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1.
Diabet Med ; 36(9): 1141-1148, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31006118

RESUMO

AIM: We investigated whether the effect of low-dose aspirin on endothelium-dependent vasodilation and arterial stiffness in people with Type 2 diabetes is different from a matched control group. We examined acute and chronic effects, and effects over the 24h dosing interval. METHODS: In an open-label parallel group intervention study, we included 21 participants with Type 2 diabetes and 21 age- and sex-matched controls. Endothelium-dependent vasodilation was assessed as the reactive hyperaemia index (lnRHI) measured by peripheral arterial tonometry (EndoPAT® ). Arterial stiffness was assessed as pulse wave velocity (PWV) measured by applanation tonometry (SphygmoCor® ). Measurements were performed prior to aspirin intake and 1h after aspirin administration (75 mg). Participants were then treated for 6 days, and measurements were repeated at 24 h and 1 h after aspirin intake. RESULTS: Baseline lnRHI did not differ between groups. The controls had an immediate increase in lnRHI after the first aspirin tablet. This was not observed in participants with diabetes (difference between groups; P < 0.05). After 1 week, both groups demonstrated increased lnRHI compared with baseline (P < 0.01). In participants with diabetes, lnRHI was significantly lower 24 h after aspirin administration compared with 1 h after administration (P < 0.05). This difference was not observed in controls (P = 0.84, difference between groups; P = 0.12). The effect on PWV did not differ between groups. CONCLUSION: Aspirin had a reduced immediate effect on endothelium-dependent vasodilation in participants with diabetes. Both groups had improved endothelial function after 1 week of treatment. Further, the effect of aspirin on endothelial function may be declining during a 24 h dosing interval in people with Type 2 diabetes. (Clinical Trial Registry No: 2016-000515-32).


Assuntos
Aspirina/farmacologia , Sistema Cardiovascular/efeitos dos fármacos , Diabetes Mellitus Tipo 2/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Idoso , Aspirina/uso terapêutico , Sistema Cardiovascular/fisiopatologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Endotélio Vascular/fisiologia , Feminino , Humanos , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Análise de Onda de Pulso , Rigidez Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
2.
J Dairy Sci ; 101(8): 7361-7374, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29778468

RESUMO

Impact patterns of human-animal relationship (HAR) and herd stress level on udder health were investigated in a cross-sectional study on 30 German and Danish organic dairy herds also taking into account influencing factors regarding housing and management. Cow behavior (avoidance distance, tolerance to tactile interaction, release behavior) was assessed in tests, milkers' behavior recorded during milking, and information about contacts with animals during routine work gathered by interview. Additionally, stockpersons' attitudes were recorded via questionnaires. Fecal cortisol metabolites were measured in approximately 30 focal cows on each farm and used as a proxy to determine the level of distress within the herd. Management and housing were assessed on-farm. The following herd udder health indicators were calculated: the prevalence of mastitis quarters (≥100,000 cells/mL), and, from milk recording data over 1 yr retrospectively, the average somatic cell score and the self-cure rates during lactation per herd. Multivariable regression models with stepwise selection were calculated at herd level. The following HAR-related factors were associated with better udder health (in at least 1 of the final models): stockpersons' higher agreement on patience being important when moving the cows and on necessary contact to cows being pleasant, higher amount of positive interactions with cows during milking, more docile cows in the release behavior test, no routine change of milkers, more contact time during routine work, no active heifer habituation to milking, and performance of barn controls beyond routine work. Lower fecal cortisol metabolite levels were related to higher self-cure rates during lactation. Concerning housing, management, and herd characteristics, the following known factors were related to impaired udder health for at least 1 of the indicators: straw yards, automatic milking system, higher average lactation number, and less antibiotic udder treatments. The results confirm earlier findings that HAR is associated with udder health and should therefore be considered in future research and mastitis control programs. First indications of negative associations between herd stress level and mastitis curing capacity should be followed up in future studies.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/métodos , Vínculo Humano-Animal , Hidrocortisona/sangue , Animais , Bovinos/metabolismo , Estudos Transversais , Feminino , Humanos , Glândulas Mamárias Animais , Leite , Estudos Retrospectivos
3.
Clin Exp Immunol ; 189(1): 103-112, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28318015

RESUMO

Mounting evidence indicates that adverse activation of the complement system plays a role in the development of diabetic vascular complications. Plasma levels of the complement proteins mannan-binding lectin (MBL) and its associated serine proteases (MASP-1 and MASP-2) are elevated in diabetes. We hypothesized that single nucleotide polymorphisms (SNPs) in the MASP1 gene may contribute to altered plasma levels of the belonging gene products; MASP-1, MASP-3 and mannan-binding lectin-associated protein of 44 kDa (MAp44) in patients with type 2 diabetes. To investigate this, we compared plasma levels of MASP-1, MASP-3 and MAp44 in 100 patients with type 2 diabetes and 100 sex- and age-matched controls. Ten carefully selected SNPs were analysed using TaqMan® genotyping assay. Additionally, we included a streptozotocin-induced diabetes mouse model to directly examine the effect of inducing diabetes on MASP-1 levels. MASP-1 levels were significantly higher among patients with type 2 diabetes compared with healthy controls (P = 0·017). Five SNPs (rs874603, rs72549254, rs3774275, rs67143992, rs850312) in the MASP1 gene were associated with plasma levels of MASP-1, MASP-3 and MAp44. In the diabetes mouse model, diabetic mice had significantly higher MASP-1 levels than control mice (P = 0·003). In conclusion, MASP-1 levels were higher among patients with type 2 diabetes and diabetic mice. The mechanism behind this increase remains elusive.


