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K Matsui

Publications and source records attributed to K Matsui.

At least 523 records · Page 29Linked to original sources
PubMed1987

Demonstration of up-regulated IL 2 receptor expression on an in vitro cloned BCL1 subline.

We have established BCL1 CL-3 cells capable of responding to B15-TRF and interleukin 2 (IL 2). This clone has both high affinity and low affinity receptors for IL 2 (IL 2R), but IL 2 by itself did not stimulate either proliferation or immunoglobulin (Ig) secretion. B15-TRF, which possesses both growth and differentiation activity, causes an increase in size of CL-3 cells and renders CL-3 cells responsive to IL 2, including an increased expression of IL 2R (eight-fold to 10-fold) and the differentiation of CL-3 cells into Ig secretion (60 to 80% of cultured cells). CL-3 cells pretreated with B15-TRF for 12 hr become competent to respond to IL 2 by up-regulation of IL 2R within 12 hr. In contrast CL-3 cells pretreated with IL 2 for 12 hr required 24 hr B15-TRF stimulation to result in IL 2R up-regulation. Thus the ordered action of B15-TRF and IL 2 is the most effective operational pathway for the up-regulation of IL 2R. This IL 2-mediated IL 2R up-regulation and induction of Ig synthesis depends upon the concentration of IL 2 in the culture. Both responses seem to be caused by IL 2 molecules bound to high affinity IL 2R. However, the possibility of involvement of low affinity IL 2R can not be vigorously excluded. In fact the level of IL 2 required for a response is far higher than that needed for activated T cell proliferation. This cloned BCL1 subline promises to be a useful tool for studying the regulation and mechanisms of B cell responses.

Animals↗
PubMed1987

Sequence analysis of the Brevibacterium lactofermentum trp operon.

Brevibacterium lactofermentum, a Gram-positive bacterium, is a commercially important amino acid producer. In this organism, the tryptophan biosynthetic enzymes are encoded within a 7725 bp HapII-BamHI fragment. Seven open reading frames were identified as trp genes by complementation tests with various B. lactofermentum and Escherichia coli tryptophan auxotrophs. Following the nomenclature established for E. coli and Serratia marcescens, the B. lactofermentum trp genes were designated trpL, trpE, trpG, trpD, trpC (including the trpF domain), trpB, and trpA. The organization of these genes is identical to that in S. marcescens. The nucleotide sequences of the putative ribosome-binding sites for the B. lactofermentum trp genes resemble those of E. coli and Bacillus subtilis. Computer analysis revealed that the trp enzymes of B. lactofermentum resemble the enzymes of the Gram-negative E. coli more closely than those of the Gram-positive B. subtilis.

Amino Acid Sequence↗
PubMed1987

Structure and function of the trp operon control regions of Brevibacterium lactofermentum, a glutamic-acid-producing bacterium.

The trp genes of Brevibacterium lactofermentum lie within a 7.72-kb HapII-BamHI fragment whose sequence has been determined (Matsui et al., 1986). The 5'- and the 3'-flanking regions of this gene cluster were subcloned as a 1.8-kb PstI-PstI and a 0.6-kb XhoI-BamHI fragment, respectively. The 5'-flanking region encodes two open reading frames (ORFs); one corresponds to trpL, while the other corresponds to the N-terminal half of the trpE gene. Within the 17 amino acid residues of the predicted leader peptide encoded by trpL are found three contiguous tryptophan residues. By subcloning parts of the 1.8-kb PstI-PstI fragment into promoter probe vectors, a promoter situated 32 bp upstream from the presumptive trpL gene was identified. The -35 and the -10 region of this promoter, TACACA and AATAAT, respectively, are very similar to the Escherichia coli trp promoter. The trp promoter of B. lactofermentum functions in E. coli. A 14-bp imperfect palindrome that overlaps the -10 region apparently functions in B. lactofermentum but not in E. coli as a trp operator. Upstream of trpE, attenuator-like sequences are found that resemble the corresponding E. coli sequences. The 0.6-kb XhoI-BamHI 3'-flanking fragment contains one ORF that encodes the C-terminal part of trpA. Downstream from trpA lies a Rho-independent terminator that resembles E. coli sequences that are situated downstream from the E. coli trp operon. Thus the trp control regions of the Gram-positive B. lactofermentum are more closely related in structure to the corresponding regions of the Gram-negative E. coli than to those of the Gram-positive Bacillus subtilis.

