RESUMO
BACKGROUND: Obesity accelerates and exacerbates the age-related changes on muscle function and exercise capacity. In addition, the middle-aged population is often overlooked when talking about the prevention of sarcopenia. This study investigated the effects of exercise alone or in combination with a high-protein diet on muscle function and physical fitness in middle-aged obese adults. MATERIALS AND METHODS: Sixty-nine middle-aged (50-64 years old) obese adults were randomly assigned to one of the following groups: control group (C; n=23), exercise group (E; n=23) or exercise plus high-protein group (EP; n=23). Individuals within the E and EP groups received 12 weeks of exercise training; whereas, the individuals in the EP group also received a high-protein diet intervention (1.6g/kg/day). Individuals within the C group were asked to maintain their lifestyle for 12 weeks. Participants were evaluated before and after the intervention. Outcome measures included maximal exercise capacity, muscle function and functional physical performance. Analysis of covariance was used to determine the effects of the intervention. RESULTS: After the intervention, the E and EP groups had greater maximal work rate, peak oxygen consumption, and muscle power during muscle contractions at 180°/sec than that in the C group (P<0.05). The EP group, but not the E group, showed significant improvement in the sit-to-stand test and climbing stairs test than the C group after the intervention (P<0.05). Within group comparisons showed that the anaerobic threshold only increased in the EP group (+12% from pre-test). CONCLUSIONS: For middle-aged obese adults, exercise with a high-protein diet not only improved muscle power and exercise capacity but also enhanced their functional physical performance.
Assuntos
Dieta Rica em Proteínas , Tolerância ao Exercício , Obesidade , Exercício Físico , Humanos , Pessoa de Meia-Idade , Músculo Esquelético , Obesidade/dietoterapiaRESUMO
Essentials Disabled-2 (Dab2) phosphorylation status in thrombin signaling of human platelet was investigated. Ser723 was the major Dab2 phosphorylation site in human platelets stimulated by thrombin. Dab2 S723 phosphorylation (pS723) caused the dissociation of Dab2-CIN85 protein complex. Dab2-pS723 regulated ADP release and integrin αIIbß3 activation in thrombin-treated platelets. SUMMARY: Background Disabled-2 (Dab2) is a platelet protein that is functionally involved in thrombin signaling in mice. It is unknown whether or not Dab2 undergoes phosphorylation during human platelet activation. Objectives To investigate the phosphorylation status of Dab2 and its functional consequences in thrombin-stimulated human platelets. Methods Dab2 was immunoprecipitated from resting and thrombin-stimulated platelet lysates for differential isotopic labeling. After enrichment of the phosphopeptides, the phosphorylation sites were analyzed by mass spectrometry. The corresponding phospho-specific antibody was generated. The protein kinases responsible for and the functional significance of Dab2 phosphorylation were defined by the use of signaling pathway inhibitors/activators, protein kinase assays, and various molecular approaches. Results Dab2 was phosphorylated at Ser227, Ser394, Ser401 and Ser723 in thrombin-stimulated platelets, with Ser723 phosphorylation being the most significantly increased by thrombin. Dab2 was phosphorylated by protein kinase C at Ser723 in a Gαq -dependent manner. ADP released from the stimulated platelets further activated the Gßγ -dependent pathway to sustain Ser723 phosphorylation. The Cbl-interacting protein of 85 kDa (CIN85) bound to Dab2 at a motif adjacent to Ser723 in resting platelets. The consequence of Ser723 phosphorylation was the dissociation of CIN85 from the Dab2-CIN85 complex. These molecular events led to increases in fibrinogen binding and platelet aggregation in thrombin-stimulated platelets by regulating αIIb ß3 activation and ADP release. Conclusions Dab2 Ser723 phosphorylation is a key molecular event in thrombin-stimulated inside-out signaling and platelet activation, contributing to a new function of Dab2 in thrombin signaling.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Plaquetas/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Trombina/farmacologia , Proteínas Supressoras de Tumor/metabolismo , Proteínas Reguladoras de Apoptose , Plaquetas/metabolismo , Fibrinogênio/metabolismo , Células HEK293 , Humanos , Fosforilação , Agregação Plaquetária/efeitos dos fármacos , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteína Quinase C/metabolismo , Serina , Fatores de TempoRESUMO
Three epithelial cell lines, CE-48T/VGH, CE-69T/-VGH, and CE-81T/VGH, were established from human squamous cell carcinoma of the esophagus. The cells were polygonal with a high nucleus-to-cytoplasm ratio. Many cells were multinucleate. Electron microscopy revealed the presence of tonofilaments and desmosomes. Chromosome analysis showed that these 3 cell lines were heteroploids of human origin. When transplanted into BALB/c (nu/nu) mice, CE-69T/VGH and CE-81T/VGH produced tumors, the histology of which proved to be carcinomas. All 3 cell lines secreted carcinoembryonic antigen. However, the secretion patterns were different. These 3 cell lines may provide useful models for the study of human esophageal cancer.
