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1.
Mucosal Immunol ; 9(1): 146-58, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26037070

RESUMO

Cellular inhibitors of apoptosis proteins (cIAPs) are critical arbiters of cell death and key mediators of inflammation and innate immunity. cIAP2 is frequently overexpressed in colorectal cancer and in regenerating crypts of ulcerative colitis patients. However, its corresponding functions in intestinal homeostasis and underlying mechanisms in disease pathogenesis are poorly understood. We found that mice deficient in cIAP2 exhibited reduced colitis-associated colorectal cancer tumor burden but, surprisingly, enhanced susceptibility to acute and chronic colitis. The exacerbated colitis phenotype of cIAP2-deficient mice was mediated by increased cell death and impaired activation of the regenerative inflammasome-interleukin-18 (IL-18) pathway required for tissue repair following injury. Accordingly, administration of recombinant IL-18 or pharmacological inhibition of caspases or the kinase RIPK1 protected cIAP2-deficient mice from colitis and restored intestinal epithelial barrier architecture. Thus, cIAP2 orchestrates intestinal homeostasis by exerting a dual function in suppressing cell death and promoting intestinal epithelial cell proliferation and crypt regeneration.


Assuntos
Colite/imunologia , Neoplasias Colorretais/imunologia , Proteínas Inibidoras de Apoptose/imunologia , Proteína Serina-Treonina Quinases de Interação com Receptores/imunologia , Ubiquitina-Proteína Ligases/imunologia , Animais , Azoximetano , Proteína 3 com Repetições IAP de Baculovírus , Morte Celular/imunologia , Sobrevivência Celular/imunologia , Colite/induzido quimicamente , Colite/genética , Colite/patologia , Colo/imunologia , Colo/patologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação da Expressão Gênica , Humanos , Inflamassomos/genética , Inflamassomos/imunologia , Proteínas Inibidoras de Apoptose/deficiência , Proteínas Inibidoras de Apoptose/genética , Interleucina-18/genética , Interleucina-18/imunologia , Masculino , Camundongos , Camundongos Knockout , Proteína Serina-Treonina Quinases de Interação com Receptores/deficiência , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Transdução de Sinais , Dodecilsulfato de Sódio , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética
2.
Eur J Surg Oncol ; 39(6): 548-53, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23522952

RESUMO

BACKGROUND: This report examines the patterns of presentation, prognostic factors and survival rate of all patients with gallbladder cancer (GBC) evaluated at our tertiary academic hospital over an 11-year period. METHODS: A retrospective review of a prospectively collected database of all patients with GBC presenting between January 1998 and December 2008 was performed. RESULTS: 102 GBC-patients were included: 69 women and 33 men (median age: 65,5 years). Forty-five patients presented with incidental gallbladder cancer (IGC) and 57 with nonincidental cancer (NIGC). Curative surgery rate was 84.4% for IGC and 29.8% for NIGC (p < 0.001). Five-year actuarial survival rate was 63.2% for patients with curative intent surgery and 0% for patients with palliative approach. Patients with IGC had a longer survival rate compared to patients with NIGC (median: 25.8 vs. 4.4 months, p < 0.0001). For patients with radical resection (42 patients), there was no difference between IGC and NIGC. The incidence of liver involvement was respectively 0%, 20.8%, 58.3%, 100% for pT1, pT2, pT3 and pT4 tumors. Univariate analysis showed that survival rate was significantly affected by perineural invasion, T, N and M-stage, R0 resection, liver involvement, CA-19.9. In multivariate analysis, liver involvement was the only independent factor. CONCLUSIONS: Majority of patients with a potentially curable disease had IGC. Almost 80% of patients with NIGC presented with unresectable disease. For patients who underwent resection with curative intent, actuarial 5-year survival was 63.2%. Liver involvement was the only independent prognostic factor. All patients with IGC and a pT2 or more advanced T stage should undergo a second radical resection.


