RESUMO
BACKGROUND: Breakdown of the intestinal barrier is a driving force of sepsis and multiple organ failure. Radical scavengers or cytokine inhibitors may have a therapeutic impact on intestinal failure. Therapeutic effects on different sites of small intestine and colon have not been compared. Therefore, we investigated time-dependent intestinal permeability changes and their therapeutic inhibition in colon and small intestine with an ex vivo model. METHODS: Male Sprague-Dawley rats were either pretreated for 24 h with lipopolysaccharide (LPS) intraperitoneally alone or in combination with a radical scavenger (pyruvate or Tempol) or a cytokine inhibitor (parecoxib or vasoactive intestinal peptide). The gastrointestinal permeability was measured by time-dependent fluorescein isothiocyanate inulin diffusion using washed and everted tube-like gut segments. Blood and tissue samples were taken to investigate the development of inflammatory cytokine level (interleukin 6) in the context of cytokine inhibition and reactive oxygen species level via nicotinamide adenine dinucleotide phosphate oxidase activity in radical scavenger groups. RESULTS: After LPS treatment, mucosal permeability was enhanced up to 170% in small intestine and colon. In the small intestine the most significant reduction in permeability was found for pyruvate and parecoxib. Treatment with vasoactive intestinal peptide and parecoxib resulted in the most pronounced reduction of permeability in the colon. CONCLUSIONS: Our data suggest that cytokine inhibitors and radical scavengers have pronounced effects in LPS-induced disrupted intestinal barrier of the colon and small intestine. Our novel model comparing different anatomic sites and different points in time after the onset of sepsis may contribute to gain new insight into mechanisms and treatment options of sepsis-related gut mucosal breakdown.
Assuntos
Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Sequestradores de Radicais Livres/uso terapêutico , Mucosa Intestinal/efeitos dos fármacos , Insuficiência de Múltiplos Órgãos/prevenção & controle , Peptídeo Intestinal Vasoativo/uso terapêutico , Animais , Óxidos N-Cíclicos/farmacologia , Óxidos N-Cíclicos/uso terapêutico , Inibidores de Ciclo-Oxigenase 2/farmacologia , Avaliação Pré-Clínica de Medicamentos , Sequestradores de Radicais Livres/farmacologia , Interleucina-6/sangue , Isoxazóis/farmacologia , Isoxazóis/uso terapêutico , Lipopolissacarídeos , Masculino , Insuficiência de Múltiplos Órgãos/etiologia , NADPH Oxidases/metabolismo , Neutrófilos/enzimologia , Permeabilidade/efeitos dos fármacos , Ácido Pirúvico/farmacologia , Ácido Pirúvico/uso terapêutico , Ratos Sprague-Dawley , Sepse/complicações , Marcadores de Spin , Peptídeo Intestinal Vasoativo/farmacologiaRESUMO
BACKGROUND: The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2. METHODS: This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy. FINDINGS: 1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent. INTERPRETATION: The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.
Assuntos
Neoplasias das Glândulas Suprarrenais/cirurgia , Neoplasia Endócrina Múltipla Tipo 2a/complicações , Neoplasia Endócrina Múltipla Tipo 2a/cirurgia , Feocromocitoma/cirurgia , Adolescente , Neoplasias das Glândulas Suprarrenais/etiologia , Neoplasias das Glândulas Suprarrenais/mortalidade , Adrenalectomia/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasia Endócrina Múltipla Tipo 2a/mortalidade , Feocromocitoma/etiologia , Feocromocitoma/mortalidade , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
Although the authors of the present review have contributed to genetic discoveries in the field of pheochromocytoma research, we can legitimately ask whether these advances have led to improvements in the diagnosis and management of patients with pheochromocytoma. The answer to this question is an emphatic Yes! In the field of molecular genetics, the well-established axiom that familial (genetic) pheochromocytoma represents 10% of all cases has been overturned, with >35% of cases now attributable to germline disease-causing mutations. Furthermore, genetic pheochromocytoma can now be grouped into five different clinical presentation types in the context of the ten known susceptibility genes for pheochromocytoma-associated syndromes. We now have the tools to diagnose patients with genetic pheochromocytoma, identify germline mutation carriers and to offer gene-informed medical management including enhanced surveillance and prevention. Clinically, we now treat an entire family of tumors of the paraganglia, with the exact phenotype varying by specific gene. In terms of detection and classification, simultaneous advances in biochemical detection and imaging localization have taken place, and the histopathology of the paraganglioma tumor family has been revised by immunohistochemical-genetic classification by gene-specific antibody immunohistochemistry. Treatment options have also been substantially enriched by the application of minimally invasive and adrenal-sparing surgery. Finally and most importantly, it is now widely recognized that patients with genetic pheochromocytoma/paraganglioma syndromes should be treated in specialized centers dedicated to the diagnosis, treatment and surveillance of this rare neoplasm.
