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1.
Eur Arch Otorhinolaryngol ; 277(1): 31-35, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31552525

RESUMO

PURPOSE: It is important for the surgeon to determine the position of the CI electrode array during and after its placement within the cochlea. Most preferably, this should be within the scala tympani to obtain the best audiological outcome. Thus, misplacement into the scala vestibuli or tip fold-over should be prevented. Since there are different ways to ensure proper positioning of the electrode array within the scala tympani (e.g., intraoperative radiography, electrophysiological recordings), our study was aimed at detecting intraoperative electrophysiologic characteristics to better understand the mechanisms of those electrode tip fold-overs. MATERIAL AND METHODS: In a multi-centric, retrospective case-control series, patients with a postoperatively by radiography detected tip fold-over in perimodiolar electrodes were included. The point of fold-over (i.e., the electrode position) was determined and the intraoperative Auto-NRT recordings were analysed and evaluated. RESULTS: Four patients were found to have an electrode tip fold-over (out of 85 implantees). Significant changes of the Auto-NRT recordings were not detected. All tip fold-overs occurred in the most apical part of the electrodes. DISCUSSION: Cochlear implantation for hearing impaired patients plays a decisive role in modern auditory rehabilitation. Perimodiolar electrode arrays may fold over during the insertion and, hence, could have a negative impact on audiological outcome. Characteristic electrophysiologic changes to possibly predict this were not found in our series.


Assuntos
Implante Coclear/efeitos adversos , Implantes Cocleares/efeitos adversos , Técnicas de Diagnóstico Otológico , Eletrodiagnóstico/métodos , Perda Auditiva Neurossensorial/cirurgia , Rampa do Tímpano/cirurgia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
J Viral Hepat ; 25(5): 465-472, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29193564

RESUMO

Interferon (IFN)-free direct-acting antiviral agents (DAAs) have revolutionized chronic hepatitis C virus (HCV) treatment; early studies suggest excellent efficacy in acute HCV. However, changes in innate immune responses during DAA therapy for acute HCV are unknown. We studied interferon-stimulated gene (ISG) expression and related cytokines/chemokines in HIV-infected patients with acute HCV receiving sofosbuvir plus ribavirin (SOF+RBV) as part of the A5327 clinical trial. ISG expression was determined from PBMCs, and circulating cytokines/chemokines were quantified from serum from study participants. The overall sustained virologic response (SVR) was 57%; all treatment failures were due to virologic relapse. Apart from NOS2a, baseline ISG/chemokine/cytokine levels were similar irrespective of treatment outcome. Downregulation of ISGs was observed at treatment week four and end of treatment (EOT), implicating HCV in establishing elevated ISGs early during HCV infection. Levels of many of these ISGs increased at post-treatment week 12 (PTW12) in relapsers only, coinciding with recurrent HCV RNA. Eleven ISGs were differentially expressed in responders vs relapsers. On-treatment viral suppression was also associated with a reduction in IP-10, CXCL11 and MIP-1ß levels. In contrast, circulating IFN-α levels were significantly higher at EOT and PTW12 in responders vs relapsers. Upregulation of peripheral ISG expression is established early in the course of HCV infection during acute HCV infection, but did not predict subsequent treatment outcome with SOF+RBV. ISGs were downregulated during therapy and increased post-therapy in relapsers. IFN-α levels were higher in responders at EOT/PTW12, suggesting that impaired type I IFN production/secretion may contribute to relapse.


Assuntos
Antivirais/uso terapêutico , Infecções por HIV/complicações , Hepatite C/tratamento farmacológico , Interferon Tipo I/sangue , Adulto , Idoso , Quimioterapia Combinada/métodos , Feminino , Humanos , Fatores Imunológicos/sangue , Masculino , Pessoa de Meia-Idade , Ribavirina/uso terapêutico , Sofosbuvir/uso terapêutico , Resposta Viral Sustentada , Resultado do Tratamento , Adulto Jovem
3.
Genes Immun ; 18(2): 82-87, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28300059

