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1.
Eur Rev Med Pharmacol Sci ; 25(2): 923-931, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33577047

RESUMO

OBJECTIVE: Achieving glycemic target is paramount to control diabetes mellitus (DM) and reduce micro-vascular and macro-vascular complications. Despite the mostly recent-developed drugs, most patients still show an above desired glycated hemoglobin (HbA1c) level due to DM complex pathophysiology, therapeutic and dietary compliance and clinical inertia in introducing or intensifying insulin therapy. To support the promising results of clinical trials on the effectiveness and safety of the degludec/liraglutide combination (IDegLira) in type 2 DM patients with C-peptide values >1 ng/ml who were previously treated with basal-bolus multiple daily-dose insulin injections. PATIENTS AND METHODS: This observational, prospective and non-randomized trial enrolled type 2 DM patients referred to our outpatient clinic between January 2019 and December 2019, who were shifted from multiple daily-dose insulin injection therapy to degludec/liraglutide combination as per the physician's decision. The main assessment was HbA1c variation at 6 months from baseline. Secondary assessments included variation in fasting glycemia, routine anthropometric assessments, blood chemistry, blood pressure and patients' quality of life (measured by the Diabetes Treatment Satisfaction Questionnaire [DTSQ]), from baseline to 6 months. RESULTS: HbA1c (8.4 vs. 7.4%; p<0.0001) and body weight (94.1 vs. 93 kg; p<0.0001) were significantly lower after 6 months for patients on the degludec/liraglutide combination. A similar trend was observed in fasting glycemia levels (159 vs. 125 mg/dl; p<0.0001). An improved glycemic control was achieved with degludec/liraglutide despite a reduction in total daily insulin units (42 U at 6 months vs. 22 U at baseline; p<0.0001). In addition, higher scores in the DTSQ were registered after 6 months on degludec/liraglutide (mean score: 27 vs. 20; p<0.0001). The combination therapy also proved more convenient than basal-bolus therapy in terms of costs, with an average per-patient cost difference of €-0.41±0.59/die (p<0.0001). CONCLUSIONS: These real-world findings show that degludec/liraglutide seems to be more effective than basal-bolus insulin in achieving glycemic control, allowing cost sustainability and improving patient satisfaction.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina de Ação Prolongada/uso terapêutico , Liraglutida/uso terapêutico , Idoso , Peso Corporal , Estudos de Coortes , Diabetes Mellitus Tipo 2/diagnóstico , Combinação de Medicamentos , Jejum , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemia/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
2.
Acta Paediatr ; 96(10): 1490-3, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17880417

RESUMO

AIM: To describe the chickenpox complications in children in Italy. METHODS: Hospital discharge data from 1 January 2002 to 15 June 2006 were queried for patients less than 18 years of age in three Italian paediatric university hospitals. RESULTS: During the study period, 349 children (189 males, 160 females) were admitted. Thirteen out of 349 (3.7%) of them had serious underlying diseases. Two hundred and sixty-one (74.8%) children (median age: 41 months, range: 6 days -to 200 months) had complicated chickenpox. Among complications, neurological disorders were the most common (100/261 = 38.3%), followed by skin and soft tissue infections (63/261 = 24.1%), lower respiratory tract infections (57/261 = 21.8%) and haematological disorders (24/261 = 9.2%). Children with neurological complications were significantly older and had a longer hospital stay than those with other complications. Three children with encephalitis and cerebellitis had developed long-term sequelae by the 6-month follow-up. The mortality rate was 0.4% (1/261 children with complicated chickenpox). CONCLUSION: Chickenpox is a disease that can provoke serious complications and long hospital stays, even in healthy children. Our findings may be useful as background to evaluate the impact of a tetravalent measles-mumps-rubella-varicella vaccine (MMRV) which is going to be introduced in Italy.


Assuntos
Varicela/epidemiologia , Hospitalização/estatística & dados numéricos , Encefalopatias/etiologia , Varicela/complicações , Vacina contra Varicela , Criança , Feminino , Humanos , Itália/epidemiologia , Tempo de Internação , Masculino , Vacina contra Sarampo-Caxumba-Rubéola , Fatores de Risco , Índice de Gravidade de Doença , Vacinas Combinadas
4.
J Biol Chem ; 276(34): 32051-5, 2001 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-11440998

