bluuebunny/crossref_metadata_2025 huggingface dataset:
The Disinfection of Anthrax-Infected Dried Hides in the Dry Condition by Means of Hydrogen Sulphide
Authors: Robertson Madge E.
Published: May 2009

1. Hydrogen sulphide has been found to have a destructive action on dry anthrax spores.

2. Disinfection of hard, dry, very resistant infected hide specimens, in conditions both of ease and difficulty of access of the disinfecting gas, has been obtained by treatment with hydrogen sulphide at 20° and at 37° C. in periods of 7–16 days.

3. The fact that hydrogen sulphide, in the experimental conditions described, penetrates to the middle of a bundle of leather pockets has been verified by its action in disinfecting (sometimes partially—sometimes completely) anthrax-infected threads placed in the middle of such a bundle.

4. Increase of the temperature at which treatment is carried out has been found to hasten disinfection.

5. Disinfection of anthrax-infected threads has been obtained by treatment with equal parts of hydrogen sulphide and air in 3 days at 60° C.

The author wishes to thank the Council of the British Leather Manufacturers' Research Association for permission to publish this paper, which was submitted to them in the private and confidential report for 1930 of the British Leather Manufacturers' Research Association.
Bacterial Synergism—The Formation byB. typhosusorB. coli anaerogenesfrom Mannitol of an Intermediate Substance from which Morgan's Bacillus produces Gas
Authors: Graham J. Gibson
Published: May 2009

In the operations of bacteria under natural conditions it is the general rule to find mixed cultures at work, the variability of the results depending upon many factors. Therefore it has been suggested by Holman (1928) that the general term “bacterial association” be used to cover such processes. When, however, the combined action of two or more micro-organisms effects changes which each by itself is incapable of achieving, the term “synergism” is applied. Synergism appears to be used now in a more restricted sense to describe a particular type of bacterial association, and has been defined by Fiallos (1925) as follows: “two bacilli neither of which causes the production of gas in certain compounds, may do so when artificially mixed together provided one of them is capable of producing acidity (never gas) in these carbon compounds, and the other though inert to these compounds (i.e. produces in them neither acid nor gas) is capable of producing gas from glucose.” In 1911 Penfold observed the production of gas from a glucose medium in whichB. typhosuswas growing along with a variant non-aerogenic strain ofB. coli communis, the latter having been derived from a typical gas-producing culture by selective growth on agar containing sodium monochloracetate. Although this organism had lost the power of gas-fermenting glucose it retained the power of gas-fermenting sodium formate. Castellani (1925, 1926 and 1927) states that he noted the phenomenon, which he calls “symbiotic,” in 1904 when investigating the fermentation reactions of bakers' yeast, which is not a pure culture but consists generally of two or more species of yeasts together with one or more types of Gram-negative bacilli.
A Water-borne Epidemic of Typhoid Fever
Authors: Ritchie John , Armstrong Edward
Published: May 2009

1. The outbreak of typhoid fever in the Ecclefechan Special Water District affected 55 per 1000 of the inhabitants (primary cases only).

2. The evidence available indicated the public water supply as the vehicle of infection.

3. A typhoid carrier was found employed in the water-collecting area.

4. Examination of the water pipes after excavation showed that surface pollution might gain access to the pipes conveying spring water to the collecting tank.

5. Secondary cases were few in number, and so far there is no evidence that foci of infection remain as sequelae of the outbreak.
The Influence of the Humidity of the Air on Capacity for Work at High Temperatures
Authors: Vernon H. M. , Warner C. G.
Published: May 2009

The physiological reactions of two subjects were investigated in air at a temperature of 70–100° F., and of 40–96 per cent. relative humidity. The experiments lasted 3 hours, and one of the subjects performed mechanical work (step climbing) at the rate of 14,000 kg. m. per hour.

The pulse rate was about 10 beats greater in dry air than in moist air of the same wet-bulb temperature. The winter observations agreed well with the effective temperature scale, but did not agree with the wet bulb, the dry-bulb or the kata-thermometer scales.

Acclimatisation effects showed themselves in experiments made at a dry-bulb temperature of 87° F. or more, but only very slightly in those made at 81° or less. Acclimatisation was fairly well marked in the summer, the pulse rate being 5 to 10 beats less than in the winter, and no longer agreeing with the effective temperature scale.

The body temperature corresponded with the pulse rate, for it was 0·3–0·6° F. higher in dry air than in moist air of the same wet-bulb temperature, and was 0·15° lower in summer than in winter. The winter observations agreed well with the effective temperature scale.

The skin temperature of the face was found to depend on thedry-bulbtemperature of the air, but that of the trunk showed no agreement with any of the scales. In moist air it was 1° F. lower than that of the face, and in dry air, 6° lower, owing to the cooling effect of increased sweating.

The gross mechanical efficiency fell off slightly at temperatures above 70 or 75° F. It was affected by the dry-bulb temperature of the air as well as the wet bulb, but not to the extent indicated by the effective temperature scale.

