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1.
Am J Transplant ; 18(7): 1680-1689, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29247469

RESUMO

We report the results of a study of survival, liver and kidney functions, and growth with a median follow-up of 24 years following liver transplantation in childhood. From 1988 to 1993, 128 children underwent deceased donor liver transplantation (median age: 2.5 years). Twenty-year patient and graft survival rates were 79% and 64%, respectively. Raised serum aminotransferase and/or γ-glutamyl transferase activities were present in 42% of survivors after a single transplantation. Graft histology (35 patients) showed signs of chronic rejection in 11 and biliary obstruction in 5. Mean total fibrosis scores were 4.5/9 and 3/9 in patients with abnormal and normal serum liver tests, respectively. Glomerular filtration rate was <90 mL·min-1 in 35 survivors, including 4 in end-stage renal disease who were undergoing dialysis or had undergone renal transplantation. Median final heights were 159 cm for women and 172 cm for men; final height was below the target height in 37 patients. Twenty-year survival after childhood liver transplantation may be close to 80%, and final height is within the normal range for most patients. However, chronic kidney disease or altered liver biochemistries are present in over one third of patients, which is a matter of concern for the future.


Assuntos
Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto , Falência Renal Crônica/mortalidade , Transplante de Fígado/mortalidade , Complicações Pós-Operatórias , Diálise Renal/estatística & dados numéricos , Sobreviventes/estatística & dados numéricos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Seguimentos , França/epidemiologia , Taxa de Filtração Glomerular , Rejeição de Enxerto/epidemiologia , Humanos , Incidência , Lactente , Falência Renal Crônica/epidemiologia , Testes de Função Renal , Masculino , Prognóstico , Fatores de Risco , Taxa de Sobrevida , Adulto Jovem
2.
Diagn Interv Imaging ; 96(3): 273-82, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25220572

RESUMO

OBJECTIVE: Pictorial review with a detailed semiological analysis of ovarian tumors in children and adolescents to provide a relevant diagnostic approach. PATIENTS AND METHODS: Retrospective study (2001-2011) of 41 patients under the age of 15 who underwent surgery for an ovarian mass with a definite pathological diagnosis. RESULTS: Sixty-two percent of the lesions were benign, 33% were malignant and 5% were borderline. Germ cell tumors were most frequent (77.5%), followed by sex cord stromal tumors (12.5%) and epithelial tumors (7.5%). Malignant tumors were more frequent in children between 0 and 2 years old. On imaging, calcifications and fat were specific for germ cell tumors; the presence of a mural nodule was predictive of a mature teratoma (P<0.001). Predictive factors for malignancy were clinical, including abdominal distension (P<0.01) or a palpable mass (P=0.05), biological, including increased hCG and/or AFP levels (P<0.001) and radiological, including tumors larger than 12 cm (P<0.05), tumoral hypervascularity (P<0.01) and voluminous ascites (P<0.01). CONCLUSION: This semiological analysis confirms the role of imaging in diagnosing the etiology of ovarian lesions in children and adolescents and emphasizes the importance identifying tumoral hypervascularity, which, in addition to classic criteria, is highly predictive of malignancy.


Assuntos
Neoplasias Ovarianas , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/cirurgia , Estudos Retrospectivos
3.
Am J Transplant ; 12(6): 1496-503, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22390346

RESUMO

Hepatic artery thrombosis (HAT), one of the most severe complications of pediatric orthotopic liver transplantation (OLT), often compromises graft and/or child survival. Of 590 OLT performed in 516 children over a 20-year period, 45 were complicated by early HAT, during the first 2 weeks after transplantation. Systematic Doppler ultrasonographic detection of HAT allowed successful surgical revascularization in 19 instances, resulting in a 20-year graft survival rate of 77% versus 24% of cases when revascularization was not attempted or failed. A combination of surgical emergency revascularization, biliary interventional radiology, biliary surgery and/or retransplantation resulted in an 80% 20-year patient survival rate, identical to that of transplanted children who did not experience early HAT. The majority of long-term survivors with their initial graft had normal liver tests, no biliary dilation on ultrasonography and minimal or moderate fibrosis on liver histology. A failed attempt at revascularization did not significantly alter patient survival. Despite these encouraging results, for the children and their parents to overcome the entire process in terms of reoperations, repeated radiological interventions, number of hospitalizations and emotional stress, remains an ordeal of such magnitude that it justifies renewed efforts to progress in the prevention of this complication.


