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Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 253 records · Page 14Linked to original sources
PubMed1992

[Effects of prostaglandin E2 on intraocular pressure, anterior chamber depth and blood flow volume of the iris and the ciliary body in rabbit eyes].

The effects of prostaglandin E2 (PGE2) on intraocular pressure (IOP), anterior chamber depth, and blood flow volume of the iris and the ciliary body of albino rabbits were investigated. Swelling and marked capillary dilatation of the ciliary body were observed after topical application of PGE2. IOP increased immediately by 200 micrograms, 400 micrograms, and 1,000 micrograms of PGE2, reached a peak within 30 minutes; then decreased gradually. The anterior chamber depth decreased only at 5 and 10 minutes after 1,000 micrograms of PGE2. The blood flow volume of the iris and the ciliary body immediately increased, and kept it up for 3 hours. Changes of IOP may be associated with an increase of blood flow attendant upon capillary dilatation of the ciliary body, and an increase of aqueous outflow due to breakdown of the blood-aqueous barrier. In addition to morphological and functional changes of the ciliary body, further factors which promote vitreous volume expansion may play an essential part in the development of malignant glaucoma.

Animals↗
PubMed1991

A new catalytic function of halohydrin hydrogen-halide-lyase, synthesis of beta-hydroxynitriles from epoxides and cyanide.

Halohydrin hydrogen-halide-lyase, which catalyzes the interconversion of halohydrins to epoxides, purified from a recombinant E. coli was found to catalyze the transformation of 1,2-epoxybutane into beta-hydroxyvaleronitrile in the presence of cyanide. Chloride inhibited competitively the formation of beta-hydroxyvaleronitrile. The enzyme also catalyzed the transformation of some other epoxides into the corresponding beta-hydroxynitriles in the presence of cyanide.

Aldehyde-Lyases↗
PubMed1991

The effects of polysaccharides on plasminogen activation by single chain-and two chain-tissue plasminogen activator.

We examined the effects of polysaccharides on t-PA mediated plasminogen activation using single-chain tissue plasminogen activator (sct-PA) and two-chain tissue plasminogen activator (tct-PA). Unfractionated heparin, low molecular weight heparin (LMW heparin) and dextran sulfates enhanced the activation rate of plasminogen by sct-PA about three-fold to six-fold. Chondroitin sulfate C did not enhance the activation. The activation of plasminogen by tct-PA was slightly enhanced by unfractionated heparin, but not by other polysaccharides. Conversion of sct-PA to tct-PA was not stimulated by polysaccharides. SDS-PAGE showed no enhancement of the conversion from sct-PA to tct-PA by plasmin in the presence of polysaccharides. However, the enhancement of sct-PA mediated activation of plasminogen by unfractionated heparin, LMW heparin and dextran sulfates in the presence of aprotinin was shown with SDS-PAGE. It was suggested that unfractionated heparin, LMW heparin and dextran sulfates form complex with sct-PA and plasminogen, and stimulate the conversion of sct-PA to tct-PA.

Animals↗
PubMed1991

Visual evoked potentials in macular hole.

Pattern reversal visual evoked potentials (VEPs) with checks of 50' and 12' were recorded in 15 patients with idiopathic unilateral macular hole. VEPs from the affected eyes were reduced in amplitude compared with those from the fellow eyes, especially with checks of 12' (percentage of the amplitude in the affected eye to that in the fellow eye was 86% +/- 19% with checks of 50' and 61% +/- 35% with checks of 12'). The latencies showed no statistically significant difference between the affected and the fellow eyes, although a marked interocular delay was found in a few patients. The degree of amplitude reduction and interocular delay had no relation to the size of the macular hole or visual acuity. The effects of experimental scotomata of various sizes on the VEPs, which were evaluated in nine normal subjects, were also variable among the subjects. We conclude that although the macula predominantly participates in the pattern VEP, an estimation of the extent of macular pathology from the VEP changes may be difficult because the VEP changes induced by a macular hole have wide individual variation and have no relation to the size of the hole.

Adult↗
PubMed1991

Immunogenicity in Aujeszky's disease virus structural glycoprotein gVI (gp50) in swine.

