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Biomedical subjects

H Inomata

Publications and source records attributed to H Inomata.

At least 145 records · Page 8Linked to original sources
PubMed1989

Effect of noradrenaline on current- and voltage-clamped muscle cells of the guinea-pig vas deferens in normal Krebs solution.

The ionic mechanism underlying the time-dependent alteration in the action potential configuration by noradrenaline (NA) was studied using vas deferens muscles voltage-clamped according to the double sucrose gap method. Early exposure to NA enhanced the inward Ca2+ current (ICa) by increasing conductance whereas late exposure diminished ICa by reducing the driving force. The degree of increase in the peak outward K+ current (IK') was higher with a greater enhancement of ICa by NA but the late outward K+ current (IK) was insensitive to NA.

Action Potentials↗
PubMed1989

Cytopathology of early cellular reaction on implant lenses in monkeys. A transmission electron microscopic study.

We carried out extracapsular lens extraction with the implantation of a modified C-loop posterior chamber lens in eight monkey eyes. The animals were killed after varying survival of up to 14 days. The intraocular lenses (IOLs) were removed and examined by transmission electron microscopy. Three different types of cells, namely, polymorphonuclear leukocytes, macrophages, and multinucleated giant cells, were observed on the surface of the IOLs. A thin, membrane-like structure composed of finely granular material covered the lens surface. These cell components were not attached directly to the lens surface, but, rather, were located on the membrane-like structure.

Animals↗
PubMed1989

Retinal vasculitis in human T-lymphotropic virus type I associated myelopathy.

Human T-lymphotropic virus type I (HTLV-I) has been recently found to be associated with slowly progressive myelopathy. We have seen 12 patients with HTLV-I associated myelopathy (HAM), three of whom showed retinal vasculitis. In addition two patients had ocular symptoms of vitreous opacity. Retinal vasculitis in these patients appears to be phlebitis and sheathing of retinal veins in the periphery of the fundus.

Female↗
PubMed1989

Cytology of intraocular lens surface: a transmission electron-microscopic study. Cytology of intraocular lens surface.

We developed a new method for specimen preparation for transmission electronmicroscopic study of cellular responses on intraocular lenses. This procedure omits propylene oxide treatment of the materials to be studied, which is normally a step in the routine preparation process for transmission electron microscopy. It was previously found that propylene oxide treatment dissolves intraocular lenses. Using our procedure, two types of cells were identified on intraocular lenses removed from monkey eyes 7 days after implantation. These cells had the typical structural features of multinucleated giant cells and of macrophages. It thus appears that this procedure will permit study of the cytology of intraocular lens surfaces.

Animals↗
PubMed1989

Degeneration of zonular fibrils in a case of exfoliation glaucoma.

We examined ultrastructurally zonules of the lens obtained from a patient with exfoliation glaucoma and lens dislocation. There was a great accumulation of exfoliation materials adjacent to and within degenerated zonules, and a gradual transition between zonular fibrils and exfoliation materials was observed. The initial change in the zonular fibrils was a loss of their regularity, next we could see fine granules deposited on degenerated zonular fibrils. A sparse and irregular deposition was found on the surface of the fibrils. Subsequently, the deposition became increased, and densely stained exfoliation materials, which were composed of a single degenerated zonular fibril and fine granules, were formed. Several fibrils accompanied by fine granules clustered together and became exfoliation materials of larger diameter. These observations suggest that degenerated zonular fibrils may develop into exfoliation materials.

Aged↗
PubMed1989

A case of ocular reticulum cell sarcoma responded to radiation therapy.

We report a case of reticulum cell sarcoma with involvement both in the brain and the eyes. The patient was a 49-year-old man. In 1985, he suffered steroid-resistant uveitis of unknown etiology in his right eye. After that, in 1986, he was aware of a weakness in the right arm and leg and of right sensory disturbances. Histopathological study of a biopsy specimen revealed a malignant lymphoma in the left thalamus, and the lesion was effectively treated by radiation to the brain. In 1987, he complained of visual disturbances in the left eye. According to the history and ocular manifestation, the disease was diagnosed as ocular reticulum cell sarcoma. Radiation therapy to his left orbital cavity was effective and inflammatory signs in the left eye subsided.

Biopsy↗
PubMed1989

Depression of voltage-dependent Ca2+ current by noradrenaline in the guinea-pig vas deferens in tetraethylammonium medium.

The actions of noradrenaline (NA) on the smooth muscle of the guinea-pig vas deferens in tetraethylammonium (TEA) medium have been studied under constant-current and voltage-clamp conditions. The marked changes observed during exposure to NA are 1) slowness in the rising phase of the action potential, delay in the falling phase and reduction in the amplitude, and 2) depression of the voltage-dependent Ca2+ current with a negative shift of its reversal potential as well as with a reduction in its conductance. These findings might suggest that NA application stimulates the voltage-independent Ca2+ machinery, but suppresses the voltage-dependent Ca2+ machinery through membrane.

Action Potentials↗
PubMed1989

[A case of spinal artery aneurysm presenting transverse myelopathy associated with coarctation of the aorta].