Assuntos
Neoplasias das Glândulas Endócrinas/genética , Feocromocitoma/genética , Neoplasias das Glândulas Endócrinas/diagnóstico , Neoplasias das Glândulas Endócrinas/terapia , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Neurofibromatose 1/genética , Paraganglioma/genética , Feocromocitoma/diagnóstico , Feocromocitoma/terapia , Medicina de Precisão , Síndrome , Doença de von Hippel-Lindau/genéticaRESUMO
BACKGROUND: It is of crucial importance to explore new therapeutic strategies capable of combating or even preventing pancreatic graft failure after transplantation caused by ischemia reperfusion damage. So far, the role of the hypoxia induced mediator vascular endothelial growth factor (VEGF) upon pancreatic microcirculation has not been described. Therefore the aim of this study was to investigate its influence, using the novel tyrosinekinase inhibitor PTK787/ZK222584 (PTK/ZK), upon functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and macromolecular permeability (P) of normal and postischemic pancreas tissue. METHODS: Sprague-Dawley rats were anesthetized and randomly assigned to five groups (n=7/group): (a) sham, (b) ischemia/reperfusion (I/R) control, (c) I/R and PTK/ZK treatment, (d) VEGF-superfusion, (e) VEGF-superfusion and PTK/ZK-treatment. A recently established method of digital dynamic intravital epifluorescence microscopy was used for evaluating the effective microvascular permeability together with FCD and LEI. RESULTS: Comparison between sham vs. I/R shows a significant upregulation of VEGF-expression followed by deterioration of microcirculation with decreased FCD, increased P and LEI. Treatment with PTK/ZK resulted in a significant decrease of P under conditions of superfusion with VEGF as well as I/R compared to corresponding groups without treatment. CONCLUSION: VEGF plays a crucial causative role involving an increase in permeability in normal as well as in postischemic pancreatitis via tyrosinkinase receptors. VEGF seems to be partly accountable for a deterioration of FCD and an upregulation of LEI via VEGF-tyrosinekinase receptor independent mechanisms. VEGF might be a promising potential therapeutic target in order to minimize edema formation caused by I/R and pancreatitis in pancreas transplantation.
Assuntos
Pâncreas/irrigação sanguínea , Traumatismo por Reperfusão/terapia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Animais , Permeabilidade Capilar , Edema/etiologia , Ensaio de Imunoadsorção Enzimática , Leucócitos/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/fisiopatologia , Fator A de Crescimento do Endotélio Vascular/análise , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal-dominant hereditary disorder associated with the development of endocrine tumors due to reduced expression of the tumor suppressor protein menin. Recent studies indicate a general role of menin in carcinogenesis, affecting the prevalence and clinical course of common non-endocrine tumors such as breast cancer, hepatocellular carcinoma and melanoma. Here we report a new germline missense mutation of Men1 in a German family with atypical tumor phenotype over three generations. Based on the type of mutation, we discuss possible changes in menin function leading to atypical tumorigenesis and present the clinical significance of such findings. CASE PRESENTATION: A German family with a history of primary hyperparathyroidism presented to our Hospital for further evaluation. Members of the family demonstrated many different atypical tumors, such as renal cell carcinoma, papillary thyroid cancer and prostate cancer. DNA sequencing from peripheral blood revealed a novel mutation: Ser38Cys [TCC>TGC] in exon 2, codon 38 of Men1. This novel mutation is located in a region of menin which is responsible for interactions with the transcription factor JunD. This factor has recently been associated with prostate cancer. DNA sequencing of two of the atypical tumors (prostate cancer, papillary thyroid cancer) did not reveal a loss of heterozygosity, indicating an impact on menin expression and function in the heterozygous state, in line with results in +/-Men1 mutant mice developing prostate cancer. CONCLUSION: The results and clinical course of disease in this case indicate the potential role of menin in the development of non-endocrine or atypical-endocrine tumors in MEN1 patients. Further investigations are needed to clarify both the general role of menin and the importance of specific mutations in carcinogenesis. Nevertheless, in families with uncommon manifestations of the syndrome early diagnostic adjustments should be considered.
