Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Scand J Immunol ; 80(5): 313-22, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25039313

RESUMO

CD8(+) Tregs display an immunoregulatory activity and may play an essential role in the immunopathology of several diseases. Therefore, their therapeutic potential is exquisite and further studies on their differentiation and function are essential. The aim of this study was to evaluate the role of the innate immune system in CD8(+) iTreg differentiation and function. Naive human CD8(+) CD25(-) CD45RA(+) T cells were cultured in Treg-inducing conditions with or without IL-1ß, TNFα or monocyte-derived dendritic cells (DCs). The differentiation of CD8(+) CD127(-) CD25(hi) FoxP3(hi) -induced Tregs (CD8(+) iTregs) is dependent on TGF-ß1 and IL-2, which had synergistic effect upon their differentiation. CD8(+) iTregs were also induced in a coculture with allogeneic mature DCs (mDCs). The CD8(+) iTregs suppressive function was confirmed, which was diminished in the presence of IL-1ß and TNFα. The IL-1ß-prevented suppressive function was associated with reduced secretion of IL-10 and IFNγ, whereas the presence of TNFα did not affect their secretion. Furthermore, the presence of TNFα reduced IL-10 and TGF-ß1 secretion by CD8(+) iTregs, whereas only IL-10 secretion was decreased by IL-1ß. Together, these results suggest that IL-1ß and TNFα prevent IL-2- and TGF-ß1-driven CD8(+) iTregs suppressive function in human T cells. Such pro-inflammatory innate immune response possibly mediates its negative tolerogenic effect through reduced IFNγ-, IL-10- and TGF-ß1-driven mechanism.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Tolerância Imunológica , Imunidade Inata , Interleucina-1beta/imunologia , Linfócitos T Reguladores/imunologia , Fator de Necrose Tumoral alfa/imunologia , Antígenos CD28/biossíntese , Linfócitos T CD8-Positivos/efeitos dos fármacos , Diferenciação Celular/imunologia , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/imunologia , Humanos , Interferon gama/imunologia , Interleucina-10/imunologia , Interleucina-1beta/farmacologia , Interleucina-2/imunologia , Interleucina-2/farmacologia , Ativação Linfocitária/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Fator de Crescimento Transformador beta1/imunologia , Fator de Necrose Tumoral alfa/farmacologia
2.
Diabetologia ; 55(3): 671-80, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22134840

RESUMO

AIMS/HYPOTHESIS: We aimed to describe the prevalence of retinopathy in an aged cohort of Icelanders with and without diabetes mellitus. METHODS: The study population consisted of 4,994 persons aged ≥ 67 years, who participated in the Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-R). Type 2 diabetes mellitus was defined as HbA(1c) ≥ 6.5% (>48 mmol/mol). Retinopathy was assessed by grading fundus photographs using the modified Airlie House adaptation of the Early Treatment Diabetic Retinopathy Study protocol. Associations between retinopathy and risk factors were estimated using odds ratios obtained from multivariate analyses. RESULTS: The overall prevalence of retinopathy in AGES-R was 12.4%. Diabetes mellitus was present in 516 persons (10.3%), for 512 of whom gradable fundus photos were available, including 138 persons (27.0%, 95% CI 23.2, 31.0) with any retinopathy. Five persons (1.0%, 95% CI 0.3, 2.3) had proliferative retinopathy. Clinically significant macular oedema was present in five persons (1.0%, 95% CI 0.3, 2.3). Independent risk factors for retinopathy in diabetic patients in a multivariate model included HbA(1c), insulin use and use of oral hypoglycaemic agents, the last two being indicators of longer disease duration. In 4478 participants without diabetes mellitus, gradable fundus photos were available for 4,453 participants, with retinopathy present in 476 (10.7%, 95% CI 9.8, 11.6) and clinically significant macular oedema in three persons. Independent risk factors included increasing age and microalbuminuria. CONCLUSIONS/INTERPRETATION: Over three-quarters (78%) of retinopathy cases were found in persons without diabetes and a strong association between microalbuminuria and non-diabetic retinopathy was found. These results may have implications for patient management of the aged.


