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T Imai

Publications and source records attributed to T Imai.

At least 541 records · Page 30Linked to original sources
PubMed1994

Germ line mutations of the ret proto-oncogene in Japanese patients with multiple endocrine neoplasia type 2A and type 2B.

We investigated mutations of the ret proto-oncogene in Japanese patients with multiple endocrine neoplasia (MEN) type 2A and type 2B. DNAs from pheochromocytomas and/or medullary thyroid carcinomas (MTCs) of five MEN 2A and three MEN 2B patients were amplified by a polymerase chain reaction (PCR) and analyzed. Tumors of four MEN 2A patients had missense mutations in Cys 634 in the extracellular domain of the ret proto-oncogene. The same mutations were detected in normal tissues of the patients, indicating that the mutations had arisen in the germ line. Using a reverse transcriptase(RT)-PCR, both normal and mutant transcripts of the ret proto-oncogene were detected in a tumor of one patient with MEN 2A mutation. In addition, three MEN 2B patients examined had the same point mutation (ATG-->ACG) at codon 918 in the tyrosine kinase domain of the ret proto-oncogene. Since all mutations identified in this study generated new restriction enzyme sites or eliminated a restriction site, the mutant alleles of affected family members could be readily detected without sequencing.

Base Sequence↗
PubMed1994

Immunohistochemical demonstration of intestinal-type alkaline phosphatase in stomach tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine in rats.

A polyclonal antibody against rat intestinal-type alkaline phosphatase (I-ALP) was generated and proven to be applicable immunohistochemically to paraffin-embedded sections. Expression of I-ALP in normal tissues, intestinal metaplasia and stomach tumors induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was then investigated in five different strains of rats. Male SD (Crj:CD), Lewis (LEW/Crj), WKY (WKY/NCrj), Wistar (Crj:Wistar) and F344 (F344/DuCrj) animals were given drinking water containing 100 micrograms/ml of MNNG for 30 weeks and were killed at week 50. Among the 5 strains, stomach adenocarcinomas were found most frequently in the SD case. The susceptibility of rats to induction of stomach carcinoma did not correlate with the development of intestinal metaplasias in each strain. Histochemical staining for mucin demonstrated all stomach tumors (adenomatous hyperplasias and well-differentiated adenocarcinomas) to consist mainly of gastric type cells (pyloric gland cell and surface mucous cell types), with intestinal-type tumor cells (goblet cell and intestinal absorptive cell types) being only occasional findings. Immunohistochemically, I-ALP was strongly positive on the striated cell borders of small intestinal absorptive cells of the villus and on brush borders of epithelial cells of kidney proximal tubules. I-ALP was also detected in the normal stomach, limited to the striated cell borders of absorptive cells of the upper one-fourth of intestinal metaplastic glands. I-ALP may thus be a useful marker for stomach tumor cells of intestinal absorptive cell type, indicative of maturation and differentiation. No stomach tumors consisting mainly of intestinal-type cells were found, and therefore there was no suggestion of any derivation from intestinal metaplasias.

Adenocarcinoma↗
PubMed1994

Cervical dural arteriovenous malformation presenting with right-sided occipitalgia: before and after successful treatment by embolization.

We report a 52-year-old man who had a 2-year history of right-sided occipitalgia. His pain was induced by anteroflexion of the neck. Neurologic examinations showed mild right C2 and C3 root signs. Cervical MR imaging disclosed an extra-medullary intradural crooked shadow at the level between C2 and C3 vertebrae, which was proven by selective angiogram of the ascending cervical artery to be a dural arteriovenous malformation located in the right C3 root sleeve. Embolization by an endovascular approach resulted in angiographic and clinical cure. These findings indicate that headache due to arteriovenous malformation in upper cervical region may be surgically treatable.

Angiography↗
PubMed1994

Assessment of rate of O2 release from single hepatic sinusoids of rats.