Assuntos
Composição Corporal , Diabetes Mellitus Tipo 2/sangue , Lectina de Ligação a Manose/sangue , Serina Proteases Associadas a Proteína de Ligação a Manose/análise , Idoso , Animais , Glicemia , Estudos de Casos e Controles , Dinamarca , Diabetes Mellitus Experimental , Feminino , Genótipo , Humanos , Modelos Lineares , Masculino , Serina Proteases Associadas a Proteína de Ligação a Manose/genética , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estreptozocina
4.
Diabet Med ; 32(2): e4-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25252000

RESUMO

BACKGROUND: Recruitment of brown adipose tissue is a promising strategy to treat obesity and Type 2 diabetes, but the physiological effects of a large amount of metabolically active brown adipose tissue in humans are unknown. CASE REPORT: In the present paper, we report a case of massive brown adipose tissue infiltration of the visceral adipose tissue depot in a person with Type 2 diabetes with a catecholamine-secreting paraganglioma. The patient was evaluated with [18F]-fludeoxyglucose positron emission tomography/computed tomography on three occasions: pre-therapy, during α-blockade and postoperatively. During surgery, biopsies of visceral and subcutaneous adipose tissue were obtained and evaluated for brown adipose tissue. At diagnosis, brown adipose tissue glucose uptake, assessed by [18F]-fludeoxyglucose-positron emission tomography, was massively increased. [18F]-fludeoxyglucose uptake was confined to known locations for brown adipose tissue, with additional uptake in the visceral adipose tissue. As a result of increased thermogenesis, resting energy expenditure was doubled. After surgical removal of the tumour, antidiabetic medicine was no longer needed, despite an 8.2-kg weight gain. CONCLUSION: These results show that human visceral adipose tissue holds an unprecedented potential for brown adipogenic differentiation; however, a detrimental effect on glucose metabolism persisted despite massive brown adipose tissue activity, with a doubling of resting energy expenditure.


Assuntos
Tecido Adiposo Marrom/metabolismo , Metabolismo Basal , Diabetes Mellitus Tipo 2/complicações , Gordura Intra-Abdominal/metabolismo , Norepinefrina/metabolismo , Paraganglioma/metabolismo , Regulação para Cima , Tecido Adiposo Marrom/diagnóstico por imagem , Adiposidade , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Paraganglioma/complicações , Paraganglioma/diagnóstico por imagem , Cintilografia
5.
Diabet Med ; 30(9): 1063-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23600518

RESUMO

AIMS: To evaluate physical activity in people with newly diagnosed Type 2 diabetes using objective measures. METHODS: We analysed data from a study aimed at assessing carotid femoral pulse wave velocity in which a piezoelectric accelerometer was worn by 100 people with newly diagnosed Type 2 diabetes and by 100 age- and sex-matched control subjects. Differences in physical activity patterns were investigated. RESULTS: Compared with the control group, the people with Type 2 diabetes spent significantly more time engaged in sedentary or lower level activities during the day, with a mean (sd) time of 926 (44) vs 898 (70) min, P < 0.001). This difference remained significant after correction for differences in BMI between the two groups. CONCLUSIONS: Using objective measurements, our findings demonstrate that people with newly diagnosed Type 2 diabetes have a more sedentary lifestyle compared with well-matched controls.


Assuntos
Diabetes Mellitus Tipo 2/etiologia , Comportamento Sedentário , Actigrafia , Atividades Cotidianas , Idoso , Índice de Massa Corporal , Dinamarca , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Sobrepeso/complicações
6.
Acta Psychiatr Scand ; 128(5): 387-96, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23350796

