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K Yonemoto

Publications and source records attributed to K Yonemoto.

35 records · Page 2Linked to original sources
PubMed1989

[Characteristics of gamma glutamyl transferase in melanoma].

Gamma glutamyl transferase (GGT) is widely distributed in mammalian tissues, and its biological heterogeneity has been demonstrated among various tissues. In order to investigate the biological characteristics of GGT in melanomas, enzyme-histochemical and biochemical studies were performed using amelanotic/melanotic and murine/human melanomas as materials. Enzyme-histochemically, GGT activity appeared to be present only in melanogenic cells in vitro. Biochemical assays of tissue extracts revealed that the specific activity was much higher in melanotic melanomas than in amelanotic. In addition, analysis of GGT-isoenzymes demonstrated that an isoenzyme band at approximately 110KD was expressed in tumorigenic or highly-metastatic tissues. These findings suggest that GGT in melanoma is closely related to the ability of melanin production and that the possible existence of a unique isoenzyme may reflect the intensity of tumorigenic and/or metastasis.

Animals↗
PubMed1985

Autosomal recessive distal muscular dystrophy: a comparative study with distal myopathy with rimmed vacuole formation.

To clarify the clinical and morphological characteristics of distal muscular dystrophy, clinical and pathological material from 4 affected persons was compared with similar studies in 4 patients with distal myopathy with rimmed vacuole formation. Although these two forms of autosomal recessive distal myopathy with onset in young adulthood were highly similar in their clinical symptoms, histochemical and electron microscopic findings of muscles subjected to biopsy were quite different. The muscle abnormalities in distal muscular dystrophy were almost the same as those in Duchenne muscular dystrophy, showing massive fiber necrosis followed by active fiber regeneration. In contrast, distal myopathy with rimmed vacuole formation showed a progressive muscle fiber atrophy and loss, rimmed vacuoles in the sarcoplasm, and no apparent fiber necrosis or regeneration.

Adolescent↗
PubMed1984

Effects of 4-tertiary butyl catechol on glutathione-metabolizing enzymes in vivo and in vitro.

4-Tertiary butyl catechol (TBC) causes depigmentation in humans and animals and stimulates formation of pheomelanosomes. In this study, we investigated the effects of noncytotoxic doses of TBC on glutathione S-transferase (GST) activity in the skin of Uscd strain mice and B16 murine melanoma cells in culture, in relation to changes in activities of glutathione reductase (GR) and gamma-glutamyl transpeptidase (GGT) reported to be involved in pheomelanogenesis. Occurrence of pheomelanosomes in skin melanocytes was demonstrated by electron microscopy and reduction (25%) of eumelanin content in melanoma cells was shown by spectrophotometry. Topical application of 1 M TBC-DMSO-acetone solution on the ear skin elevated GST activity about 27%, and activities of GGT and GR to 35% and 19%, respectively, within 1 week. Melanoma cells cultured in 10(-4) M TBC-containing medium for 2 h showed no changes in GST and GGT activities, but 12% increase of GR activity during the first 12 h. Activities of all 3 enzymes was elevated (11-17%) 24 h later. The elevation detected by 48 h was 25% for GST, 26% for GGT, and 14% for GR. The findings were interpreted to show that depigmentation produced by the antioxidant results from stimulated pheomelanogenesis through activation of glutathione-metabolizing enzymes and suppressed oxidation of eumelanin intermediates.

Animals↗
PubMed1983

Reduction in eumelanin by the activation of glutathione reductase and gamma-glutamyl transpeptidase after exposure to a depigmenting chemical.

Topical application of 4-tertiary butyl catechol (TBC) causes vitiligo in the skin of man and animals, and previous electron microscopic studies showed pheomelanin formation in the affected areas. In the present study, we investigated changes of enzyme activities, eumelanin content and amount of sulfur in tissue cultured human melanoma cells exposed to the depigmenting chemical. TBC enhanced glutathione reductase activity without changing the eumelanin content by 24 hr after exposure and subsequently (by 42 hr) increased gamma-glutamyl transpeptidase activity and sulfur content in the cells with a decrease in eumelanin content. It is suggested that this chemical alters the types of melanin formed by modulation of these enzyme activities.

Catechols↗
PubMed1983

Glutathione reductase activity in skin exposed to 4-tertiary butyl catechol.

The effect of 4-tertiary butyl catechol (TBC), a potent depigmenting chemical, on glutathione reductase (GR) in pigmented ear skin of hairless mice was investigated. Three topical applications of TBC, which cause neither skin color changes nor melanocyte degeneration, induced an increase in enzyme activity. Since the same treatment resulted in pheomelanin formation as evidenced by electron microscopy, it is suggested that the GR increase correlates at least in part with changes in melanocyte metabolism. This enzyme generates a reduced form of glutathione which may be involved in the formation of glutathionedopas, substrates for hydrolytic enzymes to produce cysteinyldopas, and pheomelanin. Elevation of GR may be an indication of melanogenesis before clinical skin color changes due to TBC appear. It may be used for the early detection of occupational leukoderma.

Animals↗
PubMed1983

A simple method of measuring the footsole pressure of normal subjects using prescale pressure-detecting sheets.

