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Biomedical subjects

H Furuta

Publications and source records attributed to H Furuta.

At least 73 records · Page 4Linked to original sources
PubMed1999

Proliferation of exogenously injected primordial germ cells (PGCs) into busulfan-treated chicken embryos.

AIM: This study was designed to investigate the effect of busulfan treatment on the proliferation of chicken primordial germ cells (PGCs) in vivo, focusing on the preferential settlement of PGCs onto the germinal ridges of chicken embryos. METHODS: Busulfan (250 ng/egg) was injected into the egg white of freshly oviposited fertilized eggs, which were then incubated. Embryonic development and viability were examined, and exogenous PGCs collected from embryonic blood vessels were injected into the germinal crescent region of recipient embryos. The number of PGCs resided onto germinal ridges of the right and left sides were compared. RESULTS: Busulfan had a slight harmful effect on the embryo viability and the PGCs proliferation. The number of PGCs resided onto the left side of germinal ridges was slightly higher as compared with the right side. CONCLUSION: Busulfan suppressed the viability of embryos and the proliferation of endogenous PGCs in the recipient embryos. However, the number of exogenous PGCs proliferated was higher in embryos treated with busulfan than those without busulfan. Data also suggest the possibility of a preferential residence of PGCs toward the left side of the germinal crescent region as compared with the right, which may be due to a more advanced functional development of the left gonad than the right.

Animals↗
PubMed1998

The novel cyclopropapyrroloindole(CPI) bisalkylators bearing 3,3'-(1,4-phenylene)diacryloyl group as a linker.

The novel cyclopropapyrroloindole(CPI) bisalkylators were synthesized and their antitumor activity was evaluated. Among these derivatives, AT-760 (5a) in which the two 3-methoxycarbonyl-2-trifluoromethylCPI (MCTFCPI) moieties are connected with a 3,3'-(1,4-phenylene)diacryloyl group, was found to exhibit more prominent cytotoxicity and antitumor activity than U-77,779 (bizelesin) (1).

Adenocarcinoma↗
PubMed1998

Stimulatory effects of 4-methylcatechol, dopamine and levodopa on the expression of metallothionein-III (GIF) mRNA in immortalized mouse brain glial cells (VR-2g).

Metallothionein (MT)-III, originally discovered as a growth inhibitory factor (GIF), is a brain specific isomer of MTs and is markedly reduced in the brain of Alzheimer's disease patients (AD) and in several other neurodegenerative diseases. We analyzed the level and regulation of mRNA expression of MT-III in immortalized fetal mouse brain glial cells (VR-2g) by reverse transcriptase-polymerase chain reaction (RT-PCR). The basal expression level of MT-III mRNA is very low in VR-2g cells. 4-Methylcatechol, dopamine (DA) and levodopa (l-3, 4-dihydroxyphenylalanine), which stimulate the synthesis of nerve growth factor (NGF), further increased the expression of MT-III mRNA in VR-2g cells.

Animals↗
PubMed1998

A missense mutation in hepatocyte nuclear factor-4 alpha, resulting in a reduced transactivation activity, in human late-onset non-insulin-dependent diabetes mellitus.

Non-insulin-dependent diabetes mellitus (NIDDM) is a heterogeneous disorder characterized by hyperglycemia resulting from defects in insulin secretion and action. Recent studies have found mutations in the hepatocyte nuclear factor-4 alpha gene (HNF-4alpha) in families with maturity-onset diabetes of the young (MODY), an autosomal dominant form of diabetes characterized by early age at onset and a defect in glucose-stimulated insulin secretion. During the course of our search for susceptibility genes contributing to the more common late-onset NIDDM forms, we observed nominal evidence for linkage between NIDDM and markers in the region of the HNF-4alpha/MODY1 locus in a subset of French families with NIDDM diagnosed before 45 yr of age. Thus, we screened these families for mutations in the HNF-4alpha gene. We found a missense mutation, resulting in a valine-to-isoleucine substitution at codon 393 in a single family. This mutation cosegregated with diabetes and impaired insulin secretion, and was not present in 119 control subjects. Expression studies showed that this conservative substitution is associated with a marked reduction of transactivation activity, a result consistent with this mutation contributing to the insulin secretory defect observed in this family.

