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PubMed2002

[Effect of rhubarb on inflammatory cytokines and complements in patients with systemic inflammation reaction syndrome and its significance].

OBJECTIVE: To study the effect of rhubarb in treating patients with systemic inflammation reaction syndrome (SIRS) and its mechanism. METHODS: The 40 patients with SIRS in the treated group were treated with conventional treatment plus rhubarb powder orally or by nasal feeding, the 38 patients in the control group were treated with conventional treatment alone. Serum tumor necrosis factor-alpha (TNF-alpha) was determined by ELISA during the admission and the 3rd day after admission, C-reactive protein (C-RP), complement 3 and 4 (C3, C4) were also determined by auto-scattering turbidimetric quantitative analysis. The parameters were compared between groups and with normal control group. RESULTS: Cure rate in the treated group was significantly higher than that in the control group accompanied with lesser occurrence of multiple organ dysfunction syndrome (MODS) and lower mortality. Serum TNF-alpha, C-RP, C3 and C4 in the SIRS patients were increased during admission, which were significantly higher than normal control, but these parameters would be reduced together with the alleviating of symptoms after treatment, particularly after rhubarb treatment. CONCLUSION: Rhubarb could improve the prognosis of patients with SIRS, its major mechanism is that rhubarb has the antagonizing effect against inflammatory cytokines and complements.

C-Reactive Protein↗
PubMed2001

Both IgG and IgM anti-pig antibodies induce complement activation and cytotoxicity.

Hyperacute rejection of pig xenografts transplanted in humans is caused by endothelial cell binding of pre-formed xenoreactive antibodies (XAb) and activation of the classical pathway of complement. Human XAb mainly consist of anti-Galalpha1 3Gal antibodies, which occur in IgM, IgG and IgA classes. Whereas IgM anti-Galalpha1 3Gal antibodies have an established role in hyperacute rejection, the potential role of IgG XAb in this process is still controversial. The aim of the present study was to assess the specificity and functional properties of IgG and IgM XAb. Both classes were present in all human plasma samples tested, with a high inter-individual variability. Levels of IgG XAb did not correlate with levels of IgM XAb. Binding to Galalpha1 3Gal is strongly correlated with binding to the pig cell line PK15, both for IgG and for IgM, pointing to Galalpha1 3Gal as the major antigen recognized. Both purified IgM and IgG induced C3 deposition on PK15 cells and complement-dependent cytotoxicity in a dose-dependent way. The combination of IgG and IgM XAb resulted in an additive effect on cytotoxicity. Affinity-purified IgG anti-Galalpha1 3Gal antibodies were 22 times less potent than IgM in induction of cytotoxicity. These results indicate a quantitative, but not a qualitative, difference between IgM and IgG anti-pig antibodies concerning their complement-activating properties. Therefore, both classes of XAb are of importance in the pathogenesis of hyperacute rejection, and the relative importance of each class may differ considerably between individual patients, depending on the ratio of IgG and IgM XAb present in serum.

Animals↗
PubMedDate not supplied

Bioeffects of the plant Mahonia sempervirens.

Water extracts of mature fruits of Mahonia sempervirens possess four biological properties: hemagglutinin, hemolysin, complement antagonism and antistreptoccocal activity. Partial characterization of the crude extract was carried out by barbital-mediated spectrophotometry, polyacrylamide gel electrophoresis, thin layer chromatography and interaction chromatography. Fractionation of the Mahonia extract by ionic exchange static adsorption resulted in the quantitative separation of the fruit red pigment with recovery of the entire anticomplementary activity and indicated that the complement inhibitor was different from the aggregating and lytic properties.

Animals↗
PubMed1989

Activated complement components C3a and C4a in cerebrospinal fluid and plasma following subarachnoid hemorrhage.

The cerebrospinal fluid (CSF) and plasma levels of the complement components C3a and C4a in 40 patients suffering from subarachnoid hemorrhage (SAH) were quantitated by radioimmunoassay. Serial measurements of the lumbar CSF levels revealed that the C3a and C4a levels were significantly elevated in the initial stage of SAH, but decreased rapidly. Within 48 hours after SAH, the mean C3a and C4a levels in the cisternal, lumbar, and ventricular CSF were significantly higher in patients with delayed ischemic neurological deficits (DIND) than in those without DIND. The serially measured plasma levels of C3a and C4a in patients with DIND were elevated more than in those without DIND, but they did not show a significant change over time. Simultaneous levels of fibrinopeptide A (FPA), an indicator of thrombin activity in CSF, were also measured by radioimmunoassay. There was a significant correlation between CSF-activated complement components and CSF FPA. These results suggest that complement activation occurred in the subarachnoid space soon after SAH, chiefly due to activation of the coagulation system. The higher CSF levels of C3a and C4a in patients with DIND may indicate a relationship between these components and the pathogenesis of cerebral vasospasms.

