Effect of serum on organogenesis of the rat testis in vitro

Summary It was observed previously that primordia of fetal rat testes when explanted in vitro in a synthetic medium at the outset of sexual differentiation differentiate seminiferous cords during the following days, but that the addition of 15% fetal bovine serum prevents this morphogenesis. In the present study, human, horse, bovine calf, and rat sera were shown to exert the same effect. Very low concentrations of human or fetal bovine serum (0.5 or 1%) were sufficient to produce the serum effect, which was only slightly reduced when the serum was heated. The serum activity was not removed by dialysis (membrane cut-off 15 000), but it disappeared after treatment with trichloroacetic or perchloric acids or after trypsin digestion. Partial purification of the active factor(s) from human serum was achieved by successive gel filtration, affinity chromatography, and ion exchange chromatography. Analysis of the active fractions by electrofocusing and immunoelectrophoresis placed the activity within the α globulin group. Among a series of purified serum proteins tested, α₂-HS-glycoprotein was found to exhibit the serum effect, though this activity was heat labile.     

A comparison of euglobulin fractions and whole serum in the hemagglutination and latex fixation tests

One hundred and thirty-two sera were investigated with the Waaler-Rose and latex fixation reactions. The reactions were performed with serum, with acid-precipitated euglobulin, and with cold-precipitated euglobulin. The material consisted of 35 sera from healthy persons, 23 from patients with various diseases, 28 from patients with joint symptoms not due to rheumatoid arthritis, and 46 from patients with classical rheumatoid arthritis.In rheumatoid arthritis sera, an increase in positive reactions was obtained in the Waaler-Rose test from 70 per cent in serum to 83 per cent in acid-precipitated euglobulin. This increase was due to a greater specificity of reactions with low titers. The cold-precipitated euglobulin gave less positive Waaler-Rose reactions than the acid-precipitated euglobulin. With the latex fixation test an increase from 65 per cent positive reactions in serum to about 71 per cent with both cold- and acid-precipitated euglobulin fractions was obtained. Here, the increase consisted of reactions negative in serum but positive in the euglobulin fractions, but again with low titers. Because the increase in positive reactions consists merely of low titer values, fractionation of sera only slightly enhances the reliability of the serological tests.Negatively reacting rheumatoid arthritis sera often had low values of the _2A globulin.     

Immunological studies of the anticryptococcal factor of normal human serum

Preliminary studies have shown a very high inhibitory activity in the alpha₂ and gamma zone of human serum towards the growth of Cryptococcus neoformans. These findings are now corroborated by single radial immunodiffusion tests, which showed the some loss of IgA and IgM globulins and of the other three globulin fractions (ceruloplasmin, alpha₂ macroglobulin and alpha₂ HS glycoprotein) which migrate in the alpha₂ zone. The data was obtained by single radial immunodiffusion tests. The losses were not statistically significant however. No change in the immunoglobulin content of the sera kept for 6 days in contact with a heat-killed suspension of C. neoformans was noted. These findings suggest, that the inhibitory activity of the normal human serum on the in-vitro growth of C. neoformans is due to the above mentioned globulin fractions and not to a single specific factor.     

Characterization of proteolytic enzymes of the midgut and excreta of the biting fly Stomoxys calcitrans

Proteolytic enzymes were characterized in the midgut and the excreta of the stable fly Stomoxys calcitrans (L) with proteins, synthetic substrates, and inhibitors. Inhibition studies suggested trypsinlike activity in sugar-fed fly midguts, whereas excreta and blood-fed fly guts exhibited other proteases. Trypsinlike activity in midguts removed 20 and 30 h after a blood meal increased from 20% to 50% of the total proteolytic enzymes present. Trypsinlike activity was inhibited with human sera, trypsin-specific inhibitors, and a protein isolated from the stable fly thorax. When human albumin and globulin fractions were incubated with trypsinlike enzymes isolated from the midgut and excreta, the albumin fraction was less inhibitory than the globulin fractions and was readily hydrolyzed by the proteolytic enzymes. These results may indicate that the proteolytic enzymes produce an abortive complex with the globulin fractions of the sera. Such a complex may explain the temporary inhibition of proteolysis by the blood meal. Soybean trypsin inhibitor fed to stable flies caused 50% inhibition in proteolytic activity in the midguts of sugar-fed stable flies and 25% inhibition in the midguts of blood-fed stable flies. Complete inhibition of proteolytic enzyme activity was achieved only in vitro. pH profiles of proteolytic enzyme activity isolated from the excreta of blood-fed stable flies indicated that several proteolytic enzymes were excreted.     

