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Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 775 records · Page 43Linked to original sources

[A simplified method for the assessment of C1 esterase inhibitor function].

From the result that the activated form of C1-s(C1-s) prolonged the kinetics of hemolysis via complement, this assay was applied to assess C1 esterase inhibitor (C1INH) function. In the kinetic assay, the complement hemolytic activity was evaluated by the time which required to cause 50% reduction of the initial turbidity of sensitized sheep erythrocytes, and was expressed as T1/2. (1) T1/2 of pooled normal human sera (p-NHS) showed dose-dependent prolongation by the addition of various amounts of C1-s. (2) Preincubation of various amounts of functionally pure C1INH with the constant amounts of C1-s inhibited dose-dependently the prolongation of T1/2 by C1-s. (3) The C1INH activity of NHS was 840 +/- 80 units/ml (n = 6) and that of the C1INH deficient serum was 80 units/ml, which were calculated from the standard curve established by the addition of various amounts of purified C1INH. This test requiring only C1-s and sensitized sheep erythrocytes is simple technically and high in sensitivity, and seems to be useful for the routine assay for C1INH function of human sera.

Animals↗

Adherent synovial cells from nonrheumatoid arthritis do not release interleukin 1 beta and prostaglandin E2 spontaneously in longterm culture.

Adherent synovial cells from both 13 patients without rheumatoid arthritis (RA) (gout, osteoarthritis and meniscal lesion) and 8 patients with RA consisted of dendritic cells, macrophage-like cells and fibroblast-like cells after cloning in a similar fashion as reported in our previous paper. All the adherent synovial cells from patients without RA did not release interleukin 1 (IL-1) beta and prostaglandin E2 (PGE2) spontaneously, while those cells released comparable amounts of IL-1 beta, but not PGE2 to RA cells after type II collagen stimulation. Only the synovial cells from RA, irrespective of morphology and cloning, released IL-1 beta and PGE2 without stimulation. Nonrheumatoid synovial cells may differ functionally from RA cells.

Arthritis, Rheumatoid↗

[Familial complete atrioventricular block of adult onset].

A family of complete atrioventricular block (FCAVB) of adult onset was reported. A 36-year-old-female had 1 degree AH block, atrial and ventricular premature beats and mild sinus node dysfunction. Her father had complete AV block and died of it. A 57-year-old uncle and a 52 years-old uncle had bradycardia from 44, 5 years of age and 51 years of age, respectively, and their ECG showed complete AV block with narrow QRS waves. They were implanted with permanent pacemakers. Her grandmother died a sudden death of Adams-Stokes attack. Acquired heart diseases were not seen in any of the family Thus, this family was thought a FCAVB of adult onset.

Adult↗

[Secundum atrial septal defect in two families].

Two families having secundum atrial septal defect (ASD) were reported. In one family, a 31-year-old male and his 60-year-old mother had secundum ASD without PR prolongation. His 38-year-old brother was diagnosed as having ASD. His grandmother, who had died at the age of 51, was suspected of having congenital heart disease. From early childhood she was noticed to have heart murmur. It was suspected that this was a case of familial ASD without PR prolongation, because it was consistent with the dominant trait of the defect. In the other family, a 16-year-old female had secundum ASD and her 18-year-old brother was also suspected of having ASD. Her 25-year-old brother had been operated on for tetralogy of Fallot, and her sister had died of an unknown congenital heart disease. All of these family members had mental retardation. Her 22-year-old brother was suspected of having a congenital heart disease, because of heart murmur from his early childhood. The parents, who were blood relations (cousins), had neither heart disease nor mental retardation. The children of this family were considered to be cases of congenital heart disease with ASD, associated with mental retardation. It was also suspected that the cause of the defect was a deleterious autosomal recessive gene.

Adolescent↗

[Plasma levels of complement fragments during hemodialysis in patients with chronic renal failure].

