Biomedical subjects

Y Kitamura

Publications and source records attributed to Y Kitamura.

At least 541 records · Page 30Linked to original sources

PubMed1990

Sequential malignant transformation of cardiac myxoma.

We describe a case of cardiac myxoma in a 44-year-old Japanese man, who died after developing metastases in the skin, brain and muscle. A satellite tumor which was attached to the wall of the abdominal aorta induced marked hypertension due to obstruction of the renal arteries. Although the primary heart tumor had typical histological features of benign cardiac myxoma, the recurrent heart tumor, which was partly resected three months before the patient's death, showed apparently malignant characteristics resembling malignant fibrous histiocytoma (MFH). Since the histological features of the initial and recurrent tumors were different, the grade of malignancy was investigated using the cellularity of the tumor as an arbitrary criterion. A gradual but significant increase in the cellularity was observed over the course of five years. Immunohistochemically, tumor cells in the muscle metastasis contained vimentin and factor VIII-related antigen, and multinucleated giant cells in the recurrent heart tumor contained desmin, which is rarely detectable in MFH. Therefore, we considered that the present case represented malignant transformation of benign cardiac myxoma.

Adult↗

PubMed1990

Epithelial cell nodules developing in the cecum of irradiated mice. Some comparisons with jejunal nodules.

A method for producing macroscopic epithelial nodules was developed in order to investigate the properties of epithelial stem cells in the large intestine of mice. The cecum was exteriorized and exposed to various doses of X-ray radiation. Numbers of nodules subsequently developing were counted and plotted against radiation dose. From the logarithmic regression line, the susceptibility to irradiation of nodule-forming stem cells (NFSC) was determined. The susceptibility of cecal NFSC was comparable to the value reported for jejunal NFSC. Mice of (C57BL/6 x DS) F1-Pgk-1b/Pgk-1a that carried X-chromosome inactivation mosaicism for the phosphoglycerate kinase gene were used for examination of nodule clonality. Most cecal nodules contained only 1 type of phosphoglycerate kinase, suggesting a monoclonal origin of the nodules. Histochemical studies showed the presence of absorptive epithelial, goblet and entero-endocrine cells in 17-day-old nodules, implying multipotentiality of the NFSC. In spite of these similarities between cecal and jejunal NFSC, the macroscopic appearance of cecal nodules was quite different from that of jejunal nodules. Only crypt-like structures were observed in the former, whereas both crypt-like and villus-like structures were present in the latter. A comparison between cecal and jejunal nodules may be useful for understanding the morphogenesis of the intestinal mucosa.

Animals↗

PubMed1990

Chondroitin sulfate proteoglycan in the extracellular matrix of the canine superior olivary nuclei.

The perineuronal extracellular matrix of the canine superior olivary nuclei was examined by the histochemical method. The extracellular matrix was stained with Alcian blue (pH 1.0 and 2.5), high iron diamine and ruthenium red. The staining intensity of Alcian blue in the extracellular matrix was remarkably reduced after chondroitinase ABC digestion but not after that of heparitinase or hyaluronidase. These results indicate that the extracellular matrix consists of proteoglycans and contains the chondroitin sulfate proteoglycan.

Animals↗

PubMed1990

Effects of WEB 1881 FU, a novel nootropic, on cholinergic and adrenergic receptors in the rat brain: action on M1-muscarinic receptors.

Effects of 4-aminomethyl-1-benzylpyrrolidin-2-one-hemifumarate (WEB 1881 FU), a novel pyrrolidinone nootropic, on acetylcholine (ACh) receptors and adrenoceptors were investigated using crude membranes of the rat brain. The affinity order of WEB 1881 FU was: M1-muscarinic (m) ACh receptor greater than M2-mACh receptor greater than alpha 2-adrenoceptor greater than beta-adrenoceptor greater than alpha 1-adrenoceptor greater than nicotinic ACh receptor. The WEB 1881 FU-competition curve for [3H]pirenzepine binding in hippocampal membranes was rightward-shifted by GTP gamma S; such behavior was also observed in the case of oxotremorine but not with scopolamine. The effects of long-term administration of WEB 1881 FU (30 mg/kg/day, i.p.) for 21 days resulted in a significant decrease in the Bmax of [3H]quinuclidinyl benzilate binding in the cerebral cortex, hippocampus and striatum. In addition, the Bmax of [3H]pirenzepine binding to hippocampal and striatal membranes and that of [3H]AF-DX 116 binding to cerebellar membranes were significantly decreased as well. From these results, WEB 1881 FU seems to act on M1-mACh receptors, and its long-term administration probably induces the down-regulation of mACh receptors, mainly M1-mACh receptors in the hippocampus and striatum and M2-mACh receptors in the cerebellum.

