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PubMed1993

Influence of butter and of corn, coconut and fish oils on the effects of recombinant human tumour necrosis factor-alpha in rats.

1. Tumour necrosis factor-alpha is produced in response to inflammatory stimuli. Fish oil can suppress the production and actions of cytokines. Little information is available on the effects of other fats on cytokine biology. We compared the effects of fats, with a wide range of fatty acid characteristics, on the effects of tumour necrosis factor-alpha on protein and zinc metabolism in rats. 2. Weanling rats were fed for 8 weeks on diets containing 10% fat in the form of corn, fish or coconut oils or butter before an intraperitoneal injection of recombinant human tumour necrosis factor-alpha was given. Measurements were made 24h after the injection. 3. In rats fed corn oil, food intake was reduced by 62% and rates of protein synthesis were increased by 86, 32 and 39% in the liver, lung and kidney, respectively. Zinc concentrations increased by 23% in the liver but decreased by 10% in the kidney. Plasma caeruloplasmin and complement C3 levels increased by 25% and 28%, respectively, and plasma albumin level decreased by 24%. 4. Fish oil prevented the increase in hepatic protein synthesis and changed the response of protein synthesis in lung and kidney to a decrease. Changes in hepatic and renal zinc concentrations were prevented. The response of the plasma caeruloplasmin level was unaltered but those of the plasma complement C3 and albumin concentrations were prevented. 5. Coconut oil and butter, although similarly low in linoleic acid, differed in their modulatory effects. With the exception of the rise in the plasma complement C3 concentration, all responses were prevented or greatly inhibited in rats fed butter.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2001

The allogeneic T and B cell response is strongly dependent on complement components C3 and C4.

BACKGROUND: The mechanisms controlling the production of antibodies against histocompatibility antigens are of prime importance in organ transplantation. METHODS: We investigated the role of complement in the response to allogeneic stimulation, using mice deficient in C3, C4, or C5 to dissect the role of the alternative, classical, and terminal complement pathways. RESULTS: After fully major histocompatibility complex disparate skin grafts, the allospecific immunoglobulin (Ig)G response was markedly impaired in C3- and C4-, but not in C5-deficient mice. This defect was most pronounced for second set responses. C3-deficient mice also demonstrated a decreased range of IgG isotypes. In contrast, there was no impairment of the allospecific IgM response. In functional T cell assays, the proliferative response and interferon-gamma secretion of recipient lymphocytes restimulated in vitro with donor antigen was decreased two- to threefold in C3-deficient mice. CONCLUSIONS: These data show impairment of allogeneic T cell and B cell function in mice with defective complement activation and suggest a predominant role for the classical pathway in stimulating alloimmunity. The terminal pathway seems unimportant in this regard. This extends the results reported for soluble protein antigens and demonstrates a surprisingly marked effect on the alloresponse despite the presence of a stringent antigenic stimulus. These results have implications for the prevention of sensitization in naïve transplant recipients.

Animals↗
PubMed1986

Isolation of human complement component C3 from small volumes of plasma.

A method for the isolation of 8-10 mg of human C3 from 20 ml of plasma is described. The procedure is simple and rapid with excellent yields in hemolytic activity (74%) and antigenic activity (68.7%). It consists of polyethylene glycol precipitation, DEAE-Sephacel chromatography, and immunoadsorption. The final product is free of contaminating proteins as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The simplicity and speed of this procedure allow for the continual availability of hemolytically active C3.

Chemical Precipitation↗
PubMed1985

Type II collagen induced arthritis in rats: clinical and immunological studies.

Immunization of laboratory rats with native Type II collagen induces arthritis in approximately 40 percent of the individuals. Histological and radiological analysis have suggested that the lesion bears several similarities to human rheumatoid arthritis. Clinical studies conducted with this model indicate that it is responsive to the treatment with clinically-used NSAID'S, steroids and immunosuppressive agents. When rats with collagen arthritis were treated with DMARD's, only those treated with D-penicillamine showed clinical improvement (radiological evaluation). Type II collagen induced arthritis is complement-dependent and is an example of an immune complex mediated injury. Thus, passive arthritis can be induced in rats by the intravenous administration of affinity-purified anticollagen IgG. The passive lesion is transient and the administered IgG is detected on the articular cartilage of the hind paws. This articular cartilage also contains complement C3. Passive arthritis is also complement-dependent. Suppression of Type II collagen arthritis can be induced by the prior intravenous treatment of rats with either Type II collagen or its constituent peptide alpha 1, (II) CB10. Antigen-induced arthritis cannot be induced in those rats that have recovered from passive arthritis.

