Enhancement of Glossiness Perception by Retinal-Image Motion: Additional Effect of Head-Yoked Motion Parallax

It has been argued that when an observer moves, a contingent retinal-image motion of a stimulus would strengthen the perceived glossiness. This would be attributed to the veridical perception of three-dimensional structure by motion parallax. However, it has not been investigated whether the effect of motion parallax is more than that of retinal-image motion of the stimulus. Using a magnitude estimation method, we examine in this paper whether cross-modal coordination of the stimulus change and the observer''s motion (i.e., motion parallax) is essential or the retinal-image motion alone is sufficient for enhancing the perceived glossiness. Our data show that a retinal-image motion simulating motion parallax without head motion strengthened the perceived glossiness but that its effect was weaker than that of motion parallax with head motion. These results suggest the existence of an additional effect of the cross-modal coordination between vision and proprioception on glossiness perception. That is, motion parallax enhances the perception of glossiness, in addition to retinal-image motions of specular surfaces.     

Diastolic suction in heart failure: Impact of left ventricular geometry,untwist, and flow mechanics

Aims

Vector flow mapping (VFM) can be used to assess intraventricular hemodynamics quantitatively. This study assessed the magnitude of the suction flow kinetic energy with VFM and investigated the relation between left ventricular (LV) function and geometry in patients with an estimated elevated LV filling pressure.

Materials and methods

We studied 24 subjects with an elevated LV filling pressure (EFP group) and 36 normal subjects (normal group). Suction was defined as flow directed toward the apex during the period from soon after systolic ejection to before mitral inflow. The flow kinetic energy index was quantified as the sum of the product of the blood mass and velocity vector and its magnitude to the peak value was measured.

Key findings

Suction flow was observed in 12 (50%) EFP-group patients and 36 (100%) normal-group subjects. The magnitude of the suction kinetic energy index was significantly smaller in EFP versus normal group (2.7 ± 3.8 vs. 5.7 ± 4.4 g/s/cm², P < 0.01). The EFP-group patients with suction had a smaller LV end-systolic volume (ESV) (P < 0.01), greater ellipsoidal geometry (P < 0.05) and untwisting rate (P < 0.01) than the EFP-group patients without suction. A regression analysis indicated a significant linear relation between the suction kinetic energy index and LVEF (r = 0.43, P = 0.04), ESV (r = − 0.40, P = 0.05), eccentricity index (r = 0.44, P = 0.04), and untwisting rate (r = 0.51, P = 0.04).

Significance

The magnitude of the suction flow kinetic energy index derived from VFM may allow the quantitative assessment of the suction flow, which correlates with LV systolic function, geometry, and untwisting mechanics.     

Comprehensive trapping of polyubiquitinated proteins using the UIM peptide of ASB2a

An alternative splicing variant of E3 ubiquitin ligase ASB2, termed ASB2a, has a distinct N-terminal sequence containing a ubiquitin-interacting motif (UIM) consensus sequence. Examination of the minimal essential region for binding to polyubiquitinated proteins indicated that the UIM consensus sequence (residues 26–41) alone is not enough, and that amino acids 12–41 from the N-terminus of ASB2a is essential for binding. ASB2a(12–41) peptide was chemically synthesized and coupled to Sepharose 4B via disulfide bonds. This ASB2a(12–41) peptide-coupled affinity resin bound both K48- and K63-linked polyubiquitinated proteins in cell lysates and comprehensively captured polyubiquitinated proteins, including polyubiquitinated β-catenin, I-κB, and EGF receptor, which were eluted with 2-mercaptoethanol under non-denaturing conditions. These results indicate that this UIM affinity purification (designated as ubiquitin-trapping) is a useful method to discover polyubiquitinated proteins and their associated proteins.     

