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1.
Int J Mol Sci ; 22(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34502532

RESUMO

Brown adipose tissue (BAT) expresses uncoupling protein-1 (UCP1), which enables energy to be exerted towards needed thermogenesis. Beige adipocytes are precursor cells interspersed among white adipose tissue (WAT) that possess similar UCP1 activity and capacity for thermogenesis. The raccoon dog (Nyctereutes procyonoides) is a canid species that utilizes seasonal obesity to survive periods of food shortage in climate zones with cold winters. The potential to recruit a part of the abundant WAT storages as beige adipocytes for UCP1-dependent thermogenesis was investigated in vitro by treating raccoon dog adipocytes with different browning inducing factors. In vivo positron emission tomography/computed tomography (PET/CT) imaging with the glucose analog 18F-FDG showed that BAT was not detected in the adult raccoon dog during the winter season. In addition, UCP1 expression was not changed in response to chronic treatments with browning inducing factors in adipocyte cultures. Our results demonstrated that most likely the raccoon dog endures cold weather without the induction of BAT or recruitment of beige adipocytes for heat production. Its thick fur coat, insulating fat, and muscle shivering seem to provide the adequate heat needed for surviving the winter.

2.
Eur J Appl Physiol ; 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34564756

RESUMO

PURPOSE: While brown adipose tissue (BAT) activity is known to be associated with both muscle and adipose tissue volumes, the association between BAT and muscle composition remains unclear, especially in adults. Therefore, the present study aimed to examine the association between BAT parameters (glucose uptake and fat-fraction) and muscle volumes and intramuscular adipose tissue contents among healthy young and middle-aged men. METHODS: BAT glucose uptake was determined using positron emission tomography with [18F]-2-deoxy-2-fluoro-D-glucose (18F-FDG) during cold exposure in 19 young and middle-aged men (36.3 ± 10.7 years). The fat-fraction of BAT was determined from volumes of interest set in cervical and supraclavicular adipose tissue depots using signal fat-fraction maps via magnetic resonance imaging (MRI). Muscle volumes and intramuscular adipose tissue contents of m. tibialis anterior and m. multifidus lumborum were measured using MRI. RESULTS: The fat-fraction of BAT was significantly associated with intramuscular adipose tissue content in m. tibialis anterior (n = 13, rs = 0.691, P = 0.009). A similar trend was also observed in m. multifidus lumborum (n = 19, rs = 0.454, P = 0.051). However, BAT glucose uptake was not associated with intramuscular adipose tissue contents in both muscles, nor were muscle volumes associated with the BAT glucose uptake and fat-fraction. CONCLUSION: The fat-fraction of BAT increases with skeletal muscle adiposity, especially in the lower leg, among healthy young and middle-aged men.

3.
Eur J Endocrinol ; 185(4): 577-586, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34374651

RESUMO

Objective: Insulinomas are rare functional pancreatic neuroendocrine tumours. As previous data on the long-term prognosis of insulinoma patients are scarce, we studied the morbidity and mortality in the Finnish insulinoma cohort. Design: Retrospective cohort study. Methods: Incidence of endocrine, cardiovascular, gastrointestinal and psychiatric disorders, and cancers was compared in all the patients diagnosed with an insulinoma in Finland during 1980-2010 (n = 79, including two patients with multiple endocrine neoplasia type 1 syndrome), vs 316 matched controls, using the Mantel-Haenszel method. Overall survival was analysed with Kaplan-Meier and Cox regression analyses. Results: The median length of follow-up was 10.7 years for the patients and 12.2 years for the controls. The long-term incidence of atrial fibrillation (rate ratio (RR): 2.07 (95% CI: 1.02-4.22)), intestinal obstruction (18.65 (2.09-166.86)), and possibly breast (4.46 (1.29-15.39) and kidney cancers (RR not applicable) was increased among insulinoma patients vs controls, P < 0.05 for all comparisons. Endocrine disorders and pancreatic diseases were more frequent in the patients during the first year after insulinoma diagnosis, but not later on. The survival of patients with a non-metastatic insulinoma (n = 70) was similar to that of controls, but for patients with distant metastases (n = 9), the survival was significantly impaired (median 3.4 years). Conclusions: The long-term prognosis of patients with a non-metastatic insulinoma is similar to the general population, except for an increased incidence of atrial fibrillation, intestinal obstruction, and possibly breast and kidney cancers. These results need to be confirmed in future studies. Metastatic insulinomas entail a markedly decreased survival.


