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Biomedical subjects

M Aizawa

Publications and source records attributed to M Aizawa.

At least 91 records · Page 5Linked to original sources
PubMed1989

Mucoepidermoid carcinoma arising in a lymphoepithelial cyst--report of a case and review of the literature on branchiogenic carcinoma.

A 59-year-old Japanese man who had recently noticed a gradual enlargement in a nodule located in the left anterior part of his neck was admitted for surgical treatment. The histopathological features of the resected tumor were consistent with a typical lymphoepithelial cyst, however, the inner surface epithelium of the cyst showed histological transition to mucoepidermoid carcinoma, which was partially invading the cyst wall. Despite clinical efforts in a systemic search, no primary lesions which could have metastasized were found. The patient hasn't shown any evidence of recurrence since his tumor resection over 2 years ago. Besides this rare case report, a review of the English literature reveals 22 cases of possible branchiogenic carcinoma over the last 10 years, including 21 cases whose histological features were of squamous cell carcinoma and 1 whose histological features revealed mucoepidermoid carcinoma. The present case is thus only the second proven case of low-grade mucoepidermoid carcinoma arising within a branchiogenic cyst.

Branchioma↗
PubMed1989

Electrophysiologic evaluation of asymptomatic patients with the Wolff-Parkinson-White pattern.

In the past 4 years, 34 asymptomatic patients with the Wolff-Parkinson-White (WPW) pattern underwent electrophysiologic study. The effective refractory period (ERP) of antegrade conduction over the accessory pathway was 288 +/- 29 msec. In three asymptomatic patients (9%), the antegrade ERP of the accessory pathway was shorter than 250 msec. The antegrade ERP of the accessory pathway became shorter than 250 msec in an additional 12 of 22 (55%) patients after isoproterenol administration. Nineteen (56%) of the asymptomatic patients showed the absence of retrograde conduction over the accessory pathway even after isoproterenol administration. The rate of induction of orthodromic reciprocating tachycardia in the asymptomatic WPW patients was 15% (5/34), which was significantly lower than that in the symptomatic patients. These data suggest that in the asymptomatic patients, the absence of retrograde conduction over the accessory pathway is the reason they remained asymptomatic, free of reciprocating tachycardia. However, even in the asymptomatic patients, some had the accessory pathway in which antegrade ERP was shorter than 250 msec. They may result in rapid ventricular conduction over the accessory pathway when atrial fibrillation develops.

Adult↗
PubMed1989

Electrically regulated cellular morphological and cytoskeletal changes on an optically transparent electrode.

Electrically regulated morphological and cytoskeletal changes of HeLa cells were studied on an optically transparent electrode (OTE), on which potential-applied surface cellular behavior and morphogenesis were easily observed. Upon application of a potential, HeLa cells in an OTE exhibited remarkable morphological changes above +0.5 V (vs. Ag/AgCl) and below 0 V. At each potential in this potential range, change in F-actin distribution was observed using a fluorescent probe (rhodamine phalloidin). These results suggest that an electrical field induces a subcellular cytoskeletal change. Electrostimulation of cells with OTE can be a valuable strategy for the manipulation of cultured human cells.

Actins↗
PubMed1989

Attenuation of the vasoconstrictor action of neuropeptide-Y by calcium-channel blockers.

Neuropeptide-Y (NPY) was administered intracoronarily in dogs to see the modification of its vasoconstrictor action by the calcium (Ca)-channel blockers nisoldipine (0.1 microgram/kg) and nifedipine (1 microgram/kg). Dogs were anesthetized and the left circumflex artery was cannulated without opening the chest by using a specially designed cannula perfused at constant pressure. The change in coronary flow due to NPY was determined before and after the systemic administration of the two Ca-channel blockers. With administration of 1 to 2 nmol of NPY, coronary blood flow decreased maximally by 23.4 +/- 7.8% without changes in perfusion pressure or central venous pressure and it became significantly less after nisoldipine: 16.0 +/- 5.7% (p less than 0.02). A similar attenuation in the decrease in coronary flow was observed in the nifedipine study: 23.2 +/- 7.5% to 12.0 +/- 6.7% (p less than 0.02). A fall in systemic arterial blood pressure was observed after administration of both Ca-channel blockers, but it was significant only after nisoldipine (p less than 0.01). Nonsignificant increases in heart rate were observed after both drugs. Nisoldipine seemed to attenuate the NPY-induced vasoconstriction in dogs, and its equimolar potency is about ten times that of nifedipine.

