Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38477483

RESUMO

CONTEXT: Proneurotensin (pNT) is associated with obesity and T2D, but the effects of Roux-en-Y gastric bypass (RYGB) on postprandial pNT levels are not well studied. OBJECTIVE: Assess effects of RYGB versus very low-energy diet (VLED) on pNT levels in response to mixed-meal tests (MMT), and long-term effects of RYGB on fasting pNT.Study participants: Cohort 1: Nine normoglycemic (NG) and ten T2D patients underwent MMT before and after VLED, immediately post-RYGB and six weeks post-RYGB. Cohort 2: Ten controls with normal weight and ten patients with obesity and T2D, who underwent RYGB or vertical sleeve gastrectomy (VSG), were subjected to MMTs and GIP infusions pre-surgery and three months post-surgery. GLP-1 infusions were performed in normal weight participants. Cohort 3: Fasting pNT was assessed pre-RYGB (n=161), two months post-RYGB (n=92) and 1-year post-RYGB (n=118) in NG and T2D patients. pNT levels were measured using ELISA. RESULTS: Reduced fasting and postprandial pNT were evident after VLED and immediately following RYGB. Reintroduction of solid food post-RYGB increased fasting and postprandial pNT. Prior to RYGB, all patients lacked a meal response in pNT, but this was evident post-RYGB/VSG. GIP- or GLP-1 infusion had no effect on pNT levels. Fasting pNT were higher 1-year post-RYGB regardless of glycemic status. CONCLUSION: RYGB causes a transient reduction in pNT as a consequence of caloric restriction. The RYGB/VSG-induced rise in postprandial pNT is independent of GIP and GLP-1 and higher fasting pNT are maintained one year post-surgically.

2.
Eur J Endocrinol ; 188(5): 421-429, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-36943311

RESUMO

OBJECTIVE: Pancreatic neuroendocrine tumors (panNETs) are the leading cause of death in patients with multiple endocrine neoplasia type 1 (MEN1). The role of somatostatin receptor positron emission tomography/computed tomography (SSTR PET/CT) in MEN1 has not been established. The aim was to assess pancreatic imaging in MEN1 in a real-life setting. DESIGN: Fifty-eight patients with MEN1 [median age 40 (range 16-72) years] underwent SSTR PET/CT imaging; either as a screening tool regardless of disease stage (n = 47) or to further characterize known panNETs (n = 11). SSTR PET/CT and matched conventional imaging were blindly analyzed. We assessed the findings and the impact of SSTR PET/CT during a median follow-up of 47 months. RESULTS: SSTR PET/CT detected three times as many panNETs as conventional imaging (P < .001). SSTR PET/CT altered the management of 27 patients (47%). Seven patients (12%) were referred for surgery, and five (9%) received systemic treatment. In 15/25 (60%) patients with no previous panNET (n = 22) or in remission after surgery (n = 3), SSTR PET/CT identified a panNET (n = 14) or recurrence (n = 1). In eight patients, SSTR PET/CT revealed a panNET not immediately visible on conventional imaging. During a median follow-up of 47 months, three became visible on conventional imaging, but none required intervention. When SSTR PET/CT was negative, no panNETs were identified on conventional imaging during 38 months of follow-up. CONCLUSIONS: SSTR PET/CT demonstrates high accuracy in the detection of panNETs and alters the clinical management in nearly half of the MEN1-patients. SSTR PET/CT enables timely diagnosis and staging of MEN1-related panNETs.


Assuntos
Neoplasia Endócrina Múltipla Tipo 1 , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Receptores de Somatostatina , Neoplasias Pancreáticas/diagnóstico , Pâncreas/patologia , Tumores Neuroendócrinos/patologia
3.
J Clin Endocrinol Metab ; 107(7): 1930-1938, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35363252

