Biomedical subjects

N Matsui

Publications and source records attributed to N Matsui.

At least 163 records · Page 9Linked to original sources

PubMed1991

Hyperbaric diuresis is associated with decreased antidiuretic hormone and increased atrial natriuretic polypeptide in humans.

When men are exposed to a hyperbaric environment, urine flow increases. In order to elucidate the mechanism of this hyperbaric diuresis, a dry saturation dive experiment was carried out. Five male subjects were exposed to a 16-21 ATA (atmospheric pressure absolute) helium-oxygen (He-O2) environment for 4 days. Five blood samples were obtained in the early morning (0600-0630 h): once at predive 1 ATA air, 3 times at 16-21 ATA He-O2, and once at postdive 1 ATA air. Eight-hour timed urine samples, 0600-1400 h, 1400-2200 h, and 2200-0600 h (night urine), were collected throughout the experimental period. Urine flow markedly increased by the exposure to hyperbaria in the presence of constant creatinine clearance. The increase was mostly attributable to the urine flow during 2200-0600 h. The secretion of antidiuretic hormone (ADH) was suppressed at daytime and night during the exposure. On the other hand, the secretion of atrial natriuretic polypeptide (ANP) increased solely at night during hyperbaria and correlated with the increases of both the nocturnal urine flow and the nocturnal urinary excretion of sodium. These results suggest that both suppressed ADH secretion and stimulated ANP secretion cause hyperbaric diuresis.

Adult↗

PubMed1991

Superinduction of cytotoxic interferon-beta in glioma cells.

The possibility for new interferon therapy was investigated using the effect of endogenous human interferon-beta (HuIFN-beta) on various culture cell lines. Cell lines were exposed to superinduction agents (poly I: poly C, cycloheximide, and actinomycin D) and the production of endogenous interferon analyzed. Quantitative determination of HuIFN-beta and messenger ribonucleic acid (mRNA) showed HuIFN-beta was induced in all of five glioma cell lines, one of two melanoma cell lines, and all of three lung carcinoma cell lines as well as fibroblasts. Northern blot analysis showed HuIFN-beta mRNA induced in glioma cells was identical to that from fibroblasts. Endogenous HuIFN-beta induced from glioma cells had a cytostatic or cytocidal effect against various human glioma cell lines, even those resistant to fibroblast-derived HuIFN-beta. These results show it may be possible to use the induction of excess endogenous cytotoxic HuIFN-beta in human glioma tissue itself.

Fibroblasts↗

PubMed1991

[Comparison of two hours' biofiltration and four hours' bicarbonate hemodialysis by multiple clinical parameters].

Ten uremic patients maintained stable on regular dialysis treatment participated in a comparison study of 2 hours' biofiltration and 4 hours' bicarbonate hemodialysis with informed consents. In biofiltration, ultrafiltrate was replaced by a solution consisting of Na 145 mEq/l, HCO3- 100 and Cl 45 at the infusion rate 2.51/hour. Dialysate composition was Na 130-149 mEq/l, K 1.0, Cl 119, Ca 2.5, Mg 0.5, CH3COO- 15 and glucose 200 mg/dl. Hemodiafilter was F80, polysulphone, 1.9 m2, manufactured by Fresenius Co. Ltd. Blood flow rate was 5 ml/min/kg.body.weight to keep urea index (Kt/V) over 1.0. B-A-B' comparison was designed in which B and B' stand for 4 hours' bicarbonate hemodialysis while A for 2 hours' biofiltration, 3 times per week for 2 months, respectively. It was intended to find out if there are aggravations of clinical parameters in A after B and/or improvements in B' after A in view of evaluation of optimum for 2 hours' biofiltration. One patient was withdrawn from biofiltration at 15th treatment in A because of frequent muscular twitchings. Others finished the whole program, thus making drop-out rate 10%. No significant differences were observed in the following parameters between B and A and between A and B': cardiothoratic ratio, pre-treatment blood pressure, human atrial natriuretic hormone, cardiovascular dynamics, total protein, BUN, serum creatinine, uric acid, beta 2 microglobulin, blood counts, blood gas analysis, electrolytes, alkaline-phosphatase, PTH-C, protein catabolic rate (PCR), lipids and liver functions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

[Polymorphonuclear leukocyte elastase (PMNE) levels in surgical patients with postoperative infections].