Animals↗
PubMed1989

[Effects of EDTPO on hard tissues in rats. 1. Comparison of histological changes produced by same molar of EDTPO, HEBP and EDTA].

Ethylenediamine-N,N,N',N'-tetrakis (methylenephosphonic acid) (EDTPO) is a potent inhibitor of both formation and dissolution of hydroxyapatite crystals in vitro as well as 1-hydroxyethylidene-1, 1-bisphosphonic acid (HEBP). The purpose of this study was to compare with the biological effects of the same molar level of EDTPO, HEBP and ethylenediamintetraaceticacid (EDTA), prototype of EDTPO, on bone, incisor dentin and serum chemistry in young rats. HEBP at 8mg P/kg does chosen based on it's toxicity, and 16mg P/kg of EDTPO and 48mg/kg of EDTA which were identical molar level with 8mg P/kg of HEBP, were injected subcutaneously at once a day for 10 days. At the end of treatment period blood for chemical analysis, and tibia and mandibular for histological examination were taken. Results obtained were; 1) EDTPO and HEBP impaired the net weight gain during experimental period, by about 80% of final body weight in control group, but EDTA did not affect. 2) The biochemical findings of serum were as follows; calcium (Ca) level increased in EDTPO and HEBP group, and inorganic phosphorus (IP) level decreased in EDTPO and HEBP group when compared to control group, and changes of Ca and IP level in EDTPO group was more remarkable than those of HEBP group. Alkalie phosphatase level was decreased in EDTPO group, but increased in HEBP group compared to control group. There were no significant differences between EDTA group and control group, excepting for decrease of Ca level. 3) In histological aspects of the tibia, EDTPO and HEBP groups revealed enlargement of growth plates, being greater in EDTPO group than HEBP group, over the control group, and showed expanded hypertrophic zone of growth plates and wide osteoid seams in the metaphysis. EDTPO group also inhibited the calcification of dentin of mandibular incisor more strongly than HEBP group. From these data, it was indicated that EDTPO is more potent inhibitor of calcification than HEBP. Both of EDTPO and HEBP group, moreover, revealed enlargement of tibial metaphysis. These phenomena suggest that EDTPO also inhibits bone resorption as well as HEBP. EDTA group did not reveal any differences compared to control group.

Animals↗
PubMed1989

[Combination therapy with medroxyprogesterone acetate and tegafur in tamoxifen- and adriamycin-resistant advanced breast cancers].

Medroxyprogesterone acetate (MPA) plus Tegafur (TGF) therapy was performed to evaluate the efficacy in a treatment for Tamoxifen- and Adriamycin-resistant advanced breast cancers. The patients were medicated in different doses on 800 mg or 1,200 mg daily po for MPA and TGF. Sixteen patients were evaluable in this trial. According to criteria of the Japan Mammary Cancer Society, one was regarded as CR and five as PR. The response rate was 37.5%. There was no difference in response rates between premenopausal and postmenopausal patients or ER positive and negative patients. No difference was noted either in response rates and incidence of side effects between two different doses of MPA. This means that an 800 mg daily dose of MPA lower than the recommended 1,200 mg might be better in the treatment for Japanese patients with advanced breast cancers. Gastrointestinal disorders, bone marrow suppression and liver dysfunction which could be found in high-dose TGF therapy, were not frequently observed in this trial. Patients could expect good quality of life during the treatment because of fewer side effects. This combination therapy with MPA and TGF was regarded as a good modality for the treatment of Tamoxifen- and Adriamycin-resistant advanced breast cancers.

Adult↗
PubMed1989

[An intensification therapy of adults acute leukemia].