Adult↗
PubMed1977

Cholesterol-dependent human complement activation resulting in damage to liposomal model membranes.

Human (but not guinea pig) complement-mediated damage. It was concluded that human complement was activated spontaneously by liposomes containing a high concentration (71 mol %) of cholesterol. This occurred in the absence of any recognizable antigen or antibody, and did not occur at a low concentration (43 mol %) of cholesterol. Activation of complement resulted in membrane damage and release of trapped liposomal glucose. The complement activity was inhibited by preheating (56 degrees C, 30 min), 10 mM Mg2EDTA3 or EGTA, and by prior adsorption with insoluble immune complexes. Almost all human sera had some reactivity, but it ranged from very low levels (less than 7% liposomal glucose release) to very high levels (greater than 50% glucose release). Complement activation appeared to be mediated by a serum factor which could be removed by adsorption and which was partially heat labile. The factor was transferred by adding heated high reacting human serum to unheated low reacting human serum, or to guinea pig serum. The serum factor, although quantitatively diminished in potency due to heat lability, caused equal activation of each of these two latter complement sources in the presence of high cholesterol liposomes. It did not cause activation of C4-deficient guinea pig complement. These data suggested that the classical complement pathway was activated. The liposomal membrane composition had an influence on this phenomenon. Activities of about half of the human sera were enhanced when galactosyl ceramide, or ceramide alone, was present in the liposomes. Activity was enhanced by longer fatty acyl chain lengths of lecithin when dimyristoyl-, dipalmitoyl-, or distearoyllecithin was employed in the liposomes. Liposomes containing sphingomyelin as the only phospholipid were not sensitive to cholesterol-dependent complement-mediated damage. It was concluded that human complement was activated in the presence of high concentrations of membrane cholesterol and that this was caused by an uncharacterized serum factor and was influenced by the lipid composition of the membrane.

Ceramides↗
PubMed1997

Measurement of anticomplementary activity in therapeutic intravenous immunoglobulin preparations.

Anticomplementary activity (ACA) of aggregates in intravenous immunoglobulin preparations (IVIG) was investigated using the modified Kabat and Meyer classical complement consumption method recommended by the European Pharmacopoeia and a C1q-coated microtitre enzyme-linked immunosorbent assay (ELISA). The physical characteristics of aggregates were found to affect complement binding. Aggregates formed by heating IVIG preparations at acid pH bound complement poorly, while aggregates formed by heating IVIG at neutral pH showed high ACA. This suggests that analysis of complement binding capacity provides a level of aggregate characterization of aggregates which is additional to quantitation by High-performance liquid chromatography ((HPLC). The correlation (r = 0.98) between the two tests was good when aggregates formed at neutral pH were compared, but decreased (r = 0.57) when aggregates formed at acid pH were included. A comparison of the results showed that there were no significant differences in the classification of aggregates with acceptable/unacceptable (i.e. pass/fail outcome) values of ACA. Between assay variation (CV = 7.6%) was lower in the ELISA test compared with the complement consumption assay (where percentage binding varied from 78.9% to 100%). Both assays are justified for the evaluation of ACA in therapeutic IVIG. The ELISA had the advantage in being more precise, less dependent on reagent source and requiring less technical expertise.

Complement Inactivator Proteins↗
PubMed1994

Kinetic modelling of liposome degradation in serum: effect of size and concentration of liposomes in vitro.

The purpose of this study is to propose a new method for quantitative evaluation of liposome degradation in serum. The time course of liposome degradation in rat serum was monitored continuously, using 6(5)-carboxyfluorescein as an aqueous phase marker. The degradation curves exhibited three characteristic phases: lag time, degradation, and plateau. This curve was described by a kinetic model with three parameters: lag time (tau), first-order degradation rate constant (k), and maximum degradation (alpha). The rate and extent of the degradation of liposomes were evaluated separately in terms of k and alpha, respectively. The effects of size and concentration of liposomes on their degradation kinetics were examined using this method. Both k and alpha increased with increasing liposomal size. The increased affinity of larger liposomes for complement was suggested to increase both k and alpha. On the other hand, alpha decreased with increasing liposomal concentration without altering k. The decreased extent of degradation was considered to result from the depletion of complement components. There was no significant effect of size and concentration of liposomes on tau. Quantitative evaluation of the rate and extent of degradation of liposomes will provide deeper insights into the interaction between liposomes and serum components, and basic information on liposomes as potential drug carriers.

