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1.
Eur Rev Med Pharmacol Sci ; 26(13): 4770-4773, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35856369

RESUMO

OBJECTIVE: Botulism is a very rare disease in Switzerland, with less than one case per year, an incidence of 0.01 cases for 100,000 inhabitants. Indeed, over the past ten years, 9 cases have been reported to Public Health registry. Foodborne botulism (FB) is caused by ingestion of preformed botulinum neurotoxin. Characteristic features should be rapidly recognized, and prompt treatment should be administered to avoid further progression towards respiratory failure and death. CASE REPORT: We report the case of a patient who developed gastrointestinal symptoms just after a sandwich consumption followed by rapidly progressive cranial nerve impairment, truncal muscle weakness in a descending pattern and respiratory failure requiring mechanical ventilation. The diagnosis of foodborne botulism was delayed due to differential diagnosis considerations. Specific antitoxin therapy was administered immediately after firm clinical conviction of botulism, without waiting for serologic results that later confirmed the diagnosis. As expected, muscle weakness recovery was slow, with persistent chronic deficits nine years later. CONCLUSIONS: This case highlights differential diagnosis issues of botulism. These include acute neuromuscular disorders such as myasthenia gravis, Guillain-Barré syndrome, or tick-borne encephalitis. The importance of careful medical history and repeated clinical evaluation to avoid misdiagnosis can be lifesaving. Our case highlights the typical warning signs.


Assuntos
Toxinas Botulínicas , Botulismo , Insuficiência Respiratória , Doença Aguda , Toxinas Botulínicas/uso terapêutico , Botulismo/diagnóstico , Botulismo/epidemiologia , Botulismo/terapia , Humanos , Debilidade Muscular/etiologia , Respiração Artificial/efeitos adversos
2.
Clin Nutr ; 36(1): 281-287, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-26775753

RESUMO

BACKGROUND & AIMS: Energy targets are a matter of debate for intensive care (ICU) patients. As the guidelines have evolved, energy targets have been reduced, while the protein intake objectives have increased. The impact of these changes remains largely unknown. This quality study aimed at investigating the clinical impact of these changes in patients with an ICU stay >3 days. METHODS: Observational cohort study over two 3 months periods (A, B), with distinct prevailing nutrition recommendations in patients admitted consecutively to a multidisciplinary ICU. Inclusion criterion: ICU stay >3 days. Recorded variables: severity scores, energy target and delivery, protein delivery, feeding route, length of stay (ICU, hospital) and hospital outcome. Data as mean, SD and IQR. RESULTS: The analysis included 389 patients, and 3920 observation days. Except for patient age (A versus B: 57.8 and 62.3 years; p = 0.010) and NRS (4.3 vs 3.9 respectively p = 0.002), the cohorts were similar. Compared to A, the mean prescribed energy target decreased by 125 kcal (1947 kcal/d vs. 1822 kcal*day-1 respectively), resulting in lower energy delivery (1353 kcal*day-1 vs. 1238 kcal*day-1; p < 0.0001), and reduced protein delivery (81 g*day-1 vs. 65 g*day-1: p < 0.0001). These differences were associated in survivors with prolonged mechanical ventilation (5.0 days vs. 6.7 days; p = 0.004), extended ICU stay (8.5 vs. 9.9 days; p = 0.0036), and longer hospital stay (23.4 vs. 26.4 days respectively; p = 0.028). Mortality was unchanged. CONCLUSIONS: A linear reduction in energy target recommendation without changing the feed composition led to an unplanned and significant reduction in protein delivery, which was associated with a prolonged duration of ventilation and an extended hospital stay.