Assuntos
Carcinoma de Células Escamosas/fisiopatologia , Neoplasias Esofágicas/fisiopatologia , Animais , Antígeno Carcinoembrionário/análise , Carcinoma de Células Escamosas/ultraestrutura , Linhagem Celular , Neoplasias Esofágicas/ultraestrutura , Humanos , Cinética , Masculino , Camundongos , Camundongos Nus , Microscopia Eletrônica , Pessoa de Meia-Idade , Transplante de Neoplasias , Transplante HeterólogoRESUMO
To elucidate the significance of tRNA hypomodified with queuine to the grade of malignancies in human solid tumors, the amount of tRNA having guanosine in place of queuosine was determined in human lung cancer and normal lung tissue, by exchanging the unmodified guanosine residue for [3H]guanine. The reaction is catalyzed by guanine:queuine tRNA transglycosylase. Total tRNA was extracted from 23 different lung cancer specimens and the precursor of isoacceptor tRNA that contains guanine instead of queuine in the first or wobble position of the anticodon [(Q-)tRNA] content was determined. In 12 cases the (Q-)-tRNA was determined in normal lung tissues as well. In each individual, the (Q-)tRNA content in lung cancer tissue was higher than that of the normal lung tissue. The (Q-)tRNA content was not correlated to the surgicopathological staging of the patients but was highly correlated to the histopathological classification of the tumors. The amounts of (Q-)-tRNA were 1.75 +/- 0.67 (SD), 2.36 +/- 0.89, 3.77 +/- 1.39, 5.18 +/- 2.32, and 7.65 +/- 1.34 pmol/A260 in normal, well, moderately, moderately to poorly, and poorly differentiated tumors. The difference from normal to moderately differentiated or less differentiated groups was significant (P less than 0.05). In 10 patients with (Q-)tRNA higher than 3.5 pmol/A260, their cancers relapsed and only 2 were alive after 4 years. In 11 patients with (Q-)tRNA less than 3.5 pmol/A260 in their lung cancer tissues, 7 patients were still alive without any evidence of disease, 3 were dead, and 1 had recurrence of disease. These results, taken together with other previous studies, suggest that a decreased queuosine content of tRNA may be a general feature of neoplasms and may be useful for grading malignancy and perhaps also for the prediction of survival in human lung cancer.
Assuntos
Carcinoma/patologia , Guanina/análogos & derivados , Neoplasias Pulmonares/patologia , RNA de Transferência/química , Carcinoma/química , Carcinoma/diagnóstico , Guanina/química , Humanos , Pulmão/química , Neoplasias Pulmonares/química , Neoplasias Pulmonares/diagnóstico , Estadiamento de Neoplasias , Prognóstico , Análise de SobrevidaRESUMO
Monocyte-derived lipid-containing macrophage (MDLM) was the major source of granulomonopoietic enhancing activity (GM-EA) but these well-differentiated cells were unable to synthesize constitutively the granulocyte-macrophage colony-stimulating activity (GM-CSA) that was contributed mostly by the younger monocytoid cells. The presence of various concentrations (0.5-10 micrograms/ml) of lipopolysaccharide (LPS) potentiated the production of GM-EA by MDLM. Enhancement of GM-EA production peaked at about 0.5 micrograms/ml of LPS, but at higher doses (10-40 micrograms/ml) LPS became suppressive. In parallel, LPS-induced production of prostaglandin E2 (PGE2) was observable only at higher doses (10-40 micrograms/ml), suggesting a correlation between PGE2 production and LPS-mediated suppression of GM-EA synthesis. At optimal concentration (0.5 micrograms/ml), LPS could effectively override the inhibitory effect of interferon-gamma on the production of GM-EA. In addition, GM-CSA production by MDLM can be partly restored by stimulation with high doses of LPS (10-40 micrograms/ml). These results suggest that MDLMs have functional potentials similar to the younger macrophages and may play an important role in the regulation of myelopoiesis through the release of GM-EA and related regulators.
