Search

The sequences of the 119 amino acids of bovine and porcine luteinizing hormone β-subunits were determined, 17 amino acid replacements being observed between these species. Variability in the primary structure was observed for porcine β-subunit, in that position 10 is occupied by both arginyl and glutamyl residues. No free amino terminal residue was detected for both porcine and bovine β-polypeptide chains and both exhibited carboxy-terminal heterogeneity. The homology of the β-subunits of luteinizing hormone from various species and the β-subunit of the bovine thyroid-stimulating hormone is discussed as the subunit of both hormones can combine with a similar α-subunit. [ABSTRACT FROM AUTHOR]

The αA2 chain of bovine α-crystallin was fragmented by means of cyanogen bromide treatment and by tryptic, chymotryptic and thermolytic digestions. Twenty tryptic peptides were obtained from the S-aminoethylated αA2 chain, accounting together for the complete sequence. The direct Edman degradation and the dansyl-Edman technique were used to determine the sequences of the tryptic peptides. The order of the tryptic peptides was deduced from overlapping peptides obtained by cyanogen bromide treatment, tryptic digestion of the maleylated chain and chymotryptic and thermolytic digestion of the S-aminoethylated chain. The sequence of the αA2 chain comprises 173 residues and corresponds to a molecular weight of 19832. [ABSTRACT FROM AUTHOR]

Two factors essential for the lysis of EAC'142 cells are described and designated as Β and d. These factors are distinct from the C'3-subunits a, b and c described earlier; they can be separated by chemical procedures. A simple assay method for both factors is given. Four highly reactive intermediates, EAC'142,a; EAC'142,a,b; EAC'142,a,b,Β and EAC'142,a,b,Β,c can be prepared and characterized by their lytic reactivity pattern against different systems of incomplete C'3. Evidence is presented that the subunits of the C'3-system interact with EAC'142 in a sequential order corresponding to the formula a-b-Β-c-d. [ABSTRACT FROM AUTHOR]

Rat liver microsomes were separated into three subfractions by means of ultracentrifugation through sucrose media of different densities and in the presence of different cations. Detergent extracts of these preparations were analysed by double diffusion in agar gel and immunoelectrophoresis with rabbit antisera against each of the subfractions. One subfraction was derived from the ‘rough’ and another from the ‘smooth’ part of the endoplasmic reticulum of the liver parenchymal cells. Their extracts contained at least thirteen soluble antigens in common. However, fraction-specific antigens were also present. Thus, the extracts of the rough (R) membranes contained at least one typical antigen, not found in any of the other fractions. An antiserum against this component also precipitated a non-migrating antigen present only in the extracts of smooth (Sa) membranes. These two antigens may represent different molecular forms of a substance involved in binding of the ribosomes or in the assembly of membrane subunits. At least eleven of the antigens common for the two fractions exhibited enzymatic activities when assayed after precipitation with antibody in the immunoelectro- phoretic plates. Six immunologically and electrophoretically distinct antigens had esterase activity with α-naphthyl propionate as substrate. Two of these esterases also split indoxyl acetate. Three other antigens with acid phosphatase activity split both α-naphthyl acid phosphate and β-glycerophosphate. Three antigens had nucleoside diphosphatase activity when tested with uridine- or inosine-diphosphate. Preliminary experiments also suggested that two additional antigens possessed NADH-diaphorase activity and thus could belong to the microsomal electron trans- port systems. The third subfraction consisted of electron-microscopically smooth membranes (Sb), enzymatically different from those of the endoplasmic reticulum. The antigens typical for the latter were either absent or present only in minor and variable concentrations. Its extracts contained at least two typical antigens. One of these was identified as contaminating ferritin. The nature and origin of the other antigen has not yet been established. All antigens described in this paper were immunologically different from the common rat serum proteins. [ABSTRACT FROM AUTHOR]

Histamine release by antigen from rat mast cells was strongly inhibited by prolonged anoxia. The inhibition was reversed by oxygen and by glucose. Thioglycollate in low concentration potentiated histamine release and in high concentration inhibited it. The effects of anoxia and thioglycollate are additive: inhibition was produced by a low concentration of thioglycollate combined with a short incubation in nitrogen. This inhibition was reversed by glucose and became a potentiation. The effects of anoxia, glucose and thioglycollate on histamine release by compound 48/80 were quantitatively similar to those on histamine release by antigen. These results are consistent with the view that two opposing mechanisms are at work: a freeing of tissue SH groups which potentiates the anaphylactic mechanism and a disruption of tissue S-S bonds which inhibits it. Oxygen lack may inhibit by a reduction of S-S bonds as well as by an exhaustion of metabolic stores. [ABSTRACT FROM AUTHOR]