Assuntos
Proteínas Alimentares/administração & dosagem , Unidades de Terapia Intensiva , Necessidades Nutricionais , Recomendações Nutricionais , Adulto , Idoso , Estudos de Coortes , Estado Terminal/terapia , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Política Nutricional , Estado Nutricional , Respiração Artificial , Resultado do Tratamento
3.
Oncogene ; 33(37): 4537-47, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-24121272

RESUMO

By the mid 1980's, it was clear that the transforming activity of oncogenic Src was linked to the activity of its tyrosine kinase domain and attention turned to identifying substrates, the putative next level of control in the pathway to transformation. Among the first to recognize the potential of phosphotyrosine-specific antibodies, Parsons and colleagues launched a risky shotgun-based approach that led ultimately to the cDNA cloning and functional characterization of many of today's best-known Src substrates (for example, p85-Cortactin, p110-AFAP1, p130Cas, p125FAK and p120-catenin). Two decades and over 6000 citations later, the original goals of the project may be seen as secondary to the enormous impact of these protein substrates in many areas of biology. At the request of the editors, this review is not restricted to the current status of the substrates, but reflects also on the anatomy of the project itself and some of the challenges and decisions encountered along the way.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/metabolismo , Quinases da Família src/metabolismo , Animais , Cateninas/fisiologia , Transformação Celular Neoplásica , Cortactina/fisiologia , Proteína Substrato Associada a Crk/fisiologia , Quinase 1 de Adesão Focal/fisiologia , Humanos , Camundongos , Proteínas dos Microfilamentos/fisiologia , Fosforilação , Proteoma , delta Catenina
4.
Rev Mal Respir ; 29(6): 775-84, 2012 Jun.
Artigo em Francês | MEDLINE | ID: mdl-22742464

RESUMO

INTRODUCTION: The lung is the organ most frequently involved by metastatic calcification. This condition is probably under-diagnosed, the patients usually being asymptomatic. This article summarizes the current knowledge concerning pulmonary metastatic calcification. BACKGROUND: The pathogenesis of pulmonary metastatic calcification is not well known, but it involves phosphate-calcium balance, renal function and pH. The most frequently encountered aetiologies are hyperparathyroidism, neoplastic bony lesions, and renal failure. The definitive diagnosis is achieved by histology, radiological examinations being insensitive. The clinical manifestations are various and can include a pulmonary restrictive syndrome, diffusion abnormalities, hypoxaemia and respiratory failure. The latter can be severe and influence the prognosis adversely: 19 cases of fatal pulmonary metastatic calcification have been reported. The treatment is aetiological and symptomatic. VIEWPOINT: The prognostic factors for a poor outcome of this potentially lethal condition remain to be determined. The management of asymptomatic patients is also uncertain. CONCLUSIONS: Pulmonary metastatic calcification is a rare condition of complex pathogenesis. The clinical manifestations are varied, ranging from asymptomatic to severe, even fatal.


Assuntos
Calcinose/etiologia , Pneumopatias/etiologia , Pulmão/patologia , Calcinose/diagnóstico por imagem , Calcinose/patologia , Humanos , Pulmão/diagnóstico por imagem , Pneumopatias/diagnóstico por imagem , Pneumopatias/patologia , Tomografia Computadorizada por Raios X
5.
Med Mal Infect ; 39(5): 344-7, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19269757

RESUMO

Hypogammaglobulinemia develops in 3 to 6% of patients with thymoma and this association is commonly referred to as thymoma with immunodeficiency (formerly Good syndrome). Recurrent infections with encapsulated bacteria and opportunistic infections associated with disorders of both humoral and cell mediated immunity frequently occur in this rare primary, adult-onset immunodeficiency. We report a case of thymoma with immunodeficiency complicated by disseminated herpes simplex virus (HSV) infection and review five additional cases of HSV-related infections reported since 1966 in patients presenting with thymoma with immunodeficiency. Patients presented with epiglottitis, keratitis, recurrent genital herpes, ulcerative dermatitis, and acute hepatitis. Four of the six cases had a fatal outcome, two of which were directly attributable to HSV infection. Since the risk of invasive opportunistic infections is high and the presentation atypical, lymphocyte count and total serum immunoglobulin should be measured regularly in all patients presenting with thymoma with immunodeficiency.


