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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 55 records · Page 3Linked to original sources
PubMed2003

Intestinal goblet cell autoantibody associated enteropathy.

This report describes a case of refractory enteropathy with circulating intestinal goblet cell autoantibodies (IGA). A 19 year old man with hyperthyroidism had suffered from protracted diarrhoea for nearly 10 years. Histological examination showed evidence of collagenous enterocolitis. The diarrhoea did not improve despite fasting under total parenteral nutrition. An immunofluorescence assay demonstrated IGA without anti-enterocyte autoantibodies, the hallmark of autoimmune enteropathy, although other criteria were fulfilled. None of 109 controls, including 55 cases of inflammatory bowel disease and one of lymphocytic colitis, had IGA. This case is considered to be a variant of autoimmune enteropathy, and might be a distinct entity.

Adult↗
PubMed2003

[Traumatic aortic regurgitation with an ascending aortic aneurysm: report of a case].

We reported a case of an aortic regurgitation due to nonpenetrating chest trauma with an ascending aortic aneurysm. A 58-year-old man was admitted to our hospital with an acute left cardiac failure. Severe aortic regurgitation and ascending aortic aneurysm were diagnosed on ultrasonic echocardiography (UCG) and computed tomography (CT) scan. On the 13th day after the injury, semi-emergency operation was done. The commissure between the right coronary and non-coronary cups was torn, and modified Bentall operation was performed. The patient recovered well and discharged uneventfully.

Aortic Aneurysm↗
PubMed2002

Cefepime or carbapenem treatment for febrile neutropenia as a single agent is as effective as a combination of 4th-generation cephalosporin + aminoglycosides: comparative study.

1998, a consensus meeting was held in Miyazaki, Japan, to develop an approach to management of febrile neutropenia (FN). The K-HOT study group decided to examine whether this proposal was applicable to clinical practice in a multicenter study. Patients who developed fever with neutrophil counts <1,000/microL were randomized to receive either a single antibiotic, cefepime or one of the carbapenems, or a combination of cefepime and an aminoglycoside. Patients who became afebrile within the first 3 days were continued on the same treatment. Patients who remained febrile were switched to a combination regimen if they were randomized to receive a single agent, and patients on combination medication were changed from cefepime to another cephalosporin. A total of 165 patients were entered into the trial. One hundred fifty-three patients were evaluable for response. The average age was 52 years, and 70% of the patients had acute leukemia. Severe neutropenia, defined as <100/microL at the time of FN, was seen in 62% of the patients on entry and during the course of treatment 71% of patients experienced neutrophil counts of <100/microL. Microbiologically documented infection was seen in 6.5% for monotherapy, and 10.5% for a combination treatment, and fever of unknown origin occurred in 75.3% and 59.2% of the patients in each regimen, respectively. Excellent to good response was seen in two-thirds of the patients in all treatment groups. Adverse events were minimal, and three early deaths were observed at days 9, 16, and 16 among patients treated with a single antibiotic and three in the combination regimen group at days 14, 15, and 20. These results indicate that cefepime or a carbapenem alone is as effective as a combination of cefepime and an aminoglycoside for treating FN.

Adult↗
PubMed2002

Regulation of endometrial granulocyte macrophage-colony stimulating factor (GM-CSF) in the ewe.

Granulocyte macrophage-colony stimulating factor (GM-CSF) increases ovine interferon-tau (oIFNtau) secretion by ovine conceptuses, but endometrial production of GM-CSF has not been characterized. Endometrial GM-CSF expression was evaluated in ovariectomized ewes implanted with estradiol-17beta (E(2)) and/or progesterone (P(4)) for 14 days, in day 14 cyclic and day 14 pregnant ewes. Relative levels of endometrial GM-CSF mRNA were 3-fold higher in E(2)- and E(2)/P(4)-treated ewes than that of control or P(4)-treated ovariectomized ewes. Levels of endometrial GM-CSF mRNA for cyclic ewes were similar to E(2)- and E(2)/P(4)-treated ewes, but amounts of GM-CSF mRNA in pregnant ewes were 2-fold higher. GM-CSF concentrations in endometrial culture media, determined by GM-CSF bioassay, for cyclic and E(2)/P(4)-treated ovariectomized ewes were 3-fold higher than those of control, E(2)- and P(4)-treated ovariectomized ewes; however, amounts of GM-CSF in pregnant ewes were 2-fold higher. Immunoreactive GM-CSF, examined by western blot, was detected in the culture medium from E(2)/P(4)-treated ovariectomized, cyclic and pregnant ewes. Luminal and glandular epithelia and stromal regions were determined to be sites of GM-CSF expression by immunohistochemistry and in situ hybridization techniques. Data indicate that combined E(2) and P(4) treatment of ovariectomized ewes is sufficient to restore GM-CSF expression to the level found in cyclic ewes; however, GM-CSF mRNA and protein in pregnant ewes is 2-fold greater than in ovariectomized or cyclic ewes. These data suggest that the conceptus, in addition to steroids, may play a role in the regulation of endometrial production of GM-CSF.