Assuntos
Fatores Estimuladores de Colônias/biossíntese , Substâncias de Crescimento/biossíntese , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Prostaglandinas E/biossíntese , Fator Estimulador de Colônias de Granulócitos , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Metabolismo dos Lipídeos , Monócitos/citologia , ProteínasRESUMO
AIM: Middle-aged and elderly women represent the main attending group in head-out aquatic exercise (HOAE). Blood pressure (BP) significantly increases both during water immersion and aquatic walking. Based on risk concerns, it is important to evaluate BP responses in postmenopausal women doing HOAE. The aim of this study was to determine BP, lactate levels, and rating of perceived exertion (RPE) changes associated with performing 3 different movements at 3 levels of exercise intensity in water. METHODS: Twelve postmenopausal women (59.9±0.6 years old) participated in 3 aquatic trials involving running (RU), rocking (RO), and scissor kicks (SK) on separate days. Systolic BP, mean arterial pressure (MAP), lactate levels, RPE, and motion cadence were measured at rest; upon reaching 50%, 65%, and 80% of heart rate reserve for 6 minutes; and 10 and 30 minutes after exercise. RESULTS: Under similar RPE responses at 3 levels of intensity, SK resulted in higher systolic BP, MAP, and lactate levels than RO at 10 minutes after exercise (P<0.05) and the lowest motion cadence (P<0.05). RO resulted in the lowest MAP and diastolic BP responses during exercise (P<0.05). RU resulted in lower responses of lactate levels at high exercise intensity (P<0.05). CONCLUSION: RO resulted in lower diastolic BP and MAP responses compared with RU and SK during exercise. These findings suggest that RO movement in aquatic exercises is more suitable for people at high risk for cardiovascular disease.
Assuntos
Pressão Sanguínea/fisiologia , Terapia por Exercício/métodos , Exercício Físico/fisiologia , Lactatos/sangue , Esforço Físico/fisiologia , Natação , Idoso , Determinação da Pressão Arterial , Estudos Cross-Over , Feminino , Frequência Cardíaca/fisiologia , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/fisiologiaRESUMO
The binding of glycosaminoglycans to a synthetic peptide (SKAQKAQAKQAKQAQKAQKAQAKQAKQW-CONH(2)), consisting of a hybrid consensus heparin binding sequence, is studied using circular dichroism, fluorescence anisotropy and nuclear magnetic resonance techniques. The results unveil certain novel features, most importantly, the peptide binds preferentially to iduronic acid containing glycosaminoglycans and the dissociation constant for the peptide-heparin complex was found to be 30 nM. Interestingly, higher order intermolecular association(s)/aggregation was not observed, especially at saturating concentrations of the ligand. The helical structure of the peptide backbone, induced upon binding to a particular glycosaminoglycan is directly related to their binding affinity. In our opinion, studies on such unconventional hybrid peptide sequences containing low density basic amino acid residues would lead to the design of sequence specific glycosaminoglycan binding peptides.