Assuntos
Ceftriaxona/uso terapêutico , Herpes Simples/complicações , Síndromes de Imunodeficiência/complicações , Timoma/complicações , Adulto , Idoso , Evolução Fatal , Feminino , Humanos , Imunoglobulinas/sangue , Masculino , Pessoa de Meia-Idade , Timoma/patologia , Neoplasias do Timo/complicações , Neoplasias do Timo/patologia
6.
Neurology ; 69(3): 255-60, 2007 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-17636063

RESUMO

BACKGROUND: Prognosis of status epilepticus (SE) depends on its cause, but there is uncertainty as to whether SE represents an independent outcome predictor for a given etiology. Cerebral anoxia is a relatively homogenous severe encephalopathy. Postanoxic SE is associated to a nearly 100% mortality in this setting; however, it is still unclear whether this is a severity marker of the underlying encephalopathy, or an independent factor influencing outcome. The goal of this study was to assess if postanoxic SE is independently associated with mortality after cerebral anoxia. METHODS: This was a retrospective observation of consecutive comatose survivors of cardiac arrest, including subjects treated with hypothermia. On the subgroup with EEG recordings in the first hospitalization days, univariate and multivariate analyses were applied to potential determinants of in-hospital mortality, and included the following variables: age, gender, type and length of cardiac arrest, occurrence of circulatory shock, presence of therapeutic hypothermia, and electrographic SE. RESULTS: Out of 166 postanoxic patients, 107 (64%) had an EEG (median latency from admission, 2 days); in this group, therapeutic hypothermia was administered in 59%. Death occurred in 71 (67%) patients. Postanoxic SE was associated with mortality regardless of type of acute cardiac rhythm and administration of hypothermic treatment. CONCLUSION: In this hospital-based cohort, postanoxic status epilepticus (SE) seems to be independently related to death in cardiac arrest survivors, suggesting that SE might determine a bad prognosis for a given etiology. Confirmation of these results in a prospective assessment is needed.


Assuntos
Hipóxia Encefálica/epidemiologia , Estado Epiléptico/epidemiologia , Adulto , Idoso , Estudos de Coortes , Feminino , Parada Cardíaca/complicações , Parada Cardíaca/epidemiologia , Parada Cardíaca/fisiopatologia , Humanos , Hipóxia Encefálica/etiologia , Hipóxia Encefálica/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Fatores de Risco , Estado Epiléptico/etiologia , Estado Epiléptico/fisiopatologia , Resultado do Tratamento
7.
Rev Med Suisse ; 2(91): 2866-70, 2006 Dec 13.
Artigo em Francês | MEDLINE | ID: mdl-17236327

RESUMO

Taking care of a critically-ill patient is of high complexity level, as it includes bio-pschosocial and cultural aspects. Until recently, physicians have paid little attention to spirituality, although it constitutes the essential of human being. Spiritual need may reveal to be of utmost importance and has influence on bio-psycho-social aspects for a patient experiencing severe disease with threatening outcome and near death. A physician may transfer the problem to a specialist, a chaplain, or may personally be able to assess this need. To put a bio-psycho-social-spiritual model of care into practice, health care givers including chaplains should set up a team work. Their educational programs should include spirituality care training. Swiss intensivists should acquire the competency to take care of their patients in a holistic manner.


Assuntos
Cuidados Críticos , Estado Terminal/psicologia , Espiritualidade , Adaptação Psicológica , Atitude Frente a Saúde , Humanos
8.
Rev Med Suisse ; 2(91): 2871-4, 2006 Dec 13.
Artigo em Francês | MEDLINE | ID: mdl-17236328

RESUMO

The merging of two intensive care units is a time of profound change, and constitutes a risk of mishaps. We report some aspects of such a project in our institution. The evaluation of various indicators reflecting the activity, patient's hospital pathways, mortality, as well as the use of specific techniques, has shown that no particular problem was observed during the first 9 months. Improvements in performance or productivity have not been demonstrated so far. The follow-up will permit to demonstrate long-term benefits. We believe that these observations may be of interest for other departmental or hospital reorganisations.