Assuntos
Carcinoma/diagnóstico , Carcinoma/mortalidade , Colecistectomia , Neoplasias da Vesícula Biliar/diagnóstico , Neoplasias da Vesícula Biliar/mortalidade , Análise Atuarial , Adulto , Idoso , Carcinoma/secundário , Carcinoma/cirurgia , Feminino , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/cirurgia , Hepatectomia , Humanos , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida
3.
Cell Death Differ ; 19(1): 5-12, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22075986

RESUMO

A decade ago, Jurg Tschopp introduced the concept of the inflammasome. This exciting discovery of a macromolecular complex that senses 'danger' and initiates the inflammatory response contributed to a renaissance in the fields of innate immunity and cell death. Jurg led the biochemical characterization of the inflammasome complex and demonstrated that spontaneous hyperactivation of this interleukin (IL)-1ß processing machinery is the molecular basis of a spectrum of hereditary periodic fever syndromes, caused by mutated forms of the inflammasome scaffolding receptor, NLRP3. The identification of the underlying mechanism in these disorders has led to their now successful therapy, with the use of the IL-1 receptor antagonist in the clinic. Jurg's pioneering work has subsequently defined a number of inflammasome agonists ranging from microbial molecules expressed during infection, to triggers of sterile inflammation, most notably gout-associated uric acid crystals, asbestos, silica and nanoparticles. More recently, Jurg introduced the critical new concept of the metabolic inflammasome, which senses metabolic stress and contributes to the onset of the metabolic syndrome associated with obesity and type 2 diabetes. Jurg was an outstanding and skillful biochemist, an elegant and rigorous researcher often far ahead of his peers. He was a truly amiable person, fair, generous and inspiring, and will be most remembered for his infectious enthusiasm. We write this review article on the inflammasome in his honor and dedicate it to his memory.


Assuntos
Inflamassomos/história , Inflamassomos/metabolismo , Inflamação/história , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/história , Proteínas de Transporte/metabolismo , Morte Celular/genética , Morte Celular/imunologia , Diabetes Mellitus Tipo 2/história , Diabetes Mellitus Tipo 2/metabolismo , História do Século XX , História do Século XXI , Humanos , Imunidade Inata/genética , Imunidade Inata/imunologia , Inflamassomos/imunologia , Inflamação/genética , Inflamação/imunologia , Interleucina-1beta/genética , Interleucina-1beta/história , Interleucina-1beta/imunologia , Síndrome Metabólica/história , Síndrome Metabólica/metabolismo , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Obesidade/história , Obesidade/metabolismo
4.
J Chir (Paris) ; 144(3): 215-8, 2007.
Artigo em Francês | MEDLINE | ID: mdl-17925714

RESUMO

UNLABELLED: This study reviews our experience with outpatient laparoscopic cholecystectomy (CCA) to evaluate the benefits of this approach to routine clinical practice. PATIENTS AND METHODS: Of 217 consecutive patients undergoing laparoscopic cholecystectomy over a one-year period (2002-2003) at our university medical center, 151 were selected for same day surgery and discharge according to the following selection criteria: non-urgent surgery, no major co-morbidities, domicile within one hour of the hospital. Patients were typically discharged the afternoon of their surgery if their clinical condition was stable. RESULTS: Of 151 planned outpatient CCA's, 122 (81%) were discharged on the day of surgery. Of these, 16 had a post-operative complication and three required readmission; no patient required reoperation. Univariate analysis revealed three factors predictive of failure of the outpatient strategy: age >65 (p=0.015), operative duration (p<0.0001), and surgical start time after 11 am (p<0.0001). CONCLUSIONS: Outpatient laparoscopic cholecystectomy can be routinely accomplished in unselected patients in an academic center. The low rate of in-patient admission is acceptable. The out-patient strategy for laparascopic cholecystectomy allows for a reduction in waiting time at our institution.


