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Biomedical subjects

K Hirose

Publications and source records attributed to K Hirose.

At least 379 records · Page 21Linked to original sources

Bacteroides gingivalis fimbriae stimulate production of thymocyte-activating factor by human gingival fibroblasts.

In a previous report (Y. Ohmori, S. Hanazawa, S. Amano, T. Miyoshi, K. Hirose, and S. Kitano, infect. Immun. 55:947-954, 1987), we showed that human gingival fibroblasts spontaneously produce thymocyte-activating factor (FTAF), which stimulates mitogen-induced thymocyte proliferation. In the present study, we examined the effect of Bacteroides gingivalis fimbriae on FTAF production by the cells, because the fimbriae may be involved in attachment of the organism to periodontal tissues. We show here that the fimbriae bind to the cells, which may subsequently lead to the stimulation of FTAF production by the cells.

Animals↗

[Effect of the nonsteroidal anti-inflammatory drug 480156-S on hepatic drug-metabolizing activity and pharmacological action of diazepam and pentobarbital in rats].

Effect of the nonsteroidal anti-inflammatory drug 480156-S on liver drug-metabolizing activity was studied in rats, and its effect was compared with that of cimetidine. Cytochrome P-450-dependent 7-alkoxycoumarin O-dealkylase activity was not affected by a single administration of 480156-S, but the activity, especially the O-demethylase but not the O-depropylase, was suppressed dose-dependently by multiple administrations. Pretreatment of rats with phenobarbital caused a diminution of the inhibitory action of 480156-S. Treatment of rats with cimetidine resulted in a marked decrease in the activity, although it recovered 24 hr later. After the pretreatment of animals with 480156-S or reference drugs, the pharmacological action of diazepam was determined using muscle relaxation and inhibitions of electroshock-induced convulsion and pentetrazole-induced clonic convulsion as the indicators. Prolonged pharmacological activity of diazepam was observed when liver drug-metabolizing activity was lowered by the pretreatment. On the other hand, pentobarbital-induced anesthesia was prolonged by the pretreatment of rats with cimetidine, but the anesthesia was not modified by the administration of 480156-S. These results suggest the inhibitory action of 480156-S on a specific form(s) of P-450 isozyme.

7-Alkoxycoumarin O-Dealkylase↗

Assessment of local area network based on the microcomputer system for data processing of perinatal medical information.

In order to control perinatal medical information, we developed a microcomputer-based local area network. This system has been in practical operation since June, 1986. We have assessed this system with regard to both patient-machine and doctor-machine interfaces. Consequently, although input operation took 20-30% longer per individual patient than before, it was more feasible for medical staff to access and retrieve the data in a real-time manner. When tested in a ten month period, this system was found to be a prototype applicable for further extending the management of the entire scope of perinatal medical information.

Computer Systems↗

An application of the Markov process for quantitative prediction of labor progress.

To quantitatively predict the progress of labor, we devised a mathematical model suitable for the Markov process. Included were 625 primiparas who went into spontaneous labor between 37 and 41 weeks of gestation with a cephalic presentation. When applying the Markov process, the sequence of labor was divided into eight categories from 4 cm cervical dilatation to delivery of the baby. Based on all data collected, a transition matrix was calculated, using a microcomputer system, in which the value in each element showed the percent of probability of progression in labor from one given state to another over a 30-minute period. This matrix was found to be available for evaluating the course of labor in clinical practise with a good predictive value and therefore the Markov process could be confirmed to be actually applicable as an analytical model.

Female↗

[A family of spino-cerebellar degeneration with disturbance of ocular movement, choreoathetosis, amyotrophy and dementia--a consideration in clinical features].

Seven cases in a family of hereditary spino-cerebellar degeneration (SCD) similar to dentatorubro-pallido-Luysian atrophy (DRPLA) were reported. The clinical features of these cases were disturbance of ocular movement (limitation of ocular movement and slow eye movement (SEM], remarkable amyotrophy, choreoathetosis, dementia and sleep apnea. The brain CT's revealed marked atrophy in pons and cerebellum. Amyotrophy had been reported in the case of DRPLA, particular ataxo-choreoathetoid form (by Hirayama). Muscle biopsy was performed in these cases, which showed scattered small angulated fiber, severe atrophic fiber with pyknotic nuclear clump, fiber type grouping and small rounded fiber were mixed. These findings indicates neurogenic change of radiculoneuropathy type (by Tanabe). In many reported cases of DRPLA and SCD with amyotrophy, this type of muscle biopsy had not been recognized. In SCD with amyotrophy, a main lesion had existed on peripheral nerve. In this case, there was no definite clinical findings (sensory disturbance, delay of conduction nerve velocity, peripheral neuropathy in nerve biopsy). In recent years, several unclassified cases of SCD with amyotrophy had been reported, which had multi-system degeneration involving peripheral neuropathy. This case is similar to these cases, which is speculates multi-systemic lesions, not only DRPLA but also peripheral nerve involvement. On neuro-otological study, velocity of saccade was slow and persuit was reserved in proband case. In younger onset case, disturbance of saccade and pursuit was mild. In older progressive case, disturbance of saccade and pursuit was progressive and accompanied with severe limitation of ocular movement. Several autopsy cases of SEM had been reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Temperature-induced change of thick filament and location of the functional sites of myosin.