RESUMO

CONTEXT: Glucose-dependent insulinotropic peptide (GIP) and meal ingestion increase subcutaneous adipose tissue (SAT) perfusion in healthy individuals. The effects of GIP and a meal on visceral adipose tissue (VAT) perfusion are unclear. OBJECTIVE: Our aim was to investigate the effects of meal and GIP on VAT and SAT perfusion in obese individuals with type 2 diabetes mellitus (T2DM) before and after bariatric surgery. METHODS: We recruited 10 obese individuals with T2DM scheduled for bariatric surgery and 10 control individuals. Participants were studied under 2 stimulations: meal ingestion and GIP infusion. SAT and VAT perfusion was measured using 15O-H2O positron emission tomography-magnetic resonance imaging at 3 time points: baseline, 20 minutes, and 50 minutes after the start of stimulation. Obese individuals were studied before and after bariatric surgery. RESULTS: Before bariatric surgery the responses of SAT perfusion to meal (P = .04) and GIP-infusion (P = .002) were blunted in the obese participants compared to controls. VAT perfusion response did not differ between obese and control individuals after a meal or GIP infusion. After bariatric surgery SAT perfusion response to a meal was similar to that of controls. SAT perfusion response to GIP administration remained lower in the operated-on than control participants. There was no change in VAT perfusion response after bariatric surgery. CONCLUSION: The vasodilating effects of GIP and meal are blunted in SAT but not in VAT in obese individuals with T2DM. Bariatric surgery improves the effects of a meal on SAT perfusion, but not the effects of GIP. Postprandial increase in SAT perfusion after bariatric surgery seems to be regulated in a GIP-independent manner.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Tecido Adiposo , Diabetes Mellitus Tipo 2/cirurgia , Polipeptídeo Inibidor Gástrico/farmacologia , Humanos , Gordura Intra-Abdominal , Obesidade , Gordura Subcutânea
4.
Cancers (Basel) ; 14(1)2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-35008325

RESUMO

PURPOSE: The aim of this study was to correlate immunohistochemical (IHC) tissue levels of SSTR1-5 with the receptor density generated from [68Ga]Ga-DOTANOC uptake in a prospective series of NF-PNENs. METHODS: Twenty-one patients with a total of thirty-five NF-PNEN-lesions and twenty-one histologically confirmed lymph node metastases (LN+) were included in this prospective study. Twenty patients were operated on, and one underwent endoscopic ultrasonography and core-needle biopsy. PET/CT with both [68Ga]Ga-DOTANOC and [18F]F-FDG was performed on all patients. All histological samples were re-classified and IHC-stained with monoclonal SSTR1-5 antibodies and Ki-67 and correlated with [68Ga]Ga-DOTANOC and [18F]F-FDG PET/CT. RESULTS: Expression of SSTR1-5 was detected in 74%, 91%, 80%, 14%, and 77% of NF-PNENs. There was a concordance of SSTR2 IHC with positive/negative [68Ga]Ga-DOTANOC finding (Spearman's rho 0.382, p = 0.043). All [68Ga]Ga-DOTANOC-avid tumors expressed SSTR2 or SSTR3 or SSTR5. Expression of SSTR5 was higher in tumors with a low Ki-67 proliferation index (PI) (-0.353, 95% CI -0.654-0.039, p = 0.038). The mean Ki-67 PI for SSTR5 positive tumors was 2.44 (SD 2.56, CI 1.0-3.0) and 6.38 (SD 7.25, CI 2.25-8.75) for negative tumors. CONCLUSION: SSTR2 was the only SSTR subtype to correlate with [68Ga]Ga-DOTANOC PET/CT. Our prospective study confirms SSTR2 to be of the highest impact for SST PET/CT signal.

5.
Acta Radiol ; 62(7): 851-857, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32722966

RESUMO

BACKGROUND: The clinical utility of positron emission tomography/magnetic resonance imaging (PET/MRI) in comparison to standard work-up with patients with known or suspected inflammatory bowel disease (IBD) is unknown. PURPOSE: To evaluate the value of 18F-fluorodeoxyglucose (18F-FDG) PET/MRI in the diagnostics of IBD and further compare the data obtained using PET/MRI to histological findings. MATERIALS AND METHODS: Ten patients with relapse in IBD or with symptoms of suspected IBD were recruited either from a gastroenterology outpatient clinic or from a hospital ward. Intestinal inflammation was assessed with histology and 18F-FDG PET/MRI. Maximum standard uptake values (SUVmax) were calculated in six regions of the intestine (small bowel, ascending, transverse, descending and sigmoid colon, and rectum) and compared to histological analysis of inflammation activity. RESULTS: The study showed that both the inflammation activity (P = 0.008) and the region of the biopsy in the intestine (P = 0.015) had a significant effect on SUV. SUVs obtained from severe inflammation activity emerged significantly from the background (P = 0.006). In addition, the SUVs obtained from moderate inflammation raised from background, but the difference was not statistically significant (P = 0.083), while SUVs of mild inflammation were at the same level with SUVs of normal bowel wall (P = 0.988). CONCLUSION: 18F-FDG PET/MRI is a promising method of detecting especially severe inflammatory bowel lesions. More data are required to define its sensitivity and specificity.


