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Biomedical subjects

T Mizokami

Publications and source records attributed to T Mizokami.

At least 37 records · Page 2Linked to original sources
PubMed1995

Human T-lymphotropic virus type I-associated uveitis in patients with Graves' disease treated with methylmercaptoimidazole.

Human T-lymphotropic virus type I (HTLV-I) is responsible for a certain form of uveitis [HTLV-I-associated uveitis (HAU)]. A previous history of Graves' disease has been reported in 9-17% of the patients with HAU. In this study, the prevalence of patients with either HTLV-I antibody or uveitis was evaluated in 819 consecutive patients with thyroid disorders between 1991 and 1992. Serum HTLV-I antibody was found in 25 of 392 patients with Graves' disease, 19 of 257 with chronic thyroiditis, and 3 of 170 with nodular goiter. Five of 25 HTLV-I-positive patients with Graves' disease developed HAU. All of these 5 patients had been treated with methylmercaptoimidazole (MMI). Within a few months before the onset of uveitis, 3 patients were hyperthyroid, and 2 were hypothyroid. In 2 of 5 patients, an exacerbation of uveitis occurred soon after the readministration of MMI for the relapse of hyperthyroidism. None of the 367 HTLV-I negative patients with Graves' disease nor 22 HTLV-I-positive patients with chronic thyroiditis or nodular goiter developed uveitis. It was therefore suggested that Graves' disease, thyroid dysfunction and/or MMI administration might be related to the development of HAU.

Adult↗
PubMed1995

Acute spontaneous hemorrhagic degeneration of the thyroid nodule with subacute thyroiditis-like symptoms and laboratory findings.

Seventeen consecutive patients (3 men and 14 women, aged 14-75 years) with a hemorrhagic degeneration of the thyroid nodule, which was confirmed by both ultrasonography and either reddish or brown fluid evacuated by fine-needle aspiration, were classified as either acute type with an episode of abrupt painful swelling of the thyroid (n = 4), or chronic type in which a painless thyroid nodule was incidentally found (n = 13). One of the four acute type patients demonstrated subacute thyroiditis-like symptoms and laboratory findings including transient painful thyrotoxicosis associated with high serum levels of thyroid hormones and thyroglobulin (Tg), a suppressed serum TSH level, a low thyroidal radioactive iodine uptake (RAIU), and accelerated erythrocyte sedimentation rate (ESR). In the other three acute type patients the serum level of Tg increased markedly, the serum thyroid hormones level increased in one, the thyroidal RAIU was low in two, and the ESR was accelerated in one. In the thirteen chronic type patients, the serum levels of the thyroid hormones and the thyroidal RAIU were within the normal range, and few inflammatory signs were observed. These findings suggest that acute hemorrhagic degeneration of the thyroid nodule may thus cause transient subacute thyroiditis-like symptoms and laboratory findings.

Acute Disease↗
PubMed1994

A high prevalence of human T-lymphotropic virus type I carriers in patients with antithyroid antibodies.

Human T-lymphotropic virus type I (HTLV-I) is a causative retrovirus of adult T-cell leukemia lymphoma and HTLV-I associated myelopathy/tropical spastic paraparesis. HTLV-I is also associated with some forms of pulmonary alveolitis, chronic arthropathy, polymyositis, and uveitis. In this study, the possible role of HTLV-I infection in the pathogenesis of autoimmune thyroid diseases with positive antithyroid antibody (ATA) to microsomal antigen or thyroglobulin was evaluated. In Fukuoka Prefecture or the northern part of Kyushu Island located in the southwestern part of Japan, the prevalence of patients with HTLV-I antibody was screened using the particle agglutination test and then was further confirmed either by the indirect immunofluorescence method or the western blot method. The observed prevalence in patients with thyroid disorders and the estimated prevalence calculated considering the sex- and age-specific prevalence among healthy blood donors (n = 16,008) were as follows: 19 (7.4%) vs 7.8 (3.0%) (p < 0.001) for ATA-positive chronic thyroiditis (n = 257), 21 (7.0%) vs 6.6 (2.2%) (p < 0.001) for ATA-positive Graves' disease (n = 298), 4 (4.3%) vs 2.1 (2.2%) (ns) for ATA-negative Graves' disease (n = 94), 1 (2.9%) vs 1.1 (3.1%) (ns) in ATA-negative hypothyroidism (n = 35), and 3 (1.8%) vs 5.0 (2.9%) (ns) for ATA-negative nodular goiter (n = 170). These findings thus suggest that HTLV-I infection may have some relationship to ATA-positive thyroid disorders.