The weight of moisture lost by sweating corresponded well with the effective temperature scale. It increased gradually in consecutive experiments made in dry air, and diminished in those made in moist air.

The degree of fatigue experienced in dry air was considerably greater than in moist air of the same wet-bulb temperature, and it corresponded with the effective temperature scale.

Acknowledgments. We wish, to express our indebtedness to the authorities at the London School of Hygiene and Tropical Medicine, and especially to Dr G. P. Crowden, for the facilities offered to us in our work.
Inoculation Experiments withBacillus fusiformisisolated from Tropical Ulcer with Observations on the Bacillus
Authors: Smith E. C.
Published: May 2009

The isolation of fusiform bacilli from typical tropical ulcer is described and an account is given of the motility and staining properties of the organisms cultivated.

Experimental inoculations, both in man and animals, are recorded in tabular form and the results of the investigation discussed.
Felton Antibody: its Distribution and Purity as determined by Salting Out Methods
Authors: Brown Annie M.
Published: May 2009

The results obtained show:

1. The limits of precipitation of Felton antibody with solid ammonium sulphate in several sera; the effect on these limits of the addition of purified Felton antibody and the removal of tricresol from the serum.

2. That within these limits of precipitation small fractions can be obtained which differ from each other in their ratio of antibody to protein.

3. That the purity of such fractions throughout a given serum may be reduced by the addition of purified Pneumococcus antibody to the serum, and apparently increased by the addition of tricresol.

4. That the distribution of antibody in serum taken at intervals from a horse during immunisation changes progressively.

5. Differences in the distribution of the two antibodies in serum from a horse immunised to both Pneumococcus type I and diphtheria toxin.
The Aronson Streptococcus
Authors: Griffith F.
Published: May 2009

The characters of the Aronson Streptococcus from Prof. Neufeld's laboratory at the “Robert Koch” Institute in Berlin have been described. This coccus resembles the pneumococcus in many respects, viz. the appearance of the colonies on the surface of horse blood agar, its virulence and capsule production in mice and rabbits, the production of a specific precipitable substance in the peritoneal washings of infected mice, the formation of firm clumps and masses when mixed with homologous antiserum, the ease of production of active and passive immunity in mice and rabbits by intraperitoneal and intravenous inoculation, the alteration in the morphology of colonies, i.e. the appearance of R forms, associated with attenuation of virulence. It differs from the pneumococcus in the following features: the round shape of the cocci, bile-insolubility and the absence of autolysis in surface colonies, the beta haemolysis of deep colonies in horse blood agar, the production of a soluble haemolysin in broth cultures, the difficulty of producing active immunity in mice by the subcutaneous injection of heat-killed vaccines.

I have obtained the Aronson Streptococcus (Neufeld type), which Lance-field places in a group containing chiefly streptococci of bovine origin, from human throats, but there was no evidence in any instance that it was producing disease, and it seems probable that it is not pathogenic for man.

The results of my investigation of this strain are in agreement with those of Yoshioka (1923), Killian (1924) and Lancefield (1933, 1934).

There are in existence other laboratory strains designated Aronson Streptococcus. These have been found to exhibit specific characters identifying them with the Str. pyogenes. It is proposed that the name Streptococcus Aronson should be confined to strains possessing the characters of Aronson N above described.
The Failure of Brilliant Green and Telluric Acid as Selective Agents for the Isolation ofBacillus typhosusfrom Faeces
Authors: Horgan E. S.
Published: May 2009

1. The causes of failure of the brilliant green enrichment method for isolation ofB. typhosusare discussed.

2. It has been shown that the negative results obtained depend partly on the number of resistantB. colistrains normally present in faeces, and partly on the use of McConkey's as a plating out medium.

3. The alleged selective action of telluric acid could not be confirmed.

4. The so-called antagonism betweenB. coliandB. typhosushas been investigated, and by the use of a selective bismuth medium it is shown that this is more apparent than real in most cases.

5. However, the existence of certain strains ofB. colior similar bacteria with a specific inhibitory effect onB. typhosushas been confirmed.

6. The value of Wilson's bismuth medium for the isolation ofB. typhosushas been demonstrated.
The Precipitation Reaction. Experiments with an Antiserum Containing Two Antibodies
Authors: Dean H. R. , Taylor G. L. , Adair Muriel E.
Published: May 2009

Ofthe chemical structure of antibodies little or nothing is known. It is generally held that the specific properties of an antiserum are closely associated with the globulin fraction. An antiserum may be distinguished from a normal serum by the precipitation of some of its globulins in the presence of the homologous antigen. The formation of a precipitate in a mixture of antigen and antiserum may be explained in either of two ways: (1) The reaction which occurs when antigen is added to antiserum may produce such physical changes in the mixture that normal globulin is precipitated. The reaction takes place between two specific substances, the antigen and the antibody, and is rendered visible by the presence of a non-specific globulin which plays the part of an indicator. (2) Or we may suppose that in the process of immunisation the antigen produces a specific alteration in the structure of the globulin. That is to say, the antibody is a specifically altered globulin, which has undergone some change in its molecular structure, in virtue of which it can react and combine with the homologous antigen.
The Utility of Lanolin as a Protective Measure Against Mineral-Oil and Tar Dermatitis and Cancer
Authors: Twort C. C. , Twort J. M.
Published: May 2009

1. A mixture of anhydrous lanolin with about equal parts of olive oil was the most efficacious ointment tested for protecting our animals from mineral-oil dermatitis and cancer.