The kinetics of hemodialysis-induced leukopenia and generation of complement fragments including C3a, C5a, C4d, iC3b and Bb were investigated in 14 patients during hemodialysis using cellulose acetate (CA), cuprophan (Cu) and ethylenevinyl alcohol (EVA) membranes. A marked leukopenia in the first 15 minutes was observed in CA and Cu. Plasma C3a levels were higher in CA than in Cu and EVA. Plasma C5a levels were higher in CA and Cu than in EVA. There was a negative correlation between the white blood cell counts and plasma C5a levels at 15 minutes (gamma = -0.85, p less than 0.001). Plasma C4d levels showed no increase in all membranes. Plasma iC3b levels were higher significantly in Cu than in CA and EVA. Plasma Bb levels in the first 15 minutes increased significantly in all membranes, and furthermore continued to increase till the end of hemodialysis in CA and Cu. This study revealed that all the membranes tested activated the complement via the alternative pathway to produce Bb, iC3b, C3a and C5a. C5a was thought to take an important role in transient leukopenia. Furthermore, Bb was accumulated during hemodialysis in CA and Cu, and its biological effects on patients undergoing hemodialysis should be studied.

Adult↗

Development and sexual maturation of Taenia crassiceps (Cestoda) in the golden hamster.

The development of cysticerci of Taenia crassiceps to mature tapeworms in the intestinal tract of cortisone-treated and untreated golden hamsters is described. The development of the worms in untreated hamsters is as follows. Maturation and branching of the uterus and the presence of ova in the uterus were observed on day 15 postinfection (PI). By day 21 PI, fertilization had taken place, as evidenced by the presence of sperm in the seminal receptacle. On day 28 PI, shelled eggs were observed in feces. The rate of development of the worms in cortisone-treated hamsters was similar to that observed in untreated hamsters. More worm recovery and a longer period of worm survival were seen in the cortisone-treated than in the untreated hamsters. Thus, both cortisone-treated and untreated golden hamsters can produce normal gravid individuals of T. crassiceps.

Animals↗

[A case of cardiac tamponade showing respiratory variation in inflow and outflow velocities in both ventricles and venous return].

A case of a 62-year-old man with a large pericardial effusion is presented. He developed clinical signs of cardiac tamponade. Two-dimensional echocardiography revealed collapse of the right ventricle in early diastole and inversion of the free wall of both atria in systole. Pulsed Doppler echocardiography demonstrated an abnormally increased respiratory variation in transvalvular blood flow velocities. Expiration caused an increase in the flow velocities across the mitral and aortic valves, and a decrease in the flow velocity across the tricuspid valve. The exaggerated respiratory variations in transvalvular flow velocities suggest that Doppler evaluation may be a valuable adjunct in the diagnosis of cardiac tamponade.

Blood Flow Velocity↗

[The studies on clinical efficacy of Tomiron in the surgical patients: skin and soft tissue infection].

We studied the clinical efficacy and prophylactic effect of Tomiron (cefteram pivoxil; CFTM-PI), a new oral cephalosporin, in the surgical patients. CFTM-PI was administered at a daily dose of 300 or 600 mg after meals. Infectious diseases in 151 patients consisted of infected atheroma, wound infection, subcutaneous abscess, furuncle, phlegmon, mastitis, lymphangitis, periproctal abscess and biliary tract infection. Fifty patients were administered CFTM-PI to prevent secondary wound infection. The clinical efficacy rate was 75.5% in the treatment of infection and 86.0% in the prophylactic use. The clinical efficacy for skin and soft tissue infection was regarded as excellent in 25, good in 74, fair in 17 and poor in 8 out of 124 cases, with a clinical efficacy rate of 79.8%. The eradication rate in 40 cases of monomicro-bial infection was 97.4%, and in 12 cases of polymicrobial infection it was 72.7%. For biliary tract infection, the clinical efficacy was excellent in 1, good in 5, fair in 1 and poor in 1, with a clinical efficacy rate of 75.0%. Adverse effects were observed in 4 (2.0%) of 201 cases: allergic reaction in 3, and sleepiness in 1. Abnormal laboratory findings were observed in 2 cases, but it is not clear if these were due to this drug. These results indicate that Tomiron is a useful oral antimicrobial agent in the treatment and prophylaxis of surgical infection, mainly skin and soft tissue infection.

Adolescent↗

Molecular cloning and sequence analysis of cDNA encoding rat adrenal cytochrome P-450(11)beta.