Assuntos
Envelhecimento , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/epidemiologia , Retina/patologia , Doenças Retinianas/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Albuminúria/complicações , Albuminúria/fisiopatologia , Albuminúria/urina , Estudos de Coortes , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/patologia , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/fisiopatologia , Nefropatias Diabéticas/urina , Retinopatia Diabética/complicações , Retinopatia Diabética/patologia , Retinopatia Diabética/fisiopatologia , Feminino , Hemoglobinas Glicadas/análise , Humanos , Islândia/epidemiologia , Edema Macular/complicações , Edema Macular/epidemiologia , Edema Macular/patologia , Masculino , Prevalência , Doenças Retinianas/complicações , Doenças Retinianas/patologia , Doenças Retinianas/fisiopatologia , Fatores de Risco , Índice de Gravidade de Doença
3.
J Clin Pharmacol ; 46(9): 1017-22, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16920896

RESUMO

Tesaglitazar is a dual peroxisome proliferator-activated receptor (PPAR) alpha/gamma agonist in development to treat lipid and glucose abnormalities associated with type 2 diabetes. This study evaluated the effects of food on tesaglitazar pharmacokinetics. In an open, randomized, 2-way crossover study, 20 healthy men received tesaglitazar 1 mg during fasting and after a high-fat, high-calorie breakfast. Blood samples were taken to assess pharmacokinetic variables. Systemic exposure to tesaglitazar was unaffected by food intake. Estimated ratios were 0.99 (90% confidence interval [CI], 0.94-1.04) for fed/fasted area under plasma concentration-time curve and 0.82 (90% CI, 0.78-0.86) for fed/fasted maximum plasma concentration (C(max)). Mean C(max) was approximately 18% lower (0.41 [95% CI, 0.38-0.43] versus 0.50 [95% CI, 0.47-0.53] mumol/L), and median time to C(max) was increased (2.00 vs 0.75 h) in fed versus fasted state. The median difference of t(max) was 1.25 h (P = .0001, signed-rank test). Tesaglitazar was well tolerated. Tesaglitazar pharmacokinetics is unaffected by food intake, allowing once-daily administration of tesaglitazar with or without food in clinical practice.


Assuntos
Alcanossulfonatos/farmacocinética , Alimentos , PPAR alfa/agonistas , PPAR gama/agonistas , Fenilpropionatos/farmacocinética , Adulto , Alcanossulfonatos/efeitos adversos , Alcanossulfonatos/sangue , Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Fenilpropionatos/efeitos adversos , Fenilpropionatos/sangue
4.
Diabetologia ; 48(9): 1716-25, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16001233

RESUMO

AIMS/HYPOTHESIS: Insulin resistance is associated with abnormalities in lipid and glucose metabolism, which are major components of metabolic syndrome and risk factors for vascular disease. This study examined the effect of tesaglitazar (Galida), a novel, dual-acting peroxisome proliferator-activated receptor alpha/gamma agonist, on lipid and glucose metabolism in patients with evidence of insulin resistance. METHODS: A 12-week, multicentre, randomised, double-blind, placebo-controlled, dose-finding study compared the efficacy and safety of oral tesaglitazar (0.1, 0.25, 0.5 and 1.0 mg/day) and placebo in 390 non-diabetic patients with hypertriglyceridaemia (plasma triglyceride concentration >1.7 mmol/l) and abdominal obesity (waist-to-hip ratio >0.90 for men and >0.85 for women). RESULTS: A 1.0-mg dose of tesaglitazar reduced fasting triglycerides (the primary endpoint) by 37% (95% CI: -43% to -30%; p<0.0001), non-HDL-cholesterol by 15% (95% CI: -20% to -10%; p<0.0001) and NEFA by 40% (95% CI: -51% to -27%; p<0.0001), and increased HDL-cholesterol by 16% (95% CI: 8 to -24%; p<0.0001). At the end of treatment there was a dose-dependent increase in patients with pattern A LDL particle diameter (40% at baseline vs 87% at 12 weeks for tesaglitazar 1.0 mg). Tesaglitazar produced significant reductions in fasting insulin concentration (-35%; p<0.0001) and plasma glucose concentration (-0.47 mmol/l; p<0.0001). Respiratory infection and gastrointestinal symptoms were the most common adverse events and were similarly frequent in all groups. CONCLUSIONS/INTERPRETATION: Tesaglitazar was well tolerated and produced significant, dose-dependent improvements in lipid and glucose metabolism and insulin sensitivity. Tesaglitazar may have the potential to prevent vascular complications and delay progression to diabetes in these patients.