2. Some commercial products consisting of mixtures of the alcohols and esters contained in lanolin were, on the whole, less efficacious: possibly the apparent benefit was mostly due to the olive oil with which they were diluted.

3. Olive oil, glycerine, commercial soaps, etc., gave varying degrees of protection, the last being particularly useful under some circumstances.

4. In experiments with gas tars, lanolin does not appear to afford protection when relatively small quantities of it are mixed with the tar or when relatively large doses of tar are applied to the animal, before or after lanolin treatment.

5. Where the experimental conditions appear to conform more to those prevailing among most tar workers, lanolin has a definite protective action.

6. Separate application of the carcinogenic agent and the prophylactic agent as a rule results in a lower yield of tumours than applications of an admixture of the two. In this respect it is to be noted that, where the animals were treated with lanolin separately, the quantity applied was several times greater than that of the tar itself (similarly in mineral oil experiments). This, of course, was not the case in our experiments with the lanolin blends.

7. Relatively more lanolin is required to protect against gas-tar dermatitis and cancer than is required to protect against toxic oils or synthetic tars. This is probably due to the presence in gas tars of special inhibitory substances. Note the analogy in the action of small quantities of acid on mineral oils, the potency being raised, whereas larger quantities may lower it.
The natural ventilation of unheated ‘closed rooms’
Authors: Carne J. B.
Published: May 2009

The experimental method for, and analysis of, more than 300 determinations of air influx rates into two unheated ‘closed rooms’ of opposite aspects each fitted (a) with wall grating, or (b) with flue, are described. The average relative efficacy for all observed wind velocities of (a) of 50 sq.in. to (b) of 15 sq.in., so far as facilitating natural ventilation in the rooms used, is found to be 1·0. The analysis reveals definite and complex relations between influx rate and wind velocity. A correlation is made with data from other sources, principally photographs of the flow forms of air streaming past grounded house models, and a theory is advanced to explain the broad features of the observations. Comparison with similar published work is made, and the fundamental necessity of simultaneous measurement of the speed and direction of the main wind stream is stressed. The advantage of the flue and the importance of openings, other than those in the room concerned, are pointed out.

The author wishes to record that the investigation was commenced at the instigation of Mr Dean Chandler, to whom he is indebted for en-couragement to publish the results of the further examination of the data obtained. He desires also to acknowledge the enthusiastic interest in the experimental work which his colleagues of the Physical Laboratory displayed throughout the investigation.

The measurements of the wind velocity, so essential to the completeness of the observations, frequently necessitated the scaling of roofs in snow, rain and gale, yet at no time were they neglected.

The author thanks Dr E. V. Evans, General Manager and Director of the South Metropolitan Gas Co., for granting permission to publish the paper.
The incidence of natural diphtheria antitoxin in horses: its influence on the results of antigenic stimulus
Authors: Basu P. N. , Roy R. N.
Published: May 2009

1. Out of 221 horses tested 34·8 % showed natural diphtheria antitoxin to the extent of 0·02 unit or more per c.c. of serum.

2. Amongst the horses in which no natural circulating antitoxin was detected, a much larger number failed to respond to stimulus than amongst those having circulating antitoxin. But, amongst the animals that did show appreciable response to primary stimulus, there was not much difference in degree of response between the horses with and those without natural circulating antitoxin.
Effect of continuous aeration on bacterial oxidation of organic matter
Authors: Allen L. A. , Eden G. E.
Published: May 2009

Growth of bacteria in an infusion of flax under quiescent conditions resulted in the formation of an acidic liquor with an appreciable content of volatile acids. When a similar infusion was aerated by a continuous current of air, the liquid tended to become alkaline and the content of volatile acids was much smaller and in some cases negligible. Aeration reduced the polluting strength of the liquor, as measured by oxygen absorbed from permanganate and by the biochemical oxygen demand, by much larger amounts than did growth under quiescent conditions.

Experiments with infusion in which the natural flora was allowed to grow, and with sterile infusion inoculated with pure strains of different types of bacteria, showed that the general effect of aeration was to alter the metabolism of the bacteria in the direction of more complete oxidation of the substrate. Balance sheets for carbon showed that the organic carbon lost from the culture was accounted for by the CO2evolved. Thus carbohydrates, which under anaerobic conditions were fermented to organic acids, neutral volatile compounds, and gases, were oxidized, when the conditions were sufficiently aerobic; to CO2and water.