Base Sequence↗
PubMed1987

Formation of roseoflavin from 8-amino- and 8-methylamino-8-demethyl-D-riboflavin.

A synthesis of roseoflavin (RoF) by Streptomyces davawensis from 8-amino- (AF) and 8-methylamino-8-demethyl-D-riboflavin (MAF) was demonstrated. The lines of evidence are: 1) the RoF formation was increased by addition of AF or MAF to the culture, 2) [2-14C]RoF was formed by addition of [2-14C]AF or [2-14C]MAF to the culture, and the location of the 14C atom at the 2-position was demonstrated by identifying [14C]urea in the hydrolysate of the RoF, 3) [N-methyl-14C]RoF was formed by addition of [methyl-14C]methionine to the culture containing AF or MAF, and the location of the 14C atom was confirmed by the photochemical conversion of the RoF to MAF, the specific radioactivity of which was about half that of the original RoF, and by localization of the 14C atom in 1,2-dihydro-6-methyl-7-dimethylamino-2-keto-1-ribityl-3-quinoxalinecarbo xylic acid (QC), which was formed from the RoF by hydrolysis.

Chromatography, Thin Layer↗
PubMed1987

Two single-base-pair substitutions causing desensitization to tryptophan feedback inhibition of anthranilate synthase and enhanced expression of tryptophan genes of Brevibacterium lactofermentum.

A 5-fluorotryptophan-resistant mutant, termed 1041, was isolated from Brevibacterium lactofermentum AJ12036. The anthranilate synthase of 1041 was insensitive to feedback inhibition by tryptophan, and the specific activities of the anthranilate synthase and anthranilate phosphoribosyltransferase of 1041 were 29- and 23-fold higher than those in parental strain AJ12036, respectively. A single-base change (adenine to cytosine) that resulted in a Ser-to-Arg substitution was found in the trpE structural gene of 1041. This substitution was identified as the cause of the desensitization to feedback inhibition by tryptophan of anthranilate synthase in 1041. Another substitution (guanine to adenine) was found at a position in which a mutation would destabilize the rho-independent terminator structure within the putative attenuator. The enhanced synthesis of tryptophan enzymes in 1041 could be caused by this substitution in the attenuator.

Amino Acid Sequence↗
PubMed1987

A rapid bioassay for quantification of atrial natriuretic polypeptides.

A quantitative bioassay for the detection and quantification of atrial natriuretic polypeptides (ANPs) was developed in a pentobarbital-anesthetized rat. Ten percent mannitol in 0.9% saline was infused to achieve stable diuresis. The conductivity of the urine, urine flow, and blood pressure were continuously recorded. A bolus injection of synthetic alpha-human atrial natriuretic polypeptide (alpha-hANP) elicited dose-dependent increases in the urine conductivity, sodium excretion, and urine volume. Changes in the urine conductivity correlated significantly with the increase in sodium excretion. By use of changes in urine conductivity, biological ANP activity of crude rat atrial extract was determined. Atrial contents of ANP in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were 25.5 +/- 1.2 microgram per atrium (n = 4) and 25.1 +/- 0.8 (n = 5) in euhydration. They were increased to 27.0 +/- 1.1 micrograms (n = 4) and 29.3 +/- 1.3 (n = 5, P less than 0.05), after 5-day water deprivation, respectively. This assay procedure provides a good tool for rapid and quantitative determination of ANPs.

Animals↗
PubMed1987

Responses of vasopressin and enkephalins to hemorrhage in adrenalectomized dogs.

