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Biomedical subjects

T Minami

Publications and source records attributed to T Minami.

At least 217 records · Page 12Linked to original sources
PubMed1995

[Initial corrosion of dental casting alloys in the oral environment].

In order to study the initial corrosive changes of dental casting alloys in the mouth, the condition and composition of the proximal surface of the class II inlay were analyzed by the scanning electron microscope (SEM) and the electron probe microanalyser (EPMA). These analyses on the same small areas of the proximal surface were carried out every week for four weeks. The results were compared with the condition and composition of the preplacement in the mouth, and also with the data from former studies. 1. Changes observed in the 70Au-3Pt-3Pd-10Ag-14Cu alloy (Au-alloy) were slight in comparison to the other alloys in this experiment, both on the surface condition and composition. 2. The 12Au-45Ag-20Pd-18Cu alloy (Pd-alloy) appeared to be stable in the mouth, but the changes were greater than that of the Au-alloy. 3. The Au- and the Pd-alloys appeared to be stabler after hardening heat treatment. 4. The greatest change was observed in the 65Ag-22Sn-13Zn alloy. 5. Little change was found in the 72Ni-19Cr-6Si alloy by visual inspection, but the dendritic structure was observed by SEM. 6. Almost all these changes of the alloys in this study showed somewhat greater changes than those observed in the conventional basic immersion tests of alloys.

Corrosion↗
PubMed1995

[A case of secondary valve replacement caused by pulmonary bioprosthetic valve endocarditis].

A 42-year-old male with pulmonary bioprosthetic valve endocarditis accompanied by residual minor leakage through a previously closed patch for ventricular septal defect (VSD), underwent reoperation with a Carpentier-Edwards bioprosthetic valve. The patient had a history of pulmonary valve replacement and VSD in 1973. A massive vegetation on the pulmonary valve was demonstrated by echocardiography. Five repeated blood cultures yielded Eikenella corrodens. After medical treatment, reoperation was performed. The patient was free of complications after the procedure. Although bioprosthetic valves have potential problems of dysfunction and calcification in long-term use, these problems develop at a significantly slower rate in right-sided positions compared with left-sided positions and bioprosthetic valve thrombosis in the pulmonary position has apparently not been reported. Mechanical prostheses for pulmonary valve replacement have a poor prognosis, with a high incidence of valve thrombosis despite adequate anticoagulant therapy. For the replacement of prosthetic valves in right-sided positions (tricuspid and pulmonary), bioprosthetic valves are now our first choice.

Adult↗
PubMed1995

[Clinical application of magnetoencephalography in pediatric neurologic diseases].

Electrical activities develop simultaneously with the establishment of magnetic fields following Biot-Savart's law. Excitation of cerebral neurons causes the development of electrical activities, and thereby produces magnetic fields. The term "magnetoencephalography (MEG)" refers to the detection and study of these magnetic fields. It is therefore possible to estimate accurately the origins of the magnetic fields, i.e. deep foci of electrical activities, from the outside of the scalp. This report describes the principle of magnetoencephalography, the recording method, and the estimation of intracerebral localization for rolandic discharges in benign childhood epilepsy with centrotemporal spikes.

Brain↗
PubMed1995

[Surgical treatment of acute aortic dissections--a clinical study using a ringed intraluminal graft].

From 1984 to 1994, surgery was performed using a ringed intraluminal graft (RIG) in 75 patients with acute aortic dissection (DeBakey's type I in 37 cases, type II in 10 cases and type III in 28 cases). The operative death rate was 24% for type I, 30% for type II and 21% for type III. The average time from onset to surgery was short (47 +/- 67 hours for type I, 34 +/- 36 hours for type II and 47 +/- 77 hours for type III). The outcome of these cases indicated that this technique was effective for saving the lives of patients in the acute early stage of aortic dissection. No characteristic complications developed after this surgery. The postoperative course of patients was followed by using CT scans, MRI, angiography. No patients developed aneurysmal formation in the ligated area or dislocation of the RIG. There were no deaths directly attributable to the RIG. Patients who were autopsied in the late postoperative period showed no aneurysm of the ligated area or necrosis of the aortic wall. In conclusion, RIG surgery effectively saved the life of patients with acute aortic dissection and the RIG could be used as prosthetic graft for long-term periods.

