Search PubMed⌕ Search

Biomedical subjects

T Ohhashi

Publications and source records attributed to T Ohhashi.

At least 73 records · Page 4Linked to original sources
PubMed1990

[A case of prostatic hemangiopericytoma].

One case of prostatic hemangiopericytoma is reported. The patient was a 38-year-old man who visited us complaining of difficulty in urination for 6 months duration. Before he came to us, he had undergone open prostatectomy under the suspicion of prostatic abscess++ at a previous hospital with failure because of very severe adhesion. He was referred to us under the histologic suspicion of prostatic sarcoma. From the histopathological study, he was finally diagnosed as having hemangiopericytoma. However, it was difficult to diagnose whether the lesion was benign or malignant in nature. After the external X-ray irradiation, he has been placed under our observation for these 20 years with roentgenographic followup. No infiltration or metastasis has been detected. Judging from these findings and our review of the literature, we concluded that the prostatic hemangiopericytoma reported here is benign in nature. To our knowledge, only 6 cases (5 cases from Europe and the US, and 1 case from Japan) have been reported heretofore.

Adult↗
PubMed1990

[Facioscapulohumeral muscular dystrophy (FSH) and hearing loss].

It has been reported that cochlea is the lesion of hearing loss in FSH. However, the details of this lesion are not yet sufficiently known. We performed detailed audiologic studies to examine hearing loss in FSH. We experienced 2 cases of FSH associated with hearing loss. Case 1 was a girl aged 5 years, and case 2 a boy aged 15 years. Clinical findings, EMG and muscle biopsy gave a diagnosis of FSH in both cases. Hearing loss was evaluated by pure tone audiography, speech audiography, tympanometry, stapedial reflex, auditory brain stem response and electrocochleography. In case 1, pure tone audiograms revealed high tone hearing loss without an A-B gap. On speech audiography, the maximum articulation score was 100% and proved normal. The tympanogram was type A. Stapedial reflex was normal bilaterally. The threshold of the 5th wave increased markedly on auditory brain stem response. On electrocochleography, the H-curve of the input-output function curves of action potential was recorded, but the L-curve was absent. There were no complaints of hearing loss in case 2, but pure tone audiograms revealed high-tone hearing loss without an A-B gap. The tympanogram was type A. Stapedial reflex was normal bilaterally. On auditory brain stem response, threshold was increased and latency was prolonged when intensity was lowered. The electrocochleograms were almost normal. It has been reported that, in electrocochleography, the L-curve represents the function of the outer hair cells and the H-curve that of the inner hair cells. The electrocochleograms in case 1 showed damage to the outer hair cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Heterogeneity in responses of isolated monkey arteries and veins to atrial natriuretic peptide.

Regional differences in responses of isolated monkey arteries and veins to atrial natriuretic peptide were investigated by recording isometric tension. Addition of atrial natriuretic peptide (4 X 10(-12) to 4 X 10(-8) M) produced a concentration-dependent relaxation in isolated monkey arteries and veins. No significant difference was observed between the responses to rat and human atrial natriuretic peptides. A marked heterogeneity in responses to rat atrial natriuretic peptide, however, was observed in arterial preparations. The decreasing order of the response was as follows: renal greater than pulmonary greater than femoral = mesenteric greater than coronary greater than middle cerebral greater than basilar arteries. A heterogeneity in the relaxation produced by atrial natriuretic peptide was also observed in monkey veins. The decreasing order of the response was as follows: pulmonary greater than mesenteric = portal greater than femoral greater than renal = inferior caval veins. On the other hand, 10(-5) M sodium nitroprusside caused a maximal relaxation in all monkey arteries and veins used. In the middle cerebral, basilar, and coronary arteries, the relaxant effects of rat atrial natriuretic peptide on KCl-induced contraction were significantly smaller than those on the preparations contracted by an agonist such as prostaglandin F2 alpha. These results suggest that there exist profound regional vasorelaxant selectivities of atrial natriuretic peptide in isolated monkey arteries and veins.

Animals↗
PubMed1988

Clinical and biochemical studies of Japanese neuronal ceroid-lipofuscinosis.

We studied clinical manifestations of Japanese patients with neuronal ceroid-lipofuscinosis (NCL). The onset of the disease and initial symptoms were almost identical to those reported previously in Caucasians. Japanese patients with NCL were not significantly clinically different from Caucasian cases. An atypical case NCL associated with a deficiency of diaminobenzidine peroxidase activity was also presented. Pathogenesis of NCL was studied on the basis of urine dolichol excretion, autofluorescent compounds in urine, thiol protease activities and protein analysis in tissues of NCL patients. Possible biochemical abnormalities in NCL are discussed.

Adolescent↗
PubMed1988

Biochemical studies on prolidase in sera from control, patients with prolidase deficiency and their mother.