Assuntos
Instituições Associadas de Saúde/organização & administração , Unidades de Terapia Intensiva/organização & administração , Humanos , Suíça
9.
J Clin Pharmacol ; 43(12): 1329-40, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14615469

RESUMO

Meropenem, a carbapenem broad-spectrum antibiotic, is regularly used in patients undergoing continuous venovenous hemodiafiltration (CVVHDF). Its disposition was studied over one dosage interval in 15 patients under CVVHDF on a steady regimen of 500 or 1000 mg every 8 to 12 hours. Meropenem levels were measured in plasma and filtrate-dialysate by high-performance liquid chromatography (HPLC) with UV detection. The mean CVVHDF flow rates were 7.1 +/- 0.9 L/h for blood (mean +/- SD), 0.5 +/- 0.3 L/h for predilution solution, 1.2 +/- 0.3 L/h for countercurrent dialysate, and 1.8 +/- 0.5 L/h for the total filtrate-dialysate. The pharmacokinetic analysis was based both on a noncompartmental approach and on a four-compartment modeling. The mean (coefficient of variation [CV]) total body clearance, volume of distribution at steady state, and mean residence time were, respectively, 5.0 L/h (46%), 14.3 L (29%), and 4.8 h (36%). The hemodiafiltration clearances calculated from plasma data alone and plasma with filtrate-dialysate data were 1.2 L/h (26%) and 1.6 L/h (39%), respectively. The compartmental model was used to optimize the therapeutic schedule of meropenem, considering reference minimal inhibitory concentration (MIC) of sensitive strains (4 mg/L). The results indicate that two different therapeutic schedules of meropenem are equally applicable to patients receiving CVVHD: either 750 mg tid or 1500 bid.


Assuntos
Injúria Renal Aguda/metabolismo , Hemodiafiltração , Tienamicinas/farmacocinética , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/mortalidade , Idoso , Área Sob a Curva , Cuidados Críticos , Esquema de Medicação , Feminino , Meia-Vida , Humanos , Masculino , Meropeném , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Modelos Biológicos , Tienamicinas/administração & dosagem , Tienamicinas/uso terapêutico
10.
Antimicrob Agents Chemother ; 47(11): 3442-7, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14576100

RESUMO

In a randomized, evaluator-blind, multicenter trial, we compared cefepime (2 g three times a day) with imipenem-cilastatin (500 mg four times a day) for the treatment of nosocomial pneumonia in 281 intensive care unit patients from 13 centers in six European countries. Of 209 patients eligible for per-protocol analysis of efficacy, favorable clinical responses were achieved in 76 of 108 (70%) patients treated with cefepime and 75 of 101 (74%) patients treated with imipenem-cilastatin. The 95% confidence interval (CI) for the difference between these response rates (-16 to 8%) failed to exclude the predefined lower limit for noninferiority of -15%. In addition, therapy of pneumonia caused by an organism producing an extended-spectrum beta-lactamase (ESBL) failed in 4 of 13 patients in the cefepime group but in none of 10 patients in the imipenem group. However, the clinical efficacies of both treatments appeared to be similar in a secondary intent-to-treat analysis (95% CI for difference, -9 to 14%) and a multivariate analysis (95% CI for odds ratio, 0.47 to 1.75). Furthermore, the all-cause 30-day mortality rates were 28 of 108 (26%) patients in the cefepime group and 19 of 101 (19%) patients in the imipenem group (P = 0.25). Rates of documented or presumed microbiological eradication of the causative organism were similar with cefepime (61%) and imipenem-cilastatin (54%) (95% CI, -23 to 8%). Primary or secondary resistance of Pseudomonas aeruginosa was detected in 19% of the patients treated with cefepime and 44% of the patients treated with imipenem-cilastatin (P = 0.05). Adverse events were reported in 71 of 138 (51%) and 62 of 141 (44%) patients eligible for safety analysis in the cefepime and imipenem groups, respectively (P = 0.23). Although the primary end point for this study does not exclude the possibility that cefepime was inferior to imipenem, some secondary analyses showed that the two regimens had comparable clinical and microbiological efficacies. Cefepime appeared to be less active against organisms producing an ESBL, but primary and secondary resistance to imipenem was more common for P. aeruginosa. Selection of a single agent for therapy of nosocomial pneumonia should be guided by local resistance patterns.


