Ion-beam manipulation of the photorefractive properties of strontium barium niobate planar waveguides.

Photorefractive planar waveguides have been fabricated in cerium-doped strontium barium niobate (Sr(x)Ba(1-x)Nb(2)O(6), SBN) single crystals by ion-beam implantation. The losses measured were as low as 0.1 and 7.

T cell tolerance and activation to a transgene-encoded tumor antigen.

Much has been learned in recent years concerning the nature of tumor antigens recognized by T cells. To apply this knowledge clinically, the nature of the host response to individual and multiple tumor antigens has to be characterized. This will help to define the efficacy of immune surveillance and the immune status of the host following exposure to tumor antigens expressed on pre-neoplastic tissue.

Acceptance of skin grafts between mice bearing different allelic forms of beta 2-microglobulin.

Single amino acid disparities in MHC class I molecules can elicit transplantation responses. Since beta 2 microglobulin (beta 2m) is noncovalently associated with class I antigens on the cell membrane we investigated whether the single amino acid polymorphism at position 85 (Asp-->Ala) in the mouse beta 2m molecule can cause skin graft rejection. A B2mb transgene was introduced into CBA(B2ma) mice which subsequently expressed both forms of beta 2m.

Conicity: A new index of body fat distribution-what does it tell us?

"Conicity" (C) is an index of body fat distribution which expresses an individuals waist circumference relative to the circumference of a cylinder generated with that persons weight and height assuming a constant for body density (Valdez [1991] J. Clin. Epidemiol.

Tolerance in TCR/cognate antigen double-transgenic mice mediated by incomplete thymic deletion and peripheral receptor downregulation.

Influenza nucleoprotein (NP)-specific T-cell receptor transgenic mice (F5) were crossed with transgenic mice expressing the cognate antigenic protein under the control of the H-2Kb promoter. Double-transgenic mice show negative selection of thymocytes at the CD4+8+TCRlo to CD4+8+TCRhi transition stage. A few CD8+ T cells, however, escape clonal deletion, and in the peripheral lymphoid organs of these mice, they exhibit low levels of the transgenic receptor and upregulated levels of the CD44 memory marker.

T cells with dual antigen specificity in T cell receptor transgenic mice rejecting allografts.

Allelic exclusion of T cell receptor (TCR) genes is incomplete: a significant percentage (10-30%) of normal human and mouse peripheral T cells express two surface TCR alpha chains, and a small percentage of peripheral human T cells have been reported to express two surface TCR beta chains. A proportion of thymocytes in TCR transgenic mice rearrange endogenous T cell receptor genes, and peripheral T cells with two TCR alpha chains, transgenic and endogenous, have been reported. T cell clones with more than a single TCR heterodimer on their surface might be expected to show specificity for more than one cognate antigen: we report here a T cell clone with dual antigen specificity, isolated from an F5 TCR influenza nucleoprotein (NP 366-374/Db)-specific transgenic female mouse which had rejected an H-2-matched male skin graft.

Immune responsiveness in mutant mice lacking T-cell receptor alpha beta+ cells.

Immune responses of mice with T-cell receptor (TCR)gamma delta+ T cells but lacking TCR alpha beta+ cells because of a disruption in the TCR alpha gene, were analysed against alloantigens, soluble protein antigen, killed Mycobacterium tuberculosis and exogenous superantigen. Rejection of skin allografts mismatched for classical major histocompatibility complex (MHC) plus multiple minor H antigens was virtually abrogated but the presence of mismatched Qa-1 non-classical MHC antigens on donor tissue resulted in a significant proportion of TCR alpha-/- mice rejecting such grafts. In view of the proposed role for gamma delta T cells in mycobacterial responses, and particularly against self- or mycobacterial heat-shock protein HSP 65, we examined these responses in TCR alpha-/- mice.

In vivo activity and in vitro specificity of CD4+ Th1 and Th2 cells derived from the spleens of diabetic NOD mice.

CD4+ T cell lines were generated from the spleens of diabetic NOD mice against crude membrane preparations derived from a rat insulinoma. Adoptive transfer of these lines into neonatal mice confirms that overt diabetes is induced by gamma-IFN-secreting Th1 cells, whereas transfer of IL-4-secreting Th2 cells resulted in a nondestructive peri-islet insulitis. Analysis of the antigens recognized by individual T cell clones from the Th1 line included reactivity against an insulinoma membrane fraction enriched in proteins of approximately 38 kD.

Aspartate at position 57 of nonobese diabetic I-Ag7 beta-chain diminishes the spontaneous incidence of insulin-dependent diabetes mellitus.

MHC class II genes have been shown to influence the development of the autoimmune disease insulin-dependent diabetes mellitus (IDDM) in the nonobese diabetic (NOD) mouse. In human IDDM it has been suggested that the presence of an aspartate at position 57 of the DQ beta-chain might be important in determining resistance to development of IDDM. The involvement of MHC class II genes in IDDM was investigated through the introduction of MHC encoding transgenes.

Developing a quality improvement database using health insurance data: a guided tour with application to Medicare's National Claims History file.

Health policy researchers are increasingly turning to insurance claims to provide timely information on cost, utilization, and quality trends in health care markets. This research offers an in-depth description of how to systematically transform raw inpatient and ambulatory claims data into useful information for health care management and research using the Health Care Financing Administration's National Claims History file as an example. The topics covered include: (a) understanding the contents and architecture of claims data, (b) creating analytic files from raw claims, (c) technical innovations for health policy studies, (d) assessing data accuracy, (d) the costs of using claims data, and (e) ensuring confidentiality.