To study responses of methionine enkephalin-like substance (MELS) and vasopressin (AVP) to hemorrhage, plasma MELS, AVP, and catecholamine levels and mean arterial blood pressure (MAP) and central venous pressure (CVP) were investigated in intact and adrenalectomized dogs (n = 34) under pentobarbital anesthesia. Plasma MELS increased significantly following a hemorrhage-induced rise in plasma epinephrine in intact dogs (n = 6). Plasma AVP rose concomitantly with a fall in CVP before MAP fell, but the subsequent fall in MAP was accompanied by a further elevation in plasma AVP concentration. In nonhemorrhaged control dogs (n = 6) these parameters did not change during the experiment. In adrenalectomized dogs (n = 6) the hemorrhage-induced increase in plasma MELS and AVP was significantly attenuated despite similar decreases in MAP as in intact dogs. In sham-operated dogs (n = 10) changes in these parameters were similar to those in intact dogs. The differences between plasma MELS in the superior vena cava and thoracic aorta did not change during hemorrhage in intact dogs (n = 6), but the differences in plasma AVP rose significantly, indicating a release of the hormone from the head. These results indicate that MELS release elicited by hemorrhage may largely arise from the adrenal gland and not the brain. Adrenalectomy attenuated AVP response to hemorrhagic hypotension.

Adrenalectomy↗
PubMed1987

Nephritogenicity of anti-Engelbreth-Holm-Swarm sarcoma antibody.

We have examined the antibody activity and nephritogenicity of anti-Engelbreth-Holm-Swarm (EHS) sarcoma antiserum in order to analyze the pathogenesis of the EHS nephropathy which has already been reported by us. An increased amount of urine protein was not recognized in rats injected with a large quantity of anti-EHS sarcoma antiserum. In addition, rats immunized with rabbit IgG before anti-EHS sarcoma antiserum injection developed no abnormal proteinuria, despite positive fluorescent staining for rat IgG as well as rabbit IgG in the glomeruli. From these results we concluded that nephritogenic antibodies could not be produced in rabbits by immunization with EHS sarcoma, which could induce the EHS nephropathy in an active model.

Animals↗
PubMed1987

Effects of centrally administered atrial natriuretic peptide on renal functions.

In order to assess the effects of centrally administered atrial natriuretic peptide (ANP) on renal water and electrolytes handling, arterial blood pressure, plasma vasopressin, renin activity, aldosterone, and ANP concentrations, synthetic alpha-human ANP (alpha-hANP) was administered intracerebroventricularly at a dose of 2.6 pmol.kg-1.min-1 for 30 min in pentobarbital-anaesthetized dogs (N = 6). In the control study (N = 6), artificial cerebrospinal fluid was infused. Intracerebroventricular administration of alpha-hANP increased significantly urine flow from 178 +/- 37 to 303 +/- 43 microliter/min (mean +/- SEM), sodium excretion from 27.3 +/- 8.9 to 54.4 +/- 10.5, mumol/min, potassium excretion from 16.1 +/- 3.7 to 24.0 +/- 5.1 mumol/min, and osmolar and negative free water clearances, accompanied by a significant rise in renal blood flow from 77.0 +/- 14.6 to 94.9 +/- 16.9 ml/min. Whereas glomerular filtration rate fell significantly, blood pressure and heart rate did not change. Plasma ANP, aldosterone, and PRA did not change significantly during the experiment, but plasma AVP were slightly but significantly decreased from 52 +/- 11 to 34 +/- 6 nmol/l. On the other hand, these parameters showed no changes in the control study, except a significant fall in glomerular filtration rate and a significant rise in PRA. Thus, it has been confirmed that ANP centrally brings about diuresis, natriuresis, and kaliuresis via some unknown mechanisms independent of the release of these hormones.

Aldosterone↗
PubMed1987

The effect of short-lasting atrial pacing on the release of atrial natriuretic peptide, vasopressin, and methionine enkephalin in man.