RESUMO

Inflammasomes are multi-protein complexes integrating pathogen-triggered signaling leading to the generation of pro-inflammatory cytokines including interleukin-18 (IL-18). Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections are associated with elevated IL-18, suggesting inflammasome activation. However, there is marked person-to-person variation in the inflammasome response to HCV and HIV. We hypothesized that host genetics may explain this variation. To test this, we analyzed the associations of plasma IL-18 levels and polymorphisms in 10 genes in the inflammasome cascade. About 1538 participants with active HIV and/or HCV infection in three ancestry groups are included. Samples were genotyped using the Illumina Omni 1-quad and Omni 2.5 arrays. Linear regression analyses were performed to test the association of variants with log IL-18 including HCV and HIV infection status, and HIV RNA in each ancestry group and then meta-analyzed. Eleven highly correlated single-nucleotide polymorphisms (r2=0.98-1) in the IL-18-BCO2 region were significantly associated with log IL-18; each T allele of rs80011693 confers a decrease of 0.06 log pg ml-1 of IL-18 after adjusting for covariates (rs80011693; rs111311302 ß=-0.06, P-value=2.7 × 10-4). In conclusion, genetic variation in IL-18 is associated with IL-18 production in response to HIV and HCV infection, and may explain variability in the inflammatory outcomes of chronic viral infections.


Assuntos
Coinfecção/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Hepatite C Crônica/imunologia , Interleucina-18/sangue , Interleucina-18/genética , Adulto , Dioxigenases/genética , Feminino , Infecções por HIV/sangue , Hepatite C Crônica/sangue , Humanos , Inflamassomos/imunologia , Masculino , Polimorfismo de Nucleotídeo Único
4.
J Viral Hepat ; 24(1): 37-42, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27666440

RESUMO

Several direct-acting antivirals (DAAs) have been approved for the treatment of chronic hepatitis C virus (HCV) infections, opening the door to highly effective interferon-free treatment regimens. Resistance-associated substitutions (RASs) have been reported both in treatment-naïve patients and following treatment with protease (NS3), phosphoprotein (NS5A) and polymerase (NS5B) inhibitors. The prevalence of naturally occurring RASs in untreated HCV-infected individuals has mostly been analysed in those infected with genotype 1 (GT1), in the late phase of infection, and only within limited regions of the genome. Furthermore, the geographic distribution of RASs remains poorly characterized. In this study, we used next-generation sequencing to analyse full-length HCV genomes for the prevalence of RASs in acute HCV infections identified in nine international prospective cohorts. RASs were analysed in 179 participants infected with all six major HCV genotypes (GT1-GT6), and the geographic distribution of RASs was assessed in 107 GT1a and GT3a samples. While RASs were detected at varied frequencies across the three genomic regions, and between genotypes, RASs relevant to multiple DAAs in the leading IFN-free regimens were rarely detected in combination. Low-frequency RASs (<10% of the viral population) were also shown to have a GT-specific distribution. The main RASs with geographic associations were NS3 Q80K in GT1a samples and NS5B N142T in GT3a. These data provide the backdrop for prospective surveillance of RASs during DAA treatment scale-up.


Assuntos
Substituição de Aminoácidos , Farmacorresistência Viral , Genótipo , Hepacivirus/genética , Hepatite C/tratamento farmacológico , Hepatite C/virologia , Adulto , Feminino , Frequência do Gene , Hepacivirus/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Proteínas Mutantes/genética , Filogeografia , Estudos Prospectivos , Análise de Sequência de DNA , Proteínas não Estruturais Virais/genética , Adulto Jovem
5.
J Viral Hepat ; 24(1): 43-52, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27808453

RESUMO

Cross-continental phylogenetic analysis is important to understand subtle molecular differences of currently circulating hepatitis C virus (HCV) subtypes. Existence of such differences can be crucial in pursuing a universal hepatitis C vaccine. We characterized molecular epidemiology of early HCV infections identified across nine cohorts [North America (n=4), Australia (n=4) and Europe (n=1)] in the International Collaborative of Incident HIV and Hepatitis C in Injecting Cohorts (InC3 ). One hundred and ninety-two full-length HCV genomes were amplified from plasma of incident infections and subjected to next generation sequencing to establish the largest cross-continental, full-length acute HCV genomic data set available to date. Genomes from the most common subtypes (1a: n=94, 2b: n=15 and 3a: n=68) were used in phylogenetic analysis. Using full genome trees, 78 sequences (44%) were found to lie within 29 phylogenetic clusters/pairs defined on the basis of molecular similarity of consensus sequences. Of these, 26 each had exclusively Australian or North American sequences indicating a strong geographical bias for molecular similarity. On further analysis of behavioural and demographic associations, binary logistic regression analysis showed that older age and non-Caucasian ethnicity were significantly associated with clustering. HCV probably evolves in micro-epidemics within geographically isolated communities.


