RESUMO
OBJECTIVE: The aim of this study is to compare two positioning techniques of 12-French (Fr) thoracic drains in terms of efficacy, safety, and patient comfort. PATIENTS AND METHODS: This is a prospective, non-randomized, competitive, non-inferiority study comparing the Seldinger vs. Trocar technique. The primary endpoint was an analysis of the factors that led to unsuccessful drainage positioning. Between the two groups, clinical variables, procedure times, pain, and complications were compared. RESULTS: Seventy-two patients were enrolled in group 1 (Seldinger) and 45 in group 2 (Trocar). The mean procedural time was 7.93±3.02 min vs. 7.09±3.67 min, respectively (p: 0.33). The mean VAS for procedural pain was 2.22±1.47 vs. 2.80±1.88, p: 0.07, and the mean at day 2 was 3.6±1.2 in the SBWGD group vs. 2.7±1.1 in the Unico Group (p: 0.04). There was no difference in terms of complications, residual effusion, and pneumothorax at the first post-procedural chest X-ray. Four days after the procedure, the drain removal rate was 11.6% in group 1 vs. 25% in group 2 p: 0.063). The chest tube was removed after a mean period of 8.87±7.20 days after resolution of pleural effusion or tube dislodgement (7 cases in group 1 vs. 11 in group 2, p: 0.053). CONCLUSIONS: The two techniques resulted in comparable pain and complication rates. Both drains are well-tolerated and efficient at draining pleural effusion, with very low rates of complications and failure. We recommend inserting a longer tube for patients who require chest drainage for an extended period of time.
Assuntos
Derrame Pleural , Pneumotórax , Humanos , Estudos Prospectivos , Drenagem/métodos , Derrame Pleural/cirurgia , Pneumotórax/etiologia , Tubos Torácicos/efeitos adversos , Instrumentos Cirúrgicos/efeitos adversosRESUMO
The widespread diffusion of low-cost but high-performance hardware is enhancing the realization of scientific equipment with features at the research laboratory level. In this paper, we demonstrate hardware implementation of a surface plasmon resonance compact device with high accuracy and measurement times appropriate for many applications. Image acquisition is realized by a Raspberry Pi single board computer with a camera module, and a Python code is used to process data. A flexible optical setup can work in two different configurations, namely, the inspection mode and angle resolved measurement mode. The inspection mode is used to precisely locate the light-emitting diode interrogation beam on the sample, avoiding uneven or faulty regions. The measurement mode allows us to monitor in real time the position of the minimum reflectivity with subpixel resolution. Performance tests show a resolution in the bulk refractive index of 4.9 × 10-6 refractive index units for 10 s acquisition time.
RESUMO
OBJECTIVE: We aim to present clinical features, imaging findings, treatment aspects of the elastofibroma dorsi (ED), which is a benign tumor arising from connective tissue at the scapular region, and long-term outcomes after surgical resection. PATIENTS AND METHODS: We evaluated retrospectively 82 patients (55 females, 27 males; mean age, 60 years; age range, 23-78 years) with ED who underwent surgery between January 1994 and May 2014; subsequently all patients were invited for follow-up, which consisted of physical and US examinations. RESULTS: Subscapular location was almost constant (79/82 patients). Right, left and bilateral location was noted in 39, 28 and 15 cases, respectively. 52/82 patients were symptomatic. The diagnosis was made on physical examination and imaging studies: 49 ultrasound, 43 computed tomography and 54 magnetic resonance examinations were performed overall. Surgical treatment consisted in marginal excision; in all cases diagnosis was confirmed by histological examination. The mean hospitalization was 3 days, with minor complications. Out of the 82 patients, only 25 gave their consent to follow-up; mean time passed after surgery was 64.7 months; 1 case of local recurrence was suspected by ultrasound and, then, confirmed by magnetic resonance imaging. CONCLUSIONS: In our series, clinical features and imaging findings of ED are consistent with current evidence; however, results of our follow-up group marks a difference from the literature, according to which there is no evidence of local recurrence after complete resection. Diagnosis of ED is based on clinical and imaging features; treatment is surgical, especially in symptomatic cases. Prolonging the clinical and US follow-up period may be useful in identifying local recurrence.
