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Biomedical subjects

K Kamitani

Publications and source records attributed to K Kamitani.

25 records · Page 2Linked to original sources
PubMed1991

[Anti-inflammatory effects of methylprednisolone aceponate in animals].

In the case of dermal application of the drugs to croton oil-induced ear edema in rats and picryl chloride-induced delayed type hypersensitivity in mice, the anti-inflammatory effect of methylprednisolone aceponate (MPA) was slightly weaker than those of clobetasol 17-propionate and diflucortolone 21-valerate, but stronger than those of hydrocortisone 17-butyrate and hydrocortisone 17-butyrate 21-propionate. Betamethasone 17-valerate applied dermally was less and more effective than MPA to ear edema in rats and delayed type hypersensitivity in mice, respectively. The anti-inflammatory effect of MPA was weaker in subcutaneous administration than in topical application to the two inflammatory models. It was suggested that MPA has strong anti-inflammatory effects and weak systemic effects by topical application. Methylprednisolone 17-propionate (MP-17P) and methylprednisolone (MP), unesterified in only the C-21 position and in both the C-17 and 21 positions of MPA, respectively, showed weaker anti-inflammatory activities than MPA by topical application to croton oil-induced ear edema. The ratio of the anti-inflammatory effects by topical application to subcutaneous administration of MPA was higher than those of MP-17P and MP. The excellent characteristics of MPA as a dermal anti-inflammatory drug are suggested to be derived from di-esterification of MP, which has a weak activity intrinsically.

Administration, Topical↗
PubMed1989

Purification and characterization of hen oviduct N alpha-acetyltransferase.

Hen oviduct N alpha-acetyltransferase was purified to homogeneity by ammonium sulfate fractionation and DEAE-cellulose, Sepharose 6B, hydroxylapatite, and CoA affinity chromatography. The molecular weights of the native N alpha-acetyltransferase and its protein subunit were estimated as 240,000 and 79,000, respectively. The purified enzyme exhibited a narrow pH optimum centered at 7.8. The enzyme was activated by dithiothreitol, cysteine, glutathione, and beta-mercaptoethanol, but inhibited by Fe2+, Mn2+, Zn2+, Ca2+, Mg2+, and all thiol-specific reagents tested. These findings suggest that a thiol group(s) is essential to the enzyme activity. Substrate specificity experiments of the purified enzyme revealed that (i) the minimal length of a peptide chain required for N alpha-acetylation is 10 residues, (ii) the amino acids, Ala, Ser, Met, and Gly, which are predominantly found in the N termini of N alpha-acetylated proteins, are not the sole determinant of N alpha-acetylation for 10 and more residue peptides, and (iii) N alpha-acetyltransferase recognizes a minute difference in the side chain structure at the N termini of ACTH1-18-NH2 and [Gly1]ACTH1-18-NH2, a productive and a nonproductive substrate, respectively.

Acetyltransferases↗
PubMed1989

Hen oviduct N alpha-acetyltransferase is a ribonucleoprotein having 7 S RNA.

Hen oviduct N alpha-acetyltransferase was clarified to have a nucleic acid as an existing constituent by the following three results: (i) an ultraviolet absorption spectrum of the purified N alpha-acetyltransferase free of S-acetyl coenzyme A (Ac-CoA) had an absorption maximum at 260 nm. (ii) A nucleic acid band stained with ethidium bromide was detected on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. (iii) An ethidium bromide band co-migrated with a fluorescent band of the protein treated with N-(7-dimethylamino-4-methylcoumarinyl)maleimide, a reagent specific for thiol groups, on polyacrylamide gel electrophoresis in the absence of sodium dodecyl sulfate. N alpha-Acetyltransferase lost its activity partially or completely by digestion with bovine pancreatic RNase A, Staphylococcus aureus nuclease, or proteinase K, showing that both the nucleic acid and the protein subunit were necessary for the enzyme activity. The nucleic acid component was identified as an RNA but not a DNA because the RNase T2 digest of the nucleic acid was composed of four 3'-ribomononucleotides and completely separated from 3'- and 5'-deoxyribomononucleotides on TLC. The chain length of the nucleic acid of 260 nucleotides estimated by formamide-polyacrylamide gel electrophoresis was calculated to be about 83,000 of the molecular weight. The contents of RNA (35.0%) and protein (65.0%) in N alpha-acetyltransferase determined on weight basis corresponded reasonably well to the contents of RNA (34.4%) and protein (65.6%) calculated based on the assumption that N alpha-acetyltransferase consisted of one molecule of 7 S RNA (Mr 83,000) and two identical Mr 79,000 protein subunits. The total molecular weight (241,000) of the holoenzyme calculated based on the above result was identical to the molecular weight (240,000) of N alpha-acetyltransferase estimated by Sepharose 6B gel filtration.