Assuntos
Procedimentos Cirúrgicos Ambulatórios , Colecistectomia Laparoscópica , Adulto , Fatores Etários , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Complicações Pós-Operatórias , Estudos Retrospectivos , Fatores de Tempo
5.
HPB (Oxford) ; 8(3): 202-5, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-18333277

RESUMO

OBJECTIVE: The aim of this study is to report our experience using self-expandable covered metallic stents (Wallstent) to treat different types of biliary strictures after orthotopic liver transplantation (OLT). PATIENTS AND METHODS: Between January 1999 and July 2004, 222 OLTs were performed with choledocho-choledochostomy (CC) bile duct reconstruction. An anastomotic biliary stricture was diagnosed and treated by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous procedures in 100 patients (45%). The group of 21 patients (mean age 57.0+/-5.6 years) that were eventually treated with a biliary Wallstent was studied retrospectively. RESULTS: Significant persistent proximal or anastomotic strictures were diagnosed in 4 and 17 patients, respectively. A Wallstent was inserted by ERCP or through a percutaneous route in 18 and 3 patients, respectively. The mean interval between diagnosis and Wallstent insertion was 179.7+/-292.8 (0-1113) days. The mean total number of procedures required per patient was 7.4+/-5.5. The mean stent primary patency duration was 10.8+/-7.8 (0.9-25.1) months with a 24-month primary patency rate of 26% at a mean follow-up time of 37.8+/-17.2 months. A hepatico-jejunostomy was performed in five patients (24%). Two patients (10%) underwent retransplantation for diffuse ischemic cholangitis or chronic rejection. The overall complication rate was 4%. CONCLUSION: Treatment of post-transplant biliary stenosis using a Wallstent is a valuable option for delaying or avoiding surgery in up to 70% of patients. Proximal stenosis can be treated in the same manner in selected patients with major comorbidities.

7.
J Clin Oncol ; 21(17): 3296-302, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-12947065

RESUMO

PURPOSE: To compare the selective matrix metalloproteinase inhibitor BAY 12-9566 with the nucleoside analog gemcitabine in the treatment of advanced pancreatic cancer. METHODS: Patients with advanced pancreatic adenocarcinoma who had not previously received chemotherapy were randomly assigned to receive BAY 12-9566 800 mg orally bid continuously or gemcitabine 1,000 mg/m2 administered intravenously on days 1, 8, 15, 22, 29, 36, and 43 for the first 8 weeks, and then days 1, 8, and 15 of each subsequent 28-day cycle. The primary end point was overall survival; secondary end points were progression-free survival, tumor response, quality of life, and clinical benefit. The planned sample size of the study was 350 patients. Two formal interim analyses were planned. RESULTS: The study was closed to accrual after the second interim analysis on the basis of the recommendation of the National Cancer Institute of Canada Clinical Trials Group Data Safety Monitoring Committee. There were 277 patients enrolled onto the study, 138 in the BAY 12-9566 arm and 139 in the gemcitabine arm. The rates of serious toxicity were low in both arms. The median survival for the BAY 12-9566 arm and the gemcitabine arm was 3.74 months and 6.59 months, respectively (P <.001; stratified log-rank test). The median progression-free survival for the BAY 12-9566 and gemcitabine arms was 1.68 and 3.5 months, respectively (P <.001). Quality-of-life analysis also favored gemcitabine. CONCLUSION: Gemcitabine is significantly superior to BAY 12-9566 in advanced pancreatic cancer.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos/uso terapêutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Compostos Orgânicos , Neoplasias Pancreáticas/tratamento farmacológico , Adenocarcinoma/patologia , Idoso , Compostos de Bifenilo , Progressão da Doença , Feminino , Humanos , Masculino , Metástase Neoplásica , Neoplasias Pancreáticas/patologia , Fenilbutiratos , Modelos de Riscos Proporcionais , Qualidade de Vida , Estatísticas não Paramétricas , Análise de Sobrevida , Resultado do Tratamento , Gencitabina
8.
Opt Lett ; 26(16): 1248-50, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18049575

RESUMO

A technique for high-speed, all-optical pattern recognition based on cross correlation in a segmented semiconductor optical amplifier (SSOA) is presented. A counterpropagating pump-probe setup is used to perform cross correlation of the spatial gain-loss pattern in the SSOA with the optical data pattern (pump), and the result is read out with a counterpropagating probe. Cross correlation of 4-bit patterns at 85 Gbits/s is experimentally demonstrated. Simulations show reasonable agreement with experimental measurements and are used to address scalability to higher bit rates and longer data patterns.

