RESUMO
The treatment of choice for non-metastatic pheochromocytoma is surgical resection. Its goals are to abolish catecholamine hypersecretion, normalize blood pressure, and prevent further tumor growth or progression to metastatic disease. Data on long-term mortality and morbidity after pheochromocytoma surgery are limited. We here report a retrospective study on the long-term outcome after surgery for apparently benign pheochromocytoma at the Radboud University Nijmegen Medical Centre. Data on clinical presentation, treatment, post-surgical blood pressure and recurrence, metastasis and death were collected of 69 consecutive patients (January 1966-December 2000; follow-up: until death or January 2006). Survival was compared with survival of a matched reference population. Two patients died of surgical complications. All ten patients with metastatic disease (including three diagnosed at first surgery) died. At follow-up, 40 patients were alive and recurrence free and three patients were lost to follow up. Two patients experienced a benign recurrence. Mean+/-s.d. follow-up was 10.2+/-7.5 (median 9, range 1-38) years. Kaplan-Meier estimates for 5- and 10-year survival since surgery were 85.8% (95% CI: 77.2-94.4%) and 74.2% (95% CI: 62.0-86.4%) for patients versus 95.5 and 89.4% in the reference population (P<0.05). Sixty-four percent of all patients with hypertension prior to surgery showed a significant decrease in blood pressure, but remained hypertensive after surgery. In conclusion, compared with the general population patients have a reduced life expectancy following pheochromocytoma surgery, due to their risk of developing metastatic disease. Only one-third becomes normotensive without antihypertensive medication. Therefore, lifelong follow-up is warranted.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Neoplasias das Glândulas Suprarrenais/cirurgia , Doenças Cardiovasculares/mortalidade , Expectativa de Vida , Feocromocitoma/secundário , Feocromocitoma/cirurgia , Neoplasias das Glândulas Suprarrenais/mortalidade , Adulto , Idoso , Pressão Sanguínea , Doenças Cardiovasculares/epidemiologia , Catecolaminas/sangue , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/cirurgia , Feocromocitoma/mortalidade , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
The clinical behavior of endocrine pancreatic tumors (EPTs) is difficult to predict in the absence of metastases or invasion to adjacent organs. Several markers have been indicated as potential predictors of metastatic disease, such as tumor size > or =2 cm, Ki67 proliferative index > or =2%, cytokeratin (CK) 19 status, and recently in insulinomas, chromosomal instability (CIN). The goal of this study was to evaluate the value of these markers, and in particular of the CIN, to predict tumor recurrence or progression and tumor-specific death, using a series of 47 insulinomas and 24 non-insulinoma EPTs. From these EPT cases, a genomic profile has been generated and follow-up data have been obtained. The proliferative index has been determined in 68 tumors and a CK19 expression pattern in 50 tumors. Results are statistically analyzed using Kaplan-Meier plots and the log-rank statistic. General CIN, as well as specific chromosomal alterations such as 3p and 6q loss and 12q gain, turned out to be the most powerful indicators for poor tumor-free survival (P< or =0.0004) and tumor-specific death (P< or =0.0113) in insulinomas. The CIN, chromosome 7q gain, and a proliferative index > or =2% were reliable in predicting a poor tumor-free survival in non-insulinoma EPTs (P< or =0.0181, whereas CK19 expression was the most optimal predictor of tumor-specific death in these tumors. In conclusion, DNA copy number status is the most sensitive and efficient marker of adverse clinical outcome in insulinomas and of potential interest in non-insulinoma EPTs. As a consequence, this marker should be considered as a prognosticator to improve clinical diagnosis, most practically as a simple multi-target test.
