bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further experiments on the golden hamster (Cricetus auratus) with tubercle bacilli and the vole strain of acid-fast bacillus (Wells)
Authors: Griffith A. Stanley 
Published: May 2009

Subcutaneous inoculations: Two strains of human origin were tested, one was of eugonic human type from the sputum of an English case of pulmonary tuberculosis; the other was of dysgonic human type obtained by Dr J. A. Young from a native in Nigeria. Both strains produced typical general tuberculosis in the hamster, the lesions on the whole showing less caseation than those set up by bovine bacilli (vide 1939).The vole strain of bacillus gave rise to generalized disease resembling tuberculosis. The duration of life of the animal was, however, prolonged and though the bacilli were abundant in the lesions there was no necrosis or caseation. Similar results in two hamsters were reported in 1939.The avian bacillus was the least pathogenic of the four types. Of the three hamsters inoculated only one (H. 17, dose 5·0 mg.) showed macroscopic foci in the liver and spleen; as these were not seen microscopically in sections it is doubtful if they were due to the action of tubercle bacilli. It is unfortunate that the specimens of Hamster 17, which died in my absence from the laboratory, were badly fixed; a smear preparation of the spleen was not made. In the others tubercle bacilli were found in the organs, but were not numerous. The peculiar result after 5·0 mg. of avian bacilli—enormous multiplication of bacilli in spleen, liver and a local gland without macroscopic tuberculous lesions—described in the first paper was not reproduced.Feeding: The four different types of bacilli were given by the mouth to six hamsters, the dose in each instance being 10 mg. of culture. Two of the hamsters, one fed with a potato culture of the vole strain, the other with a human strain, escaped infection. The remaining four hamsters, each fed with one of the four types of bacilli, developed disease, the severity of which in each instance was in harmony with that following subcutaneous inoculation of the type.
Infection of adult cattle with Mycobacterium tuberculosis avium
Authors: Glover R. E. 
Published: May 2009

A series of 35 unselected cattle tested with synthetic medium tuberculin and synthetic medium johnin was subjected to post-mortem examination. In five instances (14·3 %) avian strains of full virulence for the usual experimental animals were recovered by the inoculation of guinea-pigs with glandular suspensions or by cultural methods used for the isolation of Johne's bacillus: in two of these cases an avian type was isolated from the glands of the alimentary tract and a bovine type from the thoracic glands. In addition there were five cases (14·3%) in which evidence of avian infection was not complete. From one a strain was obtained which was culturally identical with an avian type, but it was almost completely avirulent for laboratory animals. In two, acid-fast bacilli were seen in smears from the thoracic and mesenteric glands respectively, while in two, completely calcified glands were observed which were typically tuberculous, but were devoid of acid-fast bacilli (microscopical examination of smears and sections). Cultures from the organs of guinea-pigs inoculated with glandular suspensions from the four last-mentioned cases failed to grow tubercle bacilli. In these circumstances the evidence that the infection was of the avian type is largely presumptive, but the nature and extent of the lesions suggests that such may have been the case.With, regard to the tuberculin and johnin tests, clear cut reactions to johnin were obtained in seven instances, a doubtful reaction in one and negative reactions in two. One-half of the animals were also positive to tuberculin.
The administration of vitamin C in a large institution and its effect on general health and resistance to infection
Authors: Glazebrook A. J. , Thomson Scott 
Published: May 2009

1. The vitamin C in the dietary of an institution was largely destroyed by the methods of cooking and distribution.2. Some 50 mg. of ascorbic acid per head per day were required to be added to the diet to produce an optimum excretion level.3. Large doses of ascorbic acid were given to a group of adolescents in the institution over a period of several months. A record was kept of the incidences of infectious diseases in this treated group and in the remainder (controls). The following conclusions were reached:(a) The incidences of common cold and tonsillitis were the same in the two groups.(b) The average duration of illness due to the common cold was the same in the two groups.(c) The duration of illness of tonsillitis was longer in the control group than in the test group.(d) Cases of rheumatic fever and pneumonia occurred in the control group but no case of either disease occurred in the test group.
Diphtheria amongst the Bantu
Authors: Murray J. F. 
Published: May 2009

1. A total of 499 rural and 437 urban Bantu school children were examined for their diphtheria carrier rate and Schick immunity.2. Clinical diphtheria amongst the rural and urban Bantu was also investigated.3. The virulent C.diphtheriaecarrier rate was found to be 3·2% in the rural children and 1·8% in the urban with virulent/avirulent ratios of 1: 1·1 and 1: 2·5 respectively.4. The Schick-positive rate in children aged 6–17 years was found to be 8·0% in rural children and 13·7 % in urban.5. Clinical diphtheria was rarely encountered under rural conditions, but was more common in urban natives.6. The case mortality rate in eighty-nine clinical cases was 14·4%.7. 53% of the clinical cases occurred in the 0-5 years age group.8. 89% of the strains recovered belonged to themitistype. No intermediate strains were encountered.9. The reason for the infrequency of clinical diphtheria amongst the Bantu is discussed and various theories are reviewed.10. It is concluded that the infrequency of clinical diphtheria is partly due to the environment, but that there is also a racial factor. It is suggested that the racial factor lies in an ability to produce antitoxin quickly. There is not sufficient evidence in this investigation to show whether the racial factor is genetic, but in view of Turbott's work amongst the Maoris it is suggested that the racial factor in immunity to diphtheria may be genetic amongst the Bantu also.I have pleasure in acknowledging the continued interest of Dr E. H. Cluver, Director, and Dr G. Buchanan, Deputy-Director, of the South African Institute for Medical Research in the progress of this work. I also wish to acknowledge gratefully the help given me by Dr Prestwick, Dr Miller and Dr Xuma at Alexandra Township. I am indebted to the Administration, and in particular to Dr J. W. Stirling, Principal Medical Officer of Bechuanaland Protectorate Government, for permission to carry out the investigation at Kanye. To Dr Marcus of the Seventh Day Adventist Mission, Kanye, I am deeply indebted for help and hospitality, and to Chief Bathoën who assisted me in making contact with the requisite number of school children at Kanye. My thanks are also due to the Mother Superior and Sisters of the Holy Cross Mission, Alexandra Township, and the many Bantu school teachers who gave me access to the children in their charge. Mr Barnes (S.A.I.M.R.) very kindly carried out the statistical tests of Tables 1 and 2. The travelling expenses involved in this work were defrayed by a grant from the National Research Board.
Studies in immunization by a species antigen: I. The presence of ‘species antigen’ and of ‘opposition factor’ in bacteria other than pneumococci
Authors: Day H. B. 
Published: May 2009