Assuntos
Hepacivirus/classificação , Hepacivirus/genética , Hepatite C/virologia , Filogenia , Abuso de Substâncias por Via Intravenosa/complicações , Adulto , Austrália/epidemiologia , Usuários de Drogas , Europa (Continente)/epidemiologia , Feminino , Genoma Viral , Genótipo , Hepacivirus/isolamento & purificação , Hepatite C/epidemiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Epidemiologia Molecular , América do Norte/epidemiologia , Plasma/virologia , Análise de Sequência de DNA , Adulto Jovem
6.
Schmerz ; 29(2): 171-8, 2015 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-25860198

RESUMO

BACKGROUND: Bisphosphonates (BP) are used in the treatment of severe osteoporosis and metastasis of malignant diseases. A possible relationship between the occurrence of osteonecrosis of the jaw and BP therapy was first described in 2003. Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is difficult to treat. In some cases the condition of the patients is so compromised that only minimally invasive surgery is possible. Histopathologically, osteonecrosis shows the features of chronic sequestered osteomyelitis, which can be found in different areas of the upper and lower jaw. Sometimes extensive resections of the jaw are necessary. Thus, BRONJ can cause mutilation, impairment of function and esthetics in the orofacial system and, thereby, compromise the life quality of the patients. Triggering factors are often tooth extraction without surgical plastic wound closure of the alveoli, but can also be associated with bruises from denture or other minor wounds. OBJECTIVES: The purpose of this article is to present results from our own patient collective, including therapy regime, success rate, and therapy recommendations. METHODS: The patient populations at three German hospitals were analyzed using a standard questionnaire. The patients in the study group, entered into a follow-up system for early detection of possible BRONJ, were evaluated for treatement outcome. RESULTS: The success rate for prophylactic surgery in asymptomatic patients was very high at 96 %. In the group with symptomatic BRONJ, the outcome was significantly lower (76.4 %). CONCLUSIONS: Because of the complex symptoms, close cooperation between oncologists, dentists, and maxillofacial surgeons is required in the treatment of BRONJ. Before starting therapy with bisphosphonates and during the therapy, dental treatment and monitoring of the patient' oral health is necessary.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/diagnóstico , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/terapia , Difosfonatos/uso terapêutico , Imidazóis/uso terapêutico , Idoso , Terapia Combinada , Difosfonatos/efeitos adversos , Feminino , Seguimentos , Humanos , Imidazóis/efeitos adversos , Comunicação Interdisciplinar , Colaboração Intersetorial , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Osteoporose/tratamento farmacológico , Plasmocitoma/tratamento farmacológico , Fatores de Risco , Extração Dentária , Resultado do Tratamento , Ácido Zoledrônico
7.
Genes Immun ; 15(7): 500-5, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25030430

RESUMO

The host genetic basis of mixed cryoglobulin vasculitis is not well understood and has not been studied in large cohorts. A genome-wide association study was conducted among 356 hepatitis C virus (HCV) RNA-positive individuals with cryoglobulin-related vasculitis and 447 ethnically matched, HCV RNA-positive controls. All cases had both serum cryoglobulins and a vasculitis syndrome. A total of 899 641 markers from the Illumina HumanOmni1-Quad chip were analyzed using logistic regression adjusted for sex, as well as genetically determined ancestry. Replication of select single-nucleotide polymorphisms (SNPs) was conducted using 91 cases and 180 controls, adjusting for sex and country of origin. The most significant associations were identified on chromosome 6 near the NOTCH4 and MHC class II genes. A genome-wide significant association was detected on chromosome 6 at SNP rs9461776 (odds ratio=2.16, P=1.16E-07) between HLA-DRB1 and DQA1: this association was further replicated in additional independent samples (meta-analysis P=7.1 × 10(-9)). A genome-wide significant association with cryoglobulin-related vasculitis was identified with SNPs near NOTCH4 and MHC Class II genes. The two regions are correlated and it is difficult to disentangle which gene is responsible for the association with mixed cryoglobulinemia vasculitis in this extended major histocompatibility complex region.


