Evaluation of blood flow patterns of true and false lumens in dissecting aneurysms using MR phase-contrast techniques

The magnetic resonance phase-contrast technique for the measurement of flow velocity and volume in true and false lumens was studied in six patients with chronic dissecting aneurysms. Phase-contrast images were obtained at a level perpendicular to the dissecting aneurysms of the descending aorta. As the maximum diameter of aneurysms increased, the ratio of the cross-sectional area of the false to the true lumen increased and the peak average velocity in the true lumen during systole was decreased. This technique proved invaluable for determining prognosis and operability for this condition.     

Effect of XKJ-001, a crude drug preparation, on body water distribution and water excretion in mice

The effect of XKJ-001, a crude drug preparation based on Seisho-ekki-to, was investigated on the hematocrit, plasma volume, extracellular and interstitial fluid volumes as well as water excretion in mice. Mice were housed in an animal room maintained at 34 degrees C for 3 d with water and food freely available. While the hematocrit, extracellular and interstitial fluid volumes increased, the plasma volume decreased. These results suggest that the distribution of body water in mice housed at high environmental temperature exhibit the state of water metabolism disorders (Suitai) described in Kampo medicine. After the administration of XKJ-001 (3 g/kg, once a day) for 5 d, mice were housed in an animal room maintained at 34 degrees C for 3 d. The administration of XKJ-001 was allowed to continue on the day 0, day 1 and day 2. XKJ-001 inhibited the increase in hematocrit and the changes in body water distribution of mice induced by high environmental temperature. An effect of XKJ-001 on water excretion in mice was investigated in comparison with hydrochlorothiazide (HTZ). Distilled water (D.W., 100 ml/kg) or bicarbonate saline (B.S., 100 ml/kg) was intraperitoneally injected immediately after the oral administration of XKJ-001 (1.5 g/kg) or HTZ (15 mg/kg). The water excretion was enhanced after 3 h for XKJ-001 and after 6 h for HTZ after the intraperitoneal injection of D.W. As for the intraperitoneal injection of BS, HTZ enhanced the water excretion, however, XKJ-001 exhibited no effect. These results suggest that XKJ-001 has activities on water maldistribution and facilitates the water excretion.     

Laterality of vestibular evoked myogenic potentials

To clarify the laterality of acoustically evoked vestibulocollic reflexes with a short latency (vestibular evoked myogenic potentials, VEMPs), responses on the bilateral sternocleidomastoid muscles (SCMs) to unilateral acoustic stimulation were studied. Twenty-one healthy volunteers were enrolled. Surface electrodes were placed on the upper half of each SCM (active) and on the lateral end of the upper sternum (reference). Clicks and 500-Hz tone-bursts (95 dB nHL) were used. All subjects showed positive-negative biphasic responses on the ipsilateral SCM by clicks and tone-bursts. Click-stimulation of 41 of the 42 ears did not evoke any response on the contralateral SCM. However, in one ear, positive-negative biphasic responses were evoked on the contralateral SCM. Recordings on the contralateral SCM by tonebursts showed no response in 32 ears, small positive-nega-tive biphasic responses in four ears, and small negative-positive biphasic responses in six ears. These findings show that VEMPs are ipsilateral-dominant, basically consistent with the hypothesis that they are of saccular origin.     

Japanese standard for clinical stabilometry assessment: Current status and future directions

Stabilometry is a useful tool for examining patients with functional disorders of the vestibular system. However, measurement techniques and devices vary by country. Therefore, international standardization of stabilometry is mandatory to validate the exchange of important findings. This was advocated at the 1983 Posturography Meeting in Kyoto but has not been adopted worldwide, and each country has continued to use unique regional measurement methods. In Japan, stabilometry has widespread application in medical practice in conjunction with research into its applications. With a goal of international standardization, we present details of stabilometry measurement methods and their application in Japan, together with a brief history and potential future directions of stabilometry.     

Assessment of the involvement of the macrophage migration inhibitory factor–glucocorticoid regulatory dyad in the expression of matrix metalloproteinase‐2 during periodontitis

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine and counter‐regulator of endogenous glucocorticoids (GCs). It is implicated in acute and chronic inflammatory diseases. This study investigated the role of the MIF–GC regulatory dyad in the expression and release of matrix metalloproteinase‐2 (MMP‐2) during periodontitis, in vivo and in vitro. In a Mif‐knockout (KO) mouse model of ligature‐induced periodontitis, gingival tissues and blood were collected and analysed for levels of interleukin‐6 (IL‐6), MIF, MMP‐2, and corticosterone. In addition, human gingival fibroblasts (HGFs) were tested for production of IL‐6 and MMP‐2 after stimulation with hydrocortisone (HC), MIF, tumour necrosis factor‐alpha (TNF‐α), or Fusobacterium nucleatum, a pathogen known to elicit immune responses during periodontitis. Wild‐type (WT) mice showed a local and systemic increase of MIF levels during inflammation, which was confirmed by increased local IL‐6 concentrations. Systemic GC levels were reduced in WT and Mif‐KO mice during inflammation, with overall lower concentrations in Mif‐KO mice. In vivo and in vitro, MMP‐2 production was not dependent on MIF or inflammatory stimuli, but was inhibited by HC. Therefore, MIF does not appear to stimulate expression of MMP‐2 in the gingival tissues, whereas GC upregulates MIF and downregulates MMP‐2. Our findings further suggest that MIF may regulate systemic GC levels.