Non-diabetogenic insulitis in NOD<-->B10.GD allophenic mice in spite of permissive class I MHC antigens.

Allophenic mice (embryo aggregation mouse chimeras) enable us to dissect the process of spontaneous autoimmunity under physiological conditions. Our previous experiments showed that the autoimmune process in allophenic mice of the NOD<-->C57B1/6 strain combination does not progress from insulitis to diabetes. One possible explanation for this protection is that H-2 Kd-restricted CD8+ T cells kill only NOD beta cells (Kd,Db) in the chimeric islets, while the B6 beta cells (Kb,Db) are spared from destruction.

A dehydrin cognate protein from pea (Pisum sativum L.) with an atypical pattern of expression.

Dehydrins are a family of proteins characterised by conserved amino acid motifs, and induced in plants by dehydration or treatment with ABA. An antiserum was raised against a synthetic oligopeptide based on the most highly conserved dehydrin amino acid motif, the lysine-rich (core sequence KIKEK-LPG). This antiserum detected a novel M(r) 40,000 polypeptide and enabled isolation of a corresponding cDNA clone, pPsB61 (B61).

Studies on the thymus of non-obese diabetic (NOD) mice: effect of transgene expression.

The non-obese diabetic (NOD) mouse is a good model of insulin-dependent diabetes mellitus. Autoreactive T cells may play a fundamental role in disease initiation in this model, while disregulation of such cells may result from an abnormal thymic microenvironment. Diabetes is prevented in NOD mice by direct introduction of an E alpha d transgene (NOD-E) or a modified I-A beta chain of NOD origin (NOD-PRO or NOD-ASP).

Talc deposition in skin and tissues surrounding silicone gel-containing prosthetic devices.

Background And Design: Periprosthetic capsule formation is the most common cause of morbidity associated with silicone gel-filled breast implants. All implant recipients develop capsules. However, the extent of capsule formation varies greatly among patients, ranging from a thin flexible membrane to a constrictive inelastic band of sclerotic collagen.

Separation of thymic education from antigen presenting functions of major histocompatibility complex class I molecules.

Participation of transmembrane (TM) and glycosyl-phosphatidylinositol (GPI) anchored H-2Db molecules in antigen presentation and thymic selection events was investigated using transgenic mice. Both GPI-Db and TM-Db can efficiently present H-Y antigen, influenza and lymphocytic choriomeningitis virus (LCMV) peptides to primed cytotoxic, H-2Db-restricted T cells. Transgenic mice expressing GPI-Db, although unable to reject TM-Db skin grafts, nevertheless generate secondary CTL responses which can lyse TM-Db-bearing targets, indicating that GPI-Db mice fail to delete all TM-Db-reactive T cells.

The effect of bone marrow and thymus chimerism between non-obese diabetic (NOD) and NOD-E transgenic mice, on the expression and prevention of diabetes.

The non-obese diabetic (NOD) mouse is an established animal model of the autoimmune disease, insulin-dependent diabetes mellitus (IDDM). The NOD-E mouse is a transgenic mouse which expresses the I-E molecule (absent in NOD mice). Expression of I-E protects these mice from both insulitis and IDDM.

T cell deletion follows chronic antigen specific T cell activation in vivo.

Exposure of mice transgenic for a TCR (F5) to cognate peptide antigen results in thymic depletion of CD4+CD8+ cells and expansion and activation of peripheral CD8+ TCR(tg)+ T cells. In the thymus apoptotic DNA ladder is evident as early as 3 h after peptide injection. Long exposure of intact or thymectomized F5 TCR transgenic mice to peptide antigen leads to depletion of most of the peripheral CD8+ T cells bearing the F5 receptor, with the remaining cells having lower levels of transgenic TCR compared with non-treated animals.

Waveguide mutually pumped phase conjugators.

The operation of the bridge mutually pumped phase conjugator is reported in a planar waveguide structure in photorefractive BaTiO(3). The waveguide was fabricated by the technique of ion implantation, using 1.5-MeVH(+) ions at a dose of 10(16) ions/cm(2).

Polyamine-like actions of peptides derived from conantokin-G, an N-methyl-D-aspartate (NMDA) antagonist.

Conantokins-T and -G are highly conserved polypeptides derived from Conus venoms. The N-methyl-D-aspartate (NMDA) antagonist properties of these compounds have been attributed to a potent noncompetitive inhibition of polyamine responses. Substitution of the highly conserved gamma-carboxyglutamate residues as well as modification of the N and C termini of conantokin-G abolished the inhibition of polyamine responses at the NMDA receptor complex.

Loss of the 'azoospermia factor' (AZF) on Yq in man is not associated with loss of HYA.

We have typed 9 EBV cell lines from azoospermic or severely oligospermic patients for the expression of H-Y antigen, in order to test the hypothesis of the coincidence of AZF and HYA genes. Of nine patients with cytogenetically normal Y chromosomes, 7 could be tested for HYA expression and of these 6 were H-Y positive. Of the three patients showing Yq structural abnormalities, two could be tested for H-Y expression and one was negative, the other positive.

Positive and negative selection in transgenic mice expressing a T-cell receptor specific for influenza nucleoprotein and endogenous superantigen.

A transgenic mouse was generated expressing on most (> 80%) of thymocytes and peripheral T cells a T-cell receptor isolated from a cytotoxic T-cell clone (F5). This clone is CD8+ and recognizes alpha alpha 366-374 of the nucleoprotein (NP 366-374) of influenza virus (A/NT/60/68), in the context of Class I MHC Db (Townsend et al., 1986).