We report a case of spinal artery aneurysm, secondary to the coarctation of aorta, who presented with initial signs of transverse myelopathy. A 45-year-old woman was admitted to the hospital because of quadriplegia. She had a history of subarachnoid hemorrhage traced to unknown origin. Physical examination revealed hypertension of upper limbs, but any artery of the lower limbs was not palpable. On neurological examination, she was alert, quadriplegic, and anesthetic below C4 level. Neck was stiff and meningeal signs were presented. The liquor was bloody. Myelography demonstrated complete block at C5-6. The right retrograde brachial angiography showed an aneurysm of cervical spinal artery. Digital subtraction angiography demonstrated a coarctation of the aorta. Coarctation of the aorta was considered to have caused spinal artery aneurysm, and is the first reported case in Japan.

Aneurysm↗
PubMed1989

[A statistical comparison study of glaucoma in the Third Affiliated Hospital of China Medical College and Kyushu University].

We classified 331 glaucoma patients who visited the eye clinic of the Third Affiliated Hospital of China Medical College during the 2 year period from January 1985 to December 1986 according to the type of glaucoma. The results were compared with those obtained from 275 glaucoma patients who visited the eye clinic of Kyushu University during an overlapping period of 2 years, from January 1986 to December 1987. Patients with glaucoma were found to comprise 1.5% of the 22,869 outpatients in the Third Affiliated Hospital of China Medical College, and 1.8% of the 15,585 outpatients in Kyushu University. The distribution of various types was as follows: primary angle closure glaucoma (76.4%), primary open angle glaucoma (4.8%), secondary glaucoma (11.8%), exfoliation glaucoma (0) and congenital glaucoma (5.7%) in the Third Affiliated Hospital of China Medical College, and primary angle closure glaucoma (34.5%), primary open angle glaucoma (12.7%), secondary glaucoma (22.2%), exfoliation glaucoma (14.9%) and congenital glaucoma (10.9%) in Kyushu University. The present results suggest that the incidence of primary angle closure glaucoma in China is higher than in Japan, and that the incidence of primary angle closure glaucoma is higher than that of primary open angle glaucoma in these two countries. It is of interest that the high incidence of primary angle closure glaucoma in China and Japan coincides with the study in Canadian Eskimos. The incidences of secondary glaucoma and exfoliation glaucoma in Japan are higher than in China. This might be due to differences in diagnostic facilities in the two countries.

Adult↗
PubMed1988

Necrotic changes of choroidal melanocytes in sympathetic ophthalmia.

There are various theories as to the origin of epithelioid cells in the choroid with sympathetic ophthalmia. Some investigators propose a transformation of choroidal melanocytes as the origin, and others suggest a histiomonocytic derivation. One reason this controversy exists may be the relative lack of investigations into necrotic changes of choroidal melanocytes. The structural alterations in the choroidal melanocytes of an injured eye with sympathetic ophthalmia were studied, and the sequence of events involved in degeneration and necrotic changes were elucidated. The damaged melanocytes developed vacuolation, and the melanin granules were gathered into autophagosomes or had disappeared. The nuclei of the severely damaged melanocytes became pyknotic. Degenerated cell nuclei were phagocytized by macrophages. It is concluded that choroidal melanocytes may not transform into epithelioid cells and that they disappear from the choroid following degeneration.

Choroid↗
PubMed1988

Visual pretectal neurons projecting to the dorsal lateral geniculate nucleus and pulvinar nucleus in the cat.

We observed morphological subtypes of visual pretectal neurons ascending to the dorsal thalamus, following injections of wheat germ agglutinin conjugated to horseradish peroxidase into the dorsal lateral geniculate nucleus (LGNd) or the pulvinar nucleus. These neurons are composed of fusiform cells and small-sized multipolar cells in the olivary pretectal nucleus, superficial horizontal cells, fusiform cells, small-, medium- and large-sized multipolar cells in the optic tract nucleus, and small- and medium-sized multipolar cells in the posterior pretectal nucleus. When somal size of the neurons projecting to the LGNd was compared to the size of neurons projecting to the pulvinar, the neuronal groups were not identical.

Animals↗
PubMed1988

Functional innervation and contractile properties of the human iris sphincter muscle.

To investigate the pattern of innervation and the contractile properties of human iris sphincter muscle, we have observed the effects of field stimulation, various drugs and excess-K+ solutions on isometric tension development in strips of the iris sphincter from five humans. Spontaneous mechanical responses were not observed in these tissues. Electrical field stimulation (50 V, 0.8 msec, 20 Hz) evoked a contraction which was abolished by 10(-7) M tetrodotoxin (TTX) or by 10(-6) M atropine, thereby indicating that the response was cholinergically mediated. In the presence of atropine, electrical field stimulation did not affect muscle tone, even when this was elevated by histamine. The effect of exogenously applied noradrenaline (NA) varied among the specimens, i.e. in three out of four cases a contraction was evoked while a relaxation occurred in one preparation. The contraction evoked by NA was blocked by phentolamine (10(-6) M) and the relaxation was blocked by timolol (10(-6) M). Excess-K+ solutions, dose dependently contracted the muscle strips and application of 10(-6) M atropine decreased the amplitude of these contractions. The results indicate that the human iris sphincter is innervated by excitatory cholinergic nerve fibres and that the adrenergic innervation is sparse. In addition, this muscle possesses both alpha and beta adrenoceptors. Activation of alpha receptors produces a contraction whilst activation of the beta adrenoceptors causes relaxation.

