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Biomedical subjects

H Ohashi

Publications and source records attributed to H Ohashi.

At least 325 records · Page 18Linked to original sources
PubMed1993

Membrane current responses to externally-applied ATP in the longitudinal muscle of the chicken rectum.

1. Membrane current responses to ATP in enzymically-dispersed single smooth muscle cells from the chicken rectum were investigated by the whole-cell voltage clamp technique. 2. In cells dialysed with a KCl-rich solution under voltage clamp at a holding potential of -40 mV, ATP (10 microM) produced an inward current followed by an outward current. When the holding potential was changed to 0 mV and -80 mV, the biphasic current response to ATP was converted to an outward current alone and an inward current alone, respectively. 3. External application of tetraethylammonium (TEA, 5 mM), intracellular dialysis with a CsCl-rich solution, or inclusion of EGTA (10 mM) in the pipette abolished the outward current response to ATP. 4. Neither depletion of Ca2+ store with caffeine (10 mM) nor block of voltage-gated Ca2+ channels with nifedipine (10 microM) affected the biphasic current response to ATP. After removal of the extracellular Ca2+ the outward current response to ATP was abolished. 5. alpha,beta-methylene ATP (100 microM) elicited a current similar to the ATP-induced current. In the presence of alpha,beta-methylene ATP (100 microM), application of ATP (100 microM) was without effect. 6. In CsCl-filled cells, ATP analogues elicited an inward current and the order of potency was ATP not equal to alpha, beta-methylene ATP > ADP >> AMP. 7. Inclusion of GTP gamma S (0.2 mM) or GDP beta S (2 mM) in the pipette did not affect the ATP-induced inward current in CsCl-filled cells. The reversal potential of the ATP-induced inward current was about 0 mV and was completely inhibited after replacement of the cations in the bath solution by Tris. The reversal potential remained almost unchanged after replacement of Na+ in the bath solution with 1 10 mM Ca2+, but shifted in the negative direction after replacement of Na+ or both Na+ and Ca2+ with glucosamine.8. The results suggest that ATP acts on P2 purinoceptors to cause activation of cation channels with selectivity for Ca2+ over Na+. Moreover, it appears that no G-protein-mediated mechanism is involved and increased Ca2+ entry through the cation channels causes activation of Ca2+-activated K+ channels.

Adenosine Triphosphate↗
PubMed1993

Effect of trimebutine on voltage-activated calcium current in rabbit ileal smooth muscle cells.

1. The effect of trimebutine on the voltage-dependent inward Ca2+ current was investigated by the whole-cell voltage-clamp technique in single smooth muscle cells from rabbit ileum. 2. Trimebutine (3-100 microM) reduced the Ca2+ current in a concentration-dependent manner. The inhibitory effect on the Ca2+ current was also dependent on the holding potential. The Ca2+ current after a low holding potential was inhibited to a greater extent than that after a high membrane potential: the IC50 values were 7 microM and 36 microM at holding potentials of -40 mV and -60 mV, respectively. The Ca2+ current elicited from a holding potential of -80 mV could not be reduced by as much as 50% of the control by trimebutine at concentrations as high as 100 microM. 3. Trimebutine (30 microM) shifted the voltage-dependent inactivation curve for the Ca2+ current by 18 mV in the negative direction. The affinity of the drug for Ca2+ channels was calculated to be 36 times higher in the inactivated state than in the closed-available state. 4. Blockade of the Ca2+ current by trimebutine, unlike verapamil, was not use-dependent. 5. The results suggest that trimebutine inhibits the voltage-dependent inward Ca2+ current through a preferential binding to Ca2+ channels in the inactivated state in the smooth muscle cell from rabbit ileum. The inhibitory effect of trimebutine on gastrointestinal motility is discussed in the light of the present findings.

Action Potentials↗
PubMed1993

Bupleurum falcatum L. in northern Kyushu and Yamaguchi Prefecture are genetically distinguished from other populations, based on DNA fingerprints.

