Biomedical subjects
Publications and source records attributed to M Kojima.
An immune adherence hemagglutination test was established for detection of antibodies to respiratory syncytial virus. The test was shown to be as specific as and much more sensitive than the neutralization and complement fixation tests.
A case of acromegaly with two separate growth hormone-secreting pituitary adenomas is presented. The multiplicity was suspected on computerized tomographic scan and confirmed at transsphenoidal surgery. Possible occurrence of multiple adenomas is discussed.
Neoplastic cells from 13 cases of hairy cell leukemia were investigated for immunoglobulin production and lysozyme activity by an electron-immunoperoxidase technique. In 10 cases cytoplasmic immunoglobulins were found, but lysozyme activity was absent in all cases. Immunoglobulins were detected in the perinuclear space and endoplasmic reticulum and at the surface of hairy cells. Of the cases in which immunoglobulins were detected in hairy cells, nine were positive with IgM antiserum and one with IgG antiserum. The immunoglobulins were monoclonal in all cases; six were positive with lambda antiserum and three with kappa antiserum. The class and type of surface immunoglobulins were identical to those of cytoplasmic immunoglobulins in the hairy cells. These results support the conclusion that hairy cells are commonly derived from immunoglobulin-producing B cells at an earlier stage of differentiation than plasma cells.
The pathogenic ability of hepatitis B e antigen (HBeAg) to induce membranous glomerulonephritis was evaluated by the most specific method presently available. Monoclonal antibody was raised against HBeAg, and F(ab')2 fragments were obtained and labeled with fluorescence. By this reagent, 10 out of 16 patients with membranous glomerulonephritis with hepatitis B surface antigen in the serum revealed granular deposition of HBeAg along glomerular capillary walls. Among the cases with glomerular HBeAg deposits, nine had detectable HBeAg in the serum and one had antibody to HBeAg (anti-HBe). The specificity of HBeAg staining was ascertained by blocking and inhibition tests, and the fluoresceinated anti-HBe F(ab')2 reagent did not stain the glomerular immune deposits in the patients with membranous glomerulonephritis who did not carry hepatitis B virus (HBV). None of the studied patients showed deposition of hepatitis B surface or core antigens in the glomerulus. On the basis of these results, immune complexes involving HBeAg may induce membranous glomerulonephritis in persons who carry HBV.
Previously, we isolated t-cinnamoyl-D-glucose as a possible intermediate in chlorogenic acid biosynthesis from sweet potato root. The enzyme which catalyzes the formation of t-cinnamoyl-D-glucose has been purified 539-fold from sweet potato root (Ipomoea batatas Lam.) and characterized. It required UDP-glucose as a glucosyl donor. Its molecular weight was estimated to be 45,000 by gel filtration chromatography through Sephadex G-100. Its Km values were 0.2 mM for t-cinnamic acid and 0.1 mM for UDP-glucose. It also showed activity toward various aromatic carboxylic acids other than t-cinnamic acid with the following relative activities at the concentration of 1.8 mM: t-cinnamic acid, 100; p-coumaric acid, 57; o-coumaric acid, 52; caffeic acid, 15; benzoic acid, 71; ferulic acid, 27; 4-hydroxyl-3-methoxy-benzoic acid, 35. When p-coumaric acid was used as a substrate, the enzyme introduced the glucosyl group exclusively to a carboxyl group, not to a hydroxyl group on a benzene ring. It was inhibited by p-chloromercuribenzoate and HgCl2. Its activity in the extract from sliced root decreased during the first 28 h after slicing, then increased to the original level by 75 h. The apparent decrease seemed to be caused by the appearance of an inhibitory factor of high molecular weight in the tissue extract.
A case with lymphadenopathy of the left side of the neck in a 38-year-old male is described. He had a history of several relapses of about 10 years duration. Swollen lymph nodes were histologically similar to those of the hyaline-vascular type of Castleman's disease, but contained clear-cut lymph sinus and a sheet-like proliferation of plasma cells. Lymph follicles showed proliferation and atrophic germinal centers, in which cellular hypertrophy in the wall of ramifying small blood vessels, called angiosclerosis, was frequently encountered. During its progress, the patient developed plasmacytoma of the lymph nodes with varied clinical manifestations such as polyneuropathy, disturbance of gait, unusual perspiration, hirsutism, gynecomastia, bilateral papilledema, and albumino-cytologic dissociation in cerebrospinal fluid.
Oscillatory afterpotentials in cardiac tissues are believed to result from an activation of calcium-operated cation channels of mixed selectivity (sodium, potassium), or perturbation of an electrogenic sodium-calcium exchange carrier, by an oscillatory release of calcium from sarcoplasmic reticulum. In the present experiments, the presence and properties of ouabain-induced oscillatory afterpotentials were examined in young (3-day-old) embryonic chick hearts, both fresh and organ cultured for 6-14 days. The hearts did not differentiate in organ culture, and the cells retained slowly rising spontaneous action potentials. To induce the oscillatory afterpotentials, automaticity was suppressed by elevating extracellular K+ ion concentration from 4 mM to 6 mM, and the preparations were electrically stimulated at a rate of 0.5 Hz. Stable oscillatory afterpotentials were induced with 1.3-7.5 microM ouabain. The oscillatory afterpotential amplitude was increased when the stimulation rate was increased to 3 and 4 Hz. The oscillatory afterpotentials were potentiated when extracellular Ca++ ion concentration was increased to 3.6 mM or by the addition of barium (0.1 mM). Low extracellular Na+ ion concentration (40-121 mM), strontium (4 mM), magnesium (2-4 mM), and manganese (1-4 mM) significantly depressed the oscillatory afterpotentials. These properties of the oscillatory afterpotentials are similar to those described for adult mammalian ventricular muscles and Purkinje fibers. Our results suggest that young embryonic chick hearts (which lack fast sodium channels and, instead, have slow sodium channels) possess the calcium-operated mixed cation channels at a very early developmental stage if the oscillatory afterpotentials result from the activation of the mixed cation channels by intracellular calcium.