Animals↗
PubMed2002

Successful eradication of Helicobacter pylori prevents relapse of peptic ulcer disease.

BACKGROUND: The NIH consensus conference in 1994 recommended that all patients with peptic ulcers should be tested and treated for Helicobacter pylori. Recent studies have shown that the eradication of H. pylori is associated with a significant reduction in the relapse rate of peptic ulcers, but there are few reports about long-term outcome. AIMS: To evaluate the relapse rate of peptic ulcer in the long-term follow-up of patients after H. pylori eradication therapy. PATIENTS AND METHODS: Patients infected with H. pylori (445; 88 duodenal ulcer, 357 gastric ulcer) were randomly divided into three groups. In group A, patients received 'conventional treatment' including acid decreasing therapy with a histamine H2-receptor antagonist or proton pump inhibitor (PPI). In group B, patients received 'dual therapy' including one antibiotic plus acid-decreasing therapy. In group C, patients received 'triple therapy' with PPI plus amoxicillin and clarithromycin. Eradication of H. pylori infection was assessed by histology of biopsy specimens from both the antrum and body corpus at 4 weeks, and 6 and 12 months after stopping therapy. Endoscopy was performed at intervals of 6 months for 5 years. RESULTS: Intention-to-treat eradication rates for the duodenal ulcer patients were 0% for group A, 46% for group B and 80% for group C; eradication rates for the gastric ulcer patients were 0%, 33% and 83% respectively. No recurrence was noted in the duodenal ulcer patients and only 4% of gastric ulcers recurred after successful eradication during follow-up for 5 years. In contrast, in patients with persistent H. pylori infection all DU and 92% of gastric ulcers recurred. CONCLUSION: Eradication of H. pylori infection changes the natural course of peptic ulcer.

Anti-Bacterial Agents↗
PubMed2002

[A case of mitral regurgitation with a giant thrombus thought to be caused by anti-phospholipid syndrome].

A 58-year-old woman suffered from mitral valve regurgitation with a giant thrombus in right atrium was thought to be complicated by anti-phospholipid syndrome (APS). Positive anti-loops anti-coagulant and histories of cerebral infarction and miscarriage strongly indicated the diagnosis of APS. She underwent mitral valve replacement using bileaflet mechanical prosthetic value and removal of thrombus. She recovered uneventfully and strict anti-coagulation therapy has been continuing.

Antiphospholipid Syndrome↗
PubMed2002

[Angina pectoris with a left atrial myxoma; report of a case].

A 78-year-old woman who had been diagnosed as left atrial myxoma and angina pectoris underwent simultaneous coronary artery bypass grafting (CABG) and resection of the left atrial myxoma. CABG was preceded by resection of myxoma to avoid systemic embolism of fragment of myxoma. Myocardial protection was secured by combination of antegrade and retrograde infusion of cardioplegia. The patient recovered well and discharged uneventfully.

Aged↗
PubMed2001

Successful treatment with an implantable cardioverter defibrillator for spontaneous ventricular fibrillation in dilated cardiomyopathy with very high defibrillation thresholds.

A 72-year-old male patient with idiopathic dilated cardiomyopathy who had shown recurrent episodes of drug refractory ventricular fibrillation underwent implantation of a transvenous implantable cardioverter defibrillator (ICD). Ventricular fibrillation (VF) was induced by a T wave shock at the implantation. However, the ICD device with a maximum energy of 30 J failed to terminate the VF. Reversing defibrillation polarity and/or adding a defibrillation electrode lead at the site of a high superior vena cava were also ineffective. The ICD was programmed to a maximum energy of 30 J when the device sensed spontaneous VF. During the follow-up period of 5 months, two episodes of spontaneous VF were recorded from ICD telemetry, and the ICD device terminated VF successfully with the first therapy shock in both episodes. No previous reports have shown failure to terminate induced VF at implantation of the ICD with successful termination of spontaneous VF during follow-up. Careful follow-up is needed in ICD patients, especially those with very high defibrillation thresholds.