Assuntos
Fibroma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Neoplasias de Tecidos Moles/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Fibroma/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estudos Retrospectivos , Neoplasias de Tecidos Moles/cirurgia , Adulto JovemRESUMO
The non-dioxin-like environmental toxicant 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153), member of a group of persistent organic pollutants wide-spread throughout the environment, reduces gap junction intercellular communication (GJIC), an event possibly associated with tumor promotion. Since very few studies have investigated the signaling effectors and mode(s) of action of PCB153, and it is known that the gap junction (GJ) protein Cx43 can be regulated by the bioactive sphingolipid (SL) sphingosine 1-phosphate (S1P), this in vitro study mainly addresses whether SL metabolism is affected by PCB153 in rat liver epithelial WB-F344 cells. PCB153 treatment obtained significant changes in the S1P/ceramide (Cer) ratio, known to be crucial in determining cell fate. In particular, an increase in S1P at 30 min and a decrease of the bioactive lipid at 3 h were observed, whereas Cer level increased at 1 h and 24 h. Notably, a time-dependent modulation of sphingosine kinase (SphK), the enzyme responsible for S1P synthesis, and of its regulators, ERK1/2 and protein phosphatase PP2A, supports the involvement of these signaling effectors in PCB153 toxicity. Electrophysiological analyses, furthermore, indicated that the lipophilic environmental toxicant significantly reduced GJ biophysical properties, affecting both voltage-dependent (such as those formed by Cx43 and/or Cx32) and voltage-independent channels, thereby demonstrating that PCB153 may act differently on GJs formed by distinct Cx isoforms. SphK down-regulation alone induced GJIC impairment, and, when combined with PCB153, the acute effect on GJ suppression was additive. Moreover, after enzyme-specific gene silencing, the SphK1 isoform appears to be responsible for down-regulating Cx43 expression, while being the target of PCB153 at short-term exposure. In conclusion, we provide the first evidence of novel effectors in PCB153 toxic action in rat liver stem-like cells, leading us to consider SLs as potential markers for preventing GJIC deregulation and, thus, the tumorigenic action elicited by this environmental toxicant.
Assuntos
Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Fígado/efeitos dos fármacos , Bifenilos Policlorados/toxicidade , Esfingolipídeos/metabolismo , Animais , Células Cultivadas , Dioxinas/toxicidade , Eletrofisiologia/métodos , Junções Comunicantes/fisiologia , Fígado/citologia , Lisofosfolipídeos/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Esfingosina/análogos & derivados , Esfingosina/metabolismoAssuntos
Neoplasias das Glândulas Suprarrenais/secundário , Carcinoma de Células Escamosas/secundário , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Neoplasias Pulmonares/patologia , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Idoso , Carcinoma de Células Escamosas/diagnóstico por imagem , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Radiografia , Veias CavasRESUMO
BACKGROUND AND OBJECTIVES: Pneumonectomy for non small cell lung cancer (NSCLC) after induction radio-chemotherapy (IT) has been associated with high peri-operative risk and its safety and efficacy is still debated. The aim of this retrospective study was to compare short and long-term results of pneumonectomy in patients treated with and without IT (radiotherapy plus chemotherapy) for NSCLC. MATERIALS AND METHODS: From 1995 to 2008, 85 consecutive patients underwent pneumonectomy: 49 received pre-operative radiotherapy and chemotherapy (IT group), and 36 patients did not (non-IT group). Peri-operative and long-term outcomes were compared. RESULTS: Major complications rate was 14.3% for IT group and 16.7% for non-IT group (p = n.s.). Mortality rate was 2% in IT group and 5.5% in non-IT group (p = n.s.). Post-operative hospital stay was significantly longer in the IT group (p < 0.0001) as the need for blood transfusion (p = 0.002). Indeed, the mortality rate was similar in the left- and right-sided operations. 5 years survival was 45.3% for IT group and 38.4% for non-IT group (p = n.s.) and 5 year disease free survival rates were 42.3% vs. 37.8% for the two groups, respectively (p = n.s.). Among the clinical, surgical and pathological features no differences on long term outcomes were found with regards to IT. DISCUSSION: Pneumonectomy is a feasible and safe procedure even after pre-operative IT. Our results showed a prolonged hospitalization and the need for blood transfusion in the IT group.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Quimiorradioterapia , Neoplasias Pulmonares/terapia , Pneumonectomia , Idoso , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Feminino , Humanos , Tempo de Internação , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Solitary fibrous tumors are very rare neoplasms that seldomly appear in extra-serosal soft tissues. In such cases, an accurate preoperative diagnosis is often difficult and challenging, especially in extrapleural ones. Traditionally, extrapleural solitary fibrous tumours have been regarded as indolent neoplasms similar to their intra-thoracic counterparts, although there has been some evidence that this subgroup could be a subset of more aggressive malignant tumours. For these reasons, surgical excision is mandatory and represents, to date, the best therapeutic option. In this article we report a case of a malignant solitary fibrous tumor of the chest wall in a 58-year-old man. Problems related to differential diagnosis and the possible pitfalls that can be encountered in the diagnostic process of such rare tumors are discussed.