RESUMO

OBJECTIVE: To explore the relationship between brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), cerebral deep white matter lesions (DWMLs), and measures of white matter integrity in patients with late-onset depression, with respect to vascular risk factors. METHOD: We examined 22 patients with late-onset depression and 22 matched controls. Quantification of plasma BDNF and VEGF levels were performed with enzyme-linked immunosorbent assay (ELISA) kits. Measures of white matter integrity comprised apparent diffusion coefficient (ADC) and fractional anisotropy (FA), obtained by diffusion tensor imaging (DTI). Effects of DWMLs, FA, ADC, and vascular risk factors on BDNF and VEGF were assessed using multiple linear regression. RESULTS: The BDNF and VEGF levels did not differ significantly between groups. With pooled data for patients and controls, the BDNF level was positively associated with both number (t = 2.14, P = 0.039) and volume (t = 2.04, P = 0.048) of prefrontal DWMLs and negatively associated with FA in prefrontal normal-appearing white matter (t = -2.40, P = 0.02), adjusted for age and gender. Smoking and hypercholesterolemia was positively associated with the BDNF (t = 2.36, P = 0.023) and VEGF levels (t = 2.28, P = 0.028), respectively. CONCLUSION: Our results suggest a role for BDNF in the complex pathophysiologic mechanisms underlying DWMLs in both normal aging and late-onset depression.


Assuntos
Envelhecimento , Fator Neurotrófico Derivado do Encéfalo/sangue , Transtorno Depressivo Maior , Lobo Frontal/patologia , Leucoencefalopatias , Fator A de Crescimento do Endotélio Vascular/sangue , Idade de Início , Idoso , Envelhecimento/sangue , Envelhecimento/patologia , Anisotropia , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/patologia , Imagem de Tensor de Difusão , Feminino , Humanos , Leucoencefalopatias/sangue , Leucoencefalopatias/patologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
7.
Radiother Oncol ; 188: 109887, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37659663

RESUMO

PURPOSE/OBJECTIVE: Deep-inspiration breath-hold (DIBH) during radiotherapy may reduce dose to the lungs and heart compared to treatment in free breathing. However, intra-fractional target shifts between several breath-holds may decrease target coverage. We compared target shifts between four DIBHs at the planning-CT session with those measured on CBCT-scans obtained pre- and post-DIBH treatments. MATERIAL/METHODS: Twenty-nine lung cancer and nine lymphoma patients were treated in DIBH. An external gating block was used as surrogate for the DIBH-level with a window of 2 mm. Four DIBH CT-scans were acquired: one for planning (CTDIBH3) and three additional (CTDIBH1,2,4) to assess the intra-DIBH target shifts at scanning by registration to CTDIBH3. During treatment, pre-treatment (CBCTpre) and post-treatment (CBCTpost) scans were acquired. For each pair of CBCTpre/post, the target intra-DIBH shift was determined. For lung cancer, tumour (GTV-Tlung) and lymph nodes (GTV-Nlung) were analysed separately. Group mean (GM), systematic and random errors, and GM for the absolute maximum shifts (GMmax) were calculated for the shifts between CTDIBH1,2,3,4 and between CBCTpre/post. RESULTS: For GTV-Tlung, GMmax was larger at CBCT than CT in all directions. GMmax in cranio-caudal direction was 3.3 mm (CT)and 6.1 mm (CBCT). The standard deviations of the shifts in the left-right and cranio-caudal directions were larger at CBCT than CT. For GTV-Nlung and CTVlymphoma, no difference was found in GMmax or SD. CONCLUSION: Intra-DIBH shifts at planning-CT session are generally smaller than intra-DIBH shifts observed at CBCTpre/post and therefore underestimate the intra-fractional DIBH uncertainty during treatment. Lung tumours show larger intra-fractional variations than lymph nodes and lymphoma targets.

8.
Diabetologia ; 55(12): 3341-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22961225

RESUMO

AIMS/HYPOTHESIS: Energy-dense diets that are high in fat are associated with a risk of metabolic diseases. The underlying molecular mechanisms could involve epigenetics, as recent data show altered DNA methylation of putative type 2 diabetes candidate genes in response to high-fat diets. We examined the effect of a short-term high-fat overfeeding (HFO) diet on genome-wide DNA methylation patterns in human skeletal muscle. METHODS: Skeletal muscle biopsies were obtained from 21 healthy young men after ingestion of a short-term HFO diet and a control diet, in a randomised crossover setting. DNA methylation was measured in 27,578 CpG sites/14,475 genes using Illumina's Infinium Bead Array. Candidate gene expression was determined by quantitative real-time PCR. RESULTS: HFO introduced widespread DNA methylation changes affecting 6,508 genes (45%), with a maximum methylation change of 13.0 percentage points. The HFO-induced methylation changes were only partly and non-significantly reversed after 6-8 weeks. Alterations in DNA methylation levels primarily affected genes involved in inflammation, the reproductive system and cancer. Few gene expression changes were observed and these had poor correlation to DNA methylation. CONCLUSIONS/INTERPRETATION: The genome-wide DNA methylation changes induced by the short-term HFO diet could have implications for our understanding of transient epigenetic regulation in humans and its contribution to the development of metabolic diseases. The slow reversibility suggests a methylation build-up with HFO, which over time may influence gene expression levels.


