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Biomedical subjects

N Kubota

Publications and source records attributed to N Kubota.

At least 163 records · Page 9Linked to original sources
PubMed1987

Isolation of influenza A viruses from migratory waterfowl in San-in District, western Japan in the winter of 1983-1984.

Certain species of winter migratory waterfowl in San-in District, western Japan, were surveyed for influenza virus from November 1983 to March 1984. Faeces of the waterfowl were collected regularly at five stations. Eleven influenza A viruses including H5N3 and H10N4 subtypes were isolated from 450 faecal samples from whistling swans, 28 viruses including H2N2 and H10N4 subtypes were isolated from 362 faecal samples from pintails; and subtype H13N6 was isolated from 240 faecal samples of black-tailed gulls.

Animals↗
PubMed1986

The chromosomal gene structure and two mRNAs for human granulocyte colony-stimulating factor.

Two different cDNAs for human granulocyte colony-stimulating factor (G-CSF) were isolated from a cDNA library constructed with mRNA prepared from human squamous carcinoma cells, which produce G-CSF constitutively. The nucleotide sequence analysis of both cDNAs indicated that two polypeptides coded by these cDNAs are different at one position where three amino acids are deleted/inserted. When the two cDNAs were introduced into monkey COS cells under the SV40 early promoter, both of them produced proteins having authentic G-CSF activity and some difference in the specific activity was suggested. A human gene library was then screened with the G-CSF cDNA and the DNA fragment containing the G-CSF chromosomal gene was characterized by the nucleotide sequence analysis. The human G-CSF gene is interrupted by four introns and a comparison of the structures of the two G-CSF cDNAs with that of the chromosomal gene indicated that the two mRNAs are generated by alternative use of two 5' splice donor sequences in the second intron of the G-CSF gene. When the G-CSF chromosomal gene was expressed in monkey COS cells by using the SV40 enhancer two mRNAs were detected by S1 mapping analysis.

Amino Acid Sequence↗
PubMed1986

Purification and characterization of human granulocyte colony-stimulating factor (G-CSF).

A colony-stimulating factor (CSF) has been purified to homogeneity from the serum-free medium conditioned by one of the human CSF-producing tumor cell lines, CHU-2. The molecule was a hydrophobic glycoprotein (mol. wt 19,000, pI = 6.1 as asialo form) with possible O-linked glycosides. Amino acid sequence determination of the molecule gave a single NH2-terminal sequence which had no homology to the corresponding sequence of the other CSFs previously reported. The biological activity was apparently specific for a neutrophilic granulocyte-lineage of both human and mouse bone marrow cells with a specific activity of 2.7 X 10(8) colonies/10(5) non-adherent human bone marrow cells/mg protein. The purified CSF can be regarded as a G-CSF of human origin and will become a useful material for investigation of regulatory mechanisms of human granulopoiesis.

Amino Acids↗
PubMed1986

Rapid immunochemical assay of pregnanediol-3-glucuronide in urine and its clinical application.

A rapid and simple technique for assessing ovulation and luteal function is needed in clinical practice. A sensitive immunoassay kit is presented here for clinical use. An immunoassay of pregnanediol-3-glucuronide (Pd-3G) in urine was established. The sensitivity of this assay was 0.4 mg/l of Pd-3G. The standard error range of the recovery test was within 0.8 mg/l, and the coefficients of variation of within-run and day-to-day precision test were within 4%. Cross reactions of various steroids were observed in free pregnanediol, pregnanetriol and progesterone, but their reactivity exhibited less than 4%. The Pd-3G/creatinine (mg/g) ratio was demonstrated as nearly constant over a 24-hour period. A significant rise of Pd-3G coincided with a luteinizing hormone surge and continued during the luteal phase in the ovulatory menstrual cycle. In an anovulatory cycle, Pd-3G was found to be under 4 mg/g creatinine. This Pd-3G direct-assay method could be widely used in infertility clinics.