Structural characterization of the proximal and distal histidine environment of cytoglobin and neuroglobin

Cytoglobin (Cgb) and neuroglobin (Ngb) are the first examples of hexacoordinated globins from humans and other vertebrates in which a histidine (His) residue at the sixth position of the heme iron is an endogenous ligand in both the ferric and ferrous forms. Static and time-resolved resonance Raman and FT-IR spectroscopic techniques were applied in examining the structures in the heme environment of these globins. Picosecond time-resolved resonance Raman (ps-TR3) spectroscopy of transient five-coordinate heme species produced by the photolysis of carbon monoxide (CO) adducts of Cgb and Ngb showed Fe-His stretching (nu(Fe-His)) bands at 229 and 221 cm(-1), respectively. No time-dependent shift in the nu(Fe-His) band of Cgb and Ngb was detected in the 20-1000 ps time domain, in contrast to the case of myoglobin (Mb). These spectroscopic data, combined with previously reported crystallographic data, suggest that the structure of the heme pocket in Cgb and Ngb is altered upon CO binding in a manner different from that of Mb and that the scales of the structural alteration are different for Cgb and Ngb. The structural property of the heme distal side of the ligand-bound forms was investigated by observing the sets of (nu(Fe-CO), nu(C-O), delta(Fe-C-O)) and (nu(Fe-NO), nu(N-O), delta(Fe-N-O)) for the CO and nitric oxide (NO) complexes of Cgb and Ngb. A comparison of the spectra of some distal mutants of Cgb (H81A, H81V, R84A, R84K, and R84T) and Ngb (H64A, H64V, K67A, K67R, and K67T) showed that the CO adducts of Cgb and Ngb contained three conformers and that the distal His (His81 in Cgb and His64 in Ngb) mainly contributes to the interconversion of the conformers. These structural characteristics of Cgb and Ngb are discussed in relation to their ligand binding and physiological properties.     

Contribution of comparative fish studies to general endocrinology: structure and function of some osmoregulatory hormones

Fish endocrinologists are commonly motivated to pursue their research driven by their own interests in these aquatic animals. However, the data obtained in fish studies not only satisfy their own interests but often contribute more generally to the studies of other vertebrates, including mammals. The life of fishes is characterized by the aquatic habitat, which demands many physiological adjustments distinct from the terrestrial life. Among them, body fluid regulation is of particular importance as the body fluids are exposed to media of varying salinities only across the thin respiratory epithelia of the gills. Endocrine systems play pivotal roles in the homeostatic control of body fluid balance. Judging from the habitat-dependent control mechanisms, some osmoregulatory hormones of fish should have undergone functional and molecular evolution during the ecological transition to the terrestrial life. In fact, water-regulating hormones such as vasopressin are essential for survival on the land, whereas ion-regulating hormones such as natriuretic peptides, guanylins and adrenomedullins are diversified and exhibit more critical functions in aquatic species. In this short review, we introduce some examples illustrating how comparative fish studies contribute to general endocrinology by taking advantage of such differences between fishes and tetrapods. In a functional context, fish studies often afford a deeper understanding of the essential actions of a hormone across vertebrate taxa. Using the natriuretic peptide family as an example, we suggest that more functional studies on fishes will bring similar rewards of understanding. At the molecular level, recent establishment of genome databases in fishes and mammals brings clues to the evolutionary history of hormone molecules via a comparative genomic approach. Because of the functional and molecular diversification of ion-regulating hormones in fishes, this approach sometimes leads to the discovery of new hormones in tetrapods as exemplified by adrenomedullin 2.     

Antifeedants against Locusta migratoria from the Japanese Cedar, Cryptomeria japonica

(1S,6R)-2,7(14),10-bisabolatrien-1-ol-4-one and (+)-7(14),10-bisaboladien-1-ol-4-one were isolated and identified from Cryptomeria japonica as antifeedants against Locusta migratoria L. which is well known as a serious pest to cereals throughout the world. These compounds strongly inhibited the feeding of L. migratoria only when they were combined, but each compound alone did not show any activity.