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Biomedical subjects

C E Hayes

Publications and source records attributed to C E Hayes.

At least 73 records · Page 4Linked to original sources
PubMed1990

The mouse antibody response to Trichinella spiralis defines a single, immunodominant epitope shared by multiple antigens.

Immunoblot analysis was used to characterize the Trichinella spiralis L1 larval Ag recognized by antisera from T. spiralis-infected AKR/J mice. Antisera were analyzed for reactivity with crude worm extract, excretory/secretory proteins and cuticle proteins from L1 larvae. The response was biphasic; antibodies against one set of Ag were detected 13 days after infection (group I Ag), and antibodies against a different set of Ag were detected 35 days after infection (group II Ag). Excretory/secretory and cuticle proteins were recognized only by antibodies produced late in infection. The predominant isotype in day 42 antiserum was IgG1, and 80% of these IgG1 antibodies reacted with a stage-specific determinant shared by virtually all group II Ag. A mAb reactive with the shared determinant was used to purify the group II Ag from L1 larval extract. Such affinity-purified Ag were protective when used to immunize mice against subsequent infection, and T cells from infected mice proliferated when cultured with these Ag in vitro. Other mouse strains also made a strong serum antibody response to the group II Ag. We hypothesize that immune responses to the shared epitope play an important role in determining the outcome of the host-parasite interaction during infection.

Administration, Oral↗
PubMed1990

Noise correlations in data simultaneously acquired from multiple surface coil arrays.

Multiple images acquired simultaneously from an array of surface coils can be combined to give a composite image with an improved signal-to-noise ratio (SNR) and a large field of view. The composite images' SNR can be optimized by taking advantage of noise correlations between coils and phase shifts induced by surface coil reception. Methods are derived for making optimal composite images with uniform noise or with uniform sensitivity. A simplified model is used to provide an intuitive understanding of the interaction of noise correlation and phase shift phenomena.

Humans↗
PubMed1990

The NMR phased array.

We describe methods for simultaneously acquiring and subsequently combining data from a multitude of closely positioned NMR receiving coils. The approach is conceptually similar to phased array radar and ultrasound and hence we call our techniques the "NMR phased array." The NMR phased array offers the signal-to-noise ratio (SNR) and resolution of a small surface coil over fields-of-view (FOV) normally associated with body imaging with no increase in imaging time. The NMR phased array can be applied to both imaging and spectroscopy for all pulse sequences. The problematic interactions among nearby surface coils is eliminated (a) by overlapping adjacent coils to give zero mutual inductance, hence zero interaction, and (b) by attaching low input impedance preamplifiers to all coils, thus eliminating interference among next nearest and more distant neighbors. We derive an algorithm for combining the data from the phased array elements to yield an image with optimum SNR. Other techniques which are easier to implement at the cost of lower SNR are explored. Phased array imaging is demonstrated with high resolution (512 x 512, 48-cm FOV, and 32-cm FOV) spin-echo images of the thoracic and lumbar spine. Data were acquired from four-element linear spine arrays, the first made of 12-cm square coils and the second made of 8-cm square coils. When compared with images from a single 15 x 30-cm rectangular coil and identical imaging parameters, the phased array yields a 2X and 3X higher SNR at the depth of the spine (approximately 7 cm).

Humans↗
PubMed1990

Characterization of Trichinella spiralis antigens sharing an immunodominant, carbohydrate-associated determinant distinct from phosphorylcholine.

The biochemical and immunochemical characteristics of T. spiralis molecules (group II antigens) sharing an immunodominant epitope were examined. Six major proteins, ranging from 43-68 kDa, and from pI 5.0-6.3, express the determinant. Together, they account for at least 3% by weight of the total protein in L1 larval homogenate. The antigens are glycosylated. Following periodate oxidation, they reacted with biotin aminocaproyl hydrazide, and treatment with trifluoromethanesulfonic acid decreased their Mr. Deglycosylated group II antigens lost immunoreactivity with a monoclonal antibody specific for the determinant, and oligosaccharides released by treatment with mild base blocked binding of the monoclonal antibody to native antigens. The determinant on one of the group II antigens (43 kDa) was removed by N-glycanase. Neither phosphorylcholine nor antibody to phosphorylcholine interfered with monoclonal antibody binding to native group II antigens. Together, these results suggest that the immunodominant group II antigen epitope is associated with N- and O-linked oligosaccharides, and that it is not phosphorylcholine.

Amidohydrolases↗
PubMed1989

Evidence for differential induction of helper T cell subsets during Trichinella spiralis infection.