Acute Disease↗
PubMed1994

Accumulation of platinum in the intervertebral discs and vertebrae of ovarian tumor-bearing patients treated with cisplatin.

Platinum was determined by the inductively coupled plasma mass spectrometry (ICP-MS) in the intervertebral discs and vertebrae of ovarian tumor bearing patients treated with cis-diamminedichloro-platinum (II) (cisplatin). Platinum was 0.05 ng/mL at the absolute detection limit, and platinum was undetectable in the intervertebral discs and vertebrae of human specimens without cisplatin treatments. On the other hand, platinum was detected in the intervertebral discs and vertebrae of patients administered cisplatin, and platinum concentration was at levels of 1.06-10.31 micrograms/g dry tissue in the intervertebral discs and 0.60-1.28 micrograms/g dry tissue in the vertebrae, respectively. The platinum level of intervertebral discs was 4.3-fold higher than that of the vertebrae. Thus, platinum accumulates greatly in the intervertebral discs and somewhat in the vertebrae after administering cisplatin to patients for therapy.

Adenocarcinoma↗
PubMed1994

Characterization of EP-receptor subtypes involved in allodynia and hyperalgesia induced by intrathecal administration of prostaglandin E2 to mice.

1. Intrathecal (i.t.) administration of prostaglandin E2 (PGE2) to conscious mice induced allodynia, a state of discomfort and pain evoked by innocuous tactile stimuli, and hyperalgesia as assessed by the hot plate test. We characterized prostaglandin E receptor subtypes (EP1-3) involved in these sensory disorders by use of 7 synthetic prostanoid analogues. 2. Sulprostone (EP1 < EP3) induced allodynia over a wide range of dosages from 50 pg to 5 micrograms kg-1. The maximal allodynic effect was observed at 5 min after i.t. injection, and the response gradually decreased over the experimental period of 50 min. This sulprostone-induced allodynia showed a time course similar to that induced by PGE2. 3. 17-Phenyl-omega-trinor PGE2 (EP1 > EP3) and 16,16-dimethyl PGE2 (EP1 = EP2 = EP3) were as potent as PGE2 in inducing allodynia, and more potent than sulprostone. Butaprost (EP2), 11-deoxy PGE1 (EP2 = EP3), MB 28767 (EP3), and cicaprost (prostaglandin I2 (IP-) receptor) induced allodynia, but with much lower scores. 13,14-Dihydro-15-keto PGE2, a metabolite of PGE2, did not induce allodynia. 4. 16,16-Dimethyl PGE2 as well as PGE2 induced hyperalgesia over a wide range of dosages (16,16-dimethyl PGE2: 5 pg-0.5 micrograms kg-1 PGE2: 50 pg-0.5 micrograms kg-1) with two apparent peaks at 0.5 ng kg-1 and 0.5 micrograms kg-1. Sulprostone (EP1 < EP3) and 17-phenyl-omega-trinor PGE2 (EP1 > EP3) showed a bell-shaped hyperalgesia at lower doses of 5 pg-5 ng kg-1 and 50 pg-50 ng kg-1, respectively. MB28767 (EP3)showed a monophasic hyperalgesic action over a wide range of dosages at 50 pg-S5 Microg kg-1. Butaprost(EP2) induced hyperalgesia at doses higher than 50 ng kg-1.5. These results demonstrate that PGE2 may exert allodynia through the EP1-receptor and hyperalgesia through EP2- and EP3-receptors in the mouse spinal cord.

Animals↗
PubMed1994

Increased group II phospholipase A2 in colonic mucosa of patients with Crohn's disease and ulcerative colitis.