Assuntos
Insulinoma/epidemiologia , Neoplasias Pancreáticas/epidemiologia , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Comorbidade , Finlândia/epidemiologia , Seguimentos , História do Século XX , História do Século XXI , Humanos , Incidência , Insulinoma/complicações , Insulinoma/diagnóstico , Insulinoma/mortalidade , Pessoa de Meia-Idade , Morbidade , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/mortalidade , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo
4.
Transl Psychiatry ; 11(1): 442, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34453034

RESUMO

Eating behavior varies greatly between individuals, but the neurobiological basis of these trait-like differences in feeding remains poorly understood. Central µ-opioid receptors (MOR) and cannabinoid CB1 receptors (CB1R) regulate energy balance via multiple neural pathways, promoting food intake and reward. Because obesity and eating disorders have been associated with alterations in the brain's opioid and endocannabinoid signaling, the variation in MOR and CB1R system function could potentially underlie distinct eating behavior phenotypes. In this retrospective positron emission tomography (PET) study, we analyzed [11C]carfentanil PET scans of MORs from 92 healthy subjects (70 males and 22 females), and [18F]FMPEP-d2 scans of CB1Rs from 35 subjects (all males, all also included in the [11C]carfentanil sample). Eating styles were measured with the Dutch Eating Behavior Questionnaire (DEBQ). We found that lower cerebral MOR availability was associated with increased external eating-individuals with low MORs reported being more likely to eat in response to environment's palatable food cues. CB1R availability was associated with multiple eating behavior traits. We conclude that although MORs and CB1Rs overlap anatomically in brain regions regulating food reward, they have distinct roles in mediating individual feeding patterns. Central MOR system might provide a pharmacological target for reducing individual's excessive cue-reactive eating behavior.


Assuntos
Analgésicos Opioides , Receptores Opioides mu , Comportamento Alimentar , Feminino , Humanos , Masculino , Tomografia por Emissão de Pósitrons , Receptor CB1 de Canabinoide , Estudos Retrospectivos
5.
J Nucl Med ; 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34215672

RESUMO

Surgery with curative intent can be offered to Congenital Hyperinsulinism (CHI) patients, provided that the lesion is focal. Radiolabeled Exendin-4 specifically binds the glucagon-like peptide 1 receptor (GLP-1R) on pancreatic beta cells. In this study we compared the performance of [18F]F-DOPA positron emission tomography/computed tomography (DOPA PET) and PET/CT with the new tracer [68Ga]Ga-NODAGA-exendin-4 (Exendin PET) in the preoperative detection of focal CHI. Methods: Nineteen CHI patients underwent both DOPA PET and Exendin PET prior to surgery. The images were evaluated in three settings a) standard clinical reading b) blinded expert reading and c) joined reading. Target (lesion) / non target (normal pancreas) ratio were determined using maximum standard uptake value (SUVmax). Image quality was rated by pediatric surgeons in a questionnaire. Results: Fourteen/nineteen patients having focal lesions underwent surgery. Based on clinical readings, the sensitivity of Exendin PET (100% (CI 77-100%)) was higher than that of DOPA PET (71% (CI 42-92%)). Interobserver agreement between readings was higher for Exendin than for DOPA PET (Fleiss' kappa 0.91 vs. 0.56). Exendin PET provided significantly (P = 0.021) higher target / non target ratios (2.02 ± 0.65 ) than DOPA PET (1.40 ± 0.40). On a five point scale, Pediatric surgeons rated Exendin PET superior to DOPA PET. Conclusion: Exendin PET has higher clinical sensitivity and better interobserver correlation for the detection of focal CHI than DOPA PET. Better contrast and image quality makes Exendin PET superior to DOPA PET in surgeons' intra-operative quest for lesion localization.

