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Y Minami

Publications and source records attributed to Y Minami.

At least 163 records · Page 9Linked to original sources
PubMed1994

Projections of nitric oxide synthase-containing fibers from the sphenopalatine ganglion to cerebral arteries in the rat.

The origin and distribution of cerebral perivascular nerves containing nitric oxide, a short-acting messenger or neurotransmitter, have been studied in the rat by histochemistry for reduced nicotinamide adenine dinucleotide phosphate-diaphorase activity, a specific marker for neuronal nitric oxide synthase. Positively stained nerve fibers were distributed throughout the major vessels of the cerebral arteries, though the fiber density was higher in the anterior circulation, including the circle of Willis, than in the posterior arteries. Examination using axonal transport methods indicated that nitric oxide-containing neurons in the sphenopalatine ganglion innervate the cerebral arteries bilaterally. Nitric oxide synthase in these ganglionic cells often co-existed with vasoactive intestinal polypeptide. The anatomical information obtained is discussed in terms of non-adrenergic, non-cholinergic neuronal transmission in the cerebral arteries.

Acetylcholine↗
PubMed1994

Increased processing of lymphocyte function-associated antigen-1 in human natural killer cells stimulated with IL-2.

Previously we reported that surface expression of lymphocyte function-associated antigen-1 (LFA-1), the primary leukocyte integrin on human natural killer (NK) and lymphokine-activated killer (LAK) cells, does not differ between NK and LAK cells. In contrast to surface expression, we now report that much higher levels of both precursor and mature forms of LFA-1 molecules were found relative to MHC class I, another membrane glycoprotein, with metabolic labeling of IL-2-stimulated LAK cells compared with native NK cells. An 85-90 kDa glycoprotein, found in much higher quantities in LAK compared with NK cells, appeared to be a precursor of the 95 kDa beta chain of the beta 2 integrin family in human LAK cells because: (i) pulse-chase experiments using LAK cells demonstrated decreased 35S-labeling of the 85-90 kDa molecule with a concomitant increase in the radioactivity of the mature 95 kDa LFA-1 beta chain, (ii) results of protease treatment revealed that the two molecules share virtually identical peptide maps, and (iii) endoglycosaminidase F treatment of LAK cell lysates immunoprecipitated with antibody against LFA-1 beta resulted in the disappearance of both the 85-90 and 96 kDa LFA-1 beta signals, and appearance of a signal at approximately 76 kDa. Digestion of the same immunoprecipitates with neuraminidase resulted in the disappearance of the 95 kDa signal and revealed a single molecular weight signal corresponding to 85-90 kDa. These data suggest that a core protein of approximately 76 kDa becomes N-glycosylated, perhaps terminally with sialic acid residues, to mature into the 95 kDa form. Moreover, the rate of maturation of LFA-1 was more rapid in LAK than NK cells, with half times of 0.8 versus 1.5 h for the alpha chain and 3.7 versus 4.9 h for the beta chain for LAK versus NK cells respectively. IL-2 treatment of NK cells therefore alters the processing of LFA-1 molecules during the transition to LAK cells, providing a larger intracellular reservoir with which to replenish the surface molecule. Together with our previous observation that LFA-1 is phosphorylated and transduces signal more effectively in LAK than NK cells, the findings support the notion that adhesion molecules contribute to the increased function of LAK cells.

Cells, Cultured↗
PubMed1994

The predictive power of self-rated health, activities of daily living, and ambulatory activity for cause-specific mortality among the elderly: a three-year follow-up in urban Japan.

OBJECTIVE: To examine the predictive power of self-rated health, activities of daily living (ADL), and ambulatory activity for different causes of death in a representative sample of older persons. DESIGN: Three-year prospective cohort study. SETTING: Sendai City, Japan. PARTICIPANTS: 2,552 persons 65 years and older at baseline in 1988. MEASUREMENTS: Independent variables (measured by self-report of participants) were age, sex, self-rated health, ADL, ambulatory activity level, and use of medical care. Dependent variables were mortalities from cancer, stroke, and heart disease. MAIN RESULTS: Self-rated health significantly predicted cancer mortality but not the other two causes of mortality. ADL disability was a significant predictor for stroke mortality, and limitation in ambulatory activity significantly increased the risk of heart disease mortality. The associations between ADL and stroke mortality as well as between ambulatory activity and heart disease mortality remained significant even after excluding those who reported having the index disease in 1988. CONCLUSION: The predictive powers of self-rated health, ADL function, and ambulatory activity varied significantly with the underlying causes of death among the elderly.