Assuntos
Doenças Inflamatórias Intestinais/diagnóstico por imagem , Imageamento por Ressonância Magnética , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Adulto , Feminino , Fluordesoxiglucose F18 , Humanos , Doenças Inflamatórias Intestinais/patologia , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Compostos Radiofarmacêuticos , Adulto Jovem
6.
Oncology ; 99(3): 177-185, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33120381

RESUMO

INTRODUCTION: Glucose metabolism in cancer cells differs from noncancerous cells. The expression of transketolase-like protein 1 (TKTL1), a key enzyme in the glucose metabolism of cancer cells, predicts poor prognosis in several cancer types. We studied TKTL1 as a prognostic tool and whether TKTL1 expression correlates with 18F-FDG-PET-CT among patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: This retrospective study examined two PDAC patient cohorts: 168 patients operated on at Helsinki University Hospital between 2001 and 2011, and 20 patients with FDG-PET-CT results available from the Auria Biobank. We used immunohistochemistry for TKTL1 expression, combining results with clinicopathological data. RESULTS: Five-year disease-specific survival (DSS) was slightly but not significantly better in patients with a high versus low TKTL1 expression, with DSS of 28.0 versus 17.3%, respectively (p = 0.123). TKTL1 served as a marker of a better prognosis in patients over 65 years old (p = 0.012) and among those with TNM class M1 (p = 0.018), stage IV disease (p = 0.027), or perivascular invasion (p = 0.008). CONCLUSIONS: Our study shows that TKTL1 cannot be used as a prognostic factor in PDAC with the exception of elderly patients and those with advanced disease. The correlation of TKTL1 with 18F-FDG-PET-CT requires further study in a larger patient cohort.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/metabolismo , Fluordesoxiglucose F18 , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/metabolismo , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Transcetolase/análise , Transcetolase/metabolismo , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/mortalidade , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Prognóstico , Estudos Retrospectivos
7.
J Gastrointest Surg ; 24(12): 2838-2848, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31823326

RESUMO

BACKGROUND: Adhesion formation contributes to postoperative complications in abdominal and gynaecological surgery. Thus far, the prevention and treatment strategies have focused on mechanical barriers in solid and liquid form, but these methods are not in routine use. As autologous fat grafting has become popular in treatment of hypertrophic scars because of its immunomodulatory effects, we postulated that fat grafting could also prevent peritoneal adhesion through similar mechanisms. METHODS: This was a control versus intervention study to evaluate the effect of fat grafting in the prevention on peritoneal adhesion formation. An experimental mouse model for moderate and extensive peritoneal adhesions was used (n = 4-6 mice/group). Adhesions were induced mechanically, and a free epididymal fat graft from wild type or CAG-DsRed mice was injected preperitoneally immediately after adhesion induction. PET/CT imaging and scaling of the adhesions were performed, and samples were taken for further analysis at 7 and 30 days postoperation. Macrophage phenotyping was further performed from peritoneal lavage samples, and the expression of inflammatory cytokines and mesothelial layer recovery were analysed from peritoneal tissue samples. RESULTS: Fat grafting significantly inhibited the formation of adhesions. PET/CT results did not show prolonged inflammation in any of the groups. While the expression of anti-inflammatory and anti-fibrotic IL-10 was significantly increased in the peritoneum of the fat graft-treated group at 7 days, tissue-resident and repairing M2 macrophages could no longer be detected in the fat graft at this time point. The percentage of the continuous, healed peritoneum as shown by Keratin 8 staining was greater in the fat graft-treated group after 7 days. CONCLUSIONS: Fat grafting can inhibit the formation of peritoneal adhesions in mice. Our results suggest that fat grafting promotes the peritoneal healing process in a paracrine manner thereby enabling rapid regeneration of the peritoneal mesothelial cell layer.


