Gaussia Luciferase as a Genetic Fusion Partner with Antibody Fragments for Sensitive Immunoassay Monitoring of Clinical Biomarkers.

In this study, we show the utility of Gaussia luciferase (GLuc), which is much smaller than previously found luciferases, as the fusion partner with artificial antibody species for developing sensitive immunoassay systems. As an example, we constructed a bioluminescent enzyme-linked immunosorbent assay (BL-ELISA) system determining the major glucocorticoid cortisol. A monoclonal antibody was newly elicited against a cortisol-albumin conjugate, and the genes encoding its variable domains (VH and VL) were cloned and combined to encode a single-chain Fv fragment (scFv). scFv was then linked to the wild-type GLuc gene or that encoding GLuc mutants reported to show improved emission kinetics and expressed in the periplasmic space of several Escherichia coli strains. Notably, the wild-type GLuc fusion protein (scFv-wtGLuc) showed the most suitable luminescent properties for BL-ELISAs. In our system, scFv-wtGLuc was reacted competitively with the analyte and immobilized cortisol moieties, and the bound GLuc activity was monitored with coelenterazine as the substrate. Successful batch-type luminescence detection was achieved using a plate reader without built-in injectors. The midpoint and limit of detection in a typical dose-response curve were 4.1 and 0.26 pg/assay, respectively, thus exhibiting much more sensitivity than conventional cortisol immunoassays. Serum cortisol levels (as the sum with cortisone) for healthy subjects, determined without any pretreatment, were compatible with reported reference ranges. The scFv-wtGLuc probe was stable over a year under storage as periplasmic extracts at -30 °C or with repeated freeze-thawing. These results suggest that GLuc fusions with antibody fragments might serve as useful and highly sensitive immunoassay probes in various clinical settings.

Immediate effect of spinal magnetic stimulation on camptocormia in Parkinson's disease.

OBJECTIVES: Spinal cord stimulation is a potential therapeutic option for the treatment of Parkinson's disease (PD)-associated symptoms. Repetitive trans-spinal magnetic stimulation (rTSMS) is a non-invasive and safe alternative for stimulation of spinal pathways that has not been studied for therapeutic efficacy in PD. We assessed the benefits of rTSMS on camptocormia, an often treatment-resistant postural abnormality observed in PD patients. METHODS: We compared rTSMS to sham stimulation in PD patients with camptocormia in a single-centre, randomised, single-blind, crossover, placebo-controlled study. PD patients with camptocormia were administered a single trial of rTSMS (a train of 40 stimuli) or sham treatment followed 1 week later by the alternate treatment. Primary outcome measure was thoracolumbar spine flexion angle in the standing position immediately after the trial. RESULTS: Of 320 PD patients examined, 37 had concomitant camptocormia and were randomly assigned to either the rTSMS first group (n=19) or sham first group (n=18). Flexion angle in the standing position decreased by a mean of 10.9° (95% CI 8.1 to 13.65) after rTSMS but remained unchanged after sham stimulation (mean, -0.1°; 95% CI -0.95 to 0.71). The flexion angle while sitting (secondary outcome) decreased by 8.1° (95% CI 5.89 to 10.25) after rTSMS, whereas sham treatment had no significant effect (mean, -0.8°; 95% CI -1.62 to 0.05). CONCLUSIONS: We found an immediate beneficial effect of rTSMS on camptocormia in PD patients. Although the effect was transient, this successful trial justifies further studies to test if repeated rTSMS treatments can induce longer term improvements in camptocormia associated with PD. CLINICAL TRIAL REGISTRATION: UMIN Clinical Trials Registry: UMIN000011495.

Characteristics of intracellular Ca2+ signals consisting of two successive peaks in hepatocytes during liver regeneration after 70% partial hepatectomy in rats.

Two specific signals for regulating liver regeneration were found after 70% partial hepatectomy (PH) in rats. The first finding was a sustained increasing signal of intracellular Ca2+ ([Ca2+]i) in hepatocytes, consisting of two successive peaks with the first narrow peak at 1 hour and the second broad peak increasing by day 3 and then returning to normal by day 4. The second finding was an abnormal peak in the restoring ratio (Rr) curve of liver regeneration after 70% PH at day 4, where the Rr exceeded 100% temporarily, returned to a lower level, and then proceeded to a termination phase of liver regeneration. For 4 days around the two successive [Ca2+]i peaks and abnormal peak, various physiological activities were induced to promote liver regeneration after 70% PH. mRNA expression of genes encoding Ca2+-binding proteins S100A4 and calpain was induced between the two Ca2+ peaks. Hepatocytes underwent synchronous cell proliferation as the liver was restored from 30% to 70% at day 4, and significant expression of VEGF mRNA at around day 4 promoted angiogenesis to remodel the sinusoidal system. Cytochrome P450 activity levels in microsomes and alanine aminotransferase values at 24 hours after CCl4 administration were decreased after 70% PH, which recovered transiently to the control level at day 4, returned to the decreased level, and then slowly recovered by day 10. Thus, these results indicate that day 4 is important during liver regeneration after 70% PH.

[Intracellular Ca2+ mediating biodefense signal on CCl4-induced autoprotection].

To study a role of intracellular Ca2+ on protection effects in animals against intoxication, that is, autoprotection. When carbon tetrachloride (CCl4) of 0.2 ml/kg was i.p. administered daily to male Donryu rats, the serum alanine aminotransferase (ALT) activity rose to a maximal level one day later, and then decreased to the control level within three days. Thus, the animals were not received any intoxication effect of CCl4 due to second, third and fourth administrations. Thus, animals have a sensitive and non-sensitive periods against intoxication of CCl4. In non-sense period, the animals were protective against the poison. Such protection is an autoprotection. To study a role of intracellular Ca2+ on CCl4-induced autoprotection, we measured the intracellular Ca2+ in hepatocytes isolated from rats after daily CCl4 i.p. administration. Then, the peaks of the intracellular Ca2+ centered on three days and twelve hours after the first CCl4 administration from the first to fourth administration. These results show that the peak of the intracellular Ca2+ is perfectly corresponding with the trough of the serum ALT; that is, the protective period in animals against intoxication. Therefore, this result means that intracellular Ca2+ can mediate biodefense signal caused by CCl4 intoxication.