Assuntos
Neoplasia Endócrina Múltipla Tipo 1/genética , Proteínas Proto-Oncogênicas/metabolismo , Idoso , Regulação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Linhagem , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Proteínas Proto-Oncogênicas/genéticaRESUMO
OBJECTIVES: Ischemia/reperfusion injury (IRI) of the pancreas is a serious complication following pancreatic transplantation and hemorrhagic shock. The present study was designed to investigate the influence of the potent mammalian target of rapamycin inhibitor everolimus interfering via microvascular permeability changing key proteins hypoxia-inducible factor (HIF) and vascular endothelial growth factor on pancreatic IRI-induced microvascular disturbances. METHODS: Anesthetized male Sprague-Dawley rats were assigned to 3 groups (n = 7/group): (1) sham, (2) 60-minute ischemia/reperfusion of the pancreas (I/R), and (3) I/R and everolimus (10 mg/kg BW orally). Quantification of the effective microvascular permeability (P), functional capillary density (FCD), and leukocyte-endothelial cell interaction (LEI) was performed using digital and analog intravital epifluorescence microscopy. Serum-amylase, lipase, interleukin 6, and vascular endothelial growth factor concentration were quantified using enzyme-linked immunosorbent assay. RESULTS: Sham compared with I/R (P: [×10 cm/s] 0.068 ± 0.079 vs 1.516 ± 0.314; FCD: [cm/cm] 357 ± 14 vs 258 ± 13; LEI: [cells/mm] 148 ± 25 vs 349 ± 75) demonstrates a significant increase in microcirculatory damage and all previously mentioned serum parameters. Except amylase, I/R + everolimus led to a statistically significant improvement of almost all increased parameters (P: 0.434 ± 0.296, FCD: 347 ± 16, LEI: 178 ± 30). CONCLUSIONS: Everolimus attenuated experimental microvascular and inflammatory IRI of the pancreas. Therefore, these results may warrant further investigation of everolimus as a therapeutic agent following clinical states with pancreatic ischemia/reperfusion.
Assuntos
Everolimo/farmacologia , Interleucina-6/biossíntese , Microcirculação/efeitos dos fármacos , Pancreatite/fisiopatologia , Traumatismo por Reperfusão/fisiopatologia , Receptor 4 Toll-Like/biossíntese , Fator A de Crescimento do Endotélio Vascular/biossíntese , Animais , Western Blotting , Permeabilidade Capilar/efeitos dos fármacos , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Humanos , Imunossupressores/farmacologia , Interleucina-6/sangue , Masculino , Pâncreas/irrigação sanguínea , Pâncreas/efeitos dos fármacos , Pâncreas/fisiopatologia , Pancreatite/sangue , Ratos Sprague-Dawley , Receptor 4 Toll-Like/sangue , Fator A de Crescimento do Endotélio Vascular/sangueRESUMO
The precise diagnosis of thyroid neoplasias will guide surgical management. Primary thyroid paraganglioma has been rarely reported. Data on prevalence, immunohistochemistry (IHC), and molecular genetics in a systematic series of such patients are pending. We performed a multinational population-based study on thyroid paraganglioma and analyzed prevalence, IHC, and molecular genetics. Patients with thyroid paraganglioma were recruited from the European-American-Head-and-Neck-Paraganglioma-Registry. Demographic and clinical data were registered. Histopathology and IHC were re-investigated. All patients with thyroid paraganglioma underwent molecular genetic analyses of the SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, RET, TMEM127, and MAX genes. Analyses included Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) for detection of large rearrangements. Of 947 registrants, eight candidates were initially identified. After immunohistochemical analyses of these eight subjects, 5 (0.5%) were confirmed to have thyroid paraganglioma. IHC was positive for chromogranin, synaptophysin, and S-100 and negative for calcitonin in all five thyroid paragangliomas, whereas the three excluded candidate tumors stained positive for pan-cytokeratin, a marker excluding endocrine tumors. Germline variants, probably representing mutations, were found in four of the five confirmed thyroid paraganglioma cases, two each in SDHA and SDHB, whereas the excluded cases had no mutations in the tested genes. Thyroid paraganglioma is a finite entity, which must be differentiated from medullary thyroid carcinoma, because medical, surgical, and genetic management for each is different. Notably, approximately 80% of thyroid paragangliomas are associated with germline variants, with implications for additional tumors and a potential risk for the family. As opposed to sporadic tumors, surgical management and extent of resection are different for heritable tumors, each guided by the precise gene involved.