Assuntos
DNA de Neoplasias/análise , Dosagem de Genes , Insulinoma/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Neoplasias Pancreáticas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Instabilidade Cromossômica , Cromossomos Humanos , Feminino , Seguimentos , Gastrinoma/diagnóstico , Gastrinoma/genética , Gastrinoma/mortalidade , Gastrinoma/patologia , Humanos , Insulinoma/genética , Insulinoma/mortalidade , Insulinoma/patologia , Antígeno Ki-67/análise , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Prognóstico , Sensibilidade e Especificidade , Análise de SobrevidaRESUMO
Both polyamine metabolism and DNA methylation play an important role in normal and malignant growth. Specific enzyme inhibitors or drugs that interfere with these metabolic pathways have proven to be potential anticancer agents. Since DNA methylation and polyamine metabolism depend on a common substrate, i.e. S-adenosylmethionine, interaction between both pathways can be expected. Little is known about the relationship between these pathways but studies are available indicating that polyamines and DNA methylation are directly or indirectly interconnected, metabolically as well as physiologically with respect to the regulation of cell growth, differentiation and cancer development. These considerations give rise to the possibility that, by targeting both pathways, a more profound and effective inhibitory effect on the growth of malignant cells can be achieved. In previous studies we showed that 6-MP (6-mercaptopurine) as well as MTX (methotrexate), well-known drugs in the treatment of acute lymphoblastic leukaemia, inhibit DNA methylation and induce apoptosis in malignant blood cells. Our recent results show that combined treatment with 6-MP, MTX and drugs interfering with polyamine metabolism has additive/synergistic effects on the growth, cell viability and/or apoptotic death of leukaemic cells. Such a combination therapy could have great clinical value for patients in which therapy using inhibitors of thiopurines/purine metabolism has failed.
Assuntos
Metilação de DNA , Poliaminas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Criança , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Humanos , S-Adenosilmetionina/metabolismoRESUMO
OBJECTIVE: Pheochromocytomas are uncommon tumours arising from chromaffin cells of the adrenal medulla and related paraganglia. So far, one of the few reported markers to discriminate malignant from benign tumours is the betaB-subunit of inhibin and activin, members of the transforming growth factor (TGF)-beta superfamily of growth and differentiation factors. DESIGN: We investigated the expression of the mRNAs coding for activin and inhibin subunits, their receptors and binding proteins by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and studied the presence of the inhibin betaB-subunit in human pheochromocytomas by immunohistochemistry. PATIENTS: Samples from resected pheochromocytomas of patients operated between 1973 and 2003 were used for experiments. RESULTS: The immunohistochemical investigations revealed that staining of the inhibin betaB-subunit was positive in 12 of 36 (33%) benign and 5 of 34 (15%) malignant pheochromocytomas (P > 0.05). Therefore, it was not possible to discriminate between benign and malignant tumours solely on the basis of inhibin betaB-subunit immunohistochemistry. Quantitative real-time RT-PCR in nine benign and four malignant tumours showed expression of inhibin alpha-, betaA- and betaB-subunits, the activin receptors Alk-4, ActRIIA, and ActRIIB, and the inhibin- and activin-binding proteins betaglycan and follistatin in all samples. No correlations were detected between individually coupled expression of mRNAs of these activin- and inhibin-related genes in the 13 pheochromocytomas. Only inhibin betaA-subunit expression was different in malignant compared to benign pheochromocytomas (P = 0.020). CONCLUSIONS: No clear role for activin and inhibin was found in discriminating between benign and malignant pheochromocytomas.
Assuntos
Neoplasias das Glândulas Suprarrenais/química , Biomarcadores Tumorais/análise , Subunidades beta de Inibinas/análise , Feocromocitoma/química , Receptores de Ativinas Tipo I/análise , Receptores de Ativinas Tipo I/genética , Receptores de Activinas Tipo II/análise , Receptores de Activinas Tipo II/genética , Neoplasias das Glândulas Suprarrenais/diagnóstico , Adulto , Biomarcadores Tumorais/genética , Northern Blotting/métodos , Distribuição de Qui-Quadrado , Diagnóstico Diferencial , Feminino , Folistatina/análise , Folistatina/genética , Expressão Gênica , Humanos , Imuno-Histoquímica , Subunidades beta de Inibinas/genética , Inibinas/análise , Inibinas/genética , Masculino , Pessoa de Meia-Idade , Feocromocitoma/diagnóstico , Proteoglicanas/análise , Proteoglicanas/genética , RNA Mensageiro/análise , Receptores de Fatores de Crescimento Transformadores beta/análise , Receptores de Fatores de Crescimento Transformadores beta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não ParamétricasRESUMO
Pheochromocytomas (PCCs) are neuroendocrine tumors of chromaffin tissue that produce catecholamines. They are usually located in the adrenal medulla, although in about 10% the tumors arise from extra-adrenal chromaffin tissue. The majority of PCCs arise sporadically, but PCCs occur also in the context of hereditary cancer syndromes. Familial PCC is inherited as an autosomal dominant trait alone or as a component of the multiple endocrine neoplasia Type 2 (MEN2) syndrome (RET gene), Von Hippel-Lindau (VHL) disease (VHL gene), neurofibromatosis Type 1 (NF1 gene), or familial pheochromocytoma-paraganglioma (PCC-PGL) syndrome (SDHD/B and C genes). It has been reported that 24% of apparently sporadic PCCs patients harbor germline mutations in these PCC-causing genes. We investigated the contribution of the inherited PCC-causing genes in a partly retrospectively and partly prospectively obtained series of 213 apparently sporadic PCCs. Mutation analysis was performed for RET (56 cases), VHL (136 cases), and SDHD (126 cases) and SDHB (47 cases). No germline RET mutations, six (4.4%) germline VHL mutations, two (1.5%) germline SDHD mutations, and one germline (1.6%) SDHB mutation were found. In total we found germline mutations in about 7.5% of the investigated apparently sporadic PCCs. Although 7.5% germline mutations in a series of apparently sporadic PCCs are far less than the more than 20% reported in the literature, the figure is significant enough to consider germline mutation testing for each patient with PCC.