Assuntos
Artéria Hepática/patologia , Transplante de Fígado , Trombose/patologia , Resultado do Tratamento , Criança , Humanos , Taxa de Sobrevida
4.
Semin Liver Dis ; 32(4): 273-87, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23397528

RESUMO

Congenital portosystemic shunts are present in one in 30,000 children. Among the associated risks of severe complications are neonatal cholestasis, benign and malignant liver tumors, hepatopulmonary syndrome, portopulmonary hypertension, and encephalopathy. They can be detected on prenatal ultrasonograms, during the investigation of a positive galactosemia screening test in neonates or of a complication, or be found fortuitously on an abdominal ultrasound. Small intrahepatic shunts may resolve spontaneously within one year of age, but other shunts such as extrahepatic, persistent ductus venosus or persisting intrahepatic shunts, must be closed in one or two steps, by interventional radiology techniques or surgically. The plasticity of the intrahepatic portal system allows revascularization of the liver after shunt closure, even when no intrahepatic portal structures can be detected on imaging studies. This leaves little or no place for liver transplantation in the management of these children.


Assuntos
Veia Porta/anormalidades , Malformações Vasculares/diagnóstico , Colestase/complicações , Encefalopatia Hepática/complicações , Síndrome Hepatopulmonar/complicações , Humanos , Hipertensão Pulmonar/complicações , Lactente , Recém-Nascido , Neoplasias Hepáticas/complicações , Diagnóstico Pré-Natal , Malformações Vasculares/complicações , Malformações Vasculares/cirurgia
5.
J Pediatr Gastroenterol Nutr ; 54(3): 369-73, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22027567

RESUMO

OBJECTIVES: The aim of the study was to assess the diagnosis and management of solid pancreatic neoplasm in children and the type of surgical treatment, focusing on short- and long-term outcomes. METHODS: We retrospectively reviewed the charts of all children who had undergone pancreatic resection for suspicion of pancreatic tumor in Kremlin Bicêtre Hospital, Paris, between 1986 and 2008. We studied the symptoms at diagnosis, the type of surgery, and the short- and long-term morbidity and mortality. RESULTS: Of 18 patients identified, there were 7 pseudopapillary tumors, 3 neuroblastomas, 2 rhabdomyosarcomas, 1 acinar cell carcinoma, 1 endocrine cell carcinoma, 1 renal angiomyolipoma, and 3 pancreatic cysts. Symptoms at diagnosis were abdominal trauma, abdominal mass, and jaundice. Operative procedures were duodenopancreatectomy (11), mid-pancreatic resections (2), splenopancreatectomy (2), distal pancreatectomy (1), and tumorectomy (2). There were no deaths related to surgery. The postoperative morbidity rate was 45%, including 2 cases of fistula (11%) occurring after a mid-pancreatic resection and a pancreaticoduodenectomy. The median follow-up was 4.2 years (range 2-11). There was no diabetes mellitus, but there was 1 case of fat diet intolerance requiring pancreatic enzyme substitution. All of the children had a growth curve within normal limits. CONCLUSIONS: In this experience, pancreatic resections have proven to be a safe and efficient procedure, with low long-term morbidity, for the treatment of tumoral and selected nontumoral pancreatic masses.


Assuntos
Crescimento , Pâncreas/cirurgia , Cisto Pancreático/cirurgia , Neoplasias Pancreáticas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pancreatectomia , Neoplasias Pancreáticas/complicações , Pancreaticoduodenectomia , Paris/epidemiologia , Prevalência , Valores de Referência , Estudos Retrospectivos , Resultado do Tratamento
6.
Ultrasound Obstet Gynecol ; 29(6): 708-11, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17523163

