PubMed Health⌕ Search

Biomedical subjects

S Anzai

Publications and source records attributed to S Anzai.

At least 19 recordsLinked to original sources
PubMed2005

Long-term potentiation and olfactory memory formation in the carp (Cyprinus carpio L.) olfactory bulb.

Long-term potentiation of synaptic transmission is considered to be an elementary process underlying the cellular mechanism of memory formation. In the present study we aimed to examine whether or not the dendrodendritic mitral-to-granule cell synapses in the carp olfactory bulb show plastic changes after their repeated activation. It was found that: (1) the dendrodendritic mitral-to-granule cell synapses showed three types of plasticity after tetanic electrical stimulation applied to the olfactory tract-long-term potentiation (potentiation lasting >1 h), short-term potentiation (potentiation lasting <1 h) and post-tetanic potentiation (potentiation lasting <10 min); (2) Long-term potentiation was generally induced when both the dendrodendritic mitral-to-granule cell synapses and centrifugal fiber-to-granule cell synapses were repeatedly and simultaneously activated; (3) long-term enhancement (>1 h) of the odor-evoked bulbar response accompanied the electrically-induced LTP, and; (4) repeated olfactory stimulation enhanced dendrodendritic mitral-to-granule cell transmission. Based on these results, it was proposed that long-term potentiation (as well as olfactory memory) occurs at the dendrodendritic mitral-to-granule cell synapses after strong and long-lasting depolarization of granule cells, which follows repeated and simultaneous synaptic activation of both the peripheral and deep dendrites (or somata).

Animals↗
PubMed2001

Synthesis of symmetrical polynitrohelicenes and their chiral recognition in the charge transfer complexation.

Derivatives of optically active 1,12-dimethylbenzo[c]phenanthrene-5,8-dicarboxylic acid can be nitrated regioselectively, giving symmetrically polyfunctionalized helicenes. The dicarboxylic acid or its dimethyl ester is dinitrated with fuming nitric acid in acetic acid at the 4,9-positions. When the reaction is conducted in fuming nitric acid, a 2,4,9,11-tetranitrohelicene is obtained. Analogously, 1,12-dimethylbenzo[c]phenanthrene-5,8-dinitrile gives 2,11-dinitro- or 4,9-dinitrohelicene depending on the conditions, and the former compound is converted to a 2,4,9,11-tetranitrohelicene. The tetranitrohelicenes form charge-transfer (CT) complexes with an electron-rich chiral diaminohelicene in solution. The studies on the chiral recognition reveal that the combinations of the same configuration of the helicenes form more stable complexes than that of the enantiomeric helicenes.

Journal Article↗
PubMed2000

Postoperative hyponatremia in a patient with ACTH-producing Merkel cell carcinoma.

Merkel cell carcinoma is characterized by specific neuroendocrine features and the expression of several neuropeptides. We report a case of Merkel cell carcinoma with post-surgical hyponatremia in an 85-year-old Japanese woman. A tumor on the left cheek histopathologically showed the characteristics of Merkel cell carcinoma together with Bowen's disease. Although an increased level of ACTH was found both in the tumor and in the peripheral blood, the postoperative hyponatremia in our patient seems more likely to have been caused by the stress of the operation and indapamide, considering that the ACTH level in the tumor was much lower than those in other ectopic ACTH-producing tumors in previous reports.

Adrenocorticotropic Hormone↗
PubMed1999

Effect of amino acid substitution in amphiphilic alpha-helical peptides on peptide-phospholipid membrane interaction.