Characteristics of O2 release from single hepatic sinusoids are described in relation to the sinusoidal O2 inflow for the first time. Microspectroscopic measurement of the rate of O2 release (RO2) from single sinusoids to surrounding hepatocytes was carried out at the edge of the liver of anesthetized rats. The oxyhemoglobin inflow ([HbO2] inflow) into sinusoids, which is a product of sinusoidal blood flow rate and inflowing oxyhemoglobin concentration ([HbO2]), was varied by exchange transfusion of blood with physiological saline. 1) RO2 from single hepatic sinusoids of control rats was fairly constant [0.66 +/- 0.14 (SD) nmol.cm-2.s-1, with 18 sinusoids of 9 rats] over a wide range of [HbO2] inflow (50-200 fmol/s). 2) In the cases of mild anemia, [HbO2] inflow scarcely decreased but RO2 increased, probably because of the increased metabolism of hepatocytes. 3) In the cases of severe anemia, [HbO2] inflow decreased below 50 fmol/s and RO2 decreased accordingly. 4) In all cases no difference was observed between the RO2 values obtained from periportal zone and those from pericentral zone. These results are discussed on the bases of the vascular structure and function of hepatic sinusoids and on the animal model of hemorrhagic shock.

Acute Disease↗
PubMed1994

Regulation of inducible nitric oxide synthase gene by interleukin-1 beta in rat vascular endothelial cells.

To elucidate the regulation of endothelial inducible nitric oxide synthase (iNOS), we studied the effects of interleukin (IL)-1 beta on production of nitric oxide (NO) and expression of iNOS mRNA and iNOS protein in cultured rat aortic endothelial cells (ECs) by measurement of NO2-/NO3- (NOx) and Northern blot and Western blot analyses. Among several cytokines and bacterial lipopolysaccharide tested, IL-1 beta most effectively stimulated NOx production. IL-1 beta dose and time dependently stimulated NOx production. Northern blot analysis using cDNA for mouse liver iNOS as a probe showed that IL-1 beta induced expression of iNOS mRNA and stimulated NOx production in a dose- and time-dependent manner. Transforming growth factor (TGF)-beta and dexamethasone blocked the IL-1 beta-induced NOx production as well as expression of iNOS mRNA and protein. TGF-beta dose dependently inhibited the IL-1 beta-induced NOx production and iNOS mRNA expression. Northern blot analysis for the decay of the IL-1 beta-induced iNOS mRNA revealed the approximate half-life of 4 h. These data indicate that IL-1 beta induces iNOS gene expression and de novo synthesis of iNOS and subsequent NO generation in vascular endothelium and that TGF-beta and glucocorticoid block iNOS gene expression at the transcriptional level.

Amino Acid Oxidoreductases↗
PubMed1994

Expression of epidermal growth factor and transforming growth factor-alpha in fallopian tube epithelium and their role in embryogenesis.

We studied the expression of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha in human fallopian tube epithelium at various menstrual stages. Immunohistochemical staining using anti-EGF and anti-TGF-alpha antibodies showed a specific staining in ampullary tube epithelium at late follicular and luteal stages but the staining was very weak at the early follicular stage. Quantitative reverse transcription and polymerase chain reaction (RT-PCR) using beta-actin mRNA as an internal standard revealed the menstrual-stage-specific expression of EGF and TGF-alpha gene transcripts: amounts of EGF and TGF-alpha mRNA relative to those of beta-actin were significantly higher at late follicular and luteal stages than at the early follicular stage. To clarify the biological role of these growth factors, mouse 2-cell embryos were cocultured with human fallopian tube epithelial cells with or without blocking the action of these growth factors. Cocultures significantly promoted blastocyst formation, but this promotive effect of the tubal epithelial cells was completely abolished by the addition of anti-EGF and/or anti-TGF-alpha monoclonal neutralizing antibodies to the coculture system. These results demonstrated that EGF and TGF-alpha were synthesized and expressed in fallopian tube epithelium at specific menstrual stages, and may be involved in early embryonic development.