Aged↗
PubMed2001

Up-regulation by clarithromycin of alpha(1)-acid glycoprotein expression in liver and primary cultured hepatocytes.

alpha(1)-Acid glycoprotein (AGP) is the major transport protein for cationic drugs, endogenous ligands, and some anionic drugs in plasma. Hepatic synthesis and secretion of AGP are altered during acute inflammation as well as by a number of drugs. This alteration could influence the binding of drugs and its biological function. Macrolide antibiotics are widely used in the treatment of a variety of infectious diseases. The effects of macrolide antibiotics have been studied with respect to rat AGP expression in vivo. After the individual administration of six macrolides to rats, with the exception of oleandomycin, five increased AGP levels in serum. Of these five, clarithromycin (CAM) was the most potent inducer of AGP, which reached a maximum level between 3 to 7 days after administration. CAM increased the steady-state level of AGP mRNA in liver as well as protein level in serum in a dose-dependent manner. In addition, CAM increased AGP mRNA levels in primary cultured hepatocytes. In the luciferase promoter assay, CAM potentiated dexamethasone-increased promoter activity of the AGP gene, which contained the glucocorticoid response element, in cultured rat hepatocytes, although CAM itself had no effect on its activity. The effect of CAM and dexamethasone was diminished by glucocorticoid response element deletion or mutation or by adding the antiglucocorticoid, RU486. Further, in the mouse mammary tumor virus (MMTV) promoter containing functional glucocorticoid response element, CAM potentiated dexamethasone-increased promoter activity. In the adrenalectomized rats, CAM did not increase AGP levels in serum. These findings suggest that CAM may cause transcriptional induction of AGP, at least in part, via a glucocorticoid-mediated mechanism.

5' Untranslated Regions↗
PubMed2001

Possible mechanisms for the suppressing action of 17beta-estradiol on beta-adrenoceptor-mediated vasorelaxation in rat aorta.

The mode of action of estrogen on beta-adrenoceptor-mediated relaxation was investigated by using isolated ring preparations of thoracic aorta from ovariectomized rats. Administration of 17beta-estradiol to ovariectomized rats significantly suppressed isoprenaline-induced relaxation of aortic rings. There was no alteration in the beta-adrenoceptor binding characteristics. The suppressing action of 17beta-estradiol on the N(G)-nitro-L-arginine and indomethacin-resistant relaxation induced by isoprenaline disappeared after pretreatment with N,N-diethylaminoethyl-2,2-diphenylvalerate hydrochloride (SKF 525A), an inhibitor of cytochrome P450 (CYP). The levels of CYP2C11 expression were the highest of the CYP mRNAs examined in rat aorta. 17beta-Estradiol replacement increased the expression of CYP2C11 mRNA in the aorta, compared with that in ovariectomized rats. These results suggest that estrogen suppresses beta-adrenoceptor-mediated vasorelaxation, and that the mechanisms may be associated with alterations in CYP2C11 metabolites.

Adrenergic beta-Agonists↗
PubMed2001

Morphology, electrophysiology, and calbindin immunoreactivity of myenteric neurons in the guinea pig distal colon.

The morphological and physiological characteristics of myenteric neurons in the guinea pig distal colon were determined using Lucifer yellow- or N-(2-aminoethyl) biotinamide-containing microelectrodes and intracellular recording and staining methods. The neurons in this study (n = 204) were classified on the basis of the shapes of their cell bodies and short processes or dendrites and the number of long processes or axons as Dogiel type I (n = 75 neurons; 36.8%), filamentous (n = 31 neurons; 15.2%), Dogiel type II (n = 38 neurons; 18.6%), and unclassified (n = 60 neurons; 29.4%). All Dogiel type II neurons had action potentials followed by an after-spike hyperpolarization (AH), and most of them (84%) had large, smooth somata and filamentous, short processes in addition to multiple, long processes or axons. Most of Dogiel type I, filamentous, and unclassified neurons (98%) had a single, long process, but four Dogiel type I neurons and one unclassified neuron had two long processes terminating as varicosities within other ganglia or on the surface of longitudinal muscle. The projections of monoaxonal neurons were distributed equally between oral and aboral directions, and most of them received fast excitatory postsynaptic potentials (EPSPs). All of the Dogiel type II neurons and seven Dogiel type I neurons were positive for calbindin immunoreactivity, but three filamentous neurons received fEPSPs, had spikes followed by AH, and were negative for calbindin. The presence of calbindin-immunoreactive(-IR) neurons was quite variable among the ganglia. These results confirm that neither the presence of calbindin immunoreactivity nor the absence of fEPSPs can be used as a predictor of cellular morphology or electrophysiological properties of myenteric neurons in the distal colon.

