Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Energy Fuels ; 35(13): 10898-10907, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34276127

RESUMO

1D Ca3Co2-z M z O6 (M = Co z = 0, M = Mn z = 1, and M = Fe z = 0.4) were prepared and tested electrochemically. While the iron-containing phase was not found to be active, the iron- and manganese-containing phases were found to be potentially interesting as positive electrode materials for calcium metal-based high-energy battery technologies and were investigated by operando synchrotron X-ray diffraction. Results indicate that electrochemically driven calcium deintercalation from the crystal structure (ca. 0.7 mol per formula unit) takes place upon oxidation in both cases. The oxidized phases have incommensurate modulated crystal structures with the space group R 3m(00γ)0s and a = 9.127(1) Å, c 1 = 2.4226(3) Å and c 2 = 4.1857(3) Å, and γ = 0.579 (M = Co) and a = 9.217(1) Å, c 1 = 4.9076(4) Å and c 2 = 4.3387(4) Å, and γ = 1.139 (M = Mn), which exhibit differences due to the presence of manganese and Mn/Co ordering. The degree of calcium re-intercalation within the structure was found to be extremely limited, if any. Complementary experiments carried out in lithium cells did not show any reversibility either, thus pointing at intrinsic structural/migration constraints in the oxidized phase rather than slow kinetics of high desolvation energies associated with divalent ion charge carriers.

2.
Phys Chem Chem Phys ; 19(38): 26435-26441, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28944795

RESUMO

Layered MgMoN2 was prepared by solid state reaction at high temperature between Mo and Mg3N2 in N2 which represents a simple synthetic pathway compared to the previously reported method that used NaN3 as the nitrogen source. The crystal structure of MgMoN2 was studied by synchrotron X-ray and neutron powder diffraction. The feasibility of oxidizing this compound and concomitantly extracting magnesium from the structure was assessed by both chemical and electrochemical approaches, using different protocols. The X-ray diffraction patterns of the oxidized samples do not exhibit any relevant difference with respect to that of the as prepared MgMoN2 and no differences in the cell parameters are deduced from Rietveld refinements. No hints pointing at the presence of any amorphous phase are observed either. These results are rationalized through DFT calculated energy barriers for Mg2+ ion migration in MgMoN2.

3.
N Z Vet J ; 65(5): 270-276, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28637394

RESUMO

AIMS: To objectively compare measures of bone healing, using computed tomography (CT) in dogs following bilateral tibial tuberosity advancement (TTA), between tibiae treated with and without autogenous cancellous bone grafts. METHODS: Ten dogs with bilateral cranial cruciate ligament disease requiring surgical stabilisation were prospectively recruited to undergo single-session bilateral TTA, with only one, randomly assigned, tibia receiving bone graft in the osteotomy deficit. Bone healing at the osteotomy site was assessed using CT performed 38-70 days post-operatively. CT images were evaluated using both objective measurements of osseous bridging and subjective evaluation by six radiologists. Repeated measures ANOVA was used to compare the objective outcomes between the grafted and non-grafted tibiae. RESULTS: The mean percentage of the osteotomy deficit bridged at the lateral cortex was greater in grafted (77.6, SD 35.2%) compared to non-grafted (63.0, SD 36.5%) tibiae (p=0.001), but did not differ at the medial cortex (p=0.1). The mean minimum callus width was greater in grafted (7.2, SD 3.3 mm) compared to non-grafted (3.6, SD 2.9 mm) tibiae (p<0.001). There was no difference in mean attenuation (measured in Hounsfield units) of the callus between grafted and non-grafted tibiae (p=0.5). The grafted tibia was deemed to have superior bone healing in 50/60 subjective assessments made by radiologists. CONCLUSIONS: Superior osseous bridging was detected by CT analysis following TTA using autogenous cancellous bone grafts compared with no graft. This was shown by greater bridging percentage at the lateral cortex and formation of a broader callus. Qualitative assessments made by six radiologists also supported the conclusion that bone healing was improved by use of autogenous cancellous bone graft. CT was a useful method for assessing evidence of bone healing following TTA. CLINICAL RELEVANCE: These findings justify the application of autogenous cancellous bone graft to augment healing following TTA in dogs.