The combination of the small-angle X-ray camera to use the synchrotron radiation (National Lab. of High Energy Physics, Tsukuba) and a sensitive X-ray detecting system (FCR System, Fuji Medical System Inc.) using the imaging plate enabled us to record a small angle X-ray diagram of liver rabbit muscle within few minutes. Live relaxed rabbit muscle kept at 25 degrees C gave clear relaxed pattern, in which myosin layer line can be observed up to 13th order. When it was cooled down to 5 degrees C, it gave the small-angle X-ray pattern which looks like that obtained from contracting frog muscle, whereas cooled muscle produced no tension. The 8th meridional reflection almost vanished. The pattern is different from that obtained from rigor muscle: actin layer line at 72 A spacing can not be observed. The "stiffness" and (1,1) reflection on the equator increased. This indicates that more crossbridges are at the vicinity of the thin filaments without developing tension at low temperature. This might be related to the marked decrease in the rate of the step from M*ADP to M.ADP at low temperature. The position of the ATP binding site, SH1, actin binding site(s) was determined by three-dimensional image reconstruction method. Actin-binding site was determined by comparing the three-dimensional image of actin-tropomyosin-S1 and that of actin-tropomyosin-troponin-Ca. The position of ATP binding site and SH1 was determined by three-dimensional reconstruction of the complexes of actin-tropomyosin and S1 of which the ATP binding site or SH1 was labelled with avidin. It was found that SH1 locates near the actin-binding site at the same side of S1. The distance from head-rod junction to ATP binding site and SH1 was similar. But they locate at the different side of S1 and the distance between two sites is about 5 nm, which is consistent with that obtained by energy transfer method.

Animals↗

A biological response modifier, PSK, inhibits reverse transcriptase in vitro.

We found that PSK has an antiviral effect on human immunodeficiency virus (HIV) in vitro. One of the mechanisms of this effect is attributable to the inhibition of binding of HIV with lymphocytes. Here, we found that PSK inhibits reverse transcriptase in a non-competitive way in vitro. Such inhibition may be important in its anti-HIV effect as well as its inhibitory effect on the binding of HIV with lymphocytes.

Acquired Immunodeficiency Syndrome↗

A biological response modifier, PSK, inhibits human immunodeficiency virus infection in vitro.

PSK, a biological response modifier (BRM), was studied to determine its anti-viral activity on human immunodeficiency virus (HIV) in vitro. Either a novel infection system using human T-cell lymphotropic virus type I (HTLV-I)-carrying MT-4 cells or a coculture system using MOLT-4 cells and its virus-producing cells MOLT-4/HIVHTLV-IIIB which induces multinucleated giant cells very efficiently was used. PSK almost completely blocked the cytopathic effect such as giant cell formation and HIV-specific antigen expression both in MT-4 cells and MOLT-4 cells at a concentration of 0.4 and 0.8 mg/ml, respectively. Pretreatment of the virus with PSK may specifically interfere with early stages of HIV infection by modifying the viral receptor.

Antigens, Viral↗

Dose of urokinase for intracoronary thrombolysis in patients with acute myocardial infarction.

Intracoronary thrombolysis is a logical therapeutic method and one of the challenging new treatments of acute myocardial infarction. However, a wide dose range of urokinase has been reported, and the optimal dose has not yet been established. In this study the fibrinolytic activity in patients with recanalized coronary arteries was compared with that in those with nonrecanalized arteries. The mean doses of urokinase in the recanalized and non-recanalized groups were 910,700 +/- 161,730 international units (IU) and 1,008,000 +/- 151,800 IU, respectively. The fibrinolytic activity was measured with alpha 2-plasmin inhibitor, alpha 2-macroglobulin, fibrinogen, plasminogen, and fibrin degradation products. No significant difference was observed in the fibrinolytic activity between the recanalized and nonrecanalized groups. Because the fibrinolytic activity in the two groups was thought to be activated sufficiently and to a similar degree, it appears that 1,000,000 IU of urokinase is adequate for intracoronary thrombolysis and larger doses cannot be expected to result in a higher rate of recanalization.

Cardiac Catheterization↗

Biological characterization of interleukin-1-like cytokine produced by cultured bone cells from newborn mouse calvaria.

We have investigated the role of interleukin-1 (IL-1) and IL-1-like factor in the regulatory mechanisms of a bone remodeling system. To determine whether the bone cell itself produces IL-1-like cytokine, we examined bone cells cultured from newborn mouse calvaria. Bone cells migrating from fragments of newborn mouse calvaria were used in this study. We also used bone cells obtained by consecutive digestion of the calvaria with enzymes. These bone cells were cultured in fetal calf serum-containing alpha-MEM. IL-1-like cytokine activity was measured by incorporation of [3H]thymidine into C3H/HeJ thymocytes stimulated with PHA. When treated with lipopolysaccharide (LPS) from Escherichia coli 0111 B4, the cultured bone cells produced a significant amount of IL-1-like cytokine. The maximum concentration of IL-1-like cytokine was observed in culture supernatants of the bone cells cultured for 24 hours with the LPS in serum-free medium. The IL-1-like cytokine closely resembles IL-1 in some of its biological characteristics: stimulation of mitogen-induced thymocyte proliferation, stimulation of fibroblast proliferation, pyrogenicity, and molecular weight. These results show that cultured bone cells from newborn mouse calvariae produce an IL-1-like cytokine that closely resembles IL-1.

