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Biomedical subjects

M Ishida

Publications and source records attributed to M Ishida.

At least 19 recordsLinked to original sources

Frequent loss of heterozygosity at the deleted in colorectal carcinoma gene locus and its association with histologic phenotypes in breast carcinoma.

Loss of heterozygosity (LOH) at the deleted in colorectal carcinoma gene (DCC), a tumour suppressor gene that encodes a protein with high homology to the neural cell adhesion molecule, was investigated in 42 surgical specimens of primary breast carcinoma. LOH was analysed in breast carcinoma by amplifying the DNA, spanning a variable number of tandem repeats site and a restriction fragment length polymorphism site within DCC, using the polymerase chain reaction (PCR). Cell sorting was used to enrich carcinoma cells. The expression of the DCC gene was also investigated using a reverse transcription-PCR method followed by Southern blot hybridization. LOH at the DCC locus was detected in 15 (51.7%) of 29 informative cases and 10 of 13 cases having DCC-LOH showed distinct reduction or loss of DCC expression. The DCC-LOH was closely associated with certain histological phenotypes: DCC-LOH was more frequent in scirrhous carcinomas than in solid-tubular ones (P < 0.05), and was also more frequent in carcinomas with infiltration into fat tissue over the mammary gland than in those without infiltration (P < 0.05). DCC-LOH was detected in invasive lobular carcinomas (2/2), but in none of the noninvasive ductal carcinomas (0/2). These observations suggest that malignant histological phenotypes are associated with DCC-LOH.

Alleles

Neurotoxicity of acromelic acid in cultured neurons from rat spinal cord.

Acromelic acid A, which contains the kainic acid structure in its molecule, is known to cause selective damage of interneurons in the rat lower spinal cord. In the present study, the potent neurotoxicity of acromelic acid A was demonstrated in cultured rat spinal neurons in terms of the activity of lactate dehydrogenase that was released from degenerated neurons into the culture medium. Acromelic acid A increased the lactate dehydrogenase activity in time- and concentration-dependent manners, and its EC50 was about 2.5 microM, which was much lower than that of kainic acid (70 microM) and (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (EC50; 11 microM). The maximum level of lactate dehydrogenase released by acromelic acid A was quite similar to that by kainic acid, but was about twice the level produced by (RS)-alpha-3-hydroxy-5-methyl-4-isoxazolepropionic acid. Exposure to acromelic acid A caused release of L-glutamate from the cells into the medium; however, the concentration of L-glutamate released was far below the level for inducing the neurotoxic effects. The neurotoxicity of 10 microM acromelic acid A was almost completely inhibited by 30 microM 6-nitro-7-sulphamoylbenzo(F)quinoxaline-2,3-dione and 6-cyano-7-nitroquinoxaline-2,3-dione, potent antagonists for non-N-methyl-D-aspartate receptors, but was partly (35%) reduced by 30 microM dizocilpine maleate. In cultured hippocampal neurons, the toxicity of acromelic acid A was significantly less effective (EC50: 18 microM) than that in spinal neurons, whereas the toxicity of kainic acid was almost the same in both neurons. These results suggest that acromelic acid A directly activates non-N-methyl-D-aspartate receptors on the cultured spinal neurons to induce neuronal death. A new type of non-N-methyl-D-aspartate receptors which is specific to acromelic acid A is suggested to be present at least in spinal neurons.

Amino Acids

Trazodone treatment increases plasma prolactin concentrations in depressed patients.

m-Chlorophenylpiperazine (m-CPP), which is a metabolite of trazodone, is a serotonin agonist. To examine for the possibility that m-CPP is involved in biochemical effects during treatment with the parent compound, prolactin response to trazodone treatment (150 mg at bedtime for 3 weeks) was studied in 12 depressed patients. The means +/- S.D. of plasma prolactin concentrations before treatment, 12 h, and 1, 2 and 3 weeks after initiation of treatment were 9.1 +/- 5.6, 14.7 +/- 9.1, 15.3 +/- 8.5, 13.2 +/- 7.0 and 13.0 +/- 7.0 ng/ml, respectively. The mean prolactin concentrations at 12 h (p < 0.01), 1 week (p < 0.001) and 2 weeks (p < 0.05) were significantly higher than that before treatment. The present study thus shows that trazodone treatment increases prolactin concentrations, suggesting that m-CPP is involved in biochemical effects during treatment with the parent compound.

Adult

Inhibition of trazodone metabolism by thioridazine in humans.