9.
Am J Physiol Gastrointest Liver Physiol ; 278(1): G18-23, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10644557

RESUMO

Motilin is an intestinal peptide that stimulates contraction of gut smooth muscle. The motilin receptor has not been cloned yet, but motilin-receptor agonists appear to be potent prokinetic agents for the treatment of dysmotility disorders. The aim of this study was to determine neural or muscular localization of motilin receptors in human upper gastrointestinal tract and to investigate their pharmacological characteristics. The binding of (125)I-labeled motilin to tissue membranes prepared from human stomach and duodenum was studied; rabbit tissues were used for comparison. Solutions enriched in neural synaptosomes or in smooth muscle plasma membranes were obtained. Various motilin analogs were used to displace the motilin radioligand from the various tissue membranes. The highest concentration of human motilin receptors was found in the antrum, predominantly in the neural preparation. Human motilin receptors were sensitive to the NH(2)-terminal portion of the motilin molecule, but comparison with rabbit showed that both species had specific affinities for various motilin analogs [i.e., Mot-(1-9), Mot-(1-12), Mot-(1-12) (CH(2)NH)(10-11), and erythromycin]. Motilin receptors obtained from synaptosomes or muscular plasma membranes of human antrum expressed different affinity for two motilin-receptor agonists, Mot-(1-12) and Mot-(1-12) (CH(2)NH)(10-11), suggesting that they correspond to specific receptor subtypes. We conclude that human motilin receptors are located predominantly in nerves of the antral wall, are functionally (and probably structurally) different from those found in other species such as the rabbit, and express specific functional (and probably structural) characteristics dependent on their localization on antral nerves or muscles, suggesting the existence of specific receptor subtypes, potentially of significant physiological or pharmacological relevance.


Assuntos
Motilina/metabolismo , Antro Pilórico/metabolismo , Animais , Humanos , Técnicas In Vitro , Mucosa Intestinal/metabolismo , Músculo Liso/metabolismo , Tecido Nervoso/metabolismo , Antro Pilórico/inervação , Coelhos , Distribuição Tecidual
10.
Can J Gastroenterol ; 14(8): 729-31, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11185540

RESUMO

A patient who underwent orthotopic liver transplantation for giant cell hepatitis with cirrhosis and in whom giant cell hepatitis recurred twice after orthotopic liver transplantation is reported. He was treated with ribavirin with an excellent result. The literature on this subject is reviewed. This observation clearly confirms the efficacy of ribavirin for the treatment of giant cell hepatitis, thus providing evidence for its viral origin.


Assuntos
Antivirais/uso terapêutico , Hepatite/tratamento farmacológico , Transplante de Fígado , Ribavirina/uso terapêutico , Adulto , Células Gigantes/patologia , Hepatite/patologia , Hepatite/cirurgia , Humanos , Fígado/patologia , Cirrose Hepática/cirurgia , Masculino , Recidiva
11.
J Clin Endocrinol Metab ; 84(8): 2654-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10443655

RESUMO

Hypocalcemia has only been rarely reported during surgical procedures not involving massive blood transfusions. The frequent observation in our hospital of a low serum ionized calcium level during surgery in nonacutely ill patients prompted us to investigate the calcium-PTH axis in three groups of subjects undergoing major (hepatectomy; n = 10), moderately severe, or minor surgery under general anesthesia (colectomy; n = 7, herniorrhaphy; n = 9) compared to that in one group of minor surgery cases under epidural anesthesia (herniorrhaphy; n = 15). Serum samples were obtained before anesthesia, after anesthesia but before surgery, and 40 and 120 min after the beginning of surgery in all groups of patients and for up to 3 days in major and moderately severe cases. Significant falls (P < 0.01), always proportional to the severity of the surgical/anesthesia procedure, were observed for ionized calcium (6-20%), total calcium (8-19%), and albumin (8-23%) accompanied by increases in intact PTH (105-635%). The decrease in ionized and total calcium correlated with a decrease in albumin (P < 0.001). Phosphorus, pH, and magnesium levels remained within the normal range. Adjustment of ionized calcium for variation in albumin revealed that 50-100% of the variation in ionized calcium could be attributed to a fall in albumin resulting from fluid administration to patients before admission to the surgery ward and between the onset of anesthesia and the end of surgery (1.2-5.6 L). Albumin- and pH-independent residual ionized calcium decreases of 12.2% in the hepatectomy group, 4.6% in the group of moderately severe and minor cases under general anesthesia, and 3.7% in the control group reflected the severity of the surgical/anesthesia procedure.


