Genetic analyses for dermatitis and IgE hyperproduction in the NC/Nga mouse.
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Animals↗
Biomedical subjects
N Watanabe
Publications and source records attributed to N Watanabe.
Protein tyrosine kinase activation provides an early and obligatory signal in anti-FRP-1/CD98/4F2 monoclonal antibody induced cell fusion mediated by HIV gp160.
The mechanism by which anti-fusion regulatory protein-1 (FRP-1) monoclonal antibody (mAb) induced cell fusion was investigated using U2ME-7 cells that are CD4+U937 cells transfected with the HIV gp160 gene. Protein kinase inhibitors (H-7, H-89, herbimycin A and genistein) suppressed cell fusion of Cd+U2ME-7 cells induced by anti-FRP-1 mAb. H-7 and H-89 also inhibited the cell aggregation, but herbimycin A and genistein did not. Intriguingly, only when herbimycin A was added either before or simultaneously with addition of anti-FRP-1 mAb, was cell fusion suppressed, suggesting that tyrosine kinase is related with the initial step of polykaryocyte formation. Anti-FRP-1 mAb induced the rapid tyrosine phosphorylation of multiple cellular proteins. These effects occurred within 1 min and returned to near baseline by 60 min. The rapid tyrosine phosphorylation was suppressed by herbimycin A and genistein. Although it remains to be determined which protein tyrosine kinase(s) is involved in this response, pp130 tyrosine phosphorylation appears to be a specific and early signal transmitted after the interaction of FRP-1 with a specific antibody. pp130 was present in the cytosol fraction and was distinct from pp125FAK, p130CAS, vinculin, and beta 1-integrin. Thus, our study may present evidence for a novel pathway of protein tyrosine kinases that phosphorylate specific, still unknown protein substrates during polykaryocyte formation.
Antibodies, Monoclonal↗
Oxidative stress on mitochondria and cell membrane of cultured rat hepatocytes and perfused liver exposed to ethanol.
BACKGROUND & AIMS: The precise pathogenic significance of oxidative injury in the evolution of alcohol-induced liver disease is still obscure. The present report was designed to investigate whether ethanol alters the production of active oxidants and biological activities of hepatocytes. METHODS: The following parameters in rat hepatocytes were investigated by using fluorescence probes in vitro and ex vivo: (1) mitochondrial membrane potential and membrane permeability transition, (2) oxygen radicals generation, (3) membrane barrier function, and (4) glutathione level. RESULTS: Ethanol (50 mmol/L) increased oxidative stress in hepatocytes and subsequently induced an increased mitochondrial permeability transition and a decreased membrane potential. These ethanol-induced alterations were attenuated by an inhibitor of alcohol dehydrogenase and an intracellular oxidant scavenger, whereas they were enhanced by diethyl maleic acid, a glutathione depletor. Ethanol plus diethyl maleic acid but not ethanol alone increased the number of hepatocytes with membrane barrier dysfunction. A continuous infusion of ethanol (50 mmol/L) increased oxidative stress and decreased mitochondrial membrane potential in the pericentral area of isolated perfused rat liver. CONCLUSIONS: Active oxidants generated during ethanol metabolism increase mitochondrial permeability transition and modulate mitochondrial energy synthesis in hepatocytes. Reduction of glutathione level enhances mitochondrial dysfunction and impairs membrane barrier function of hepatocytes.
Alcohol Dehydrogenase↗
Neuropathological findings in the cerebro-oculo-facio-skeletal (Pena-Shokeir II) syndrome.
An autopsy case is described of an infant with cerebro-oculo-facio-skeletal (COFS) (Pena-Shokeir II) syndrome who died of pneumonia at the age of 5 months, and the pathology of the CNS in this case and the cases in literature were reviewed. Neuropathological examination revealed a partial defect of the corpus callosum, lobulation of the caudate nucleus and putamen, polymicrogyria in the parietal lobes and neuronal heterotopia in the cerebral and cerebellar white matter. The migration disorders suggest that the onset starts in the early fetal period.
Agenesis of Corpus Callosum↗
CD18/ICAM-1-dependent nitric oxide production of Kupffer cells as a cause of mitochondrial dysfunction in hepatoma cells: influence of chronic alcohol feeding.