Assuntos
Osteotomia/veterinária , Joelho de Quadrúpedes/cirurgia , Tíbia/cirurgia , Tomografia Computadorizada por Raios X/veterinária , Cicatrização , Animais , Ligamento Cruzado Anterior , Transplante Ósseo/veterinária , Osso Esponjoso , Cães , Osteotomia/métodos
4.
Clin Microbiol Infect ; 23(3): 197-202, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27756713

RESUMO

OBJECTIVE: In Lao People's Democratic Republic, the high burden of vaccine-preventable diseases is thought to be mainly due to low vaccine coverage. We investigated the seroprotective response against diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type b (DTPw-HepB-Hib) vaccine in children. METHODS: Serum was collected from 1131 children aged 9 to 50 months and their mothers in a cross-sectional study between December 2013 and July 2014. All children had records of three injections of the DTPw-HepB-Hib vaccine. Serum was analysed for hepatitis B surface antigen (HBsAg), anti-HBsAg (anti-HBs), anti-hepatitis B virus core antigen (anti-HBc), anti-diphtheria and anti-tetanus antibodies. Stool samples were collected for detection of parasites. Demographic and nutritional information were also obtained. RESULTS: Protective levels of anti-HBs antibodies were found in 394 (37.9%) of 1039 children; 529 (55.7%) of 950 and 809 (85.2%) of 950 children were seroprotected against diphtheria and tetanus. Time since vaccination, age, home birth and malnutrition only partially explained the poor vaccine responses. Overall, 81 (7.8%) of 1039 children and 445 (40.3%) of 1105 of mothers were anti-HBc positive. Ten (1.0%) of 1039 of the children and 77 (7.0%) of 1105 of the mothers were HBsAg carriers. CONCLUSIONS: After a full documented course of vaccination, seroprotective rates were unusually low and disparate against components of the pentavalent vaccine. These can only partially be explained by the negative predictors identified. Although many children had been infected, only few were chronic carriers of HBsAg. Our study demonstrates an urgent need to monitor the serologic response to vaccination, particularly in resource-poor countries.


Assuntos
Anticorpos Antibacterianos/sangue , Vacina contra Difteria, Tétano e Coqueluche/administração & dosagem , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Vacinas Anti-Haemophilus/administração & dosagem , Vacinas Anti-Haemophilus/imunologia , Anticorpos Anti-Hepatite B/sangue , Vacinas contra Hepatite B/administração & dosagem , Vacinas contra Hepatite B/imunologia , Soro/imunologia , Adulto , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Laos , Masculino , Resultado do Tratamento , Adulto Jovem
5.
Vet Comp Orthop Traumatol ; 27(4): 263-70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24817090

RESUMO

Dogs treated for congenital medial patellar luxation were reviewed for the purpose of determining the incidence of postoperative major complications requiring surgical revision and the risk factors for their occurrence. Major complications occurred in 18.5% of the patellar luxation stabilization procedures with implant associated complications being the most frequent, patellar reluxation the second, and tibial tuberosity avulsion the third most common major complication. Other complications included patellar ligament rupture and trochlear wedge displacement. When recession trochleoplasty was performed in addition to tibial tuberosity transposition, a 5.1-fold reduction in the rate of patellar reluxation was observed. Release of the cranial belly of the sartorius muscle further reduced the incidence of patellar reluxation, while patella alta (pre- or postoperative) and patellar luxation grade were not found to influence the rate of reluxation. Tibial tuberosity avulsion was 11.1-times more likely when using a single Kirschner wire to stabilize a transposition, compared with two Kirschner wires. Independent to the number of Kirschner wires used, the more caudodistally the Kirschner wires were directed, the higher the risk for tibial tuberosity avulsion. Tension bands were used in 24.4% of the transpositions with no tuberosity avulsion occurring in stifles stabilized with a tension band. Overall, grade 1 luxations had a significantly lower incidence of major complications than other grades, while body weight, age, sex, and bilateral patellar stabilization were not associated with risk of major complication development.