Aujeszky's disease virus (ADV) envelope glycoprotein gVI (gp50) was purified from virus-infected Vero cells by ion-exchange and immunoaffinity chromatography and its usefulness as a subunit vaccine was evaluated in active and passive immunization studies. Four-week-old piglets were immunized intramuscularly (IM) with purified gVI twice two weeks apart and challenged intranasally (IN) 10 days after the second immunization with 30 LD50 (10(8)PFU) of a virulent strain of ADV. Pigs, vaccinated with 100 micrograms of purified gVI, produced virus neutralizing antibodies and did not develop clinical signs after challenge exposure. The challenge virus was not isolated from nasal swabs and tonsils of gVI-vaccinated pigs, whereas non-vaccinated control pigs developed illness after challenge exposure with the same virulent ADV strain which was later recovered from their nasal swabs and tonsils. Pregnant sows vaccinated twice with purified gVI (IM) at a three week interval produced virus neutralizing antibodies in colostrum. Four-day-old sucking piglets born of vaccinated sows were passively protected by colostral antibodies against intranasal challenge with a lethal dose of virulent ADV. Sera from gVI-vaccinated pigs were distinguished from experimentally infected swine sera by their differential reactivity in enzyme-linked immunosorbent assay (ELISA) using four major viral glycoproteins (excluding gVI) as antigen purified by the use of lentil-lectin.

Animals↗
PubMed1991

The permeability of capillaries in the eustachian tube mucosa.

The transendothelial passage of horseradish peroxidase (HRP) and diffusion of HRP into the pericapillary space, injected intravenously into cats, was studied at the light and electron microscopic level in the mucosa of the eustachian tube. The permeability of capillaries in the pharyngeal two-thirds of the tube was higher than in the tympanic one-third though all the subepithelial capillaries were of the continuous type. In the lamina propria of the subepithelium in the pharyngeal two-thirds much HRP was found 10 min after its intravenous injection, but in the tympanic one-third, it was absent in the perivascular spaces. The capillaries of the pharyngeal two-thirds had many projections and marginal folds inside the capillary lumen and large pinocytotic vacuoles containing HRP as well as many micropinocytotic vesicles. On the other hand, the capillaries in the tympanic one-third had many micropinocytotic vesicles too, but only a few large pinocytotic vacuoles.

Animals↗
PubMed1991

An electron microscopic study of acetylcholinesterase-activity and vasoactive intestinal peptide- and neuro-peptide Y-immunoreactivity of the intraepithelial nerve fibers in the nasal gland of the guinea pig.

In combination with transmission electron microscopy (TEM), histochemistry for acetylcholinesterase (AChE) and immunohistochemistry for vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) were carried out on the intraepithelial nerve fibers of the guinea-pig nasal gland. AChE-positive nerve profiles and VIP-immunoreactive nerve profiles were detected in abundance within the epithelium of the glandular acini and within the epithelium of intralobular excretory ducts including the intercalated and striated ducts. Intraepithelial NPY-immunoreactive nerve profiles were also considerably large in number in the nasal gland, but less frequent than the other two types of nerve profiles; furthermore, the NPY-immunoreactive nerve profiles appeared absent within the epithelium of the striated duct. All the intraepithelial nerve varicosities were in close spatial contact with the epithelial cells of the acinus and the duct and also with the myoepithelial cells, which were commonly seen in the acinus and the intercalated duct. Throughout the present study, however, no membranous specializations could be found between the nerve varicosities and the epithelial cells or the myoepithelial cells. The present results suggest an intense and delicate regulation through the collaboration among ACh, VIP and NPY of the secretory activity of the guinea-pig nasal gland, including the emission of acinar secretions into the duct through contraction of the myoepithelium and modification of the secretion contents by the duct epithelium.

Acetylcholinesterase↗
PubMed1991

Transient deviation of closed eye on head torsion. A kind of neck-ocular reflex.

Electrooculographically, torsion of the head with closed eyes causes little appearance of VOR, but a transient ocular deviation (TOD) of about 30 degrees and a maximum velocity of not less than 200 degrees/sec. TOD occurs more significantly during torsion of the head alone than during rotation of the whole body, with a two-fold greater degree of deviation, suggesting the importance of the input from the cervical afferent. TOD occurs even in a condition in which torsion of the head is made to try with the head fixed and as a result of this maneuver, a torsional force is put on the neck toward the direction of head torsion, but the head does not rotate (vestibular afferent is inoperative). Thus, it is supposed that TOD occurs as a result of the fact that the lateral gaze center is activated by perception of the directional information of head torsion from the cervical afferent.