RESUMO

Protein networks asymetrically distributed to basolateral and apical epithelial membranes maintain cell polarity and homeostasis of epithelial tissues. Genetic studies in non-vertebrates assigned two families of basolateral proteins, MAGUK (membrane-associated and guanylate kinase) and LAP (leucine-rich repeats and PDZ) proteins, to a common pathway crucial for the epithelial architecture and acting as a gatekeeper to malignancy. In mammals, three LAP proteins have been described, Densin-180, Erbin, and hScribble. Here, we identify a protein called Lano (LAP and no PDZ) only present in vertebrates and presenting strong identities with LAP proteins. Despite the lack of PDZ domain, Lano is located at the basolateral side of epithelial cells in a similar manner to Erbin and hScribble. Using in vitro and in vivo experiments, we demonstrate that Lano directly interacts with the PDZ domains of MAGUK proteins, including hDLG (human disc large), in epithelial cells. A second pool of Lano is complexed to Erbin. These LAP-MAGUK protein complexes coexist at the basolateral side of epithelial cells. We provide evidence for a direct interaction between LAP and MAGUK proteins, and we propose that various LAP-MAGUK networks targeted to the basolateral side of epithelial cells participate to homeostasis of epithelial tissues and tumor growth.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana , Núcleosídeo-Fosfato Quinase/metabolismo , Sequência de Aminoácidos , Animais , Células COS , Células CACO-2 , Proteínas de Transporte/química , DNA Complementar , Células Epiteliais/enzimologia , Células Epiteliais/metabolismo , Guanilato Quinases , Humanos , Dados de Sequência Molecular , Ligação Proteica , Homologia de Sequência de Aminoácidos
5.
J Biol Chem ; 276(18): 15256-63, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11278603

RESUMO

Identification of protein complexes associated with the ERBB2/HER2 receptor may help unravel the mechanisms of its activation and regulation in normal and pathological situations. Interactions between ERBB2/HER2 and Src homology 2 or phosphotyrosine binding domain signaling proteins have been extensively studied. We have identified ERBIN and PICK1 as new binding partners for ERBB2/HER2 that associate with its carboxyl-terminal sequence through a PDZ (PSD-95/DLG/ZO-1) domain. This peptide sequence acts as a dominant retention or targeting basolateral signal for receptors in epithelial cells. ERBIN belongs to the newly described LAP (LRR and PDZ) protein family, whose function is crucial in non vertebrates for epithelial homeostasis. Whereas ERBIN appears to locate ERBB2/HER2 to the basolateral epithelium, PICK1 is thought to be involved in the clustering of receptors. We show here that ERBIN and PICK1 bind to ERBB2/HER2 with different mechanisms, and we propose that these interactions are regulated in cells. Since ERBIN and PICK1 tend to oligomerize, further complexity of protein networks may participate in ERBB2/HER2 functions and specificity.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , Proteínas/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Transporte/química , Linhagem Celular , Proteína 1 Homóloga a Discs-Large , Proteína 4 Homóloga a Disks-Large , Guanilato Quinases , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Dados de Sequência Molecular , Ligação Proteica , Homologia de Sequência de Aminoácidos , Técnicas do Sistema de Duplo-Híbrido , Proteína da Zônula de Oclusão-1
6.
Nat Cell Biol ; 2(7): 407-14, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10878805

RESUMO

The ERBB receptors have a crucial role in morphogenesis and oncogenesis. We have identified a new PDZ protein we named ERBIN (ERBB2 interacting protein) that acts as an adaptor for the receptor ERBB2/HER2 in epithelia. ERBIN contains 16 leucine-rich repeats (LRRs) in its amino terminus and a PDZ (PSD-95/DLG/ZO-1) domain at its carboxy terminus, and belongs to a new PDZ protein family. The PDZ domain directly and specifically interacts with ERBB2/HER2. ERBIN and ERBB2/HER2 colocalize to the lateral membrane of human intestinal epithelial cells. The ERBIN-binding site in ERBB2/HER2 has a critical role in restricting this receptor to the basolateral membrane of epithelial cells, as mutation of the ERBIN-binding site leads to the mislocalization of the receptor in these cells. We suggest that ERBIN acts in the localization and signalling of ERBB2/HER2 in epithelia.


Assuntos
Proteínas de Transporte/metabolismo , Polaridade Celular , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Receptor ErbB-2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Aminoácidos , Animais , Sítios de Ligação , Transporte Biológico , Células CACO-2 , Linhagem Celular , Membrana Celular/química , Membrana Celular/metabolismo , Cães , Ativação Enzimática , Células Epiteliais/química , Imunofluorescência , Humanos , Intestinos/citologia , Peptídeos e Proteínas de Sinalização Intracelular , Rim/metabolismo , Camundongos , Dados de Sequência Molecular , Mutação , Ligação Proteica , Estrutura Terciária de Proteína , RNA Mensageiro/análise , RNA Mensageiro/genética , Alinhamento de Sequência , Especificidade por Substrato , Técnicas do Sistema de Duplo-Híbrido
7.
Eur J Gastroenterol Hepatol ; 12(5): 511-5, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10833093