Age of Onset↗
PubMed1998

Successful peripheral T-lymphocyte-directed gene transfer for a patient with severe combined immune deficiency caused by adenosine deaminase deficiency.

Ten patients with adenosine deaminase deficiency (ADA-) have been enrolled in gene therapy clinical trials since the first patient was treated in September 1990. We describe a Japanese ADA- severe combined immune deficiency (SCID) patient who has received periodic infusions of genetically modified autologous T lymphocytes transduced with the human ADA cDNA containing retroviral vector LASN. The percentage of peripheral blood lymphocytes carrying the transduced ADA gene has remained stable at 10% to 20% during the 12 months since the fourth infusion. ADA enzyme activity in the patient's circulating T cells, which was only marginally detected before gene transfer, increased to levels comparable to those of a heterozygous carrier individual and was associated with increased T-lymphocyte counts and improvement of the patient's immune function. The results obtained in this trial are in agreement with previously published observations and support the usefulness of T lymphocyte-directed gene transfer in the treatment of ADA-SCID.

Adenosine Deaminase↗
PubMed1998

Elevation of serum IgE level and peripheral eosinophil count during T lymphocyte-directed gene therapy for ADA deficiency: implication of Tc2-like cells after gene transduction procedure.

We have successfully carried out T-cell-directed gene therapy for a boy with severe combined immunodeficiency due to adenosine deaminase deficiency (ADA SCID) and unexpectedly found an elevation of serum IgE level and peripheral eosinophil count during the course. More than 90% of transduced cells cultured for 7-11 days before infusion into the patient were positive for CD8 and expressed Th2-type cytokine genes such as IL-4, IL-5 and IL-13. Furthermore, CD4(+) T-depleted PBMC (peripheral blood mononuclear cells) from the patient synthesized IgE in vitro by stimulation with IL-4. Collectively, these results suggested that Tc2-like cells in the transduced cells have distinct immunological functions to help IgE synthesis and activate eosinophils.

Adenosine Deaminase↗
PubMed1998

Expression of mRNA encoding vasopressin V1a, vasopressin V2, and ANP-B receptors in the rat cochlea.

The expression of mRNAs encoding vasopressin V1a, V2, and ANP-B receptors in the rat cochlea was examined by PCR and in situ hybridization. After reverse-transcription of rat cochlear RNA, cDNA was amplified by PCR using pairs of primers specific to these receptors. After subcloning of the PCR products, clones with sequences identical to those cloned previously from the rat liver (V1a receptor), kidney (V2 receptor) and brain (ANP-B receptor) were obtained. The localization of expression of those receptors in the developing and adult rat cochlea was examined by in situ hybridization using 35S-labeled cRNA probes. The V1a and V2 receptors were expressed throughout the whole of the neonatal rat cochlea, while no expression was detected in the adult cochlea. The ANP-B receptor was expressed throughout the whole of the neonatal cochlea. In the adult cochlea, expression was observed in the spiral ganglion and the spiral ligament. These results suggest that vasopressin may play a role in the development of the cochlea, and that natriuretic peptide may play a role in the function of the spiral ganglion and the spiral ligament.

Aging↗
PubMed1998

Evidence for differential regulation of calcium by outer versus inner hair cells: plasma membrane Ca-ATPase gene expression.

