed. RESULTS: The differences in the mucosal thickness between the left and right sides were not significant. In the Ca-M2 regions, T was the thickest, and L3 was the thinnest of all the measured points in the same regions. L was significantly less than B in posterior regions (P < 0.01). On the other hand, M2 at L4 was thinnest of all the measured regions from Ca to M2 (P < 0.01), and was thicker than IC, IL, P1, and P2 at B2. CONCLUSIONS: Since the mucosal thickness of denture-bearing area in the edentulous mandible is not uniform; the tissue surface of the denture base or custom tray should be selectively relieved, which may reduce the risk of denture-induced irritations.


Assuntos
Processo Alveolar/anatomia & histologia , Dentaduras , Arcada Edêntula , Mandíbula/anatomia & histologia , Mandíbula/citologia , Membrana Mucosa/citologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Biomed Mater Eng ; 25(1 Suppl): 65-71, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25538057

RESUMO

The scaffolds prepared from the tissue decellularization conserve the porous 3-D structure and provide an optimal matrix for the tissue regeneration. Since decade, the enzymatic digestion, chemical reagent treatment and mechanical actions such as eversion and abrasion have been used to remove the cells from the intact matrix. In this study, we optimized an enzymatic method to decellularize the umbilical artery to construct a 3-D porous scaffold which is suitable for the culture of mesenchymal stem cells (MSCs). The scaffold maintained the interconnected porous structure. It remained the similar high water content 95.3 ± 1% compared to 94.9 ± 0.6% in the intact umbilical artery (p>0.05). The decellularization process decreased the stress from 0.24 ± 0.05 mPa to 0.15 ± 0.06 mPa (p<0.05). However the decellularization did not change the strain of the artery (45 ± 15% vs. 53 ± 10%, p>0.05). When the scaffold was transplanted to the subcutaneous tissue in the wild type mice, there were less T cells appeared in the surrounding tissue which meant the decreased the immunogenicity by decellularization. This scaffold also supported the adhesion and proliferation of the MSCs. In this study, we constructed a biological compatible porous scaffold from the decellularized umbilical artery which may provide a suitable scaffold for cell-matrix interaction studies and for tissue engineering.


Assuntos
Materiais Biocompatíveis/síntese química , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Tecidos Suporte , Artérias Umbilicais/química , Animais , Adesão Celular/fisiologia , Proliferação de Células/fisiologia , Sistema Livre de Células , Células Cultivadas , Força Compressiva , Módulo de Elasticidade , Desenho de Equipamento , Análise de Falha de Equipamento , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Humanos , Teste de Materiais , Camundongos , Porosidade , Resistência à Tração , Engenharia Tecidual/instrumentação , Artérias Umbilicais/metabolismo
18.
Infect Immun ; 82(7): 3023-32, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24799627

RESUMO

Certain verocytotoxin-producing Escherichia coli (VTEC) O157 phage types (PTs), such as PT8 and PT2, are associated with severe human infections, while others, such as PT21, seem to be restricted to cattle. In an attempt to delve into the mechanisms underlying such a differential distribution of PTs, we performed microarray comparison of human PT8 and animal PT21 VTEC O157 isolates. The main differences observed were in the vtx2-converting phages, with the PT21 strains bearing a phage identical to that present in the reference strain EDL933, BP933W, and all the PT8 isolates displaying lack of hybridization in some regions of the phage genome. We focused on the region spanning the gam and cII genes and developed a PCR tool to investigate the presence of PT8-like phages in a panel of VTEC O157 strains belonging to different PTs and determined that a vtx2 phage reacting with the primers deployed, which we named Φ8, was more frequent in VTEC O157 strains from human disease than in bovine strains. No differences were observed in the production of the VT2 mRNA when Φ8-positive strains were compared with VTEC O157 possessing BP933W. Nevertheless, we show that the gam-cII region of phage Φ8 might carry genetic determinants downregulating the transcription of the genes encoding the components of the type III secretion system borne on the locus of enterocyte effacement pathogenicity island.