Assuntos
Glicosaminoglicanos/química , Peptídeos/química , Sequência de Aminoácidos , Configuração de Carboidratos , Dicroísmo Circular , Sequência Consenso , Polarização de Fluorescência , Heparina/química , Lisina , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos/síntese química , Conformação Proteica , Dobramento de ProteínaRESUMO
In the present study an immunofluorescence using KH-2 cells as target cells, has been developed for the screening of 1200 serum samples from normal individuals and 450 of cases from patients with various malignancies. The positive anti-HTLV-I antibody rate in the former group is 0.083% (1/1200) and while in the latter it is found to be 1.8% (8/450) (including 3 adult T-cell leukemia/lymphoma cases of the 92 hematopoietic and 5 of 358 non-hematopoietic malignancies). The differences between the two groups are found to be significantly different (p value is less than 0.0001). In addition to the 3 adult T-cell leukemia/lymphoma cases, the 5 seropositive cancer patients are of 5 different diseases. We have searched for the adult T-cell leukemia virus antigen and the p19 core protein in lymphoid cells of seropositive persons and the only positive cases were from cells of two proven adult T-cell leukemia (ATL) patients. Our results suggest that Taiwan is not an endemic area of adult T-cell leukemia virus and that KH-2 cells may be used for the detection of anti-HTLV-I antibodies.
Assuntos
Anticorpos Antivirais/análise , Neoplasias/imunologia , Adolescente , Adulto , Idoso , Antígenos Virais/análise , Criança , Anticorpos Antideltaretrovirus , Feminino , Antígenos HIV , Humanos , Leucemia/imunologia , Leucemia/microbiologia , Linfoma/imunologia , Linfoma/microbiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/microbiologia , Taiwan , Proteínas do Core Viral/análiseRESUMO
Dysphagia is often present early, with varying degrees of involvement, in patients with myasthenia gravis. Twenty-five patients with a clinical status of myasthenia gravis were graded according to a modified Osserman classification and the esophageal manometric results were reported according to their clinical status. The results were also compared with those in 20 normal control subjects. Twenty-four patients (96%) had abnormal motility. The only patient who was in class I had a normal tracing. There was no significant difference in function of the lower esophageal sphincter, but a significant decrease in mean amplitude (15.1 +/- 6.1 versus 29.7 +/- 4.7 mm Hg) and a prolongation in mean duration of the peristaltic wave (7.4 +/- 2.8 versus 4.5 +/- 0.2 seconds) was noted in the upper esophagus. The cricopharyngeal sphincter pressure also showed a significant decrease (23.4 +/- 9.5 versus 43.1 +/- 3.1 mm Hg), but relaxation and coordination were good. The mean amplitudes, mean duration of peristaltic waves, and cricopharyngeal pressures between the myasthenic and control populations were statistically significant, with a p value of 0.001. Besides this, frequent spontaneous contractions, simultaneous contractions, and biphasic repetitive contractions typical of peristaltic dysfunction were also found in myasthenic patients. Motor dysfunction of the esophagus as assessed by manometric study correlates well with Osserman's modified clinical classification.
Assuntos
Esôfago/fisiopatologia , Miastenia Gravis/fisiopatologia , Adolescente , Adulto , Idoso , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Junção Esofagogástrica/fisiopatologia , Feminino , Humanos , Masculino , Manometria/métodos , Pessoa de Meia-Idade , Miastenia Gravis/classificação , Miastenia Gravis/complicações , PeristaltismoRESUMO
Between 1974 and 1984, 1,188 patients with esophageal malignancies were treated in the Division of Thoracic Surgery of Veterans General Hospital, Taipei. The rate of resectability was 42.6%. Since 1974, the stomach has been used as esophageal substitute, and through 1984, a total of 368 patients were collected. The routes of reconstruction included retrosternal (77.2%), posteromediastinal (7.1%), and intrathoracic (15.7%). The rates of postoperative complications and surgical mortality in these 368 patients were 26.3% and 6.5%, respectively. Leakage of anastomosis was the most frequent complication. The incidence of stricture of esophagogastrostomy was 25.5%. All strictures were relieved by esophageal dilations. An average of 3.9 