Animals↗

Spontaneous production of thymocyte-activating factor by human gingival fibroblasts and its autoregulatory effect on their proliferation.

The purpose of this study was to examine whether human gingival fibroblasts produce a cytokine which modulates in immune and inflammatory responses including alterations in connective tissue metabolism in periodontal tissue. We found that a cultured human gingival fibroblast cell line (Gin-1) and freshly isolated human gingival fibroblasts produced thymocyte-activating factor(s), so we called the factor(s) fibroblast-derived thymocyte-activating factor (FTAF). Growth of the producing cell was itself modulated by the factor(s). Gin-1 cells spontaneously produced a significant amount of FTAF in a cell growth-dependent manner. Maximum activity was observed in conditioned medium from stationary-phase cells. The activity in conditioned medium of cultures lacking serum was significantly higher than that in those containing serum. Treatment of Gin-1 cell cultures with cycloheximide, an inhibitor of protein synthesis, markedly inhibited FTAF production. When Gin-1 cells were stimulated by triggering with muramyl dipeptide or sonicated extracts of Bacteroides gingivalis, FTAF production was significantly stimulated. Freshly isolated human gingival fibroblasts from gingival biopsies of healthy donors also produced FTAF which enhanced thymocyte proliferation. Peaks of thymocyte proliferation activity in conditioned medium from Gin-1 cells were observed in fractions having molecular weights of 25,000, 35,000, and 45,000, as determined by Sephadex G-75 column chromatography. The peak fractions (partially purified FTAF) significantly suppressed the proliferation of Gin-1 cells themselves as evaluated by [3H]thymidine uptake. The suppressive effect of partially purified FTAF was, at least partially, mediated by endogenous prostaglandin for the following reasons: addition of indomethacin, and inhibitor of prostaglandin synthesis, abrogated the suppressive effect; partially purified FTAF stimulated the production of prostaglandin E2 by the cells; and the suppression of cell proliferation was reinforced by addition of exogenous prostaglandins. These observations suggest that gingival fibroblasts play a significant role in regulation of cell growth of lymphocytes and in their own growth under physiological conditions and in pathological states in periodontal connective tissue.

Acetylmuramyl-Alanyl-Isoglutamine↗

A ruptured large aneurysm of the ductus arteriosus.

A 60 year old man was admitted with acute back pain followed by hoarseness. An aneurysm of the ductus arteriosus Botalli was diagnosed and an operation was recommended because of the high risk of complications such as rupture, embolism, or infection. The patient and his family refused surgery, however. The patient died suddenly of a rupture of the aneurysm a year later; necropsy confirmed the diagnosis. Several diagnostic methods were used and enhanced computed tomography gave the best representation of the aneurysm as it was seen at necropsy. This case indicates that enhanced computed tomography is probably the most useful investigation in patients with this type of aneurysm and it confirms the importance of an aneurysmectomy.

Coronary Aneurysm↗

[The inhibitory activities of 480156-S and its related compounds on prostaglandin synthetase].

The inhibitory activities of 2-arylpropionic acids on prostaglandin synthetase were in the order of: Flurbiprofen (ID50, 0.10 microM) greater than Indomethacin (0.28 microM) greater than Ketoprofen (0.34 microM) greater than Naproxen (2.5 microM) greater than 480156-S (6.0 microM) greater than Ibuprofen (6.5 microM) greater than Benoxaprofen (47.9 microM). The S(+)-enantiomers had 15-300 times higher inhibitory activities than the corresponding R(-)-enantiomers. 2-Phenylpropionic acid and the metabolites of 480156-S (M-I, M-II and M-III) did not show any inhibitory activity on prostaglandin synthetase. Therefore, the presence of a hydrophobic substituent group, such as thiazolyloxy, on the benzene ring of 2-phenylpropionic acid is essential for the inhibition of prostaglandin synthetase, and the compound with the para substituent showed the highest inhibitory activity. The substituent groups also influence the inhibitory activity. Thiazolylamino (compound No. 320) and 3-methyl-4-thiazolin-2-ylidenamino (229) showed higher inhibitory activity than thiazolyloxy (156), and N-methyl-N-thiazol-2-ylamino (185) showed the lowest activity. The placement of a fluoro atom at the 3-position or two chloro atoms at the 3,5-positions of the benzene ring increased the inhibitory activity of the prostaglandin synthetase, but this did not necessarily occur with the placement of a chloro atom at the 3-position. Inhibitory activities of 480156-S-related compounds against prostaglandin synthetase showed a good correlation with their anti-inflammatory activities, but did not correlate with their analgesic activities.

Analgesics↗