The immunochemical protein content of group II phospholipase A2 (PLA2) and PLA2 enzymatic activity were measured for colonic mucosal biopsy samples obtained from patients with either Crohn's disease of the colon or ulcerative colitis, and control patients without inflammatory bowel disease. Immunoreactive group II PLA2 (IR-PLA2 II) content and PLA2 activity in actively inflamed colonic mucosa of Crohn's disease patients were significantly higher than those in inactively inflamed mucosa of Crohn's disease patients and the colonic mucosa of controls. IR-PLA2 II content and PLA2 activity in severely inflamed mucosa of ulcerative colitis patients were significantly higher than those in the colonic mucosa of the controls. Mucosal PLA2 enzymatic activity was closely correlated with mucosal IR-PLA2 II content in patients with Crohn's disease and ulcerative colitis. These results suggest that an increase in PLA2 enzymatic activity in inflamed colonic mucosa of Crohn's disease and ulcerative colitis was mainly attributed to increased protein content of group II PLA2, and that an increase in mucosal group II PLA2 may be involved in the pathogenesis of intestinal inflammation of Crohn's disease and ulcerative colitis.

Adolescent↗
PubMed1994

Reduction of dental plaque deposition in humans by oolong tea extract.

The inhibitory effect of oolong tea extract (OTE) containing polymerized polyphenols on plaque deposition was examined in 35 human volunteers. Thirty-five human volunteers, aged 18-29 years, who received extensive oral prophylactic procedures were requested to refrain from all oral hygiene procedures for 4 days, and to rinse their mouth with 0.5 mg/ml OTE solution in 0.2% ethanol before and after every intake of food and before sleeping at night. No restriction regarding meals was given during the test period, except to refrain from teas or coffee. Plaque deposition was evaluated after disclosing the teeth with Erythrocin at the termination of this experiment. The study was repeated 1 week after the first trial, but only 0.2% ethanol without OTE was used for mouthrinsing in the second trial. OTE was found to significantly inhibit plaque deposition in volunteers, although mouthrinsing with OTE solution had no significant effect on the number of mutans streptococci in unstimulated whole saliva.

Adolescent↗
PubMed1994

Nephrotoxicity induced by adenine and its analogs: relationship between structure and renal injury.

Twenty-four adenine analogs were administered to mice and the relationship between the structure of analogs and the occurrence of renal injury was examined. Plasma urea nitrogen (UN) and creatinine levels were measured 24 h after oral administration of analogs. Both levels increased in the adenine-, 8-azaadenine-, isoguanine-, or 6-dimethyl aminopurine (6-DMAP)-administered group, but did not increase in the other analog groups. From light microscopy, the damages of tubuli, mainly of proximal tubuli, were observed in the kidneys of these four groups. The common property of these compounds is the strong basicity of nitrogen which binds the 6-position of the purine ring. Furthermore, UN and creatinine increased time-dependently with intravenous administration of isoguanine. When adenine was intravenously administered, UN slightly increased at 1 h, but creatinine was unchanged. No changes were observed in the 6-DMAP- or 8-azaadenine-administered group. The basicity of nitrogen which binds to the 6-position of the purine ring is thus considered to be related to the occurrence of renal injury with oral administration, and isoguanine has high affinity with the kidney.

Adenine↗
PubMed1994

Nephrotoxicity induced by a single dose of adenine: effects of 4-aminopyrazolo[3,4-d]pyrimidine and allopurinol.

The effects of allopurinol and 4-aminopyrazolo[3,4-d]pyrimidine (4APP) on adenine-induced renal injury in mice were examined. Plasma urea nitrogen (UN) and creatinine levels increased after the oral administration of adenine to mice. However, plasma UN and creatinine levels decreased inversely with the dose of 4APP when a different dosage of 4APP was administered together with adenine. Yet 4APP did not have any effect on the UN or creatinine levels when 4APP was administered after adenine administration. Plasma UN and creatinine levels increased in the allopurinol-administered group as in the adenine-administered group. Moreover, from light microscopic observation by hematoxylin-eosin staining, microvacuolic changes in the proximal tubuli were detected in the mouse kidney in the adenine-administered group, and epithelial cell loss, degeneration and microvacuolic changes in the proximal tubuli were observed in the mouse kidney in the adenine-and-allopurinol-administered group. However, there were no changes in the proximal tubuli in the mouse kidney in the adenine-and-4APP-administered group. These findings suggested that 4APP inhibits the action of adenine in the mouse kidney.