esophageal dilations were performed per patient (range, 1 to 15). Radical lymph node dissection was not routinely performed in our series. The actuarial 2-year and 5-year survival rates were 26.4% and 7.6%, respectively. Among 76 patients undergoing cervical esophagogastrostomy and surviving for more than 1 year, late complications occurred as follows: acid/bile regurgitation, 46.1%; postprandial fullness of abdomen, 38.2%; dumping syndrome, 13.2%; distended stomach with dyspnea, 11.8%; aspiration pneumonia, 6.6%; and gastric ulcer, 6.6%. Moreover, compared with patients without pyloroplasty, those with pyloroplasty were found to have a higher incidence of bile regurgitation (55.5% versus 8.6%), dumping syndrome (33.3% versus 6.9%), aspiration pneumonia (16.7% versus 3.4%), and gastric ulcer (22.2% versus 1.7%).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia , Esôfago/fisiologia , Complicações Pós-Operatórias/mortalidade , Estômago/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
To evaluate the status of tumor recurrence and the possible factors relevant to tumor recurrence among patients who survived more than 5 years after subtotal esophagectomy for the treatment of squamous cell carcinoma of the esophagus, a total of 104 patients who received treatment between 1959 and 1986 were reviewed. In 18 of these 104 patients, local or distant tumor recurrence developed, for a tumor recurrence rate of 17.3%. Eleven (61.1%) of these 18 patients eventually died of carcinomatosis despite further radiotherapy or chemotherapy, or both, and 4 patients with the disease are still alive. Three patients continue to survive after aggressive therapy was instituted for control of the locally recurrent tumor. Sixty-nine of the 104 patients are alive without tumor recurrence after the initial esophagectomy, and the remaining 17 patients died of miscellaneous causes. Tumor recurrence appears to be the most important factor affecting the prognosis in long-term survivors with resectable esophageal carcinoma. Among the 11 patients who died of tumor recurrence, 10 died within 5 to 9 years of their esophagectomy. The incidence of various modes of tumor recurrence among these 18 patients was as follows: blood-borne metastasis, 61%; lymph node recurrence, 33%; and locoregional organ recurrence, 33%. Factors that may be pertinent to a higher tumor recurrence rate include male sex, moderate to poor tumor differentiation, the presence of lymph node metastasis, and late stage of disease (stage IIb or worse). However, we could not find any statistical significance among these possible factors.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/cirurgia , Esofagectomia , Recidiva Local de Neoplasia/patologia , Idoso , Análise de Variância , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores Sexuais , Taxa de Sobrevida , SobreviventesRESUMO
This report reviews our experience with 96 patients with benign or malignant stricture of the esophagus who underwent interposition of the left colon with or without esophageal resection from July 1982 to June 1987. There were 67 male and 29 female patients ranging in age from 8 to 80 years. Thirty-seven patients had fibrotic stricture secondary to corrosive injury of the esophagus, 42 had cancer of the esophagus, and 17 had cancer of the gastric cardia. The incidence of postoperative complications and surgical mortality, respectively, was 16.2% and 2.7% for patients with corrosive stricture of the esophagus, 35.7% and 11.9% for patients with cancer of the esophagus, and 35.2% and 5.8% for patients with cancer of the gastric cardia. Reconstruction resulted in good function in 75.6% of the patients with corrosive stricture of the esophagus, 66.6% of the patients with cancer of the esophagus, and 70.5% of patients with cancer of the gastric cardia. The morbidity and mortality were higher in the group with malignant esophageal strictures because of advanced age, poor general condition of the patient, and extent of the surgical procedure needed. Cervical anastomotic leakage was the most frequently encountered complication (13.5%), and all the poor-function results were caused by this complication. In our experience, reconstruction of the esophagus with left colon is a satisfactory method that can be accomplished with acceptable morbidity and mortality. The left colon is a durable and functional substitute.