The magnitude of the effects observed depended largely on the nature of the organisms present, and partly on the strength of the infusion in which they grew. With pure cultures ofBact. coli, Bact. aerogenesandBacillus subtilis,and with the natural mixed flora of the flax, aeration at moderate rates in bottles for 3–5 days reduced the value for oxygen absorbed from permanganate by 43–52 %, and the biochemical oxygen demand by 26–92 %, indifferent experiments. The organic carbon content of the infusion was reduced by 30–31 % byBact. aerogenes,byBacillus subtilisand by the mixed flora. With streptococci and with a strain ofAchromobacteriumthe effects observed were very small. Aeration at higher rates with diffused air in small open tanks reduced the organic carbon content of a flax infusion by 50 % in about 80 hr., and of a beetroot infusion by 50 % in about 60 hr. Sugar was destroyed during the aeration and disappeared rapidly from the flax infusion in the early stages.

The work described in this paper was carried out in connexion with an investigation of retting of flax and disposal of waste waters, made, as an extramural research, for the Ministry of Supply as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research. The paper is published by permission of the Chief Scientific Officer, Ministry of Supply, and of the Department.
Detection of Q fever antibodies in whey by the anti-globulin sensitization test and other techniques
Authors: Stoker M. G. P. , Marmion B. P.
Published: May 2009

1. Samples of whey from individual cows and herds infected withR. burnetiand from uninfected cows and herds have been tested forR. burnetiantibodies.

2. The haemolytic complement-fixation test, the conglutinating complement-absorption test, the direct agglutination test and the anti-globulin sensitization test were compared for sensitivity in detecting whey antibody.

3. The direct agglutination test was generally more sensitive than either of the complement-fixation tests, particularly when it was enhanced by centrifugation of the sensitized rickettsiae. The anti-globulin sensitization test, however, gave the highest titres andit appeared to be specific.

4. The practical application of these techniques and certain theoretical considerations are discussed.
The conglutination phenomenon. VIII. A. quantitative study of the components in six different complements essential for conglutination
Authors: Blomfield A. M.
Published: May 2009

1. A quantitative study has been made of the activity of C′1, C′2 and C′4 in the complements of the horse, cat, pig, man, guinea-pig and rabbit.

2. Evidence is presented which suggests that either there may be two types of C′4, the one haemolytic and the other conglutinating, or else that the manifestation of this complement component varies under conditions not yet understood.

3. In certain complements it appears that the serum proteins functioning as C′1 with the bovine anti-sheep red cell antibody are distinct from those functioning as C′1 with an antibody of similar specificity from an immune rabbit serum.
Internal bacterial taints (‘bone taint’ or ‘souring’) of cured pork legs
Authors: Ingram M.
Published: May 2009

1. The kinds of bacteria found inside hams and bacon gammons are listed and discussed.

2. Taintinǵ of lightly-or un-injected hams is caused by a flora composed chiefly of various faecal Clostridia and/or faecal Streptococci, which are probably intrinsic to the animal's body. In bacon gammons which are heavily injected with brine, the characteristic flora consists of psychrophilic halophiles, mostly Micrococci, probably derived mainly from the brine; if injection is only partly effective, the intrinsic flora may develop also, faecal Streptococci being the type most likely to survive.

3. Within sound hams, bacteria are virtually absent; in tainting, the numbers may become enormous even before curing is finished. Injected gammons, on the contrary, generally contain bacteria in moderate numbers, but they multiply relatively slowly.

4. In hams, the taint is always confined within a group of muscles near the bone which are less acid, and initially less salty, than the outer muscles. In gammons, off-flavours caused by bacteria may occasionally develop in the outer layers as well.

5. A ham properly cured without injection, and internally ‘ sterile’, can be made to keep almost indefinitely. The bacteria injected into gammons slowly cause internal off-flavours even in cool storage. For long storage, it would seem wise to sterilize brine used for injection, and the addition of acid might be beneficial.
Arthropod transmission of rabbit fibromatosis (Shope)
Authors: Dalmat Herbert T.
Published: May 2009

The mosquitoes Aedes aegypti, A. triseriatus, Culex pipiens, C. quinquefasciatus, and Anopheles quadrimaculatus were all found to be efficient experimental vectors of Shope's virus-induced fibromas of cottontail rabbits, transmitting the virus during interrupted feedings as well as after long intervals from an infective meal. The reduviid bugs, Triatoma infestans, T. phyllosoma pallidipennis and Rhodnius prolixus, and the bedbug, Cimex lectularius, were also capable of transmitting fibroma by interrupted or delayed feeding.

Evidence from various types of experiments indicated that arthropod transmission is mechanical, the virus being extremely stable in the insects. Some experiments did indicate the possibility of virus proliferation. Although mosquitoes did seem to serve as ‘flying pins’ when transmitting virus by interrupted feeding, they certainly were distinctive in that they maintained their ability to transmit for very long periods of time. To transmit fibromas, arthropods actually must draw virus up between the stylets of the mouthparts; mosquitoes were unable to transmit by feeding through skin moistened with a suspension of fibroma virus or by feeding subsequent to having their mouthparts painted with a virus suspension.

