Antagonistic action of RU38486 on the activity of transforming growth factor-beta in fibroblasts and lymphoma cells

Transforming growth factor-beta (TGF-beta) is a multifunctional protein involved in the control of proliferation, differentiation and other functions in many cell types. The anchorage-independent growth of some established lines of untransformed fibroblasts in soft agar is induced by TGF-beta and requires in addition exogenous EGF for certain target cells, notably rat NRK-49 cells. The formation of colonies of NRK-49F cells is completely inhibited by the synthetic 11-beta substituted nor-steroid RU38486 added at a final concentration of 1.3 X 10(-5) M. We also explored the effect of TGF-beta on Daudi and Raji lymphoma cells by measuring the production of Epstein-Barr Virus (EBV) early antigens (EA). In Daudi cells an induction capacity giving rise to 10-16% positive EA-cells was observed; in Raji cells the induction only reached between 6 and 8%. The induction was partially inhibited by the anti-steroid RU38486 in both systems. Thus, RU38486 not only antagonizes the glucocorticoid hormone action but also interferes with the effects of TGF-beta in fibroblasts and in lymphoma cells. The molecular basis of the interactions observed was investigated by considering (1) the binding to specific receptors, (2) transfection experiments, in order to examine if the interference of the anti-steroid with TGF-beta activities occurs at the transcriptional level as in the case of glucocorticoid induction. The results suggest that the blocking by antiglucocorticoids of the effects of TGF-beta and glucocorticoids, in fibroblasts and lymphoma cells, occurs by different mechanisms.

Factors interfering with the 1 mg dexamethasone suppression test in depression

The 1 mg dexamethasone suppression test (DST) was performed in 50 depressive inpatients in order to investigate factors which might interfere with its sensitivity and specificity for endogenous depression: improvement within one week after the test, recent admission to a psychiatric ward, and weight loss. Four out of five endogenous depressive patients whose depression improved within one week after the test had normal suppression, thus supporting the assumption that normalization of the DST may precede the improvement in depression. Nonendogenous depressive patients had an accumulation of pathologic test results on the day after admission that may be due to "admission stress". However, in endogenous depressives this effect was not observed. An influence of weight loss on the percentage of suppressors and nonsuppressors was not demonstrable. It is concluded that in the evaluation of DST results time parameters should be considered to a greater degree.

Effect of human airway lysozyme on the in vitro growth of type I Streptococcus pneumoniae

The effects of purified human airway lysozyme and hen egg-white lysozyme on growth rate and viability of growing type I Streptococcus pneumoniae were studied. Exposure of bacteria to human and hen lysozyme at the same final concentration (100 micrograms/ml) for 1.5-4.5 h resulted in a marked reduction of the number of colony-forming units per ml compared to control cultures. After a 1.5-h exposure to human or hen lysozyme, the remaining percentage of colony forming units per ml was 54% and 69%, respectively. The onset of growth only appeared after a 3.5-h exposure period for human lysozyme whereas it began at 2.5 h for hen lysozyme. After 3.5 h and 4.5 h of exposure, the number of colony-forming units was significantly lower (p less than 0.05) in human lysozyme-treated bacteria cultures compared to control cultures. Parallel electron microscopic observations of Streptococcus pneumoniae cultures confirmed that the density of pneumococci was less in the presence of either human lysozyme or hen lysozyme in comparison to control cultures, and showed the presence of numerous long, ribbon-like material and cytoplasmic condensations liberated in the culture medium.

Cysteinyl leukotrienes as mediators of staphylococcal enterotoxin B in the monkey

The role of cysteinyl leukotrienes (LTs) in the action of staphylococcal enterotoxin B (SEB) was investigated in unsensitized monkeys using inhibitors of prostanoid synthesis and LT action and by measuring generation of LT in vivo. LY 171883, a selective LTD4/LTE4 receptor antagonist, proved highly efficient in inhibiting immediate-type hypersensitivity reactions in the skin and protecting against the emetic response provoked by SEB in a concentration-dependent manner. Inhibition of prostanoid formation by pretreatment of monkeys with indomethacin or aspirin did not influence SEB responses. Based on chromatographic and radioimmunologic analysis, the generation of endogenous cysteinyl LTs was demonstrated in vivo. The concentration of LTE4, the major biliary cysteinyl LT detected, increased ten-fold and a novel cysteinyl LT metabolite in urine indicated strongly enhanced LT generation upon challenge with SEB. Cysteinyl LTs are important mediators in the pathophysiology of SEB-induced enteric intoxication. Therefore, cysteinyl LT antagonists may be of therapeutic value in the treatment of this intestinal disorder.