Assuntos
Colo/transplante , Neoplasias Esofágicas/cirurgia , Estenose Esofágica/cirurgia , Transplante Heterotópico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estenose Esofágica/induzido quimicamente , Esôfago , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidadeRESUMO
(G2019S) mutation of leucine-rich repeat kinase 2 (LRRK2) is the most common genetic cause of both familial and sporadic Parkinson's disease (PD) cases. Twelve- to sixteen-month-old (G2019S) LRRK2 transgenic mice prepared by us displayed progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurons and parkinsonism phenotypes of motor dysfunction. LRRK2 is a member of mixed lineage kinase subfamily of mitogen-activated protein kinase kinase kinases (MAPKKKs). We hypothesized that (G2019S) mutation augmented LRRK2 kinase activity, leading to overphosphorylation of downstream MAPK kinase (MKK) and resulting in activation of neuronal death signal pathway. Consistent with our hypothesis, (G2019S) LRRK2 expressed in HEK 293 cells exhibited an augmented kinase activity of phosphorylating MAPK kinase 4 (MKK4) at Ser(257), and protein expression of active phospho-MKK4(Ser257) was upregulated in the SN of (G2019S) LRRK2 transgenic mice. Protein level of active phospho-JNK(Thr183/Tyr185) and phospho-c-Jun(Ser63), downstream targets of phospho-MKK4(Ser257), was increased in the SN of (G2019S) LRRK2 mice. Upregulated mRNA expression of pro-apoptotic Bim and FasL, target genes of phospho-c-Jun(Ser63), and formation of active caspase-9, caspase-8 and caspase-3 were also observed in the SN of (G2019S) LRRK2 transgenic mice. Our results suggest that mutant (G2019S) LRRK2 activates MKK4-JNK-c-Jun pathway in the SN and causes the resulting degeneration of SNpc dopaminergic neurons in PD transgenic mice.
Assuntos
Neurônios Dopaminérgicos/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , MAP Quinase Quinase 4/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 11 Semelhante a Bcl-2 , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Modelos Animais de Doenças , Proteína Ligante Fas/metabolismo , Células HEK293 , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/metabolismo , Substância Negra/metabolismoRESUMO
Diverse death phenotypes of cancer cells can be induced by Photofrin-mediated photodynamic therapy (PDT), which has a decisive role in eliciting a tumor-specific immunity for long-term tumor control. However, the mechanism(s) underlying this diversity remain elusive. Caspase-3 is a critical factor in determining cell death phenotypes in many physiological settings. Here, we report that Photofrin-PDT can modify and inactivate procaspase-3 in cancer cells. In cells exposed to an external apoptotic trigger, high-dose Photofrin-PDT pretreatment blocked the proteolytic activation of procaspase-3 by its upstream caspase. We generated and purified recombinant procaspase-3-D(3)A (a mutant without autolysis/autoactivation activity) to explore the underlying mechanism(s). Photofrin could bind directly to procaspase-3-D(3)A, and Photofrin-PDT-triggered inactivation and modification of procaspase-3-D(3)A was seen in vitro. Mass spectrometry-based quantitative analysis for post-translational modifications using both (16)O/(18)O- and (14)N/(15)N-labeling strategies revealed that Photofrin-PDT triggered a significant oxidation of procaspase-3-D(3)A (mainly on Met-27, -39 and -44) in a Photofrin dose-dependent manner, whereas the active site Cys-163 remained largely unmodified. Site-directed mutagenesis experiments further showed that Met-44 has an important role in procaspase-3 activation. Collectively, our results reveal that Met oxidation is a novel mechanism for the Photofrin-PDT-mediated inactivation of procaspase-3, potentially explaining at least some of the complicated cell death phenotypes triggered by PDT.
