Motion illusion activates the visual motion area of the brain: a near-infrared spectroscopy (NIRS) study

Near-infrared spectroscopy (NIRS) enables noninvasive measurement of concentration changes of oxy- and deoxy-hemoglobin. The present study investigated cerebral representations of motion illusion by NIRS and examined several experimental procedures to determine an efficient procedure that can shorten the experimental time. We compared hemodynamic responses to figures with and without motion illusion. The number of repetitions of the tasks in the experiments and other factors were also examined. Results showed significant responses around area MT/V5 to the motion illusion from the analyses of three cycles (blocks) of presentation of illusion induction stimulus. These findings indicate that motion illusion can be detected by NIRS, and we propose a concise and efficient procedure for NIRS.     

The effect of public self-consciousness on forced laughter

The purpose of this study was to investigate the effect of public self-consciousness on forced laughter. Participants (N = 409) were asked to imagine a group of either friends or acquaintances, and then to indicate how often he or she exhibited forced laughter toward the group members. They also completed Self-Consciousness Scale (Fenigstein, Scheier, & Buss, 1975). Results indicated that persons with high public self-consciousness reported more frequent expressions of all types of forced laughter--expression control, intimacy maintenance, action control, and affect manipulation--than those who were low, regardless of interpersonal intimacy level. Besides public self-consciousness, both gender and intimate feeling toward group members influenced frequency of forced laughter. Implications for the nature of public self-consciousness and forced laughter were discussed.     

Relationship between oral sensory thresholds and depressive moods

AIMS: The aims were to compare the sensory thresholds on the tip of the tongue with on the dorsum of the hand, and to investigate the relationship between the sensory threshold and depressive mood with volunteers whose psychological conditions were normal. METHODS: Fifty-five subjects (28 women, 27 men) took psychiatric structured diagnostic interview and Self-rating Depression Scale (SDS). In the next step, the quantitative sensory tests (light touch sensation and thermal sensory test) were carried out on the tongue and the hand. Then we investigated the relationship between depressive moods and sensory thresholds on the tongue and the hand using logistic regression model. RESULT: The sensory thresholds on the tip of the tongues were significantly different from those on the dorsum of the hands. Only on tongue tip, increment of SDS had relation to the thresholds of innoxious thermal stimulation (OR=0.152, 95% CI. 0.049-0.478) and noxious heat stimulation (OR=0.352, 95% CI. 0.169-0.734). CONCLUSION: This finding might support for the idea that depressive mood had closer association with the tongue of the orofacial areas than the dorsum of the hand.     

In vivo antitumor activity of pegylated zinc protoporphyrin: targeted inhibition of heme oxygenase in solid tumor

High expression of the inducible isoform of heme oxygenase (HO-1) is now well known in solid tumors in humans and experimental animal models. We reported previously that HO-1 may be involved in tumor growth (Tanaka et al., Br. J. Cancer, 88: 902-909, 2003), in that inhibition of HO activity in tumors by using zinc protoporphyrin (ZnPP) significantly reduced tumor growth in a rat model. We demonstrate here that poly(ethylene glycol)-conjugated ZnPP (PEG-ZnPP), a water-soluble derivative of ZnPP, exhibited potent HO inhibitory activity and had an antitumor effect in vivo. In vitro studies with cultured SW480 cells, which express HO-1, showed that PEG-ZnPP induced oxidative stress, and consequently apoptotic death, of these cells. Pharmacokinetic analysis revealed that PEG-ZnPP-administered i.v. had a circulation time in blood that was 40 times longer than that for nonpegylated ZnPP. More important, PEG-ZnPP preferentially accumulated in solid tumor tissue in a murine model. In vivo treatment with PEG-ZnPP (equivalent to 1.5 or 5 mg of ZnPP/kg, i.v., injected daily for 6 days) remarkably suppressed the growth of Sarcoma 180 tumors implanted in the dorsal skin of ddY mice without any apparent side effects. In addition, this PEG-ZnPP treatment produced tumor-selective suppression of HO activity as well as induction of apoptosis. The major reason for tumor-selective targeting of PEG-ZnPP is attributed to the enhanced permeability and retention effect that is observed commonly in solid tumors for biocompatible macromolecular drugs. These findings suggest that tumor-targeted inhibition of HO activity could be achieved by using PEG-ZnPP, which induces apoptosis in solid tumors, probably through increased oxidative stress.     

