The content of fibronectin in the blood of patients with psoriasis]

Fibronectin, a high-molecular glycoprotein, one of acute-phase proteins, contributes to cellular proliferation and macrophagal activity regulation, and its blood plasma levels are an indicator of the reticuloendothelial system functional activity. Blood plasma fibronectin levels were measured in psoriasis patients before and after hemoperfusion. These levels were found significantly increased in the course of hemoperfusion treatment, this being associated with disappearance of psoriatic elements. A correlation between blood plasma fibronectin level and NBT test parameters, on the one hand, and severity of psoriasis course and efficacy of therapy, on the other, has been revealed.     

Peritoneal defence mechanisms and Staphylococcus aureus in patients treated with continuous ambulatory peritoneal dialysis (CAPD)

Peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients due to S. aureus is associated with an adverse clinical outcome, suggesting impaired clearance of this organism by the host. The ability of peritoneal macrophages (PM0) derived from CAPD patients to take up S. aureus and mount a respiratory burst was investigated. Whilst significant activity was observed in the absence of opsonin, both parameters of phagocytosis were augmented by addition of 20% pooled human serum (PHS), complement-depleted PHS, and fibronectin. When used as sole opsonin, fibronectin resulted in a dose-related increase in chemiluminescent response by both blood neutrophils and PM0. The opsonic activity of dialysis effluent, as judged by neutrophil chemiluminescence, correlated with IgG and fibronectin content, but not with complement as assessed by C3 levels. The addition of urokinase to dialysate improved its opsonic properties whilst having no effect on the activity of PHS-20%; this would suggest that the formation of fibrin in dialysate, promoted by S. aureus, interferes with phagocytosis. This and the low IgG, complement and fibronectin levels in dialysate may explain in part the relatively poor clearance of this organism from the peritoneum.     

Lipid metabolic indices in patients with the gastrointestinal form of food poisoning

The serum concentration of some substances of lipid nature was studied in 103 patients with food toxinfections with relation to the severity of a course and period of the disease. The levels of cholesterol, triglycerides, diglycerides, nonesterified fatty acids (NEFA), and phospholipids were determined using thin-layer chromatography. A mild course of the disease was characterized by a slight rise of lipid concentration. Moderately severe courses were characterized by hyperlipidemia with an increase in the level of NEFA, lysophosphatidylcholine (LPC), phosphatidylcholine. Patients with a severe course demonstrated a decrease in the concentration of most lipid fractions with an increase in the amount of LPC and NEFA. All disorders were observed on the 1st-2nd day of the disease and disappeared against a background of routine rehydration therapy by the 5th-7th day of disease, in patients with a severe course of the disease by the 10th day.     

The plasma fibronectin level in food poisoning

Blood plasma content of fibronectin was studied in 125 patients with food poisoning using rocket immunoelectrophoresis. enzyme immunoassay and antibody neutralization reaction. During the development of the process the content of fibronectin was reduced in most of the patients. This parameter usually drops at the peak of the disease and is normalized on recovery. Measurement of fibronectin in blood plasma can be an additional criterion for determining the degree of severity and the course of the disease and recovery of patients. This method that makes use of the antibody neutralization reaction is simple, can be rapidly performed and produces accurate results.     

ACCESSORY PLASMA FACTORS INVOLVED IN THE BACTERICIDAL TEST FOR TYPE-SPECIFIC ANTIBODY TO GROUP A STREPTOCOCCI : II. HUMAN PLASMA COFACTOR(S) ENHANCING OPSONIZATION OF ENCAPSULATED ORGANISMS

A study was made of the nature of the thermolabile plasma factors in human blood which promote the phagocytosis of Group A streptococci in vitro in the presence of optimal amounts of type-specific M antibody. The plasmas of individuals with strong opsonic activity (normal) were compared with those of some individuals whose opsonic activity was consistently weak (deficient). A general relationship was established between encapsulation of streptococci and the opsonic requirement for thermolabile plasma factor(s). Marked differences in phagocytosis of Group A organisms by human bloods were demonstrated with encapsulated strains only. Human bloods deficient in the cofactor required for opsonization of encapsulated streptococci (coopsonin) showed a normal rate of phagocytosis against all other organisms and particles studied. Furthermore, coopsonin-deficient bloods contained normal levels of four components of complement, of properdin, of lysozyme, and of direct bactericidal activity against several species of Gram-negative organisms and of E. coli bacteriophage. The independence of the streptococcal coopsonin from complement was also demonstrated by absorption of plasma with bentonite and with zymosan. Under appropriate conditions, the coopsonin was reduced without significant loss of complement. The data support the concept that the capsule of the streptococcus imposes an opsonic requirement for a plasma factor(s) which is present in varying amounts in human bloods and which appears to be independent of the complement system. The possibility that it is accessory to the latter components has not been excluded.     

