Rhabdom Size and Chromophore Contents under the Daily Light Cycle in the Blowfly, Lucilia cuprina

The eyes of the fly have been employed in an extensive range of studies, but the existence of diurnal rhythmicity, which is involved in the adaptation to different light environments between the day and night is still unclear. The rhythmicity of the photoreceptor cells of the blowfly Lucilia cuprina was observed over a precise time schedule under a daily light cycle. Both the morphology of the photoreceptive structure called rhabdom and the amount of the visual pigment chromophore were mostly constant. Each photoreceptor area measured from the cross sections and each amount of chromophore was ca. 22.5±1.85 μm2 and ca. 1.4 pmol, respectively. The number of the multivesicular bodies, assuming the indicator of the photoreceptive membrane turnover, was small compared with other reports of arthropods. We confirmed that there is no diurnal rhythmicity either in the morphology of rhabdom or in the visual pigment contents under the daily light cycles

Phosphoramidon inhibits the generation of endothelin-1 from exogenously applied big endothelin-1 in cultured vascular endothelial cells and smooth muscle cells

AbstractWhen cultured porcine aortic endothelial cells (ECs) were incubated with porcine big endothelin-1 (bit ET-I1–39), there was a time-dependent increase in immunoreactive (IR)-ET in the culture supernatant, in addition to an endogenous IR-ET release fron the cells. Reverse-phase HPLC of the culture supernatant revealed one major IR-ET component corresponding to the elution position of synthetic ET-1, thereby indicating that the additional increase in IR-ET was due to the conversion of big ET-1 to mature ET-11–21. Phosphoramidon, a metalloproteinase inhibitor, strongly suppressed this increase in IR-ET as well as the endogenous IR-ET release. Cultured vascular smooth muscle cells (VSMCs) also released IR-ET. The apparent conversion of exogenously applied big ET-1 to ET-1 and its inhibition by phosphoramidon were observed using cultured VSMCs, although the enzyme inhibitor did not influence the basal secretion of IR-ET from VSMCs. These results suggest that both cultured ECs and VSMCs can generate ET-1 from exogenously applied big ET-1 via action of the same type of phosphoramidon-sensitive metalloproteinase, which is also involved in the endogenous ET-1 generation in ECs

Distribution of blue-sensitive photoreceptors in amphibian retinas

AbstractPreviously, we reported that an opsin (Rc-MS) belonging to the SWS2 group opsins is expressed in bullfrog green rods [Hisatomi, O. et al., FEBS Lett., 1999, 447, 44–48]. An anti-Rc-MS antiserum recognized the cones of the Japanese common newt, Cynops pyrrhogaster, which has no green rods. We isolated a cDNA encoding an SWS2 group opsin (Cp-SWS2) from this newt and found that Cp-SWS2 is expressed in a small population of the cones. Our results suggest that SWS2 opsins can be expressed in either green rods or cones of caudata. It seems reasonable to suppose that green rods arose before amphibia were divided into caudata and anura

Evaluation of hemodynamic imaging findings of hypervascular hepatocellular carcinoma: comparison between dynamic contrast-enhanced magnetic resonance imaging using radial volumetric imaging breath-hold examination with k-space-weighted image contrast reconstruction and dynamic computed tomography during hepatic arteriography

To compare the visualization of hemodynamic imaging findings of hypervascular hepatocellular carcinoma (HCC) on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using radial volumetric imaging breath-hold examination with k-space-weighted image contrast reconstruction (r-VIBE-KWIC) versus dynamic computed tomography during hepatic arteriography (dyn-CTHA). We retrospectively reviewed the databases of preoperative DCE-MRI using r-VIBE-KWIC, dyn-CTHA, and postoperative pathology of resected specimens. Fourteen patients with 14 hypervascular HCCs underwent both DCE-MRI and dyn-CTHA. The imaging findings of the tumor and adjacent liver parenchyma were assessed on both modalities by two readers. The tumor enhancement time was also compared between the two modalities. On DCE-MRI/dyn-CTHA, early staining, peritumoral low-intensity or low-density bands, corona enhancement, and washout of HCC were observed in 14/14 (100%), 10/12 (83%), 11/14 (78%), and 4/14 (29%) patients, respectively. Pathologically, four HCCs with low-density bands on dyn-CTHA had no fibrous capsules. The median tumor enhancement time on DCE-MRI and dyn-CTHA was 24 (9-24) and 23 (8-35) s, respectively. The correlation coefficient between the two groups was 0.762 (P < 0.002). DCE-MRI using r-VIBE-KWIC has diagnostic potential comparable with that of dyn-CTHA in the hemodynamic evaluation of hypervascular HCC except for the washout phenomenon.ArticleJAPANESE JOURNAL OF RADIOLOGY.36(4):295-302(2018)journal articl