[Treatment of aluminum-induced osteopathy with desferrioxamine in dialysis-dependent renal failure]

Presenting two patients on long-term dialysis with marked osteopathy due to aluminium intoxication we described the symptoms, pathogenesis and therapy of the disease. Two patients were treated with the chelating agent desferrioxamine which lead to a striking improvement in clinical symptoms and removal of aluminium from bone. Osteopathy due to aluminium intoxication is refractory to Vitamin D and its metabolites. Using reversed osmosis in dialysis the high aluminium levels in bone result mainly from the long-term use of phosphate binders. Therapy of choice is the treatment with desferrioxamine.

Evaluation of the 99mtechnetium labelling effect on Pseudomonas aeruginosa surface properties

Gamma emitter isotopes present some advantages over beta emitters as radioisotopic microbial labels. The labelling of bacteria with 99mtechnetium (99mTc) has recently been described. However, it was not ascertained whether the labelling process modifies microbial physicochemical surface properties important in the interaction between bacteria and eukaryotic cells. In the present study, we evaluated the effect of the labelling process on Pseudomonas aeruginosa surface charge, hydrophobicity, adherence to human buccal epithelial cells and phagocytosis by human leukocytes. No significant differences in electrophoretic mobility or cationized ferritin distribution was observed on the cell surface of labelled and unlabelled bacteria. 99mTc labelling did not modify the hydrophobicity adhesiveness or phagocytosis of P. aeruginosa. It is concluded that bacterial labelling with 99mTc may be a useful method for the numeration of bacteria and the analysis of their functional properties.

Effects of leukotrienes on gastric acid and alkaline secretions

This study was designed to determine the influence of leukotriene C4 on gastric acid and alkaline secretion. Leukotriene C4 was found to be a potent inhibitor of gastric acid secretion induced in vagally innervated and denervated portions of the stomach of conscious dogs by a variety of stimulants such as histamine, pentagastrin, and meat feeding. Leukotriene C4 was also an effective inhibitor of acid formation in the isolated gastric glands stimulated by histamine or dibutyryl cyclic adenosine monophosphate without or with addition of indomethacin, indicating that this compound acts directly on the parietal cells without mediation of endogenous prostaglandins. Leukotriene C4 was also an effective stimulant of gastric alkaline secretion. However, this effect was probably mediated by an increase in the generation of endogenous prostaglandin, as it was accompanied by an increase in the luminal release of prostaglandin E2 and indomethacin prevented both the stimulation of alkaline secretion and luminal prostaglandin E2 release by leukotriene C4.

Integrity of the C-terminal part of tyrosine aminotransferase revealed by an anti-peptide serum

A synthetic peptide corresponding to the seven carboxy-terminal amino acids of tyrosine aminotransferase was coupled to ovalbumin or keyhole limpet haemocyanin, and the resulting conjugates were used to raise anti-peptide antibodies by immunization of rabbits. The crude sera were purified and tested for recognition of the whole enzyme by enzyme-linked immunosorbent assay and immunoprecipitation in extracts from [35S] methionine labeled hepatoma cells. Our results support the existence of an intact C-terminus. If processing takes place, it will rather occur at the N-terminus of this hepatic enzyme.

C1q inhibits the expression of B lymphoblastoid cell line interleukin 1 (IL 1)

Although the existence and ubiquity of the C1q receptor is well established, its role in health and disease is largely unknown. Interleukin 1 (IL 1) is the major immunoregulatory molecule produced by macrophages and B lymphoblastoid cell lines. In this paper we present evidence that occupancy of C1q receptors by C1q on B lymphoblastoid cell lines inhibits "IL 1-like" activity, which is constitutively produced by these cells. When 5 X 10(6) Raji cells were cultured (24 hr at 37 degrees C) in the presence or absence of various concentrations of C1q (final concentration; 5 to 50 micrograms/ml) and the cellfree supernatants were analyzed for their effect on thymocyte proliferation by using the concanavalin A co-mitogenesis assay for IL 1, a statistically significant dose-dependent reduction of 3H-TdR incorporation was observed. Similar results were obtained when Daudi and Wil2WT cells were used, whereas Molt4, which is a T cell lymphoblastoid cell line, neither produced "IL 1-like" activity nor was affected by C1q. When immune complex-bound C1q was used instead of free C1q, inhibition of B cell IL 1 activity was also observed. Mixing experiments showed that Raji cells incubated with C1q released an inhibitor of IL 1-induced thymocyte proliferation. C1q alone had no effect on thymocyte proliferation in the presence or absence of human IL 1. In addition, the effect of C1q on IL 1 activity was abrogated either when the C1q was heat inactivated (56 degrees C, 60 min) or when the C1q was incubated with the cells in the presence of F(ab')2 anti-C1q. On the basis of these data, it is concluded that B cell receptor-bound C1q may play an important role in immunoregulation.