Adult↗
PubMed1994

Postpartum exacerbation of HTLV-I associated myelopathy/tropical spastic paraparesis followed by an episode of painless thyroiditis.

A 28-year-old woman noticed a progressive gait disturbance after her first delivery. At the age of 32, the gait disturbance improved during her second pregnancy, but became worse after delivery and eventually resulted in a scissoring gait. At the age of 34, she became transiently thyrotoxic and was diagnosed as having painless thyroiditis and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). The findings of this case suggest that the postpartum exacerbation of HAM/TSP was probably due to a rebound phenomenon after immunosuppression during pregnancy, and that the immunological abnormalities associated with HAM/TSP might have played some role in the development of painless thyroiditis.

Adult↗
PubMed1994

[A case of Bacillus cereus prosthetic valve endocarditis].

A rare case of prosthetic valve endocarditis by Bacillus cereus was reported. The patient was 43-year-old Japanese man, who had mitral valve replacement 5 months prior to this admission. Remitral valve replacement was immediately done successfully. His postoperative course was uneventful for 8 months.

Adult↗
PubMed1993

A study of the influence of arrangement of upper posterior artificial teeth on pronunciation: Japanese sounds articulated on the posterior palate.

To clarify the standard of bucco-lingual tooth arrangement in complete denture construction, the influence of the bucco-lingual position of upper posterior artificial teeth on pronunciation was investigated. Wearing 7 kinds of experimental artificial teeth with the upper posterior ones arranged in 7 different positions, patients pronounced 5 test sounds: "ka", "ki", "kw", "ke" and "ko". Resultant sounds were evaluated in terms of how the bucco-lingual position of posterior artificial teeth influenced pronunciation as determined with by aural pronunciation judgment test and frequency analysis using a 1/3 octave-band real-time analyzer. Pronunciation disorders caused by the arrangement of the upper posterior artificial teeth in complete dentures occur when the lingual surfaces of the upper molars is located more than 1/4 inward of the distance between the right and left denture border from the buccal denture border or less than 1/10 of that distance outward from the buccal denture border. Results of the aural pronunciation judgment test indicated that the influence of the arrangement of the upper posterior artificial teeth on pronunciation depends on the vowel following the consonant of the sound. When the vowel following the consonant is a back vowel, as in "ka", "kw" and "ko" the sound was barely influenced, but when the vowel is a front vowel. as in "ke" and "ki", the sound was markedly influenced. We established the frequency spectrum of the consonant of the normally pronounced 5 test sounds as the standard frequency spectral range and compared distorted and misheard sounds with it.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

A study of the judging the anteroposterior mandibular position by gripping the temporal muscle region.

Greene proposed a method for judging the suitability of the mandibular position from the bulging of the temporal muscle. Using his method, we studied the effect of anteroposterior alteration of mandibular position on the building of this muscle. In the temporal muscle, the area suitable for gripping to check mandibular position was, anteroposteriorly, the point 3/5 of the length between the upper margin of the external auditory meatus and the point of intersection of the Frankfort plane and the line perpendicular to it which was drawn from the outer canthus. Vertically, it was approximately at the point 3/5 of the distance from the bottom of the line from the Frankfort plane to the upper edge of the temporal muscle. In patients whose anteroposterior changes in the tapping point were small, anteroposterior changes of 0.2 mm in mandibular position could be detected. However, in patients who had large anteroposterior changes in the tapping point, anteroposterior changes of 0.5 mm in mandibular position could not be verified.

Dental Occlusion, Centric↗
PubMed1993

Relationship between impression method of mucosa-borne area and denture pressure supportability.

In order to develop a more rational impression method, we examined the relationship between impression method and denture pressure supportability through the denture. Measured with denture bases prepared from impressions taken under various pressures, pressure supportability generally increased with increasing impression pressure. However, the pressure supportability of a denture base prepared from a slight-pressure impression taken under minimum pressure was greater in some cases than for a middle-pressure impression performed under a more pressure. The impression pressure required to produce maximum pressure supportability were calculated based on the area projected from the occlusal plane and ranged from 1.24 to 2.44 kg/cm2 (0.12 to 0.24 MPa). Values calculated based on the surface area of the denture-supporting mucosa ranged from 0.83 to 2.48 kg/cm2 (0.08 to 0.24 MPa). Pressure supportability of the great-pressure impression was 1.3 to 2.6 times higher than that of the slight-pressure impression and 1.2 to 1.8 times greater than that of the alginate impression. Viewed from a clinical standpoint, the great-pressure impression is more effective than the alginate and no-pressure (slight-pressure) impressions in increasing denture pressure supportability.

