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Biomedical subjects

H Ohashi

Publications and source records attributed to H Ohashi.

At least 307 records · Page 17Linked to original sources
PubMed1994

[Surgical treatment of supravalvular aortic stenosis].

In the last 14 years, 7 consecutive patients with supravalvular aortic stenosis (SVAS) underwent surgical treatment for SVAS and/or for associated lesions. There were 5 male and 2 female patients ranging in age from 3 months to 12 years. Six of them had associated other cardiac anomalies; two had severe multiple peripheral pulmonary stenoses (PPS) and one each had ventricular septal defect (VSD), valvular pulmonary stenosis, coarctation of aorta with patent ductus arteriosus (PDA), total anomalous pulmonary venous return (TAPVR) with pulmonary branch stenosis, PPS and left lower pulmonary venous obstruction. The type of SVAS were localized in all and 5 of them underwent successful surgical repair of SVAS (3 with extended aortoplasty and 2 with patch aortoplasty). In 2 patients with VSD or valvular pulmonary stenosis, associated cardiac anomalies and SVAS were repaired simultaneously. Four patients had undergone previous operations, which included repair of severe multiple PPS by extended peripheral pulmonary arterioplasty (case 4, 6), repair of coarctation of aorta and division of PDA (case 5), repair of TAPVR (Ia + IIa) and pulmonary branch stenosis (case 7). There was no operative death and one patient died late postoperatively (case 7) due to right heart failure in a follow up period of 3 to 14 years. In conclusion, it is important to select the appropriate surgical treatment according to the location and the severity of associated other cardiac anomalies as well as the severity of SVAS, and extended peripheral pulmonary arterioplasty is considered to be a recommended method for the relief of severe multiple PPS associated with SVAS.

Aorta↗
PubMed1994

[Comparison of long-term clinical results and cost-effectiveness of percutaneous coronary angioplasty and coronary artery bypass grafting].

Cost-effectiveness was studied in 313 cases who had PTCA and 161 cases who had CABG as a first measure of interventional therapy for their coronary heart disease. Follow-up time ranged from 2 years to 5 years and 9 months with a mean interval of 3 years and 10 months. In the PTCA group a mean of 1.33 successfully dilated vessels/patient was obtained, but a total of 100 additional PTCA or bypass surgery procedure was necessary in the follow-up period. In the CABG group a mean of 2.60 patent grafts/patient was obtained. Mean length of hospital stay and charge was 21.9 days and 2,071 thousand yen in the PTCA group, and 82.2 days and 5,122 thousand yen in the CABG group through the entire follow up period. Cardiac event-free survival rate was significantly worse in the PTCA group. In the subgroup of two vessel disease, mean number of successfully dilated targets or patent grafts was 1.32 in the PTCA group and 1.88 in the CABG group. Total length of hospital stay and charge was 24.1 days and 2,352 thousand yen in the PTCA group and 86.2 days and 4,903 thousand yen in the CABG group. Cardiac event-free survival rate was significantly worse in the PTCA group. In the subgroup of three vessel disease, PTCA yielded 1.34 dilated target vessels, whereas CABG 2.66 patent grafts, which was two times more than the former one. Total length of hospital stay and charge was 32.7 days and 2,612 thousand yen in the PTCA group, and 82.4 days and 5,225 thousand yen in the CABG group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Effects of manidipine hydrochloride on renal function in renal parenchymal hypertensive patients].

The incidence of renal parenchymal hypertension is highest in patients with secondary hypertension. It is important to prevent the progression of renal dysfunction by appropriate treatment, especially by means of antihypertensive drugs. Calcium channel blockers are considered to have the advantage as antihypertensive drugs of maintaining the renal blood flow, even though the perfusion pressure may be decreased. However, these drugs can involve the risk of deteriorating the glomerular function due to hyperfiltration. To investigate whether calcium channel blockers can prevent the deterioration of renal function in renal parenchymal hypertensive patients, we administered manidipine hydrochloride (20 mg, once a day, 24 weeks) to 16 outpatients and evaluated its effects on blood pressure and renal function. The following results were obtained. (1) The systolic and diastolic pressure decreased from 2 and 4 weeks after administration, respectively. A stable antihypertensive effect appeared thereafter and no change was observed in the pulse rate. (2) The renal vascular resistance tended to decrease slightly. The glomerular filtration rate and renal blood flow did not change in spite of the decreased perfusion pressure. (3) No changes were seen in urinary protein, endocrine factors and cardiac function. (4) In some of the cases with decreased GFR (< 70ml/min), the drug could not prevent deterioration of the renal function and did not produce an antihypertensive effect.

Adult↗
PubMed1994

[Additional palliative operation and staged definitive operation for pulmonary atresia with intact ventricular septum].

