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Biomedical subjects

H Yamane

Publications and source records attributed to H Yamane.

At least 127 records · Page 7Linked to original sources
PubMed1991

The efficacy of Lasix-vitamin therapy (L-V therapy) for sudden deafness and other sensorineural hearing loss.

The efficacy of Lasix-vitamin therapy (L-V therapy) for sudden deafness (SD) was compared with that of conventional therapeutic regimens. There was no significant difference in efficacy between the two therapies. However, in fresh cases (within 7 days from onset of SD), L-V therapy gave a cure rate of 42.3% and an effectiveness rate of 88.4%, these rates being higher than those obtained with conventional therapy; and in cases treated within 4 weeks, L-V therapy was significantly more effective than conventional therapy. Besides, in cases with severe hearing loss (more than 70 dB hearing level) or vestibular symptoms, which were important factors of prognosis, L-V therapy proved more efficient. The efficacy of L-V therapy for other sensorineural hearing loss was also evaluated. In Meniere's disease, L-V therapy proved effective in 45.9% of cases, but with only a 20-30% effectiveness rate in other cases, e.g. idiopathic hearing loss, head and neck injury, noise-induced hearing loss and chronic otitis media.

Adult↗
PubMed1991

Some aspects of hearing change in Meniére's patients.

Fifteen patients with Meniére's disease (8 male and 7 female) in whom as of December 1988 a follow-up audiovestibular study could be made for 2 to 10 years, and who received conservative treatment were assessed for prognosis of the disease, particularly for hearing. Hearing, when compared with the initial level, was deteriorated in 8 ears (by 60 dB HL or more in all cases), remained unchanged in 8 ears (41-68.8 dB HL) and improved in 2 ears (by 21.3 or 35 dB HL). The vertigo period was longer and attacks tended to occur more frequently in the groups with deteriorated hearing and with unchanged hearing than in the group with improved hearing. Patients whose hearing (during remission) dropped by more than 10 dB from the initial hearing level (during remission) within 3 years of the first audiovestibular examination tended to show a further declining hearing level afterwards. This was interpreted as indicating that the outcome of hearing can be predicted on the basis of observations (audiograms) made during the initial 3 years of the disease.

Adolescent↗
PubMed1991

Influence of IL-6 on proliferation and differentiation of tonsillar lymphocytes and detection of IL-6 producing cells in tonsil.

When tonsillar B cells were cultured in the presence of exogenous interleukin-6 (IL-6), a small portion of them differentiated into plasma cells which seemed to have IL-6 receptors on their surfaces. The number of plasma cells tended to be greater in the tonsils of children than in the tonsils of adults. When tonsillar cells collected by Ficoll-Conray's method were cultured in medium containing IL-6, T cells differentiated and the number of activated T cells increased. Of the four subsets of T cells, this effect of IL-6 was strongest on cytotoxic T cells. IL-6-mediated proliferation and activation of cytotoxic T cells tended to be greater in the tonsils of children than in those of adults. IL-6 is produced in some tonsillar macrophages. The number of macrophages producing IL-6 was very different in different subjects. However, the number of macrophages producing IL-6 in tonsils of children tended to be greater than the number in tonsils of adults.

Adolescent↗
PubMed1991

Strial circulation impairment due to acoustic trauma.

Blood circulation in the cochlear lateral wall after exposure to a non-physiological level of sound (120-125 dB SPL, 3 h) was investigated immunohistologically. Kanamycin (KM), which was expected to function as a tracer of blood flow, was administered to guinea pigs 5 min to 21 h after sound termination. At 5-30 min, KM was scarce in the capillaries of the stria vascularis (CSVs), whereas abundant KM was present in the spiral ligament vessels. These findings differed markedly from those in non-sound-exposed animals. After the initial period, KM gradually did enter into the CSVs, but its pattern of existence there differed from the normal pattern. These observations suggest that acoustic trauma causes blood stagnation in the strial capillaries, leading to strial dysfunction.

Animals↗
PubMed1991

[Replacement of the ascending aorta and aortic valve with a composite graft using a reversed St. Jude medical mitral valve prosthesis].

Between 1981 and 1989, ten patients underwent replacement of the ascending aorta and aortic valve by a composite graft for an aneurysm of the ascending aorta with aortic regurgitation. The first two cases using an SJM aortic valve prosthesis and Teflon felt-pledgeted mattress sutures for the proximal anastomoses required a coronary bypass graft from the tube graft to the anterior descending coronary artery because of difficulty in completing the graft-left coronary ostial anastomoses. In the subsequent seven cases, an SJM mitral valve prosthesis with a large, soft cuff for a valved conduit was sewn in reverse and a thin wall Teflon roll was used for the Teflon felt of the pledgeted mattress suture in the proximal anastomoses. As a result, anastomoses between the tube graft and coronary ostia were performed easily and successfully in eight patients. One case with Marfan syndrome required reoperation nine years after the first operation for recurrence of the aneurysm of the aortic arch. Thus, the need for careful and continued follow-up is important in the Marfan syndrome.