Adenine↗
PubMed1994

[Turcot's syndrome].

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Adenomatous Polyposis Coli↗
PubMed1994

[Turcot's syndrome].

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Adenomatous Polyposis Coli↗
PubMed1994

Gradient of mineral contents of vertebral column with special reference to intervertebral discs.

To study quantitatively the mineral elements in the vertebral column, we examined the vertebrae and intervertebral discs resected from three normal cadavers which died at middle age, by inductively coupled plasma atomic emission spectrometry. The relative contents of calcium, phosphorus, and sodium in vertebrae were high in the order from cervical to lumbar vertebrae. The ratios of calcium per phosphorus were 1.80 +/- 0.25 in cervical vertebrae, 1.59 +/- 0.22 in thoracic vertebrae, and 1.23 +/- 0.24 in lumbar vertebrae. The ratio of cervical vertebrae was the highest among them. In regard to intervertebral discs, both the relative contents of calcium and phosphorus were very much higher in the intervertebral discs between the 4th and 8th thoracic vertebrae than the others.

Bone Density↗
PubMed1994

[A case of sudden death of a patient with hypopituitarism].

We report a 29-year-old woman who died due to pituitary insufficiency. After a normal delivery 2 years previously, she had suffered from amenorrhea and displayed decreased libido. She was discovered in convulsions by her husband when he returned home, and was admitted to an emergency hospital. Despite various treatments, she died. Her blood glucose level on admission was low, 32 mg/dl. Autopsy findings showed thin public hair and almost no axillary hair. The right and left adrenal glands weighed 1.7 g and 1.2 g, respectively. Histologically, the anterior pituitary gland showed severe bleeding and necrosis, and the middle lobe showed lymphocytic infiltration; the posterior lobe was almost normal. The adrenal glands showed marked atrophy of the cortex and deposition of calcium in the medulla. The thyroid gland, which weighted 15 g, showed diffuse interstitial lymphocytic infiltration, indicative of chronic lymphocytic thyroiditis. Atrophy of the ovaries and uterine endometrium was also observed. These findings indicated that death had been due to pituitary insufficiency. The histopathology of the pituitary, which showed lymphoid hypophysitis, and its association with lymphoid thyroiditis suggested that the pituitary insufficiency was not due to ischemic injury after delivery, a condition which can result from massive hemorrhage, but rather had arisen as a result of an autoimmune process.

Death, Sudden↗
PubMed1994

[A case of ruptured left ventricular aneurysm due to syphilitic myocarditis].

This case involved a 20-year-old male who on May, 14, 1992, lost consciousness while working and went into a state of shock. He was taken to a hospital, where cardiac tamponade was diagnosed. He was later transferred to this hospital. Based on the results of echocardiography, coronary arteriography and left ventriculography, a ruptured ventricular aneurysm was diagnosed. The patient underwent emergency surgery. Serologic tests for syphilis performed at admission were definitely positive. Histopathological examination of the wall of the ventricular aneurysm disclosed fibrous myocarditis and peripheral coronary endarteritis accompanied by infiltration of plasma cells and lymphocytes. Immunohistological study revealed treponeme in the histiocytes of the aneurysmal wall. The diagnosis was a ruptured ventricular aneurysm caused by syphilitic myocarditis. Since the advent of penicillin therapy, cardiovascular syphilis, particularly syphilitic myocarditis, has become a rare disease. The chief interest of this case is that treponeme was detected in the lesion of myocarditis.

Adult↗