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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 703 records · Page 39Linked to original sources
PubMed1994

Effect of body characteristics on the variables of signal-averaged electrocardiograms in healthy subjects.

Late potentials have been reported to be affected by body size or left ventricular mass. To our knowledge, however, the effect of subadipose tissue, which is known to influence QRS amplitudes of the surface ECG on the variables of late potentials, has not been evaluated. The relationships between the variables of late potentials and various obesity indices were assessed in 45 men, aged 24 to 38 years, without structural heart disease and bundle branch blocks. QRS duration (DUR), root mean square voltage in the last 40 ms (RMS), and low-amplitude signals < 40 microV (LAS) were obtained by signal-averaged ECG. Left ventricular mass (LV mass) was determined by echocardiography. The DUR and RMS had no correlation with body height, weight, body mass index (BMI), sum of skin folds (triceps and subscapular), or LV mass. Positive linear correlations were found between LAS and weight (r = 0.48, p < 0.002), BMI (r = 0.54, p < 0.002), sum of skin folds (r = 0.57, p < 0.002), and percent BMI (r = 0.54, p < 0.002). Subadipose tissue may shift the onset of the 40-microV point of LAS to the left with a consequent prolongation of LAS by attenuation of the QRS complex. These data suggest that the use of LAS alone or as a combination in an obese population for the definition of positive late potentials is inappropriate.

Adult↗
PubMed1994

Synergistic insulin release induced by glucose and carbachol is not associated with an increase in cytoplasmic free calcium levels.

Synergistic insulin release is observed in combination with muscarinic agonist and glucose. In order to define the role of changes in the cytoplasmic free Ca2+ level ([Ca2+]i), the effect of combination with carbachol and glucose on both phosphoinositide breakdown in rat pancreatic islets and [Ca2+]i dynamics in single fura 2-loaded B-cells was investigated. When the islets were prelabeled with myo-[2-3H]inositol, phosphoinositide breakdown was obtained and inositol trisphosphate levels were increased in the presence of carbachol (0.5 mM). Inositol trisphosphate levels induced by carbachol were further increased by co-stimulation with 16.7 mM glucose. [Ca2+]i in single-B-cells was increased by 16.7 mM glucose. A prompt, transient rise in [Ca2+]i was induced by carbachol. However, carbachol failed to augment the [Ca2+]i response in the presence of 16.7 mM glucose. These data suggest that a synergistic release of insulin occurs without an amplification of [Ca2+]i regardless of an increase in inositol trisphosphate.

Animals↗
PubMed1994

[52-week oral toxicity study of lactitol (NS-4) in rats followed by 9-week recovery test].

Twenty five male and 25 female Slc:SD rats were given orally lactitol, a hepatic encephalopathy drug, for 52 weeks at doses of 0, 0.4, 2 or 10 g/kg/day. A 9 week recovery test was conducted after the discontinuation of the drug treatment. Treatment related death, soft stool, diarrhea, decreased body weight gain and food intake and increased water consumption were observed in the 10 g/kg group. Urinalysis showed increased Ca excretion in the 2 and 10 g/kg groups. In the 10 g/kg group, there were increased Ca++ excretion and urine specific gravity and decreased K+ and Na+ excretion and urine volume. Hematologic examination showed decreased platelet count in the 10 g/kg group. Biochemical examination revealed higher A/G ratio in the 2 and 10 g/kg groups. In the 10 g/kg group, there were lowered level of total cholesterol, triglyceride, phospholipid, Na+, Cl- and total protein. Distention of the cecum with increased organ weight was seen pathologically in the 2 and 10 g/kg groups. In the 10 g/kg group, cecal mucosa was hyperplasic. The adrenal gland was hypertrophic in the zona glomerulosa in the 2 and 10 g/kg groups. In the 10 g/kg group, the adrenal weight was increased. Dilatation of renal tubules was also found in the 10 g/kg group. The above mentioned changes were satisfactorily reversible except for the increased cecum weight in the 10 g/kg group. Based on the results obtained, the NOAEL of this study was suggested to be 0.4 g/kg/day.