Animals↗
PubMed1994

Induction of nitric oxide synthase gene by interleukin-1 beta in cultured rat cardiocytes.

BACKGROUND: Impaired myocardial contractility in septic shock is protracting, which may be caused by cytokine-induced nitric oxide (NO) synthesis in the heart. However, the cellular mechanism by which cytokines induce nitric oxide synthase (NOS) in cardiocytes remains obscure. METHODS AND RESULTS: We studied the effect of human recombinant interleukin-1 beta (IL-1 beta) on synthesis of NO2-/NO3- (NOx) and the expression of NOS mRNA and protein in cultured neonatal rat cardiocytes. IL-1 beta dose-dependently (0.1 to 10 ng/mL) stimulated NOx production as a function of time (6 to 48 hours). Northern blot analysis using complementary DNAs for rat brain-type constitutive (c) NOS and mouse macrophage-type inducible (i) NOS as probes showed that IL-1 beta induced expression of mRNA for iNOS but not for cNOS, starting after 6 hours and reaching a maximum after 48 hours in cardiocytes. IL-1 beta similarly induced iNOS mRNA expression in cultured adult rat cardiocytes in a time-dependent manner. Western blot analysis using specific antibody against the N-terminal fragment of mouse iNOS revealed the expression of 130-kD iNOS-like protein in IL-1 beta-treated cardiocytes. Northern blotting and immunocytochemical study revealed that IL-1 beta-induced iNOS mRNA and iNOS-like immunoreactivity were exclusively localized to cardiac myocytes but also to nonmyocytes, to a lesser extent. NG-mono-methyl-L-arginine, an NOS inhibitor, completely blocked the IL-1 beta-induced NOx production, whose effect was reversed by L-arginine but not by D-arginine. Dexamethasone inhibited the IL-1 beta-induced NOx production as well as iNOS mRNA expression. Cycloheximide and actinomycin D completely inhibited the IL-1 beta-induced NOx production and iNOS mRNA expression. Neither a calmodulin inhibitor (W-7), a protein kinase C inhibitor (calphostin C), nor a Ca2+ channel antagonist (nicardipine) showed any effect on the IL-1 beta-induced NOx production. CONCLUSIONS: These data demonstrate that IL-1 beta induces macrophage-type iNOS mRNA expression mainly by cardiac myocytes but also by nonmyocytes to a lesser extent, and subsequent de novo protein synthesis of iNOS leads to excessive local production of NO by cardiocytes.

Amino Acid Oxidoreductases↗
PubMed1994

C-type natriuretic peptide upregulates vascular endothelin type B receptors.

Cultured rat vascular smooth muscle cells (VSMCs) possess receptors for potent vasoconstrictor endothelin-1 (ET-1) as well as potent vasodilator natriuretic peptides (atrial, brain, and C-type natriuretic peptides [ANP, BNP, and CNP, respectively]). However, little is known about molecular interactions between endothelin receptors and natriuretic peptides in VSMCs. To elucidate whether natriuretic peptides regulate vascular endothelin receptors, we studied the effects of three natriuretic peptides on the capacity of 125I-ET-1 binding and expression of endothelin type A (ETA) and type B (ETB) receptor mRNAs in cultured rat VSMCs. CNP (10(-6) mol/L) increased 125I-ET-1 binding capacity in a time-dependent manner (6 to 48 hours) and stimulated cyclic GMP (cGMP) generation in a dose-dependent manner (10(-8)) to 10(-6) mol/L). Pretreatment with CNP (10(-8) to 10(-6) mol/L) and 8-bromo-cGMP (10(-5) to 10(-3) mol/L) for 24 hours resulted in dose-dependent increases in 125I-ET-1 binding in VSMCs. The three natriuretic peptides at the highest concentration (10(-6) mol/L) increased 125I-ET-1 binding and stimulated cGMP generation with almost the same rank order of efficacy (CNP > BNP > ANP). Scatchard analysis of binding studies revealed that CNP (10(-6) mol/L) and 8-bromo-cGMP (10(-3) mol/L) increased vascular endothelin receptor number by 28% and 88%, respectively, without changing its affinity. Pretreatment with both CNP and 8-bromo-cGMP increased ET-1-stimulated inositol 1,4,5-trisphosphate formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1994

