Survey of tortoises with urolithiasis in Japan

Urolithiasis is a disease often seen in tortoises at veterinary hospitals, however there have been no comprehensive research reports of tortoises with urolithiasis in Japan. In this study, we analyzed tortoises diagnosed with urolithiasis at three domestic veterinary hospitals. Based on medical records, we assessed the diagnostic method, species, sex, body weight, dietary history, husbandry, clinical signs, clinical examination, treatment for urolithiasis, and clinical outcome. The total number of cases in the 3 facilities was 101. As for species of tortoises, the most common was the African spurred tortoise (Centrochelys sulcata) with 42 cases (41.6%), followed by the Indian star tortoise (Geochelone elegans) with 30 cases (29.7%). Six other species were confirmed to have calculi. Almost all cases (99 cases, 98%) had a single calculus, and only 2 had multiple calculi. The prevalence of urolithiasis for the total number of tortoises having visited to one institution during the same period was 5.1%. Of the 86 cases that underwent calculi removal, 64 (74.4%) were successfully removed via the vent, and the efficacy of this method was confirmed. Nineteen cases (22%) were approached via plastronotomy, among which only 2 died postoperatively. In this study, we could not clarify the relationship between calculi formation and diets or other husbandry factors.     

Gigantic photoresponse in 1/4-filled-band organic salt (EDO-TTF)2PF6

We report that the organic salt (EDO-TTF)2PF6 with 3/4-filled-band (1/4-filled in terms of holes), which forms an organic metal with strong electron and lattice correlation, shows a highly sensitive response to photoexcitation. An ultrafast, photoinduced phase transition from the insulator phase to the metal phase can be induced with very weak excitation intensity at near room temperature. This response makes the material attractive for applications in switching devices with room-temperature operation. The observed photo-induced spectroscopic change shows that this photoinduced phase transition process is caused by the cooperative melting of charge ordering assisted by coherent phonon generation.     

Cloning of a membrane protein that induces a slow voltage-gated potassium current

A rat kidney messenger RNA that induces a slowly activating, voltage-dependent potassium current on its expression in Xenopus oocytes was identified by combining molecular cloning with an electrophysiological assay. The cloned complementary DNA encodes a novel membrane protein that consists of 130 amino acids with a single putative transmembrane domain. This protein differs from the known ion channel proteins but is involved in the induction of selective permeation of potassium ions by membrane depolarization.     

Biochemical and genomic analysis of neoculin compared to monocot mannose-binding lectins

Neoculin occurring in an edible tropical fruit is a heterodimeric protein which has both sweetness and a taste-modifying activity that converts sourness to sweetness. Both the primary and the overall tertiary structures of neoculin resemble those of monocot mannose-binding lectins. This study investigated differences in biochemical properties between neoculin and the lectins. Structural comparison between the mannose-binding sites of lectins and the corresponding regions of neoculin showed that there is at least one amino acid substitution at each site in neoculin, suggesting a reason for the lack of its mannose-binding ability. This was consistent with hemagglutination assay data demonstrating that neoculin had no detectable agglutinin activity. DNA microarray analysis indicated that neoculin had no significant influence on gene expression in Caco-2 cell, whereas kidney bean lectin (Phaseolus vulgaris agglutinin) greatly influenced various gene expressions. These data strongly suggest that neoculin has no lectin-like properties, encouraging its practical use in the food industry.