Plasma tumor necrosis factor soluble receptors in chronic renal failure.

Two soluble tumor necrosis factor receptors (sTNFRs) were detected in the plasma of patients with different degrees of chronic renal failure (CRF) and of long-term hemodialysis (HD) patients. In uremic undialyzed patients, plasma levels of both sTNFRs increased progressively with declining renal function. A linear correlation was found between sTNFR plasma levels and plasma creatinine concentration.

Suppressed murine mammary tumor virus (MuMTV) expression in RIII female mice treated neonatally with goat antiserum to MuMTV.

Passive immunization of newborn inbred RIII (R3) mice with the globulin fraction of goat antiserum to murine mammary tumor virus (MuMTV) successfully suppressed MuMTV expression in the milk of some of the treated mice throughout nine successive lactations. No mammary tumors developed in the MuMTV-suppressed mice during the first 9 months, whereas all untreated R3 female breeders expressed MuMTV in the milk of the third lactation, and all developed tumors before 9 months of age (mode and median: 189 days).

Hybridization kinetics of ribonucleic acid and deoxyribonucleic acid from antigen-stimulated mouse spleen cells.

In an attempt to explore the mechanism by which antigenic stimulation alters gene expression in lymphoid cells in vivo, three different hybridization techniques have been used to compare the complexity of the genome of lymphoid cells from normal and from immune BALB/c mice. RNA/DNA hybridization experiments at a DNA excess of 1000 demonstrated that normal RNA and immune RNA hybridized identically with DNA extracted from mouse spleen cells before and after immunization and with liver DNA. These findings indicate that DNA sequences complementary to immune RNA or to normal RNA are represented in a number of copies not significantly different in the genome of normal lymphoid cells and in that of immune lymphoid cells.

Receptors for immune complexes on cells within a non-lymphoid murine tumor.

In this paper we present evidence that antibodies unrelated to the tumor cell can comprise part of the in vivo Ig surface coat of cells derived from the non-lymphoid murine tumor, TA3/St. This was shown by incubating TA3 cells originating from other OA or BSA preimmunized mice with radioiodinated 125I-OA and 131I BSA. Radioiodine-labeled 125I-OA specifically fixed to cells derived from TA3/St tumors originating from OA-preimmunized mice.

Hyphal walls of isolated lichen fungi: autoradiographic localization of precursor incorporation and binding of fluorescein-conjugated lectins.

The hyphal walls of three mycobionts, isolated from the lichens Xanthoria parietina, Tornabenia intricata and Sarcogyne sp. were investigated by two techniques: microautoradiography of fungal colonies exposed to radioactive carbohydrate precursors: and binding, in vivo, of fluorescein conjugated lectins to hyphal walls of such colonies. N-[3H] acetylglucosamine was readily incorporated into tips, young hyphal walls and septa of the three mycobionts and the free-living fungus Trichoderma viride, but not into Phytophthora citrophthora, indicating that chitin is a major component of the mycobionts' hyphal walls.

Isolation of lymphocyte subpopulations from rabbit peripheral blood. Comparison of methods based on recovery of rosette-forming cells and on recovery of Ig-bearing cells from a digestible immunoadsorbent.

Two methods to obtain lymphocyte subpopulations, defined by specific surface receptors, from rabbit peripheral blood cells were compared as to cell recovery, yield and purity of the obtained fractions: a) the formation of rosettes between lymphocytes and SRBC or SRBC coated with an antigen--antibody--complement complex (D-SRBC), followed by isolation of the rosettes and recovery of the RFC, b) retention of surface-Ig bearing cells on an immunoadsorbent to which antibody to rabbit Ig was covalently attached via a digestible gelatin bridge, with subsequent recovery of the retained cells by the enzymatic digestion of the bridge. Purity of the isolated cell fractions was assessed in all cases by the percentage of cells staining with FITC-labeled goat anti-rabbit Ig. Using the rosette method, all of the RFC could be recovered from rosettes and a very pure, surface-Ig negative, sub-population of cells was obtained: however, the overall number of rosettes formed (SRBC and D-SRBC) was low (8-9% of the nucleated PBC).

Effect of vinblastine on the early events in the humoral immune response of mice to SRBC.

The effect of vinblastine (VLB), a mitotic blocking agent, on the number of plaque-forming cells (PFC) and on the metabolic activities of spleen cells of mice reimmunized with SRBC was studied. When VLB (75 mug/mouse) and antigen were administered simultaneously, the number of pfc, on the 4th day after immunization, was reduced to 40% of control levels. However, when the same amount of VLB was administered to mice 24 h after immunization, it reduced the number of PFC to 10% of control levels.

The presence of cells expressing immune-complex receptors in non-lymphoid murine tumors.

In this study we demonstrated that cells lodging in tumors have the capacity to fix antibody or immune complexes in vivo and in vitro. Although some of the fixation is probably by host, at least in one system studied, tumor cells, per se, were found to exhibit immune complex fixation.

Reassociation kinetics of deoxyribonucleic acid in antigen-stimulated mouse-spleen cells.

In order to directly compare the complexity of the genome of lymphoid cells which have been antigenically stimulated, with that of non-immunized and non-lymphoid cells, DNA was pulse labeled and extracted from BALB/c mouse spleen cells at various time intervals after antigenic stimulation in vivo; the reassociation rates of these newly synthesized DNA preparations were compared with those of the total mouse spleen DNA, obtained from same sources and at the same times. DNA labeled for 60 min at 43, 53, or 72 h after antigenic restimulation, reassociated faster than the corresponding total DNA. On the other hand, the ressociation profile of DNA, labeled for 60 min during the first 24 after restimulation did not differ from that of the total DNA extracted at the same time.

'Gelbsilber' rabbits: a closed colony of high responders to the lactic dehydrogenase isoenzyme LDH-H4. Possible mechanisms controlling the response.

'Gelbsilber' (GS) rabbits which had been maintained for an unknown time as a closed colony, were found to respond uniformly well to the pig lactic dehydrogenase isoenzyme of the H4 type (P-LDH-H4), to which most New Zealand white (NZW) rabbits produced no detectable antibody. Two to three per cent of the splenic lymphoid cells of GS rabbits after secondary immunization were found to produce antibody to P-LDH-H4, while no such cells were detected in NZW rabbits. No differences were detected between the electrophoretic mobility of endogenous LDH of GS and NZE rabbits.

The soluble proteins of rat seminal vesicle fluid. Some physico-chemical and immunological properties.

The native secretion of rat seminal vesicles was found to contain about 290 mg of protein/ml. The ionic strength of the secretion was low (33 millimho. cm).

Selective simulation of allelic expression: effectf antibodies to allotypic markers on lymphoid cells.

Peripheral blood leukocytes from rabbits which were heterozygous (b(5)/b(9)) for markers on their immunoglobulin light chains were maintained in vitro for up to 24 hours in the presence or absence of antibody to b9. After culture they were transferred into lethally irradiated b(4)/b(4)hosts. Recipients of cells exposed to antibodies to allotype markers showed a striking increase in concentration of circulating b9 molecules and number of b9 plasma cells in their spleens compared pared to control animals receiving untreated cells from the same donor.