Kupffer cell complement receptor clearance function after surgical injury and phagocytosis of immune complexes: effect of changes in plasma fibronectin

The present study evaluated the effect of changes in plasma fibronectin levels on the degree of depression of in vivo clearance function of Kupffer cell complement receptors after injury and the phagocytosis of immune complexes. In vitro studies have suggested that fibronectin may act as an opsonin for the clearance of immune complexes from the blood by binding to C1q and may influence the expression and activation of immune receptors on macrophages. Complement receptor clearance function was assessed in rats from the hepatic uptake of rat erythrocytes coated with antierythrocyte IgM. Increasing plasma fibronectin by the injection of purified fibronectin or decreasing fibronectin by the injection of gelatin had no effect on complement receptor function in otherwise normal animals. Surgical injury depressed both plasma fibronectin levels and complement receptor function. Injection of fibronectin at the time of injury prevented the depression of receptor function; however, when fibronectin was given 1 hour after injury, receptor function remained depressed even though fibronectin levels were increased. The phagocytosis of immune complexes (IgG-coated rat erythrocytes [EIgGs]) depressed complement receptor function but did not depress plasma fibronectin levels. The depression of receptor function caused by the phagocytosis of EIgGs was prevented by administering fibronectin and was potentiated by administering gelatin, which decreased plasma fibronectin levels. Therefore, plasma fibronectin concentrations can influence in vivo Kupffer cell complement receptor function under certain conditions that lead to the depression of complement receptor function.     

Fibronectin in liquid and frozen stored blood components

To quantitate the concentration of fibronectin in blood components to determine if the fibronectin present in liquid and frozen stored blood products deteriorates in vitro, we measured the concentration of this opsonic protein at the beginning and at the end of storage. In addition, electroblotting studies were performed to ascertain if aggregation or degradation of fibronectin occurred during component preparation or storage. Results showed that fibronectin concentration was stable in whole blood, single donor plasma, platelet concentrates, fresh-frozen plasma, and cryoprecipitate. By electroblotting, aggregated or degraded fibronectin was found in some components, especially cryoprecipitate. Most of the fibronectin, however, appeared to be unaffected by component preparation or storage.     

Preparation of antihemophilic factor and fibronectin from human plasma cryoprecipitate

Starting with human plasma cryoprecipitate, fibronectin was separated from antihemophilic factor (AHF) by fractional precipitation under mild conditions resulting in excellent recovery of AHF in the supernatant solution of the cryoprecipitate. Separation of fibronectin enabled accelerated sterile filtration of the supernatant solution containing AHF even after three- to fourfold concentration (by ultrafiltration) to desired potency. The sterile AHF concentrate, dispensed at 1000 u per vial and lyophilized, was completely dissolved within 3 minutes upon addition of 30 ml of pure water. The expected increment in circulating factor VIII and its hemostatic effects were found following intravenous infusion into factor VIII-deficient patients. Yield of AHF of five successive batches, each starting with the cryoprecipitate from some 12,000 units of fresh-frozen plasma, averaged 51 percent. The fibronectin precipitate was purified by affinity on insolubilized gelatin with chaotropic elution at pH 5.5 followed by removal of the chaotrope by diafiltration. Thermal denaturation of adventitious fibrinogen resulted in electrophoretically pure fibronectin which, following lyophilization and reconstitution with pure water, retained biological properties in an in vitro assay designed to reflect opsonic activity. The yield of fibronectin for seven successive batches, each starting with the cryoprecipitate from some 900 units of fresh-frozen plasma, averaged 10 percent.     

