Biomedical subjects

S Horie

Publications and source records attributed to S Horie.

At least 109 records · Page 6Linked to original sources

PubMed1995

The epidermal growth factor-like domain of recombinant human thrombomodulin exhibits mitogenic activity for Swiss 3T3 cells.

Thrombomodulin (TM) is an anticoagulant endothelial cell surface glycoprotein containing six tandem epidermal growth factor (EGF)-like structures. We prepared a recombinant TM peptide (rTME1-6, from R214GHWA to DSGK466 of native TM) composed of these six EGF-like structures and investigated the effect of rTME1-6 peptide on the growth of the Swiss 3T3 fibroblast cell line. It was found that rTME1-6 induced proliferation of Swiss 3T3 cells and accelerated [3H]thymidine uptake into their DNA. [3H]Thymidine uptake increased in a dose-dependent manner, plateauing at 50 ng/mL rTME1-6, which was 1.8 times the control level. rTME1-6 peptide (50 ng/mL) also accelerated the DNA synthesis of human dermal fibroblasts (HDFs), A549 (a human lung cancer cell line), HepG2 (a human hepatocarcinoma cell line), and U937 cells (a human monocytic cell line) to 1.5, 1.6, 1.4, and 1.2 times the control level, respectively. The magnitude of the acceleration of DNA synthesis in Swiss 3T3 induced by rTME1-6 was approximately 20% of that of EGF on a molar basis. The uptake of [3H]thymidine was accelerated synergistically by coculture of the cells with rTME1-6 and insulin, similar to the coculture with EGF and insulin. The effects of rTME1-6 were abolished by addition of polyclonal antihuman TM IgG, whereas the actions of insulin and EGF were not influenced. Glucose uptake in Swiss 3T3 cells also increased 1.6 times over control levels by culture with 50 ng/mL rTME1-6 (1.25 nmol/L), compared with 2.7 times by 10 ng/mL EGF (1.66 nmol/L). Binding of [125I]EGF (0.5 ng/mL, 0.083 nmol/L) by the cells was inhibited by about 60% by addition of an eight-fold molar excess of nonlabeled EGF (0.664 nmol/L), whereas no inhibition of [125I]EGF binding was observed, even in the presence of a 1,000-fold molar excess (83 nmol/L) of rTME1-6. Specific binding of [125I]rTME1-6 on the cells showed a saturation curve, and the apparent concentration of rTME1-6 required for half maximum binding of the peptide on the cells was calculated to be 31.5 ng/mL. Thus, the overall results indicated that the rTME1-6 peptide had mitogenic activity for Swiss 3T3 cells, accelerated DNA synthesis and glucose uptake, and that the mitogenic activity might be mediated by binding of the peptide to a specific site different from the EGF receptor.

3T3 Cells↗

PubMed1995

Intracellular alkalinization by NH4Cl increases cytosolic Ca2+ level and tension in the rat aortic smooth muscle.

Intracellular pH (pHi) is elucidated to be an important regulator of various cell functions, but the role of pHi in smooth muscle contraction remains to be clarified. The purpose of the present study is to examine the effects of cell alkalinization by exposure to NH4Cl on cytosolic Ca2+ level ([Ca2+]i) and on muscle tone. We attempted simultaneous measurements of both [Ca2+]i and contractile force in rat isolated thoracic aorta from which the endothelium was removed. NH4Cl (10-80 mM) increased both [Ca2+]i and muscle tone in the presence of external Ca2+. These responses were reproducible. The removal of Ca2+ from the nutrient solution partially inhibited the rise in [Ca2+]i and the smooth muscle contraction induced by NH4Cl. In addition, the Ca2+ channel blocker verapamil also partially attenuated the responses to NH4Cl. The NH4Cl-induced responses were gradually reduced as NH4Cl was repeatedly added in a Ca(2+)-free solution. Norepinephrine (NE, 1 microM) induced a transient increase in [Ca2+]i and sustained contraction in the absence of external Ca2+, and the subsequent application of NE had little effect on [Ca2+]i. After internal Ca2+ stores were depleted by exposure to NE, the subsequent application of NH4Cl induced increases in [Ca2+]i and tension of the aorta in a Ca(2+)-free solution. These results suggest that NH4Cl mainly evokes Ca2+ release from the internal Ca2+ stores that are not linked with adrenergic alpha-receptor and causes Ca2+ influx through voltage-dependent Ca2+ channels in the vascular smooth muscle.

