RESUMO
Development of a strategy to mitigate nitrous oxide (N2O) emitted from biological sources is important in the nexus of wastewater treatment and greenhouse gas emission. To this end, immobilization of N2O-reducing bacteria as a biofilm has the potential to ameliorate oxygen (O2) inhibition of the metabolic activity of the bacteria. We demonstrated the effectiveness of calcium alginate gel entrapment of the nosZ clade II type N2O-reducing bacterium, Azospira sp. strain I13, in reducing levels of N2O, irrespective of the presence of O2. Azospira sp. strain I13 cells in the gel exhibited N2O reduction up to a maximum dissolved oxygen concentration of 100 µM in the bulk liquid. The maximum apparent N2O uptake rate, [Formula: see text] , by gel immobilization did not appreciably decrease, retaining 72% of the N2O reduction rate of the cell suspension of Azospira sp. strain I13. Whereas gel immobilization increased the apparent half-saturation constant for N2O, [Formula: see text] , and the apparent O2 inhibition constant, [Formula: see text] , representing the degree of O2 resistance, correspondingly increased. A mechanistic model introducing diffusion and the reactions of N2O consumption was used to describe the experimental observations. Incorporating Thieles modulus into the model determined an appropriate gel size to achieve N2O reduction even under aerobic conditions.
Assuntos
Biodegradação Ambiental , Bactérias Fixadoras de Nitrogênio/metabolismo , Óxido Nitroso/isolamento & purificação , Óxido Nitroso/farmacocinética , Águas Residuárias/microbiologia , Purificação da Água/métodos , Alginatos/química , Alginatos/farmacocinética , Bactérias/metabolismo , Biofilmes , Simulação por Computador , Géis , Ácido Glucurônico/química , Ácido Glucurônico/farmacocinética , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacocinética , Eliminação de Resíduos de Serviços de Saúde/métodos , Modelos Teóricos , Bactérias Fixadoras de Nitrogênio/química , Oxigênio/metabolismo , Instalações de Eliminação de ResíduosRESUMO
CUB domain-containing protein-1 (CDCP1) is a trans-membrane protein predominantly expressed in various cancer cells and involved in tumor progression. CDCP1 is phosphorylated at tyrosine residues in the intracellular domain by Src family kinases and recruits PKCδ to the plasma membrane through tyrosine phosphorylation-dependent association with the C2 domain of PKCδ, which in turn induces a survival signal in an anchorage-independent condition. In this study, we used our cell-free screening system to identify a small compound, glycoconjugated palladium complex (Pd-Oqn), which significantly inhibited the interaction between the C2 domain of PKCδ and phosphorylated CDCP1. Immunoprecipitation assays demonstrated that Pd-Oqn hindered the intercellular interaction of phosphorylated CDCP1 with PKCδ and also suppressed the phosphorylation of PKCδ but not that of ERK or AKT. In addition, Pd-Oqn inhibited the colony formation of gastric adenocarcinoma 44As3 cells in soft agar as well as their invasion. In mouse models, Pd-Oqn markedly reduced the peritoneal dissemination of gastric adenocarcinoma cells and the tumor growth of pancreatic cancer orthotopic xenografts. These results suggest that the novel compound Pd-Oqn reduces tumor metastasis and growth by inhibiting the association between CDCP1 and PKCδ, thus potentially representing a promising candidate among therapeutic reagents targeting protein-protein interaction.
Assuntos
Proliferação de Células/efeitos dos fármacos , Metástase Neoplásica/tratamento farmacológico , Proteínas de Neoplasias/metabolismo , Proteína Quinase C-delta/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Células A549 , Animais , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Células HEK293 , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
It is widely accepted that daily exercise improves the dynamic standing balance of elderly persons. In the current study, 77 community-dwelling Japanese elderly persons (aged 71.1 +/- 0.5 years) participated in a daily exercise program to assess its effect on their dynamic standing balance. The daily exercise consisted of walking, stretching, muscle strengthening, and balance exercises. The program ran for 31 months and the dynamic standing balance was assessed at the start of the program and again at 3, 7, 12, 19, 24, and 31 months. In most of the tests of dynamic standing balance, the measured values improved drastically in the first 7 months; thereafter, they either reached a plateau or continued to improve more slowly. These findings can contribute to the future planning of community-based exercise programs; in particular, the length of the program and the timing of changes to the exercise load.
Assuntos
Acidentes por Quedas , Terapia por Exercício , Equilíbrio Postural , Características de Residência , Fatores Etários , Idoso , Envelhecimento , Análise de Variância , Feminino , Indicadores Básicos de Saúde , Inquéritos Epidemiológicos , Humanos , Japão , Masculino , Fatores de Risco , Fatores de TempoRESUMO
The objective of this study was to assess the effect of comprehensive exercise program widely accepted as a community-based physical intervention for the prevention of falling in the elderly persons on their controlling standing balance. Twenty-six community-dwelling elderly persons (13 males and females; 69.8 ± 2.8 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise without exercise equipments. The intervention was continued for three months. Indicators of standing balance related to static balance, dynamic balance and postural response were measured before and after the intervention. As an effect of the intervention on static balance, the sway of center of pressure (COP) in the static stance significantly increased. In the dynamic balance, significant improvements were observed in one leg standing time, the 10-m gait time, functional reach. Additionally, the maximal movable length of COP which subjects can move voluntarily to right and left significantly increased. In the postural response, the integrated electromyography (IEMG) induced by postural response for sudden postural perturbation significantly decreased in the lower leg muscles. Since less muscular activities were sufficient to maintain posture, it was suggested that postural response was elicited more efficiently following the intervention. This study suggested that the comprehensive exercise program, which has been widely introduced as community-based interventions for the prevention of falling, have extensive effects on the control of standing balance covering static balance, dynamic balance and postural response in the elderly persons.