Assuntos
Paraganglioma , Neoplasias da Glândula Tireoide , Adulto , Idoso , Calcitonina/metabolismo , Cromogranina A/metabolismo , Proteínas de Ligação a DNA/metabolismo , Complexo II de Transporte de Elétrons/genética , Feminino , Alemanha/epidemiologia , Humanos , Queratinas/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação , Paraganglioma/epidemiologia , Paraganglioma/genética , Paraganglioma/patologia , Prevalência , Sistema de Registros , Proteínas S100/metabolismo , Succinato Desidrogenase/genética , Sinaptofisina/metabolismo , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Fatores de TranscriçãoRESUMO
BACKGROUND: After pancreas transplantation, endocrine function is determined by the insulin secretory capacity of the transplanted pancreas. The authors evaluated the predictive value of postoperative oral glucose tolerance test (OGTT) and stimulated insulin secretion on long-term endocrine function. METHODS: Forty-one patients after pancreas-kidney transplantation with systemic venous drainage were studied. Patients were categorized to have normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) (World Health Organization criteria: NGT, <7.8 mM; IGT, 7.8-11.1 mM 120 min after glucose intake) and high or low total insulin secretion. Mean follow-up of graft function and patient outcome was 10.2+/-0.5 years after OGTT. RESULTS: Patients with IGT had grafts with a longer ischemia time and a significantly worse urine amylase excretion as compared with patients with NGT. Using Kaplan-Meier survival analysis, patients with NGT had better long-term pancreatic function as compared with IGT in the follow-up after performing the first OGTT (mean, 10.9+/-0.2 vs. 8.8+/-0.9 years of graft function; P=0.02), but there was no difference in patient survival and kidney graft function. Also, high insulin secretion predicted significantly longer pancreas graft function as compared with low insulin secretion (P=0.04). CONCLUSIONS: Although IGT does not lead to poorer long-term patient survival and kidney graft function, it does predict compromised long-term endocrine function of the transplanted pancreas. Therefore, postoperative OGTT are useful tools for identification of patients at risk of long-term endocrine graft failure after pancreas transplantation.
Assuntos
Glicemia/metabolismo , Transplante de Rim/fisiologia , Transplante de Pâncreas/fisiologia , Adulto , Amilases/sangue , Área Sob a Curva , Creatinina/metabolismo , Feminino , Seguimentos , Teste de Tolerância a Glucose , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto , Humanos , Insulina/sangue , Insulina/metabolismo , Secreção de Insulina , Masculino , Fatores de TempoRESUMO
A third of patients with paraganglial tumors, pheochromocytoma, and paraganglioma, carry germline mutations in one of the susceptibility genes, RET, VHL, NF1, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127, and MAX. Despite increasing importance, data for long-term prognosis are scarce in pediatric presentations. The European-American-Pheochromocytoma-Paraganglioma-Registry, with a total of 2001 patients with confirmed paraganglial tumors, was the platform for this study. Molecular genetic and phenotypic classification and assessment of gene-specific long-term outcome with second and/or malignant paraganglial tumors and life expectancy were performed in patients diagnosed at <18 years. Of 177 eligible registrants, 80% had mutations, 49% VHL, 15% SDHB, 10% SDHD, 4% NF1, and one patient each in RET, SDHA, and SDHC. A second primary paraganglial tumor developed in 38% with increasing frequency over time, reaching 50% at 30 years after initial diagnosis. Their prevalence was associated with hereditary disease (P=0.001), particularly in VHL and SDHD mutation carriers (VHL vs others, P=0.001 and SDHD vs others, P=0.042). A total of 16 (9%) patients with hereditary disease had malignant tumors, ten at initial diagnosis and another six during follow-up. The highest prevalence was associated with SDHB (SDHB vs others, P<0.001). Eight patients died (5%), all of whom had germline mutations. Mean life expectancy was 62 years with hereditary disease. Hereditary disease and the underlying germline mutation define the long-term prognosis of pediatric patients in terms of prevalence and time of second primaries, malignant transformation, and survival. Based on these data, gene-adjusted, specific surveillance guidelines can help effective preventive medicine.
