Magnetic resonance imaging of old myocardial infarction in young patients with a history of Kawasaki disease

BACKGROUND

On magnetic resonance imaging (MRI) using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) as contrast medium, images of infarct regions are enhanced in acute myocardial infarction (AMI). In old myocardial infarction (OMI), thinning of the myocardial walls is present, but images are no longer enhanced by Gd-DTPA. On the other hand, MI in children with a history of Kawasaki disease (KD), several differences from adult MI are observed.

HYPOTHESIS

The aim of this study was to evaluate the lesions that result from OMI in children with a history of KD using MRI with Gd-DTPA as a contrast medium.

METHODS

The subjects were 16 young patients with a history of KD who were diagnosed as having OMI. Of these, both thinning of the myocardial wall and MRI enhancement by Gd-DTPA were observed in 4 cases, thinning alone was observed in 6 cases, Gd-DTPA image enhancement alone was observed in 3 cases, and neither thinning nor Gd-DTPA image enhancement was observed in 3 cases.

RESULTS

The Gd-DTPA-image-enhanced, OMI-induced lesions observed in patients with KD were different from those observed in adults; this might be attributable to histologic differences.

CONCLUSION

Magnetic resonance imaging using Gd-DTPA can evaluate myocardial thinning and presence of circulation noninvasively at the same time and is considered to be useful for long-term follow up of the patients with KD and OMI.

Citicoline enhances frontal lobe bioenergetics as measured by phosphorus magnetic resonance spectroscopy

Citicoline supplementation has been used to ameliorate memory disturbances in older people and those with Alzheimer's disease. This study used MRS to characterize the effects of citicoline on high-energy phosphate metabolites and constituents of membrane synthesis in the frontal lobe. Phosphorus ((31)P) metabolite data were acquired using a three-dimensional chemical-shift imaging protocol at 4 T from 16 healthy men and women (mean +/- SD age 47.3 +/- 5.4 years) who orally self-administered 500 mg or 2000 mg Cognizin Citicoline (Kyowa Hakko Kogyo Co., Ltd, Ibaraki, Japan) for 6 weeks. Individual (31)P metabolites were quantified in the frontal lobe (anterior cingulate cortex) and a comparison region (parieto-occipital cortex). Significant increases in phosphocreatine (+7%), beta-nucleoside triphosphates (largely ATP in brain, +14%) and the ratio of phosphocreatine to inorganic phosphate (+32%), as well as significant changes in membrane phospholipids, were observed in the anterior cingulate cortex after 6 weeks of citicoline treatment. These treatment-related alterations in phosphorus metabolites were not only regionally specific, but tended to be of greater magnitude in subjects who received the lower dose. These data show that citicoline improves frontal lobe bioenergetics and alters phospholipid membrane turnover. Citicoline supplementation may therefore help to mitigate cognitive declines associated with aging by increasing energy reserves and utilization, as well as increasing the amount of essential phospholipid membrane components needed to synthesize and maintain cell membranes.

Development of micromachining technology in ion microbeam system at TIARA, JAEA

An ion-beam-lithography technique has been progressed in the microbeam systems at Japan Atomic Energy Agency (JAEA) Takasaki. In order to obtain a high-precision measure for microbeam size estimation with a high precision, we applied this technique combined with the electroplating process to make a Ni relief pattern as a resolution standard used in secondary electron imaging. As a result, the smallest beam size could be recorded. The scattering of ions in the materials influenced the spatial resolution and this is also discussed.

Intracellular changes of metal elements by fucoidan extracted from brown seaweed (Cladosiphon okamuranus)

