Search PubMed⌕ Search

Biomedical subjects

K Ichimura

Publications and source records attributed to K Ichimura.

At least 217 records · Page 12Linked to original sources
PubMed1978

Effect of chlorpromazine on the in vitro immune response.

The effect of chlorpromazine at concentrations from 10(-7) to 5 X 10(-5)M on the in vitro plaque-forming cell responses to sheep erythrocytes was tested. If CPZ was present in cultures during the whole incubation period, concentrations of CPZ more than 5 X 10(-6)M inhibited the PFC responses, whereas concentrations between 5 X 10(-7) and 5 X 10(-6)M had a slightly enhancing effect. If a defined concentration of CPZ (1.3 or 1.5 X 10(-5)M) was added to cultures for a brief period of time (12 or 24 h) at various intervals after the initiation of culture and antigenic stimulation, PFC responses were inhibited most effectively during the first brief periods of incubation. The later the drug was added, the more the extent of inhibition decreased. On the other hand, CPZ had no effect or a slightly enhancing effect when added in the very late period (72--95 h) of incubation. These findings suggest that the observed immunosuppression could be attributed mainly to the impairment of early cellular events, presumably cell interaction events, preceding the process of DNA synthesis and cell proliferation of antibody-forming cells and their precursors.

Animals↗
PubMedDate not supplied

Attachment and invasion of high- and low-metastatic clones of RCT sarcoma in a three-dimensional culture system.

High- and low-metastatic clones established from poorly differentiated murine sarcoma (RCT sarcoma) spontaneously developed in C3H/He mice were used in this study. Attachment and invasion, which are factors likely related to metastatic ability, of these clones were investigated in a three-dimensional culture system using embryonic chick heart fragments and tumor cell aggregates. The effects of Nocodazole, which interferes with the function of microtubules, and cytochalasin B, which affects the actin assembly in cytoplasmic extensions, on these factors were also examined. Metastatic ability was correlated with attachment and invasiveness of RCT sarcoma. Invasiveness of tumor cells was suppressed by the addition of Nocodazole to the culture medium. Since the disappearance of cell polarity, resulting from the inhibition of tubulin assembly, was found to coincide with the suppression of invasion, directional migration is considered to be involved in the invasion of tumor cells. Cytochalasin B caused a marked decrease in the ratio of attachment of tumor aggregates to embryonic chick heart fragments. The increased ability of invasion and attachment of RCT(+) cells compared with RCT(-) cells seems to contribute to their propensity to metastasize.

Animals↗
PubMedDate not supplied

A second primary squamous cell carcinoma arising in a radial forearm flap used for reconstruction of the hypopharynx.

A 63-year-old man had undergone hypopharyngectomy for hypopharyngeal carcinoma in 1985. A free radial forearm flap was used for reconstruction of the pharynx. Ten years after the surgery, a second primary squamous cell carcinoma occurred in the neopharynx. Persistent exposure to alcohol, saliva and foodstuffs was considered as a possible cause of second primary carcinoma. Long-term follow-up is indicated in patients undergoing reconstruction using cutaneous or musculocutaneous flaps.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Immunohistochemical localization of proliferating cells and epidermal growth factor receptors in mouse olfactory epithelium.

We investigated age-related changes in proliferating cells and epidermal growth factor receptors (EGFRs) in mouse olfactory epithelium using an immunohistochemical method with the antiproliferating cell nuclear antigen (PCNA) antibody and the antihuman EGFRs antibody. Many PCNA-positive cells occurred in the surface and basal layers of the olfactory epithelium in the embryonal and neonatal mice. However, only some PCNA-positive cells occurred in the basal layer of adult mice, and only a few presented in the basal layer of aged mice. EGFRs were observed in all layers of the olfactory epithelium at the embryonal and neonatal stages, but were not identified in the olfactory epithelium at the adult or aged stages. We believe that a decrease in EGFRs in the olfactory epithelium induces the inhibition of cell proliferation, with the resultant atrophy of the olfactory epithelium.

Age Factors↗
PubMedDate not supplied

Vascular effects of neuropeptides on nasal mucosa.

We used dog nasal blood vessels and an in vitro muscle tension-detecting technique to examine the vascular effects of several neuropeptides: vasoactive intestinal polypeptide, substance P, neurotensin, somatostatin, and neuropeptide Y (NPY). Electrically induced vasoconstriction was inhibited by every peptide except neurotensin, which enhanced this response. Every preparation treated with somatostatin, and one tissue treated with NPY, showed an enhanced noradrenaline-induced contraction. Only NPY caused a tissue contraction. Preparations precontracted by methoxamine were relaxed by every peptide. These results indicate that all peptides examined have marked but varied vasoactivities.

Animals↗