RESUMO

We report a case of aneurysmal dilatation of a vitelline vein observed antenatally. Intra-abdominal vascular dilatation was diagnosed on ultrasound examination at 24 weeks' gestation. The relationship with the umbilicus and portal vein suggested the diagnosis of umbilical vein varix. Fetal tolerance remained excellent in spite of a gradual increase in the size of the dilated vein. Postnatal ultrasound examination revealed thrombosis of the aneurysm with gradual extension to the portal vein and the onset of serious coagulation problems. Operative findings on postnatal day 9 included the absence of intra-abdominal umbilical vein, and the presence of an abnormal, dilated and thrombosed vein connecting the umbilicus to the portal vein and following the trajectory of the right vitelline vein. Corrective surgery was attempted by resection of the aneurysm and portal thrombectomy, but this did not prevent the development of portal obstruction syndrome with cavernous hemangioma. This anomaly, in which the fetal venous return uses the vitelline vein in the absence of the umbilical vein, does not appear to have been described before. The mechanism in question could be anastomosis between the right vitelline vein and umbilical vein. Antenatal diagnosis should enable early surgical management before the formation of a portal thrombosis.


Assuntos
Aneurisma/diagnóstico por imagem , Ducto Vitelino/irrigação sanguínea , Adulto , Aneurisma/cirurgia , Feminino , Humanos , Recém-Nascido , Masculino , Gravidez , Resultado do Tratamento , Ultrassonografia Doppler em Cores , Ultrassonografia Pré-Natal/métodos , Veias/anormalidades , Veias/diagnóstico por imagem , Ducto Vitelino/diagnóstico por imagem
7.
Int J Pediatr Otorhinolaryngol ; 67(12): 1361-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14643482

RESUMO

OBJECTIVES: The purpose of this study focused on cervical neuroblastoma (NB) was to assess the prognosis, define the most suitable methods of investigation, and evaluate risk factors for complications following primary surgery. METHODS: Between 1990 and 1999, we conducted two consecutive prospective multicentric studies (NBL90 and NBL94) on localized NB. Because the first study (1990-1994) found surgery-related morbidity and mortality, several surgical risk factors (i.e. adhesion to major vessels, size, friability, and dumb bell tumor) were defined and used prospectively as criteria of resectability in the second study (1994-1999). RESULTS: Of 617 cases included in the two studies, 43 involved cervical NB including 17 cervicothoracic tumors. With a median follow-up of 4 years, overall survival and event-free survival rates were 91 and 81%, respectively with no significant difference between cervical or cervicothoracic NB. Seventeen patients were included in the second study; surgery was used as the first line treatment in 11. Full pre-operative work-up was performed in eight patients, demonstrating one or more risk factors in three. The remaining three patients underwent emergency surgery with no pre-operative work-up or only ultrasound: two developed serious complications. All three patients presenting documented risk factors developed post-operative complications versus only two of the eight patients who presented no risk factor (n = 5) or were inadequately evaluated (n = 3) (P = 0.06). None of the five patients in whom full work-up demonstrated no risk factor had post-operative complications (P = 0.02). CONCLUSIONS: Cervical neuroblastoma has a favorable prognosis. Surgery is the treatment of choice but there is a risk of complications. Appropriate pre-operative work-up is mandatory to evaluate resectability. The surgical risk factors defined for our second study seem to be significant predictors of post-operative complications.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Neuroblastoma/cirurgia , Complicações Pós-Operatórias/prevenção & controle , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Masculino , Neuroblastoma/mortalidade , Cuidados Pré-Operatórios , Prognóstico , Estudos Prospectivos , Fatores de Risco , Taxa de Sobrevida
8.
J Aerosol Med ; 16(2): 121-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12823906

RESUMO

The purpose of this study was to define nebulization conditions providing delivery of aerosols of EPI-hNE4, an inhibitor of human neutrophil elastase (HNE). EPI-hNE4 was nebulized with Pari LC Star and tested at three concentrations (2.5, 5, and 10 mg/mL). The inhaled mass was measured over 15 min. Particle size distribution was measured by cascade impaction. The effect was also tested of mixing EPI-hNE4 with a (99m)Tc human serum albumin (HSA) tracer on the aerodynamic properties of the aerosol. The inhibitory activity of EPI-hNE4 after nebulization was assessed on purified HNE. The inhaled mass was 32.3 +/- 3.5% (mean +/- SD) after 10 min and 44.2 +/- 3.8% (mean +/- SD) after 15 min. Mass median aerodynamic diameter ranged between 1.2 and 1.8 microm. The (99m)Tc HSA EPI-hNE4 aerosol was similar in terms of particle size distribution (y = 1.0338x - 0.003, r = 0.83). (99m)Tc activity was predictive of EPI-hNE4 mass distribution (y = 1.0278x - 1.6991, r = 0.89). The inhibitory capacity of aerosolized samples remained unchanged after up to 10 min of nebulization. EPI-hNE4 can be nebulized efficiently without decrease in its activity. Mixing this inhibitor with (99m)Tc HSA should allow quantification of its deposition in CF patients.