Animals↗
PubMed2005

An adult with acute poststreptococcal glomerulonephritis complicated by hemolytic uremic syndrome and nephrotic syndrome.

We report the case of a 47-year-old man with the simultaneous occurrence of clinical and laboratory features consistent with acute poststreptococcal glomerulonephritis (APSGN), hemolytic uremic syndrome (HUS), and nephrotic syndrome. Acute nephritic syndrome occurred 3 weeks after having pharyngeal pain and diarrhea. He presented with edema and hypertension on admission. Laboratory evaluation showed hemolytic anemia with fragmentation, thrombocytopenia, elevated lactic dehydrogenase level, low haptoglobin level, low complement C3 level, and elevated antistreptolysin-O titer. Serum creatinine level was 1.22 mg/dL (108 micromol/L), and urinalysis showed marked proteinuria, with protein of 8.7 g/d, and hematuria. The renal biopsy specimen was characteristic of APSGN, but not HUS. Moderate expansion of the mesangial matrix, moderate proliferation of epithelial and endothelial cells, and marked infiltration of neutrophils was seen by means of light microscopy, and many subepithelial humps were seen by means of electron microscopy. Neither fibrin deposition nor evidence of thrombotic microangiopathy was found. Complement C3 deposition along the capillary wall and tubules was seen in an immunofluorescence study. The patient was administered plasma infusion at 320 mL/d and antihypertensive drugs. Serum complement C3 and haptoglobin levels returned to normal within 3 weeks. This is a rare case of the simultaneous occurrence of APSGN, HUS, and nephrotic syndrome.

Acute Disease↗
PubMed1998

Complement activation and cytokine generation after modified Fontan procedure.

BACKGROUND: The modified Fontan procedure separates the systemic and pulmonary circulations in patients born with a functional single ventricle. Delayed recovery is frequently observed after this procedure. It was our hypothesis that complement activation or cytokine generation may contribute to the pathophysiology of this problem. METHODS: We measured activated complement C3, thromboxane B2, interleukin-6, and tumor necrosis factor-alpha levels by immunoassay in 16 patients undergoing Fontan procedure. Patient plasma samples were obtained preoperatively, on initiation of cardiopulmonary bypass, after administration of protamine, and 1, 4, 8, and 24 hours postoperatively. RESULTS: There was no early or late mortality in this cohort of patients. Low cardiac output developed in 3 of 16 patients, and pleural effusions developed in 5. The median length of hospital stay was 9 days. Activated complement C3 levels increased from a baseline of 1,486 +/- 564 to 4,600 +/- 454 ng/mL after cardiopulmonary bypass and administration of protamine, and returned to baseline by 24 hours. The level of interleukin-6 increased from 42 +/- 32 to 176 +/- 22 pg/mL and at 24 hours remained elevated at 71 +/- 15 pg/mL. Neither thromboxane B2 nor tumor necrosis factor-alpha levels increased significantly. CONCLUSIONS: The data demonstrate threefold to four-fold increases in activated complement C3 and interleukin-6, indicating that both humoral and cellular systems are affected. It is our conclusion that complement and cytokine activation may contribute to the delayed recovery observed after Fontan procedure.

Antibody Formation↗
PubMed1987

Non-enzymic glycation of individual plasma proteins in normoglycemic and hyperglycemic patients.