Assuntos
Crioglobulinas/análise , Hepatite C/complicações , Polimorfismo de Nucleotídeo Único , Vasculite/genética , Estudos de Casos e Controles , Cromossomos Humanos Par 6/genética , Crioglobulinemia/etiologia , Crioglobulinemia/genética , Feminino , Genes MHC da Classe II , Estudo de Associação Genômica Ampla , Humanos , Masculino , Proteínas Proto-Oncogênicas/genética , Receptor Notch4 , Receptores Notch/genética , Vasculite/etiologia
9.
J Viral Hepat ; 18(7): e366-71, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21692949

RESUMO

Chronic hepatitis C infection is associated with hypolipidaemia that resolves with viral clearance. Lipid levels in a subgroup of patients rebound to levels that may increase the risk of coronary heart disease. The impact of acute hepatitis C infection and its clearance on lipid levels is unknown. We undertook a retrospective evaluation of subjects with acute hepatitis C infection evaluating lipid levels before, during and following acute infection. Thirty-eight subjects with acute hepatitis C infection had lipid levels available. Twelve patients had pre-infection and intra-infection lipid levels available. Cholesterol (197.8-152.4 mg/dL, P = 0.025), low-density lipoprotein (LDL) (116.1-76.3 mg/dL, P = 0.001) and non-high-density lipoprotein (non-HDL) cholesterol (164.0-122.7 mg/dL, P = 0.007) decreased dramatically during acute hepatitis C virus infection. Nineteen patients who achieved viral clearance had lipid levels available during infection and following resolution of infection. In these patients, cholesterol (145.0-176.0 mg/dL, P = 0.01), LDL (87.0-110.1 P = 0.0046) and non-HDL cholesterol (108.6-133.6 mg/dL, P = 0.008) increased significantly. No change was seen in patients who developed chronic infection. Four patients had lipid levels before, during and following resolution of infections and had increased postinfection LDL, cholesterol and non-HDL cholesterol from pre-infection levels, indicating acute infection may be associated with an increase in postinfection lipid levels and may confer an increased risk of coronary heart disease. Acute hepatitis C infection results in hypolipidaemia with decreased LDL, cholesterol and non-HDL cholesterol levels that increase following infection resolution. Levels may increase above pre-infection baseline lipid levels and should be monitored.


Assuntos
Hepatite C/sangue , Lipídeos/sangue , Doença Aguda , Adulto , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Doença das Coronárias/sangue , Feminino , Hepacivirus/genética , Humanos , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Fatores de Risco , Triglicerídeos/sangue
10.
Science ; 267(5201): 1150-3, 1995 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-17789197

RESUMO

Numerical simulations of three-dimensional convection with temperature-dependent viscosity and viscous heating at realistic Rayleigh numbers for Earth's mantle reveal that, in the strongly time-dependent regime, very intense localized heating takes place along the top portion of descending cold sheets and also at locations where the ascending plume heads impinge at the surface. For a viscosity contrast of 100, these localized heat sources exceed the internal heating due to the radioactive decay of chondritic materials by more than an order of magnitude. The horizontally averaged viscous dissipation is concentrated in the top of the convecting layer and has a magnitude comparable with that of radioactive heating.

11.
Br J Oral Maxillofac Surg ; 57(10): 1063-1067, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31594713

RESUMO

The intraoral approach is favoured by many patients and surgeons for the treatment of fractures of the condylar neck, but the limited space offered by this approach can make positioning and fixation of the osteosynthesis plate difficult. A rhombic-shaped plate was designed specifically for use with the intraoral approach, and introduced into our clinical practice in 2012. We present the clinical and functional results in 81 patients with 98 fractures of the condylar neck who we have treated with this technique. Of these six required surgical revision, and ultimately all but two had satisfactory occlusion and mandibular function. Our complication rate of 6/81 (7.4%) compares favourably with those reported elsewhere, and confirms that open reduction and internal fixation of condylar fractures using the Rhombic plate through an intra-oral approach provides good outcomes.