Assuntos
Fibrose Cística/tratamento farmacológico , Nebulizadores e Vaporizadores , Proteínas/administração & dosagem , Administração por Inalação , Aerossóis , Desenho de Equipamento , Humanos , Modelos Lineares , Tamanho da Partícula , Serpinas
9.
Arch Pediatr ; 9(12): 1226-9, 2002 Dec.
Artigo em Francês | MEDLINE | ID: mdl-12536102

RESUMO

UNLABELLED: Classically, testicular torsion occurs in neonates or during puberty. Between these two ages, is it really an exception? METHOD AND PATIENTS: In order to answer the question, we reviewed the charts of the patients referred to the department of pediatric surgery of Bicêtre hospital between 1992 and 2001. We studied the preoperative examinations, the operative data and the long term evolution. Cases of torsion occurring during neonatal or pubertal periods were excluded. RESULTS: During nine years, 86 patients with "acute scrotum symptoms" underwent surgery. The ages of patients ranged from one month to 11 years (average age: five years) in 26 patients, among which 12 had true testicular torsion. Consultation at the emergency room occurred after one to 72 hours (average of 17). The localization of the pain was on the left in eight cases and on ectopic testicle in two. The testicular volume was increased in 11 cases. Cremasteric reflex was absent in four cases. The doppler flow was normal in four cases and absent in four. During surgery, the testis appearance was considered as normal in six testicles, as necrotized in three (and an orchidectomy was performed) and as ischemic in three. In seven cases, a peroperative contralateral testicle fixation was performed and later one in two. The postoperative course was simple, without infection and with a normal testicular volume in eight cases, increased in one ischemic testis. Testicular atrophy was noted in an ischemic testis, after several months. CONCLUSION: Whatever the age, testicular torsion remains a surgical emergency even with a normal doppler flow.


Assuntos
Torção do Cordão Espermático/cirurgia , Fatores Etários , Criança , Pré-Escolar , Gráficos por Computador , Ecocardiografia Doppler , Humanos , Lactente , Masculino , Estudos Retrospectivos , Torção do Cordão Espermático/diagnóstico , Torção do Cordão Espermático/epidemiologia , Resultado do Tratamento
10.
FEBS Lett ; 507(3): 362-6, 2001 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11696372

RESUMO

A library of 121 pseudopeptides was designed to develop reversible inhibitors of trypanosomal enzymes (cruzain from Trypanosoma cruzi and congopain from Trypanosoma congolense). The peptides share the framework: Cha-X1-X2-Pro (Cha=cyclohexyl-alanine, X1 and X2 were phenylalanyl analogs), based on a previous report [Lecaille, F., Authié, E., Moreau, T., Serveau, C., Gauthier, F. and Lalmanach, G. (2001) Eur. J. Biochem. 268, 2733-2741]. Five peptides containing a nitro-substituted aromatic residue (Tyr/Phe) and one a 4-chloro-phenylalanine at the X1 position, and 3-(2-naphthyl)-alanine, homocyclohexylalanine or 3-nitro-tyrosine (3-NO(2)-Tyr) at the X2 position, were selected. They inhibited congopain more effectively than cruzain, except Cha-4-NO(2)-Phe-3-NO(2)-Tyr-Pro which bound the two parasitic enzymes similarly. Among this series, Cha-3-NO(2)-Tyr-HoCha-Pro and Cha-4-NO(2)-Phe-3-NO(2)-Tyr-Pro are the most selective for congopain relative to host cathepsins. No hydrolysis occurred upon prolonged incubation time with purified enzymes. In addition introduction of non-proteogenic residues in the peptidyl backbone greatly enhanced resistance to proteolysis by mammalian sera.


