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1.
Inflamm Intest Dis ; 6(1): 48-60, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33850839

RESUMO

INTRODUCTION: Infliximab (IFX) therapy is efficacious for inducing and maintaining symptomatic remission in patients with Crohn's disease (CD), but whether this benefit results in reduced hospitalization rates and therefore may improve patients' quality of life in an economically sensible way is conflicting so far. METHODS: We conducted a noninterventional, multicenter, open-label, prospective study to evaluate the effect of originator IFX treatment on patient-reported outcomes and disease-related hospitalizations in adult CD patients in Germany treated for the first time with IFX according to label. RESULTS: Two hundred and ninety-four patients were included in the study. We observed a statistically significant reduction in the number of CD-related hospitalizations from the year before baseline (mean 1.00 per patient, SD ± 0.93) to the mean value of the 1st (0.62, SD ± 0.95) and 2nd year (0.32, SD ± 0.75) of the observation period (p < 0.0001). After 3 months of IFX therapy, work productivity and activity increased by an average of 12.6 and 17.1%, respectively. Patient's clinical outcome was markedly improved as the total CD activity index (CDAI) sum score continuously decreased from baseline to month 24 and the mean score of the total inflammatory bowel disease questionnaire (IBDQ) changed substantially from 141 at baseline to 172 after 24 months of IFX treatment. Additionally, the number of work incapacity days declined. Recently, no new safety issues of IFX have been identified. CONCLUSION: In this large, prospective, multicenter study on disease-related hospitalization rates, work productivity, capacity for daily activities, and HRQoL in patients with CD, IFX significantly reduces their hospitalization rates and improves work productivity, daily activity, and quality of life over 24 months.

2.
Endoscopy ; 50(9): 878-885, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30036893

RESUMO

BACKGROUND: Previous studies have shown that multiple colonoscope features have to be changed before an improvement in adenoma detection rate (ADR) becomes obvious, such as with changing from one instrument generation to the next but one. We wanted to evaluate whether such an effect can also be observed in a private-practice screening setting. METHODS: In a randomized study, we compared the latest generation colonoscopes from one company (Olympus Exera III, 190) with the next to last one (Olympus 165), including only patients presenting for screening colonoscopy. The primary outcome was ADR achieved with 190 colonoscopes (190-C) in comparison with 165 colonoscopes (165-C). RESULTS: 1221 patients (46.1 % men; mean age 62.2 years, standard deviation 6.6) were included (599 screened with the Olympus Exera III, 190). The ADR difference in favor of the 190-C instrument (32 % [95 % confidence interval (CI) 26 % to 39 %] vs. 28 % [95 %CI 22 % to 34 %] in the 165-C group) failed to reach statistical significance (P = 0.10); only the rate of small (< 5 mm) adenomas was significantly increased at 22.5 % (95 %CI 19 % to 26 %) vs. 15.6 % (95 %CI 13 % to 18 %; P = 0.002). Furthermore, significantly more adenomas were found in the 190-C group, with an adenoma rate (all adenomas/all patients) of 0.57 (95 %CI 0.53 to 0.61) vs. 0.47 (95 %CI 0.43 to 0.51; P < 0.001). CONCLUSIONS: This randomized comparative trial in a private-practice screening setting only partially confirmed the results of prior studies that, with multiple imaging improvements achieved over two instrument generations, an increase in overall adenoma number becomes measurable.


Assuntos
Adenoma/diagnóstico , Colonoscópios/normas , Colonoscopia , Neoplasias Colorretais/diagnóstico , Desenho de Equipamento , Teste de Materiais , Adenoma/patologia , Idoso , Colonoscopia/instrumentação , Colonoscopia/métodos , Neoplasias Colorretais/patologia , Feminino , Alemanha , Humanos , Masculino , Programas de Rastreamento/instrumentação , Programas de Rastreamento/métodos , Teste de Materiais/métodos , Teste de Materiais/estatística & dados numéricos , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Melhoria de Qualidade
3.
Endosc Int Open ; 5(4): E282-E290, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28393103