Assuntos
Neoplasias das Glândulas Suprarrenais/patologia , Paraganglioma/patologia , Feocromocitoma/patologia , Adolescente , Neoplasias das Glândulas Suprarrenais/genética , Criança , Pré-Escolar , DNA de Neoplasias/química , DNA de Neoplasias/genética , Feminino , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Estimativa de Kaplan-Meier , Expectativa de Vida , Estudos Longitudinais , Masculino , Paraganglioma/genética , Feocromocitoma/genética , Análise de Sequência de DNARESUMO
OBJECTIVES: Reason for the unsuccessful use of antioxidants in transplantation might be the unknown kinetics of reactive oxygen species (ROS) release. In this study, we compared the kinetics of ROS release from rat pancreata in the presence and absence of blood. METHODS: In vivo, ischemia-reperfusion injury (IRI) was induced in pancreata of male Wistar rats by occlusion of the arterial blood supply for 1 or 2 hours. In vitro, isolated pancreata were single-pass perfused with Krebs-Henseleit bicarbonate solution. Reactive oxygen species were quantified by electron spin resonance spectroscopy using CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) as spin label. Thiols (glutathione), nicotinamide adenine dinucleotide phosphate-oxidase activity, myeloperoxidase activity, and adenosine triphosphate content were measured. RESULTS: During reperfusion, an increase in IRI-induced ROS in arterial blood was noted after 2 hours of warm ischemia. In sharp contrast, ROS release was immediate and short lived in blood-free perfused organs. The degree of tissue damage correlated with nicotinamide adenine dinucleotide phosphate-oxidase activity and adenosine triphosphate content. Antioxidative capacity of tissues was reduced. CONCLUSIONS: Electron spin resonance spectroscopy in conjunction with spin labels allows for the detection of ROS kinetics in pancreatic IRI. Reactive oxygen species kinetics are dependent on the length of the ischemic period and the presence or absence of blood.
Assuntos
Pâncreas/irrigação sanguínea , Espécies Reativas de Oxigênio/sangue , Traumatismo por Reperfusão/fisiopatologia , Trifosfato de Adenosina/análise , Animais , Artérias , Espectroscopia de Ressonância de Spin Eletrônica , Cinética , Masculino , NADPH Oxidases/metabolismo , Pâncreas/química , Pâncreas/enzimologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Marcadores de Spin , Superóxidos/sangueAssuntos
Neoplasias das Glândulas Suprarrenais/genética , Neoplasia Endócrina Múltipla Tipo 2a/genética , Feocromocitoma/genética , Proteínas Proto-Oncogênicas c-ret/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Éxons , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Penetrância , Adulto JovemRESUMO
OBJECTIVES: Test the efficacy of liposomal gemcitabine (GemLip) on primary tumor and metastases using the pancreatic tumor cell line AsPC1 implanted orthotopically into nude mice. METHODS: The efficacy of gemcitabine and GemLip cells was tested on luciferase-transduced AsPC1 cells in vitro as well as implanted orthotopically into the pancreata of nude mice. RESULTS: In vitro, the IC50s for GemLip and gemcitabine were 20 nM and 140 nM, respectively. However, when applied against established tumors, GemLip (8 mg/kg) blocked tumor growth for 5 consecutive weeks according to bioluminescence measurements in vivo. Gemcitabine (240 mg/kg) had no effect on luciferase-monitored tumor growth. When analyzed at the time of necropsy, GemLip strongly reduced tumor size (-64% +/- [SD] 27%; ***P < 0.0001), whereas gemcitabine only weakly (-36% +/- 37%) affected tumor size. Empty liposomes had no effect on the tumor size. GemLip and empty liposomes both significantly interfered with the metastatic spread to the liver, as measured using luciferase assays (GemLip, *P = 0.01; empty liposomes, *P = 0.036). In addition, they showed effects against spleen, as well as peritoneal metastases. CONCLUSIONS: GemLip presents an effective new formulation of gemcitabine, combining the targeting and protective features of the liposomes with their antimetastatic effects to target pancreatic cancer.
Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Lipossomos/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Peritoneais/secundário , Animais , Linhagem Celular Tumoral , Desoxicitidina/farmacologia , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Feminino , Luciferases/genética , Camundongos , Camundongos Nus , Transplante de Neoplasias , Transdução Genética , GencitabinaRESUMO
BACKGROUND: Ischemia-reperfusion injury of the pancreas causes impairment of microcirculation leading to pancreatitis. Postischemic pancreatitis is the most common reason for graft failure in pancreas transplantation. In animal models, octreotide has been described to have beneficial effects on acute pancreatitis by reducing pancreatic enzyme release and edema formation by preventing the increase of macromolecular extravasation. In contrast to earlier experimental setups, this study investigated the influence of octreotide on ischemia-reperfusion pancreatitis when administered before induction of ischemia. METHODS: Sprague-Dawley rats were randomly assigned to three groups: (1) sham-operated animals (sham group, n=7); (2) 1 hr ischemia followed by 1 hr reperfusion (control group, n=7); (3) administration of 50 microg/kg octreotide intravenously 15 min before ischemia (octreotide group, n=7). At the end of reperfusion, intravital fluorescence microscopy was performed assessing the functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and the microvascular permeability. Finally serum amylase and lipase were measured. RESULTS: The application of octreotide significantly reduced the ischemia-reperfusion-induced reduction of FCD (318.4+/-44.1 cm/cm vs. 257.4+/-11.7 cm/cm, P<0.001). The increase of LEI due to ischemia-reperfusion (466.9+/-52.2 cells/mm) was reduced in the octreotide group (264.4+/-55.1, P=0.001). Permeability was significantly lower in the octreotide group (0.56+/-0.57x10 cm/sec vs. 2.2.1+/-0.54x10 cm/sec, P<0.001). The level of serum lipase was reduced significantly after octreotide therapy (72.4+/-53.4 U/L vs. 136.7+/-66.5 U/L, P=0.026). CONCLUSION: Octreotide significantly attenuated pancreatic dysfunction caused by ischemia-reperfusion when given before ischemia. Furthermore, we could prove for the first time a beneficial role of octreotide on preservation of the microvascular barrier for macromolecules.
Assuntos
Isquemia/prevenção & controle , Microcirculação/efeitos dos fármacos , Octreotida/uso terapêutico , Pancreatite/tratamento farmacológico , Traumatismo por Reperfusão/prevenção & controle , Animais , Gasometria , Capilares/efeitos dos fármacos , Capilares/fisiologia , Infusões Intravenosas , Masculino , Octreotida/administração & dosagem , Pancreatite/etiologia , Ratos , Ratos Sprague-DawleyRESUMO
Reactive oxygen species (ROS) were drawn to the attention in the setting of organ transplantation when the 'injury hypothesis' postulated a link between oxidative stress and the activation of the innate immunity of the recipient. While the occurrence of ROS during organ transplantation is undoubted, their onset and magnitude remain largely unknown. We therefore measured ROS using a novel cyclic hydroxylamine spin probe CMH (1-hydroxy-3- methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) during syngeneic experimental pancreas transplantation in rats in vivo. Organs were subjected to two different cold preservation methods [University of Wisconsin preservation solution (UW) or normal saline] for 18 h. During the first 90 min of reperfusion, samples were collected and analysed using electron paramagnetic resonance signalling. Isolated blood-free perfused organs (IPO) were used for comparison. Analysis showed that it is feasible to detect ROS using CMH spin probes. While IPO organs displayed a very early ROS release, there was no ROS increase in the UW preserved group compared to NaCl. These findings were in line with conventional markers of organ damage such as serum lactate, glucose, potassium as well as tissue ATP levels. CMH spin probes might become a useful tool for the in vivo animal testing of antioxidative substances in models of solid organ transplantation.
