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Biomedical subjects

A Niimi

Publications and source records attributed to A Niimi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Use of new magnetic attachments for implant-supported overdentures.

A newly designed magnetic attachment system for external hexed implants with a standard abutment platform has been developed. This system has certain definite advantages over bar attachments and ball attachments, which are frequently utilized for implant-supported overdentures. Especially, it can be applied to cases with reduced vertical dimension of occlusion because the total height of the magnet and the keeper is only 2.3 mm when assembled. In addition, detrimental lateral stresses to the fixture are greatly alleviated due to very low attractive forces horizontally. Favorable clinical results using this new magnetic attachment system have been obtained, and it may be considered a useful addition to overdenture therapy using any external hexel implant with a standard abutment platform, such as the Brånemark implant system.

Aged↗
PubMed1998

[A case of miliary tuberculosis with brain tuberculoma, following intraocular tuberculosis].

A 52-year-old woman with visual loss of her left eye consulted a ophthalmology clinic. She was conducted left vitrectomy and administered corticosteroid under the diagnosis of uveitis of unknown cause. But her visual acuity was not improved. Although re-surgery was planned, pus retention was found in her left eye. After her left eye was resected, fever and general malaise appeared suddenly. Her chest X-ray film revealed diffuse micronodular opacities. Acid-fast bacilli were detected from her sputum and identified to be Mycobacterium tuberculosis. She was diagnosed miliary tuberculosis, and then antituberculous chemotherapy consisting of 4 drugs was started. Granulomatous inflammation destructing retina and numerous acid-fact bacilli were found in histologic examination of the resected eye. This case was thought to be miliary tuberculosis disseminated from intraocular tuberculosis. After 2 months of therapy, neurologic symptoms which might be caused by brain tuberucloma appeared and deteriorated rapidly. But by adding corticosteroid to antituberculous therapy, symptoms were diminished gradually.

Anti-Inflammatory Agents↗
PubMed1997

A comparative study of removal torque of endosseous implants in the fibula, iliac crest and scapula of cadavers: preliminary report.

This study was undertaken to compare removal torque of endosseous implants in the fibula, iliac crest and scapula of cadavers. The fibulae, iliac crests and scapulae were harvested from the right side of 5 formalin-preserved cadavers. Endosseous implants (Brånemark System) were placed at 3 points of each bone. The removal torque of the implant was measured by a torque gauge manometer (Tohnichi 15 BTG-N). After measurement of the removal torque, the bone was cut at each implant site. The thicknesses of cortical and total bone were measured. The mean removal torques were 46.3 N cm in the fibulae, 15.2 N cm in the iliac crests and 21.4 N cm in the scapulae. There was a statistically significant difference in mean removal torque between the three bones. The total bone thicknesses were 11.7 mm in the fibulae, 9.9 mm in the iliac crests and 8.2 mm in the scapulae. The cortical bone thicknesses were 5.0 mm in the fibulae, 1.6 mm in the iliac crests and 1.8 mm in the scapulae. Significant correlation between the removal torque and the cortical bone thickness was found. However there was no significant correlation between the removal torque and the total bone thickness. In conclusion, the implants inserted in the fibulae showed the highest removal torques as compared to the ones inserted in the iliac crests and the scapulae. Moreover the removal torque was related to the thickness of the cortical bone in the implant sites.

Adult↗
PubMed1997

Implant-supported prostheses after maxillary cancer resection: preliminary report.

A preliminary study of 4 partial maxillectomy patients who received a total of 17 endosseous implants and implant-supported prostheses after oral cancer resection is reported. The masticatory function index (chewing efficiency) after implant placement was higher than the preoperative value. Speech with an implant-supported prosthesis improved as compared with previous prostheses or without a prosthesis. All of the patients received radiation and adjunctive hyperbaric oxygen therapy. The success rate after a 2-year follow-up period was 88.2 percent.

Aged↗
PubMed1997

Yield of computed tomography and bronchoscopy for the diagnosis of Mycobacterium avium complex pulmonary disease.

