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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 19 recordsLinked to original sources
PubMed1992

Differences in myocardial fluoro-18 2-deoxyglucose uptake in young versus older patients with hypertrophic cardiomyopathy.

The purpose of this study was to determine whether regional myocardial glucose use in patients diagnosed as having hypertrophic cardiomyopathy (HC) at a younger age differs from that in those diagnosed at middle to old age. Sixteen patients with HC (group 1 aged less than 40 years (n = 8); group 2 aged greater than 40 (n = 8) were studied using positron emission tomography and fluoro-18 2-deoxyglucose (FDG). All patients were diagnosed as having HC within 6 years of the study. Contiguous regions of interest were selected circumferentially on each cross-sectional image of the left ventricular wall. In each region of interest, % FDG fractional uptake was calculated. In each patient, % left ventricular FDG fractional uptake was determined as a mean value of % FDG fractional uptake in each region of interest. Moreover, as a measure of nonhomogeneity, the % interregional coefficient of variation in FDG fractional uptake was calculated in each patient. Whereas % left ventricular FDG fractional uptake did not differ between the 2 groups, the % interregional coefficient of variation in FDG fractional uptake was increased in group 1 compared with that in group 2 (11.5 +/- 3.6 vs 7.4 +/- 1.6%; p less than 0.02). Interventricular septum/left ventricular posterior wall thickness ratio and total counts in cross-sectional image did not differ between the 2 groups. These data suggest that patients diagnosed as having HC at a younger age have more nonhomogeneous myocardial metabolic characteristics than do patients diagnosed at middle or old age, and support the notion that HC in the young may be different from that in the middle-aged or elderly.

Adolescent↗
PubMed1992

Suppression of anti-skin-allograft response by photodamaged effector cells--the modulating effects of prednisolone and cyclophosphamide.

Using a murine model of skin allotransplantation, we have demonstrated previously that inhibition of specific response to alloantigen is inducible by immunization of the host with intravenously administered photoinactivated antigraft effector T cells. This hyporesponsiveness, which was demonstrated by specific inhibition of mixed leukocyte culture (MLC), inhibition of cytotoxic T lympholysis (CTL), specific suppression of the delayed type hypersensitivity (DTH) response, and prolongation of specific skin allograft survival, was adoptively transferable by CD8+ radiosensitive T lymphocytes. In this study, we extend those results to evaluate the effects of an immunosuppressive agent (prednisolone) and an alkylating drug (cyclophosphamide) on the induction of this specific suppressive cellular response. Our results reveal that the administration of prednisolone reduces the induction of the specific hyporesponsiveness to alloantigen, as demonstrated by maintenance of the DTH response to alloantigen and continued accelerated rejection of skin allografts. In contrast, the administration of cyclophosphamide augmented this specific suppressive response to alloantigen in the DTH assay and in prolongation of specific skin allograft survival. These results indicate that adjuvant immunomodulating chemotherapy alters the immune response to photoinactivated effector T cells.

Animals↗
PubMed1992

Induction of a cell-transferable suppression of alloreactivity by photodamaged lymphocytes.

We have reported previously that splenocytes from BALB/c mice acutely rejecting CBA/j skin allografts were exposed to 8-methoxypsoralen (8-MOP) and ultraviolet A light and infused several times intravenously into naive BALB/c recipients; the recipients were hyporesponsive to CBA/j alloantigens in skin graft and delayed-type hypersensitivity assays, as well as in mixed leukocyte culture and cytotoxicity assays. We currently expand on this work by showing that donor-specific tolerance can be transferred adoptively to naive syngeneic animals via unfractionated splenocytes from mice rendered tolerant by the previous protocol. This suppressed response to alloantigen was transferred optimally with splenocytes taken from mice on the sixth day after the final treatment with PET cells. We further demonstrate that the cells that are adoptively transferring suppression are radiosensitive, Thy-1+, Lyt-2+, L3T4- T lymphocytes.

Animals↗
PubMed1992

Hepatic encephalopathy associated with acquired portosystemic shunts in a dog.

An 8-month-old dog with a history of gastrointestinal disturbances and neurological signs was presented with hyperammonemia. Necropsy revealed ascites, portosystemic collaterals, and an irregularly surfaced small liver. Histologically, there were diffuse neuronal necrosis and focal spongiform changes in the brain, and marked fibrosis in the liver. Hepatic encephalopathy was diagnosed.