Assuntos
Cefalosporinas/uso terapêutico , Cilastatina/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Imipenem/uso terapêutico , Pneumonia Pneumocócica/tratamento farmacológico , Inibidores de Proteases/uso terapêutico , Tienamicinas/uso terapêutico , APACHE , Adulto , Idoso , Cefepima , Cefalosporinas/efeitos adversos , Cilastatina/efeitos adversos , Cuidados Críticos , Infecção Hospitalar/microbiologia , Método Duplo-Cego , Quimioterapia Combinada , Determinação de Ponto Final , Feminino , Humanos , Imipenem/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pneumonia Pneumocócica/microbiologia , Estudos Prospectivos , Inibidores de Proteases/efeitos adversos , Respiração Artificial , Tienamicinas/efeitos adversos
11.
Cardiovasc Surg ; 10(5): 508-11, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12379412

RESUMO

A 39-year-old man was admitted for upper abdominal pain and shortness of breath. The chest roentgenogram demonstrated cardiomegaly and left lower lobe atelectasis. Echocardiography showed circumferential pericardial effusion with signs of cardiac tamponade. Pericardial biopsy and fluid analysis were consistent with fibrino-purulent pericarditis. Despite broad-spectrum antibiotics, percutaneous and subsequently surgical drainage, pericardial effusion and tamponade recurred. We report successful treatment of a non-resolving fibrino-purulent pericardial effusion by combined intrapericardial irrigation of fibrinolytics and systemic corticosteroids administration as an alternative to pericardectomy.


Assuntos
Anti-Inflamatórios/uso terapêutico , Pericardite/tratamento farmacológico , Ativadores de Plasminogênio/uso terapêutico , Prednisona/uso terapêutico , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Doença Aguda , Adulto , Quimioterapia Combinada , Humanos , Masculino , Pericardiectomia , Pericardite/diagnóstico por imagem , Irrigação Terapêutica , Ultrassonografia
13.
J Pharm Biomed Anal ; 29(1-2): 17-33, 2002 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-12062661

RESUMO

Meropenem, a carbapenem antibiotic displaying a broad spectrum of antibacterial activity, is administered in Medical Intensive Care Unit to critically ill patients undergoing continuous veno-venous haemodiafiltration (CVVHDF). However, there are limited data available to substantial rational dosing decisions in this condition. In an attempt to refine our knowledge and propose a rationally designed dosage regimen, we have developed a HPLC method to determine meropenem after solid-phase extraction (SPE) of plasma and dialysate fluids obtained from patients under CVVHDF. The assay comprises the simultaneous measurement of meropenem's open-ring metabolite UK-1a, whose fate has never been studied in CVVHDF patients. The clean-up procedure involved a SPE on C18 cartridge. Matrix components were eliminated with phosphate buffer pH 7.4 followed by 15:85 MeOH-phosphate buffer pH 7.4. Meropenem and UK-1a were subsequently desorbed with MeOH. The eluates were evaporated under nitrogen at room temperature (RT) and reconstituted in phosphate buffer pH 7.4. Separation was performed at RT on a Nucleosil 100-5 microm C18 AB cartridge column (125 x 4 mm I.D.) equipped with a guard column (8 x 4 mm I.D.) with UV-DAD detection set at 208 nm. The mobile phase was 1 ml min(-1), using a step-wise gradient elution program: %MeOH/0.005 M tetrabutylammonium chloride pH 7.4; 10/90-50/50 in 27 min. Over the range of 5-100 microg ml(-1), the regression coefficient of the calibration curves (plasma and dialysate) were >0.998. The absolute extraction recoveries of meropenem and UK-1a in plasma and filtrate-dialysate were stable and ranged from 88-93 to 72-77% for meropenem, and from 95-104 to 75-82% for UK-1a. In plasma and filtrate-dialysate, respectively, the mean intra-assay precision was 4.1 and 2.6% for meropenem and 4.2 and 3.7% for UK-1a. The inter-assay variability was 2.8 and 3.6% for meropenem and 2.3 and 2.8% for UK-1a. The accuracy was satisfactory for both meropenem and UK-1a with deviation never exceeding 9.0% of the nominal concentrations. The stability of meropenem, studied in biological samples left at RT and at +4 degrees C, was satisfactory with < 5% degradation after 1.5 h in blood but reached 22% in filtrate-dialysate samples stored at RT for 8 h, precluding accurate measurements of meropenem excreted unchanged in the filtrate-dialysate left at RT during the CVVHDF procedure. The method reported here enables accurate measurements of meropenem in critically ill patients under CVVHDF, making dosage individualisation possible in such patients. The levels of the metabolite UK-1a encountered in this population of patients were higher than those observed in healthy volunteers but was similar to those observed in patients with renal impairment under hemodialysis.