Assuntos
Metilação de DNA , Dieta Hiperlipídica , Músculo Esquelético/metabolismo , Proteínas de Transporte de Cátions/genética , Ilhas de CpG/genética , Estudos Cross-Over , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Metilação de DNA/genética , Epigênese Genética , Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Homeodomínio/genética , Humanos , Resistência à Insulina/genética , Masculino , Músculo Esquelético/fisiologia , Hipernutrição , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Proteínas Proto-Oncogênicas c-akt/genética , Reação em Cadeia da Polimerase em Tempo Real , Transativadores/genética , Fatores de Transcrição/genética , Adulto Jovem , Transportador 8 de Zinco
9.
Front Immunol ; 13: 1080388, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36618347

RESUMO

Introduction: Accumulating evidence support that mannan-binding lectin (MBL) is a promising prognostic biomarker for risk-stratification of diabetic micro- and macrovascular complications. Serum MBL levels are predominately genetically determined and depend on MBL genotype. However, Type 1 diabetes (T1D) is associated with higher MBL serum levels for a given MBL genotype, but it remains unknown if this is also the case for patients with T2D. In this study, we evaluated the impact of MBL genotypes on renal function trajectories serum MBL levels and compared MBL genotypes in newly diagnosed patients with T2D with age- and sex-matched healthy individuals. Furthermore, we evaluated differences in parameters of insulin resistance within MBL genotypes. Methods: In a cross-sectional study, we included 100 patients who were recently diagnosed with T2D and 100 age- and sex-matched individuals. We measured serum MBL levels, MBL genotype, standard biochemistry, and DEXA, in all participants. A 5-year clinical follow-up study was conducted, followed by 12-year data on follow-up biochemistry and clinical status for the progression to micro- or macroalbuminuria for the patients with T2D. Results: We found similar serum MBL levels and distribution of MBL genotypes between T2D patients and healthy individuals. The serum MBL level for a given MBL genotype did not differ between the groups neither at study entry nor at 5-year follow-up. We found that plasma creatinine increased more rapidly in patients with T2D with the high MBL expression genotype than with the medium/low MBL expression genotype over the 12-year follow-up period (p = 0.029). Serum MBL levels did not correlate with diabetes duration nor with HbA1c. Interestingly, serum MBL was inversely correlated with body fat percentage in individuals with high MBL expression genotypes both at study entry (p=0.0005) and 5-years follow-up (p=0.002). Discussion: Contrary to T1D, T2D is not per se associated with increased MBL serum level for a given MBL genotype or with diabetes duration. Serum MBL was inversely correlated with body fat percentage, and T2D patients with the high MBL expression genotype presented with deterioration of renal function.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Lectina de Ligação a Manose , Humanos , Diabetes Mellitus Tipo 2/genética , Lectina de Ligação a Manose/genética , Seguimentos , Estudos Transversais , Genótipo , Rim/fisiologia
10.
Diabetologia ; 53(12): 2526-30, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20859612

RESUMO

AIMS/HYPOTHESIS: We studied the associations of size at birth and prematurity with type 2 diabetes, insulin sensitivity and beta cell function in the Danish population-based Inter99 study (ClinicalTrials.gov NCT00289237). METHODS: Information about size at birth and prematurity was identified from original midwife records in 4,744 middle-aged Danes. Type 2 diabetes status, insulin sensitivity (Matsuda index) and beta cell function (disposition index) were assessed using a 75 g oral glucose tolerance test. Participants born prematurely were compared with a group of at-term participants born small for gestational age. RESULTS: An increase in birthweight of 1 kg was associated with a 51% (OR 0.49, 95% CI 0.35-0.69) reduced risk of type 2 diabetes. Ponderal index, reflecting thinness at birth, was associated with type 2 diabetes to the same extent as birthweight. The prevalence of type 2 diabetes was increased to a similar degree in participants born prematurely and participants born small for gestational age, although the former had a higher ponderal index at birth. In addition, birthweight z-scores, reflecting fetal growth rate, were unrelated to the risk of type 2 diabetes and to other measures of glucose regulation in participants born prematurely. While low birthweight was inversely associated with insulin sensitivity and beta cell function, prematurity was associated solely with decreased insulin sensitivity. CONCLUSIONS/INTERPRETATION: While the association between birthweight and risk of type 2 diabetes is mediated via combined effects on beta cell function and insulin sensitivity, prematurity seems to influence risk of type 2 diabetes via attenuated insulin sensitivity only and independently of fetal growth rates.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Recém-Nascido de Baixo Peso , Nascimento Prematuro/epidemiologia , Adulto , Peso ao Nascer/fisiologia , Dinamarca/epidemiologia , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Intolerância à Glucose/epidemiologia , Humanos , Recém-Nascido de Baixo Peso/fisiologia , Recém-Nascido , Resistência à Insulina , Células Secretoras de Insulina/fisiologia , Pessoa de Meia-Idade , Gravidez , Distribuição Aleatória , Fatores de Risco
11.
Diabetologia ; 53(9): 1908-16, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20490451