Assuntos
Catepsinas/antagonistas & inibidores , Inibidores de Cisteína Proteinase/química , Inibidores de Cisteína Proteinase/farmacologia , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Catepsina B/antagonistas & inibidores , Catepsina L , Catepsinas/metabolismo , Cumarínicos/metabolismo , Cisteína Endopeptidases/efeitos dos fármacos , Dipeptídeos/metabolismo , Proteínas de Protozoários/antagonistas & inibidores , Relação Estrutura-Atividade
11.
Int J Parasitol ; 31(13): 1429-33, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11595229

RESUMO

In order to test the hypothesis that trypanosome cysteine proteinases (CPs) contribute to pathology of trypanosomosis, cattle were immunised with CP1 and/or CP2, the major CPs of Trypanosoma congolense, and subsequently challenged with T. congolense. Immunisation had no effect on the establishment of infection and the development of acute anaemia. However, immunised cattle, unlike control cattle, maintained or gained weight during infection. Their haematocrit and leukocyte counts showed a tendency to recovery after 2-3 months of infection. Cattle immunised with CP2 mounted early and prominent IgG responses to CPs and to the variable surface glycoprotein following challenge. Thus trypanosome CPs may play a role in anaemia and immunosuppression; conversely, anti-CP antibody may modulate the trypanosome-induced pathology.


Assuntos
Doenças dos Bovinos/parasitologia , Cisteína Endopeptidases/imunologia , Proteínas de Drosophila , Trypanosoma congolense/imunologia , Tripanossomíase Africana/imunologia , Animais , Anticorpos Antiprotozoários/sangue , Bovinos , Doenças dos Bovinos/imunologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Hematócrito/veterinária , Imunização/veterinária , Imunoglobulina G/sangue , Contagem de Leucócitos/veterinária , Masculino , Microscopia de Contraste de Fase/veterinária , Parasitemia/veterinária , Trypanosoma congolense/enzimologia , Trypanosoma congolense/crescimento & desenvolvimento , Tripanossomíase Africana/sangue , Tripanossomíase Africana/parasitologia , Aumento de Peso
12.
Int J Parasitol ; 31(13): 1435-40, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11595230

RESUMO

The catalytic domains of two closely related cysteine proteinases (CP1 and CP2) from Trypanosoma congolense, referred to as C1 and C2, were expressed as proforms in Escherichia coli (C1) and in the baculovirus system (C1 and C2). While the bacterial expression system did not allow recovery of active C1, the baculovirus system led to secretion of inactive zymogens which could be processed at acidic pH into mature enzymes. Active C1 and C2 were purified from serum-free culture supernatants by anion-exchange chromatography and characterised. Their kinetic parameters and pH activity profiles confirmed the relatedness between C2 and native CP2 (congopain). These properties also underline major functional differences between C1 and C2, that appear to relate to discrete but essential sequence differences. It is likely that these two enzymes perform distinct roles in vivo, in the parasite and/or in the host-parasite relationships.


Assuntos
Cisteína Endopeptidases/fisiologia , Trypanosoma congolense/enzimologia , Sequência de Aminoácidos , Animais , Baculoviridae/genética , Domínio Catalítico , Cromatografia por Troca Iônica/veterinária , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/imunologia , Cisteína Endopeptidases/metabolismo , Eletroforese em Gel de Poliacrilamida/veterinária , Epitopos/genética , Epitopos/imunologia , Epitopos/fisiologia , Escherichia coli/virologia , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Dobramento de Proteína , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Trypanosoma congolense/genética
13.
Eur J Biochem ; 268(16): 4408-13, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11502200

RESUMO

Despite the wide use of prostate-specific antigen (PSA) as a marker of prostate cancer, analysis of its gene products has not yet been completed. The structure of two alternative mRNAs (0.9 and 1.65 kb) of the hKLK3 gene that retain the third intron is reported here. These partially spliced transcripts were detected by hybridization or RT-PCR in normal prostate tissue, benign prostate hyperplasia (BPH) and cancerous prostate tissues, and also in the prostate LNCaP cell line. Insertion of the unspliced intron creates an in-frame stop codon and results in a truncated prepro PSA variant of 180 amino-acid residues. This novel variant, designated PSA-RP2, has an alternate C-terminal tail and lacks the serine residue essential for the catalytic activity of PSA. Prepro PSA-RP2 was transiently produced in COS-7 cells and detected in the spent medium using an anti-PSA serum. Secreted PSA-RP2 was glycosylated with an apparent molecular mass of 25 kDa. Our findings suggest that PSA-RP2 contributes to the molecular heterogeneity of free-PSA in the serum of patients with benign or malignant prostate tumors.