Between 1981 and 1992, 38 consecutive patients underwent initial operation for pulmonary atresia with intact ventricular septum. Transpulmonary valvotomy using balloon occlusion of RV outflow was carried out in 24 patients at a mean age of 20 days. An additional Blalock-Taussig shunt was required in 4 patients early in the series. Based on a retrospective review on the patients early in the series, initial palliative procedure had been decided in conformity with the value of an index of RV development (RVDI) = RVEDV% x TVD% x RVODmm/BSAm2 x 10(-5), and recent 3 patients with RVDI < 0.35 and patent RV outflow underwent concomitant valvotomy and Blalock-Taussig shunt. Fourteen patients with muscular atresia of RV outflow or major sinusoidal coronary artery communication underwent Blalock-Taussig shunt. There were 1 operative and 3 late deaths and second Blalock-Taussig shunt was required in 6 patients. Definitive repair was carried out in 20 patients between 1985 and 1994. Fifteen patients with RVEDV > 30% of normal had biventricular repair (partial closure of ASD in 6) and 5 underwent Fontan type repair. In terms of the definitive procedures, when the RV.TV index (= RVEDV% x TVD% x 10(-4)) is greater than 0.4, complete repair should be performed. When the index is between 0.2 and 0.4, the atrial septal defect should only be partially closed when the outflow tract is reconstructed. In those cases with an index of less than 0.2, the Fontan procedure seems to be a procedure of choice.

Humans↗
PubMed1993

Characterization of a fusion protein composed of the extracellular domain of c-kit and the Fc region of human IgG expressed in a baculovirus system.

The extracellular domain of c-kit, which is the receptor for stem cell factor (SCF), was fused genetically to the Fc portion of human immunoglobulin G1. This chimeric protein, c-kitFc, was then expressed in the baculovirus system. The fusion product was secreted into the serum-free culture medium as a soluble dimeric form of approximately 210 Kda. The recombinant protein was easily purified by protein A affinity chromatography at approximately 25 micrograms protein per ml of medium. Binding assay and cross-linking assay showed that the fusion protein retained high affinity for binding SCF (Kd = 0.3 nM). Addition of the chimeric protein into the culture medium of SCF-dependent cells inhibited cell proliferation in a dose-dependent manner. These results suggest that the dimeric c-kitFc protein can be used as an antagonist of SCF for the study of hematopoietic progenitor cells.

Animals↗
PubMed1993

Secretory cell immunoscreening assay--a highly sensitive screening method for secretory cells.

We have developed a rapid and sensitive screening method to detect the secretory product from transformed secretory cells. Polyclonal antibodies against the target secretory protein are first adsorbed onto a nitrocellulose membrane and are then called solid-phase antibodies. Then this membrane is placed on top of target protein-secreting adherent animal cell colonies. After trapping the secreted protein on the membrane, the protein is detected using the highly sensitive enhanced chemiluminescence detection system. Thus, this method is named the secretory cell immunoscreening assay (SCISA). We have screened recombinant BHK-21 cells, which secrete human interleukin-6 (hIL-6) for highly productive clones. With the SCISA method, it is possible to detect less than 100 pg of hIL-6 secreted by a single colony. We are also able to select highly productive colonies rapidly and easily from a large sample population of transformed cell colonies.

Animals↗
PubMed1993

Characterization of type I IGF receptor and IGF-I mRNA expression in cultured human and bovine glomerular cells.

Glomerular hypertrophy is reported in several endocrine disorders such as acromegaly and diabetes mellitus, where abnormalities of growth hormone and insulin-like growth factor (IGF-I) have been reported. In the present report, we have cultured bovine and human glomerular endothelial cells, and bovine glomerular epithelial and mesangial cells, and characterized the expression of IGF-I mRNA and its receptor in these cells. High affinity, specific receptors for IGF-I were identified in all three types of cells by radioreceptor assays. Receptor number (Ro) derived by Scatchard analysis revealed an unusually high number of Type I IGF receptors, approx. 1.2 x 10(5) receptors/cell in glomerular endothelial cells. Affinity crosslinking studies and immunoprecipitation with antibodies against the Type I IGF receptor identified the alpha-subunit of the IGF-I receptor as having a molecular mass of 140 kDa. Biologically, IGF-I was more potent than insulin or IGF-II in stimulating DNA synthesis in glomerular endothelial cells. Northern blot analysis showed that glomerular and aortic endothelial cells expressed IGF-1 mRNA of 1.7 kb. In contrast, renal glomeruli showed several IGF-1 mRNAs of 7.5, 1.7 and 1.2 kb. Thus, the demonstration of both a prepondence of Type I IGF receptors coupled with the growth promoting effects of IGF-I in glomerular endothelial and epithelial cells, as well as the local production of IGF-I mRNA suggests that IGF-I serves an important role as an autocrine or paracrine regulator of the growth of renal glomeruli.