Mycobacterium avium complex (MAC) pulmonary disease with nodules and bronchiectasis is increasing. But the usefulness of computed tomography (CT) and bronchoscopy for diagnosis and the significance of MAC isolation from respiratory secretions are still unclear. For a 4-yr period, we prospectively examined the role of bronchoscopy with bronchial washing and transbronchial lung biopsy in 26 patients who had clusters of small nodules in the periphery of the lung associated with ectatic changes of the draining bronchi on the CT scan. None of them was infected with human immunodeficiency virus. Thirteen of the 26 patients (50%) had cultures positive for MAC, six in the sputum and 13 in the bronchial washing. Epithelioid granuloma was demonstrated in eight of 13 patients with culture-positive MAC and in two of 13 patients in whom MAC was culture-negative. Rapidly growing mycobacteria were cultured in the two patients. Seven of the eight biopsy-positive patients received treatment and responded by sputum conversion and/or radiographic improvement. We found that the CT finding was a useful clue to suspect MAC pulmonary disease and that the bronchial washing was more sensitive than the routine expectorated sputum for MAC isolation. Demonstration of granuloma in more than half of the MAC-positive patients would suggest that MAC may have invaded the lung tissue rather than colonized in the airways.

Adult↗
PubMed1997

[2 cases of lung disease caused by Mycobacterium avium complex occurred in middle-aged women without underlying disorders, which we observed for more than 30 years].

We reported 2 cases of Mycobacterium avium complex lung disease occurred in middle-aged women without underlying disorders, which we could observe for more than 30 years. One case was a 42-year-old woman started with bloody sputum, and the other was a 43-year-old woman with cough and sputum. In both cases, chest X ray films were normal on their first visit. More than 15 years after their first visit, Mycobacterium avium complex was isolated from their sputum or bronchial washing. During the observation, a cluster of small nodules in the periphery of the lung and bronchiectasis appeared and deteriorated, and excretion of the bacilli increased gradually. Their past history and family history were normal. Since lung disease caused by Mycobacterium avium complex progresses very slowly, long-time observation would be necessary to consider its pathogenesis.

Adult↗
PubMed1997

[Evaluation of mycobacteria growth indicator tube (MGIT) for drug susceptibility testing of Mycobacterium tuberculosis isolates].

Fifty six clinical isolates of Mycobacterium tuberculosis were tested for drug susceptibility in Mycobacteria Growth Indicator Tube (MGIT) containing 0.1 microgram/ml of INH, 1.0 microgram/ml of RFP, 3.5 micrograms/ml of EB and 0.8 microgram/ml of SM. These results were compared with those obtained by testing the same M.tuberculosis isolates by the absolute concentration method using 1% Ogawa egg slant containing 0.1 microgram/ml of INH, 10 micrograms/ml of REP, 2.5 micrograms/ml of EB and 20 micrograms/ml of SM. Fifty six isolates consisted of 18 pansensitive strains, 27 multidrug resistant strains and 11 single drug resistant strains. The results of individual drugs showed excellent agreement between the MGIT and the Ogawa methods, and overall agreement rate of the two methods were 96.4%. The results were just the same for all drugs in 48 out of 56 strains studied. The drug resistance could be observed much earlier by the MGIT method (mean 5.9 days) than by the Ogawa method (more than 21 days). In conclusion, the MGIT system could be a promising new drug susceptibility test which might become available in Japan replacing the Ogawa method.

Antitubercular Agents↗
PubMed1997

[Blood rheological study in rats with fatty liver--with special reference to effects of ethyl icosapentate].

A blood rheological study was conducted using Kikuchi's micro-channel method in rats with fatty liver. Effects of eicosapentaenoic acid (EPA) on blood rheology were also evaluated. Male SD rats given normal feed served as the control. One group was given choline-deficient feed for 4 weeks (EPA (-) group), while another group was daily given EPA (1000 mg/kg) for 4 weeks together with choline-deficient feed (EPA (+) group). The micro-channel passage time was determined using 100 microliters of whole blood. The passage time significantly increased in the EPA (-) group compared to the control (p < 0.01). It significantly decreased in the EPA (+) group compared to the EPA (-) group (p < 0.01). Findings obtained in the present study suggested that blood rheological factors are related to the development of fatty liver and that EPA inhibits fatty changes of the liver by improving these rheological factors.

Animals↗
PubMed1996

Late respiratory response and associated eosinophilic inflammation induced by repeated exposure to toluene diisocyanate in guinea pigs.