Administration, Oral↗
PubMed1994

Familial pheochromocytoma associated with von Recklinghausen's disease.

We report a 19-year-old woman who presented with headache, vomiting, and elevated blood pressure; pheochromocytoma and von Recklinghausen's neurofibromatosis were diagnosed. Her mother had the same skin lesions and was also found to have pheochromocytoma. Both patients underwent surgical resection and the postoperative courses were uneventful; the daughter subsequently married and delivered a healthy child. Although both pheochromocytoma and von Recklinghausen's disease are derived from neuroectoderm and are inherited disorders, concomitant familial occurrence of these two diseases is very rare, only three families have been reported previously worldwide.

Adrenal Gland Neoplasms↗
PubMed1994

"Kissing aneurysms" of the internal carotid artery.

Five patients with kissing aneurysms (adherent internal carotid-posterior communicating artery and ipsilateral internal carotid-anterior choroidal artery aneurysms) are reported. There was female predominance and the subarachnoid hemorrhage was commonly due to rupture of the proximal posterior communicating artery aneurysm. Despite the demonstration of angiographic cleavage, the two aneurysms adhere to each other, which makes surgical dissection difficult. Meticulous dissection of the aneurysmal necks and preservation of the blood flow in the anterior choroidal artery are of vital importance.

Adult↗
PubMed1994

A patient with primary hypoparathyroidism developing hypercalcemia associated with adult T-cell leukemia/lymphoma.

A 38-year-old woman was admitted to our hospital with symptoms and signs of hypocalcemia in 1977 and a diagnosis of primary hypoparathyroidism was made with a positive Ellsworth Howard test. She was then lost to follow up until 1992 when she returned this time with symptoms and signs of hypercalcemia. An inguinal lymph node was biopsied showing non-Hodgkin's lymphoma, diffuse pleomorphic type and monoclonal integration of proviral human T-cell lymphotropic virus-1 DNA was detected in lymph node cells indicating ATLL. Serum parathyroid hormone-related peptide (PTHrP) was slightly elevated and the tumor cells were positively stained with anti-PTHrP serum. Combination chemotherapy with vincristine, adriamycin, cyclophosphamide and prednisolone was given to the patient with disappearance of the lymphadenopathy and subsequent normalization of PTHrP levels. Interestingly, the signs and symptoms of hypocalcemia reappeared after the treatment requiring replacement therapy with calcium and vitamin D.

Adult↗
PubMed1994

[Magnetic resonance imaging and cerebrospinal fluid examinations in a case of central nervous involvement of systemic lupus erythematosus].

A 69-year-old woman was admitted to our hospital with a 7-month history of sensory disturbance of the bilateral lower extremities. Since she developed paraplegia of the extremities, urinary incontinence and left hemiplegia several days after admission, neurologic involvement both in the lumbar cord, and in the cervical cord or the brain was suspected. While no abnormalities were noted by computerized tomography of the brain. T2-weighted magnetic resonance imaging (MRI) clearly demonstrated foci in the periventricular and the basal ganglia regions bilaterally. Furthermore, the levels of immunoglobulin G and interleukin 6 were increased in the cerebrospinal fluid (CSF). From physical and other laboratory findings in addition to the MRI and CSF findings, she was diagnosed as having systemic lupus erythematosus with central nervous involvement. The administration of prednisolone resulted in marked improvement in her neurologic symptoms in two months. Thus, it is considered that the MRI and CSF examinations are useful for the diagnosis and treatment of central nervous involvement of systemic lupus erythematosus.

Aged↗
PubMed1994

Action of KC-399, a newly synthesized potassium channel opener, on mechanical activity and 86Rb efflux in rat aorta.

