The Keio Journal of Medicine
Online ISSN : 1880-1293
Print ISSN : 0022-9717
ISSN-L : 0022-9717
Volume 49, Issue 1
Displaying 1-4 of 4 articles from this issue
  • Thomas F. Tedder, Shinichi Sato, Jonathan C. Poe, Manabu Fujimoto
    2000 Volume 49 Issue 1 Pages 1-13
    Published: 2000
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    The fate of B lymphocytes is dependent on intrinsic and B cell antigen receptor (BCR)-induced signals. These signals are modified and interpreted by other cell-surface molecules such as CD19 and CD22 that govern mature B cell activation. This review assesses our current understanding of how CD19 and CD22 regulate B lymphocyte signaling and how alterations in these response-regulators contribute to autoimmunity in mice and humans. We propose that CD19 functions as a specialized adapter protein that regulates B lymphocyte signaling and autoantibody production. Overexpression of CD19 by B cells in systemic sclerosis patients correlates with autoantibody production and transgenic mice that overexpress CD19 produce similar autoantibodies. CD19 establishes a novel Src-family kinase activation loop that regulates basal signal transduction thresholds in resting B cells and amplifies Src-family kinase activation following BCR ligation. Reciprocally, CD22 is a potent regulator of CD19 function. These observations provide insight into how CD19 and CD22 govern the molecular ordering and intensity of signals transduced in B cells that may contribute to autoimmunity.
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  • Suresh Nair, Damodar Rout, Girish Menon, Rajneesh Kachhara, Robindra N ...
    2000 Volume 49 Issue 1 Pages 14-19
    Published: 2000
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    A retrospective analysis of 48 patients of medial paratrigonal arteriovenous malformations (AVMs) which constituted 18% of the total 258. AVMs surgically managed in our institute for 16 years was carried out to study their clinical presentation, radiological features, operative approaches and functional outcome. While hemorrhage was the initial presenting symptom in 35, it was longstanding headache in 10, focal seizures in two and progressive weakness in one. However, 41 of these presented with bleed at the time of admission to our hospital and in 15 there was history of multiple bleeds. Twelve and eleven patients had field cut and hemiparesis respectively. Arterial supply to the malfor-mation was quite uniform with posterior (43 patients) and anterior cerebral (25 patients) being the most frequent source. Venous drainage was predominantly into the galenic system (70%). Preopera-tive embolization was carried out in six patients. While the AVM was excised through a parasagittal interhemispheric approach in 34 patients, the nidus was approached through a direct transcortical (superior parietal lobule) approach in fourteen patients. There was only one operative mortality. Twelve patients whose preoperative fields were normal developed field cut postoperatively. An im-provement of the preoperative field deficit was noted only in one patient. While eight of the ten patients with preoperative weakness improved and remained independent the remaining two were moderately disabled. Only two of the 10 patients who developed postoperative weakness remained severely disabled. Our operative results suggest that these AVMs which are prone to recurrent bleeds can be resected with acceptable morbidity. Hemianopia resulting from bleed or surgery is unlikely to improve.
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  • John Koo, Wennie Liao
    2000 Volume 49 Issue 1 Pages 20-25
    Published: 2000
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    Because physicians from different nations frequently acquire the use of a new medication at different times, the international exchange of experiences with the new medication is valuable in max-imizing its efficacy worldwide. In recent years, many new therapeutic agents have been approved for treating psoriasis in the United States. These include the topical agent calcipotriol and the systemic agents acitretin and cyclosporine. In addition to new agents, a new therapeutic paradigm, sequential therapy, has been introduced recently. It is the hope of the authors that by sharing this paradigm and experiences with these agents in the United States, dermatologists in Japan may gain further insight into optimizing the use of these agents in the treatment of psoriasis.
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  • Minoru Tomita, Norihiro Suzuki, Edith Hamel, David Busija, Martin Laur ...
    2000 Volume 49 Issue 1 Pages 26-34
    Published: 2000
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    The present symposium during Brain 99 was convened to explore the current aspects of the neural (extrinsic and intrinsic) and chemical control of the microvasculature in the brain with specific relevance to stimuli and rapid flow responses. N. Suzuki demonstrated the presence of neurokinin-1 receptors along the axons of vasoactive intestinal polypeptide-containing cerebrovascular para-sympathetic nerves. Since the receptors were activated by substance P, calcitonin gene-related peptide and neurokinin released from coexisting sensory nerve fibers, the parasympathetic (vasodilating) fibers could effect rapid local flow increases. N. Suzuki, however, considered this as part of an elaborate de-fensive network protecting the brain from invasions by noxious substances. E. Hamel discussed the responses of the microvessels to neurotransmitters and suggested that nitric oxide (NO) released from intrinsic neurons may serve as a relay in the flow activation responses by intracerebral cholinergic fibers originating in the basal forebrain nuclei. D. Busija summarized a vasodilating system of activated N-methyl-D-asparate receptors located on neurons involving Ca influx-NO production, and activated ATP-sensitive potassium channels located in the vascular system. According to Busija, such inter-actions were disrupted during hypoxia and ischemia due to cyclooxygenase-derived superoxide anion. M. Lauritzen observed a 10 times larger increase in blood flow on stimulation of the climbing nerve as compared with that following the parallel nerve stimulation. The former transmitters are considered by him to be NO and K, and the latter NO and adenosine. Each speaker singled out NO as a common mediator for the microvasculature in the rapid local flow increases.
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