Characterization of a peptide analog of a determinant of type II collagen that suppresses collagen-induced arthritis

Immunization of susceptible strains of mice with type II collagen (CII) elicits an autoimmune arthritis known as collagen-induced arthritis (CIA). One analogue peptide of the immunodominant T cell determinant, A9 (CII245-270 (I260-->A, A261-->B, F263-->N)), was previously shown to induce a profound suppression of CIA when coadministered at the time of immunization with CII. In the present study, A9 peptide was administered i.p., orally, intranasally, or i.v. 2 to 4 wk following CII immunization. We found that arthritis was significantly suppressed even when A9 was administered after disease was induced. To determine the mechanism of action of A9, cytokine responses to A9 and wild-type peptide A2 by CII-sensitized spleen cells were compared. An increase in IL-4 and IL-10, but not in IFN-gamma, was found in A9 culture supernatants. Additionally, cells obtained from A9-immunized mice produced higher amounts of IL-4 and IL-10 when cultured with CII compared with cells obtained from mice immunized with A2, which produced predominantly IFN-gamma. Suppression of arthritis could be transferred to naive mice using A9-immune splenocytes. Lastly, phosphorylation of TCRzeta was not altered in the immunoprecipitates from the lysates of cells exposed to analogue peptides (A9 and A10) together with wild-type A2 in a T cell line and two I-Aq-restricted, CII-specific T hybridomas. We conclude that analogue peptide A9 is effective in suppressing established CIA by inducing T cells to produce a Th2 cytokine pattern in response to CII.     

Low-speed tack measurements of fluids and inks

Low-speed tack measurements (≈ 0.1–6.0 rad/s or ≈ 1–57 RPM) have been determined for polymeric-based solution inks and oil-based dispersion inks, tripropylene glycol (TPG), Igepal (I-530), and N-350 (viscosity calibration standard) fluids using a metal roller/incline method. The inks and fluids were tested under “unaged” or reference conditions at 25°C. The inks were “aged” at 70°C and, subsequently, tack measurements were made at 25°C. The tack (T_i) and angular speed (W_i) for the inks were empirically fitted as functions of incline angle (α) and “aged” time, t_cd. A correlation was also made for tack and percent weight change, ΔW_i. Other factors, such as viscosity, surface tension, humidity, and “aging” temperature, T_cd, were also found to affect the magnitude and variation of tack. Additionally, the results suggest that low-speed tack measurements are quite useful for selecting solution inks containing polymeric substances that possess the desirable spreading, mixing, and pressing properties in high-speed/high-volume printing and the component compatibility necessary for long-term performance. © 1995 John Wiley & Sons, Inc.     

Image formation of alkyl-pendent aromatic polyimide by photocoupling with aromatic ketones

Positive and negative photostructures are formed after the polyimide (PI) of 4,4′-biphthalic anhydride (BPA) and 4,4′-diamino-3,3′-dimethyldiphenylmethane (DADMDPM), PI(BPA/DADMDPM) is doped with Michler′s ketone (MK) and benzophenone (BP), respectively, and is subjected to UV light (400 ± 50 nm) irradiation and solvent development. The principle of positive feature formation is based on the photocoupling of MK with PI, which increases PI solubility and thus enables a positive pattern to be developed. The phenomenon of negative photopatterning results from intermacromolecular H-bonding between the carbonyl group of the imide ring and the hydroxy group which is formed in the photoinduced coupling reaction between BP and PI. Lithographic evaluation shows that the MK-doped positive-acting PI film cannot form useful patterns because UV wavelengths are strongly absorbed by MK, which limits the depth of photocoupling in the film. On the other hand, 2-μm-wide lines can be resolved in the BP-doped negative-acting 0.6-μm-thick PI film.     