To clarify the involvement of cytochrome P4502D6 (CYP2D6) in the metabolism of trazodone, the effects of coadministration of thioridazine, which is an inhibitor of this isozyme, on plasma concentrations of trazodone and its active metabolite m-chlorophenylpiperazine (m-CPP) were studied. The subjects were 11 depressed patients receiving trazodone at bedtime for 1-18 weeks. The dose was 150 mg in 10 patients and 300 mg in one. Thioridazine 40 mg/day was coadministered for 1 week, and blood samplings were performed before and after the coadministration. Thioridazine significantly (p < 0.001) increased plasma concentrations of both trazodone (713 +/- 252 vs. 969 +/- 370 ng/ml) and m-CPP (61 +/- 22 vs. 94 +/- 34 ng/ml). The present study thus suggests that CYP2D6 is involved in the metabolism of trazodone.

Adult

Genetic analysis of porcine H3N2 viruses originating in southern China.

From immunological and phylogenetic analyses of H3 influenza viruses isolated from pigs and ducks in the People's Republic of China (China), Hong Kong, Taiwan and Japan, between 1968 and 1982, we arrived at the following conclusions. The H3 haemagglutinin and N2 neuraminidase genes from swine isolates can be segregated into four mammalian lineages, including: (i) the earliest human strains; (ii) early swine strains including Hong Kong isolates from 1976-1977; (iii) an intermediate strain between the early swine and recent human strains; and (iv) recent human strains. In this study we found an unusual swine strain (sw/Hong Kong/127/82) belonging to the third lineage which behaved like those of the early swine-like lineage in the haemagglutination inhibition test; but neuraminidase inhibition profiles with monoclonal antibodies indicated that this virus is related to late human strains. On the basis of pairwise comparisons of complete or partial nucleotide sequences the genes encoding the three polymerase proteins (PB2, PB1, PA), the nucleoprotein, the membrane protein and possibly the nonstructural proteins of sw/Hong Kong/127/82 are of the swine H1N1 lineage, whereas genes encoding the two surface glycoproteins belong to the human H3N2 lineage. In contrast, all RNA segments of one swine isolate (sw/Hong Kong/81/78) are similar to those of recent human H3N2 viruses. This study indicated that frequent interspecies infections between human and swine hosts appeared to occur during 1976-82. Although the evolutionary rates of human (0.0122/site/year), swine (0.0127/site/year) and avian (0.0193/site/year) virus genes are similar when based upon synonymous substitutions, nonsynonymous substitutions indicated that viral genes derived from human and swine viruses evolved about three times faster (0.0026-0.0027/site/year) than those of avian viruses (0.0008/site/year). Furthermore, the evolutionary mechanism by which human and swine H3 haemagglutinin genes evolve at a similar rate, based on nonsynonymous substitutions, appeared to be quite different from previous evidence which showed that human H1 haemagglutinin genes evolved three times faster than those of swine viruses. However, comparison of the number of nonsynonymous substitutions in the antigenic sites (A-E) of haemagglutinin molecules demonstrated that swine viruses evolve at a rate that is about one fifth to one tenth that of human viruses, reflecting the conservative nature of the antigenic structure in the former.

Amino Acid Sequence

Antigenic and genetic characteristics of H1N1 human influenza virus isolated from pigs in Japan.

Two strains of influenza A virus were isolated from pigs in northern Japan in 1992. Serological tests showed that the haemagglutinin (HA) and neuraminidase (NA) antigens were more closely related to those of recent human H1N1 viruses than to those of swine H1N1 viruses. The HA and NA genes of isolate A/sw/Obihiro/5/92 were shown to be closely related to those of current human H1N1 viruses. Evolutionary trees constructed from nucleotide sequences showed that the HA and NA genes of A/sw/Obihiro/5/92 were apparently on a branch cluster containing human strains isolated between 1990 and 1992.

Animals

High-performance liquid chromatographic determination of trazodone and 1-m-chlorophenylpiperazine with ultraviolet and electrochemical detector.

A high-performance liquid chromatographic (HPLC) assay was developed for the determination of trazodone and its metabolite, 1-m-chlorophenylpiperazine (m-CPP), in plasma. The high level of trazodone in plasma was detected by ultraviolet absorbance at 254 nm and the low level of m-CPP in plasma was detected by coulometric electrochemical detection at 840 mV on the series arrangement of two detectors. Pilsicainide as an internal standard for both compounds was monitored by both detectors. Trazodone and m-CPP in plasma were extracted by a rapid and simple procedure based on CN bonded-phase extraction, and C8 reversed-phase HPLC separation. Determination was possible for trazodone in the concentration range 100-2000 ng mL-1 and for m-CPP in the concentration range 5-100 ng mL-1. The recoveries of trazodone and m-CPP added to plasma were 81.0-84.2 and 68.0-73.2%, respectively, with coefficients of variation of less than 7.3 and 8.2%, respectively. The method is applicable to high level monitoring of trazodone and low level monitoring of m-CPP in plasma of healthy volunteers and patients treated with trazodone.

