RESUMO
New experimental data are reported that demonstrate the use of a novel vibrating membrane filter (VMF) for the combined recovery and concentration of two species of nematodes, S. feltiae and P. hermaphrodita, from mature liquid fermentation cultures. The disk membrane module had a working surface area of 0.2 m(2) and was operated at a constant flow rate of 0.2 m(3) h(-1). The recovery of the viable nematodes from the spent media and nonviable nematodes was assisted by an independently imposed oscillatory motion of the disk assembly, which produced an intense shear field at the membrane surface with calculated mean values on the order of 10(4) s(-1). Adult (nonviable) nematodes in the fermentation culture were preferentially dissolved in a detergent (sodium dodecylsulfate) and successfully separated from the juveniles using the VMF equipment. Permeate fluxes on the order of 15 to 30 L/m(2/)h were achieved for an operating transmembrane pressure of 800 mbar. Industrial-scale liquid fermentation for the manufacture of nematodes as biopesticides produces the viable nematode life stages in low-concentration suspension containing large quantities of spent media and other waste material. The VMF equipment provided a flexible operation for separation, cleaning, and concentration of viable nematodes from the fermentation broths.
Assuntos
Insetos/patogenicidade , Nematoides/parasitologia , Animais , Fermentação , Filtração/instrumentação , Filtração/métodos , Membranas Artificiais , Nematoides/fisiologia , Controle Biológico de Vetores/instrumentação , Controle Biológico de Vetores/métodos , VibraçãoRESUMO
The BMP family of polypeptide growth factors has been shown to play diverse roles in establishing embryonic patterning and tissue fates. We report the cloning of the zebrafish homologue of BMP-2, examine its expression during embryogenesis, and find that it is localized to the distal end of the long arm of zebrafish chromosome 20. A missense mutation of the bmp2 gene has recently been shown to be responsible for the early dorsalized phenotype of the zebrafish swirl mutant [Kishimoto et al., 1997]. Given the dynamic expression of bmp2 in the developing embryo and the complex interactions of BMP signaling response in vertebrates, it is possible that other mutant phenotypes, due to altered bmp2 gene expression, will eventually map to or interact with this genetic locus.
Assuntos
Proteínas Morfogenéticas Ósseas/genética , Genes , Fator de Crescimento Transformador beta , Peixe-Zebra/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas/biossíntese , Mapeamento Cromossômico , Clonagem Molecular , DNA Complementar/genética , Embrião não Mamífero/metabolismo , Embrião não Mamífero/ultraestrutura , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Peixe-Zebra/embriologiaAssuntos
Viscosidade Sanguínea/efeitos dos fármacos , Claudicação Intermitente/tratamento farmacológico , Isquemia/tratamento farmacológico , Perna (Membro)/irrigação sanguínea , Animais , Clofibrato/farmacologia , Clofibrato/uso terapêutico , Fibrina , Fibrinogênio/análise , Humanos , Claudicação Intermitente/sangue , Isquemia/sangue , CoelhosRESUMO
A sensitive animal model was used to investigate treatment designed to improve vascular graft patency. A Dacron graft was inserted into the infrarenal vena cava of 30 rabbits. Half were treated with subcutaneous Arvin for 28 days after operation. This produced a significant lowering of the post operative plasma fibrinogen. The patency rate of the grafts in the treated rabbits was significantly greater than in the control rabbits.
Assuntos
Ancrod/farmacologia , Prótese Vascular , Endopeptidases/farmacologia , Fibrinogênio , Animais , Fibrinogênio/análise , Polietilenotereftalatos , Coelhos , Veia Cava Inferior/cirurgiaRESUMO
The plasma fibrinogen concentration is directly related to blood viscosity, which in turn is inversely related to blood flow. The way in which the plasma fibrinogen level affects the clinical status of patients with peripheral vascular disease is discussed with reference to both retrospective and prospective studies of patients undergoing major arterial surgery. Animal experiments are described in which the effect of reducing the plasma fibrinogen level with oral clofibrate and parenteral Arvin (ancrod) on the patency of Dacron arterial grafts was studied.
Assuntos
Fibrinogênio/análise , Procedimentos Cirúrgicos Vasculares , Ancrod/farmacologia , Animais , Velocidade do Fluxo Sanguíneo , Vasos Sanguíneos/anatomia & histologia , Viscosidade Sanguínea/efeitos dos fármacos , Temperatura Corporal , Clofibrato/farmacologia , Depressão Química , Hematócrito , Humanos , Claudicação Intermitente/tratamento farmacológico , Complicações Pós-Operatórias , CoelhosRESUMO
Ankle systolic pressure measurements in 67 patients with intermittent claudication treated with Clofibrate for an average period of 11 months and 32 untreated patients suggest that 1) patients with a raised initial plasma fibrinogen concentration have more severe disease than those with low initial plasma fibrinogen concentration and 2) the response to treatment with Clofibrate is significantly better in those with a raised plasma fibrinogen concentration. On the basis of the patients own estimation of their claudication distance there was marked symptomatic inprovement in the treated patients. There was also a significant decrease in mean plasma fibrinogen levels in the treated patients and it is suggested that the hypofibrinogenemic effect of Clofibrate may be responsible for the benefit of this drug in patients with vascular disease.