Assuntos
Neoplasias das Glândulas Suprarrenais/genética , Feocromocitoma/genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-ret/genética , Succinato Desidrogenase/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genéticaRESUMO
Endocrine pancreatic tumors (EPTs) comprise a highly heterogeneous group of tumors with different clinical behavior and genetic makeup. Insulinomas represent the predominant syndromic subtype of EPTs. The metastatic potential of insulinomas can frequently not be predicted using histopathological criteria, and also molecular markers indicating malignant progression are unreliable because of the small number of cases per subtype studied so far. For the identification of reliable indicators of metastatic disease, we investigated 62 sporadic insulinomas (44 benign and 18 tumors with metastases) by means of comparative genomic hybridization (CGH). In addition, the role of MEN1 (multiple endocrine neoplasia type 1) gene mutations was determined to assess specific chromosomal alterations associated with dysfunction of this endocrine tumor-related tumor suppressor gene. Only one case with a somatic MEN1 mutation was identified (1527del7bp), indicating that the MEN1 gene plays a minor pathogenic role in sporadic insulinomas. CGH analysis revealed that the total number of aberrations per tumor differs strongly between the benign and the malignant group (4.2 vs 14.1; P<0.0001). Furthermore, chromosome 9q gain was found to be the most frequent aberration in both benign and malignant insulinomas, whereas chromosome 6q losses and 12q, 14q and 17pq gains are strongly associated with metastatic disease. Our study shows that chromosomal instability, as defined by > or =5 gains together with > or =5 losses, or total number of gains and losses > or =8, rather than parameters such as tumor size and proliferation index, is the most powerful indicator for the development of metastatic disease in patients with sporadic insulinoma.
Assuntos
Instabilidade Cromossômica/genética , Insulinoma/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Proteínas Proto-Oncogênicas/genética , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Insulinoma/genética , Insulinoma/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica , Hibridização de Ácido Nucleico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , PrognósticoAssuntos
Amônia/análise , Carcinoma Hepatocelular/patologia , Hidrolases/farmacologia , Neoplasias Hepáticas/patologia , Arginina/metabolismo , Carcinoma Hepatocelular/microbiologia , Meios de Cultura , Humanos , Concentração de Íons de Hidrogênio , Neoplasias Hepáticas/microbiologia , Mycoplasma/patogenicidade , Células Tumorais Cultivadas , Raios XRESUMO
A hallmark of Type 2 diabetes mellitus (T2DM) is chronic hyperglycemia, which is thought to play a role in pancreatic beta-cell failure. Here we investigated whether treatment of Zucker diabetic fatty (ZDF) rats, an animal model for T2DM, with the renal glucose transport inhibitor phlorizin could prevent alterations in the pancreatic islets. ZDF rats were treated with phlorizin or vehicle for 13 weeks starting with 6-week-old rats and before the onset of hyperglycemia. During the treatment, blood glucose levels in sham-treated ZDF rats increased rapidly from 7.7 +/- 0.3 to 24.8 +/- 0.6 mmol/l, whereas those in phlorizin-treated ZDF rats increased only slightly, but significantly, from 7.0 +/- 0.2 to 8.9 +/- 0.6 mmol/l. Phlorizin prevented the decrease in plasma insulin levels and caused a higher increase in body weight of the ZDF rats. Compared to 6-week-old untreated ZDF rats, in 19-week-old sham- and phlorizin-treated ZDF rats similar changes were found in islet architecture (more irregular boundaries and a disrupted mantle of peripheral islet cells) and in the mitochondria at the ultrastructural level (swelling of the matrix and disruption of the cristae). Using reverse transcriptase-polymerase chain reaction, no differences in mRNA expression levels were found for insulin, islet amyloid polypeptide (IAPP), and the prohormone convertase (PC) 1 and PC2 between 6-week-old untreated ZDF rats and 19-week-old sham- and phlorizin-treated ZDF rats. However, immunohistochemistry revealed similar decreases in insulin and IAPP protein expression in 19-week-old sham- and phlorizin-treated ZDF rats compared to those in 6-week-old untreated ZDF rats. These observations indicate that during aging of ZDF rats phlorizin treatment does not prevent the decreases in insulin and IAPP protein expression and the progressive histopathological changes in the pancreatic islets. Therefore, it is highly unlikely that these changes are caused by chronic hyperglycemia.