Animals↗
PubMed1987

Assessment of qualitative and quantitative data from pathological hairs--a critical evaluation of scanning electron microscope and proton induced X-ray emission analyses.

Analysis of single hair fibres in genetic disorders is a desirable complement to the clinical diagnosis. The scanning electron microscope (SEM) allows detailed study of the surface morphology of hair fibres which may explain some mechanical characteristics of the pathological hair. Quantitative elemental data may indicate biochemical or metabolic abnormalities. In this preliminary study we assess the feasibility of combining SEM and proton induced X-ray emission (PIXE) analysis on single hair fibres from 12 cases of genetic disease influencing the integument status. We conclude that SEM is a valuable tool in the analysis of hair pathology. The macro-PIXE technique involves some methodological and technical problems which in many cases are likely to be solved by using a proton microbeam. However, this means that routine methods have to be abandoned and careful selection of the material for analysis is an imperative necessity.

Adolescent↗
PubMed1993

Reduced CR1 expression on aged human erythrocytes: immuno-electron microscopic and functional analysis.

Recognition and clearance of aged human erythrocytes (AE) is a complex process involving immune and non-immune reactions. Complement activation on the surface of AE and deposition of the C3b complement component appear to facilitate this process. Complement receptor type 1 (CR1, CD35) expressed on the surface of human erythrocytes binds to C3b molecules and promotes their inactivation by complement factor I. This may protect the erythrocytes from lysis by complement and by phagocytes. It has been previously reported that aging of human erythrocytes is accompanied by a decrease in the number of CR1 molecules expressed on their surface. Results presented here further support this finding with for the first time a presentation of immune-electron microscopic observation. Haemagglutination and binding assays showed that AE express significantly fewer CR1 (CD35) molecules than young erythrocytes (YE). This is associated in AE with reduced CR1-like factor I co-factor activity and increased deposition in vivo of C3, C4 and properdin as well as increased sensitivity to lysis in vitro by homologous and heterologous complement. Three different immuno-electron microscopical techniques have been used to clearly show the quantitative difference in CR1 (CD35) expression between AE and YE. Finally our results demonstrate that the previously reported clustered arrangement of CR1 (CD35) on human erythrocytes is similar on aged and young erythrocytes.

Antibodies, Monoclonal↗
PubMed1977

Detection of antibodies specific for herpes simplex virus in human sera by the enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay (ELISA) was used for the detection in human sera of antibody to herpes simplex virus antigens. Development and standardization of the assay suggested that antigenic purity, temperature of reactions, concentration of enzyme-conjugated antiglobulin, and concentrations of test sera are all critical parameters of a successful ELISA procedure. When ELISA titers of 30 human sera were compared to micro-complement fixation titers of the same sera, a significant degree of correlation was observed, but quantitatively ELISA was found to be up to 200 times more sensitive. The sensitivity of the assay and its adaptability to automation should provide an additional method for study or diagnosis of infection with herpes simplex virus.

Animals↗
PubMed2006

Quantitative analysis of photon density of states for a realistic superlattice with omnidirectional light propagation.

Omnidirectional light propagation in a realistic superlattice is investigated. This work complements two previous articles [Phys. Rev. E 59, 3624 (1999); 61, 5802 (2000)] that analyzed the cases of transverse electric (TE) and transverse magnetic (TM) polarization modes, respectively, of the dielectric superlattice modeled by means of Dirac delta functions. We present a quantitative analysis of the transmission functions, the band structures, the equifrequency surfaces, and the photon density of states (PDOS) for both TE and TM modes of the real superlattice without any approximations on the given dielectric function profiles. One of the advantages is that the Brewster effect can be manifested via our approach. In addition, the modes corresponding to TM evanescent waves that are absent from the Dirac comb model can be predicted. Finally, the exact PDOS of the realistic superlattice for the TE and TM modes can be obtained, respectively. These results are relevant to the spontaneous emission by an atom or to dipole radiation in one-dimensional periodic structures.

Journal Article↗
PubMed1979

Cytotoxic T cells: Lyt phenotype and blocking of killing activity by Lyt antisera.