Assuntos
Doenças Peritoneais , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tecido Adiposo , Animais , Humanos , Camundongos , Doenças Peritoneais/etiologia , Doenças Peritoneais/prevenção & controle , Peritônio/patologia , Peritônio/cirurgia , Complicações Pós-Operatórias/patologia , Aderências Teciduais/etiologia , Aderências Teciduais/prevenção & controle
8.
EJNMMI Res ; 9(1): 116, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31872324

RESUMO

BACKGROUND: Predicting the aggressive behavior of non-functional pancreatic neuroendocrine tumors (NF-PNET) remains controversial. We wanted to explore, in a prospective setting, whether the diagnostic accuracy can be improved by dual-tracer functional imaging 68Ga-DOTANOC and 18F-FDG-PET/CT in patients with NF-PNETs. METHODS: Thirty-one patients with NF-PNET (90% asymptomatic) underwent PET-imaging with 18F-FDG and 68Ga-DOTANOC, followed by surgery (n = 20), an endoscopic ultrasonography and fine-needle biopsy (n = 2) or follow-up (n = 9). A focal activity on PET/CT greater than the background that could not be identified as physiological activity was considered to indicate tumor tissue. The imaging results were compared to histopathology. The mean follow-up time was 31.3 months. RESULTS: Thirty-one patients presented a total of 53 lesions (40 histologically confirmed) on PET/CT. Thirty patients had a 68Ga-DOTANOC-positive tumor (sensitivity 97%) and 10 patients had an 18F-FDG-positive tumor. In addition, one 68Ga-DOTANOC-negative patient was 18F-FDG-positive. 18F-FDG-PET/CT was positive in 19% (3/16) of the G1 tumors, 63% (5/8) of the G2 tumors and 1/1 of the well-differentiated G3 tumor. 68Ga-DOTANOC-PET/CT was positive in 94% of the G1 tumors, 100% of the G2 tumors and 1/1 of the well-differentiated G3 tumor. Two out of six (33%) of the patients with lymph node metastases (LN+) were 18F-FDG-positive. The 18F-FDG-PET/CT correlated with tumor Ki-67 (P = 0.021). Further, the Krenning score correlated with tumor Ki-67 (P = 0.013). 18F-FDG-positive tumors were significantly larger than the 18F-FDG-negative tumors (P = 0.012). 18F-FDG-PET/CT showed a positive predictive value of 78% in the detection of potentially aggressive tumors (G2, G3, or LN + PNETs); the negative predictive value was 69%. CONCLUSIONS: 18F-FDG-PET/CT is useful to predict tumor grade but not the LN+ of NF-PNETs. Patients with 18F-FDG-avid NF-PNETs should be referred for surgery. The 68Ga-DOTANOC-PET/CT also has prognostic value since the Krenning score predicts the histopathological tumor grade. TRIAL REGISTRATION: The study has been registered at ClinicalTrials.gov; Non-functional Pancreatic NET and PET imaging, NCT02621541.

9.
Endocr Connect ; 7(7): 888-896, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29941634

RESUMO

AIMS/HYPOTHESIS: The mechanisms for improved glycemic control after bariatric surgery in subjects with type 2 diabetes (T2D) are not fully known. We hypothesized that dynamic hepatic blood responses to a mixed-meal are changed after bariatric surgery in parallel with an improvement in glucose tolerance. METHODS: A total of ten morbidly obese subjects with T2D were recruited to receive a mixed-meal and a glucose-dependent insulinotropic polypeptide (GIP) infusion before and early after (within a median of less than three months) bariatric surgery, and hepatic blood flow and volume (HBV) were measured repeatedly with combined positron emission tomography/MRI. Ten lean non-diabetic individuals served as controls. RESULTS: Bariatric surgery leads to a significant decrease in weight, accompanied with an improved ß-cell function and glucagon-like peptide 1 (GLP-1) secretion, and a reduction in liver volume. Blood flow in portal vein (PV) was increased by 1.65-fold (P = 0.026) in response to a mixed-meal in subjects after surgery, while HBV decreased in all groups (P < 0.001). When the effect of GIP infusion was tested separately, no change in hepatic arterial and PV flow was observed, but HBV decreased as seen during the mixed-meal test. CONCLUSIONS/INTERPRETATION: Early after bariatric surgery, PV flow response to a mixed-meal is augmented, improving digestion and nutrient absorption. GIP influences the post-prandial reduction in HBV thereby diverting blood to the extrahepatic sites.