This study was undertaken to elucidate the intracellular changes of metal elements after the administration of fucoidan extracted from Cladosiphon okamuranus. TRL1215 cells (normal rat liver cell line) were treated with 0, 0.1, or 1.0 mg/ml fucoidan and incubated in 5% CO2 at 37 degrees C. The cellular levels of Mg, Al, Fe, and Zn were significantly increased in the 1.0 mg/ml fucoidan-treated cells compared to those of the 0.1 mg/ml fucoidan-treated cells and the control. Next, TRL1215 cells were cultured on Mylar film overnight. At 24 h after 5-bromo-2'-deoxyuridine dosing, 0, 0.1, or 1.0 mg/ml fucoidan was treated for 9 h. The cellular distribution of elements was analyzed using in-air micro-micro-particle induced X-ray emission. The X-ray spectra showed that yields of Al, Mg, and Zn were high in order of the 1.0 mg/ml fucoidan-treated sample, the 0.1 mg/ml fucoidan-treated sample, and the control. Fe yield was mildly increased by fucoidan administration. In fucoidan-treated cells, the focal accumulation of Br was correlated spatially with phosphorous-rich region, suggesting that Br was localized within the nucleus. Al distribution provided a spatial association with Br map. These data suggest that fucoidan increases the accumulations of Al, Mg, Fe, and Zn in normal rat hepatocytes, and fucoidan-binding Al is postulated to be transferred into the nucleus.

In-Air Micro-Particle Induced X-ray Emission Analysis of Asbestos and Metals in Lung Tissue

Inhalation of asbestos increases the risk of lung cancer and pulmonary fibrosis. It is difficult to directly assess the distribution and content of inhaled particles in lung tissue sections. The purpose of this study is to employ an in-air micro particle induced X-ray emission (in-air micro-PIXE) system for assessment of the spatial distribution and content of asbestos and other metals in lung tissue. A proton ion-microbeam from this system was applied to irradiate lung tissue of patients with or without asbestosis, tumor tissue from both groups, and asbestos fibers ( in vitro). The content of each element composing asbestos and those of other metals were calculated and their distribution was assessed from the characteristic X-ray pattern for each element obtained after irradiation. This in-air micro-PIXE system could identify the location of asbestos bodies composed of Si, Mg, and Fe in lung tissue sections. Macrophage and lymphocytes accumulated in that area. This new system also revealed deposits of titanium, nickel, and cobalt in the lung tissues, in addition to asbestos bodies. The Si and Fe content were higher in lungs with asbestosis than in lungs without asbestosis or in tumor tissue. Analysis of asbestos fibers composed of chrysotile, crocidolite, and amosite showed that the ratios of Si, Fe, and Mg corresponded with those for the chemical structures. In-air micro-PIXE analysis is useful for assessing the distribution and quantities of asbestos bodies and also other metals in lung tissue comparing to immune-related cell localizations, and is also useful for analysis of standard asbestos fibers.

Analysis of tissue cadmium distribution in chronic cadmium-exposed mice using in-air micro-PIXE

This study undertook the analysis of tissue cadmium (Cd) distribution using in-air micro-particle-induced X-ray emission (PIXE) and the examination of the involvement of metal ions in parenteral Cd toxicity. A mouse was injected intraperitoneally with 3 mg/kg body weight of CdCl2 thrice weekly. After 27 wk, the liver and kidney were excised and fixed in 10% formalin solution for 4 h and then embedded in paraffin. Thin paraffin sections were used to analyze trace elements with in-air micro-PIXE and to examine metallothionein protein and histological changes. Cd distribution was determined by micro-PIXE in the liver and renal cortex of the Cd-exposed mouse, and the net Cd count was higher in the liver than in the renal cortex. The net iron (Fe) count was higher in the liver of the Cd-exposed mouse compared to the control, and an opposite tendency was observed in the renal cortex. Wide cellular Cd distribution was demonstrated in the liver and renal cortex of the chronic Cd-exposed mouse compared to the control. Metallothionein staining was increased by chronic exposure to Cd both in the liver and kidney, and nephrotoxicity was more apparent than hepatotoxicity. The modification of tissue Fe and calcium distribution by an intraperitoneal injection of Cd might be involved in Cd-induced toxicity.