Prolidase activity in serum from normal subjects and the mother of two patients was readily detected without adding Mn2+ to the assay, and the activity was increased by addition of Mn2+ to the assay or preincubation with Mn2+. However, the activity in serum from patients with prolidase deficiency against gly-pro, leu-pro and val-pro could not be detected irrespective of Mn2+ conditions and activity against met-pro, ala-pro and phe-pro also showed a marked reduction compared to controls. Both normal and the patients' mother's prolidase activity against gly-pro was reduced about 20% at 60 degrees C compared to the activity at 37 degrees C, but the addition of Mn2+ at 55 degrees C increased the activity about 1.8-fold, whereas prolidase activity of patients could not be increased by the addition of Mn2+. The addition of Co2+ increased prolidase activity in serum from control and the patients' mother but did not increase the heat stability. These results indicate that prolidase in serum from patients with prolidase deficiency is altered rather than markedly reduced in amount.

Dipeptidases↗
PubMed1988

Dual effects of histamine on spontaneous activity in isolated bovine mesenteric lymphatics.

The mode of action of histamine on spontaneous contractions is isolated bovine mesenteric lymphatics was investigated by recording isometric tensions. Histamine at lower concentrations between about 5 x 10(-8) and 10(-6) M caused a dose-dependent deceleration of the rhythm of spontaneous contractions. Higher concentrations of histamine (more than about 5 x 10(-6) M) produced a dose-related acceleration of the rhythm in association with a slight elevation of basal tone in 115 of 173 preparations. In 58 of 173 lymphatic preparations, histamine at concentrations ranging from about 5 x 10(-8) to 10(-5) M caused only the positive chronotropic effect. The histamine-induced positive and negative chronotropic effects were unaltered by pretreatment with alpha- and beta-adrenergic antagonists but were dose-dependently antagonized by pretreatment with H1- or H2-blockers (diphenhydramine or cimetidine). The specific H1- and H2-agonists, 2-pyridylethylamine (2PEA) and dimaprit caused dose-related positive and negative chronotropic effects, respectively, on spontaneous contractions of isolated bovine mesenteric lymphatics. The effect of 2PEA was significantly blocked by pretreatment with 10(-6) M diphenhydramine, whereas the effect of dimaprit was suppressed by 10(-6) M cimetidine. These results suggest that both H1- and H2-receptors are located on the plasma membrane of smooth muscle cells in bovine mesenteric lymphatics, and that the excitations of H1- and H2-receptors respectively produce an acceleration and a deceleration of the rhythm of spontaneous contractions in lymphatic smooth muscles.

Animals↗
PubMed1988

Existence of two types of postjunctional alpha-adrenoceptors in the isolated canine internal carotid artery.

The pharmacological characteristics of postjunctional alpha-adrenoceptors in isolated canine internal carotid arteries were investigated by the use of selective agonists and antagonists for alpha 1- and alpha 2-adrenoceptors. Norepinephrine, phenylephrine, and xylazine caused concentration-dependent contractions in the helical strips. The contraction induced by 10(-4)M xylazine was significantly smaller than that produced by 10(-4)M norepinephrine or 10(-4)M phenylephrine. The contraction induced by 10(-4)M phenylephrine was almost the same value as that induced by 10(-4)M norepinephrine. Phentolamine (10(-8) and 10(-7)M) caused a parallel shift to the right of the concentration-response curve to norepinephrine. The contractile responses to low concentrations of norepinephrine were significantly suppressed by pretreatment with an alpha 2-antagonist such as yohimbine (10(-9) and 10(-8)M) or DG5128 (10(-7) and 10(-6)M). On the other hand, the responses to higher concentrations of norepinephrine were mainly reduced by low concentrations of an alpha 1-antagonist, prazosin (3 x 10(-10) and 3 x 10(-9)M). These results suggest that both alpha 1- and alpha 2-adrenoceptors are located on the plasma membrane of smooth muscle cells in canine internal carotid arteries and that the norepinephrine-induced contractions at low and high concentrations are mainly mediated by activation of alpha 2- and alpha 1-adrenoceptors, respectively.

Animals↗
PubMed1987

Responses of monkey, rabbit and dog internal carotid arteries to atrial natriuretic factor.

Effects of atrial natriuretic factor (ANF) on monkey, rabbit and dog internal carotid arteries were investigated. ANF caused a concentration-dependent relaxation in arterial strips submaximally precontracted with noradrenaline, 5-hydroxytryptamine, or high-potassium solution (10-30 mM). The response was greatest in the monkey arteries and least in the dog arteries. These results suggest that there is a marked species difference in the ANF-induced relaxation of the internal carotid arteries.

Animals↗
PubMed1987

Comparison of viscoelastic properties of walls and functional characteristics of valves in lymphatic and venous vessels.

The principal function of the lymphatic and venous system is to maintain a favorable environment for cells of the body. As a consequence mainly of hydrostatic forces, shifts of fluid usually occur between the vascular system and the extracellular space. To compensate for these shifts the veins are capable of active and passive changes in capacity that serve to modulate the filling pressure of the heart by adjusting the central blood volume. In addition to the venous function, the lymphatic function also contributes to compensate for the fluid shifts by drainage from the interstitial space. Namely, the general function of the lymphatic system is to return fluid and protein which escapes from the blood capillaries to the lymph circulation. To elucidate the mode of venous and lymph transport, therefore, it is of essential importance to obtain basic knowledge of the mechanical characteristics of the walls of the vessels and the functional characteristics of the lymphatic and venous valves dividing two adjacent compartments. In this communication, in order to answer the question, "Are Lymphatics Different From Blood Vessels?", I would like to review a comparison of viscoelastic properties of walls and functional characteristics of valves in lymph and venous vessels by use of our original data obtained with isolated canine veins and thoracic ducts and with isolated bovine mesenteric lymphatics (1-9).