Assuntos
Placas Ósseas , Fixação Interna de Fraturas , Fraturas Mandibulares , Humanos , Côndilo Mandibular/lesões , Côndilo Mandibular/cirurgia , Fraturas Mandibulares/cirurgia , Redução Aberta , Resultado do Tratamento
12.
Trop Doct ; 38(3): 167-70, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18628548

RESUMO

In Cambodia, spina bifida is rare, but frontoethmoidal meningoencephalocoeles (MECs) are common. Mean life expectancy for patients with congenital MECs may be <20 years, but the complex treatment required has not been available in the country until recently. During visits by combined neurosurgical/craniofacial teams from both Germany and France, a method of repair has been developed that is suitable for the local conditions, affordable and has allowed Cambodian surgeons to learn how to successfully treat MECs. The surgical technique and initial results with 30 patients have been described in a previous publication. This paper presents the outcomes of 128 cases and illustrates that it is cost-effective for these patients to be treated in Cambodia.


Assuntos
Encefalocele , Osso Etmoide/cirurgia , Osso Frontal/cirurgia , Meningocele , Complicações Pós-Operatórias , Adolescente , Camboja/epidemiologia , Criança , Pré-Escolar , Análise Custo-Benefício , Encefalocele/diagnóstico , Encefalocele/economia , Encefalocele/cirurgia , Feminino , Humanos , Lactente , Masculino , Meningocele/diagnóstico , Meningocele/economia , Meningocele/cirurgia , Complicações Pós-Operatórias/classificação , Complicações Pós-Operatórias/epidemiologia , Resultado do Tratamento
13.
Br J Oral Maxillofac Surg ; 55(6): 623-625, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28460872

RESUMO

It is difficult to fix fractures of the condylar head of the mandible. Several techniques have been described which show satisfactory outcomes, but stability can be questionable, and some can cause irritation of the soft tissues. We describe a technique and first results of treating such fractures with resorbable magnesium-based headless bone screws (Magnezix® 2.7mm CS; Syntellix AG, Hanover, Germany).


Assuntos
Implantes Absorvíveis , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Côndilo Mandibular/cirurgia , Fraturas Mandibulares/cirurgia , Ligas , Humanos , Magnésio , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/lesões , Fraturas Mandibulares/diagnóstico por imagem
14.
Aust Dent J ; 61(1): 62-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25819677

RESUMO

BACKGROUND: Tooth extractions lead to morphological changes of the alveolar ridge. For oral rehabilitation sufficient bone volume of the alveolar ridge is required. This clinical study compared the ability of Bio-Oss® Collagen to autogenous bone to preserve bone volume after tooth extraction. METHODS: A total of 17 patients with 20 extraction sites were examined. After extraction, 10 sockets were each filled with either autogenous bone or Bio-Oss® Collagen and covered with a resorbable membrane. The width of the alveolar ridge was measured postoperatively, and after 4 and 6 months respectively. Prior to implant insertion, a bone biopsy was taken from the grafted sites and evaluated histologically. RESULTS: The width of the alveolar ridge in the Bio-Oss® Collagen group decreased about 5.33 ± 6.62% after 4 months and 9.45 ± 10.51% after 6 months. The reduction in the group augmented with autogenous bone was 14.31 ± 21.41% after 4 months and 19.17 ± 8.38% after 6 months. No statistically significant differences were observed. The histological examination showed comparable area fractions of total bone in both groups (Bio-Oss® Collagen: 59.99 ± 24.23%; autogenous bone: 61.55 ± 25.13%; p = 1.0). CONCLUSIONS: The present study demonstrated that autogenous bone and Bio-Oss® Collagen are suitable for ridge preservation. However, both techniques could not entirely prevent tissue volume loss.