Assuntos
Alcanossulfonatos/uso terapêutico , Glicemia/metabolismo , PPAR alfa/antagonistas & inibidores , PPAR gama/antagonistas & inibidores , Fenilpropionatos/uso terapêutico , Alcanossulfonatos/efeitos adversos , Glicemia/efeitos dos fármacos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Ácidos Graxos não Esterificados/sangue , Feminino , Humanos , Insulina/sangue , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fenilpropionatos/efeitos adversos , Placebos , Segurança , Triglicerídeos/sangue
6.
Appl Microbiol Biotechnol ; 55(5): 578-84, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11414324

RESUMO

The thermostable cellulase Cel12A from Rhodothermus marinus was produced at extremely low levels when expressed in Escherichia coli and was cytotoxic to the cells. In addition, severe aggregation occurred when moderately high concentrations of the enzyme were heat-treated at 65 degrees C, the growth optimum of R. marinus. Sequence analysis revealed that the catalytic module of this enzyme is preceded by a typical linker sequence and a highly hydrophobic putative signal peptide. Two deletion mutants lacking this hydrophobic region were cloned and successfully expressed in E. coli. These results indicated that the N-terminal putative signal peptide was responsible for the toxicity of the full-length enzyme in the host organism. This was further corroborated by cloning and expressing the hydrophobic N-terminal domain in E. coli, which resulted in extensive cell lysis. The deletion mutants, made up of either the catalytic module of Cel12A or the catalytic module and the putative linker sequence, were characterised and their properties compared to those of the full-length enzyme. The specific activity of the mutants was approximately three-fold higher than that of the full-length enzyme. Both mutant proteins were highly thermostable, with half-lives exceeding 2 h at 90 degrees C and unfolding temperatures up to 103 degrees C.


Assuntos
Celulase/biossíntese , Celulase/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Bactérias Aeróbias Gram-Negativas/enzimologia , Sequência de Bases , Biotecnologia , Varredura Diferencial de Calorimetria , Clonagem Molecular , Primers do DNA/genética , Estabilidade Enzimática , Expressão Gênica , Genes Bacterianos , Bactérias Aeróbias Gram-Negativas/genética , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Deleção de Sequência
7.
Appl Microbiol Biotechnol ; 49(3): 277-84, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9581291

RESUMO

A gene library from the thermophilic eubacterium Rhodothermus marinus, strain ITI 378, was constructed in pUC18 and transformed into Escherichia coli. Of 5400 transformants, 3 were active on carboxymethylcellulose. Three plasmids conferring cellulase activity were purified and were all found to contain the same cellulase gene, celA. The open reading frame for the celA gene is 780 base pairs and encodes a protein of 260 amino acids with a calculated molecular mass of 28.8 kDa. The amino acid sequence shows homology with cellulases in glycosyl hydrolase family 12. The celA gene was overexpressed in E. coli when the pET23, T7 phage RNA polymerase system was used. The enzyme showed activity on carboxymethylcellulose and lichenan, but not on birch xylan or laminarin. The expressed enzyme had six terminal histidine residues and was purified by using a nickel nitrilotriacetate column. The enzyme had a pH optimum of 6-7 and its highest measured initial activity at 100 degrees C. The heat stability of the enzyme was increased by removal of the histidine residues. It then retained 75% of its activity after 8 h at 90 degrees C.