Assuntos
Antibacterianos/sangue , Cromatografia Líquida de Alta Pressão/métodos , Hemodiafiltração/métodos , Soluções para Hemodiálise/análise , Tienamicinas/sangue , Estabilidade de Medicamentos , Humanos , Meropeném , Reprodutibilidade dos Testes
14.
Anesthesiology ; 96(3): 595-9, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11873033

RESUMO

BACKGROUND: The driving pressure gradient for cerebral perfusion is the difference between mean arterial pressure (MAP) and critical closing pressure (CCP = zero flow pressure). Therefore, determination of the difference between MAP and CCP should provide an appropriate monitoring of the effective cerebral perfusion pressure (CPP(eff)). Based on this concept, the authors compared conventional measurements of cerebral perfusion pressure by MAP and intracranial pressure (CPP(ICP)) with CPP(eff). METHODS: Simultaneous synchronized recordings of pressure waveforms of the radial artery and blood flow velocities of the middle cerebral artery were performed in 70 head trauma patients. CCP was calculated from pressure-flow velocity plots by linear extrapolation to zero flow. RESULTS: Intracranial pressure measured by intraventricular probes and CCP ranged from 3 to 71 and 4 to 70 mmHg, respectively. Linear correlation between ICP and CCP was r = 0.91. CPP(ICP) was 77 +/- 20 mmHg and did not differ from CPP(eff); linear correlation was r = 0.92. However, limits of agreement were only +/- 16.2 mmHg. Therefore, in 51.4% of the patients, CPP(ICP) overestimated CPP(eff) by 19.8 mmHg at most. CONCLUSION: Assuming that CPP(eff) (MAP - CCP) takes into account more determinants of cerebral downstream pressure, in individual cases, the actual gold standard of CPP determination (MAP - ICP) might overestimate the CPP(eff) of therapeutic significance.


Assuntos
Traumatismos Craniocerebrais/fisiopatologia , Traumatismos Craniocerebrais/cirurgia , Pressão Intracraniana/fisiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Ventrículos Cerebrais/fisiologia , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/fisiologia , Monitorização Intraoperatória , Procedimentos Neurocirúrgicos , Artéria Radial/fisiologia , Respiração Artificial
15.
Mol Endocrinol ; 15(12): 2182-96, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11731619

RESUMO

Treatment of HC11 mammary epithelial cells with the lactogenic hormone PRL promotes differentiation and induction of milk protein gene expression via stimulation of the Janus kinase (JAK)/signal transducer and activator of transcription pathway. We have previously shown that autocrine activation of epidermal growth factor (EGF) receptor interferes with normal PRL-induced differentiation. Here we show that PRL activation of JAK2 was dramatically reduced in HC11 cells pretreated with EGF, demonstrating that the target of EGF receptor activation is JAK2 kinase. Using an in-gel protein tyrosine phosphatase (PTP) assay, we observed that the activity of a 125-kDa PTP was up-regulated in HC11 cells in response to EGF. A specific antiserum was used to demonstrate that the 125-kDa PTP was PTP-PEST and to show that EGF treatment of HC11 cells led to an increase in the level of PTP-PEST. In intact HC11 cells, PTP-PEST was constitutively associated with JAK2, and in response to EGF treatment there was an increased level of PTP-PEST in JAK2 complexes. An in vitro phosphatase assay, using PRL-activated JAK2 as the substrate and lysates from HC11 cells as the source of PTP-PEST, revealed that JAK2 could serve as a PTP-PEST substrate. However, in intact cells the regulation of JAK2 by PTP-PEST was complex, since transient overexpression of PTP-PEST had a negligible effect on PRL-induced JAK2 activation. EGF's negative influence on JAK2 activity was blocked by actinomycin D treatment of HC11 cells, suggesting that EGF induced a protein that mediated the effects of PTP-PEST on JAK2. In support of this model, PTP-PEST-containing lysates from EGF-treated HC11 cells dephosphorylated JAK2 to a greater extent than lysates prepared from control cells.