Animals↗
PubMed1986

Pre- and postjunctional alpha-adrenoceptors at sympathetic neuroeffector junction in bovine mesenteric lymphatics.

We studied isolated bovine mesenteric lymphatics to elucidate the pharmacological characteristics of pre- and postjunctional alpha-adrenoceptors at the sympathetic neuroeffector junction. Cylindrical strips were incubated with [3H]-noradrenaline and mounted for superfusion. Electrical stimulation (2 Hz, 0.5 msec, 50 V) augmented the fractional release of labeled noradrenaline. Exogenous noradrenaline and clonidine caused a depression of the evoked tracer release. Phenoxybenzamine and yohimbine markedly enhanced the evoked overflow of adrenergic transmitter. Rings of lymphatic vessels were mounted for isometric tension recording in organ chambers filled with Krebs-Ringer bicarbonate solution. The vessels contracted when exposed to phenylephrine and clonidine. The ED50 of clonidine was significantly lower than that of phenylephrine. Prazosin caused a parallel shift to the right of the dose-response curve to phenylephrine. The antagonist, however, suppressed the magnitude of the maximum response to clonidine. Yohimbine caused parallel shift to the right of the dose-response curves to phenylephrine and clonidine, respectively. The Schild plots for yohimbine demonstrated that the drug was a competitive antagonist to phenylephrine and clonidine. The pA2 value of yohimbine to clonidine (7.6 +/- 0.4) was larger than that to phenylephrine (6.2 +/- 0.4). The pA2 value of prazosin to phenylephrine was 7.2 +/- 0.3. These results suggest that prejunctional alpha-adrenoceptors are involved in the negative feedback mechanism for autoregulation of noradrenaline release during postganglionic sympathetic nerve stimulation, and that both alpha 1- and alpha 2-like adrenoceptors do exist on lymphatic smooth muscle cells.

Adrenergic Fibers↗
PubMed1986

Histochemical studies of the adrenergic innervation of canine cerebral arteries.

The glyoxylic acid method was used to examine the adrenergic innervation of the major cerebral arteries of the circle of Willis in dogs. Fluorescent nerve fibers were observed in whole-mount preparations of the part of the internal carotid artery lying in the cavernosus sinus, the anterior, middle and posterior cerebral arteries, the posterior communicating artery and the basilar artery. Adrenergic nerve fibers were most abundant in the proximal portions of the anterior, middle and posterior cerebral arteries as well as in the posterior communicating artery. The distal smaller arteries were less densely innervated than larger ones. The basilar artery contained a moderate number of fluorescent fibers while the internal carotid artery lying in the cavernosus sinus had a very sparse innervation. The peak wavelengths of the excitation and emission spectra of the fluorescence were analyzed by means of a microepifluorescence spectrophotometer and were about 415 and 465 nm, respectively. These values suggest that the fluorescent fibers are adrenergic ones containing norepinephrine.

Adrenergic Fibers↗
PubMed1985

Galanin potentiates electrical stimulation and exogenous norepinephrine-induced contractions in the rat vas deferens.

In order to evaluate the mode of action of galanin (GAL) on the neuroeffector mechanism of peripheral sympathetic nerve fibers, the effects of this peptide were tested on the electrical stimulated and the unstimulated preparations of the isolated rat vas deferens in the presence of 10(-7) M atropine. The contractile responses, which were mediated predominantly by activation of postganglionic noradrenergic nerve fibers were dose-dependently potentiated by GAL in concentrations ranging from 1 to 50 nM. The facilitatory action induced by GAL in high concentrations (greater than 10 nM) usually returned to the control level at 2-3 min and were tachyphylactic. The potentiating action of GAL was not modified by pretreatment with 10(-7) M propranolol. Contractions produced by exogenous norepinephrine (NE) in the unstimulated preparations were not affected by pretreatment with low concentrations (less than 5 nM) of GAL. On the other hand, the contractions were dose-dependently potentiated 1 min after pretreatment with higher concentrations (greater than 10 nM) of GAL, which recovered 15 min after constant flow washout. Contractions developed by exogenous 5-hydroxytryptamine were not affected, or slightly inhibited, by GAL (1-50 nM). In some preparations without electrical stimulation, high concentrations of GAL caused a slight contraction, which was not blocked by pretreatment with 10(-6) M phentolamine and 10(-6) M tetrodotoxin. These results suggest that GAL receptors exist presynaptically in the rat vas deferens and that stimulation of the receptors by GAL potentiates the release of NE from the nerve terminals during postganglionic sympathetic nerve stimulation. Other mechanisms for GAL action, such as influence on neuronal uptake and catecholamine metabolism, cannot be ruled out.

Animals↗