OBJECTIVE: The study was designed to establish an animal model of toluene diisocyanate (TDI)-induced late respiratory response and to investigate airway inflammatory cell dynamics in this model. METHODS: Guinea pigs were exposed to 2, 4-TDI dissolved in ethyl acetate by nasal application according to three schedules. Schedule 1 consisted of sensitization and multiple challenge (n = 58): 10% TDI was applied once daily for 7 days (sensitization) followed by challenges with 5% TDI once weekly for 4 weeks. Schedule 2 consisted of sensitization only (n = 5): 10% TDI was applied once daily for 7 days. Schedule 3 consisted of single challenge only (n = 12): 5% TDI was applied only once. As controls, ethyl acetate was applied according to the three schedules described above. Each animal was premedicated with metyrapone before each challenge. Bronchoalveolar lavage and histologic examination were performed at various times after the last challenge. RESULTS: Schedule 1 induced immediate and late respiratory responses at a prevalence of 63% and 56%, respectively. Schedules 2 and 3 induced an immediate response in some animals but no late response. Neither immediate nor late response was observed in control animals. All of the subgroups of schedule 1 that developed late responses (examined at 2, 3, 6, 24 and 168 hours) showed a significant increase of eosinophils in bronchoalveolar lavage fluid and tissue compared with the corresponding control of each (examined at the same time points). Two of the subgroups with late responses (examined at 3 and 6 hours) were compared with their corresponding subgroups, which were given the same treatment, failed to develop late response, and were examined at the same time points; they again proved to have a significant increase of eosinophils in both samples. Subgroups of schedule 1 without late response (30 minutes, 3 and 6 hours), schedule 2 (6 hours), or schedule 3 (2 and 6 hours) did not show significant changes in lavage or tissue cell composition, except for the schedule 1 subgroup examined at 6 hours, which showed a significant increase of eosinophils only in the tissue compared with its control. CONCLUSIONS: Sensitization and multiple challenge with TDI induced immediate and/or late respiratory responses at a high prevalence in guinea pigs. Eosinophilic but not neutrophilic inflammation was involved in the late response.

Animals↗
PubMed1996

Histologic study of the effect of hyperbaric oxygen therapy on autogenous free bone grafts.

PURPOSE: This study was undertaken to evaluate the effect of hyperbaric oxygen therapy on autogenous free bone grafts transplanted from iliac crest to the mandibles of rabbits. MATERIALS AND METHODS: A piece of corticocancellous bone harvested from iliac crest was grafted to a same-size bone defect in the mandibles of 16 Japanese white rabbits. In 8 rabbits, 20 and 10 sessions of hyperbaric oxygen (HBO) treatment were carried out twice per day (2.4 ATA 60 min.) before and after operation, respectively. The other 8 rabbits served as controls. The graft and surrounding bone were sampled at 1, 2, 4, or 8 weeks after transplantation, and the effects of HBO were evaluated by light micrography and contact microradiography. RESULTS: At 1 week after grafting, osteoid formation in the experimental group was much greater than in the control group. Union between the grafted and the host bone was observed in the experimental group at 2 weeks after grafting, but it was not observed in the control group until 4 weeks. Although it was difficult to differentiate grafted from host bone in the experimental group at 4 weeks, it was readily distinguishable in the control group. CONCLUSIONS: These results indicate that HBO accelerates the union of autogenous free bone grafts.

Animals↗
PubMed1996

Bronchial mucoid impaction due to the monokaryotic mycelium of Schizophyllum commune.

We report, to our knowledge, the first case of mucoid impaction of the bronchi due to a hypersensitivity reaction to the monokaryotic mycelium of Schizophyllum commune. The patient was hospitalized because of mild asthma attacks, persistent cough, peripheral eosinophilia, and "gloved finger" shadows on a chest roentgenogram. Bronchoscopic examination disclosed mucoid impactions that consisted of accumulations of eosinophils, Charcot-Leyden crystals, and nondichotomously branched hyphae in B3, B9, and B10 of the left lung. Cultures of the mucous plugs and sputum samples yielded white, felt-like mycelial colonies that were later identified as the monokaryotic mycelium of S. commune by use of mating tests with established monokaryotic and dikaryotic strains of S. commune. The results of tests for serum antibody to S. commune cytosol antigen were positive. Repeated bronchoscopies for performing bronchial toilet were effective in removing the mucous plugs and relieving the patient's symptoms. We suggest that the monokaryotic mycelium of S. commune should be considered as one of the fungi that can cause hypersensitivity-related lung diseases.