15.
Oncogene ; 8(2): 289-98, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8426738

RESUMO

We have analysed the expression of p53 at the mRNA level, and extensively at the protein level by immunostaining, Western blotting, and ELISA measurements revealing a p53 increase in 8 out of 14 cell lines established from human pancreatic carcinomas. The mRNA levels closely paralleled the protein levels in most of the cell lines. Overexpression of p53 in tumor cells correlated with mutations in the p53 gene. Immunocytochemistry was also performed with tissue cryosections showing a nuclear p53 staining in 8 out of 12 exocrine, and 2 out of 2 endocrine tumors. In addition, nonmalignant peri-tumoral tissue specimens and cells derived from pancreatic juice of acute pancreatic patients were also positively stained. These findings may suggest functions of p53 in stress situations induced by acute inflammation or tissue regeneration. Genomic mutations in the tumor suppressor gene were associated with point mutations in either codon 12, 13 or 61 in the c-K-RAS oncogene in about two-thirds of cell lines. The frequent activations of a RAS oncogene in combination with mutations of a tumor suppressor gene are likely to contribute to the malignant phenotype of pancreatic adenocarcinomas.


Assuntos
Genes p53 , Genes ras , Neoplasias Pancreáticas/genética , Sequência de Bases , Western Blotting , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Dados de Sequência Molecular , Mutação , Pâncreas/química , Mutação Puntual , RNA Mensageiro/análise , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/análise
16.
J Invest Dermatol ; 115(1): 12-8, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10886501

RESUMO

Degradation of angiogenic mediators might be an underlying cause of chronic wounds. To test this hypothesis, we evaluated the expression and integrity of vascular endothelial growth factor, a potent angiogenic mediator, and its receptors, Flt-1 and KDR, in chronic venous leg ulcerations. Immunohisto- chemical, in situ hybridization, and semiquantitative reverse transcriptase polymerase chain reaction analyses all indicate that expression of vascular endothelial growth factor is elevated in ulcerative tissue, with vascular endothelial growth factor mRNA being especially pronounced in the hyperplastic epithelium of the wound margin. Flt-1 and KDR protein and mRNA were detected in the papillary vessels in close vicinity to the lesional epithelium of chronic wounds. Although increased expression of vascular endothelial growth factor protein was detected in the epidermis, the intensity of this staining was weak compared with the epidermal staining in psoriatic lesions and compared with the strong vascular endothelial growth factor mRNA signal in chronic wounds and psoriasis. To analyze whether this apparent decrease in immunoreactivity could be the result of degradation of vascular endothelial growth factor by proteolytic activities from the wound environment, we examined the stability of recombinant vascular endothelial growth factor in wound fluid from chronic leg ulcers. As demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, incubation of rVEGF165 with chronic, but not acute, wound fluid resulted in rapid proteolytic degradation of rVEGF165. Protease inhibitor studies indicate that serine proteases, such as plasmin, are involved in this degradation. Together, our data show that, although vascular endothelial growth factor expression is elevated in chronic wounds, increased proteolytic activity in this environment results in its degradation, which may contribute to an impaired wound healing response.


Assuntos
Fatores de Crescimento Endotelial/metabolismo , Linfocinas/metabolismo , Ferimentos e Lesões/metabolismo , Doença Crônica , Estabilidade de Medicamentos , Fatores de Crescimento Endotelial/biossíntese , Exsudatos e Transudatos/metabolismo , Fibrinolisina/fisiologia , Expressão Gênica , Humanos , Úlcera da Perna/metabolismo , Linfocinas/biossíntese , Inibidores de Proteases/farmacologia , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas/genética , RNA Mensageiro/metabolismo , Receptores Proteína Tirosina Quinases/genética , Receptores de Fatores de Crescimento/genética , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes/metabolismo , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular , Receptor 1 de Fatores de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
17.
Biomaterials ; 22(20): 2799-809, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11545315