RESUMO

BACKGROUND: The aim of the present study was to evaluate the effect of combined treatment with alpha-interferon (alpha-IFN) and ursodeoxycholic acid (UDCA) on liver function tests and serum HCV-RNA in patients with chronic hepatitis C who had not responded to alpha-IFN alone. METHOD: One hundred and three patients (60 men, 43 women, mean age 49 +/- 1.3 years) who had not responded (both HCV-RNA positive and increased serum ALT levels) to 4 consecutive months of treatment with alpha-IFN (3 MU three times weekly) were randomly assigned to receive UDCA (IFN-UDCA, 53 patients, 600 mg/day) in addition to the same alpha-IFN dose, or to continue alpha-IFN alone (IFN-controls, 50 patients). After stopping alpha-IFN, patients who had received UDCA continued to receive UDCA for an additional 6-month period. The two groups were comparable for sex, basal ALT, basal yGT, genotype distribution and liver histology, while mean age was lower in controls (53 +/- 1.8 vs 46 +/- 1.8 years; P< 0.01). RESULTS: Twenty (38%) out of 53 IFN-UDCA patients had normal ALT, compared with only six (12%) out of 50 IFN-control patients (P < 0.01). HCV-RNA became undetectable in four IFN-UDCA patients. Three months after withdrawal of alpha IFN, 15 IFN-UDCA responders, but none of the IFN-controls, had normal ALT values (P< 0.01); 6 months after withdrawal, nine IFN-UDCA responders still had normal ALT (P= NS) and HCV-RNA was still undetectable in four of them. Portal and periportal inflammation showed a statistically significant improvement (Fisher's exact test P< 0.01) in IFN-UDCA patients as compared with IFN-controls, while no effect was observed on portal fibrosis. CONCLUSIONS: These data demonstrate that UDCA improves the response rate to alpha-IFN. Furthermore, in 8% of IFN-UDCA patients the response rate was sustained and associated with HCV-RNA clearance.


Assuntos
Antivirais/uso terapêutico , Colagogos e Coleréticos/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , Ácido Ursodesoxicólico/uso terapêutico , Análise de Variância , Distribuição de Qui-Quadrado , Quimioterapia Combinada , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
J Clin Endocrinol Metab ; 85(2): 793-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10690892

RESUMO

Free fatty acids (FFA) are known to interfere with glucose metabolism. Moreover, it has been shown that they are able to impair the endothelium-dependent vasodilation. Therefore, we sought to determine whether their negative effect on endothelial function depends on their chain length or on their ability to modify PG production. Fourteen normal volunteers were studied under baseline conditions and then randomly allocated to two of the following four studies: 1) long chain triglyceride (LCT) emulsion and heparin infusion (n = 7), 2) infusion of an emulsion containing 56% medium chain triglycerides (MCT) and 44% LCT plus heparin (n = 7), 3) infusion of LCT and heparin preceded by an i.v. bolus of 900 mg lysine-salicylate (ASA; n = 7), and 4) after an i.v. bolus of ASA (n = 7). Basal forearm blood flow (FBF), endothelium-dependent vasodilation in response to intraarterial acetylcholine (Ach), and endothelium-independent vasodilation in response to intraarterial nitroprusside were assessed by venous occlusion plethysmography. Both LCT and MCT infusions significantly increased basal FBF from 1.58 +/- 0.35 to 2.60 +/- 0.76 and 2.28 +/- 0.56 mL/min 100 mL tissue, respectively (both P < 0.05). This increase was also observed for LCT plus heparin, but not after ASA alone. The percent increase in FBF during Ach was lowered during both LCT (252 +/- 34% of the ratio infused/control arm at maximal Ach dose) and MCT (255 +/- 41%) compared to the baseline conditions (436 +/- 44%; both P < 0.05). The response to Ach was also lower during LCT plus ASA, whereas it was similar to baseline with ASA alone. No differences were observed in the response to nitroprusside among the experimental conditions. In conclusion, 1) the effect of FFA on endothelium-dependent vasodilation is independent of their chain length; 2) both LCT and MCT increase baseline FBF, independently from cyclooxygenase inhibition; and 3) acute ASA administration does not affect endothelium-dependent vasodilation. The FFA effect on the endothelial response to Ach may contribute to altered endothelial function and, hence, to the development and progression of atherosclerotic cardiovascular disease.