Chromatography, High Pressure Liquid

Dietary salt decreases cytosolic calcium in platelets from Dahl salt-sensitive rats.

To determine whether abnormal cellular Ca2+ handling is involved in salt-induced hypertension of Dahl salt-sensitive rats (DS), we investigated Ca2+ handling in fura 2-loaded platelets of DS and Dahl salt-resistant rats (DR) fed a high-NaCl (8%) or a low-NacL (0.3%) diet for 4 wk from 5 wk of age. At 5 wk of age, blood pressure, resting cytosolic Ca2+ concentration ([Ca2+]i), the thrombin-evoked increase in [Ca2+]i and the size of internal Ca2+ stores of DS were comparable with those of DR. After 4 wk on the diets, resting [Ca2+]i of DS on high-NaCl diet was lower than that of DS on low-NaCl diet, and there was no effect of high salt intake on resting [Ca2+]i in DR. In DS, high salt intake attenuated the [Ca2+]i response to thrombin in the presence of external Ca2+. In contrast, the [Ca2+]i response to thrombin in the absence of external Ca2+ was enhanced by high salt intake in DS. The size of internal Ca2+ stores was increased by high salt intake in DS but not in DR. These data suggest that it is not obligatory for hypertension to be accompanied by an increase in platelet [Ca2+]i.

Animals

Angiotensin II activates pp60c-src in vascular smooth muscle cells.

The angiotensin II type-1 (AT1) receptor, a G protein-coupled receptor, lacks intrinsic kinase activity. However, recent data show that angiotensin II (Ang II) stimulates tyrosine phosphorylation of phospholipase C-gamma 1 (PLC-gamma 1), Stat91 (one of the signal transducers and activators of transcription), and paxillin in vascular smooth muscle cells. The tyrosine kinases responsible for these phosphorylation events are unknown. Src family kinases have been shown to phosphorylate PLC-gamma 1 and to be activated by G protein-coupled receptors. We hypothesized that pp60c-src associates with the AT1 receptor and is activated after Ang II stimulation of smooth muscle cells. We immunoprecipitated pp60c-src from Ang II-stimulated vascular smooth muscle cells and measured pp60c-src activity by autophosphorylation and by phosphorylation of enolase. Both assays demonstrated an approximately threefold increase in pp60c-src activity within 1 minute. A similar increase in Ang II-stimulated pp60c-src activity was observed in Chinese hamster ovary cells transfected with the AT1 receptor but not in untransfected cells. These data are the first to show that pp60c-src is activated by Ang II. To determine if pp60c-src associated with the AT1 receptor, the AT1 receptor was immunoprecipitated (with two different antibodies), and Western blots were performed with two different anti-pp60c-src antibodies. No pp60c-src was detected. In addition, direct interaction between the AT1 receptor and pp60c-src could not be demonstrated by using a glutathione S-transferase (GST)-AT1 fusion protein to bind proteins from cell lysates stimulated by Ang II.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II

The pegs on the decorated tubules of the contractile vacuole complex of Paramecium are proton pumps.

Our previous study has shown that the decorated tubules (collectively known as the decorated spongiome) of the contractile vacuole complex (CVC) in Paramecium are the site of fluid segregation, as the binding of microinjected monoclonal antibody (mAb) DS-1 to the tubules reduced the CVC's fluid output. In this study, we showed by immunogold labeling on cryosections that the antigenic sites for mAb DS-1 were located on the 15 nm 'pegs' protruding from the cytosolic surface of the decorated tubules. In immunofluorescence studies, both polyclonal antibodies against the subunits of the V-ATPase of Dictyostelium discoideum and against the 57 kDa B-subunit of the V-ATPase of chromaffin granules gave identical labeling patterns to that produced by mAb DS-1. On cryosections, all three antigens were located most consistently near or on the pegs of the decorated tubules. These data support the notion that the pegs on the membrane of the decorated tubules represent the V1 complex of a proton pump. Concanamycin B, a potent inhibitor of V-ATPase activity and of acidification of lysosomes and endosomes, strongly and reversibly inhibited fluid output from the CVC but had minimal effect on the integrity of the decorated spongiome as observed by immunofluorescence. Such inhibition suggests that a V-ATPase is intimately involved in fluid segregation. Exposing Paramecium to 12 degrees C or 1 degrees C for 30 minutes resulted in the dissociation of the decorated tubules from the smooth spongiome that borders the collecting canals; thus the DS-1-reactive A4 antigen, the 75 kDa and 66 kDa antigens were all found dispersed in the cytosol.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Rapid bulk replacement of acceptor membrane by donor membrane during phagosome to phagoacidosome transformation in Paramecium.

