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A Shimada

Publications and source records attributed to A Shimada.

At least 181 records · Page 10Linked to original sources
PubMed1996

Immunohistochemical localization of metallothionein in the olfactory pathway of dogs.

Dogs raised in the open air were used in this study. Metallothionein (MT) immunoreactivity was observed in the nucleus and/or cytoplasm of sustentacular cells of the olfactory epithelium in the nasal mucosa, whereas there was few MT-positive cells in the respiratory epithelium. MT immunoreactivity was also observed in astrocytes in all layers of the the olfactory bulb cortex; glial cells surrounding the glomeruli in the olfactory bulb showed prominent immunoreactivity for MT. Adult dogs exhibited stronger immunoreactivity for MT than young. Northern blot analysis demonstrated substantial levels of MT mRNA in the olfactory mucosa and olfactory bulb. Physiological roles of MT localized in the olfactory pathway of dogs were discussed.

Age Factors↗
PubMed1996

Clinical and pathological findings of a Yorkshire terrier affected with necrotizing encephalitis.

A three-year-old, male Yorkshire terrier was presented with blindness, circling, hind limb weakness, and convulsive seizure for the past 3 months. Characteristic clinical findings were chronic, progressive neurological signs involving cerebrum and brain stem, an elevation of brain-type isoenzyme of serum creatine kinase, appearance of high voltage slow activity in electroencephalogram, and multifocal lesions in the cerebral hemispheres on magnetic resonance imaging. Necrotizing encephalitis of Yorkshire terrier was diagnosed after postmortem pathological examination. This is the first case report of the disease in Japan.

Animals↗
PubMed1996

Pathogenic and protective roles of CD45RB(low) CD4+ cells correlate with cytokine profiles in the spontaneously autoimmune diabetic mouse.

The adoptive transfer of splenocytes from diabetic NOD mice to NOD-scid/scid (NOD-scid) recipients results in diabetes. This model was used to test the effect of cotransfer of splenocyte subsets from young nondiabetic NOD mice. As shown previously in other NOD models, the CD4+ subset from young nondiabetic mice significantly delayed the onset of diabetes in splenocyte cotransfers (P < 0.001). The data presented here showed that the development of diabetes in NOD-scid recipients correlated with a rapid increase in peripheral CD45RB(low) CD4+ cells. However, the CD45RB(low) subset of CD4+ cells from young nondiabetic mice protected from diabetes transfer in this model. We therefore examined whether CD45RB(low) CD4+ cells from diabetic mice were pathogenic rather than protective. CD45RB(low) CD4+ splenocytes from diabetic NOD mice were transferred along with CD8+ splenocytes from diabetic mice into NOD-scid recipients, and all of the recipients became diabetic within 5 weeks posttransfer. In contrast, no recipients (0 of 10) of CD45RB(high) CD4+ cells along with CD8+ splenocytes from diabetic mice became diabetic within 5 weeks posttransfer (P < 0.001). A correlate for the difference between CD45RB(low) CD4+ cells from diabetic NOD mice and CD45RB(low) CD4+ cells from nondiabetic mice, which showed protective effect in splenocyte cotransfers, was found in cytokine production after stimulation with anti-CD3 antibodies in vitro. CD45RB(low) CD4+ cells from diabetic mice showed a significantly higher ratio (approximately fivefold) of gamma-interferon (IFN-gamma) to interleukin (IL)-4 when compared with CD45RB(low) CD4+ cells from nondiabetic mice (P < 0.001). In conclusion, the function of the CD45RB(low) population of CD4+ cells changes from a protective to a pathogenic one during the development of disease in the NOD mouse. This change in function correlates with cytokine production in vitro; increased IFN-gamma-to-IL-4 ratio is associated with pathogenic potential and occurs coincident with (or after) the onset of diabetes.

Animals↗
PubMed1996

Immune response to heat-shock protein correlates with induction of insulitis in I-E alpha d transgenic NOD mice.

To evaluate the correlation between heat-shock protein (HSP) and insulitis, we compared lymphocyte proliferative response to Mycobacterium leprae HSP65 of NOD mice with that of I-E alpha d transgenic NOD (I-E+NOD) mice, which show no insulitis. We found that splenocytes from 15-week-old NOD mice showed a more marked proliferative response to HSP than did those from age-matched I-E+NOD mice (P < 0.05). We then transferred splenocytes from 12-week-old NOD mice into I-E+NOD mice to induce insulitis in the recipients and examined antibody levels against HSP. By 6 weeks posttransfer, insulitis was successfully transferred to four out of five recipients of NOD splenocytes and antibody levels against HSP were significantly higher in the NOD splenocyte-transferred group than in controls, which showed no insulitis (P < 0.01). These results suggest that immune response to HSP correlates with insulitis in NOD mice. Our results support the assertion that HSP is a useful antigen for investigating the etiology of IDDM.