Assuntos
Endotélio Vascular/fisiologia , Ácidos Graxos não Esterificados/sangue , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Adulto , Inibidores de Ciclo-Oxigenase/farmacologia , Combinação de Medicamentos , Emulsões , Ácidos Graxos não Esterificados/química , Feminino , Antebraço/irrigação sanguínea , Heparina/farmacologia , Humanos , Lisina/análogos & derivados , Lisina/farmacologia , Masculino , Nitroprussiato/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Triglicerídeos/química , Triglicerídeos/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
9.
Acta Diabetol ; 37(4): 201-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11450504

RESUMO

An extrapancreatic effect of sulfonylureas has been postulated. However, in vivo results have been disputed because the amelioration of insulin action that follows sulfonylurea may represent the relief from glucose toxicity rather than a direct effect of the drug. Therefore, we studied the hypoglycemic action of gliclazide acutely and after 2 months of therapy in seven type 2 diabetic patients. All patients received a 240-minute i.v. glucose infusion with [3-3H]glucose. In a random order, 160 mg gliclazide (study 1) or placebo (study 2) was given orally before glucose infusion. Finally, the effect of 160 mg gliclazide was reassessed after a two-month treatment with the same sulfonylurea (80 mg t.i.d.). Basal plasma glucose, insulin, C-peptide and endogenous glucose production (EGP) were similar before the two initial studies. During glucose infusion, EGP was more suppressed after gliclazide in spite of comparable increase in plasma insulin and C-peptide. After the two-month therapy, basal plasma glucose levels and HbA1c were lower while plasma insulin and C-peptide were higher with respect to baseline (p < 0.05). Gliclazide further reduced plasma glucose, the incremental area above baseline, and EGP during glucose infusion, while plasma insulin and C-peptide achieved higher plateaus (p < 0.05). When data were pooled, plasma glucose concentration and EGP correlated both in the basal state (r = 0.71) and during the last hour of glucose infusion (r = 0.84; both p < 0.05). These data suggest that gliclazide enhances the suppression of EGP induced by insulin and that this effect is greater with chronic treatment because of concomitant improvement of insulin secretion.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Gliclazida/efeitos adversos , Hipoglicemia/fisiopatologia , Hipoglicemiantes/efeitos adversos , Doença Aguda , Glicemia/efeitos dos fármacos , Peptídeo C/sangue , Doença Crônica , Diabetes Mellitus Tipo 2/sangue , Gluconeogênese , Técnica Clamp de Glucose , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemia/induzido quimicamente , Insulina/sangue , Cinética , Pessoa de Meia-Idade , Placebos , Análise de Regressão , Fatores de Tempo , Trítio
10.
Leukemia ; 13(9): 1374-82, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10482988

RESUMO

The FLT3 receptor tyrosine kinase and its ligand, FL, regulate the development of hematopoietic stem cells and early B lymphoid progenitors. FL has a strong capacity to boost production of dendritic and natural killer cells in vivo, thereby providing a new and promising tool for anti-cancer immunotherapy. Intracellular FLT3 signaling involves tyrosine phosphorylation of several cytoplasmic proteins including SHC. We have found that upon FLT3 activation SHC phosphorylation occurs at tyrosine 239/240 and 313. SHC possesses two phosphotyrosine-binding domains: an amino-terminal phosphotyrosine binding (PTB) and a carboxy-terminal Src Homology 2 (SH2) domain. Neither is required for SHC phosphorylation, but the PTB domain is necessary and sufficient for SHC binding to the SH2 containing inositol phosphatase (SHIP). Overexpression of SHC increases the level of SHIP phosphorylation on tyrosines in response to FLT3 activation, suggesting that SHC availability is a limiting step for SHIP phosphorylation. This effect is observed only if the SHC PTB domain is functional. Interestingly, SHC overexpression in FLT3-activatable Ba/F3 cells limits FLT3-dependent cell growth and this effect requires tyrosine 313. Taken together, the present data show that SHC can antagonize cell proliferation induced by FLT3 stimulation and regulate phosphorylation of the SHIP negative regulator. In addition, our study provides the structural bases for SHC phosphorylation and formation of the SHC/SHIP complex.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Domínios de Homologia de src , Animais , Linhagem Celular , Ativação Enzimática , Genes myc , Código Genético , Cinética , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Fosforilação , Retroviridae/genética , Proteínas Adaptadoras da Sinalização Shc
11.
Am J Gastroenterol ; 94(8): 2246-50, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10445557