Animals↗
PubMed1992

DNA associated with the cell membrane is involved in the inhibition of the skin rejection response induced by infusions of photodamaged alloreactive cells that mediate rejection of skin allograft.

Cell membrane DNA (cmDNA) is a form of DNA located on the surface of human and murine T-cells. It has recently been characterized as a target for photomodification by 8-methoxypsoralen (8-MOP) and long-wave ultraviolet light (UV-A). Whereas 8-MOP itself is biologically inert, photoactivated 8-MOP is covalently bound to pyrimidine bases in DNA. We have investigated the possible involvement of cmDNA photomodification in the induction of the suppression of skin allograft rejection in BALB/c mice preimmunized with 8-MOP/UV-A photodamaged alloreactive cells which mediates this allograft rejection. This suppression is demonstrated by inhibition of delayed-type hypersensitivity (DTH) and mixed leukocyte culture (MLC) responses. Splenocytes from BALB/c mice undergoing rejection of CBA/j skin graft which contained an expanded population of the effector T lymphocytes that mediate the rejection were treated with DNAse to remove cmDNA before or after treatment with 8-MOP and UV-A prior to infusion into naive BALB/c recipients. Mice that received pretreated effector cells were tested for MLC responses to CBA/j or B10 alloantigens before and after the DTH response. The DTH response of all groups of pretreated BALB/c mice to the relevant alloantigen was specifically suppressed as compared with the response of control mice. However, adoptive transfer of the suppression of the DTH response was optimally demonstrable only in syngeneic recipients of cells from donor mice treated with photodamaged alloreactive cells. Also, splenocytes from BALB/c mice immunized with photodamaged alloreactive cells demonstrated highly significant hyporesponsiveness and suppression of the MLC response of naive mice to the relevant alloantigen in the case of the primary MLC response, and to both alloantigens in the secondary MLC response which was totally eliminated by prior pretreatment of these effector cells with DNAse. Therefore, it appears that the suppression of the DTH response can be induced by pretreatment of the effector cells with DNAse and/or 8-MOP and UV-A but is adoptively transferable optimally only from mice which are recipients of photodamaged alloreactive cells. Moreover, the effectiveness of this treatment is decreased by prior removal of cmDNA from these cells. The presence of cmDNA is necessary for induction of suppression of the primary and secondary MLC responses in mice treated with photodamaged cells of allograft rejection.

Animals↗
PubMed1992

Four Japanese cases of episodic angioedema with eosinophilia.

Here we describe four young Japanese women aged 25-33 years, whose clinical findings are characterized by episodic angioedema, marked leukocytosis with eosinophilia, benign course with spontaneous remission or low-dose prednisolone treatment. The recognized causes of eosinophilia, such as allergy, parasite, and collagen diseases, and the causes of edema, such as heart, kidney, and liver diseases, were ruled out. The findings in these patients are very similar to those reported as episodic angioedema with eosinophilia, which is clearly distinct from the so-called hypereosinophilic syndrome. We suggest that this syndrome is not rare, and should be widely recognized as a new clinical entity for accurate and prompt diagnosis.

Adult↗
PubMed1992

Rapid endothelialization of vascular prostheses by seeding autologous venous tissue fragments.

A method was developed to obtain rapid endothelialization of a fabric vascular prosthesis by seeding autologous venous tissue fragments into its wall. In an animal study, complete endothelialization was observed in the entire inner surface of the prosthesis within 2 weeks after implantation. A piece of peripheral vein was minced with scissors and then stirred into saline to create a tissue suspension. This suspension was enmeshed into the wall of a highly porous fabric vascular prosthesis by repeated pressurized injections with a syringe. The prostheses (7 mm inside diameter and 5.7 cm in length), seeded with tissue fragments, were implanted into the descending thoracic aorta of 25 dogs, and they were removed from 1 hour to 2 months after implantation. Twenty-five prostheses, preclotted with fresh blood, were used as control prostheses. In the seeded graft, a thin fibrin layer covered the inner surface just after implantation, but countless numbers of endothelial cells migrated from the fragments and came up to the luminal surface like multiple "mushrooms" under the fibrin layer. Smooth muscle cells made multiple layers underneath the endothelial cell layer. The healing proceeded equally at every part. By this active migration and proliferation, the inner surface was completely healed within 2 weeks.

