RESUMEN
Rho family small GTPases regulate lymphocyte migration induced by chemokines. However, how lymphocyte migration is regulated by Rho GTPases remains to be elucidated. Here, we identified FilGAP, a Rac-specific GAP, as a negative regulator of lymphocyte polarization and migration. Depletion of FilGAP in mouse pro-B BAF cells increased cellular elongation and membrane protrusion after stimulation of the cells with SDF-1α, which caused increased migration speed. Although FilGAP is detectable both at the front and rear of polarized cells, FilGAP appears to be concentrated at the tip of retracting lamellae of moving lymphocytes. Moreover, depletion of FilGAP increased activation of Rac at the front of polarized cells. Thus, FilGAP may inhibit lamellae extension at the front of moving lymphocytes.
Asunto(s)
Quimiocina CXCL12/metabolismo , Quimiotaxis , Proteínas Activadoras de GTPasa/metabolismo , Linfocitos/citología , Animales , Línea Celular , Polaridad Celular , Proteínas Activadoras de GTPasa/genética , Humanos , Linfocitos/metabolismo , Ratones , Proteínas de Unión al GTP rac/metabolismoRESUMEN
Glycerol conversion was conducted in hot-compressed water (HCW: 573-673 K, 25-34.5 MPa) using a batch and a flow apparatus and the influences of temperature, H(2)SO(4), glycerol concentration, and pressure, were examined. The yield of acrolein was enhanced by higher glycerol and H(2)SO(4) concentration, and higher pressure. Approximately 80% selectivity of acrolein was obtained at 90% of glycerol conversion with an acid catalyst in supercritical condition (673 K and 34.5 MPa). The rate constant of acrolein decomposition was always higher than that of acrolein formation in the absence of acid catalyst but the rate constant of acrolein formation could be overcome that of acrolein decomposition by addition acid in supercritical condition.
Asunto(s)
Acroleína/síntesis química , Glicerol/química , Calor , Cinética , Sensibilidad y Especificidad , Ácidos Sulfúricos/química , Agua/químicaRESUMEN
Glucose reactions were conducted in hot compressed water (473-773 K, 4-40 MPa) by means of a batch-type reactor. The reactions in the heating period (about for 60s) were observed. More than 80% of the glucose was consumed in the heating period above 573 K. Gasification of glucose was promoted with increasing temperature. The effect of heating rate (from 4.2 to 15.8K/s) on glucose conversion was also examined, and gasification of glucose was enhanced with increasing the heating rate.
Asunto(s)
Glucosa/química , Calor , Agua/química , Biomasa , Dióxido de Carbono/síntesis química , Monóxido de Carbono/síntesis química , Gases , PresiónRESUMEN
The effects of the homogeneous catalysts (H(2)SO(4) and NaOH) and heterogeneous catalysts (TiO(2) and ZrO(2)) on glucose reactions were examined in hot compressed water (473 K) by a batch-type reactor. From the homogeneous catalyst studies, we confirmed that the acid catalyst promoted dehydration, while isomerization of glucose to fructose was catalyzed by alkali. Anatase TiO(2) was found to act as an acid catalyst to promote formation of 5-hydroxymethylfuraldehyde (HMF). Zirconia (ZrO(2)) was a base catalyst to promote the isomerization of glucose. The effects of the additives were also confirmed through fructose reactions.
Asunto(s)
Glucosa/química , Hidróxido de Sodio/química , Ácidos Sulfúricos/química , Titanio/química , Circonio/química , Catálisis , Fructosa/síntesis química , Furaldehído/análogos & derivados , Furaldehído/síntesis química , Calor , Isomerismo , Presión , Agua/químicaRESUMEN
Splenic cysts are uncommon, and cysts derived from the accessory spleen are rare. We report a case of a huge splenic cyst derived from the accessory spleen in the omentum, concomitant with multiple epithelial cysts of the primary spleen. Both serum and cystic fluid concentrations of carbohydrate antigen (CA)19-9 were markedly elevated. A huge monolocular cyst occupied the entire abdomen. A total of 71 of aspirated cystic fluid was turbid and yellowish-brown. The cyst wall, which consisted of CA19-9-positive squamous epithelium, contained approximately 2 x 3 x 1cm of splenic tissue. There was a separate multicystic 16 x 8-cm spleen in the normal position. The CA19-9 serum level returned to normal postoperatively.