Inflammatory chemical mediators during conventional ventilation and during high frequency oscillatory ventilation.

Inflammatory chemical mediators, platelet-activating factor (PAF), thromboxane (TX) B2, and 6-keto-prostaglandin (PG)F1 alpha, were extracted from lung lavage fluid after conventional mechanical ventilation (CMV) and high frequency oscillatory ventilation (HFOV) to clarify the relation between mode of ventilation and lung injury in surfactant-depleted rabbit lungs. Anesthetized adult rabbits were tracheostomized, and surfactant depletion was induced by repeated saline lavage. Lung lavage for measurement of mediators was performed after 4 h of CMV at an FIO2 of 1.0 and a mean airway pressure of 15 cm H2O or HFOV (15 Hz) at an FIO2 of 1.0 or 0.21 and a mean airway pressure of 15 cm H2O. The number of total cells and polymorphonuclear leukocytes (PMN) and the levels of PAF, TXB2, and 6-keto-PGF1 alpha were measured by radioimmunoassay. Total respiratory compliance (Crs) was measured by the passive flow-volume curve method. The numbers of PMN, and the levels of PAF and TXB2 in lung lavage fluid were significantly greater during CMV than during HFOV. HFOV resulted in decreased production of PAF and TXB2 in a surfactant-depleted rabbit lung. Crs was significantly less during CMV than during HFOV. These results suggest that HFOV could prevent the release of such inflammatory chemical mediators and result in less lung injury than CMV.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Induction of nitric oxide synthase by cyclic AMP in rat vascular smooth muscle cells.

By measurements of NO2-/NO3- (NOx) production and Northern blot analysis, we studied the effects of a membrane-permeable cAMP derivative, 8-bromo-cAMP, on the expression of inducible nitric oxide synthase (iNOS) gene and the synthesis of NOx in cultured rat vascular smooth muscle cells (VSMCs). 8-bromo-cAMP stimulated NOx production and increased steady-state levels of iNOS mRNA in rat VSMC in a time- and dose-dependent manner. NG-monomethyl-L-arginine, a NOS inhibitor, completely blocked the 8-bromo-cAMP-induced NOx production, whose effect was partially, but significantly reversed by an excess L-arginine, but not by D-arginine. Compounds that increase intracellular cAMP levels (cholera toxin, forskolin, and 3-isobutyl-1-methylxanthine), all stimulated NOx production. Dexamethasone inhibited the stimulated NOx production, as well as the induction of iNOS mRNA by cAMP. Both actinomycin D and cycloheximide completely blocked the stimulated NOx production by cAMP. Actinomycin D abolished the cAMP-induced iNOS mRNA, whereas cycloheximide remarkably increased iNOS mRNA levels in the presence and absence of 8-bromo-cAMP (superinduction). Actinomycin D, but not dexamethasone, completely abolished the cycloheximide-induced iNOS mRNA. The half-life of cAMP-induced iNOS mRNA was approximately 2 h, whereas no decay in the cycloheximide-induced iNOS mRNA was observed during 12 h. These results demonstrate that iNOS gene is upregulated by cAMP and the superinduction of iNOS mRNA is attributable to increased mRNA stability in rat VSMC.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Phenotypic change of endothelin receptor subtype in cultured rat vascular smooth muscle cells.