RESUMO

OBJECTIVES: The aims of this long-term, prospective randomized study were to evaluate the clinical usefulness of alpha-interferon in treating chronic HBV infection and to establish whether clearance of viral replication markers and normalization of liver function tests induced by alpha-interferon were sustained. METHODS: Sixty-four patients with chronic wild type (HBeAg-positive) hepatitis B, enrolled between 1983 and 1987, were randomized into two groups. Thirty-three patients received alpha-interferon (5 MU/m2 three times weekly for 6 months; treated group), and 31 were not treated (controls). Treated and control patients were prospectively followed for a mean of 86.4 +/- 6.96 and 79.7 +/- 6.8 (p = NS) months, respectively. RESULTS: Clearance of the following viral markers was found in treated and control patients as follows: HBV-DNA, 26 (78.9%) and 18 (58.1%) (p = 0.106); HBeAg, 30 (90.9%) and 19 (61.2%) (p < 0.007); and HBsAg, 12 (36.4%) and three (9.8%) (p < 0.017). Persistent abnormal ALT levels were found in 11 (33.3%) treated and in 22 (70.9%) control patients (p < 0.025). Four control and three treated patients developed portal hypertension whereas two control and one treated patient developed hepatocellular carcinoma. Seven patients (five treated and two controls) were retrospectively found to have hepatitis C virus (HCV) coinfection before enrollment. To date, all coinfected patients remain positive for HCV-RNA. Also, all HCV coinfected patients, except one in the treated group, had persistent increased serum ALT levels. One of the coinfected patients developed portal hypertension. CONCLUSIONS: Chronic HBV hepatitis patients responding to interferon treatment had a faster, more complete, and sustained clearance of viral markers than controls; HCV coinfection does not seem to negatively affect the clearance of HBV replicative markers. However when coinfection occurs, hepatic disease persists despite HBV marker clearance.


Assuntos
Hepatite B Crônica/terapia , Interferon-alfa/administração & dosagem , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Hepatite B Crônica/diagnóstico , Humanos , Interferon-alfa/efeitos adversos , Testes de Função Hepática , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Replicação Viral/efeitos dos fármacos
12.
Assist Inferm Ric ; 18(2): 65-71, 1999.
Artigo em Italiano | MEDLINE | ID: mdl-10909328

RESUMO

The educational process of a diabetic patient is a long life experience. The monitoring experience of the educational activity with diabetic patients is described. Nurses working at the Diabetic Centre in Rovigo perceived difficulties in the communication with IDDM patients (Insulin Dependent Diabetes Mellitus) especially at the first diagnosis of the disease and during the first patients' encounters. A thorough assessment of the nurse patient communication (analysis of the problems perceived and specific problems encountered; videotapes of nurse-patient communication and discussion with the psychologist on the verbal and non verbal communication styles adopted; discussion with the team on the content of the communication) was the occasion for modifying the information protocols. The experience involved also the nurses caring for patients in the general wards, in order to guarantee continuity in care and information between the ward and the Centre. A 'Survival Kit' for newly diagnosed IDDM patients was devised and an agreement was reached not only on contents to be taught during the first encounters but also on skills that the patients is expected to acquire and on the teaching methods.


Assuntos
Comunicação , Diabetes Mellitus Tipo 1/enfermagem , Diabetes Mellitus Tipo 1/psicologia , Relações Enfermeiro-Paciente , Planejamento de Assistência ao Paciente/normas , Educação de Pacientes como Assunto/métodos , Adolescente , Adulto , Criança , Hospital Dia , Feminino , Humanos , Itália , Masculino , Avaliação em Enfermagem/métodos , Pesquisa em Avaliação de Enfermagem , Autocuidado/métodos , Autocuidado/psicologia
13.
J Biol Chem ; 273(24): 14962-7, 1998 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-9614102

RESUMO

The FLT3 receptor tyrosine kinase and its ligand, FL, play an important role in early hematopoietic development. We have found that CBLB, a recently characterized molecule closely related to the CBL protooncogene product, is phosphorylated on tyrosine(s) following FL treatment of JEA2 human pro-B cells and THP1 monocytic cells. Treatment of JEA2 cells with interleukin (IL)-7 induces CBLB phosphorylation as well. FL and IL-7, respectively, induce and increase association of tyrosine-phosphorylated SHC and the p85 subunit of phosphatidylinositol 3'-kinase with CBLB. In these cells, CBLB constitutively binds the GRB2 adaptor predominantly through its N-terminal SH3 domain, to form a complex that is distinct from the GRB2.CBL and GRB2.SOS1 complexes. Together with the fact that CBLB is consistently found in blast cells from acute leukemias and in peripheral blood mononuclear cells, this suggests that CBLB has a role in tyrosine kinase-regulated signaling pathways in many hematolymphoid cells.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular , Antígenos CD/fisiologia , Proteínas de Membrana/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Receptores Proteína Tirosina Quinases/fisiologia , Receptores de Interleucina/fisiologia , Proteínas Oncogênicas de Retroviridae/metabolismo , Transdução de Sinais/fisiologia , Proteína Adaptadora GRB2 , Regulação da Expressão Gênica/genética , Hematopoese/fisiologia , Humanos , Interleucina-7/farmacologia , Proteína Oncogênica v-cbl , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Fosfotirosina/análise , Proteínas/metabolismo , Receptores de Interleucina-7 , Proteínas Adaptadoras da Sinalização Shc , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Células Tumorais Cultivadas , Tirosina Quinase 3 Semelhante a fms
14.
Leukemia ; 12(3): 301-10, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9529123