Adult↗
PubMed1992

Preserved thyroidal secretion of thyroxine in acromegalic patients with suppressed hypophyseal secretion of thyrotrophin.

OBJECTIVE: We have assessed the mechanisms which maintain euthyroidism in acromegalic patients despite the suppression of thyrotrophin (TSH) secretion. MATERIALS: Fourteen untreated patients with acromegaly were analysed. Ten patients were also studied after pituitary surgery. METHODS: Thyroid hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and thyroidal uptake of radioactive iodine, thyrotrophin releasing hormone (TRH) test and basal metabolic rate (BMR) were measured before and after pituitary surgery. RESULTS: Nine patients had palpable goitres. The TSH response to TRH stimulation was suppressed in eight patients, who maintained normal serum levels of total T3, T4 and free T4. The patients with normal TSH response had lower levels of free and total T4 than controls. The response of TSH to TRH correlated inversely with the serum level of total and free T4, and also with the plasma level of IGF-I (r = -0.74, P less than 0.05, n = 9). After pituitary surgery, the serum levels of total and free T4 were elevated for at least up to 6 months, with a decrease in the T3/T4 ratio and the BMR. CONCLUSION: GH may have a direct stimulatory action on the thyroid secretion of T4 possibly via increased IGF-I, despite suppressed TSH secretion. The post-operative elevation of serum T4 suggests the persistent secretion of T4 from the thyroid gland, in spite of instantaneous normalization of the accelerated conversion of T4 to T3, even after reduction of excess GH secretion.

Acromegaly↗
PubMed1992

Effect of captopril on isoproterenol-induced cardiac hypertrophy and polyamine contents.

It is well known that isoproterenol (ISO) a nonselective beta adrenoceptor agonist induces cardiac hypertrophy. It can be assumed that, in addition to its direct cardiac effect, ISO has a cardiac trophic effect via stimulation of the renin angiotensin system. Synthesis of polyamines is facilitated in cardiac hypertrophy and polyamine levels are rapidly elevated prior to an increase in heart weight. In the present study, we investigated whether captopril (30 mg/kg body weight, daily) could attenuate cardiac hypertrophy and elevation of cardiac polyamine levels in rats, which effects were elicited by a chronic (1- or 2-weeks) and repeated administration of a small dose (0.5 mg/kg body weight) of ISO. Cardiac hypertrophy was assessed by an increase in the wet weight and RNA content of the heart. Polyamines were analyzed by HPLC. Captopril alone did not affect either heart weight/body weight ratio or cardiac contents of polyamines and nucleic acids at the end of the second week. In isoproterenol-treated rats, the above parameters, except for putrescine content on day 14, were significantly increased on both day 7 and day 14. Captopril slightly attenuated ISO-induced cardiac hypertrophy and significantly prevented the ISO-evoked increase in the contents of RNA, spermidine, and spermine at the end of the second week. These results suggest that the ISO-evoked increase in cardiac polyamines was mediated, at least in part, by the renin angiotensin system, which was stimulated by ISO.

Animals↗
PubMed1992

Reversible primary hypothyroidism and elevated serum iodine level in patients with renal dysfunction.

Recovery of thyroid function in patients with both thyroid and renal dysfunction was studied. Among 245 patients with primary hypothyroidism (serum TSH greater than 10 mU/l), 36 had mild to severe renal dysfunction (serum urea nitrogen greater than 7.1 mmol/l and creatinine greater than 106 mumol/l). Of these 36 patients, recovery of the thyroid function after iodine restriction was observed in 30 (83%), in whom an elevated serum non-hormonal iodine level (median 236, range 67-15,591 micrograms/l, N = 19) and a high thyroidal radioactive iodine uptake (51.5 +/- 29.3% at 24 h, N = 26) were observed. The perchlorate discharge test was positive in 7 of 13 patients examined, suggesting an iodide organification defect rather than an atrophic or destructive change in the thyroid. Antithyroid antibodies were negative in 22 patients (73%) and an almost normal thyroid gland or colloid goitre was confirmed histologically in 8 of them. After a 13.2 mg potassium iodide loading test, 24 h urinary excretion of iodine was about 60% in normal controls, but only 10% in a different group of six euthyroid patients with renal dysfunction. These findings suggest that impaired renal handling of iodine rather than autoimmune mechanism may have a significant role in the pathogenesis of reversible hypothyroidism found in patients with renal dysfunction, probably through a prolonged Wolff-Chaikoff effect.

