[Update drug therapy of juvenile rheumatoid arthritis].
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Biomedical subjects
Publications and source records attributed to N Watanabe.
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Stable xenon-enhanced computed tomography (Xe-CT), a relatively inexpensive addition of an inhalation system to the CT, has been a common method for the measurement of rCBF in recent years. Although the 133Xe clearance method has been accepted as a standard method since the 1970s, a comparative study of rCBF between Xe-CT and 133Xe-SPECT has not been reported. We studied the validity of Xe-CT for evaluating rCBF in comparison with 133Xe-SPECT. From May 1993 to December 1994, rCBF studies in 31 cases were performed using both methods within one month of each other. We evaluated rCBF of the unilateral cerebral hemisphere at a slice of OM + 80 mm level. Finally, Eleven cases were excluded from the analysis because of the existence of ventricle in the image and/or discrepancy in the clinical state between the two examinations. In the remaining 20 cases, there was a significant correlation of rCBF between Xe-CT (Y) and 133Xe-SPECT(X)(Y = 0.95X-1.7, r = 0.86, p < 0.001, n = 40). The results supported the usefulness of Xe-CT for the quantitative assessment of rCBF. As compared with SPECT, Xe-CT offers the advantages of much higher spatial resolution, allowing more precise reference of flow and anatomy, and providing quantitative information on rCBF in deeper regions of the brain.
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The adherence and emigration of leukocytes have been implicated as a rate-limiting step in the microvascular disturbance in a variety of pathogenic events. The objective of the present study was to investigate leukocyte-endothelial cell adhesion and endothelial barrier function in rat mesenteric microvessels exposed to ethanol, which is known to cause inflammation and injury in various organs. Mesentery of male Wistar rats was used for intravital microscopic observations. Leukocyte adherence and albumin leakage were monitored in single postcapillary venules using the intravital fluorescence microscope. Superfusion of 50 mM ethanol elicited the leukocyte adherence and albumin leakage within 60 min. Pretreatment with a monoclonal antibody directed against either CD18 or intercellular adhesion molecule-1 (ICAM-1) significantly prevented the ethanol-induced increase in leukocyte adherence and decrease in barrier function of endothelium. These results suggest that ethanol-induced leukocyte adherence is mediated by CD18 on leukocytes and ICAM-1 on endothelial cells. The present study further supports that CD18/ ICAM-1-dependent leukocyte-endothelial adhesive interactions lead to macromolecular leakage in the postcapillary venules exposed to ethanol.
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Fusion regulatory protein (FRP)-1 regulates virus-mediated cell fusion and fusion of monocytes. Eleven of fifteen N-terminal amino acids of FRP-1 were the same as the amino acid sequence of 4F2/CD98 heavy chain. FRP-1 molecules were detected in Con A- or IL-2-stimulated lymphocytes, while FRP-1 was rare on resting lymphocytes. These properties of FRP-1 are similar to those of 4F2/CD98. Treatment of monocytes with anti-4F2/CD98 mAbs resulted in cell fusion, and other mAbs directed against 4F2/CD98 induced formation of multinucleated giant cells of Cd+U2ME-7 cells, a CD4+U937 cell line transfected with the HIV gp160 gene. Both anti-4F2/CD98 and anti-FRP-1 mAbs reacted with murine L929 cells expressing human 4F2/CD98 transiently or constitutively. When Newcastle disease virus (NDV)-infected L929 cells expressing human FRP-1/CD98 were incubated with mAb 4-5-1, an anti-FRP-1 mAb, multinucleated giant cells were induced; thus, FRP-1/CD98 molecules expressed in L929 cells are functional for fusion regulatory activity.
Clostridium botulinum C3 exoenzyme specifically ADP-ribosylates rho-p21 in eukaryotic cells. Trp18 and Glu173 of this enzyme were substituted with other amino acids via site-directed mutagenesis. All substitutions at Glu173 caused a significant reduction in affinity for NAD and diminished ADP-ribosyltransferase activity. On the other hand, the activity of enzymes with the substitution at Trp18 remained intact. Swiss 3T3 cells treated with the enzyme with the Trp18 substitution showed the typical morphologic changes of the C3 exoenzyme phenotype. In contrast, no changes were found in cells incubated with the Glu173-substituted enzyme. These results indicate that the Glu173 residue of the C3 exoenzyme plays a key role in interacting with NAD and in expression of ADP-ribosyltransferase activity, which is essential for the phenotypic change by C3 exoenzyme treatment.
To investigate the role of phosphorylation of a precursor form of interleukin-1 alpha (pre-IL-1 alpha), we obtained cells producing either phosphorylated or unphosphorylated pre-IL-1 alpha. Although calcium-dependent proteolytic processing of unphosphorylated pre-IL-1 alpha could be observed in cell lysates, proteolytic processing was not induced by treatment with calcium ionophore in intact cells producing the unphosphorylated pre-IL-1 alpha. Further, unphosphorylated pre-IL-1 alpha showed no calcium-dependent binding to acidic phospholipids at concentrations below 5 x 10(-6) M. These results suggested that phosphorylated pre-IL-1 alpha became susceptible to proteolytic processing by association with the cell membrane in a calcium-dependent manner.