Assuntos
Tumores Fibrosos Solitários/patologia , Parede Torácica/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Malacoplakia is a rare inflammatory condition characterized by the accumulation of benign macrophages associated with pathognomonic Michaelis-Gutmann bodies (MGBs). It is usually found in the genito-urinary tract, and has been associated with immunocompromised states. In this short report, we present 5 patients with pulmonary nodules clinically suspicious for primary or metastatic lung cancer. The histologic examination of the surgical specimens revealed a nonspecific granulomatous chronic disease, and despite the paucity of classical MGBs, a pulmonary malacoplakia was suspected. In all cases the opportunistic pathogen Rhodococcus equi (R. equi) was identified by 16S rRNA gene sequence analysis, leading to the final pathological diagnosis of malacoplakia. We conclude that pulmonary malacoplakia associated with R. equi is a rare disease affecting also immunocompetent patients. The pathogenesis and the diagnostic problems are discussed. Since infection by R. equi is treatable, the importance of its early recognition should be emphasized.
Assuntos
Infecções por Actinomycetales/diagnóstico , DNA Bacteriano/análise , DNA Ribossômico/análise , Malacoplasia/diagnóstico , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Infecções Respiratórias/diagnóstico , Rhodococcus equi/genética , Ribotipagem/métodos , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/patologia , Infecções por Actinomycetales/cirurgia , Idoso , Biópsia por Agulha Fina , Diagnóstico Precoce , Feminino , Humanos , Malacoplasia/microbiologia , Malacoplasia/patologia , Malacoplasia/cirurgia , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Valor Preditivo dos Testes , Infecções Respiratórias/microbiologia , Infecções Respiratórias/patologia , Infecções Respiratórias/cirurgia , Rhodococcus equi/classificação , Tomografia Computadorizada por Raios XRESUMO
AIM: Postoperative air leaks and in particular persistent air leaks (>5 days) after pulmonary resection still represent a common complication and the first cause of hospital stay delay. Aim of this experimental trial was to investigate the efficacy of the use of bovine pericardium strips (in terms of reduction of postoperative leakage and hospital stay) in "critical" patients (COPD, emphysema etc.) who underwent pulmonary resection. METHODS: From October 2010 to February 2011, eight patients (experimental group, Group A) were preoperative selected and underwent pulmonary resection with bovine pericardium strips (Peri-Strips Dry; Synovis ). The inclusion criteria of a "frail patient" were established by a dedicate pneumologist according with clinical and functional data (predicted postoperative FEV1 ranging from 35% and 80% of the theorical predicted value). For comparison, from January 2010 to September 2010, we retrospectively reviewed the data of 28 patients who satisfied the same inclusion criteria and underwent pulmonary resection with standard surgical procedures. This group of patients represents our control group (Group B). RESULTS: There were no significant differences between the two groups in age, gender, preoperative risk factors for developing a postoperative air leak, preop FEV1 and type of resection. No technical deficiencies in the use of bovine pericardium strips were observed in Group A. Postoperative leakage was significant different in the two groups being persistent air leak detected in 0% in Group A versus 17.8% of Group B (P=0.046). Consequently, chest tube duration (6.75±0.84 days [Group A] vs. 9.70±1.26 days (Group B), P=0.019) and hospital stay (10.13±0.83 days [Group A] vs. 12.95±1.37 days [Group B], P=0.013) were lower in the experimental group. CONCLUSION: Bovine pericardium strips are safe and easy-to-do technique to reduce postoperative air leaks after pulmonary resection in "critical" patients.