Aged↗
PubMed1996

Increase in hepatic tissue blood flow by teprenone.

The major objective of the present study was to evaluate mechanisms by which teprenone, a gastric mucosal protecting agent, increases hepatic mucosal blood flow using male Sprague-Dawley rats. Hepatic and gastric blood flow was measured using a laser blood flow meter after administration of teprenone, dissolved in Tween 80, into the inferior vena cava. Teprenone itself increased hepatic and gastric blood flow. It also increased hepatic and gastric blood flow in rats with acute hepatic disorders due to carbon tetrachloride (CCL4) and improved histological changes, such as inflammatory cell infiltration and fatty changes in the liver. The fact that blood endothelin (ET) concentrations increased after administration of teprenone suggest that teprenone has great affinity for ET beta receptors and shows ET beta-receptor antagonist-like effects. Hepatic blood flow decreased after administration of N-nitro-L-arginine methyl ester, a nitric oxide (NO) synthetase inhibitor, suggesting that teprenone increase NO activity. Teprenone was thought to increase hepatic and gastric blood flow by different mechanisms, because it increased gastric mucosal prostaglandin E2 concentrations.

Animals↗
PubMed1996

Murine model of invasive pulmonary aspergillosis following an earlier stage, noninvasive Aspergillus infection.

Aspergillus spp. occasionally cause invasive pulmonary aspergillosis following noninvasive infection in patients with underlying bronchopulmonary disorders regardless of their systemic immunological conditions. We developed a murine model of invasive pulmonary aspergillosis following an earlier stage, noninvasive Aspergillus infection. BALB/c mice were inoculated intratracheally with agarose beads containing Aspergillus fumigatus conidia. Two weeks after inoculation, half of the mice were immunosuppressed with cortisone acetate. During a 4-week observation period, the survival rate of infected immunosuppressed mice was significantly lower (P < 0.01) than that of infected nonimmunosuppressed mice. The number of CFU in the lungs gradually decreased in the nonimmunosuppressed mice, whereas a time-related significant increase (P < 0.05) of CFU was demonstrated in the immunosuppressed mice. In the lungs of the nonimmunosuppressed mice, there was marked accumulation of neutrophils, lymphocytes, and macrophages (in this order) around the agarose beads in the bronchi. Aspergillus hyphae were surrounded by the inflammatory cells and did not invade the lung parenchyma. In contrast, in the immunosuppressed mice, Aspergillus hyphae proliferated markedly and invaded the lung parenchyma after immunosuppression. In this model, the two-dimensional extents of the lesions were also evaluated with an image-processing system. Time-related increase of the area of peribronchial necrotic lesions was significant (P < 0.05) after immunosuppression. This model should therefore be useful for investigating the pathophysiology of noninvasive Aspergillus infection and invasive pulmonary aspergillosis and also for clarifying the mechanism of conversion to the invasive disease from the noninvasive stage.

Animals↗
PubMed1996

[A patient with myotonic dystrophy who presented with chest roentgenographic abnormalities and alveolar hypoventilation].

A 52-year-old man had been asymptomatic except for nasal speech since his third decade of life. A chest roentgenogram obtained during a health screening one year before admission revealed elevation of the right hemidiaphragm and infiltrates in the right lower lung field. Because the pulmonary shadows had gradually increased, he was admitted to the hospital, for further examination. Based on physiological findings and on the results of electromyography, myotonic dystrophy was diagnosed. The chest roentgenographic abnormalities were regarded as resulting from complications of this disease. Arterial blood gas analysis showed hypercapnic hypoxia and a spirogram showed that the vital capacity and maximum voluntary ventilation were about half of their respective predicted values. The hypercapnic ventilatory response was also abnormally low. An overnight study of oxygen saturation showed episodes of marked desaturation, and polysomnography revealed central sleep apnea. Inhalation of capsaicin showed an abnormally high cough threshold. Patients with undiagnosed myotonic dystrophy rarely present with chest roentgenographic abnormalities.

Electromyography↗
PubMed1995

Inflammatory bronchial polyps associated with asthma: resolution with inhaled corticosteroid.