10.
Diabetes Res Clin Pract ; 131: 208-216, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28778047

RESUMO

AIMS: Metformin therapy is associated with diffuse intestinal 18F-fluoro-deoxyglucose (FDG) accumulation in clinical diagnostics using routine FDG-PET imaging. We aimed to study whether metformin induced glucose uptake in intestine is associated with the improved glycaemic control in patients with type 2 diabetes. Therefore, we compared the effects of metformin and rosiglitazone on intestinal glucose metabolism in patients with type 2 diabetes in a randomized placebo controlled clinical trial, and further, to understand the underlying mechanism, evaluated the effect of metformin in rats. METHODS: Forty-one patients with newly diagnosed type 2 diabetes were randomized to metformin (1g, b.i.d), rosiglitazone (4mg, b.i.d), or placebo in a 26-week double-blind trial. Tissue specific intestinal glucose uptake was measured before and after the treatment period using FDG-PET during euglycemic hyperinsulinemia. In addition, rats were treated with metformin or vehicle for 12weeks, and intestinal FDG uptake was measured in vivo and with autoradiography. RESULTS: Glucose uptake increased 2-fold in the small intestine and 3-fold in the colon for the metformin group and associated with improved glycemic control. Rosiglitazone increased only slightly intestinal glucose uptake. In rodents, metformin treatment enhanced intestinal FDG retention (P=0.002), which was localized in the mucosal enterocytes of the small intestine. CONCLUSIONS: Metformin treatment significantly enhances intestinal glucose uptake from the circulation of patients with type 2 diabetes. This intestine-specific effect is associated with improved glycemic control and localized to mucosal layer. These human findings demonstrate directs effect of metformin on intestinal metabolism and elucidate the actions of metformin. Clinical trial number NCT02526615.


Assuntos
Glicemia/metabolismo , Hipoglicemiantes/uso terapêutico , Mucosa Intestinal/metabolismo , Metformina/uso terapêutico , Tiazolidinedionas/uso terapêutico , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Método Duplo-Cego , Humanos , Masculino , Metformina/farmacologia , Pessoa de Meia-Idade , Ratos , Rosiglitazona , Tiazolidinedionas/farmacologia
11.
Endocr Connect ; 6(3): 179-187, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28258126

RESUMO

OBJECTIVE: Meal ingestion is followed by a redistribution of blood flow (BF) within the splanchnic region contributing to nutrient absorption, insulin secretion and glucose disposal, but factors regulating this phenomenon in humans are poorly known. The aim of the present study was to evaluate the organ-specific changes in BF during a mixed-meal and incretin infusions. DESIGN: A non-randomized intervention study of 10 healthy adults to study splanchnic BF regulation was performed. METHODS: Effects of glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) infusions and mixed-meal were tested in 10 healthy, glucose tolerant subjects using PET-MRI multimodal imaging technology. Intestinal and pancreatic BF and blood volume (BV) were measured with 15O-water and 15O-carbon monoxide, respectively. RESULTS: Ingestion of a mixed-meal led to an increase in pancreatic and jejunal BF, whereas duodenal BF was unchanged. Infusion of GIP and GLP-1 reduced BF in the pancreas. However, GIP infusion doubled blood flow in the jejunum with no effect of GLP-1. CONCLUSION: Together, our data suggest that meal ingestion leads to increases in pancreatic BF accompanied by a GIP-mediated increase in jejunal but not duodenal blood flow.