Neuroprotection and neurosupplementation in ischaemic brain

Possible strategies for treating ischaemic stroke include: (i) neuroprotection (preventing damaged neurons from undergoing apoptosis in the acute phase of cerebral ischaemia), and (ii) neurosupplementation (the repair of broken neuronal networks with newly born neurons in the chronic phase of cerebral ischaemia). In this paper, we review our recent progress in development of these distinct new strategies for treatment of damaged brain following a stroke. Firstly, we investigated the role of endogenous IL-6 (interleukin-6), which is one of the cytokines drastically induced by ischaemic stimuli, by administering IL-6RA (anti-IL-6 receptor monoclonal antibody) to mice. We found that endogenous IL-6 plays a critical role in neuroprotection and that its role may be mediated by STAT3 (signal transducer and activator of transcription-3) activation. Secondly, we studied the endogenous sources of the newly born neurons in the ischaemic striatum by region- and cell-type-specific cell labelling techniques. The results revealed that the SVZ (subventricular zone) is the principal source of the neuronal progenitors that migrate laterally towards the infarcted regions, and differentiate into newly born neurons. Finally, we developed a restorative stroke therapy with a bio-affinitive scaffold, which is an appropriate poly-porous structure releasing bioactive substances such as neurotrophic factor. This bio-affinitive scaffold is able to give an appropriate environment for newly born neurons. In future, we will combine these strategies to develop more effective therapies for treatment of strokes.

Expression of superficial zone protein in mandibular condyle cartilage

OBJECTIVE

Superficial zone protein (SZP) has been shown to function in the boundary lubrication of articular cartilages of the extremities. However, the expression of SZP has not been clarified in mandibular cartilage which is a tissue that includes a thick fibrous layer on the surface. This study was conducted to clarify the distribution of SZP on the mandibular condyle and the regulatory effects of humoral factors on the expression in both explants and fibroblasts derived from mandibular condyle.

METHODS

The distribution of SZP was determined in bovine mandibular condyle cartilage, and the effects of interleukin-1beta (IL-1beta) and transforming growth factor-beta (TGF-beta) on SZP expression were examined in condyle explants and fibroblasts derived from the fibrous zone of condyle cartilage.

RESULTS

SZP was highly distributed in the superficial zone of intact condyle cartilage. The SZP expression was up-regulated by TGF-beta in both explants and cultured fibroblasts, whereas the expression was slightly down-regulated by IL-1beta. A significant increase in accumulation of SZP protein was also observed in the culture medium of the fibroblasts treated with TGF-beta.

CONCLUSIONS

These results suggest that SZP plays an important role in boundary lubrication of mandible condylar cartilage, is synthesized locally within the condyle itself, and exhibits differential regulation by cell mediators relevant to mandibular condyle repairing and pathologies.

Inhibitory effects of Lactobacillus reuteri on visceral pain induced by colorectal distension in Sprague-Dawley rats

BACKGROUND AND AIMS

Probiotic bacteria are being investigated as possible treatments for many intestinal disorders. The present study aimed to explore the effects of live, heat killed, or gamma irradiated Lactobacillus reuteri on cardio-autonomic response and single fibre unit discharge in dorsal root ganglia to colorectal distension in healthy Sprague-Dawley rats housed under conventional conditions. The effects of this treatment on somatic pain were also examined.

METHODS

1x10(9) bacteria were given by gavage for nine days. Colorectal distension occurred under anaesthesia. Heart rate was measured through continuous electrocardiography. Single fibre unit discharge was recorded from the 6th left lumbar dorsal root ganglion. Somatic pain was evaluated by the tail flick and paw pressure tests.

RESULTS

Colorectal distension caused a pressure dependent bradycardia in the control (native medium) group. Treatment with live, heat killed, or gamma irradiated bacteria as well as their products (conditioned medium) prevented the pain response even during the maximum distension pressure (80 mm Hg). Both viable and non-viable bacteria significantly decreased dorsal root ganglion single unit activity to distension. No effects on somatic pain were seen with any treatment.

CONCLUSIONS

Oral administration of either live or killed probiotic bacteria or conditioned medium inhibited the constitutive cardio-autonomic response to colorectal distension in rats through effects on enteric nerves. These data may provide a novel explanation for beneficial probiotic effects on visceral pain.

Dilated coronary arterial lesions in the late period after Kawasaki disease

OBJECTIVES

There are two types of late coronary dilated lesions after Kawasaki disease: new aneurysms and expanding aneurysms. The development of coronary dilated lesions late after Kawasaki disease was investigated.