Acetyltransferases↗
PubMed1989

[Clinical study on mandibular condylar fracture. 1. Retrospective study in 100 patients with 130 temporomandibular joint fractures with special consideration in the treatment for the various locations and forms of the fractures].

Clinical retrospective investigation was conducted on mandibular condylar fractures of 100 hospitalized cases at the Department of Oral Surgery, Kyoto University Hospital during the period from 1973 to 1983. The following results were obtained, 1. There were 74 males and 26 females. The age of the patients at the time of injury ranged from 4 to 78 years old. The average age was 28.1 years old. 2. Twenty-six patients were treated within a week of injury, 22 cases within 2-weeks and 33 cases were treated after more tham 3 weeks. 3. Of the 100 cases, 70 were unilateral fractures and 30 were bilateral. The incidence of the concomitant fractures of the mandible were higher in bilateral than in unilateral condylar fractures. 4. On fracture level and form 130-site in 100 patients were divided according to the classification of Maclennan and Kubo. Dislocated and high condylar fractures were most frequently observed. 5. Surgical reduction was mainly achieved in low neck fracture, and the contrary conservative treatment was observed in the higher level fracture. On the other hand condylectomy was infrequently indicated in the dislocated head fracture.

Adolescent↗
PubMed1989

[Clinical study on mandibular condylar fracture. 2. Long-term follow-up study in 48 patients with 66 joints].

Sixty-six joints in 49 patients with mandibular condylar fracture were investigated by means of long-term follow-up observation. The group of patients consisted of 39 males and 10 females with ages from 15 to 75 years. The classification of the fractures was follows: MacLennan type 1; four, type 2; four, type 3; 39, and type 4; 39 joints respectively. Treatment was as follows: 25 joints were by conservative therapy, 31 joints were by surgical fixation, and 10 joints condylectomy. The follow-up period of observation ranged from 18 months to 10 years and one month an average of five years and seven months. Clinical assessment was based upon Nakatomi's dysfunction index on mandibular condylar fracture, of which the criteria are as follows; Excellent (No clinical dysfunction sign on the TMJ), Fair (Slight pain, noise, and limited range of motion of the mandible, but clinically no affected mastication), Poor (Moderate dysfunctioned jaw), and Failure (Severe dysfunctioned jaw). 23 joints in 18 patients were ranked as having excellent results. 31 joints in 22 patients were assessed as fair. Ten joints in seven patients were defined as poor, and the remaining two joints in two patients were failures. The overall success rate was 81.7%. There are no statistical differences between patient's groups based on age, sex, uni/bilateral modality, with/without other concomitant fracture, surgical/conservative procedure, location and form of fractures, and duration of period from injury. These results indicated that the conservative procedure would be the first choice as a reasonable and less invasive procedure for functional repair of mandibular condylar fracture. On the other hand, as most patients had some dysfunction sign on the TMJ after mandibular condylar fracture, a more appropriate treatment, surgical or otherwise, should be found.

Adolescent↗
PubMed1980

Partial purification and properties of the amino-terminal amino acid-acetylating enzyme from hen's oviduct.

By using the synthetic peptide ACTH1-24 as a model substrate, an enzyme that may be involved in the amino-terminal acetylation of certain proteins and growing nascent polypeptide chains has been found in hen's oviduct. It was partially purified by a four-step procedure comprising extraction from the homogenates, ammonium sulfate fractionation, chromatography on a column of QAE-Sephadex A-50, and gel filtration on a Sepharose 6B column. An enzyme preparation purified about 40-fold from the homogenates transferred the acetyl group from acetyl coenzyme A preferentially to the amino-terminal amino acids of several ACTH-related peptides at an optimum pH of around 7.2. This occurred to different extents depending on the peptide length and on the nature of the amino-terminal residue. The molecular weight of the enzyme was estimated to be approximately 250,000 by gel filtration.

Acetylation↗