An endothelium-derived vasoactive peptide, endothelin (ET)-1, is a potent constrictor and mitogen for vascular smooth muscle cells (VSMC). To determine whether vascular ET receptor subtypes phenotypically change during in vitro culture conditions, we studied the expression of ET receptor subtypes, ET-induced phosphoinositide breakdown, and DNA synthesis in cultured rat VSMCs during serial passages. Binding studies using [125I]ET-1 as a radioligand revealed that the early passage (10th-15th) VSMCs possess predominantly ETA receptors, whereas the late passage (30th-35th) VSMCs possess predominantly ETB receptors in addition to ETA receptors. Northern blot analysis using cDNAs for rat ETA and ETB receptors as probes also demonstrated the predominant expression of ETA receptor mRNA in the early passage and ETB receptor mRNA in the late passage, whereas only ETA receptor mRNA was expressed in intact medium of rat aorta. ET-1 had a greater effect than ET-3 in stimulating inositol 1,4,5-trisphosphate formation, whereas ET-1 and ET-3 almost equipotently stimulated insitol 1,4,5-trisphosphate formation in the late passage VSMC even in the presence of an ETA receptor antagonist. ET-1-induced DNA synthesis was almost completely inhibited by an ETA receptor antagonist in the early passage VSMC. In contrast, ET-1, ET-3, and an ETB receptor agonist remarkably stimulated DNA synthesis in the late passage VSMC, which was completely inhibited by a nonselective ET receptor antagonist, but not by an ETA receptor antagonist. Our data provide the first evidence that a phenotypic change in VSMC in culture is concomitantly associated with a change in the ET receptor subtype that potentiates mitogenic activity and suggest that switching the ET receptor subtype from ETA to ETB during phenotypic change may in part contribute to the development of vascular lesions, such as in atherosclerosis.

Animals↗
PubMed1994

Epidermal growth factor promotes adipogenesis of 3T3-L1 cell in vitro.

We have reported the importance of epidermal growth factor (EGF) for the induction of obesity in mice. In this study, we studied the effects of EGF on the induction of lipogenic enzymes and on the accumulation of triglyceride in a differentiated mouse adipocyte cell in vitro. Mouse 3T3-L1 preadipocytic cells differentiated into mature adipocytes after the differentiation procedure by insulin, dexamethasone, and methyl-isobutyl-xanthine. 125I-EGF binding studies in the differentiated 3T3-L1 cells showed specific 125I-EGF bindings, and they expressed gene transcripts for EGF receptors by reverse transcription and polymerase chain reaction at all differentiative stages examined. Although EGF showed inhibitory effects on the triglyceride accumulation when administered to the preadipocytic 3T3-L1 cells, EGF enhanced the adipogenesis in the differentiated cells in dose- and time-dependent manners. Administration of EGF at 0.1-1 nM from 4 days after the differentiation procedure for 10 days, significantly enhanced the acyl-Co A synthetase and lipoprotein lipase messenger RNA levels, both of which are rate-limiting enzymes to synthesize triglyceride in adipocytes. Moreover, 0.1-1 nM EGF increased the amounts of triglyceride accumulated in the cells, in proportion to the acyl-Co A synthetase and lipoprotein lipase messenger RNA levels. EGF rather failed the adipogenesis at 10 nM. Time course studies revealed that 1 nM EGF significantly increased the intracellular triglyceride levels from 4 through 16 days administration. These results suggest that EGF shows biphasic effects on adipocytes: although EGF inhibits preadipocytes differentiation into mature adipocytes, it promotes adipogenesis in the differentiated adipocytes.

3T3 Cells↗
PubMed1994

Sex-dependent expression of a transcription factor, Ad4BP, regulating steroidogenic P-450 genes in the gonads during prenatal and postnatal rat development.