RESUMO

The adhesion, orientation and proliferation of human gingival epithelial cells and human maxillar osteoblast-like cells in primary and secondary culture were studied on glossy polished, sandblasted and plasma-sprayed titanium surfaces by scanning electron microscopy and in thin sections. The primary cultured explants of human gingival epithelial cells attached, spread and proliferated on all titanium surfaces with the greatest extension on the polished and the smallest extension on plasma-sprayed surfaces. In secondary suspension cultures of gingival keratinocytes, attachment spreading and growth was only observed on polished and plasma-sprayed surfaces, but not on sandblasted surfaces. Moreover, the attachment of these cells depended on the seeding concentration as well as on the coating with fetal calf serum. Cells on polished surfaces developed an extremely flat cell shape, but on sandblasted and plasma-sprayed surfaces a more cuboidal shape. In contrast human maxillar osteoblasts seeded as secondary suspension cultures attached very well to all three differently textured titanium surfaces and showed identical growth patterns independent of the titanium surface structure. These findings suggest that cell morphology, orientation, proliferation and adhesion of human gingival epithelial cells in primary or secondary culture are dependent on the texture of the titanium surface whereas no such differences were observed for maxillar osteoblast-like cells. In conclusion, the soft tissue integration and response is more influenced by the surface texture than the process of osseointegration.


Assuntos
Adesão Celular , Divisão Celular , Gengiva/citologia , Queratinócitos/citologia , Maxila/citologia , Osteoblastos/citologia , Titânio , Fosfatase Alcalina/metabolismo , Células Cultivadas , Colágeno/metabolismo , Meios de Cultura , Implantes Dentários , Ensaio de Imunoadsorção Enzimática , Gengiva/metabolismo , Gengiva/ultraestrutura , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Queratinócitos/metabolismo , Queratinócitos/ultraestrutura , Microscopia Eletrônica de Varredura , Osteoblastos/enzimologia , Osteoblastos/metabolismo , Osteoblastos/ultraestrutura , Propriedades de Superfície
18.
Biomaterials ; 23(16): 3319-28, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12099274

RESUMO

The optimization of seeding and culturing of human osteoblast-like cells on three collagen-based biomaterials (bovine, equine and calf collagen membrane) was studied by cell proliferation and cell colonization (scanning electron microscopy) analysis. Osteoblasts of five patients were seeded onto the three biomaterials and two different parameters were varied: the time intervals between initial seeding and adding culture medium (2 h 6 h. 12 h, 24 h) and the seeding concentration (1 x 10(5), 1 x 10(6), 2 x 10(6)cells/ml) of cells onto biomaterials. The results of the study demonstrated that the time interval between seeding osteoblasts and adding culture medium as well as the seeding concentration effects the cell proliferation and the cell colonization. The best proliferation rate was achieved by adding the culture medium 2 h after initial seeding and with a seeding density of 1 x 10(5) cells/ml. Moreover, all three biomaterials resulted in different proliferation rates. The best proliferation rate resulted with the bovine collagen membrane. In conclusion, the examined parameters are very important for the development of the tissue engineering techniques and in a larger perspective also for reconstructive surgery.


Assuntos
Materiais Biocompatíveis/farmacologia , Técnicas de Cultura de Células/métodos , Divisão Celular/efeitos dos fármacos , Osteoblastos/citologia , Fosfatase Alcalina/metabolismo , Animais , Bovinos , Colágeno/farmacologia , Colágeno/ultraestrutura , Cavalos , Humanos , Microscopia Eletrônica de Varredura , Osteoblastos/efeitos dos fármacos
19.
Brain Res ; 770(1-2): 277-88, 1997 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-9372230