A state of immunological unresponsiveness to bovine serum albumin (BSA) or human gamma globulin (HGG) can be produced in guinea pigs by contact with these proteins either before and soon after birth, or even soon after birth alone. As judged by failure of treated animals to show immune elimination of the antigen, or anaphylaxis on reinjection, the animals were completely unresponsive when tested up to 5 months after birth. Administration of 6-mercaptopurine to guinea pigs, even in lethal doses, did not prevent the development of antibodies to HGG. After administration of BSA or HGG, labelled with 131I, to pregnant guinea pigs, their offspring at term contained significant amounts of the labelled proteins. HGG was catabolized in new-born guinea pigs with the same half-life as in adults. [ABSTRACT FROM AUTHOR]

The article presents a paper that reviews the psychological theories of electroconvulsive therapy (ECT). It considered the theoretical approaches towards explaining the effects of electroconvulsive shock (ECS) on animals. As the work of ECS with animals has been more empirical than corresponding work with human beings, it has led to more consistent findings and a sounder basis of theorizing. Hence, theories drawn from animal research may be able to give useful leads for explaining the effects of ECT on human beings. The main conclusion arising out of this reviews is that the researchers have come very little way towards explaining the effects of ECT. It is further suggested that help in the solution of the problem may be obtained from utilizing the results of experimentation on animals.

The article investigates the role of the vital dye trypan blue in the formation of calcified tissues of mesenchymal origin and the permeability of these tissues in white rats and rhesus monkeys. The study found trypan blue deposits in the bone and dentin being formed when the dye was in the circulatory system.

The article discusses the effect of desalivation on dental caries and fluorine storage in control rats and in castrated rats who received diethylstilbestrol or testosterone. Topics include studies that focused on the surgical removal of salivary glands, the removal of the parotid and submandibular glands, and salivary dysfunction in hamster dentition. Comparison data related to weight and lesions is provided

The article offers information on neuroanatomical hypotheses. According to a researcher, stimulation is a basic inclination inherent in all living tissues towards the expression of its characteristic activity. It is also a derivative tendency in the early life history of the animal wherein it is subjected to perform random movements to various kinds of external stimulation and to the gratification of internal needs. This concept, which was developed by extensive experimentation with rats, posits that supplementation is still useful in understanding the notion of deprivation.

The article cites several animal experimentation. A researcher has discovered that albino rats which had been taken as pets were less timid and less apprehensive as opposed to those who had received infrequent handling. These animals were also known to survive thyroidectomy. Another researcher also identified that albino rats who had experienced gentle handling, stroking, and caressing or tactile simulation via strokes of a brush gained more body weight than did the nonstimulated ones. It is identified that the severity of stimulation largely contributes to this fact.

The article looks at several rodent model systems used in research on periodontal disease. The advantages of using rats rather than hamsters or other laboratory rodents are discussed. Theoretical considerations that must be made prior to the use of animal models in experiments are reviewed, including etiological factors.

Focuses on the effect of discovery of armadillo as a valuable animal model for the study of Mycobacterium leprae. Biological features peculiar to armadillo; Significance of mice on unravelling the immunological complexities of leprosy; Identification of an important aspect of lepromatoid leprosy on armadillo.

The author discusses the questions concerning relative doses of strontium (Sr)-90 in experimental animals and man. He pointed out that leveling trend in infant mortality is cannot be due to a natural minimum having been reached, not only as congenital malformations account the infant deaths. On the other hand, main argument links to the amounts of Sr-90 used in animal experiments. Furthermore, he describes the clues of unforeseen action of Sr-90, first was peak of infant mortality do not occur immediately after a nuclear test, and the other came from the work of Walter A. Muller, in which he measured the actual dose to the gonads of male mice following the injection of Sr-90.

The article focuses on a study of carbonates' effect on the acid solubility rate of dental enamel. Research methods include the use of cattle teeth that were de-mineralized and re-mineralized with a solution of pure apatite or one enriched with carbonate ions. The conclusion is that remineralization in the carbonate solution makes the enamel material more resistant to acid attack.