Aged↗
PubMed1988

Participation of T lymphocyte in corneal edema in the early stage of herpetic stromal keratitis.

The participation of T lymphocytes in the immunopathogenesis of corneal opacity in herpetic stromal keratitis was investigated. In BALB/c mice infected intracorneally with herpes simplex virus type 1, corneal opacity was manifested 10 days after infection, while in athymic mice corneas remained almost clear. Histologically, all opaque corneas revealed stromal edema accompanied by the diffuse presence of polymorphonuclear cells and lymphocytes. When complement (C')-treated immune spleen cells were adoptively transferred into athymic mice 6 or 72 h after corneal infection, stromal keratitis with mild opacity was observed 10 days after transfer. The athymic mice given anti-Thy 1.2+C'-treated immune spleen cells failed to develop corneal opacity. The difference, as revealed by light and electron microscopy, was the presence or absence of lymphocytic infiltration and edema in the posterior third layers of the stroma and endothelial lesions. The endothelium was infiltrated by lymphocytes or macrophages and showed various stages of destruction. The main cause of corneal opacity in the early stage of herpetic stromal keratitis is thought to be stromal edema due to an adverse effect on the endothelium by immune T lymphocytes.

Animals↗
PubMed1988

Posterior chamber lens implantation: histopathological report of a successful case.

Using electron microscopy, we examined an eye obtained at autopsy in which a C-loop intraocular lens had been implanted into the posterior chamber 2 years and 4 months prior to the patient's death. The lens was affixed with the superior loop outside the capsular bag and the inferior loop within the capsular bag. The two ciliary epithelial layers to which the superior loop was attached were thinned; the pigmented epithelial layer was completely absent and the nonpigmented epithelial layer was disrupted, suggesting breakdown of the blood-aqueous barrier. Proliferating lens epithelial cells, basement membrane-like material, collagen fibers and microfibrils were seen surrounding the inferior loop. The lens capsule, the zonular fibers and the ciliary epithelium adjacent to the inferior loop showed no pathological changes.

Anterior Eye Segment↗
PubMed1988

A patient with Graves' disease who developed hypothyroidism associated with thyroid stimulation blocking immunoglobulin during anti-thyroid drug therapy.

A girl, 12 years of age, developed Graves' disease compounded with rheumatic fever and idiopathic thrombocytopenic purpura. Thrombocytopenia improved under short-term treatment with steroids and her mitral valvular insufficiency, due to the rheumatic fever, disappeared 4 years later. Initially, she had been treated with propylthiouracil (PTU) for 28 months. She suffered a relapse 9 months after stopping PTU and so she was given further PTU therapy. However, hypothyroidism developed 11 months after the initiation of therapy and continued, though further PTU treatment was discontinued. She now receives 1-thyroxine and maintains a euthyroid state. At the onset of the patient's hyperthyroidism, the TSH-binding inhibitor immunoglobulin (TBII) and the thyroid stimulating antibodies (TSAb) were found to be positive. During the remission period, only the thyroid stimulation blocking immunoglobulin (TSBI) was weakly positive. At relapse, only TBII was mildly positive. When hypothyroidism developed, both TBII and TSBI were positive, and TSAb was negative in all testings of her diluted IgGs. The patient's TBII and thyroid dysfunction were unaffected by high-dose intravenous gammaglobulin therapy or by treatment with prednisolone 0.5 mg/kg/day for 2 weeks. In conclusion, the emergence of TSBI during or after anti-thyroid drug therapy might possibly lead to hypothyroidism in patients with Graves' disease.

Antithyroid Agents↗
PubMed1988

Optimum replacement dose of thyroid hormone assessed by highly sensitive TSH determination in patients with congenital hypothyroidism.

Serum thyroid hormone concentrations were measured in 100 samples from 25 patients with congenital hypothyroidism who were clinically well while receiving L-T4 therapy. Thyroxine concentrations were significantly higher than those of controls (p less than 0.01), while triiodothyronine was not significantly different. These samples were divided into four groups according to serum thyroid stimulating hormone concentrations as measured by highly sensitive immunoradiometric assay (IRMA-TSH). Serum thyroid hormone concentrations were compared among groups. The replacement dose of L-T4 and serum thyroid hormone in groups with undetectable IRMA-TSH were significantly higher than those in groups with normal or increased IRMA-TSH. These results show that serum thyroxine concentrations increase in most patients with congenital hypothyroidism on L-T4 therapy. Therefore, thyroxine concentrations above normal are not necessarily of clinical significance if IRMA-TSH is detectable. Undetectable IRMA-TSH might indicate the necessity for a reduction in the L-T4 replacement dose in patients with congenital hypothyroidism.

Child↗