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Biomedical subjects

A Ohkubo

Publications and source records attributed to A Ohkubo.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Comparison of positivity between density gradient centrifugal method and whole blood method in lymphocyte surface marker analysis with flow-cytometry].

The lymphocyte surface marker analysis with flow-cytometry is usually performed using a density gradient centrifugal method or a whole blood method. We have compared these two methods using several monoclonal antibodies and have found the significant difference in positivity all monoclonal antibodies except TCR-1 (anti alpha/beta receptor on T-lymphocyte). We found the significantly higher positivity of Leu12 and HLA-DR as well as lower of the other monoclonal antibodies by using whole blood method than by density gradient centrifugal method. We conclude that it is necessary to make a distinct description of the method used in the surface marker analysis.

Adult↗
PubMed1990

[Rapid detection and identification of mycobacterial DNA by PCR].

We have developed a highly sensitive and rapid PCR assay for detection and identification of mycobacterial species. Two sets of PCR primers were prepared; one was for the 19 kDa antigen gene and the other for the dna J gene. The PCR for 19 kDa antigen gene was found to be specific to the M. tuberculosis complex; M. tuberculosis, M. bovis and M. africanum. On the other hand, the PCR for the dna J gene was able to detect a broad spectrum of mycobacterial species including M. tuberculosis, M. avium, M. intracellulare and M. kansasii. The sensitivity of PCR was similar to that of the culture method for precultured M. tuberculosis whereas PCR was much more sensitive than the culture for clinical samples. The procedure of decontamination by sodium hydroxide for clinical samples could reduce the viability of M. tuberculosis while it did not affect mycobacterial DNA. The nucleotide sequence homologies among major mycobacteria were also determined following PCR for the dna J gene. This allowed us to make restriction maps for each mycobacterium. We have demonstrated that the PCR-RFLP for the dna J gene will be a useful laboratory test for rapid identification of tuberculous and nontuberculous mycobacterial species.

Base Sequence↗
PubMed1990

Factitious proteinuria in a young girl.

A 16-year-old girl showed waxing and waning proteinuria and fat globules in urine for three years. There were no other abnormal findings except for the urinalysis. The renal biopsy findings did not indicate glomerular disease. Electrophoresis of the urinary protein showed two abnormal fractions at the alpha and beta globulins. Immunoelectrophoresis demonstrated that these abnormal proteins were not derived from human serum proteins, but were egg proteins. It appears that the proteinuria was factitious and that egg proteins were injected into the bladder, as they were also present in the bladder urine.

Adolescent↗
PubMed1989

Developmentally regulated expression of vascular smooth muscle myosin heavy chain isoforms.

Two types of smooth muscle myosin heavy chain (MHC) isoforms, SM1 and SM2, were recently identified to have different carboxyl termini (Nagai, R., Kuro-o, M., Babij, P., and Periasamy, M. (1989) J. Biol. Chem. 264, 9734-9737). SM1 and SM2 are considered to be generated from a single gene through alternative RNA splicing. In this study we investigated expression of vascular MHC isoforms during development in rabbits at the mRNA, protein, and histological levels. In adults, all smooth muscle cells reacted with both anti-SM1 and anti-SM2 antibodies on immunofluorescence, suggesting the coexpression of SM1 and SM2 in a single cell. In fetal and perinatal rabbits, however, only anti-SM1 antibody consistently reacted with smooth muscles. Reactivity with anti-SM2 antibody was negative in the fetal and neonatal blood vessels and gradually increased during 30 days after birth. These developmental changes in SM1 and SM2 expression at the histological level coincided with mRNA expression of each MHC isoform as determined by S1 nuclease mapping, indicating that expression of SM1 and SM2 is controlled at the level of RNA splicing. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of myosin from fetal and perinatal aortas revealed the presence of large amount of SM2. Interestingly, fetal SM2 did not cross-react with our anti-SM2 antibody on immunoblotting. We conclude that expression of SM1 and SM2 are differentially regulated during development and that a third type of MHC isoform may exist in embryonic and perinatal vascular smooth muscles.

Animals↗
PubMed1989

Polyamine detection system for high-performance liquid chromatography involving enzymatic and chemiluminescent reactions.