RESUMO

Proliferation and survival of hematopoietic progenitors are partially dependent on the interaction between the FLT3 receptor tyrosine kinase (RTK) and its ligand, FL. This biological function depends primarily on tyrosine phosphorylation of cellular targets that initiate several transduction cascades. These events return to their basal levels upon activation of specific phosphatases. We analyzed tyrosine phosphorylation events in response to FL, in human cell lines of different hematopoietic origins that express endogenous FLT3, namely the myelomonocytic, monocytic, pre-B and pro-B lineages. This study aimed at determining (1) the identity of FLT3 downstream substrates in physiologically relevant cells and (2) distinct substrate involvement in myeloid or early B cells. The two prominent tyrosine-phosphorylated proteins are p52SHC and p115CBL in myeloid cell lines and p52SHC and an uncharacterized p115 in early B cell lines. Following FL stimulation, a concomitant increase in both CBL phosphorylation and complex formation with p85 subunit of phosphatidylinositol 3' kinase is observed. In contrast, the GRB2/CBL association observed in unstimulated cells is not modified after stimulation, and SHC is never detected in anti-CBL immunoprecipitates. FL-inducible binding of CBL to the CRKII adaptor molecule is also demonstrated. This study presents a picture of the signaling events triggered by activation of endogenous FLT3 receptor in human hematopoietic cells, including the existence of a B cell-specific FLT3 substrate.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular , Células-Tronco Hematopoéticas/fisiologia , Fosfoproteínas/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Transdução de Sinais , Linfócitos B , Linhagem Celular , Proteína Adaptadora GRB2 , Células-Tronco Hematopoéticas/citologia , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Fosfotirosina/análise , Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-crk , Proteínas Recombinantes/metabolismo , Proteínas Adaptadoras da Sinalização Shc , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Especificidade por Substrato , Transfecção , Células Tumorais Cultivadas , Tirosina Quinase 3 Semelhante a fms , Domínios de Homologia de src
15.
Blood ; 90(1): 111-25, 1997 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9207445

RESUMO

The class III receptor tyrosine kinase FLT3/FLK2 (FLT3; CD135) represents an important molecule involved in early steps of hematopoiesis. Here we compare cell-surface expression of FLT3 on bone marrow (BM) and cord blood (CB) cells using monoclonal antibodies (MoAbs) specific for the extracellular domain of human FLT3. Flow cytometric analysis of MACS-purified BM and CB cells showed that 63% to 82% of BM CD34+ and 88% to 95% of the CB CD34+ cells coexpress FLT3. Clonogenic assays and morphological characterization of FACS-sorted BM CD34+ cells demonstrate that colony-forming unit-granulocyte-macrophage (CFU-GM) and immature myelo-monocytic precursor cells are enriched in the subpopulation staining most brightly with the FLT3 MoAb whereas the majority of the burst-forming units-erythroid (BTU-E) and small cells with lymphoid morphology are found in the FLT3- population. In contrast, statistically indistinguishable proportions of CFU-granulocyte-erythrocyte-megakaryocyte-macrophage (CFU-GEMM) and more primitive cobblestone area forming cells (CAFC) were detected in both fractions, albeit the FLT3+ fraction consistently showed more CAFC activity than the FLT3- fraction. Although in both, BM and CB the majority of CD34+CD117+ (KIT+), CD34+CD90+ (Thy-1+), and CD34+CD109+ cells coexpress FLT3, three-color phenotypic analyses are consistent with the functional findings and suggest that the most primitive cells defined as CD34+CD38-, CD34+CD71low, CD34+HLA-DR-, CD34+CD117low, CD34+CD90+, and CD34+CD109+ express low levels of cell-surface FLT3 and were therefore not enriched to a statistically significant extent with the bright versus negative sorting scheme. Thus, clear segregation of the most primitive progenitors from BM CD34+ cells was confounded by low apparent levels of FLT3 cell-surface expression on these cells, whereas myeloid progenitors unambiguously segregated with the FLT3 brightest cells and erythroid progenitors with the FLT3 dimmest. Additional phenotypic analyses using MoAbs against progenitor/stem cell markers including the mucinlike molecule MGC-24v (CD164), the receptor tyrosine kinases TIE, FMS (CD115), and KIT (CD117) further illustrate the differences in surface antigen expression profiles of BM and CB CD34+ cells. Notably, CD115 is rarely detected on CB CD34+ cells, whereas 20% to 25% of the BM CD34+FLT3+ cells are CD115+. Furthermore, 80% to 95% of the CB CD34+CD117+ but only 60% to 75% of the BM CD34+CD117+ cells coexpress FLT3. Only a negligible amount of CD34+CD19+ are detected in CB, while in BM 20% to 30% of CD34+CD19+ presumed pro/pre-B cells coexpress FLT3. In contrast, the majority of the CD34+CD164+ and CD34+TIE+ subsets in both CB and BM coexpress FLT3. Analysis of unseparated cells showed that FLT3 expression is not restricted to CD34+ subsets. About 65% to 70% of lymphocyte-gated BM CD34-FLT3+ cells are positive for the monocytic marker CD115 whereas 25% to 30% of these cells consist of CD10 expressing B-cell precursors. Finally, CD34- monocytes in BM, CB, and PB express FLT3 whereas granulocytes are FLT3-. Our data show that detectable FLT3 appears first at low levels on the surface of primitive multilineage progenitor cells and disappears during defined stages of B-cell development, but is upregulated and maintained during monocytic maturation.