A simple method of measuring the pressure beneath the footsole was described using 'Prescale', pressure detecting sheets. These are two sheets, one coated with microcapsules which contain a color-producing agent, and the other coated with a color-developing agent. As the applied pressure determines the amount of microcapsules that rupture, the coloring sheet reveals its density corresponding to the pressure applied. At the application of this method, normal subjects were studied quantitatively on distribution of the pressure beneath the footsole. The results were compared with the structure of the foot as revealed by X-ray examination in order to study the correlation between the two. The clinical benefits and indication of this method were discussed.

Adult↗
PubMed1983

Measurement of the footsole pressure distribution of normal subjects by pressure sensitive films.

A simple method measuring the pressure on the footsole was described using "Prescale", pressure sensitive films. Prescale consists of two films, one coated with microcapsules which contain a color-producing agent and rupture when a pressure is applied, and the other coated with a color-developing agent. Then, when a pressure is applied on the former film, the latter one display a color of various density corresponding to the pressure applied. Distribution of the pressure on the footsole was studied in normal subjects by this method. Pressure distribution in each subject was compared with his foot structure examined radiologically. And the clinical implications and indication of this method were discussed.

Biomechanical Phenomena↗
PubMed1981

Effect of chest wall vibration on ventilation in patients with spinal cord lesion.

Changes of respiration caused by chest wall vibration were studied in 13 patients with cervical cord lesions. Vibrators applied on the chest wall were intermittently triggered by the patient's respiratory movements. The vibrators were triggered to be applied in three ways. 1) Upper vibrations were bilaterally applied during inspiration on the 2nd or 3rd parasternal intercostal spaces (insp "in-phase" vibration). 2) Lower vibrations were bilaterally applied during expiration on the 7th-to 10th intercostal spaces anterior to midaxillary lines (exp "in-phase" vibration). 3) Inspiratory and expiratory vibrations were combined to produce alternating in phase vibration. Both inspiratory and expiratory vibrations increased tidal volume (VT), but the alternating in-phase vibration increased it to significantly higher values (P less than 0.05). Minute volume of ventilation (VE l/min) also increased with insp or exp in-phase vibration. The alternating in-phase vibration increased VE l/min to even higher values (P less than 0.05). The responses described probably depend on segmental vibration reflexes arising in the inspiratory and expiratory intercostal muscles underlying the vibrators. The alternating in-phase vibration may well be useful to improve the breathing in patients with respiratory insufficiency.

Adolescent↗
PubMed1978

Single-skinned human muscle fibers: activation by calcium and strontium.

Single-skinned fibers were prepared from human skeletal muscle. Tension generation was measured in solutions containing different amounts of free calcium or strontium ion. Fibers were classified into two types, on the basis of distinct differences in their regulation by strontium. One group developed maximal tension in 3 x 10-5 M free strontium, whereas the other developed minimal or no tension in the same concentration of strontium. It seemed most probable that the former represented type 1 (slow twitch) fiber and the latter type 2 (fast twitch) fiber because of similar patterns observed in guinea pig soleus and extensor digitorum longus muscle fibers.

Calcium↗
PubMedDate not supplied

Evaluation and treatment of shoulder subluxation in hemiplegia: relationship between subluxation and pain.

Shoulder subluxation in hemiplegic patients has been recognized as a difficult problem to manage. In the study contained herein, our aims are to evaluate shoulder subluxation, to clarify if shoulder subluxation causes pain, and to discuss the treatment of shoulder subluxation. The study included 75 hemiplegic patients with shoulder subluxation. Each patient was evaluated for the degree of shoulder pain, motor recovery of the upper limb, and shoulder range of motion. Some indexes for evaluating subluxation were measured with radiographs of the shoulders. Arthrograms of the affected shoulder joint were taken in 23 patients. The following results were found: (1) shoulder pain was significant more frequently in left hemiplegia; (2) vertical disparity was strongly correlated with discrepancy of the descendant ratio; (3) severe inferior subluxation had a tendency to show medial displacement of the humeral head; (4) there were correlations between shoulder pain and shoulder range of motion, especially external rotation; (5) adhesive changes in the arthrograms were seen in most subjects. These results indicate that there is no relation between shoulder subluxation and pain, and adhesive capsulitis is a main cause of shoulder pain. We conclude that correct positioning and shoulder range of motion exercises are advisable in hemiplegic patients with shoulder subluxation.

Adult↗
PubMedDate not supplied

Pathological and laboratory findings in LEC/Otk rats that spontaneously develop hepatic injury.

The LEC strain of rats that spontaneously develops hepatic injury has been introduced into specific pathogen-free (SPF) conditions (SPF-LEC/Otk). The present communication describes the clinical and pathological features of the SPF-LEC/Otk rats. The characteristic features of these animals are as follows: (i) Jaundice develops in almost all rats with increase in the P-GPT level; (ii) The animals show episodes of jaundice, a high P-GPT level and liver cell necrosis, but only slight inflammatory cell infiltration; (iii) The liver cells show characteristic microvesicular fatty changes; (iv) The P-GPT level shows increases, first at 18 weeks and then at 25 weeks of age; (v) The rats show immunological disorders, such as deficiency of immunoglobulins, especially IgG1, and of helper T cells; (vi) Infectious agents such as viruses do not seem to be involved, although this possibility cannot be absolutely excluded; (vii) The immunological disorders are not directly associated with the occurrence of liver cell necrosis; and (viii) The pattern of inheritance (autosomal single-recessive trait) of the disease strongly suggests that it is due to a genetic metabolic disorder.

Alanine Transaminase↗