Assuntos
Envelhecimento , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Insulina/sangue , Ilhotas Pancreáticas/patologia , Obesidade , Florizina/farmacologia , Amiloide/metabolismo , Animais , Glicemia/análise , Peso Corporal , Insulina/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Masculino , Proteínas de Transporte de Monossacarídeos/antagonistas & inibidores , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos ZuckerRESUMO
The importance of polyamines in prostatic growth and differentiation has prompted studies to evaluate the clinical relevance of the ornithine decarboxylase/polyamine system in prostatic cancer. These studies show that differences in biological behaviour of prostatic (cancer) cells are associated with changes in polyamine levels and/or the activity of their metabolic enzymes. Faulty antizyme regulation of polyamine homoeostasis may play an important role in the growth and progression of prostatic carcinoma. Treatment of human prostate carcinoma cells with inhibitors of polyamine metabolic enzymes or polyamine analogues induces cell growth arrest or (apoptotic) cell death. Our recent in vitro studies using conformationally restricted polyamine analogues show that these compounds inhibit cell growth, probably by inducing antizyme-mediated degradation of ornithine decarboxylase. Sensitivity of human prostate cancer cells for these compounds was increased in the absence of androgens. These results suggest that these analogues might have chemotherapeutic potential in case prostatic cancer has become androgen-independent. Pilot data in an in vivo model show that these analogues have effects on tumour cell proliferation, vascularity, blood perfusion and tissue hypoxia. Overall, these studies show that polyamines may serve as important biomarkers of prostatic malignancy and provide a promising target for chemotherapy of prostatic cancer.
Assuntos
Poliaminas Biogênicas/fisiologia , Neoplasias da Próstata/patologia , Antineoplásicos/farmacologia , Poliaminas Biogênicas/antagonistas & inibidores , Biomarcadores Tumorais , Divisão Celular/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Humanos , Masculino , Neoplasias da Próstata/tratamento farmacológicoRESUMO
BACKGROUND: To gain further insight into the molecular cell biologic features of prostate development, we investigated the proliferative activity of prostate epithelial and stromal cells and their topographic relationship with neuroendocrine (NE) cell distribution and regional heterogeneity. METHODS: Consecutive sections from 43 prostates taken during autopsy representing fetuses (12-38 weeks of gestation), infants, prepubertal males and adults were double stained for chromogranin A and MIB-1. MIB-1 labeling index (LI) was calculated in the budding tips, forming acini, major collecting ducts, adjacent and non-adjacent stromal compartments. Furthermore, the topographic relationship between proliferating cells and NE cells was evaluated. RESULTS: In the first half of gestation, cell proliferation as revealed by MIB-1 LI was significantly higher in epithelial structures and stroma than in older fetuses and other age groups. MIB-1 LI was higher in budding tips than in other epithelial regions. MIB-1 LI in stroma adjacent to budding tips was not higher than that adjacent to other epithelial branching segments. Co-expression of chromogranin A and MIB-1 staining was not observed. MIB-1 LI was lower in cells in the direct vicinity of chromogranin A positive NE cells than at a distance from NE cells. CONCLUSIONS: Prostate development in the first half of gestation is explosive. Thereafter, the prostate basically is a slow-growing organ. Budding tips are the major growth foci during early prostate development, while stromal growth is evenly distributed throughout the prostate, probably indicating that stromal-epithelial interactions do not manifest in enhanced proliferation at their interface. NE cells may have an inhibitory effect on proliferation of exocrine epithelial cells and are probably only associated with differentiation of prostate exocrine cells in the prostate.