Activities of Daily Living↗
PubMed1994

The carboxy-terminal region of mammalian HSP90 is required for its dimerization and function in vivo.

The majority of mouse HSP90 exists as alpha-alpha and beta-beta homodimers. Truncation of the 15-kDa carboxy-terminal region of mouse HSP90 by digestion with the Ca(2+)-dependent protease m-calpain caused dissociation of the dimer. When expressed in a reticulocyte lysate, the full-length human HSP90 alpha formed a dimeric form. A plasmid harboring human HSP90 alpha cDNA was constructed so that the carboxy-terminal 49 amino acid residues were removed when translated in vitro. This carboxy-terminally truncated human HSP90 alpha was found to exist as a monomer. In contrast, loss of the 118 amino acid residues from the amino terminus of human HSP90 alpha did not affect its in vitro dimerization. Introduction of an expression plasmid harboring the full-length human HSP90 alpha complements the lethality caused by the double mutations of two HSP90-related genes, hsp82 and hsc82, in a haploid strain of Saccharomyces cerevisiae. The carboxy-terminally truncated human HSP90 alpha neither formed dimers in yeast cells nor rescued the lethal double mutant.

Amino Acid Sequence↗
PubMed1994

Evidence for a critical role for the cytoplasmic region of the interleukin 2 (IL-2) receptor gamma chain in IL-2, IL-4, and IL-7 signalling.

The high-affinity interleukin 2 receptor (IL-2R) consists of at least three distinct subunits: the IL-2R alpha chain (IL-2R alpha), beta chain (IL-2R beta), and gamma chain (IL-2R gamma). It has been shown that the cytoplasmic region of IL-2R beta, but not of IL-2R alpha, is essential for IL-2 signalling to the cell interior. In the present study, we examined the functional role of the IL-2R gamma cytoplasmic region in the IL-3-dependent mouse hematopoietic cell line BAF-B03, which expresses the endogenous IL-2R alpha and IL-2R gamma, or its subline F7, which additionally expresses human IL-2R beta cDNA. We show that overexpression of a mutant IL-2R gamma, lacking all but 7 amino acids of its cytoplasmic region, results in the selective inhibition of IL-2-induced c-fos gene activation and cellular proliferation in F7 cells. When two chimeric receptor molecules in which the cytoplasmic regions of IL-2R beta and IL-2R gamma had been swapped with each other (IL-2R beta/gamma and IL-2R gamma/beta) were coexpressed in BAF-B03, the cells responded to IL-2. These results indicate the critical importance of the IL-2-induced functional cooperation of the two cytoplasmic regions. Finally, we provide evidence that the IL-2R gamma cytoplasmic region is also critical for the IL-4 and IL-7-induced growth signal transduction in BAF-B03.

Animals↗
PubMed1994

[Changes in physical disability among Japanese elderly].

In order to investigate the natural course of physical disability among the elderly, the ability to perform activities of daily living (ADL) was examined on a probability sample (N = 3384) of residents aged 65 years and over in Sendai City, Japan, in 1988 and 1991. Information on ability to perform four ADL tasks-dressing, eating, using the toilet, and bathing-were collected by self-report. In 1988, 7.2% of the males and 7.9% of the females reported at least one ADL dependency. The prevalence of disability was the highest in bathing, followed by dressing, using the toilet, and the lowest in eating. The Cox proportional hazard models on three-year mortality indicated that those who were ADL dependent at baseline had 4.1 times the mortality risk of those who were ADL independent. Among those who were ADL independent in 1988 and who were alive in 1991, 5.0% of the males and 4.8% of the females became dependent in at least one ADL task in 1991. The incidence of disability was the highest in bathing, followed by dressing, using the toilet, and the lowest in eating. Among those who were ADL dependent in 1988 and who were alive in 1991, about one-third of them improved in ADL functioning. Improvement was more common among those who were younger in age. These results suggest that levels of ADL functioning is highly dynamic, and that physical disability is, to a certain extent, reversible among the elderly.

Activities of Daily Living↗
PubMed1993

Cloning and sequencing of the cDNA encoding a mouse IL-2 receptor gamma.