7.
Nat Metab ; 3(6): 798-809, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34158656

RESUMO

Brown adipose tissue (BAT) thermogenesis is activated by feeding. Recently, we revealed a secretin-mediated gut-BAT-brain axis, which stimulates satiation in mice, but the purpose of meal-induced BAT activation in humans has been unclear. In this placebo-controlled, randomized crossover study, we investigated the effects of intravenous secretin on BAT metabolism (measured with [18F]FDG and [15O]H2O positron emission tomography) and appetite (measured with functional magnetic resonance imaging) in healthy, normal weight men (GUTBAT trial no. NCT03290846). Participants were blinded to the intervention. Secretin increased BAT glucose uptake (primary endpoint) compared to placebo by 57% (median (interquartile range, IQR), 0.82 (0.77) versus 0.59 (0.53) µmol per 100 g per min, 95% confidence interval (CI) (0.09, 0.89), P = 0.002, effect size r = 0.570), while BAT perfusion remained unchanged (mean (s.d.) 4.73 (1.82) versus 6.14 (3.05) ml per 100 g per min, 95%CI (-2.91, 0.07), P = 0.063, effect size d = -0.549) (n = 15). Whole body energy expenditure increased by 2% (P = 0.011) (n = 15). Secretin attenuated blood-oxygen level-dependent activity (primary endpoint) in brain reward circuits during food cue tasks (significance level false discovery rate corrected at P = 0.05) (n = 14). Caloric intake did not significantly change, but motivation to refeed after a meal was delayed by 39 min (P = 0.039) (n = 14). No adverse effects were detected. Here we show in humans that secretin activates BAT, reduces central responses to appetizing food and delays the motivation to refeed after a meal. This suggests that meal-induced, secretin-mediated BAT activation is relevant in the control of food intake in humans. As obesity is increasing worldwide, this appetite regulating axis offers new possibilities for clinical research in treating obesity.


Assuntos
Tecido Adiposo Marrom/metabolismo , Saciação , Secretina/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Encéfalo/fisiologia , Ingestão de Energia , Metabolismo Energético , Comportamento Alimentar , Trato Gastrointestinal/fisiologia , Glucose/metabolismo , Humanos , Camundongos , Termogênese
8.
Transl Psychiatry ; 11(1): 259, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33934103

RESUMO

Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D2 receptor (D2R) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dopamine interaction. Here we addressed this issue by studying 20 healthy non-obese and 25 morbidly obese women (mean BMI 41) eligible for bariatric surgery. Brain MOR and D2R availability were measured using positron emission tomography (PET) with [11C]carfentanil and [11C]raclopride, respectively. Either Roux-en-Y gastric bypass or sleeve gastrectomy was performed on obese subjects according to standard clinical treatment. 21 obese subjects participated in the postoperative PET scanning six months after bariatric surgery. In the control subjects, MOR and D2R availabilities were associated in the ventral striatum (r = .62) and dorsal caudate (r = .61). Preoperatively, the obese subjects had disrupted association in the ventral striatum (r = .12) but the unaltered association in dorsal caudate (r = .43). The association between MOR and D2R availabilities in the ventral striatum was recovered (r = .62) among obese subjects following the surgery-induced weight loss. Bariatric surgery and concomitant weight loss recover the interaction between MOR and D2R in the ventral striatum in the morbidly obese. Consequently, the dysfunctional opioid-dopamine interaction in the ventral striatum is likely associated with an obese phenotype and may mediate excessive energy uptake. Striatal opioid-dopamine interaction provides a feasible target for pharmacological and behavioral interventions for treating obesity.


Assuntos
Cirurgia Bariátrica , Obesidade Mórbida , Analgésicos Opioides , Dopamina , Feminino , Humanos , Obesidade Mórbida/cirurgia , Tomografia por Emissão de Pósitrons , Receptores de Dopamina D2 , Perda de Peso
9.
Am J Physiol Endocrinol Metab ; 320(5): E989-E998, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33843281

RESUMO

Cardiovascular effects of glucagon-like peptide-1 receptor (GLP-1R) agonist therapies are potentially mediated by anti-inflammatory effects on atherosclerosis. Our study demonstrates that 68Ga-NODAGA-exendin-4, a radioligand specifically targeting GLP-1R, detects GLP-1R expression in inflamed atherosclerotic lesions in nondiabetic and diabetic hypercholesterolemic mice. Immunofluorescence staining suggests that GLP-1R is primarily localized in M2 macrophages in lesions. This study describes a new potential tool that may have translational relevance for studies of pharmacological modification of GLP-1R signaling in atherosclerosis.