While cottontail tumours at peak virus titres are always infective for suitable insects, the fibromas of adult domestic rabbits generally are not infective, even though the virus titre is equivalent. However, the tumours of suckling domestic rabbits do become infective for insects.
The influence of the age of the host on local virus multiplication and on the resistance to virus infections
Authors: Mclaren Anne , Sanders F. K.
Published: May 2009

1. The susceptibility of mice of different ages to intramuscular, intraperitoneal, and oral administration of EMC virus, and to intracerebral and intramuscular injection of both the Texas and the Connecticut-5 strains of Coxsackie virus have been studied. In all cases susceptibility decreases with age. The development of resistance to a given virus may vary in rate and extent according to the route by which the virus is given.

2. The multiplication of small amounts of EMC virus in muscle, and of the Texas and Connecticut-5 strains of Coxsackie virus in both muscle and brain, has been studied in mice of different ages. A very high degree of multiplication of all three viruses was observed in both muscle and brain of young mice, but no significant multiplication of the EMC virus in older muscle could be detected with these small inocula, nor of either of the Coxsackie strains in older muscle or brain.

3. Multiplication of EMC virus in young mice was shown to take place within the muscle itself. Haemagglutination tests showed that less haemagglutinin, as well as less infective virus, was produced in the muscles of older mice following the injection of small amounts of virus.

4. Multiplication of EMC and GDVII viruses could be demonstrated even in older mice if a sufficiently large amount of virus was inoculated initially.

5. The rapid initial disappearance of infectivity from the site of inoculation was shown to be mainly due to dispersal of inoculated virus around the body.

6. The simplest hypothesis which will accommodate the observed data on virus multiplication and on the development of resistance with age appears to be that the accessibility of the host cell to virus decreases with age. We found no evidence that the ability of the host cell to support virus multiplication declines with age.

This work was done in the Department of Zoology, Oxford University. One of us was in receipt of a Medical Research Council training grant. The expenses of the research were met by a grant from the Nuffield Foundation, to whom we should like to express our gratitude.
Grading of coagulase-positive staphylococci in the control of hospital cross-infection
Authors: Thomas C. G. A. , Penikett E. J. K.
Published: May 2009

The fermentation of mannitol by coagulase-positive staphylococci has been studied. It was found difficult to obtain reproducible results by methods which could be conveniently used in a routine department.

A method of grading based on the fermentation of mannitol has been examined. Organisms of the supposedly most dangerous grade (Grade A) were isolated slightly more frequently from lesions than from carriers, but from all sources a high proportion of strains belonged to this grade.

It was not possible to correlate the grades to which staphylococci were assigned with their production of diffusible antigens.

In this hospital it seems that the proportion of strains assigned to Grade A has become very much higher than it was 15 years ago.

We thank Prof. R. Knox, Mr J. B. Blaikley, Dr W. H. H. Merivale, and Dr R. H. Gorrill for the help and advice they have given us in the course of this investigation and numerous members of the nursing staff of Guy's Hospital for their co-operation in checking records and answering questions.
Estimate of molecular equivalents of antibody required for prophylaxis and therapy of poliomyelitis
Authors: Stevens K. M.
Published: May 2009

Calculations have been carried out which suggest that as few as 6 × 104molecules of anti-poliovirus antibody per millilitre of serum may be sufficient to prevent the clinical disease under certain epidemic conditions. Other calculations have been made involving therapy of the experimental disease in monkeys and certain factors required for successful serum therapy have been discussed.
Further experiments on the adaptation of Mahoney, Type 1, poliomyelitis virus to suckling mice
Authors: Selzer Golda , Butchart M.
Published: May 2009

The Mahoney, Type 1, poliomyelitis virus had been through six to-and-fro monkey kidney-tissue culture and suckling mouse passages. Early paralysis was produced in groups of mice inoculated directly from infected tissue-culture fluid, but mouse-to-mouse passage failed to produce paralysis except in an occasional mouse. At the 7th tissue-culture mouse passage, the virus harvested from paralysed mice was inoculated into 100 mice. One mouse developed paralysis within 24 hr. From this mouse a variant of Mahoney virus was isolated which has now been through seventy-five mouse-to-mouse passages and produces paralysis in 90–100% of mice within 3 days.

The authors would like to express their deep appreciation of Prof. A. Kipps' constant interest and encouragement.
The health of laboratory mice A comparison of general health in two breeding units where different systems are employed
Authors: Tuffery A. A.
Published: May 2009

Two units, within a mouse-breeding colony, with different breeding systems, have been compared from the point of view of general healthiness of the breeding stock. In one unit the monogamous-pair system, involving post-partum oestrus mating, was employed and in the other the harem system, with isolation of the pregnant females for each litter-down until after the post-partum oestrus. The two units were housed separately and had different staffs. The monogamous-pair unit was accommodated in four small rooms not directly connected; the harem unit in two larger connecting rooms. The methods of cageing, bedding, feeding, watering, care, culling and subsequent procedures were identical for both units and the same system of recording individual detailed information relating to health and breeding was followed for the two units. The size of the two populations studied was 1198 and 1024, respectively, the larger number belonging to the harem unit in which the mice were retained for a significantly longer period. These mice were moved more frequently and handled much more often.