Between January 1980 and March 1983, a study was conducted on the effects of intensification therapy in 20 adult acute leukemia patients who had achieved complete remission with induction therapy. Intensification therapy consisted of cyclic administration of six combination therapies given at gradually longer intervals, using daunorubicin, cytosine arabinoside, 6-mercaptopurine and prednisolone (DCMP), cyclocytidine (DCyMP), vincristine (DCVP), behenoyl-ara-c (BHAC-DMP), aclacinomycin (BHAC-AMP) and (ACM-MP). Six combinations were given sequentially at one-month intervals, at 2-, 3-, 4-, 5- and eventually 6-month intervals, until 5-year survival. The median remission duration was 38 months for AML, and 17 months for ALL. The median survival was 66 months for AML, and 37 months for ALL. The five year survival rate was 50%. Nine of the 20 patients are still alive. Methotrexate and prednisolone were administered intrathecally for prophylaxis of CNS leukemia on Day 4 for each intensification therapy. There was no CNS leukemia. This intensification protocol was shown to be effective in improving the prognosis of adults acute leukemia.

Acute Disease↗
PubMed1988

HLA-DQ system and insulin-dependent diabetes mellitus in Japanese: does it contribute to the development of IDDM as it does in Caucasians?

Fifty-six unrelated Japanese patients with insulin-dependent diabetes mellitus (IDDM) were HLA-typed, and restriction fragment length polymorphism (RFLP) analysis was performed after enzyme digestion with Bam HI and Taq I by using both DR and DQ probes. As previously reported, increased frequencies of Bw54, Cw1, DR4, and DRw53, which are in strong linkage disequilibrium in the Japanese population and make the characteristic Japanese haplotype, were confirmed. DQw4, a new allele of the DQ system recognized by the monoclonal antibody HU-46 and in linkage disequilibrium with this haplotype, presented the highest IDDM association. The RFLP analysis also showed the strongest correlation to IDDM when the DQ probe was applied. These results indicate that HLA-DQ might play the most important role in the development of IDDM in Japanese as well as in Caucasians. The correlation of DQ beta amino acid sequences strongly associated with IDDM in Japanese are discussed in this study, and contrasting results were found when such sequences were compared with those of Caucasians.

Amino Acid Sequence↗
PubMed1988

The functional link between the immune suppression gene and Mhc class II molecules.

The immune response to bovine insulin (BI) in the rat is controlled by the major histocompatibility complex (Mhc)-linked immune response gene (Ir-BI) and immune suppression gene (Is-BI). In the present study, we investigated the low responsiveness to BI in the WKAH rat (RT1k) and attempted to explore the functional link between Is-BI and Mhc class II molecules. Lymph node cells (LNC) from the low responder (WKAH) rats responded well to BI when a large amount of antigen was added to the culture in vitro or after OX8-bearing (OX8+) T cells were eliminated. These LNC, after the elimination of OX8+ cells, could show the RT1.Dk-restricted proliferative response upon in vitro challenge with BI, BI-B chain, or pork insulin. In addition, OX8+ T cells, which were activated with BI and antigen-presenting cells (APC) in vitro, suppressed the anti-BI response of W3/25-bearing proliferating T cells from BI-immunized rats. The results have demonstrated that proliferating T-cell repertoires do exist to BI, which recognize BI-B chain in the context of RT1.Dk molecules in the WKAH rat, and that the state of low responsiveness is mediated to a great extent by antigen-specific OX8+ suppressor T (Ts) cells. Furthermore, the elimination of APC or the addition to RT1.Bk-specific monoclonal antibody in the in vitro secondary activation culture of Ts cells diminished the suppressive activity of OX8+ Ts cells. In the induction phase of Ts cells it therefore seems to be necessary for these cells to recognize BI together with RT1.Bk molecules on APC.

Animals↗
PubMed1988

Pure squamous cell carcinoma of the thyroid gland--report of an autopsy case and review of the literature.

A rare autopsy case of primary squamous cell carcinoma of the thyroid gland is reported herein. A 61-year-old Japanese woman with a swelling of the left neck underwent surgery and the resulting tumor was histopathologically diagnosed as pure squamous cell carcinoma of the thyroid gland. She had had the nodule for 20 years, and it was histologically diagnosed as having been a well-encapsulated, follicular adenoma. Histopathological observation of the resected glands also revealed the coexistence of pure squamous cell carcinoma, which presumably originated from the adenoma. Postoperatively, an esophagotracheal fistula formed due to local invasion of the tumor cells. The patient's state gradually deteriorated and she died of severe bronchopneumonia and renal dysfunction, 4 months after the operation. Autopsy revealed no distant metastases, but severe septicemia caused by bacterial infection affecting the systemic organs was found, which presumably resulted in multiple organ failure.

Carcinoma, Squamous Cell↗