Assuntos
Fator de Crescimento Epidérmico/farmacologia , Regulação da Expressão Gênica , Glândulas Mamárias Animais/fisiologia , Proteínas do Leite , Prolactina/fisiologia , Proteínas Tirosina Fosfatases/fisiologia , Proteínas Proto-Oncogênicas , Animais , Western Blotting , Células Cultivadas , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/fisiologia , Eletroforese em Gel de Poliacrilamida , Feminino , Janus Quinase 2 , Luciferases/análise , Glândulas Mamárias Animais/enzimologia , Camundongos , Testes de Precipitina , Proteína Tirosina Fosfatase não Receptora Tipo 12 , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Proteínas Tirosina Quinases/fisiologia , Fator de Transcrição STAT5 , Transativadores/antagonistas & inibidores , Transativadores/fisiologia
16.
Biochem J ; 360(Pt 1): 57-66, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11695992

RESUMO

Paxillin is a focal-adhesion-associated, tyrosine-phosphorylated protein. In cells transformed by the src, crk or BCR-Abl oncogenes, the phosphotyrosine content of paxillin is elevated. In normal cells paxillin functions in signalling following integrin-dependent cell adhesion or exposure to a number of stimuli, including growth factors and neuropeptides. These stimuli induce tyrosine phosphorylation of paxillin, regulating the association of Src homology 2 domain-containing signalling molecules with paxillin. There are multiple sites of tyrosine phosphorylation on paxillin. To elucidate the role of paxillin in transducing signals in response to various stimuli, it is essential to identify all of the sites of phosphorylation on paxillin and to define which residues are phosphorylated in response to distinct stimuli. We describe two new sites of tyrosine phosphorylation on paxillin, residues at positions 40 and 88. Using paxillin variants with phenylalanine substitutions at phosphorylation sites and phospho-specific paxillin antibodies, tyrosine phosphorylation of paxillin in response to distinct stimuli was examined. The results demonstrate that Tyr(31) and Tyr(118), which are binding sites for Crk, are major sites of tyrosine phosphorylation following cell adhesion or stimulation with platelet-derived growth factor or angiotensin II. Thus multiple stimuli may elicit similar signalling events downstream of paxillin.


Assuntos
Proteínas do Citoesqueleto/química , Fosfoproteínas/química , Proteínas Proto-Oncogênicas/química , Tirosina/metabolismo , Animais , Sítios de Ligação , Adesão Celular , Embrião de Galinha , Meios de Cultura Livres de Soro/farmacologia , Proteínas do Citoesqueleto/metabolismo , DNA Complementar/metabolismo , Paxilina , Peptídeos/química , Fosfoproteínas/metabolismo , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-crk , Transdução de Sinais , Domínios de Homologia de src
17.
Oncogene ; 20(44): 6459-72, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11607845

RESUMO

Paxillin is a focal adhesion-associated, phosphotyrosine-containing protein that may play a role in several signaling pathways. Paxillin contains a number of motifs that mediate protein-protein interactions, including LD motifs, LIM domains, an SH3 domain-binding site and SH2 domain-binding sites. These motifs serve as docking sites for cytoskeletal proteins, tyrosine kinases, serine/threonine kinases, GTPase activating proteins and other adaptor proteins that recruit additional enzymes into complex with paxillin. Thus paxillin itself serves as a docking protein to recruit signaling molecules to a specific cellular compartment, the focal adhesions, and/or to recruit specific combinations of signaling molecules into a complex to coordinate downstream signaling. The biological function of paxillin coordinated signaling is likely to regulate cell spreading and motility.