Assuntos
Próstata/embriologia , Próstata/crescimento & desenvolvimento , Adulto , Antígenos Nucleares , Criança , Pré-Escolar , Cromogranina A , Cromograninas/metabolismo , Desenvolvimento Embrionário e Fetal/fisiologia , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Lactente , Antígeno Ki-67 , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/metabolismo , Gravidez , Próstata/citologia , Estatísticas não Paramétricas , Células Estromais/citologia , Células Estromais/metabolismoRESUMO
Various pathologic conditions, such as hemorrhage, hemolysis and cell injury, are characterized by the release of large amounts of heme. Recently, it was demonstrated that heme oxygenase (HO), the heme-degrading enzyme, and heme are able to modulate adhesion molecule expression in vitro. In the present study, the effects of heme and HO on inflammation in mice were analyzed by monitoring the biodistribution of radiolabeled liposomes and leukocytes in conjunction with immunohistochemistry. Small liposomes accumulate in inflamed tissues by diffusion because of locally enhanced vascular permeability, whereas leukocytes actively migrate into inflammatory areas through specific adhesive interactions with the endothelium and chemotaxis. Exposure to heme resulted in a dramatic increase in liposome accumulation in the pancreas, but also intestines, liver, and spleen exhibited significantly increased vascular permeability. Similarly, intravenously administered heme caused an enhanced influx of radiolabeled leukocytes into these organs. Immunohistochemical analysis showed differential up-regulation of the adhesion molecules ICAM-1, P-selectin, and fibronectin in liver and pancreas in heme-treated animals. Heme-induced adhesive properties were accompanied by a massive influx of granulocytes into these inflamed tissues, suggesting an important contribution to the pathogenesis of inflammatory processes. Moreover, inhibition of HO activity exacerbated heme-induced granulocyte infiltration. Here it is demonstrated for the first time that heme induces increased vascular permeability, adhesion molecule expression, and leukocyte recruitment in vivo, whereas HO antagonizes heme-induced inflammation possibly through the down-modulation of adhesion molecules.
Assuntos
Heme Oxigenase (Desciclizante)/fisiologia , Heme/farmacologia , Inflamação/etiologia , Animais , Permeabilidade Capilar/efeitos dos fármacos , Moléculas de Adesão Celular/metabolismo , Quimiotaxia de Leucócito/efeitos dos fármacos , Regulação para Baixo , Heme/farmacocinética , Heme Oxigenase (Desciclizante)/imunologia , Imuno-Histoquímica , Inflamação/imunologia , Inflamação/patologia , Lipossomos , Fígado/imunologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Modelos Biológicos , Pâncreas/imunologia , Pâncreas/patologia , Distribuição TecidualRESUMO
Quality control of immunochemical and/or immunocytochemical analyses warrants constant reproducibility and reliability of assay performance. In this respect, stable reference preparations containing known quantities of the components to be assessed may serve purposes in the quality assessment of antigen expression levels, including those of the plasminogen activation system. Quality control preparations for the immunocytochemical assessment of urokinase-type plasminogen activator (uPA) were developed using different combinations of cultured cell lines (BLM and IF6), each expressing immunochemically well-defined (by enzyme-linked immunosorbent assay[ELISA]) amounts of the respective component. Cytospins and frozen sections cut from sucrose/Tissue-Tek blocks containing these cell lines demonstrated stable and homogeneous expression of uPA. An excellent correlation was found between the immunocytochemical staining results and the data obtained by ELISA. Because these cell lines are available in practically unlimited quantities, large numbers of nearly identical quality control preparations can be made over a long period of time. Therefore, the incorporation of (combinations of) cell lines in cytospins or sucrose/Tissue-Tek blocks represents a simple model system in establishing quality control preparations for immunocytochemical assessment of components of the plasminogen activator system.
Assuntos
Controle de Qualidade , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Imuno-Histoquímica , Melanoma/enzimologia , Melanoma/patologia , Reprodutibilidade dos Testes , Células Tumorais CultivadasRESUMO
Thus far, histopathological changes in the pancreatic islets of Zucker Diabetic Fatty (ZDF) rats, an animal model of type 2 diabetes mellitus (or non-insulin-dependent diabetes mellitus), have only been studied in male rats and in 18-weeks old rats or younger. In this study, we have examined in both male and female ZDF rats the histopathological changes longitudinally, from 6 to 32 weeks of age. We studied islet architecture and cellular distribution of the various islet hormones both in ZDF and control rats. In the ZDF rats, aging was initially associated with an enlargement of the islets. From 18 weeks onwards, no further enlargement was noted but islet boundaries became increasingly irregular, leading to the appearance of projections of endocrine cells into the surrounding exocrine tissue. At the islet boundaries as well as within the islets progressive fibrosis was observed with increasing amounts of collagen and reticular fibers. In the islets, staining intensity of both insulin and islet amyloid polypeptide (IAPP) increased slightly till 10 weeks of age and thereafter decreased rapidly. In contrast, the staining intensities of glucagon, somatostatin, and pancreatic polypeptide (PP) did not change. Even at the age of 32 weeks, just the beta-cells and not the other endocrine islet cells appear to be affected. In control rats, aging evoked only minor changes. Thus, we observed that during prolonged development of diabetes mellitus in both male and female ZDF rats histopathological changes in the pancreatic islets became progressively more severe, eventually leading to disintegration of the islets.