Assuntos
Hipocalcemia/etiologia , Procedimentos Cirúrgicos Operatórios , Abdome/cirurgia , Adulto , Idoso , Feminino , Humanos , Concentração de Íons de Hidrogênio , Hipofosfatemia/etiologia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Albumina Sérica/análise
12.
Opt Lett ; 24(5): 324-6, 1999 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18071494

RESUMO

We have demonstrated that spatial gain modulation in a segmented semiconductor optical amplifier can be converted to a temporal signal. A four-segment amplifier was used to generate digital return-to-zero patterns at 40 Gbits/s , and this technique should be readily scalable to more than 100 Gbits/s .

13.
Opt Lett ; 24(15): 1074-6, 1999 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18073945

RESUMO

We describe an erbium fiber laser that is passively mode locked by a novel, precision antireflection-coated semiconductor saturable-absorber mirror that incorporates an additional two-photon absorber. It is shown that passive mode locking evolves from a Q-switching instability. The results are achieved by use of saturable absorbers that provide a large (15%) nonlinear (saturable) loss. Exploiting two-photon absorption can substantially reduce the peak power of the Q-switched pulses, which results in improved reliability of the laser. Moreover, two-photon absorption can be used to produce an optimal stability range for saturable-absorber mode locking.

14.
Liver Transpl Surg ; 3(5): 532-7, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9346797

RESUMO

The purpose of this study was to evaluate the prognostic value of clinical measures of the severity of disease in cirrhotic patients who were candidates for liver transplantation at our institution. The records of the 132 cirrhotic patients who were candidates for a first transplantation between January 1, 1987, and December 31, 1994, were reviewed. One hundred nine patients (82.6%) received grafts, and 23 (17.4%) died while on the waiting list. The variables examined included level of medical urgency at the time of enlistment, date of transplantation, serum creatinine level, variables that constitute the Child-Pugh score and Shaw's risk score (serum bilirubin and albumin, prothrombin time, ascites, encephalopathy, nutritional status, age, and operative blood loss), and 6-month survival status after transplantation. The proportion of patients who died awaiting a graft increased as a function of the Child-Pugh score at enlistment (score 5-6, 0%, n = 6; score 7-9, 7%, n = 54; score 10-11, 18%, n = 33; score 12-15, 33%, n = 39; P = .01). Six-month survival rates after transplantation were similar irrespective of the Child-Pugh score or Shaw's risk score. Stepwise multiple logistic regression models identified the degree of ascites, serum bilirubin, and operative blood loss as significant variables for the prediction of overall mortality 6 months posttransplantation (model chi 2 = 12.8; P = .025; r = 0.32), but the model explained only 10% of the outcomes observed. We concluded that the Child-Pugh score is a valid prognostic index for survival up to the time of transplantation for cirrhotic patients on the waiting list; however, clinical measures of the severity of cirrhosis are poor predictors of 6-month survival after transplantation.


Assuntos
Cirrose Hepática/diagnóstico , Transplante de Fígado/mortalidade , Adolescente , Adulto , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Taxa de Sobrevida
15.
Radiology ; 204(3): 780-6, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9280259

RESUMO

PURPOSE: To evaluate the long-term results of peripheral biliary diversion by means of anastomoses of the left lobe of the liver to the stomach. MATERIALS AND METHODS: Transhepatic perforation of the left lobe of the liver into the lesser curvature of the stomach was performed in 35 patients with a presumed diagnosis of malignant obstructive jaundice. Jaundice was found to be caused by a malignant stricture in 32 patients and a benign stricture in three. Perforation was performed under fluoroscopic, endoscopic, and laparoscopic guidance in 33 patients and without laparoscopy in the other two. The hepaticogastric anastomosis was secured with a gastrostomy tube; patency of the tract was maintained with placement of a metallic stent. Kaplan-Meier analysis was used to evaluate survival, anastomosis patency rate, and jaundice recurrence. RESULTS: Technical success was achieved in all patients. Two (6%) patients had anastomotic obstruction. The actuarial survival rate was 91%, 80%, 59%, and 26% at 1, 3, 6, and 12 months. The mean patency was 234 days +/- 252. The jaundice-free rate among surviving patients was 100%, 96%, 93%, and 80% at 1, 3, 6, and 12 months. The reintervention rate was 14%. Late cholangitis occurred in seven (20%) patients. CONCLUSION: This peripheral diversion procedure appears to be safe and shows good long-term patency.


