bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of phagocytosis on the growth and survival of avian tubercle bacilli in embryonic chicken tissue cultivatedin vitro
Authors: Fell Honor B. , Brieger E. M. 
Published: May 2009

1. Explants of embryonic chick tissue were infected with avian tubercle bacilli of different degrees of virulence to study (a) some of the factors on which control of infection in tissue cultures depends and (b) the viability of bacilli ingested by wandering cells.2. Embryonic lung cultures could control infection for 2–3 weeks owing to the intense phagocytic activity of the many wandering cells which they contained. The tissue appeared unharmed by infection with bacilli of either virulent or avirulent strains.3. The wandering cells largely protected the much less phagocytic fibroblasts from intracellular infection.4. This protective action of wandering cells towards less phagocytic cell types was limited by three factors: (1) the density of the infection relative to the volume of the explant, (2) the growth-rate of the infecting strain and (3) the proportion of wandering cells which the tissue contained.5. Even under the most favourable conditions control of bacillary growth in the tissue was only temporary, largely owing to the gradual disappearance of the wandering cells during repeated subcultivation.6. As control of bacillary growth was lost, the lung fibroblasts became packed with bacteria, but they appeared undamaged and might even undergo normal mitotic division. Eventually the ingested bacilli seemed to kill the cells by proliferating until they burst the cytoplasm.7. Embryonic avian tissue cultures though infected with a highly virulent strain never showed the rapid, widespread necrosis observed by Maximow in cultures of adult rabbit tissue infected with a virulent bovine strain. Possible explanations of this disparity are discussed.8. A special method was devised for testing the viability of bacilli phagocyted by macrophages. It showed that phagocyted bacilli, whether virulent or avirulent, survived for at least 21 days; when the host wandering cells were killed the ingested organisms were capable of immediate and profuse growth on suitable nutritive medium.
The conglutination phenomenon. III. The conglutinating complement absorption test in experimental glanders
Authors: Hole N. H. , Coombs R. R. A. 
Published: May 2009

1. Observations on the sera of ponies, taken at frequent intervals for 321 days after oral administration ofP. mallei, are described.2. It was found that the conglutinating complement absorption test was more sensitive than the haemolytic complement fixation test as a means of diagnosis. It detected the antibodies earlier in the course of the disease and demonstrated their presence over a longer period of time.3. The possibility of another practical use of this reaction as an adjunct to the allergic test is considered. Ten days after an intradermo-palpebral test a pony, which had been previously sensitized and whose serum antibody titre at that time was below 10, developed a serum titre of over 160 as demonstrated by the conglutinating complement absorption test. Under similar circumstances 11 unsensitized ponies developed no detectable serum antibodies.
A tellurite medium for the identification and isolation of corynebacterium diphtheriae
Authors: Handley W. R. C. 
Published: May 2009

1. The preparation and characteristics of a tellurite medium, containing, in addition to a peptone and Lemco agar base, a tryptie hydrolysate of casein, sodium lactate, L-cystine, sheep serum, an extract of sheep red blood corpuscles and 0·01% potassium tellurite, is described for use in the identification and isolation of Corynebacterium diphtheriae.2. The colonial appearances of the three types of C. diphtheriae on the medium are described, and the distinguishing features between these and the colonial appearances of diphtheroids and other organisms liable to occur on pathological material are indicated.3. Recommendations are made concerning what has so far proved to be the most suitable manner of inoculation of pathological material on to the medium.The author would like to express his thanks to Prof. F. C. Happold for suggesting the problem, to Dr R. E. Jones for encouragement during the course of the work, to Miss K. Gilliver, M.A., for assistance in the preparation of the manuscript and to Miss G. M. Jenkins for technical assistance.
The occurrence of natural antibodies in rabbit sera in relation to the paracolon group of organisms
Authors: Schwabacher Herta 
Published: May 2009

1. Naturally occurring agglutinins to paracolon bacilli have been found in seven out of ten sera from non-immunized rabbits and in one anti-Salmonellaand two anti-paracolon immune rabbits' sera after complete absorption with the immunizing strain.2. The a antigen of Stamp & Stone, which is known to occur as a natural agglutinin, has been demonstrated in one out of nine paracolon bacilli.3. Rabbits which before immunization show agglutinins to the immunizing strain or to an α antigen should not be used for the preparation of diagnostic antisera for intestinal Gram-negative bacilli.
The nuclear cycle in bacteria
Authors: Bisset K. A. 
Published: May 2009

1. Strains ofBact. coliand related bacteria possess a life cycle resembling that of Myxobacteria. The vesicular, resting nucleus is contained in a microcyst, which is formed by a process suggestive of sexual conjugation.2. The microcyst germinates by the transformation of the resting nucleus into the chromosome-like bodies typical of active, vegetative cultures. These may be analogous to the chromosome complexes of yeasts. The period of germination of microcysts corresponds to the lag phase of cultures.3. The nucleus remains permanently in the mitotic condition during the active, vegetative phase of growth, and reproduces by an asexual and a sexual method.4. Older cultures may be transformed directly into microcysts or may first adopt a secondary, vegetative phase, in which the nucleus is in the form of a single, central body.5. Microcyst formation differs from spore formation in that it lacks the obvious reduction processes associated with spore formation, upon which a few original observations are included.
The effect of radiation from the surroundings on subjective impressions of freshness
Authors: Munro A. F. , Chrenko F. A. 
Published: May 2009

The effects of radiation from the surroundings on the impressions of freshness of 106 men and 39 women members of the staff of the Building Research Station were investigated during the first 6 months of 1948. Subjects were exposed to three types of environment: (1) where the walls were cooler than the air, (2) where the walls and air were at the same temperature, and (3) where the walls were warmer than the air. The tests were carried out in calm air.It was found that the difference between the mean radiant temperature and the air temperature affected freshness impressions, but the effect was relatively slight. Environments which felt cool tended to feel fresh, yet a rise in the mean radiant temperature—which would increase the warmth of the environment—tended to produce an impression of greater freshness. At a given equivalent temperature, environments with the surroundings warmer than the air were found to be definitely fresher than cold- and neutral-wall environments. This was thought to be mainly due to the fact that the humidity of the air in the warm-wall environment was lower than that in the other two environments. Changes in humidity insufficient to affect sensations of warmth affect impressions of freshness. Under the conditions of these experiments, and to keep freshness impressions constant, a rise of 1° F. in the temperature of calm air must be compensated by a fall of about 5% in the relative humidity.The subjects had a distinct preference for the warm-wall environment; 73% of them found it pleasanter than either the cold- or the neutral-wall environment.Freshness impressions are considered to be related to transient fluctuations in the rate of heat loss from the head.
Effect of treatment at the sewage works on the numbers and types of bacteria in sewage
Authors: Allen L. A. , Brooks Eileen , Williams Irene L. 
Published: May 2009

Over a period of about 10 months samples were taken at frequent intervals from various stages of treatment at two sewage works; one of these was a small rural works treating only domestic sewage, and the other treated the sewage of an industrial town. These samples were submitted to bacteriological and to chemical examination.The total plate counts, the counts ofcoli-aerogenesbacteria, and the counts ofStreptococcus faecalisin settled sewage were higher in the warmer than in the colder months of the year.Though the average total numbers of bacteria in the sewage containing trade wastes were appreciably higher than that of the domestic sewage the counts of faecal organisms were somewhat lower.Treatment at the works considerably reduced not only the polluting strength of the sewage but also the numbers of bacteria. At the works receiving sewage from an industrial town an average of about 80% of bacteria in settled sewage were removed by treatment in the bio-aeration plant, percolating filters, and humus tanks, and a further 8–10% were removed by subsequent treatment in pressure sand or anthracite filters. At the small rural works, where the rate of treatment was much lower, rather more than 90% of the bacteria were, on the average, removed by treatment in percolating filters and humus tanks, and a further 6% by subsequent passage through shallow gravity sand filters.The final effluents discharged from the works still contained large numbers of bacteria. Their effect on the bacterial content of the streams to which they are discharged may be gauged from the fact that, in the effluent from the small rural sewage works, which was of consistently good quality when judged by chemical criteria, there were on the average about 160,000 cells of faecalBacterium coliand about 20,000 faecal streptococci per 100 ml. Numbers in the effluent from the works in the industrial town were even higher. Sand filters of the type investigated here could therefore not be relied upon to produce an effluent of good bacterial quality.The 44°C. test in MacConkey broth, prescribed by the Ministry of Health (1939) for examination of water, was found, when applied to samples of sewage or sewage effluent, to be almost specific forBacterium coli, type I. Growth with formation of acid in sodium azide broth incubated at 45° C. was found to be an almost specific test forStreptococcus faecalis.
Measurements of rate of mutation of flagellar antigenic phase inSalmonella typhi-murium
Authors: Stocker B. A. D. 
Published: May 2009

Change of flagellar antigenic phase in the Salmonellas is considered as resulting from the mutation and back mutation.A rapid method of determining the phase of numerous colonies ofSalmonella typhi-muriumis described; melted sloppy agar containing antibody for one phase is layered on tplates on which colonies have grown. On brief incubation, colonies of the agglutinated phase produce narrow dense sharp edged zones of opacity, while colonies of the other phase wide diffuse zones of swarming organisms.A theoretical analysis shows that if the growth rates of the phases are equal the proportion of cells of ‘mutant’ phase in a culture initially all in one phase and maintained in continuous logarithmic growth will (at first) increase linearly with the number of generations at a rate proportional to the mutation rate. In one strain ofSalm, typhi-muriumexperiments showed the rates of growth of the phases to be equal; the proportion of cells of mutant phase in cultures of this strain during long periods of continuous growth has been measured; linear rates of increase were found, and the mutation rates are calculated.The variance in proportion of cells of mutant phase in replicate cultures has been measured; the findings are correlated with theoretical considerations.Certain anomalous decrease in proportion of cells of mutant phase during prolonged growth are described, and a possible explanation is proposed.Eight further strains have been investigated by the same methods; in the nine strains, the rates of mutation from group to specific phase range from 10-4to 4.7 X 10-3per bacterial generation cycle, and the rates of the reverse mutation from 10-5to 8.6 X 10-4. In all the strains, including two of varietybinns, the rate of mutation from group to specific is higher than the rate of the reverse change; it is shown theoretically that such strains will tend towards an equilibrium composition in which the specific phase will predominate; in one rapidly mutating strain such an equilibrium has been demonstrated.In a limited experiment, alteration of medium and of temperature of incubation caused to detectable alteration of rate of mutation per bacterial generation.Stable O mutants, and poorly flagellated mutants which back-mutate to the fully motile form, are described.The experimental findings are compared with reports in the literature on the phase ofSalm. typhi muriumas isolated. The behavior of strains of varietybinnsis discussed, and it is suggested that this description should not now be applied to strains in which a specific phase can be demonstrated. The biological funtion of mutablility of phase is discussed.
A search for bacteriophages active upon bacteria of the Brucella genus
Authors: Williams Smith H. 
Published: May 2009

1. None of forty-eight strans of Brucella abortus, ten of Br. melitensis and seven or Br.suis were shown to be lysogenic.2. It was not possible to ‘adapt’ bacteriophages that were active upon other species of bacteria to lyse brucellas.3. Thirty samples of faeces, mainly from cows, four sewage samples, twelve specimens of uterine fluid from cows that had aborted, and twenty samples of bulk milk failed to yield bacteriophages active upon brucellas.
The formation of precipitates on mixing anti-horse sera
Authors: Naylor G. R. E. 
Published: May 2009

1. Five anto-horse sera which did not contain antibodies for horse-serum crystalbumin have been shown by absorption experiments to contain horse-serum crystalbumin.2. All five sera precipitated when mixes with other anti-horse sera containing anti-crystalbumin, precipitation being due to the presence of horse-serum crystalbumin in one antiserum and of anti-crystalbumin in the other.3. Antigen and its homologous antibody were never found together in the serum of an animal, and contradictory results in other experiments are probably due to impure multiple antigens.4. It is concluded that anti-horse sera may contain some of the antigenic components of injected horse serum together with antibodies to other antigens of the horse serum, but not homologous antigen and antibody. Consequently, the ‘mutual’ precipitation of anti-horse sera is due to the presence of a number of antigens in horse serum, one or more of which, present in one anti-horse serum, in the absence of its homologous antibody, may precipitate when mixed with another anti-horse serum which contains the homologous antibody.5. The use in these experiments of a single α-procedure optimum as the indicator of an antigen-antibody reaction illustrates a method enabling the investigation of problems involving single antigen-antibody reactions, even though the available reagents consist of mistures of antigens and mixtures of antibodies.
The conglutination phenomenon. IV. An experimental investigation of the factors determining the adsorption of complement by an antigne-antiserum mixture
Authors: Blomfield A. M. , Coombs R. R. A. , Hole N. H. 
Published: May 2009

1. Salmonella antisera from a number of animals, including man, have been examined by conglutinating complement-absorption and haemolytic complement-fixation tests for the presence of anitbodies. Both a soluble antigen and a particulate antigen of washed suspended orgainsms have been used. The behavior of the antisera was comparable with that previously recorded with the mallein antimallein system, in so far as the reactions obtained with the different complements followed the same general pattern.2. Two factors were found to explain the failure of certain antisera, in conjunction with the antigen, to adsorb certain complements. On the one hand, a few antibodies themselves appeared incapable of fixing a particular complement. On the other hand, although some antisera failed to fix specific complements, their antibodies, isolated from the serum, were able to fix the complements concerned. In these cases it appeared that the heated serum contained a non-specific factor that prevented the adsorption of the complements.3. The existence of such non-specific factors in certain heat-inactivated sera is illustrated in Figs. 11–14. An examination of the mechanism involved does not appear to implicate the procomplementary effect of sera, although this effect in itself is a complex problem requiring further elucidation. The few experiments carried out indicate that the factor in the inactivated serum does not come into play and inhibit the adsorption of complement by an antigen-antibody complex without the initial intervention of some component of complement. Only after this has occurred is the inhibitory factor able to block any further complement adsorption.4. We have discussed the implications of these experiments and their possible relationships to the complementoid phenomena described by previous workers.
An experimental study of haemolytic disease of the newborn due to isoimmunization of pregnancy. II. Report of an attempt to produce anti-red cell isoantibodies in guinea-pigs, together with a note on the blood picture of one-day-old guinea-pigs
Authors: Mynors L. S. , Heard D. H. , Coombs R. R. A. 
Published: May 2009

1. Repeated inoculation of thirty-six guinea-pig does with random blood of guinea-pig bucks failed to produce any demonstrable anti-red cell isoantibodies.2. A note is included on the blood picture of a small series of newborn guinea-pigs aged between 12 and 24 hr.
Infantile gastro-enteritis with special reference to the specific serological type O55 B5 H6 (Betatype) ofBacterium coli
Authors: Smith J. , Galloway W. H. , Speirs A. L. 
Published: May 2009

1. An account is given of the relationship ofBact. colitype O55 B5 H6 to cases of infantile gastro-enteritis.2. In Aberdeen this organism has now largely replaced the O111 variety (alpha) which had been the prevalent type during 1947 and 1948 in its association with the disease.3. A brief description has been given of the clinical findings, which show no marked deviation from those found in similar cases elsewhere. The actual severity of the illness as judged by the mortality rate has been greatly lessened.4. The value of medication with chloromycetin in a small number of cases has been discussed. It is believed that the use of the drug eliminates the organism from the bowel in certain cases and helps to reduce the number of cross-infections even in a cubicle ward. The average weekly weight increase of children on chloromycetin was almost double that of a group of healthy, untreated children.5. Several small outbreaks of infantile diarrhoea associated with the O55 B5 H6 type in wards and institutions have been recorded. In some the numbers of symtomless carriers of the O55 type have exceeded those of clinical cases also harbouring the same organism.6. ‘O’ and ‘H’ agglutination tests made with suspensions of the prevalent strain ofBact. colion sera from cases examined early in the disease were mostly negative. Such positive titres as were obtained were low. Examination of paired acute and convalescent sera from 29 cases gave some evidence of increasing titre during the course of the disease in eight cases, but such increase was of low order.7. The present bacteriological evidence suggests that further specific types ofBact. coliwill be found to be associated with the disease.
The pathogenicity of the spores of Clostridium botulinum
Authors: Keppie J. 
Published: May 2009

1. The injection of mice with botulinum spores, freed from all traces of superficial toxin, can cause death but only if a very large number is given. This number was found in the case of a highly toxic strain to be of the order of 20 million spores given intramuscularly. This dose was fatal in the absence of spore germination.2. In human botulism it is concluded that the spores of Clostridium botulinum persent in spoiled foodstuffs are not of importance compared with the toxin produced by the initial growth of the contaminating organisms.3. Toxin could be demonstrated in the cytoplasm of botulinum spores when these were disintegreted by mechanical means. This is of theoretical interest as the toxin within the spores is more heat-stable than the extracellular form.4. A local anaerobic myositis could be produced in mice by the intramuscular injection of spores plus 2·5% CaCl2. The number of viable spores in the LD50 was of the order of 50,000.5. Calcium chloride solution in the commonly used strength of 2·5% was shown regularly to cause a drop in the number of botulinum spores in a given suspersion of some 40% and a parallel loss of viability of about 60%.
Phage typing of Staphylococcus aureus
Authors: Hood A. M. 
Published: May 2009

Phage adsorption by resistant staphylococci was studied.Staphylococcal cultures previously allowed to adsorb phage to which they were resistant remained as sensitive to their appropriate phages as normal cultures of the same strains.When pooled related and unrelated phages were incubated with their propagating strains, the results resembled those obtained when these phages were incubated separately with the same strains.The lytic effects of thirty-two phages at test dilutions were tested singly and when pooled into five mixtures. All the phage-propagating strains and over 500 strains received for typing were tested. The results were in agreement.Thirty-two phages at their test dilution in nutrient broth remained stable, whether pooled or not, at 0 to + 5° C. for various times. Briefly summarized, serological group A phages were stable for at least 1 month, and group B phages were stable for only 2–3 weeks.Broth cultures of staphylococci incubated for 18 hr. at 30° C. were as phage-sensitive as the same cultures when left at room temperature for 24 hr.A new method of phage typing staphylococci by means of phage pools, as satisfactory as the standard method, and less laborious, is described.
Bacteriophage inhibition by extracts from phage-insensitive bacteria of the genusPseudomonas
Authors: Mead T. H. , van den Ende M. 
Published: May 2009

1. An electrophoretically homogeneous antigen preparation extracted from a strain (LII) ofPseudomonas aeruginosaby trichloracetic acid inhibits four phages active against this strain, and two phages (5 and 14) to which it is resistant but which attack a mutant strain LIII–3 bi.2. An extract prepared in the same way from strain LIII–3 bi has no antigenic or inhibitory properties. Lysis of LIII–3 bi organisms by chloroform, however, yields a potent inhibitor active against several phages.3. TCA extracts from immunologically distinctPs. strains AII, BII and GII also inhibit phages 5 and 14 to which these strains are resistant.4. The effect of a third phage (13) onPs. LIII–3 bi is activated by the extract from strain LII which normally inhibits phages 5 and 14. Prolonged contact with very dilute solutions of the extract also causes activation of phage 5. Activation of phage 14 has not been observed.5. The above findings are discussed in relation to current theories of phage action and phage inhibition.