Adult↗
PubMed1991

Positional nystagmus due to alteration of the specific gravity in the labyrinth.

Horizontal positional nystagmus having characteristics similar to ice water caloric nystagmus was induced by injecting heavy water into the rabbit middle ear cavity or facial nerve through the stylomastoid foramen. Furthermore, with general administration of glycerol to normal subjects, horizontal positional nystagmus as with general administration of heavy water to experimental animals was observed. It is possible that alteration of the specific gravity arising from infiltration of heavy water or glycerol into the labyrinth accounts for the manifestation of positional nystagmus. These studies on positional nystagmus may be one of the means to elucidate the mechanism of caloric nystagmus and to examine the function of the human blood-labyrinth-barrier.

Adolescent↗
PubMed1991

[Visual evoked potential and relative afferent pupillary defect in patients with unilateral optic neuritis].

The relationships between relative afferent pupillary defect (RAPD) and visual evoked potential (VEP), visual acuity or visual field in 14 patients with idiopathic unilateral optic neuritis, were investigated during the period of recovery from an acute episode. Grading of RAPD into four steps mainly based upon an escape phenomenon in a swinging flashlight test, was used to determine the degree of RAPD. The degree of RAPD significantly correlated with a reduction in VEP amplitude, visual acuity and loss of central visual field, while it did not correlate with delay in VEP latency. These results suggest that RAPD is mainly related to the integrity of central vision, and that grading of RAPD, as well as a comparison of VEP amplitude between the affected and contralateral eyes, is useful for an objective evaluation of visual functions of the affected eyes in patients with unilateral optic neuritis.

Adolescent↗
PubMed1991

[Recovery of visual field defects in ischemic optic neuropathy and idiopathic optic neuritis].

Fifty-four eyes of 41 patients with optic nerve disease demonstrating acute visual field defects without any traumatic, compressive, or other known etiology were classified into four categories. Those showing poor recovery of visual field defects were ischemic optic neuropathy which was subclassified into either anterior ischemic optic neuropathy (AION) or posterior ischemic optic neuropathy (PION) according to the ophthalmoscopic changes in the optic nerve head. Those showing good recovery of visual field defects were idiopathic optic neuritis which was subclassified into either papillitis or retrobulbar neuritis according to the ophthalmoscopic pathology of the optic disc. Patients with ischemic optic neuropathy were significantly older than those with optic neuritis. All eyes with optic neuritis showed good recovery of vision, whereas those with ischemic optic neuropathy showed varying outcomes of vision. With regard to the pattern of field defect, central or paracentral scotoma was predominant in all but eyes with AION in which altitude defect predominated. Pale swelling of the optic nerve head and angiographic evidence of circulatory disturbance in the optic disc or adjacent choroid were common findings in eyes with AION, whereas such findings were never observed in eyes with papillitis. The amplitude of pattern visual evoked potential was significantly lower in eyes with PION than in those with retrobulbar optic neuritis. Four patients classified as optic neuritis developed into multiple sclerosis in the follow-up study. It was concluded that poor recovery of visual field defect is one of the most convincing evidences for the diagnosis of ischemic optic neuropathy.

Adult↗
PubMed1991

[A case of rheumatoid arthritis developing pemphigus-like skin lesion during treatment with bucillamine].

Bucillamine is a useful medication for treatment of rheumatoid arthritis (RA) but some patients develop side effects from it. Here, we report a patient with RA developing a pemphigus-like skin lesion during treatment with bucillamine. A 55 year old woman with RA (stage III, class II) had been treated with bucillamine in our hospital since September 1988. Her symptoms of RA had gradually improved after administration of bucillamine but the generalized skin rash with itching developed in June 1989. Skin biopsy revealed spongiosis, the infiltration of lymphocytes in the epidermis and inter-cellular deposition of IgG. These findings were consistent with the histological change of pemphigus. Since symptoms of the skin disappeared two months later after the discontinuation of bucillamine. We considered that her pemphigus-like lesion was induced by this drug. D-penicillamine is one of the drugs which induce pemphigus. Though the mechanisms of this side effect have not been clear, it is thought that autoantibody induced by D-penicillamine could be one of the cause of pemphigus. Because the chemical structure of bucillamine is similar to that of D-penicillamine, the autoimmune mechanisms may also play a role in the onset of the pemphigus-like lesion in this case.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Ultrastructure of the nerve endings in the rat tongue mucosa.