Fibronectin replacement in patients with fulminant hepatic failure

Patients with fulminant hepatic failure have low levels of the plasma opsonizing protein fibronectin together with cardiovascular disturbances similar to those in septic shock where microembolization of capillary beds by particulate debris has been proposed to lead to multi-organ failure. Six patients with fulminant hepatic failure received a bolus injection of a concentrated fibronectin-rich preparation. The mean plasma immunoreactive fibronectin level increased from 53 +/- SE 12 micrograms ml-1 initially to 295 +/- 30 micrograms ml-1 (P less than 0.001) at 1 h after fibronectin administration. The in vitro plasma opsonic activity was also increased from 5.6 +/- 3.6% of control to 102 +/- 13% (P less than 0.005) at 1 h. No similar effect was observed with the clearance of microaggregated albumin, but as its clearance is probably not dependent on fibronectin it may reflect a different aspect of reticuloendothelial cell function. No significant changes were observed in cardiopulmonary function or oxygen utilization and it is possible this is because clearance of opsonized particles is limited by damage to Kupffer cells.     

血浆纤维结合蛋白的动态变化在骨折愈合中的临床意义

采用酶标仪比浊法研究１１８名骨折患者愈合过程中１～７周血浆纤维结合蛋白（Ｆｎ）变化规律及骨折损伤程度与Ｆｎ的关系。实验结果表明，骨折后１～３周，Ｆｎ明显减少，第４～５周Ｆｎ呈缓慢上升，第６周恢复正常。因此看出Ｆｎ与骨折损伤、修复程度有密切关系，并起着十分重要的作用。     

Plasma fibronectin concentrations in blood products

Plasma fibronectin is an important opsonic protein of the mononuclear phagocyte system (MPS). In this study, plasma fibronectin concentrations were measured in stored and fresh whole blood, fresh frozen plasma and AGH cryoprecipitate. Stored whole blood had the lowest concentrations (151±50 mg/l). The concentrations in fresh whole blood plasma (227±66 mg/l) and fresh frozen plasma (224±78 mg/l) were similar but significantly higher than in stored whole blood (p<0.05). In contrast, AHG cryoprecipitate had the highest fibronectin concentrations (3249±502 mg/l) (p<0.001). In correcting fibronectic deficiency the best results can thus be expected from an infusion of cryoprecipitate, but fresh whole blood and fresh frozen plasma may also increase depressed fibronectin levels.     

冷沉淀纤维结合蛋白的含量及其在急性白血病患者体内的动态观察

采用环状单向免疫扩散法,测定了40例正常人血浆纤维结合蛋白(FN)含量,其 X~2±SD 为292.48±43.11μg/ml;30例急性白血病患者 FN 为209.49±69.56μg/ml。两组相比,p<0.01。同时还观察到血浆 FN 水平与血型无相关性(p>0.05)。另外还测定了本所制备的89袋冷沉淀,FN 含量为1.5583±0.4476mg/ml,与国外有关报道一致,且 FN 回收率高于文献值(p<0.001)。对8例急性非淋巴细胞白血病伴发热感染者各输冷沉淀100ml,输后4小时 FN 上升高峰接近正常组值,因此输注冷沉淀可纠正病人低 FN 水平。本研究结果提示,冷沉淀有可能作为具有调理活性的制品而用于新的临床适应证。     

Conversion of an M- group A streptococcus to M+ by transfer of a plasmid containing an M6 gene

An M28-derived group A streptococcal strain deleted for the gene encoding M protein was converted to M+ by introduction of a plasmid carrying emm6, the structural gene for type 6 M protein from strain D471. The reconstituted M+ strain, JRS2, resists phagocytosis in human blood and is opsonized by anti-M6 hyperimmune serum, but not by anti-M28 serum. Immunofluorescent microscopy and ELISA demonstrate the presence of M protein on its surface. In addition, JRS2 removes opsonic antibodies from hyperimmune rabbit sera generated by immunization with purified ColiM6 protein and with a synthetic amino-terminal peptide derived from M6. Immunization of rabbits with JRS2 generates opsonic anti-M6 antibodies. These results indicate that the cloned emm6 gene contains the information necessary to convert a phagocytosis-sensitive streptococcus to phagocytosis resistance. Furthermore, it also contains the determinants for M type specificity and those required to elicit opsonic antibodies. It thus appears to determine all the traits associated with M protein.     