Diabetic patients in poor glycemic control show increased glycation of total plasma proteins, but little is yet known about the relative extents to which the various individual proteins are glycated. Thus, we studied the non-enzymic glycation of several major plasma proteins and plasma protein fractions in normal and diabetic patients. In vivo glycation for most plasma proteins was very low in non-diabetic patients, only gamma globulin showing more than 5% glycation. In diabetic plasmas, glycation was much greater, immunoglobulins again showing the greatest proportion, followed in descending order by albumin, complement C3, fibrinogen, transferrin, haptoglobin, and alpha-1-antitrypsin. When plasma proteins were glycated in vitro, this order was IgG greater than complement C3 greater than albumin greater than transferrin greater than haptoglobin greater than alpha-1-antitrypsin. In general, proteins with the longest biological half-lives, such as IgG and albumin, showed the greatest in vivo glycation. On the other hand, proteins with high intrinsic glycability, such as complement C3, showed moderate glycation, despite a short half-life. Except for albumin, more basic proteins showed greater glycation than acidic proteins, but there was poor correlation between mole percent lysine and glycation. Evidently the relative extents of glycation of different plasma proteins are a complex function of integrated glucose concentrations over time and of the half-life and chemical characteristics of each protein.

Blood Protein Electrophoresis↗
PubMed1993

Progesterone and dexamethasone inhibition of estrogen-induced synthesis of DNA and complement in rat uterine epithelium: effects of antiprogesterone compounds.

Progesterone (P) blocks estrogen induction of cell proliferation and synthesis of complement C3 in the epithelium of the immature rat uterus. Here it is shown that dexamethasone (Dex) exerts a similar inhibitory effect on these two parameters. Furthermore, analysis of the newly synthesized, secreted proteins produced during a 20 h explant culture period showed that not only does the uterus synthesize complement C3 but it is capable of proteolytically cleaving complement into its biologically active peptides. Since large doses of P are required for its inhibitory effects and since P can interact with the glucocorticoid receptor (GR), the role of the GR in mediating the P effect was questioned. Two antiprogesterone compounds with reportedly differing antiglucocorticoid activity, ZK98.734 and RU486, were tested for their ability to antagonize the inhibitory actions of P and Dex. Attenuation of estrogen-induced epithelial DNA synthesis by either P or Dex was fully overcome by concurrent administration of either ZK98.734 or RU486. On the other hand, while either antagonist was effective against the inhibitory action of P on estrogen-induced complement C3 synthesis, only ZK98.734 was fully effective in blocking inhibition by Dex. Thus, unlike its activity in rat hepatic cells, ZK98.734 is a potent antiglucocorticoid in the immature rat uterus. Because of this antiglucocorticoid activity, differential antagonism of the P response was not possible using these two steroid analogs. Although these observations support the notion of GR mediated inhibition of estrogen action in the uterus, they do not answer the question of whether P might act through a GR mediated pathway.

Animals↗
PubMed2000

Relative binding affinity does not predict biological response to xenoestrogens in rat endometrial adenocarcinoma cells.

The possible adverse effects of the so-called environmental estrogens have raised considerable concern. Developmental, endocrine and reproductive disorders in wildlife animals have been linked to high exposure to persistent environmental chemicals with estrogen-like activity (xenoestrogens); yet, the potential impact of environmental estrogens on human health is currently under debate also due to lack of data. A battery of in vitro assays exist for identifying compounds with estrogenic activity, but only a few models are available to assess estrogenic potency in a multiparametric analysis. We have recently established the endometrial adenocarcinoma cell line RUCA-I; it enables us to compare estrogenic effects both in vitro and in vivo as these cells are estrogen responsive in vitro and grow estrogen sensitive tumors if inoculated in syngeneic animals in vivo. Here we report in vitro data concerning (a) the relative binding affinity of the selected synthetic chemicals Bisphenol A, nonylphenol, p-tert-octylphenol, and o,p-DDT to the estrogen receptor of RUCA-I cells and (b) the relative potency of these compounds in inducing increased production of complement C3, an endogenous estrogen-responsive gene. Competitive Scatchard analysis revealed that xenoestrogens bound with an at least 1000-fold lower affinity to the estrogen receptor of RUCA-I cells than estradiol itself, thereby exhibiting the following affinity ranking, estradiol>>>nonylphenol>bisphenol A approximately p-tert-octylphenol>o,p-DDT. Despite these low binding affinities, bisphenol A, nonylphenol and p-tert-octylphenol increased production of complement C3 in a dose dependent manner. Compared with estradiol, only 100-fold higher concentrations were needed for all the compounds to achieve similar levels of induction, except o,p-DDT which was by far less potent. Northern blot analyses demonstrated that the increased production of complement C3 was mediated by an increased transcription. In summary, cultured RUCA-I cells represent a valuable endometrial derived model system to assess the relative potencies and the molecular mode of action of environmental estrogens in vitro. Our results further show that no intimate correlation exists between the relative binding affinity and the biological response of these compounds. Therefore, data obtained from single-parametric analyses may result in misleading conclusions. On the other hand, the presented in vitro data will provide us with tools to study the activity of xenoestrogens in vivo and thus carry risk assessment one step further.