THE IMMUNOLOGICAL SPECIFICITY OF THE EUGLOBULIN AND PSEUDOGLOBULIN FRACTIONS OF HORSE AND H^MAN SERUM

That portion of horse and human serum globulin precipitated by 33 per cent saturation with ammonium sulfate and precipitated on subsequent dialysis was taken as euglobulin; and the fraction precipitated between 33 and 50 per cent saturation and remaining in solution on subsequent dialysis was taken as pseudoglobulin. The sera of rabbits injected with either of these antigens gave precipitation with both. However, two distinct and fraction-specific antibodies could be demonstrated by absorbing the sera with the one antigen, and testing the supernatant fluid with the other. The experimental results are adequately explained on the basis that there are at least two antigenically distinct globulins in serum which we may term globulin I and globulin II and which are largely associated with so called euglobulin and pseudoglobulin respectively. The ordinary methods of salting out and dialysis do not effect complete separation and each globulin preparation contains a trace of the other antigen. The antisera to these euglobulin and pseudoglobulin preparations therefore contain antibodies to both antigens. Each protein solution precipitates all the antibody specific for the one antigen and in addition, by virtue of the trace of contaminating protein, precipitates a portion, and only a portion of the antibody specific for the other antigen. The fact that antisera to whole serum contain these same fraction-specific antibodies suggests that this immunological specificity is an inherent property of two globulins present as such in serum and is not an artifact induced by their precipitation and purification. Lipoids extracted from the globulins by ether, petroleum ether, and alcohol give no demonstrable reaction with antisera to these globulins; antisera absorbed with a large excess of lipoid are not affected as regards their reactivity with the original protein; and globulins extracted with ether and petroleum ether at room temperature are not affected as regards their reactivity with antisera. It is concluded that the immunological specificity of the globulin fractions as evidenced by the precipitation reaction is not determined by lipoids associated with the protein.     

Evaluation of antibody inhibition assays of melanoma antigens in sera to monitor tumor growth in melanoma patients

Summary It was reported previously that melanoma leukocyte-dependent antibody (LDA) in the sera of melanoma patients was inhibited by small-molecular-weight (small-mol.-wt.) glycoproteins which were similar to cell surface antigens identified in cell membrane extracts of melanoma cells. The present study was to determine whether measurement of the levels of these factors in sera may be a useful monitor of tumor growth in melanoma patients. Small-mol.-wt. fractions were obtained by gel filtration or membrane chromatography of acidified sera and tested for their ability to inhibit LDA in ⁵¹Cr release cytotoxic assays. A panel of LDA was used, consisting of three antisera from melanoma patients, which appeared relatively specific for melanoma, and three non-melanoma antisera against carcinoembryonic antigen, ₂ microglobulin, and fetal antigens. The results showed that in patients with melanoma, approximately 70% had melanoma LDA-inhibitory activity detected in the small-mol.-wt. fractions of their sera when these were tested against the panel of melanoma LDA. The specificity of the inhibitory activity for melanoma LDA was shown by failure of the serum fractions to inhibit non-melanoma LDA and by absence of inhibitory activity in equivalent serum fractions from non-melanoma carcinoma patients for melanoma LDA. The levels of melanoma LDA-inhibitory activity in the serum fractions appeared to correlate with tumor growth, as shown by clearance of the inhibitory activity after surgical removal of melanoma and reappearance in the serum of patients who subsequently developed recurrent melanoma. The 30% false-negative rate indicated that the assays could not be used to reliably exclude melanoma, but the close correlation with tumor growth and the low number of false-positive results suggested that in 70% of patients detection of these small-mol.-wt. antigens would be of value to detect recurrence from melanoma and to monitor the effectiveness of therapy.     