Ammonium Chloride↗

PubMed1995

[Hereditary tubulo-interstitial nephropathy].

Most of the hereditary tubulointerstitial nephropathy see the cyst formation in the kidney. Among them, juvenile nephronophthisis and medullary sponge kidney, which primarily involve the tubule structures of the renal medulla, are associated with variable enlargement of the distal tubules and collecting ducts and with interstitial fibrosis and inflammation of a variable extent. Juvenile nephronophthisis features sodium wasting, anemia, and renal failure. Eighty % of juvenile nephronophthisis is an autosomal recessive disorder, and it also has a variant form which is an autosomal dominant disease. A gene for autosomal recessive juvenile nephronophthisis is now mapped to 2q13, although no linkage has been observed in autosomal dominant variant to this region. Thus genetic heterogeneity between autosomal recessive variant and autosomal dominant variant of juvenile nephronophthisis is suggested. Juvenile nephronophthisis progress to end-stage renal failure. In contrast, medullary sponge kidney, which features nephrocalcinosis and urinary stones, is a relatively benign condition and occurs occasionally in the same family.

Benzothiadiazines↗

PubMed1995

Cytochrome P-450scc-catalyzed production of progesterone from cholestenone.

Cholestenone, which is a 3-keto derivative of cholesterol, was incubated with cytochrome P-450SCC in a reconstituted hydroxylation system. Cholestenone was metabolized to progesterone with a turnover number of about 9 nmol/min/nmol P-450 in the presence of 0.01% Tween20. This value was about 70% of the maximal value for cholesterol. The final reaction product, progesterone, and three other minor reaction products, 20 alpha-hydroxycholest-4-en-3-one, 22R-hydroxycholest-4-en-3-one, 20,22-dihydroxycholest-4-en-3-one, were identified on the basis of its retention times on HPLC, thus suggesting them to be intermediates of side-chain cleavage of cholestenone. The results suggest that cholestenone is metabolized by two pathways, that is, the first hydroxylation occurs either at the C-20 position or at the C-22 position.

Animals↗

PubMed1995

[Frequency analysis of crackles recorded with a stethoscope-equipped recorder].

Crackles were recorded with one of two systems in a total of 58 cases and compared. In one system a stethoscope was attached to a microphone; in the other system no stethoscope was used (see reference 9). Coarse crackles were recorded with the stethoscope system in 11 patients, and with the microphone-only system in 12 patients. Most patients with coarse crackles had bronchiectasis. Fine crackles were recorded with the stethoscope system in 13 patients, and with the microphone-only system in 22 patients. Most patients with fine crackles had idiopathic pulmonary fibrosis. Each record was examined visually, and all crackles recorded during one inspiration were selected. Power spectra were estimated with the maximum entropy method and peak frequencies were determined with the damped least-squares method. Type-I crackles were defined as those with all peak frequencies below 800 Hz; these low-pitched sounds may correspond to coarse crackles. Type-II crackles were defined as those with peak frequencies over 800 Hz regardless of the existence of peaks below 800 Hz; these high-pitched sound may correspond to fine crackles. The "%Type II" was defined as the percentage of the total crackles that were Type-II crackles. The %Type II value among coarse crackles was 10 +/- 16% with the stethoscope and 3 +/- 7% with the microphone. Among fine crackles, the values were 65 +/- 22% with the stethoscope and 79 +/- 23% with the microphone. For both kinds of equipment, the %Type II differed significantly between coarse and fine crackles (p < 0.01). The stethoscope-transmitted sound had components that could be used to differentiate fine crackles from coarse crackles. For clinical purposes, crackles recorded with a stethoscope are as useful as those recorded with a microphone only.

Auscultation↗

PubMed1994

Mediation of renal cyst formation by hepatocyte growth factor.