Animals↗
PubMed1996

Beta-cell destruction may be a late consequence of the autoimmune process in nonobese diabetic mice.

The NOD mouse is an animal model of IDDM that shows many of the characteristics of human IDDM. It has been proposed that beta-cell destruction in IDDM progresses over time in a linear manner. Recently, we and others have demonstrated that T helper type 1 (Th1) cells have pathogenic roles in the NOD model and proposed that cytokine balances change as the disease progresses. However, it has not been demonstrated how or when the cytokine balances change or how the beta-cell destruction progresses. We have recently demonstrated that the cytokine profiles of CD45RB(low) CD4+ cells correlate either with their pathogenic or with their protective roles in the NOD mouse. To further analyze this apparent correlation between the shift in cytokine level and IDDM, we examined the anti-CD3-induced cytokine profiles of this subset from NOD mice of various ages compared with that from age-matched I-Ak transgenic NOD and BALB/c mice as controls. A significantly higher ratio of anti-CD3-induced interferon-gamma/interleukin-4 was found in diabetic NOD mice (P < 0.0001) but not in age-matched nondiabetic NOD mice. This cytokine ratio did not change significantly until the onset of diabetes in NOD mice. Based upon these results, we propose that IDDM in the NOD mouse progresses as a predominant inflammatory beta-cell dysfunction without actual beta-cell destruction until late in the disease process. This supports the possibility that late-stage immunotherapy may preserve islet beta-cell mass.

Animals↗
PubMed1995

Reversible phosphorylation of both Tyr7 and Tyr10 in the alpha-chain of pig stomach H+,K(+)-ATPase by a membrane-bound kinase and a phosphatase.

When pig stomach membrane H+,K(+)-ATPase preparations were incubated with [gamma-32P]ATP and Mg2+ with vanadate, 32P was incorporated into the alpha-chain of H+,K(+)-ATPase to a steady-state level of approximately 0.7 mol of phosphotyrosine (Tyr(P))/mol of phosphoenzyme intermediates. The addition of a membrane H+,K(+)-ATPase preparation with Mg2+ accelerated the liberation of 32P from Tyr(P) residues in the alpha-chain. Mild tosylphenylalanyl chloromethyl ketone-trypsin treatment solubilized 32P-containing peptides from the alpha-chain almost completely. A reverse-phase column chromatography of the supernatant gave two peaks of 32P-peptide with similar total radioactivities. The amino acid sequence of both peaks was shown to be Gly-Lys-Ala-Glu-Asn-Tyr-Glu-Leu-Tyr-Gln--, which is consistent with the amino-terminal sequence of the alpha-chain of H+,K(+)-ATPase deduced from cDNA from pig stomach except that the initial Met was absent. The comparison of the recovery of amino acid from each Edman cycle showed that the phosphorylation of Tyr10 occurred preceding the phosphorylation of Tyr7. These data and others suggested the presence of a novel membrane-bound enzyme system to participate in reversible phosphorylation of both Tyr residues in the alpha-chain of H+,K(+)-ATPase.

Amino Acid Sequence↗
PubMed1995

Lipid accumulation and foam cell formation in Chinese hamster ovary cells overexpressing very low density lipoprotein receptor.

The rabbit very low density lipoprotein receptor gene was introduced into LDL receptor-negative Chinese hamster ovary cells (ldl-A7). Incubation of the transfected cells with rabbit beta-VLDL (5 to 8 micrograms protein/ml), for 6 days, induced foam cell formation. The cells accumulated lipid droplets visualized by oil red-O staining; the cellular cholesteryl ester and triglyceride content increased two- to threefold. [3H]Oleate incorporation into cholesteryl [3H]oleate was stimulated threefold by incubation of cells with beta-VLDL (20 micrograms protein/ml). Northern blot analysis revealed the presence of VLDL receptor mRNA in rabbit resident alveolar macrophages. Incubation of the macrophages with beta-VLDL (20 micrograms protein/ml) for 24 hours induced foam cell formation but had virtually no effect on VLDL receptor mRNA abundance. These results suggest that the VLDL receptor on macrophages may play an important role in foam cell formation.