Animals↗

PubMed1990

[A study on enoxacin concentration in human prostatic tissue].

To examine the penetration of enoxacin into prostatic tissue of patients with benign prostatic hypertropHy, the serum concentration and prostatic tissue level of enoxacin were measured. Enoxacin was administered orally at a dose of 200 mg, three times 2 days and one day before and once on the day of the operation. Blood and prostatic tissue samples were taken during the operation. The mean concentration of enoxacin was 2.84 +/- 0.349 g/ml in serum and 4.60 +/- 0.631 micrograms/ml in the prostatic tissue.

Aged↗

PubMed1990

[Urinary excretion of glycine.prolile dipeptidile aminopeptidase, N-acetyl-beta-D-glucosaminidase, alanine aminopeptidase and low molecular protein in patients with renal cell carcinoma].

Urinary excretion of glycine.prolile dipeptidile aminopeptidase (GP-DAP), N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP) and beta 2-microglobulin (beta 2-M), alpha 1-microglobulin (alpha 1-M) was studied preoperatively in 32 patients with renal cell carcinoma. The excretion indices of GP-DAP, AAP and NAG were significantly higher than those in the healthy control group. The excretion of these enzymes obviously reflected the degree of the tumor progression. However, positive rates were not remarkable (37% for GP-DAP, 37% for AAP and 28% for NAG). The excretion of beta 2-M and alpha 1-M was not increased in renal cell carcinoma patients.

Acetylglucosaminidase↗

PubMed1990

Intraperitoneally injected cultured mast cells suppress recruitment and differentiation of bone marrow-derived mast cell precursors in the peritoneal cavity of W/Wv mice.

Bone marrow-derived mast cell precursors form large mast cell colonies in methylcellulose and are designated as L-CFU-Mast. The effect of differentiated mast cells on recruitment and differentiation of L-CFU-Mast was investigated by using genetically mast cell-deficient WBB6F1-W/Wv mice. Giant granules of C57BL/6-bgJ/bgJ (Chediak-Higashi syndrome) mice were used as a marker to identify the origin of L-CFU-Mast and differentiated mast cells. Practically no L-CFU-Mast are present in the peritoneal cavity of WBB6F1-W/Wv mice. When bone marrow cells of WBB6F1(-)+/+ mice were i.v. injected, the concentration of +/+(-)type L-CFU-Mast increased in the peritoneal cavity of WBB6F1-W/Wv mice and became several times greater than that of nontreated WBB6F1(-)+/+ mice. This increase of L-CFU-Mast was suppressed by a prior i.p. injection of bgJ/bgJ-type cultured mast cells. The differentiation of the +/+(-)type L-CFU-Mast to morphologically identifiable mast cells was also suppressed by the i.p. injection of bgJ/bgJ-type cultured mast cells. The present results suggest that the suppression of recruitment and differentiation of L-CFU-Mast is a physiological function of differentiated mast cells.

Animals↗

PubMed1990

[Clinical evaluation of urinary glycyl-prolyl dipeptidyl aminopeptidase in patients with urological disease].

Urinary glycyl-prolyl dipeptidyl aminopeptidase (GP-DAP) activity was measured in 18 healthy adults and 252 patients with urological diseases. The GP-DAP activity was significantly higher in patients with prostatic cancer, bladder cancer or renal cancer and also in patients with acute prostatitis or pyelonephritis than in healthy adults. GP-DAP activity was also studied during anticancerous chemotherapy and proved to be a sensitive parameter for renal damage as are urinary N-acetyl-beta-D-glucosaminidase, alanine aminopeptidase, beta 2-microglobulin, alpha 1-microglobulin, and albumin. The analysis of tissue activities suggested that GP-DAP was located not only in the renal parenchyma but also in the prostate and seminal vesicles.