C1q inhibits the expression of B lymphoblastoid cell line interleukin 1 (IL 1)

Although the existence and ubiquity of the C1q receptor is well established, its role in health and disease is largely unknown. Interleukin 1 (IL 1) is the major immunoregulatory molecule produced by macrophages and B lymphoblastoid cell lines. In this paper we present evidence that occupancy of C1q receptors by C1q on B lymphoblastoid cell lines inhibits "IL 1-like" activity, which is constitutively produced by these cells. When 5 X 10(6) Raji cells were cultured (24 hr at 37 degrees C) in the presence or absence of various concentrations of C1q (final concentration; 5 to 50 micrograms/ml) and the cellfree supernatants were analyzed for their effect on thymocyte proliferation by using the concanavalin A co-mitogenesis assay for IL 1, a statistically significant dose-dependent reduction of 3H-TdR incorporation was observed. Similar results were obtained when Daudi and Wil2WT cells were used, whereas Molt4, which is a T cell lymphoblastoid cell line, neither produced "IL 1-like" activity nor was affected by C1q. When immune complex-bound C1q was used instead of free C1q, inhibition of B cell IL 1 activity was also observed. Mixing experiments showed that Raji cells incubated with C1q released an inhibitor of IL 1-induced thymocyte proliferation. C1q alone had no effect on thymocyte proliferation in the presence or absence of human IL 1. In addition, the effect of C1q on IL 1 activity was abrogated either when the C1q was heat inactivated (56 degrees C, 60 min) or when the C1q was incubated with the cells in the presence of F(ab')2 anti-C1q. On the basis of these data, it is concluded that B cell receptor-bound C1q may play an important role in immunoregulation.

Staphylococcal enterotoxin B as a nonimmunological mast cell stimulus in primates: the role of endogenous cysteinyl leukotrienes

The immediate-type skin reaction and the emetic response in unsensitized monkeys on challenge with staphylococcal enterotoxin B (SEB) were studied to define the role of cysteinyl leukotrienes (LTs) in the action of the toxin. LY 171883, a selective LTD4/LTE4 receptor inhibitor, antagonized SEB-induced skin reactions and emetic responses completely. Inhibition of prostanoid formation by indomethacin, however, and pretreatment with BW 755C, a dual lipoxygenase and cyclooxygenase inhibitor, did not influence these reactions. The generation of endogenous cysteinyl LTs upon intragastric SEB administration was established in vivo. There was a tenfold increase in LTE4, the major biliary cysteinyl LT, and a novel cysteinyl LT metabolite in urine occurred, indicating strongly enhanced LT generation on SEB challenge. These results provide the first evidence that cysteinyl LTs may be important mediators in the pathophysiology of SEB-induced effects, as a model for pseudo-allergic reactions.

Isolation of the outer envelope from Borrelia burgdorferi

Borrelia burgdorferi consists of an inner protoplasmic cylinder, containing the genome and cytoplasmic elements, surrounded by a number of axial filaments, all completely encased within a multiple-layered outer envelope structure (OE). In this study, a sodium dodecyl sulfate-mediated technique was used to isolate the OE from Borrelia burgdorferi in an attempt to better understand this structure in terms of its antigenic reactivity to Lyme disease patient sera. Electron microscopic evidence suggested that the OE product was relatively free of other spirochete cellular components. SDS-PAGE analysis indicated that the electrophoretic pattern of the OE was consistent with that of the remaining protoplasmic cylinder (PC) and whole spirochete controls. Antigenic determinants in the OE were recognized by sera from Lyme disease patients in Western blots. Chemical analysis of the OE revealed a composition of 45.90% protein, 50.75% lipid and 3.33% carbohydrate. The OE comprised 16.5% by lyophilized dry weight of the whole spirochete. Antigenic determinants located within or associated with this structure are likely to play a significant role in the development of immunity in the infected host.

A role for interleukin-1 in the pathogenesis of Lyme disease

Interleukin-1 (IL-1) is the major immunoregulatory molecule produced by macrophages in response to a variety of environmental insults including chemicals, phagocytosis, bacteria, and bacterial products. Macrophages stimulated by Borrelia burgdorferi produced large quantities of IL-1 when spirochetes were added to macrophages at a ratio of 10 spirochetes per macrophage. The release of IL-1 was dose dependent: a single spirochete per macrophage was sufficient to produce significant quantities of IL-1. Spirochetal lipopolysaccharide was not required for this activity in that polymyxin B in the spirochete-macrophage culture had no effect on IL-1 production. Normal murine fibroblasts cultured with this IL-1 were shown to have an increased rate of DNA synthesis and an increase in secreted collagenase. IL-1 was found in joint fluids from Lyme disease patients. When IL-1 was injected intradermally into the backs of rabbits, the injection sites became indurated, erythematous, and warm to the touch after 4 hrs and annular lesions much like those of erythema chronicum migrans were seen in some animals after 24 hrs. B. burgdorferi is a powerful inducer for IL-1 in vitro, and it is reasonable to presume that it acts similarly in Lyme disease patients. Our results suggest that IL-1 in turn, may play a role in many of the clinical manifestations of Lyme disease.