Animals↗
PubMed1993

Processing of a fusion protein by endoprotease in COS-1 cells for secretion of mature peptide by using a chimeric expression vector.

The subtilisin-related proprotein convertase furin is expressed in various mammalian tissues. Expecting that COS-1 cells have a furin-like endoprotease, we constructed a fusion expression vector for production of a recombinant foreign protein having no signal peptide or a protein in truncated form into secreted mature protein. A cDNA fragment encoding N-terminal procalcitonin (pro-CT) of human calcitonin precursor was inserted into the mammalian expression vector pME18S. We used PCR techniques to generate four kinds of cDNAs encoding the C terminus of the pro-CT with Arg residues at P4 (Arg-Xaa-Lys-Arg), P6 (Arg-Xaa-Xaa-Xaa-Lys-Arg), or both (Arg-Xaa-Arg-Xaa-Lys-Arg), in addition to the Lys-Arg motif at the cleavage site, in order to determine the conditions for efficient processing in nonendocrine cells, such as COS-1 cells. The cDNA coding for the Fc fragment of human immunoglobulin G1 was fused in-frame to the cDNA encoding pro-CT at its C terminus. Upon transfection of the chimeric plasmids into COS-1 cells, almost all of the fusion protein with the Arg residues at both P4 and P6 were processed into secreted Fc product, even without cotransfection of furin. These results indicate that COS-1 cells have a furin-like endoprotease and suggest that pro-CT, with the Arg residues at both P4 and P6, can be used as a carrier peptide for expression of a foreign protein having no signal peptide or a protein in truncated form in COS-1 cells.

Amino Acid Sequence↗
PubMed1993

Effect of trimebutine on K+ current in rabbit ileal smooth muscle cells.

The effect of trimebutine on the K+ current in rabbit ileal smooth muscle cells was investigated using the whole-cell patch-clamp technique. Trimebutine (10 microM) inhibited an outward current consisting of a Ca(2+)-dependent K+ current (IKCa) and Ca(2+)-independent K+ current (IKv), elicited by stepping from -80 to -20 mV or more positive. Trimebutine reduced dose dependently the IKv amplitude with an IC50 of 7.6 microM and IKCa amplitude with an IC50 of 23.5 microM. The IKv inhibition was neither voltage- nor use-dependent. Trimebutine (1-100 microM) decreased the amplitude and discharge rate of spontaneous transient outward currents. Trimebutine (30 microM) produced a sustained membrane depolarization of about 10 mV accompanied by a decrease in membrane conductance. The results suggest that the excitatory effects of trimebutine on the gastrointestinal tract may be attributable to the inhibitory action on the K+ current.

Animals↗
PubMed1993

Premature aging and immunodeficiency: Mulvihill-Smith syndrome?

We report on a 30-year-old woman with premature aging, immunodeficiency, and other abnormalities. She had many manifestations of the Mulvihill-Smith syndrome, a disorder that has been described in 4 sporadic individuals, ranging in age from 4 to 17 years. The common manifestations include short stature, microcephaly, a senile face with an underdeveloped lower half, diminished facial subcutaneous fat, multiple pigmented nevi, sensorineural hearing loss, and a low IgG level. Our patient also had severe mental retardation, brachydactyly, severe T cell dysfunction, and suffered from severe verruca vulgaris and a chronic, active Epstein-Barr virus infection. The fact that her parents were first cousins suggests autosomal recessive inheritance of her disorder. Two alternative possibilities were considered: the disorder in the patient represents the Mulvihill-Smith syndrome with immune deficiency as a sign of its advanced stage, or a hitherto undescribed syndrome.

Adult↗
PubMed1993

New diagnostic method for Pallister-Killian syndrome: detection of i(12p) in interphase nuclei of buccal mucosa by fluorescence in situ hybridization.

Detection of the supernumerary isochromosome 12p [i(12p)] was performed on buccal smear preparations from 2 patients with Pallister-Killian syndrome, 21 (patient 1) and 15 months (patient 2) old, by interphase fluorescence in situ hybridization (FISH) using a chromosome 12-specific alpha satellite probe. Isochromosome 12p-positive cells were identified by observing 3 signals over the nucleus, while diploid cells had 2 signals. The proportion of i(12p)-positive cells thus identified was high in the epithelial cells of buccal mucosa at 68 and 53% from patients 1 and 2, respectively. Further, the frequencies of i(12p)-positive cells were also studied in PHA-stimulated peripheral lymphocytes, cultured skin fibroblasts (both patients), and directly harvested T and B-cells (patient 1). Of these tissues, buccal mucosa showed the highest proportion of i(12p)-positive cells. These findings indicate that epithelial cells of buccal mucosa are likely to retain i(12p)-positive cells. Detection of i(12p) using direct buccal smear preparations by interphase FISH is a rapid, effective and non-invasive method for confirming the diagnosis of the Pallister-Killian syndrome.