Aortic Aneurysm↗
PubMed1991

[Coronary artery bypass surgery in dialysis patient].

In patients with chronic renal failure undergoing hemodialysis for a long period, arteriosclerosis progresses rapidly, and the incidence of ischemic heart diseases is high. We performed coronary artery revascularization in a patient with chronic renal failure complicated by angina pectoris in whom discontinuation of dialysis was sometimes needed for hypotension during dialysis. Her postoperative course was uneventful. Problems in intra and postoperative management of dialysis patients are reported.

Angina Pectoris↗
PubMed1990

Use of new phosphonylating and coupling agents in the synthesis of oligodeoxyribonucleotides via the H-phosphonate approach.

New phosphonylating and coupling agents for the synthesis of oligodeoxyribonucleotides via H-phosphonate approach have been developed. Tris(1,1,1,3,3,3-hexafluoro-2-propyl) phosphite, prepared by the reaction of lithium salt of 1,1,1,3,3,3-hexafluoro-2-propoxide with PCl3, reacts with deoxyribonucleosides in the presence of a catalytic amount of triethylamine to produce in the high yield the corresponding deoxyribonucleoside 3'-H-phosphonate units. The use of a new coupling reagent, 1,3-dimethyl-2-chloro-imidazolinium chloride (DMCI) for the internucleotidic H-phosphonate bond formation via the H-phosphonate approach is also discussed in detail.

Base Sequence↗
PubMed1990

Gibberellin A(3) Is Biosynthesized from Gibberellin A(20) via Gibberellin A(5) in Shoots of Zea mays L.

[17-(13)C,(3)H]-Labeled gibberellin A(20) (GA(20)), GA(5), and GA(1) were fed to homozygous normal (+/+), heterozygous dominant dwarf (D8/+), and homozygous dominant dwarf (D8/D8) seedlings of Zea mays L. (maize). (13)C-Labeled GA(29), GA(8), GA(5), GA(1), and 3-epi-GA(1), as well as unmetabolized [(13)C]GA(20), were identified by gas chromatography-selected ion monitoring (GC-SIM) from feeds of [17-(13)C, (3)H]GA(20) to all three genotypes. (13)C-Labeled GA(8) and 3-epi-G(1), as well as unmetabolized [(13)C]GA(1), were identified by GC-SIM from feeds of [17-(13)C, (3)H]GA(1) to all three genotypes. From feeds of [17-(13)C, (3)H]GA(5), (13)C-labeled GA(3) and the GA(3)-isolactone, as well as unmetabolized [(13)C]GA(5), were identified by GC-SIM from +/+ and D8/D8, and by full scan GC-MS from D8/+. No evidence was found for the metabolism of [17-(13)C, (3)H]GA(5) to [(13)C]GA(1), either by full scan GC-mass spectrometry or by GC-SIM. The results demonstrate the presence in maize seedlings of three separate branches from GA(20), as follows: (a) GA(20) --> GA(1) --> GA(8); (b) GA(20) --> GA(5) --> GA(3); and (c) GA(20) --> GA(29). The in vivo biogenesis of GA(3) from GA(5), as well as the origin of GA(5) from GA(20), are conclusively established for the first time in a higher plant (maize shoots).

Journal Article↗
PubMed1989

Coronary flow velocity waveforms in aortic stenosis and the effects of valve replacement.

In 6 patients with pure aortic stenosis, the flow velocity waveforms in the left anterior descending coronary artery were studied using an 80-channel 20-MHz pulsed Doppler velocimeter before and immediately after aortic valve replacement. All patients showed normal coronary arteriograms. The left anterior descending coronary artery flow velocity waveform in aortic stenosis was characterized by a reverse flow in the first half of systole and a slowly increasing diastolic inflow. After aortic valve replacement, the reverse flow in the first half of systole disappeared in all patients, but an end-systolic reverse flow was discerned in 5 of 6 patients. The increasing rate of the diastolic inflow was augmented in all patients. After aortic valve replacement, the time from onset of diastole to the diastolic peak velocity was shortened from 176.8 +/- 28.8 to 90.5 +/- 18.8 ms (p less than 0.01), and the diastolic peak velocity increased from 90.5 +/- 28.0 to 122.5 +/- 17.2 cm/s (p less than 0.05). Blood pressure and heart rate, however, did not change significantly before and after valve replacement. These changes in the left coronary artery velocity waveforms after valve replacement suggest the beneficial effects of removal of aortic stenosis on human coronary artery inflow.