Acetylglucosaminidase↗

PubMed1990

Crystalline light-chain deposition and amyloidosis in the thyroid gland and kidneys of a patient with myeloma.

A 48-year-old Japanese woman died of multiple myeloma (lambda light-chain type) with chronic renal failure. Histological examination revealed deposition of a homogeneous substance and crystals in the kidneys and thyroid gland. The homogeneous substance was stained with Congo red after permanganate treatment but did not stain with antibody to amyloid A protein, and it was recognized as AL-type amyloid. Crystals were not stained with Congo red, but crystals were stained with antibody to the lambda light chain. Since AL-type amyloid is considered to be derived from a myeloma light chain, the present case showed two different types of deposition, both of which were derived from the same myeloma protein.

Amyloid↗

PubMed1990

Effects of sulfhydryl-modifying reagents, 3-nitro-2-pyridinesulfenyl compounds, on the coupling between inhibitory receptors and GTP-binding proteins Gi/Go in rat brain membranes.

To gain insight into the coupling mechanism of inhibitory receptors, 5-hydroxytryptamine1A receptors and alpha 2-adrenoceptors, with GTP-binding proteins (G proteins) in the central nervous system, we examined the effects of two 3-nitro-2-pyridinesulfenyl compounds, S-(3-nitro-2-pyridinesulfenyl)-L-cysteine [Cys(Npys)] and N-t-butoxy-carbonyl-S-(3-nitro-2-pyridinesulfenyl)-L-cysteine [Boc-Cys(Npys)], on 1) specific binding of [3H]8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (5-hydroxytryptamine1A agonist) and [3H]clonidine (alpha 2-agonist) to rat brain membranes, 2) [35S]guanosine 5'-O-(3-thio)triphosphate (GTP gamma S) binding, and 3) pertussis toxin (islet-activating protein) (IAP)-catalyzed ADP-ribosylation of purified Go (an IAP-sensitive G protein present in abundance in the mammalian brain). Treatment with Cys(Npys) led to decreased [3H]8-OH-DPAT and [3H]clonidine binding, similar to the inhibitory effects of IAP and N-ethylmaleimide (NEM) on such binding. However, further treatment of Cys(Npys)-pretreated membranes with dithiothreitol completely abolished the inhibitory effect of Cys(Npys) on the binding of both ligands. On the other hand, treatment with Boc-Cys(Npys) inhibited the effect of several GTP analogs (GTP gamma S, guanylyl-imidodiphosphate, guanylyl)-(beta, gamma-methylene)-diphosphate, and GTP) on [3H]8-OH-DPAT and [3H]clonidine binding. Dithiothreitol and mercaptoethanol treatment of Boc-Cys(Npys)-pretreated membranes did not lead to a recovery of the effect of GTP analogs on agonist binding. Regardless of the presence or absence of GTP gamma S, agonist binding to Boc-Cys(Npys)-pretreated membranes was decreased by further addition of NEM or Cys(Npys). Cys(Npys) blocked [35S]GTP gamma S binding as well as IAP-catalyzed ADP-ribosylation in purified Go. In contrast, Boc-Cys(Npys) partially inhibited ADP-ribosylation and did not affect [35S]GTP gamma S binding. These results suggested that Cys(Npys) modifies the receptor-coupling domain in G proteins, followed by the uncoupling of inhibitory receptors from G proteins, similar to the effects of NEM and IAP. Boc-Cys(Npys), however, seems to stabilize the coupling state between the receptors and G proteins, thus abolishing the GTP gamma S effect.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1990

[Plasma methotrexate concentrations in urothelial cancer chemotherapy].

The plasma methotrexate (MTX) concentration was measured during 50 courses of chemotherapy on 26 urothelial cancer patients. A dose of 300 mg/body MTX was infused within 2 hours and plasma concentrations were measured at the scheduled times. Plasma level at the end of infusion was (2.3 +/- 0.8) x 10(-5) M/L, (2.9 +/- 1.9) x 10(-5) M/L at the 6th-hour, and (1.9 +/- 1.8) x 10(-7) M/L at the 24th-hour after the infusion. The plasma MTX concentration values were inversely correlated with creatinin clearance. In 6 cases of Kock pouch bladder, clean intermittent self catheterization of urine caused no meaningful increase of MTX.