Assuntos
Colestase/cirurgia , Fígado/cirurgia , Estômago/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica , Ductos Biliares Intra-Hepáticos/cirurgia , Neoplasias do Sistema Biliar/complicações , Colangiografia , Colestase/diagnóstico por imagem , Colestase/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos , Complicações Pós-Operatórias , Stents , Procedimentos Cirúrgicos Operatórios/métodos
16.
Artigo em Inglês | MEDLINE | ID: mdl-9269023

RESUMO

Accurate assessment of alveolar ridge morphology and inferior alveolar canal location is critical in the presurgical planning phase for dental implant therapy. This study examined the accuracy and validity of linear tomography in the presurgical assessment of potential mandibular implant sites. Seven subjects (six oral and maxillofacial surgeons and one oral radiologist) traced the mandibular cortical bone and inferior alveolar canal on linear tomographic images taken from five mandibles on five separate occasions over 5 weeks. Tracings and the sectioned mandibles were scanned into a computer and assessed for eight measurement criteria. Statistically significant findings were present for intraobserver variability, interobserver variability, and differences between the perceived and actual anatomic structures within the assessed plane of section. These findings demonstrate that the inherent dimensional instability of linear tomography severely limits its diagnostic and clinical role in preoperative implant site assessment.


Assuntos
Implantação Dentária Endóssea , Arcada Edêntula/diagnóstico por imagem , Mandíbula/diagnóstico por imagem , Processo Alveolar/diagnóstico por imagem , Análise de Variância , Humanos , Variações Dependentes do Observador , Planejamento de Assistência ao Paciente , Reprodutibilidade dos Testes , Tomografia por Raios X
17.
Can J Physiol Pharmacol ; 74(12): 1327-32, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9047043

RESUMO

In cirrhosis, intrahepatic shunts and capillarization of sinusoids can result in impaired extraction of substrates by the liver irrespective of the metabolic capacity of the liver (intact hepatocyte theory). To evaluate the role of anomalies of uptake in impaired drug disposition, we studied the steady-state hepatic clearance and single-pass hepatic uptake of propranolol in isolated perfused livers obtained from patients with cirrhosis at the time of transplantation and from organ donors with normal liver architecture. The kinetics of propranolol transport in the liver were characterized by means of the multiple-indicator dilution technique, and the outflow pattern of propranolol in the hepatic veins was resolved into throughput material, which had swept past the hepatocytes along with albumin, and returning material, which had entered the cells but returned in the outflow after escaping cellular sequestration and metabolism. The steady-state clearance of propranolol was decreased in cirrhotics compared with organ donors, and the outflow profile differed between the two groups. In cirrhotic livers, half of the propranolol in the outflow consisted of throughput material and the other half of returning material; in organ donors, all of the propranolol in the outflow was returning material. In the presence of albumin and alpha 1-acid glycoprotein in the perfusate, about 80-85% of propranolol was protein bound; removal of albumin and alpha 1-acid glycoprotein from the perfusate it cirrhotic livers resulted in an increase in the free fraction of propranolol, an increase in steady-state extraction, and a decrease in the throughput component of propranolol in the outflow. We conclude that impaired uptake of protein-bound propranolol, as a result of capillarization and intrahepatic shunts, contributes to its impaired elimination in cirrhosis.