Action Potentials↗
PubMed2001

The effects of hydraulic pressure on atrial natriuretic peptide during rehabilitative head-out water immersion.

To study the hydraulic effects of subtotal immersion as a rehabilitative hydrotherapy, we examined the change in serum levels of atrial natriuretic peptide, catecholamine, cortisol and interleukins in 12 healthy volunteers. The subjects soaked in 42 degrees C water of 70 cm depth up to chin level in the upright seated position for 10 min. The serum level of atrial natriuretic peptide increased significantly 15 min after the start of subtotal immersion, though that of brain natriuretic peptide did not change. The serum dopamine level increased significantly 15 min after immersion, though neither the serum epinephrine nor norepinephrine levels did. In addition, 30 min after the start of immersion, the serum levels of atrial natriuretic peptide and dopamine decreased to those before immersion. The serum level of adrenocorticotropic hormone increased 15 min after immersion, though those of cortisol, interleukin-1beta and 6, and tumor necrotic factor-alpha did not change. It is suggested that 10-min head-out water immersion increased atrial natriuretic peptide partly due to increased venous return or right atrial load by hydraulic pressure.

Adrenocorticotropic Hormone↗
PubMed2001

FGF-10 stimulates limb regeneration ability in Xenopus laevis.

By reciprocal transplantation experiments with regenerative and nonregenerative Xenopus limbs, we recently demonstrated that the regenerative capacity of a Xenopus limb depends on mesenchymal tissue and we suggested that fgf-10 is likely to be involved in this capacity (Yokoyama et al., 2000, Dev. Biol. 219, 18-29). However, the data obtained in that study are not conclusive evidence that FGF-10 is responsible for the regenerative capacity. We therefore investigated the role of FGF-10 in regenerative capacity by directly introducing FGF-10 protein into nonregenerative Xenopus limb stumps. Exogenously applied FGF-10 successfully stimulated the regenerative capacity, resulting in the reinduction of all gene expressions (including shh, msx-1, and fgf-10) that we examined and the regeneration of well-patterned limb structures. We report here for the first time that a certain molecule activates the regenerative capacity of Xenopus limb, and this finding suggests that FGF-10 could be a key molecule in possible regeneration of nonregenerative limbs in higher vertebrates.

Animals↗
PubMed2001

Health effects of fluoride pollution caused by coal burning.

Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

Adult↗
PubMed2001

Nicorandil--induced ATP release in endothelial cells of rat caudal artery is associated with increase in intracellular Ca(2+).

The effect of nicorandil, an ATP-sensitive K(+) channel opener, on the level of intracellular Ca(2+) ([Ca(2+)](i)) and on ATP release in endothelial cells of the rat caudal artery was examined using a fluorescent confocal microscopic imaging system and high-performance liquid chromatography (HPLC) with fluorescent detection, respectively. Nicorandil significantly increased [Ca(2+)](i) and the overflow of ATP and its metabolites. The former reaction was abolished in the absence of extracellular Ca(2+), but it did not change in the presence of thapsigargin or cyclopiazonic acid. The increase in the overflow of ATP and [Ca(2+)](i) induced by nicorandil was markedly suppressed by glibenclamide, an ATP-sensitive K(+) channel blocker. The increase of [Ca(2+)](i) induced by nicorandil was significantly and inversely correlated with the level of intracellular ATP in the endothelial cells, suggesting that activation of ATP-sensitive K(+) channels by nicorandil increases Ca(2+) influx in endothelial cells. The increase of [Ca(2+)](i) might be associated with ATP release.

Adenosine↗