The transfer of valine into haemoglobin from various isoaccepting species of Val-tRNA obtained from Escherichia coli and yeast, which differ in the specificity for codon recognition has been investigated using a rabbit reticulocyte cell-free system. It was demonstrated that the Val-tRNA species which bind to ribosomes in response to the codon GUG preferentially transferred valine into both a and β-globin chains and that the other species of Val-tRNA which cannot repond to GUG were scarcely utilized in the haemoglobin synthesis. Several possibilities to explain this phenomenon were examined and consequently it has been strongly suggested that valine codons in mRNA for rabbit globin, at least for α-globin chain, are very rich in GUG and possibly GUA. [ABSTRACT FROM AUTHOR]

The limited proteolysis of a fully active mercury derivative of rabbit muscle aldolase affects all four subunits of the enzyme, but not in a uniform way. At least four out of the nine peptides liberated are cleaved off from only two subunits. The specific activity of the product (aldolase-T) is 50% of that of the native enzyme. The combined kinetic and peptide analytical study of aldol- ase-T formation has shown that the diminished activity is the consequence of the splitting off of a particular tyrosine-containing peptide from all four subunits of aldolase, and of the cleavage of a peptide bond in the vicinity of residue Cys-341 in only two subunits. The data presented, together with the results of the polyacrylamide gel electrophoresis of aldolase-T in the absence and presence of sodium dodecylsulfate, support the idea that the structure of oligomeric aldolase is of type AABB. Large segments of one kind of the subunits can be split off without affecting the tetrameric structure. A tentative sequence of the C-terminal 60 amino acids of aldolase is also presented. [ABSTRACT FROM AUTHOR]

6-Phosphogluconate dehydrogenase has been obtained in the pure, crystalline form from sheep liver by an extensive modification of an earlier purification procedure. The absorption coefficient, A2801%, estimated from disc weight measurement, is 11.4. The amino acid composition is reported. The molecular weight of the enzyme from measurements by several methods is 94000 ± 2000, and there are two subunits in the molecule. From studies of the reaction of the native enzyme with 5,5′-dithiobis(2-nitrobenzoic acid) and p-hydroxymercuribenzoate, there appear to be two reactive thiol groups per subunit which are essential for activity and are protected by 6- [ABSTRACT FROM AUTHOR]

RUPPENTHAL, G. C.; HARNOW, M. K.; EISELE, C. D.; HARLOW, H. F.; and SUOMI, S. J. Development of Peer Interactions of Monkeys Reared In a Nuclear-Family Environment. CHILD-DEVELOPMENT, 1974, 45, 670-682. Rhesus monkeys were reared for the first 3 yr of life in a nuclear-family environment which permitted continual access to their mothers and fathers and limited access to peers and to other adults of both sexes. The subjects rapidly developed sophisticated patterns of social behavior seldom observed in laboratory-reared monkeys and maintained levels of interactive play longer chronologically than has been reported for feral-raised monkeys. Sex difference with respect to grooming and play behaviors emerged early in life and were maintained by the present subjects. Implications of the findings are discussed. [ABSTRACT FROM AUTHOR]

A migration inhibition test on spleen explants from NZB mice of different ages (4, 8 and 12 months) was performed using 40 μg/mI of DNA. The results have shown increased positivity with ageing of experimental animals. [ABSTRACT FROM AUTHOR]

Focuses on the use of animal models for the generalization of clinical results to become directly applicable to the human system. Significance of dimensional analysis in physiology in minimizing the number of animal experiments required and permit the application of results to other cases by simple calculations; Involvement of mathematical technique for finding those combinations or groupings of variables in the analysis; Application of engineering modeling techniques to physiologic problems.

Various solvents were used to remove osmium-reactive phospholipids and free fats from guinea-pig back epidermis before post-fixation in osmium. After extraction, the osmium stained material which remained was probably due to proteins with reactive amino acids. After brief fixation in glutaraldehyde, followed by immersion of the tissue in pyridine, a phospholipid solvent, followed by osmium post-fixation, the unkeratinized epidermal cells were practically unstained. Removal of phospholipid from the keratohyalin granules revealed them as aggregates of smaller particles, probably the protein component. The thickened plasma membranes of the horny cells were darkly stained in osmium. Removal of material from the interiors of these cells left empty spaces between the meshwork of filaments, indicating absence of matrix keratin. The contrast between the darkly stained keratinized cell membranes and filaments, and unstained unkeratinized cells was marked after lipid extraction. [ABSTRACT FROM AUTHOR]