Renaturation kinase assay was used to detect protein kinases activated by lysophosphatidic acid (LPA) in cultured rat 3Y1 fibroblasts. LPA activated several Ser/Thr protein kinases with apparent molecular weights of 145K, 85K, 64-65K (a doublet), and 60K (each named p145, p85, p64165 and p60, respectively) in addition to p43 mitogen activated protein (MAP)-kinase. Experiments using pertussis toxin and botulinum C3 exoenzyme showed that p145, p85, and p64165 kinases were activated by a pertussis toxin-insensitive rho p21-dependent pathway and that the activation of MAP-kinase was mediated by both the pertussis toxin-sensitive rho p21-independent and the pertussis toxin-insensitive rho p21-dependent pathways.
BACKGROUND: Gastric teratoma is an uncommon tumor and usually occurs in infancy or childhood. To the authors' knowledge, malignant transformation in gastric teratoma has not been reported previously. METHODS: An 83-year-old Japanese man presented with a large polypoid gastric tumor composed of teratomatous components and invasive adenocarcinoma. Numerous blocks of this tumor were analyzed histologically and immunohistochemically. RESULTS: Histologically, the gastric tumor consisted of teratomatous components with diverse maturation, such as fibroblastic mesenchymal cells, striated muscle cells, cartilaginous islands, neuroepithelial components, glial tissues, squamous cell nests, glandular components, and foci of adenocarcinoma infiltrating the benign gastric tissues adjacent to the tumor stalk. Metastatic foci of teratomatous components in the resected lymph nodes contained adenocarcinomatous glands. An immunohistochemical study helped confirm the differentiation in the immature components and the differential diagnosis between atypical neuroepithelial cells and the adenocarcinoma. CONCLUSION: This study indicates that the adenocarcinoma arose from immature gastric teratoma. A review of the literature suggests that this is the oldest reported patient with gastric teratoma and to the authors' knowledge is the first report describing gastric teratoma with malignant transformation.
In higher eukaryotes, the cyclin-dependent kinases (CDKs) are negatively regulated by phosphorylation on threonine 14 (T14) and tyrosine 15 (Y15). In fission yeast, the Wee1 and mitosis inhibitory kinase 1 (Mik1) protein kinases phosphorylate Y15 in Cdc2. WEE1Hu is the only known protein kinase that can carry out this inhibitory phosphorylation on Y15 in higher eukaryotes. In the present study, we examined the endogenous products of WEE1Hu in human cells and found that the original WEE1Hu cDNA lacked 214 amino acids at the N-terminus. The predicted full-length protein has weak, but significant, similarity over its entire length with Mik1. Thus, we suggest that 'WEE1Hu' is a Mik1-related protein rather than a Wee1 homologue. When isolated in immunoprecipitates, the endogenous WEE1Hu phosphorylated several cyclin-associated CDKs on Y15. WEE1Hu activity increased during S and G2 phases in parallel with the level of protein. Its activity decreased at M phase when WEE1Hu became transiently hyperphosphorylated. In addition, a decrease in WEE1Hu protein level was observed at M/G1 phase. Apparently, the hyperphosphorylation and degradation in combination caused inactivation of WEE1Hu at M phase and the following G1 phase. These results suggest that the activity of WEE1Hu is regulated by phosphorylation and proteolytic degradation, and that WEE1Hu plays a role in inhibiting mitosis before M phase by phosphorylating cyclin B1-Cdc2.
Annexin XI is a newly identified annexin which localizes mainly in the nucleus of rat embryonic fibroblasts. There are no typical nuclear localization signals (NLS) in the molecule. To define the region responsible for its nuclear localization, a series of mutants and chimeric cDNA were constructed. These were transiently expressed in COS-7 cells, and the subcellular distributions of the mutants and chimeric proteins were determined by indirect immunofluorescence microscopy. Wild-type annexin XI was located predominantly within the nucleus. Deletion of the N-terminal tail domain (residues 3-196) changed the distribution of the protein from the nucleus to the cytoplasm whereas deletion of the C-terminal core domain (residues 208-504) still kept the protein sorting to the nucleus. Three other mutants lacking 60-80 amino acids in the N-terminal region (residues 3-61, 61-115, and 115-197, respectively) no longer efficiently imported into the nucleus. Furthermore, Escherichia coli beta-galactosidase polypeptide was efficiently localized to the nucleus only when fused with the whole N-terminal region of annexin XI (residues 1-207), not with part of the N-terminal region. In primary cultured rat hepatocytes, annexin XI was distributed in the cytoplasm but not in the nucleus. These results suggest that the whole N-terminal tail domain of annexin XI is necessary and sufficient for its nuclear localization, and may function as NLS in a cell-type specific manner.
