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Biomedical subjects

Y Honma

Publications and source records attributed to Y Honma.

At least 397 records · Page 22Linked to original sources
PubMed1976

Light and scanning electron microscopic studies on the esophageal spines in the Pacific ridley turtle, Lepidochelys olivacea.

The peculairly specialized esophagus of the Pacific ridley turtle, Lepidochelys olivacea, was described by light and scanning electron microscopic studies. The esophagus is lined by a stratified squamous epithelium with remarkable keratinization, and its major part forms a number of large spines which have been called "pharyngeal teeth." The epithelium consists of three strate: stratum germinativum, stratum spinosum and stratum corneum. The surface of the spine is covered by a scaly keratin of possibly sloughing cells, and the cornified layer on the spine is very thick (more than 100 mu), reaching 3 to 7 times the depth of the corresponding layer in other parts. This peculiar structure in the marine turtle without toothed jaws prabably is used for breaking food into small pieces.

Animals↗
PubMed1976

Changes in the cells of the adenohypophysis associated with the diadromous migration of the threespine stickleback, Gasterosteus aculeatus L.

The adenohypophysis of the threespine stickleback, Gasterosteus aculeatus, was studied light-microscopically to determine and estimate the cell types and their function. For these purposes, the adult specimens obtained during the period from migration to spawning were examined. Further, the juveniles caught in the spawning bed were subjected artificially to sea water. The rostral pars distalis (RPD) consists mainly of two types of cells: dorsally shifted lead hematoxylin (PbH)-positive cells bordering the neurohypophysis correspond to corticotrophs, and antero-ventrally shifted acidophil cells are identified as prolactin cells. The latter undergo marked hypertrophy and active state just at the time of entering the river (February), while no detectable change was seen in the former throughout anadromous migration. The role of prolactin on the osmoregulation in freshwater environment is thus suggested. The proximal pars distalis (PPD) consists mainly of two cell types: the basophil cells in round shape are regarded as the gonadotrophs and the acidophil cells in ellipsoid shape are considered to be somatotrophs. The size of the gonadotrophs reaches the maximum at the time of spawning. A few AF-positive cells of elongate shape occur in the dorsal region and are identified as thyrotrophs. In the pars intermedia (PI), two types of cells are discernible: PAS-positive and PAS-negative cells. The latter attained their maximal size in the earliest time of anadromous migration.

Animals↗
PubMed1975

Hydrogenated benzo[f]quinolines and benz[e]indoles as analgetics. 1.

A series of octahydrobenzo[f]quinolines(IIIa) and hexahydro-1H-benz[e]indoles(IIIb), rigid structures related to 3-phenylpiperidine and pyrrolidine analgetics, has been synthesized. Structure-activity relationships were investigated by varying the structural parameters including a change in the stereochemistry of the ring junction. Several of the resulting compounds had analgetic activity on the order of meperidine.

Analgesics↗
PubMed1975

Androgenic regulation of rapidly synthesized RNA in the rat ventral prostate.

The influence of castration on the incorporation of nucleotide precursors into RNA of isolated prostatic tissue has been investigated. Castration brought about an apparent increase of incorporation by increasing the specific activity of the uridine nucleotide pool and not by an enhancement in synthesis of rapidly labelled RNA. An actual decrease in this reaction was shown by dividing the radioactivity incorporated into RNA by the specific activity of the uridine nucleotide. Administration of testosterone brought about enhanced synthesis of RNA in the prostates of rats castrated for 3 days as early as 4 h after injection, reaching maximum effect at 8 h. No significant difference was found between the turnover rates of rapidly labelled RNA from castrated, androgen-treated castrated and intact rats. The increased prostatic permeability to nucleosides as an early action of androgens in this organ is discussed.

Adenine↗