WE REEXAMINED TWO QUESTIONS CONCERNING LYT ANTIGENS OF CYTOTOXIC T CELLS OF THE MOUSE: is Lyt-1 antigen expressed on cytotoxic effector cells and can cytotoxicity be blocked by antibody to Lyt antigens in the absence of added complement? A 3-hr (51)Cr-release assay with splenic effector cells and leukemia or myeloma target cells was used to measure cell-mediated cytotoxicity. The cytotoxic activity of effector cells against allogeneic targets was abolished by exposure to Lyt-1, Lyt-2, or Lyt-3 antiserum and complement. Specificity was established by tests with C57BL/6 Lyt congenic mice and absorption studies with thymocytes. Similarly, the cytotoxicity of effector cells directed against semisyngeneic myeloma targets was reduced by Lyt-1, -2, or -3 antiserum and complement. Effector cell cytotoxicity against another semisyngeneic target was only marginally affected by Lyt-1 antiserum and complement, but was abolished by Lyt-2 or -3 antiserum and complement. It appears likely that cytotoxic T cells are a heterogeneous population with regard to Lyt-1 expression and that past studies indicating an apparent absence of Lyt-1 on cytotoxic T cells revealed a quantitative, not qualitative, feature of these cells. With regard to the activity of Lyt antisera in the absence of added complement, selective blocking of effector cell cytotoxicity for allogeneic and semisyngeneic targets was found with Lyt-2 and Lyt-3 antisera but not with Lyt-1 antiserum. The specificity of blocking was established by tests with Lyt congenic mice and absorption studies with thymocytes. With the exception of blocking by antisera to the H-2 haplotype expressed by the target cell, no effector cell blocking was observed with alloantisera or heteroantisera to a range of other cell surface molecules present on mouse lymphoid cells. One possibility to account for the selective blocking by Lyt-2 and Lyt-3 antisera is that Lyt-2,3 determinants on the surface of cytotoxic T cells have a close spatial relation to the T cell receptor.

Animals↗
PubMed1984

Effect of erythrocyte membrane modulation by lysolecithin on complement-mediated lysis.

Alterations of the physiochemical properties of membranes, such as acyl chain length of phospholipids, cholesterol content, and disturbance of the bilayer packing, affect the efficiency of membrane attack by C5b-9. In the present study, we explored the effect of lysolecithin (LL), a naturally occurring derivative of membrane phospholipids, on membrane damage by C5b-9. Sublytic doses of the L isomer of palmitoyl-lysolecithin were incorporated into the erythrocyte membranes of guinea pig (gpE) or sheep (shE) and the cells were then lysed with C5b6-C9. Marked enhancement of complement-mediated lysis was observed with LL-treated gpE after 2 hr of incubation, whereas the lytic enhancement was either nil or only marginal in shE. Studies on the kinetics of LL incorporation and metabolism in gpE membranes with 14C-LL showed that LL was rapidly incorporated and catabolized to generate free fatty acid (FA). Maximal accumulation of labeled FA in the membrane and loss of membrane-incorporated LL, resulting in approximately equimolar amounts of LL and FA, occurred at 2 hr, concomitant with enhancement of complement-mediated lysis. In shE such a breakdown of LL occurred only minimally. This quantitative difference in LL breakdown between gpE and shE was in accord with lysophospholipase activity that was two and one-half to seven times more active in gpE than shE membranes. When an ether-linked analog of LL (1-O-hexadecyl-sn-phosphorylcholine), which is resistant to lysophospholipase, was incorporated in gpE, the lytic enhancement was not observed. The results of our experiments indicate that the membrane modulating effect of LL on lysis by C5b-9 requires the enzymatic breakdown of LL.

Animals↗
PubMed1987

Complement activation in IgA nephropathy.

Activation of alternative complement pathway is presumed to be important pathogenically in IgA nephropathy since renal biopsies usually exhibit glomerular deposition of C3 and P (properdin). Surprisingly, little is known about plasma complement activation in this disease, and the plasma C3 and C4 concentrations are usually normal or increased. We quantitated C3 activation in 202 plasmas from 81 patients with IgA nephropathy using a sensitive new assay that detects a neoantigen [iC3b-C3d neoantigen) which appears when C3b is inactivated to iC3b, C3dg, or C3d. This assay accurately quantitates small amounts of in vivo C3 activation. The concentration of iC3b-C3d neoantigen in plasma was significantly increased, indicating C3 activation in 37% of the pediatric and 57% of the adult plasmas assayed. When data from serial determinations in the patients were analyzed, 75% of the adult and 57% of the pediatric patients had C3 activation on at least one occasion. Classical pathway activation, quantitated by C4 activation was found in 20% of the adult and 5% of the pediatric plasmas. No association was found between elevated iC3b-C3d neoantigen concentration and history of macroscopic hematuria, chronic renal insufficiency or degree of proteinuria. These studies show that complement activation can frequently be detected in the plasma of IgA nephropathy patients. However, the pathophysiologic significance of this complement activation remains to be determined.

Adult↗
PubMed1982

Intravascular activation of complement and acute lung injury. Dependency on neutrophils and toxic oxygen metabolites.