Assuntos
Diabetes Mellitus/patologia , Ilhotas Pancreáticas/patologia , Obesidade , Envelhecimento , Amiloide/análise , Animais , Colágeno/análise , Feminino , Glucagon/análise , Insulina/análise , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Ilhotas Pancreáticas/química , Masculino , Polipeptídeo Pancreático/análise , Ratos , Ratos Zucker , Somatostatina/análiseRESUMO
PURPOSE: The mechanisms that cause diabetes to impair the development of anastomotic strength in the intestine are poorly understood. We investigated whether short-term uncontrolled diabetes causes alterations in microscopic aspects of anastomoses from the ileum and colon. METHODS: Eighteen Wistar rats were rendered diabetic one week before operation by intravenous streptozotocin injection (50 mg/kg), resulting in nonfasting blood glucose levels of approximately 20 mmol/l. Another 18 age-matched rats were used as controls with a normal blood glucose range of 5 to 7 mmol/l. All rats underwent resection and anastomosis of both the ileum and colon. Animals were killed at one, three, or seven days after operation. Cellular and architectural parameters of anastomotic healing were scored in hematoxylin and eosin-stained sections. Anastomotic collagen content was analyzed by image analysis in picrosirius red-stained sections. RESULTS: Anastomotic necrosis, edema, and epithelial recovery were not affected by diabetes. In diabetic rats, the number of polymorphonuclear cells and macrophages was significantly (P = 0.025 and 0.0002, respectively) increased in ileal anastomoses one and three days after operation. In colonic anastomoses, the number of polymorphonuclear cells was increased at one (P = 0.001) and seven (P = 0.014) days after operation. Repair of the submucosal-muscular layer in colonic anastomoses from diabetic rats was impaired seven days after surgery (P = 0.0071), but in ileal anastomoses no difference was found. In the anastomotic area, collagen deposition at postoperative Days 1, 3, and 7 remained unaffected by diabetes. CONCLUSION: Experimental diabetes leads to alterations in cellular components involved in the early phase of repair of intestinal anastomoses but not to a reduced accumulation of wound collagen.
Assuntos
Anastomose Cirúrgica , Colo/cirurgia , Diabetes Mellitus Experimental/patologia , Íleo/cirurgia , Deiscência da Ferida Operatória/patologia , Cicatrização/fisiologia , Animais , Colágeno/ultraestrutura , Colo/patologia , Edema/patologia , Íleo/patologia , Contagem de Leucócitos , Linfócitos/patologia , Macrófagos/patologia , Masculino , Necrose , Neutrófilos/patologia , Ratos , Ratos WistarRESUMO
BACKGROUND: Recent studies indicate that N-terminally bis-ethylated-polyamine analogs have significant antitumor activity in several human solid-tumor models. In this study, the in vitro and in vivo antitumor potential of the polyamine analog N(1), N(11)-diethylnorspermine (DENSpm) in human prostate carcinoma cells was examined. METHODS: The antiproliferative and biochemical effects of DENSpm were tested in four human prostate cancer cell lines, i.e., PC-3, TSU-pr1, DU-145, and JCA-1. The in vivo antitumor potential was explored in two groups of nude mice bearing small or more developed xenografts of the DU-145 cell line. The mice were treated with 40 mg/kg DENSpm, three times per day for two cycles of 6 days, on days 1-6 and 8-13. RESULTS: In vitro studies showed that all four tested human prostate carcinoma cell lines were sensitive to DENSpm in micromolar concentrations. In tumor-bearing mice, DENSpm clearly prevented tumor growth in both size groups, which became significant after day 17. Treatment with DENSpm evoked intracellular accumulation of the analog and various regulatory responses, e.g., downregulation of the polyamine biosynthesis, the induction of the catabolic enzyme spermidine/spermine N(1)-acetyltransferase (SSAT), and the depletion or decrease of natural polyamines. The cellular sensitivity to growth inhibition by DENSpm only correlated with the degree of ODC inhibition and SSAT induction. CONCLUSIONS: DENSpm has sustained inhibitory effects on the growth of human prostate carcinoma cells in vitro as well in vivo. This polyamine analog may provide a new tool in the chemotherapy of prostate cancers with various phenotypes.
Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Espermina/análogos & derivados , Espermina/farmacologia , Acetiltransferases/biossíntese , Acetiltransferases/metabolismo , Animais , Antineoplásicos/metabolismo , Poliaminas Biogênicas/metabolismo , Carcinoma/enzimologia , Carcinoma/patologia , Divisão Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Indução Enzimática/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Ornitina Descarboxilase/metabolismo , Inibidores da Ornitina Descarboxilase , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia , Espermina/metabolismo , Transplante Heterólogo , Células Tumorais CultivadasRESUMO
The natural polyamines (putrescine, spermidine and spermine) are ubiquitous low-molecular aliphatic amines that play multifunctional roles in cell growth and differentiation. Recently, evidence has merging that polyamines are actively involved in cell death. Changes in polyamine homeostasis have been reported during cell death of nerve cells, in programmed cell death of embryonic cells and in various in vitro models of apoptosis. Polyamines and many of their structural analogs exert cytotoxic effects in vitro as well in vivo. Furthermore, polyamine analogs and inhibitors of the polyamine anabolic/catabolic pathways modulate processes of cell death in a cell-type specific way. Much ambiguity exists in the working mechanisms by which polyamines mediate apoptosis since they have been shown to act as promoting, modulating or protective agents in apoptosis. Nevertheless, from the studies reviewed here it can be concluded that polyamines are critically involved in cellular survival which makes them suitable targets for therapeutic intervention that is specifically directed to cell death pathways.
Assuntos
Apoptose , Poliaminas/metabolismo , Animais , Humanos , Ratos , Regulação para CimaRESUMO
To investigate whether polyamines may be valuable diagnostic and prognostic markers in prostate cancer, the presence of polyamines was studied in various human prostatic tissues using both proton magnetic resonance (MR) spectroscopy and high-pressure liquid chromatography (HPLC). The HPLC results showed that normal and benign hyperplastic prostatic tissues were characterized by a high content of spermine. Spermine levels were reduced in tumor tissue, especially in prostatic carcinoma with metastases, and in xenografts of human prostatic carcinoma cells. These preliminary results indicate that spermine may be used as a biomarker for malignant behavior. The MR spectroscopy study showed that it is possible to detect spermine resonances in prostatic biopsy material by one-dimensional and two-dimensional J-resolved MR spectroscopy at high field (600 MHz). Localized one-dimensional in vitro MR spectra obtained at the clinical field strength of 1.5 T showed spermine signals in the region between 3.0 and 3.3 ppm. In in vivo MR spectra of the human prostate, however, these signals were obscured by resonances of choline (3.2 ppm) and creatine (3.0 ppm).
Assuntos
Biomarcadores Tumorais/análise , Espectroscopia de Ressonância Magnética/métodos , Próstata/química , Neoplasias da Próstata/química , Espermina/análise , Cromatografia Líquida de Alta Pressão , Humanos , Masculino , Prognóstico , Hiperplasia Prostática/metabolismo , Neoplasias da Próstata/diagnóstico , Células Tumorais CultivadasRESUMO
PURPOSE: After acute arterial obstruction of the lower extremity, muscle damage is the critical determinant for clinical outcome. The extent of muscle damage and limb viability are currently assessed by clinical examination, which is inaccurate. Tc-99m-pyrophosphate (PYP) has been applied for imaging ischaemia-reperfusion damage. More recently, a new imaging agent, Tc-99m-glucarate (GLUC), was introduced for delineating early myocardial infarction after ischaemia-reperfusion. The aim of this study was to determine if GLUC could delineate early skeletal muscle damage after ischaemia-reperfusion. Both tracers were used in a novel murine model of hindlimb ischaemia-reperfusion. METHODS: In anaesthetised mice, ischaemia of one hindlimb was maintained for 2, 3 and 4h using a tourniquet, followed by a reperfusion period of 1h. Additionally, reperfusion periods of 3, 24 and 96h were studied after 3h of ischaemia. PYP or GLUC was injected 45min before end of reperfusion. Concentrations of both agents were determined in blood, reperfused and contralateral muscle. Reperfused-to-contralateral muscle ratios were calculated. In separate experiments, muscle biopsies were obtained for histologic examination. RESULTS: Ischaemia and reperfusion damage was demonstrated histologically. Using scintigraphy GLUC depicted reperfusion significantly better than PYP. After 2, 3 and 4h of ischaemia, the reperfused-to-contralateral ratios for GLUC were 10.7+/-0.9, 8.9+/-0.9 and 8.6+/-1.1, as compared to 4.5+/-0.7, 4.9+/-0.4 and 4.5+/-0.4 for PYP (P<0.05 at all points). For longer periods of reperfusion, the ratios for GLUC decreased to similar levels as observed for PYP. CONCLUSION: The present study indicates that GLUC is a specific early marker of myocyte necrosis after ischaemia-reperfusion. GLUC may become an useful agent for clinical, early, non-invasive monitoring of skeletal muscle damage after ischaemia-reperfusion.