Assuntos
Idoso Fragilizado , Neoplasias Pulmonares/cirurgia , Pericárdio/transplante , Pneumonectomia/efeitos adversos , Grampeamento Cirúrgico/métodos , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos de Casos e Controles , Bovinos , Humanos , Tempo de Internação , Pneumonectomia/métodos , Enfisema Pulmonar/etiologia , Enfisema Pulmonar/cirurgia , Procedimentos Cirúrgicos Pulmonares/métodos , Fatores de Risco , Fatores de Tempo , Transplante Heterólogo , Resultado do TratamentoRESUMO
Liposarcomas are the second most common soft tissue sarcoma in adults. They occur predominantly in the lower limbs and retroperitoneum, whereas primary mediastinal liposarcomas are extremely rare. Liposarcomas are often asymptomatic and may reach a considerable size before causing any symptoms related to direct invasion or compression of other thoracic organs. We report a case of a 69-year-old woman with a giant primary pericardial liposarcoma causing cardiac tamponade and discuss its clinical and imaging features and surgical treatment and review the literature.
Assuntos
Neoplasias Cardíacas/cirurgia , Lipossarcoma/cirurgia , Pericárdio/cirurgia , Idoso , Feminino , HumanosRESUMO
OBJECTIVE: We have analyzed short- and long-term variations of pulmonary function in locally advanced non-small cell lung cancer after induction chemoradiotherapy. METHODS: Twenty-seven patients with stage IIIA (N2) non-small cell lung cancer underwent resection with radical intent after induction chemoradiotherapy in the period 2003 to 2006. Pulmonary function has been evaluated by spirometry, diffusing capacity of the lung for carbon monoxide, and blood gas analysis before induction chemoradiotherapy (T0), 4 weeks after induction chemoradiotherapy and before surgery (T1), and 1 (T2), 3 (T3), 6 (T4), and 12 months (T5) after surgery. RESULTS: A 22.80% decrease of diffusing capacity of the lung for carbon monoxide (P < .001) was observed at T1. At T2 significant decreases in the following were present: vital capacity, -20.50% (P < .001); forced vital capacity, -22.50% (P < .001); forced expiratory volume in 1 second, -23.00% (P < .001); peak expiratory flow, -29.0 (P < .001); forced expiratory flow 25% to 75%, -13.7% (P = .005); and diffusing capacity of the lung for carbon monoxide, 43.6% (P < .001). However, in the interval between T2 and T5, a progressive improvement of lung function in most parameters was observed, but only diffusing capacity of the lung for carbon monoxide presented a significant increase (P < .001). Within the same time gap (T2 to T5), subjects 65 years of age or younger showed an increasing trend for vital capacity, forced expiratory volume in 1 second, total lung capacity, and residual volume significantly different from that of elderly patients, in whom a decrease in these parameters is reported. CONCLUSIONS: An impairment of respiratory function is evident in the immediate postoperative setting in patients with non-small cell lung cancer receiving induction chemoradiotherapy. In the long-term period, a general recovery in diffusing capacity of the lung for carbon monoxide was found, whereas an improvement of forced expiratory volume in 1 second, vital capacity, total lung capacity, and residual volume was detected in the younger population only.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/fisiopatologia , Neoplasias Pulmonares/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estudos Prospectivos , Testes de Função Respiratória , Fatores de TempoRESUMO
Until recently, skeletal myoblasts (SkMBs) have been the most widely used cells in basic research and clinical trials of cell based therapy for cardiac repair and regeneration. Although SkMB engraftment into the post-infarcted heart has been consistently found to improve cardiac contractile function, the underlying therapeutic mechanisms remain still a matter of controversy and debate. This is basically because SkMBs do not attain a cardiac-like phenotype once homed into the diseased heart nor they form a contractile tissue functionally coupled with the surrounding viable myocardium. This issue of concern has generated the idea that the cardiotropic action of SkMBs may depend on the release of paracrine factors. However, the paracrine hypothesis still remains ill-defined, particularly concerning the identification of the whole spectrum of cell-derived soluble factors and details on their cardiac effects. In this context, the possibility to genetically engineering SkMBs to potentate their paracrine attitudes appears particularly attractive and is actually raising great expectation. Aim of the present review is not to cover all the aspects of cell-based therapy with SkMBs, as this has been the object of previous exhaustive reviews in this field. Rather, we focused on novel aspects underlying the interactions between SkMBs and the host cardiac tissues which may be relevant for directing the future basic and applied research on SkMB transplantation for post ischemic cardiac dysfunction.