RESUMO

AIMS/HYPOTHESIS: The fetal insulin hypothesis suggests that variation in the fetal genotype influencing insulin secretion or action may predispose to low birthweight and type 2 diabetes. We examined associations between 25 confirmed type 2 diabetes risk variants and birthweight in individuals from the Danish Inter99 population and in meta-analyses including Inter99 data and reported studies. METHODS: Midwife records from the Danish State Archives provided information on mother's age and parity, as well as birthweight, length at birth and prematurity of the newborn in 4,744 individuals of the population-based Inter99 study. We genotyped 25 risk alleles showing genome-wide associations with type 2 diabetes. RESULTS: Birthweight was inversely associated with the type 2 diabetes risk alleles of ADCY5 rs11708067 (beta = -33 g [95% CI -55, -10], p = 0.004) and CDKAL1 rs7756992 (beta = -22 g [95% CI -43, -1], p = 0.04). The association for the latter locus was confirmed in a meta-analysis (n = 24,885) (beta = -20 g [95% CI -29, -11], p = 5 x 10(-6)). The HHEX-IDE rs1111875 variant showed no significant association among Danes (p = 0.09); however, in a meta-analysis (n = 25,164) this type 2 diabetes risk allele was associated with lower birthweight (beta = -16 g [95% CI -24, -8], p = 8 x 10(-5)). On average, individuals with high genetic risk (>or=25 type 2 diabetes risk alleles) weighed marginally less at birth than those with low genetic risk (<25 type 2 diabetes risk alleles) (beta = -35 g [95% CI -69, -2], p = 0.037). CONCLUSIONS/INTERPRETATION: We report a novel association between the fetal ADCY5 type 2 diabetes risk allele and decreased birthweight, and confirm in meta-analyses associations between decreased birthweight and the type 2 diabetes risk alleles of HHEX-IDE and CDKAL1. No strong general effect on birthweight can be ascribed to the 25 common type 2 diabetes risk alleles.


Assuntos
Adenilil Ciclases/genética , Peso ao Nascer/genética , Quinase 5 Dependente de Ciclina/genética , Diabetes Mellitus Tipo 2/genética , Estudo de Associação Genômica Ampla/métodos , Proteínas de Homeodomínio/genética , Fatores de Transcrição/genética , Alelos , Feminino , Genótipo , Humanos , Recém-Nascido , Gravidez , tRNA Metiltransferases
12.
Diabetologia ; 53(9): 1998-2007, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20512309

RESUMO

AIMS/HYPOTHESIS: Insulin resistance in skeletal muscle is a key factor in the development of type 2 diabetes and although some studies indicate that this could be partly attributed to reduced content and activity of various proximal and distal insulin signalling molecules, consensus is lacking. We therefore aimed to investigate the regulation of proximal insulin signalling in skeletal muscle and its effect on glucose metabolism in a large non-diabetic population. METHODS: We examined 184 non-diabetic twins with gold-standard techniques including the euglycaemic-hyperinsulinaemic clamp. Insulin signalling was evaluated at three key levels, i.e. the insulin receptor, IRS-1 and V-akt murine thymoma viral oncogene (Akt) levels, employing kinase assays and phospho-specific western blotting. RESULTS: Proximal insulin signalling was not associated with obesity, age or sex. However, birthweight was positively associated with IRS-1-associated phosphoinositide 3-kinase (PI3K; IRS-1-PI3K) activity (p = 0.04); maximal aerobic capacity (VO2(max)), paradoxically, was negatively associated with IRS-1-PI3K (p = 0.02) and Akt2 activity (p = 0.01). Additionally, we found low heritability estimates for most measures of insulin signalling activity. Glucose disposal was positively associated with Akt-308 phosphorylation (p < 0.001) and Akt2 activity (p = 0.05), but not with insulin receptor tyrosine kinase or IRS-1-PI3K activity. CONCLUSIONS/INTERPRETATION: With the exception of birthweight, 'classical' modifiers of insulin action, including genetics, age, sex, obesity and VO2(max) do not seem to mediate their most central effects on whole-body insulin sensitivity through modulation of proximal insulin signalling in skeletal muscle. We also demonstrated an association between Akt activity and in vivo insulin sensitivity, suggesting a role of Akt in control of in vivo insulin resistance and potentially in type 2 diabetes.