Granule exocytosis in natural killer (NK) cells induced by K562 target cells and by PMA/A23187 was examined by measuring N-benzyloxycarboxy-L-lysine esterase activity. We obtained a cultured human NK cell-rich population containing around 90% of CD16+ cells by culturing peripheral blood mononuclear cells with mitomycin C-treated Daudi cells in the presence of IL-2. Granule exocytosis in the cultured NK cells was induced by K562 cells in a target/effector cell ratio-dependent manner. The granule exocytosis induced by K562 cells was inhibited neither by EGTA nor by TMB-8, an intracellular calcium antagonist, nor by a combination of these two reagents, while the exocytosis induced by PMA/A23187 was inhibited in a dose-dependent manner both by EGTA and by TMB-8. However, the cytotoxic activity of the cultured NK cells was inhibited by EGTA, suggesting that calcium is required not for the induction of granule exocytosis but for other steps including its requirement for the exertion of perforin activity.
Nicorandil is an antianginal drug that causes potent coronary vasodilation of both epicardial and resistance vessels. To measure the dose-response kinetics of bolus injections of intracoronary nicorandil and to compare the vasodilatory response to nicorandil with that of intracoronary papaverine in humans, coronary blood flow velocity was measured in 30 patients using a 3Fr intravascular Doppler catheter. Continuous intravenous nitroglycerin 6 to 8 micrograms/min was infused to achieve maximal vasodilation of the epicardial vessels. Bolus doses of nicorandil dissolved in warmed saline solution were injected into the left (0.1, 0.2, 0.5, 1.0, 1.5, and 2.0 mg) and right (0.1, 0.2, 0.4, 0.8, 1.0, and 1.5 mg) coronary arteries. Intracoronary nicorandil caused a dose-dependent increase in coronary flow velocity and a decrease in coronary vascular resistance. Maximal vasodilatory effects equivalent to those obtained with 12 +/- 2 mg of intracoronary papaverine were induced with nicorandil 1.5 mg in the left coronary artery, and effects similar to those of 10 +/- 2 mg of papaverine were produced with nicorandil 1.0 mg in the right coronary artery. The time from injection of nicorandil to the onset of maximal hyperemia and duration of hyperemia were significantly shorter after nicorandil than after papaverine in both coronary arteries. Each dose of nicorandil produced no clinical symptoms and fewer changes in systemic hemodynamics and electrocardiographic QT intervals than did papaverine. These results suggest that a bolus administration of intracoronary nicorandil can safely, quickly, and reliably induce maximal coronary hyperemia comparable to that achieved with intracoronary papaverine in humans.
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BACKGROUND: Seroprevalence of antibody to human T-lymphotropic virus type I (HTLV-I) is high in the island of Kyushu, Japan. Reports on the etiological analysis of HTLV-I in patients with uveitis primarily document cases in this island. We studied the seroprevalence of HTLV-I at the Department of Ophthalmology in Yokohama City University Hospital and in Odawara Municipal Hospital, which are in the Kanto Plain on the island of Honshu, Japan. METHODS: The subjects were 741 patients who visited the two hospitals. The presence of serum antibodies against HTLV-I was assessed using the method of particle agglutination. RESULTS: Of 454 patients with nonuveitic ocular diseases, 9 (1.98%) were seropositive. Of 143 patients with definite diagnosis of uveitis, 1 (0.70%) was seropositive. Of 144 patients with non-specific uveitis (etiology undefined), 8 (5.56%) were seropositive. Thus, the prevalence of serum antibodies to HTLV-I was higher in patients with non-specific uveitis than in patients with specific uveitis or nonuveitic ocular diseases. Common ocular symptoms of 8 HTLV-I-infected patients with non-specific uveitis were compatible with the clinical features of uveitis described as HTLV-I-associated uveitis (HAU). CONCLUSION: It is important to suspect HAU in patients with uveitis of unknown etiology, even outside known areas of prevalence.
Laparoscopic cholecystectomy using an ultrasound surgical aspirator has been performed in our department since March 1991. The horn cover was altered in order to be inserted through a trocar 10 mm in diameter. The main purpose of this device is to explore Calot's triangle by fragmentation and aspiration of the fatty tissue without damaging the nerves, vessels, and cystic duct. First the serosa of the Calot's triangle is cut via electrocautery with the sharp-angle hook dissector we designed. Then the cystic duct and cystic artery are efficiently exposed by the ultrasound surgical aspirator. This procedure is perfectly adapted for laparoscopic cholecystectomy. We obtained favorable results with the ultrasound surgical aspirator in 135 cases including 40 cases with a negative gallbladder, as evaluated by endoscopic retrograde cholangiography. In conclusion, the ultrasound surgical aspirator is suitable for skeletonizing the cystic duct and cystic artery, and the procedure is perfectly safe.