Adenocarcinoma↗
PubMed1979

Incompatibility between complement components C3 and C5 of guinea-pig and man, an indication of their interaction in C5 activation by classical and alternative C5 convertases.

The use of heterologous combinations of guinea-pig and human complement components for titration of C5 with convertases of the alternative and classical pathway has been investigated. In addition to the known unfavourable combination of C2hu with C4gp partial incompatibilities were detected between heterologous C3 and C5 as well as between CZhu and C5gp. The incompatibility between heterologous C3 and C5 is of special interest since it indicates an interaction of these two non-enzymic components. Concomitant binding studies have demonstrated that a reduced efficiency of C5 convertases correlates with decreased binding affinity of surface-fixed C3b for C5 when heterologous components are offered. Hence, the present studies give further evidence that surface-bound C3b has the function of a co-factor which binds C5; this interaction is required for C5 activation via the classical as well as the alternative pathway, i.e. by the C3/C5 convertases C42 and C3bB.

Animals↗
PubMed1988

A discontinuous factor H binding site in the third component of complement as delineated by synthetic peptides.

Factor H, a very important regulator of alternative pathway activation, exerts its effects by binding to the third component complement, C3. In this study we present evidence that factor H reacts with at least two sites in the third component of complement (C3), and we have mapped one of these sites within the C3d fragment of C3. By using direct binding assays of an anti-human H anti-idiotypic antibody (alpha alpha H) and of H to C3 fragments, it was shown that both bound to the C3b and C3d (but not to C3c) fragments of C3. Cleavage of C3d by CNBr generated two major fragments with Mr values of 12,500 (residues 997-1107) and 8,600 (residues 1178-1252). Binding studies with these two fragments showed that only the Mr 8,600 fragment bound to both H and alpha alpha H. Several synthetic peptides (A58, 1192-1249; P28, 1187-1214; P16, 1194-1209; P14, 1201-1214; B17, 1206-1222; J28, 1222-1249; and J16, 1234-1249) were synthesized according to the primary sequence of the Mr 8,600 fragment. Based on the differential binding of these synthetic peptides to H, their inhibitory effect on H binding to C3b or C3d, and their effect on H cofactor activity, we mapped the H binding site in C3 to a discontinuous site spanning residues 1187-1249 of the C3 sequence. By studying the inhibition of H binding to C3b or C3d by the different synthetic peptides, we also present evidence that a second binding site in C3b for H exists.

Amino Acid Sequence↗
PubMed2004

Immune status with empyema thoracis.

OBJECTIVE: To evaluate the humoral and cell mediated immune status of children with empyema thoracis. METHODS: Serum IgG, IgA, IgM, Complement C3 assay and cell mediated immunity (CMI) tests were performed in 33 patients of empyema thoracis, and 14 healthy age matched controls. RESULTS: The mean serum IgG and IgA levels in empyema thoracis and its subgroups were significantly raised as compared to controls. The overall values of IgG and IgA were 104% (p<0.001) and 114% (p<0.01) of normal mean, respectively. The mean serum IgM and complement C3 levels did not differ significantly in both the groups. The frequency of negative skin reaction to purified protein derivative (PPD) was significantly higher in children with empyema thoracis as compared to controls (p<0.05). The mean absolute lymphocyte count (ALC) was significantly decreased and serum adenosine deaminase (ADA) activity was significantly raised in empyema thoracis in comparison to controls. The overall ALC was 76.1% (p<0.01) and serum ADA activity was 169.4% (p<0.001) of normal mean, respectively. No significant differences were observed in the mean levels of immunoglobulins, complement C3 and CMI tests between pyothorax and pyopneumothorax and pleural fluid culture positive and negative cases. CONCLUSIONS: Thus, both humoral and cell mediated immunity were affected in empyema thoracis patients. However, CMI demonstrated more pronounced change in comparison to humoral immunity.