Assuntos
Doenças do Cão/congênito , Luxação Patelar/congênito , Complicações Pós-Operatórias/veterinária , Animais , Doenças do Cão/cirurgia , Cães , Luxação Patelar/cirurgia , Luxação Patelar/veterinária , Estudos Retrospectivos , Fatores de Risco
6.
Clin Microbiol Infect ; 20(10): O664-71, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24512201

RESUMO

In the Lao People's Democratic Republic (PDR), mumps is not a notifiable disease and mumps vaccine is currently not included in the routine childhood immunization programme. In order to assess the burden of disease, we investigated the seroprevalence of mumps-specific IgG antibodies across four provinces. In addition, we genetically characterized mumps viruses from the past 3 years from several outbreaks and single cases. Blood and/or throat swabs from suspected cases were investigated for specific IgM antibodies or viral RNA. Mumps cases occurred between March and November in 2011-2013 and 5- to 15-year-olds were most affected. Four sequences from an outbreak in the north of Lao PDR in 2011 were identical and belonged to genotype G. Eight sequences from two outbreaks and two individual cases from 2012 and 2013 belonged to genotype J. In addition, sera collected from 2379 healthy infants and school pupils aged between 9 months and 19 years and from pregnant women aged between 16 and 46 years were investigated for mumps-specific IgG. Overall, 58.2% were positive, 39.5% were negative and the remaining 2.3% were equivocal. The seropositivity increased with age, with the lowest percentage found in <1-year-old infants (9.1%) and the highest in the cohort of pregnant women (69.2%). More female subjects than male subjects were seropositive (60.4 vs. 54.9%). There were some differences between the locations. Mumps should be a notifiable disease in Lao PDR in order to get more accurate case numbers and cost estimates for public health-care, and vaccination of children and high-risk groups should be considered.


Assuntos
Imunoglobulina G/sangue , Vírus da Caxumba/genética , Caxumba/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Lactente , Laos/epidemiologia , Masculino , Pessoa de Meia-Idade , Caxumba/sangue , Caxumba/imunologia , Caxumba/virologia , Vírus da Caxumba/classificação , Vírus da Caxumba/imunologia , Vírus da Caxumba/isolamento & purificação , Filogenia , Gravidez , RNA Viral/análise , Adulto Jovem
7.
Aust Vet J ; 90(8): 297-300, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22827623

RESUMO

A Cavalier King Charles Spaniel was presented with acute onset, life-threatening dysphagia suspected to be secondary to medulla oblongata compression caused by caudal occipital malformation syndrome. The patient required urgent tracheostomy tube placement to remain stable and was subsequently cured of the presenting neurological deficits by foramen magnum decompressive surgery. Neurogenic dysphagia is a relatively common presenting sign in human Chiari malformation syndromes, but has not been described as a major clinical sign in veterinary patients. Caudal occipital malformation syndrome should be included in the differential diagnosis list for susceptible breeds presenting with dysphagia. Early recognition favours expeditious surgical intervention and a positive outcome in human patients, and this may also be the case in veterinary patients.


Assuntos
Malformação de Arnold-Chiari/veterinária , Descompressão Cirúrgica/veterinária , Transtornos de Deglutição/veterinária , Doenças do Cão/cirurgia , Forame Magno/cirurgia , Osso Occipital/anormalidades , Animais , Malformação de Arnold-Chiari/complicações , Malformação de Arnold-Chiari/cirurgia , Descompressão Cirúrgica/métodos , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/cirurgia , Cães , Feminino , Osso Occipital/cirurgia , Resultado do Tratamento
8.
Clin Exp Dermatol ; 34(8): e941-4, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19549245

RESUMO

T cells are sensitized during varicella-zoster virus (VZV) infection and are important for control of viral spread and reactivation. In this report, we show that human keratinocytes infected with VZV inhibited upregulation of major histocompatibility complex (MHC) class I, MHC class II and intercellular adhesion molecule-1 after interferon (IFN)-gamma treatment. The ability of keratinocytes to upregulate MHC class I in response to IFN-alpha, tumour necrosis factor (TNF)-alpha and Toll-like receptor (TLR)-3 ligand was also diminished upon VZV infection. VZV-infected keratinocytes treated with IFN-gamma had significantly reduced capacity to stimulate antigen-specific T cells compared with uninfected cells. Interference with IFN-alpha, TNF-alpha, IFN-gamma and TLR-3 signalling in keratinocytes by VZV may contribute to immune evasion of the adaptive immune response.