Intravascular activation of the complement system with cobra venom factor results in acute lung injury, which has been quantitated by increases in lung vascular permeability. Cobra venom factor preparations devoid of phospholipase A2 activity retain full lung-damaging capacity. The lung injury is associated with the preceding appearance of chemotactic activity in the serum coincident with the development of a profound neutropenia. The chemotactic activity is immunochemically related to human C5a. Morphologic studies have revealed discontinuities in the endothelial cell lining of lung alveolar capillaries, damage and/or destruction of endothelial cells in these areas, plugging of pulmonary capillaries with neutrophils that are in direct contact with vascular basement membrane, the presence of fibrin in alveolar spaces and in areas adjacent to damaged endothelial cells, and intraalveolar hemorrhage. Lung injury is dramatically attenuated in animals that have been previously neutrophil depleted. Teh intravenous injection of superoxide dismutase or catalase also provides significant protection from the pulmonary damage. Very little protection from the pulmonary damage. Very little protection is afforded by pretreatment of rats with antihistamine. These studies suggest that intravascular activation of the complement system leads to neutrophil aggregation and activation, intrapulmonary capillary sequestration of neutrophils, and vascular injury, which may be related to production of toxic oxygen metabolites by complement-activated neutrophils.

Animals↗
PubMed1977

Isotope-labelled alpha-amino-isobutyric acid as an indicator in cytotoxicity tests.

The effect of rabbit antisera on the uptake and release of alpha-amino-isobutyric acid (AIBA) in LS- and P-388 cells was investigated. In the presence of homologous antiserum and complement, the uptake of AIBA was inhibited. In the absence of complement, no effect of antiserum was seen. Using prelabelled cells, the efflux of AIBA was greatly accelerated in the presence of antiserum and complement. The AIBA-uptake method was compared with the trypan blue exclusion test and the 51Cr release technique. The AIBA-uptake method was more sensitive in quantitative cytotoxic studies.

Aminoisobutyric Acids↗
PubMed1984

Serum IgM/A, IgA and functionally distinct IgM anti-type III pneumococcal polysaccharide (SIII) antibodies in BALB/c and athymic (nude) mice.

The influence of hereditary absence of thymus upon the synthesis of IgA, complement-fixing (CF) hybrid IgM/A, CF-IgM and non-CF-IgM antibodies to pneumococcal type III polysaccharide (SIII) injected into BALB/c and athymic nude mice was studied. Techniques involved the differential absorption of the serum antibodies by protein-A of Staphylococcus aureus (Sa), coprecipitation in gels with 125I-SIII and autoradiography. IgM/A anti-SIII activity was not demonstrable in nude mice but was produced in significant amounts, by day 5, in BALB/c mice injected with SIII. By day 8, nude mice produced more IgA anti-SIII antibodies than BALB/c mice injected with the same antigen. IgA anti-SIII antibodies were not detected in either strain 5 days after SIII administration. The absence of hybrid IgM/A anti-SIII antibodies in athymic mice, prior to the appearance of monotypic IgA anti-SIII antibodies at day 8, suggests that IgM/A and not IgA synthesis is largely T cell-dependent. The evidence also implies that hybrid IgM/A antibody production, maximal on day 5 in BALB/c mice, and absent from nude mice, is not an essential product in the switching from IgM to IgA synthesis. Both strains of mice produced comparable amounts of complement-fixing (CF)-IgM and NCF-IgM anti-SIII antibodies, with the production of non-complement-fixing (NCF)-IgM anti-SIII in athymic mice being delayed. Results indicate that attempts to quantitate the levels of IgA by assays incorporating anti-IgA anti-sera may be complicated by the presence of IgM/A hybrid antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Dynamic visualization of expressed gene networks.

Cellular biochemical machineries, what we call pathways, consist of dynamically assembling and disassembling macromolecular complexes. While our models for the organization of biochemical machines are derived largely from in vitro experiments, do they reflect their organization in living cells? We have developed a general experimental strategy that addresses this question by allowing the quantitative probing of molecular interactions in intact living cells. The experimental strategy is based on protein fragment complementation assays (PCA), a method whereby protein interactions are coupled to refolding of enzymes from cognate fragments where reconstitution of enzyme activity acts as the detector of a protein interaction. A biochemical machine or pathway is defined by grouping interacting proteins into those that are perturbed in the same way by common factors (hormones, metabolites, enzyme inhibitors, etc). In this review, we describe how we go from descriptive to quantitative representations of biochemical networks at an individual to whole genome level and how our approach will lead ultimately to better descriptions of the biochemical machineries that underlie living processes.

Animals↗