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Biomedical subjects

H Masuzaki

Publications and source records attributed to H Masuzaki.

At least 91 records · Page 5Linked to original sources
PubMed1996

Transvaginal color Doppler studies in gestational trophoblastic disease.

Three women with gestational trophoblastic disease were examined using transvaginal color Doppler at the initial diagnosis and after each course of chemotherapy. In all cases, the examination before chemotherapy revealed hypoechoic areas surrounded by irregular echogenic areas and numerous intramyometrial flow signals. Pulsed Doppler examination revealed a low pulsatility index (PI) in the uterine arteries. After the completion of chemotherapy, a decrease in the vascularity and increase in the PI of the uterine arteries were demonstrated in two cases. These findings were closely consistent with the decrease in serum levels of beta-human chorionic gonadotropin. However, in the patient who developed permanent arteriovenous communication, hypervascularity persisted and the PI of the uterine arteries remained low, even after clinical remission was achieved. The present study indicates that transvaginal color Doppler ultrasonography is useful for the evaluation of gestational trophoblastic disease, both at the time of diagnosis and after chemotherapy.

Adult↗
PubMed1996

Genomic cloning and localization to chromosome 11p15.5 of the human achaete-scute homolog 2 (ASCL2).

The mouse achaete-scute homolog-2 gene (Mash2), a member of the achaete-scute gene family, encodes a transcription factor that plays an important role in the development of the trophoblast. It has recently been reported that Mash2 is genomically imprinted and mapped to the distal region of mouse chromosome 7, where other imprinted genes, Ins2, Igf2 and H19 are located. We isolated a clone carrying the partial human homolog, ASCL2, from a human genomic phage library using a PCR product for the rat Ascl2-cDNA as a probe. By fluorescence in situ hybridization using a phage clone as a probe whose insert contained the partial human ASCL2, we assigned ASCL2 to human chromosome 11p15.5. Sequence comparisons of the human ASCL2 clone and the rat Ascl2-cDNA showed 86.9% identity spanning 206 nucleotides and 85.3% deduced polypeptide-sequence identity over 68 residues.

Amino Acid Sequence↗
PubMed1996

Regulation of very-low-density lipoprotein receptor in hypertrophic rat heart.

To elucidate the regulation of very-low density-lipoprotein (VLDL) receptor, we have studied its gene expression in the heart of spontaneously hypertensive rats-stroke prone (SHR-SP, an animal model for hypertension-induced cardiac hypertrophy) compared with Wistar-Kyoto rats. RNase protection assay showed that ventricular VLDL receptor mRNA falls to 41% of normal levels at 4 weeks when hypertension is not yet fully developed, and drops further to 14% at 13 weeks, when cardiac hypertrophy is established. Lipoprotein lipase mRNA decreases in parallel with VLDL receptor mRNA. In cultured neonatal rat ventricular cardiomyocytes, VLDL receptor mRNA decreases in parallel with the process of cardiocyte hypertrophy during the 24 hours after treatment with 10-8 mol/L endothelin-1, falling to 40% of the initial value. These results demonstrate that there is downregulation of VLDL receptor gene expression in cardiac hypertrophy both in vivo and in vitro and suggest that the regulation of the VLDL receptor is possibly linked with the switch in energy substrate from lipid to glucose known to occur in cardiac hypertrophy.

Animals↗
PubMed1995

Structural organization and chromosomal assignment of the human obese gene.

The obese (ob) gene has been identified through a positional cloning approach; the mutation of this gene causes marked hereditary obesity and diabetes mellitus in mice. We report here the isolation and characterization of the human ob gene. Southern blot analysis demonstrated a single copy of the ob gene in the human genome. The human ob gene spanned approximately 20 kilobases (kb) and contained three exons separated by two introns. The first intron, approximately 10.6 kb in size, occurred in the 5'-untranslated region, 29 base pair (bp) upstream of the ATG start codon. The second intron of 2.3 kb in size was located at glutamine +49. By rapid amplification of 5'-cDNA ends, the transcription initiation sites were mapped 54-57 bp upstream of the ATG start codon. The 172-bp 5'-flanking region of the human ob gene contained a TATA box-like sequence and several cis-acting regulatory elements (three copies of GC boxes, an AP-2-binding site, and a CCAAT/enhancer-binding protein-binding site). By the fluorescence in situ hybridization technique, the ob gene was assigned to human chromosome 7q31.3. This study should establish the genetic basis for ob gene research in humans, thereby leading to the better understanding of the molecular mechanisms underlying the ob gene.