Assuntos
Cirrose Hepática/metabolismo , Fígado/metabolismo , Propranolol/farmacocinética , Transporte Biológico , Humanos , Técnicas In Vitro , Fígado/irrigação sanguínea , Perfusão , Ligação Proteica
19.
Hepatology ; 23(1): 24-31, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8550044

RESUMO

In cirrhosis, capillarization of sinusoids could result in impaired exchanges between the hepatocytes and the blood perfusing the liver and contribute to liver failure irrespective of the metabolic capacity of the liver. To characterize anomalies of the hepatic microcirculation, we used the multiple-indicator dilution approach in isolated perfused livers obtained from patients with cirrhosis at the time of transplantation, and from organ donors with normal or near-normal livers or hepatic steatosis. In organ donors, the sinusoidal volume and the permeability of sinusoids to albumin, sucrose, and water were found to be comparable to that of normal dog and rat livers. The sinusoidal volume and the extravascular volume (EVV) accessible to diffusible tracers were larger after hepatic artery than after portal vein injection, probably because of an unshared arterial sinusoidal bed. In cirrhotic livers, two kinds of alterations were found: the appearance of a barrier between the sinusoids and the hepatocytes (capillarization) and intrahepatic shunts. The extravascular space accessible to albumin decreased with increasing severity of cirrhosis, and the diffusion of sucrose in the space of Disse showed a barrier-limited pattern, instead of the normal flow-limited behavior. In cirrhotic livers, a correlation was found between the hepatic extraction of indocyanine green (ICG) and the extravascular space accessible to albumin (r = .84, P < .05), suggesting that the impaired access of this protein-bound dye to the hepatocyte surface contributed to its impaired elimination. Intrahepatic shunts were found between portal and hepatic vein (21% +/- 16% of portal flow), but not between hepatic artery and hepatic veins. We conclude that (1) the behavior of diffusible tracers in human livers with normal liver architecture is comparable to that reported in normal animals; (2) the permeability of sinusoids in cirrhotic livers is abnormal, (3) permeability changes are related to changes in liver function in cirrhosis.


Assuntos
Circulação Hepática , Adolescente , Adulto , Idoso , Permeabilidade Capilar , Circulação Colateral , Artéria Hepática/fisiopatologia , Veias Hepáticas/fisiopatologia , Humanos , Técnicas In Vitro , Técnicas de Diluição do Indicador , Verde de Indocianina , Cirrose Hepática/fisiopatologia , Cirrose Hepática/cirurgia , Transplante de Fígado , Microcirculação , Pessoa de Meia-Idade , Perfusão , Veia Porta/fisiopatologia
20.
Ann Chir ; 50(8): 601-5, 1996.
Artigo em Francês | MEDLINE | ID: mdl-9035431

RESUMO

UNLABELLED: The impact of aprotinin on blood losses during orthotopic liver transplantation (OLT) has been studied retrospectively. PATIENTS AND METHODS: From September 1984 to July 1995, 152 patients underwent 168 OLT in our center. Seventy three patients (group I) received epsilon-aminocaproic acid as an antifibrinolytic agent and 95 patients (group II) received aprotinin. RESULTS: There was a significant reduction in the mean duration of the surgery (I = 743 +/- 25 min; II = 302 +/- 10 min; p < 0.001) and in the post reperfusion time (I = 282 +/- 13 min; II = 126 +/- 6 min; p < 0.001) in the group II. The need for blood products during the operation was also reduced (blood units; I = 21.7 +/- 2.3 units; II = 4.6 +/- 0.4 units; p < 0.001). There was less infectious and hemorrhagic complications requiring reoperation in group II. We have not seen an increased incidence of thrombotic complications in the patients receiving aprotinin. Other variables such as the use of hemoclips, veno-venous bypass and the type of preservation solution were also considered. CONCLUSION: Aprotinin use during OLT is efficient and superior to epsilon-aminocaproic acid in reducing blood losses. Combined with the non-utilisation of a veno-venous by-pass and the use of hemoclips, it helps reduce the operating time and the postoperative complications.


Assuntos
Aprotinina/administração & dosagem , Perda Sanguínea Cirúrgica/prevenção & controle , Hemostáticos/administração & dosagem , Transplante de Fígado , Adulto , Testes de Coagulação Sanguínea , Transfusão de Sangue , Creatinina/sangue , Feminino , Humanos , Cuidados Intraoperatórios , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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