Assuntos
Transplante de Pâncreas/fisiologia , Espécies Reativas de Oxigênio/sangue , Animais , Masculino , Pirrolidinas , Ratos , Ratos Endogâmicos Lew , Marcadores de SpinRESUMO
OBJECTIVES: Microcirculatory derangements caused by ischemia and reperfusion (I/R) play a pivotal role in acute and graft pancreatitis. The inducible enzyme heme oxygenase 1 (HO-1) has been shown to decrease I/R injury by modulation of capillary perfusion in other organs. It was the aim of this study to evaluate the effect of HO-1 induction on pancreatic microcirculation after I/R. METHODS: Rats were randomized into 4 groups: (1) sham controls; (2) 1-hour ischemia and 2-hour reperfusion (I/R); (3) I/R + cobalt protoporphyrin (CoPP), an HO-1 inducer; and (4) I/R + CoPP + tin protoporphyrin, an HO inhibitor. Functional capillary density (FCD) and leukocyte endothelium interaction were analyzed using intravital microscopy during reperfusion. Expression of HO-1 mRNA, HO-1 protein, and HO activity were assessed by Northern blot, Western blot, and an HO activity assay. RESULTS: Functional capillary density decreased significantly in the I/R group as compared with sham controls. Cobalt protoporphyrin treatment increased FCD to control values. In contrast, HO inhibition in CoPP-pretreated animals lowered FCD and increased leukocyte endothelium interaction significantly. Cobalt protoporphyrin administration increased HO-1 mRNA, protein, and HO activity, whereas activity of the enzyme was reduced after injection of tin protoporphyrin. CONCLUSIONS: Heme oxygenase 1 plays a beneficial role in pancreatic microcirculatory derangements after I/R. This could be of therapeutic relevance after pancreas transplantation and other forms of postischemic pancreatitis.
Assuntos
Heme Oxigenase-1/metabolismo , Microcirculação/fisiologia , Pâncreas/irrigação sanguínea , Pancreatite/enzimologia , Traumatismo por Reperfusão/enzimologia , Animais , Capilares/enzimologia , Endotélio Vascular/fisiologia , Endotélio Vascular/fisiopatologia , Leucócitos/fisiologia , Masculino , Microcirculação/efeitos dos fármacos , Pancreatite/induzido quimicamente , Protoporfirinas/toxicidade , RNA/genética , RNA/isolamento & purificação , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Spontaneous or iatrogenic esophageal perforations after endoscopic procedures are potentially life-threatening events with a considerable mortality rate. The aim of this study was to demonstrate that a nonoperative endoscopic treatment with self-expanding metal stents may have a lower morbidity and mortality rate compared with surgical treatment. METHODS: A nonrandomized observational study was conducted with 15 consecutive patients between January 1997 and June 2004. Benign spontaneous and iatrogenic esophageal perforations after endoscopic procedures were treated with self-expandable metal stents. RESULTS: Seven patients (group 1) underwent stent insertion with an average time delay of 45 minutes. In 8 patients (group 2), the median delay was 123 hours. All patients in group 1 had an uneventful recovery and left hospital 5 days (range, 3 to 9) after stent insertion. One patient in group 2 (1 of 8) died of pneumonia after 6 days. In any other cases, perforations healed successfully after stent placement, but the clinical course was generally complicated with sepsis and multiple organ failure. The average hospital stay was 44 days (range, 15 to 70). CONCLUSIONS: Immediate insertion of a self-expandable metal stent enables an excellent outcome with minimal mortality and morbidity without the need for operation. Even in cases of old esophageal perforations, sealing with self-expandable metal stents is still a good option although the clinical course is much less impressive than in early treated perforations.
