Idiopathic paraproteinaemia V. Expression of Igh1 and Igh5 allotypes within the homogeneous immunoglobulins of ageing (C57BL/LiARij X CBA/BrARij)F1 mouse.

The role of genetic factors linked to the immunoglobulin loci and the development of idiopathic paraproteinaemia (IP)--a benign B-cell proliferative disorder--was investigated in F1 hybrid mice of low (CBA/BrARij) and high (C57BL/LiARij) IP frequency strains. Igh1 and Igh5 allotypes were used as markers for the (parental type) origin of homogeneous immunoglobulins (H-Ig) which appeared in the sera of the F1 mice with ageing. The frequencies of H-Ig in the F1 mice were intermediate with those of the parental strains.

Human bone marrow cells positive for terminal deoxynucleotidyl transferase (TdT), HLA-DR, and a T cell marker may represent prothymocytes.

Recent evidence suggests that prothymocytes, which occur in a low frequency in murine bone marrow (BM), are already committed to thymocyte differentiation and discrete from precursor B cells as well as pluripotent hematopoietic stem cells. Furthermore, it was suggested that, in rodents, prothymocytes are positive for the nuclear enzyme terminal deoxynucleotidyl transferase (TdT) and a T cell surface antigen. The human prothymocyte has not been identified as yet.

Thermophilic anaerobic biodegradation of [C]lignin, [C]cellulose, and [C]lignocellulose preparations.

Thermophilic (55 degrees C) anaerobic enrichment cultures were incubated with [C-lignin]lignocellulose, [C-polysaccharide]lignocellulose, and kraft [C]lignin prepared from slash pine, Pinus elliottii, and C-labeled preparations of synthetic lignin and purified cellulose. Significant but low percentages (2 to 4%) of synthetic and natural pine lignin were recovered as labeled methane and carbon dioxide during 60-day incubations, whereas much greater percentages (13 to 23%) of kraft lignin were recovered as gaseous end products. Percentages of label recovered from lignin-labeled substrates as dissolved degradation products were approximately equal to percentages recovered as gaseous end products.

Suppression of antigraft immunity by preimmunization. IV. Persistence by long-lived recirculating suppressor T cells.

Delayed-type hypersensitivity (DTH) against histocompatibility (H) antigens in mice, which normally arises after s.c. immunization, can be prevented by i.

Secondary delayed type hypersensitivity to H-2 subregion-coded alloantigens.

Secondary type delayed type hypersensitivity (DTH) in mice against class I alloantigens or non-H-2 alloantigens is characterized by an earlier appearance of DTH reactivity after booster immunization compared with the development of DTH reactivity after primary immunization. In contrast to the primary and secondary DTH against class I or non-H-2 alloantigens, the development of secondary DTH against class II alloantigens or a set of alloantigens that includes class II alloantigens is not faster than the development of primary DTH. Thus, primary and secondary immunization with class II alloantigens prevents secondary type DTH reactivity to simultaneously administered class I alloantigens and non-H-2 alloantigens.

Sizing dielectric spheres and cylinders by aligning measured and computed resonance locations: algorithm for multiple orders.

An algorithm for determining the size of dielectric spheres and cylinders by aligning measured and computed resonance locations is presented. The orders of the resonance locations need not be known a priori. The algorithm is applicable to several types of scattering and emission spectra of spheres and cylinders if the index of refraction including dispersion is known and uniform, or nearly uniform, throughout the sphere or cylinder.

Frequency analysis of the antibody specificity repertoire of mitogen-reactive B cells and "spontaneously" occurring "background" plaque-forming cells in nude mice.

The antibody specificity repertoire of lipopolysaccharide (LPS)-reactive B cells has been determined in the spleens and bone marrow (BM) of C57BL/Ka athymic nude mice using a limiting dilution culture system that allows the growth and development of every LPS-reactive B cell into a clone of IgM-secreting cells. In addition, the numbers of "spontaneously" occurring ("background") IgM-, IgG-, and IgA-secreting cells as well as the "background" IgM antibody specificity repertoire has been assessed in spleens and BM. The frequencies of antigen-specific LPS-reactive B cells of C57BL/Ka nude and thymus-bearing mice showed a great similarity and ranged from 1 in 1000 to 1 in 2500 for sheep red blood cells (SRBC), horse red blood cells (HRBC), and goat red blood cells (GRBC), from 1 in 10 to 1 in 25 for 5-iodo-3-nitrophenyl-coupled (SRBC), from 1 in 15 to 1 in 150 for 4-hydroxy-3,5-dinitrophenyl-coupled SRBC, and from 1 in 70 to 1 in 140 for 2,4,6-trinitrophenyl-coupled SRBC.

Frequency analysis of functional immunoglobulin C- and V-gene expression by mitogen-reactive B cells in germfree mice fed chemically defined ultra-filtered "antigen-free" diet.