In a 50 year old man who complained of cough and sputum, a small endobronchial tumour was found in the left main bronchus and was biopsied via bronchoscopy. The histological diagnosis was inflammatory polyp with marked infiltration of eosinophils. Six years later, the patient developed asthma. At the same time, another polyp was found in the posterior basal bronchus of the right lower lobe. The appearance of the first polyp was unchanged endoscopically and histologically. Inhalation of beclomethasone dipropionate, 200 micrograms b.i.d., was started and symptoms of asthma soon subsided. In addition, the two polyps regressed and eventually disappeared after one year of treatment. Inhaled corticosteroids, being noninvasive and relatively safe, appear to be a possible therapeutic option in inflammatory bronchial polyps, especially in cases where the patient has asthma as an underlying condition, or the polyps are small and their management is not urgent.

Administration, Inhalation↗
PubMed1995

Interstitial pneumonitis-like lesions in guinea-pigs following repeated exposure to toluene diisocyanate.

The inhalation of isocyanates, such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate (HDI) can induce hypersensitivity pneumonitis (HP) as well as bronchial asthma in humans, but the precise pathological features and their pathogenetic mechanisms have not been elucidated. To provide insight into the pathological features of isocyanate-induced hypersensitivity pneumonitis in humans, we repeatedly exposed guinea-pigs to TDI following previous sensitization to TDI and examined the inflammatory response in the pulmonary lesions. Following sensitization with 10% TDI ethyl acetate solution for seven consecutive days, guinea-pigs were exposed to 5% TDI ethyl acetate solution once a week for 4 weeks. As a control, guinea-pigs were exposed to ethyl acetate alone in the same manner. Furthermore, other guinea-pigs received a single exposure to 5 or 20% TDI ethyl acetate solution. The TDI solutions or ethyl acetate were applied to the bilateral nasal mucosa of guinea-pigs for 30 s-day-1. Histological examination of lung specimens of guinea-pigs repeatedly exposed to TDI after previous sensitization by TDI inhalation revealed interstitial pneumonitis-like lesions in which mononuclear cells and eosinophils were mainly involved. Lungs of control and nonsensitized guinea-pigs showed insignificant histological changes. We demonstrated that interstitial pneumonitis-like lesions, indistinguishable from isocyanate-induced hypersensitivity pneumonitis in humans, can be caused by repeated but not single exposure to TDI in guinea-pigs.

Alveolitis, Extrinsic Allergic↗
PubMed1995

Aspergillus culture filtrates and sputum sols from patients with pulmonary aspergillosis cause damage to human respiratory ciliated epithelium in vitro.

Aspergillus species frequently colonize lower respiratory tracts and lungs with localized underlying conditions (healed tuberculous cavity, cystic fibrosis, bronchiectasis, etc.) even in subjects without systemic predisposing factors. We investigated the in vitro effects of culture filtrates of Aspergillus species and sputum sols from patients with pulmonary aspergillosis on ciliary beat frequency (CBF) and epithelial integrity of human respiratory ciliated epithelium. Culture filtrates of 25 clinically isolated fungi (16 Aspergillus fumigatus, three Aspergillus niger, one Aspergillus flavus, three Candida albicans, and two Cryptococcus neoformans) were obtained by culturing the fungi in Medium-199 at 37 degrees C for 7 days, and five sputum sols were obtained from patients with pulmonary aspergillosis infected by A. fumigatus. During 6 h experiments using a photometric technique, 14 out of 16 A. fumigatus culture filtrates caused progressive and significant reduction in CBF associated with marked epithelial disruption, whilst the culture filtrates of A. niger and A. flavus caused minor epithelial damage without slowing of CBF, and Medium-199 alone (Control) showed neither epithelial damage nor slowing of CBF. All of the sputum sols also caused significant slowing of CBF as well as epithelial disruption. Culture filtrates of C. albicans and Cr. neoformans had no effects on human respiratory epithelium. We conclude that Aspergillus species, especially A. fumigatus release a factor (or factors) which causes damage to respiratory epithelium and slows CBF, and that these factors may contribute to the colonization of the lower respiratory tracts by the Aspergillus species and may possibly contribute to the further proliferation and spread of the lesions in pulmonary aspergillosis.

Adult↗