Assuntos
Antígeno Prostático Específico/genética , Processamento Alternativo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Humanos , Masculino , Dados de Sequência Molecular , Antígeno Prostático Específico/análise , Antígeno Prostático Específico/química , Proteínas Recombinantes/análise
14.
Biol Chem ; 382(5): 811-5, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11517935

RESUMO

Although papain-like enzymes are strongly inhibited by their natural tight-binding inhibitors of the cystatin superfamily, cathepsins B and L may still retain some residual proteolytic activity toward Z-Phe-Arg-AMC in the presence of an excess of kininogen. This activity is abolished by adding E-64 or chicken cystatin. Cathepsins B and L show a single band of gelatinolytic activity when subjected to gelatin-SDS-PAGE. Adding high Mr kininogen, low Mr kininogen, T-kininogen, or chicken cystatin to cathepsin L results in additional intense bands of enzyme activity corresponding to the protease-inhibitor complexes. Cathepsin B does not produce these additional bands. This gelatinolytic activity was inhibited by E-64, but not by EDTA, PMSF or Pefabloc. Cathepsin L also specifically generated kinins from high and low molecular weight kininogens in vitro, but cathepsin B did not. T-kininogen did not release any immunoreactive kinins when complexed with cathepsin L, as previously observed using tissue kallikreins. The ability of cathepsin L to generate vasoactive peptides raises the question of the physiological significance of this mechanism during inflammation.


Assuntos
Catepsina B/metabolismo , Catepsinas/metabolismo , Animais , Catepsina L , Catepsinas/antagonistas & inibidores , Galinhas , Cistatinas/metabolismo , Cisteína Endopeptidases , Inibidores de Cisteína Proteinase/metabolismo , Corantes Fluorescentes , Humanos , Calicreínas/antagonistas & inibidores , Calicreínas/metabolismo , Cininogênio de Alto Peso Molecular/metabolismo , Cininogênio de Baixo Peso Molecular/metabolismo , Cininogênios/metabolismo , Cininas/metabolismo , Ligação Proteica
15.
Hum Mol Genet ; 10(14): 1465-73, 2001 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-11448938

RESUMO

The bHLH-PAS transcription factor SIM1 is required for the development of the paraventricular nucleus (PVN) of the hypothalamus. Mice homozygous for a null allele of Sim1 (Sim1(-/-)) lack a PVN and die perinatally. In contrast, we show here that Sim1 heterozygous mice are viable but develop early-onset obesity, with increased linear growth, hyperinsulinemia and hyperleptinemia. Sim1(+/-) mice are hyperphagic but their energy expenditure is not decreased, distinguishing them from other mouse models of early-onset obesity such as deficiencies in leptin and melanocortin receptor 4. Quantitative histological comparison with normal littermates showed that the PVN of Sim1(+/-) mice contains on average 24% fewer cells without a selective loss of any identifiable major cell type. Since acquired lesions in the PVN also induce increased appetite without a decrease in energy expenditure, we propose that abnormalities of PVN development cause the obesity of Sim1(+/-) mice. Severe obesity was described recently in a patient with a balanced translocation disrupting SIM1. Pathways controlling the development of the PVN thus have the potential to cause obesity in both mice and humans.


Assuntos
Hiperfagia/genética , Obesidade/genética , Núcleo Hipotalâmico Paraventricular/anormalidades , Proteínas Repressoras , Fatores de Transcrição/fisiologia , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Tecido Adiposo Marrom/citologia , Tecido Adiposo Marrom/metabolismo , Fatores Etários , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Constituição Corporal/genética , Feminino , Sequências Hélice-Alça-Hélice , Heterozigoto , Insulina/sangue , Masculino , Camundongos , Camundongos Endogâmicos , Neurônios/patologia , Fatores Sexuais , Fatores de Transcrição/genética
16.
Biochim Biophys Acta ; 1547(2): 387-96, 2001 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-11410295

