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.     

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.

     

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.     

Functional interleukin 2 receptors on B cells lacking Tac antigens

Human B lymphoblastoid line, SKW 6-4, cells were induced to IgM-secreting cells by high concentrations of interleukin 2 (IL 2). These cells were found to be unreactive with anti-Tac antibody and did not express mRNA detectable for Tac antigen. In Scatchard plot analysis, low-affinity IL 2-binding sites were found on SKW 6-4 cells. Moreover, analysis of the IL 2-binding molecules revealed ones (molecular weight 70,000 and 75,000) distinct from Tac antigen. It is conceivable that IL 2 exerts its effect through its interaction with these novel IL 2-binding molecules in SKW 6-4 cells.     

Two cases of limited cutaneous nodular amyloidosis with primary Sj?gren's syndrome]

We described two female patients with primary Sj?gren's syndrome associated with localized cutaneous nodular amyloidosis (LCNA), in which amyloid protein was derived from immunoglobulin light chain. Case 1; a 70-year-old female had complained with polyarthralgia, low-grade fever and parotid gland swelling. She was diagnosed as primary Sj?gren's syndrome. Three years later she noticed brown color small tumor on the thigh and yellow to brown nodules on the bilateral calves of legs. Skin biopsy from the left thigh revealed amyloid L protein deposition, which was positive for anti-lambda light chain staining, in almost entire dermis. Infiltration of lymphocytes and plasma cells around the amyloid deposit were prominent. Case 2; a 51-year-old female had noticed increasing eruption on the hip. Skin biopsy revealed amyloid L protein deposition in the dermis, which was negative for anti-lambda nor kappa light chain staining. When she was refereed to our hospital, she complained of xerostomia and xerophthalmia. She was diagnosed as primary Sj?gren's syndrome. In both cases, histological examination of a minor salivary gland biopsy revealed infiltration of lymphocytes and plasma cells but not amyloid deposit. Serum M protein and urine Bence-Jones protein were not detected. These cases represent localized amyloidosis without systemic involvement. It is widely recognized that Sj?gren's syndrome is frequently accompanied by B cell lymphoproliferative disorders. In LCNA, infiltration of plasma cells around the amyloid deposits was frequently prominent. The relation between these two disorders is discussed.     

Nuclear magnetic resonance studies on bacterial copolyesters of 3-hydroxybutyric acid and 3-hydroxyvaleric acid

Copolyesters of 3-hydroxybutyric acid (HB) and 3-hydroxyvaleric acid (HV), P(HB-co-HV), were isolated from Alcaligenes eutrophus and characterized by solution NMR, solid-state ¹³C CP/MAS NMR, and differential scanning calorimetry. The ¹³C CP/MAS NMR analysis was compatible with that of a random copolyester of oxy-(1-methyl-3-oxotrimethylene) ( B ) and oxy-(1-ethyl-3-oxotrimethylene) ( V ) units which adopts a regular conformation of a 2₁ -helix in the solid state throughout a wide range of compositions varying from 0 to 90 mol-% V units. The chain dynamics of P(HB-co-HV) in chloroform was studied by analysis of the ¹³C and ¹H NMR spectra. The carbon-13 spin-lattice relaxation times (T₁) and nuclear Overhauser enhancements (NOE) indicated that the copolyester molecules in chloroform are not rigid but rather flexible. The conformational preferences of the copolyester molecules were determined by analysis of the ¹H NMR spectra.     

Structure of the functional interleukin-2 receptor: Evidence for the association of human p55 and murine p75 molecules in a mouse T cell line

The structural basis of the high affinity interleukin-2 receptorwhich was previously reconstituted in a cultured murine T cellline, EL4 by expressing either wild-type Tac antigen complementaryDNA (cDNA) or a chimeric cDNA was characterized. The chimericcDNA encodes a membrane portion whose extracellular portionconsists of that of Tac antigen whereas transmembrane and cytoplasmicportions consists of those the human insulin beta chain. TheTac antigen/anti-Tac antibody complex was treated by chemicalcrosslinking reagents, purified by goat anti-mouse immunoglobulin(lg), and was analysed by SDS–PAGE. We here demonstrated the presence in mouse EL4 transfectantsof a novel membrane protein which is closely associated withthe products of transfected cDNAs in the absence of interleukln-2.The protein is 75 kDa in size and is detected in cells whichexpress high affinity interieukln-2 receptor but not in cellswhich only express low affinity interleukin-2 receptor. Thetransmembrane region and the cytoplasmic region of Tac antigenis not necessary for the formation of the complex consistingof Tac antigen and 75 kDa molecule, indicating that a murine75 kDa molecule associates with Tac antigen extra-cellularly.