Adenosine Deaminase↗
PubMed1995

Hepatocyte growth factor and retinoic acid exert opposite effects on synthesis of type 1 and type 2 acute phase proteins in rat hepatoma cells.

Rat hepatoma cells H-35 cultured in serum-free medium were exposed to interleukin-6 (IL-6), interleukin-1 (IL-1), hepatocyte growth factor (HGF), retinoic acid (RA), or a mixture of these factors. Production of acute phase proteins, responding to IL-6 alone (type 2) or to the mixture of IL-6 and IL-1, was assessed by electroimmunoassay and the corresponding mRNAs were compared by Northern blot analysis. HGF enhanced IL-6-induced synthesis of alpha-2-macroglobulin but reduced synthesis of C3 complement and alpha-1-acid glycoprotein. Retinoic acid reduced the response to IL-6 of alpha-2-macroglobulin but enhanced that of alpha-1-acid glycoprotein and especially of C3 complement. In general, changes in protein secretion were correlated with the contents of their corresponding cellular mRNAs. These results indicate that hepatocyte growth factor can enhance basal or IL-6-induced gene expression of type 2 and reduce the expression of type 1 acute phase proteins, whereas the action of retinoic acid is opposite. The modulation of acute phase response by HGF and RA likely involves transcriptional factors and regulatory sequences in the genes coding for these two types of acute phase proteins.

Acute-Phase Proteins↗
PubMed1977

Gingival fluid and serum in periodontal diseases. II. Evidence for cleavage of complement components C3, C3 proactivator (factor B) and C4 in gingival fluid.

1. C3 activation products C3c and C3d can be demonstrated in gingival pocket fluid from patients with severe periodontitis. 2. Quantitatively, C3d levels in GF are comparable to levels attained consequent to immune-complex and tryptic activation of human serum. 3. The alternate pathway of complement activation occurs in the periodontal pocket, as demonstrated by conversion of C3 proactivator (Factor B) to C3-activator Bb. 4. C4 is present in an altered form in some, but not all, GF's. This form is electrophoretically similar to that generated from serum by C1s and several proteolytic enzymes.

Complement C3↗
PubMed1993

Temporal sequence of changes in tear film composition during sleep.

Overnight eye closure induces a shift in the nature and composition of the tear film, from a dynamic reflex tear-rich to a stagnant secretory IgA-rich layer. This is accompanied by the induction of a state of sub-clinical inflammation, as evidenced by increases in albumin levels, plasminogen activation, conversion of complement C3 to C3c, and the recruitment of polymorphonuclear (PMN) cells into the tear film. To determine the time course and functional relationship between these potentially interdependent processes, tear samples were collected from ten non-contact lens wearers after 1, 2, 3 and 5 hours of sleep. A subgroup of 6 subjects also self-collected tear samples after 8 hours of sleep. Tear samples were analysed for albumin by quantitative immunofixation assay, secretory IgA (sIgA) by radial immunodiffusion assay, plasmin-like activity using a chromogenic substrate, and complement C3 to C3c conversion by immunoblot assay. Epithelial and PMN cells in the precorneal tear film were recovered from corneal washings from the same subjects after 1, 3, 5 and 8 hours of sleep, and quantified. Results revealed that, unlike epithelial cells which exhibited a slow progressive accumulation as a function of the period of sleep, PMN cell concentration exhibited a lag phase, with recruitment occurring after between 3 and 5 hours of eye closure. This was preceded by plasminogen activation, increases in albumin and sIgA levels, and complement C3 to C3c conversion, all of which occurred within 1 to 3 hours after eye closure. Plasmin-like activity appeared to plateau after 3 hours and then decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