Tissue fluid pressure in the periodontal ligament was measured in dog canine teeth placed in traumatic occlusion for 48 hours. The pressure in experimental teeth was 19 mm Hg, which is significantly higher than the 10 mm Hg recorded for contralateral control teeth. [ABSTRACT FROM AUTHOR]

Treatment of incompletely formed teeth in dogs revealed that a paste made of calcium hydroxide and water is superior to two widely used root canal filling materials. Success was based on the absence of an inflammatory response in the periapical tissues and continued root formation. [ABSTRACT FROM AUTHOR]

The article discusses the study showing the ways of using animals in psychotherapy in the U.S. Members and Fellows of the American Psychological Association were sent with a questionnaire that includes queries about the use of animals in psychotherapy. Results show that 64% of the total sample returned the questionnaire and of these 21% reported that they use animals or animal content in psychotherapy. Moreover, it was determined that most of the respondents use animals to cultivate or model the positive nature of interpersonal relationships. The respondents also cited the dog and cat as the most frequently used animals.

The kinetics of the adenine nucleotide exchange in liver mitochondria have been measured by rapid sampling techniques and analysed according to a simple exchange model. The exchange was found to follow accurately a first order reaction if related only to the portion of endogenous ADP and ATP, i.e. the endogenous AMP content is subtracted from the total adenine nucleotide pool. The first order reaction rate increases inversely to the size of the endogenous ADP + ATP pool. The translocation activity can then be obtained in μmoles × min-1 × g protein-1 by multiplying the first order rate constant with the size of the ADP + ATP pool. The translocation activity with external AMP was also found to follow first order kinetics. The activity for AMP was 0.3 μmoles × min-1 × g protein-1 as compared to 25 μmoles × min-1 × g protein-1 for ADP and 10 μmoles × min-1 × g protein-1 for ATP at 6°. The kinetics of the exchange activity with ATP remained first order under the various conditions of the energy transfer system which regulate the activity of the ATP exchange. The regulation of the ATP exchange in the energy-rich and the energy-depleted state was evaluated in terms of translocation activities. The temperature dependence of the translocation activity was measured for ADP and ATP in the range between 0 and 20°. In the Arrhenius plot the dependence on the temperature showed different slopes above and below 8° for both ADP and ATP. In the lower range EA for ADP was 34 kcal and above 8° 21 kcal, while the EA for ATP was 35 kcal in the lower range and 23 kcal above 8°. The concentration dependence of the adenine nucleotide exchange, as measured at low concentrations of mitochondria, gave an approximately linear relation up to 10 to 25 μM ADP and ATP in the ‘Eadie’-plot. In this range KmADP = 1.3 and KmATP = 2.5 μM; with Mg++ KmADP = 4 and KmATP = 12 μM was obtained. [ABSTRACT FROM AUTHOR]

Oxygen uptake was monitored in perfused livers from normal and phenobarbital treated rats. Basal rates (200–250 μatoms × g-1 × h-1), as well as antimycin A (80–100 μatoms × g-1 x h-1) and cyanide (30–35 μatoms × g-1 × h-1) insensitive respirations were similar in both groups. The addition of aminopyrine to livers from fed, phenobarbital treated rats caused a maximal stimulation of oxygen uptake of 60 μatoms × g-1 x h-1. Half-maximal effect was observed with 0.1–0.2 mM aminopyrine. Prior addition of antimycin A or cyanide did not diminish the stimulation by aminopyrine. In livers from fasted, phenobarbital treated rats, the maximal stimulation was smaller (30–35 μatoms × g-1 × h-1), and no increase in oxygen uptake was observed in the presence of antimycin A. The data support the hypothesis that extramitochondrial NADPH generation controls mixed function oxidase activity in the intact cell. Since highest rates were observed under conditions of enhanced glycogenolysis, it is suggested that the main source of NADPH generation is via dehydrogenases of the hexosemonophosphate shunt. In the glycogen depleted state, however, it is predicted that reducing equivalents from mitochondrial oxidations are transferred into the extra- mitochondrial space. A substrate shuttle mechanism is proposed which provides these reducing equivalents in the form of malate for the extramitochondrial generation of NADPH via malic enzyme. [ABSTRACT FROM AUTHOR]

Flavoproteins of intact and fractionated mitochondria have been studied by means of spectrophotometric and fluorimetric techniques. The high and low redox potential fluorescent flavoproteins of rat liver mitochondria previously assigned to the respiratory chain are located in the soluble fraction obtained on ultrasonic disintegration. In intact mitochondria, the low potential species has a redox potential of –279 mV at pH 7.2 and 25° measured by fluorescence or absorbance, and undergoes a 2 equivalent reduction. After ultrasonic disruption of mitochondria, its redox potential is -294 mV at pH 7.2 and 25° In submitochondrial particles, low potential flavoprotein reducible by NADH in the presence of rotenone is not fluorescent, appears to have a redox potential more positive than -209 mV and is attributed mainly to cytochrome b5 reductase and cytochrome b5. Mersalyl can be used to selectively inhibit cytochrome b5 reductase, and it has been possible to estimate the concentration of the low redox potential flavoprotein free from cytochrome b5 interference. The high redox potential fluorescent flavoprotein is recovered in the soluble fraction after ultrasonic disruption of rat liver mitochondria and can be reduced by succinate in the presence of antimycin A inhibited particulate fraction. This fuorescent species is also found in rat kidney mitochondria but not in blowfly mitochondria. In submitochondrial particles, a non-fluorescent high redox potential species is found which may be flavoprotein or non-heme iron. This species has a redox potential of +30 mV at pH 7.2 and 25° and undergoes 1 equivalent reduction. Flavoprotein fluorescence measurements are subject to significant errors caused by absorption of the exciting light, and consequently do not always measure flavoproteins free from interference by other respiratory carriers, e. g. cytochromes and non-heme iron proteins. [ABSTRACT FROM AUTHOR]

The formation of polar, saturated C19steroids with a 3-keto-5α-configuration after incubation of 17β-hydroxyandrost-4-en-3-one (testosterone) with 105,000 × g microsomes of adult male rat liver was investigated. The metabolites were isolated by thin-layer chromatography and were identified as 2β-,6β-(tentatively), 7α-, and 16α-hydroxy-5α-dJhydrotestosterone by means of gas chromatography-mass spectrometry. The same compounds were also isolated after incubation with 2β-,6β-,7α-, and 16α-hydroxytestosterone, respectively. Incubation with 5α-dihydrotestosterone, however, resulted in the formation of 2βi-,7α-, and 16α-hydroxy-5α-dihydrotestosterone whereas no 6β-hydroxy-5α-dihydrotestosterone could be found. [ABSTRACT FROM AUTHOR]

Three factors essential for the lysis of EAC'142 cells are described and designated as a, b and c. These factors exhibit characteristic properties with respect to certain inactivating agents. They can be neatly separated by chemical fractionation. A simple assay method is described for each factor. Preparative methods for two highly reactive intermediate cellular products are given. Evidence is presented suggesting that besides a, b and c at least two additional factors are involved in the lytic action of C'3. [ABSTRACT FROM AUTHOR]

Rabbit hyperimmune γ-globulin was produced against type 5 adenovirus. This was digested with pepsin to produce bivalent fragments of antibody. These fragments retained the capacity to precipitate with antigen, but were defective in their power to neutralize virus infectivity. Their neutralizing capacity deviated from that of native antibody in the following ways : The proportion of virus neutralized was smaller. The progressive neutralization of virus ceased within 10–15 minutes of mixing virus and fragments of antibody. The rate of neutralization of virus depended only on the concentration of fragments of antibody, and was independent of the relative proportions of virus and antibody fragments. Over the ranges tested the antibody fragments inactivated an approximately constant proportion of virus irrespective of the amount of virus used in the primary, mixture. There is a brief discussion of the significance of these results for an understanding of the mechanism by which complete antibody neutralizes virus infectivity. [ABSTRACT FROM AUTHOR]

Extracts of rabbit adrenal tissue, containing an adrenal-specific antigen able to elicit the formation of autoantibody, have been characterized physically and chemically. The extinction coefficient was shown to be 10·3 at 208 mμ. Ultracentrifugal analysis revealed a group of components; the predominant one was a 3·9S boundary. Additional components had sedimentation coefficients of 6·0S, 11·8S and 18·1S. Starch block electrophoresis was unsuccessful in providing significantly purified antigen. There was a suggestion of a possible occurrence of two antigen. Some degree of fractionation was achieved was by salting-out with ammonium sulphate. The antigenic material was associated with the fraction precipitating between 0·00 and 1·50 M of this salt. These studies also provided some evidence that the antigen was associated with the 6·6S sedimenting component. Enzymic digestion with chymotrypsin readily caused destruction of the activity, indicating that the antigen is essentially a protein. [ABSTRACT FROM AUTHOR]

Antisera to Bordetella pertussis are bactericidal for some strains of B. pertussis in the presence of complement and lysozyme. Phase I bacilli, virulent for mice by the intracerebral and intranasal routes, are sensitive to the bactericidal effect; most mouse avirulent strains are not. Most of the bactericidal antisera belong to one of two types according to the concentration of antibody and complement that are optimally lethal. Type 1 antisera are bactericidal in the range 1/30 to 1/900 with guinea-pig serum as the complement source at 1/18 to 1/100. Type 2 antisera are characterized by a zone without bactericidal activity over similar antiserum and complement dilutions. Their bactericidal activity is made evident by diluting the antiserum further, by increasing the amount of complement, or by adding tissue homogenates, body fluids or crystalline lysozyme. The two types are further characterized by the differing requirements of the bactericidal system for the individual components of haemolytic complement. The combined lethal action of antibody, complement and lysozyme is rapid. In the early stages it is partly inhibited by substances in the medium used for estimating viable counts indicating that in its initial stages the reaction is bacteriostatic rather than bactericidal. [ABSTRACT FROM AUTHOR]

Haemolysis of sensitized erythrocytes (EA) can be carried out by incubating them successively with R2, followed by R1. When heated guinea-pig serum is present during the incubation of R2 with EA it inhibits haemolysis, though it has no effect when present during the incubation with R1. This inhibition is stronger with aged preparations of R2 which have much lower titres of C′4 than fresh preparations, though this increased inhibition does not occur because of the inactivation of C·4. Pre-incubation of EA with heated serum does not cause inhibition of their subsequent haemolysis by R2 and R1. Guinea-pig serum that has been decomplemented with an antigen-antibody precipitate and then heated is still inhibitory. Heated serum has no inhibitory action when haemolysis is carried out with whole guinea-pig serum in which all the components of complement are present simultaneously. [ABSTRACT FROM AUTHOR]

A new histocompatibility locus, H-4, in the first linkage group of the mouse, has been identified. The gene-order in this linkage group is H-1, c, p, with H-4 very close to p but its position relative to p undetermined. There is 8.5 ± 2.1 per cent crossing over between H-1 and c in the heterozygous female, 5.4 ± 3.7 per cent in the heterozygous male. At least 4 alleles at the H-1 locus have been identified. The distribution of H-1 alleles in various inbred and co-isogenic resistant stocks is shown in Table 11. The mean survival of skin grafts made between various co-isogenic strain pairs, differing at H-1, ranges from 32 to 91 days, with a minimum survival of individual grafts of 20 days and a maximum of 124 days. Ovarian grafts between the same strain pairs show much longer survival. The significance of these results for estimates of gene numbers is discussed; the higher published estimates are favoured. [ABSTRACT FROM AUTHOR]

The fate of intradermally injected bovine serum albumin, labelled with lissamine rhodamine was studied in actively and passively sensitized guinea pigs, and compared with the fate of the same protein in control animals. In the latter, the antigen is taken up by macrophages, apart from a discharge of antigen to the regional lymph nodes. In the sensitized animals, in which severe Arthus reactions occurred, an accumulation of antigen in vessel walls and lumina of capillaries and venules was observed. Polynuclear leucocytes take antigen after a few hours. This is a specific reaction absent with simultaneously injected protein to which the animal is not sensitized. [ABSTRACT FROM AUTHOR]

Guinea pigs were rendered incapable of making circulating antibody against bovine serum albumin (BSA) or human gamma globulin (HGG), by prenatal and/or neonatal contact with these antigens. They were then treated with a water in oil emulsion of picryl BSA, or with HGG in Freund's adjuvant, or with HGG precipitated with excess rabbit antibody and suspended in a water in oil emulsion, such as to produce a state of delayed hypersensitivity to BSA or HGG respectively in control animals. The guinea pigs which would not make antibody failed to become hypersensitive to these antigens. In one group of unresponsive animals treatment with HGG in Freund's adjuvant resulted in antibody production, but no phase of delayed hypersensitivity was observed. [ABSTRACT FROM AUTHOR]