Assuntos
Coração/fisiologia , Mioblastos Esqueléticos/transplante , Infarto do Miocárdio/terapia , Comunicação Parácrina/fisiologia , Regeneração/fisiologia , Animais , Terapia Genética/métodos , Humanos , Modelos Biológicos , Infarto do Miocárdio/cirurgia , Transplante de Células-Tronco/métodosRESUMO
Actin cytoskeleton profoundly influence a variety of signaling events, including those related to cell growth, survival and differentiation. Recent evidence have provided insights into the mechanisms underlying the ability of cytoskeleton to regulate signal transduction cascades involved in muscle development. This review will deal with the most recent aspects of this field paying particular attention to the role played by actin dynamics in the induction of skeletal muscle-specific genes.
Assuntos
Actinas/metabolismo , Diferenciação Celular , Citoesqueleto/metabolismo , Expressão Gênica , Músculo Esquelético/citologia , Animais , Fenômenos Fisiológicos Celulares , Humanos , Músculo Esquelético/fisiologia , Transdução de SinaisRESUMO
Although sphingosine 1-phosphate (S1P) has been considered a potent regulator of skeletal muscle biology, acting as a physiological anti-mitogenic and prodifferentiating agent, its downstream effectors are poorly known. In the present study, we provide experimental evidence for a novel mechanism by which S1P regulates skeletal muscle differentiation through the regulation of gap junctional protein connexin (Cx) 43. Indeed, the treatment with S1P greatly enhanced Cx43 expression and gap junctional intercellular communication during the early phases of myoblast differentiation, whereas the down-regulation of Cx43 by transfection with short interfering RNA blocked myogenesis elicited by S1P. Moreover, calcium and p38 MAPK-dependent pathways were required for S1P-induced increase in Cx43 expression. Interestingly, enforced expression of mutated Cx43(Delta130-136) reduced gap junction communication and totally inhibited S1P-induced expression of the myogenic markers, myogenin, myosin heavy chain, caveolin-3, and myotube formation. Notably, in S1P-stimulated myoblasts, endogenous or wild-type Cx43 protein, but not the mutated form, coimmunoprecipitated and colocalized with F-actin and cortactin in a p38 MAPK-dependent manner. These data, together with the known role of actin remodeling in cell differentiation, strongly support the important contribution of gap junctional communication, Cx43 expression and Cx43/cytoskeleton interaction in skeletal myogenesis elicited by S1P.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Lisofosfolipídeos/farmacologia , Mioblastos Esqueléticos/efeitos dos fármacos , Esfingosina/análogos & derivados , Animais , Biomarcadores , Cálcio/metabolismo , Proteínas do Citoesqueleto/metabolismo , Regulação para Baixo/efeitos dos fármacos , Condutividade Elétrica , Inibidores Enzimáticos/farmacologia , Expressão Gênica/efeitos dos fármacos , Cinética , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Mutantes/metabolismo , Mioblastos Esqueléticos/citologia , Miogenina/metabolismo , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Esfingosina/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidoresRESUMO
We have previously shown that sphingosine 1-phosphate (S1P) can induce intracellular Ca(2+) mobilization and cell contraction in C2C12 myoblasts and that the two phenomena are temporally unrelated. Although Ca(2+)-independent mechanisms of cell contraction have been the focus of numerous studies on Ca(2+) sensitization of smooth muscle, comparatively less studies have focused on the role that these mechanisms play in the regulation of skeletal muscle contractility. Phosphorylation and activation of myosin by Rho-dependent kinase mediate most of Ca(2+)-independent contractile responses. In the present study, we examined the potential role of Rho/Rho-kinase cascade activation in S1P-induced C2C12 cell contraction. First, we showed that depletion of Ca(2+), by pre-treatment with BAPTA, did not affect S1P-induced myoblastic contractility, whereas it abolished S1P-induced Ca(2+) transients. These results correlated with the absence of troponin C and with the immature cytoskeletal organization of these cells. Experimental evidence demonstrating the involvement of Rho pathway in S1P-stimulated myoblast contraction included: the activation/translocation of RhoA to the membrane in response to agonist-stimulation in cells depleted of Ca(2+) and the inhibition of dynamic changes of the actin cytoskeleton in cells where Rho functions had been inhibited either by overexpression of RhoGDI, a physiological inhibitor of GDP dissociation from Rho proteins, or by pretreatment with Y-27632, a specific Rho kinase inhibitor. Contribution of protein kinase C in this cytoskeletal rearrangement was also evaluated. However, the pretreatment with Gö6976 or rottlerin, specific inhibitors of PKC alpha and PKC delta, respectively, failed to inhibit the agonist-induced myoblastic contraction. Single particle tracking of G-actin fluorescent probe was performed to statistically evaluate actin cytoskeletal dynamics in response to S1P. Stimulation with S1P was also able to increase the phosphorylation level of myosin light chain II. In conclusion, our results strongly suggest that Ca(2+)-independent/Rho-Rho kinase-dependent pathways may exert an important role in S1P-induced myoblastic cell contraction.
