Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 667 records · Page 37Linked to original sources

PubMed1988

High-level expression of human BSF-2/IL-6 cDNA in Escherichia coli using a new type of expression-preparation system.

BSF-2 (B cell stimulatory factor-2/IL-6) is a member of the lymphokine family and responsible for B cell differentiation. Expression plasmids of human BSF-2 cDNA were constructed using a trp promotor/operator and a trpA terminator. In an extract of Escherichia coli HB101 holding "direct" expression plasmid pBSF-2D, activity of BSF-2 was detected, but overproduction was not observed. A "fused" expression system was therefore developed to prepare the recombinant protein. In this system, cDNA was expressed as a fused protein with human IL-2 N-terminal peptide. In the case of the fused BSF-2 expression plasmid, pBSF-2F, inclusion bodies were observed and overproduction of the protein occurred. As this fused protein had a Phe-Arg-Ala sequence at the junction of hIL-2 and BSF-2, it was possible to process mature BSF-2 from the fused BSF-2 by treatment with kallikrein and aminopeptidase P. From 1 liter of E. coli culture, 45 mg of mature BSF-2 was purified; it had a relative biological activity equal to that of natural BSF-2 purified from T cells.

Amino Acid Sequence↗

PubMed1988

The appearance of a highly digitalis-sensitive isoform of Na+,K+-ATPase during maturation in vitro of primary cultured rat cerebral neurons.

Immature neurons from the cerebra of 17-day rat fetuses were cultured, and changes in Na+, K+-ATPase activity of the cells were investigated during maturation in culture. The Na+, K+-ATPase activity of the particulate fraction from the cells increased during the course of culture, up to 0.38 +/- 0.01 (mumol/min/mg protein) (= 8.25 +/- 0.85 (mumol/min/mg DNA] by day 13 in culture. The values were more than 3 and 19 times those of the 17-day fetal cerebrum on the bases of protein and DNA, respectively. The enzyme in the immature neurons was mainly a weakly digitalis-sensitive form in terms of the inhibition pattern of the Na+,K+-ATPase activity by strophanthidin. Along with the maturation in vitro of the neurons, a highly digitalis-sensitive form of the enzyme was shown to appear and increase by the biphasic inhibition patterns of Na+,K+-ATPase activity by strophanthidin and of K+ uptake activity by ouabain. The enzyme activity of the highly sensitive form overwhelmed that of the weakly sensitive form by day 13 in culture. In cultured rat cerebral astrocytes, the enzyme was judged to be only the weakly digitalis-sensitive form from the simple inhibition patterns of the Na+,K+-ATPase and K+ uptake activities by digitalis.

Brain↗

PubMed1988

Nerve growth factor induces Na+,K+-ATPase in a nerve cell line.

The effects of nerve growth factor (NGF) on induction of Na+,K+-ATPase were examined in a rat pheochromocytoma cell line, PC12h. Na+,K+-ATPase activity in a crude particulate fraction from the cells increased from 0.37 +/- 0.02 (n = 19) to 0.55 +/- 0.02 (n = 20) (means +/- SEM, mumol Pi/min/mg of protein) when cultured with NGF for 5-11 days. The increase caused by NGF was prevented by addition of specific anti-NGF antibodies. Epidermal growth factor and insulin had only a small effect on induction of Na+,K+-ATPase. A concentration of basic fibroblast growth factor three times higher than that of NGF showed a similar potency to NGF. The molecular form of the enzyme was judged as only the alpha form in both the untreated and the NGF-treated cells by a simple pattern of low-affinity interaction with cardiotonic steroids: inhibition of enzyme activity by strophanthidin (Ki approximately 1 mM) and inhibition of Rb+ uptake by ouabain (Ki approximately 100 microM). As a consequence, during differentiation of PC12h cells to neuron-like cells, NGF increases the alpha form of Na+,K+-ATPase, but does not induce the alpha(+) form of the enzyme, which has a high sensitivity for cardiotonic steroid and is a characteristic form in neurons.

Adrenal Gland Neoplasms↗

PubMed1988

Age-related changes in regional cerebral blood flow and brain volume in healthy subjects.

Using the xenon-133 inhalation method, we studied the age-related decline in regional cerebral blood flow, calculated as the initial slope index (ISI), in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (154 men and 123 women), ranging in age from 19 to 88 years. The decline in the ISI was rapid in younger age groups and gradual in older age groups. The ISI was higher in women than in men older than 40 years. Using computed tomography, we studied the age-related decline in brain volume index (BVI; 100% X brain volume/cranial cavity volume) in neurologically normal subjects without any risk factors for cerebral arteriosclerosis (92 men and 49 women), ranging in age from 37 to 86 years. The decline in the BVI was gradual in younger age groups and rapid in older age groups. The BVI was higher in women than in men older than 60 years.