Assuntos
Proteínas de Bactérias/genética , Celulase/genética , Genes Bacterianos/genética , Bactérias Aeróbias Gram-Negativas/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sequência de Bases , Celulase/química , Celulase/metabolismo , Eletroforese em Gel de Poliacrilamida , Bactérias Aeróbias Gram-Negativas/genética , Bactérias Aeróbias Gram-Negativas/crescimento & desenvolvimento , Dados de Sequência Molecular , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
8.
Cancer Nurs ; 20(2): 120-8, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9145561

RESUMO

The aim of this phenomenological study was to explore caring and uncaring encounters with nurses and other health professionals from the perspective of the person who has been diagnosed and treated for cancer. Through thematic analysis of in-depth dialogues with five women and four men in the remission or recovery phase of cancer, three major categories regarding caring and uncaring encounters were identified. The essential structure of a caring encounter was found to be threefold: 1. the nurse/health professional perceived as caring: an indispensable companion on the cancer trajectory; 2. the resulting mutual trust and caring connection; and 3. the perceived effect of the caring encounter: a sense of solidarity, empowerment, well-being, and healing. The essential structure of an uncaring encounter is also threefold: 1. the nurse/health professional perceived as uncaring: an unfortunate hindrance to the perception of well-being and healing; 2. the resulting sense of mistrust and disconnection; and 3. the perceived effect of the uncaring encounter: a sense of uneasiness, discouragement, and a sense of being broken down. The findings emphasize the primacy of competence in professional caring, as well as that of genuine concern, openness and a willingness to connect with others. The often devastating effects of uncaring encounters on the recipient of nursing and health care raises the question whether uncaring as an ethical and a professional problem should perhaps be dealt with as malpractice in nursing and health care.


Assuntos
Atitude Frente a Saúde , Empatia , Neoplasias/enfermagem , Neoplasias/psicologia , Relações Enfermeiro-Paciente , Adulto , Idoso , Comportamento Agonístico , Competência Clínica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Metodológica em Enfermagem , Enfermagem Oncológica , Poder Psicológico
9.
Health Care Women Int ; 17(4): 361-79, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8850769

RESUMO

The objective of this study was to explore the essential structure of caring and uncaring encounters with nurse-midwives and other health professionals during labor and delivery as perceived by women who have given birth. The phenomenological perspective of qualitative research theory guided the methodological approach to the study, in which true dialogues were entered into with 10 mothers in Akureyri and Reykjavik, Iceland. The overriding theme of the women's experience of caring and uncaring was "empowerment or discouragement." Within that theme, four major categories were identified: (a) the nurse-midwife perceived as caring--an indispensable companion on the journey through labor and delivery; (b) the woman's perception of the effects of the encounter with the caring nurse-midwife--the sense of being empowered; (c) the nurse-midwife perceived as uncaring--an unfortunate hindrance to a successful birth experience; (d) the woman's perception of the effects of the encounter with the uncaring nurse-midwife--the sense of being discouraged. Findings indicate that the nurse-midwife who satisfies a woman's need for professional caring during the birth experience is likely to be more effective in meeting nursing and midwifery care goals than the nurse-midwife who does not and is perceived as uncaring.


Assuntos
Empatia , Trabalho de Parto/psicologia , Enfermeiros Obstétricos/psicologia , Relações Enfermeiro-Paciente , Satisfação do Paciente , Adulto , Feminino , Humanos , Islândia , Pesquisa Metodológica em Enfermagem , Gravidez
10.
Midwifery ; 12(2): 48-61, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8718109

RESUMO

OBJECTIVE: The aim of this study was to explore the essential structure of the lived experience of childbearing, as seen from the perspective of women who have given birth. DESIGN, SETTING, AND PARTICIPANTS: The phenomenological perspective of qualitative research theory guided the methodological approach to the study, in which interactive interviews were conducted with a purposeful sample of fourteen mothers of healthy babies in Akureyri and Reykjavik, the two most inhabited places in Iceland. FINDINGS: The metaphor of a woman journeying through labour and delivery was chosen to symbolize the lived experience of giving birth to a healthy baby. This encompasses four major categories: influences of circumstances and expectations before the journey's commencement; a sense of self during the journey which encompasses a sense of being in a private world, the sense of control, the need for caring and understanding and the need for a sense of security; the journey through labour and delivery itself; and finally the first sensitive hours of motherhood and the perception of the uniqueness of birth as a life experience at the journey's end. The study has the potential of increasing the knowledge and understanding of giving birth as a life experience, and therefore, has implications for midwives and nurses, as well as for women and their supporters. KEY CONCLUSIONS: The lived experience of giving birth is a powerful life experience which is coloured by circumstances and expectations of the woman, her sense of self during the journey, the journey itself, as well as the first sensitive hours of motherhood. IMPLICATIONS FOR PRACTICE: The study has the potential of increasing the knowledge and understanding of giving birth as a life experience, and therefore, has implications for midwives/nurse, as well as for women and their supporters.