The H-2-compatible mouse strains, AKR and B10.BR, exhibit disparate responses to infection with the parasitic nematode Trichinella spiralis. The resistant AKR mice expel intestinal adult worms faster than susceptible B10.BR mice. We tested antibody and lymphokine responses in these strains. With respect to antibody responses, the B10.BR mice had 3- to 10-fold more serum IgE and T. spiralis-specific IgG1 and IgA than AKR mice. The B10.BR mice also had greater numbers of IgG and IgA plaque-forming cells than AKR mice. In contrast, AKR mice produced T. spiralis-specific IgG2a, whereas the B10.BR mice did not. The antibody response kinetics of these strains were similar. We also analyzed lymphokine secretion after restimulating lymphocytes in vitro with T. spiralis Ag. The AKR mesenteric lymph node cells produced more IFN-gamma and less IL-4 than the B10.BR mesenteric lymph node cells. The B10.BR splenocytes produced more IL-4 than the AKR splenocytes, although splenocyte IFN-gamma production was not different. The kinetics of IL-4 production also differed between the two strains. In summary, resistant AKR mice produced more IFN-gamma and T. spiralis-specific IgG2a than susceptible B10.BR mice, which produced more IL-4, IgE, and T. spiralis-specific IgG1. Our results are consistent with differential activation of Th cell subsets in T. spiralis-infected AKR and B10.BR mice.

Animals↗
PubMed1989

Characterization of a helper T lymphocyte defect in vitamin A-deficient mice.

Vitamin A-deficient mice exhibited sharply decreased IgG1 responses to protein Ag in vivo and in vitro. We traced the cellular basis for these impaired responses to a functional defect in A-deficient Th. Ag-presenting cells and B cells from A-deficient mice showed no functional defects. The A-deficient T cells proliferated normally in response to Ag but failed to provide the B cell stimulus for Ag-specific IgG1 responses. The A-deficient mice had fewer Th by limiting dilution analysis, and retinyl acetate supplementation in vitro restored Th frequency to control levels. Because added retinyl acetate reversed the Th functional block, these vitamin A-deficient T cells must be primarily defective in activation, not in establishment of immunologic memory.

Animals↗
PubMed1987

Contrasting impairments in IgM and IgG responses of vitamin A-deficient mice.

Mice fed a semipurified, vitamin A-deficient diet (A- mice) and control animals fed the same diet with added retinyl acetate (A+ mice) were used to investigate the effect of vitamin A deficiency on primary immunoglobulin responses to protein antigens. At age 6 weeks, A- mice had serum retinol concentrations that were 46% of A+ controls. When immunized with a single antigen dose, these mice produced an antigen-specific IgM response equivalent to controls, but their IgG1 and IgG3 responses were sharply diminished (less than 30% of A+ controls). At age 8 weeks, A- mice had 20% of A+ serum retinol concentrations and less than 17% of A+ liver retinyl palmitate levels. Responding to a single antigen dose, A- mice produced approximately equal to 70% as much IgM as A+ controls. Their IgG1 response was less than 30% and their IgG3 response less than 3% of A+ controls. The IgG1 response kinetics were identical in A- and A+ mice. Diminished serum antibody responses in A- mice were attributable to fewer immunoglobulin-secreting plasma cells rather than to a decline in IgM or IgG secretion rate per cell. Total serum IgG3 levels, irrespective of antigen specificity, were slightly elevated in A- mice compared to A+ controls. The inefficient clonal expansion of responding B lymphocytes and contrasting impairment of IgM and IgG responses observed in vitamin A-deficient mice are discussed with respect to a possible helper/inducer-T-lymphocyte defect.

Animals↗
PubMed1987

Impaired immunity in vitamin A-deficient mice.

Vitamin A deficiency was produced in mice and was used to investigate the role of vitamin A in immune function. Cellular immunity, as measured by delayed-type hypersensitivity, diminished in early deficiency before weight and appetite changes occurred and declined further as the deficiency progressed. Humoral immunity, as measured by serum immunoglobulin M (IgM) responses to a protein antigen (hemocyanin), also declined. The kinetics of antibody production were unaffected by the deficiency. The T-cell number remained unchanged, but B-cell and macrophage numbers were increased in vitamin A--deficient mice. Surface expression of membrane glycoproteins (Thy-1, Lyt-1, Lyt-2, L3T4, IgM, Mac-1) was unchanged by the deficiency, as were lymphocyte numbers and distribution. The results suggest that vitamin A deficiency is associated with a functional immune system defect.