A cDNA clone encoding cytochrome P-450(11)beta of rat adrenal has been cloned and sequenced using a bovine P-450(11)beta cDNA insert (pcP-450(11 beta)-2; (1987) J. Biochem. 102, 559-568) as a probe. The nucleotide sequence contains an open reading frame sufficient to encode the entire amino acid sequence of a P-450(11)beta precursor protein consisting of 499 amino acids including an extension peptide of 24 amino acids at the NH2-terminus. The cDNA contains 1247 nucleotides at the 3'-noncoding region including 51 nucleotides of poly A, but lacks the 5'-noncoding region. The deduced amino acid sequence shows 61% similarity to that of bovine P-450(11)beta. Putative binding sites for heme and steroid are highly conserved among steroidogenic P-450s of known structure.

Adrenal Glands↗

The primary structure of a membrane-associated phospholipase A2 from human spleen.

The complete primary structure of membrane-associated phospholipase A2 purified from a human splenic membrane fraction was determined by sequence analysis of the peptides generated by lysyl endopeptidase and Staphylococcus aureus V8 protease cleavage. The enzyme consists of 124 amino acid residues corresponding to a molecular weight of 13,904. The primary structure reveals the characteristics of Group II phospholipases A2 and a large ratio of basic amino acid residues to acidic ones, that ratio being 3.4 : 1.

Amino Acid Sequence↗

cDNA cloning and sequence determination of rat membrane-associated phospholipase A2.

Based on the partial amino acid sequences of membrane-associated phospholipase A2 (PLA2M), belonging to group II, purified from rat spleen, the cDNA encoding PLA2M was cloned by a new cloning strategy utilizing enzymatic cDNA amplification. At the N-terminus of the coded 146 residues, which were deduced from the cDNA sequence, the putative signal peptide was found despite the tight adherence of this enzyme to the membrane. The sequence of rat PLA2M exhibits 75% homology with that of human group II PLA2 in the protein-coding region. The result of RNA blot analysis showed that rat ileal mucosa contains the largest amount of the PLA2 transcript among the tissues examined.

Amino Acid Sequence↗

Loss of constitutional heterozygosity in colorectal tumors from patients with familial polyposis coli and those with nonpolyposis colorectal carcinoma.

Familial polyposis coli (FPC) is an autosomal dominant tumorigenic disorder, the major gene of which is mapped to chromosome 5q. We searched for a gene loss in colorectal tumors from FPC patients, as related to tumorigenesis by inactivation of tumor suppression genes, using restriction fragment length polymorphism analysis. The findings were compared with those in the case of nonpolyposis colorectal carcinomas (NPCC). We examined specimens from 39 FPC patients, including 21 adenocarcinomas and 49 adenomas, and 23 colorectal carcinomas from 22 NPCC patients. For this, we used 53 polymorphic DNA markers on all autosomes. Frequent loss of heterozygosity in colorectal carcinoma from FPC patients was observed on chromosomes 5 (24%), 14 (20%), 17 (31%), 18 (40%), and 22 (35%) and also on chromosomes 5 (32%), 14 (30%), 17 (27%), 18 (20%), and 22 (19%) in NPCC. Although loss of heterozygosity in adenoma from FPC patients was observed on nine chromosomes, the frequencies were less than 7%. As we fractionated tumors only macroscopically, actual frequencies of loss of heterozygosity are probably somewhat higher. However, these results do suggest that tumor suppression genes for colorectal carcinoma may locate on chromosomes 5, 14, 17, 18, and 22 and that they may play a critical role in carcinogenesis in both FPC and NPCC patients.

Adenoma↗

Rate enhancement of the electron transfer the adrenodoxin-adrenodoxin reductase system by dicarboxylic acids.

The rate of electron transport in the cytochrome P-450 system in adrenocortical mitochondria was studied with purified adrenodoxin reductase, adrenodoxin and cytochrome c. Oxaloacetate enhanced the rate at concentrations of less than 1 mM; malate, succinate and fumarate enhanced the rate to a lesser extent; and pyruvate and alpha-ketoglutarate had no appreciable effect. The rate enhancement was observed when the reagents were preincubated with adrenodoxin, but not with adrenodoxin reductase. Rate enhancement was also evident when the rate limiting step was at adrenodoxin in the electron transport system.

