Overexpression of the Del1 gene causes dendritic branching in the mouse mesentery

In the present study, we established transgenic mice overexpressing Del1, a ligand of integrins, to examine the effect of overexpression of Del1 on vascular morphogenesis. In the wild-type mouse, mesenteric vessels are shaped like rakes consisting of a long stalk and short branches at the periphery. In contrast, those in transgenic mice showed typical dendritic architecture consisting of a few large primary branches with smaller spreading branches. The phenotype of mice overexpressing Del1 suggests the existence of a tissue-specific mechanism for branching morphogenesis in the mesentery.     

A mathematical model of optimized radioiodine-131 therapy of Graves' hyperthyroidism

Background

The current status of radioiodine-131 (RaI) dosimetry for Graves' hyperthyroidism is not clear. Recurrent hyperthyroidism and iatrogenic hypothyroidism are two problems which interact such that trying to solve one leads to exacerbation of the other. Optimized RaI therapy has therefore begun to be defined just in terms of early hypothyroidism (ablative therapy) as physicians have given up on reducing hypothyroidism.

Methods

Optimized therapy is evaluated both in terms of the greatest separation of cure rate from hypothyroidism rate (non-ablative therapy) or in terms of early hypothyroidism (ablative therapy) by mathematical modeling of outcome after radioiodine and critically discussing the three common methods of RaI dosing for Graves' disease.

Results

Cure follows a logarithmic relationship to activity administered or absorbed dose, while hypothyroidism follows a linear relationship. The effect of including or omitting factors in the calculation of the administered I–131 activity such as the measured thyroid uptake and effective half-life of RaI or giving extra compensation for gland size is discussed.

Conclusions

Very little benefit can be gained by employing complicated methods of RaI dose selection for non-ablative therapy since the standard activity model shows the best potential for cure and prolonged euthyroidism. For ablative therapy, a standard MBq/g dosing provides the best outcome in terms of cure and early hypothyroidism.     

Early ultrastructural changes in the biliary epithelial cells of BALB/c and DDY mice immunized with swine serum

Electron microscopic observations were carried out on the biliary epithelial cells of BALB/c and DDY mice which had received an intraperitoneal injection of 0.2 ml of swine serum twice a week for 2 or 4 weeks. The most characteristic feature of the biliary epithelial cells of BALB/c mice was a marked increase in the number of vesicles having a close spatial relationship with the well-developed Golgi apparatus or rough endoplasmic reticulum (rER). In contrast, marked dilation of rER filled with moderately electron-dense material was conspicuous in the biliary epithelial cells of DDY mice. A prominent increase in the number of blebs and lateral and basal cytoplasmic protrusions in the dilated intercellular space of the biliary epithelium, and submucosal eosinophil infiltration, collagen fiber proliferation and gland hyperplasia with increased mucin secretion were common to both strains. This experimental model of bile duct disease also seems to be useful for investigating alteration of protein synthesis and secretion in epithelial cells.     

Factors influencing the incidence and severity of swine-serum-induced bile duct lesion in mice

The detailed histopathology of the swine-serum (SS)-induced bile duct lesion and some factors influencing the incidence and severity of the lesion were examined. The lesion was expressed as an eosinophilic and proliferative cholangitis affecting almost the full length of the biliary tract. It appears to be a useful new model of bile duct diseases. The co-existence of sufficient anti-SS antibody together with repeated injection of SS were necessary to produce this lesion. The lesion could be induced reproducibly by intraperitoneal injection of 0.05 to 0.2 ml of swine serum twice a week for 4 weeks in young BALB/c mice.     

Immunopathological correlation between mesangial C3d-deposition and C3d-fixing circulating immune complexes in lupus nephritis

By a direct immunofluorescent technique, glomerular C3d deposition was examined in a total of 50 renal biopsy specimens from patients with lupus nephritis. C3d deposition was then compared with disease activity, glomerular IgG and C3c deposition, and the levels of circulating immune complexes (CIC) measured by a solid-phase anti-C3d assay. There was a good correlation between disease activity and the positivity of glomerular C3d deposits (P less than 0.001), as well as C3c deposits (P less than 0.001). Even in clinically inactive patients, a relatively high percentage (59%) of C3d deposits were positive compared with C3c deposits (17%). Mesangial C3d deposition correlated with clinical disease activity more significantly (P less than 0.005) than capillary wall C3d deposition (P less than 0.025). C3d deposits were detected in all of the 30 cases with positive C3c deposits, and moreover, in 15 of the 20 (75%) cases with negative C3c deposits. Glomerular IgG deposits were almost always associated with C3d deposits, both in mesangial areas and along capillary walls, with statistical significance (P less than 0.005, P less than 0.001, respectively). The serum levels of C3d-fixing immune complexes (IC) were significantly correlated with the positivity and intensity of mesangial C3d deposits. This study demonstrates glomerular deposition of C3d in patients with lupus nephritis and reveals a significant correlation between mesangial C3d deposition and disease activity.     