Assuntos
Músculo Esquelético/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Adulto , Fatores Etários , Peso ao Nascer/fisiologia , Western Blotting , Feminino , Glucose/metabolismo , Glucose/farmacologia , Técnica Clamp de Glucose , Humanos , Insulina , Proteínas Substratos do Receptor de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Obesidade/fisiopatologia , Receptor de Insulina/metabolismo , Fatores Sexuais , Transdução de Sinais/efeitos dos fármacos
13.
Phys Med ; 75: 58-68, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32540647

RESUMO

The aim of this study was to evaluate the dosimetric effect of continuous motion monitoring based localization (Calypso, Varian Medical Systems), gating and intrafraction motion correction in prostate SBRT. Delivered doses were modelled by reconstructing motion inclusive dose distributions for different localization strategies. Actually delivered dose (strategy A) utilized initial Calypso localization, CBCT and additional pre-treatment motion correction by kV-imaging and Calypso, and gating during the irradiation. The effect of gating was investigated by simulating non-gated treatments (strategy B). Additionally, non-gated and single image-guided (CBCT) localization was simulated (strategy C). A total of 308 fractions from 22 patients were reconstructed. The dosimetric effect was evaluated by comparing motion inclusive target and risk organ dose-volume parameters to planned values. Motion induced dose deficits were seen mainly in PTV and CTV to PTV margin regions, whereas CTV dose deficits were small in all strategies: mean ± SD difference in CTVD99% was -0.3 ± 0.4%, -0.4 ± 0.6% and -0.7 ± 1.2% in strategies A, B and C, respectively. Largest dose deficits were seen in individual fractions for strategy C (maximum dose reductions were -29.0% and -7.1% for PTVD95% and CTVD99%, respectively). The benefit of gating was minor, if additional motion correction was applied immediately prior to irradiation. Continuous motion monitoring based localization and motion correction ensured the target coverage and minimized the OAR exposure for every fraction and is recommended to use in prostate SBRT. The study is part of clinical trial NCT02319239.

14.
J Diabetes Complications ; 34(2): 107439, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31672457

RESUMO

AIM: To evaluate if diffusion-tensor-imaging MR-Neurography (DTI-MRN) can detect lesions of peripheral nerves due to polyneuropathy in patients with type 2 diabetes. METHODS: Ten patients with type 2 diabetes with polyneuropathy (DPN), 10 patients with type 2 diabetes without polyneuropathy (nDPN) as well as 20 healthy controls (HC) were included. DTI-MRN covered proximal (sciatic nerve) and distal regions (tibial nerve) of the lower extremity. Fractional-anisotropy (FA) and diffusivity (mean (MD), axial (AD) and radial (RD)) were calculated and compared to neuropathy severity. Conventional T2-relaxation-time and proton-spin-density data were obtained from a multi-echo SE sequence. Furthermore, we evaluated sensitivity and specificity of DTI-MRN from receiver operating characteristics (ROC). RESULTS: The proximal and distal FA was lowest in patients with DPN compared with nDPN and HC (p < 0.01). Likewise, proximal and distal RD was highest in patients with DPN (p < 0.01). MD and AD were also significantly different though less pronounced. ROC curve analyses of DTI separated nDPN and DPN with area-under-the-curve values ranging from 0.65 to 0.98. T2-relaxation-time and proton-spin-density could not differentiate between nDPN and DPN. CONCLUSION: DTI-MRN accurately detects DPN by lower nerve FA and higher RD. These alterations are likely to reflect both proximal and distal nerve fiber pathology in patients with type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Neuropatias Diabéticas/diagnóstico por imagem , Imagem de Tensor de Difusão , Polineuropatias/diagnóstico por imagem , Idoso , Neuropatias Diabéticas/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polineuropatias/etiologia , Nervo Isquiático/diagnóstico por imagem , Nervo Isquiático/fisiopatologia , Nervo Tibial/diagnóstico por imagem , Nervo Tibial/fisiopatologia
15.
Phys Med Biol ; 65(24): 245045, 2020 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-33157544

RESUMO

A deeper understanding of biological mechanisms to promote more efficient treatment strategies in proton therapy demands advances in preclinical radiation research. However this is often limited by insufficient availability of adequate infrastructures for precision image guided small animal proton irradiation. The project SIRMIO aims at filling this gap by developing a portable image-guided research platform for small animal irradiation, to be used at clinical facilities and allowing for a precision similar to a clinical treatment, when scaled down to the small animal size. This work investigates the achievable dosimetric properties of different lowest energy clinical proton therapy beams, manipulated by a dedicated portable beamline including active focusing after initial beam energy degradation and collimation. By measuring the lateral beam size in air close to the beam nozzle exit and the laterally integrated depth dose in water, an analytical beam model based on the beam parameters of the clinical beam at the Rinecker Proton Therapy Center was created for the lowest available clinical beam energy. The same approach was then applied to estimate the lowest energy beam model of different proton therapy facilities, Paul Scherrer Institute, Centre Antoine Lacassagne, Trento Proton Therapy Centre and the Danish Centre for Particle Therapy, based on their available beam commissioning data. This comparison indicated similar beam properties for all investigated sites, with emittance values of a few tens of mm·mrad. Finally, starting from these beam models, we simulated propagation through a novel beamline designed to manipulate the beam energy and size for precise small animal irradiation, and evaluated the resulting dosimetric properties in water. For all investigated initial clinical beams, similar dosimetric results suitable for small animal irradiation were found. This work supports the feasibility of the proposed SIRMIO beamline, promising suitable beam characteristics to allow for precise preclinical irradiation at clinical treatment facilities.