Apart from a small outbreak of Tyzzer's disease (in the harem-bred unit) and sporadic cases in both units spread over the whole period of the survey—some 3–4 years—the general health of the two units was good. There were no cases of salmonella infection, mousepox, pasteurellosis or other serious infections. Throughout the period both units maintained a high standard of productivity and there was no evidence that the mating of the monogamous pairs at the post-partum oestrus led to any weakness or ill health. As would be expected, however, the losses from death and culling were greater among the females in both units.

The health record of the monogamous-pair bred unit was consistently higher than that of the harem-bred unit. There were more cases of Tyzzer's disease in the harem-bred mice and more evidence generally of ill health in this unit. Infertility was three times greater with the harem-bred mice as compared with those in the monogamous-pair unit.

Details of the two systems are discussed and although the records maintained for the two may not be strictly comparable it is concluded that, under the conditions obtaining, the monogamous-pair breeding system yielded a healthier colony of mice than the harem breeding system.

I should like to thank Dr J. S. Patterson and Mr R. Cook for placing many of their records at my disposal, Mr S. Peto and his staff for carrying out much of the tedious compilation of data, and Dr D. W. Henderson, F.R.S., for affording me facilities for this work. To these I am especially grateful for their interest, advice and assistance.
Diphtheria-tetanus-pertussis vaccine combined with Bordetella parapertussis vaccine
Authors: Köhler-Kubelka Neda
Published: May 2009

Investigations carried out to ascertain the ability of various strains of Bordetella pertussis and B. parapertussis to produce agglutinins have shown that the agglutinin response is considerably greater with B. parapertussis.

Children inoculated with a combined vaccine in which the parapertussis element contained B. parapertussis in only one-twelfth of the concentration of B. pertussis in the pertussis element showed agglutinins in their sera in titres well above 1:300 for both organisms. There were no cross-reactions and the serological responses were specific throughout. The vaccine used was the standard diphtheria-tetanus-pertussis (DTP) prophylactic to which had been added a vaccine prepared from recently isolated strains of B. parapertussis.

Agglutinin titres of both whooping cough components with the combined vaccine were somewhat lower in mice than was the case when monovalent vaccines were used, but they were considered to be satisfactory.

It is suggested that the agglutination production test in mice could be used for the assessment of protective power of B. parapertussis vaccines against infection.

I wish to thank Dr Ikić, director of the Institute of Immunology, Zagreb, who enabled me to perform all these examinations, further to Dr B. Mravunac and Dr Z. Radanov for having carried out vaccination in children and for the clinical examination of post vaccination reactions.
The titration of toxoplasma-antibody
Authors: van Soestbergen A. A.
Published: May 2009

In toxoplasma-antibody titrations with the dye-test the tolerances of the parasite Toxoplasma gondii are approximately normally distributed on the logarithm of the serum dilution. Log LD 50 (the logarithm of the titre), the variance of the tolerance distribution and the variances of the sample distributions were estimated by probit analysis of data obtained with titrations of a serum which contained the antibody. An empirical expression was derived relating the fraction of parasites attacked by the antibody to the time of incubation with the antibody. Approximately the same values for the titre and the variance of the distribution were obtained for every incubation period between 20 min. and 4 hr.

The author is indebted to Mr J. C. A. Zaat and to Dr E. F. Drion of the Statistical Division of the Central Organization TNO for helpful discussions and assistance with the statistical calculations. The technical assistance of Miss A. K. Fast is gratefully acknowledged.
On combining estimates of relative potency in bioassay
Authors: Bennett B. M.
Published: May 2009

Biological assays based on a quantitative response in particular (e.g. hormone assays) typically involve the estimation of (log) relative potency (=M) with respect to some standard preparation on the basis of one or more symmetrical determinations usually at equally spaced (log) dose intervals. It is the purpose of this paper to consider further statistical aspects of estimates ofM, and especially confidence limits forMbased on a combination of separate assays. These are given as examples of tests of linear hypotheses. Two applications are given on the combining of quantitative bio-assay data.
An improved smallpox vaccine
Authors: Amies C. R.
Published: May 2009

Detailed instructions are given for the preparation of a purified and stabilized suspension of vaccinia elementary bodies. This is intended to take the place of crude glycerinated calf or sheep lymph vaccine. The technique consists of a series of procedures involving mechanical disintegration of the skin pulp, maintenance of dispersion by means of a non-ionic detergent, fractional centrifugation and bacterial disinfection. Stability of the purified virus is secured by suspending it in a dilute buffer containing peptone and polyvinylpyrrolidone. Experiments are described which illustrate the remarkable heat resistance of the virus in this suspending medium. The PVP-peptone also serves as an excellent menstruum for lyophilization. Production of this vaccine should be well within the competence of any properly equipped virus laboratory. Clinical trials are in progress.