The present study was designed to monitor the process for hepatoma cell injury induced by Kupffer cells. The non-activated Kupffer cells isolated from male Wistar rats reduced the mitochondrial membrane potential in the cocultured AH70 cells, which was indicated by the decreased rhodamine 123 (Rh123) fluorescence. Increased level of nitrite and nitrate in the medium and induction of iNOS in Kupffer cells were observed after coculture with AH70 cells. Incubation with either NG-monomethyl-L-arginine or aminoguanidine attenuated the increased nitric oxide (NO) production of Kupffer cells and the decreased Rh123 fluorescence of AH70 cells. Fluo-3, a calcium-sensitive probe, fluorescence in Kupffer cells increased after coculture with AH70 cells. Addition of TMB-8, a calcium inhibitor, or monoclonal antibody directed against ICAM-1 or CD18 prevented the increases in fluo-3 fluorescence and NO production of Kupffer cells and Kupffer cell-induced mitochondrial dysfunction in AH70 cells, suggesting the involvement of calcium mobilization and CD18/ICAM-1. It is therefore suggested that the Kupffer cell-mediated mitochondrial dysfunction of hepatoma cells largely depends on NO production by iNOS, and that the NO production by Kupffer cells is triggered by CD18/ICAM-1-dependent interaction with hepatoma cells and subsequent calcium mobilization. In other series of experiments, male Wistar rats fed ethanol for 4 weeks were used. The NO production and calcium mobilization of Kupffer cells and reduction of the mitochondrial membrane potential in cocultured hepatoma cells were diminished in the case of Kupffer cells isolated from chronically ethanol-fed rats, while CD18 and ICAM-1 expression was still observed. Thus, the present study further suggests that NO-dependent anti-hepatoma cell activity of Kupffer cells is suppressed in chronically ethanol-fed animals.
Alcoholism↗
Reproducibility of home blood pressure measurements over a 1-year period.
We compared the reproducibility over time of blood pressure measured at the health examinations (screening blood pressure) and blood pressure measured at home (home blood pressure). Both screening and home blood pressure were measured in subjects of a rural community. Subjects measured their own blood pressure at home once in the morning using a semiautomatic oscillometric blood pressure measuring device at least three times (on at least 3 days) in each of two 4-week periods separated by one year. Similarly, two screening blood pressure measurements were obtained from the subjects at each of two health examinations also taken 1 year apart. A total of 136 untreated subjects without cardiovascular complications (40 men and 96 women, 56 +/- 11.7 years, mean +/- SD) were analyzed in the study. The correlations between the first and second blood pressure measurements of the subjects were significantly higher for the home blood pressure measurements (systolic: r = 0.844 and diastolic: r = 0.830) than for the screening blood pressure measurements (systolic: r = 0.692 and diastolic: r = 0.570). The mean differences between the first and second home blood pressure (0.8 +/- 7.7 mm Hg for systolic BP and 0.9 +/- 5.5 mm Hg for diastolic BP) were significantly smaller than those for the screening blood pressure (-3.9 +/- 13.8 for systolic BP and -3.1 +/- 10.2 for diastolic BP) (P < .001 for both comparisons), suggesting that the reproducibility of home blood pressure over time is superior to that of screening blood pressure. Such reliable blood pressure measurements obtained at home have a clinical significance for the diagnosis and treatment of hypertension and as a tool for evaluating the efficacy of antihypertensive drugs. Home blood pressure measurements also may be more useful than screening blood pressure measurements in predicting future cardiovascular events.
Adult↗
Relation between nocturnal decline in blood pressure and mortality. The Ohasama Study.
To investigate the relation between nocturnal decline in blood pressure and mortality, we obtained ambulatory blood pressures in 1542 residents aged 40 years or over of a rural Japanese community. Subjects were followed-up for a mean of 5.1 years and were then subdivided into four groups according to the percent decline in nocturnal blood pressure: 1) extreme dippers: percent decline in nocturnal blood pressure > or = 20% of the daytime blood pressure; 2) dippers: decline of > or = 10% but < 20%; 3) nondippers: decline of > or = 0% but < 10%; and 4) inverted dippers: no decline. The relationship between the decline in nocturnal blood pressure and mortality was examined by the Cox proportional hazards regression model adjusted for age, sex, smoking status, previous history of cardiovascular disease, and the use of antihypertensive medication. The mortality risk was highest in inverted dippers, followed by nondippers. There was no difference in mortality between extreme dippers and dippers. This relationship was observed for both treated and untreated subjects, was more pronounced for cardiovascular than for noncardiovascular mortality, and did not change after the data were adjusted for 24-h, daytime, and nighttime blood pressure levels.