RESUMO

The rat tissue kallikrein rK9 is most abundant in the submandibular gland and the prostate. It has been successfully expressed in the Pichia pastoris yeast expression system. A full-length cDNA coding for the mature rK9 was fused in frame with yeast alpha-factor cDNA. The fusion protein was secreted into the medium with high yield without being processed by the yeast KEX2 signal peptidase. Mature rK9 was efficiently released from the fusion protein by trypsin and was purified to homogeneity by one-step affinity chromatography using soya bean trypsin inhibitor (SBTI) as affinity ligand. The identity of the recombinant enzyme was checked by N-terminal amino acid sequencing, Western blot analysis and kinetic studies. The dual trypsin- and chymotrypsin-like enzymatic specificity of rK9 was assessed by determining specificity constants (k(cat)/K(m)) for the hydrolysis of fluorogenic substrates, the peptide sequences of which were derived from proparathyroid hormone (pro-PTH) and from semenogelin-I. Our results confirmed the presence of an extended binding site in the rK9 active site. We also identified a far more sensitive substrate of this enzyme than those previously described, Abz-VKKRSARQ-EDDnp, which was hydrolysed with a catalytic efficiency k(cat)/K(m) of 420000 M(-1)s(-1). Finally, we showed that four of the five major proteins contained in secretions of rat seminal vesicles were rapidly degraded by recombinant rK9.


Assuntos
Calicreínas/isolamento & purificação , Sequência de Aminoácidos , Animais , Sítios de Ligação , Calicreínas/biossíntese , Calicreínas/química , Masculino , Pichia/metabolismo , Antígeno Prostático Específico/química , Proteínas/química , Ratos , Proteínas Recombinantes/isolamento & purificação , Sêmen/química , Sêmen/metabolismo , Glândulas Seminais/metabolismo , Especificidade por Substrato , Calicreínas Teciduais/química
17.
Eur J Biochem ; 268(10): 2960-8, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11358513

RESUMO

Insulin-like growth factors (IGFs) are important growth regulators of both normal and malignant prostate cells. Their action is regulated by six insulin-like growth factor binding proteins (IGFBPs). The proteolytic cleavage of IGFBPs by various proteases decreases dramatically their affinity for their ligands and therefore enhances the bioavailability of IGFs. To elucidate the putative biological role of prostatic kallikreins hK2 and hK3 (prostate-specific antigen) in tumour progression, we analyzed the degradation of IGFBP-2, -3, -4 and -5 by these two tissue kallikreins. We found that hK3, already characterized as an IGFBP-3 degrading protease, cleaved IGFBP-4 but not IGFBP-2 and -5, whereas hK2 cleaved all of the IGFBPs much more effectively, and at concentrations far lower than those reported for other IGFBP-degrading proteases. The proteolytic patterns after cleavage of IGFBPs by hK2 and hK3 were similar and were not modified in the presence of IGF-I. Heparin, but not other glycosaminoglycans, enhanced dramatically the ability of hK3 but not hK2 to degrade IGFBP-3 and IGFBP-4. More importantly, the IGFBP fragments generated by hK2 and hK3 had no IGF-binding capacity, as assessed by Western ligand blotting. Our results suggest that the prostatic kallikreins hK2 and hK3 may influence specifically the tumoral growth of prostate cells through the degradation of IGFBPs, to increase IGF bioavailability.


Assuntos
Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/fisiologia , Antígeno Prostático Específico/química , Calicreínas Teciduais/química , Sítios de Ligação , Western Blotting , Relação Dose-Resposta a Droga , Glicosaminoglicanos/farmacologia , Heparina/metabolismo , Heparina/farmacologia , Humanos , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Ligantes , Masculino , Próstata/metabolismo , Neoplasias da Próstata/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Fatores de Tempo
18.
Eur J Pediatr Surg ; 11(1): 36-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11370981

RESUMO

Experience of the International Society of Paediatric Oncology (SIOP) Trials and Studies indicates that the preoperative chemotherapy in Wilms' tumour improves stage distribution, decreases complication rate and reduces postoperative treatment. However, some situations may lead to prompt primary surgery. The aim of the study is to assess reasons leading to primary emergency nephrectomy. Records of 720 patients with non-metastatic unilateral nephroblastoma who were registered in the SIOP Trial and Study 9 were reviewed. Twenty-four (3%) cases of primary emergency nephrectomy were identified. Reasons leading to emergency nephrectomy were massive bleedings from ruptured tumours in 13 patients, suspicion of an "acute abdomen" in 7, bowel occlusion in 2 and other in 2. Postoperative treatment included radiotherapy in 71% of cases and anthracyclines in 92%. Complications were frequent and happened in 25% of patients, the outcome however, was favourable and 22 of 24 patients are alive (from 9 to 79 months). The 7 patients with a suspicion of an "acute abdomen" probably constitute the group which could have been markedly reduced if adequately diagnosed and observed prior to surgery.