Plasma fibronectin level in patients with depression of hematopoiesis

Plasma fibronectin is regarded to play an important part in a decrease of the resistance to infections. To specify the role of fibronectin in the pathogenesis of infectious complications in patients with depressions of hemopoiesis, the content of this opsonin was measured by ELISA in 113 patients with different patterns of hemoblastoses, lymphoproliferative diseases and with an aplastic syndrome. In 42 patients, the concentration of opsonin was measured in the presence of the superimposed infection of varying gravity. The fibronectin content was examined in 39 patients before, during and after completion of the cytostatic polychemotherapy. It turned out that in patients with paraproteinemic hemoblastoses, lymphogranulomatosis, aplastic anemia, chronic lympholeukemia, acute lympho- and myelo(mono)blastic leukemias, cyclic neutropenia, chronic myelosis and hematosarcomas, the concentration of fibronectin remained normal in the absence of infections. The computation of the linear correlation ratio did not reveal any association between the opsonin level and the concentration of neoplastic elements in the peripheral blood. Repeated measurements of the fibronectin level in patients whose underlying disease ran its course in association with marked neoplastic fever failed to detect any deficiency of the glycoprotein. The lowering of the fibronectin level was recorded in patients with a grave concomitant infection of the type of sepsis, necrotic enteropathy and lobar pneumonia. The degree of opsonin deficiency correlated with the patients' disease gravity. Prolonged reduction in the blood fibronectin level was of unfavourable prognostic importance. Cytostatic polychemotherapy, myelotoxic agranulocytosis as well as infectious complications of low gravity did not influence the concentration of fibronectin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma fibronectin enhances phagocytosis of opsonized particles by human peripheral blood monocytes

We have investigated the effect of plasma fibronectin (Fn) on binding and phagocytosis of sheep erythrocytes (E) by human peripheral blood monocytes. Unopsonized E were not phagocytosed in the absence or presence of Fn, but Fn enhanced the phagocytosis of E bearing IgG. Sheep erythrocytes sensitized with IgM and C3b were ingested only when monocytes were exposed to Fn. The Fn enhancement of phagocytosis occurred for both fluid-phase and glass-adherent monocytes. Experiments in which Fn was washed out before mixing monocytes with opsonized E demonstrated that the Fn effect occurred because of interaction with the monocytes and not the opsonized particles. Chromatography of the Fn on Biogel A 1.5m showed that the phagocytosis-enhancing activity exactly co-chromatographed with the Fn protein. Fn did not increase the number of monocyte membrane receptors for the Fc fragment of monomeric IgG. We conclude that Fn enhances monocyte phagocytosis, not by binding to particles as a conventional opsonin, but by stimulating monocytes to ingest already opsonized particles more avidly.     

Several aspects of the pathogenesis of disturbances of hemostasis in patients with diffuse toxic goiter

Components of the kallikrein-kinin system of the blood and some hemostatic indices were studied in parallel in 32 patients with diffuse toxic goiter. A decrease in the levels of prekallikrein, kininogen, the activity of kallikrein and kininase inhibitors in the blood plasma of the examinees resulted in raised activity of the kallikrein-kinin system in decompensated thyrotoxicosis. Hemostatic changes were characterized by signs of chronic disseminated intravascular coagulation. It was shown that kinin formation and blood coagulation were correlated. A certain parallelism in the increment of the activity of the kinin system and disorders of hemocoagulation was noted with an increase in a degree of severity of thyrotoxicosis. A tendency to improved indices was also noted after thyrostatic therapy.     

Complement-mediated phagocytosis of Pseudomonas aeruginosa.