A mouse cDNA encoding an interleukin-2 receptor gamma (mIL-2R gamma) was cloned. The primary amino acid sequence deduced from the nucleotide sequence exhibits 70% overall similarity with human IL-2R gamma and, in particular, the predicted cytoplasmic region shows a higher degree of similarity (about 84.7%).

Amino Acid Sequence↗
PubMed1993

Significance of the amino terminus of rat testis fructose-6-phosphate, 2-kinase:fructose-2,6-bisphosphatase.

In order to assess the functional properties of the extreme amino-terminal peptide of rat testis fructose-6-phosphate,2-kinase: fructose-2,6-bisphosphatase, 24 and 30 amino acids from the NH2 terminus were deleted using oligonucleotide-directed mutagenesis. The expressed wild-type (WT) and the mutant (Del 24 and Del 30) enzymes were purified to homogeneity. These enzymes were homodimers of subunit M(r) values 54,000, 51,300, and 50,600. Deletion of 1-24 and 1-30 residues resulted in over 70% loss of Fru-6-P,2-kinase activity and 2-fold increase in Fru-2,6-bisphosphatase. KmFru-6-P increased 7.5-fold, but there was no significant change in KmFru-2,6P2 of the phosphatase. These mutant enzymes were more susceptible to protein concentration-dependent dissociation and thermal inactivation. In 2 M urea the kinase and the phosphatase activities of WT increased 17 and 56%, respectively, but no activation of any of the mutant enzymes was observed. At higher urea concentrations, all the enzymes were inactivated. Unfolding in urea, followed with intrinsic tryptophan fluorescence, showed that the unfolding proceeded in at least two stages. Fluorescence intensity at 338 nm of all these enzymes decreased below 2 M urea in which the enzyme activities remained the same (Del 24) or activated (WT). The second stage of unfolding was seen as the maximum shifted to 342 nm in 2-4 M urea, presumably involving dissociation. Complete unfolding above 4 M urea resulted in further shift in fluorescence maximum to 350 nm.

Amino Acid Sequence↗
PubMed1993

Crystallization and preliminary X-ray diffraction studies of C-1027-AG, the apoprotein of the macromolecular antitumor antibiotic C-1027 from Streptomyces globisporus.

C-1027-AG, the apoprotein of the macromolecular antitumor antibiotic C- 1027, isolated from Streptomyces globisporus, was crystallized by the vapor-diffusion procedure using 2-methyl-2,4-pentanediol as a precipitant. The crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit-cell dimensions a = 55.1, b = 61.3 and c = 79.1 A. Assuming that the asymmetric unit contains two or three molecules, the V(m) value is calculated as 3.2 or 2.1 A(3) Da(-1), respectively. A total of 7630 independent reflections was obtained up to 2.5 A resolution with synchrotron radiation, the merging R factor being 0.077 for 24 713 measurements.

Journal Article↗
PubMed1993

The calmodulin-binding domain of the mouse 90-kDa heat shock protein.

The mouse 90-kDa heat shock protein (HSP90) and Ca(2+)-calmodulin were cross-linked at an equimolar ratio using a carbodiimide zero-length cross-linker. To identify the calmodulin-binding domain(s) of HSP90, CNBr-cleaved peptide fragments of HSP90 were mixed with Ca(2+)-calmodulin and cross-linked. Amino acid sequence determination revealed that an HSP90 alpha-derived peptide starting at the 486th amino acid residue was contained in the cross-linked products, which contains a calmodulin-binding motif (from Lys500 to Ile520). A similar motif is present also in HSP90 beta (from Lys491 to Val511). The synthetic peptides corresponding to these putative calmodulin-binding sequences were found to be cross-linked with Ca(2+)-calmodulin and to prevent the cross-linking of HSP90 and Ca(2+)-calmodulin. Both HSP90 alpha and HSP90 beta bind Ca2+. The HSP90 peptides bind HSP90 and thereby inhibit the binding of Ca2+. In addition, the HSP90 peptides augment the self-oligomerization of HSP90 induced at elevated temperatures. These results suggest that the calmodulin-binding domain of HSP90 might interact with another part of the same molecule and that Ca(2+)-calmodulin might modulate the structure and function of HSP90 through abolishing the intramolecular interaction.

