scholarly journals STUDIES IN THE SEROLOGY OF SYPHILIS

1930 ◽  
Vol 52 (5) ◽  
pp. 747-768 ◽  
Author(s):  
Harry Eagle
Keyword(s):  
Complement Fixation ◽  
Colloidal Suspension ◽  
Fold Increase ◽  
Lower Surface ◽  
Dark Field ◽  
Alcoholic Solution ◽  
Alcoholic Extract ◽  
Subsequent Formation ◽  
Cent Concentration ◽  
Unit Surface

When cholesterinized antigen is dropped into an excess of water, the rapid flocculation of cholesterin crystals is prevented by the fact that, as tiny aggregates form, they adsorb a protective surface of hydrophilic lecithin (i.e., antigen) which endows the particles with its own stable surface properties and thus prevents further aggregation. The colloidally dispersed antigen-cholesterin particles have approximately the same isoelectric point (pH 1.9), critical potential (1 to 5 millivolts) and coagulation value (0.75 M NaCl) as pure antigen particles of the same concentration, while the corresponding values for cholesterin are pH 2.1 to 3.4 (probably due to an associated impurity), >100 millivolts, and <0.001 N NaCl, respectively. Presumably, this adsorption of antigen by the cholesterin nucleus is determined by the fact that the former has a lower surface tension against water. At any rate, many surface active substances (serum; alcoholic extract of milk, egg or any animal tissue; Na-oleate; Na-glycocholeate; Na-taurocholate) cause a similar stable dispersion of cholesterin; and conversely, many otherwise water-insoluble substances of the most diverse chemical structure can be made to form a stable colloidal suspension by adding antigen to their alcoholic solutions before dropping into water. The colloidal suspension formed by antigen alone is very finely dispersed: only a few of the particles exceed the limits of dark field visibility. Cholesterin causes a marked increase in the number of these particles, out of all proportion to its mass; thus, one part of cholesterin to five of antigen causes a ten-fold increase in such visible particles, at the expense of the submicroscopic micellae formed by antigen alone. At the same time, the suspension becomes much more turbid. The particles remain discrete until the cholesterin: antigen ratio exceeds 1:1, when slight microscopic aggregation is observed; microscopic flocculation is seen only when this ratio exceeds 5:1, when there is not sufficient antigen to act as an efficient protective colloid. Cholesterin therefore causes a coarsened dispersion of antigen by forming a relatively large nucleus upon which antigen is adsorbed. As shown in the text, the larger the antigen particle the greater is its avidity for reagin per unit surface or mass. Thus, the coarse sol formed by dropping water-into-antigen is about twice as efficient as a finely dispersed antigen-into-water sol of the same concentration. The coarsened dispersion caused by cholesterin completely explains the greater sensitivity of the cholesterinized antigen in complement fixation. The same factor obtains in the flocculation reactions. In addition, the coarsened dispersion acts as a preliminary quasi-aggregation, facilitating by just so much the subsequent formation of visible clumps (or sedimenting aggregates) upon the addition of syphilitic serum; moreover, there is less surface in a coarse sol, with more reagin per unit surface, and correspondingly more efficient flocculation. The foregoing would be of purely academic interest were it not for the following considerations. From several points of view cholesterin is unsatisfactory as a sensitizer for antigen. Its solubility in alcohol is small. Even the 0.6 per cent concentration used in the Kahn test is difficult to keep in solution. Yet, as our experiments show, its sensitizing action increases indefinitely with its concentration. If it were sufficiently soluble, even 3 per cent could be used to advantage, increasing the sensitivity of 1½ per cent antigen for complement fixation some 200 to 400 per cent, instead of about 50 per cent, as does 0.2 per cent cholesterin. Since, as we have shown, the sensitizing action of cholesterin upon antigen is due solely to the coarse dispersion it causes, and since it is quite inert during the actual combination of the lipoid particles with reagin, it can be replaced by any substance with similar physical properties. The problem in hand was therefore to find a water-insoluble substance, very soluble in alcohol, with so high an interfacial tension against water that, as in the case of cholesterin, microscopic particles would adsorb antigen when the alcoholic solution of the two is dropped into water. Given such a substance, it would be possible to obtain a more sensitive antigen for both complement fixation and flocculation, but particularly for the former. These theoretical expectations have been realized in a group of substances shortly to be reported: they make possible an antigen which is from 2 to 10 times as efficient in the Wassermann test as any now available.