In order to study the effect of atrial tachycardia on the release of atrial natriuretic peptide (ANP), AVP, and methionine enkephalin (M-Enk), plasma concentrations of these peptides in the right ventricle were determined in patients with various arrhythmias (N = 10) during cardiac catheterization and incremental atrial pacing. Each pacing (100 per min, the maximum rate for 1:1 atrioventricular conduction, and 200 per min) lasted 4 to 5 min. Plasma ANP was significantly increased from 53.1 +/- 12.2 in the resting condition to 168.9 +/- 59.9 pmol/l at a pacing rate of 200 beats per min (P less than 0.05); plasma AVP tended to decrease, but not significantly, and plasma M-Enk did not change at all. Pulse pressure in the right atrium (PPRA) and mean right atrial pressure (MRAP) tended to increase during the pacing, and at the rate of 200 beats per min PPRA was significantly higher than at the rate of 100 beats per min. Mean arterial blood pressure, plasma osmolality, and plasma sodium and potassium concentrations did not change significantly. There were significant correlations between plasma ANP and PPRA, MRAP and heart rate. These results indicate that atrial pacing stimulates ANP release with a rise in right atrial pressure, but does not influence M-Enk and AVP releases.

Adult↗
PubMed1987

Nonsurgical collection of embryos in Shiba goats.

A method of nonsurgical embryo collection in the Shiba goat, a native Japanese miniature goat breeding nonseasonally, was developed. The apparatus used for flushing the uterus was made on the model of the two-way catheter for cows. Embryo collection was performed on days 5 to 7 in 37 females superovulated with PMSG and hCG and resulted in successful recovery of 69 embryos in 19 females (51.4%). The average number of embryos collected from each successful female was 3.6. The recovery rate of embryos calculated on the basis of the number of embryos recovered and corpora lutea observed by culdoscopy in 15 successful females was 89.5%. This nonsurgical method seem to be efficient enough for collecting morulae and blastocysts in Shiba goats.

Animals↗
PubMed1987

[Fundamental study on ataxic mice (wriggle mouse Sagami)].

Wriggle mouse Sagami (WMS), a newly discovered BALB/C mouse strain, is characterized by its locomotor instability, abnormal gait pattern and neck wriggling. Although the growth of WMS mice is delayed, compared with normal BALB/C mice, the brain size corresponds to the relatively smaller body weight. In gross or histological examinations no local atrophy appears in the cerebrum, cerebellum, brain stem or spinal cord. The c-GMP level in the WMS cerebellum is decreased, but the c-AMP level is normal. The ataxic gait is not improved significantly by the administration of thyrotropin releasing hormone (TRH). These results indicate that the mechanism inducing ataxia and abnormal gait pattern in WMS may be different from those in other genetically-determined ataxic mice, e. g., Rolling mouse Nagaya (RMN), PCD, Staggerer and Reeler.

Animals↗
PubMed1987

Sonography for early diagnosis of enlarged parathyroid glands in patients with secondary hyperparathyroidism.

High-resolution sonography of the neck was performed in 207 patients undergoing renal dialysis to determine the usefulness of sonography in the evaluation of secondary hyperparathyroidism. The sonograms in 62 (30%) of the patients showed enlarged parathyroid glands, with an average of 2.3 glands per patient. Both the number and size of enlarged glands were increased in patients who had been receiving dialysis treatment for more than 6 years. Of the patients who had enlarged parathyroid glands on sonography, only 61% had bone pain, and only 63% had evidence of hyperparathyroidism on bone radiographs. Serum levels of amino-terminal parathormone were within normal limits in 26% of these patients. In 14 patients who underwent total parathyroidectomy, the accuracy of sonography for the detection of enlarged parathyroid glands was 77% (40/52 lesions). Sonography is a valuable technique for the detection of enlarged parathyroid glands in patients with secondary hyperparathyroidism associated with renal dialysis.

Adult↗
PubMed1987

Theca lutein cysts with maternal virilization and elevated serum testosterone in pregnancy.

A clinicopathological study was performed on a pregnant patient with bilateral multiple ovarian cysts, who presented with pre-eclampsia, marked virilization and exceedingly high levels of serum testosterone. The female fetus showed no evidence of virilization. Microscopic examination of the ovaries revealed theca lutein cysts with granulosa cells which showed the existence of testosterone by immunoperoxidase staining.

Adult↗