Assuntos
Infecções por Herpesviridae/imunologia , Herpesvirus Humano 3/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Infecções por Herpesviridae/genética , Herpesvirus Humano 3/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Evasão da Resposta Imune , Queratinócitos/imunologia , Regulação para Cima
9.
Vet Comp Orthop Traumatol ; 21(3): 221-30, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18536848

RESUMO

A retrospective multi-centre study was carried out in order to compare outcomes between cemented and uncemented total hip arthoplasties (THA). A quantitative orthopaedic outcome assessment scoring system was devised in order to relate functional outcome to a numerical score, to allow comparison between treatments and amongst centres. The system combined a radiographic score and a clinical score. Lower scores reflect better outcomes than higher scores. Consecutive cases of THA were included from two specialist practices between July 2002 and December 2005. The study included 46 THA patients (22 uncemented THA followed for 8.3 +/- 4.7M and 24 cemented THA for 26.0 +/- 15.7M) with a mean age of 4.4 +/- 3.3 years at surgery. Multi-variable linear and logistical regression analyses were performed with adjustments for age at surgery, surgeon, follow-up time, uni- versus bilateral disease, gender and body weight. The differences between treatment groups in terms of functional scores or total scores were not significant (p > 0.05). Radiographic scores were different between treatment groups. However, these scores were usually assessed within two months of surgery and proved unreliable predictors of functional outcome (p > 0.05). The findings reflect relatively short-term follow-up, especially for the uncemented group, and do not include clinician-derived measures, such as goniometry and thigh circumference. Longer-term follow-up for the radiographic assessments is essential. A prospective study including the clinician-derived outcomes needs to be performed in order to validate the outcome instrument in its modified form.


Assuntos
Artroplastia de Quadril/veterinária , Cimentos Ósseos/uso terapêutico , Displasia Pélvica Canina/cirurgia , Prótese de Quadril/veterinária , Animais , Artroplastia de Quadril/métodos , Cimentos Ósseos/efeitos adversos , Cães , Feminino , Prótese de Quadril/normas , Modelos Lineares , Modelos Logísticos , Masculino , Osteoartrite do Quadril/cirurgia , Osteoartrite do Quadril/veterinária , Prognóstico , Falha de Prótese/veterinária , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
10.
Clin Exp Immunol ; 152(3): 522-31, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18363743

RESUMO

Varicella zoster viru (VZV)-specific T cell responses are believed to be vital in recovery from primary VZV infection and also in the prevention of viral reactivation. While glycoprotein E (gE) is the most abundant and one of the most immunogenic proteins of the virus, there are no data addressing potential T cell epitopes within gE, nor the phenotype of specific T cells. Using interferon gamma enzyme-linked immunospot assays and intracellular cytokine assays, we identified gE-specific immune responses in 20 adult healthy immune donors which were found to be dominated by the CD4+ subset of T cells. We characterized three immune dominant epitopes within gE restricted through DRB1*1501, DRB1*07 and DRB4*01, and used DRB1*1501 class II tetrameric complexes to determine the ex vivo frequency and phenotype of specific T cells. In healthy immune donors, the cells were largely positive for CCR7, CD28 and CD27, but expressed variable CD62L and low levels of cutaneous lymphocyte associated antigen with evidence of recent activation. In summary, we show that circulating gE-specific CD4+ T cells are detected at a relatively high frequency in healthy immune donors and show evidence of recent activation and mixed central and effector memory phenotype. These data would be compatible with frequent exposure to replicative cycle antigens in healthy donors and are consistent with a role for gE-specific CD4+ T cells in the control of viral replication.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Herpesvirus Humano 3/imunologia , Ativação Linfocitária/imunologia , Proteínas do Envelope Viral/imunologia , Adulto , Apresentação de Antígeno , Diferenciação Celular , Linhagem Celular Transformada , Células Cultivadas , Epitopos de Linfócito T/análise , Antígenos HLA-DR/sangue , Cadeias HLA-DRB1 , Humanos , Epitopos Imunodominantes/análise , Imunofenotipagem , Queratinócitos/imunologia , Pessoa de Meia-Idade
11.
Br J Dermatol ; 158(3): 456-62, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18205875

RESUMO

BACKGROUND: Blockade of lymphocyte function associated antigen-1 (LFA-1) is proving successful in the management of psoriasis and other inflammatory skin conditions including atopic dermatitis (AD), but the dependence of allergen-specific CD4+ T-cell function on LFA-1 has not been studied extensively. OBJECTIVES: We sought to investigate the potential ability of LFA-1 inhibition to influence keratinocyte presentation of allergen to specific T-helper (Th) 2 cell clones. METHODS: Using human leucocyte antigen class II tetrameric complexes, we generated Der p 1-specific DRB1*1501-restricted CD4+ T-cell lines (n=5) and clones (n=4) from the peripheral blood of five adults with AD. RESULTS: Using doses of anti-LFA-1 present in vivo, we observed significant inhibition (P<0.05) of allergen-specific CD4+ T-cell production of interleukin-4 with such inhibition occurring during presentation of allergen by keratinocytes. CONCLUSIONS: These data show that at doses present in vivo, LFA-1 blockade inhibits keratinocyte presentation to allergen-specific Th2 cells, suggesting one mechanism through which anti-LFA-1 may be beneficial therapeutically.