Assuntos
Trabalho de Parto/psicologia , Mães/psicologia , Adulto , Feminino , Humanos , Islândia , Enfermeiros Obstétricos , Pesquisa Metodológica em Enfermagem , Gravidez , Autoimagem , Inquéritos e Questionários
11.
Cancer Nurs ; 19(1): 29-36, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8904384

RESUMO

This phenomenological study was designed to explore the lived experience of having cancer, as perceived by people who have been diagnosed and treated for cancer. The aim of the study was to add to the knowledge and understanding of this complex human phenomenon. Data were collected through in-depth interviews with nine people who were in the remission or recovery phase of cancer. The interviews were tape-recorded and transcribed verbatim for each participant. Through intersubjective interactions and thematic analysis, the essential description of the lived experience of having cancer was constructed. The overriding theme of the lived experience of having cancer is "experiencing existential changes." Five basic subthemes were identified in the participants accounts, all of which are part of the existential changes involved in the lived experience of having cancer. These are: uncertainty, vulnerability, isolation, discomfort, and redefinition. The study can increase the understanding of what it is like to have cancer.


Assuntos
Atitude Frente a Saúde , Convalescença/psicologia , Existencialismo , Acontecimentos que Mudam a Vida , Neoplasias/psicologia , Adaptação Psicológica , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pesquisa Metodológica em Enfermagem , Inquéritos e Questionários
13.
Equine Vet J ; 23(4): 300-2, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1915232

RESUMO

Three hundred and three horses, exported from Iceland to Norway, Sweden, Denmark, Switzerland or Germany were tested for their distribution of leucocyte antigens. One hundred and thirty-six horses were affected with summer eczema. The panel of sera recognised the internationally accepted ELA-specificities A 1 to A10, and the nine work shop specificities W 11 to W 15 and W 18 to W 21. Also, some local specificities, characterised in Switzerland (Be I, Be III, Be 8, Be 25, Be 26, Be 27), and two non major histocompatibility complex (MHC)-linked antigens (Ely 1:1, Ely 2) were included. Only one antigen, Be 8, gave a statistically significant difference in distribution between the two populations: Relative risk = 2.5, x2 = 10.11, corrected P less than 0.01.


Assuntos
Ceratopogonidae/imunologia , Dermatite Atópica/veterinária , Antígenos de Histocompatibilidade/sangue , Doenças dos Cavalos/imunologia , Animais , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Doenças dos Cavalos/genética , Cavalos , Linfócitos/imunologia , Masculino , Estações do Ano
16.
Res Vet Sci ; 47(3): 283-7, 1989 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2595084

RESUMO

Twenty-three Icelandic horses were challenged with extracts of four species of biting midges: Culicoides pulicaris, C chiopterus, C obsoletus and C impunctatus. Fourteen of the tested horses were affected with summer eczema. The horses were challenged intradermally with 0.1 ml of whole-body extracts of midges at a concentration of 0.01 or 0.005 per cent weight/volume. The skin reactions were measured after 30 minutes, 60 or 180 minutes and four, 24 and 48 hours after injection. Antigen titration showed that the reaction was dependent on the antigen concentration. Eight of nine unaffected horses failed to respond to any of the four antigens; the remaining animal responding to two of the four antigens. Ten of the 14 affected horses responded to at least three of the four antigens, while two of the animals in this group failed to respond to any. The mean responses to C chiopterus, C obsoletus and C impunctatus, read after 30 minutes, 60 minutes and four hours were significantly higher in the affected horses than in the unaffected horses. A significant difference was also found in the mean response to C chiopterus and C impunctatus, read after 24 hours.


Assuntos
Ceratopogonidae/imunologia , Dermatite/veterinária , Ectoparasitoses/veterinária , Doenças dos Cavalos/etiologia , Hipersensibilidade/veterinária , Animais , Antígenos/imunologia , Dermatite/etiologia , Ectoparasitoses/complicações , Feminino , Cavalos , Hipersensibilidade/etiologia , Testes Intradérmicos/veterinária , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...