Assuntos
Perfuração Esofágica/complicações , Perfuração Esofágica/terapia , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Endoscopia Gastrointestinal , Perfuração Esofágica/etiologia , Feminino , Humanos , Doença Iatrogênica , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Insuficiência de Múltiplos Órgãos/etiologia , Desenho de Prótese , Sepse , Resultado do Tratamento , CicatrizaçãoRESUMO
BACKGROUND: Scavenging of nitric oxide by hemoglobin-based oxygen carriers could aggravate microcirculatory failure in splanchnic organs after hemorrhagic shock as a consequence of vasoconstrictive side effects. The aim of this study was to compare the effects of two recombinant human hemoglobin solutions, a second-generation product bearing reduced nitric oxide-scavenging properties (rHb2.0) due to site directed mutagenesis of the heme pocket and a first-generation recombinant hemoglobin (rHb1.1) with scavenging capacity similar to native hemoglobin, on the pancreatic microcirculation after hemorrhagic shock. METHODS: Twenty-eight pentobarbital-anesthetized rats were bled to a mean arterial pressure of 40 mmHg and maintained at this level for 1 h. Using an intravital microscope, the length of erythrocyte-perfused pancreatic capillaries per observation area (functional capillary density) were measured in animals resuscitated by volumes of hydroxyethyl starch, rHb1.1, or rHb2.0 equivalent to the shed blood volume. Animals without shock induction served as control. RESULTS: As compared with control (438 +/- 10 cm(-1)), animals treated with hydroxyethyl starch (315 +/- 44 cm(-1)) and rHb1.1 (288 +/- 67 cm(-1)) showed a significant reduction of functional capillary density after 2 h of resuscitation. rHb2.0 was able to restore functional capillary density (410 +/- 42 cm(-1)) and mean arterial pressure to baseline values. CONCLUSION: rHb2.0 was effectively able to restore pancreatic microcirculation after hemorrhagic shock. This may be related to the compound's effective lack of nitric oxide-scavenging properties. This hemoglobin solution or ones similar to it might be uniquely valuable for resuscitation from hemorrhagic shock.
Assuntos
Sequestradores de Radicais Livres/sangue , Hemoglobinas/uso terapêutico , Óxido Nítrico/sangue , Pancreatopatias/tratamento farmacológico , Choque Hemorrágico/tratamento farmacológico , Animais , Modelos Animais de Doenças , Humanos , Masculino , Microcirculação/efeitos dos fármacos , Microcirculação/metabolismo , Pâncreas/irrigação sanguínea , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Pancreatopatias/sangue , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/uso terapêutico , Choque Hemorrágico/sangueRESUMO
We report a case of a 55-year-old woman who was transferred from another center to our university clinic after diagnostic laparotomy with a pancreatic head tumor which was seen to encase the portal vein. Although intraoperative biopsies were performed, a histologic diagnosis of the tumor was not possible before giving suspect to a malignant tumor being resectable only with a vascular resection. In a second operation we performed a pylorus-preserving pancreatoduodenectomy. Due to adhesion of the tumor to the portal vein, a segmental resection and end-to-end anastomosis of the portal vein was necessary. Postoperative histologic diagnosis revealed an ancient schwannoma which was removed in toto being a rare report of this benign tumor in the pancreatic head. Ten months after the operation the patient is without any health problems. Partial resection of the portal vein, which is considered to be a safe procedure in high volume centers, stands in contrary to surgical nihilism of pancreatic head tumors suspecting advanced tumors with vascular involvement.
Assuntos
Neurilemoma/cirurgia , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia , Feminino , Humanos , Pessoa de Meia-Idade , Neurilemoma/diagnóstico por imagem , Neurilemoma/patologia , Obesidade , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
This study was undertaken to examine the impact of ischemia-reperfusion (I/R) injury on microcirculation and apoptosis in experimental pancreas transplantation. Pancreatic grafts were subjected to different preservation solutions and cold ischemia times (CITs): University of Wisconsin (UW), 6-h CITs (group U6); UW, 18-h CITs (group U18); normal saline, 6-h CITs (group S6); and normal saline, 6-h CITs with Z-Asp-2,6-dichlorobenzoyloxymethylketone (pan-caspase inhibitor; group S6 & CI). Nontransplanted animals served as controls. At 1- and 2-h reperfusion microcirculation was assessed by means of intravital microscopy. Apoptosis was detected by in situ nick end-labeling method (TUNEL) at 2-h reperfusion. Deterioration of microcirculation was lowest in group U6 and highest in groups S6 and S6 & CI compared with controls. The apoptotic index (cells per high power fields) of groups U6, U18 and S6 correlated well with functional capillary density (r=- 0,70, p < 0.0001) and leucocyte sticking (r= 0,69, p < 0.0001) at 1-h reperfusion. Caspase inhibition had no impact on microcirculation but significantly reduced AI compared with group S6 (p < 0.001). These data suggest that pancreatic I/R injury-induced apoptotic cell death well predicts the extent of [corrected] microcirculatory impairment. Caspase inhibition might be a promising strategy in reducing I/R injury in pancreas transplantation.