We investigated the expression of Ad4BP (also known as SF-1), a transcription factor regulating steroidogenic P-450 genes, in the steroidogenic tissues such as adrenal glands, testes and ovaries through the prenatal and postnatal life of rats. Ad4BP was detected in the primordial adrenal glands and gonads of the 13.5 day postcoitum (d.p.c.) fetus. After the appearance of Ad4BP, a steroidogenic P-450 (P-450(SCC)) was also detected in the adrenal glands and its amount increased gradually. In the fetal gonads of 14.5 d.p.c., a significant amount of Ad4BP was detected in the somatic cells of the testes, whereas only a trace amount was present in the ovaries. The sexually dimorphic expression of Ad4BP continued throughout the neonatal age. Drastic alterations occurred during the first to third week of postnatal age accompanied by functional and structural changes of the gonads. The expression of Ad4BP in the testes attained a maximal level one week after birth and decreased markedly thereafter. By contrast, increase of Ad4BP in the ovary was detected after the first postnatal week. Expression of P-450c17 showed a good correlation with the proliferation of Leydig cells in the testes and theca cells in the ovaries. Immunohistochemical studies revealed the presence of Ad4BP in Sertoli cells as well as Leydig cells up to the pubertal age. In the adult rat testis, however, staining of Sertoli cells decreased significantly. Ad4BP was detected in granulosa, theca, corpus luteum and interstitial gland cells in the ovary although the expression levels in granulosa cells varied among follicles. It is suggested that the Müllerian inhibitory substance gene may be a target of Ad4BP since this gene has a conserved Ad4-binding site within the promoter, which is recognized by Ad4BP expressed in the fetal testes.

Adrenal Glands↗
PubMed1994

[Effects of a novel orally-active antiallergic drug, quinotolast (FK021), on airway clearance].

The effects of a novel antiallergic drug, quinotolast (FK021, sodium 5-(4-oxo-1-phenoxy-4H-quinolizine-3-carboxamido) tetrazolate monohydrate), on airway clearance was studied in comparison with those of tranilast (an orally-active antiallergic drug). FK021 (10 mg/kg, p.o.) did not influence the rabbit airway secretion, whereas tranilast (100 mg/kg, p.o.) caused a slight suppression. Neither FK021 (10(-10)-10(-5) g/ml) nor tranilast (10(-6), 10(-4) g/ml) had any effect on pulmonary surfactant secretion in rat type II pneumocytes. FK021 (10 mg/kg, p.o.) caused a significant increase in the mucociliary transport rate in quails, whereas tranilast (320 mg/kg, p.o.) had no effect. Antitussive effects were examined in normal guinea pigs and guinea pigs made bronchitic by an exposure to SO2. FK021 (10 mg/kg, p.o.) and tranilast (320 mg/kg, p.o.) significantly depressed the cough reflex induced by citric acid in normal animals. FK021 (32 mg/kg, p.o.), but not tranilast (320 mg/kg, p.o.), showed antitussive effects on citric acid-induced cough in bronchitic animals. These results suggest that FK021 may have favorable effects on expectoration and cough reflex observed in the patients with chronic obstructive pulmonary diseases such as asthma.

Administration, Oral↗
PubMed1994

Selective inhibition of mouse placental lactogen II secretion by tumour necrosis factor-alpha.

The placental members of the prolactin-GH-placental lactogen (PL) gene family of the mouse include mPL-I, mPL-II, proliferin (PLF) and proliferin-related protein (PRP). The aim of the present study was to assess the effects of tumour necrosis factor-alpha (TNF-alpha) on the secretion of these proteins in primary cultures of placental cells from days 7, 9 and 12 of pregnancy. The effects of epidermal growth factor (EGF) on the secretion of PLF and PRP were also determined. EGF has previously been shown to stimulate mPL-I and inhibit mPL-II secretion. Incubation of placental cells from day 7 of pregnancy for 5 days with 10 nmol human (h)TNF-alpha/l did not affect the mPL-II concentration of the medium, but similar treatment of cells from days 9 or 12 of pregnancy resulted in a significant reduction in the mPL-II concentration of the medium by the second or third day of culture. The intracellular concentration of mPL-II, the number of cells that released mPL-II as assessed by reverse haemolytic plaque assay, and steady-state levels of mPL-II mRNA as assessed by Northern analysis were also reduced by hTNF-alpha treatment. The lowest concentration of hTNF-alpha that significantly inhibited mPL-II secretion by cells from day 12 of pregnancy was 0.01 nmol/l. hTNF-alpha treatment did not affect the secretion of mPL-I, PLF or PRP, as assessed by the concentrations of these proteins in the medium during a 5-day incubation. Incubation of the cells with 20 ng EGF/ml also did not affect the PLF or PRP concentration of the medium during 5 days of culture. To determine whether the effect of hTNF-alpha on mPL-II secretion was mediated by interleukin-6 (IL-6), the IL-6 concentration of the medium of control and hTNF-alpha-treated cells was determined. Bioactive and immunoreactive IL-6 could not be detected in medium from either treatment group. The presence of binding sites for hTNF-alpha was assessed in cells from day 12 of pregnancy. Scatchard analysis detected a single class of binding sites having a Kd of 1.61 +/- 0.34 nmol/l, with about 1350 sites per cell. The results of this study demonstrate that hTNF-alpha inhibits the secretion of mPL-II by placental cells from days 9 and 12 of pregnancy, suggesting that TNF-alpha may be one of the factors that regulate the production of this hormone in vivo.

Animals↗
PubMed1994

Involvement of epidermal growth factor (EGF)/EGF receptor autocrine and paracrine mechanism in human trophoblast cells: functional differentiation in vitro.

We have studied the expression of epidermal growth factor (EGF) and EGF receptors (EGF-R) in isolated human trophoblast cells at various stages of differentiation and also the biological significance of the EGF/EGF-R autocrine and paracrine mechanism. Cytotrophoblast cells were isolated from human placental tissues of 6-9 weeks of gestation. Trophoblast cells underwent morphological and functional differentiation during in vitro culture. The expression of EGF and EGF-R protein and mRNA was studied in trophoblast cells cultured for 0-5 days, using immunocytochemical staining, and reverse transcription and polymerase chain reaction. Monoclonal antibodies (mAbs) against EGF and EGF-R showed specific staining in trophoblast cells at all stages of differentiation. Both EGF and EGF-R gene transcripts were detected in RNA samples isolated from trophoblast cells at all stages. These data suggest the presence of an EGF/EGF-R autocrine and paracrine mechanism in human trophoblast cells. Next, we examined the biological significance of this mechanism on trophoblast cell differentiation in vitro. EGF added to the culture medium significantly increased human chorionic gonadotrophin-beta (hCG-beta) secretion and, more importantly, anti-EGF neutralizing mAbs significantly reduced both hCG-beta and human placental lactogen secretion from trophoblast cells in culture. All these results suggest that human trophoblast cells express both EGF and EGF-R, and that EGF may play an important role in the functional differentiation of human trophoblast cells.

Base Sequence↗
PubMed1994

Selegiline (L-deprenyl) and L-dopa treatment of Parkinson's disease: a double-blind trial.

To confirm the clinical utility of selegiline (L-deprenyl), a selective inhibitor of monoamine oxidase B, as an anti-Parkinson's disease (PD) agent, the first Japanese multi-center, double-blind comparative study of this drug was conducted. The subjects were patients who had responded poorly or suffered with other problems related to L-dopa treatment. A total of 112 patients in two groups, one given selegiline at a dose of 7.5 mg/day (Group D, n = 60) and another given a placebo (Group P, n = 52), were compared over an 8-week treatment period. The percentage patients showing "moderate improvement" or better was 34.5% in Group D, while that in Group P was 11.5% (P < 0.01). In the assessment of overall safety, 66.7% in Group D showed no adverse reactions, which was not significantly different from the result of 78.9% for Group P.

Aged↗