Hepatocyte growth factor (HGF) is a potent mitogen for renal tubular cells, and HGF and its receptor (c-met proto-oncogene product, Met) can induce lumen formation in epithelial cells. We measured the concentration of HGF in cyst fluids from patients with renal cystic diseases. The concentration of HGF was high in proximal cyst fluid (mean 2.45 vs 0.42 ng/mL in distal cysts). Cyclic AMP concentration was higher in distal than in proximal cysts (663 vs 6.0 pmol/L). mRNA of HGF and Met were co-expressed in cyst walls from cases with polycystic kidney disease. These findings suggest that HGF is a growth factor that may mediate human renal cyst genesis.

Base Sequence↗

PubMed1994

Enhancement of thrombin-thrombomodulin-catalysed protein C activation by phosphatidylethanolamine containing unsaturated fatty acids: possible physiological significance of phosphatidylethanolamine in anticoagulant activity of thrombomodulin.

The effects of phospholipid vesicles and their fatty acid compositions on the acceleration of Protein C activation by thrombin-thrombomodulin was studied in vitro. Four main phospholipid fractions were prepared from cultured human umbilical vein endothelial cells, and purified thrombomodulin from human placenta was reconstituted into vesicles consisting of phosphatidylcholine (PtdCho) alone, PtdCho plus phosphatidylethanolamine (PtdEtn), PtdCho plus phosphatidylserine (PtdSer) and PtdCho plus PtdIns (1:1, w/w in each case). Vesicles of PtdCho, PtdIns/PtdCho, PtdSer/PtdCho and PtdEtn/PtdCho increased thrombin-thrombomodulin-catalysed protein C activation by 1.2-, 1.9-, 4.3- and 8.4-fold respectively compared with that in the absence of phospholipid. This Protein C activation was not affected by distearoyl PtdEtn/distearoyl PtdCho, whereas it was markedly increased with increasing content of unsaturated fatty acid in PtdEtn. The thrombin-dependent Protein C activation by thrombomodulin reconstituted into dilinolenoyl PtdEtn/distearoyl PtdCho was 14.6 times that by thrombomodulin reconstituted into distearoyl PtdEtn/distearoyl PtdCho, as a result of a decrease in the dissociation constant (Kd) for thrombin and the Michaelis constant (Km) for Protein C of thrombomodulin. Binding of Protein C to PtdEtn/PtdCho fixed to a microwell plate required the presence of CaCl2 and increased with increasing degree of unsaturation of fatty acid in PtdEtn. As PtdEtn appeared on the outside of the plasma membrane in cultured human umbilical vein endothelial cells after thrombin stimulation, it was presumed that Protein C activation could be elevated by PtdEtn at the outer surface of the plasma membrane via an increased affinity between thrombomodulin, thrombin and Protein C, resulting from both increased formation of the thrombin-thrombomodulin complex via a conformational change in thrombomodulin and increased binding of Protein C to the membrane phospholipid in a Ca(2+)-dependent manner.

Calcium Chloride↗

PubMed1994

CD11b/CD18 (Mac-1) is required for degranulation of human eosinophils induced by human recombinant granulocyte-macrophage colony-stimulating factor and platelet-activating factor.

Recent evidence suggests adhesion molecules play an important role in the function of leukocytes. Because human eosinophils are known to express beta 2 integrins, we hypothesized that these adhesion molecules mediate the effector function of eosinophils. Normal human eosinophils incubated in albumin-coated polystyrene plates released granule protein and produced superoxide anion when stimulated with human recombinant granulocyte-macrophage CSF (rGM-CSF), platelet-activating factor (PAF), or PMA. Simultaneous monitoring of eosinophil adhesion and degranulation showed that degranulation was always preceded by cellular adhesion regardless of stimuli. Furthermore, eosinophil degranulation induced by human rGM-CSF and PAF was abolished in suspension culture of the cells when the cell suspensions were gently stirred. To identify the molecules involved in this adhesion-dependent degranulation, we have investigated the effects of mAbs (mAb) against beta 2 integrins. mAb reactive with CD18 markedly inhibited the eosinophil adhesion and degranulation induced by PAF and human rGM-CSF. mAb reactive with CD11b also moderately inhibited the adhesion and degranulation. In contrast, mAb reactive with CD11a slightly enhanced or showed no effect on the adhesion and degranulation by human rGM-CSF or PAF. Superoxide production induced by human rGM-CSF and PAF was also abolished by the treatment of cells with anti-CD18 mAb. mAb against CD11b and CD18 had little effect on degranulation and superoxide production induced by PMA. These results indicate that CD11b/CD18 (Mac-1)-dependent cellular adhesion plays an important role in the degranulation and superoxide production of eosinophils induced by human rGM-CSF and PAF, and that these mechanisms may be employed in vivo where eosinophils contact with stromal cells and/or proteins.