METHODS

Between 1978 and 2003, 562 patients with coronary arterial lesions underwent selective coronary angiography on at least two occasions.

RESULTS

Of the 562 patients studied, 17 new dilated or expanding lesions were found in 15 patients (3%, 11 boys, four girls). The time of detection of new aneurysms after Kawasaki disease ranged from 1.9-19.2 years (median 11.4 years) and their diameters ranged from 2.0-6.5 mm (median 4.4 mm). Thirteen new aneurysms occurred in vessels in which previous aneurysms had regressed and all new aneurysms were associated with localised stenosis. A new aneurysm at the bifurcation or in the branches was seen in 14 (93%) and 13 were eccentric (87%). Of two expanding aneurysms, one involved the right coronary artery in one patient and the other the left anterior descending coronary artery. One expanding aneurysm increased from 4.4 mm to 19.5 mm over 17 years, and the other expanding aneurysm increased from 10 mm to 15 mm in one year.

CONCLUSIONS

Neither new nor expanding aneurysms have caused cardiac events. New aneurysms often develop as a pre-stenotic or post-stenotic dilatation secondary to localised stenosis. New and expanding aneurysms may be caused by haemodynamic factors in addition to the abnormality of the coronary arterial wall after severe acute vasculitis. Coronary arterial wall abnormalities were stenosis as well as, rarely, dilatation of the vessels in the late period. It is important to recognise that the changes of the coronary arterial wall persist late after regression of a large aneurysm.

Incidence of stenotic lesions predicted by acute phase changes in coronary arterial diameter during Kawasaki disease

To clarify the incidence of stenotic lesions according to the coronary arterial diameter in the acute phase. we investigated 190 patients with coronary arterial lesions who underwent an initial coronary angiogram (CAG) less than 100 days after the onset of Kawasaki disease. The largest diameters of the major branches were measured in the initial CAGs. The diameter of the large group was > or = 8.0 mm, that of the medium group was > or = 6.0 mm but < 8.0 mm, and that of the small group was > or = 4.0 mm but < 6.0 mm. There were 121 patients in the large group, 85 in the medium group, 77 in the small group. We investigated the stenotic lesions in the follow-up CAGs and evaluated the incidence of stenotic lesions in each group by the Kaplan-Meier method. The mean interval from the initial CAGs to the latest CAG was 97 months. The incidence of stenosis at 5, 10, and 15 years in the large group was 44, 62, and 74%, respectively. In the medium group the corresponding values were 6, 20, 58%, respectively. None of the patients in the small group developed stenotic lesions. Dilatation of more than 6.0 mm produces a high probability of irreversible change in the coronary arterial wall, leading to subsequent stenotic lesions.

The neuroprotective effect of a free radical scavenger and mild hypothermia following transient focal ischemia in rats

Edaravone, a novel free radical scavenger, has been reported to reduce ischemic damage in rats subjected to transient focal ischemia. The aim of this study is, therefore, to investigate the effect of a combined therapy with edaravone and mild hypothermia of 35 degrees C. Sprague-Dawley rats were subjected to MCA occluding an intraluminal suture technique for 2 hrs. The rats were reperfused for 24 h and decapitated for infarct and edema analysis. Animals were randomly devided into four groups: (I) vehicle + normothermia (control) (II) vehicle + mild hypothermia (III) Edaravone + normothermia (IV) Edaravone + mild hypothermia. Mild hypothermia alone had no reduction of the brain damage. The edaravone alone significantly reduced edema volume. The combined treatment with edaravone and mild hypothermia reduced both infarct and edema volume. In addition, this treatment provided for the best functional outcome. These results demonstrate that free radical scavenger, edaravone attenuates brain edema and that the combined therapy with edaravone and mild hypothermia significantly reduces not only edema but also infarct on transient focal cerebral ischemia in rats. The neuroprotective effects seen in this study may be due to the combined interaction of antiedema activity between edaravone and mild hypothermia, suppressing free radical production.