Assuntos
Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/metabolismo , Proteínas do Citoesqueleto/fisiologia , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Fosfoproteínas/fisiologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Adesão Celular , Movimento Celular , Núcleo Celular/metabolismo , Humanos , Dados de Sequência Molecular , Paxilina , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Domínios de Homologia de src
18.
Am J Respir Crit Care Med ; 164(5): 802-6, 2001 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-11549536

RESUMO

To investigate whether respiratory acidosis modulates ventilator-induced lung injury (VILI), we perfused (constant flow) 21 isolated sets of normal rabbit lungs, ventilated them for 20 min (pressure controlled ventilation [PCV] = 15 cm H(2)O) (Baseline) with an inspired CO(2) fraction adjusted for the partial pressure of CO(2) in the perfusate (PCO(2) approximately equal to 40 mm Hg), and then randomized them into three groups. Group A (control: n = 7) was ventilated with PCV = 15 cm H(2)O for three consecutive 20-min periods (T1, T2, T3). In Group B (high PCV/normocapnia; n = 7), PCV was given at 20 (T1), 25 (T2), and 30 (T3) cm H(2)O. The targeted PCO(2) was 40 mm Hg in Groups A and B. Group C (high PCV/hypercapnia; n = 7) was ventilated in the same way as Group B, but the targeted PCO(2) was approximately equal to 70 to 100 mm Hg. The changes (from Baseline to T3) in weight gain (Delta WG: g) and in the ultrafiltration coefficient (Delta K(f) = gr/min/ cm H(2)O/100g) and the protein and hemoglobin concentrations in bronchoalveolar lavage fluid (BALF) were used to assess injury. Group B experienced a significantly greater Delta WG (14.85 +/- 5.49 [mean +/- SEM] g) and Delta K(f) (1.40 +/- 0.49 g/min/cm H(2)O/100 g) than did either Group A (Delta WG = 0.70 +/- 0.43; Delta K(f) = 0.01 +/- 0.03) or Group C (Delta WG = 5.27 +/- 2.03 g; Delta K(f) = 0.25 +/- 0.12 g/min/cm H(2)O/ 100 g). BALF protein and hemoglobin concentrations (g/L) were higher in Group B (11.98 +/- 3.78 g/L and 1.82 +/- 0.40 g/L, respectively) than in Group A (2.92 +/- 0.75 g/L and 0.38 +/- 0.15 g/L) or Group C (5.71 +/- 1.88 g/L and 1.19 +/- 0.32 g/L). We conclude that respiratory acidosis decreases the severity of VILI in this model.


Assuntos
Acidose Respiratória , Hipercapnia , Respiração Artificial/efeitos adversos , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/prevenção & controle , Animais , Hemodinâmica , Coelhos , Síndrome do Desconforto Respiratório/fisiopatologia
20.
Biochim Biophys Acta ; 1540(1): 1-21, 2001 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-11476890

RESUMO

The focal adhesion kinase, FAK, is an important component of an integrin-dependent signaling pathway, which functions to transmit signals from the extracellular matrix into the cytoplasm. FAK is an essential gene product, since the fak-/- mouse exhibits embryonic lethality. A number of important biological processes, including cell motility and cell survival, are controlled by integrin-dependent signals and FAK has been implicated in regulating these processes. This review will focus upon recent findings providing insight into the mechanisms by which FAK transmits biochemical signals and elicits biological effects.


Assuntos
Integrinas/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais , Animais , Movimento Celular , Sobrevivência Celular , Citoplasma/metabolismo , Ativação Enzimática , Evolução Molecular , Matriz Extracelular/metabolismo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Adesões Focais/metabolismo , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Modelos Químicos , Proteínas Tirosina Quinases/antagonistas & inibidores
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