Total DNA was extracted from leaves of Bupleurum falcatum originating from eight different habitats in Japan and hybridized with digoxigenin-labeled rice ribosomal DNA after digestion with various restriction enzymes. The resulting DNA fingerprints allowed us to distinguish the geographic populations of B. falcatum when the DNA was digested with Dra I, Kpn I or Taq I. A dendrogram based on the RFLP profiles indicated that B. falcatum distributing in northern Kyushu and Yamaguchi Prefecture is classified into a taxon or subtaxon that can be differentiated from the plants grown in other regions.

DNA↗
PubMed1993

Contractile responses to histamine and GTP gamma S in beta-escin-treated skinned smooth muscle of guinea pig ileum.

To characterize the calcium (Ca2+)-releasing effects of histamine and GTP gamma S, the drug-induced tension developments were measured in beta-escin-treated skinned longitudinal smooth muscle of guinea pig ileum. Intracellular Ca2+ stores were loaded with Ca2+ by incubating the muscle for 10 min in a Ca(2+)-containing solution. Histamine (10-100 microM), applied after Ca(2+)-loading, produced a transient rise in tension. The effect of histamine was not preserved after treatment with 20 mM caffeine, a Ca(2+)-store releaser. The effect of histamine was potentiated by GTP; inhibited by GDP beta S, an antagonist of GTP for binding to G-proteins; or heparin, an antagonist of inositol 1,4,5-trisphosphate (IP3) for binding to its receptor; and mimicked by IP3. When GTP gamma S (20 microM) was applied and continued to be present for 15 min, a transient rise in tension followed by a small, sustained rise in tension was elicited. The effect of GTP gamma S was completely inhibited by GDP beta S. The initial, transient component of the biphasic GTP gamma S response was abolished or markedly inhibited after treatment with caffeine, heparin or the calcium ionophore A23187. The present results suggest that histamine and GTP gamma S cause a release of Ca2+ from caffeine-sensitive stores which is mediated by IP3 formed through a G-protein-coupled mechanism. The GTP gamma S-induced Ca2+ release is not considered to involve such an IP3-independent process as described in chemically-skinned arterial muscle.

Animals↗
PubMed1993

[Do blood glucose levels in the elderly have different metabolic significance than in non-elderly subjects?].

Diagnostic criteria of diabetes mellitus in elderly people are still controversial. The major questions are whether (1) effects of hyperglycemia in generating diabetic complications are the same as in younger diabetics, (2) too many diabetics might be diagnosed in the elderly by the criteria proposed by WHO and Japan Diabetes Society. To answer these questions, we carried out two studies. Blood glucose data were collected from population-based studies and from voluntary health check-up studies. Fasting blood glucose values were classified by sex and the age (-49, 50-64, 65-years old). Population-based studies showed no age-dependent change in blood glucose. However, data from health check-up studies showed an increase in median values from the group aged 50-64 and the 65 and older group. Two-hour values after glucose tolerance tests were classified by age and the fasting blood glucose (-99, 100-119, 120-139, and 140- mg/dl). The eldest and 140- mg/dl group showed the highest 2-hour values. Effects of hyperglycemia on the appearance of diabetic complications were studied in patients being follow-up in three diabetes clinics. Patients who has a history of one year or less and without any retinopathy on the first visit to the clinic were registered. Data were analyzed by the Kaplan-Meier method and the appearance of retinopathy was used as the end point. There were no difference in the rate of appearance of retinopathy between the age groups (-49, 50-64 and 65-years old). No age effect on the hyperglycemia-dependent appearance of retinopathy could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Clonality in refractory anemia].