RESUMO

Background and study aims The success of any colonoscopy procedure depends upon the quality of bowel preparation. We evaluated the efficacy and safety of a new tailored dosing (TD) regimen compared with the approved PICOPREP day-before dosing regimen (DBD) in the European Union. Patient and methods Patients (≥ 18 years) undergoing colonoscopy were randomised (2:1) to TD (Dose 1, 10 - 18 hours; Dose 2, 4 - 6 hours before colonoscopy) or DBD (Dose 1 before 8:00AM on the day before colonoscopy; Dose 2, 6 - 8 hours after Dose 1). The primary endpoint of overall colon cleansing efficacy was based on total Ottawa Scale (OS) scores (0 - 14, excellent-worst). The key secondary endpoint was a binary endpoint based on the ascending colon OS (success 0 or 1, failure [≥ 2]). Convenience and satisfaction were evaluated similar to the primary and key secondary endpoints. Safety and tolerability were also evaluated. Results Use of the PICOPREP TD regimen resulted in a statistically significant reduction in the mean total Ottawa Scale score compared to the PICOPREP DBD regimen (-3.93, 95 % confidence intervals [CI]: - 4.99, - 2.97; P < 0.0001) in the intent-to-treat analysis set. The PICOPREP TD regimen also resulted in a statistically significant increase in the odds of achieving an ascending colon OS score ≤ 1, compared to the PICOPREP DBD regimen (estimated odds ratio 9.18, 95 % CI: 4.36, 19.32; P < 0.0001). There was no statistically significant difference in the overall rate of treatment-emergent adverse events (12 % (TD) and 5.7 % (DBD), respectively, P = 0.2988). The convenience and satisfaction were comparable in the two groups. Conclusion The TD regimen was superior to the DBD regimen for overall and ascending colon cleansing efficacy. ClinicalTrials.gov Identifier: NCT02239692.

4.
Clin Cancer Res ; 18(17): 4621-32, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22753592

RESUMO

PURPOSE: Aurora kinases play a crucial role in cell-cycle control. Uncontrolled expression of aurora kinases causes aneuploidy and tumor growth. As conservative treatment options for advanced gastroenteropancreatic neuroendocrine tumors (GEP-NET) are disappointing, aurora kinases may be an interesting target for novel therapeutic strategies. EXPERIMENTAL DESIGN: Human GEP-NETs were tested for aurora kinase expression. The efficacy of the new aurora kinase inhibitor danusertib was evaluated in two human GEP-NET cell lines (BON1 and QGP) in vitro and in vivo. RESULTS: The majority of ten insulinomas and all 33 nonfunctional pancreatic or midgut GEP-NETs expressed aurora A despite a mostly high degree of cell differentiation. Both human GEP-NET cell lines expressed aurora kinase A and B, and high Ser10 phosphorylation of histone H3 revealed increased aurora B activity. Remarkably, danusertib led to cell-cycle arrest and completely inhibited cell proliferation of the GEP-NET cells in vitro. Decreased phosphorylation of histone H3 indicated effective aurora B inhibition. In a subcutaneous murine xenograft model, danusertib significantly reduced tumor growth in vivo compared with controls or mice treated with streptozotocine/5-fluorouracil. As a consequence, decreased levels of tumor marker chromogranin A were found in mouse serum samples. In a newly developed orthotopic model for GEP-NET liver metastases by intrasplenic tumor cell transplantation, dynamic MRI proved significant growth inhibition of BON1- and QGP-derived liver metastases. CONCLUSIONS: These results show that danusertib may impose a new therapeutic strategy for aurora kinase expressing metastasized GEP-NETs.


Assuntos
Benzamidas/administração & dosagem , Neoplasias Gastrointestinais , Neoplasias Hepáticas/tratamento farmacológico , Proteínas Serina-Treonina Quinases , Pirazóis/administração & dosagem , Animais , Aurora Quinase A , Aurora Quinase B , Aurora Quinases , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromogranina A/sangue , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/metabolismo , Neoplasias Gastrointestinais/patologia , Histonas/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Camundongos , Terapia de Alvo Molecular , Tumores Neuroendócrinos/tratamento farmacológico , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Transplante Heterólogo
5.
J Biol Chem ; 285(50): 38905-14, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20843811

RESUMO

The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-ß-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-ß, both CCK and gastrin inhibit proliferation in PSC.