The extent to which a donor membrane will be retrieved, or if it is retrieved at all after it fuses with an acceptor membrane, is usually difficult to determine. We have studied the dynamics of membrane retrieval in the phagosome system of Paramecium multimicronucleatum using six monoclonal antibody markers. Our previous freeze-fracture and transmission electron microscopic studies have indicated that extensive changes take place in the membrane of the young phagosome as it progresses through its cycle. Using immunofluorescence and immunoelectron microscopy to determine the times of entry and exit of these individual antigens into the digestive vacuole system, we showed that two hydrophilic antigens, one located on the cytosolic and one on the lumenal side of the discoidal membrane (phagosome membrane precursor), were completely retrieved from the phagosome by tubulation within the first three minutes. At the same time that this membrane was retrieved, membrane from a second population of vesicles, the acidosomes, fused with the phagosome to produce the phagoacidosome. On the basis of immunogold localization on cryosections of a total of six antigens, the two specific for phagosome/discoidal vesicle membrane as well as four specific for the acidosome/phagoacidosome membrane, this replacement is total. We also showed that in the presence of the actin-active drug cytochalasin B, this replacement was essentially prevented. However, when vacuole acidification was neutralized by ammonium chloride, this replacement process continued unaffected after a lag. Consequently, acidification, per se, is not required to trigger the replacement of the phagosome membrane. We conclude, on the basis of these studies as well as our previous freeze-fracture studies that during phagoacidosome formation most of the acceptor membrane is retrieved and is replaced by the donor membrane. This shows that at least one cell type possesses the mechanisms needed to substantially replace the membrane of a phagosomal compartment when radical and rapid changes are needed to modulate the digestive and absorptive processes.

Ammonium Chloride

Two kinds of neutral serine proteinases in salted muscle of anchovy, Engraulis japonica.

Two kinds of proteinases, type-I and type-II, were purified or partially purified from salted muscle of anchovy, Engraulis japonica. Mol. wts. of type-I and type-II proteinases were estimated to 25,000 and 37,000, respectively, on electrophoretic analysis. Both proteinases strongly hydrolyzed synthetic tri or tetrapeptide substrates specific to trypsin, alpha-thrombin, and an activated protein C, while they hardly hydrolyzed Arg-MCA and benzoyl Arg-MCA derivatives. The proteinases were inhibited by common trypsin inhibitors. Optimal pH for the proteinase activities were pH 6.8 (type-I) and pH 7.0 to 7.5 (type-II), and the proteinases showed the highest activities at 45 degrees C (type-I) and 50 degrees C (type-II). The N-terminal amino acid sequence of type-I proteinase, 1I-2V-3G-4G ... (29 residues were identified), was significantly similar to sequences of trypsins and tryptases. Based on these findings, both proteinases were presumed to be kinds of tryptases in E. japonica muscle.

Amino Acid Sequence

Intraplatelet free calcium concentrations and alcohol-related blood pressure elevation in a middle-aged male population.

Elevated intracellular free calcium (Ca2+) has been proposed as a mechanism of alcohol-induced hypertension from animal experimental studies, but this has not been confirmed in man. In the present study, intraplatelet Ca2+ concentration (plt.[Ca2+]i) was measured in 83 middle-aged men, and the associations between alcohol consumption, age, body mass index (BMI), hematological and serum biochemical variables, plt.[Ca2+]i and blood pressure were analyzed. Plt.[Ca2+]i did not show a significant univariate correlation with alcohol consumption or with blood pressure, but did so with serum gamma-glutamyl transpeptidase (gamma-GTP) levels. Age, BMI and serum gamma-GTP were selected as independent contributors to blood pressure, and gamma-GTP alone was selected as the determinant of plt.[Ca2+]i by multiple regression analyses. The association between gamma-GTP and plt.[Ca2+]i was shown to be common or at least very similar in both drinkers and nondrinkers by generalized linear model analysis. Therefore, chronic alcohol consumption in humans may relate to elevations of plt.[Ca2+]i, not mainly by the direct action of alcohol but by some metabolic alterations after alcohol consumption. The significance of elevated plt.[Ca2+]i in drinkers in the development of hypertension, however, remains obscure.

Adult

Serum levels of six pancreatic enzymes as related to the degree of renal dysfunction.

