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Biomedical subjects

M Arima

Publications and source records attributed to M Arima.

At least 55 records · Page 3Linked to original sources
PubMed1995

MRI in neurofibromatosis type I: using fluid-attenuated inversion recovery pulse sequences.

Cranial magnetic resonance imaging results of 14 patients with neurofibromatosis type I were examined with T2-weighted fluid-attenuated inversion recovery pulse sequences, as well as conventional T2-weighted spin-echo sequences. Definition was better in 62 of 79 lesions or groups of lesions on fluid-attenuated inversion recovery images than on T2-weighted spin-echo images. The lesions were demonstrated not only in the brainstem, cerebellum, globus pallidus, and cerebral white matter, but also in the hippocampus, pulvinar thalami, and splenium of the corpus callosum. The latter 3 lesions have not been demonstrated or emphasized in previous studies. It is concluded that fluid-attenuated inversion recovery imaging is more effective in detecting multiple lesions in patients with neurofibromatosis type I than conventional T2-weighted spin-echo imaging.

Adolescent↗
PubMed1995

Endoscopic ultrasound-guided pancreatography: a case report.

Endoscopic ultrasound-guided pancreatography was performed on a 48-year-old man with a diagnosis of pancreatic stone. A pylorus-preserving pancreaticoduodenectomy had been performed previously on this patient, approximately two years earlier, following the diagnosis of a tumor-forming pancreatitis. Endoscopic retrograde pancreatography and conventional ultrasound-guided percutaneous pancreatography had failed to yield a diagnosis. However, endoscopic ultrasound-guided pancreatography was performed successfully, delineating the pancreatic duct and a filling defect caused by intraductal calculi. Endoscopic ultrasound-guided pancreatography will be a potential alternative in cases when endoscopic retrograde pancreatography has failed or proved non-diagnostic.

Calculi↗
PubMed1995

Role of platelet-activating factor in the release of neutrophil and eosinophil chemotactic attractants from cultured guinea-pig tracheal epithelial cells.

Platelet-activating factor (PAF) has been implicated in the pathogenesis of allergic disease, particularly bronchial asthma, by recruitment and activation of inflammatory cells. In an effort to further elucidate this function of PAF, guinea-pig tracheal mucosa was cultured in the presence of PAF in vitro, and culture supernatants were injected intradermally into normal guinea-pigs. After 6 h, recruitment of the inflammatory cells in the tissue was evaluated as a marker of chemotactic activity. Neutrophil and eosinophil recruitment increased significantly 1 h after PAF stimulation, the latter more than the former. After fractionation of the culture supernatant using molecular sieve filters, the fraction of 10-30 kDa showed greater chemotactic activity than the fractions of below 10 kDA or greater than 30 kDA. This activity was inhibited in a dose-dependent manner (over about 1-100 mg/ml) by treatment with anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody. These results suggest that PAF induces the release of chemotactic factors for neutrophils and eosinophils from guinea-pig tracheal epithelial cells, and one of these factors may be GM-CSF.

Animals↗
PubMed1995

Effect of YM264 on the airway hyperresponsiveness and the late asthmatic response in a guinea pig model of asthma.

We investigated the effects of YM264, a specific platelet-activating factor (PAF) antagonist, on the airway hyperresponsiveness (AH) and the late asthmatic response (LAR) of guinea pigs that were sensitized by exposure to aerosolized ovalbumin (OA). Respiratory resistance (Rrs) was determined by the oscillation technique. Airway responsiveness was evaluated by administering a dose of histamine at which the Rrs reached 200% of the baseline value (H200). Animals were administered 1 or 3 mg/kg of YM264 orally 30 min before and again at 3 h after exposure to OA. YM264 significantly suppressed AH 24 h after and 5 days after the exposure. YM264 also suppressed the development of the LAR and accumulation of eosinophils and neutrophils in the tracheal mucosa of guinea pigs. These observations suggest that PAF is involved in the AH and the development of the LAR in asthma. PAF antagonists may play a beneficial role in the treatment of asthma.

Aerosols↗
PubMed1995

[Effect of BAY u3405-thromboxane A2 receptor antagonist, on biphasic airway responses induced by platelet-activating factor in actively sensitized guinea pigs].

