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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 271 records · Page 15Linked to original sources
PubMed1996

[Isolation rate of Pseudomonas aeruginosa from surgical infections and their susceptibilities].

Pseudomonas aeruginosa isolated from surgical infections during the period from July 1982 to June 1995 were investigated in a multicenter study involving 19 hospitals in Japan, and the following results were obtained. 1. Though the isolation rate of P. aeruginosa was not high from primary infections, it was more frequently isolated from postoperative infections throughout the study period. Enterococcus spp., P. aeruginosa and Staphylococcus aureus including MRSA were predominant among postoperative infections. From the postoperative cases that had previous antibiotic treatment, Enterococcus spp., MRSA and P. aeruginosa were more predominantly isolated than from those without previous treatments with antibiotics. 2. Cefozopran, ceftazidime, cefsulodin, aztreonam, carumonam, gentamicin, amikacin and ofloxacin had strong activities against P. aeruginosa. We recognize recently that antibiotic-resistant strains of P. aeruginosa against imipenem and ofloxacin have been increasing year by year.

Anti-Bacterial Agents↗
PubMed1996

[MR angiography and MR cholangiopancreatography].

MR angiography is an adjunctive for noninvasive evaluation of blood vessels and MR cholangiopancreatography is for bile duct and pancreatic duct. Clinical applications of MR angiography has been focused mainly on head and neck and its applications to the abdomen are still limited. However, this technique has the good potential for the evaluation of portal vein system. MR cholangiopancreatography can depict bile ducts and pancreatic duct simultaneously and three-dimensionally. This technique can evaluate the causes of the lesion and its extent noninvasively. In this article the practical uses of MR angiography and MR cholangiography in the abdomen are discussed.

Abdomen↗
PubMed1996

[A case report of Stanford type A acute thrombosed aortic dissection complicating cardiac tamponade].

An 85-year-old man was admitted with shock due to cardiac tamponade. Plain computed tomography showed a dilated ascending aorta but did not clearly show an aortic dissection. We performed an emergency operation with median sternotomy without the benefit of findings from enhanced computed tomography and aortography. Soon after the bloody pericardial effusion was decompressed during the operation, bleeding from the ascending aorta occurred. An intimal tear was found in the distal ascending aorta, and the pseudolumen was filled with fresh thrombus. The ascending aorta was replaced. The patient had an uneventful postoperative recovery and was discharged 1 month after the operation. We conclude that patients with Stanford type A acute thrombosed aortic dissection complicating cardiac tamponade should undergo early graft replacement.

Acute Disease↗
PubMed1996

[PT-INR as a parameter for anticoagulant therapy after valve replacement surgery].

We retrospectively analyzed the intensity of anticoagulant therapy in the 195 patients who underwent valve replacement surgery with mechanical valves. An optimal level or target range of prothrombin time-international normalized ratio (PT-INR) was sought. Previously, we employed a range of 10 to 25% of thrombotest value, which corresponded to the range of 1.5 to 3.5 of PT-INR value. In one patient who underwent mitral valve replacement, PT-INR valve was 1.72 when he developed an episode of cerebral thromboembolism. There was no tendency in PT-INR value in 51 patients who developed non-critical bleeding. As a while, PT-INR value was over 4.0 in 2 patients who required a in-hospital treatment for major bleeding complications. Based on our experience, we recommend a range of 2.0 to 3.0 of PT-INR value after valve replacement surgery with mechanical valves.

Adult↗
PubMed1996

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents. Special references to bacteria isolated between July 1994 and June 1995].

Isolated bacteria from infections in general surgery during the period from July 1994 to June 1995 were investigated by a multicenter study in Japan, and the following results were obtained. One hundred and fifty-three strains were isolated from primary infections, and 143 strains were isolated from postoperative infections. From primary infections, both anaerobic Gram-positive and-negative bacteria were predominant, and from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was highest, followed by that of Staphylococcus aureus from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Streptococcus intermedius was highest from primary infections, but from postoperative infections anaerobic Gram-positive bacteria was uncommon. Among aerobic Gram-negative bacteria, Escherichia coli was most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order. From postoperative infections, P. aeruginosa was most predominantly isolated, followed by Serratia marcescens and E. coli. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. We have noticed that resistant strains against imipenem and ofloxacin were increasing among P. aeruginosa and resistant strains against cefazolin were increasing among E. coli. MICs of cefazolin against four out of 30 strains of E. coli were higher than 100 micrograms/ml, and MICs of imipenem was higher than 50 micrograms/ml against 5 out of 22 strains of P. aeruginosa.