To study the role of lysozomal enzyme released from polymorphonuclear leukocytes during postoperative infections, plasma levels of PMNE were measured serially in 53 patients who underwent digestive surgery. The patients were divided into two groups, 18 patients with postoperative infections (infected group), and 35 patients without infections (non-infected group). The PMNE levels in the non-infected group elevated during one week with peak value in one postoperative day, but returned to preoperative levels in two weeks. The levels of fibronectin (FN), C3, C4 and antithrombin III (ATIII) were decreased after surgery, but returned within seven postoperative days. On the contrary, the PMNE levels in the infected group remained high two weeks after operations and elevated higher than those of non-infected group before clinical signs of infections. In infected group, the levels of FN and ATIII were significantly decreased two weeks after surgery, compared to those of non-infected group. Correlations were demonstrated between the amount of PMNE and the decrease in the levels of FN and ATIII. It is suggested PMNE might play a role in the pathobiochemical alterations including of acceleration of coagulation during postoperative infections. The measurement of the levels of PMNE in the postoperative course seems to be an useful index to early diagnosis of postoperative infections.

Aged↗

PubMed1990

Ultrasonic level diagnosis of lumbar disc herniation.

Although the use of diagnostic ultrasound to measure the spinal canal has been proposed, the value of ultrasound for lumbar disc herniation has not been yet fully assessed. The purpose of this investigation was to evaluate the effectiveness of ultrasound in the level diagnosis of herniated nucleus pulposus. Prospective ultrasound examinations were performed on 80 consecutive patients with clinically suspected lumbar disc herniation. In 41 discs of those 40 patients with surgically confirmed lumbar disc herniation, there were 32 discs (78%) with true-positive ultrasound diagnoses, 37 discs (90%) with true-positive myelographic diagnoses, and 20 patients (50%) with true-positive neurologic diagnoses. Conversely, ultrasound diagnoses showed positive echogram in 24 (60%) of 40 nonoperative patients. These results suggest that ultrasound is of value as an aid for diagnosing the level of lumbar disc herniation.

Adolescent↗

PubMed1990

Adrenocorticotropin increases expression of c-fos and beta-actin genes in the rat adrenals.

It is widely accepted that expression of protooncogenes is coupled with cellular proliferation and differentiation. Since ACTH stimulates not only steroidogenesis but also cellular proliferation, we investigated whether ACTH affects the expression of c-fos, c-myc, and beta-actin genes. The effect of ACTH on adrenal glands was studied in hypophysectomized rats. Changes in the mRNA levels were studied by Northern and dot blot analyses. It was demonstrated that ACTH induces increases in mRNAs encoding c-fos and beta-actin in adrenal glands of hypophysectomized rats. When stimulated by ACTH (5 IU/100 g BW), the mRNA levels of both genes increase rapidly; the maximum levels are observed at 30 min for c-fos and 6 h for beta-actin. Both mRNAs declined to near-control levels by 6-24 h. The levels of mRNAs encoding cholesterol side-chain cleavage cytochrome P-450 and 21-hydroxylase cytochrome P-450 began to increase 3 and 12 h after ACTH administration, respectively. This increase continued for 24 h after ACTH treatment. Increases in total adrenal RNA and adrenal weight occurred slowly after ACTH treatment. On the other hand, the levels of c-myc mRNA were very low and were not increased by ACTH administration. These results suggest that increased expression of c-fos and beta-actin genes by ACTH may have important roles in mediating its action on adrenals.

Actins↗

PubMed1990

Combined 17 alpha-hydroxylase/17,20-lyase deficiency due to a 7-basepair duplication in the N-terminal region of the cytochrome P45017 alpha (CYP17) gene.