Our previous study in activity sensitized guinea pigs demonstrated an LAR-like increase in respiratory resistance (Rrs) at 3 to 9 hr after PAF inhalation. The result suggested possible involvement of the priming effect of active sensitization and PAF. Mean while, thromboxane A2 (TXA2) is known to be induced by PAF. The present study investigated the involvement of TXA2 in the guinea pig LAR model with a new TXA2 receptor antagonist, BAY u3405. One hr after BAY u3405 administration to guinea pigs sensitized by ovalbumin, the Rrs following inhalation of PAF was subsequently determined. Infiltration of inflammatory cells in the airway tissue 9 hr after PAF inhalation was also observed. While a re-increase in Rrs was found in all the cases in the control group, the re-increase in Rrs was inhibited significantly in the BAY u3405 administration group, 4 to 9 hr after PAF inhalation. The numbers of eosinophils and lymphocytes in the airway tissue were significantly decreased in the BAY u3405 administration group, as compared with the control group. From these results, the possibility is suggested that TXA2 and its direct effect on the airway and the migration-enhancing effect on eosinophils and T lymphocytes, as well as PFA, are involved in the development of LAR by PAF.

Airway Resistance↗
PubMed1995

[Wilson's disease--evolutive panorama of diagnosis and treatment in the last forty years].

In 1912, Wilson and Fleischer independently reported autopsied patients with progressive neurological disorder associated with cirrhosis of the liver, and they proposed that the syndrome could be a specific disease of toxic origin. In 1952, Scheinberg demonstrated a deficiency of serum ceruloplasmin in Wilson's disease, and it became possible to diagnose the illness while the patient was still asymptomatic. In 1956, Walshe introduced penicillamine as the most excellent drug for treatment of the disease. These epoch-making discoveries encouraged Japanese physicians to make early diagnosis and to try prevention of the disease. This lecture was to review the changing panorama in the diagnosis, treatment and prognosis of the disease in the period of forty years focusing on the experiences in Japan. Early detection of the patients based on hypoceruloplasminemia made it possible to investigate the onset ages of an elevation of serum GOT or GPT and the appearance of Kayser-Fleischer (KF) rings. So far, the youngest patients who exhibited high GPT level and KF rings were three years and five years old, respectively. It became popular that an unexpected elevation of serum transaminase in apparently healthy children of three years or more prompted to examine the possibility of Wilson's disease, and an increasing number of non-familial patients in late infancy have been detected. Now, the mass-screening for Wilson's disease is in progress. Follow-up studies on the prophylaxis for more than thirty years definitely proved that the appearance of clinical symptoms was prevented with the continued penicillamine therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Adenosine induces C1- efflux in endothelial cells via a pertussis toxin-sensitive G protein.

To examine the biological role of adenosine A1 receptors in bovine pulmonary artery endothelial cells, we measured intracellular Cl-concentration [Cl-]i, using 10mM 6-methoxy-N-(3-sulfopropyl) quinolinium monohydrate (SPQ). N6-cyclopentyladenosine (CPA), a selective A1 agonist, at 10(-8)M to 10(-5)M, rapidly decreased [Cl-]i by 30% to 51%, without a rapid elevation in [Ca2+]i and cyclic AMP. This reduction in [Cl-]i was completely inhibited by 10(-8)M FK453 (a selective A1 antagonist), 500ng/ml pertussis toxin (IAP), and 2.5mM N-phenylanthranilic acid (NPA) (a Cl- channel blocker). We conclude that an A1 receptor in endothelial cells activates Cl- efflux via a PTX-sensitive G protein.

Adenosine↗
PubMed1994

Dendritic and histochemical development and ageing in patients with Down's syndrome.

Mental retardation and dementia characteristic of Down's syndrome (DS) have a complex pathogenesis. Golgi and immunohistochemical studies were done on DS patients and controls from foetuses and elderly adults. Golgi studies on the cerebral cortex revealed that the postsynaptic spines on the basal dendrites increase from neonate to 15 years of age and gradually decrease after 20 years in controls, but poorly increase in children and rapidly decrease in adults with DS. This deficient synaptogenesis and dendritic atrophy may be related to mental retardation. On the other hand, immunohistochemistry on proteins, whose genes are located on chromosome 21, revealed that c-terminal protein of beta-amyloid appears in neurons of DS, S-100-positive glia increases in the hippocampus of neonates and adults, and membrane protein OK-2 is expressed earlier and is more widespread in the DS brains. The overexpression and early appearance of gene products in DS brains may be related to the pathogenesis of or predisposition to mental disorders or to dendritic hypogenesis.