We have developed a new specific detection system for polyamines, separated by high-performance liquid chromatography, to replace the usual o-phthalaldehyde (OPA) postlabeling method. This system utilizes a chemiluminescent reaction to determine the amount of hydrogen peroxide generated through the enzymatic oxidation of polyamines. With this method, as little as 5 pmol of putrescine could be accurately determined (S/N = 4), and linearity between the amount of this polyamine and the relative chemiluminescence intensity was observed up to 500 pmol. In the cases of cadaverine, spermidine, and spermine, the linearity continued to 1 nmol. The within-assay coefficients of variation for these four polyamines ranged between 0.97% and 2.03%. As compared with the OPA method, the new method is highly specific for polyamines due to the high specificity of the enzyme used. Another advantage of the new method is the direct determination of polyamines in urine samples that contain various compounds that interfere with the OPA method.

Chromatography, High Pressure Liquid↗
PubMed1989

Structure and transcription of the glycoprotein gene of attenuated HEP-Flury strain of rabies virus.

The mRNA-encoding G protein of the attenuated HEP-Flury strain of rabies virus was sequenced by the cDNA cloning technique. The G-mRNA was composed of 2059 nucleotides, with the coding region located from the 28th to 1602nd nucleotide, and was capable of encoding a polypeptide of 524 amino acids. Although the coding region was highly homologous (90% or more) to that of ERA and PV strains, the 3' noncoding region of the HEP virus G-mRNA was longer than that reported for other strains by some 400 nucleotides. The extra sequence was homologous to the long G-L intergenic sequence of the PV viral genome. The HEP virus genome lacked the postulated polyadenylating signal (TG-AAAAAAAA) that should have been found just before the "long G-L intergenic region," which indicates that the long G-L intergenic region of the HEP virus is integrated into the preceding G gene, and is transcribed only as a portion of the G-mRNA molecule. In the ERA virus-infected cells, however, two species of G-mRNA (1.9 and 2.3 kb long) were produced. The longer G-mRNA also contained the sequence complementary to the long G-L intergenic region and the shorter one did not. These findings suggest that two different poly(A)-tailing signals (one is present just before and another at the end of the long G-L intergenic region) work toward terminating the transcription of the ERA virus G gene and that the longer G-mRNA is produced as a readthrough product.

Amino Acid Sequence↗
PubMed1989

Measurement of serum alkaline phosphatase isozyme I in brain-damaged patients.

The authors measured alkaline phosphatase isozyme I (ALP-I) in sera of 24 brain-damaged patients and four with disorders other than brain damage. The study population comprised three patients with postresuscitation encephalopathy, four with ruptured cerebral aneurysms, 14 with acute subdural hematoma and cerebral contusion, and three with nontraumatic intracerebral hemorrhage. ALP-I detected in brain damage is physicochemically different from the other known ALP-Is that appear in patients with obstructive jaundice or hepatoma. In the brain-damaged patients, ALP-I became elevated about 7 days after admission and markedly increased as secondary brain damage developed. Excluding patients who died within 9 days of admission, the maximum serum ALP-I concentration was well correlated with the functional outcome. In cases in which barbiturate therapy was effective, the appearance of ALP-I was delayed and its elevation was suppressed. The results of this study suggest that measurement of serum ALP-I is useful not only in the management but also in predicting the prognosis of brain damage.

Adolescent↗
PubMed1989

Frequency dependence of the suppressive effects of vibration on atherosclerosis in the rabbit.

Whole-body vibration suppresses the development of atherosclerosis in the rabbit (Oki and Matoba, 1987). The present study was designed to clarify whether the effect of vibration on atherosclerosis depends on the frequency of vibration. Longitudinal vibrations at a frequency of 30 or 60 Hz was applied to 12 New Zealand white rabbits for 12 weeks. The gradual decrease in body weight and blood hematocrit in the vibration groups with time were parallel to the changes in the controls. The rate of increase in serum lipid concentrations induced by a cholesterol-rich diet was significantly suppressed in the vibration groups, as compared to the controls. This may be due to the vibration and not the diet. The aortic wall was thinner at 60 Hz than at 30 Hz, whereas the ratios of trace metals (Ca/Mg and Zn/Cu) in the aortic tissues were smaller at 30 Hz. The area of plaque formation in the intima was smaller at 60 Hz than at 30 Hz (p less than 0.05). Thus, the suppressive effect of vibration on the development of atherosclerosis in the aorta may be greater at a frequency of 60 Hz than at 30 Hz. Vibration may play an important role in lipid metabolism.