17 alpha-Hydroxylase deficiency is characterized by defects in either or both of the 17 alpha-hydroxylase/17,20-lyase activities. We have elucidated the molecular basis of the combined deficiency of these activities in a Japanese female who is genotypically male and the child of a consanguineous marriage. The complete exonic sequence of the patient's CYP17 (P45017 alpha) gene revealed a seven-basepair duplication (GCGCACA) in exon 2 which leads to a frame shift and, subsequently, a premature stop codon. Because this stop codon occurs N-terminal to the heme-binding sequence, the presence of this mutation leads to the absence of a functional P45017 alpha-protein in adrenal cortex and testis. This, in turn, leads to an absence of sex steroids and excessive secretion of steroids with mineralocorticoid activity and, consequently, female external genitalia and hypertension in this 46XY patient.

Adolescent↗

PubMed1990

Specific induction of fibronectin gene in rat liver by thyroid hormone.

The regulation of fibronectin (FN) gene expression by thyroid hormone was studied. Rats were rendered hypothyroid by thyroidectomy, and the administration of T4 or T3 was used to produce rats in various thyroid states. RNA was extracted from fresh liver, kidney, and heart, and FN mRNA was determined by dot blot hybridization with a 32P-labeled rat FN cDNA probe. The specificity of the hybridization was assessed by Northern blot analysis. In liver, thyroidectomy decreased the abundance of FN mRNA by half, and daily administration of physiological doses of T4 or T3 for 5-6 days restored FN mRNA to the control level. The administration of pharmacological doses of thyroid hormones induced a further increase in the abundance of FN mRNA. A significant dose-dependent correlation between serum levels of T4 and the abundance of FN mRNA was observed in liver. A receptor-saturating dose of T3 (200 micrograms) given to thyroidectomized rats produced a significant increase in FN mRNA within 6 h after injection, indicating that expression of the FN gene was induced relatively rapidly. Moreover, a nuclear run-off assay revealed that thyroid hormone induces expression of the FN gene at least in part at a transcriptional level. The amount of FN mRNA was also determined in kidney and heart of the same rats. Although the abundance of FN mRNA changed by thyroidectomy or the administration of thyroid hormone in those organs, the magnitude of changes were slight compared with those observed in liver. These results suggested that a marked and dose-dependent induction of the FN gene by thyroid hormone occurs specifically in liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Mechanisms of atrial natriuretic peptide (ANP) secretion by rat hearts perfused in vitro--Ca2(+)-dependent signal transduction for ANP release by mechanical stretch.

Effects of temperature, contraction frequency, and intraatrial pressure on immunoreactive ANP release were investigated in isolated rat hearts perfused in Langendorff or working mode. A reduction of temperature from 37 C to 27 degrees C caused a decrease of ANP release by 64% indicating its marked temperature-dependency (Q10 = 2.92). An increase of atrial contraction frequency from 300 to 500/min in Langendorff-perfused hearts did not cause a significant change in the ANP release. An elevation of left atrial filling pressure of working hearts from 8 to 18 and 28 cmH2O was associated with pressure-dependent, and reversible increase of the ANP release. This pressure-induced release of ANP was inhibited in a low calcium (50% Ca2+) medium or by nifedipine (10(-7) M). N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W-7, 10(-7)M), a potent calmodulin inhibitor, or ryanodine (10(-8)M) had similar inhibitory action against the pressure-induced increase of ANP release. These results indicate that ANP secretion is primarily regulated by mechanical stretch or distension of the atrial wall, while the atrial contraction frequency is less important as a physiological stimulus for the secretion. The stretch-induced ANP secretion may require an influx of calcium through the voltage-dependent Ca2+ channels. It was also suggested that Ca2+ release from the sarcoplasmic reticulum leading to an activation of calcium-calmodulin kinase may be included in the intracellular processes of ANP release by mechanical stretch.

Animals↗

PubMed1990

Age-related changes in growth hormone and prolactin messenger RNA levels in the rat.