Assuntos
Aterosclerose/metabolismo , Diabetes Mellitus Experimental/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Acetatos/farmacocinética , Animais , Apolipoproteínas B/genética , Apolipoproteínas B/metabolismo , Aterosclerose/complicações , Aterosclerose/diagnóstico , Aterosclerose/genética , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/diagnóstico , Diabetes Mellitus Experimental/genética , Exenatida/farmacocinética , Feminino , Radioisótopos de Gálio/farmacocinética , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Compostos Heterocíclicos com 1 Anel/farmacocinética , Hipercolesterolemia/complicações , Hipercolesterolemia/diagnóstico , Hipercolesterolemia/genética , Hipercolesterolemia/metabolismo , Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tomografia por Emissão de Pósitrons/métodos , Receptores de LDL/genética , Receptores de LDL/metabolismo
10.
JCI Insight ; 6(10)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-33848266

RESUMO

Bariatric surgery is the most effective method for weight loss in morbid obesity. There is significant individual variability in the weight loss outcomes, yet factors leading to postoperative weight loss or weight regain remain elusive. Alterations in the µ-opioid receptor (MOR) and dopamine D2 receptor (D2R) systems are associated with obesity and appetite control, and the magnitude of initial brain receptor system perturbation may predict long-term surgical weight loss outcomes. We tested this hypothesis by studying 19 morbidly obese women (mean BMI 40) scheduled to undergo bariatric surgery. We measured their preoperative MOR and D2R availabilities using positron emission tomography with [11C]carfentanil and [11C]raclopride, respectively, and then assessed their weight development association with regional MOR and D2R availabilities at 24-month follow-up. MOR availability in the amygdala consistently predicted weight development throughout the follow-up period, but no associations were found for D2R. This is the first study to our knowledge to demonstrate that neuroreceptor markers prior to bariatric surgery are associated with postoperative weight development. Postoperative weight regain may derive from dysfunction in the opioid system, and weight loss outcomes after bariatric surgery may be partially predicted based on preoperative brain receptor availability, opening up new potential for treatment possibilities.

11.
J Clin Med ; 10(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806715

RESUMO

The melanocortin system is involved in the control of adiposity through modulation of food intake and energy expenditure. The single nucleotide polymorphism (SNP) rs17782313 near the MC4R gene has been linked to obesity, and a previous study using magnetoencephalography has shown that carriers of the mutant allele have decreased cerebrocortical response to insulin. Thus, in this study, we addressed whether rs17782313 associates with brain glucose uptake (BGU). Here, [18F]-fluorodeoxyglucose positron emission tomography (PET) data from 113 Finnish subjects scanned under insulin clamp conditions who also had the rs17782313 determined were compiled from a single-center cohort. BGU was quantified by the fractional uptake rate. Statistical analysis was performed with statistical parametric mapping. There was no difference in age, BMI, and insulin sensitivity as indexed by the M value between the rs17782313-C allele carriers and non-carriers. Brain glucose uptake during insulin clamp was not different by gene allele, and it correlated with the M value, in both the rs17782313-C allele carriers and non-carriers. The obesity risk SNP rs17782313 near the MC4R gene is not associated with brain glucose uptake during insulin clamp in humans, and this frequent mutation cannot explain the enhanced brain glucose metabolic rates in insulin resistance.

12.
Obesity (Silver Spring) ; 29(3): 543-549, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33528921

RESUMO

OBJECTIVE: Gray matter (GM) volume in different brain loci has been shown to vary in obesity and diabetes, and elevated fasting plasma nonesterified fatty acid (NEFA) levels have been suggested as one potential mechanism. The hypothesis presented in this study is that brown adipose tissue (BAT) activity may correlate with GM volume in areas negatively associated with obesity and diabetes. METHODS: A total of 36 healthy patients (M/F: 12/24, age 39.7 ± 9.4 years, BMI 27.5 ± 5.6 kg/m2 ) were imaged with positron emission tomography using fatty acid analog [18 F]FTHA to measure NEFA uptake and with [15 O]H2 O to measure perfusion during cold exposure, at room temperature during fasting, or during a postprandial state. A 2-hour hyperinsulinemic euglycemic clamp was performed to measure whole-body insulin sensitivity (M value, mean 7.6 ± 3.9 mg/kg/min). T1-weighted magnetic resonance imaging at 1.5 T was performed on all patients. RESULTS: BAT NEFA uptake was associated directly with GM volume in anterior cerebellum and occipital lobe (P ≤ 0.04) when adjusted for age, gender, and intra-abdominal fat volume and with anterior cerebellum, limbic lobe, and temporal lobe GM volumes when adjusted for M value. CONCLUSIONS: BAT NEFA metabolism may participate in protection from cognitive degeneration associated with cardiometabolic risk factors, such as central obesity and insulin resistance. Potential causal relationships between BAT activity and GM volumes remain to be examined.