Aortic Valve↗
PubMed1989

[Effects of nitroglycerin on the graft flow during aortocoronary bypass surgery].

The effects of an intravenous infusion of nitroglycerin on the hemodynamics and bypass graft flow to left coronary artery were studied in sixteen patients during coronary artery surgery. Systolic blood pressure, cardiac output and left ventricular minute work were not affected by 0.2 microgram/kg/min of nitroglycerin but graft flow volume especially diastolic graft flow increased significantly and the characteristics of flow velocity waveform in the graft became more diastolic predominant. By 1 microgram/kg/min of nitroglycerin a significant decrease in systolic blood pressure, cardiac output and graft flow were recognized, however diastolic graft flow was preserved despite of a decrease in left ventricular minute work. These findings demonstrate that nitroglycerin can be safely administered intravenously during aortocoronary bypass surgery, and suggest that nitroglycerin improves the balance of myocardial oxygen demand and supply, and relieves myocardial ischemia.

Animals↗
PubMed1989

[Two cases of miliary tuberculosis following prosthetic valve replacement].

Pyrexia which occurs at late stage after prosthetic heart valve replacement must be suspected to be caused by prosthetic valve endocarditis (PVE). However, since confirmatory diagnosis is difficult, we are concerned about the treatment for so many cases. We encountered two cases who were suspected PVE at late stage after prosthetic aortic valve replacement and diagnosed miliary tuberculosis at autopsy. Here, we present a report of the two cases.

Aged↗
PubMed1988

Coronary flow characteristics of left coronary artery in aortic regurgitation before and after aortic valve replacement.

In 6 patients with pure aortic regurgitation, the velocity waveform in the left anterior descending coronary artery (LAD) was measured using an 80-channel 20-MHz-pulse Doppler velocimeter before and immediately after aortic valve replacement. All patients showed normal coronary angiograms. Flow velocity was analyzed by both zero-cross and fast Fourier transform methods in real time. The LAD flow in severe aortic regurgitation was characterized by an increase in the systolic flow component, a small and rapidly decreased diastolic flow, an irregular velocity profile across the vessel, and a wider velocity spectrum. After aortic valve replacement, systolic flow decreased by 36.3 +/- 21.7% (p less than 0.01), whereas diastolic flow increased by 81.4 +/- 51.8% (p less than 0.05). The ratio of diastolic flow to total LAD flow increased from 63 +/- 13% to 82 +/- 7% (p less than 0.05). The velocity profile became more parabolic and had a narrow spectrum. These results suggest that operation for aortic regurgitation induces beneficial effects on the myocardial inflow immediately after valve replacement.

Adult↗
PubMed1988

The dominant non-gibberellin-responding dwarf mutant (D8) of maize accumulates native gibberellins.

The endogenous gibberellins (GAs) were examined from young vegetative shoots of the dominant mutant, Dwarf-8, a GA-nonresponder, and normal maize; GA(44), GA(17), GA(19), GA(20), GA(29), GA(1), and GA(8), members of the early-13-hydroxylation pathway, were identified from both kinds of shoots by full-scan mass spectra and Kovats retention indices. In addition, we report the identification of 3-epi-GA(1), GA(3), GA(4), GA(5), GA(7), GA(9), GA(12), GA(15), GA(24), GA(34), and GA(53) by using the same criteria. [1,7,12,18-(14)C(4)]GA(53) and -GA(44), [17-(2)H(2)]GA(19), and [17-(13)C,(3)H(2)]GA(20), -GA(29), -GA(1), -GA(8), and -GA(5) were used as internal standards to determine the endogenous levels of these GAs by measurement of isotope dilution, using capillary gas chromatography and selected ion monitoring. Shoots of Dwarf-8 accumulate relatively high levels of GA(20), GA(1), and GA(8). The accumulation of GA(1) appears to be related to gene dosage. Since Dwarf-8 contains the same pattern of GAs as normals (including GA(1) and GA(3)), the genetic control point probably lies after GA(1) (and GA(3)). Thus Dwarf-8 may be a GA receptor mutant or a mutant that controls a product downstream from the binding of the bioactive GA to a receptor.

Journal Article↗
PubMed1988

Endogenous Gibberellins from Sporophytes of Two Tree Ferns, Cibotium glaucum and Dicksonia antarctica.