Clonality analysis, by means of polymorphisms of X-linked genes and their methylation patterns, was performed in 41 female patients with various types of refractory anemia. Bone marrow cells, peripheral blood cells, and granulocytic and lymphocytic fractions were analysed by Southern blotting with PGK, HPRT, and M27 beta probes. Clonal hematopoiesis was evidenced in 8 of 19 patients with aplastic anemia, 4 of 6 patients with RA or RARS, 3 of 7 patients with PNH, and 5 of 9 patients whose hematological characteristics did not meet the criteria of either of these entities. For aplastic anemia, clonal hematopoiesis was demonstrated in higher frequency in the patients who had longer history after diagnosis. In refractory anemia, as a whole, no clear correlation was observed between existence of clonal hematopoiesis and morphological characteristics of hematological cells.

Anemia, Aplastic↗
PubMed1993

[Blalock-Taussig shunts in infants less than 6 months of age with special reference to the long-term administration of prostaglandin E1].

Classical Blalock-Taussig (B-T) shunt operation was performed in 14 neonates (group N) and 22 infants (group P). A mean age of group N patients was thirteen days and that of group P patients was two months. Preoperatively prostaglandin E1 (PGE1) was administered in all patients and was continued for a mean of 7 days (range 2 hours to 21 days) in group N, and a mean of 78 days (range 42 to 158 days) in group P. Body weight (4359 +/- 339 g), size of subclavian artery (3.7 +/- 0.5 mm in diameter) and size of pulmonary artery (6.4 +/- 1.2 mm in diameter) at operation of group P patients were larger than those (3212 +/- 490 g, 3.4 +/- 0.4 mm, 5.1 +/- 1.3 mm) of group N. But there were no differences in operation time (165 +/- 22 minutes in group N vs 174 +/- 25 minutes in group P) and clamp time of pulmonary artery (31 +/- 10 minutes in group N vs 30 +/- 5 minutes in group P) between 2 groups. There was no operative death in both groups. There were one late death in group N and three late death in group P. Five patients in group N and nine patients in group P required additional B-T shunt at the mean follow up interval of two years.(ABSTRACT TRUNCATED AT 250 WORDS)

Alprostadil↗
PubMed1993

[Syphilitic orchitis: report of a case].

Syphilitic orchitis ir recently a rare disease in Japan. A 44-year-old man visited our hospital with the complaint of swelling of the right scrotum. He first noticed it about a half year ago, but the swelling mitigated without any therapy. The right testis was about the size of a hen's egg, elastic hard, and slightly rugged when he first visited our hospital. Treponema pallidum hemagglutination assay (TPHA) and rapid plasma reagin (RPR) were positive. We performed high orchiectomy because we could not deny the possibility of testicular tumor. Pathologically, granulomatous inflammation with lympho-plasmacytic infiltration and endoarteritis obliterans of the small arteries were seen in the specimen. It was diagnosed as granulomatous inflammation possibly caused by syphilitic orchitis. Syphilitic orchitis is usually quite difficult to distinguish from other types of granulomatous diseases of the testes, for example tuberculous orchitis. Various types of stains and careful examination of the specimen were thought to be necessary to distinguish these diseases.

Adult↗
PubMed1993

[Analyses of ventricular arrhythmias in patients with progressive systemic scleroderma (PSS) by ambulatory electrocardiography].

Disorder of cardiac conduction and automaticity have been widely reported in patients with progressive systemic scleroderma (PSS). In the present study, ventricular arrhythmias were monitored by 24-hour ambulatory electrocardiographic recording (Holter monitor) in 30 female patients with PSS and 20 apparently healthy female controls. The following results were obtained: 1) In the waking state, 8 cases of 30 patients showed grade III, IVA or IVB of ventricular arrhythmias, according to Lown's classification. On the other hand, ventricular arrhythmias, such as grade III, IVA or IVB, were not observed in the control group. 2) In the patient group, grade IVA arrhythmias were observed during defecation, driving or light working, and grade IVB were during defecation, urination, light working or sleeping. These results suggest that it is important to examine arrhythmias by Holter monitors in patients with PSS.

Adult↗
PubMed1993

[Early and long-term results of sternocostal elevation combined with bridge external traction for funnel chest in children].

