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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 757 records · Page 42Linked to original sources
PubMed1984

Osteoblast collagenase: collagenase synthesis by clonally derived mouse osteogenic (MC3T3-E1) cells.

Latent collagenase was isolated by heparin-Sepharose affinity chromatography from the culture medium of clonally derived mouse osteogenic (MC3T3-E1) cells. Collagenase synthesis by MC3T3-E1 cells was significantly stimulated by the addition of parathyroid hormone to the serum-containing culture medium. The cellular origin of the isolated collagenase was confirmed by demonstrating the characteristic 3/4 and 1/4 fragments of collagen alpha-chain, as well as inhibition of the enzyme by anti-mouse bone collagenase antibody.

Animals↗
PubMed1984

Effect and follow-up study on varicella vaccine.

Attenuated liver varicella vaccine (Oka strain) was used to vaccinate 242 children and 5 adults between August 1976 and December 1982; namely emergency vaccinations were given to 163 cases, including 35 high risk children, on 17 occasions, and non-emergency vaccinations were given to 84 cases including 7 high risk ones in remission. The viral doses varied from 250 to 3,000 PFU. Vaccinations prevented subsequent infection in all cases. Emergency vaccinations were given within 100 h after contact of the subjects with cases of varicella. Humoral and/or cellular immunity was acquired in 97.6% (40/41) of the high risk group and 91.8% (179/195) of the non-high risk group. As clinical reactions, rashes and fever developed in 43.9% (18/41) and in 17.0% (7/41) of high risk patients, and 7.8% (16/204) and 1.0% (2/204) of the non-high risk patients respectively. Reactions were generally slight, but were severe or atypical in 3 immunocompromized patients. Follow-up studies were carried out every year since 1980. Among the 41 high risk patients, herpes-zoster developed in 4, and varicella in 5 patients. Among the 179 non-high risk patients, there were no cases of herpes-zoster but 21 cases (12.3%) of varicella, which were mostly extremely mild. Six patients were revaccinated because of their humoral and/or cellular immunity decreased, and as a result acquired an immune response again. Criteria for varicella vaccination and details of the results of vaccination and follow-up studies are described.

Adult↗
PubMed1984

[Clinical evaluation of ceftazidime in the treatment of pediatric infections].

Ceftazidime (CAZ) was evaluated for its safety and efficacy in 31 children. Of the 25 confirmed bacterial infections, 23 were cured by the CAZ therapy (efficacy rate, 92%). CAZ was assessed as effective in acute pharyngitis with vomiting (4), acute laryngitis (1), pneumonia (8), urinary tract infections (5), acute gastroenteritis (1), infection accompanying acute leukemia (septicemia suspected) (1), acute purulent meningitis (2) and abscess of the lateral cervical cyst (1). The main pathogens which responded to CAZ were H. influenzae, S. pyogenes, E. coli and P. aeruginosa. As adverse events, mild melena with prolonged prothrombin time (1) was found to be associated with the CAZ therapy. Half-life of the CAZ serum level was 0.97 +/- 0.10 hours, and urinary excretion was high. Penetration into the CSF in 2 cases of acute purulent meningitis was satisfactory. The data suggest that CAZ is a safe and effective injectable antibiotic when used in children with infections of CAZ-susceptible bacteria including P. aeruginosa.

Adolescent↗
PubMed1984

[Three cases of intracranial chordoma. Typical chordoma and chondroid chordoma].