Animals↗
PubMed1986

Monoclonal antibodies to the porcine intestinal receptor for 1,25-dihydroxyvitamin D3: interaction with distinct receptor domains.

Monoclonal antibodies to different domains of the porcine intestinal 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] receptor have been produced. A nuclear extract enriched in the 1,25-(OH)2D3 receptor was prepared from small intestinal mucosa of young pigs. The receptor was purified an additional 6600-fold by chromatography on DNA-cellulose, ammonium sulfate precipitation, gel filtration high-performance liquid chromatography, and DEAE-Sepharose chromatography, with an overall yield of 23% and an average purity of 24%. A BALB/c mouse immunized with this material developed serum polyclonal antibodies to the 1,25-(OH)2D3 receptor, as demonstrated by a change in sedimentation of the porcine receptor on sucrose gradients. Spleen cells from this animal were fused with mouse myeloma cells (P3-NSI/1-Ag4-1, SP2/0-Ag14), and 24 hybridomas secreting antibodies to the 1,25-(OH)2D3 receptor were identified by both a radiometric immunosorbent assay and an immunoprecipitation assay. Twenty-one hybridoma lines were cloned by limiting dilution and further characterized as subclass IgG1 antibodies with the exception of one which is an IgA. All but two of the antibodies cross-react with the 1,25-(OH)2D3 receptor from both mammalian (human, monkey, and rat) and avian (chicken) intestine; two antibodies recognize only porcine intestinal receptor. All antibodies are unreactive to the vitamin D serum transport protein. Eight of the antibodies bind denatured receptor on an immunoblot. A solid-phase competition assay was used to identify four groups of antibodies that bind to distinct epitopes on the 1,25-(OH)2D3 receptor. One antibody from each of the four groups was used to examine the effect of antibody binding on the DNA-binding activity of the receptor-hormone complex. One antibody completely inhibited the binding of the 1,25-(OH)2D3 receptor complex to DNA-cellulose, suggesting that the epitope for this antibody may be located in the polynucleotide binding domain of the protein. Antibodies from two additional groups only slightly perturbed DNA binding, while one had no effect, suggesting that these antibodies bind to receptor epitopes distant from the region of the polypeptide directly involved in polynucleotide binding. These antibodies that are directed to several different binding sites on the 1,25-(OH)2D3 receptor provide important new tools to probe the biochemistry and topology of the 1,25-(OH)2D3 receptor and to investigate its role in mediating target tissue response to hormone.

Animals↗
PubMed1986

The effects of myotoxin from midget faded rattlesnake (Crotalus viridis concolor) venom on neonatal rat myotubes in cell culture.

Neonatal rat myoblasts were isolated and grown in culture until they fused into multinucleated myotubes. A small percentage of the myotubes showed spontaneous contractions when maintained in Dulbecco's Modified Eagle's Medium with 10% fetal bovine serum. Incubation of mature myotubes (at least 3 days after fusion) with myotoxin II from Crotalus viridis concolor venom at a concentration as low as 18.5 nM caused a marked increase in the number of myotubes demonstrating contractile activity. The increase was apparent within 24 hr of myotoxin application. The response of the myotubes appeared to be specific since, of the proteins tested, only native myotoxins caused the increase in contractile activity. This tissue culture system offers a rapid screening assay that requires less time and fewer animals than the assays currently in use for determining myotoxic activity.

Animals↗
PubMed1986

Methodology of in vivo human sodium MR imaging at 1.5 T.

The methodology of sodium-23 (Na-23) imaging is reported in relationship to the physiological factors that determine the chemical environment of the Na-23 nucleus. Contrast resolution is given as a function of imaging time and spatial resolution. Data showing the optimal relaxation time for sodium imaging are given, and the linear quantitative relationship between sodium concentration and voxel intensity for our imaging system is confirmed. The major problem facing in vivo sodium imaging is the ability to differentiate intracellular sodium from extracellular sodium. The sodium in blood serum (extracellular) and packed red blood cells (intracellular) both exhibit biexponential T2 decay. These results indicate that T2 measurements alone will be insufficient for discriminating extracellular from intracellular sodium. Instead, other methods based on the underlying physiological properties of in vivo sodium imaging, such as the diffusion coefficient, will be necessary to truly separate extracellular from intracellular sodium.

Brain Neoplasms↗
PubMed1985

The I-J glycoprotein: genetic control, biochemistry, and function.