Animals↗
PubMed1989

Sensitive, simple staining method for use in electrophoretic determination of amylase isoenzymes in serum.

We have developed a sensitive and simple staining method for use in electrophoretic analysis of serum alpha-amylase (EC 3.2.1.1) isoenzymes. The principle of this method is as follows. alpha-Amylase hydrolyzes 4-nitrophenylmaltoheptaoside to generate oligosaccharide, which is then converted to gluconolactone in the presence of oligosaccharide dehydrogenase (no EC no. assigned), with concomitant reduction of 1-methoxy-5-methylphenazinium methylsulfate (1-m-PMS) to 1-m-PMSH. The hydrogen in 1-m-PMSH is then transferred to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide to yield formazan. Each of the isoenzymes can then be measured densitometrically. The mean (and SD) values for total amylase, P1, S1, and S2 as determined by this method with sera from 25 healthy adults in fasting were 251 (64), 104 (35), 126 (40), and 22 (11) U/L, respectively. Between-assay CVs (n = 10) for determinations of P1, S1, and S2 were 3.54%, 4.03%, and 7.01%, respectively.

Amylases↗
PubMed1988

Clinical usefulness of an enzymatic determination of total urinary polyamines, excluding cadaverine.

In one widely used enzymatic method for urinary polyamines, the total concentrations of four polyamines--putrescine, spermidine, spermine, and cadaverine--are determined. We report here a simple enzymatic method for measuring the total concentrations of urinary polyamines except cadaverine. The coefficients of variation (CV) for within-run measurements by this method were 4.3% (means = 17.2 mumol/L) and 1.5% (means = 66.5 mumol/L), between-run CVs were 4.8% (means = 16.8 mumol/L) and 1.8% (means = 67.5 mumol/L). The central 95% normal reference interval was 12.3-29.1 mumol/g creatinine for men and 14.1-36.8 mumol/g creatinine for women. In some cases, physiological variations in urinary polyamine excretion were large, mainly because of variations in cadaverine excretion, even in health. Pathological changes in polyamine production in the body may therefore be more easily shown by the excretion of total polyamines excluding cadaverine than by that including cadaverine.

Adult↗
PubMed1987

The nature of the mutagenicity and carcinogenicity of nitrated, aromatic compounds in the environment.

Gaseous substances such as nitrogen dioxide (NO2) and sulfur dioxide (SO2) stimulate the process of nitration of polycyclic aromatic hydrocarbons, and the transformation products display a broad spectrum of mutagenicity, genotoxicity, and carcinogenicity. Bacterial mutation by nitroarenes is specific. Tetracyclic nitroarenes are thought to be the most mutagenic compounds in the Salmonella test system, and some are carcinogenic in rats and mice. Furthermore, it was found that the mutational nitroarenes produced mostly DNA damage, which is subject to recombination repair in the rec assay system using Bacillus subtilis. Nitroarenes in the environment seem to be ubiquitous; the majority of the compounds are emitted directly from diesel emissions, kerosene heaters, and gas and liquefied-gas burners or heaters. In nitroarenes induced during incomplete combustion, nitropyrene and nitrofluoranthene derivatives are the most important mutagens/carcinogens for determining the chronic toxicity of nitroarenes overall.

Animals↗
PubMed1986

Urinary protein as measured with a pyrogallol red-molybdate complex, manually and in a Hitachi 726 automated analyzer.

In this new method for determining urinary protein, the reaction is complete within 10 min at 37 degrees C. This method is applicable to automated as well as manual measurements. Protein concentration and absorbance at 600 nm are linearly related throughout a wide range of concentrations, 10 to 16 000 mg/L. However, the chromogenicity of the gamma-globulins in this method is 70% of that of albumin, as estimated from results by a biuret method. Within-run CVs were less than 3.3%; the day-to-day CV was 2.9%. Errors due to interfering components in urine are less than 2%. The normal range for urinary protein as measured by this method was from 28 to 141 mg/day. Results by this method (y) and by a trichloroacetic acid-biuret method (x) correlated well (n = 80, r = 0.995; y = 0.99x - 2.9).

Adult↗