Antibodies, Monoclonal↗

PubMed1994

Variability in the disposition of chlorzoxazone.

Chlorzoxazone is 6-hydroxylated by cytochrome P450 2E1 (CYP 2E1), which bioactivates many toxic and carcinogenic molecules. Seventeen volunteers of varying age, ethnicity, and gender received a 250 mg tablet of chlorzoxazone and their blood and urine were sampled frequently for 8 h. V/F = 42 +/- 21 L and CL/F = 412 +/- 120 mL min-1. Comparison of these values with a study by other investigators using a suspension dosage form suggested that relative Ftablet approximately 0.7. The fraction excreted in the urine as 6-hydroxychlorzoxazone (fe,6-OH) was 0.39 +/- 0.20 and that portion of the total CL accounted for by CYP 2E1-mediated metabolism (CL6-OH) was 163 +/- 95 mL min-1. Thus, while V/F and CL/F varied by factors of less than five, fe,6-OH varied 16-fold and CL6-OH varied 28-fold. These results suggested that there was considerable inter-individual variability in the metabolism of chlorzoxazone to 6-hydroxychlorzoxazone. This variability will significantly affect the construction of physiologically based pharmacokinetic models that use the 6-hydroxylation of chlorzoxazone as a marker for an individual's CYP 2E1 phenotype.

Administration, Oral↗

PubMed1994

Differential effects of Na+, K(+)-ATPase inhibition by ouabain on acid secretory responses to histamine and bethanechol in the mouse isolated stomach.

1. The effect of Na+,K(+)-ATPase inhibition by ouabain on gastric acid secretion was studied in the mouse isolated whole stomach preparation. 2. Ouabain caused a transient enhancement of histamine-induced gastric acid secretion followed by an inhibitory phase. On the other hand, ouabain caused a rapid reduction of bethanechol-stimulated acid secretion without an enhancement phase. 3. In dibutyryl cyclic AMP-induced acid secretion, ouabain led to a transient increase in acid secretion followed by a fall, as was seen with the histamine stimulation. Ouabain caused a rapid reduction of A23187-induced acid secretion. 4. Ouabain by itself increased basal acid secretion, and thereafter slowly suppressed the acid secretion. 5. Atropine inhibited both the ouabain-induced enhancement of the stimulated gastric acid secretion and the ouabain-induced stimulation of basal acid secretion. 6. The present study showed that Na+,K(+)-ATPase inhibition by ouabain caused a phasic enhancement of the stimulated gastric acid secretion through release of endogenous acetylcholine when the secretagogues act via an intracellular cyclic AMP pathway. It also inhibited the stimulated acid secretion irrespective of secretagogues, probably through its inhibitory effect on Na+,K(+)-ATPase in the gastric parietal cell.

Animals↗

PubMed1994

Decreased cyclosporin A absorption after treatment with GoLytely lavage solution in rats.

Recently we observed a case in which the cyclosporin A absorption decreased after treatment with GoLytely lavage solution in a kidney transplant patient. In this study, we confirmed the decrease of the blood concentration of cyclosporin A after oral administration by GoLytely (Macrogol 3350) based on experiments with rats. The peak blood cyclosporin A concentration, and the area under the blood drug concentration-time curve from 0 to 24 h in the GoLytely-administered group were significantly lower than the control group. In the case of gastrointestinal dysfunction such as diarrhoea, or in treatment with laxatives such as GoLytely lavage solution, whole blood cyclosporin levels must be carefully monitored, and intravenous cyclosporin A may be more suitable for providing adequate immunosuppression.

Analysis of Variance↗

PubMed1994

Thrombomodulin induction by all-trans retinoic acid is independent of HL-60 cells differentiation to neutrophilic cells.