Growth hormone (GH) secretion declines with age, while prolactin (PRL) secretion increases in rats. The age-related changes in the pituitary GH and PRL mRNA levels in the Wistar Tw rat were studied at 6, 12 and 18 months of age by cytoplasmic dot hybridization. Hormone and mRNA concentrations were expressed as values per micrograms GH-cell or PRL-cell DNA. Concurrent decrease in GH concentrations and GH mRNA concentrations with age was observed in female rats, but not in male rats. GH mRNA concentrations (per microgram GH-cell DNA) in male rats at 12 and 18 months of age were 88 and 66% of those at 6 months of age, but there was no difference. GH mRNA concentrations in female rats at 12 and 18 months of age were 51 and 53% of those at 6 months of age. A concurrent decrease in PRL concentrations and PRL mRNA concentrations was observed in both male and female rats. PRL mRNA concentrations (per microgram PRL-cell DNA) in male rats at 12 and 18 months of age were 37 and 18% of those at 6 months of age. PRL mRNA concentrations in female rats at 12 and 18 months of age were 51 and 31% of those at 6 months of age. Pituitaries in 12- and 18-month-old females contained more PRL and PRL mRNA than those at 6 months of age. These increases in PRL and PRL mRNA contents may result from the increase in the number of PRL cells, although each PRL cell had less PRL and PRL mRNA. These results suggest that the age-related changes in pituitary GH and PRL levels occurred at the transcription level of GH and PRL syntheses, and that the age-related changes in GH-cell and PRL-cell populations are responsible for the changes in GH and PRL secretions.

Aging↗

PubMed1990

Alteration in the expression of genes for cholesterol side-chain cleavage enzyme and 21-hydroxylase by hypophysectomy and ACTH administration in the rat adrenal.

The changes in steady-state levels of mRNA for cholesterol side-chain cleavage cytochrome P-450 (P-450scc) and steroid 21-hydroxylase cytochrome P-450 (P-450c21) caused by hypophysectomy and ACTH treatment were determined in rat adrenals. Hypophysectomy caused marked decreases in adrenal weight and total RNA per gland. Administration of ACTH resulted in increases in adrenal weight and total RNA. A significant correlation between the amount of RNA and adrenal weight was observed. Both P-450scc and P-450c21 mRNAs were decreased by hypophysectomy and increased by ACTH treatment. P-450scc mRNA decreased to 20% and P-450c21 mRNA to 76% of control values 1 day after hypophysectomy. ACTH caused a significant increase in P-450scc mRNA after 3 h. However, a significant increase in P-450c21 mRNA was observed 12 h after administration of ACTH. These results are concordant with previous studies in vitro utilizing cultured adrenocortical cells. Moreover, the induction of steady-state levels of P-450scc mRNA was faster than that observed by other investigators in studies in vitro. These results may indicate that integrity of the adrenal gland in vivo is important for the action of ACTH.

Adrenal Glands↗

PubMed1990

Pro-opiomelanocortin gene expression in silent corticotroph-cell adenoma and Cushing's disease.

The silent corticotroph-cell adenoma (SCCA) is characterized by the presence of immunoreactive adrenocorticotropic hormone (ACTH) in the tumor tissue in patients without symptoms of Cushing's disease. To elucidate the pathophysiology of SCCA, the expression of pro-opiomelanocortin (a ACTH precursor) genes was studied in a patient with SCCA and in three patients with Cushing's disease. Pro-opiomelanocortin messenger ribonucleic acid (mRNA) was found in the SCCA tissue to a greater degree than in the adenomas of the patients with Cushing's disease. Northern blot analysis revealed that the size of pro-opiomelanocortin mRNA present in the SCCA tissue was indistinguishable from that in the adenomas associated with Cushing's disease. A ribonuclease mapping study indicated that there were no point mutations in the coding sequence of pro-opiomelanocortin mRNA present in the SCCA tissue. Because of the presence of pro-opiomelanocortin mRNA and immunoreactive ACTH in the adenoma tissue, it is proposed that translation of the mRNA and subsequent accumulation of ACTH precursor occurred in the SCCA. Thus, the absence of Cushing's disease symptoms in this SCCA could not be caused by abnormality in the coding sequence of the pro-opiomelanocortin gene or in ribonucleic acid processing. The occurrence of abnormality at or after the translational steps was strongly suggested.