Three cases of intracranial chordoma: 2 cases of typical chordoma and a case of chondroid chordoma, were reported and the clinico-pathological difference between these two types of chordoma was discussed. It is well known that typical chordoma is composed of physaliferous cells containing various quantities of intracytoplasmic mucin histologically, whereas chondroid chordoma as Heffelfinger reported in 1973 is composed of cellular area with scanty myxoid matrix and Chondroid matrix. Clinical course of the typical chordoma shows recurrence of the tumor within 2 years after surgical removal and radiation therapy in the majority of the cases, and the average survival range is said to be about 4.1 years, while chondroid chordoma takes benign course with average survival of 24.1 years after surgery and radiation therapy. One of our two patients with typical chordoma died from the recurrence two years after surgery and radiation therapy. However, the patients with chondroid chordoma showed no sign of recurrence over 2 years after subtotal removal and radiation. Surgical approach for the removal of the tumor was discussed as well. When the tumor is rather small and located at the upper clival region, transsphenoidal approach may be preferable, otherwise other approach should be chosen. When tumor has forward extension over the clivus, subtemporal approach will be most favorable with wider operative field. Identification of vessels and nerves around the tumor will be readily obtained by this approach.

Adult↗
PubMed1984

Decrease in L-type pyruvate kinase activity in rat liver by some promoters of hepatocarcinogenesis.

A probably promoter-specific decrease of L-type pyruvate kinase (L-PK) in Wistar rat liver is described. The possibility of utilizing the decrease in L-PK activity for screening of hepatic promoters is discussed. A significantly decreased level of activity of L-PK was observed during continuous feedings of the hepatocarcinogen 3'-methyl-4-dimethylaminoazobenzene [(3'-MeDAB) CAS: 55-80-1], which initiates and promotes hepatocarcinogenesis, and of the known hepatic promoters phenobarbital [(PB) CAS: 50-06-6] and dichlorodiphenyltrichloroethane (CAS: 50-29-3) for at least 4 weeks. In contrast, if it occurred, the decrease in L-PK activity by the nonpromoting agents amobarbital (CAS: 57-43-2) and diphenylhydantoin. (CAS: 57-41-0) was temporary and almost overcome by the 4th week. The depression of L-PK activity caused by PB was reversible, was inversely correlated with PB concentration in the diet, and seemed to be organ-specific. Although hepatic promoters lowered L-PK activity in this study, data are so limited that a much more extensive study is necessary before a general conclusion can be drawn. In contrast to L-PK activity, the activity of K-type pyruvate kinase (K-PK) was induced by injections of the carcinogen diethylnitrosamine (CAS: 55-18-5) or the hepatotoxin CCl4 (CAS: 56-23-5) or by the feeding of 3'-MeDAB. However, feeding of PB or 2-methyl-4-dimethylaminoazobenzene (CAS: 54-88-6), which initiates but does not promote hepatocarcinogenesis, did not increase K-PK activity.

Animals↗
PubMed1984

Evaluation of a histologic classification of mouse liver tumors based on pyruvate kinase isozymes and status of host lipids.

The histologic classification of mouse liver tumors, i.e., hepatic nodules type 1 and type 2 and hepatocellular carcinomas, was evaluated by a comparison of several biologic and biochemical markers that have been shown to be useful for the grading of tumor malignancy. The liver tumors were induced by N,N'-2,7-fluorenylenebisacetamide (CAS: 304-28-9; N,N'-fluoren-2,7-ylenebisacetamide) administration to male CD-1 mice. The ability to induce L-type pyruvate kinase activity in response to a high-carbohydrate diet disappeared in almost all the liver tumors. However, fairly good correlations were observed between the histologic classification and the relative weights of liver and intraperitoneal fat pads, between the histologic classification and the level of serum total cholesterol, and between the histologic classification and the K-type pyruvate kinase activity. The results suggest that the present histologic classification reflects the degree of tumor malignancy, and therefore, it would be useful for the classification of mouse liver tumors.

Animals↗
PubMed1984

Effect of influenza virus infection on allergic sensitization to aerosolized ovalbumin in mice.

An IgE antibody specific to ovalbumin was produced when C3H mice were first infected with influenza A virus before challenge with the aerosolized antigen. No antibody could be detected in those animals without preceding viral infection. Antigen inhalation immediately after virus infection could not induce the IgE antibody. A time lag of at least 2 days was required to sensitize the infected mice with inhaled antigen. The study revealed that allergic sensitization could be elicited only during the acute stage of the infection, but not in the convalescent stage. We concluded therefore that the inflammation of respiratory mucous membrane might allow inhaled antigens to penetrate the barrier, resulting in reaginic antibody production that has the capacity to serve as an allergic response.