The purpose of the present study is to evaluate the effects of addition of a bridge external traction to our conventional sternocostal elevation technique in the surgical management of funnel chest in children. During the period from 1970 to 1979, a total of 29 children with funnel chest were treated surgically using sternocostal elevation technique (Group I). Operative technique consisted of total subperichondral resection of deformed costal cartilages (usually 3rd to 8th, bilaterally), transection of deformed portion of the sternum in 2-3 points and fixation of the sternum in elevated position using 2 Kirschner wires, and shortening resuturing of the opened perichondrium. Since 1980, an addition of the bridge external traction to our conventional sternocostal elevation technique was applied for about 10 days after operation in 82 consecutive children (Group II). The vertebral index (B/A = sagittal diameter of vertebral body/minimum sternovertebral distance), D/C ratio (maximum sagittal depth of depression of sternum/distance from anterior surface of the vertebral body to the sternum at Louis's angle) and E/C ratio (E = minimal sagittal distance from anterior surface of the vertebral body to the sternum) were measured in all cases and compared before and after operation and also between the two Groups. Preoperatively, there was no significant difference in all 3 indices between the two Groups. Postoperative B/A, D/C and E/C ratio in Group I were 0.28 +/- 0.06, 0.14 +/- 0.19, 1.09 +/- 0.32 (mean +/- SD), respectively. There were a significant drop in D/C ratio and a significant elevation in E/C ratio after operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Anorectal anomaly in Pfeiffer syndrome.

A Japanese girl with Pfeiffer syndrome is described. She has clinical and radiological manifestations typical of the syndrome. In addition, she had an imperforate anus not described previously in the syndrome. This seems to expand the phenotype associated with Pfeiffer syndrome or represent a new acrocephalosyndactyly syndrome.

Acrocephalosyndactylia↗
PubMed1993

[Acute aortic dissection due to cross-clamp injury during coronary artery bypass grafting--a report of successfully repaired case].

A case with successfully repaired acute aortic dissection due to cross-clamp injury during coronary bypass surgery was reported. A 54-year-old man had usual coronary artery bypass surgery by using 3 saphenous vein grafts (4 distal anastomosis). Immediately after the completion of cardiopulmonary bypass, acute aortic dissection, which was caused by aortic cross-clamp, was noted. Cardiopulmonary bypass was resumed and the injured ascending aorta was replaced with prosthetic graft under profound hypothermia and circulatory arrest. An "Island flap" of the ascending aorta (3 x 4 cm in diameter), containing 3 proximal anastomotic positions of vein grafts, was excised from the aortic wall, and was re-implanted into the frontal wall of the aortic prosthesis. The patient well tolerated the operative procedure, and fully recovered from the serious condition after 6 days of IABP support and 11 days of inotropic support. He is doing quite well one year after the surgery. This case is believed to be the first reported one of such reconstructive method for acute aortic dissection during the coronary bypass surgery.

Acute Disease↗
PubMed1993

[Lp(a) lipoprotein in patients on maintenance hemodialysis--a study from apo(a) isoform].

It has been suggested that lipid abnormalities may be involved in the development of cardiovascular disorders in patients on maintenance hemodialysis (HD). Hypertriglyceridemia commonly accompanies this condition and is associated with decreased concentrations of HDL-cholesterol. Recent clinical interest has been paid to the disturbances of Lp(a) and apo (a) isoform in relation to cardiovascular disorders. Although high concentrations of Lp(a) are associated with ischemic heart disease, we are unaware of the availability of such data concerning patients on maintenance hemodialysis. We therefore compared levels of Lp(a) and the frequency of occurrence of their isoforms in 310 patients (chronic glomerulonephritis, N = 221; diabetic nephropathy, N = 77; polycystic kidney disease, N = 12) on maintenance hemodialysis and in 212 normal subjects. The following results were obtained. (1) HD patients showed significantly elevated levels of Lp(a) compared to normal subjects. (2) Studies of apo (a) isoform showed that HD patients showed high frequency of S2 and low frequency of S4. (3) HD patients, especially long-term patients, showed high frequency of double band (S2/S3). (4) There were no significant differences in the levels of Lp(a) and in the frequency of apo(a) isoform among 3 different etiological studies.