Assuntos
Antígenos CD4/imunologia , Queratinócitos/metabolismo , Antígeno-1 Associado à Função Linfocitária/imunologia , Psoríase/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Feminino , Citometria de Fluxo/métodos , Humanos , Interleucina-4/imunologia , Masculino , Linfócitos T Auxiliares-Indutores/citologia
13.
Vet Comp Orthop Traumatol ; 20(3): 169-74, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17846681

RESUMO

The tibial wedge osteotomy (TWO), a procedure that reduces the tibial plateau slope, has become an established surgical technique for the treatment of cranial cruciate ligament injuries in dogs, yet variation from the desired postoperative tibial plateau slope of 6 degrees has been noted. The objectives of this study were to investigate the geometric implications of this procedure and to identify factors that affect the postoperative angles. The records of 35 consecutive cases that had a TWO performed were reviewed and comparisons were made between the alignment of the cortices and level of the osteotomy using duplicated tracings of a preoperative radiograph. The existing method for calculating the size of wedge to be removed was found to result in a postoperative slope greater than the expected 6 degrees. Our results indicate that the desired postoperative angle is more likely to be achieved if the cranial cortices are aligned and the osteotomy is performed proximally.


Assuntos
Ligamento Cruzado Anterior , Doenças do Cão/cirurgia , Artropatias/veterinária , Osteotomia/veterinária , Tíbia/cirurgia , Animais , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/patologia , Cães , Artropatias/cirurgia , Osteotomia/métodos , Radiografia , Registros/veterinária , Estudos Retrospectivos , Resultado do Tratamento
14.
QJM ; 100(1): 19-27, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17175560

RESUMO

BACKGROUND: T cells that express Cutaneous Lymphocyte-Associated antigen (CLA) have the potential of migrating to the skin, and are hypothesized to play a role in cutaneous atopic disease. AIM: To investigate the immune phenotype and cytokine responses to Der p 1 stimulation of CLA+ T cells in extrinsic atopic dermatitis (EAD). DESIGN: In vitro testing, with controls. METHODS: Peripheral blood mononuclear cells (PBMC) were obtained from EAD patients (n=27) and non-atopic healthy individuals (n=22). Phenotypic analysis of naive, CLA+ and non-CLA+ memory/effector CD4+ and CD8+ T cells used markers of cell activation, differentiation, adhesion, apoptosis and chemokine receptor expression. Cytokine responses in these cells were studied following Der p 1 stimulation. RESULTS: CLA+ T cells from EAD patients expressed significantly higher levels of CD25, HLA-DR, CD38, CD71, CXCR1, CXCR2 and lower levels of bcl2, CCR5, CCR7, CXCR3, and CD62L (p<0.05). DISCUSSION: In EAD patients, CLA+ T cells express increased levels of markers associated with activation, adhesion and apoptosis, show differences in the level of expression of differentiation markers and display a distinct chemokine receptor preference, compared with cells from healthy controls. These data suggest a significant role for CLA+ T cells in the pathogenesis of cutaneous atopic disease.


Assuntos
Antígenos de Neoplasias/imunologia , Dermatite Atópica/imunologia , Glicoproteínas de Membrana/imunologia , Receptores de Retorno de Linfócitos/análise , Pele/imunologia , Linfócitos T/imunologia , Adulto , Antígenos de Dermatophagoides/imunologia , Antígenos de Diferenciação de Linfócitos T , Proteínas de Artrópodes , Cisteína Endopeptidases , Feminino , Humanos , Masculino
15.
Clin Exp Dermatol ; 31(5): 689-94, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16780501