Assuntos
Terapia com Prótons/instrumentação , Animais , Estudos de Viabilidade , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia Guiada por Imagem , Síncrotrons
16.
Diabetologia ; 52(4): 698-704, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19183937

RESUMO

AIMS/HYPOTHESIS: We followed type 2 diabetic patients over a long period to evaluate the predictive value of ambulatory pulse pressure (PP) and decreased nocturnal BP reduction (non-dipping) for nephropathy progression. METHODS: Type 2 diabetic patients (n = 112) were followed for an average of 9.5 (range 0.5-14.5) years. At baseline, all patients underwent 24 h ambulatory BP measurement. Urinary albumin excretion rate was evaluated by three urinary albumin:creatinine ratio measurements at baseline and follow-up. RESULTS: At baseline, patients who subsequently progressed to a more advanced nephropathy stage (n = 35) had reduced diastolic night/day BP variation and higher 24 h systolic BP and PP values; they also had more advanced nephropathy and were more likely to smoke than those with no progression of nephropathy (n = 77). In a Cox regression analysis, independent predictors of nephropathy progression were 24 h PP (p < 0.01), diastolic night:day BP ratio (p = 0.02) and smoking (p = 0.02). The adjusted hazards ratio (95% CI) for each mmHg increment in 24 h PP was 1.04 (1.01-1.07), whereas the adjusted hazards ratio (95% CI) for each 1% increase in diastolic night:day BP ratio was 1.06 (1.01-1.11). Only one of 33 patients (3.0%) with both a diastolic night:day BP ratio and a 24 h PP below the median progressed, whereas 17 of 32 patients (53.1%) with both a diastolic night:day BP ratio and a 24 h PP equal to or above the median progressed to a more advanced nephropathy stage (p < 0.001). CONCLUSIONS/INTERPRETATION: Ambulatory PP, impaired nocturnal BP decline and smoking are strong, independent predictors of nephropathy progression in type 2 diabetic patients.


Assuntos
Pressão Sanguínea/fisiologia , Ritmo Circadiano , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/fisiopatologia , Pulso Arterial , Idade de Início , Idoso , Albuminúria , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Creatinina/urina , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/urina , Progressão da Doença , Feminino , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/métodos , Análise de Regressão
17.
Diabetologia ; 52(7): 1298-307, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19288077

RESUMO

AIMS/HYPOTHESIS: We studied the physiological, metabolic and hormonal mechanisms underlying the elevated risk of type 2 diabetes in carriers of TCF7L2 gene. METHODS: We undertook genotyping of 81 healthy young Danish men for rs7903146 of TCF7L2 and carried out various beta cell tests including: 24 h glucose, insulin and glucagon profiles; OGTT; mixed meal test; IVGTT; hyperglycaemic clamp with co-infusion of glucagon-like peptide (GLP)-1 or glucose-dependent insulinotropic polypeptide (GIP); and a euglycaemic-hyperinsulinaemic clamp combined with glucose tracer infusion to study hepatic and peripheral insulin action. RESULTS: Carriers of the T allele were characterised by reduced 24 h insulin concentrations (p < 0.05) and reduced insulin secretion relative to glucose during a mixed meal test (beta index: p < 0.003), but not during an IVGTT. This was further supported by reduced late-phase insulinotropic action of GLP-1 (p = 0.03) and GIP (p = 0.07) during a 7 mmol/l hyperglycaemic clamp. Secretion of GLP-1 and GIP during the mixed meal test was normal. Despite elevated hepatic glucose production, carriers of the T allele had significantly reduced 24 h glucagon concentrations (p < 0.02) suggesting altered alpha cell function. CONCLUSIONS/INTERPRETATION: Elevated hepatic glucose production and reduced insulinotropic effect of incretin hormones contribute to an increased risk of type 2 diabetes in carriers of the rs7903146 risk T allele of TCF7L2.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Incretinas/sangue , Insulina/sangue , Fatores de Transcrição TCF/genética , Adolescente , Alelos , Diabetes Mellitus Tipo 2/epidemiologia , Genótipo , Peptídeo 1 Semelhante ao Glucagon/administração & dosagem , Peptídeo 1 Semelhante ao Glucagon/sangue , Técnica Clamp de Glucose , Teste de Tolerância a Glucose , Glutaminase/administração & dosagem , Glutaminase/sangue , Humanos , Hiperinsulinismo/epidemiologia , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/administração & dosagem , Peptídeos e Proteínas de Sinalização Intracelular/sangue , Fígado/metabolismo , Masculino , Fatores de Risco , Fatores de Transcrição TCF/metabolismo , Proteína 2 Semelhante ao Fator 7 de Transcrição , Trítio , Adulto Jovem
18.
Diabetologia ; 52(10): 2122-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19669124