To clarify the characteristics of KC-399, a newly synthesized potassium channel opener, we investigated the effects of KC-399 and lemakalim on the contractions induced by norepinephrine (NE 1 microM) and K+ (30 and 90 mM) and on 86Rb efflux in rat thoracic aorta. KC-399 (0.01-10 nM) and lemakalim (0.001-10 microM) induced relaxation in aortic rings precontracted with 30 mM K+ or NE, but not with 90 mM K+. The vasorelaxant effect of KC-399 was almost 500 times more potent than that of lemakalim. The vasorelaxation with KC-399 developed more slowly and was more resistant to washout than that induced by lemakalim. Glibenclamide (0.1-1 microM), a blocker of ATP-sensitive K-channels, produced concentration-dependent inhibition of the relaxant action of KC-399 in aorta treated with 30 mM K+. KC-399 (3-100 nM) and lemakalim (0.3-10 microM) stimulated 86Rb efflux in rat aorta; the potency of KC-399 was approximately 100 times greater than that of lemakalim. The effects of KC-399 on 86Rb efflux persisted after an 18-min washout period, but those of lemakalim did not. The stimulatory effects of KC-399 (10 and 30 nM) and lemakalim (1 and 3 microM) on 86Rb efflux were also significantly reduced by glibenclamide (1 microM). These results suggest that KC-399 is a potent and long-lasting vasodilator in vitro and that opening of the ATP-sensitive K+ channel may be involved in its mechanism of action.

Adenosine Triphosphate↗
PubMed1994

Differential insulin secretory activity in rat pancreatic islets and HIT cells.

We compared insulin secretory activity from rat pancreatic islets with that from a hamster beta-cell line (HIT-T). Insulin release from HIT cells was maximally stimulated with glucose at a concentration of 11.1 mM, and rather inhibited by higher concentrations of glucose. Blunted insulin release induced by glucose was shown in the isolated rat islets exposed to either streptozotocin (2.2 mM) for 30 min or alloxan (2 mM) for 5 min, whereas glucose-induced insulin release from HIT cells was not affected by pre-treatment with such beta-cell toxin. When pancreatic islets and HIT cells were cultured for 7 days with 10 mM nicotinamide, an inhibitor of poly (ADP-ribose) synthetase, glucose-induced insulin release from the islets was inhibited, whereas insulin release from HIT cells was rather enhanced. Insulin release induced by either arginine or leucine was also enhanced in HIT cells cultured with nicotinamide. These findings indicate that the multiple components of insulin stimulus-secretion coupling in HIT cells are considerably different from those in rat pancreatic islets.

Alloxan↗
PubMed1994

Dependence on very hot hot-spring bathing in a refractory case of atopic dermatitis.

A 21-year-old female with atopic dermatitis showed "dependence" on very hot hot-spring bathing. Her skin disease had been refractory to various treatments including steroid therapy for a long time. Without medical supervision she took four 3-minute 47 degrees C hot-spring baths daily for a month for the purpose of improving her skin symptom. Subsequently, she could not stop bathing in very hot hot-spring water of her own will. However, a month's isolation in a hospital relieved her of the situation. The mechanism of the dependence on very hot hot-spring bathing may be explained by a transient rise in the plasma beta-endorphin level due to hyperthermal stress.

Adult↗
PubMed1994

Non-steroidal anti-inflammatory drugs associated with gastroduodenal injury and Helicobacter pylori.

OBJECTIVE: To clarify the relationship between non-steroidal anti-inflammatory drug (NSAID)-associated gastroduodenal mucosal injury and Helicobacter pylori infection. DESIGN AND METHODS: The incidence of H. pylori infection was determined in a group of patients treated with NSAID for rheumatoid arthritis for > or = 3 months and in a control group of patients with mainly abdominal symptoms but without rheumatoid arthritis and not being treated with NSAID. The incidence of H. pylori infection was also determined in patients treated with different NSAID and antirheumatic drugs. In addition, the minimum inhibitory concentration of several NSAID against H. pylori was investigated. RESULTS: The incidence of H. pylori infection in the NSAID group tended to be lower than in the control group, and was significantly lower in patients with gastric ulcers. The incidence of infection did not differ between patients treated with one or with more than one NSAID. Differences in the infection rate were found between individual NSAID, with indomethacin being associated with a particularly low rate. No differences in the infection rate were found between different antirheumatic drugs. The minimum inhibitory concentration of ibuprofen was low. CONCLUSION: H. pylori appears to have little effect on gastroduodenal mucosal injury associated with long-term NSAID administration.

