Effect of dietary zinc deficiency on ischemic vulnerability of the brain

Deficiency of zinc, which modulates glutamate release, might increase ischemic vulnerability of the brain. We examined effects of dietary zinc deficiency for 2 weeks on ischemic vulnerability in several brain regions using dynamic positron autoradiography technique and [¹⁸F]2-fluoro-2-deoxy-d-glucose with rat brain slices. In the normal diet group, the cerebral glucose metabolic rate (CMRglc) was not significantly different from that of the ischemia-unloaded control even after the loading of ischemia for 45 min. However, in the zinc-deficient diet group, CMRglc was significantly lower than that of the ischemia-unloaded control after loading of ischemia for 45 min. With treatment of MK-801 (NMDA receptor antagonist) from the start of ischemia loading, CMRglc was not significantly different from that of the ischemia-unloaded control. These findings, obtained for all analyzed brain regions, suggest that dietary zinc deficiency increased ischemic vulnerability in the brain, and that glutamate might contribute to this effect through activation of the NMDA receptor.     

Effect of carteolol hydrochloride on ocular blood flow dynamics in normal human eyes

PURPOSE: The effect of topical 2% calteolol hydrochloride on the ocular blood flow dynamics in normal human eyes was studied. MATERIALS AND METHODS: Ten healthy volunteers were studied using color Doppler imaging and scanning laser Doppler flowmetry. In the first experiments, one eye received 30 microliters of 2% carteolol hydrochloride twice daily for 7 days and the fellow eye a placebo in a randomized masked manner. The blood flow velocity of the central retinal artery, the ophthalmic artery, and the short posterior ciliary artery, the blood flow volume of the peripapillary retina (PPR), intraocular pressure (IOP), ocular perfusion pressure (OPP) and pulse rate (PR) were measured before treatment, 2 hours after the initial instillation, and after the last instillation on the 7th day. In the control experiments, 30 microliters of placebo was instillated in both eyes, and the above parameters were measured according to the same time schedule as in the first experiments. RESULTS: In the carteolol-treated eyes, the systolic maximum (p = 0.012) and diastolic minimum (p = 0.019) blood flow velocities of the ophthalmic artery, and the blood flow volume of the superior (p = 0.003), central (p = 0.001) and inferior (p = 0.000) PPR showed significant increases in the first experiments compared with the control experiments. IOP and OPP in both eyes showed significant reduction in the first experiments compared with the control study. CONCLUSION: These results indicated that topical carteolol hydrochroride increases the blood flow of the intraorbital microcirculation and PPR.     

A qualitative and quantitative analysis of rhythmic activities during a mental task and sleep spindles

The frequency, configuration, and distribution of sleep spindles are similar to some of the rhythmic activities seen during task performance. In the present study, the relationship between rhythmic activities during sleep and arithmetic addition was investigated in male university students with (n = 10) and without (n = 10) frontal midline theta activity (Fmtheta). Electroencephalograms (EEGs) during addition in both groups were compared at frontal and central areas on three consecutive days. Polysomnograms were recorded at the same regions on four consecutive nights for each group. The amount of theta rhythm during a mental task (Fmtheta) and in nocturnal sleep at Fz and Cz electrodes was greater for the Fmtheta group than for the non-Fmtheta group, while the amount of beta rhythm at both sites was smaller in the Fmtheta group than in the non-Fmtheta group. There were no differences between the groups in the amount of alpha rhythm at either site. The frequency of alpha rhythm at Fz and Cz in both situations was slower for the Fmtheta group than for the non-Fmtheta group, but there were no differences in the frequency of theta and beta rhythms between the groups at either site. These results suggest that rhythmic activities during a mental task and in sleep may correlate with each other.     

Appearance of frontal midline theta activity in patients with generalized anxiety disorder

The appearance of frontal midline theta activity (Fmθ), recognized as distinct EEG theta rhythm in the frontal midline area during performance of a mental task, reflects feelings of relief from anxiety in humans. In the present study, EEGs were recorded, and the Hamilton Rating Scale for Anxiety and the state anxiety scale of Spielberger's State-Trait Anxiety Inventory were evaluated once a week in 28 patients with generalized anxiety disorder. The Taylor Manifest Anxiety Scale and the trait anxiety scale of Spielberger's State-Trait Anxiety Inventory were used to assess anxiety before and after the tests. The present results suggest that the appearance of Fmθ might be closely related to an improvement in the anxiety symptoms associated with generalized anxiety disorder.     

Altered expression of natural killer cell inhibitory receptors (KIRs) on T cells in bronchoalveolar lavage fluid and peripheral blood of sarcoidosis patients

BACKGROUND AND AIM OF THE WORK: The role for natural killer cell inhibitory receptors (KIRs) on T cells is not fully understood, but signalling through KIRs on T cells may inhibit T cell receptor mediated activation, and KIR expression has been suggested to be one mechanism of controlling T cell mediated immune responses. An aberrant KIR expression on T cells could thus be of importance in autoimmune as well as infectious disorders. Sarcoidosis patients have several immunological impairments that have not been clarified, and we here examined the KIR expression on CD4+ and CD8+ peripheral blood (PBL) and bronchoalveolar lavage (BAL) T cells of sarcoidosis patients and controls. METHODS: We used three KIR specific monoclonal antibodies, namely DX9 (specific for p70), DX27 (p58) and DX22 (specific for CD94, that belongs to another major group of KIRs) and flow cytometry. RESULTS: p70 was expressed lower in patient CD8+ PBL (median 2.3%) compared to controls (6.3%) (p < 0.01). In patients, p58 was expressed by less CD8+ BAL lymphocytes (median 1.2%) compared to PBL (6.8%) (p < 0.01) while CD94 was expressed by more CD8+ BAL lymphocytes (median 14.5%) compared to PBL (9.6%) (p < 0.01). Moreover, in CD8+ PBL, CD94 and p58 were expressed significantly lower in patients with an active vs. inactive disease, and in patients with chest radiographic stage I vs. stage II, respectively. CONCLUSIONS: The significantly altered expression of distinct KIRs on CD8+ T cells in sarcoidosis, especially in patients with signs of an active disease, indicate these cells to be dysregulated and implicate them in the pathogenesis of the disease.     

Influence of cigarette smoke on the L-ascorbic acid metabolism and the activities of drug-metabolizing enzyme in rats

This study clarified the influence of cigarette smoke on the L-ascorbic acid (AsA) metabolism and the activities of drug-metabolizing enzyme in rats. The test rats (group T) were exposed to weak sidestream smoke from cigarettes for 2 h, everyday for 57 days. AsA concentration in the tissues and excreted amount of AsA in urine of group T tended to be higher than those of control group (group C). The plasma AsA concentration and the activities of aniline hydroxylase and 7-ethoxycoumarin O-deethylase of group T were significantly higher than those of group C. There was no significant difference in the activity of UDP glucuronosyltransferase or in the liver cytochrome P-450 content between these two groups.