Animals↗
PubMed1995

DNA alterations detected in the progeny of paternally irradiated Japanese medaka fish (Oryzias latipes).

A nonmammalian test system for germ-cell mutagenesis has been developed by using the Japanese medaka fish. We describe a system for detecting DNA alterations in F1 progeny descended from the gamma-irradiated male medaka that uses an arbitrarily primed polymerase chain reaction and fingerprinting. A combination of these two methods has some advantages for screening changes in genomic DNA of individual progeny because this detection system can (i) screen for mutational events before embryos with dominant lethal mutations are eliminated during development and (ii) detect DNA changes in the progeny of irradiated males without functional selection and bias, such as resistance to chemicals. DNA alterations are detected as changes in patterns (i.e., band loss and/or band gain) of DNA fingerprints of progeny descended from males whose spermatozoa or spermatids were gamma-irradiated (4.75 or 9.50 Gy). We determined the frequency of gamma-irradiation-induced band loss in arbitrarily primed polymerase chain reaction fingerprints of DNA from severely malformed embryos with dominant lethal mutations and hatched viable embryos. The frequency of band loss in both dominant lethal embryos and hatched viable embryos increased with increasing gamma-ray dose, although more so in the former. We detected a new band in the fingerprints as a heritable DNA alteration but not a viability- or phenotype-affecting DNA alteration in two viable mutants recovered after gamma-irradiation experiments. A cloned amplified fragment of the new band contained a repeated sequence of p(ATGT)n.

Animals↗
PubMed1995

Partial sequence of ribulose-1,5-bisphosphate carboxylase/oxygenase and the phylogeny of Prochloron and Prochlorococcus (Prochlorales).

The prochlorophytes, oxygenic photosynthetic prokaryotes having no phycobiliprotein but possessing chlorophylls a and b, have been proposed to have a common ancestry with green chloroplasts, yet this is still controversal. We report here that partial sequence comparisons of the large subunit of ribulose-1,5'-bisphosphate carboxylase/oxygenase, including sequence data from two prochlorophytes, Prochlorococcus and Prochloron, indicate that Prochlorococcus is more closely related to a photosynthetic bacterium, Chromatium vinosum (gamma-purple bacteria), than to cyanobacteria, while Prochloron is closely related to the prochlorophyte Prochlorothrix and to cyanobacteria. The molecular phylogenetic tree indicates that a common ancestor of Prochlorococcus and gamma-purple bacteria branched off from the land plant lineage earlier than Prochloron, Prochlorothrix, and cyanobacteria.

Amino Acid Sequence↗
PubMed1995

Holmium: yttrium-aluminum-garnet laser for endoscopic lithotripsy.

OBJECTIVES: To evaluate the holmium:yttrium-aluminum-garnet (Ho:YAG) laser for endoscopic lithotripsy on patients diagnosed with urinary tract calculi. METHODS: Thirty-eight procedures utilizing transurethral ureterolithotripsy or percutaneous nephroureteral lithotripsy were evaluated: 5 renal calculi, 31 ureteral calculi (most in the upper ureter), 1 ureteropelvic junction calculus, and 1 bladder calculus. These were mainly in cases that, after being treated with extracorporeal shock-wave lithotripsy (ESWL), were contraindicated for further ESWL. Laser parameters included energy of 0.5 to 1.0 J/pulse and pulse rate of 5 to 10 Hz. RESULTS: Composition of calculi was determined in 26 procedures. The Ho:YAG laser was effective for fragmenting all types of calculi. Patient outcome evaluated at 6 weeks after treatment showed that 33 of 38 procedures (87%) were effective. Residual calculi in 4 of the 5 unsuccessful procedures were less than 5 mm in size and judged to be able to pass spontaneously. In the remaining procedure, the calculus was passed spontaneously 3 months after treatment. No severe damage to tissues or adverse effects to the body were observed due to the Ho:YAG laser. CONCLUSIONS: On the basis of these results, we determine that this wavelength is effective for lithotripsy in addition to its previously reported usefulness for soft tissue applications, and, thus, is a cost-effective and highly useful clinical device.

Adult↗
PubMed1995

Hemodialysis: relationship between signal intensity of the posterior pituitary gland at MR imaging and level of plasma antidiuretic hormone.