It was previously found that a cationic amphiphilic peptide, Ac-(Leu-Ala-Arg-Leu)3-NHCH3 (4(3)), caused the destabilization of a phospholipid membrane and showed strong antibacterial activity [Lee et al. Biochim. Biophys. Acta 1986; 862: 211-219]. In order to investigate the effect of changing alpha-helix propensity, hydrophobicity and basicity in 4(3) on the peptide conformation and activity, the 4(3) analogs, [Gly (or Val)6]4(3), [Gly (or Val)2,6]4(3), [Gly (or Val)2,6,10]4(3), [Gln3]4(3), [Gln3,7]4(3) and [Gln3,7,11]4(3) were synthesized. Except for [Val2,6]4(3) and [Val2,6,10]4(3), which mainly formed a beta-structure, other peptides formed an alpha-helix and showed moderate membrane-perturbing activity toward neutral and acidic lipid vesicles. All the peptides other than [Val2,6,10]4(3) and [Gln3,7,10]4(3) had the antibacterial activity comparable with that of 4(3). The relationship between the membrane-perturbing activity and the antibacterial activity was not always parallel. Conclusively, the Ala-->Val substitution in 4(3) causes the change of peptide conformation and the presence of a cationic amino acid residue is necessary for the antibacterial activity.

Amino Acid Sequence↗
PubMed1999

Squamous cell carcinoma in a renal transplant recipient with linear porokeratosis.

A 40-year-old man developed squamous cell carcinoma on a perianal lesion of linear porokeratosis after renal transplantation. The tumor metastasized to the left inguinal lymph node 25 months after the primary tumor was excised. p53 overexpression was observed in the tumor cells, but not in the porokeratotic lesion. Interestingly, continuous subcutaneous infusion of peplomycin for the lymph node metastasis significantly improved the warty lesions of porokeratosis. In this patient, immunosuppressive agents might have accelerated the development of carcinoma on a skin area with malignant potential.

Adult↗
PubMed1998

Pretibial myxedema with Graves' disease: a case report and review of Japanese literature.

We report a case of pretibial myxedema with Graves' disease in an 18-year-old Japanese woman. The physical examination revealed waxy indurated plaques with prominent hair follicle openings and nonpitting edema disseminated on her lower legs. Histology from an edematous lesion revealed that the dermis was markedly thickened with abundant mucin, especially hyaluronic acid, and the collagen fibers in this portion were splitting up into fibrils. We also reviewed 112 cases of pretibial myxedema reported in the Japanese literature.

Adolescent↗
PubMed1997

Dermatomyositis associated with primary intramuscular B cell lymphoma.

A rare case of dermatomyositis associated with primary intramuscular malignant lymphoma is described. A 40-year-old Japanese woman noticed swelling of the right thigh during the treatment of dermatomyositis with prednisolone, azathioprine and cyclophosphamide. A biopsy specimen taken from the right quadriceps muscle revealed infiltration of lymphoma cells which were positive for CD20. We reviewed 12 cases of dermatomyositis associated with malignant lymphoma reported in Japanese literature between 1984 and 1996.

Adult↗
PubMed1995

[Intermittent-dose ara-C/daunomycin therapy combined with cyclosporin-A and G-CSF led to a fourth remission in a patient with acute promyelocytic leukemia].

A 50-year-old female was admitted with acute promyelocytic leukemia (APL) in August, 1988. She was treated with behenoyl-ara-C, daunomycin, 6-mercaptopurine and prednisolone (BH-AC.DMP), which led to a complete remission. Thereafter, she was treated with 2 courses of BH-AC.DM and discharged from hospital. Intensification therapy was performed twice a year, with 1 course of BH-AC.DM and 5 courses of intermittent-dose ara-C/mitoxantrone which ended in March, 1992. She had a relapse in September, 1993 and was treated with all-trans retinoic acid, which led to a second remission. A second relapse occurred in May, 1994, and intermittent-dose ara-C/mitoxantrone, combined with granulocyte colony-stimulating factor (G-CSF), led to a third remission. However, she had a third relapse in September, 1994. She was treated with a trial of G-CSF (300 micrograms/body, day 1-7), to stimulate dormant leukemic cells to enter the cell cycle, and cyclosporin-A (78 mg/kg, day 2-5), in order to overcome daunomycin resistance in refractory leukemia, combined with daunomycin (45 mg/m2, day 3-5) and ara-C (1.4 g/m2, day 3-7), after obtaining informed consent. The fourth remission needed 46 days after combination chemotherapy because of severe myelosuppression. It was suggested that intermittent-dose ara-C/daunomycin therapy combined with G-CSF and cyclosporin-A may be useful for relapsed and refractory leukemia.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Behavioral study of visits by aged outpatients to medical facilities in Japan.