Aged↗
Preparation of yttrium-90-labeled human macroaggregated albumin for regional radiotherapy.
Human macroaggregated albumin (MAA), which is currently labeled with technetium-99m (99mTc) and 99mTc-MAA, is used clinically as a pulmonary perfusion agent and was directly labeled with yttrium-90 (90Y)-acetate. This study evaluated whether 90Y-MAA could be potential radiotherapeutic agent for regional radiotherapy against malignant tumors. MAA suspended in 0.1 M sodium acetate buffer, pH 5.8, was incubated with 90Y-acetate and purified in order to get rid of unstable binding of 90Y by electrophoresis. The radiochemical purity of 90Y-MAA in normal human serum was estimated by an agarose electrophoresis method and was more than 94% over 168 h in vitro. Following the intratumoral administration of 90Y-MAA, the time course of tumor radioactivity and the biodistribution in nude mice bearing human neuroblastoma were investigated up to 168 h. More than 93% of the radioactivity of the injected dose was found on the subcutaneous tumor over 168 h. The bone radioactivity was shown as 0.06 +/- 0.03% injection dose/gram tissue (% ID/g) (n = 5) at 24 h, 0.73 +/- 0.20% ID/g at 72 h, 0.92 +/- 0.16% ID/g at 120 h, and 2.51 +/- 0.59% ID/g at 168 h. A slight increase in radioactivity was noted in the liver, kidneys, and spleen over the 168-h periods. In conclusion, 90Y-MAA may be a potential agent for regional radiotherapy (brachytherapy) because of the sufficient persistence in the tumor following an intratumoral administration.
Albumins↗
Short-period-induced hypertension could improve tumor-to-nontumor ratios of radiolabeled monoclonal antibody.
This study was undertaken to find optimum period of hypertensive treatment for the improvement of tumor targeting of 111In-labeled monoclonal antibody. Angiotensin II was infused into tumor-bearing mice at an infusion rate of 2.0 micrograms/kg/min determined by the dose-finding study. The infusion was continued for up to 72 h, and biodistribution of 111In-DTPA-A7, a murine IgG1, was observed 72 h postinjection. Tumor-to-nontumor ratios were best improved with the infusion for 0.5-3 h. However, with the longer infusion, the effect deteriorated by the increase of nontumor uptakes, and body-weight loss became remarkable. It could be concluded that hypertensive treatment for a short period could be safely performed to benefit targeting of radiolabeled monoclonal antibody.
Angiotensin II↗
Characterization of a 180 kDa molecule apparently reactive with recombinant L-selectin.
In the present study we identified a 180 kDa molecule (p180) in rat lymph nodes (LN) apparently reactive with silkworm derived recombinant L-selectin (LEC-IgG) in a Ca(2+)-dependent manner. Analysis of amino acid sequence revealed that p180 has a strong homology to the macrophage mannose receptor (MMR), which was corroborated by the observation that p180 reacted with polyclonal anti-alveolar MMR antibody and mannosyl-BSA-agarose. In agreement with this notion, the binding of p180 to the silkworm LEC-IgG was inhibited by alpha-methyl-D-mannoside. However, in sharp contrast to its reactivity against the silkworm LEC-IgG, p180 failed to bind LEC-IgG produced by COS-7 cells, suggesting that p180 reacted with the silkworm LEC-IgG through the recognition of oligomannose-type oligosaccharides expressed on the silkworm products and that the lectin activity of L-selectin was not involved in the interaction. These results, together with the immunohistochemical studies showing that p180 was absent from the majority of high endothelial venules (HEV) but present in medullary macrophages, led us to conclude that p180 obtained from LN lysates by the use of the silkworm LEC-IgG is not a physiological ligand for L-selectin, warning against the use of recombinant proteins expressed in the baculovirus/ silkworm expression system for the detection of carbohydrate ligands.