RESUMO

BACKGROUND: Several studies have investigated levels of T-cell-derived interleukin (IL)-10 in individuals with atopic dermatitis, with conflicting results. AIMS/HYPOTHESIS: In order to address whether stratification of disease severity may help resolve the different findings, the hypothesis was tested that individuals with severe atopic dermatitis have a lower frequency of circulating IL-10-producing, allergen-specific CD4+ T cells than do individuals with mild disease. METHODS: Using peripheral blood mononuclear cells derived from individuals with severe (n=12) and mild atopic dermatitis (n=10) and from nonatopic controls (n=10), we investigated production by CD4+ T cells of tumour necrosis factor (TNF)-alpha, IL-4, IL-5, IL-13 and IL-10 in response to phorbol myristate acetate/ionomycin and Der p1 allergen. RESULTS: It was observed that there were significantly higher frequencies of allergen-specific circulating CD4+ T cells producing TNF-alpha- IL-4-, IL-5- and IL-13, and lower frequencies of these cells producing IL-10 in individuals with severe atopic dermatitis compared with mildly affected individuals and nonatopic controls (P<0.01 for all comparisons). Furthermore, the Der p1-specific CD4+ T cells were enriched within the subset of cells positive for cutaneous lymphocyte-associated antigen. CONCLUSIONS: Analysis of levels of allergen-specific CD4+ T-cell production of IL-10 in relation to disease severity argues in favour of a role for IL-10 in the control of atopic dermatitis.


Assuntos
Linfócitos T CD4-Positivos/citologia , Dermatite Atópica/imunologia , Interleucina-10/biossíntese , Linfócitos T CD4-Positivos/imunologia , Citometria de Fluxo/métodos , Humanos , Interleucinas/biossíntese , Estimulação Química
16.
Br J Dermatol ; 153(5): 987-91, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16225611

RESUMO

BACKGROUND: Systemic immunosuppression is a significant risk factor for cutaneous squamous cell carcinoma (SCC). p53 is mutated and overexpressed in up to 90% of cutaneous SCC lesions. Despite considerable evidence that the immune response is important in the control of cutaneous SCC, there are no studies documenting potential tumour-associated antigens. OBJECTIVES: We tested the hypothesis that individuals with cutaneous SCC have functional circulating CD8+ T cells specific for p53. METHODS: Interferon-gamma immunosorbent assays were used to screen peripheral blood mononuclear cells for reactivity to six p53-derived HLA-A*0201-restricted epitopes from HLA-A*0201-positive patients and controls. RESULTS: We observed significantly elevated frequencies of p53-specific CD8+ T cells in seven of 26 individuals with cutaneous SCC and in one of 10 controls. The degree of lymphocytic infiltrate significantly correlated with the frequency of CD8+ T cells specific for p53 epitopes, but not with control epitopes. CONCLUSIONS: Overall, these data suggest that p53 may represent a target for CD8+ T cells in a proportion of individuals with cutaneous SCC.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/imunologia , Neoplasias Cutâneas/imunologia , Proteína Supressora de Tumor p53/imunologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Epitopos de Linfócito T/imunologia , Feminino , Antígenos HLA-A/análise , Antígeno HLA-A2 , Humanos , Interferon gama/biossíntese , Linfócitos do Interstício Tumoral/imunologia , Masculino , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Proteína Supressora de Tumor p53/metabolismo
17.
Clin Exp Immunol ; 141(1): 107-15, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15958076

RESUMO

Factors controlling the expression of cutaneous lymphocyte-associated antigen (CLA) by T cells are poorly understood, but data from murine and human CD4(+) T cell systems have suggested that cytokines play an important role. However, there are no data examining the influence of cytokines on the expression of CLA by human antigen-specific CD8(+) T cells. Peripheral blood mononuclear cells (PBMC) were isolated from 10 HLA-A*0201-positive healthy individuals. Using HLA-peptide tetrameric complexes refolded with immunodominant peptides from Epstein-Barr virus (EBV), cytomegalovirus (CMV) and influenza A virus, we investigated the temporal associations of CLA expression by viral-specific CD8(+) T cells following stimulation with antigen. Ex vivo influenza matrix-specific CD8(+) T cells expressed significantly (P < 0.05) greater levels of CLA than EBV BMLF1 and CMV pp65-specific CD8(+) T cells (mean 9.7% influenza matrix versus 1.4% BMLF1 versus 1.1% pp65) and these differences were sustained on culture. However, regardless of viral specificity, interleukin (IL)-12 and IL-4 induced significant (P < 0.05) dose-dependent up-regulation and down-regulation of CLA expression, respectively, with IL-4 showing a dominant negative effect. In many cases, IL-4 resulted in complete abrogation of detectable CLA expression by the viral-specific CD8(+) T cells. Overall these data demonstrate that CLA expression by human viral-specific CD8(+) T cells is highly dynamic and that IL-4 causes significant down-regulation. Disorders associated with a type 2 cytokine shift may reduce the efficiency of skin homing by viral-specific CD8(+) T cells. Furthermore, the ability to modify the local and systemic microenvironment may offer novel therapeutic strategies that influence tissue-specific T cell homing.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Interleucina-4/imunologia , Glicoproteínas de Membrana/metabolismo , Receptores de Retorno de Linfócitos/metabolismo , Dermatopatias Virais/imunologia , Antígenos de Diferenciação de Linfócitos T , Antígenos de Neoplasias , Células Cultivadas , Citomegalovirus/imunologia , Dermatite Atópica/complicações , Dermatite Atópica/imunologia , Regulação para Baixo/imunologia , Epitopos de Linfócito T/imunologia , Citometria de Fluxo/métodos , Herpesvirus Humano 4/imunologia , Humanos , Interleucina-12/imunologia , Orthomyxoviridae/imunologia , Pele/imunologia , Dermatopatias Virais/etiologia
18.
Br J Dermatol ; 151(6): 1160-4, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15606510