Adrenodoxin↗

[Single-daily-dose treatment of ceftriaxone for biliary tract infections and bacterial counts in bile].

To evaluate the effects of ceftriaxone (CTRX) administered once daily, the biliary concentration of CTRX and daily changes in the bacterial count in bile from an indwelling T-tube were measured concomitantly. The effects on prophylaxis of postoperative infections after biliary tract surgery were also examined mainly due to clinical symptoms. The biliary CTRX levels increased rapidly and were sustained as high as 92.5-219 micrograms/ml in all patients even 24 hours after 2 g of CTRX was infused intravenously once daily. Five of 7 patients whose bile samples were positive for bacteria showed high CTRX levels in bile and almost no bacteria present after treatment. CTRX-sensitive bacteria eliminated 1 or 2 hours after the administration in response to the increase of biliary CTRX levels. The changes in bacteria count of bile may be closely related to CTRX antibiotic activity. As an antibiotic prophylaxis, other 18 patients with biliary diseases received intravenous infusion of 2 g of CTRX once daily for 5-7 days (mean 5.9 days). Thus, once-daily dose treatment of CTRX 2 g may have antibiotic effects on biliary infection and postoperative prophylaxis of biliary infections and it is indicated that the prolonged biliary levels of CTRX are essential for its efficacy.

Adult↗

Expression of human erythropoietin cDNA in human lymphoblastoid Namalwa cells: the inconsistency of a stable expression level with transient expression efficiency.

Recombinant plasmids for the expression of human erythropoietin (EPO) cDNA in Namalwa cells were constructed. From the results of the EPO expression efficiency in transiently transfected cells, it was found that the simian virus 40 (SV40) early promoter directs EPO synthesis more efficiently in Namalwa cells than does the long terminal repeat promoter of Rous sarcoma virus and that the 3'-noncoding sequence including splice junction and polyadenylation site derived from the rabbit beta-globin gene are more effective than those of the SV40 early gene. However, in stable transformants, no simple relationship was found between the expression level of EPO cDNA and the structure of the introduced expression vectors.

Base Sequence↗

Multiple molecular forms of cytochrome P-450SCC purified from bovine corpus luteum mitochondria.

Cytochrome P-450 related to side-chain cleavage of cholesterol (P-450SCC) was isolated from bovine corpus luteum mitochondria in the form of its stable cholesterol complex. The isolation procedure included ammonium sulfate fractionation and chromatography on omega-aminohexyl-Sepharose (AH-Sepharose). Corpus luteum P-450SCC was resolved into one minor (AH-I) and two major (AH-II and AH-III) fractions by the chromatography. Results of re-chromatography suggested the possibility that AH-III Fraction was originally complexed with lipidic material. The two major fractions purified by the re-chromatography (AH-IIR and AH-IIIR Fractions) showed essentially a single band on sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and their absorption spectra were indistinguishable from each other. Both fractions were further resolved into two major and some minor bands of P-450SCC by isoelectric focusing on polyacrylamide gel in the presence of a non-ionic detergent, as detected by protein staining, heme staining and immunoblot analysis with anti-bovine P-450SCC monoclonal antibody. Both AH-IIR and AH-IIIR Fractions were further resolved by high-performance liquid chromatography (HPLC) on SP-TSK gel column into two fractions, SP-I and SP-II. These fractions had the same N-terminal amino acid sequence, showed similar catalytic activity and resolved into one major and a few minor bands on isoelectric focusing on polyacrylamide gel. Much more heterogeneity was observed in purified P-450SCC preparations from bovine adrenal cortex mitochondria. These results indicated the presence of multiple molecular forms of corpus luteum P-450SCC as well as adrenal cortex P-450SCC. Computer simulation studies were carried out in order to analyze the mechanism of formation of multiple bands on isoelectric focusing. The multiple bands of corpus luteum P-450SCC could be explained by postulating the presence of two isozymes (or molecular forms) having a pair of sites each with or without a charged group.

Adrenal Cortex↗