Amino Acid Sequence↗
PubMed1995

Augmented expression of the obese gene in the adipose tissue from rats fed high-fat diet.

Expression of the obese (ob) gene is augmented in the adipose tissue in several rodent models of genetic obesity. In the present study, we examined the ob gene expression in a rodent model of acquired obesity obtained by pure overfeeding of normal rats. Male Sprague-Dawley rats at 8 weeks of age were fed standard diet or high-fat diet. Rats fed high-fat diet developed moderate degree of obesity, hyperglycemia, and hyperlipidemia as compared with rats fed standard diet. Northern blot analysis revealed that the ob gene is expressed abundantly in the adipose tissue obtained from the epididymal, mesenteric, subcutaneous, retroperitoneal, and interscapular fat pads in rats fed standard diet. Expression of the ob gene was augmented in all the adipose tissue examined in rats fed high-fat diet. The present study demonstrates that the ob gene expression is augmented in the adipose tissue in diet-induced obesity, thereby suggesting the pathophysiologic roles of the ob gene in acquired obesity.

Adipose Tissue↗
PubMed1995

Establishment of functional imprinting of the H19 gene in human developing placentae.

We have found that the imprinted H19 gene can be expressed either biallelically or monoallelically in the developing human placentae. H19 biallelic expression is confined to the placenta until 10 weeks of gestation, after which it becomes exclusively maternal, and does not affect allele-specificity or levels of IGF2 expression. The promoter region of H19 is hypomethylated at all stages of placental development, while the 3' portion shows progressive methylation of the paternal allele with gestation. Our observations demonstrate that the establishment of functional H19 imprinting occurs during the early development of the placenta and provide an opportunity to understand the mechanism by which the H19 primary imprint is manifested in somatic cells.

Alleles↗
PubMed1995

Local injection of methotrexate dissolved in saline versus methotrexate suspensions for the conservative treatment of ectopic pregnancy.

To compare the local injection of methotrexate (MTX) dissolved in saline and MTX suspensions for the laparoscopic treatment of ectopic pregnancy in terms of success rate and postoperative tubal patency. A total of 26 patients with unruptured ectopic pregnancies were selected from among 60 women with ectopic pregnancies admitted to the Nagasaki University clinic. Of these patients, 12 were treated with MTX dissolved in saline solution (solution group) and 14 with MTX suspensions consisting of lipiodol (LPD) with phosphatidylcholine (PC) added as a dispersing stabilizer (suspension group). Except for one case treated under transvaginal guidance, all the patients were treated by laparoscopy. Persistent ectopic pregnancy was recognized in seven cases (58%) in the solution group but in only two cases (14%) in the suspension group. Moreover, rupture occurred in two cases in the solution group but in no case in the suspension group. A patent treated tube was found in seven of 10 cases in the saline group and in 10 of 12 cases in the suspension group. During the follow-up period of 6-31 months, five women in the saline group and three women in the suspension group had an intrauterine pregnancy. In this study, the local injection of MTX is considered to be a reasonable method for the treatment of unruptured ectopic pregnancy, and the MTX suspension seems to be more effective and useful than MTX solution.

Adolescent↗
PubMed1995

Decreased expression of the very low density lipoprotein receptor mRNA in the cardiac ventricle of spontaneously hypertensive rats.

1. To elucidate the functional implication of very low density lipoprotein (VLDL) receptor, we studied the gene expression of VLDL receptor in rats. The VLDL receptor mRNA was highly expressed in the cardiac ventricle and skeletal muscle. Intermediate amounts of VLDL receptor mRNA were detected in adipose tissue, adrenal gland, brain and lung. Thus the tissue distribution of VLDL receptor mRNA in rats was similar to that reported previously in rabbits. 2. We studied the gene expression of the VLDL receptor in the heart of stroke-prone spontaneously hypertensive rats (SHRSP), an animal model for hypertension-induced cardiac hypertrophy. RNase protection assay showed that the level of ventricular VLDL receptor mRNA was already decreased to one half when hypertension was not fully developed, and further diminished to one fifth when cardiac hypertrophy was established. 3. It is reported that energy utilization in SHRSP hypertrophied myocardium is impaired. Our results suggest that inactive fatty acid metabolism in the ventricle of SHRSP is related to the lowered expression of the VLDL receptor which is postulated as a gate for triglyceride-rich lipoprotein particle.