scholarly journals Supplementary note on the constitution of chlorophyll

1883 ◽  
Vol 36 (228-231) ◽  
pp. 285-286
Keyword(s):  
Carbon Disulphide ◽  
Alcoholic Solution ◽  
The Other ◽  
Green Product ◽  
Alcoholic Extract ◽  
Fatty Matter ◽  
Absorption Bands ◽  
Yellow Colour ◽  
Green Colour ◽  
Dark Green

After the reading of the note on chlorophyll at the meeting of the society on December 13th, I was reminded by Professor Stokes that e and others had succeeded in separating the complex to which the erm chlorophyll had previously been applied into two substances, or ather groups of substances, one characterised by its green colour and ed fluorescence, the other showing a more distinctly yellow colour without fluorescence, and he suggested to me that it would be advisable to ascertain whether the property of yielding glucose by decomposition with acids might not belong to one of these substances or groups of substances only. Professor Stokes at the same time kindly communicated to me the details of the process whereby he succeeded n effecting the separation referred to, a process depending on the action of carbon disulphide in' removing some of the bodies contained n an alcoholic solution of crude chlorophyll in preference to others. The process employed for the same purpose by Mr. Sorby is essentially the same. Before applying disulphide of carbon to an alcoholic extract of green leaves according to the process of Professor Stokes, it was necessary first to remove the ready-formed glucose, tannin, and other matters soluble in water, which almost always exist in such extracts, and which would by their presence have rendered the result of the experiment quite uncertain. This was done in the way I have already described. An ethereal solution of chlorophyll prepared by my method was evaporated, and the residue having been dissolved in alcohol, the solution was mixed with a quantity of carbon disulphide larger than the alcohol would dissolve, and the mixture well shaken. The carbon disulphide acquired a dark green colour, while the supernatant alcoholic liquid, containing principally the xanthophyll of Professor Stokes and Mr. Sorby, was yellow with a tinge of green. The two liquids having been separated, the lower dark green one was washed several times with alcohol to remove any of the xanthophyll that might still be present, and having then been mixed with a large quantity of alcohol, a current of air was passed through it to remove the excess of carbon disulphide as directed by Professor Stokes. In this way I obtained two liquids, one intensely green, the other deep yellow with only a tinge of green. The two liquids were found to contain substances essentially different so far as regards their products of decomposition with acids. The yellow liquid having been mixed with dilute sulphuric acid was evaporated in the waterbath, water being added during evaporation, until the liquid had lost nearly all its colour. A quantity of yellow fatty matter separated during evaporation, and this having been filtered off the liquid was found to contain an abundance of glucose. The yellow fatty matter insoluble in water, dissolved easily in alcohol, but the yellow solutio showed none of the characteristic absorption bands of “acid chloro phyll.” The dark green liquid, treated in exactly the same way yielded a dark green product insoluble in water. The filtrate Iron this gave a slight reaction with Fehling’s solution, but so trifling comparatively that I am inclined to attribute it to the presence o some substance not completely removed from the disulphide of carboi solution by washing with alcohol. The dark green product of tin action of acid insoluble in water was soluble, though with difficultyin boiling alcohol, the solution being dull green and showing the absorption bands due to “acid chlorophyll.” If, therefore, chloro phyll be defined as the constituent of the green parts of plants, which gives a spectrum showing the well-known bands at the red end, and yields by decomposition with acids the product or products going by the name of “acid chlorophyll,” of which Fremy’s phyllocyanin is the most important and most characteristic, then chlorophyll is not a glucoside. The glucoside which accompanies it and resembles it as regards solubility in various menstrua may have to be sought among the group of bodies to which the generic name of xanthophyll has been applied.

Effects of Coppicing on Growth Rates, Stomatal Characteristics and Water Relations in Eucalyptus camaldulensis Dehn

1980 ◽  
Vol 7 (1) ◽  
pp. 81 ◽  
Author(s):  
T.J Blake
Keyword(s):  
Transpiration Rate ◽  
Stem Elongation ◽  
Eucalyptus Camaldulensis ◽  
Fold Increase ◽  
Lower Surface ◽  
Stomatal Resistance ◽  
Stomatal Characteristics ◽  
Unit Leaf ◽  
Diffusive Resistance ◽  
Stomatal Length

Stem elongation, transpiration rate, water potential, diffusive resistance and stomatal characteristics were compared in intact and coppiced (decapitated) seedlings of E. camaldulensis. Stump sprouts from coppiced seedlings showed a threefold increase in the rate of stem elongation, a doubling in transpiration rate per seedling and a 5–8-fold increase in transpiration per unit leaf area compared with intact seedlings. Reversion to more juvenile leaf morphology following decapitation was accompanied by decrease in leaf stomatal resistance. Increased stomatal length and higher stomatal frequency on the lower surface of coppice leaves appears to explain the increased transpiration rate following decapitation compared with intact seedlings.

The Bilharzia Complement Fixation Reaction in Goats infected with Schistosoma mattheei and Schistosoma bovis

1933 ◽  
Vol 11 (4) ◽  
pp. 181-186 ◽  
Author(s):  
N. Hamilton Fairley
Keyword(s):  
Complement Fixation ◽  
Alcoholic Extract ◽  
Schistosoma Bovis ◽  
Fixation Reaction ◽  
Positive Results

1. The sera of 18 goats were investigated for the bilharzia complement fixation reaction, using as antigen alcoholic extract of the livers of snails (Planorbis exustus) infected with cercariae of S. spindale.2. The sera of 5 out of 7 goats harbouring S. mattheei, and of 4 out of 4 goats exposed to alimentary infection with S. bovis yielded positive results, the range of complement fixation varying from 5 to 20 M.H.D.'s.3. The sera of non-infected goats and of 3 goats exposed to infection with cercariae of S. mansoni from which these animals appear naturally immune, yielded negative reactions.4. The complement fixation reaction with cercarial antigen (S. spindale) has now been applied to infestation with 3 human and 4 cattle schistosomes, and its group applicability to mammalian schistosomiasis may be regarded as proven.

scholarly journals THE COMPLEMENT FIXATION REACTION AS APPLIED TO LEPROSY

1923 ◽  
Vol 38 (2) ◽  
pp. 219-232 ◽  
Author(s):  
Paul A. Lewis ◽  
Joseph D. Aronson
Keyword(s):  
Blood Serum ◽  
Complement Fixation ◽  
Alcoholic Extract ◽  
Diagnostic Significance ◽  
Antibody Absorption ◽  
Normal Individuals ◽  
Fixation Reaction ◽  
Fast Group

By means of a method differing in important details from those of previous investigators it has been determined that the blood serum of cases of leprosy exhibits the ability to fix complement with a wide variety of antigens including to a greater or less extent those derived from any culture of the acid-fast group of bacteria available to us. This property of multiple fixation may sufficiently characterize the disease to be of diagnostic significance, although our experience is hardly sufficient to enable us to speak with complete assurance on this point. Certainly, control sera from normal individuals, from cases of tuberculosis, or from cases of syphilis as obtained in our locality have entirely failed to react with certain antigens, whereas serum from cases of leprosy have so reacted to the extent of over 93 per cent. The most characteristic fixation given by the leprosy sera is that with Bacillus lepræ (Clegg) used as antigen, either in the form of a bacterial emulsion or of an alcoholic extract of the dried culture. Antibody absorption may be demonstrated in the acid-fast group if the absorbing bacteria are removed by filtration. Otherwise the resulting fluid is strongly anticomplementary. Leper serum is not deprived of the complement-fixing body when so treated with either Bacillus tuberculosis or Bacillus lepræ (Clegg).

scholarly journals Impact of the melt–albedo feedback on the future evolution of the Greenland Ice Sheet with PISM-dEBM-simple

2021 ◽  
Vol 15 (12) ◽  
pp. 5739-5764
Author(s):  
Maria Zeitz ◽  
Ronja Reese ◽  
Johanna Beckmann ◽  
Uta Krebs-Kanzow ◽  
Ricarda Winkelmann
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Fold Increase ◽  
Lower Surface ◽  
Surface Melting ◽  
Balance Model ◽  
Dynamic Simulations ◽  
Albedo Feedback ◽  
Future Evolution ◽  
Surface Warming

Abstract. Surface melting of the Greenland Ice Sheet contributes a large amount to current and future sea level rise. Increased surface melt may lower the reflectivity of the ice sheet surface and thereby increase melt rates: the so-called melt–albedo feedback describes this self-sustaining increase in surface melting. In order to test the effect of the melt–albedo feedback in a prognostic ice sheet model, we implement dEBM-simple, a simplified version of the diurnal Energy Balance Model dEBM, in the Parallel Ice Sheet Model (PISM). The implementation includes a simple representation of the melt–albedo feedback and can thereby replace the positive-degree-day melt scheme. Using PISM-dEBM-simple, we find that this feedback increases ice loss through surface warming by 60 % until 2300 for the high-emission scenario RCP8.5 when compared to a scenario in which the albedo remains constant at its present-day values. With an increase of 90 % compared to a fixed-albedo scenario, the effect is more pronounced for lower surface warming under RCP2.6. Furthermore, assuming an immediate darkening of the ice surface over all summer months, we estimate an upper bound for this effect to be 70 % in the RCP8.5 scenario and a more than 4-fold increase under RCP2.6. With dEBM-simple implemented in PISM, we find that the melt–albedo feedback is an essential contributor to mass loss in dynamic simulations of the Greenland Ice Sheet under future warming.

Immunological Studies on Experimental Infection of Pigs withAscaris suumGoeze, 1782 I. An Introduction with a Review of the Literature and the Demonstration of Complement-fixing Antibodies in the Serum

1961 ◽  
Vol 35 (3-4) ◽  
pp. 319-344 ◽  
Author(s):  
L. F. Taffs
Keyword(s):  
Life Cycle ◽  
Hydrochloric Acid ◽  
Antibody Response ◽  
Experimental Infection ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Antibody Concentration ◽  
Alcoholic Extract ◽  
Review Of The Literature ◽  
Pig Serum

1. An introduction to a study of immunity againstA. suumin the pig is given. A review of the literature on the life cycle, a note on terminology and a general discussion on immunity to helminths has also been included.2. By first removing the procomplementary activity of pig serum to guineapig complement with hydrochloric acid, it was possible to apply the complement fixation test to a study of the antibody response to experimental infection withA. suum.3. Using an alcoholic extract of uterus, oviducts and ovaries of the adult femaleAscarisworm as antigen, antibodies against this nematode were first detected in two experimentally infected pigs ten days after infection. A peak of antibody concentration from the thirteenth to the seventeenth day of infection was followed by a decline in the antibody content of the serum to the forty-first day; after which no antibody was detected.

scholarly journals The growth of vaccinia virus in the chorio-allantois of the developing chick embryo and the production of complement-fixing antigen and haemagglutinin

1956 ◽  
Vol 54 (1) ◽  
pp. 102-113 ◽  
Author(s):  
H. B. Maitland ◽  
Barbara M. Tobin
Keyword(s):  
Chick Embryo ◽  
Vaccinia Virus ◽  
Growth Curve ◽  
Complement Fixation ◽  
Fold Increase ◽  
Growth Cycle ◽  
Soluble Antigen ◽  
Elementary Body

1. Elementary body suspensions of vaccinia virus placed on the chorio-allantoic membrane of the developing chick embryo showed immediately an enhanced infectivity which may amount to a several-fold increase in titre.2. In studying the growth curve of vaccinia virus in the chorio-allantois the distribution of virus between the liquid and the membrane had to be taken into account.3. Some virus disappeared after inoculation, but this did not necessarily indicate a non-infective phase in a growth cycle.4. Virus began to increase in 4–5 hr. and proceeded without stepwise increments, reaching a maximum in about 36 hr.5. Haemagglutinin and complement-fixing ‘soluble’ antigen were formed during the growth of virus, and the titre of each was directly related to the amount of virus. They were detectable when the titre of virus reached respectively 106.5–10.70 and 105.5–106.0 pocks per ml.6. Haemagglutinin may have been acting as a complement-fixing antigen.7. Neither haemagglutination nor complement-fixation provided evidence for the occurrence of a non-infective phase of virus as part of a growth cycle.

The Complement Fixation Reaction in Schistosoma japonicum with Cercarial Antigen prepared from Oncomelania hupensis

1935 ◽  
Vol 13 (1) ◽  
pp. 25-40
Author(s):  
Mary N. Andrews
Keyword(s):  
Schistosoma Japonicum ◽  
Positive Reaction ◽  
Complement Fixation ◽  
Clonorchis Sinensis ◽  
Alcoholic Extract ◽  
Human Beings ◽  
Oncomelania Hupensis ◽  
Weak Reaction ◽  
Negative Results ◽  
Fixation Reaction

1. The preparation of a cercarial antigen from infected livers of Oncomelania hupensis the intermediate host of Schistosoma japonicum in China is described.2. The sera of 49 human beings and five dogs have been investigated for the Schistosome complement fixation reaction, using as antigens Bilharzial cercarial antigen, and an alcoholic extract of the livers of Oncomelania hupensis infected with cercariae of S. japonicum.3. Thirty-seven of the 49 sera examined were from cases of Schistosomiasis, and of these 24 gave a positive complement fixation reaction, and 2 others a weak reaction.4. Of the five dogs examined three were infected with Schistosoma japonicum. These gave positive reactions.5. In 24 cases both antigens were used, and the results obtained were almost identical.6. The Bilharzial antigen was used in 33 cases including 25 cases of Schistosomiasis, of which 19 gave a positive reaction.7. In 40 cases the Oncomelania antigen was used. This series included 32 cases of Schistosomiasis of which 23 gave a positive reaction and 3 a weak positive reaction.8. Negative results were obtained with 50 strongly positive Wasserman sera, and with 2 cases of infection with Fasciolopsis buski, and two cases of Clonorchis sinensis. Ascaris and hookworm infestations also gave negative results.

Magnetic-domain imaging techniques

1993 ◽  
Vol 51 ◽  
pp. 1022-1023
Author(s):  
Ian R. McFadyen
Keyword(s):  
Magnetic Particles ◽  
Imaging Techniques ◽  
Colloidal Suspension ◽  
Polarized Light ◽  
Magnetic Domain ◽  
Chemical Vapor ◽  
Sample Surface ◽  
Dark Field ◽  
Magnetic Domains ◽  
Domain Boundaries

The concept of domains in ferromagnets was introduced by Weiss in 1906. However, they were not observed until 1931 when Bitter showed that domain boundaries could be observed by decorating them with fine magnetic particles. Since then the field of magnetic domain imaging has expanded enormously.The original Bitter technique involved the decoration of a magnetic sample with a colloidal suspension of fine magnetic particles (usually magnetite) and observation by dark field optical microscopy. This is still a commonly used method and has been extended to finer particles, which include clusters directly deposited on the magnetic sample from a chemical vapor and observation of the clusters in the SEM or TEM at magnifications in excess of 20,000x.Another very popular means of observing magnetic domains employs the magneto-optic Kerr effect. Both polar and longitudinal Kerr techniques has been utilized. In the polar Kerr technique a magnetic sample is illuminated by a beam of plane polarized light normal to the sample surface.

scholarly journals PURIFICATION AND CONCENTRATION OF ANTIGENS FOR COMPLEMENT FIXATION BY METHODS OF DIALYSIS, ADSORPTION, AND EXTRACTION

1921 ◽  
Vol 33 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Augustus B. Wadsworth ◽  
Frank Maltaner
Keyword(s):  
Complement Fixation Test ◽  
Complement Fixation ◽  
Fixation Test ◽  
Alcoholic Extract ◽  
Aqueous Extracts ◽  
Serum Globulin ◽  
Antigenic Activity ◽  
Culture Filtrates

Antigens were prepared from the culture filtrates of tubercle bacilli and by extraction of washed and dried organisms with organic and aqueous solvents and from tissues of organs showing tuberculous lesions. A comparison of these preparations by means of the complement fixation test showed that the aqueous extracts were most active antigenically. The antigenic activity of the aqueous preparations and also of the slightly active culture filtrates was increased by means of dialysis and adsorption with serum globulin followed by extraction with alcohol and concentration of the alcoholic extract in vacuo.

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