The nature of the opsonic factors in nonimmune human serum for six blood culture isolates of Pseudomonas aeruginosa was investigated by measuring uptake of [3H] adenine-labeled bacteria by human PMNs. Normal human serum, C2- and C4-deficient sera, zymosan-treated serum, and immunoglobulin-deficient sera were used as opsonic sources. Heat inactivation of each of these serum sources markedly reduced its opsonic capacity for all Pseudomonas strains, suggesting that the serum C system was essential for opsonization. Five strains were opsonized in the absence of the classical C pathway; however, kinetic studies revealed that opsonization proceeded at a faster rate when the classical pathway was present. In spite of markedly reduced factor B and C3 levels, zymosan-treated serum retained significant opsonic activity for one of the strains tested. Four strains were poorly opsonized by immunoglobulin-deficient serum, and C activation by these strains appeared to depend upon the presence of antibodies. Two strains, however, were effectively opsonized in a relative absence of antibodies. Thus, in the nonimmune state, phagocytosis of P. aeruginosa is mediated primarily via the C system, and antibodies appear to play a role in the opsonization of some but perhaps not all Pseudomonas strains.     

A FURTHER CONTRIBUTION TO THE KNOWLEDGE OF THE OPSONINS

1. The determination of Wright''s index of the opsonic content of the blood and other fluids of the body is open to serious and in part unavoidable errors and should be abandoned in its present form. 2. Conclusions based upon the determination of the opsonic content of the blood, according to Wright''s method, are accordingly not uniformly reliable. 3. The percentage index is a valuable check on Wright''s bacillary index, but likewise does not furnish an adequate idea of the opsonic content of the blood, unless carried out with progressive dilutions to the point of opsonic extinction. 4. The opsonins of normal blood serum are not specific. 5. The specificity of the opsonins in "immune" sera has not been satisfactorily established, but appears probable. 6. An opsonic immunity, in the sense of a continued high opsonic content of the blood does not exist. 7. In the blood and exudates of infected individuals substances may be present which exercise an inhibitory effect upon phagocytosis.     

Lower expression of the alpha2,3-sialylated fibronectin glycoform and appearance of the asialo-fibronectin glycoform are associated with high concentrations of fibronectin in human seminal plasma with abnormal semen parameters.

BACKGROUND: Sialic acid isoforms expressed on glycoconjugates are known to be involved in different biological functions. The aim of this study was to compare alpha2,3- and/or alpha2,6-linked sialic acid expression on fibronectin in the seminal plasma of male partners from infertile couples. The data obtained were analyzed in relation to normal and abnormal semen parameters, as well as to fibronectin concentrations. METHODS: Fibronectin concentrations were determined by ELISA using a specific monoclonal antibody. The relative degree of sialic acid linked to fibronectin glycans either by alpha2,3 or alpha2,6 isomeric linkage was estimated by lectin-fibronectin ELISA utilizing lectins from Maackia amurensis and Sambucus nigra, respectively. RESULTS: High seminal fibronectin concentration was more frequently associated with abnormal semen parameters. The glycans of seminal plasma fibronectin, in contrast to blood plasma fibronectin, contained sialic acid more frequently attached by alpha2,3 than by alpha2,6 isomeric linkage. The relative amounts of both alpha2,3- and alpha2,6-linked sialic acid fibronectin isoforms were lower in the seminal plasma of men suspected of infertility. CONCLUSIONS: Seminal fibronectin showed an oncofetal type of sialylation and the distribution of hypo- and asialylated fibronectin glycoforms were associated with abnormal semen parameters and with high concentrations of fibronectin.     

Effect of delayed refrigeration on plasma factors in whole blood collected in CPDA-2

Extension of the time within which whole blood may be separated into components offers logistic advantages for the operation of remote mobile drawing teams. We evaluated the effect of an 8-hour hold of whole blood at room temperature before preparation of components. Plasma coagulation activity and opsonic factor content were studied in 14 units drawn into the anticoagulant-preservative solution citrate-phosphate-dextrose-adenine (CPDA-2). At the time of collection, an additional 7-ml aliquot was drawn into 1 ml of CPDA-2, the plasma separated and frozen immediately. Components were prepared from whole blood units allowed to rest undisturbed at 22 +/- 1 degrees C for 8 hours. After 8 hours, a significant decrement of about 10 percent was found in the concentration of fibrinogen, plasminogen, fibronectin, and activity of Factor V. Factor VIII activities (VIIIAHF and VIIIAGN) were not significantly different after 8 hours. Our results indicate that room temperature storage for 8 hours before component processing has minimal effects on potentially labile plasma protein factors using CPDA-2 anticoagulant-preservative solution.