In the guinea pig anaphylatoxin produces mast cell damage that is similar to that produced by antigen-antibody reaction but is different from that produced by chemical histamine liberators. This damage is inhibited by iodoacetate, p­chloromercuribenzoate, phenol and cold, but is not inhibited by calcium lack or previous heating of the tissue to 45° C. Mepyramine reduces but does not abolish the contraction of the ileum produced by anaphylatoxin. Previous heating of a sensitized ileum to 45° C., although completely abolishing the anaphylactic response, does not interfere with the contraction induced by anaphylatoxin. Furthermore desensitization to anaphylatoxin does not modify the anaphylactic contraction. The implication of anaphylatoxin with the anaphylactic reaction is discussed. It is concluded: (a) that anaphylatoxin shares with the anaphylactic reaction part of the pathway leading to histamine release; (b) that the mechanism of action of anaphylatoxin is quite different from that of the chemical histamine liberators. [ABSTRACT FROM AUTHOR]

Normal adult spleen cells were antigenically stimulated by incubation with isolated flagella from Salmonella bacteria, and after neutralization of free antigen and washing, were transferred to normal and sublethally X-irradiated mice and rats of various ages by intraperitoneal injection. Neonatal rats and Hall Institute mice could not produce antibody following such injections, but more mature rats and Hall Institute mice, and neonatal C3H mice, could produce antibody. Cells from immunized spleens were secondarily stimulated in vitro and transferred to neonatal and more mature recipients. Regardless of the age of the recipients, antibody production typical of a secondary response ensued. Cells from neonatal rat spleens were stimulated in vitro and transferred to more mature recipient rats. Some antibody production resulted. The theoretical implications of these findings are discussed. [ABSTRACT FROM AUTHOR]

A comparison is made of the titres of complement from different animals when reacting with antisera from different species, in the immune-adherence phenomenon. A failure of reaction between rabbit antibody and horse and pig complement is noted. This may be overcome by the addition of heated guinea pig serum. Whereas a similar failure of reaction between rabbit antibody and horse complement in immune haemolysis is also overcome by the addition of ammonia-treated guinea pig serum, this does not occur in immune-adherence. This is interpreted as meaning that there is a further heat-stable ammonia-sensitive co-factor necessary for immune-adherence in addition to the four components of complement. This co-factor is also inactivated by zymosan. The behaviour of mouse complement in immune-adherence indicates a relative deficiency in C'2 as in immune haemolysis. Conglutinin is shown to inhibit immune-adherence irrespective of the species of complement used. [ABSTRACT FROM AUTHOR]

Delayed hypersensitivity was passively transferred in guinea-pigs by lymph node and peritoneal exudate cells. This transfer was unaffected by irradiation with 1000 r given in vitro but was reduced by 1500, 2000 and 3000 r. [ABSTRACT FROM AUTHOR]

A series of multiple intravenous injections of bovine serum albumin, starting with doses too small to be immunogenic, has been used for the induction of tolerance in adult rabbits. With normal outbred animals, approximately 50 per cent of the rabbits were rendered completely tolerant by an injection schedule with 0·1 mg as the initial dose and a total dose of 9 mg given over a period of 5–7 weeks. The mechanism of this ‘low-dose tolerance’ is discussed. [ABSTRACT FROM AUTHOR]

Attempts were made to immunize F1 hybrid mice to their inbred parental strains by active immunization with either living or dead parental cells and by adoptive transfer of isogenic (F1) lymph node cells to irradiated hybrids that subsequently received parental bone marrow. Cumulative mortality studies and erythrocyte serotyping revealed that many mice survived and retained their parental grafts for long periods of time. In most experiments reported here, 59Fe uptake by erythrocytes and spleens of chimeras 1 week after marrow transplantation was used as a measure of erythropoiesis and thereby of success or failure of the marrow graft. Pre-treatment (‘pre-immunization’)of hybrids with parental spleen cells produced no evidence of specific immunization. However, pre-treatment with spleen cells from parent 1 was detrimental to subse- quently transplanted marrow from parent 2 and vice-versa. Adoptive transfer of viable F1 lymph node cells failed to decrease growth of parental cells in irradiated F1 hybrids. These findings indicate that the poor-growth phenomenon of particular parent-F1 combinations cannot be explained in terms of classical immune rejection of parental cells by F1 hybrids. Instead, growth of parental cells in the F1 environment is inhibited or delayed. [ABSTRACT FROM AUTHOR]

Immunizing injections of rat liver and kidney mitochondrial fractions were administered to rabbits, and the effects of injecting the antisera into rats were investigated. Rats receiving antiserum to rat liver mitochondria showed impaired clearance of sulphobromphthalein, and developed hepatic fibrosis which in one animal progressed to cirrhosis. There was no increase in albuminuria and the kidneys showed no histological differences from those of control rats receiving normal rabbit serum. Renal changes were virtually confined to rats receiving antiserum to rat kidney mitochondria : these animals excreted increased amounts of protein and showed increased cellularity of the glomeruli, tubular casts and hydropic changes in the tubular epithelium. The significance of these findings is discussed. [ABSTRACT FROM AUTHOR]

Rat organ homogenates were fractionated by differential centrifugation and the fractions were incorporated into incomplete Freund's adjuvant and administered intramuscularly to rabbits. Gel-diffusion precipitin and complement-fixation tests showed the development of antibodies which reacted with rat, and in lower titres with rabbit organ fractions. The rabbit antisera to liver and kidney fractions reacted with preparations of both these organs, and antisera to liver fractions (nuclei, mitochondria and supernate) reacted with all three of these preparations. Hepatic lesions were observed in those animals which developed anti-bodies shown capable of reacting in vitro with liver tissue constituents. These changes were most pronounced in rabbits immunized with liver mitochondria, in which inflammatory changes and fibrosis were related to the biliary ductules, and in those immunized with liver nuclear or kidney mitochondrial fractions, in which the changes appeared mainly around the larger interlobular hepatic ducts. Changes occurred also in the kidneys, but were observed also in control animals injected with normal rat serum. [ABSTRACT FROM AUTHOR]

Radioiodine-labelled homologous serum albumin and heterologous γ-globulin reached the extravascular space of the guinea-pig thymus in concentrations comparable with those in the spleen and in lymph-nodes. The uptake of proteins in a locally X-irradiated involuting thymus gland was approximately doubled at 6, 12, 24 and 48 hours compared with non-irradiated controls. At 7 days the concentration was greater than in the other lymphoid tissues examined, namely spleen, cervical and mesenteric lymph-nodes, and was greater than in control glands by a factor of two to four. Localization of foreign material was studied with Evans Blue and carbon black which were found in macrophages of the capsule, cortex and medulla, and in Hassall's corpuscles. The foreign material showed a marked increase in the parenchyma of glands during involution whether produced by X-irradiation, cortisone or corticotrophin. The significance of these findings in relation to the formation of germinal centres in the thymus in pathological conditions is discussed. [ABSTRACT FROM AUTHOR]

Cephalothin and cephaloridine, antibiotics with the 7-amino cephalosporanic acid nucleus, have been shown to form protein conjugates which were able to stimulate production of haemagglutinating, precipitating and guinea-pig skin-sensitizing antibodies in the rabbit. A high degree of cross-reaction with the benzyl penicilloyl determinant group was demonstrated, but evidence was found of only very limited cross-reaction with the haptenic determinant of the penicillin nucleus, 6-amino penicillanic acid. Cephalothin did not induce contact sensitivity in guinea-pigs. These results are discussed with particular respect to the relative parts which the side chain and nucleus of these related antibiotics play in determining antigenic specificity. [ABSTRACT FROM AUTHOR]

Attempts were made to desensitize guinea-pigs (which had been actively sensitized to bovine serum albumin) by injecting them 2 days before challenge with a near-lethal dose of the antigen under protection of antihistamine. No statistically significant desensitization occurred although there was a significant drop in the mean serum antibody titre as well as in the mean complement levels. However, antibody titre and sensitivity to anaphylaxis could not be correlated. [ABSTRACT FROM AUTHOR]

The antigen-elimination test has been calibrated by means of passive immunization experiments. The effect of altering the amounts of antigen or antibody used in this test has been demonstrated. Experiments have been carried out to investigate the possibility of inducing immunological paralysis in mice immune to BGG. It was found necessary to start with an injection of 300 mg BGG, and follow this by a course of twice-weekly injections of exponentially (×2) decreasing amounts. X-irradiation increased the ability of antigen to paralyse. The difference between non-immunogenic antigens (BGG in mice) and immunogenic antigens (BSA, etc.) is discussed. The possible role of intracellular antibody in determining the amount of antigen necessary to induce immunological paralysis is also discussed. [ABSTRACT FROM AUTHOR]