Animals↗
PubMed1992

[Surgical treatment for lung cancer cases with an interlobar pleural involvement].

Among surgically resected 192 lung cancer cases, eleven with a interlobar pleural involvement (p 3) were studied to clarify their characters. The five year survival rate of interlobar p 3 was 12.5% (15.6% in case of excluding death of other diseases), which was better than that of the other parietal p 3. Result of surgical treatment of lobectomy + partial resection for interlobar p 3 had better tendency compared with that of bilobectomy or pneumonectomy. But, unfortunately it was necessary for interlobar p 3 to care the local recurrence in the future. We hope that the general rule of the treatment for interlobar p 3 was carefully discussed furthermore, including the safety margin in the partial resection or the classification on T factor.

Adenocarcinoma↗
PubMed1991

Inhibition of antiskin allograft immunity induced by infusions with photoinactivated effector T lymphocytes (PET cells). Is in vivo cell transferrable?

We previously reported producing donor-specific tolerance to alloantigens by intravenous exposure to pretreated antidonor T cells. The current study extends that work by adoptively transferring the donor-specific tolerance into naive syngeneic recipients. Eight days after BALB/c mice received histoincompatible CBA/j skin grafts, their splenocytes which included an expanded population of cells mediating rejection were treated with 100 ng/ml 8-methoxypsoralen (8-MOP) photoactivated by 1 Joule/cm2 of ultraviolet A (UVA) light prior to infusion into naive BALB/c recipients. Whereas 8-MOP itself is biologically inert, photoactivated 8-MOP crosslinks DNA by covalently binding to pyrimidine bases. Recipient BALB/c mice which had been previously demonstrated to be hyporesponsive to CBA/j alloantigens in mixed leukocyte culture (MLC), cytotoxicity (CTL) and in vivo delayed type hypersensitivity (DTH) assays were the donors of spleen cells for the adoptive transfer experiments. Fifty to one hundred million viable spleen cells from these pretreated BALB/c mice were transferred into naive syngeneic recipients which then were tested for DTH response and allograft survival to the relevant and irrelevant antigens. The radiosensitivity of this transferrable suppression was evaluated by exposing the adoptively transferred cell population to 3200 rads of C-irradiation prior to cell transfer. The phenotype of the cells transferring this suppressive response was performed by depleting specific populations of cells with monoclonal antibodies prior to cell transfer. In vivo the DTH response of the pretreated BALB/c mice was specifically suppressed to the relevant alloantigen, correlating with retention of CBA/j skin grafts for up to 42 days post engraftment without visual evidence of rejection, in comparison to control mice complete rejection of the skin graft in less than 8 days. In vitro, splenocytes from BALB/c recipients of pretreated syngeneic splenocytes containing large numbers of BALB/c anti-CBA/j T cells proliferated less in MLC and generated lower cytotoxic T cell responses to CBA/j alloantigens than did controls and suppressed the naive and sensitized BALB/c MLC and CTL responses to CBA/j alloantigen. This specific suppressive response to alloantigen was optimally transferred into syngeneic naive recipients when the adoptive transfer was performed on the sixth day after the last infusion received by the spleen cell donor mice. The adoptive transfer of this suppressive response was abrogated by the prior X-irradiation of the donor spleen cells and significantly abolished by the depletion of Thy-1+, Lyt-2+, L3T4- T lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Simultaneous determination of residual synthetic antibacterials in fish by high-performance liquid chromatography.

