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Biomedical subjects

N Katayama

Publications and source records attributed to N Katayama.

At least 271 records · Page 15Linked to original sources
PubMed1989

Lactivicin, a naturally occurring non-beta-lactam antibiotic having beta-lactam-like action: biological activities and mode of action.

Lactivicin is moderately active against a wide range of Gram-negative bacteria and highly active against Gram-positive bacteria. It shows various biological activities commonly observed with beta-lactam antibiotics, such as higher activity against beta-lactam hypersensitive mutants than against their parents, sensitivity to beta-lactamases, inhibitory activity against beta-lactamases and ability to induce beta-lactamase activity. The primary lethal target of lactivicin in Escherichia coli is highly likely to be penicillin-binding protein (PBP) 1; lactivicin strongly lysed E. coli cells with induction of spheroplasts at its MIC, and showed high affinity for PBPs 1A and 1B. At concentrations above x 5 MIC, however, lactivicin dominantly exhibited secondary antibacterial action possibly owing to inhibition of crucial SH proteins engaged in the fundamental membrane functions. In contrast, against Bacillus subtilis, lactivicin showed the typical beta-lactam action under a wide range of concentrations. It showed high affinity for PBPs 1, 2 and 4, the possible lethal targets of beta-lactam antibiotics in this organism. In conclusion, lactivicin is the first non-beta-lactam antibiotic showing beta-lactam action through binding to PBPs.

Anti-Bacterial Agents↗
PubMed1989

[Neoplastic angioendotheliosis of B-lymphocyte origin: an autopsy report].

A 56-year-old male presented with fever of unknown origin and subacute dementia which progressed to death with seizure, coma and acute deterioration of general conditions. He had splenomegaly but not skin eruption or lymph node swelling. Autopsy findings showed that mononuclear tumor cells were widespread within the lumens of small blood vessels, indicating the features of neoplastic angioendotheliosis. The involved organs were shown to be brain, lung, adrenal grand, testis, bone marrow, heart and thyroid gland. To determine the origin of tumor cells, an immunohistochemical study was carried out using a panel of monoclonal antibodies. The results indicated that the tumor cells were of B-lymphocyte origin. These findings support the possibility that neoplastic angioendotheliosis is a lymphoma with proliferation in small blood vessels throughout the body.

B-Lymphocytes↗
PubMed1989

Intensive chemotherapy followed by autologous bone marrow transplantation for a patient having wide-spread embryonal carcinoma in the central nervous system.

A patient with an intracranial embryonal carcinoma, which was resistant to cisplatin-based combined chemotherapy and radiotherapy, developed spinal seeding. Alpha fetoprotein (AFP), human chorionic gonadotropin (HCG) and the beta chain of HCG (NCG beta) in serum or cerebrospinal fluid immediately returned to elevated levels despite sequential chemotherapy and resection. Accordingly, we treated this patient with spinal irradiation and intensive combination chemotherapy (cisplatin etoposide, vinblastine, cyclophosphamide and actinomycin D) followed by autologous bone marrow transplantation. With this treatment, the clinical manifestations showed a tendency to improve and, furthermore, the serum levels of AFP and HCG returned to normal. These findings suggest autologous bone marrow transplantation to be a potential approach to the treatment of patients with embryonal carcinomas.

Adult↗
PubMed1989

[Spontaneous transient remission in adult acute myeloid leukemia].

A spontaneous complete remission for one month duration was observed in a 54-year-old female with acute myeloid leukemia. She had no documentation of apparent infection and blood transfusions, although they were ordinarily associated with spontaneous remission.

Female↗
PubMed1989

Putative involvement of protein kinase C in proliferation of human myeloid progenitor cells.

The effects of two different potent inhibitors of protein kinase C, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7) and staurosporine on human myeloid (CFU-C) and late erythroid progenitor cells (CFU-E) were studied using an in vitro clonal assay. Our objective was to determine whether protein kinase C has a role in signal transduction related to proliferation of these committed progenitor cells. The presence of H-7 or staurosporine led to an inhibition of colony formation stimulated by crude colony-stimulating factor (CSF), interleukin-3 (IL-3), granulocyte-macrophage CSF (GM-CSF), granulocyte CSF (G-CSF), or macrophage CSF (M-CSF) in a dose-dependent manner. N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004), a weaker analog of H-7, did not inhibit proliferation of CFU-C. Neither H-7 nor staurosporine had any effect on CFU-E formation. H-7 and staurosporine dose-dependently inhibited the protein kinase C from K562 cells. The potential of these compounds to inhibit proliferation of CFU-C correlated well with the magnitude of their inhibition of protein kinase C from K562 cells. The inhibition of proliferation of CFU-C appears to relate to the potential of these compounds to inhibit protein kinase C. Thus, activation of protein kinase C is presumably involved in the proliferation of CFU-C, and the regulatory system of CFU-E appears to differ from that of CFU-C.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1989

[A novel phenotype (CD 4+, Leu 7+) in large granular lymphocyte leukemia: a case report].

We report a case of a 72-year-old man with large granular lymphocyte (LGL) leukemia. Immunophenotypical analysis of the abnormal cells showed the following results: CD 2+, CD 3+, CD 4+, CD 8-, CD 11+, CD 16-, Leu 7+. These cells had natural killer (NK) activity, responded to PHA and recombinant interleukin-2 (rIL-2), and showed neither helper nor suppressor function in B-cell differentiation. Molecular genetical analysis showed monoclonal rearrangement of T-cell receptor beta-chain gene, indicating they are of T-cell origin. These findings provide information on biological characteristics of normal CD 4+, Leu 7+ cells.

Aged↗
PubMed1988

Clinical response to busramustine (KM-2210) in chronic lymphocytic leukemia: a pilot evaluation of estrogen receptor in relation to its therapeutic effect.

Busramustine (KM-2210), the benzoate of a 17 beta-estradiol-chlorambucil conjugate, was administered to 11 patients with chronic lymphocytic leukemia (CLL) which included eight cases of B-cell CLL and three cases of T-cell CLL. Four patients had received prior chemotherapy. Busramustine was given orally at an initial daily dose of 50-100 mg continuously, and the dose was modified according to hematological improvement. Two cases of B-cell CLL achieved clinical complete responses, six cases including two of T-cell CLL and four of B-cell CLL achieved partial responses and one case of B-cell CLL achieved improvement. The partial and complete response rate was 72.7%. Four patients showed estrogen receptor activity of CLL cells ranging from 3.5 to 57.5 fmol/mg cytosol protein, but there seemed to be no correlation between the estrogen receptor activity of the CLL cells and the therapeutic effects of busramustine. Toxic effects included diarrhea (2/11) and estrogen-related symptoms including breast pain (4/11), genital bleeding (2/5), gynecomastia (2/6) and loss of libido (2/6). The findings of this preliminary study suggest that busramustine is effective in the treatment of CLL, irrespective of the presence of the estrogen receptor.

Adult↗