The frequencies of lipopolysaccharide (LPS)-reactive B cells and their antibody specificity repertoire have been determined in the spleen and bone marrow (BM) of conventional (CV) and "antigen-free" C3H/HeCr mice of various ages. The antigen-free mice were germfree (GF)-raised and were fed an ultrafiltered solution of chemically defined (CD) low m.w.

Characterization of suppressor T cells in graft-versus-host reactions.

Intravenous (i.v.) immunization of mice with irradiated (2000 rads) allogeneic lymphoid cells induces the generation of suppressor T cells.

Differential influence of 2'-deoxyguanosine on the induction and expression of suppressor T lymphocytes in vivo.

Subcutaneous (sc) immunization of mice with allogeneic spleen cells can induce delayed-type hypersensitivity (DTH) to histocompatibility antigens. Intravenous immunization with irradiated allogeneic spleen cells, on the other hand, induces suppressor T (Ts) lymphocytes. These Ts cells are capable of suppressing the host-versus-graft (HvG) DTH reactivity which normally arises after sc immunization.

Graft-vs.-host reactions: mechanisms and contemporary theories.

A graft-vs.-host (GvH) reaction can be initiated by injection of immunocompetent lymphocytes into a histoincompatible host that is unable to reject these cells. The reaction is characterized by splenomegaly, hepatomegaly, lymph node atrophy, body weight loss, dermatitis, and diarrhea, often leading to mortality.

The long-lasting state of specific nonresponsiveness induced by intravenous immunization with alloantigens is due to the generation of recirculating suppressor T cells.

We investigated whether the long-lasting state of nonresponsiveness that is induced by intravenous immunization with alloantigens is mediated by suppressor T cells, or is caused by inactivation or deletion of the relevant alloreactive T cell clones. The data from parabiosis and thoracic duct drainage experiments suggest that the state of nonresponsiveness depends on recirculating non-proliferating Ts memory cells.

Isotypes and specificities of immunoglobulins produced by germ-free mice fed chemically defined ultrafiltered "antigen-free" diet.

The regulation of the "spontaneously" occurring ("background") Ig synthesis of mice has been studied by determining the numbers of IgM-, IgG- and IgA-secreting cells and a part of the IgM antibody-specificity repertoire in spleen, bone marrow (BM) and mesenteric lymph nodes (MLN) of conventional and "antigen-free" mice. These antigen-free mice were germ-free raised and fed an ultrafiltered solution of chemically defined low molecular weight nutrients, and thus devoid of exogenous antigenic stimulation. The secretion of IgM, IgG and IgA by spleen, BM and MLN cells was assessed in the protein A plaque assay, while specific IgM antibody-secreting cells were detected by plaque assays specific for differently haptenated sheep red blood cells.

Interaction of Legionella micdadei with human monocytes.

We have recently shown that Legionella micdadei is ingested, but not killed, by human neutrophils. Herein we investigate the role of human monocytes in defense against this organism. Serum and monocytes from normal donors having no detectable antibody to L.

Relative contributions of bacteria and fungi to rates of degradation of lignocellulosic detritus in salt-marsh sediments.

Specifically radiolabeled [C-lignin]lignocellulose and [C-polysaccharide]lignocellulose from the salt-marsh cordgrass Spartina alterniflora were incubated with an intact salt-marsh sediment microbial assemblage, with a mixed (size-fractionated) bacterial assemblage, and with each of three marine fungi, Buergenerula spartinae, Phaeosphaeria typharum, and Leptosphaeria obiones, isolated from decaying S. alterniflora. The bacterial assemblage alone mineralized the lignin and polysaccharide components of S.

T-lymphocyte subpopulations in patients with various courses after hepatitis B virus infection.

The course of a hepatitis B virus infection is probably determined by the cellular immune response of the host, which is partly regulated by the T helper and T suppressor cells. We therefore counted immunoregulatory T-cell subsets in the peripheral blood of 97 patients with various courses of hepatitis B virus infection: 23 of these patients were asymptomatic HBsAg carriers without detectable liver disease, 13 had chronic persistent hepatitis B, 19 had chronic active hepatitis B (11 HBeAg, 8 anti-HBe), 7 had chronic active hepatitis with anti-HBs or anti-HBc, and 35 were healthy controls with anti-HBs after recovery from acute hepatitis B. Peripheral blood mononuclear cells were specifically labelled with monoclonal Leu-1 (T cells), Leu-2a (T suppressor/cytotoxic cells), and Leu-3a (T helper cells) antisera and analyzed by flow cytometry.

Anaerobic biodegradation of the lignin and polysaccharide components of lignocellulose and synthetic lignin by sediment microflora.

Specifically radiolabeled [C-lignin]lignocelluloses and [C-polysaccharide]lignocelluloses were prepared from a variety of marine and freshwater wetland plants including a grass, a sedge, a rush, and a hardwood. These [C]lignocellulose preparations and synthetic [C]lignin were incubated anaerobically with anoxic sediments collected from a salt marsh, a freshwater marsh, and a mangrove swamp. During long-term incubations lasting up to 300 days, the lignin and polysaccharide components of the lignocelluloses were slowly degraded anaerobically to CO(2) and CH(4).