A simple and rapid high-performance liquid chromatographic (HPLC) method for the simultaneous determination of sulphamonomethoxine (SMMX), sulphadimethoxine (SDMX), sulphisozole (SIZ), nalidixic acid (NA), oxolinic acid (OXA), piromidic acid (PMA), furazolidone (FZ) and sodium nifurstyrenate (NFSA) in cultured fish was developed. The drugs were extracted with 0.2% metaphosphoric acid-methanol (6:4), followed by a Bond Elut C18 clean-up procedure. The HPLC separation was carried out on an Inertsil ODS column (150 x 4.6 mm I.D.) using 5 mM aqueous oxalic acid-acetonitrile (55:45) as the mobile phase with detection at 265 nm (0.04 a.u.f.s.). The calibration graphs were rectilinear from 1 to 20 ng for OXA, from 2 to 50 ng for SMMX, SDMX, SIZ, NA, PMA and FZ and from 5 to 100 ng for NFSA. The recoveries of each drug added to fish were 65.0-89.5%. The detection limits were 0.02 micrograms/g for OXA, 0.05 micrograms/g for SMMX, SDMX, SIZ, NA, PMA and FZ and 0.1 micrograms/g for NFSA.

Anti-Infective Agents↗
PubMed1991

Protective mechanism of sodium molybdate against the acute toxicity of cadmium in rats. II. Prevention of cytoplasmic acidification.

In order to clarify the protective mechanism of sodium molybdate against the acute toxicity of cadmium chloride in rat, the effect of in vivo sodium molybdate pretreatment on the cytotoxic action of cadmium in isolated hepatocytes was studied. The cytosolic pH of hepatocytes isolated from untreated rats immediately decreased with incubation in either neutral Hank's balanced salt solution (HBS), pH 7.4, containing 5 microM cadmium chloride minimum or acidic HBS (pH 7.1, 6.8, 6.5, and 6.2). The presence of 5 microM cadmium in HBS adjusted to pH 7.1 aggravated cytosolic acidification induced by the acidic medium alone. Cell viability of hepatocytes incubated in HBS at pH 6.2 was significantly reduced as compared to that of control cells in HBS at pH 7.4, but the presence of cadmium in the acidic HBS had no aggravating action against such a toxic action of the acidic medium although cellular uptake of the metal in the medium increased, as compared to that in HBS at pH 7.4. Molybdenum pretreatment alleviated cytoplasmic acidification induced by the treatment with HBS at pH 7.4 or 7.1 containing cadmium or by extracellular acid load without cadmium. This pretreatment also prevented the loss of cell viability induced by the treatment with HBS at pH 6.2 but could not attenuate that when cadmium was present in the medium. These facts suggest that molybdenum pretreatment alleviated the acute toxicity of cadmium in rat by preventing cytoplasmic acidification caused by the harmful metal.

Animals↗
PubMed1991

Intrapulmonary bronchial circulation during hemorrhage.

Experiments were conducted on 119 anesthetized and artificially ventilated rats to evaluate effects of a physiological stimulus (hemorrhage) to the sympothoadrenal system on the bronchial circulation. In the presence of a sufficient dose of a vasopressin V1-receptor antagonist, moderate (81 mmHg on average, 33 rats) or severe hypotension (69 mmHg, 28 rats) was produced by controlled hemorrhage (11 or 9 rats, respectively), or by treatment with phenoxybenzamine (0.1 mg/kg, i.v., 12 rats, or 1.0 mg/kg, 10 rats), or the highly selective alpha 1-adrenoceptor antagonist, bunazosin (0.01 mg/kg i.v., 10 rats, or 0.1 mg/kg, 9 rats). During hypotension, the intrapulmonary bronchial blood flow (microsphere method) was decreased in a dose-dependent manner in the two antagonist-treated groups. However, these decreases were only of a moderate degree compared to the severe decrease in the hemorrhage group. Although the bronchovascular resistance was not significantly changed after treatment with either antagonist, this variable was greatly elevated during severe hemorrhagic hypotension, reaching 240 +/- 51% (P less than 0.001 with either antagonist study) of its baseline level. Changes in the pulmonary arterial and left atrial pressures, plasma vasopressin concentration, and renin activity were found to be less influential on these responses in 58 rats. Overall, we concluded that the sympathoadrenal mechanism powerfully increased the resistance and decreased the blood flow of the intrapulmonary bronchial circulation.

Animals↗
PubMed1991

Endocytosis of the TCR/CD3 complex and the class-I major histocompatibility complex in a human T cell line.