The I-J molecule is a mannosylated protein expressed early in T cell ontogeny in partially shielded form, later fully exposed on an activated T cell subset. Others determined a 25-30,000 molecular weight for cellular (Kumagai et al. 1984) and secreted forms (Taniguchi et al. 1984). Both the cell membrane and secreted types seem to govern genetically-restricted interactions completing suppressor cell circuits. The soluble I-J polypeptide has no antigen-binding site, but associates with an antigen-binding chain via disulfide bonding (Taniguchi et al. 1984, Lei et al. 1983). Similarly, evidence suggests that cellular I-J molecules are part of or proximal to T cell antigen receptor complexes (Fig. 4). At least two genes control T cell I-Jk expression, one apparently in I-E, another on chromosome 4. Undiscovered loci may also participate. Since I-J+ T cells do not transcribe I-region DNA, the I-E gene must be an untranscribed regulatory element in T cells or a protein translated in the host environment. If in the host environment, it probably does not function enzymatically to form T cell I-J epitopes; removed from the host, T cells biosynthesize complete I-J determinants. Host I-E gene products may regulate I-J expression in an early T cell maturation step. For example, the E alpha E beta proteins of thymic macrophages and epithelial cells may drive the expansion of T cells with E alpha E beta-complementary receptors encoded by I-J genes outside H-2. Genetic control of this self receptor would then apparently map to the selective ligand gene, I-E, as well as the I-J structural gene elsewhere (Klyczek et al. 1984b). This attractive theory, proposed in its original form by Jerne (1971) and later by Schrader (1979), has received significant support. Definitive proof must await further experimentation.

Animals↗
PubMed1984

T cell surface I-J glycoprotein. Concerted action of chromosome-4 and -17 genes forms an epitope dependent on alpha-D-mannosyl residues.

Two genes acting in concert control murine T cell I-Jk expression. We determined I-Jk expression with I-Jk--specific monoclonal antibodies WF8 .C12.8 and five others produced in our laboratory in a cytotoxicity assay. Previous experiments established that an H-2k gene and a chromosome 4 gene, Jt , regulate I-Jk expression. We show here that B10. HTT and B10.S( 9R ) do not differ at the H-2k locus required for I-Jk expression. Rather B10. HTT , like B10.A(3R), lacks some important non--H-2 gene (possibly Jt ). The intra--H-2k I-J--controlling locus maps to the right of the I-A subregion. The I-Jk determinant involves a carbohydrate structure associated with protein; inhibiting either protein synthesis or glycosylation prevents T cell I-Jk reexpression after proteolytic removal. Treatment with alpha-mannosidase destroys I-Jk determinants, implicating terminal alpha-D-mannosyl residues in the I-Jk epitope. Models for H-2 and Jt control of I-J expression are discussed.

Animals↗
PubMed1984

Chromosome 4 Jt gene controls murine T cell surface I-J expression.

Data are presented suggesting a resolution to the paradox concerning the murine response subregion I-J, which encodes a suppressor T cell marker. The controversy arose when sequences corresponding to I-J DNA were not found in the central immune response region described by immunogeneticists. New evidence is presented that T cell surface I-J expression results from the action of at least two complementing genes. One gene is within the H-2 region on chromosome 17; the second gene, termed Jt, is on chromosome 4. The two recombinant mouse strains B10.A(3R) and B10.A(5R) originally used to define the I-J subregion apparently differ not within the H-2 region but elsewhere.

Animals↗
PubMed1984

T cell determinant mapping between K and I-A with I-region properties.

We investigated genes in the chromosomal segment between K and I-A. Recombination in strains AQR and A.TL previously established the right-hand K region and left-hand I-A subregion boundaries. This report provides evidence that strains AQR and A.TL differ in their intra-I-region crossover points; AQR has k haplotype genes between K and I-A which A.TL lacks. Using three different strain combinations, we produced antibodies specific for a T lymphocyte determinant, Iat.W41, encoded by genes in the Kk to I-Ak interval. Like A.TL, B10.MBR (an intra-I-region recombinant) lacks the Iat.W41-controlling gene. Immunofluorescence analysis and a cytotoxicity assay detected Iat.W41 determinants on mature T lymphocyte subset; thymocytes, bone marrow cells, B cells and macrophages do not express this specificity. Iat.W41-bearing lymphocytes display the Thy-1.2 antigen, but not Ly-1 or Ly-2 determinants. Iat.W41 expression is independent of non-H-2 genes. In addition to a strong mixed leukocyte reaction, genes between K and I-A contribute to a graft-versus-host reaction. The Iat.W41-controlling locus appears distinct from previously identified I-A loci.

Animals↗