OBJECTIVES: Currently, serum total amylase, pancreatic isoamylase (P-amylase), lipase, trypsin(ogen), phospholipase A2 (PLA2), and elastase I are advocated to be useful in diagnosing pancreatic diseases. However, the most useful among the above six enzymes in patients with impaired renal function has not been fully clarified. We, therefore, studied the relation of the serum levels of the above enzymes and creatinine clearance (CrCl) in normal controls and patients with chronic renal insufficiency or failure. METHODS: PLA2 and elastase I were assayed by RIA, trypsin(ogen) by EIA and others by activity. Subjects were 24 healthy controls and 47 patients with impaired renal function and no apparent pancreatic diseases. RESULTS: 1) Elastase I was significantly elevated only in patients with a CrCl of 10 ml/min or less, whereas others were elevated already in patients with a CrCl below 40 ml/min; 2) in 12 patients with a CrCl between 13 and 39 ml/min, lipase tended to be less frequently raised than others, except elastase I, although the difference was statistically insignificant; 3) in 28 patients with a CrCl between 40 and 74 ml/min, lipase was less frequently elevated than others, except elastase I and PLA2; 4) in seven patients with a CrCl of 10 ml/min or below, elastase I tended to be less frequently elevated than others, although the difference was statistically insignificant; and 5) the degree of elevation was within 2.5 times the upper limits of reference values in all enzymes, except trypsin(ogen) (within 4.8 times). CONCLUSIONS: Elastase I was least vulnerable to impaired renal function followed by lipase. We, therefore, recommend combined assays of elastase I and lipase for detecting pancreatic diseases in patients with renal insufficiency. When cut-off levels are set at 2.5 times the upper limit of reference values, P-amylase or PLA2 can replace lipase.

Aged

[Characterization of peripheral blood natural killer (NK) cells in two patients with CD16+ CD56- NK cell-lineage granular lymphocyte-proliferative disorder].

In normal peripheral blood natural killer (NK) cells, the subset of CD16+ CD56+ cells is predominant, and that of CD16+ CD56- cells is rarely present. Because we have found the expansion of CD16+ CD56- NK cells in the peripheral blood of two patients with NK cell-lineage granular lymphocyte-proliferative disorders (NK-GLPD), the clinical findings and cellular characteristics of these patients were compared with those of CD16+ CD56+ NK-GLPD patients. Although CD16+ CD56- and CD16+ CD56+ NK-GLPD cells were morphologically different, clinical findings and courses, and NK activity did not differ significantly. Because strong NK activity was demonstrated in CD16+ CD56- NK-GLPD cells, the CD56 antigen, one of the adhesion molecules, did not seem to play a major role in NK cell-mediated cytotoxicity. The CD56 antigen is known to be more strongly expressed by immature NK cells than by mature NK cells. However, because interleukin 2-activated CD16+ CD56- NK-GLPD cells rapidly expressed the CD56 antigen, the degree of CD56 antigen expression did not always correlate with the maturity of NK cells.

Aged

[Progressive pulmonary fibrosis in a case of Sjögren's syndrome with asbestos exposure].

A 62-year-old man had an occupational history of exposure to asbestos for 27 years (1947-1974). Dry mouth, dry eyes and swollen gums were noted in 1974. Sjögren's syndrome was diagnosed in 1975. The chest radiograph in 1984 showed bilateral pleural thickening and small reticular opacities in the left lower lung field. In 1990, he complained of dyspnea and cough, and diffuse interstitial pneumonia was diagnosed. While being treated for diffuse interstitial pneumonia, pulmonary fibrosis progressed rapidly, and advanced pulmonary fibrosis was obvious in 1992. Laboratory data showed hyper gamma-globulinemia (36.8%) and a high level of IgG (3772 mg/dl) in 1976. These values decreased to within the normal ranges during the subsequent clinical course. The results of lymphocyte subset counts in 1988 were normal. With the progression of diffuse interstitial pneumonia in 1990, the lymphocyte subset counts showed a low percentage of CD4 (19.2%), a low CD4/8 ratio (0.46), and a low percentage of CD20 (26.8%). In 1992, as pulmonary fibrosis progressed despite treatment, the disorder of lymphocyte subsets became worse. The CD4 percentage was very low (5.0%), as was the CD4/8 ratio (0.08), and the percentage of CD20 (1.4%); the CD8 percentage was high (64.7%), as was the percentage of Leu 7 (49.0%). These immunologic and pulmonary changes could be not explained by Sjögren's syndrome. Determining what factor induced these changes is difficult, but asbestos exposure is a likely cause.

Asbestos