Assuntos
Colágeno/biossíntese , Regulação da Expressão Gênica , Pâncreas/metabolismo , Células Estreladas do Pâncreas/metabolismo , Receptor de Colecistocinina B/biossíntese , Receptores da Colecistocinina/biossíntese , Animais , Butadienos/farmacologia , Colágeno Tipo I/metabolismo , Inibidores Enzimáticos/farmacologia , Gastrinas/metabolismo , Masculino , Nitrilas/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
6.
J Clin Oncol ; 27(28): 4656-63, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19704057

RESUMO

PURPOSE: Somatostatin analogs are indicated for symptom control in patients with gastroenteropancreatic neuroendocrine tumors (NETs). The ability of somatostatin analogs to control the growth of well-differentiated metastatic NETs is a matter of debate. We performed a placebo-controlled, double-blind, phase IIIB study in patients with well-differentiated metastatic midgut NETs. The hypothesis was that octreotide LAR prolongs time to tumor progression and survival. PATIENTS AND METHODS: Treatment-naive patients were randomly assigned to either placebo or octreotide LAR 30 mg intramuscularly in monthly intervals until tumor progression or death. The primary efficacy end point was time to tumor progression. Secondary end points were survival time and tumor response. This report is based on 67 tumor progressions and 16 observed deaths in 85 patients at the time of the planned interim analysis. RESULTS: Median time to tumor progression in the octreotide LAR and placebo groups was 14.3 and 6 months, respectively (hazard ratio [HR] = 0.34; 95% CI, 0.20 to 0.59; P = .000072). After 6 months of treatment, stable disease was observed in 66.7% of patients in the octreotide LAR group and 37.2% of patients in the placebo group. Functionally active and inactive tumors responded similarly. The most favorable effect was observed in patients with low hepatic tumor load and resected primary tumor. Seven and nine deaths were observed in the octreotide LAR and placebo groups, respectively. The HR for overall survival was 0.81 (95% CI, 0.30 to 2.18). CONCLUSION: Octreotide LAR significantly lengthens time to tumor progression compared with placebo in patients with functionally active and inactive metastatic midgut NETs. Because of the low number of observed deaths, survival analysis was not confirmatory.


Assuntos
Neoplasias Intestinais/tratamento farmacológico , Tumores Neuroendócrinos/tratamento farmacológico , Octreotida/uso terapêutico , Dor Abdominal/induzido quimicamente , Antineoplásicos Hormonais/efeitos adversos , Antineoplásicos Hormonais/uso terapêutico , Diarreia/induzido quimicamente , Método Duplo-Cego , Feminino , Humanos , Neoplasias Intestinais/metabolismo , Neoplasias Intestinais/patologia , Avaliação de Estado de Karnofsky , Antígeno Ki-67/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/patologia , Octreotida/efeitos adversos , Placebos , Prognóstico , Estudos Prospectivos , Qualidade de Vida , Análise de Sobrevida , Resultado do Tratamento
7.
Clin Gastroenterol Hepatol ; 7(11): 1241-6, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19560556

RESUMO

BACKGROUND & AIMS: Although chronic pancreatitis and liver cirrhosis are common sequelae of excess alcohol consumption, the 2 conditions are rarely associated. We studied the prevalence of simultaneous liver cirrhosis and chronic pancreatitis in alcoholics. METHODS: Postmortem autopsy data from 620 individuals with a history of excess alcohol consumption and 100 nonalcoholics (controls) were analyzed. The individuals were classified into groups based on macroscopic observations of pancreas (no injury, acute pancreatitis, fibrosis, and chronic pancreatitis) and liver (no injury, moderate steatosis, severe steatosis, and cirrhosis). The same classification system was used for histological data, which was used to confirm and correlate macroscopic results. RESULTS: Out of the 183 patients with liver cirrhosis, 33 (18%) had chronic pancreatitis and 93 (51%) had pancreatic fibrosis. Out of the 230 patients with severe steatosis, 37 (16%) had chronic pancreatitis and 97 (42%) were found to have a pancreatic fibrosis. Thirty-three (39%) with chronic pancreatitis also showed liver cirrhosis and 37 (44%) showed severe steatosis. Thirty-eight percent of the patients with a pancreatic fibrosis were found also to have liver cirrhosis and in another 40% severe steatosis. Thirty-five patients showed neither hepatic or pancreatic injury. We found no chronic pancreatitis or liver cirrhosis in the control group (n = 100). CONCLUSIONS: Contrary to common belief there is a close association between pancreatic and hepatic injury in patients with increased alcohol consumption, and the degree of organ damage between the 2 organs correlate.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Álcoois/toxicidade , Cirrose Hepática/epidemiologia , Fígado/efeitos dos fármacos , Pâncreas/efeitos dos fármacos , Pancreatite Alcoólica/epidemiologia , Comorbidade , Feminino , Histocitoquímica , Humanos , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Pâncreas/patologia , Pancreatite Alcoólica/induzido quimicamente , Pancreatite Alcoólica/patologia , Prevalência , Índice de Gravidade de Doença
9.
J Hepatol ; 41(1): 112-8, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15246216