Anti-Bacterial Agents↗
PubMed1996

[Recent progress in development of psychotropic drugs (4)--Anticonvulsants: an overview on the mechanisms of action].

Conventional anticonvulsants can be classified into three types according to their mechanisms of action: (1) those which act on voltage-dependent Na+ channels such as phenytoin, (2) those which act on T-type Ca2+ channels such as ethosuximide, and (3) those which enhance GABA receptor-mediated inhibitory neurotransmission such as phenobarbital or valproate. However, recent studies on experimental models of epilepsy have suggested that the neural mechanisms underlying experimental epileptogenesis are based on: (1) increments in cellular excitability through changes in the function of Na(+)- or Ca2+ channels, (2) desinhibition or inhibition failure, and (3) enhancement of excitatory amino acid receptor-mediated excitatory neurotransmission. These findings might help us to understand the recently developed anticonvulsants and vice versa. In this review, newly developed anticonvulsants are categorized according to the neural mechanisms underlying epileptogenesis, particularly actions on excitatory and inhibitory neurotransmission.

Animals↗
PubMed1996

[The Somatropin Reference Standard (Control 951) of the National Institute of Health Sciences].

Somatropin material was examined for preparation of the "Somatropin Reference Standard". The candidate material was evaluated by a domestic collaborative study in which eight laboratories participated. The protein content was determined to be 4.5 mg/Vial based on amino acid analysis. Because of the possibility of application as a chemical reference standard for assay by the HPLC method, a physico-chemical evaluation of the candidate material was also performed. By SE-HPLC, the content of polymer, dimer were determined to be 0.54%, 0.98%, respectively. By RP-HPLC, the early peak area ascribed to desamido and sulfoxide form was 1.07% of the total peak area. And for informational data, the potency of the candidate material, being estimated by three different biological methods, weight gain assay, tibia test and adiposeconversion assay is 14.8 IU/vial. Based on the above results, the candidate was authorized as the Somatropin Reference Standard of the National Institute of Health Sciences.

Amino Acids↗
PubMed1996

Does adenotonsillectomy affect the course of bronchial asthma and nasal allergy?

Twenty-five bronchial asthma patients who underwent adenotonsillectomy were studied for postoperative changes of respiratory symptoms, doses or frequency of medications, and required hospitalization. Postoperative evaluation proved that 22 patients (88%) improved their asthmatic symptoms, 15 patients (60%) were able to eliminate all of their medications, and 7 patients (28%) were able to eliminate some of their medication. There were no patients with aggravated conditions. Out of 17 patients with nasal allergy, only 3 patients (18%) improved their nasal symptoms. The results suggest that adenotonsillectomy might change some conditions of allergic states in children.

Adenoidectomy↗
PubMed1996

Profile of immunoglobulin production in adenoid and tonsil lymphocytes.

The adenoids and tonsils are thought to be essential parts of the system protecting against pathogens invading the upper respiratory tracts. We have examined IgA-spot forming cells (SFC) as well as IgG- and IgM-SFC in human adenoid and tonsil lymphocytes. The majority of SPC were revealed to be IgG type in adenoid and tonsil lymphocytes. However, when the changes in the number of SFC were examined following 6 days of incubation in the presence of LPS and Con A, an increase in IgA-SFC was noted in both adenoid and tonsillar lymphocytes, suggesting that adenoid and tonsillar lymphocytes differentiate into IgA forming cells under appropriate conditions.

Adenoids↗
PubMed1995

Electron paramagnetic resonance investigation of cytochrome P-450c21 from bovine adrenocortical microsomes: a new enzymatic activity.