12.
Diabetes ; 66(4): 880-885, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28096259

RESUMO

Bariatric surgery results in notable weight loss and alleviates hyperglycemia in patients with type 2 diabetes (T2D). We aimed to characterize the vascular effects of a mixed meal and infusion of exogenous glucose-dependent insulinotropic polypeptide (GIP) in the splanchnic region in 10 obese patients with T2D before and after bariatric surgery and in 10 lean control subjects. The experiments were carried out on two separate days. Pancreatic and intestinal blood flow (BF) were measured at baseline, 20 min, and 50 min with 15O-water by using positron emission tomography and MRI. Before surgery, pancreatic and intestinal BF responses to a mixed meal did not differ between obese and lean control subjects. Compared with presurgery, the mixed meal induced a greater increase in plasma glucose, insulin, and GIP concentrations after surgery, which was accompanied by a marked augmentation of pancreatic and intestinal BF responses. GIP infusion decreased pancreatic but increased small intestinal BF similarly in all groups both before and after surgery. Taken together, these results demonstrate that bariatric surgery leads to enhanced splanchnic vascular responses as a likely consequence of rapid glucose appearance and GIP hypersecretion.


Assuntos
Cirurgia Bariátrica , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Obesidade/cirurgia , Circulação Esplâncnica/fisiologia , Glicemia/efeitos dos fármacos , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Polipeptídeo Inibidor Gástrico/farmacologia , Humanos , Insulina/metabolismo , Intestinos/irrigação sanguínea , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/metabolismo , Obesidade/fisiopatologia , Radioisótopos de Oxigênio , Pâncreas/irrigação sanguínea , Tomografia por Emissão de Pósitrons , Período Pós-Prandial , Circulação Esplâncnica/efeitos dos fármacos
13.
EJNMMI Res ; 6(1): 91, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27957723

RESUMO

BACKGROUND: Several radiometal-labeled, exendin-based tracers that target glucagon-like peptide-1 receptors (GLP-1R) have been intensively explored for ß cell imaging. The main obstacle has been the high uptake of tracer in the kidneys. This study aimed to develop a novel GLP1-R-specific tracer, with fluorine-18 attached to exendin-4, to label ß cells for clinical imaging with PET (positron emission tomography). We hypothesized that this tracer would undergo reduced kidney uptake. 18F-labeled [Nle14,Lys40]exendin-4 analog ([18F]exendin-4) was produced via Cu-catalyzed click chemistry. The biodistribution of [18F]exendin-4 was assessed with ex vivo organ γ-counting and in vivo PET imaging. We also tested the in vivo stability of the radiotracer. The localization of 18F radioactivity in rat and human pancreatic tissue sections was investigated with autoradiography. Receptor specificity was assessed with unlabeled exendin-3. Islet labeling was confirmed with immunohistochemistry. The doses of radiation in humans were estimated based on biodistribution results in rats. RESULTS: [18F]exendin-4 was synthesized with high yield and high specific activity. Results showed specific, sustained [18F]exendin-4 uptake in pancreatic islets. In contrast to previous studies that tested radiometal-labeled exendin-based tracers, we observed rapid renal clearance of [18F]exendin-4. CONCLUSIONS: [18F]exendin-4 showed promise as a tracer for clinical imaging of pancreatic ß cells, due to its high specific uptake in native ß cells and its concomitant low kidney radioactivity uptake.

