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K Miyazaki

Publications and source records attributed to K Miyazaki.

At least 685 records · Page 38Linked to original sources
PubMed1984

Assessment of the role of surgery for stage III bronchogenic carcinoma.

In order to assess the role of surgery for stage III bronchogenic carcinoma, we reviewed our results of 282 patients who were treated with surgical resection or various other therapy modalities. The survival in patients who underwent surgical resection was significantly better than those with nonresectable carcinoma. However, superior survival results were demonstrated only in patients with complete resection. In contrast, the survival in patients with palliative resection was similar to that in patients with exploratory thoracotomy and inoperable carcinoma. On the other hand, all patients with T3N2 lesions died of their disease within two years after surgery even when undergoing complete resection. Thus, we conclude that radical resection should be indicated in patients with T3N0-1 and T1-2N2 lesions if complete resection is expected.

Adenocarcinoma↗
PubMed1984

Effect of chenodeoxycholic and ursodeoxycholic acids on isolated adult human hepatocytes.

Chenodeoxycholic and ursodeoxycholic are effective cholelitholytic agents, but differ in their side effects. Chenodeoxycholic acid administration induces diarrhea and a transient rise of GOT, which are virtually nonexistent with ursodeoxycholic acid treatment. Lithocholic acid, a bacterial metabolite of chenodeoxycholic acid, has been implicated as a possible hepatotoxin. In the present investigation, the effect of chenodeoxycholic acid or ursodeoxycholic acid and their glycine and taurine conjugates on isolated human hypatocytes was directly assessed. Chenodeoxycholic acid had drastic effects on isolated human hepatocytes by reducing the number of microvilli and disrupting cell membranes. Pronounced release of GOT was observed. In contrast, ursodeoxycholic acid produced only slight morphological changes and enzyme release. Conjugation of each respective bile acids had a moderating effect.

Adult↗
PubMed1984

Forskolin stimulates adenylate cyclase activity, adenosine 3',5'-monophosphate production and peptide release from the intermediate lobe of the rat pituitary gland.

Forskolin stimulates adenylate cyclase activity in a cell-free homogenate of the intermediate lobe (IL) of the rat pituitary gland. L-Isoproterenol, a beta-adrenergic agonist, enhances and apomorphine, a D-2 agonist, inhibits the forskolin-stimulated adenylate cyclase activity. Guanosine triphosphate is obligatory for the dopaminergic attenuation of the forskolin-enhanced enzyme activity. When tested upon enzymatically dispersed IL cells, forskolin enhances the release of both cAMP and immunoreactive alpha MSH-like peptides. These effects of forskolin upon the IL are discussed within the context of a previously published working hypothesis that cAMP in some way triggers the calcium-dependent release of hormones from the IL.

Adenylyl Cyclases↗
PubMed1984

Bromocriptine-induced changes in the biochemistry, physiology, and histology of the intermediate lobe of the rat pituitary gland.

Treatment of rats with 2-Br-alpha-ergocryptine (bromocriptine; CB 154) elicits biochemical, physiological, and histological changes in the intermediate lobe (IL) of the rat pituitary gland, suggesting a decrease in activity in the IL. CB 154 treatment decreases 1) the capacity of the IL to synthesize proopiomelanocortin (POMC), 2) the content of mRNA directing the synthesis of POMC, and 3) the capacity of the IL to synthesize the peptides desacetyl alpha MSH, N,O-diacetyl alpha MSH, and alpha MSH. CB 154 treatment also causes a 40% loss of IL protein and an atrophy of the IL. CB 154 treatment has a biphasic effect upon the IL content of alpha MSH-like peptides; the drug first increases and then diminishes the content of these molecules. Control experiments using CB 154-treated IL tissue suggest that these effects of CB 154 are not a toxic effect of CB 154 on the IL. Spiroperidol reverses the effects of CB 154 on POMC synthesis and POMC mRNA content; by itself, spiroperidol increases the IL synthesis of POMC, the IL content of POMC mRNA, and the capacity of the IL to synthesize immunoreactive alpha MSH. Stalk section of rat pituitary gland also results in an increase in the capacity of the IL to synthesize POMC. These results suggest that a D-2 dopamine receptor mediates a tonic inhibition of the function of the IL.

Adrenocorticotropic Hormone↗
PubMed1984

Adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase activity in rodent pituitary tissue: possible role in cAMP-dependent hormone secretion.

A cAMP-dependent protein kinase occurs in the intermediate lobe of the rat pituitary gland and the ACTH-secreting tumor AtT-20/D16-16 derived from the mouse pituitary gland. Exposure of either tissue to drugs increasing cAMP production and hormone release (forskolin, cholera toxin, or isoproterenol in the case of the intermediate lobe; forskolin or isoproterenol in the case of the AtT-20 cells) increases the cAMP-dependent protein kinase activity of a tissue homogenate in the absence, but not in the presence, of added cAMP. The potencies of these drugs to induce changes in the protein kinase activity ratio (i.e. enzyme activity in the absence of cAMP to enzyme activity in the presence of 3 microM cAMP) are comparable with their potencies as stimulants of hormone secretion. In either tissue, A23187, a calcium ionophore that stimulates hormone release but not cAMP production, does not change the protein kinase activity ratio. In the case of the AtT-20 cells, dexamethasone blocks the release of ACTH simulated by either isoproterenol or forskolin, but does not alter the enhancement of protein kinase activity induced by these drugs. Conversely, dexamethasone does not block the A23187-stimulated release of ACTH. The data suggest that cAMP modulates (but does not trigger) hormone secretion from the rodent pituitary gland by a mechanism involving activation of the cAMP-dependent protein kinase. Several possible sites for this modulatory effect of cAMP are discussed.

