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Biomedical subjects

Y Yoshizawa

Publications and source records attributed to Y Yoshizawa.

At least 19 recordsLinked to original sources
PubMed1992

Effect of retinoid status on alpha, beta and gamma retinoic acid receptor mRNA levels in various rat tissues.

We have investigated the effects of retinoids, vitamin D and thyroid hormone on the levels of retinoic acid receptor (RAR)alpha, RAR beta and RAR gamma mRNAs in intact animals. Although vitamin A deficiency caused no significant changes in the levels of RAR alpha and RAR gamma mRNAs, the level of RAR beta transcripts was greatly decreased in various tissues of vitamin A-deficient rats, but was restored rapidly to a normal level after administration of retinoic acid. Retinol also restored the RAR beta mRNA level, but the magnitude and kinetics of the induction differed from those by retinoic acid. The use of specific inhibitors demonstrated that this autoregulation of RAR beta gene expression in vivo occurred at the transcriptional level. In addition, from these results it was postulated that the maintenance of the normal RAR beta mRNA levels seemed to require a threshold serum retinol concentration (about 25 micrograms/dl). Moreover, we found that administration of retinol and retinoic acid to normal rats caused the overexpression of RAR beta transcripts (2-15-fold) when compared with the control levels of RAR beta mRNA, although the levels of RAR alpha and RAR gamma mRNAs were not affected. Vitamin D and thyroid hormone did not modulate the levels of RAR transcripts. These findings clearly indicate the specific ligand regulation of RAR beta gene expression in intact animals. The altered levels of RAR beta according to retinoid status may affect retinoid-inducible gene expression.

Animals↗
PubMed1992

[A case of small liver cancer presenting as a huge mediastinal mass].

A 61-year-old male was admitted because of hemoptysis. He had a 9 year history of liver cirrhosis associated with HB viral chronic hepatitis. Physical examination revealed no abnormalities. Laboratory investigations revealed positive HBs antigen with normal alpha-fetoprotein. Chest X-ray film showed large mediastinal lymph nodes and an endobronchial polypoid mass in the distal end of the right main bronchus. The right main PA was narrowed due to compression by the mediastinal mass. Bronchoscopic examination revealed a polypoid mass in the right main bronchus. The biopsy specimen was histologically diagnosed as undifferentiated large cell carcinoma. The patient developed respiratory failure, and died 3 weeks after admission. Autopsy revealed a small liver cancer of 1.3 cm diameter within the cirrhotic liver, associated with a small abdominal lymph node metastasis and large mediastinal lymph node swellings. Thromboembolism in the bilateral main pulmonary arteries was concluded to be the cause of death. The mediastinal mass which directly invaded into the right main bronchus had a close histological similarity with the liver cancer, showing undifferentiated carcinoma cells with bizarre nuclei and abundant cytoplasm. An immunohistological study revealed cells positive for alpha-fetoprotein in the mediastinal lymph nodes. The patient was diagnosed as having small liver cancer with mediastinal lymph node metastases. A survey of the literature revealed only a few cases of advanced hepatoma associated with prominent mediastinal metastases. This is the first reported case of small liver cancer presenting with large mediastinal lymph node metastases.

Carcinoma↗
PubMed1992

[A case of intrabronchial dissemination of candida pseudohyphae presenting as respiratory failure].

A 63-year-old man was admitted to our hospital because of fever, skin eruption, leukocytopenia and liver dysfunction. He was receiving H2-blocker for gastric ulcer of the time he developed his symptoms. The H2-blocker was discontinued because of its possible association with leukocytopenia, and steroids were administered. On the 4th day of hospitalization, he suddenly developed expiratory wheeze and dyspnea, resembling an asthmatic attack. WBC was 400/mm3 with 65% neutrophils. Chest X-ray showed hyper inflation and increased thickness of bronchiolar walls. Bronchodilators had no effect and the patient died of respiratory failure on the 8th day. At autopsy, most bronchioles were filled with candida pseudohyphae. The large airways and lung parenchyma were not involved, except for focal bacterial pneumonia. Histological findings suggestive of bronchial asthma such as constriction of bronchial smooth muscle or infiltration of eosinophils were not observed Candida infection was also found in the pharynx, stomach, bowel, and kidneys. Candidiasis is becoming a more important contributory cause of death in compromised hosts. Although rare, this case suggests that patients with bronchopulmonary candidiasis present with expiratory wheeze resembling asthmatic attack.