The expression of mRNA encoding plasma membrane calcium ATPase (PMCA) subunit isoforms (1-4) and splice variants was examined in the adult and developing rat cochlea by PCR and in situ hybridization. High levels of PMCA mRNA expression were observed in the neurons of the spiral ganglion, and in hair cells. Spiral ganglion neurons expressed PMCA 1-3 beginning in embryonic development, reaching high levels shortly after birth, and continuing into adulthood. Inner hair cells expressed PMCA 1 at moderate levels from birth to the time of onset of cochlear function on postnatal day 12, and strongly from then until adulthood. Outer hair cells expressed PMCA 2 at high levels from shortly after birth through adulthood. The data suggest that the calcium clearance requirements of inner and outer hair cells are distinct. PMCA 2 is the isoform with the highest affinity for calmodulin, and has also been associated with high levels of inositol triphosphate. Its presence in outer hair cells suggests that regulation of the enzyme by calmodulin may be particularly important for this hair cell type. It further suggests that inositol phosphate may play a unique role in the outer hair cell.

Animals↗
PubMed1998

Membrane potential in isolated epithelial cells of the endolymphatic sac in the guinea-pig.

The membrane potential (Em) in epithelial cells isolated from the intermediate portion of the endolymphatic sac (ES) of the guinea-pig was recorded using the whole-cell patch-clamp technique. In the steady state the Em was -53.5+/-1.5 mV (n = 74), which is similar to that in epithelial cells of other tissues. Application of 1 MM ouabain induced a depolarization of Em by approximately 10 mV (n = 6), suggesting that an active ion transport process by Na+-K+-ATPase may be present in the ES epithelial membrane. Increasing extracellular K+ concentrations from 5 to 100 mM induced a significant membrane depolarization that was close to the K+ equilibrium potential calculated by the Nernst equation, indicating that K+ may be a predominant permeable ion in the ES epithelial membrane. Total replacement of extracellular Na+ with NMDG+ led to a significant membrane hyperpolarization of 38.7+/-2.5 mV (n = 18), suggesting that Na+ may be another major permeable ion for the ES epithelial membrane. Reducing extracellular Cl- concentrations from 149.3 to 7 mM had no significant effect on Em, indicating that Cl- may be a negligible permeable ion in the ES epithelial membrane.

Animals↗
PubMed1998

Changes in work performances in obstructive sleep apnea patients after dental appliance therapy.

The effects of dental appliances on work performances of obstructive sleep apnea syndrome (OSAS) is not well examined. This study evaluated the polysomnographic and psychological findings before and after therapy. Nine patients were diagnosed OSAS by nocturnal polysomnography. The psychological batter, was performed from 13:00 to 14:00, which consisted of Uchida-Kraepelin psychodiagnostic test (U-K's test) and Bourdon's cancellation test (Bourdon's test). Approximately 3 months after the treatment, the examinations were performed. Apnea and desaturation index decreased significantly after the therapy. In addition, sleep architecture improved after the therapy compared with that before the therapy. Dysfunction of task performances, such as mean level of work amounts in U-K's test, mean error, mean performance time and mean deviation in Bourdon's test improved after therapy. We conclude that dental appliances therapy is effective not only to apnea but also to work performance in OSAS.

Adult↗
PubMed1998

Genetic analysis of 13 families with X-linked chronic granulomatous disease reveals a low proportion of sporadic patients and a high proportion of sporadic carriers.

X-linked chronic granulomatous disease (X-CGD) is the most common type of CGD, whose responsible gene has been identified and termed as CYBB, according to the gp91-phox, a subunit of cytochrome b558. Although approximately 200 different mutations of the gp91-phox gene have been reported, no precise study of the proportion of sporadic cases in X-CGD, based on molecular genetic analysis, has been reported. We made a genetic analysis of six newly identified X-CGD patients together with that of eight previously reported X-CGD patients. The mutations newly detected were three missense mutations, two splice mutations, and one insertion of 2 bases. All of the mutations were novel. Twelve mothers (two of them came from the same family) and four maternal grandmothers from 13 different X-CGD families were available for further genetic studies. It was revealed that a proportion of sporadic patients was low and that of sporadic carriers was high. These results suggest that the mutation for the disease originates mainly from male gametes.

Alternative Splicing↗
PubMed1998

Characterization of the promoter of the mouse prohormone convertase PC2 gene.