Assuntos
Tecido Adiposo Marrom/metabolismo , Substância Cinzenta/diagnóstico por imagem , Tecido Adiposo Marrom/anatomia & histologia , Tecido Adiposo Marrom/diagnóstico por imagem , Adulto , Jejum/metabolismo , Ácidos Graxos/administração & dosagem , Ácidos Graxos/farmacocinética , Ácidos Graxos não Esterificados/administração & dosagem , Ácidos Graxos não Esterificados/farmacocinética , Feminino , Técnica Clamp de Glucose , Substância Cinzenta/anatomia & histologia , Voluntários Saudáveis , Humanos , Resistência à Insulina/fisiologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Tomografia por Emissão de Pósitrons/métodos , Período Pós-Prandial
13.
Diabetes Obes Metab ; 23(7): 1505-1517, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33625777

RESUMO

AIM: To explore the early effects of dapagliflozin on myocardial function and metabolism in patients with type 2 diabetes without heart failure. MATERIALS AND METHODS: Patients with type 2 diabetes on metformin treatment were randomized to double-blind, 6-week placebo or dapagliflozin 10 mg daily treatment. Investigations included cardiac function and structure with myocardial resonance imaging; cardiac oxygen consumption, perfusion and efficiency with [11 C]-acetate positron emission tomography (PET); and cardiac and hepatic fatty acid uptake with [18 F]-6-thia-heptadecanoic acid PET, analysed by ANCOVA as least square means with 95% confidence intervals. RESULTS: Evaluable patients (placebo: n = 24, dapagliflozin: n = 25; 53% males) had a mean age of 64.4 years, a body mass index of 30.2 kg/m2 and an HbA1c of 6.7%. Body weight and HbA1c were significantly decreased by dapagliflozin versus placebo. Dapagliflozin had no effect on myocardial efficiency, but external left ventricular (LV) work (-0.095 [-0.145, -0.043] J/g/min) and LV oxygen consumption were significantly reduced (-0.30 [-0.49, -0.12] J/g/min) by dapagliflozin, although the changes were not statistically significant versus changes in the placebo group. Change in left atrial maximal volume with dapagliflozin versus placebo was -3.19 (-6.32, -0.07) mL/m2 (p = .056). Peak global radial strain decreased with dapagliflozin versus placebo (-3.92% [-7.57%, -0.28%]; p = .035), while peak global longitudinal and circumferential strains were unchanged. Hepatic fatty acid uptake was increased by dapagliflozin versus placebo (0.024 [0.004, 0.044] µmol/g/min; p = .018), while cardiac uptake was unchanged. CONCLUSIONS: This exploratory study indicates reduced heart work but limited effects on myocardial function, efficiency and cardiac fatty acid uptake, while hepatic fatty acid uptake increased, after 6 weeks of treatment with dapagliflozin.


Assuntos
Diabetes Mellitus Tipo 2 , Inibidores do Transportador 2 de Sódio-Glicose , Simportadores , Compostos Benzidrílicos/uso terapêutico , Glicemia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Método Duplo-Cego , Feminino , Glucose , Glucosídeos , Hemoglobina A Glicada/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Sódio , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico , Resultado do Tratamento
14.
Physiol Rep ; 9(3): e14718, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33580902