Airway Obstruction↗
PubMed1992

[Survey of MRSA infection in Ibaraki-ken--Ibaraki Association for infectious diseases].

This study which was undertaken at several major hospitals in Ibaraki-ken revealed that, 1) the proportion of Staphylococcus aureus in all the isolates ranged from 5% to 17% and the prevalence of MRSA in isolates of Staphylococcus aureus varied from 51% to 82% depending upon each individual hospital. 2) the clinical response to FOM and CMZ combination therapy was 88.9% and, to FOM and CZON was 57.1% showing no statistical differences between the two regimens. 3) in vitro analyses assessed by the FIC index of 251 isolates revealed that FOM had an additive or synergistic effect with CMZ in 53.8%, with CZON in 66.9%, with minocycline (MINO) in 43.8%, with cefamandole (CMD) in 61.8%, with cefazolin (CEZ) in 62.9% and with imipenem/cliastatin sodium (IPM/CS) in 68.9% at all isolates. 4) the cumulative curve of susceptibility to single CMZ and the combination of CMZ and FOM revealed that the blood levels of CMZ at 3 hours after intravenous administration covered 57% of isolates when used alone and 82% of isolates when in combination with FOM. The blood levels of CZON at 3 hours covered 5% of isolates when used alone and 41% when in combination with FOM. The extent of the therapeutic effect increased from 6% to 42% by CMD, from 12% to 54% by CEZ, from 20% to 58% by IPM/CS and from 78% to 84% by MINO. The combination of CMZ and FOM was found to be the most effective for enhanced effects on MRSA in vitro.

Anti-Bacterial Agents↗
PubMed1991

Sequential changes in lung injury induced by preformed immune complexes.

Immune complexes formed in the airside may be involved in the early parenchymal changes in hypersensitivity pneumonitis. The present study was undertaken to compare the responses of animals after an intratracheal injection with preformed immune complexes to those of patients with acute hypersensitivity pneumonitis, with special emphasis on sequential bronchoalveolar lavage findings and the possible role of chemotactic factors in the immune complex-induced lung injury. An increased number and percentage of polymorphonuclear cells could be detected in bronchoalveolar lavage fluids of guinea pigs within 48 hr following an intratracheal injection of preformed immune complexes. Chemotactic factor activity preceded the observed increase of polymorphonuclear cells in bronchoalveolar lavage fluids, suggesting a role for chemotactic factors in the sequestration of these cells in the lung. In addition, this study confirmed the usefulness of bronchoalveolar lavage in evaluating the pulmonary findings because the changes in bronchoalveolar lavage cell populations correlated with sequential histological findings. The sequential characteristics of the involved areas were noted to be of a peribronchial or bronchiolar infiltration with polymorphonuclear cells at early stages, then alveolar sac infiltration, followed by mild infiltration of mononuclear cells into the alveolar walls. The findings suggest a possible role for chemotactic factors in the accumulation of polymorphonuclear cells, and the sequential changes of bronchoalveolar lavage and histological findings in animals are comparable to those in patients with acute hypersensitivity pneumonitis.

Alveolitis, Extrinsic Allergic↗
PubMed1991

Effects of vitamin E-enriched egg yolk on lipid peroxidation, hemolysis and serum lipid concentration in young and old rats.

Effects of a diet containing different amount of vitamin E-enriched egg yolk powder on lipid peroxidation, hemolysis, and serum lipid concentration were examined in young and old rats. Young and old rats were fed experimental diets containing 5.6% or 22.5% of normal egg yolk powder, and 5.6% or 22.5% of vitamin E-enriched egg yolk powder. When young rats were fed these diets, their tocopherol concentrations in testes, heart, kidneys, and retroperitoneum fat pads increased according to the diet tocopherol contents. Lipid peroxide levels in these tissues were inversely proportional to the tocopherol concentrations. The liver and serum, however, did not show the above relationship. In the rats fed vitamin E-enriched egg yolk diets hemolysis did not increase, in contrast to those fed normal egg yolk diets. The rats fed a 5.6% vitamin E-enriched egg yolk diet had a lower serum cholesterol level than those fed a normal egg yolk diet. In old rats, one control group was used to determine initial tocopherol concentration and two other groups were fed 5.6% normal and vitamin E-enriched egg yolk diets. The vitamin E-enriched egg yolk rats showed lower weights of the body, liver, and retroperitoneum fat pads at the end of the experiment. The normal egg yolk group had atrophied testes. The tissue and serum tocopherol concentrations were increased in the vitamin E-enriched egg yolk group, whereas they were decreased in the normal egg yolk group. In the vitamin E-enriched egg yolk group, lipid peroxide, hemolysis and serum cholesterol, especially HDL-cholesterol, did not increase. These results indicate that egg yolk tocopherol was absorbed and prevented lipid peroxidation and hemolysis in young and old rats, and testes atrophy in old rats.