The expression of thrombomodulin (TM), an antithrombotic factor, was investigated during neutrophilic differentiation of the HL-60 human myeloblastic cell line treated with all-trans retinoic acid (ATRA) or dimethyl sulfoxide (DMSO). Differentiation of the cells into neutrophilic cells progressed in a time- and dose-dependent fashion with ATRA or DMSO, as confirmed by the characteristic appearance of nitroblue tetrazolium (NBT) reduction and phagocytic activities, without induction of nonspecific esterase activity. TM antigen and cofactor activity for thrombin-dependent protein C activation were not detected in untreated HL-60 cells and the cells cultured with DMSO, but were expressed in a time-dependent manner in the cells cultured with ATRA. The level of TM expression in the HL-60 cells was not dose-dependent on ATRA concentrations, but maximum TM expression was obtained at 10(-7) M ATRA. TM expression levels decreased in cells cultured with greater than 10(-6) M ATRA, although the extent of cell differentiation into neutrophilic cells progressed at the higher ATRA concentrations. Since the TM antigen levels in the ATRA-treated cells also paralleled the TM mRNA levels, the data suggests that TM induction in the HL-60 cells cultured with ATRA reflected the levels of TM biosynthesis and was independent of HL-60 differentiation into neutrophilic cells. It was postulated that the appearance of TM with cofactor activity in neutrophilic cells differentiated from leukemic cells may contribute to prevention of vascular thrombosis in differentiation therapy of patients with acute promyelocytic leukemia by ATRA.

Cell Differentiation↗

PubMed1994

[An autopsy case of lymphoepithelioma-like carcinoma of the mediastinum].

A case of lymphoepithelioma-like carcinoma of the mediastinum is reported. A 67-year-old male was admitted to Tokyo Medical College Hospital, in February of 1992, for evaluation of an abnormal mediastinal shadow on chest X-ray. The mediastinal tumor was biopsied using mediastinoscopy. Histological diagnosis was undifferentiated carcinoma and radiation therapy was performed. Six months after treatment, he complained of dyspnea. Combination chemotherapy was performed. Although the tumor size decreased, he died of pneumonia. Histological findings at autopsy included nesting of large carcinoma cells with vacuolar nuclei and large nucleoli, interstitial lymphocytic infiltration similar to that of lymphoepithelioma of the epipharynx, and lymphoepithelioma-like carcinoma in the thymus. The epipharynx and thymus were, however, intact at autopsy. We found no other origins of this tumor, including the trachea and lung. This case was therefore diagnosed as lymphoepithelioma-like carcinoma of the mediastinum.

Aged↗

PubMed1993

Different thrombomodulin induction in monocytic, macrophagic and neutrophilic cells differentiated from HL-60 cells.

Thrombomodulin (TM) antigen and its cofactor activity for thrombin-dependent protein C activation were not detected in the untreated HL-60 human promyelocytic cell line, but appeared in cells cultured with 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25(OH)2D3: 10-1,000 nM) or phorbol 12-myristate 13-acetate (PMA: 0.1-10 nM) accompanied by an increase in TM mRNA levels. The induction of TM increased in parallel with the appearances of both nonspecific esterase activity, a typical marker of monocyte/macrophage lineages, and phagocytic activity. The TM antigen level induced in 1 alpha,25(OH)2D3-treated cells was 8 times higher than that in PMA-treated cells. Trace amounts of TM antigen were induced in neutrophilic cells differentiated from HL-60 by treatment with retinoic acid. These results indicated that different levels of TM were induced in monocytic, macrophagic and neutrophilic cells differentiated from HL-60 cells.

Calcitriol↗

PubMed1993

Laparoscopic adrenalectomy: the initial 3 cases.

Laparoscopic adrenalectomy was performed on 3 patients with primary aldosteronism. Traction with 2 steel skewers placed subcutaneously over the costal arch was combined with conventional intraperitoneal carbon dioxide gas insufflation. This combination provided a good operative field at 8 mm. Hg insufflation pressure. The laparoscopic approach to the adrenal gland requires neither a large skin and muscle incision nor resection of rib(s), and offers lower morbidity and rapid convalescence. Laparoscopic adrenalectomy is a new minimally invasive operation for the treatment of adrenal adenoma.