Adult↗
PubMed1991

Effect of captopril on isoproterenol-induced myocardial ornithine decarboxylase activity.

Polyamines are thought to play an essential role in cellular hypertrophy and proliferation. Ornithine decarboxylase (ODC) catalyzes the first and probably the rate-limiting step in biosynthesis of polyamines. In this study, we evaluated the pathophysiological role of the renin-angiotensin system in isoproterenol-induced cardiac hypertrophy, using myocardial ODC activity as an indicator of cardiac hypertrophy. Isoproterenol caused an eight-fold increase of myocardial ODC activity in normotensive Wistar rats within 4 h after injection. Captopril suppressed the induction of ODC by isoproterenol to two-thirds of the control level. These results indicate that the renin-angiotensin system may participate in the induction of myocardial hypertrophy by isoproterenol.

Animals↗
PubMed1991

Mandibular alveolar ridge extension method using a surgical splint with porous hydroxyapatite (HAP) particles.

The mandibular alveolar ridge extension method is a surgical technique to extend the alveolar ridge up to the required level. Using a surgical splint prepared to meet the clinical requirements establishes the desirable alveolar ridge extension with porous hydroxyapatite (HAP) particles. Before the operation, a working cast of the extremely resorpted mandibular alveolar ridge is remodeled into its desired shape with paraffin wax, and the extended surgical splint is cured by clear acrylic resin. After subperiosteal tunnel dissection, the surgical splint is fixed to the mandible with circummandibular ligatures; then the HAP particles are injected into the tunnel. After healing, a treatment denture is cured between the artificial dentition and the surgical splint with self curing resin. In this method, the HAP particles are injected into the subperiosteal tunnel that is created between the surface of alveolar bone and the periosteum covered by the surgical splint; the migration of HAP particles completes the extension of the alveoral ridge.

Alveolar Ridge Augmentation↗
PubMed1990

New screening system for unruptured cerebral aneurysms--combination of an expert system and DSA examination.

We have designed a screening system to diagnose unruptured aneurysms, including the use of digital subtraction angiography (DSA). We surveyed 115 patients who had undergone clipping procedures after subarachnoid hemorrhage (SAH) and questioned them with regard to the subjective symptoms. Sixty-eight of 92 patients who returned the questionnaire reported, prior to rupture, headache, eye pain, and neck pain most frequently, and also impairment of extraocular movements, ptosis, visual field defects, and motor and sensory disturbances. Nineteen (47.5%) of 40 patients who had complete pain relief after surgery complained of headache from 1 week to 1 month before SAH. In addition, nine patients (22.5%) complained of headache for several years, and were also pain-free after surgery. For the indication of DSA, we employed an expert system based on fuzzy set theory. Seven groups of parameters are: Group 1, a basic questionnaire concerning age, sex, and past and family histories; Group 2, 15 warning signs selected on the basis of retrospective study; and Groups 3-7, detailed questions concerning each sign. Scoring weights assigned to each condition based on the results of the retrospective study, and threshold values were determined by several neurosurgeons. The certainty factors for intermediate hypotheses were calculated from these weights and threshold values and summed up, from which the conclusion was obtained. Twelve new cases of unruptured cerebral aneurysm were diagnosed using this screening system. This system may improve the ability to diagnose cerebral aneurysms before rupture.

Aged↗
PubMed1988

Abnormal polyamine metabolism in hypertensive cardiac hypertrophy.

In order to assess myocardial hypertrophic activity during the process of hypertensive cardiac hypertrophy in the presence and absence of treatment with anti-hypertensive agents, we analyzed myocardial polyamine concentrations in spontaneous hypertensive (SHR) rats and control rats of Wistar Kyoto (WKY) strain. The anti-hypertensive agents studied were diltiazem, hydralazine and captopril, each of which was administered for 5 weeks. In comparison with WKY rats, SHR rats showed elevated blood pressure and enlarged hearts with higher myocardial spermidine concentration. Although blood pressure was lowered in the diltiazem-treated SHR rats, heart weight and myocardial spermidine concentration increased as in untreated SHR rats. In the hydralazine-treated group increases in both blood pressure and myocardial spermidine concentration were suppressed, while an increase in heart weight was not. In the captopril-treated group, increases in blood pressure, heart weight and spermidine concentration were all suppressed. Since spermidine level appears to be a sensitive indicator of hypertrophic activity in the heart, this study suggests that captopril exerts an inhibitory effect on hypertensive cardiac hypertrophy whereas diltiazem does not. It also suggests that hypertrophy may reach a certain plateau level earlier in the hydralazine-treated animals than in others.

Animals↗