Mild hypothermia enhances the neuroprotective effects of a selective thrombin inhibitor following transient focal ischemia in rats

The aim of this study is to determine whether a selective thrombin inhibitor, Argatroban, would prevent neuronal cell death and whether extra-mild hypothermia (35 degrees C) would enhance the neuroprotective effect of a selective thrombin inhibitor following transient focal ischemia in rats. Sprague-Dawley rats were subjected to MCAo using an intraluminal suture technique for 2 hrs. The rats were reperfused for 24 h and decapitated for infarct and edema analysis. Argatroban-treated animals received a continuous injection of argatroban (3.0 mg/kg) for 24 hrs after onset of ischemia, while vehicle-treated groups received same dose of vehicle. During ischemia, temporal muscle and rectal temperatures were monitored and maintained at 37 degrees C in the normothermic animals and at 35 degrees C in the hypothermic animals. Argatroban ameliorated the cortical ischemic damage significantly (p < 0.05). Moreover, argatroban with mild hypothermia decreased the cortical infarct or edema volume significantly compared with those of groups I and III (p < 0.05). Argatroban improved neurological symptoms significantly and also improved survival rate. These results demonstrate that extra-mild hypothermia (35 degrees C) enhances neuroprotective effects of a selective thrombin inhibitor, argatroban, suggesting that this combined therapy may be a new therapeutic strategy for the treatment of acute stroke.

Dietary intake of the flower extracts of German chamomile (Matricaria recutita L.) inhibited compound 48/80-induced itch-scratch responses in mice

The antipruritic effects of the diets containing German chamomile on the compound 48/80-induced scratching in ddY mice were examined. Since it is reported that an injection of compound 48/80, but not histamine, induced scratching behaviour due to itch but not to pain in ddY mice (Kuraishi et al., 1995), compound 48/80-induced scratching in ddY mice seems to be a suitable parameter for evaluating antipruritic agents independent of histamine receptor antagonism. In the mice fed the diet containing 1.2 w/w % of the ethyl acetate extract of dried flower of German chamomile (Matricaria recutita L.) for 11 days, the compound 48/80-induced scratching behaviour was significantly suppressed. The ethyl acetate extract of German chamomile dose dependently suppressed compound 48/80-induced scratching without affecting body weight increase. The ethyl acetate fraction of the ethanol extract and the ethanol extract of hot water extraction residue of German chamomile flower also showed strong inhibition on the compound 48/80-induced scratching. The inhibitory effects of the dietary intake of the German chamomile extracts on compound 48/80-induced itch-scratch response were comparable to oxatomide (10 mg/kg, p.o.), an anti-allergic agent.

Expression of low-frequency Ala108Pro substitution in the platelet glycoprotein Ibbeta gene

We determined the gene frequency of the glycoprotein (GP) Ibbeta Ala108Pro substitution. The Pro108 allele was not found in 208 healthy Japanese and 200 healthy Caucasians. In vitro expression studies showed surface expression of the GPIbbeta Pro108 variant, suggesting the possibility of the involvement of the substitution as an alloantigen.

Identification of six novel MYH9 mutations and genotype-phenotype relationships in autosomal dominant macrothrombocytopenia with leukocyte inclusions

The autosomal dominant macrothrombocytopenia with leukocyte inclusions, May-Hegglin anomaly (MHA), Sebastian syndrome (SBS), and Fechtner syndrome (FTNS), are rare platelet disorders characterized by a triad of giant platelets, thrombocytopenia, and characteristic Döhle body-like leukocyte inclusions. The locus for these disorders was previously mapped on chromosome 22q12.3-q13.2 and the disease gene was recently identified as MYH9, the gene encoding the nonmuscle myosin heavy chain-A. To elucidate the spectrum of MYH9 mutations responsible for the disorders and to investigate genotypephenotype correlation, we examined MYH9 mutations in an additional 11 families and 3 sporadic patients with the disorders from Japan. Korea, and China. All 14 patients had heterozygous MYH9 mutations, including three known mutations and six novel mutations (three missense and three deletion mutations). Two cases had Alport manifestations including deafness, nephritis, and cataracts and had R1165C and E1841K mutations, respectively. However, taken together with three previous reports, including ours, the data do not show clear phenotype-genotype relationships. Thus, MHA, SBS, and FTNS appear to represent a class of allelic disorders with variable phenotypic diversity.