Assuntos
Células da Medula Óssea , Sangue Fetal/citologia , Células-Tronco Hematopoéticas/citologia , Proteínas Proto-Oncogênicas/biossíntese , Receptores Proteína Tirosina Quinases/biossíntese , Medula Óssea/metabolismo , Diferenciação Celular , Feminino , Sangue Fetal/metabolismo , Citometria de Fluxo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Imunofenotipagem , Recém-Nascido , Gravidez , Receptores de Superfície Celular , Tirosina Quinase 3 Semelhante a fms
16.
Riv Inferm ; 16(4): 215-8, 1997.
Artigo em Italiano | MEDLINE | ID: mdl-9510824

RESUMO

The educational experience of a Diabetic Care Centre, throughout 15 years is described using the metaphor of the tree. Each course organized for different patients with different needs is a branch that contributes to the development of the tree. The importance of a common philosophy and the team work are considered pivotal for the growth and development of the educational tree. One hundred twenty-nine courses have been organized to data and 239 follow-up evaluations were performed.


Assuntos
Centros Comunitários de Saúde/tendências , Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Educação de Pacientes como Assunto/métodos , Educação de Pacientes como Assunto/tendências , Humanos , Itália , Modelos Educacionais , Equipe de Assistência ao Paciente
17.
Metabolism ; 45(10): 1196-202, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8843172

RESUMO

The mechanism of the hypoglycemic action of gliclazide was evaluated in 17 diet-treated non-insulin-dependent diabetes mellitus (NIDDM) patients. In study A, five patients received a 240-minute glucose infusion along with [3-3H]glucose infusion. In study B, seven patients received a 240-minute isoglycemic insulin clamp along with [3-3H]glucose infusion. And in study C, five patients received a somatostatin infusion with basal replacing doses of insulin and glucagon. The three studies (A, B, and C) were repeated twice. Gliclazide (240 mg orally) was administered on one occasion, and placebo was given on the second occasion. Basal hepatic glucose production (HGP) and utilization and plasma glucose, insulin, C-peptide, glucagon, and free fatty acid (FFA) concentrations were similar before administration of gliclazide and placebo. In study A, plasma glucose, its incremental area, and HGP were reduced by gliclazide administration (all P < .05), but glucose utilization was not significantly affected. The increase in plasma insulin and C-peptide concentrations was similar with gliclazide and placebo, although the plasma insulin to glucose ratio was increased with gliclazide. HGP decremental area was correlated with the reduction in plasma glucose incremental area (r = -.63, P < .05). In study B, gliclazide administration produced a larger suppression of HGP, but the overall rate of glucose utilization was not different in the two studies. In study C, plasma glucose concentration and HGP progressively decreased in both studies, without a difference between gliclazide and placebo. These results suggest that under conditions of hyperglycemia and hyperinsulinemia gliclazide elicits a larger suppression of HGP.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Gliclazida/farmacologia , Glucose/biossíntese , Hipoglicemiantes/farmacologia , Fígado/metabolismo , Glicemia/análise , Diabetes Mellitus Tipo 2/sangue , Ácidos Graxos não Esterificados/sangue , Feminino , Glucagon/farmacologia , Hormônios/sangue , Humanos , Insulina/farmacologia , Cinética , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Somatostatina/farmacologia
18.
Ann Ital Med Int ; 11 Suppl 2: 48S-52S, 1996 Oct.
Artigo em Italiano | MEDLINE | ID: mdl-9004820