The effects of clonidine premedication on the blood pressure and tachycardiac responses to ephedrine in elderly and young patients during propofol anesthesia

We studied the pressor and tachycardiac responses to ephedrine in elderly and young patients given either clonidine or midazolam during propofol anesthesia. In the first experiment, elderly (>60 yr) and young (20-45 yr) patients were randomly allocated to one of four groups according to age and premedicated regimens (n = 16 each; elderly-clonidine [EC], elderly-midazolam [EM], young-clonidine [YC], and young-midazolam [YM]). Under propofol anesthesia, ephedrine was injected, and hemodynamic measurements were made. In the second experiment, with clonidine premedication, elderly patients (n = 16) were given a reduced dose of propofol (EC-LP) and young patients (n = 16) were given an increased dose of propofol (YC-HP). Ephedrine was injected, and he- modynamic measurements were performed. The in-creases in mean blood pressure and heart rate were larger in the EC group than in the EM, YM, and EC-LP groups (P < 0.05). In the YC-HP group, the pressor response to ephedrine tended to be augmented as compared with the YC group but was not statistically significant. These results suggest that clonidine premedication augmented the pressor and tachycardiac responses to ephedrine, especially in elderly patients during a standard dose of propofol anesthesia, and that clonidine, age, and propofol could be involved in the augmentation of the blood pressure and tachycardiac responses to ephedrine. IMPLICATIONS: Clonidine premedication augments the pressor and tachycardiac responses to ephedrine in elderly patients during standard or large doses of propofol anesthesia but does not augment during small doses of propofol anesthesia. Clonidine, age, and propofol could be involved in the augmentation of the pressor and tachycardiac responses to ephedrine.     

The impact of donor chemical overdose on the outcome of liver transplantation

BACKGROUND: To overcome the critical shortage of liver grafts, many centers have been widening the acceptance criteria for liver donation. Use of liver grafts from victims who have suffered chemical overdose (COD) may be one option that could help to expand the donor pool. However, this practice has been poorly documented. METHODS: Of 1,195 orthotopic liver transplantations performed at our institution between June 1994 and March 2001, 22 involved livers (1.8%) were retrieved from COD donors. Donor and recipient characteristics and posttransplantation outcomes were analyzed retrospectively. RESULTS: The main chemicals causing brain death of the donor were carbon monoxide (n=4), cocaine (n=4), tricyclic antidepressants (n=3), 3,4-methylenedioxy- methamphetamine (n=2), opiates (n=2), aspirin (n=1), gamma hydroxybutyrate (n=1), heroin (n=1), insulin (n=1), verapamil (n=1), barbiturate (n=1), and brompheniramine/phenylpropanolamine (n=1). Primary nonfunction developed in one patient who had received a liver from an 3,4-methylenedioxymethamphetamine-intoxicated donor. Another patient died of fungal meningitis 10 days after transplantation with a functioning graft. The remaining 20 patients experienced acceptable early graft function, as demonstrated by initial mean peak values of bilirubin (4.8 mg/dL), aspartate aminotransferase (624 U/L), and alanine aminotransferase (730 U/L). One-year graft survival rate estimated by the Kaplan-Meier method was 86%. CONCLUSIONS: Satisfactory outcomes of graft function were achieved in orthotopic liver transplantations from COD donors. The cautious use of liver grafts from selected COD donors may be a worthwhile method of increasing the availability of scarce donor organs.