Age Factors↗
PubMed1990

Accelerator mass spectrometry of 36Cl produced by neutrons from the Hiroshima bomb.

Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine 36Cl/Cl ratios of samples from a tombstone exposed to neutrons from the Hiroshima bomb. The ratios were determined from the surface to deeper positions. The depth profile of 36Cl/Cl can be used for estimating the neutron energy distribution and intensity near the hypocentre in Hiroshima.

Chlorine↗
PubMed1989

Hypersensitivity pneumonitis induced by toluene diisocyanate: sequelae of continuous exposure.

A 41-year-old automobile paint sprayer showed the clinical features of hypersensitivity pneumonitis 1 week after he had begun to work with paint materials containing toluene diisocyanate. His symptoms began 6 to 8 hours after exposure to the agent and spontaneously disappeared by the next morning. He had diffuse, fine reticulonodular shadows on a chest roentgenogram and a restrictive impairment of pulmonary function. Immunoglobulin G antibody to toluene diisocyanate-human serum albumin was present in bronchoalveolar lavage fluid and sera: IgA antibody was present only in bronchoalveolar lavage fluid. Also, the patient had sensitized bronchoalveolar lymphocytes to toluene diisocyanate-human serum albumin. The histologic findings suggested hypersensitivity pneumonitis. The results of bronchoalveolar lavage, which was repeated on four separate occasions, showed lymphocytosis and a predominance of suppressor-cytotoxic T cells. The findings from serial determinations of humoral antibodies showed no changes consistent with the results of clinical and laboratory studies. In contrast, blastogenic responses of bronchoalveolar lymphocytes to toluene diisocyanate markedly decreased, and the patient showed clinical improvement despite continued exposure to the agent.

Adult↗
PubMed1989

Characterization of a nalidixic-acid-resistant mutant of Escherichia coli as a strict aerobe.

An Escherichia coli mutant, C18, which plates at an efficiency of 5.0 x 10(-4) under anaerobic condition, was isolated among spontaneous nalidixic-acid-resistant mutants. This strict aerobic mutation was mapped by P1 cotransduction with a gyrA linked transposon Tn10 and found to be at the gyrA gene. A low degree of superhelicity of pBR322 DNA isolated from C18 was demonstrated by agarose gel electrophoresis with various concentrations of ethidium bromide. The superhelical density of pBR322 isolated from C18 was 80% of the value of pBR322 isolated from wild-type bacteria cultured under aerobic condition, and 50% cultured under anaerobic condition. These results lead us to conclude that a certain mutation of the gyrA gene causes a decrease in DNA superhelicity and prevents anaerobic growth.

Aerobiosis↗
PubMed1989

Accessory cell function of human alveolar macrophages in antigen-induced T lymphocyte proliferation.

We compared the accessory cell function of human alveolar macrophages (AM) to that of human blood monocytes (Mo) obtained by bronchoalveolar lavage and venipuncture from normal volunteers. Graded numbers of either AM or Mo were added to autologous peripheral blood T lymphocytes that were stimulated with a purified protein derivative of tuberculin (PPD). Either AM or Mo were cocultured with allogeneic T lymphocytes in mixed lymphocyte reaction (MLR) experiments. Both AM and Mo supported the PPD-induced T lymphocyte proliferation and allogeneic MLR at low ratios of AM or Mo to T lymphocytes with similar efficiency. However, AM showed marked suppressive effects at higher ratios of AM to T lymphocytes (1:1). PPD-pulsed AM, but not AM killed by physical treatments (heat, freeze-thaw, sonication), induced T lymphocyte proliferation. An indirect immunofluorescent study demonstrated that most AM express HLA-DR antigens. Furthermore, AM synthesized DR antigens with molecular weights of 33,000 and 29,000-31,000 daltons. When AM were treated with both anti-DR monoclonal antibody and complement, PPD-induced T lymphocyte proliferation and MLR were diminished. These results suggest that human AM function as accessory cells in the antigen-induced T lymphocyte proliferation and DR antigens on AM play an important role in the accessory cell function.