RESUMO

Intraperitoneal (i.p.) administration of sulfated CCK octapeptide (CCK-8S) has been shown to induce changes in neuronal activity in the nucleus of the solitary tract (NTS) and area postrema (AP), sensory parts of the dorsal vagal complex (DVC), and in the paraventricular nucleus of the hypothalamus (PVN), as determined by activation of c-fos expression. Whether peripheral CCK influences neuronal activity in the locus coeruleus (LC)/subcoeruleus nucleus (SC) was investigated in awake rats at intraperitoneal (i.p.) injection of CCK-8S by c-Fos immunohistochemistry. CCK-8S i.p. (25, 50, and 100 micrograms/kg, respectively) dose-dependently increased the average number of c-Fos-LI-positive cells/section in the LC/SC by the factor 5.9, 8.2, and 11.7, respectively. Pretreatment with the CCK-A receptor antagonist MK-329 (devazepide; 1 mg/kg and 2 mg/kg i.p.) reduced the CCK-induced increase in c-fos expression in the LC/SC by 54% and 75%, respectively; the CCK-B receptor antagonist L-365,260 had no effect. Perivagal capsaicin pretreatment diminished the CCK-induced increase in the number of c-Fos-LI-positive cells in the LC/SC by 65%. In comparison, the CCK-A antagonist devazepide (1 mg/kg and 2 mg/kg i.p.) reduced the increase in c-fos expression by 76% and 88% in the PVN, 69% and 88% in the NTS, 86% and 83%, respectively, in the AP. Capsaicin diminished the CCK-induced increase in c-Fos-LI-positive cells in the PVN by 64%, in the NTS by 60%, but in the AP only by 25%. Immunostaining against the nuclear antigen c-Fos and the cytoplasmatic antigen tyrosine hydroxylase (TH) showed that 40% of all c-Fos-LI-positive cells in the LC/SC were TH-LI positive at 25 micrograms CCK/kg. The data indicate that CCK-8S i.p. induces modulation of neuronal activity in the LC/SC, DVC and PVN predominantly by peripheral action of CCK-A receptors and capsaicin-sensitive vagal afferents. These findings suggest that the LC/SC is involved in CNS-mediated regulatory influences of peripheral CCK.


Assuntos
Locus Cerúleo/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Proteínas Proto-Oncogênicas c-fos/biossíntese , Receptores da Colecistocinina/metabolismo , Nervo Vago/metabolismo , Animais , Capsaicina/metabolismo , Capsaicina/farmacologia , Catecolaminas/fisiologia , Relação Dose-Resposta a Droga , Imuno-Histoquímica , Injeções Intraperitoneais , Locus Cerúleo/química , Locus Cerúleo/citologia , Masculino , Neurônios Aferentes/química , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/enzimologia , Nootrópicos/farmacologia , Núcleo Hipotalâmico Paraventricular/química , Núcleo Hipotalâmico Paraventricular/citologia , Proteínas Proto-Oncogênicas c-fos/análise , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Colecistocinina A , Receptor de Colecistocinina B , Receptores da Colecistocinina/agonistas , Receptores da Colecistocinina/antagonistas & inibidores , Sincalida/análogos & derivados , Sincalida/farmacologia , Núcleo Solitário/química , Núcleo Solitário/citologia , Núcleo Solitário/metabolismo , Estresse Fisiológico/metabolismo , Estresse Fisiológico/fisiopatologia , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/análise , Nervo Vago/química , Nervo Vago/citologia
20.
Brain Res ; 728(2): 157-65, 1996 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-8864477

RESUMO

Brain corticotropin-releasing factor (CRF) is involved in stress-related alterations of gastric acid secretion. CRF in the locus coeruleus has been shown to induce anxiogenic behavioral responses and to mimic stress-induced alterations of colonic motor function. Whether the locus coeruleus/subcoeruleus nucleus (LC/SC) is a site of action for CRF to alter gastric acid secretion was investigated in urethane-anesthetized gastric fistula rats. In sham-operated animals, CRF (126-420 pmol) microinfused bilaterally into the LC/SC induced a dose-dependent inhibition of pentagastrin (PG)-stimulated gastric acid secretion of 60-81% within the first hour after microinjection. At the 420 pmol dose, this inhibitory effect of CRF into the LC/SC lasted throughout the whole observation period of 120 min. After bilateral vagotomy, basal and PG-stimulated gastric acid secretion at microinjection of vehicle was reduced. Nevertheless, microinfusion of 420 pmol CRF into the LC/SC still inhibited significantly gastric acid secretion by 62.1%. In contrast, in spinal cord transected animals bilateral microinfusion of 420 pmol CRF into the LC/SC did not reduce PG-stimulated gastric acid secretion. These data indicate that CRF acts in the LC/SC to induce a long lasting inhibition of peripherally stimulated gastric acid secretion via spinal pathways. These findings suggest a possible role of the LC/SC in the regulation of gastric secretion and of endogenous CRF at these sites in the stress-related inhibition of gastric acid secretion by affecting autonomic nervous system activity.


Assuntos
Hormônio Liberador da Corticotropina/farmacologia , Ácido Gástrico/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Locus Cerúleo/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Sprague-Dawley , Vagotomia
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