All the work involved in the performance of the tissue culture assays was carried out by my former assistant Mr Edmund Bischoff. It is a pleasure to acknowledge both his technical skill and his enthusiasm. Mr T. C. Campbell provided the crude calf pulp used in the preparation of some of the purified suspensions.
A note on two attenuated strains of myxoma virus isolated in Great Britain
Authors: Chapple Paul J. , Bowen E. T. W.
Published: May 2009

Two strains of myxoma virus isolated from naturally infected wild rabbits have been described. They showed similar clinical symptoms, the most striking feature being the flat primary lesion. In fifteen rabbits the Brecon strain gave a mean survival time of 26·3 days with a range of 17–47 days, and one recovery. Of 5 rabbits inoculated with the Durham strain three became clinically infected and two remained healthy, the latter were found to be fully susceptible on reinoculation. The three infected rabbits all recovered.

The field strains of virus were compared with known myxoma strains—Glenfield, Cornwall, A & H and KM 13. The first three are fully virulent, while KM 13 is attenuated and characteristic of the field strains now being isolated in Australia. The similarity between the clinical symptoms and mean survival time of KM 13 and the Brecon strain was noted.

It is suggested that the two field strains described in this paper may be the first indication that the evolution of myxoma virus in this country is similar to the evolution of the virus in Australia.

One of us (P.J.C.) is greatly indebted to the Director for allowing this work to be carried out at M.R.E. whilst laboratory accomodation was being prepared at Worplesdon. We are grateful for the help and encouragement of Dr J. C. N. Westwood of M.R.E. To Prof. F. Fenner who gave us the Australian strains of myxoma virus and to Mr J. H. Darbyshire of the Central Veterinary Laboratory who supplied the tissues from which the two attenuated strains were isolated, we extend our thanks.
Antigenic differences between strains of foot-and-mouth disease virus of type SAT 1
Authors: Hyslop N. St G. , Davie J. , Carter Sally P.
Published: May 2009

Antigenic differences between the strains RV 11 and SA 13/61 of foot-and-mouth disease virus (type SAT 1) were studiedin vivoby cross-protection tests. Cattle inoculated with formolized antigen of either strain developed good immunity to experimental infection with the identical strain but little resistance to the other strain.

In vitrothe results of complement fixation tests and of serum-virus neutralization tests in tissue culture were consistent with the observations madein vivo. The results of studies on the serological relationships between four strains of type SAT 1 are presented.

The importance of strain differences in the epizootiology and control of the disease is discussed briefly.

The authors wish to thank Dr I. A. Galloway and Dr J. B. Brooksby for their advice and criticism, and to acknowledge the valuable technical assistance of Mr K. Herniman, Mr R. L. G. King and Mr E. Scoates.
Variations in the clinical pattern of experimentally induced colds
Authors: Roden A.T.
Published: May 2009

An analysis has been made of the records of 5290 attendances at the Common Cold Research Unit, Salisbury, during the years 1946 to 1957. Materials prepared from the nasal washings of persons suffering from colds were administered to 993 volunteers, of whom 386 (38·9 %) showed definite evidence of infection within a few days. The attack rate of these experimentally induced colds was lower during the months October to March than from April to September. The difference was statistically significant as regards male but not as regards female volunteers.

Six strains of virus were propagated by passage from volunteer to volunteer, in one instance up to the eighth serial transfer from the original material, without apparent loss of pathogenic properties. Comparison of the clinical effects of these strains, and of a number of miscellaneous strains, revealed several differences which were minor in character but, statistically, highly significant. These comprised differences in attack rate, severity, incubation period, duration and relative frequency of symptoms, which could not be ascribed to seasonal or other influences.

It was concluded that the observed variations in the clinical pattern of the experimentally induced colds were attributable to qualitative differences in the strains of virus used.

I wish to thank Sir Christopher Andrewes, F.R.S., for his unfailing help and encouragement at every stage of this investigation and all my colleagues at the Common Cold Research Unit for much useful comment and discussion. I am indebted to the Statistics Department of the Ministry of Labour and National Service for processing the records and to Mr R. G. Carpenter for assistance with some of the statistical analyses.
Naso-pharyngeal carriage of Haemophilus influenzae type B
Authors: Turk D.C.
Published: May 2009

H.influenzae type b, the sero-type which causes meningitis, was isolated from 3 (2·4 %) of 127 naso-pharyngeal swabs from white non-Jamaican children resident in Jamaica, and from 14 (2·9 %) of 473 such swabs from a mixed group of Jamaican children. Much higher frequencies were found in households in which cases of haemophilus meningitis had recently occurred (41 %), in the nursery of an orphan home (up to 70%) and in a day-nursery. In the orphan home nursery the high frequency persisted over a number of months, but no case of meningitis or other relevant disease occurred. A high concentration of this organism is therefore compatible with normal health, and the significance of high concentrations in the homes of meningitis patients is not certain.

I am indebted to the Standing Advisory Committee for Medical Research in the British Caribbean for a grant towards the cost of materials; to a number of colleagues at the University College of the West Indies, notably Dr E. H. Back, Senior Lecturer in Paediatrics, and the staff of the Department of Social and Preventive Medicine; to those in charge of the orphan home, the day-nursery, the play-school and the other institutions visited; to many cooperative parents and children and to my wife for help in the collection of specimens.
A trial of reinforcing doses of diphtheria toxoid absorbed through the buccal mucosa
Authors:   A Report by the Public Health Laboratory Service and the Manchester Education Committee School Health Service
Published: May 2009

Diphtheria toxoid lozenges were given to eighty-eight children aged 10–12 years who had previously been immunized by parenteral injection, and the antitoxin titres before and after administration were compared with those in a similar group of forty-six children who received formol toxoid by injection.