Amino Acid Sequence↗
The serum factor from patients with ulcerative colitis that induces T cell proliferation in the mouse thymus is interleukin-7.
The disturbance of immune regulatory T cells is related to the pathogenesis of ulcerative colitis. Here we demonstrated and characterized the serum factor from ulcerative colitis patients that induced proliferation of intrathymic T cells. The factor isolated from the patient sera by a combination of gel filtration and anion-exchange chromatography induced proliferation of CD4+CD8- intrathymic T cells in the organ-cultured embryonic mouse thymus. Purification and amino acid sequence analysis of the serum factor demonstrated that the N-terminal 12 sequence was homologous to that of interleukin-7. SDS-PAGE and Western blot confirmed that purified serum factor was interleukin-7. Enzyme immunoassay demonstrated that the serum interleukin-7 concentration was significantly increased in the patients. PCR and Southern blot hybridization demonstrated that interleukin-7 mRNA expression was increased in the thymus tissues from patients but decreased in the colonic mucosa. Since interleukin-7 is a crucial cytokine for proliferation and differentiation of T cells in the thymus, the present study indicates that interleukin-7 may contribute to the disturbance of immune regulatory T cells in ulcerative colitis.
Amino Acid Sequence↗
Altered surface expression of effector cell molecules on neutrophils in myelodysplastic syndromes.
The surface expression of effector cell molecules on neutrophils was examined in 18 patients with myelodysplastic syndromes (MDS) and 20 healthy control subjects. The MDS patients were further classified as low clinical risk (L-MDS, n=7) and high clinical risk (H-MDS, n=11). The expression of Fc receptors for IgG (FcR), complement receptors (CR) and cellular adhesion molecules on neutrophils was determined by flow cytometry and monoclonal antibodies. The effect of granulocyte colony-stimulating factor (G-CSF) and tumour necrosis factor-alpha (TNF) on L-selectin shedding and CR up-regulation on neutrophils was also examined. The percentage of FcRI-positive neutrophils and CD11b/CR3 expression on neutrophils were significantly increased in the H-MDS patients when compared to the controls. In contrast, the expression of FcRII, FcRIII, L-selectin, LFA-1 and CD18 on neutrophils was significantly reduced in the H-MDS patients compared with the controls. The L-MDS neutrophils exhibited lower expressions of CR1, L-selectin, LFA-1 and CD18 than those of the controls. Neutrophils from some H-MDS patients showed impaired L-selectin shedding and CR up-regulation after stimulation with G-CSF or TNF, although these were not significantly different when assessed in the whole H-MDS group. These findings suggest that an altered surface expression of effector cell molecules and an impaired modulation of cellular adhesion molecules on neutrophils may contribute to the increased susceptibility to bacterial infections in MDS patients.
Aged↗
Oxidative stress-mediated apoptosis of hepatocytes exposed to acute ethanol intoxication.
The present study was designed to investigate whether acute ethanol intoxication increases the production of active oxidants, and subsequently promotes apoptosis of hepatocytes. Hepatocytes were isolated from male Wistar rats, and cultured in the presence or absence of ethanol. The fluorescence in situ nick end labeling method and an enzyme-linked immunosorbent assay (ELISA) system to quantify fragmented DNA were used to estimate apoptotic change in hepatocytes. Nuclear morphological alterations and membrane barrier dysfunction of hepatocytes were assessed by staining with Hoechst 33342 and propidium iodide (PI). Intracellular glutathione level was determined as the fluorescence of monochlorobimane (MCLB), which forms conjugate with glutathione to become fluorescent. Ethanol (100 mmol/L) increased the amount of fragmented DNA and the number of apoptotic hepatocytes in vivo as well as in vitro. These ethanol-induced alterations in hepatocytes were attenuated by simultaneous incubation with either 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, or dimethylthiourea, an intracellular oxidant scavenger. Diethyl maleic acid (DMA), a glutathione depletor, enhanced the induction of apoptotic change, and decreased membrane barrier function in ethanol-treated hepatocytes, whereas ethanol per se did not increase the number of PI-positive hepatocytes. Furthermore, combination of ethanol and DMA but not ethanol alone decreased the hepatocyte MCLB fluorescence. Taken together, the present study suggests that active oxidants produced during ethanol metabolism mediate fragmentation of DNA in hepatocytes, and that intracellular antioxidants such as glutathione play a critical role in the cytoprotective mechanisms of hepatocyte against lethal cell death, ie, apoptosis, induced by ethanol.