Adherence of type I Streptococcus pneumoniae to tracheal epithelium of mice infected with influenza A/PR8 virus

Bacterial adherence to virus-infected respiratory tract cells may be one of the several mechanisms whereby virus predisposes to bacterial pneumonia. To evaluate the effect of influenza virus infection on pneumococcus adhesion, 39 mice were infected with PR8/A influenza virus. The adherence of radiolabeled pneumococcus to mice tracheal cells was determined 2, 4, and 6 days after viral inoculation. The pneumococcal adhesion to infected tracheas was significantly enhanced on Day 6 (p less than 0.001). Scanning and transmission electron microscopy revealed that by the fourth and sixth days after virus inoculation, the ciliated and the secretory cells of the tracheal epithelium had desquamated and the mucosa were coated with a continuous layer of basal cells. In a few cases, a desquamation of the basal layer was observed and the exposed basement membrane appeared as a pole of attraction for bacteria. Pneumococci were never seen attached to control tracheas. In contrast, they were observed adhered to the microvilli of the basal cells and, to a greater extent, to the exposed basement membrane.

Isolation and characterization of a primitive interleukin-1-like protein from an invertebrate, Asterias forbesi

Interleukin 1 (IL-1) is the major immunoregulatory molecule produced by macrophages and other related cells. It acts as the molecular orchestrator of nonspecific host defense mechanisms against multifarious insults. In this study we report the characterization of an IL-1-like protein from the starfish Asterias forbesi. IL-1-like activity was found in the coelomocytes of this invertebrate and was also isolated and purified from the coelomic fluid. The coelomocytes were capable of phagocytosing latex particles and were adherent to plastic tissue culture dishes. Starfish IL-1 stimulated murine thymocyte proliferation directly and to a greater degree in the presence of submitogenic concentrations of concanavalin A. Starfish IL-1 also stimulated fibroblast proliferation and fibroblast protein synthesis. It was found to have a Mr of 29,500 and pI values of 7.5, 5.9, and 4.8. Starfish IL-1 activity was inhibited by an antibody to human IL-1. These characteristics suggest starfish IL-1 to be very similar to murine and human IL-1. The similarities to vertebrate IL-1 considered along with the evolutionary position of the starfish suggest that IL-1 is an important, ancient, and functionally conserved molecule.

Anti-idiotypic antibodies that inhibit immediate-type skin reactions in unsensitized monkeys on challenge with staphylococcal enterotoxin

The staphylococcal enterotoxin B (SEB)-induced immediate-type skin reaction in unsensitized monkeys was used as a nonimmunological mast cell stimulus to examine whether the toxin exerts its effect via specific receptors on the target cell membrane. Anti-idiotypic antibodies (anti-Id) were raised in BALB/c mice against monoclonal anti-SEB antibodies (anti-SEB) and purified by idiotype affinity chromatography. The anti-Id nature of the antibody was demonstrated by its ability to inhibit the binding of 125I-labeled anti-SEB to the ligand in a concentration-dependent manner. Moreover, binding of anti-SEB to anti-Id was antagonized by the SEB ligand in a competitive way. These antibodies completely abolished skin reactions in unsensitized monkeys on challenge with SEB and impeded those provoked by staphylococcal enterotoxins A and C1 but did not have the biological activity of the toxin. These data are compatible with the view that receptors for staphylococcal enterotoxins may exist on the membrane of mast cells in the skin of unsensitized monkeys. The data suggest an experimental approach for producing anti-cell receptor antibodies that are of potential value to influence the course of staphylococcal enterotoxin-mediated effects.

[Modified rapid test for the semiquantitative determination of cystine in the urine]

The present study describes a modified method of the semiquantitative determination of cystine in the urine which is based on the decomposition of cystine by dithionite ions and formation of a mixed nickel/cystein/sulfide-complex. The method is suitable as rapid and search test, it guarantees an acceptable reproducibility as well as the exactness of the values and is simply to be performed in every clinical-chemical laboratory. The criteria of analytic applicability are confirmed in comparisons of methods. It must be urged to treat fresh urines.