PURPOSE: To investigate the correlation between signal intensity of the posterior pituitary gland on magnetic resonance (MR) images and levels of plasma antidiuretic hormone (ADH) in patients undergoing hemodialysis. MATERIALS AND METHODS: The cases of 25 patients undergoing hemodialysis (15 men and 10 women, aged 24-75 years [mean, 51 years]) were prospectively evaluated. Laboratory testing and MR imaging were performed both before and after hemodialysis in 14 patients and only before hemodialysis in 11 patients. RESULTS: Before hemodialysis, nine patients (36%) had normal hyperintensity in the posterior pituitary gland, with almost normal plasma ADH levels and slightly elevated plasma osmolality. In six patients (24%) with less hyperintensity than is characteristic in the posterior pituitary gland, plasma ADH levels were slightly increased or normal. In 10 patients (40%) with an isointense posterior pituitary gland, plasma ADH and osmolality levels were evaluated. CONCLUSION: Elevated plasma osmolality may cause increased plasma ADH concentration and a lack of hyperintensity in the posterior pituitary gland at MR imaging.

Adult↗
PubMed1995

Demonstration of Mycoplasma hyorhinis as a possible primary pathogen for porcine otitis media.

A study of the pathology of the ear was performed on 479 pigs ranging in age from 1 day to 1 year. Histologically, 364 (76.0%) of 479 pigs were affected with otitis. Eustachitis was the most common and preceded an inflammation of other sites of the ear, and an acute eustachitis occurred from as early as 1 week of life. Immunohistochemical examination of frozen cryostat sections revealed Mycoplasma hyorhinis (Mhr) antigens on the luminal surface of the eustachian epithelia in 14 (50.0%) of 28 piglets examined. All the pigs positive for Mhr had an acute eustachitis. Ultrastructural examination on the auditory tubes with positive immunostaining disclosed many mycoplasmas among the cilia. Mhr was isolated from the auditory tubes and tympanic cavities of 19 (67.9%) and 16 (57.1%) of 28 piglets examined, respectively. Porcine otitis media may be caused primarily by Mhr infection in the auditory tube.

Animals↗
PubMed1995

Vitamin D toxicosis in cats: natural outbreak and experimental study.

A pathological study on 5 of 21 cats affected naturally with systemic calcinosis was performed. The animals ranged in age from 1 to 9 years. Hematology and serum chemistry analyses showed the elevated values of phosphorus, blood urea nitrogen and serum creatinine. X-ray examination disclosed the increased density of systemic bones. Histologically, marked calcification was present at the vascular walls of almost all the organs including the lungs, trachea, kidneys, heart, aorta, alimentary tracts, choroid plexus and bones. In the lungs, kidneys and stomach, the calcified lesions were associated with deposition of oxalate crystals. Serum chemistry showed more elevated values of 25-hydroxycholecalciferol (vitamin D) of the affected cats than the normal level. Retrospective examination revealed that these cats had been fed the commercial pet foods containing a large amount of vitamin D (6,370 IU/100 g diet) from their young age, and its value was about ten times as much as that of the control food (680 IU/100 g diet). Pathological changes found in the cats from the experimental vitamin D3 toxicosis were similar to those in the natural cases. In addition, tissue levels of calcium, phosphorous and zinc in the lungs and kidneys were markedly elevated in both natural and vitamin D-intoxicated cases. These findings suggest that long-term feeding of the pet food containing excessive vitamin D was responsible for the outbreak of the systemic calcinosis in the cats.

Animals↗
PubMed1995

Islet-infiltrating lymphocytes from prediabetic NOD mice rapidly transfer diabetes to NOD-scid/scid mice.

In an effort to study the development of diabetes in NOD mice, our laboratory developed a novel adoptive transfer model using NOD-scid/scid (NOD-scid) mice as recipients of islet-infiltrating lymphocytes from donor prediabetic female NOD mice. We first confirmed previous results that demonstrated that splenocytes of diabetic and prediabetic female NOD mice could transfer diabetes to NOD-scid mice. We demonstrated that the kinetics of disease transfer were dependent on the age of transferred lymphocytes and reiterated the kinetics of diabetes in conventional female NOD mice. We then demonstrated that islet-infiltrating lymphocytes from prediabetic female NOD mice could transfer diabetes. In contrast with the age-dependent transfer of diabetes seen using splenocytes, islet-infiltrating lymphocytes obtained from prediabetic female NOD mice aged > or = 40 days rapidly transferred diabetes to NOD-scid recipients. The time required to transfer insulin-dependent diabetes mellitus (IDDM) using islet-infiltrating lymphocytes from young prediabetic mice (25 +/- 9 days) was not statistically different from the time required to transfer IDDM using splenocytes from overtly diabetic mice (32 +/- 5 days). Cotransfer of splenocyte cells or CD4+, but not CD8+ spleen cells, from 60- to 80-day-old prediabetic female NOD mice together with either splenocytes from diabetic mice or islet-infiltrating lymphocytes from prediabetic NOD mice delayed the rapid transfer of IDDM, suggesting that CD4+ cells mediated immunoregulation. Use of the NOD-scid islet-infiltrating lymphocyte-adoptive transfer model should help elucidate the pathophysiology of the early inflammatory events leading to insulitis and subsequent beta-cell destruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

A space-occupying lesion in the liver due to Capillaria infection.