Amino Acid Sequence↗
PubMed1993

Functional coupling of the src-family protein tyrosine kinases p59fyn and p53/56lyn with the interleukin 2 receptor: implications for redundancy and pleiotropism in cytokine signal transduction.

The binding of interleukin 2 (IL-2) to the IL-2 receptor (IL-2R) induces a rapid increase in tyrosine phosphorylation of cellular proteins. In a previous study, we have shown that p56lck (lck), a src-family protein tyrosine kinase (src-PTK), physically and functionally associates with the IL-2R beta chain (IL-2R beta). To further investigate a role of src-PTKs in IL-2 signaling, we analyzed a mouse pro-B-cell line, in which lck is not expressed detectably. We observed that in this cell line, IL-2 induces activation of at least two src-PTKs, p59fyn (fyn) and p53/56lyn (lyn). Interestingly, stimulation of this cell line with IL-3 also induces activation of src-PTKs. The activation of fyn or lyn seems to be selective for stimulation with IL-2 or IL-3 since stimulation with IL-6 fails to activate them. Furthermore, we provide evidence for the physical association of fyn with IL-2R beta. Taken together with previous results, our current study suggests that different src-PTKs, each of which is expressed in a cell-type-specific manner, can participate in the IL-2 signal transduction.

Animals↗
PubMed1993

Biased usage of two restricted VH gene segments in VH replacement.

AT8-1-12-5, an intracytoplasmic gamma 2b-producing (mu- gamma 2b+) pre-B cell line transformed with Abelson murine leukemia virus continuously generated intracytoplasmic mu, gamma 2b-producing (mu+ gamma 2b+) cells during propagation in culture. Southern blotting, DNA cloning and sequence analysis showed that these mu+ gamma 2b+ cells were generated from the mu- gamma 2b+ pre-B cells by VH replacement events. The gene segments involved in these replacement events were restricted to only two VH gene segments, VH7.1 (VH7183 family) and VH6.2 (VHQ52 family). Cell staining using the monoclonal anti-VH141 antibody 3-5-6f that specifically recognized the VH6.2 but not VH7.1 gene products indicated that half of the VH replacement events occurring in AT8-1-12-5 used the VH6.2 gene segment. Deletion mapping indicated that the incoming VH gene segments, VH7.1 and VH6.2 were proximal to the resident VH gene segment, VH12.5 (VH7183 family). These results provided direct evidence of the biased usage of VH gene segments in VH replacement and have several implications for the mechanisms of VH replacement.

Amino Acid Sequence↗
PubMed1993

Association of p56lck with IL-2 receptor beta chain is critical for the IL-2-induced activation of p56lck.

Previous studies demonstrate that p56lck, a member of the src-family of protein tyrosine kinases (PTKs), can physically associate with the interleukin-2 (IL-2) receptor beta chain (IL-2R beta) and that IL-2 receptor engagement stimulates p56lck activity. To examine the mechanisms underlying p56lck PTK activation by IL-2, we established a mouse pro-B cell line, BAF-B03, expressing both IL-2R beta (either the wild-type or mutant forms) and mouse p56lck at high levels. BAF-B03 cells expressing a mutant IL-2R beta chain lacking an 'acidic' region of the cytoplasmic domain, previously shown to be essential for association with p56lck, fail to induce p56lck PTK activation upon IL-2 stimulation. This suggests that the association of p56lck with the IL-2R beta chain, despite its low stoichiometry, is required for the activation of cellular p56lck PTK upon IL-2 stimulation. Intriguingly, BAF-B03 cells expressing an IL-2R beta chain which lacks a different cytoplasmic region, the 'serine-rich' region, also fail to activate p56lck in response to IL-2. Hence, physical association of p56lck with the IL-2R beta chain is not by itself sufficient to permit IL-2-mediated regulation of this PTK. Additional experiments suggest that one result of PTK activation is the accumulation of c-fos and c-jun transcripts.

Animals↗
PubMed1993

Beta-microseminoprotein immunoreactivity as a new prognostic indicator of prostatic carcinoma.