Adrenocorticotropic Hormone↗
PubMed1984

Intestinal absorption of several beta-lactam antibiotics. V. Effect of amino beta-lactam analogues and dipeptides on the absorption of amino beta-lactam antibiotics.

The absorption mechanism of amino beta-lactam antibiotics was investigated by using the whole small intestine of a rat. Mutual inhibition among amino beta-lactam analogues and the effects of dipeptides were studied. The influences of glycylglycine on the absorption of cephradine at the four different parts of intestine were also studied. Similarly to the case of cephalexin and cephradine, the absorption of amoxicillin was significantly inhibited by cyclacillin, cephradine, and cephalexin, but the absorption of ampicillin was not reduced by all tested antibiotics. In the experiments using dipeptides (6.0 mM), the absorption of cyclacillin was reduced significantly by glycylglycine, not by L-carnosine. And cephalexin absorption was influenced by L-carnosine (6.0, 10 mM), not by glycylglycine (6 mM). On the contrary, the absorption of cephradine was not reduced at all by these dipeptides. And from the experiment using the four different parts of intestine, it was shown that the transport interaction of glycylglycine with cephradine was observed in only one segment (the upper part of jejunum). These result suggest that the carrier-mediated transport system correlated to dipeptides participates only to a small degree in the common absorption mechanisms of these amino beta-lactam antibiotics.

Amoxicillin↗
PubMed1984

The effects of tunicamycin on anterior pituitary hormone producing cells in the rat.

An electron microscopic study was performed to clarify the effects of tunicamycin, a glycosylation inhibitor, on rat anterior pituitary cells. Tunicamycin (10, 50, and 100 micrograms/250 g B.W.) was intraperitoneally injected into rats, which were sacrificed 24 hrs later. Protein hormone producing GH and prolactin cells, and ACTH cells which are known to have a glycosylated precursor, showed no recognizable ultrastructural changes. TSH cells and gonadotrophs, both of which secrete glycoprotein hormones consisting of alpha and beta subunits, showed remarkable dilatation of the rough endoplasmic reticulum, and decreased numbers of secretory granules. These results suggest that the role of glycosylation in TSH cells and gonadotrophs may have a different biological significance from that in ACTH cells.

Adrenocorticotropic Hormone↗
PubMed1984

Inhibition of human B cell activation by diterpine forskolin: interference with B cell growth factor-induced G1 to S transition of the B cell cycle.

We have previously demonstrated that a series of sequential steps are involved in the induction of a resting human B cell to proliferate. In this system, initial activation signals were delivered by either in vivo or in vitro stimulation, and proliferative signals were delivered by a B cell growth factor (BCGF) that was derived from a human T-T cell hybridoma. The involvement of adenosine 3',5'-monophosphate (cAMP) in regulating the growth and differentiation of lymphocytes has been of considerable interest. Diterpine forskolin has been reported to be a unique adenylate cyclase activator in membranes from mammalian tissues that results in elevations of intracytoplasmic cAMP. We have examined the effect of this drug on the progression of human B cells through their activation cycle. It was found that forskolin causes a rapid and sustained increase of cytoplasmic cAMP in purified small and large B cells. In the in vitro costimulation of small resting B cells with anti-mu plus BCGF, forskolin inhibited the proliferative response of B cells in a dose-dependent manner. This forskolin-mediated suppression of B cell proliferation was found when the drug was added to the cultures as late as 36 hr after initial stimulation. Of note is the fact that the anti-mu-induced RNA synthesis as well as cell enlargement in resting B cells was not inhibited by the addition of forskolin, whereas BCGF-induced proliferative response of activated B cells was markedly inhibited by the drug. Thus, these data demonstrate that forskolin, an agent that elevates cytoplasmic cAMP levels, has relatively little effect on early events in the human B cell cycle (G0 to G1) transition, but selectively inhibits the progression of BCGF-induced G1 to S phase transition of B cells.

Adolescent↗
PubMed1984

Clinical features and classification of hepatolithiasis.

A newer classification of hepatolithiasis based on the prevailing pathology was applied to 59 cases of hepatolithiasis. The results indicated once again the preponderance of stones and strictures in the left lateral segmental ducts. In addition, involvement of peripheral segmental ducts is most commonly found in the anterior inferior area of the right hepatic lobe and in the left lateral inferior area duct of the left lateral hepatic segment. Such incidence of segmental or area involvement is expected to rise because of improved techniques for imaging the hepatobiliary tree. The disease classification presently used offers several advantages. It is solely based on an exact description of the prevailing pathology and therefore is devoid of subjective bias such as that involved in designating without much factual basis whether disease is primary or secondary or is congenital or acquired. The coding used offers easier compilation of data, which can be stored in a computer for later retrieval and computation.

Adult↗