Effects of steroid hormones in fetal bovine serum on plating and cloning of human cells in vitro

Summary Fetal bovine sera from each of three different commercial sources were tested for their ability to support cloning of human fibroblastoid cells in vitro. Cloning efficiencies varied according to serum source. Serum (10 samples) from company A did not support growth, while sera (10 samples) from companies B and C provided adequate to excellent conditions for cloning and growth. Cells from neonatal foreskin or embryonic lung responded to each serum similarly. Bovine serum albumin type H7 from company C supported cell growth in media without serum. Sera containing 1.0 ng per ml or more of progesterone inhibited growth, whereas sera containing less than 1.0 ng per ml supported cloning and growth. In the low progesterone sera, the concentration of 17-β-estradiol exceeded 100 pg per ml. Growth supporting sera could be made non-supportive by adding 0.1 μg per ml of progesterone. The addition to non-supportive sera of 0.1 μg per ml of 17-β-estradiol or hydrocortisone made these sera supportive of cell growth. Addition of estrogen or hydrocortisone to a culture medium that inhibits growth, with subsequent reversal of the inhibitory effect, implies that these hormones competitively regulate growth of responsive cells in vitro. Supported in part by NIH-NCI-EC2074.     

Possible Association between Dysfunction of Vitamin D Binding Protein (GC Globulin) and Migraine Attacks

To identify the genetic causality of migraine and acute, severe melalgia, we performed a linkage analysis and exome sequencing in a family with four affected individuals. We identified a variant (R21L) in exon 2 of the GC globulin gene, which is involved in the transportation of vitamin D metabolites and acts as a chemotaxic factor; this variant was co-segregated within the family. To investigate the relationship between GC globulin and melalgia, we investigated the cytokine levels in serum samples from the patients and control subjects using a cytokine antibody array. GC globulin can bind to both MCP-1 and RANTES in human serum but has a higher affinity to MCP-1. In cell culture systems, MCP-1 was able to bind to overexpressed wild-type GC globulin but not to the GC globulin variant, and the GC globulin binding affinity to MCP-1 was significantly lower in sera from the patients than in sera from control subjects. A higher concentration of MCP-1 was also observed in sera from the patients. Thus, the dysfunctional GC globulin affected cytokine release, especially the release of MCP-1, and MCP-1 might play important roles in melalgia and migraine.     

Delineation of the Site of Action of an Antistaphylococcal α-Globulin

S ummary . The isolation of an antibacterial α-globulin from the sera of humans as well as selected animal species has been reported. While antibacterial agent (ABA) reduced the respiration of intact cells by 55%, the anti-respiratory effect was increased to 67% and 85% for spheroplasts and L-forms, respectively. Studies indicated that neither cell wall nor peptidoglycan could absorb ABA quickly enough to inhibit its membrane damaging effects. Although the ribitol teichoic acid-free mutant Staphylococcus aureus H52A5 was not susceptible to ABA, the lack of ribitol teichoic acid may have altered structurally the cell wall so that ABA access to the cell membrane was precluded. The activity of ABA was neutralized by prior exposure of staphylococci to exogenous coagulase, presumably by masking unknown receptor sites for ABA on the cell surface. In our studies with cell wall deficient organisms, we could not demonstrate coagulase reversal of ABA activity.     

Serum proteins in young hedgehogs

Four serum protein components are present at birth: α-, β- and γ-globulins and albumin.
The preferential transfer of γ rather than β-globulin, which occurs both prenatally and postnatally in this species, is reflected in the initial amounts of these proteins present at birth and in the relatively rapid increase in the concentration of γ-globulin which occurs postnatally. By five weeks of age seven protein components are discernible in the serum, which is comparable in this respect to adult serum.
The albumin/globulin ratio changes from about 1.5 at birth to about 0.3-0.4 in the active adult.     

The Fluorescent Antibody Method in the Study of Immunopathologic Conditions

Histochemical studies of immunopathologic conditions were carried out, using Coons'' fluorescent antibody technique. Experimental conditions studied were: serum sickness, generalized anaphylaxis, the Arthus reaction and experimental glomerulonephritis. Human diseases studied were those referred to as “collagen diseases”. Specific immunologic reactants were localized in the lesions of all experimental conditions studied, thus offering objective evidence of a possible immunologic pathogenesis of the lesions. In human diseases, gamma globulin was localized in the lesions of rheumatic fever, rheumatoid arthritis, systemic lupus erythematosus and amyloidosis. Although the finding of gamma globulin in human lesions might suggest that it is an antibody, such an interpretation should be made with care since the gamma globulin could be deposited on a non-immunologic basis.The tissue-localizing properties of sera from different disease states showed appreciable variability within a given disease, as well as similar localizing properties among sera of different diseases. It is suggested that these serum factors (“autoantibodies”) might result as a host response and are not primarily involved in the pathogenesis of the disease.     

Separation and assay of lysins and lysin-inhibitor complexes in blood and tissues

1. A process of extraction and assay, which combines the features of several existing methods, is described for the lytic materials which can be obtained from blood, plasma, serum, and tissues. At least two alcohol-soluble substances, one ether-soluble ("soap-like") and the other insoluble in ether in the cold ("lysolecithin-like"), can be obtained from preincubated blood, plasma, or serum. The hemolytic activity (or concentration) of the soap-like lysin obtained from blood is greater than that of the lysolecithin-like substance, but for plasma and serum the reverse is true, i.e. the red cells are involved in the production of the soap-like lysin, and probably supply some of it when acted upon by enzymes contained in plasma and serum. Preincubation of the blood or plasma increases the yield of lysin two- or threefold, and small quantities of both soap-like and lysolecithin-like lysins can be obtained from unpreincubated blood or plasma. 2. The soap-like lysins obtained from preincubated mouse liver are some 5 to 15 times as active as, or occur in some 5 to 15 times the concentration of, those obtained from blood or plasma. The lysolecithin-like lysins of preincubated liver are about twice as active as, or occur in about twice as great concentration of, those obtained from blood. Because of the shape of the time-dilution curve for these lysins, the relations between their activities, or concentrations, are often quite different from those which one would anticipate if one were to consider only the times required for the production of hemolysis. 3. Paper chromatography can be used to separate the soap-like and the lysolecithin-like lysins obtainable from small quantities of preincubated mouse liver homogenates or preincubated mouse blood. The presence of lysins is detected by their effect on the red cells of a suspension as it wets the paper. Various technical procedures for separating lytic components and for demonstrating that they move on the paper along with protein components are described. 4. Paper strip electrophoresis can be used to show that the supernatant fluid of a preincubated mouse liver homogenate contains at least two protein components and at least two lytic components, not very closely associated in their electrophoretic behavior. 5. Observations on the physical nature of the alcohol- and ether-soluble lysin point to its having a soap-like character. Its activity, as well as that of the lysolecithin-like lysin, is inhibited by cholesterol, by lecithin, and by various fractions of serum. Some of these effects have been studied quantitatively. The most inhibitory of the protein fractions are those which contain lipoproteins; i.e., II + III and IV + V.     

Enzyme-linked immunosorbent assay of antigens from Candida albicans circulating in infected mice and rabbits: The role of mannan

Various antisera raised either to antigens ofCandida albicans or to sub-lethal infections of blastospores (convalescent sera) were tested for their efficacy in diagnosing systemic disease in artifically infected animals. Globulin from convalescent serum, when conjugated with alkaline phosphatase and used in enzyme-linked immunosorbent assays (ELISA), was the only antiserum type which detected circulatingCandida-related antigen in the serum of infected animals. Conjugates made from anti-mannan, anti-blastospore or antimycelial globulin did not detect antigen. Mannan did not appear to be related to an antigen produced in sera of experimentally infected mice. The significance of these results in the diagnosis of systemic candidosis is discussed.     

Demonstration of a specific binding protein for testosterone and 5alpha-dihydrotestosterone in rabbit serum. Separation from the corticosteroid binding globulin (CBG)

Rabbit serum contains a specific androgen binding protein which can be separated from the corticosteroid binding globulin (CBG) in rabbit serum by sucrose gradient ultracentrifugation and polyacrylamide gel electrophoresis. It has a sedimentation constant of 4–5 S (mean 4.4 S) and high binding affinities for 5α-dihydrotestosterone, 5α-androstan-3α, 17β-diol and testosterone but negligible affinity for androstenedione, progesterone or corticosterone. Concentrations of the androgen binding protein expressed as 5α-dihydrotestosterone (DHT) binding capacity at saturation are higher in adult female (4.0 ± 0.3 μg DHT bound/100 ml) than in adult male sera (1.4 ± 0.8 μg DHT bound/100 ml). Immature male sera contain slightly higher amounts than adult females.     

Immunologic effects of morphine administration in rabbits.

Long-term effects of morphine administration or immunologic test responses were studied in female rabbits. Implantation of morphine-containing pellets was found to be more effective than injection of morphine sulfate solutions in promoting increased serum binding of 140-morphine. A large part of the increased morphine binding by sera associated with administration of morphine was found in serum fractions containing gamma-globulin and was absent in gamma-globulin-free fractions. These sera showed some degree of specificity for the morphine configuration in tests with other narcotics. They also gave positive immunologic test reactions in passive hemagglutination and radial immunodiffusion tests involving serum albumins conjugated with morphine derivatives. Other evidence for immunologic responsiveness against morphine by morphine-pretreated rabbits was shown by cutaneous hypersensitivity reactions against morphine-carrier conjugates and by a diminution of the serum morphine-binding response in rabbits given an immunosuppressive dose of cyclophosphamide. Failure of naloxone, a morphine antagonist, to alter the serum morphine-binding response suggested that serum levels of the morphine-binding globulin studied here were not direclty related to morphine withdrawal.     

Precipitation Reactions in Agar Between Swine Serum and Homologous Pancreas Extracts

Hyperimmune anti-hog cholera and nonimmune swine sera yielded approximately 50% more precipitation reactions in agar-gel diffusion tests with pancreas extracts from SPF noninfected swine than with extracts obtained from swine experimentally infected with virulent hog cholera virus. The pancreas-reacting property of swine serum was determined to be relatively heat stable, withstanding 68 C for 30 minutes. Of various swine serum fractions tested, the only one that reacted with pancreas extracts contained gamma, beta and alpha-globulins. In the absence of alpha-globulin, precipitation reactions were not observed. Sera of newborn SPF piglets, containing 50% alpha-2 globulin, formed more intense precipitation lines with swine pancreas extracts than were formed by the sera of their dams with the same extracts. The pancreas-reacting activity of swine sera was completely removed by absorption with pancreatic tissue. This property was not removed by absorption with guinea pig kidney, or beef, swine or human erythrocytes. Maceration of pancreatic tissue released reactive substances in a polydispersed form. This was demonstrated by the ability of almost all supernates and sediments from differential centrifugation of such preparations to form precipitation lines with swine sera. Reactive substances from swine pancreas were found to be relatively heat labile, being inactivated in one hour at 56C. No evidence was obtained in this study to indicate that the observed precipitation reactions were related to hog cholera virus and its corresponding antibody. The reactions are believed to have resulted from the interaction of protein-related substances present in normal swine pancreas with a relatively heat stable component, possibly alpha-globulin, in swine serum.     

Normal human serum stimulates murine erythroid precursor growth in in vitro culture

When introduced into cultures of murine CFU-E human sera inhibited the formation of erythroid colonies. However, after absorbtion on murine cells and heating all tested sera became stimulatory. Crude sera were separated into two fractions by DEAE chromatography: the first fraction was stimulatory. The second was toxic but the toxicity could be eliminated by heating; the fraction then became slightly stimulatory. Attempts at characterizing the molecular weight of the stimulatory activity led to variable results, suggesting either that the stimulatory activity(ies) could polymerize or be fixed on different serum proteins. All sera from 11 different anemic patients were also shown to be stimulatory.     

The cytotoxic effects of the anti‐bacterial peptides on leukocytes

Antimicrobial peptides are small molecular weight proteins with a large antibacterial spectrum. They can reach high local concentrations in tissues with active inflammation, being largely produced by immunocompetent cells. However, their effect on eukaryotic cells is still unclear. We have, therefore, studied three structurally different antimicrobial peptides (cecropin P1, PR‐39 and NK‐lysin) for their cytotoxic effects on blood mononuclear cells. None of the antimicrobial peptides tested exhibited significant cytotoxic effect on resting lymphocytes isolated either from peripheral blood or from the spleen with the exception of high concentrations (ten times higher than IC100 for Escherichia coli) of NK‐lysin. Activated lymphocytes were, however, more sensitive to the cytotoxic effect of the antimicrobial peptides. Both activated T‐cells and B‐cells were dose dependent sensitive to NK‐lysin while only activated B‐cells but not activated T‐cells were sensitive to PR‐39. Cecropin did not exhibit any cytotoxic effect on activated lymphocytes either. By using several cell lines (3B6, K562, U932 and EL‐4) we were able to show that NK‐lysin has a broad necrotic effect while PR‐39 has a cell specific apoptotic effect dependent on the specifically cellular uptake. In conclusion we show here that antimicrobial peptides are not cytotoxic for the resting eukaryotic cells but can be cytotoxic on activated immune cells through distinct mechanisms of cell death. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.     

Bovine-Associated Mucoprotein

Bovine-associated mucoprotein (BAMP), solubilized with water from the delipidated membranes of bovine milk fat globules, is not restricted to fat globules or to the alveolar epithelial cells from which they are formed. BAMP also has a widespread distribution on other bovine glandular epithelial cells and on undifferentiated cells in lymphoid germinal centers and in several fetal tissues. Free BAMP is present in bovine colostrum, milk, other secretory fluids, and in fetal serum but is absent from adult and colostrum-deprived calf sera. In bronchoalveolar fluids, BAMP is preferentially found in the mucusrich fraction. BAMP is antigenically distinct from all adult serum proteins, free secretory component, β₂-microglobulin, lactoferrin, α-lactalbumin, β-lactoglobulin, and five different caseins. BAMP as a free protein constitutes one-sixth of the total amount of BAMP present in milk. The BAMP-related component of fetal serum lacks antigenic determinants present on the BAMP of milk as demonstrated by immunoprecipitation and partial blocking of immunofluorescence. The fetal component is not fetuin or α₁-fetoprotein. These data suggest that BAMP may be useful in studies of the membranes of proliferating or differentiating epithelial cells.     

Identification of Eggshell Membrane Proteins and Purification of Ovotransferrin and β-NAGase from Hen Egg White

Exposure of selected Gram-positive and Gram-negative bacterial pathogens to egg shell membranes (ESM) significantly reduced their thermal resistance and/or inactivated cells. Although the components responsible for this antibacterial activity have not been conclusively identified, several proteins associated with the ESM activity have been identified including β-N-acetylglucosaminidase, lysozyme and ovotransferrin, with each displaying varying degrees of antibacterial activity. Numerous attempts to purify active fractions of β-N-acetylglucosaminidase, lysozyme and ovotransferrin from the ESM proved somewhat limited; however, hen egg white (HEW) β-N-acetylglucosaminidase was purified using a two-step chromatographic procedure, isoelectric focusing followed by cation exchange chromatography. Pure fractions of ovotransferrin were also obtained in the process. SDS-PAGE electrophoresis and Matrix-Assisted Laser Desorption Time-of-Flight Mass Spectrometry were then used to partially characterize the individual protein components. Purified protein fractions such as these will be required in order to fully elucidate the mechanism responsible for the antimicrobial properties associated with the ESM.