Assuntos
Ácido Glucárico/análogos & derivados , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/patologia , Compostos de Organotecnécio , Compostos Radiofarmacêuticos , Traumatismo por Reperfusão/diagnóstico por imagem , Traumatismo por Reperfusão/patologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Necrose , CintilografiaRESUMO
BACKGROUND: Knowledge concerning differentiation of neuroendocrine (NE) cells during development of the human prostate is rather fragmentary. Using immunohistochemistry combined with a morphometric method, we investigated the distribution and density of NE cells in the developing human prostate, with special emphasis on the topographical relationship of NE cells with the developing gland. METHODS: Consecutive sections from a total of 42 human prostates taken during autopsy of fetuses (12-38 weeks of gestation), prepubertal males, and young adults were immunostained for chromogranin A and serotonin. Computer-assisted image analysis was used to assess the total number of cells in the different parts of the branching glandular anlage, i.e., budding tips and acini/ducts. Next, the number of NE cells was counted manually. The NE cell density (NE cell index) was then determined. RESULTS: NE cells could first be detected in the prostate from 13 weeks of gestation. By 21 weeks of gestation, all prostates contained NE cells. NE cells were mainly confined to the acinous/ductal regions, while most of the budding tips lacked NE staining. NE cell indexes of individuals were highly variable, mostly in the youngest age group. CONCLUSIONS: In the normal prostate, NE cell density probably remains constant in acini/ducts from fetuses to young adulthood. The presence of neuroendocrine cells in well-developed glandular structures at such an early fetal age and their absence in the less differentiated budding tips possibly indicates that differentiation of NE cells is associated with glandular maturation. NE cells occur preferentially in the acinous/ductal region, implying a paracrine function during secretory differentiation of exocrine epithelial cells.
Assuntos
Diferenciação Celular , Desenvolvimento Embrionário e Fetal , Sistemas Neurossecretores/citologia , Próstata/citologia , Adolescente , Adulto , Contagem de Células , Criança , Humanos , Lactente , Recém-Nascido , Masculino , Próstata/embriologia , Próstata/crescimento & desenvolvimento , Hiperplasia Prostática/fisiopatologiaRESUMO
Ornithine decarboxylase (ODC), a regulatory enzyme of polyamine biosynthesis, is involved in cell growth and differentiation. Lack of information about the exact cellular and subcellular localization of ODC is one of the main obstacles to precise interpretation of the biological roles of the ODC/polyamine system. Here we describe the development and optimization of an immunocytochemical method to detect ODC in cells and tissues. For this purpose a monoclonal antibody (MP16-2) against a defined epitope of ODC protein was developed. Specificity of the antibody for ODC was substantiated by Western blotting and ELISA analysis using cell and tissue homogenates. In cultured cells, optimal staining results were obtained after fixation with crosslinking fixatives followed by permeabilization with methanol. In rat tissues, ODC immunoreactivity was best preserved in paraffin sections fixed with Bouin's fixative. Antigen retrieval using SDS and citrate buffer substantially increased ODC immunostaining and decreased background staining. Localization studies of ODC in different cell lines showed that strongest staining for ODC was found in the nucleoplasm of mitotic cells, whereas confluent cells showed moderate perinuclear staining. Immunocytochemical studies of various rat tissues showed high cytoplasmic immunostaining of ODC in epithelial cells of kidney, prostate, and adrenal medulla of testosterone-treated rats, in glandular epithelium of small intestine, and in pancreas of neonatal and adult rats. (J Histochem Cytochem 47:1395-1404, 1999)