Adult↗

PubMed1988

Penetration of cefpiramide and cefazolin into peritoneal capsular fluid in rabbits.

Penetration of cefpiramide and cefazolin into a specific extravascular fluid was measured with rabbits bearing capsules in the peritoneal cavity. A general feature of slow accumulation and elimination of drugs from extravascular sites having low surface area/volume ratios has also been observed in this study. The capsular concentration-time profiles were well expressed by the following equation: C(CF) = A(CF)[e-kel(CF)(t-to)-e-kp(CF)(t-to)], where C(CF), A(CF), kp(CF), kel(CF), and to indicate capsular concentration at time t, constant for the dimension of concentration, capsule penetration rate constant, capsule elimination rate constant, and lag time before penetration occurs, respectively. The kp(CF), kel(CF), and to were 0.139 h-1, 0.059 h-1, and 0.45 h, respectively, for cefpiramide, and 0.448 h-1, 0.0145 h-1, and 0.14 h, respectively, for cefazolin. A(CF) was 22.7 micrograms/ml for cefpiramide and 4.53 micrograms/ml for cefazolin, being parallel to the area under the plasma concentration-time curve for free drug from to to infinity (20.1 micrograms.h/ml for cefpiramide and 3.43 micrograms.h/ml for cefazolin). In conclusion, it is suggested that as well as kp(CF) and kel(CF), the area under the plasma concentration-time curve for free drug from to to infinity may play an important role regarding the circulating reservoir of drugs in determining capsular concentration-time profiles in experimental models for particular extravascular sites of infection, like abscesses into which drugs cannot easily penetrate.

Animals↗

PubMed1988

Renal tubular mechanisms for excretion of cefpiramide (SM-1652) in association with its long-lasting pharmacokinetic properties.

To investigate possible mechanisms for the long-lasting pharmacokinetic properties of cefpiramide, pharmacokinetic and renal clearance studies were carried out using rabbits. Cefazolin was employed as a reference compound. In pharmacokinetic studies, the plasma half-life (t1/2 beta) for cefpiramide was 2.7 times as long as that for cefazolin. The total body clearance (ClT) and renal clearance (ClR) for cefazolin were approximately 2.3 times larger than those for cefpiramide. In renal clearance studies, the clearance by glomerular filtration (Clf) for cefpiramide exceeded Clf for cefazolin by 2.5 times, because of lower plasma protein binding of cefpiramide. In contrast, the clearance by tubular secretion (Cls) for cefpiramide was one-fifth as small as Cls for cefazolin. The overall renal clearance (Clr) for cefazolin was 3.6 times as large as Clr for cefpiramide, being in good agreement with the cefazolin/cefpiramide ratios of ClT and ClR. Therefore, the long-lasting pharmacokinetic properties of cefpiramide was suggested to be due to the fact that cefpiramide undergoes renal tubular secretion to less extent.

Animals↗

PubMed1988

In vivo effects of thyroid hormone, glucocorticoid, androgen, and somatotropin on RNA polymerase I activities in isolated liver nuclei.

In the 'template-engaged' form activity of RNA polymerase I in nuclei of normal rat livers, about 40% of the activity was found to be influenced by thyroid hormones and glucocorticoids and can be eliminated by 1 h treatment with cycloheximide. On the other hand, the 'free' form activity of the enzyme in rat liver nuclei and the total amount of the enzyme in nucleoli were scarcely affected by these hormones. These results suggest that a considerable portion of rRNA synthesis in rat liver nucleoli is regulated by the initiation of rDNA transcription, probably with the participation of glucocorticoid- and thyroid hormone-dependent short-lived protein(s). When somatotropin, in addition to glucocorticoids and thyroid hormones, was depleted by hypophysectomy, the 'template-engaged' form activity of RNA polymerase I was reduced to 30% of the normal level. The activity was restored completely by a single injection of triiodothyronine plus somatotropin, but not by injections of the individual hormones. From these results, it is likely that the stimulating effects of glucocorticoids and thyroid hormones on rRNA synthesis are maintained by the action of somatotropin which seems to occur in a different mechanism from those of the former two hormones. In contrast to these hormones, androgen showed no acute effect on 'template-engaged' form activity of RNA polymerase I in liver nuclei.

Adrenalectomy↗

PubMed1988

Antihypertensive effect of NKY-722, a new water-soluble 1,4-dihydropyridine derivative, on conscious spontaneously hypertensive rats.

3-(4-Allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridine dicarboxylate dihydrochloride (NKY-722) produced a dose-dependent antihypertensive effect in conscious spontaneously hypertensive rats (SHR). In this respect NKY-722 was more potent and longer-acting than nicardipine. In canine isolated mesenteric arteries, exposed to a Ca2+-free medium containing high K+, NKY-722 inhibited Ca2+-induced contraction in concentration-dependent manner, suggesting the calcium antagonism as the mechanism of action.

Animals↗

PubMed1988