Adrenalectomy↗

PubMed1993

Catecholaminergic innervation of oxytocin neurons in the paraventricular nucleus of the rat hypothalamus as revealed by double-labeling immunoelectron microscopy.

The catecholaminergic innervation of neurons that contain oxytocin in the paraventricular nucleus (PVN) of the rat hypothalamus was examined by a combination of methods in the same tissue sections at the electron-microscopic level as follows: (1) Rats were treated with 5-hydroxydopamine (5-OHDA) with peroxidase-antiperoxidase (PAP) staining of sections for oxytocin prior to embedding. (2) Preembedding immunoperoxidase staining with avidin-biotin complexes was used to demonstrate tyrosine hydroxylase (TH) activity, with postembedding staining with immunocolloidal gold for visualization of oxytocin. (3) Prior to embedding, a double-staining technique was used that was based on consecutive staining with silver-gold-intensified PAP complex and 3,3'-diaminobenzidine. We used an antiserum against oxytocin and an antiserum against dopamine-beta-hydroxylase (DBH) for localization of antigens. We found that TH- and DBH-like immunoreactive terminals were distributed throughout the rat hypothalamus and were abundant in all parts of the PVN. Ultrastructural observations revealed 5-OHDA-labeled, TH- or DBH-like immunoreactive axon terminals that contained granular vesicles (70-80 nm in diameter) and small clear synaptic vesicles (30-50 nm in diameter). The terminals appeared at times to be making synapses with cell bodies and with the processes of oxytocin-containing neurosecretory neurons in the PVN. These findings provide morphological evidence for a direct synaptic influence of catecholaminergic elements on the secretory activity of oxytocin-containing neurosecretory neurons in the rat hypothalamic PVN.

Adrenergic Fibers↗

PubMed1993

Chronic regulation of the Na/H antiporter.

This review focuses on studies from our laboratory investigating the mechanisms of chronic regulation of the Na/H antiporter in renal and nonrenal cells. Tissue culture provides an ideal tool for investigating this problem because it avoids many complicating effects that would occur in an intact animal during a chronic study. Chronic decreases in extracellular fluid pH cause an increase in Na/H antiporter activity that is dependent on protein synthesis and associated with an increase in NHE-1 (isoform of the sodium-hydrogen antiporter) mRNA abundance. This effect is associated with acid-induced increases in a number of immediate early genes, including c-fos, c-jun, junB, and egr-1. In primary cultures of rabbit proximal tubule cells, activation of protein kinase C for 2 hours causes an increase in Na/H antiporter activity that persists 24 hours later, is dependent on transcription and translation, and is associated with an increase in NHE-1 mRNA abundance. Chronic activation of protein kinase A in opossum kidney (OKP) cells causes an increase in Na/H antiporter activity that persists 16 to 20 hours later and is dependent on protein synthesis. This latter effect is of particular interest because it is opposite in direction to the acute inhibitory effect of protein kinase A on the Na/H antiporter in these cells.

Animals↗

PubMed1993

Effects of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, an inhibitor of Cl(-)-HCO3- exchanger, on stress-induced gastric lesions in rats.

The effect of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), an inhibitor of Cl(-)-HCO3- exchanger, on stress-induced gastric lesions was studied in rats. The stress exposure to rats was performed by restraint plus water-immersion (22 degrees C) for 6 h. Oral administration of DIDS produced a dose-dependent reduction in the gastric lesion formation. The ED50 value for DIDS was 94.4 mg/kg (64.2 - 138.8 mg/kg; 95% confidence limits) and the maximum effect was observed at the dose of 300 mg/kg with an inhibition of 95%. A dose-dependent reduction in lesions was also observed after administration of omeprazole, an inhibitor of proton pump. The ED50 value for omeprazole was 3.1 mg/kg (1.8 - 5.4 mg/kg; 95% confidence limits) and the effect was maximum at 16 mg/kg with an inhibition of 92%. These results indicated that DIDS protected the gastric mucosa against stress-induced lesions. It is speculated that the antiulcerous activity of DIDS may give a clue for the development of a new class of therapeutic drugs for the prevention and healing of gastric ulcers.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