RESUMO

BACKGROUND/AIMS: Somatostatin analogues inhibit cell proliferation by stimulation of distinct somatostatin receptor (SSTR) subtypes. In recent years, these compounds have been introduced into the therapy of advanced hepatocellular carcinoma (HCC). The efficacy of this treatment is under debate due to the controversial results of clinical trials. Despite the widespread clinical use of somatostatin analogues in HCC, little is known about the expression of each of the five SSTRs in these tumors. METHODS: We analyzed the expression of SSTR subtypes in 56 HCCs by immunohistochemistry using subtype-specific antibodies. Six of the samples were also investigated by RT-PCR using subtype-specific oligonucleotide primers. RESULTS: HCCs display differential, individual expression patterns as well as variable expression levels for SSTRs. The overall expression rate of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 is 46, 41, 64, 0, and 75%, respectively. No significant correlation was observed between SSTR expression and tumor stage, differentiation, histological tumor type, or underlying liver disease. CONCLUSIONS: Individual patterns and levels of SSTR expression might determine the response to treatment with somatostatin analogues in HCC. Selective treatment of these tumors based on the analysis of SSTR subtype expression might lead to an increase in response rates.


Assuntos
Carcinoma Hepatocelular/fisiopatologia , Neoplasias Hepáticas/fisiopatologia , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Criança , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Lactente , Fígado/patologia , Fígado/fisiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proteínas de Membrana , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Regul Pept ; 118(1-2): 111-7, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-14759564

RESUMO

Gastrin-induced release of calcitonin from medullary thyroid carcinomas (MTC) is based on the expression of the cholecystokinin(2)-receptor (CCK(2)R) in these tumors. Recently, we have shown that the CCK(2)R is expressed not only in MTC but also in C-cells within the normal thyroid gland. The functions of the CCK(2)R in MTC and C-cells are largely unknown. We therefore explored the effects of gastrin-induced CCK(2)R stimulation in the highly differentiated MTC cell line, TT. CCK(2)R expression in TT-cells is detectable by RT-PCR as well as immunocytochemistry. Stimulation of the CCK(2)R by gastrin induces immediate release of calcitonin from TT-cells. Moreover, quantitative (LightCycler) RT-PCR demonstrates that gastrin stimulates transcription of the calcitonin and chromogranin A genes in TT-cells. TT-cell proliferation, assessed by counting of viable cells and (3)H-thymidine uptake, is markedly increased by gastrin. This effect is inhibited by the CCK(2)R-specific antagonist L-365,260. Our findings suggest physiological functions for the CCK(2)R in calcitonin-secretion and gene expression as well as a pathophysiological role in MTC proliferation. CCK(2)R antagonists might have therapeutic potential in these tumors.


Assuntos
Calcitonina/metabolismo , Carcinoma Medular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Receptor de Colecistocinina B/fisiologia , Neoplasias da Glândula Tireoide/metabolismo , Calcitonina/genética , Carcinoma Medular/genética , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Linhagem Celular Tumoral , Cromogranina A , Cromograninas/genética , Cromograninas/metabolismo , Gastrinas/farmacologia , Humanos , Receptor de Colecistocinina B/efeitos dos fármacos , Receptor de Colecistocinina B/genética , Neoplasias da Glândula Tireoide/genética , Fatores de Tempo
11.
Mol Pharmacol ; 65(3): 753-60, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14978254

RESUMO

It has been proposed that mutations that induce constitutive activity in G-protein-coupled receptors (GPCRs) concomitantly enhance the ability of partial agonists to trigger second-messenger signaling. Using the cholecystokinin type 2 receptor (CCK-2R) as a model system, we have explored whether this association applies to a diverse set of activating mutations. Consistent with established principles, constitutively active CCK-2Rs resulting from amino acid substitutions within the third intracellular loop each systematically increased partial agonist activities versus corresponding wild-type values. In contrast, activating mutations within transmembrane domain segments near the extracellular loops led to an increase in efficacy of only a subset of compounds but decreased or did not change the function of others. When transmembrane domain amino acid substitutions were introduced in combination with intracellular amplifying mutations, observed changes in ligand activity were defined by the product of two discernible factors 1) systematic amplification caused by an equilibrium shift from the inactive to the active receptor conformation and 2) ligand-specific alterations in signaling, which probably result from mutation-induced changes in the putative binding pocket. These findings illustrate functional heterogeneity among GPCR mutants with ligand-independent signaling. A subgroup of activating mutations facilitates receptor isomerization to the active state and in parallel perturbs ligand receptor interactions. These mutants do not adhere to the previously proposed "hallmark criteria" of constitutive activity.