Adenoma↗

PubMed1990

Prolactin gene expression in human growth hormone-secreting pituitary adenomas.

To elucidate the mechanism of hyperprolactinemia often observed in patients with growth hormone (GH)-secreting pituitary adenomas, the presence of immunoreactive prolactin (ir-PRL) and prolactin (PRL) messenger ribonucleic acid (mRNA) in the tumor tissue was examined by immunohistochemistry and cytoplasmic dot hybridization. Hyperprolactinemia was observed in three of 18 patients with GH-secreting adenoma. The tumor tissue was demonstrated to contain ir-PRL in nine patients and PRL mRNA in 13. The presence of ir-PRL in the tumor tissue was always associated with positive PRL mRNA, indicating production of PRL in GH-secreting tumors. Among the three patients with hyperprolactinemia, both ir-PRL and PRL mRNA was revealed in the tumor tissue of one, PRL mRNA but not ir-PRL was detected in the adenoma tissue of another, and neither PRL mRNA nor ir-PRL was found in the tumor tissue of the third. The association of hyperprolactinemia with the presence of both ir-PRL and PRL mRNA or PRL mRNA alone is indicative of PRL production and secretion. However, the absence of ir-PRL and PRL mRNA in the tumor tissue may indicate that hyperprolactinemia is caused by the suppression of PRL inhibitory factor due to hypothalamic dysfunction by the tumor mass. Thus, the study of PRL gene expression and immunohistochemistry in GH-secreting adenomas is valuable to understanding the pathophysiology of pituitary tumors.

Adenoma↗

PubMed1990

[Experimental study on maturational therapy of osteosarcoma cell].

We investigated the differentiation-inducing effects of dibutyryl cyclic AMP (dBc AMP) on several cultured osteosarcoma cell lines (DUNN, MOLONEY, OST, FBJ). 1. Cell growth rates of all the osteosarcoma cell lines were reduced by 3mM dBc AMP. 2. Both alkaline phosphatase activity and 45Ca2(+)-uptake were promoted by 3mM dBc AMP. 3. There was, in each cell line except for the OST cells, a marked enlargement of the cell processes under the light microscopic observation. At the electron microscopic level, there were also many findings indicating an increase in cell functions. These results suggest that the differentiation may be induced by cAMP in osteosarcoma cells, and that the differentiation therapy by cAMP-related drugs is promising for a clinical application.

Alkaline Phosphatase↗

PubMed1989

Arthroscopic versus open synovectomy in the rheumatoid knee.

We report the clinical and radiological results after arthroscopic synovectomy (41 knees) and open capsulosynovectomy (26 knees) in patients with rheumatoid arthritis, with an average follow-up of more than ten years. The clinical outcome was much the same in both groups, but there was gradual deterioration, especially after eight years. Radiological changes of osteoarthritis were worse in the knees treated by open capsulosynovectomy compared with the arthroscopic group. Arthroscopic synovectomy has many advantages and we believe that it is better than open capsulosynovectomy for patients with rheumatoid arthritis of the knee.

Adolescent↗

PubMed1989

The ontogeny of growth hormone in the human fetal pituitary.