Adolescent↗
PubMed1993

Erythroid potentiating activity of tissue inhibitor of metalloproteinases on the differentiation of erythropoietin-responsive mouse erythroleukemia cell line, ELM-I-1-3, is closely related to its cell growth potentiating activity.

The erythroid-potentiating activity (EPA) of the tissue inhibitor of metalloproteinase-1 (TIMP-1) was re-examined using ELM-I-1-3, a mouse erythroleukemia cell line, which responded well to erythropoietin. Depletion of pre-existing TIMP-1 from fetal calf serum in culture medium using monoclonal antibody suppressed erythropoietin-induced differentiation as measured by the induction of hemoglobin, commitment assay and globin mRNAs. The removal of TIMP-1 also suppressed the proliferation of ELM-I-1-3 as measured by cell number and de novo DNA synthesis. These changes were reversed by the addition of purified TIMP-1 to the culture medium. Anti-TIMP-1 antibody also blocked both hexamethylene bisacetamide (HMBA)-induced erythroid differentiation and the proliferation of both ELM-I-1-3 and Friend erythroleukemia cells. Considering previous reports analyzing the chemical induction of Friend mouse erythroleukemia cell differentiation, our results suggest that erythropoietin- or HMBA-induced erythroid differentiation might also be coupled with cell proliferation. Our 3H thymidine-uptake experiment shows that TIMP-1 removal was also effective in the inhibition of cell growth of various other cell lines in addition to erythroleukemia cell lines. These results suggest that EPA action of TIMP-1 on erythroid leukemia cell lines is closely related to its activity to promote the cell growth of various cell lines and cells including erythroleukemia cell lines.

Acetamides↗
PubMed1992

Pigmentary dysplasias and chromosomal mosaicism: report of 9 cases.

Chromosomes were studied in 9 individuals with pigmentary dysplasias of the skin and other abnormalities. Of the 9 individuals, 5 were chromosomal mosaics in both blood lymphocytes and skin fibroblasts (46,XY/47,XY, + 13;46,XX/47,XX, + 14;46,XY/47,XY, + 18;46,XX/47,XX, + 18;46, XX/47,XX, + mar), while the other 4 individuals were chromosomally normal in both tissues studied. The pigmentary dysplasias involved hypo- or hyperpigmented patches/flecks or lines/whorls. The latter ran along Blachko lines on the back, abdomen and the limbs. These patterns varied not only between individuals but also between different regions of an individual. The possibility of chimerism was studied but ruled out (1/32 to 1/256) in 7 individuals, using chromosomal heteromorphisms in the patients and their parents as markers.

Adolescent↗
PubMed1992

Growth stimulating activity of heat shock protein 90 alpha to lymphoid cell lines in serum-free medium.

A growth stimulating factor was purified from the culture supernatant of human-human hybridoma SH-76 cells in serum-free RPMI 1640 medium by the serial use of DEAE anion and heparin affinity chromatographies. The factor was a 85 kDa protein on SDS-polyacrylamide gel electrophoresis. N-terminal amino acid sequence (PEETQTQDQPME) of the protein was coincident with that of heat shock protein 90 alpha (HSP90 alpha). The protein reacted with anti-HSP90 monoclonal antibody. These results suggest that the protein was a member of HSP90 alpha family after taking other circumstantial evidence into account. The protein stimulated the growth of some lymphoid cell lines such as human B-lymphoblastoid cell line HO-323-3 hybridomas derived from HO-323, and several other lymphoid cell lines. There were several lymphoid cell lines which did not respond to the protein. Growth stimulating activity of the protein was heat-unstable and significantly decreased at above 60 degrees C. These are the first data that describe growth-stimulating activity of heat shock protein 90 alpha.

Amino Acid Sequence↗