Atypical gaze patterns in children and adults with autism spectrum disorders dissociated from developmental changes in gaze behaviour

Eye tracking has been used to investigate gaze behaviours in individuals with autism spectrum disorder (ASD). However, traditional analysis has yet to find behavioural characteristics shared by both children and adults with ASD. To distinguish core ASD gaze behaviours from those that change with development, we examined temporo-spatial gaze patterns in children and adults with and without ASD while they viewed video clips. We summarized the gaze patterns of 104 participants using multidimensional scaling so that participants with similar gaze patterns would cluster together in a two-dimensional plane. Control participants clustered in the centre, reflecting a standard gaze behaviour, whereas participants with ASD were distributed around the periphery. Moreover, children and adults were separated on the plane, thereby showing a clear effect of development on gaze behaviours. Post hoc frame-by-frame analyses revealed the following findings: (i) both ASD groups shifted their gaze away from a speaker earlier than the control groups; (ii) both ASD groups showed a particular preference for letters; and (iii) typical infants preferred to watch the mouth rather than the eyes during speech, a preference that reversed with development. These results highlight the importance of taking the effect of development into account when addressing gaze behaviours characteristic of ASD.     

Synchronization of spontaneous eyeblinks while viewing video stories

Blinks are generally suppressed during a task that requires visual attention and tend to occur immediately before or after the task when the timing of its onset and offset are explicitly given. During the viewing of video stories, blinks are expected to occur at explicit breaks such as scene changes. However, given that the scene length is unpredictable, there should also be appropriate timing for blinking within a scene to prevent temporal loss of critical visual information. Here, we show that spontaneous blinks were highly synchronized between and within subjects when they viewed the same short video stories, but were not explicitly tied to the scene breaks. Synchronized blinks occurred during scenes that required less attention such as at the conclusion of an action, during the absence of the main character, during a long shot and during repeated presentations of a similar scene. In contrast, blink synchronization was not observed when subjects viewed a background video or when they listened to a story read aloud. The results suggest that humans share a mechanism for controlling the timing of blinks that searches for an implicit timing that is appropriate to minimize the chance of losing critical information while viewing a stream of visual events.     

Anti-tumor effects of depleting and non-depleting anti-CD27 monoclonal antibodies in immune-competent mice

CD27 plays an important role in T-cell co-stimulation and is also expressed on lymphomas. In the present study, we generated novel depleting and non-depleting monoclonal antibodies (mAbs) against mouse CD27 and characterized their co-stimulatory activity in vitro and anti-tumor effects in immune-competent mice bearing syngeneic T-cell lymphoma (EG7) expressing or lacking CD27. A profound anti-tumor effect was observed with a non-depleting mAb (RM27-3E5), but not with a depleting mAb (RM27-3C1), against either EG7/CD27(+) or EG7/CD27(−) tumors, which was associated with the induction of EG7-specific cytotoxic T lymphocytes (CTLs). Consistently, the anti-tumor effect of RM27-3E5 was abolished in T cell-deficient nude mice. These results indicate that a non-depleting agonistic mAb against CD27 is promising for cancer therapy by co-stimulating tumor-specific CTL induction.     

Deficit in visual temporal integration in autism spectrum disorders

Individuals with autism spectrum disorders (ASD) are superior in processing local features. Frith and Happe conceptualize this cognitive bias as ‘weak central coherence’, implying that a local enhancement derives from a weakness in integrating local elements into a coherent whole. The suggested deficit has been challenged, however, because individuals with ASD were not found to be inferior to normal controls in holistic perception. In these opposing studies, however, subjects were encouraged to ignore local features and attend to the whole. Therefore, no one has directly tested whether individuals with ASD are able to integrate local elements over time into a whole image. Here, we report a weakness of individuals with ASD in naming familiar objects moved behind a narrow slit, which was worsened by the absence of local salient features. The results indicate that individuals with ASD have a clear deficit in integrating local visual information over time into a global whole, providing direct evidence for the weak central coherence hypothesis.     