Animals↗
PubMed1995

A new approach to methotrexate and lipiodol suspensions for ectopic pregnancy: preliminary in vitro and animal experiments.

OBJECTIVES: To measure and evaluate the in vitro release of MTX from suspensions of methotrexate (MTX) and lipiodol (LPD), and to investigate the MTX concentration and fertility rate using an animal model. METHODS: This study was divided into three components: a) An in vitro Release Study, b) Animal Study No. 1 (concentration of tissue and plasma levels), and c) Animal Study No. 2 (fertility rate after MTX suspension). RESULT: The releasing rate in vitro was more rapid with MTX-S (MTX dissolved in saline) than with either MTX-LPD (MTX dissolved in lipiodol) or MTX-LPD-PC (MTX suspended in lipiodol and phosphatidylcholin, i.e., MTX suspension). The tissue concentration tended to be higher with an MTX suspension than with MTX-S. There was no significant difference in the fertility rate or the nidation index among the 3 groups (Groups 1, 2, and 3). CONCLUSION: The injection of an MTX suspension is useful for increasing the tissue concentration and maintaining the long-term effectiveness of MTX, and this technique might offer a new approach in the treatment of ectopic pregnancy (EP) or in second-line therapy for persistent EP.

Animals↗
PubMed1995

Molecular cloning of rat obese cDNA and augmented gene expression in genetically obese Zucker fatty (fa/fa) rats.

The obese (ob) gene has recently been isolated through a positional cloning approach, the mutation of which causes a marked hereditary obesity and diabetes mellitus in mice. In the present study, we isolated rat ob cDNA and examined the tissue distribution of the ob gene expression in rats. We also studied the gene expression in genetically obese Zucker fatty (fa/fa) rats. The rat ob gene product, a 167 amino acid protein with a putative signal sequence, was 96 and 83% homologous to the mouse and human ob proteins, respectively. Northern blot analysis using the rat ob cDNA probe identified a single mRNA species of 4.5 kb in size in the adipose tissue, while no significant amount of ob mRNA was present in other tissues in rats. The ob gene was expressed in the adipose tissue with region specificities. The rank order of the ob mRNA level in the adipose tissue was epididymal, retroperitoneal, and pericardial white adipose tissue > mesenteric and subcutaneous white adipose tissue > or = interscapular brown adipose tissue. The ob gene expression occurred in mature adipocytes rather than in stromalvascular cells isolated from the rat adipose tissue. Expression of the ob gene was markedly augmented in all the adipose tissue examined in Zucker fatty (fa/fa) rats at the stage of established obesity. The present study leads to the better understanding of the physiologic and pathophysiologic roles of the ob gene.

Adipose Tissue↗
PubMed1995

Human obese gene expression. Adipocyte-specific expression and regional differences in the adipose tissue.

The obese (ob) gene, the mutation of which results in severe hereditary obesity and diabetes in mice, has recently been isolated through positional cloning. In this study, we isolated a full-length human ob complementary DNA (cDNA) clone and examined the tissue distribution of ob gene expression in humans. The nucleotide sequences of the human ob cDNA coding region were 83% identical to those of the mouse and rat ob cDNA coding regions. Analysis of the deduced amino acid sequences revealed that the human ob protein is a 166-amino acid polypeptide with a putative signal sequence and is 84 and 83% homologous to the mouse and rat ob proteins, respectively. Northern blot analysis using the cloned human ob cDNA fragment as a probe identified a single messenger RNA (mRNA) species 4.5 kb in size found abundantly in the adipose tissues obtained from the subcutaneous, omental, retroperitoneal, perilymphatic, and mesenteric fat pads. However, no significant amount of ob mRNA was present in the brain, heart, lung, liver, stomach, pancreas, spleen, small intestine, kidney, prostate, testis, colon, or skeletal muscle. The ob mRNA level in the adipose tissue varied from region to region even in the same individual. Furthermore, in the human adipose tissue, ob gene expression occurred in mature adipocytes rather than in stromal-vascular cells. This study is the first report of the elucidation of ob gene expression in human tissues, thereby leading to better understanding of the physiological and clinical implications of the ob gene.