RESUMO

BACKGROUND: Mucous membrane pemphigoid (MMP) is a chronic blistering skin disease frequently associated with circulating autoantibodies directed to a number of antigens including the NC16A region of BP180. NC16A domain-specific T cells have been identified in the blood of individuals with bullous pemphigoid (BP), pemphigoid gestationis and linear IgA disease, but there are no data investigating the potential role for such T cells in the pathogenesis of MMP. OBJECTIVES: To test the hypothesis that NC16A-specific T cells exist in the peripheral blood of individuals with MMP. METHODS: We isolated peripheral blood mononuclear cells from 10 patients with MMP, 17 with BP and 10 healthy controls and examined the immunogenicity of overlapping peptides spanning the NC16A domain using interferon (IFN)-gamma enzyme-linked immunospot assay. RESULTS: Significant IFN-gamma production was observed in response to the NC16A peptides in two of the patients with MMP and two of the patients with BP but in none of the normal controls. These data suggest that in a minority of individuals with MMP, NC16A domain-specific T cells circulate at sufficiently high frequency to be detectable directly ex vivo and to show rapid effector function. CONCLUSIONS: Overall, these findings are the first to examine the potential role for antigen-specific autoreactive T cells in the pathogenesis of MMP, and confirm that in some individuals the NC16A domain may be an important target antigen.


Assuntos
Autoantígenos/imunologia , Penfigoide Mucomembranoso Benigno/imunologia , Subpopulações de Linfócitos T/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos de Linfócito T/imunologia , Humanos , Epitopos Imunodominantes/imunologia , Interferon gama/biossíntese , Colágenos não Fibrilares , Penfigoide Bolhoso/imunologia , Colágeno Tipo XVII
19.
Clin Exp Immunol ; 132(3): 379-84, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12780682

RESUMO

Cutaneous squamous cell carcinoma is typically characterized by the over-expression of the tumour suppressor protein p53. Considerable evidence suggests that immune competence is important in the control of cutaneous SCC. We discuss the immunobiology of p53 and its relevance to cutaneous SCC, including the potential interaction with human papillomavirus.


Assuntos
Carcinoma de Células Escamosas/imunologia , Neoplasias Cutâneas/imunologia , Proteína Supressora de Tumor p53/imunologia , Carcinoma de Células Escamosas/virologia , Humanos , Imunocompetência , Papillomaviridae , Infecções por Papillomavirus/complicações , Neoplasias Cutâneas/virologia , Infecções Tumorais por Vírus/complicações
20.
BJOG ; 109(11): 1295-7, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12452469

RESUMO

Lead contamination of the environment is an important public health consideration. There is evidence of declining blood lead levels in Britain, however, there is still concern about chronic exposure of the fetus and young children to low levels of lead and the effect that this has on neurodevelopment. Hair lead levels have been found to correlate well with body lead contamination. This study is the first to document the level of hair lead in pregnant women and their babies from an urban British population. There was no evidence of toxic maternal lead levels and the fetus is protected by the placental barrier.


Assuntos
Exposição Ambiental/análise , Feto/química , Cabelo/química , Chumbo/análise , Gravidez/metabolismo , Adulto , Inglaterra/epidemiologia , Feminino , Humanos , Valores de Referência , Saúde da População Urbana
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA