[Effect of total fasting on serum protein concentrations (author's transl)]

During a period of total fasting restricted to three weeks, haptoglobin, transferrin and beta1A-globin showed a marked, continuous decline. The complement was finally distinctly below the reference range. Macroglobulins and coeruloplasmin rised until the tenth day and decreased thereafter. IgG globulin remained essentially unchanged while immunoglobulins gammaA and gammaM showed an increase. On account of the considerable fluctuations observed in the protein fractions fasting in this form at least beyond a period of 21 days does not seem justified.

[The mechanization of the enzyme immunological determination of phenytoine with the Centrifichem (author's transl)]

The separation of free from bound antigen is not required in homogeneous enzyme immunoassays (EMIT). Therefore this technique can easily be mechanized. For the mechanization of the enzyme immunological determination of serum levels of Phenytoine the fast analyzer (CENTRIFICHEM) was found most satisfactory in our laboratory. The marked advantages over manual methods are: 1. The amount of sample and reagents needed can be reduced by half. 2. The intra- and interassay variance are significantly better compared to values found with manual techniques. 3. 60 samples can be determined in duplicate in under two hours.

Effect of hog anaphylatoxin (C 5a) on vascular permeability and leukocyte emigration in vivo

The effects of highly purified hog anaphylatoxin (C 5a) on leukocyte emigration were investigated in guinea pigs in vivo using two experimental models: 1. Subcutaneous infusions. Sterile solutions of C 5a in saline infused at a rate of 1.8 mug C 5a/h (0.2 ml/h) for 10 h induced a dense accumulation of leukocytes, mainly neutrophils but also some eosinophils at the site of application; In control infusions with saline alone comparatively few leukocytes were found. 2. Single injections into the pleural cavity. 10 or 20 mug C 5a (dissolved in 2 ml saline) caused a dose-dependent increase in leukocyte number and volume of pleural exudate. Bradykinin in a dose of 18 mug produced similar fluid exudation as 20 mug C 5a but had no significant effect on leukocyte accumulation. Intrapleural injections of C 5a further caused the appearance of i.v. injected Evans blue in the pleural cavity. This effect, indicating an increase in vascular permeability lasted for about 3 h; Since at least one of the two models used - subcutaneous infusion -simulates natural conditions -continuous local generation of C 5a in small amounts at the site of an inflammatory lesion-the results indicate that C 5a once formed by complement activation in natural defense reactions may contribute to local increase in vascular permeability and leukocyte infiltration.

Purification and some properties of factor D of the human properdin system

Factor D has been purified by gel and ion exchange chromatographies, and by ultrafiltration through different membranes. The final preparation appeared pure in various analytical tests. The molecular weight of human D is 21,500 according to gel chromatography, the isoelectric point was found at pH 7.8. Factor D is an active esterolytic enzyme, it cleaves N-alpha-acetyl-L-lysine methyl ester and N-alpha-acetyl-L-glycyl-L-lysine methyl ester. Both peptide esters inhibit the hydrolytic activation of factor B by D in the presence of cobra venom factor. D is also inhibited by diisopropyl-fluorophosphate and by penylmethyl-sulfonyl-flouride.

Induction of platelet aggregation by the complement-derived peptides C3a and C5a

The effect of two complement-derived peptides, hog serum C3a and C5a, on platelet aggregation in platelet-rich plasma and suspensions in Tyrode solution was investigated. 1. Guinea-pig platelets were aggregated by both C3a and C5a; the spasmogenically inactive product of C3a, C3ai, also induced aggregation. Threshold concentrations were in the range of 10(-6)--10(-9) M depending on the peptide and platelet preparation. 2. Cat platelets were aggregated by C5a (threshold concentrations 10(-7)--10(-8) M) but not by C3a. 3. Platelets from pig, rabbit and man were not aggregated by either of the two peptides in concentrations of up to 5 X 10(-6) M. 4. When C5a was administered repeatedly in subthreshold doses guinea-pig platelets became tachyphylactic to C5a but were still aggregable by C3a or ADP. Conversely, platelets desensitized to C3a still reacted to C5a or ADP. Tachyphylaxis towards C5a developed also when platelets were incubated with C5a in the absence of free Ca2+ under which condition they do not react. The tachyphylaxis in this case became evident after recalcification of the medium. The lack of cross-desensitization indicates that C3a and C5a react via different receptors. 5. C3a and C5a were injected i.v. into guinea pigs. Histological examination of the lungs revealed that some of the smaller vessels (20-30 mu in diameter) were occluded by platelet aggregates. In addition signs of severe acute emphysema were seen in animals treated with C5a, but only slight emphysema in C3a-treated animals. Intravenous injections of C3a into guinea pigs caused but weak respiratory distress and drowsiness and never killed an animal (at doses of up to 20 mg per kg body weight), whereas C5a caused the well-known severe respiratory failure and death already at doses of 0.03 mg/kg body weight.

Inefficient Utilization of the Fifth Component of Guinea Pig Complement in Cobra Venom Factor-Induced Complement Lysis; Efficient Utilization of Human C5

Interaction of cobra venom factor with properdin Factors B and D̄ leads to generation of a C3- and C5-cleaving enzyme complex consisting of CVF and the larger fragment (Bb) of Factor B (Vogt et al., Hoppe-Seyler's Z. Physiol. Chem. 355:171, 1974). On incubation with EDTA-serum (C-EDTA) and red cells the CVFB̄ complex activates the terminal complement sequence and induces hemolysis (Pickering et al., Proc. Natl. Acad. Sci. 62:521, 1969). Hunsicker et al. (J. Immunol. 110:128, 1973) found that this indirect lysis involving activation of C5 in the fluid phase and subsequent cell fixation of C, C8 and C9, is inefficient when guinea pig C-EDTA is used but becomes marked when a trace of human serum is added. The enhancing activity provisionally called “Factor E” by Hunsicker et al., has been purified from human serum and identified as the fifth component of human complement, by immunoelectrophoresis, reaction with anti-C5 antiserum and functional tests.

Complex Formation of Properdin Factor B with C3b, an Essential Step in the Generation of the C3b Dependent C3 Cleaving Enzyme of the Properdin System

Earlier studies demonstrated that in the presence of Mg++ human factor B interacts with C3b as obtained by trypsin treatment of human C3, and only subsequent to this interaction can be cleaved and activated by Factor D̄. Mg++-dependent binding of highly purified B to C3b was demonstrated by the use of agarose to which trypsin-activated C3̄ had been fixed (Vogt et al., Z. Immunitaet forsch 149:440, 1975). Highly purified human C3b has now been prepared by treating partially purified C3hu with an insolubilized CVFB̄ complex, and fractionating the product on DEAE-cellulose and OH-apatite. The C3b preparation gave a single precipitation line in immunoelectrophoresis with anti-whole human serum, developed fusing precipitation bands with anti-C3c and anti-C3d sera in double immunodiffusion and did not react with antiserum against the B antigen of human C3. C3b and Mg++ were essential for cleavage of B by D̄ and for generation of C3-cleaving activity.

[Significance of serum digoxin concentration and its influencing factors]

In recent years it has become possible by means of a radioimmunoassay to measure Digoxin concentration in the serum of digitalized patients. With this method it could be shown that the resorption of Digoxin is decreased by partial resection of the samll intestines, by malabsorption syndromes, after ingestion of Neomycin, Colestyramine and antacids. In renal insufficiency, however, the elimination half-life period of Digoxin is increased conspiciously (from about 35 hours up to about 120 hours). This results in a raised serum concentration of cardiac glycosides unless the dosage is decreased considerably. The incidence of Digitalis intoxication in Digitalis treated patients has been reported to rank as high as 20%. There is, however, no strict correlation between the serum glycoside level and the clinical symptoms, because the glykoside concentration in the serum does not represent the pharmacologically active concentration at the receptor. Experimental investigations of cardiac glycoside binding to the receptor for cardiac glycosides in human heart cell membranes revealed, that receptor bound Digoxin for instance is diminished in serious renal insufficiency and it depends on the serum concentration of potassium, calcium and magnesium. In hypoxia, after myocardial infarction and in myxedema the sensitivity for cardiac glycosides is increased. The opposite is true in hyperthyreoidism, fever and in children. All of these factors have to be kept in mind and paid attention to in the clinical evaluation of the measured Digoxin concentration in the serum.

Purification of a human serum protein ("factor E") which enhances cobra venom factor-induced indirect lysis. Identification with the fifth component of complement

Complexes formed of Cobra venom factor (CVF) and activated factor B (B) by interaction of CVF and B with trypsin or factor D are capable of activating the third and fifth complement component. When incubated with sheep or guinea pig red cells and guinea pig serum in the presence of EDTA, these CVFB complexes produce "indirect lysis". Addition of a human serum factor, earlier designated as factor E (6), greatly enhances the efficiency of this lytic system. The component with this activity has been purified to homogeneity (disc and immunoelectrophoresis). In chromatographic fractionations it was inseparable from the fifth complement component, it was inactivated by and reacted with several anti-C5 antisera, and kinetics of inactivation by heat (56 degrees C) and trypsin were the same for factor E and hemolytic C5 activities. It is concluded that factor E is the fifth component of human complement. Guinea pig C5 is not capable of supporting indirect lysis in a comparable manner, for as yet unknown reasons. Some possible explanations are discussed.

Incompatibility between C3b and B of guinea-pig and man and its influence on the titration of the alternative pathway factors D and B in these two species

The incubation of the proteins C3b, B, D and C3 induces enzymatic activation of B and of C3. This system of purified components was applied to the titration of the guinea-pig and human factors D and B in various homologous and heterologous reaction mixtures. On the basis of functional as well as of immunological tests, the D enzymes of both species were found to be related proteins. First, titrations of factor B revealed that both D enzymes activate homologous and heterologous B with comparable efficiency. Secondly, a rabbit anti-D antiserum raised against guinea-pig D was found to form a precipitation line of partial identity with guinea-pig and human D. In contrast to the compatibility between heterologous D and B, heterologous combinations of C3b and B were found to be incompatible. This incompatibility was indicated by low titres of D in the presence of heterologous C3b and B; in contrast, in the presence of homologous C3b and B, the titres of D were up to one hundred-fold higher. The reason for this effect was found to reside in inefficient complex formation between heterologous C3b and B. Therefore titrations of D and B should be only performed in the presence of homologous C3b and B.

Formation and composition of the C3 activating enzyme complex of the properdin system. Sequential assembly of its components on solid-phase trypsin-agarose

An active C3 cleaving enzyme is generated when properdin factor B (glycine-rich beta-glycoprotein, GBG) is activated (GBG is cleaved) by factor D in the presence of C3b and Mg++. Factor D can be replaced by trypsin in this reaction but even then C3b and Mg++ are required. In the absence of C3b and/or Mg++ trypsin does not generate C3 cleaving activity from GBG although it cleaves GBG and releases its GGG fragment (B) under these conditions as well. Addition of C3b to GGG immediately after its release does not yield a C3 cleaving enzyme. These findings indicate that C3b, GBG and Mg++ interact, and that only in association with C3b can GBG be cleaved in a way that its enzyme activity, residing in a C3b, GGG complex, is expressed. The complex is labile (half-life at 20 degrees C: 9 minutes); Mg++ does not affect its stability nor is it essential for the activity. It was possible to sequentially fix on agarose the essential components of the C3 cleaving enzyme and thus to elucidate the single steps and the order of its formation. C3 was activated and the resulting C3b fragment fixed on agarose by incubating C3 with trypsin covalently bound to the agarose. The agarose-C3b intermediate was capable of binding GBG provided Mg++ was present. GBG could then be cleaved by factor D or trypsin added in solution; the solid-phase-fixed complex obtained had C3 cleaving activity, in the presence as well as absence of Mg++. Omission of any of these steps or components, or changes in the sequence did not give rise to an active enzyme. Mixtures of C3b, GBG and Mg++ have weak C3 cleaving activity by themselves. C3 cleavage in such incubation mixtures proceeds slowly for hours and is not accompanied by cleavage of GBG. There is thus complete analogy between the CVF-dependent and C3b-dependent C3 cleaving systems. C3b and CVF act in the same way, they form a reversible, weakly active C3 cleaving complex with GBG and Mg++, the activity of which is markedly enhanced but becomes subject to decay when GBG is cleaved by trypsin-like enzymes while bound to CVF or C3b.

Effects of pressoreceptor stimulation on micturition relfex and urethral pressure profile in rabbits

The influence of pressoreceptor stimulation on the micturition reflex and urethral pressure profile was studied. Stimulation of pressoreceptors of the aortic arch and carotid sinus causes an increase of parasympathetic tone and a decrease of sympathetic tone. Striated muscular tone was also decreased. Pressoreceptor stimulation was simulated by electrical stimulation of the depressor nerve in the rabbit. Our studies show that with pressoreceptor stimulation micturition occurred with 24 per cent less bladder filling and 32 per cent less intravesical pressure than before stimulation, and urethral pressure profile showed a 17 per cent decrease of the maximum and mean urethral pressure. The interpretation of the action of parasympathicomimetic and sympathicomimetic drugs on bladder and bladder neck must take into consideration the cardiovascular effects of these drugs and therefore the effect on the pressoreceptors.

Cleavage of the third complement component (C3) and generation of the spasmogenic peptide, C3a, in human serum via the properdin pathway: demonstration of inhibitory as well as enhancing effects of epsilon-amino-caproic acid

Human and guinea pig serum loses hemolytic activity of the third complement component (C3) during incubation at 37 degrees C. The loss is due to specific C3 cleavage involving the properdin system. This is concluded from the finding that C3 inactivation is prevented by EDTA, by elimination of properdin factor B, and unimpaired in C4 deficient guinea pig serum. In the presence of 1 M epsilon-amino-caproic acid (EACA) spontaneous C3 cleavage is considerably enhanced and accompanied by the appearance of biologically active C3a. Lower concentrations of EACA inhibit rather than enhance C3 cleavage in serum. The inhibitory effect of EACA is due to interference with the interaction of the properdin factors and their action on C3 as demonstrated in various systems: the assembly of an active C3-cleaving complex on zymosan, its regeneration after decay by factor D and factor B (GBG), cleavage of GBG by C3b and factor D in systems of purified components, and cleavage of C3 by preformed properdin complexes. Reactions involving the cobra venom factor were likewise depressed. In all these systems EACA was inhibitory even at 1M concentration. No single step in the development or action of an active properdin system was found to be enhanced by 1 M EACA. The enhancing effect of high concentrations of EACA on C3 cleavage in serum may be explained by its observed inhibition of C3b inactivator (C3bINA). This factor controls the properdin system by destroying C3b. In serum the inhibitory effect of 1 M EACA on C3bINA appears to allow escape of the properdin system from its control and thus to increase its net activity toward C3 despite inhibition of the enzymic reactions proper. At lower concentrations the effect of EACA on C3bINA is apparently less significant; therefore, at low concentrations of EACA, its inhibitory effects on C3 cleavage by the properdin system in serum prediominate.

[Effect of aprotinin in acute myocardial infarction (clinical double-bind study (author's transl)]

In a double-bind study 164 patients with acute myocardial infarction, admitted to an intensive-care unit within 72 hours of infarction, were randomly treated for three days either with aprotinin (Trasylol-82 persons) or placebo (82 persons). Retrospective analysis proved both patient groups to have been comparable in all other respects. There was no definite influence on the course of the infarction, haemodynamic changes, arrythmias or mortality rate. Trasylol thus has no therapeutic importance in the treatment of acute myocardial infarction.

Mixed lymphocyte culture stimulatory and responding capacity of lymphocytes from patients with lymphoproliferative diseases

Lymphocyte reactivity in vitro was studied in patients with Hodgkin's disease, chronic lymphocytic leukaemia and lymphosarcoma. The responding capacity to phytohaemagglutinin (PHA) was markedly depressed and delayed in all three groups of patients compared with the PHA response observed in lymphocyte cultures from normal individuals. In one-way mixed lymphocyte culture experiments a significant decrease in responding capacity of the patients' lymphocytes to lymphocytes from normal donors could be demonstrated. In contrast, the stimulatory capacity of the patients' lymphocytes was found to be intact, or only slightly reduced.

Lymphocyte function in patients with Hodgkin's disease

Lymphocyte functions in vitro were tested in patients with Hodgkin's disease. The PHA-induced lymphocyte stimulation and the responding capacity in the one-way mixed lymphocyte culture reaction was found to be severely depressed. In contrast, the PHA-induced production of a human mononuclear leukocyte chemotactic factor was not significantly impaired.

Histamine release, formation of prostaglandin-like activity (SRS-C) and mast cell degranulation by the direct lytic factor (DLF) and phospholipase A of cobra venom

Cobra venom, alone and in combination, on mast cell degranulation, histamine release and formation of prostaglandin-like activity (SRS-C) was studied in perfused guinea-pig lungs and in mast cell-containing rat peritoneal cell suspensions. For comparison, the effect of equivalent doses of whole cobra venom was investigated. 1. Cobra venom caused mast cell degranulation, histamine release and SRS-C formation in both systems. For comparable effects much higher doses had to be used in guine-pig lungs than in rat peritoneal cell suspensions. 2. Phase A showed little degranulation of mast cells in both systems, a limited histamine release in rat peritoneal cell suspensions and none in perfused guinea-pig lungs. It caused a considerable SRS-C formation in both, lung tissue and peritoneal cell suspensions. 3. DLF caused histamine release, SRS-C formation and mast cell degranulation in both systems; in rat peritoneal cell suspensions it acted almost as strong as equivalent doses of cobra venom, in guinea pig lungs it was much less active. 4. In rat peritoneal cell suspensions the effects of DLF and phase A in combination did not exceed the sum of their single effects. In guinea-pig lungs these two substances interacted in a potentiating synergism. It is concluded that DLF is the main cytotoxic principle of cobra venom, whereas ph-ase A alone is not cytotoxic. The difference in the synergism of DLF and ph-ase A between rat peritoneal cells and guinea-pig lungs may be due to two different actions of DLF and species differences as regards sensitivity against these actions.

Lymphocyte transformation and production of a human mononuclear leucocyte chemotactic factor in patients with Hodgkin's disease

Human peripheral lymphocytes stimulated in vitro with phytohaemagglutinin (PHA) produce a factor with chemotactic activity for homologous monocytes. The production of this factor and lymphocyte transformation was investigated in patients with Hodgkin's disease. It has been found that the PHA response as measured by incorporation of [³H]thymidine was markedly depressed in patients when compared to the response of normal lymphocytes. In contrast, the production of the chemotactic factor was not significantly depressed in patients with Hodgkin's disease.

Effect of L-asparaginase and hydrocortisone on human lymphocyte transformation and production of a mononuclear leucocyte chemotactic factor in vitro

Human peripheral lymphocytes stimulated in vitro with PHA produce a soluble factor which is chemotactic for homologous monocytes. The synthesis of this factor was found to precede the blastogenic response as measured by [³H] thymidine incorporation. In cultures of unseparated leucocytes the maximum of chemotactic activity was detected after 24 hr, whereas in supernatants from purified lymphocyte suspensions the maximal synthesis occurs after 72 hr. High doses of L-asparaginase from E. coli which have been found to prevent lymphocyte transformation completely have no influence on the production of the chemotactic factor. Therefore it seems possible that the induction of DNA synthesis by PHA and its effect on the production of a chemotactic factor depend on different biochemical mechanisms. In contrast hydrocortisone leads to a dose-dependent inhibition of both DNA synthesis and chemotactic response.

Stimulation of B cells by poly A: poly U and poly I: poly C in vitro

Both poly I:poly C and poly A:poly U stimulate [³H]thymidine incorporation by spleen cells derived from normal or from cortisone-treated mice. The highest rate of stimulation was detected in the spleen cells of nude mice. Compared with spleen cells, thymus cells and cortisone-resistant thymus cells gave only a small but reproducible response. The results suggest that double-stranded polynucleotides act preferentially on B cells in the same way as dextran sulphate.

Effects of hydrocortisone treatment and whole body irradiation on mouse lymphocyte stimulation in vitro

Whole body irradiation was found to reduce the number of nucleated cells in the thymus and the spleen of C57B1 mice to the same extent as hydrocortisone treatment. Equal numbers of thymus and spleen cells from either hydrocortisone-treated or irradiated mice and matched controls were cultured and stimulated with various mitogens. An increased stimulation of DNA synthesis by PHA, Con A and PWM was found in thymus and spleen cells after hydrocortisone treatment as well as after whole body irradiation. In contrast, the response to LPS, known as a typical B-cell mitogen, was not affected by any of the procedures.

Stimulation of B-cells by dextran sulphate in vitro

Dextran sulphate (DS) stimulates [³H]TdR incorporation in spleen cells of various strains of mice including athymic nude mice. In spleen cells of normal mice an additive effect of DS on the PHA-response was detected. The results suggest that DS is a B-cell mitogen. It seems that the mitogenic activity of polyanions may be related to their effects on antibody formation.

Identification of a Heat Labile Human Serum Factor (UF) with GBG; Participation in Anaphylatoxin-Forming Systems

A heat-labile factor of human serum (UF) which together with properdin is implicated in classical anaphylatoxin (AT) formation by zymosan has been purified. It is a β-globulin, m.w., about 90000; pI, 5.7 (4°C). Functionally, UF is identical with properdin factor B, immunochemically with GBG. No antigenic relation exists between conglutinogen-activating factor and UF.

By treatment of human serum with zymosan UF is cleaved into two fragments carrying the antigenic determinants of glycine-rich α-globulin (GAG) and glycine-rich γ-globulin (GGG), respectively. A fraction of GGG is bound to the zymosan together with other factors, forming a labile, C3 and C5 cleaving, and AT-releasing complex. The same cleavage of UF is seen when serum is treated with free or insolubilized CVF. Insolubilized CVF incubated with human serum and washed acquires stable C3-cleaving and AT-releasing activities, inhibitable by anti-CVF or anti-UF serum. No such activity develops when insolubilized CVF is incubated with serum lacking UF or with purified UF alone.