Suppression of eosinophilic airway inflammation by treatment with alpha-galactosylceramide

To clarify the essential role of NKT cells in allergy, we investigated the contribution of NKT cells to the pathogenesis of eosinophilic airway inflammation using alpha-galactosylceramide (alpha-GalCer), a selective ligand for NKT cells. Although continuous administration of alpha-GalCer during ovalbumin (OVA) sensitization increased OVA-specific IgE levels and worsened eosinophil inflammation, a single administration of alpha-GalCer at the time of OVA challenge completely prevented eosinophilic infiltration in wild-type mice. This inhibitory effect of alpha-GalCer was associated with a decrease in airway hyperresponsiveness, an increase in IFN-gamma, and decreases in IL-4, IL-5 and IL-13 levels in the bronchoalveolar lavage fluids. Analysis of lung lymphocytes revealed that production of IFN-gamma increased in NK cells, but not in T or NKT cells, following alpha-GalCer administration. Induction of vascular cell adhesion molecule-1 in the lungs of wild-type mice was also significantly attenuated by treatment with alpha-GalCer. These effects of alpha-GalCer were abrogated in J alpha281-/- mice, which lack NKT cells, and in wild-type mice treated with anti-IFN-gamma Ab. Hence, our data indicate that alpha-GalCer suppresses allergen-induced eosinophilic airway inflammation, possibly by inducing a Th1 bias that results in inhibition of eosinophil adhesion to the lung vessels.     

Simultaneous localization of histamine and factor VIII-related antigen in the endothelium of the human umbilical vein

Simultaneous immunoelectron microscopic localization of histamine and factor VII-related antigen was examined on the same ultrathin section of the endothelium of the human umbilical vein from full-term deliveries by means of the double-immunolabeling technique. Small gold particles demonstrating antibody reaction with histamine are preferentially located in the cytoplasmic matrix and organelles, especially in mitochondria and on the luminal membrane surface of the endothelial cells. The gold particles representing histamine immunoreactivity also located on some of Weibel Palade (WP) bodies. In contrast, large gold particles demonstrating factor VII-related antigen are concentrated preferentially on most WP bodies. Single labeling of either histamine or factor VIII-related antigen shows similar results to those of the double labeling. The present study indicates that some WP bodies are involved in storage of both factor VIII-related antigen and histamine, but others store factor VIII-related antigen only. This difference in contents of WP bodies may be induced during the development and maturation process of this inclusion. At any rate, it is reasonable to consider that WP bodies have important roles in both vascular tonus and hemostasis during the vascular obliteration.     

Crystal Growth in Poly(L‐lactide) Thin Film Revealed by in situ Atomic Force Microscopy

Direct visualization of crystal growth in poly(L ‐lactide) thin films was carried out by using a temperature‐controlled atomic force microscopy (AFM). At the initial stage of crystallization, edge‐on lamellar crystals have nucleated and elongated. Subsequently, the edge‐on lamellar crystals showed S‐shaped morphology and changed their orientation from edge‐on manner to flat‐on one. The curvature of edge‐on lamellar crystal has been discussed in terms of inclination and distortion of polymer chains in the crystal. In addition, mechanism on the formation of flat‐on crystal from edge‐on lamellae was proposed as derivative growth on the basis of in situ AFM observation of crystal growth and enzymatic degradation.

     

Tumor necrosis factor alpha-induced interleukin-8 production via NF-kappaB and phosphatidylinositol 3-kinase/Akt pathways inhibits cell apoptosis in human hepatocytes

Tumor necrosis factor alpha (TNF-alpha) not only induces apoptotic signals but also causes antiapoptotic and regenerative responses in the liver. However, the molecular mechanism(s) of the latter events remains unclear. In the present study, we examined TNF-alpha-induced genes in Hc human normal (unsensitized) hepatocytes by cDNA microarray analysis. Interleukin-8 (IL-8) induction was the most pronounced of the upregulated genes. The IL-8 protein level was also increased. IL-8 belongs to the ELR-CXC chemokine family and appears to exert mitogenic and antiapoptotic functions in other cell systems. IL-8 expression by TNF-alpha was inhibited when two survival signals, nuclear factor kappaB (NF-kappaB) and phosphatidylinositol 3-kinase (PI3K)/Akt, were inhibited by a mutant form of inhibitor of NF-kappaB (IkappaB); by dominant negative (kinase-dead) Akt; or by treatment with LY 294002, an inhibitor of PI3K. TNF-alpha induced apoptosis in Hc cells that were sensitized by inhibition of NF-kappaB and PI3K activation. IL-8 administration protected mice against concanavalin A-induced hepatitis in vivo. IL-8 also rescued the sensitized Hc cells, at least in part, from TNF-alpha-induced apoptosis in vitro. TNF-alpha inhibited DNA synthesis in unsensitized Hc cells in the absence of serum. Exogenous IL-8 reversed, though anti-IL-8 neutralization antibody enhanced, growth inhibition by TNF-alpha. These results indicate that IL-8, the production of which is stimulated by TNF-alpha, inhibits apoptosis of sensitized hepatocytes and releases normal (unsensitized) hepatocytes from growth inhibition induced by TNF-alpha.     

Non-IgG1 nature of cutaneous basophil hypersensitivity factor in contact sensitivity. II. Demonstration of antigen-dependent basophil chemotactic activity of cutaneous basophil hypersensitivity factor

It was recently demonstrated that there was a specific activity to induce basophil-rich skin reaction in the sera of contact-sensitized guinea pigs (CBH factor, CBH-F). In the in vitro chemotactic assay system, CBH-F was shown to have weak basophil chemotactic activity but enhanced its activity in the presence of corresponding antigen(s). Furthermore, basophil chemotaxis in reaction to the antigen(s) was observed when the cells were preincubated with CBH-F. It worked mainly for Percoll-separated bone marrow basophils but not for oil-induced peritoneal macrophages. Immunological analysis revealed that CBH-F was a protein with a small molecular weight (MW 4-6 X 10(4] with an antigen binding site and isoelectric point of between 4.5 and 5.0. It did not show any characteristics of IgG1 or IgG2 on immunoadsorbent column and immunoelectrophoresis. Enzyme treatment with insoluble trypsin eliminated the chemotactic activity but this was not the case with neuraminidase treatment.