Adolescent↗
PubMed1994

Effects of cytotoxic factors of Helicobacter pylori on superoxide generation in situ in the rabbit stomach.

OBJECTIVE: To evaluate the effect of certain cytotoxic products of Helicobacter pylori on superoxide generation in situ and on the infiltration by polymorphonuclear cells into the gastric mucosa. The agents studied were ammonia, a culture supernatant of H. pylori, and N-formyl-methionyl-leucyl-phenylalanine (FMLP), a chemotactic factor. METHODS: One or two of these agents were dripped onto rabbit gastric epithelium. The number of polymorphonuclear cells in gastric mucosa were counted histologically. Superoxide generation was measured by a chemiluminescence method, using a Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one , a chemiluminescence probe that responds to the generation of superoxides and singlet oxygen radicals. Bovine erythrocyte copper zinc superoxide dismutase was dripped to confirm that the increase in photon counts was a direct consequence of the generation of superoxides. RESULTS: The greatest infiltration of polymorphonuclear cells into the gastric mucosa was observed with the administration of 1 mmol/l FMLP followed by 5.9 mmol/l ammonia, and 10 mmol/l FMLP followed by 59 mmol/l ammonia. There was no increase in the number of polymorphonuclear cells in the other experiments. Increased chemiluminescence was observed in conjunction with the infiltration of polymorphonuclear cells and was inhibited by superoxide dismutase. CONCLUSIONS: Acute gastritis and superoxide generation in situ were induced by ammonia after pretreatment with FMLP.

Ammonia↗
PubMed1994

Successful treatment with auranofin in a patient with elderly-onset Still's disease.

We report a successful treatment with auranofin in a case of elderly-onset Still's disease. The administration of non-steroidal anti-inflammatory drugs, mizoribine and prednisolone were not only insufficient to suppress the disease activity but were followed by the development of multiple gastric ulcers and severe osteoporosis. On the contrary, treatment with auranofin, 9 mg per day, was effective enough to maintain the disease inactive without any side effects. We also found that plasma levels of interleukin-6 and tumor necrosis factor-alpha were significantly elevated in our patient, suggesting a possible involvement of inflammatory cytokines in this disease.

Age of Onset↗
PubMed1994

[Surgery of bilateral pulmonary aspergilloma].

A 60-year-old man with cough and fever was admitted to our hospital. Chest radiography revealed multiple bullae and fungus balls in both lungs. He was treated with MCZ and FCZ for about 2 months, but the chest radiograph shadows did not improve and the fever continued. A two-stage operation was performed. The bullae were incised and the fungus balls were removed, then a muscle flap plombage was made with a pectoralis major muscle, a latissimus dorsi muscle and an intercostal muscle. The postoperative course was uneventful and respiratory function was preserved.

Aspergillosis↗
PubMed1994

[A case of malignant fibrous histiocytoma in the mediastinum].

A 81-year-old man was admitted to the hospital because he complained of hoarseness. Chest radiography showed a mass in the right upper mediastinum. An operation was done to remove the mass and make a conclusive diagnosis. Histologically, the tumor tissue consisted of spindle-shaped fibroblast-like cells and round histiocyte-like cells with bizarre giant cells. Part of the tissue had a storiform pattern. These findings led a diagnosis of malignant fibrous histiocytoma (MFH) of the "usual type". MFH is known to occur frequently in the soft tissues of extremities, trunk, and retroperitoneum, but it is seldom detected in the mediastinum. We report here a rare case of primary MFH in the mediastinum.

Aged↗