Adolescent↗
PubMed1994

Effect of inhaled cyclosporin A on the allergen-induced late asthmatic response and increased in airway hyperresponsiveness in a guinea pig model of asthma.

Oral administration of cyclosporin (CsA), a potent inhibitor of helper T cell function, prevents the allergen-induced late asthmatic response (LAR) and the increase in airway hyperresponsiveness (AH) seen in actively sensitized guinea pigs. The systemic administration of this agent in humans has been associated with serious side effect, therefore, the effects of inhaled CsA were therefore examined in guinea pigs that were actively sensitized by repeated exposure to nebulized ovalbumin. Respiratory resistance (Rrs) of the animals was measured by an oscillation method and the extent of AH was inferred from the inhaled concentration of histamine required to increase Rrs by 200%. The magnitude of ovalbumin-induced immediate bronchoconstriction after sensitization was similar in CsA-treated and nontreated control animals. However, a LAR was observed in 4/5 control animals but in 0/5 CsA-treated animals. The increase in AH observed 24 hours after antigen exposure in control animals was significantly inhibited by prior CsA inhalation. Significant CsA concentrations were detected by radioimmunoassay in the lungs of CsA-treated animals. Thus, inhaled CsA should be further investigated because it may be useful treating asthma while avoiding side effects.

Administration, Inhalation↗
PubMed1994

[A case of peritoneal metastasis of breast cancer successfully treated by multidisciplinary therapy with hyperthermia therapy].

A 53-year-old female with peritoneal metastasis of breast cancer was treated with hyperthermia with chemotherapy. One course consisted of THP 60 mg and FT 400 mg/iv (day 1), CPM 100 mg and MPA 800 mg/daily/po) with RF heating of hyperthermia monthly. After completion of 10 courses of this regimen, ascites completely disappeared and peritoneal metastases were not found observed in any peritoneal cavity with abdominal CT and ultrasound. Peritoneal metastasis of breast cancer was one of the worst reactions with any therapy. The patient has been living for about four years without any signs of recurrence, with the tumor markers within the normal range after surgery. Thermochemotherapy seems a very promising treatment modality for peritoneal metastasis of breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

Effects of ArF:excimer laser irradiation on human enamel and dentin.

Round enamel and dentin surfaces of sound and carious extracted human teeth were irradiated by an ArF:excimer laser for up to 180 sec. Thermographic measurements indicated that the temperature rise due to heat accumulation caused by laser irradiation on these enamel and dentin surfaces was up to 19 degrees C (10 HZ with 540 J/cm2), and the temperature returned to the preirradiation value within 10 sec after the irradiation was stopped. Under light microscopy, no carbonization was evident on these surfaces, and a simple recess was formed by abrasion or vaporization in the irradiated regions. In the secondary SEM, uniformly distributed fine pores and prism structures appeared slightly on the enamel surfaces. Between the peritubular and the intertubular dentin, there appeared a distinct difference in the dissolved area. The laser almost completely removed carious regions of the enamel and the dentin, and penetration extended beyond the carious regions. In the backscattered electron SEM, highly mineralized layers were observed on the enamel and dentin surfaces dissolved by the laser.

Dental Caries↗
PubMed1993

Vesicoureteral reflux in infants under one year old. Follow-up study and consideration on development of renal scarring.

In an attempt to clarify reflux nephropathy (RN), 67 infants aged under one year with vesicoureteral reflux (VUR) were retrospectively classified into two groups, non-surgical and surgical. They were evaluated on VUR grading, VUR spontaneous cessation rate, and incidence of scarring. As a whole, spontaneous cessation rate was 61 percent. The cessation rate was higher for infants with lower VUR grading. The average age at cessation was 2.5 years. Some patients showed no scarring at presentation despite severe VUR. However, most cases of renal scarrings at the time of presentation belonged to grade IV or V. Scarring advanced in 3 kidneys of the non-surgical group and in 13 kidneys of the surgical group. Of these 16 kidneys, 7 were rated as grade IV and 9 as grade V. An association between development of scarring and recurrent urinary tract infections was suggested.

Cicatrix↗