Assuntos
Caspase 3/metabolismo , Éter de Diematoporfirina/farmacologia , Metionina/química , Fármacos Fotossensibilizantes/farmacologia , Sequência de Aminoácidos , Apoptose/efeitos dos fármacos , Caspase 3/genética , Domínio Catalítico , Linhagem Celular Tumoral , Éter de Diematoporfirina/uso terapêutico , Humanos , Células Jurkat , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Isótopos de Nitrogênio/química , Oxirredução , Isótopos de Oxigênio/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Ligação Proteica , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem , Raios UltravioletaRESUMO
A total of 265 patients with non-small cell lung cancer at stages 1 and 2 by preoperative clinical staging were divided into 4 stages after exploratory thoracotomy. Patients at each stage were further divided into subgroups to receive different adjuvant therapies. The cumulative 5-year survival rate showed to be 44.4% for stage 1, 35.5% for stage 2, 7.4% for stage 3 and 0% for stage 4. Histologically, the rate was 28.8% for squamous cell carcinoma, 23.4% for adenocarcinoma, and 29.8% for large cell carcinoma and carcinoma poorly differentiated. For patients at stage 1, it made no significant difference whether they underwent surgical resection only or combined with postoperative intrapleural BCG injection. For patients at stage 2, there was no significant difference between surgical resection only and resection combined with postoperative radiotherapy. For patients at stage 3, who underwent surgical resection combined with chemotherapy and/or radiotherapy, it seemed that combined chemotherapy and radiotherapy presented better results than radiotherapy or chemotherapy alone.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Terapia Combinada , Humanos , Neoplasias Pulmonares/mortalidade , Estadiamento de Neoplasias , Taxa de SobrevidaRESUMO
Cardiotoxins are small proteins that are found in the venoms of snakes from the Elapidae family. These toxins are known to bind to and disrupt the organization, integrity, and function of the cell membrane. Most of the well-studied cardiotoxins cause depolarization of membrane potentials and/or lysis of red cells. In contrast, CTX V from Naja naja atra displays poor hemolytic activity but is proficient at inducing aggregation and fusion of sphingomyelin vesicles [Chien et al. (1991) J. Biol. Chem. 266, 3252-3259]. To determine whether the unique activity of this CTX is attributable to its tertiary structure, the solution structure of CTX V was determined by NMR methods. On the basis of these studies, this cardiotoxin has the same general topology as other members of the family, and thus its unusual properties do not arise from any gross structural differences that are detectable by solution NMR methods. Molecular dynamics calculations indicate that residues 36-50 show concerted fluctuations. On the basis of sequence similarity, we postulate that residues 30-34 are important in determining the specificity of cardiotoxins for fusion versus lysis of vesicles.
Assuntos
Proteínas Cardiotóxicas de Elapídeos/química , Sequência de Aminoácidos , Simulação por Computador , Espectroscopia de Ressonância Magnética , Modelos Químicos , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Soluções , TermodinâmicaRESUMO
Egg sphingomyelin vesicles were used to assay aggregation/fusion activities of proteins from Taiwan (Naja naja atra) venom to avoid the problem of phospholipase A2 contamination during protein purification. It led to the identification of a new cardiotoxin (CTX) analogue protein (CTX V) with major aggregation/fusion, but few hemolysis, activities. On the contrary, cardiotoxin (CTX III) induced significant hemolysis of human red blood cells but exhibited few aggregation/fusion activities. To study the structure/activity relationship of these CTX-induced processes, the amino acid sequence of CTX V was determined and its aggregation/fusion activity was compared with that of CTX III by transmission electron microscopy, quasielastic laser light scattering, differential scanning calorimetry, and fluorescence spectroscopy. The results show that the CTX-induced fusion process at temperatures slightly above that of the gel to liquid-crystalline phase transition of sphingomyelin vesicles can ultimately convert small sonicated vesicles into large fused vesicles with sizes of 1-2 microns. The abilities of CTX V to induce the leakage of sphingomyelin vesicles content and to cause the fusion of vesicles are approximately 10-fold higher than those of CTX III. Based on the CTX structures determined in the present and other studies, it is suggested that the amino acid residue X within the well conserved sequence of -Cys-Pro-X-Gly-Lys-Gln-Leu-Cys- plays a role in the interaction of CTX with lipid molecules. The lipid phase transition could further enhance the protein-lipid interaction in the process leading to the fusion of vesicles.