Adult↗
PubMed1986

Fraction of pluripotent hemopoietic stem cells in DNA synthesis varies with generation age.

The fraction of pluripotent hemopoietic stem cell (CFU-S) in DNA synthesis (S phase) was evaluated for day 7 through 13-spleen colonies. The CFU-S in S phase in normal bone marrow decreased progressively, from 43% on day 7, to 23% on day 11, and 4% on day 13. The cycling fraction of 5-fluorouracil (5FU)-treated CFU-S was also evaluated. The S phase fraction for CFU-S surviving 5FU was 100.0, 58.8, 54.7, and 25.6% at day 7, 9, 11, and 13, respectively, and the proportion of the fraction also was not constant. The S phase fraction for CFU-S surviving 5FU was much higher than that for normal bone marrow cells; this might be attributed to the extensive regenerating ability of CFU-S surviving 5-FU. The results obtained suggest that a stem cell population in S-phase may exhibit a hierarchy based on the "generation-age hypothesis" (Rosendaal, Hodgson, and Bradley 1979) of the stem cell compartment.

Animals↗
PubMed1985

[An immunochemical assay of pregnanediol 3-glucuronide in urine and its variation in the peri-ovulatory period].

A rapid, simple and sensitive immunochemical assay of pregnanediol 3-glucuronide (Pd-3G) in urine was established. The standard error range of the recovery test was within 0.8 microgram/ml, and the coefficient variation of the within run and day to day precision tests were within 4%. Cross reactivity of various steroids exhibited less than 4%. A significant rise of Pd-3G (mg)/creatinine (g) coincided with the LH surge and continued during the luteal phase in the ovulatory menstrual cycle. In an anovulatory cycle, Pd-3G was found to be under 4 mg/g. This Pd-3G direct assay method could be widely used for assessing ovulation and luteal function.

Adult↗
PubMed1985

New method for bioavailability assessment of slow-release preparations of theophylline.

Variability in an individual's clearance of theophylline is an important consideration when estimating bioavailability. A method is described for compensating for this problem, using the serum concentration of theophylline and urinary excretion data on its major metabolites to make an estimation of the clearance after oral administration using the intravenous dose as reference. The method is particularly useful for assessing the bioavailability of slow-release theophylline preparations.

Administration, Oral↗
PubMed1985

Chronic effects of a beta-adrenoceptor blocking drug, 4-[3-(tert-butylamino)-2-hydroxypropoxy]-N-methylisocarbostyril hydrochloride (N-696), in hypertensive rats.

4-[3-(tert-Butylamino)-2-hydroxypropoxy]-N-methylisocarbostyril hydrochloride (N-696) is a new beta-adrenoceptor blocking drug with direct vasodilatory activity, and may be classified into the fourth generation. Antihypertensive effects of N-696 were studied for 12 weeks in spontaneously (SHR), two kidney, one clip (CLIP), and deoxycorticosterone-salt (DOC) hypertensive rats. Propranolol (PPL) was used as the reference drug. In indirect blood pressure (BP) determination at the tail, milder prewarming condition was employed to observe antihypertensive effects clearly. Rats were prewarmed in rat holders on a hot plate for 30-60 min. Surface temperature of the hot plate was 35-45 degrees C. N-696 (20 mg/kg per day p.o.) and PPL (100 mg/kg per day, p.o.) treatments significantly decreased heart rate (HR) and maximum BP determined indirectly in SHR rats, even at the early stage of the experiments. These antihypertensive effects were shown also by mean BP determined directly at the 12th week. N-696 and PPL treatments showed no significant antihypertensive effects in CLIP rats, and slight antihypertensive effects in DOC rats. N-696 treatments showed a tendency to decrease plasma renin concentration (PRC) in SHR and DOC rats, whereas PPL treatments significantly decreased PRC in these hypertensive rats. N-696 and PPL treatments prevented nephrosclerosis and vascular lesions in SHR and DOC rats only slightly.

Adrenergic beta-Antagonists↗