14.
J Nucl Med ; 56(8): 1163-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26045314

RESUMO

UNLABELLED: Accurate diagnosis of the nature of pancreatic cysts is challenging but more important than ever, in part because of the increasing number of incidental cystic findings in the pancreas. Preliminary data suggest that (18)F-FDG PET/CT may have a significant influence on clinical decision making, although its role is still evolving. Our aim was to prospectively compare the accuracy of combined (18)F-FDG PET and contrast-enhanced CT ((18)F-FDG PET/CT), multidetector CT (MDCT), and MR imaging in differentiating malignant from benign pancreatic cysts. METHODS: Thirty-one consecutive patients with pancreatic cysts were enrolled in the study. They underwent a protocol including (18)F-FDG PET/CT, MDCT, and MR imaging combined with MR cholangiopancreatography, all of which were evaluated in a masked manner. The findings were confirmed macroscopically at surgery or histopathologic analysis (n = 22) or at follow-up (n = 9). RESULTS: Of the 31 patients, 6 had malignant and 25 had benign lesions. The diagnostic accuracy was 94% for (18)F-FDG PET/CT, compared with 77% and 87% for MDCT (P < 0.05) and MR imaging, respectively. (18)F-FDG PET/CT had a negative predictive value of 100% and a positive predictive value of 75% for pancreatic cysts. The maximum standardized uptake value was significantly higher in malignant (7.4 ± 2.6) than in benign lesions (2.4 ± 0.8) (P < 0.05). When the maximum standardized uptake value was set at 3.6, the sensitivity and specificity were 100% and 88%, respectively. Furthermore, when compared with MDCT and MR imaging, respectively, (18)F-FDG PET/CT altered the clinical management of 5 and 3 patients, respectively. CONCLUSION: (18)F-FDG PET/CT is an accurate imaging modality for differentiating between benign and malignant pancreatic cysts. We recommend the use of (18)F-FDG PET/CT in the evaluation of diagnostically challenging pancreatic cysts.


Assuntos
Fluordesoxiglucose F18 , Imageamento por Ressonância Magnética/métodos , Cisto Pancreático/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Colangiopancreatografia Retrógrada Endoscópica/métodos , Meios de Contraste/química , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/métodos , Cisto Pancreático/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/diagnóstico por imagem , Estudos Prospectivos , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
PET Clin ; 9(1): 27-36, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25029931

RESUMO

(18)F-fluorodihydroxyphenylalanine (FDOPA) is a powerful tool for the diagnosis and detection of neuroendocrine tumors when planning and monitoring surgical and oncologic therapies. Pheochromocytomas, paragangliomas, and medullary thyroid cancers especially are amenable to FDOPA imaging because of the high specific uptake of this amino acid analogue and excellent tumor-to-background contrast on PET/computed tomography.


Assuntos
Di-Hidroxifenilalanina/análogos & derivados , Tumores Neuroendócrinos/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Carcinoma Neuroendócrino , Humanos , Neoplasias Intestinais/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Paraganglioma/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem
16.
World J Emerg Surg ; 7(1): 36, 2012 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-23190741

RESUMO

The CIAO Study ("Complicated Intra-Abdominal infection Observational" Study) is a multicenter investigation performed in 68 medical institutions throughout Europe over the course of a 6-month observational period (January-June 2012).Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.2,152 patients with a mean age of 53.8 years (range: 4-98 years) were enrolled in the study. 46.3% of the patients were women and 53.7% were men. Intraperitoneal specimens were collected from 62.2% of the enrolled patients, and from these samples, a variety of microorganisms were collectively identified.The overall mortality rate was 7.5% (163/2.152).According to multivariate analysis of the compiled data, several criteria were found to be independent variables predictive of patient mortality, including patient age, the presence of an intestinal non-appendicular source of infection (colonic non-diverticular perforation, complicated diverticulitis, small bowel perforation), a delayed initial intervention (a delay exceeding 24 hours), sepsis and septic shock in the immediate post-operative period, and ICU admission.Given the sweeping geographical distribution of the participating medical centers, the CIAO Study gives an accurate description of the epidemiological, clinical, microbiological, and treatment profiles of complicated intra-abdominal infections (IAIs) throughout Europe.

17.
Duodecim ; 128(18): 1851-8, 2012.
Artigo em Finlandês | MEDLINE | ID: mdl-23087998

RESUMO

In Finland, the 5-year survival rate of pancreatic adenocarcinoma is 3%. Surgery is the only treatment that may be curative. Adjuvant chemotherapy after radical surgery is beneficial and patients with locally advanced disease may also benefit from chemoradiotherapy. The treatment of metastatic pancreatic cancer, expert symptomatic and palliative care is essential. New therapeutic approaches, e.g. combined cytostatics and/or targeted biologic drugs are being investigated to improve patient outcome.