Antibodies, Monoclonal↗
PubMed1989

Ovarian cysts in precocious puberty.

We describe a 7-year-old girl with precocious puberty in whom a single large cyst (5 cm) and several small cysts (8-10 mm) in the single remaining ovary were detected by the ultrasound examination. Endocrinological examinations confirmed the diagnosis of central precocious puberty. Pathologic findings after the removal of the cystic lesions revealed that the large cyst was derived from degenerated follicular cysts and the small cysts were identical to follicular cysts: all were considered to have been formed by gonadotropin stimulation. In general, surgical removal of an ovarian follicular cyst in central precocious puberty is inappropriate. However, in this unusual patient who had a degenerated large cyst, surgery seemed to be appropriate because of a previously removed teratoma in the contralateral ovary.

Child↗
PubMed1989

[Serial changes in lung injury produced by preformed immune complexes].

A previous study demonstrated increased levels of C5a des Arg and increased numbers of polymorphonuclear cells (PMNs) in bronchoalveolar lavage (BAL) fluids of acutely ill patients with summer type hypersensitivity pneumonitis (HP), suggesting the role of immune complexes (IC) in the early stage of HP. The present study was undertaken to compare the BAL findings in patients with acute HP and in animals which were injected intratracheally with preformed IC and to determine the correlation between the sequential BAL findings and the serial histology in animals. The results indicated that total cells recovered by BAL increased up to 24 hours. However, the most striking observation was that the increased number and percentage of PMNs in BAL cells shortly after the intratracheal injection, which the number of macrophages in BAL cells tended to be high, the increase was not statistically significant. Histological examinations revealed peribronchial and intraalveolar infiltration with PMNs at the early stage when intraalveolar infiltration were predominant, and the latest lesions consisted of infiltration with mononuclear cells in the alveolar walls. Furthermore, the cellular findings of BAL cells reflected the histological findings in involved lungs. The present study demonstrated that the sequential BAL changes of acutely ill patients with HP were similar to those of IC-injected animals, suggesting the possibility that IC formed in the airways is involved in the early stage of HP.

Alveolitis, Extrinsic Allergic↗
PubMed1989

[The motility of lung lymphocytes in hypersensitivity pneumonitis and sarcoidosis].

Hypersensitivity pneumonitis (HP) and pulmonary sarcoidosis (Sa) are characterized by an accumulation of large numbers of lymphocytes within the interstitium and the epithelial surface of the lung. Although the lymphocytes in bronchoalveolar lavage fluid (BALF) are representative of interstitial cells in these diseases, the mechanism involved in an accumulation of lymphocytes on the epithelial surface are yet unknown. To explore the possibility that the lymphocytes on the epithelial surface are migrated cells from the interstitium, we studied the motility of the BALF lymphocytes in five patients with HP and nine patients with Sa and compared them to that of peripheral blood lymphocytes. The lymphocyte migration assay was performed using blind well chemotaxis chambers and cells migrated into the cellulose nitrate membranes were assessed. The total migrated cell numbers of BALF lymphocytes in HP and Sa were 753.3 +/- 86.5 and 334.2 +/- 41.0, respectively. The migration distance of BALF lymphocytes in HP and Sa assessed with leading front method were 50.2 +/- 3.8 microns and 57.9 +/- 4.6 microns, respectively. The motility of BALF lymphocytes in HP and Sa was significantly greater than that of peripheral blood lymphocytes and the motility of BALF lymphocytes were comparable to that of PHA-activated lymphocytes. The motility of BALF lymphocytes were correlated with the proportion of lymphocytes in BALF cells and the proportion of Ia+T lymphocytes. These results suggest that BALF lymphocytes in these diseases are activated and enhanced motility may facilitate the accumulation of lymphocytes to the epithelial surface.

Alveolitis, Extrinsic Allergic↗