Animals↗
Development of atopic dermatitis-like skin lesion with IgE hyperproduction in NC/Nga mice.
Atopic dermatitis (AD) usually develops in patients with an individual or family history of allergic diseases, and is characterized by chronic relapsing inflammation seen especially in childhood, association with IgE hyperproduction and precipitation by environmental factors. However, the exact etiology of AD has been unclear. To further explore the pathogenesis and treatment of AD, a suitable animal model is required. We found that skin lesions, which were clinically and histologically very similar to human AD, spontaneously appeared on the face, neck, ears and dorsal skin of inbred NC/Nga mice when they were raised in non-sterile (conventional) circumstances, but not under specific pathogen-free conditions. Plasma levels of total IgE in conventional NC/Nga mice were markedly elevated from 8 weeks of age, correlating with clinical skin severity of dermatitis. Immunohistochemical examination of the skin lesion showed increased numbers of mast cells and CD4+ T cells containing IL-4 necessary for IgE synthesis. Thus, NC/Nga mice suffered from dermatitis very similar to human AD with IgE hyperproduction, which may be triggered by some environmental factor(s).
Animals↗
Requirement of CD28-CD86 co-stimulation in the interaction between antigen-primed T helper type 2 and B cells.
The interaction between CD28 and its ligands, CD80 and CD86, is crucial for an optimal activation of antigen-specific T cells. However, the requirement of CD80 or CD86 co-stimulation in Th2 cell differentiation and activation is controversial. Freshly isolated murine CD4+ and CD8+ T cells were incubated with P815 transfectants expressing a similar level of either CD80 or CD86 in the presence of anti-CD3 mAb. Both CD80 and CD86 co-stimulated the proliferation of CD4+ and CD8+ T cells at comparable time-kinetics and magnitude, but CD86 alone was able to co-stimulate IL-4 and especially IL-10 production in CD4+ T cells. In typical Th2-dependent immune responses elicited by Nippostrongylus brasillensis infection, the anti-CD86 mAb treatment but not the anti-CD80 mAb treatment efficiently inhibited antigen-specific IgE and IgG1 production, which was accompanied with the reduced IL-4 production. Our results suggest that CD86 co-stimulation plays a dominant role not only in the primary activation of Th2 cells but also in the secondary interaction between antigen-primed Th2 cells and B cells.
Animals↗
Interaction of the pre-domain of interleukin-1 with the mature domain.
The two interleukin 1 precursors (preIL-1alpha and beta) with a molecular mass of 33 kDa are proteolytically processed to the mature carboxyl-terminal 17-kDa proteins. In this study we newly developed a monoclonal antibody against the precursor domain of IL-1beta (ED7), of which the binding to preIL-1beta was hindered by a polyclonal antibody against the mature domain of IL-1beta. Immunoprecipitation of limited proteolysed preIL-1beta by ED7 suggested that the epitope for ED7 may not be localized at the junction between preIL-1beta and mature IL-1beta. We therefore examined the possibility that the pre-domain of IL-1beta might interact with the mature domain by using chemical cross-linking. V8 protease yielded a mature 17.5-kDa protein from untreated preIL-1beta, but not chemically cross-linked preIL-1beta. However, cleavage of the cross-link with 2-mercaptoethanol liberated a mature 17.5-kDa protein from preIL-1beta, suggesting that the pre-domains of IL-1beta might interact with the mature domain. Similar phenomena were observed with preIL-1alpha. Such an intermolecular interaction may inhibit or modulate the biological activity of mature IL-1s.
Animals↗
Contralateral cerebellar activation in frontal lobe epilepsy detected by ictal Tc-99m HMPAO brain SPECT.
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Aged↗
Pentavalent Tc-99m DMSA accumulation in a medullary carcinoma of the thyroid.
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Calcitonin↗