Biomedical subjects
Publications and source records attributed to Zenichiro Kato.
Ten patients with SSPE were surveyed during the last 4 years from the viewpoint of clinical safety for use of ribavirin therapy. Although effectiveness varied among cases, they were all treated safely with intraventricular ribavirin. This study suggests that treatment is safe and well-tolerated.
We report the reversible magnetic resonance imaging (MRI) findings in a 2-year-old girl with acute cerebellitis. The high signal intensity in the cerebellum was obvious on diffusion-weighted images, and the splenium of the corpus callosum also showed high signal intensity on T2-weighted images and on diffusion-weighted images. The lesion in the splenium quickly returned to normal 72 hours later, whereas the hyperintensity in the cerebellum persisted for 1 week until clinical improvement was achieved. The findings in our patient suggested the particular vulnerability of the splenium of the corpus callosum compared to other regions and the importance of the MRI examinations including diffusion-weighted images in the early stage of encephalitis.
We identified a novel heterozygous single-nucleotide substitution 1400 T right curved arrow C (Leu 467 Pro) in the seventh exon of the interferon-gamma receptor 1 (IFNGR1) gene. This substitution was detected in 6 of the 89 allergic patients but not in the 72 non-allergic subjects. There was a difference in the L467P frequency between the allergic patients and the non-allergic subjects (Fisher's exact test: p=0.033). The 6 patients with L467P have allergic diseases such as bronchial asthma and/or allergic rhinitis. Furthermore, a familial analysis for L467P revealed a linkage between allergic diseases and L467P. Serum IgE levels of the patients with L467P were higher than those of the non-allergic subjects (p=0.001). Our previous studies have been shown that interferon-gamma (IFN-gamma) production by PBMCs in the allergic patients was lower than that in the non-allergic subjects. In this study, although IFN-gamma production in the allergic patients with L467P was equivalent to that in the non-allergic subjects, their serum IgE levels were high and they had allergic diseases. Our results suggest that some allergic patients have IFNGR dysfunction, and that L467P in the IFNGR1 gene is one of candidate susceptibility genes for allergic diseases.
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BACKGROUND: We previously reported that serum IgE levels were negatively correlated with the amount of IFN-gamma produced by phytohemagglutinin-stimulated or IL-12-stimulated PBMCs and that one of the mechanisms of the pathogenesis of atopy was the reduced IFN-gamma production, which led to upregulated IgE production. OBJECTIVE: IL-18 is also known to be a strong inducer of IFN-gamma production. However, it has not yet been determined whether IL-18 is associated with atopic disease. METHODS: We investigated the response to IL-18 or IL-12 stimulation and the sequence of IL-18 receptor (IL-18R) alpha chain cDNA in 41 nonatopic controls and 39 atopic patients. RESULTS: Serum IgE level was negatively correlated with IFN-gamma production by PBMCs stimulated with IL-18. The IL-18R alpha chain cDNA of atopic patients was sequenced. We identified a 3-base deletion of the IL-18R alpha chain cDNA (950delCAG ), which was generated by alternative splicing, as determined on the basis of genomic sequence data for the IL-18R alpha chain gene. PBMCs with the predominant expression of 950delCAG significantly showed the reduced IFN-gamma production after IL-18 stimulation. There was a significant difference in the expression pattern of the IL-18R alpha chain transcript between the atopic patients and the nonatopic controls. CONCLUSION: According to these results, the dominant expression of the 950delCAG transcript of IL-18R alpha chain cDNA, which was associated with reduced IFN-gamma production by IL-18 stimulation and high serum IgE levels, is predisposition to some atopic diseases.
To evaluate the autonomic nervous system of patients with breath-holding spells after iron treatment, we attempted to determine whether a dysregulation of the autonomic nervous system reflexes exists in children with severe cyanotic breathholding spells. An electrocardiogram for each subject was recorded for 24 hours in the subject's home and parasympathetic activity was investigated by the fast Fourier transform method. Hematologic data and clinical symptoms of all three patients treated with iron improved and attacks of severe breath-holding spells disappeared. After iron treatment was started, the heart rate variability increased during sleep. It appears that supplementation of iron is effective in improving the dysregulation of autonomic nervous system reflexes.
Subacute sclerosing panencephalitis is an encephalopathy caused by a persistent measles virus infection. We examined a 13-year-old girl with subacute sclerosing panencephalitis and performed a magnetic resonance spectroscopic study to evaluate the in vivo pathophysiologic abnormality. The results suggested the occurrence of inflammatory processes and glial proliferation prior to neuronal loss even in magnetic resonance imaging (MRI)-negative regions as well as in MRI-positive regions. The additional resonance peaks were also detected, but further studies should be performed to determine the precise pathophysiologic mechanisms. Novel in vivo modalities such as spectroscopy would be useful as a tool to measure responses to therapy.
The developmental changes of the ratio of unbound theophylline to total serum concentration have been demonstrated, suggesting clinical usefulness. However, the molecules that can replace the theophylline binding sites of albumin could influence theophylline-binding affinity. We evaluated the intrinsic factors influencing the unbound theophylline ratio. The results suggested that physicians should note that a more intense response might be obtained in children with various intrinsic factors even at the same total theophylline concentration.