RESUMO

BACKGROUND: Sympathetic activity causes changes in electrocardiogram (ECG) during cold exposure and the changes have been studied mostly during hypothermia and less during mild acute nonshivering cold exposure. Cold-induced sympathetic activity also activates brown adipose tissue (BAT) and increases arterial blood pressure (BP) and plasma catecholamine levels. We examined changes in ECG parameters during acute nonshivering cold exposure and their associations with markers of sympathetic activity during cold exposure: brachial blood pressure (BP), plasma catecholamine levels, and BAT activity measured by positron emission tomography (PET). METHODS AND RESULTS: Healthy subjects (M/F = 13/24, aged 20-55 years) were imaged with [15 O]H2 O (perfusion, N = 37) and [18 F]FTHA to measure plasma nonesterified fatty acid uptake (NEFA uptake, N = 37) during 2-h nonshivering cold exposure. 12-lead ECG (N = 37), plasma catecholamine levels (N = 17), and brachial BP (N = 31) were measured at rest in room temperature (RT) and re-measured after a 2-h nonshivering cold exposure. There were significant differences between RT and cold exposure in P axis (35.6 ± 26.4 vs. 50.8 ± 22.7 degrees, p = 0.005), PR interval (177.7 ± 24.6 ms vs.163.0 ± 28.7 ms, p = 0.001), QRS axis (42.1 ± 31.3 vs. 56.9 ± 24.1, p = 0.003), and QT (411.7 ± 25.5 ms vs. 434.5 ± 39.3 ms, p = 0.001). There was no significant change in HR, QRS duration, QTc, JTc, and T axis during cold exposure. Systolic BP (127.2 ± 15.7 vs. 131.8 ± 17.9 mmHg, p = 0.008), diastolic BP (81.7 ± 12.0 vs. 85.4 ± 13.0 mmHg, p = 0.02), and plasma noradrenaline level increased during cold exposure (1.97 ± 0.61 vs. 5.07 ± 1.32 µmol/L, p = 0.001). Cold-induced changes in ECG parameters did not correlate with changes in BAT activity, brachial BP, plasma catecholamines, or skin temperature. CONCLUSIONS: During short-term nonshivering cold exposure, there were increases in P axis, PR interval, QRS axis, and QT compared to RT in healthy adults. Cold-induced changes in ECG parameters did not correlate with BAT activity, brachial BP, or plasma catecholamine levels which were used as markers of cold-induced sympathetic activity.

16.
Diabetes Care ; 44(3): 788-794, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33446523

RESUMO

OBJECTIVE: Whereas insulin resistance is expressed as reduced glucose uptake in peripheral tissues, the relationship between insulin resistance and brain glucose metabolism remains controversial. Our aim was to examine the association of insulin resistance and brain glucose uptake (BGU) during a euglycemic hyperinsulinemic clamp in a large sample of study participants across a wide range of age and insulin sensitivity. RESEARCH DESIGN AND METHODS: [18F]-fluorodeoxyglucose positron emission tomography (PET) data from 194 participants scanned under clamp conditions were compiled from a single-center cohort. BGU was quantified by the fractional uptake rate. We examined the association of age, sex, M value from the clamp, steady-state insulin and free fatty acid levels, C-reactive protein levels, HbA1c, and presence of type 2 diabetes with BGU using Bayesian hierarchical modeling. RESULTS: Insulin sensitivity, indexed by the M value, was associated negatively with BGU in all brain regions, confirming that in insulin-resistant participants BGU was enhanced during euglycemic hyperinsulinemia. In addition, the presence of type 2 diabetes was associated with additional increase in BGU. On the contrary, age was negatively related to BGU. Steady-state insulin levels, C-reactive protein and free fatty acid levels, sex, and HbA1c were not associated with BGU. CONCLUSIONS: In this large cohort of participants of either sex across a wide range of age and insulin sensitivity, insulin sensitivity was the best predictor of BGU.


Assuntos
Diabetes Mellitus Tipo 2 , Hiperinsulinismo , Resistência à Insulina , Teorema de Bayes , Glicemia , Encéfalo/diagnóstico por imagem , Glucose , Técnica Clamp de Glucose , Humanos , Hiperinsulinismo/diagnóstico por imagem , Insulina , Tomografia por Emissão de Pósitrons
17.
J Nucl Med ; 62(4): 577-583, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32817143

RESUMO

Sialic acid-binding immunoglubulinlike lectin 9 (Siglec-9) is a ligand of vascular adhesion protein 1. A 68Ga-labeled peptide of Siglec-9, 68Ga-DOTA-Siglec-9, holds promise as a novel PET tracer for imaging of inflammation. This first-in-humans study investigated the safety, tolerability, biodistribution, and radiation dosimetry of this radiopharmaceutical. Methods: Six healthy men underwent dynamic whole-body PET/CT. Serial venous blood samples were drawn from 1 to 240 min after intravenous injection of 162 ± 4 MBq of 68Ga-DOTA-Siglec-9. In addition to γ-counting, the plasma samples were analyzed by high-performance liquid chromatography to detect intact tracer and radioactive metabolites. Radiation doses were calculated using the OLINDA/EXM software, version 2.2. In addition, a patient with early rheumatoid arthritis was studied with both 68Ga-DOTA-Siglec-9 and 18F-FDG PET/CT to determine the ability of the new tracer to detect arthritis. Results: 68Ga-DOTA-Siglec-9 was well tolerated by all subjects. 68Ga-DOTA-Siglec-9 was rapidly cleared from the blood circulation, and several radioactive metabolites were detected. The organs with the highest absorbed doses were the urinary bladder wall (0.38 mSv/MBq) and kidneys (0.054 mSv/MBq). The mean effective dose was 0.022 mSv/MBq (range, 0.020-0.024 mSv/MBq). Most importantly, however, 68Ga-DOTA-Siglec-9 was comparable to 18F-FDG in detecting arthritis. Conclusion: Intravenous injection of 68Ga-DOTA-Siglec-9 was safe and biodistribution was favorable for testing of the tracer in larger group of patients with rheumatoid arthritis, as is planned for the next phase of clinical trials. The effective radiation dose of 68Ga-DOTA-Siglec-9 was within the same range as the effective radiation doses of other 68Ga-labeled tracers. Injection of 150 MBq of 68Ga-DOTA-Siglec-9 would expose a subject to 3.3 mSv. These findings support the possible repeated clinical use of 68Ga-DOTA-Siglec-9, such as in trials to elucidate the treatment efficacy of novel drug candidates.