Assuntos
Proteínas Cardiotóxicas de Elapídeos/química , Venenos Elapídicos/química , Fosfolipídeos/química , Esfingomielinas/química , Sequência de Aminoácidos , Animais , Cromatografia em Gel , Proteínas Cardiotóxicas de Elapídeos/toxicidade , Cobaias , Hemólise/efeitos dos fármacos , Lipídeos de Membrana/química , Microscopia Eletrônica , Dados de Sequência Molecular , Espectrometria de FluorescênciaRESUMO
Paris formosana Hayata (Liliaceae) grown in the mountain areas of Taiwan, has been used as a folk remedy for snake bite, and as an anti-inflammatory or anti-neoplastic agent. The effects of formosanin-C, a diosgenin saponin isolated from Paris formosana, on immune responses and transplantable murine tumor were studied. In culture systems, formosanin-C (0.03-0.16 microM) displayed significant enhancement of the blastogenic response of human peripheral blood cells to phytohemagglutinin. Formosanin-C also significantly increased the 3H-thymidine incorporation of ConA-stimulated lymphocytes at concentrations of 0.1 and 0.01 microM. The responsiveness of the granulocyte/macrophage colony-forming cells (GM-CFC) to mouse fibroblast cells L929 conditioned medium was altered in the presence of 0.01 and 0.001 microM of formosanin-C. In addition, formosanin-C given intraperitoneally activated natural killer cell activity at doses of 1-2.5 mg/kg. An intraperitoneal injection of 2.5 mg/kg of formosanin-C markedly induced interferon production, the peak blood level of which was observed 24 h after formosanin-C injection. Growth of subcutaneously transplanted MH134 mouse hepatoma was retarded by intraperitoneal treatment with 1-2.5 mg/kg of formosanin-C. The activity of 5-fluorouracil against MH-134 mouse hepatoma was potentiated by intraperitoneal treatment with formosanin-C. These results suggest that formosanin-C might display antitumor activity in association with modification of the immune system.
Assuntos
Adjuvantes Imunológicos , Antineoplásicos Fitogênicos , Diosgenina/análogos & derivados , Saponinas/farmacologia , Animais , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Indutores de Interferon , Células Matadoras Naturais/efeitos dos fármacos , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C3H , Plantas MedicinaisRESUMO
Sixty-one patients underwent operations for malignant thymomas between 1961 and 1989. Twenty-three patients had associated myasthenia gravis (MG), an incidence of 37.7%. Upon being admitted to the hospital, the patients' most common symptoms included chest pain, MG, cough, and dyspnea. Only 7 of 61 (11.5%) patients had no symptom. Tumor staging of 58 patients with invasive thymomas was performed according to Masaoka classification. The patients were classified as follows: Stage II disease, 5; Stage III, 41; Stage IVa, 8; and Stage IVb, 4. In addition, thymic carcinoma was present in three patients. The series had a resection rate of 55.7%. The incidence of operative complications was 16.3%. Only one patient died of myocardial infarction; the incidence of operative mortality was 1.6%. The patients with MG had a higher rate of resection (69.6%) and a higher incidence of complete thymectomy (14 of 23 patients; 60.9%). Mixed lymphoepithelial tumors and epithelial cell predominant tumors were the most frequent histologic patterns (45.9% and 34.4%, respectively). Fifty-two patients had postoperative radiation therapy, and 10 patients had chemotherapy. The overall cumulative survival rates in the series were 59% and 34% at 5 and 10 years, respectively. The results demonstrated that the factors affecting the prognosis may include resectability, postoperative irradiation or chemotherapy, MG, and tumor staging. The influence of histologic variation on survival rates could not be clearly defined in the series. Surgical resection, particularly complete thymectomy, followed by irradiation is the primary option of therapeutic management for malignant thymoma.
Assuntos
Timoma/patologia , Neoplasias do Timo/patologia , Adolescente , Adulto , Idoso , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Terapia Combinada , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/epidemiologia , Miastenia Gravis/etiologia , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Timectomia , Timoma/mortalidade , Timoma/terapia , Neoplasias do Timo/mortalidade , Neoplasias do Timo/terapiaRESUMO
Surgical intervention of diaphragmatic eventration is urgent and life-saving in infants but is rarely in adults. In the past 22 years, Seven adults with diaphragmatic eventration were encountered at the Division of thoracic surgery, Dept. of surgery, VGH, Taipei. The age on diagnosis ranged from 32 to 65 years with mean of 44 years old. Male and left diaphragm were more frequently affected (6 men, 1 woman; 6 left, 1 right). All of them received operation of plication. In spite of good immediate postoperative return of the diaphragms to normal position with clinical improvement found in all patients, 5 dyspneic patients were found to have gradual diaphragmatic rise or relapse of respiratory symptoms after repair. Diaphragmatic eventration could cause compression of lung by abdominal organs and reinforcement of diaphragm through plication might increase the diaphragm strength and diminish the clinical symptoms. Yet according to our series, we recommend surgical intervention is only for existence of distress stemmed from it and unresponsive to medical therapy.