RESUMO

AIMS/HYPOTHESIS: An association between elevated fasting plasma glucose and the common rs560887 G allele in the G6PC2/ABCB11 locus has been reported. In Danes we aimed to examine rs560887 in relation to plasma glucose and serum insulin responses following oral and i.v. glucose loads and in relation to hepatic glucose production during a hyperinsulinaemic-euglycaemic clamp. Furthermore, we examined rs560887 for association with impaired fasting glycaemia (IFG), impaired glucose tolerance (IGT), type 2 diabetes and components of the metabolic syndrome. METHODS: rs560887 was genotyped in the Inter99 cohort (n = 5,899), in 366 young, healthy Danes, in non-diabetic relatives of type 2 diabetic patients (n = 196), and in young and elderly twins (n = 159). Participants underwent an OGTT, an IVGTT or a 2 h hyperinsulinaemic-euglycaemic clamp. RESULTS: The rs560887 G allele associated with elevated fasting plasma glucose (p = 2 x 10(-14)) but not with plasma glucose levels at 30 min (p = 0.9) or 120 min (p = 0.9) during an OGTT. G allele carriers had elevated levels of serum insulin at 30 min during an OGTT (p = 1 x 10(-4)) and relatives of type 2 diabetes patients carrying the G allele had an increased acute insulin response (p = 4 x 10(-4)) during an IVGTT. Among elderly twins, G allele carriers had higher basal hepatic glucose production (p = 0.04). Finally, the G allele associated with the risk of having IFG (OR 1.26, 95% CI 1.08-1.47, p = 0.002), but not with IGT (OR 0.94, 95% CI 0.82-1.08, p = 0.4) or type 2 diabetes (OR 0.93, 95% CI 0.84-1.04, p = 0.2). CONCLUSIONS/INTERPRETATION: The common rs560887 G allele in the G6PC2/ABCB11 locus is associated with increased fasting glycaemia and increased risk of IFG, associations that may be partly related to an increased basal hepatic glucose production rate.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Glicemia/genética , Jejum/sangue , Glucose-6-Fosfatase/genética , Glucose/biossíntese , Insulina/metabolismo , Fígado/metabolismo , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Adulto , Feminino , Genótipo , Teste de Tolerância a Glucose , Humanos , Masculino , Pessoa de Meia-Idade
19.
Allergy ; 63(12): 1624-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19032235

RESUMO

BACKGROUND: In the United Kingdom, approximately 10.8 million people suffer from asthma, placing an economic burden on the society of more than 2 billion pounds sterling per year. For allergic asthma, treatment options consist of allergen avoidance, symptomatic treatment and allergen-specific immunotherapy (SIT). Only SIT addresses the underlying cause of the disease, reducing symptoms and offering the potential for long-term improvement. Grazax--the first tablet-based SIT--is indicated for the treatment of patients with grass pollen-induced rhinoconjunctivitis, including those with co-existing asthma. OBJECTIVE: To assess the cost-effectiveness of Grazax in patients with rhinoconjunctivitis and co-existing asthma. METHODS: A prospective pharmacoeconomic analysis was carried out as part of a multinational clinical trial assessing the efficacy of Grazax (n = 79) compared with placebo (n = 72). Both groups had access to symptomatic medication; thus the placebo group represented current standard care. Pooled data on health resource use, productivity loss because of absence from work and quality of life (Quality Adjusted Life Years, QALYs) were collected in the trial. Reduced productivity at work was estimated from the literature. A societal perspective was adopted with a 9-year time horizon. The NHS price of Grazax of 2.25 pounds sterling per tablet was used. RESULTS: The QALY gain was significantly higher for patients treated with Grazax than the placebo group receiving symptomatic medication alone (0.197 discounted QALYs gained 9 years into the future - equal to an extra 72 days of perfect health over 9 years). The levels of resource use and productivity loss were higher for the placebo group. As a result, the cost per QALY gained with Grazax was 4319 pounds sterling , which is highly cost-effective. Price sensitivity analyses demonstrated that Grazax remained cost-effective up to a tablet price of 5.07 pounds sterling . CONCLUSION: SIT with Grazax is a cost-effective strategy compared with standard management of patients with rhinoconjunctivitis and co-existing asthma.


Assuntos
Asma/tratamento farmacológico , Dessensibilização Imunológica/economia , Extratos Vegetais/farmacologia , Poaceae/imunologia , Rinite Alérgica Perene/terapia , Rinite Alérgica Sazonal/terapia , Antígenos de Plantas/economia , Antígenos de Plantas/imunologia , Antígenos de Plantas/uso terapêutico , Asma/economia , Asma/imunologia , Análise Custo-Benefício , Humanos , Phleum/imunologia , Extratos Vegetais/economia , Extratos Vegetais/imunologia , Poaceae/efeitos adversos , Pólen/imunologia , Estudos Prospectivos , Anos de Vida Ajustados por Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Rinite Alérgica Perene/economia , Rinite Alérgica Perene/imunologia , Rinite Alérgica Sazonal/economia , Rinite Alérgica Sazonal/imunologia
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