Assuntos
Amina Oxidase (contendo Cobre)/metabolismo , Antígenos CD/química , Moléculas de Adesão Celular/metabolismo , Radioisótopos de Gálio/química , Compostos Heterocíclicos com 1 Anel/química , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/química , Adulto , Feminino , Humanos , Ligantes , Masculino , Compostos Radiofarmacêuticos/efeitos adversos , Compostos Radiofarmacêuticos/farmacocinética , Segurança , Solubilidade , Distribuição Tecidual
19.
Clin Endocrinol (Oxf) ; 94(2): 250-257, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32974918

RESUMO

OBJECTIVE: Insulinomas are rare pancreatic neoplasms, which can usually be cured by surgery. As the diagnostic delay is often long and the prolonged hyperinsulinemia may have long-term effects on health and the quality of life, we studied the long-term health-related quality of life (HRQoL) in insulinoma patients. DESIGN, PATIENTS AND MEASUREMENTS: The HRQoL of adults diagnosed with an insulinoma in Finland in 1980-2010 was studied with the 15D instrument, and the results were compared to those of an age- and gender-matched sample of the general population. The minimum clinically important difference in the total 15D score has been defined as ±0.015. The clinical characteristics, details of insulinoma diagnosis and treatment, and the current health status of the subjects were examined to specify the possible determinants of long-term HRQoL. RESULTS: Thirty-eight insulinoma patients participated in the HRQoL survey (response rate 75%). All had undergone surgery with a curative aim, a median of 13 (min 7, max 34) years before the survey. The insulinoma patients had a clinically importantly and statistically significantly better mean 15D score compared with the controls (0.930 ± 0.072 vs 0.903 ± 0.039, P = .046) and were significantly better off regarding mobility, usual activities and eating. Among the insulinoma patients, younger age at the time of survey, higher level of education and smaller number of chronic diseases were associated with better overall HRQoL. CONCLUSIONS: In the long term, the overall HRQoL of insulinoma patients is slightly better than that of the general population.

20.
Genes Brain Behav ; 20(4): e12708, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33070440

RESUMO

Cryptochrome 2 (Cry2) is a core clock gene important for circadian regulation. It has also been associated with anxiety and depressive-like behaviors in mice, but the previous findings have been conflicting in terms of the direction of the effect. To begin to elucidate the molecular mechanisms of this association, we carried out behavioral testing, PET imaging, and gene expression analysis of Cry2-/- and Cry2+/+ mice. Compared to Cry2+/+ mice, we found that Cry2-/- mice spent less time immobile in the forced swim test, suggesting reduced despair-like behavior. Moreover, Cry2-/- mice had lower saccharin preference, indicative of increased anhedonia. In contrast, we observed no group differences in anxiety-like behavior. The behavioral changes were accompanied by lower metabolic activity of the ventro-medial hypothalamus, suprachiasmatic nuclei, ventral tegmental area, anterior and medial striatum, substantia nigra, and habenula after cold stress as measured by PET imaging with a glucose analog. Although the expression of many depression-associated and metabolic genes was upregulated or downregulated by cold stress, we observed no differences between Cry2-/- and Cry2+/+ mice. These findings are consistent with other studies showing that Cry2 is required for normal emotional behavior. Our findings confirm previous roles of Cry2 in behavior and extend them by showing that the effects on behavior may be mediated by changes in brain metabolism.

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