Partial eigenstructure assignment and its application to largescale systems

The notion of partial eigenstructure assignment (PEA) via linear state feedback control in linear multivariable systems is introduced. This notion is a natural extension of eigenstructure assignment and partial eigenvalue assignment. Some theoretical basis for PEA is provided, and a parametric expression for feedback gain matrices achieving PEA is derived. An effective numerical algorithm for PEA tailored to large-scale systems is presented. As an extension of the algorithm, a recursive algorithm for eigenstructure assignment is presented. These algorithms possess the following desired properties: (1) compared to existing methods, the presented algorithms significantly reduce the required computation time via transforming high-dimensional matrix computations into low-dimensional matrix computations; (2) they can be implemented in a parallel fashion. The proposed algorithm for PEA is applied to modal control of large flexible space structure systems     

Grain-Boundary Migration in Nonstoichiometric Solid Solutions of Magnesium Aluminate Spinel: II, Effects of Grain-Boundary Nonstoichiometry

The grain-boundary chemistry of magnesium aluminate spinel solid solutions MgO· n Al₂O₃ in which grain growth measurements were reported in part I has been investigated in order to understand the mechanism of grain-boundary migration. It is found that although segregation of impurity Ca and Si is common, much larger deviations in grain-boundary stoichiometry are present. There is an excess of Al and O relative to Mg at grain boundaries in all compositions. Grain-boundary migration appears to be rate-limited by solute drag from intrinsic defects accommodating lattice nonstoichiometry, rather than by extrinsic solutes, consistent with the observed impurity tolerance of grain-boundary mobility. Different rate-limiting defects are proposed for magnesia-rich and alumina-rich spinels.     

Using multithreshold quadratic sigmoidal neurons to improveclassification capability of multilayer perceptrons

This letter proposes a new type of neurons called multithreshold quadratic sigmoidal neurons to improve the classification capability of multilayer neural networks. In cooperation with single-threshold quadratic sigmoidal neurons, the multithreshold quadratic sigmoidal neurons can be used to improve the classification capability of multilayer neural networks by a factor of four compared to committee machines and by a factor of two compared to the conventional sigmoidal multilayer perceptrons.     

Subpubic sinus: a remnant of cloaca

A 14-month-old girl had purulent discharge from a sinus over the subpubic region for 2 weeks. Radiography and voiding cystourethrography revealed a 4.5 cm. long fistula extending to the retropubic region without any connection to the lower urinary tract. The fistula was excised. Histological findings revealed that the fistula had 3 different types of epithelium: stratified squamous, transitional and columnar. Clinical and pathological findings indicated that the sinus was most likely a remnant of the cloaca.     

Surface morphology and photoluminescence of InAs quantum dots grown on [11~0]-oriented streaked islands under ultra-low V/III ratio

The influences of the low V/III ratio on the surface morphologies and temperature-dependent photoluminescence spectrum of InAs-GaAs quantum dots (QDs) prepared by organometallic vapor phase epitaxy are investigated. Due to the accumulation of In adatoms at the multiatomic step edge on [001] 2/sup 0/ off toward an [111] n-type GaAs substrate, InAs island growth with /spl sim/1 ML coverage takes place prior to the InAs QD formation. With increasing InAs coverage, self-assembled InAs QDs are observed near the InAs islands, which is attributed to the recapture of desorbed In atoms nucleating with supplied As atoms on the edge along [11~0]-orientation of the GaAs substrate.     

Use of polymerase chain reaction to assess efficacy of leprosy chemotherapy

The assessment of chemotherapy efficacy in leprosy is difficult, since the only reliable method for determining whether the causative organism, Mycobacterium leprae, is viable depends on its growth in mouse foot pads. In an attempt to replace this expensive, time-consuming test, methods based on the polymerase chain reaction (PCR) have been developed. These methods depend on detection of DNA, which is more susceptible to degradation on cell death than are other cell components, so should be a more accurate indicator of viability. We have used a specific PCR assay to detect M leprae DNA in skin biopsy samples from leprosy patients. By use of limiting dilution PCR (LD-PCR), the concentration of M leprae DNA in the original sample could be measured. The DNA concentration was more closely correlated with the morphological index (derived from a staining technique that distinguishes morphologically intact and damaged bacteria) than with the number of bacteria visible (bacterial index, BI, which counts both alive and dead bacteria). In a longitudinal study of multibacillary patients on multi-drug therapy, skin biopsy samples were collected before treatment and 3, 6, 12, and 24 months after the start of therapy. While the BI showed little or no change during treatment, the number of genomes detected by PCR fell sharply, in parallel with the MI. We propose that PCR can be used as a rapid measure of M leprae viability and that this approach can be used for monitoring individual leprosy patients and for assessment of existing and new regimens. The method may be applicable to other infectious diseases in which culture of the causative organism is slow or impossible.