Ultrastructure of the sensory nerve endings in the dorsal tongue mucosa of Sprague Dawley rats was described. Thick bundles of nerve endings, the presence of branches and organized or free nerve endings were found in the subepithelial space. Lamellar corpuscles containing several terminal axons were found in close contact with basal lamina of the epithelium. The lamellar cells envelope the axons at different levels. The cytoplasm of lamellae contains numerous microfilaments, microtubules, mitochondria and caveolae. The terminal axons measure 0.5 to 1.0 micron in diameter and present several forms. Short axoplasmic protrusions and dilated ends were observed. The axons contain numerous mitochondria, microtubules, neurofilaments and small clear vesicles.

Actin Cytoskeleton↗
PubMed1991

Histopathological study of von Ebner's lingual salivary glands in Trypanosoma cruzi-infected mice.

In the present study we describe the histopathological alterations induced by RC strain of Trypanosoma cruzi in the mouse von Ebner's lingual salivary glands during the acute period of infection: Amastigotes were found in von Ebner's gland acini cells, excretory duct cells, intralobular connective tissue, inside the acini lumen and muscle fibres. Desorganized parenchyma with impairment at the acinar and duct level, and intense lymphoplasmocytic infiltrate were seen.

Animals↗
PubMed1991

[Thermography of collagen diseases with Raynaud's phenomenon].

In forty-four patients with collagen diseases accompanied with Raynaud's phenomenon(systemic lupus erythematosus(SLE)10, progressive systemic sclerosis(PSS)15, primary Sjögren's syndrome(PSJS)18 and mixed connective tissue disease(MCTD)1), we analyzed the thermography of fingers after thermal stimulation with cold water(15 degrees C, 30 seconds). In normal controls, the temperature of the distal points of fingers was higher and recovered more quickly than that of the proximal points(proximal interphalangeal joint; PIP). But in the patients with Raynaud's phenomenon, the temperature of distal point of fingers was lower and recovered more slowly than that of proximal points. Because the difference of the temperature between the distal and the proximal points (DP)is a good parameter to distinguish these two thermographic patterns, we analysed DP. DP is less influenced by room temperature than the temperature of fingers and the recovery temperature after thermal stimulation which have been used as indicators of Raynaud's phenomenon. DP in the normal controls was significantly higher than that in the patients. DP in PSS was lower than that in SLE and PSJS, and statistically associated with the markers of disease activities, such as erythrocyte sedimentation rate, titers of anti-RNP antibody and diffusing capacity of lung. These results show that thermographic pattern and the value of DP are the useful indicator of severity of Raynaud's phenomenon.

Adult↗
PubMed1991

[Pneumoperitoneum without perforation of the gastrointestinal tract in a patient with systemic lupus erythematosus].

Pneumoperitoneum often occurs after the perforation of the gastrointestinal tract. However, pneumoperitoneum without the perforation has been reported as one of the complications of collagen diseases, the cause of which is usually the rupture of pneumatosis cystoides intestinalis (PCI). PCI is sometimes observed in the patients with scleroderma and mixed connective tissue disease but rarely in the patients with systemic lupus erythematosus. We reported here a case of systemic lupus erythematosus developed the pneumoperitoneum without the perforation of gastrointestinal tract. A 51-year-old female who had been diagnosed as systemic lupus erythematosus and taken steroid for 12 years, visited our hospital because of general malaise. She had no abdominal symptoms but the roentgenographic examinations revealed the pneumoperitoneum. The laparotomy was performed and there were no findings of the perforation of the gastrointestinal tract. Because PCI is hardly recognized macroscopically after the rupture and the pneumoperitoneum due to PCI is often asymptomatic, we considered the cause of the pneumoperitoneum in this case was the rupture of PCI. The mechanisms of the formation of PCI in patients with collagen diseases were also discussed in this paper.

Female↗
PubMed1990

Central changes in hypothyroid myopathy: a case report.

A muscle biopsy from a patient with hypothyroid myopathy showed striking central changes. "Cores" were seen in most type 1 fibers with oxidative enzyme preparations. Electron microscopy of these areas revealed Z disc streaming, myofilament disruption, and absent mitochondria. The myopathy rapidly improved with thyroxine treatment. This biopsy is of interest, as numerous "cores" have not previously been reported in hypothyroid myopathy.

Humans↗