To examine the ontogeny of growth hormone synthesis and secretion in human fetus, growth hormone messenger ribonucleic acid was measured in 11 pituitaries from fetuses of 16 to 27 weeks of gestation by hybridization of cytosol ribonucleic acid with complementary deoxyribonucleic acid labeled with phosphate 32. Pituitary growth hormone content and serum growth hormone, thyroxine, and cortisol concentrations were assessed by radioimmunoassay. Growth hormone messenger ribonucleic acid content in the fetal pituitary increased from the early midtrimester, reaching a level 15.3 times higher at 27 weeks of gestation than the value at 16 weeks. However, growth hormone content in the pituitary showed no evident change during 16 to 21 weeks of gestation and started to increase after 22 weeks. Serum concentration of growth hormone was variable but always greater than 50 ng/ml, and the maximal level was observed at 20 weeks of gestation (141 ng/ml). Although serum thyroxine concentration in the fetuses showed no correlation with pituitary growth hormone content or serum growth hormone concentration, serum concentration of cortisol was correlated positively with growth hormone content in the fetal pituitary. These results suggest that the maturation of the growth hormone synthesis and secretion system in the fetal pituitary occurs after 22 weeks of gestation and that cortisol may play some role in the ontogenesis of growth hormone.

Fetal Blood↗

PubMed1989

Potentiation of atrial natriuretic peptide-stimulated cyclic guanosine monophosphate formation by glucocorticoids in cultured rat renal cells.

1. The effect of steroid hormones on atrial natriuretic peptide (ANP)-stimulated cyclic guanosine monophosphate (cyclic GMP) formation was studied in cultured rat renal cells. 2. ANP increased cyclic GMP formation in a dose-dependent manner, while cyclic AMP was not changed by ANP. 3. Steroid hormones did not affect basal cyclic GMP levels in cultured rat renal cells. 4. Dexamethasone at 10(-8) M increased ANP (human and rat ANP)-stimulated cyclic GMP dose-dependently in cultured rat renal cells. Cortisol, corticosterone and aldosterone at a concentration of 10(-7) M also potentiated ANP-stimulated cyclic GMP formation, although triiodothyronine, oestradiol and testosterone were ineffective. Potentiation of ANP action by these steroids seems to parallel glucocorticoid activity. 5. Dexamethasone did not affect cyclic GMP formation stimulated by sodium nitroprusside which stimulates soluble guanylate cyclase in the cytosol. Therefore, the potentiating action of dexamethasone may be mediated through the action on particulate guanylate cyclase at the plasma membrane. 6. It is suggested that the diuretic action of glucocorticoids may, at least in part, be mediated through the potentiating effect of glucocorticoids on cyclic GMP response to ANP.

Animals↗

PubMed1989

Studies on the role of glycosylation for human corticosteroid-binding globulin: comparison with that for thyroxine-binding globulin.

The role of glycosylation on the secretion and the stability of human corticosteroid binding globulin (CBG) was studied. Cells of the human hepatoma line were labeled by [35S]methionine in presence of or absence of tunicamycin (TM). Media or cells were harvested at 0, 3, 6, and 20 h after the addition of excess unlabeled methionine. Media and cell lysates were incubated with anti-CBG serum and immune complexes were precipitated with Staphylococcus aureus protein A (Pansorbin). Immunoprecipitates were analyzed by fluorography after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunoprecipitation of T4-binding globulin (TBG) was also carried out with anti-TBG serum. Fluorographic analysis revealed three forms of CBG: CBG1, a glycosylated, mature, and secretory form with apparent mol wt of 70 K; CBG2, a glycosylated precursor which due to incomplete carbohydrate processing has an apparent mol wt of 54 K; and CBG3, a nonglycosylated form consisting of the 40 K core protein. In absence of TM, CBG1 was observed in media and CBG2 was detected in cell lysates. The proportion of CBG1 increased during the chase, whereas that of CBG2 decreased, indicating that CBG was secreted after processing of the oligosaccharides on CBG2. In presence of TM, CBG3 was found both in media and cell lysates. The sum of CBG3 in the medium and the cell lysate decreased during the chase, whereas that of CBG1 and CBG2 remained unchanged. Similar to CBG, TBG1 (mature form, 60 K) and TBG2 (partially processed glycosylated form, 54 K) were observed in media and cell lysates, respectively, in absence of TM. However, TBG3 (nonglycosylated, 44 K) was not detected in medium. These results indicate that glycosylation is not a key factor for the secretion of CBG but is important for its stability. On the other hand the glycosylation is indispensable for the secretion of TBG.

Cell Line↗