Effects of contrast media on erythrocyte aggregation during sedimentation

To evaluate the effects of contrast media (CMs) on erythrocyte aggregation, we measured the erythrocyte sedimentation with Westergren method at 25 degrees C. CMs were diatrizoate (Urografin 76%) for ionic CM and iopamidol (Iopamiron 370) for nonionic CM. Swine red blood cells (RBCs) were suspended in autologous plasma containing diatrizoate (URO), iopamidol (IOP), and saline (SAL) at 6.7% w/w, as well as in plasma alone (PLA), at 40% of the hematocrit. Sigmoid sedimentation curves were fitted to the Puccini et al. (1977) equation, and the average number of RBCs per aggregate m was calculated by Stokes' law against the time t. According to the Murata-Secomb (1988) theory we estimated the collision rate K between two aggregates from dm/dt in the stationary phase during sedimentation. Corresponding to the maximal ESR, the dm/dt (in cells/s) was 0.52 in PLA, 0.09 in SAL, 0.06 in URO and 0.03 in IOP, so that K also decreased in proportion to dm/dt from 145 fL/s in PLA to 8 fL/s in IOP. Both the ionic and nonionic CMs tend to inhibit the RBC aggregation more than that in SAL; the latter iopamidol appears to be inhibitory more than the former diatrizoate in autologous plasma.     

Advanced glycation end product-induced apoptosis and overexpression of vascular endothelial growth factor and monocyte chemoattractant protein-1 in human-cultured mesangial cells

Advanced glycation end products (AGE) have been implicated in the pathogenesis of glomerulosclerosis in diabetes. However, their involvement in the development of the early phase of diabetic nephropathy has not been fully elucidated. We investigated the effects of AGE on growth and on vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1) expression in human cultured mesangial cells. We prepared three immunochemically distinct AGE by incubating bovine serum albumin (BSA) with glucose, glyceraldehyde, or glycolaldehyde. When human mesangial cells were cultured with various types of AGE-BSA, viable cell numbers as well as DNA syntheses were significantly decreased. All of the AGE-BSA were found to significantly increase p53 and Bax protein accumulations and subsequently induce apoptotic cell death in mesangial cells. An antioxidant, N-acetylcysteine, significantly prevented the AGE-induced apoptotic cell death in mesangial cells. Human mesangial cells stimulated prostacyclin production by co-cultured glomerular endothelial cells. Furthermore, various types of AGE-BSA were found to up-regulate the levels of mRNAs for VEGF and stimulate the secretion of VEGF and MCP-1 proteins in mesangial cells. The results suggest that AGE disturbed glomerular homeostasis by inducing apoptotic cell death in mesangial cells and elicited hyperfiltration and microalbuminuria by stimulating the secretion of VEGF and MCP-1 proteins, thereby being involved in the pathogenesis of the early phase of diabetic nephropathy.     

Targeted disruption of Np95 gene renders murine embryonic stem cells hypersensitive to DNA damaging agents and DNA replication blocks

NP95, which contains a ubiquitin-like domain, a cyclin A/E-Cdk2 phosphorylation site, a retinoblastoma (Rb) binding motif, and a ring finger domain, has been shown to be colocalized as foci with proliferating cell nuclear antigen in early and mid-S phase nuclei. We established Np95 nulligous embryonic stem cells by replacing the exons 2-7 of the Np95 gene with a neo cassette and by selecting out a spontaneously occurring homologous chromosome crossing over with a higher concentration of neomycin. Np95-null cells were more sensitive to x-rays, UV light, N-methyl-N"-nitro-N-nitrosoguanidine (MNNG), and hydroxyurea than embryonic stem wild type (Np95(+/+)) or heterozygously inactivated (Np95(+/-)) cells. Expression of transfected Np95 cDNA in Np95-null cells restored the resistance to x-rays, UV, MNNG, or hydroxyurea concurrently to a level similar to that of Np95(+/-) cells, although slightly below that of wild type (Np95(+/+)) cells. These findings suggest that NP95 plays a role in the repair of DNA damage incurred by these agents. The frequency of spontaneous sister chromatid exchange was significantly higher for Np95-null cells than for Np95(+/+) cells or Np95(+/-) cells (p < 0.001). We conclude that NP95 functions as a common component in the multiple response pathways against DNA damage and replication arrest and thereby contributes to genomic stability.     