RESUMO

Cholestasis syndromes are characterized by a reflux of compounds usually excreted with bile. ATP dependent carriers and cytoskeleton proteins guarantee physiological bile flux. There are several clinical conditions in which this system is affected. Intrahepatic cholestasis is characterized by damage to hepatocytes or intrahepatic bile ducts. Primary biliary cirrhosis and primary sclerosing cholangitis represent examples of cholestatic chronic liver disease. The pathogenesis of these two conditions seems to be mediated by immunological reactions. Moreover, hepatitis viruses are able to induce cholestasis.


Assuntos
Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/fisiopatologia , Hepatopatias/complicações , Colestase Intra-Hepática/etiologia , Doença Crônica , Diagnóstico Diferencial , Humanos
19.
J Biol Chem ; 271(22): 12956-63, 1996 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-8662748

RESUMO

The FLT4 gene encodes two isoforms of a tyrosine kinase receptor, which belongs to the family of receptors for vascular endothelial growth factor. As the result of an alternative processing of primary mRNA transcripts, the long isoform differs from the short isoform by an additional stretch of 65 amino acid residues located at the C terminus and containing three tyrosine residues, Tyr1333, Tyr1337, and Tyr1363. Only the long isoform is endowed with a transforming capacity in fibroblasts. We show that this activity is related to the capacity of the tyrosine 1337-containing sequence to interact with the phosphotyrosine binding domain of the SHC protein. This demonstrates that a functional property of this newly described domain includes relay of mitogenic signals. In addition, it shows that the same receptor can mediate different functions through the optional binding of the phosphotyrosine binding domain and that the alternative use of this domain is sufficient to direct the signal toward different pathways.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas Adaptadoras de Transporte Vesicular , Fosfotirosina/metabolismo , Proteínas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Animais , Sequência de Bases , Linhagem Celular Transformada , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Oligodesoxirribonucleotídeos , Testes de Precipitina , Ligação Proteica , Ratos , Receptores Proteína Tirosina Quinases/genética , Receptores de Superfície Celular/genética , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Adaptadoras da Sinalização Shc , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Tirosina/genética , Receptor 3 de Fatores de Crescimento do Endotélio Vascular
20.
Leukemia ; 10(2): 238-48, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8637232

RESUMO

FLT3/FLK2 is a receptor tyrosine kinase (RTK) which is thought to play an important role in early stages of hematopoiesis. Monoclonal antibodies (mAbs) against the extracellular domain of human FLT3 were generated to study the cell surface expression of this class III RTK on normal bone marrow cells and on leukemic blasts from patients with acute leukemias. Functional analysis of five mAbs (SF1 series) revealed that all of them can mimic to variable extents the activity of the FLT3 ligand (FL) upon receptor activation and modulation, while only one mAb weakly inhibited ligand binding. Using flow cytometry, we detected surface expression of FLT3 on cell lines of the myeloid (4/8) and B lymphoid (7/10) lineages. On normal human bone marrow cells, the expression of FLT3 is restricted, in agreement with a presumed function of this receptor at the level of the stem cells and early committed progenitors. Expression of FLT3 was found on a fraction of CD34-positive and CD34-negative cells. Three-color analysis further revealed that most of the CD34 FLT3+ cells coexpress CD117 (KIT) at a high level. Finally, FLT3 is expressed on leukemic blasts of 18/22 acute myeloid leukemias (AML) and 3/5 acute lymphoid leukemias (ALL) of the B lineage, providing a possible application in diagnosis and therapy of these diseases.


Assuntos
Células-Tronco Hematopoéticas/enzimologia , Leucemia/enzimologia , Proteínas de Membrana/metabolismo , Células-Tronco Neoplásicas/enzimologia , Receptores Proteína Tirosina Quinases/metabolismo , Anticorpos Monoclonais , Antígenos CD34/metabolismo , Linfoma de Burkitt/enzimologia , Membrana Celular/enzimologia , Citometria de Fluxo , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/patologia , Humanos , Leucemia/imunologia , Leucemia/patologia , Leucemia Mieloide Aguda/enzimologia , Células-Tronco Neoplásicas/imunologia , Células-Tronco Neoplásicas/patologia , Proteínas Proto-Oncogênicas c-kit/metabolismo
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