Adult↗

PubMed1990

Regulation of mast cell differentiation studied using the diffusion chamber technique.

A homogeneous population of mast cells was obtained by culturing bone marrow cells of WBB6F1(-)+/+ mice. The proliferation of the cultured mast cells in diffusion chambers was investigated to examine whether the diffusion chamber technique was applicable for study of the regulation of mast cell proliferation. WBB6F1-W/Wv mice are genetically deficient in mast cells. When cultured mast cells of WBB6F1(-)+/+ mouse origin were directly injected into the peritoneal cavity of WBB6F1-W/Wv mice, the mast cells survived. In contrast, WBB6F1(-)+/+ mouse-derived cultured mast cells did not survive in diffusion chambers implanted in the peritoneal cavity of either WBB6F1-W/Wv or WBB6F1(-)+/+ mice. Because the coinoculation of NIH/3T3 cells supported the proliferation of mast cells in diffusion chambers, a certain type of cells in the peritoneal cavity appeared to have the same mast cell-supporting activity as NIH/3T3 cells. The magnitude of either interleukin 3-dependent or NIH/3T3 cell-dependent proliferation of mast cells in diffusion chambers was not significantly influenced by the genotype of chambers recipients (i.e., WBB6F1(-)+/+ or WBB6F1-W/Wv mice), suggesting that the previously reported inhibitory effect of mast cells on differentiation of mast cells may be mediated by direct contact between mast cells.

Animals↗

PubMed1990

Differences in irradiation susceptibility and turnover between mucosal and connective tissue-type mast cells of mice.

Although precursors of mast cells are derived from the bone marrow, phenotypes of mast cells are influenced by the tissues in which final differentiation occurs. Connective tissue-type mast cells (CTMC) and mucosal mast cells (MMC) are different in morphological, biochemical, immunological, and functional criteria. The purpose of the present study was to obtain information about the differentiation process of MMC. First, we compared changes in irradiation susceptibility in mice during the differentiation process of CTMC and MMC. The decrease in irradiation susceptibility was remarkable in the CTMC differentiation process, but it was moderate in that of MMC. Some morphologically identifiable CTMC in the peritoneal cavity had proliferative potential and were highly radioresistant, whereas such a radioresistant population of MMC was not detectable in the gastric mucosa. Second, we estimated the turnover of CTMC and MMC by determining the proportion of mast cells that were labeled with continuously administered bromodeoxyuridine. The turnover of MMC was significantly faster than that of CTMC. The absence of the radioresistant mast cell population in the gastric mucosa appeared to be related to the short life span of MMC.

Animals↗

PubMed1989

Ligand-binding characteristics of [3H]QNB, [3H]prazosin, [3H]rauwolscine, [3H]TCP and [3H]nitrendipine to cerebral cortical and hippocampal membranes of senescence accelerated mouse.

The senescence accelerated mouse (SAM) is known as a murine model of aging and memory dysfunction. In the cerebral cortical membranes of male 9-month-old SAM mice, the Bmax values of [3H]rauwolscine and [3H]nitrendipine binding, and the values of both Kd and Bmax of [3H]TCP binding in the accelerated aging strain SAM-P/8, were significantly increased compared with the values in the control strain SAM-R/1. In hippocampal membranes, however, the Bmax values of [3H]quinuclidinyl benzilate and [3H]nitrendipine binding were significantly decreased in SAM-P/8 compared with those in SAM-R/1. These results suggest that muscarinic acetylcholine receptors, alpha 2-adrenoceptors, N-methyl-D-aspartate receptor channels and L-type Ca2+ channels are changed in cerebral cortex and hippocampus in SAM-P/8 at 9 months.

Aging↗

PubMed1989

Proliferative potential of degranulated murine peritoneal mast cells.