In this study we analyzed the changing behavior patterns of aged persons seeking medical care at hospitals and clinics over a recent ten-year period. The results showed a rapid increase in the number of aged outpatients receiving care at hospitals since 1977. In contrast, the number of aged outpatients receiving care at clinics since 1977 fluctuated with an overall downward trend, indicating outpatients' preference to seek treatments in hospital as opposed to clinics. The following are expected to affect future outpatient care rate differences between clinics and hospitals: differences in care rates for new outpatients, and differences between the sexes and among the types of illnesses treated. Having an especially large effect are: hypertension and heart diseases, diseases of the circulatory system also known as "adult diseases"; diseases of the digestive system, and diseases of the respiratory system.

Aged↗
PubMed1994

Antioxidant action of thiopalmitic acid on microsomal lipid peroxidation.

The antioxidant action of thiopalmitic acid (SH-Pal) was studied in a lipid peroxidation system using microsomes from rat liver. The Fe(II)/ascorbic acid (AsA)-induced lipid peroxidation, as measured by the amount of thiobarbituric acid-reactive substances (TBA-RS), was progressively inhibited by the addition of increasing amounts of SH-Pal. The inhibitory effect of SH-Pal in this experimental system was greater than that of alpha-tocopherol, glutathione (GSH) and palmitic acid. The antioxidative effect was abolished gradually by the addition of increasing amounts of N-ethylmaleimide to the system. Similarly, microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH or CCl4/NADPH was inhibited in a dose-dependent fashion by the addition of SH-Pal. Moreover, SH-Pal was able to reduce 1,1-diphenyl-2-picrylhydrazyl (DPPH). The alpha-tocopherol content of the microsomal lipid peroxidation system decreased rapidly when no SH-Pal was present. However, upon adding SH-Pal (90 microM), the decrease in the alpha-tocopherol content of the assay system was markedly reduced. These findings indicate that SH-Pal acts as an antioxidant and free radical scavenger in lipid peroxidation carried out by rat liver microsomes.

Adenosine Diphosphate↗
PubMed1991

Characteristics of Staphylococcus aureus isolated from lesions of horses.

Seventy-six Staphylococcus aureus strains isolated from various lesions of horses were characterized. All of the 76 strains were identified as biotypes B (38.2%) and C (61.8%). Of 55 strains tested, 42 (76.4%) were differentiated into 7 coagulase types. Coagulase types V and VII were predominant in the metritis strains. Coagulase type II was found most frequently in the strains from phlegmon, dermatitis, sinusitis, empyema sinus, and nasal catarrh. Forty-two (55.3%) of the 76 strains were differentiated into 24 phage patterns. Twenty (58.8%) of 34 typable strains from metritis were lysed by the human group I phage 52, and group II phages 3A, 3C, 55 and 71. Forty-five (59.2%) of the 76 strains were resistant to 1 or more of 6 antibiotics. Strains resistant to penicillin G, irrespective of source, were most frequent (95.6%). Forty (93.0%) of 43 strains resistant to penicillin G alone or in combination with other antibiotics produced beta-lactamase. Only 8 (10.5%) of the 76 strains produced enterotoxins A (n = 2), B (n = 1) or C (n = 5), and they all were isolated from metritis. Only 1 strain isolated from phlegmon and 2 from metritis produced exfoliative toxin (ET) and toxic shock syndrome toxin-1 (TSST-1), respectively. The latter 2 strains also produced enterotoxin C. The results of the present study showed the first evidence of the presence of both ET- and TSST-1-producing S. aureus isolated from horses.

Animals↗