Human beta-microseminoprotein (beta-MSP), isolated from seminal plasma, is one of the proteins secreted by the prostate gland. To determine whether the beta-MSP immunoreactivity can be a prognostic indicator of prostatic carcinoma, the beta-MSP immunohistochemical distribution has been examined in needle biopsy specimens taken from 96 patients with prostatic carcinoma. Although no significant correlation was found between the beta-MSP immunoreactivity and the histological grade (Gleason score), patients with a positive beta-MSP expression had a significantly better prognosis than those with a negative beta-MSP expression (P = 0.01). Further, a multivariate analysis of six possible parameters (age, clinical stage, histological grade, serum prostatic acid phosphatase, beta-MSP immunoreactivity, and the type of initial treatment) has shown the difference in the beta-MSP immunoreactivity to be a significant, independent, prognostic indicator of prostatic carcinoma (P = 0.04).

Aged↗
PubMed1993

The interleukin-2 receptor complex and signal transduction: role of the beta-chain.

Proliferation of lymphocytes is regulated by a variety of cytokines, among which interleukin-2 (IL-2) is well characterized for its potent ability to promote cell growth. The IL-2 signal(s) is transmitted to the cell interior via its homologous receptor (IL-2R). The functional high affinity IL-2R is a multichain complex consisting of at least three distinct components, IL-2R alpha, beta and gamma. None of these components possess an intrinsic protein tyrosine kinase (PTK) domain. cDNA expression studies, have revealed the critical role of IL-2R beta, but not IL-2R alpha, in the IL-2R-mediated intracellular signaling process. Studies utilizing mutants of IL-2R beta identified an essential cytoplasmic region, defined as the 'serine-rich' region, for IL-2-induced cell growth. With respect to the involvement of PTK(s) in IL-2R mediated signal transduction, it has been demonstrated that p56lck, a member of the src-family PTKs interacts with the IL-2R beta. In fact, IL-2 stimulation increases the PTK activity of p56lck. Another cytoplasmic region of the receptor, defined as the 'acidic' region has been found to be critical for the association of p56lck with the IL-2R beta. Interestingly the 'serine-rich' and 'acidic' regions of IL-2R beta are both required for the PTK activation of p56lck. Expression studies with mutant IL-2R beta cDNAs have revealed a bifurcation in the IL-2 signaling pathway. One pathway involves the src-family PTK activation which is linked to the activation of p21ras and the subsequent induction of c-fos/c-jun protooncogenes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Histochemical localization of nitric oxide synthase in rat enteric nervous system.

The localization of nitric oxide synthase, the enzyme responsible for producing the short-acting messenger nitric oxide, has been determined in the digestive tract of the rat using histochemistry for reduced nicotinamide adenine dinucleotide phosphate-diaphorase activity, a specific marker for neuronal nitric oxide synthase. Positively stained neurons were found throughout the entire digestive tract from the esophagus to the rectum. Positive neuronal somata were very common in the myenteric ganglia. Dense positive fibers were distributed in internodal strands, the secondary plexus, the tertiary plexus, and were particularly abundant in the deep muscular plexus, while very few were observed in the submucosal ganglia. The density of these positive structures was higher in the small and large intestine than in the esophagus and stomach. The pattern of distribution suggested that some of these positive cells innervate gut muscles. Double-staining revealed that in these enteric neurons, nitric oxide synthase does not co-localize with acetylcholinesterase. Instead, vasoactive intestinal polypeptide almost always coexists with nitric oxide synthase in the myenteric plexus. Thus, nitric oxide and vasoactive intestinal polypeptide may be co-transmitters in a population of non-adrenergic, non-cholinergic neurons in the enteric nervous system.

Acetylcholinesterase↗
PubMed1993

The incidence of colon, breast and prostate cancer in Italian migrants to Victoria, Australia.

The incidence of cancers of the colon, breast and prostate in Australian and Italian born residents of Victoria, Australia were compared with the incidence of these cancers in Italy. Italian migrants' rates were between those of the Australian born and those from Italian cancer registries. Italian migrants' rates for colon cancer (males 23.1 and females 15.8 per 100,000) differed from rates in Ragusa (males 12.1 and females 10.4 per 100,000) but not from rates in Parma or Varese. The migrants' breast cancer rate was similar to the rate in Ragusans (48.7 vs 46.7) and their prostate cancer rate of 27.3 was higher than all Italian registries. Modelling identified that Italian migrants' rates by age were intermediate to Australian and Italian rates, but indistinguishable from cancer rates in Ragusa, except for colon cancer which demonstrated an interaction with age.

Adult↗