The results showed that a course of two lozenges at an interval of 1 week was a satisfactory means of reinforcing immunity in the children. The antitoxin response was less than that after injection, but a substantial response occurred in the children with low initial titres.

It is suggested that the lozenges might replace an injection as a means of reinforcing immunity in children aged 10–12 years and that they might be a valuable means of rapidly reinforcing the immunity of a large number of children in an epidemic.

The lozenges must be given under supervision to ensure that the children allow them to dissolve slowly in their mouths.

We should like to thank Dr J. D. Abbott of the Public Health Laboratory, Manchester, for separating the sera.
The use of gamma radiation for the elimination of salmonellae from various foods
Authors: Ley F. J. , Freeman Barbara M. , Hobbs Betty C.
Published: May 2009

Studies on the use of gamma radiation for the elimination of salmonellae from whole egg, frozen horse-meat, desiccated coconut and bone meal show the extent to which the nature of the medium influences the resistance of these organisms to gamma radiation. There is also a variation in radiation resistance between different serotypes; S. typhi-murium was consistently the most resistant of those examined.

Based on experiments with artificially inoculated or naturally contaminated products, and also on dose/survival curve data, the dose requirement for the elimination of salmonellae from frozen whole egg is estimated at 0·5 Mrad., which gives a 107 reduction in numbers of S. typhi-murium; for frozen horsemeat 0·65 Mrad., giving a 105 reduction; and for bone meal between 0·5 and 0·75 Mrad., giving between 105 and 108 reduction. A dose of 0·45 Mrad. appears effective for desiccated coconut, with a reduction of 103, but such a radiation dose affects the quality of this product.

We are grateful to Dr E. S. Anderson of the Enteric Reference Laboratory for phage typing and for the provision of a strain of S. typhi-murium for experi ments. Also we thank Dr Joan Taylor of the Salmonella Reference Laboratory for the serological typing of salmonellae, and Miss M. E. Smith and other colleagues of the Food Hygiene Laboratory who carried out the routine bacteriological examination.

We wish to thank Mr N. C. Roberts of J. Rannoch Ltd. for his co-operation in the large-scale frozen egg experiment, and also Mrs G. M. Ison of S. Wallace Ltd. in respect of the experiment on frozen horse-meat.
The kinetics of influenza-virus adsorption on iron oxide in the process of viral purification and concentration
Authors: Larin N. M. , Gallimore P. H.
Published: May 2009

This paper reports a study carried out to clarify the mechanisms involved in adsorption of influenza A and B viruses on iron oxide. Accordingly, the amounts of virus that are adsorbed from virus suspensions of varying concentrations per unit surface area of magnetic or non-magnetic oxide at fixed temperature and time have been determined. The principles involved are clearly the same as those involved in multiple equilibria during the interaction of particles with a large number of combining sites with different intrinsic affinity. Consequently, the amount of virus that is adsorbed per unit mass of iron oxide depends on the size of the adsorbent area, not on its magnetic property. Owing to a significant difference between the affinities of influenza A and B particles for the binding sites on iron oxide, unit surface area of the adsorbent is invariably capable of adsorbing significantly greater amounts of influenza A than B particles. The practical implications of these findings are that a better understanding of the mechanisms involved in virus adsorption on iron oxide will permit a more efficient separation of virus particles from impurities. The simplicity and the rapidity of the technique and the cheapness of the equipment required suggest that the iron oxide method is of great value for both small- or large-scale viral purification, whether it is used as a single step procedure or as a primary step followed by zonal separation.
Antigenic properties of the envelope of influenza virus rendered soluble by surfactant-solvent systems
Authors: Larin N. M. , Gallimore P. H.
Published: May 2009

Dissociating chemical treatments employing surfactant-solvent systems were applied to purified influenza A and B viruses to obtain viral preparations possessing a significantly higher or lower haemagglutinating activity than the intact virus. All preparations, whether with high or low haemagglutinating activity, with the exception of envelope protein solubilized by Triton X-100, were significantly lacking in the ability to excite the formation of haemagglutination-inhibiting and virus-neutralizing antibodies in inoculated ferrets. In contrast to other treatments, Triton X-100 treatment of virus significantly enhanced the antigenicity of viral protein as judged by virus neutralization and haemaggmtination inhibition tests. Yet the haemagglutinating activity of the envelope protein solubilized with Triton X-100 was about 1 % that of the intact virus. Results suggest that the correlation assumed to exist between the haemagglutinating activity of influenza virus and its ability to excite the formation of humoral antibodies is coincidental. Another important point is that the specific antigenicity of viral protein may be lost or enhanced owing to effects, other than solubilization, by surface-active agents.