Assuntos
Receptor de Colecistocinina B/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/fisiologia , Animais , Células COS , Ligantes , Mutação , Receptor de Colecistocinina B/genética , Receptores Acoplados a Proteínas G/genética
12.
J Mol Neurosci ; 20(2): 115-24, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12794305

RESUMO

The Cholecystokinin type 1 and type 2 receptors (CCK-1R and CCK-2R) share >50% amino acid identity, as well as subnanomolar affinity for the endogenous peptide cholecystokinin octapeptide (CCK-8). Although it is likely that these two receptor subtypes share amino acids that confer CCK-8 affinity, it has been difficult to identify such residues. We have examined the role of several transmembrane domain (TMD) IV residues that are common to both CCK receptor subtypes. In both the CCK-1R and CCK-2R, we demonstrate that alanine substitution of two TMD IV residues, which are highly conserved among all known CCK receptor subtypes and species homologs, significantly decrease CCK-8 affinity. Despite the observed decrease in peptide binding, the mutant receptors maintain close to wild-type affinity for the respective subtype selective nonpeptide ligands, 3H-labeled L-364,714 (CCK-1R) and 3H-labeled L-365,260 (CCK-2R), suggesting conserved tertiary structure of these mutants. Assessment of CCK-8-induced inositol phosphate production at each of the mutant CCK receptors revealed normal peptide efficacy. In contrast, peptide potencies are reduced in parallel with the observed decreases in affinity. Taken together, these findings suggest that important peptide affinity determinants are localized on TMD IV, a region that has not previously been considered a major contributor to ligand affinity in either CCK receptors or other G protein-coupled peptide receptors.


Assuntos
Membrana Celular/metabolismo , Células Eucarióticas/metabolismo , Receptores da Colecistocinina/química , Alanina/genética , Alanina/metabolismo , Sequência de Aminoácidos/genética , Animais , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/genética , Ligação Competitiva/efeitos dos fármacos , Ligação Competitiva/genética , Células COS , Membrana Celular/genética , Evolução Molecular , Humanos , Mutação/genética , Estrutura Terciária de Proteína/genética , Ensaio Radioligante , Receptor de Colecistocinina A , Receptor de Colecistocinina B , Receptores da Colecistocinina/genética , Sincalida/metabolismo , Sincalida/farmacologia , Trítio
13.
Eur J Endocrinol ; 146(1): 89-96, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11751073

RESUMO

OBJECTIVE: The cholecystokinin(2)-receptor (CCK(2)R) promotes secretion and cell growth induced by its ligands cholecystokinin (CCK) and gastrin. The receptor has recently been shown to be expressed in human medullary thyroid carcinomas (MTCs). The objective of this study was to analyze CCK(2)R expression in MTC samples of different tumor stages as well as in non-malignant thyroid tissues. DESIGN AND METHODS: Using RT-PCR we investigated 19 MTC samples and TT-cells (a human MTC cell line), as well as samples of normal thyroid. In addition, we performed immunohistochemistry using calcitonin- and CCK(2)R-specific antibodies on MTCs and samples of C-cell hyperplasia. RESULTS: We demonstrate for the first time that CCK(2)R is expressed not only in MTCs but in all samples of normal thyroid tissue. Using immunohistochemistry the receptor could be localized on calcitonin-secreting C-cells. The highest incidence of CCK(2)R expression in MTCs was observed in early-tumor stages, whereas CCK(2)R could not be detected in advanced or metastasized tumors. CONCLUSIONS: The expression of CCK(2)R in C-cells suggests a physiological function for gastrin and/or CCK in the regulation of calcitonin release, presumably related to bone and calcium metabolism. Moreover, these ligands might act as growth factors in MTCs. Efforts in the development of CCK(2)R scintigraphy for the detection of MTC lesions might have to consider a lower incidence of the receptor in advanced tumor stages.


Assuntos
Carcinoma Medular/metabolismo , Receptores da Colecistocinina/biossíntese , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Adolescente , Adulto , Idoso , Comunicação Autócrina/fisiologia , Carcinoma Medular/patologia , Colecistocinina/metabolismo , Feminino , Gastrinas/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mutação/genética , Oncogenes/genética , Pentagastrina , Receptor de Colecistocinina B , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estimulação Química , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia
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