Prohormone convertase 2 (PC2) is a member of a family of mammalian subtilisin-like endoproteases that are involved in the processing of prohormones, neuropeptides and many other precursor derived proteins. The expression of PC2 is restricted to neuroendocrine tissues such as pancreatic islets, the pituitary and the brain. To understand the regulation of the PC2 gene, we cloned and characterized the promoter region of the mouse PC2 gene. The transcriptional start site of the mouse PC2 gene is identical to that of the human. There is 79% identity in the sequences of the promoter regions between the mouse and human PC2 genes. The mouse PC2 gene, like the human, does not have a TATA-like motif in the region just upstream of the start of the transcription. Studies with promoter-reporter gene, chloramphenicol acetyltransferase (CAT), constructs showed that the region from -400 to -170 bp was necessary for high level expression of the mouse PC2 gene in the betaTC-3 insulinoma cells.

Animals↗
PubMed1998

[Efficacy of the MIDCAB doughnut: a new instrument for immobilization and hemostasis during MIDCAB].

A new instrument for the immobilization and hemostasis of an anastomotic site during off-pump bypass is described. The instrument called "MIDCAB doughnut" was used safely and accurately in 31 patients who underwent MIDCAB without CPB. In these, the instrument was applied in 44 anastomotic sites on the beating heart (30 left anterior descending, 7 right coronary, and 7 obtuse marginal arteries). It can make an operative field motionless and bloodless without distal snaring, because of air sucked fixation of an entire circuit of the anastomotic site. There was no operative and hospital deaths. Postoperative angiography revealed a 100% patency rate of the grafts. MIDCAB doughnut can improve a quality of the anastomosis during beating bypass surgery.

Cardiac Surgical Procedures↗
PubMed1998

[Minimally invasive direct coronary artery bypass grafting (MIDCAB) for right and circumflex coronary artery systems].

BACKGROUND: Single-vessel coronary bypass grafting of the left internal thoracic artery (LITA) to the left anterior descending coronary artery (LAD) with mini-thoracotomy has been shown to produce excellent results with almost no mortality. However this procedure cannot be used in patients with double or triple vessel disease. METHODS: Between Aug. 96 and Dec. 97, 17 pts underwent minimally invasive direct coronary artery bypass (MIDCAB) to right (RCA) and circumflex coronary artery (CX). LITA and RITA were thoracicscopically harvested and the right gastroepiploic artery (RGEA), inferior epigastric artery, and radial artery were then harvested. A limited left thoracotomy in combination with limited anterior right thoracotomy (n = 3) or right lower parasternal incision extending to below the xiphoid process (n = 6) were made. The double MIDCAB as performed in 16 pts and triple in 1 pt. RESULTS: There was no operative death. At follow up, all pts are alive and well. The postoperative angiographic studies showed 30/31 grafts were patent. CONCLUSION: The utility of multi-vessel MIDCAB for the LAD, CX and RCA with in-site arterial grafts has been demonstrated in the present study. This less invasive surgical technique may become a viable option for the management of multi-vessel coronary artery disease.

Aged↗
PubMed1998

Effect of acetazolamide on cation concentration in the endolymph of the endolymphatic sac.

Acetazolamide (ACTZ), a carbonic anhydrase inhibitor, has been reported to decrease the endolymphatic sac (ES) DC potential (ESP) in the guinea pig. To assess the involvement of cation transport in the ESP change by ACTZ we examined the effect of ACTZ upon the K+ and Na+ activities of the ES endolymph in the guinea pig using ion-sensitive microelectrode. ACTZ (10 mg/kg), a dose that produces the ESP maximum reduction, produced a significant increase in Na+ activity of the ES endolymph with no change in K+ activity. The results suggest that Na+ transport may be directly or indirectly involved in ESP reduction by ACTZ, and that a Na(+)-H+ exchanger may be involved in Na+ influx pathway from endolymph to the ES epithelial cells.

Acetazolamide↗