Design and synthesis of lignostilbene-alpha,beta-dioxygenase inhibitors

Lignostilbene-alpha,beta-dioxygenase cleaves the olefinic double bond of phenolic stilbenes by a mechanism similar to that of 9-cis-epoxycarotenoid dioxygenase, a key enzyme in abscisic acid biosynthesis. Several analogues of stilbene were designed and synthesized, and their efficacy as inhibitors of lignostilbene-alpha,beta-dioxygenase was examined. The compound (Z)-1-(4-hydroxyphenyl)-1-fluoro-2-phenylethene (2) was found to be a potent inhibitor of this enzyme with an IC(50) of 3 microM.     

The action of gravity in agravitropic Zea primary roots: Effect of gravistimulation on the extracellular free-Ca2+ content in the 1-mm apical root tip in the dark

The action of gravity stimulation in darkness was examined in agravitropic primary roots of Zea mays L. (cv. Golden Cross Bantam 70). Contents of diffusible and nitric-acid-extractable Ca²⁺ in 1-mm apical tips of roots gravistimulated in the dark were measured by flowinjection analysis as free Ca²⁺ and bound Ca²⁺, respectively. The free-Ca²⁺ content increased transiently, reaching a maximum 0.5 h after gravistimulation. This transient increase was also observed when gravistimulation was applied by changing the orientation of the roots back from horizontal to vertical again. On the other hand, the bound-Ca²⁺ content decreased transiently following gravistimulation. Furthermore, when the root caps were treated with 10 mM 2-(N-morpholino) ethanesulfonic acid buffer, the elevation of free Ca²⁺ following gravistimulation was prevented. These results indicate that gravity perception and the initial transduction steps proceed in the dark, and moreover that the elevation of free Ca²⁺ brought about by the interaction of Ca²⁺/H ⁺ in the apoplast of root tips may be involved in transmission of the gravity signal.Abbreviations FIA flow-injection analysis - Mes 2-(N-morpholino) ethanesulfonic acid - Pipes 1,4-piperazinediethanesulfonic acid - Quin 2 2-[(2-bis-[carboxymethyl]amino-5-methylphenoxy)methyl]-6-methoxy-8-bis(carboxymethyl) aminoquinoline     

Hyaluronidase expression in cultured growth plate chondrocytes during differentiation

Hyaluronan (HA) is a major component of the extracellular matrix of cartilage, contributes to its structural and functional integrity, and has various important roles in the differentiation of chondrocytes. HA metabolism is regulated by both anabolic and catabolic processes; however, the details have not yet been clarified. The purpose of this study was to clarify the expression patterns of hyaluronidase (HAase) mRNAs (from the relevant HAase genes: the HYALs) and HAase activity during chondrocyte differentiation. Cartilage tissue and growth plate chondrocytes were isolated from the ribs of 4-week-old male Japanese rabbits. The expression of HYAL mRNAs in cartilage was analyzed by in situ hybridization. The expression levels of HYAL mRNAs in the culture were analyzed for each of the chondrocyte differentiation stages by means of quantitative real-time polymerase chain reaction analysis. Enzymatic activity in the conditioned medium from the cultures was examined by using HA zymography and an enzyme-linked immunosorbent-like assay. The expression levels of HYAL1 and HYAL2 mRNAs were enhanced about 2.8-fold and 3.2-fold at the maximum during the early matrix forming stage, respectively, and by about 3.2-fold and 2.0-fold at the maximum in the hypertrophic stage, respectively. HYAL3 mRNA was not detected throughout the experimental period. HAase activity was enhanced at the early matrix forming and hypertrophic stages. These results suggest that selective expression of HYALs is essential for extracellular HA metabolism during chondrocyte differentiation.This research was supported by Grants-in-Aid (no. 11557166) for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan