bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of ACTH, cortisone, sphingomyelin, sphingosine and phenergan (antihistamine) in inhibiting the skin reaction in cattle sensitized toTrichomonas foetusantigen
Authors: Kerr W. R. , Robertson Muriel 
Published: May 2009

1. ACTH, cortisone, sphingomyelin and sphingosine produce a delayed in-hibition of the skin reaction in cattle sensitized toTrichomonas foetusantigen when they are injected intramuscularly. The inhibition is greatest 6–9 hr. after injection of the inhibitor, but may sometimes be further delayed. This reaction is associated with an absolute lymphopoenia of slightly variable duration.N-acetylsphingosine retains the desensitizing effect of crude sphingomyelin and is of much the same potency as cortisone acetate of Merck.2. The lymphopoenia associated with the injection of ACTH and cortisone occurs also with sphingosine, and these three substances are also alike in not producing the desensitizing effect until some hours after the injection.3. Phenergan, a synthetic anti-histamine, has a different action, and its desensitizing effect which appears to depend on a direct antagonizing of the oedema-provoking substance resulting from the junction of antibody and antigen (hapten) takes effect apparently as soon as the injected drug itself is present at the site of the injection of the specific testing fluid.4. Methods of testing the capacity of the hormones and drugs to prevent the skin reaction locally and to nullify the action of thein vitroantigen-antibody mixtures which can produce a reaction in normal animals are described.Phenergan alone of the substances dealt with has any power to act locally. Phenergan mixed with the antigen-antiserum complexin vitroprevents the formation of the characteristic swelling in a normal animal.Phenergan mixed with the specific testing fluid prevents the development of the skin reaction when the mixture is injected intradermally into a sensitive animal.Cortisone and sphingosine do not have this action.We are indebted to the Medical Research Council for supplies of ACTH and cortisone and to Sir Charles Harington for N-acetylsphingosine.The personal encouragement of Prof. H. G. Lamont and the support afforded by the Ministry of Agriculture, Northern Ireland, are gratefully acknowledged.
Observations on the antigenic structure ofPseudomonas aeruginosa
Authors: van den Ende M 
Published: May 2009

Twenty-four selected strains ofPseudomonas aeruginosahave been classified on the results of precipitin tests with trichloracetic acid extracts into six serological groups.This differentiation was confirmed by O agglutination.Four of the six serological groups can be further subdivided according to their sensitivity to one or more of nine phages.Alcohol treatment reduces agglutinability of some strains, particularly if alcohol is added to very concentrated suspensions of bacteria in the preparation of O suspensions.The precipitation method has been applied to eighty successive strains ofPs. aeruginosaisolated, and with the available sera seventy-two could be placed into one or other of the six serological groups.I am grateful to Mr G. S. Turner and Miss D. L. Deeks for their able and enthusiastic assistance in this work, and to all the members of my staff for their constant helpful co-operation.The Virus Research Unit was in receipt of additional financial assistance from the Nkana-Kitwe and Chingola Poliomyelitis research funds.
The estimationin vitroof small amounts of diphtheria antitoxin by means of a haemagglutination technique
Authors: Fisher Stephen 
Published: May 2009

1. Treatment of washed sheep erythrocytes with dilute solutions of tannic acid rendered them capable of adsorbing diphtheria toxin from solution. Diphtheria toxoid was not adsorbed under similar conditions.2. Cells thus sensitized with diphtheria toxin were agglutinable by a proportion of children's sera and human cord sera; sera of rabbits, mice and horses, immunized with soluble or adsorbed diphtheria toxoid, also agglutinated sensitized cells, as did also the sera of children suffering from diphtheria and treated with antitoxic serum. Clear-cut results were usually obtained, but the end-point of titrations on horse sera was, in some cases, difficult to determine.3. Using intradermal toxin neutralization tests, a highly significant linear relationship was demonstrated between the haemagglutinating titres of children's sera for the sensitized red cells, and the antitoxin content of their sera. The antitoxin content corresponding to the smallest detectable amount of haemagglutinating antibody was 0·008 unit per ml. serum.4. The haemagglutinating titre was an accurate measure of the mean antitoxin level of a group of sera and a close measure of the antitoxin content of most specimens in individual tests.
Studies on the susceptibility of Rickettsia burneti to chemical disinfectants, and on techniques for detecting small numbers of viable organisms
Authors: Malloch R. A. , Stoker M. G. P. 
Published: May 2009

1. The susceptibility of the Henzerling strain of R. burneti to phenol, formalin, ‘Lysol’, ‘Dettol’, ‘Cetavlon’, and ether was investigated.2. Preliminary investigation of techniques showed that, with one passage, guinea-pigs, mice and fertile hens' eggs were of similar susceptibility to small numbers of viable organisms, but the greater feasibility of sub-passage from the eggs increased the sensitivity and made this the technique of choice.3. Under the condition of testing, ‘Lysol’ was the most active disinfectant. Treatment of the rickettsial seed with 1% ‘Lysol’ at 37° C. was in fact the only effective method for destroying completely the infectivity in 3 hr.4. Some living organisms survived contact for 3 hr. with each of the other chemicals in concentrations up to 1%. A rough quantitative comparison of these agents was made.5. The failure of 1% phenol to destroy R. burneti raised the possibility of this organism surviving as a contaminant in vaccine lymph. This problem was investigated and is discussed.
The properties of differentSalmonellaVi antigens
Authors: Felix A. 
Published: May 2009

The labile Vi antigens ofSalmonella typhi, Salm. paratyphi AandB, and ofSalm. typhi-muriumwere compared, especially in their response to various chemical and physical agents.1. Inactivation by dilute acid:(a) The TVi antigen is the most resistant to acid treatment, the BVi antigen is most readily inactivated and the AVi antigen holds an intermediate position.(b) Pure Vi sera may be obtained by absorption with acid-treated bacilli, but this technique gives irregular results.(c) Contrary to Kauffmann's statements, the TVi antigen is not ‘destroyed’ by acid treatment.2. Inactivation by dilute alkali:(a) All the Vi antigens so far tested are susceptible to dilute alkali.(b) Complete inactivation, or extraction, of the Vi antigens is ensured when the yield of alkali-treated bacteria represents no more than 25% of the original bacterial count.(c) The most reliable method of preparing a pure Vi serum is by absorption of the Vi + O serum with alkali-treated organisms of the same strain as that employed in immunization.(d) Immunization with alkali-treated bacilli results in the elaboration of pure 0 antisera entirely devoid of Vi antibody.3. Inactivation by heat (in aqueous suspensions):(a) The TVi antigen is the one most readily inactivated, the BVi antigen is the one most resistant and the AVi antigen holds an intermediate position.(b) These differences are only of minor significance, since similar differences have been established for the TVi antigen itself when it is contained in the two varieties of Vi strain of Salm. typhi.4. Treatment with alcohol:(a) Most of the properties of the threeSalmonellaVi antigens remain unimpaired by alcohol treatment.(b) The physico-chemical behaviour of alcohol-treated or heated bacilli, as exemplified by agglutinability by pure Vi antiserum, depends on the presence of other constituents of the bacterial cell.5. Treatment with formalin:(a) The Vi agglutinability of the differentSalmonellais preserved undamaged for long periods of time. The 0 inagglutinability ofSalm. typhiis also well maintained.(b) It is not yet known whether formolized AVi and BVi antigens undergo an alteration that leads to ‘functional deficiency’ of the corresponding antibody similar to that of the altered T Vi antibody.6. Treatment with phenol produces a reversible inactivation of the agglutinogenic activity of the T Vi antigen but not of the A Vi and B Vi antigens.7. The inadequacy of the symbols employed by Kauffmann for expressing the changed reactivity of differently treated antigens is emphasized.
The experimental infection of calves with Mycobacterium Ulcerans
Authors: Tolhurst Jean C. , Buckle Glen , Wellington N. A. M. 
Published: May 2009

Skin lesions with histopathology similar to that seen in lesions in man have been produced in calves by the experimental inoculation of cultures of Myco. ulcerans. Sensitization of infected calves to mammalian tuberculin as well as to ulceranin has been demonstrated.It is considered unlikely that cattle are a reservoir of infection for man.The expenses of this investigation were met by a research grant from the Board of Management, Alfred Hospital.We are indebted to Dr A. V. Jackson, Director of Pathology, Alfred Hospital, for the reports on histopathology.
The experimental reproduction of enterotoxaemia in piglets
Authors: Field H. I. , Goodwin R. F. W. 
Published: May 2009

1. Whole cultures ofClostridium welchii, Type C (organisms plus toxin), produced enterotoxaemia and death when fed to new-born piglets.2. The disease could rarely be produced by suspensions of washed organisms given in the same way but was readily initiated by feeding bacteria-free toxin from Type C cultures.3. Piglets dying from enterotoxaemia induced by bacteria-free toxin showed all the extensive pathological changes of the natural disease; their intestines contained Type C organisms and far greater quantities of toxin than had been given by mouth.4. Type C organisms could not be demonstrated in the intestines of piglets from healthy litters of the same age, although such animals were carriers of the Type A strain.5. The clinical signs, with particular reference to the development of hypo-glycaemia, and the pathology of both natural and experimentally induced cases of enterotoxaemia are described.6. In the light of these findings the pathogenesis and epidemiology of enterotoxaemia in the piglet are discussed.We wish to thank Mrs B. L. Wardale and Mr P. J. D. V. Brett for general assistance. This study was aided financially by a general grant to one of us (R.F.W.G.) from the Agricultural Research Council.
Variation of host resistance to influenza viruses in the allantois
Authors: White D. O. , de St Groth S. Fazekas 
Published: May 2009

1. Methods are described for altering the susceptibility of the surviving allantois to infection by influenza viruses.2. Under natural conditions susceptibility is a linear function of age between 10 and 18 days of incubation. The drop is 0·11 log10unit per day for all strains of influenza tested.3. In whole eggs this decline is masked by the effect of acid allantoic fluid which prevents infection when the pH falls below 6. The effect is not directed against the virus particle, nor does it do permanent damage to the cell, as surviving tissues are equally susceptible whatever the pH of the allantoic fluid that bathed themin ovo.4. Surviving membranes can be made less susceptible by incubating the eggs at 35° rather than 38° C.; by maintenance for 24 hr.in vitro; by use of deficient or inappropriate medium. These methods lower susceptibility more for some strains than for others.5. All treatments which lower susceptibility also increase its variation from egg to egg.
The comparative rodenticidal efficiency of five anti-coagulants
Authors: Bentley E. W. , Larthe Yvonne 
Published: May 2009

1. Results are presented of palatability tests and chronic toxicity tests with five anti-coagulant rodenticides at a variety of concentrations against wild Rattus norvegicus, R. rattus and Mus musculus. These results are compared with similar data for warfarin. Estimates are also given of the acute oral toxicity of two of the five, fumarin and diphacinone, to white rats.2. The toxicity of the compounds vis-à-vis warfarin is examined from the standpoint of the risks to domestic animals involved in their use as rodenticides.3. Coumachlor, 2-isovaleryl-1, 3-indandione and 2-naphthyl-1, 3-indandione are considered to be less effective than warfarin against R. norvegicus. Their effectiveness against R. rattus remains to be demonstrated.4. Fumarin appears to be about as good as warfarin against R. norvegicus and R. rattus at similar concentrations. It appears to be slightly less effective against M. musculus.5. Diphacinone at 0·0025% is regarded as a good alternative to 0·005% warfarin against R. norvegicus. At 0·0125% it is probably more effective against R. rattus than is 0·025% warfarin. The two poisons are about equally effective at this strength against M. musculus, but diphacinone is probably slightly more dangerous for domestic animals.6. The results of a small number of field trials with fumarin and diphacinone are briefly summarized.So many of our colleagues and others have helped at some stage or other of our investigations that it would be tedious to mention them all by name. We must, however, single out for our special thanks Mrs M. Rowe and Miss E. Taylor who carried out a large number of the laboratory tests, Mr A. Taylor on whose chemical experience and facilities we have freely drawn and Mr C. H. B. Worrall, Miss B. Jones, Mr S. R. Surtees and Mr J. H. Cuthbert (Department of Agriculture for Scotland) who carried out the field trials.
Observations on the growth in nutrient broth of mixtures ofEscherichia colistrains, and of faecal specimens harbouring pathogenicEscherichia coliserotypes
Authors: Dixon J. M. S. 
Published: May 2009

Experiments were made with five pathogenic serotypes and five non-pathogenicEsch. colistrains to study the competitive growth of mixed coli cultures in nutrient broth. In associations incubated at either 37 or 44°C. the organism inoculated in smallest numbers increased proportionately after 18 or more hours' incubation. The greater the initial disparity, the greater was the increase. Broth culture favoured the pathogenic strains only when these were numerically inferior in the inoculum. The tendency to numerical equation increased with increasing length of incubation.A study was made of the use of nutrient broth as an aid to the isolation of pathogenicEsch. colistrains from the faeces of infants. 120 positive specimens were examined. Nutrient broth incubated at 44° C. was the most successful method, and when used as a complement to direct plating resulted in an additional 19·6% of positive specimens. The main value of nutrient broth as an enrichment method is in the examination of the faeces of suspected carriers and convalescent patients, in which the pathogen is likely to be outnumbered by non-pathogenicEsch. colistrains.I wish to thank Prof. Scott Thomson for his advice and helpful criticism, and Dr R. W. S. Harvey for his interest and encouragement.
The fate of131I-labelled diphtheria toxin and toxoid in the skin of immune and allergic guinea-pigs
Authors: Long D. A. 
Published: May 2009

Highly purified crystalline diphtheria toxin-protein, and toxoid prepared from it, were labelled with131I, without change of potency, and injected intradermally into immune and allergic guinea-pigs. It is probable that actively immunized guinea-pigs localize these antigens and that localization is due to hypersensitivity of a type that cannot be transferred with serum; it is possibly of the delayed (tuberculin-type) of allergy.It is a pleasure to acknowledge the gift of highly purified (crystalline) diphtheria toxin, and toxoid prepared from it, from Dr C. G. Pope of the Wellcome Research Laboratories, England. Dr S. P. Masouredis of the Central Blood Bank of Pittsburgh kindly labelled these antigens, using the technique he devised. Dr W. J. Kuhns generously provided the human precipitating and non-precipitating diphtheria antitoxin*.The collimator head was made by Mr J. Nechaj of the University of Pittsburgh.All these collaborators gave me advice on matters of which I was ignorant; for this I am grateful.
Fate of tubercle bacilli in early experimental infection of the mouse
Authors: Gray David F. 
Published: May 2009

1. The question of a possible eclipse phase during the first week of experimental mouse tuberculosis has been examined.2. Using fluorescence microscopy to examine sections and to perform counts of stainable bacilli for comparison with counts of culturable bacilli in the lungs it was found that bacilli multiplied very slowly during the first 5 days, and rapidly from about the sixth day onwards.3. At all times there was close agreement between stainable and culturable bacilli in the lungs.4. During the lag phase, the bacilli occurred as widely scattered, often weakly acid-fast cells that were difficult to defect by Ziehl–Neelsen staining.5. Active removal of bacilli by phagocytes is believed not to be important at this stage.6. After 5 or 6 days, clusters of bacilli, rapidly increasing in number and size and strongly acid fast, were readily detected in the lungs.
The influence of ambient temperature on the course of myxomatosis in rabbits
Authors: Marshall I. D. 
Published: May 2009

Ambient temperature profoundly affects the mortality rate and symptomatology in rabbits infected with an attenuated strain of myxoma virus. Simulated summer temperatures allowed at least 70% of infected rabbits to recover, whereas only 8% recovered when held at simulated winter temperatures. Similar fluctuating high temperatures did not reduce the lethality of rabbitpox or of a highly virulent strain of myxoma virus.On the chorio-allantoic membrane of developing chicken embryos the proliferation of myxoma virus was almost completely inhibited at 39° C., but the yield of rabbitpox virus was not reduced at this temperature.The serological response and viraemia in rabbits held under different conditions of ambient temperature were investigated. Low temperatures resulted in high titres of circulating virus and soluble antigens, whereas at high temperatures anti-body appeared early. Haemolysin production was not affected by ambient temperature.The widely variable response of rabbits infected with the attenuated strain of myxoma virus when held at mild temperatures indicates that there is a considerable variation in the innate resistance of the host to the invasion of the virus. This resistance is enhanced by high and reduced by low ambient temperatures, so that the host response is relatively uniform under these conditions. The precise nature of this innate resistance has not been elucidated.Now that attenuated strains of virus are common and many rabbits exhibit enhanced genetic resistance, seasonal temperatures will have an important influence on the mortality rate in epizootics of myxomatosis.It is a pleasure to acknowledge the skilled technical assistance of Mr A. Brand.
Transmissible drug resistance in an epidemic strain ofSalmonella typhimurium
Authors: Datta Naomi 
Published: May 2009

Among 309 cultures ofSalmonella typhimurium, phage-type 27, fifteen, isolated from eight patients, were found to be resistant to the three drugs, streptomycin, tetracycline and sulphathiazole. This triple resistance could be transferred by growth in mixed broth culture to a strain ofSkigella sonneiand back again to sensitive cultures ofS. typhimurium. In whole cultures the resistance was stable, but spontaneous loss could be demonstrated in a small proportion of the organisms in such cultures. No elimination of resistance was demonstrated after treatment with acriflavine. Resemblances to the multiple drug resistance in enteric bacteria reported from Japan are noted.The author is most grateful to Dr E. S. Anderson, Director of the Enteric Reference Laboratory, Colindale, N.W. 9, for phage-typing the cultures ofSalmonella typhimurium, and to Dr K. Patricia Carpenter, Director of the Dysentery Reference Laboratory, for supplying cultures ofSh. sonneiwhich were essential for the experimental work.
Dynamics of infection of the blood stream and internal organs of white mice withSalmonella typhiby intraperitoneal injection
Authors: Gerichter B. , Boros D. L. 
Published: May 2009

An LD 50 doseS. typhi(strain Ty was injected intraperitoneally into white mice, and the number of micro-organisms was determined after 1 min. and subsequently, in the blood, and after 3 hr. and subsequently, in the spleen and liver. The course of the infection was observed for 34 days.The number of bacteria gradually increased in the blood stream during the first post-infective hours. It was possible to differentiate by external signs from the sixth post-infective hour and onwards between sick animals and recovering ones. This difference corresponded to the bacterial concentration in the blood stream and internal organs.In the sick animals the increase in the bacterial count of blood stream continued till 9–10 hr. after the inoculation, when it reached its first peak. During the following 8 hr. a clear decrease in the blood count was evident which was attributed to the ‘clearing mechanism’ of the blood. The onset of a new bacterial rise in the blood stream appeared 18 hr. after the inoculation and reached a second peak during the further 6–8 hr.In contrast to the observed decrease in the bacterial blood count, a steady and gradual increase in the count of the internal organs was seen; it was steadily progressive till the exitus.In the recovering animals a steady decrease in the bacterial blood count was recorded. Between 24 and 26 hr. the number of micro-organisms in the blood and spleen was found to be 400 times less in the recovering animals than in the moribund ones. From 48 hr. and onwards a slow and gradual decrease in the bacterial count of the surviving animals was observed. The blood became sterile after 25 days. In the spleen and liver of the surviving animals after 48 hr. a new increase in the bacterial count is evident, accompanied by hyperplasia of the spleen. The number of bacteria reached a new peak in the liver on the third day and in the spleen on the fourth day after the infection.Subsequently a slow and gradual decrease in the bacterial count was observed in both organs, but even after 34 days a small number of persisting bacteria in the spleen and liver tissue may be found.
The bactericidal properties of compounds which protect living cells against freezing damage
Authors: Nash T. 
Published: May 2009

Most air disinfectants fail at low relative humidity. Those which remain active appear to be the same compounds which, in other circumstances, can protect living cells against the lethal damage caused by freezing to low temperatures and then thawing. The compounds are either simple glycols, whose respective activities in the two fields are already known, or the weaker Lewis bases, whose air disinfectant properties have not hitherto been investigated. It is suggested that both freezing protection and bactericidal action are due to the special solvent properties of these compounds, which come into play when most of the water usually present has been removed, by freezing or by drying respectively.I am indebted to Dr 0. M. Lidwell for the loan of air sampling equipment, and to Dr L. N. Owen and to the Shell Chemical Co. for the gift of various diols.