Administration, Intranasal↗
PubMed1983

Leumorphin is a novel endogenous opioid peptide derived from preproenkephalin B.

Using synthetic leumorphin, we obtained antisera for leumorphin and set up two radioimmunoassays (RIAs) with different specificities. Gel exclusion chromatography coupled with the two RIAs showed the existence of a considerable amount of leumorphin-like peptide in water extracts from porcine neuro-intermediate pituitaries. Reverse phase high performance liquid chromatography revealed that leumorphin-like peptide in the water extracts was indistinguishable from synthetic leumorphin. These results along with potent opioid activity of leumorphin indicate that leumorphin is a novel endogenous opioid peptide derived from preproenkephalin B.

Animals↗
PubMed1983

Reaction of biological phenolic antioxidants with superoxide generated by cytochrome P-450 model system.

Scavenging of a superoxide and simultaneous formation of free radicals with phenolic antioxidants were investigated with cobalt and iron tetraphenylporphyrin-thiolate complexes as models of P-450 enzymes. The kinetics of decay of the superoxide and development of free radical ESR signal intensities were studied. Based on a molecular orbital calculation of the hyperfine splitting, the radical species generated were confirmed to be those of phenoxyl radicals. The biological implication of superoxide, including active oxygen forms, for the reaction was discussed.

Antioxidants↗
PubMed1983

A novel opioid peptide, leumorphin, acts as an agonist at the kappa opiate receptor.

The primary structure of the common precursor of porcine beta-neo-endorphin and dynorphin (preproenkephalin B) has shown the existence of a third leucine-enkephalin (leu-enkephalin) sequence with a C-terminal extension of 24 amino acids. This nonacosapeptide, named leumorphin, was approximately 70 times more potent than leu-enkephalin in inhibiting the contraction of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. This action of leumorphin, like those of beta-neo-endorphin and dynorphin, was antagonized less effectively by naloxone than that of leu-enkephalin, but more effectively by Mr2266, an antagonist relatively specific for the kappa type opiate receptor. The inhibitory action of leumorphin or beta-neo-endorphin on the contraction of the guinea pig ileum muscle strip was reduced in a dose-dependent manner by pretreatment with dynorphin and vice versa. Leumorphin as well as beta-neo-endorphin and dynorphin inhibits the contraction of the rabbit vas deferens which is known to have only the kappa type opiate receptor. This action was also effectively antagonized by Mr2266. It is concluded that leumorphin has potent opioid activity and acts at the kappa receptor, like other opioid peptides derived from preproenkephalin B.

Animals↗
PubMed1983

Rimorphin (dynorphin B) exists together with alpha-neo-endorphin and dynorphin (dynorphin A) in human hypothalamus.

Rimorphin (dynorphin B) has been demonstrated to exist together with alpha-neo-endorphin and dynorphin(1-17) (dynorphin A) in the human hypothalamus. The content of rimorphin was comparable to that of alpha-neo-endorphin and somewhat higher than that of dynorphin. This result is quite similar to the recent observations in bovine, porcine and rat neural tissues, suggesting that rimorphin is derived from preproenkephal in B together with alpha-neo-endorphin and dynorphin in man.

Adult↗
PubMed1983

Biosynthesis of O-phosphoserine-containing phosphoproteins by isolated bone cells of mouse calvaria.

Five groups of isolated bone cells from mouse calvaria were incubated with [3H]serine and the presence and amount of O-[3H]phosphoserine used as an indication of phosphoprotein synthesis. Cells in the osteoblastic fraction were the most active in synthesizing phosphoproteins, and unlike the other cell groups, released most of the phosphoproteins into the tissue culture medium. When subjected to molecular sieving and ion-exchange chromatography, the phosphoproteins synthesized by the bone cells of the osteoblastic group behaved like the phosphoproteins extracted from mouse calvaria by EDTA.

Animals↗