Assuntos
Cálcio/metabolismo , Diferenciação Celular/fisiologia , Lisofosfolipídeos , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Actinas/metabolismo , Animais , Fracionamento Celular , Células Cultivadas , Citoesqueleto/metabolismo , Corantes Fluorescentes/metabolismo , Humanos , Camundongos , Microscopia de Força Atômica , Fibras Musculares Esqueléticas/citologia , Toxina Pertussis/metabolismo , Proteína Quinase C/metabolismo , Troponina C/metabolismoRESUMO
In hypogravity conditions unloading of skeletal muscle fibres causes alterations in skeletal muscle structure and functions including growth, gene expression, cell differentiation, cytoskeletal organization, contractility and plasticity. Recent studies have identified sphingosine I -phosphate (SPP) as a lipid mediator capable of eliciting intracellular Ca2+ transients, cell proliferation, differentiation, suppression of apoptosis, as well as cell injury repair. The aim of this research is to evaluate a possible involvement of SPP in skeletal muscle cells differentiation and repair from space-flight damage. Particularly, we investigated the Ca2+ sources and the changes on the cytoskeletal rearrangement induced by SPP in a mouse skeletal (C2C12) myoblastic cell line. Confocal fluorescence imaging revealed that SPP elicited Ca2+ transients which propagated throughout the cytosol and nucleus. This response required extracellular and intracellular Ca2+ mobilization. SPP also induced cell contraction through a Ca2(+)- independent/Rho-dependent pathway. The nuclear Ca2+ transients are suggestive for an action of SPP in the differentiation program and damage repair.
RESUMO
Sphingomyelinase (SMase) and ceramidase (CDase) activities participate in sphingomyelin (SM) metabolism and have a role in the signal transduction of a variety of ligands. In this study evidence is presented that caveolin-enriched light membranes (CELMs) of murine endothelial cells, characterized by high SM, ceramide (Cer) and cholesterol content, bear acid and neutral SMase as well as neutral CDase activities. Localization of neutral CDase in CELMs was confirmed by Western analysis. Notably, cell treatment with cyclodextrin, which depleted cell cholesterol, did not affect acid or neutral SMase activities but significantly enhanced neutral CDase activity in CELMs, indicating a negative role for cholesterol in CDase regulation. These findings suggest that neutral CDase is implicated, together with SMase activities, in the control of caveolar Cer content that may be critical for caveola dynamics.
Assuntos
Amidoidrolases/metabolismo , Caveolinas/metabolismo , Membrana Celular/enzimologia , Endotélio Vascular/enzimologia , Animais , Fracionamento Celular , Linhagem Celular , Membrana Celular/química , Centrifugação com Gradiente de Concentração , Ceramidases , Ceramidas/metabolismo , Endotélio Vascular/citologia , Camundongos , Ceramidase Neutra , Esfingomielina Fosfodiesterase/metabolismo , Esfingomielinas/metabolismoRESUMO
Previous studies showed that in C2C12 cells, phospholipase D (PLD) and its known regulators, RhoA and protein kinase Calpha (PKCalpha), were downstream effectors in sphingosine 1-phosphate (SPP) signalling. Moreover, the role of PKC for SPP-mediated PLD activation and the requirement of PKCalpha for RhoA translocation were reported. The present results demonstrated that inactivation of RhoA, by overexpression of RhoGDP dissociation inhibitor (RhoGDI) as well as treatment with C3 exotoxin, attenuated SPP-stimulated PLD activity, supporting the involvement of RhoA in the stimulation of PLD activity by the bioactive lipid in C2C12 myoblasts. In addition, the effect of PKCalpha inhibitor Gö6976 on the SPP-induced PLD activation in myoblasts, where RhoA function was inactivated, was consistent with a dual regulation of the enzyme through RhoA and PKCalpha. Interestingly, the subcellular distribution of PLD isoforms, RhoA and PKCalpha, in SPP-stimulated cells supported the view that the functional relationship between the two PLD regulators, demonstrated to occur in SPP signalling, represents a novel mechanism of regulation of specifically localized PLD.