The fate of mast cells after degranulation was investigated. Purified peritoneal mast cells of WBB6F1-+/+ mice were sensitized with monoclonal anti-dinitrophenol (DNP) IgE antibodies and stimulated with DNP conjugated with human serum albumin. Mast cells were vitally stained with neutral red, and highly degranulated mast cells were identified under a phase-contrast microscope and individually picked up with the micromanipulator. When these highly degranulated mast cells were individually plated in methylcellulose, their potential to produce a cluster or a colony was comparable to that of morphologically intact mast cells. Moreover, when highly degranulated mast cells were injected into the skin of genetically mast cell-deficient WBB6F1-W/Wv mice, the proportion of injection sites at which mast cell clusters appeared was comparable to the value observed when morphologically intact mast cells were injected. The present result indicates that proliferative potential of mast cells is not reduced by their degranulation.

Animals↗

PubMed1989

Observations of some oxygen-containing and sulfur-containing organic molecules in cold dark clouds.

Observations of nine oxygen- and sulfur-containing organic molecules have been made toward the cold dark clouds TMC-1 and L134N. We have confirmed the presence of para-ketene (H2C2O) in TMC-1, have for the first time observed ortho-ketene, and find a total ketene column density approximately 1 x 10(13) cm-2. Thioformaldehyde (H2CS) is easily detectable in both TMC-1 and L134N, with a column density about 5 times larger in the former source (approximately 3 x 10(13) cm-2). The fractional abundance of ketene is comparable to the predictions of ion-molecule chemistry, while that of thioformaldehyde in TMC-1 is one to two orders of magnitude greater than that expected from such models at steady state. Interstellar sulfur chemistry thus continues to be poorly understood. We set upper limits for the column densities of formic acid (HCOOH), vinyl alcohol (CH2CHOH), methyl formate (HCO2CH3), formamide (NH2CHO), methyl mercaptan (CH3SH), isothiocyanic acid (HNCS), and thioketene (H2C2S) in both sources.

Astronomical Phenomena↗

PubMed1989

Kinetic study of the reaction of vitamin C with vitamin E radicals (tocopheroxyls) in solution.

New stable vitamin E radicals (7-tert-butyl-5-isopropyltocopheroxyl (4), 5,7-diisopropyltocopheroxyl (5), 7-tert-butyl-5-methyltocopheroxyl (6), and 5,7-diethyltocopheroxyl (7] with two bulky alkyl substituents at ortho positions (C-5 and C-7) have been prepared, and the reaction rates of vitamin C (ascorbic acid (1) and 6-O-stearyl ascorbic acid (2] with these tocopheroxyl radicals in benzene/ethanol/water (2:1:0.1, v/v) solution have been determined spectrophotometrically, using a stopped-flow technique. The second-order rate constants, k2, obtained vary in the order of 10(3), and decrease dramatically in the order 7 greater than 6 greater than 5 greater than 4, as the size of two ortho-alkyl groups in tocopheroxyl increases. The result suggests that the effect of steric hindrance on the reaction rate is considerable. These reaction rates were compared with those of vitamin C with alpha-tocopheroxyl reported by Packer et al. (Nature 278 (1979) 737-738) and Scarpa et al. (Biochim. Biophys. Acta 801 (1984) 215-219).

Ascorbic Acid↗

PubMed1989

Substance P induces granulocyte infiltration through degranulation of mast cells.

Substance P, a potent vasodilatory neuropeptide, is released from peripheral nerve endings of sensory neurons by various stimuli. Although in vitro incubation of rat and human mast cells with substance P causes their degranulation, it is not known whether inflammatory changes induced by substance P are mediated by degranulation of mast cells. We investigated this point by using genetically mast cell-deficient WBB6F1-W/Wv and WCB6F1-Sl/Sld mice. The s.c. injection of substance P induced degranulation of mast cells in the skin of WBB6F1-+/+ mice, and then a marked eosinophil infiltration around the degranulated mast cells. However, WBB6F1-W/Wv and WCB6F1-Sl/Sld mice showed little or no eosinophil infiltration in the skin after the injection of substance P. When the mast cell deficiency of WBB6F1-W/Wv mice was rescued either systemically by bone marrow transplantation or locally by injection of cultured mast cells, injection of substance P induced the infiltration of eosinophils, suggesting that substance P-induced eosinophil infiltration was mediated through degranulation of mast cells.

Animals↗