Assuntos
Neoplasias Renais/cirurgia , Nefrectomia , Tumor de Wilms/cirurgia , Criança , Pré-Escolar , Ensaios Clínicos como Assunto , Serviços Médicos de Emergência , Humanos , Lactente , Neoplasias Renais/complicações , Neoplasias Renais/patologia , Estadiamento de Neoplasias , Complicações Pós-Operatórias , Estudos Retrospectivos , Ruptura Espontânea , Tumor de Wilms/complicações , Tumor de Wilms/patologia
19.
Eur J Biochem ; 268(9): 2733-41, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11322895

RESUMO

The S2 subsite of mammalian cysteine proteinases of the papain family is essential for specificity. Among natural amino acids, all these enzymes prefer bulky hydrophobic residues such as phenylalanine at P2. This holds true for their trypanosomal counterparts: cruzain from Trypanosoma cruzi and congopain from T. congolense. A detailed analysis of the S2 specificity of parasitic proteases was performed to gain information that might be of interest for the design of more selective pseudopeptidyl inhibitors. Nonproteogenic phenylalanyl analogs (Xaa) have been introduced into position P2 of fluorogenic substrates dansyl-Xaa-Arg-Ala-Pro-Trp, and their kinetic constants (Km, kcat/Km) have been determined with congopain and cruzain, and related host cathepsins B and L. Trypanosomal cysteine proteases are poorly stereoselective towards D/L-Phe, the inversion of chirality modifying the efficiency of the reaction but not the Km. Congopain binds cyclohexylalanine better than aromatic Phe derivatives. Another characteristic feature of congopain compared to cruzain and cathepsins B and L was that it could accomodate a phenylglycyl residue (kcat/Km = 1300 mM-1.s-1), while lengthening of the side chain by a methylene group only slightly impaired the specificity constant towards trypanosomal cysteine proteases. Mono- and di-halogenation or nitration of Phe did not affect Km for cathepsin L-like enzymes, but the presence of constrained Phe derivatives prevented a correct fitting into the S2 subsite. A model of congopain has been built to study the fit of Phe analogs within the S2 pocket. Phe analogs adopted a positioning within the S2 pocket similar to that of the Tyr of the cruzain/Z-Tyr-Ala-fluoromethylketone complex. However, cyclohexylalanine has an energetically favorable chair-like conformation and can penetrate deeper into the subsite. Fitting of modeled Phe analogs were in good agreement with kinetic parameters. Furthermore, a linear relationship could be established with logP, supporting the suggestion that fitting into the S2 pocket of trypanosomal cysteine proteases depends on the hydrophobicity of Phe analogs.


Assuntos
Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Endopeptidases , Trypanosoma/enzimologia , Animais , Domínio Catalítico , Catepsina L , Catepsinas/química , Catepsinas/metabolismo , Técnicas In Vitro , Cinética , Modelos Moleculares , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Fenilalanina/análogos & derivados , Fenilalanina/química , Conformação Proteica , Especificidade por Substrato , Trypanosoma congolense/enzimologia , Trypanosoma cruzi/enzimologia
20.
Prog Urol ; 11(1): 109-12, 2001 Feb.
Artigo em Francês | MEDLINE | ID: mdl-11296629

RESUMO

The surgical treatment of malignant renal tumours in children (nephroblastomas) is part of a multimodal therapeutic strategy, defined by the International Society of Paediatric Oncology protocol. Resection of the primary tumour and determination of the post-operative stage determine subsequent treatment. The modalities of the surgical procedure are described together with the particular cases concerning infants under the age of 6 months, extension to the renal vein and inferior vena cava, emergency surgery, bilateral, tumours or tumour in a solitary kidney, lymph node involvement, metastatic nephroblastomas and complications of surgery.


Assuntos
Neoplasias Renais/cirurgia , Cirurgia Geral , Humanos , Lactente , Pediatria
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