Assuntos
Colífagos/classificação , Colífagos/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/virologia , Toxina Shiga II/metabolismo , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Colífagos/genética , DNA Viral/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Genoma Viral , Genótipo , Humanos , Itália/epidemiologia , Análise de Sequência com Séries de Oligonucleotídeos , Toxina Shiga II/genética
19.
PLoS One ; 8(9): e75392, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24086522

RESUMO

The putative virulence and antimicrobial resistance gene contents of extended spectrum ß-lactamase (ESBL)-positive E. coli (n=629) isolated between 2005 and 2009 from humans, animals and animal food products in Germany, The Netherlands and the UK were compared using a microarray approach to test the suitability of this approach with regard to determining their similarities. A selection of isolates (n=313) were also analysed by multilocus sequence typing (MLST). Isolates harbouring bla(CTX-M-group-1) dominated (66%, n=418) and originated from both animals and cases of human infections in all three countries; 23% (n=144) of all isolates contained both bla(CTX-M-group-1) and bla(OXA-1-like) genes, predominantly from humans (n=127) and UK cattle (n=15). The antimicrobial resistance and virulence gene profiles of this collection of isolates were highly diverse. A substantial number of human isolates (32%, n=87) did not share more than 40% similarity (based on the Jaccard coefficient) with animal isolates. A further 43% of human isolates from the three countries (n=117) were at least 40% similar to each other and to five isolates from UK cattle and one each from Dutch chicken meat and a German dog; the members of this group usually harboured genes such as mph(A), mrx, aac(6')-Ib, catB3, bla(OXA-1-like) and bla(CTX-M-group-1). forty-four per cent of the MLST-typed isolates in this group belonged to ST131 (n=18) and 22% to ST405 (n=9), all from humans. Among animal isolates subjected to MLST (n=258), only 1.2% (n=3) were more than 70% similar to human isolates in gene profiles and shared the same MLST clonal complex with the corresponding human isolates. The results suggest that minimising human-to-human transmission is essential to control the spread of ESBL-positive E. coli in humans.


Assuntos
Bovinos/microbiologia , Galinhas/microbiologia , Cães/microbiologia , Resistência a Medicamentos/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , beta-Lactamases/metabolismo , Ração Animal/microbiologia , Animais , Escherichia coli/metabolismo , Alemanha , Humanos , Análise em Microsséries , Tipagem de Sequências Multilocus , Países Baixos , Especificidade da Espécie , Reino Unido , Virulência
20.
Inflamm Bowel Dis ; 19(11): 2326-38, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23989750

RESUMO

BACKGROUND: Mucosa-associated Escherichia coli are abundant in inflammatory bowel disease (IBD), but whether these bacteria gain intracellular access within the mucosa is uncertain. If E. coli does gain intracellular access, the contribution of bacterial pathogenicity to this requires further elucidation. This study aimed to quantify and characterize mucosa-associated and intracellular E. coli in patients with IBD and in healthy control subjects (HC). METHODS: Mucosal biopsies from 30 patients with Crohn's disease (CD), 15 with ulcerative colitis (UC), and 14 HC were cultured with or without gentamicin protection to recover intracellular or mucosa-associated E. coli, respectively. Overall, 40 strains (CD: n = 24, UC: n = 9, and HC: n = 7) were characterized by phylogenetic typing, adhesion and invasion assays, detection of virulence factors, antimicrobial resistance genes, and proteomic analysis. RESULTS: Mucosa-associated E. coli were more abundant in CD and UC than in HC (2750 versus 1350 versus 230 median colony-forming units per biopsy; P = 0.01). Intracellular E. coli were more prevalent in CD (90%) than in UC (47%) or HC mucosal biopsies (0%) (P < 0.001). Of 24 CD strains, 2 were adherent and invasive, but there were no unifying pathogenicity determinants that could distinguish most CD strains from UC or HC strains, or intracellular isolates from mucosa-associated isolates. CONCLUSIONS: Intracellular E. coli are more common in CD than in UC and not identified in HC. Most intracellular E. coli did not have characterizing pathogenic features, suggesting a significant role for defects in mucosal immunity or barrier dysfunction in their ability to gain intracellular access.


Assuntos
Biomarcadores/metabolismo , Colite Ulcerativa/microbiologia , Doença de Crohn/microbiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/patogenicidade , Mucosa Intestinal/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aderência Bacteriana , Células CACO-2 , Estudos de Casos e Controles , Células Cultivadas , Colite Ulcerativa/genética , Colite Ulcerativa/imunologia , Doença de Crohn/genética , Doença de Crohn/imunologia , DNA Bacteriano/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Feminino , Seguimentos , Humanos , Mucosa Intestinal/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteoma/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fatores de Virulência/análise , Adulto Jovem
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