Adipocytes↗
PubMed1995

[The relationship between blood flow redistribution in umbilical artery and middle cerebral artery and fetal growth in intrauterine growth retardation].

The aim of this study was to evaluate the usefulness of umbilical artery and middle cerebral artery PI and the ratio of these values as predictors of fetal growth-retardation and adverse perinatal outcome. In 100 normal fetuses and 105 intrauterine growth-retarded fetuses Doppler velocity waveforms were recorded from the umbilical artery and middle cerebral artery, and we calculated the incidence of low birth weight, gestational age at delivery, fetal distress and umbilical artery blood gas. The results were as follows: 1. There were moderate correlations between umbilical PI and birth weight (r = -0.43, p < 0.0001) and between middle cerebral artery PI and birth weight (r = 0.37, p < 0.0001) and a close correlation between cerebral-umbilical PI ratio and birth weight (r = 0.71, p < 0.0001). 2. There was a significant association between the cerebral-umbilical PI ratio and the HC/AC ratio (r = -0.46, p < 0.0001). 3. The cerebral-umbilical PI ratio was the best predictor of birth weight, fetal distress and neonatal mortality compared with umbilical artery PI and middle cerebral artery PI. In growth retarded fetuses, high umbilical artery PI and low middle cerebral artery PI, the so called "brain sparing effect" was demonstrated. The cerebral-umbilical PI ratio provided a better predictor of IUGR and adverse perinatal outcome than umbilical artery PI and middle cerebral artery PI alone.

Blood Flow Velocity↗
PubMed1994

Effects of estradiol on very low density lipoprotein receptor mRNA levels in rabbit heart.

The VLDL receptor, a newly identified lipoprotein receptor, has a domain structure homologous with the LDL receptor but has one additional cysteine rich repeat in the ligand binding domain. To study the regulation of the VLDL receptor in vivo, we administered 17 alpha-ethinyl estradiol to rabbits and examined its effects on VLDL receptor mRNA levels in the heart, one of the organs with highly expressed VLDL receptors, by RNA blotting. The ventricular level of VLDL receptor mRNA increased dramatically after estradiol administration. We could not detect VLDL receptor mRNA in the liver even after estradiol administration. We have confirmed the enhanced expression of liver LDL receptor mRNA by estradiol, however, only weak expression of the LDL receptor was detected in the ventricle of the rabbit heart. These results suggest that estradiol exerts its effect on the VLDL receptor gene expression in the heart.

Animals↗
PubMed1994

A point mutation at ATP-binding region of the ALD gene in a family with X-linked adrenoleukodystrophy.

A prenatal diagnosis was performed in a family with X-linked adrenoleukodystrophy (ALD). A fetus was at high risk of suffering the disease by segregation analysis and by very long chain fatty acid-CoA synthetase activity assay. A transition (G to A) at codon 617 of the candidate ALD gene was detected by reverse transcription PCR (RT-PCR) based sequencing of the fetal liver RNA. The mutation was located in highly conserved ATP-binding site in this gene and deduced amino acid transversion R617H was thought to be the cause of ALD in this family.

Adenosine Triphosphate↗
PubMed1994

Influence of ovarian endometrioma on fertility.

OBJECTIVE: This study examines the influence of ovarian endometrioma on fertility. STUDY DESIGN: For 117 infertile women who were diagnosed as having endometriosis by laparoscopy and who underwent danazol therapy, we examined (1) the relationship between ovarian endometrioma and level of bead-phagocytotic macrophages in ascites and the interleukin-1 beta level, (2) the relationship between ovarian endometrioma and pregnancy rate during the 36 months after danazol therapy, and (3) the relationship between ovarian endometrioma and pregnancy rate, considering the severity of the lesion on the bilateral tubes and the pelvic peritoneum. RESULTS: (1) The levels of bead-phagocytotic macrophages in patients with or without ovarian endometrioma were 68% and 67%, respectively (not significant). Similarly, no significant difference was seen in the interleukin-1 beta positive rate between the two groups. (2) The pregnancy rates of the former group and the latter group were 36% and 43%, respectively (not significant). (3) The existence or absence of ovarian endometrioma made no significant difference in the pregnancy rate in a group of patients with no lesions in the bilateral tubes or in another group with no lesions and scattered endometriotic implants on the peritoneum. CONCLUSIONS: It seems unlikely that ovarian endometrioma itself significantly impedes fertility after danazol therapy.

Adult↗