A space-occupying lesion 3.5 by 2.0 cm in size caused by Capillaria infection was revealed ultrasonographically in segment 6 (S6) of the liver of a 32-year-old woman from Okinawa, Japan, who was hospitalized with a complaint of pain in the right upper quadrant. Laboratory examination showed leukocytosis of 10,400/mm3 with 22% eosinophils and slight impairment of liver function. The tumor was removed surgically and found to be a necrotic granuloma with eosinophilic infiltration formed around a degenerated nematode. The causative agent was presumed to be Capillaria hepatica based on the morphology of the bacillary bands and stichosome observed in the sectioned worm and in the fragments of worm recovered by dissecting the tumor tissue that was embedded in paraffin.

Adult↗
PubMed1995

Effects of insulin, insulin-like growth factor-I, and phorbol esters on neutral cholesteryl esterase activity in cultured rat vascular smooth muscle cells.

We investigated the effects of insulin, insulin-like growth factor-I (IGF-I), and phorbol 12-myristate 13-acetate (PMA) on neutral cholesteryl esterase activity in cultured rat vascular smooth muscle cells. Insulin and IGF-I at concentrations between 10(-9) mol/L and 10(-6) mol/L significantly decreased neutral cholesteryl esterase activity in growth-arrested vascular smooth muscle cells in a dose-dependent manner but with no influences on the intracellular concentration of 3',5'-adenosine monophosphate (cyclic AMP). Treatment of cells with KT5720 (10(-7) mol/L to 10(-5) mol/L), a specific inhibitor of cyclic AMP-dependent protein kinase, significantly decreased neutral cholesteryl esterase activity in a dose-dependent manner. Incubation of cells for 6 to 12 hours with PMA (10(-9) mol/L to 10(-6) mol/L), an activator of protein kinase C, significantly increased neutral cholesteryl esterase activity in a dose-dependent manner. However, down-regulation of protein kinase C activity by long-term incubation (18 to 48 hours) with PMA resulted in a significant decrease in neutral cholesteryl esterase activity. Treatment of cells with UCN-01 (10(-7) mol/L to 10(-5) mol/L), a specific protein kinase C inhibitor, decreased the enzyme activity in a dose-dependent manner and completely blocked the activation of the enzyme by PMA. When insulin or IGF-I at a concentration of 10(-6) mol/L was present in the medium containing CL 277,082--an inhibitor of acyl coenzyme A:cholesterol acyltransferase--cellular cholesteryl ester content of the cells significantly increased. In contrast, after the treatment with PMA at a concentration of 10(-6) mol/L in the presence of CL 277,082, the net cholesteryl ester content of the cells significantly declined. These data suggest that both insulin and IGF-I may increase cholesteryl ester accumulation in arterial smooth muscle cells by decreasing arterial cholesteryl ester hydrolysis. The data also suggest that neutral cholesteryl esterase is activated not only by cyclic AMP-dependent protein kinase but also by protein kinase C. Thus growth factors may exert their antilipolytic or lipolytic actions specifically by modulating neutral cholesteryl esterase activity in vascular smooth muscle cells. Neutral cholesteryl esterase of vascular smooth muscle cells may be regulated by recholesteryl esterase of vascular smooth muscle cells may be regulated by reversible phosphorylation, with the phosphorylated form being the active form.

Alkaloids↗
PubMed1995

Genetic linkage map of a fish, the Japanese medaka Oryzias latipes.

In the Japanese medaka, Oryzias latipes, 227 informative random amplified polymorphic DNA markers were detected. Segregations of a total of 170 loci, which included three pigment-pattern loci, five enzyme-coding loci, and one male-determining factor, were examined using intraspecific backcrosses of three inbred strains, two of which were highly polymorphic with respect to the remaining strain. The results were used to prepare a genetic linkage map of and medaka. The map consists of 28 linkage groups and spans about 2480 contiguous centimorgans (cM) with an average of 323 kilobase pairs (kb)/cM.

Animals↗