Assuntos
Neoplasias Pancreáticas/terapia , Produtos Biológicos/uso terapêutico , Quimiorradioterapia , Quimioterapia Adjuvante , Finlândia/epidemiologia , Humanos , Metástase Neoplásica , Cuidados Paliativos , Neoplasias Pancreáticas/epidemiologia , Taxa de Sobrevida
19.
World J Emerg Surg ; 7(1): 15, 2012 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-22613202

RESUMO

The CIAO Study is a multicenter observational study currently underway in 66 European medical institutions over the course of a six-month study period (January-June 2012).This preliminary report overviews the findings of the first half of the study, which includes all data from the first three months of the six-month study period.Patients with either community-acquired or healthcare-associated complicated intra-abdominal infections (IAIs) were included in the study.912 patients with a mean age of 54.4 years (range 4-98) were enrolled in the study during the first three-month period. 47.7% of the patients were women and 52.3% were men. Among these patients, 83.3% were affected by community-acquired IAIs while the remaining 16.7% presented with healthcare-associated infections. Intraperitoneal specimens were collected from 64.2% of the enrolled patients, and from these samples, 825 microorganisms were collectively identified.The overall mortality rate was 6.4% (58/912). According to univariate statistical analysis of the data, critical clinical condition of the patient upon hospital admission (defined by severe sepsis and septic shock) as well as healthcare-associated infections, non-appendicular origin, generalized peritonitis, and serious comorbidities such as malignancy and severe cardiovascular disease were all significant risk factors for patient mortality.White Blood Cell counts (WBCs) greater than 12,000 or less than 4,000 and core body temperatures exceeding 38°C or less than 36°C by the third post-operative day were statistically significant indicators of patient mortality.

20.
J Nucl Med ; 52(12): 1855-63, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22052128

RESUMO

UNLABELLED: Serum calcitonin and carcinoembryonic antigen (CEA) are markers of recurrent or persistent disease in medullary thyroid cancer (MTC). However, conventional imaging often fails to localize metastatic disease. Our aim was to compare fluorine-labeled dihydroxyphenylalanine ((18)F-DOPA) and (18)F-FDG PET/CT with multidetector CT (MDCT) and MRI in recurrent or persistent MTC. METHODS: Nineteen MTC patients with increased calcitonin or CEA on follow-up (mean ± SD, 93 ± 91 mo; range, 4-300 mo) after primary therapy were prospectively imaged with 4 techniques: (18)F-DOPA PET/CT, (18)F-FDG PET/CT, MDCT, and MRI. Images were analyzed for pathologic lesions, which were surgically removed when possible. The correlation between the detection rate for each method and the calcitonin and CEA concentrations and histopathologic findings was investigated. RESULTS: On the basis of histology and follow-up, one or more imaging methods accurately localized metastatic disease in 12 (63%) of 19 patients. The corresponding figures for (18)F-DOPA PET/CT, (18)F-FDG PET/CT, MDCT, and MRI were 11 (58%) of 19, 10 (53%) of 19, 9 (47%) of 19, and 10 (59%) of 17, respectively. Calcitonin and CEA correlated with (18)F-DOPA PET/CT (P = 0.0007 and P = 0.0263, respectively) and (18)F-FDG PET/CT findings (both P < 0.0001). In patients with an unstable calcitonin doubling time (n = 8), (18)F-DOPA and (18)F-FDG PET/CT were equally sensitive. In contrast, for patients with an unstable CEA doubling time (n = 4), (18)F-FDG PET/CT was more accurate. CONCLUSION: For most MTC patients with occult disease, (18)F-DOPA PET/CT accurately detects metastases. In patients with an unstable calcitonin level, (18)F-DOPA PET/CT and (18)F-FDG PET/CT are complementary. For patients with an unstable CEA doubling time, (18)F-FDG PET/CT may be more feasible. MRI is sensitive but has the highest rate of false-positive results.


Assuntos
Di-Hidroxifenilalanina/análogos & derivados , Fluordesoxiglucose F18 , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Calcitonina/metabolismo , Antígeno Carcinoembrionário/metabolismo , Carcinoma Neuroendócrino , Proliferação de Células , Feminino , Seguimentos , Humanos , Antígeno Ki-67/metabolismo , Cinética , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estudos Prospectivos , Recidiva , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...