Abnormalities, Multiple↗
PubMed1993

Detection of a cryptic paracentric inversion within band 11p13 in familial aniridia by fluorescence in situ hybridization.

We report the first familial case of dominantly inherited aniridia with a cryptic inversion within band 11p13. High-resolution chromosome analysis gave a suspicion of a tiny constitutional aberration around band 11p13 and fluorescence in situ hybridization using 11p cosmids successfully confirmed that the aniridia patients of this family have an inversion within band 11p13. The distal breakpoint of the inversion is telomeric to a candidate aniridia gene (AN2) and suggests that more genes might be involved in the etiology of aniridia. In situ hybridization is a powerful tool to detect cryptic rearrangements in sporadic or familial patients with aniridia. This family indicated the importance of careful observation of the 11p13 region of aniridia patients, even if the aniridia was autosomal dominantly inherited.

Adult↗
PubMed1993

Oscillations of receptor-operated cationic current and internal calcium in single guinea-pig ileal smooth muscle cells.

In single cells isolated from guinea-pig ileal smooth muscle, held under voltage clamp at -40 mV or -50 mV by patch pipette in the whole-cell recording mode, carbachol (CCh) evoked an oscillatory inward cationic current. The frequency of current oscillations increased with increasing CCh concentration. CCh-evoked current oscillations were followed very closely by oscillations in intracellular free Ca2+ estimated from the Indo-1 signal, and were abolished by inclusion of EGTA in the pipette solution. Ryanodine and heparin, but not nifedipine, blocked the generation of current oscillations. CCh-evoked current oscillations were abolished upon withdrawal of extracellular calcium and restored upon its reintroduction. Inclusion of GTP[gamma S] in the pipette solution caused the generation of an oscillatory inward current, which was blocked by ryanodine. The present results are consistent with the hypothesis that CCh-evoked cationic current is gated by activation of a G protein and is steeply dependent on [Ca2+]i, fluctuations in the release of Ca2+ from stores during carbachol's action produce oscillations in [Ca2+]i which cause similar oscillations in the cationic current.

Animals↗
PubMed1993

The Costello syndrome: are nasal papillomata essential?

Two patients with the Costello syndrome are presented. One was a 7-year-old girl with a history of infantile hypotonia and feeding difficulties. The other was a 3 5/12-year-old boy with a history of neonatal sepsis and respiratory problems. Both had relative macrocephaly at birth, curly hair, large ear lobes, epicanthic folds, a low nasal bridge, thick lips, a short and wide nose, a short neck, a barrel chest, redundant skin, tight Achilles tendons, and pes equinovarus. Nasal papillomata, as described in Costello's two patients, were absent in both patients. Borochowitz et al. (1992) described five patients with what we interpreted as the Costello syndrome but without nasal papillomata. In view of these findings, nasal papillomata are not likely to be essential in the diagnosis of the Costello syndrome.

Abnormalities, Multiple↗
PubMed1993

Long-term palliation after systemic-to-pulmonary artery shunt using an internal mammary artery.

We report the long-term results after systemic-to-pulmonary artery shunts using the internal mammary arteries in 2 patients. The systemic-to-pulmonary artery shunts using the internal mammary arteries were created in 2 children. Both of them are doing well 11 years and 7 years after operation. This procedure could be a reasonable alternative to classic Blalock-Taussig shunt for patients with diminutive pulmonary arteries as it offered good long-term palliation.

Angiography↗
PubMed1993

Development of vagal innervation to the muscle of the avian gizzard.

The development of the vagal innervation to the gizzard has been investigated in chick embryos and young chicks. The membrane potential, first measurable on the 15th day of incubation, was -54 +/- 0.5 mV and increased with development to -67 +/- 0.4 mV. The latter value was attained 5 days after hatching and persisted thereafter. Stimulation of intramural nerves elicited a cholinergic, excitatory junction potential (EJP) for the first time, only in a small fraction of cells, on the 20th day of incubation. Within 3 days after hatching, cholinergic transmission showed the same features as in older chicks. Stimulation of the vagus nerve elicited no membrane potential responses before hatching but as early as 4 days after hatching, non-adrenergic, inhibitory junction potentials (IJPs) were evoked. In the next 10 days or so, the IJP was replaced with a cholinergic EJP as seen in mature tissues. After atropine (0.1-1 microM) treatment, both vagal and intramural nerve stimulation evoked a non-adrenergic IJP in a small fraction of cells immediately after hatching. The fraction of cells exhibiting the IJP increased with growth and reached 100% 5 days after hatching. Hexamethonium (50 or 100 microM) abolished the vagally-evoked EJPs. The vagally-evoked IJPs remained unchanged after application of hexamethonium in the early days after hatching, but later they were abolished in about half of the cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