We investigated the expression of the T cell receptor (TCR)/CD3 complex on a CD4-positive human T cell lymphoma cell line treated with phorbol myristate acetate (PMA) and/or CA2+ ionophore using fluorescence flow cytometry and fluorescence microscopic analysis. PMA induced a significant decrease in the expression of the CD3 complex on the cell membranes. Fluorescence microscopy confirmed that the down regulation is due to internalization of the antigens. Ca2+ ionophore treatment had no effect on the internalization of the CD3 complex. Double staining revealed that the vesicles containing the internalized CD3 complex and those containing intra-cytoplasmic class I major histocompatibility complex antigen had similar distribution in the PMA-stimulated cells, implying coexistence of these two antigens in a cytoplasmic perinuclear distribution.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Inhibition of anti-skin allograft immunity induced by infusions with photoinactivated effector T lymphocytes--the congenic model.

We have previously reported the capacity to produce donor-specific tolerance to alloantigens by intravenous exposure to pretreated antidonor T cells. The current study has refined this system by using congenic mice differing only at the H-2 major histocompatibility complex genetic loci. Twelve days after B10 mice received MHC-incompatible B10.D2 skin grafts, their splenocytes that included an expanded population of cells mediating rejection were treated with 100 ng/ml 8-methoxypsoralen (8-MOP) photoactivated by 1 J/cm2 of ultraviolet A prior to infusion into naive B10 recipients. Whereas 8-MOP itself is biologically inert, photoactivated 8-MOP crosslinks DNA by covalently binding to pyrimidine bases. Recipient B10 mice were tested for tolerance to B10.D2 alloantigens in mixed leukocyte culture (MLC), cytotoxicity (CTL), and to in vivo delayed type hypersensitivity assays and challenged with a fresh B10.D2 graft. In vivo, the DTH response of the pretreated B10 mice was specifically suppressed to the relevant alloantigen, correlating with retention of B10.D2 skin grafts for up to 22 days postengraftment without visual evidence of rejection, in comparison to control complete rejection of the skin graft in less than 12 days. In vitro, splenocytes from B10 recipients of pretreated syngeneic splenocytes containing large numbers of B10 anti-B10.D2 T cells proliferated less in MLC and generated lower cytotoxic T cell responses to B10.D2 alloantigens than did controls and suppressed the B10 MLC and CTL responses to B10.D2 alloantigen. These results reveal that, in a highly defined congenic transplantation system, infusions of photoinactivated effector cells resulted in selective inhibition of the in vivo responses that correlated with allograft rejection and permitted prolonged retention of histoincompatible skin grafts. This approach may have significant practical applicability for treatment of human disorders caused by aberrant T cells.

Animals↗
PubMed1991

Synthesis and platelet aggregation inhibitory activities of 3-(2-oxopropylidene)azetidin-2-one derivatives. II.

A series of 3-acylidene-4-methylazetidin-2-one derivatives bearing various substituents at the 1-position of the azetidin-2-one ring was synthesized. These compounds were evaluated for platelet aggregation inhibitory activities. Most of the compounds synthesized showed potent inhibitory activities against rabbit platelet aggregation induced by adenosine diphosphate or collagen in vitro. Structure-activity relationships are also discussed.

Animals↗
PubMed1991

Different distribution of cadmium in the liver supernatant between in vivo and in vitro.

Distribution of cadmium (Cd) in liver supernatant was examined by gel filtration chromatography after injecting Cd intravenously into female Wistar rats and also by adding Cd in vitro into the control supernatant. Supernatants were analyzed on an HPLC Asahipak GST-520 column and on-line ICP (inductively coupled argon plasma-atomic emission spectrometer) analysis of the eluate (HPLC-ICP). The relative intensity of the three main Cd-associated peaks changed with time after injection of Cd into rats. The three peaks were tentatively assigned as Cd-binding protein-I and -II (Cd-BP-I and -II) and metallothionein (MT) in the order of respective elution from the column. Relative affinities of Cd for the three peaks were determined by injecting different doses of Cd into rats as follows: MT greater than Cd-BP-II greater than Cd-BP-I. Cd-BP-II was assigned as the major Cd-BP other than MT in the liver supernatant and it contained zinc that can be replaced by Cd. Comparison between the in vivo and in vitro Cd distributions indicated that the former distribution is not reproducible under any in vitro conditions examined and the latter distribution is dependent mostly upon incubation temperature.

Animals↗