Cytochrome P-450c21 (CYP21A1) purified from bovine adrenocortical microsomes was investigated by electron paramagnetic resonance (EPR) spectroscopy to clarify the interactions among heme active center, protein surroundings, water molecules and bound substrates or analogues. The low-spin EPR signals of the oxidized enzyme (as purified) consisted of two species; one at gz = 2.39, gy = 2.23, and gx = 1.925 (component A) and the other at gz = 2.42, gy = 2.23, and gx = 1.916 (component B). The component A is probably representing a product-bound form, whereas the component B indicates either occupation of the substrate-binding site with a substrate analogue or absence of steroid at the site. Upon addition of progesterone, the component A signal completely disappeared and the intensity of high-spin signal (g = 8.06, 3.54) increased. Addition of 17 alpha-hydroxyprogesterone caused a development of a new low-spin signal at gz = 2.42, gy = 2.21, and gx = 1.966 (component C) and a further increase in intensity of the high-spin signal (g = 8.06, 3.54). Addition of 20 beta-hydroxyprogesterone caused an increase in intensity of the component C signal (and the g = 8 high-spin signal) even stronger than did 17 alpha-hydroxyprogesterone. These observations suggest that 20 beta-hydroxyprogesterone binds to the cytochrome P-450c21 active center in a very similar manner as 17 alpha-hydroxyprogesterone does and, therefore, may be a metabolizable substrate. A new enzymatic pathway catalyzed by cytochrome P-450c21 was confirmed with a reconstituted enzymatic system consisting of cytochrome P-450c21, NADPH-cytochrome P-450 reductase and an NADPH-generating system. 20 beta-Hydroxyprogesterone was converted to progesterone via a putative 20 beta-oxidase reaction in a comparable turnover number to that of the 21-hydroxylation of 17 alpha-hydroxyprogesterone.

Adrenal Cortex↗
PubMed1995

The mouse prostaglandin E receptor EP2 subtype: cloning, expression, and northern blot analysis.

A functional cDNA clone for the mouse prostaglandin (PG) E receptor EP2 subtype was isolated from a mouse cDNA library. The mouse EP2 receptor consists of 362 amino acid residues with seven putative transmembrane domains. [3H]PGE2 bound specifically to the membrane of Chinese hamster ovary cells stably expressing the cloned receptor. This binding was displaced by unlabeled prostanoids in the order of PGE2 = PGE1 >> iloprost, a stable PGI2 agonist > PGF2 alpha > PGD2. Binding was also inhibited by butaprost (an EP2 agonist) and to a lesser extent by M&B 28767 (an EP3 agonist), but not by sulprostone (an EP1 and EP3 agonist) or SC-19220 (an EP1 antagonist). PGE2 and butaprost increased the cAMP level in the Chinese hamster ovary cells in a concentration-dependent manner. Northern blot analysis revealed that EP2 mRNA is expressed most abundantly in the uterus, followed by the spleen, lung, thymus, ileum, liver, and stomach.

Amino Acid Sequence↗
PubMed1995

NBQX, a selective antagonist of the AMPA receptor, affects neither field potentials nor long-term potentiation in vivo.

NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline), a selective antagonist of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate) receptors, at an anticonvulsant dose of 40 mg/kg (i.p.), was shown in vivo to have no effects on either the field potentials in the piriform cortex or those in the dentate gyrus of the hippocampus. The same dose of NBQX also exerted no significant effects on long-term potentiation in the hippocampus. These results suggest that the mechanism underlying the anticonvulsant action of NBQX in vivo does not involve a suppressive action on physiological synaptic transmission. The possible clinical usefulness of AMPA receptor antagonists as antiepileptic drugs is suggested.

Animals↗
PubMed1995

Suppression of the formation of sister chromatid exchanges by low concentrations of ginsenoside Rh2 in human blood lymphocytes.

To assess the antimutagenic potentials of ginsenoside Rh2 (Rh2), its effects on the baseline and mitomycin C-induced sister chromatid exchange (SCE) were examined in human peripheral blood lymphocytes (PBLs). The SCE frequency in PBLs treated with various concentrations of Rh2 for 72 h was decreased in a dose-dependent manner and was significantly lower than the baseline levels at 1.0 x 10(-10) M and 1.0 x 10(-7) M. The SCE frequency in PBLs treated with both Rh2 and mitomycin C was significantly (P < 0.001) less than that in PBLs treated with only mitomycin C. Cell cycle kinetics, as indicated by the proliferation and mitotic indices, was not significantly affected by Rh2 of various concentrations in the PBLs throughout the present experiments. This is the first report which showed convincingly a reduction of SCE in normal human cells. The mechanism remains to be elucidated in future studies.

Adult↗