Assuntos
Toxinas Botulínicas , Isoenzimas/fisiologia , Lisofosfolipídeos , Fosfolipase D/metabolismo , Proteína Quinase C/fisiologia , Esfingosina/farmacologia , Proteína rhoA de Ligação ao GTP/fisiologia , ADP Ribose Transferases/farmacologia , Animais , Carbazóis/farmacologia , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Inibidores de Dissociação do Nucleotídeo Guanina/genética , Indóis/farmacologia , Músculo Esquelético/metabolismo , Proteína Quinase C-alfa , Transporte Proteico , Esfingosina/análogos & derivados , Transfecção , Inibidores da Dissociação do Nucleotídeo Guanina rho-EspecíficoRESUMO
OBJECTIVE: The prognosis of non-small cell lung cancer (NSCLC) with brain metastasis is very poor, with median survival rate below 6 months, even if treated with palliative radio and/or chemotherapy. To assess the effectiveness of surgical treatment for this kind of patients we reviewed our experience. METHODS: From January 1989 to October 1999, 30 patients (26 males and four females; mean age: 58.7 years) with NSCLC and single brain metastasis underwent surgical treatment of both primary lung cancer and secondary cerebral lesion. Patients (pts) were divided into two major groups. In group 1 (G1) 20 pts (18 males and two females) presented a synchronous brain metastasis. In group 2 (G2) 10 pts (eight males and two females) presented a metachronous brain metastasis during the follow-up period (range 3-24 months since the primary tumor). Patients selected in G1 had T1-2, N0-1 clinical staging, good 'performance status' (ECOG:0--1; Karnofsky index > 70%), age < 75 years. Craniotomy has always been the first approach. In G2 also patients with locally advanced tumors (T3 and/or N2) were included. Whole brain radiotherapy and/or chemotherapy was the post-operative choice treatment. RESULTS: Histologic findings have shown: adenocarcinoma in 17 cases (12 in G1; five in G2), squamous cell carcinoma in 10 cases (six in G1; four in G2), large cell carcinoma in 2 (one in G1; one in G2) and large cell neuroendocrine carcinoma in one (G1). Survival analysis (Kaplan--Meier method) has shown an overall value of 80% at 1 year (95% in G1; 50% in G2), 41% at 2 years (47% in G1; 30% in G2) and 17% at 3 years (14% in G1; 20% in G2). Overall median survival is 23 months (23 in G1; 11 in G2); mean survival 27.8 months (30.3 months in G1; 22.8 months in G2). According to univariate analysis prognosis is definitively better in N0 tumors compared to N1-2 tumors and in adenocarcinoma cases compared to other histotypes (P < 0.05). CONCLUSIONS: We can conclude that combined surgical therapy is, nowadays, the choice treatment for this kind of patients, even though restricted to selected cases. The knowledge of prognostic factors may optimize indications for surgery.
Assuntos
Neoplasias Encefálicas/patologia , Carcinoma Pulmonar de Células não Pequenas/secundário , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Adenocarcinoma/mortalidade , Adenocarcinoma/cirurgia , Adenocarcinoma/terapia , Adulto , Idoso , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/terapia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Terapia Combinada , Feminino , Humanos , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos RetrospectivosRESUMO
Rho GTPases participate in various important signaling pathways and have been implicated in myogenic differentiation. Here the first evidence is provided that in C2C12 myoblasts sphingosine 1-phosphate (SPP) rapidly and transiently induced membrane association of Rho A in a pertussis toxin-insensitive manner. The bioactive lipid preferentially relocalized the GTPase to Golgi-enriched membrane. Translocation of Rho A was abolished by inhibition or down-regulation of protein kinase C (PKC). Notably, treatment with Gö6976, an inhibitor of conventional PKCs, which selectively blocked PKC alpha in these cells, prevented SPP-induced Rho A translocation. Conversely rottlerin, a selective inhibitor of PKC delta, was without effect, demonstrating that SPP signaling to Rho A involves PKC alpha but not PKC delta activation. This novel functional relationship between the two proteins may have a role in SPP-mediated regulation of downstream effectors.