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We studied the effect of N-(3,4-dimethoxycinnamoyl)anthranilic acid (N-5'), an orally applicable anti-allergic drug, on the histamine release induced by calcium ionophores (A23187 and X537A) and ATP from rat peritoneal exudate cells (PEC). X537A (0.1-33.3 micrograms/ml) induced histamine release in a concentration-related manner, and 2.0 micrograms/ml of X537A induced release to the same extent as allergic histamine release. Histamine release induced by 2.0 micrograms/ml of X537A increased with longer incubation time, reaching a peak of about 100% at 120 min. N-5' had no effect on histamine release induced by X537A at the concentrations used (1-1000 microM), but DSCG exhibited significant inhibition at 1-100 microM. A23187 (0.05-0.5 microgram/ml) induced histamine release in a concentration-related manner, and it seemed that 0.033 microgram/ml of A23187 induces the same degree of histamine release as the allergic one. A23187 induced rapid histamine release which attained maximum 1 min after the addition. N-5' exhibited a significant concentration-dependent inhibitory effect on histamine release induced by A23187, and DSCG also exhibited significant inhibition (10 and 1000 microM). N-5' significantly inhibited histamine release induced by 100 microM ATP. These results indicate that N-5' and DSCG effect the histamine release induced by ionophore A23187 and X537A by different manners, and they suggest the possibility that N-5' inhibits some Ca++-dependent processes in histamine release, including the influx of Ca++ into cells, which is a trigger of the A23187 and ATP effects.
[N-methyl-3H]-7-Chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2H-1,4- benzodiazepin-2- one ( [3H]fludiazepam) was prepared by phase transfer catalytic N-methylation of the corresponding nor-derivative with [3H]methyl iodide [407 GBq/mmol (11 Ci/mmol)] in a radiochemical yield of 34%. The specific activity was 271.6 GBq/mmol (7.34 Ci/mmol).
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A new indole N-glycoside antibiotic SF-2140 which shows antiviral and weak antibacterial activity has been obtained from the cultured broth of an actinomycete strain. Strain SF-2140, designated Actinomadura albolutea sp. nov., was isolated from a soil sample collected in Hyogo Prefecture, Japan.
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In an attempt to solve the conflict concerning the correlation between the Lyt-2 phenotype of T cells subsets and the type of the MHC antigens involved in the recognition by T cells, class 2 (I region) antigen-specific CTL were studied for their Lyt phenotypes and the sensitivity to the blocking effects of anti-Lyt-2,3 antibodies. To avoid contamination by CTL to class 1 antigens such as Qa antigens, A.TH anti-A. TL attackers and A.TH anti-A attackers were tested on LPS blasts of the A strain and the A.TL stain, respectively. By using these combinations, it was shown that the majority of I region-specific killers were Thy-1+, Lyt-1+23+. Specific target cell lysis by these cells were, however, found to be far less sensitive to the blocking effects of various monoclonal antibodies to the Lyt-2,3 antigens than conventional class 1-specific CTL. This conclusion was drawn by directly comparing the sensitivity of the I region-specific and K region-specific killing by identical numbers of the same attacker cells (A.TH anti-A). No significant difference was seen between the primary and the hyperimmune CTL. Lyt-2-, Thy-1+ killer cells with I region specificity could be induced when Lyt-2-depleted A.TH responder cells were stimulated in vitro. Such Lyt-2- killer cells were not induced to the H-2K alloantigen.
The cardiovascular effects of 3,4-dihydro-6-[4-(3,4- dimethoxybenzoyl )-1-piperazinyl]-2(1H)- qu inolinone ( OPC -8212) were investigated in isolated ventricular muscles of various mammalian species, anaesthetized dogs and conscious dogs. In the isolated ventricular muscles of the dog, cat, rabbit and guinea pig, OPC -8212 (3 X 10(-6)-3 X 10(-4) mol/l) increased the developed tension in a concentration-related manner and these positive inotropic effects of OPC -8212 were 1/140-1/120 those of dobutamine but 5-17 times and 8-25 times those of amrinone and theophylline, respectively. The positive inotropic effect of OPC -8212 was not modified by pindolol or phentolamine. In the isolated rat ventricular muscle, OPC -8212, amrinone and theophylline exerted no positive inotropic effect, although dobutamine did. In anaesthetized dogs, OPC -8212 (0.1-3 mg/kg i.v.) was nearly as active as amrinone in producing an increase in left ventricular contractile force. However, OPC -8212 was much less active than amrinone in increasing heart rate and decreasing blood pressure. In conscious dogs OPC -8212 at doses of 1 and 3 mg/kg i.v. increased peak LV dP/dt by 27% and 59%, respectively, without significant changes in heart rate and blood pressure. OPC -8212 did not affect the dog heart Na+,K+-ATPase activity. These results suggest the following: (1) OPC -8212 has a mechanism of action different from those of catecholamines and cardiac glycosides, (2) it has a useful profile in the treatment of heart failure because it caused a selective positive inotropic effect with no obvious positive chronotropic and vascular effects.