Gibberellin A(1) (GA(1)), 3-epi-GA(1), GA(4), GA(9), 11alpha-hydroxyGA(12), 12alpha-hydroxyGA(12), GA(15), GA(17), GA(19), GA(20), GA(25), GA(37), GA(40), GA(58), GA(69), GA(70), and GA(71) have been identified from Kovats retention indices and full scan mass spectra by capillary GC-MS analyses of purified extracts from sporophytes of the tree fern, Cibotium glaucum. Abscisic acid, dihydrophaseic acid, an epimer of 4'-dihydrophaseic acid, and the epimeric ent-6alpha, 7alpha, 16alpha, 17-(OH)(4) and ent-6alpha, 7alpha, 16beta, 17-(OH)(4) derivatives of ent16, 17-dihydrokaurenoic acid, in addition to the epimeric 16alpha, 17- and 16beta, 17-dihydroxy-16, 17-dihydro derivatives of GA(12), were also identified in extracts of C. glaucum. An oxodihydrophaseic acid and a hydroxydihydrophaseic acid were also detected. In extracts of sporophytes of Dicksonia antarctica, GA(4), GA(9), 12alpha- and 12beta-hydroxyGA(12), GA(15), GA(25), and GA(37) were identified by the same criteria, as well as abscisic acid, phaseic acid, 8'-hydroxymethylabscisic acid and dihydrophaseic acid. This is the first time that GA(40) has been identified in a higher plant; it is also the first report of the natural occurrence of the two gibberellins, 11alpha- and 12beta-hydroxyGA(12). The total gibberellin (GA) content in C. glaucum (tall) was at least one order of magnitude greater than that of D. antarctica (dwarf) based on total ion current response in GC-MS and bioassay data. Abscisic acid was a major component of D. antarctica and the oxodihydrophaseic acid was a major component of C. glaucum.

Journal Article↗
PubMed1988

Qualitative and Quantitative Analyses of Gibberellins in Vegetative Shoots of Normal, dwarf-1, dwarf-2, dwarf-3, and dwarf-5 Seedlings of Zea mays L.

Gibberellins A(12) (GA(12)), GA(53), GA(44), GA(19), GA(17), GA(20), GA(29), GA(1), and GA(8) have been identified from extracts of vegetative shoots of normal (wild type) maize using full scan capillary gas chromatography-mass spectrometry and Kovats retention indices. Seven of these gibberellins (GAs) have been quantified by capillary gas chromatography-selected ion monitoring using internal standards of [(14)C(4)]GA(53), [(14)C(4)]GA(44), [(2)H(2)] GA(19), [(13)C(1)]GA(20), [(13)C(1)]GA(29), [(13)C(1)]GA(1), and [(13)C(1)]GA(8). Quantitative data from extracts of normal, dwarf-1, dwarf-2, dwarf-3, and dwarf-5 seedlings support the operation of the early 13-hydroxylation pathway in vegetative shoots of Zea mays. These data support the positions in the pathway blocked by the mutants, previously assigned by bioassay data and metabolic studies. The GA levels in dwarf-2, dwarf-3, and dwarf-5 were equal to, or less than, 2.0 nanograms per 100 grams fresh weight, showing that these mutants are blocked for steps early in the pathway. In dwarf-1, the level of GA(1) was very low (0.23 nanograms per 100 grams fresh weight) and less than 2% of that in normal shoots, while GA(20) and GA(29) accumulated to levels over 10 times those in normals; these results confirm that the dwarf-1 mutant blocks the conversion of GA(20) to GA(1). Since the level of GAs beyond the blocked step for each mutant is greater than zero, each mutated gene probably codes for an altered gene product, thus leading to impaired enzyme activities.

Journal Article↗
PubMed1988

Furosemide-induced alteration of drug pathway to cochlea.

The ototoxicity of aminoglycosides is known to be enhanced by post-treatment with loop diuretics. The present experimental study was undertaken to elucidate the mechanism of this enhancement immunohistologically. Intravenously administered kanamycin (KM) reached the organ of Corti rapidly (within 10 min) via the capillaries of the basilar membrane and spiral limbus. Besides this direct pathway, KM penetrated through the perilymphatic space pathway. This penetration, however, took a much longer time (90 min). In contrast, in the case when KM was followed by intravenous furosemide (FM), KM reached the perilymphatic region within a short time (1-5 min). The KM content of the organ of Corti ascertained 1-5 min after FM injection seemed almost equivalent to that determined 90 min after injection of KM alone. This FM-induced change in the time-course penetration pattern of KM might have a bearing on the enhancement of its otoxicity.

Animals↗