The experiments here described proved that preparations made from widely different classes of bacteria are capable of inducing immunity in mice against pneumococci. The success of these preparations was found to depend on the differential separation of an active immunizing antigen from another bacterial constituent—an ‘opposition factor’—which interferes with immunization. Further investigation and comparison depend largely on the discovery of a really effective method for the isolation and purification of the active antigen. Until its chemical nature is determined, the identity of the pneumococcal species antigen with similarly acting substances found in other bacteria remains unproved.Pathogenic bacteria depend for their virulence and invasiveness on certain products individual to the species or type, and specific immunity is due to the development of the appropriate antibodies. But chemotherapy, as in the case of the sulphonamides, interferes with a less specialized metabolic process of the microbes and is neither species nor type specific in action. It is reasonable to infer that bacteria may possess in common a vital process associated with the presence of a common constituent which may be antigenic. ‘Species antigen’ may be a substance of this nature.In view of the wide distribution of ‘species antigen’ among bacteria generally, it is probable that this constituent has already been separated and named in accordance with its presence in a particular species, but irrespective of its potential immunizing capacity.So far as pneumococci are concerned, there is good evidence that species antigen may be identical with the species C carbohydrate. Tillett (1927) found that rabbits injected with successive courses of heat-killed pneumococci, whether of types I, II, III or of avirulent rough strains, developed an equal increase of resistance to infection by type III Pneumococcus. In 1936 Enders, Wu & Shaffer varied the procedure, and by injections of rough pneumococci prepared an antiserum which gave passive protection to rabbits against infection by type III Pneumococcus. This antiserum lost its protective power after absorption with the species C carbohydrate.
Diphtheria in Glasgow 1934–42
Authors: Carter H. S. 
Published: May 2009

1. A general survey of diphtheria in Glasgow during 1934–42 has been made. Over 11,000 strains ofC. diphtheriaehave been typed and the incidence of the types is recorded.2. The period has been marked by a change in the predominant type of organism fromintermediustogravis, andgravisinfections are now responsible for most of the mortality, though the average case fatality rate due to them is not high.3. Diphtheria on the whole has been mild and complications relatively few, but some shift in the death-rate incidence to the higher age periods with increase in the corresponding case fatality rate has taken place. A small shift in the age incidence of diphtheria is noted.4. Some account of the effect of immunization is given.5. Comment is made upon colony variation among the types ofC. diphtheriae.
The epidemiology of Q fever
Authors: Derrick E. H. 
Published: May 2009

In seven years 176 cases of Q fever have been diagnosed in Queensland. Nearly all the 129 patients who lived in Brisbane were associated with meat works. Most of the forty-seven country patients worked on dairy farms.Investigation of native animals, cattle and ticks, has indicated in outline the natural history of Q fever, which is set out diagrammatically in Fig. 1. (Several steps in this outline need confirmation and much detail remains to be filled in.)First there is a basic cycle of infection with the bandicoot (and probably other bush animals) as reservoir, andHaemaphysalis humerosa(and probablyIxodes holocyclus) as vector. A bush worker may interrupt this cycle and get Q fever from the attack ofIxodes holocyclus.Cattle become infected, probably throughIxodes holocyclusand perhaps through other ticks. It is possible that there is a secondary cycle: cattle-Haemaphysalis bispinosa-cattle.Ticks on the cattle (Boophilus annulatus microplusorHaemaphysalis bispinosa) are probably the source of human infection. It is suggested that inhalation of tick faeces is the likely mode of entry ofRickettsia burneti.
The typing of strains of Bact. paratyphosum B by the biochemical method of kristensen and Bòjlen
Authors: Macnaughtan Jean 
Published: May 2009

Results are given of the typing (by biochemical fermentation tests) of 290 strains of Bact. paratyphosum B isolated during an epidemic in the north of Scotland. Of these strains 283 were of type R3I1. Seventy-four strains isolated in or around Edinburgh later in the same year, and 107 strains from three patients were also typed. Some variation (2·4 % in the north and 4 % in Edinburgh) was observed, but, in general, typing by the fermentation of rhamnose and inosite is of epidemiological significance.I am indebted to Dr Kirkpatrick for supplying strains of Bact. paratyphosum B and providing access to the necessary records, to Dr Seiler for epidemiological notes on the Edinburgh cases, and to Prof. Mackie for his valuable advice and encouragement.
On refection in rats and on the nature of the growth promoted by the addition of small quantities of milk to vitamin-free diets
Authors: Hopkins Frederick Gowland , Leader Violet Ruby 
Published: May 2009

1. In the course of this investigation we have dealt with many cases of refection, but during a period of several years we never obtained the condition except when raw potato starch was the carbohydrate in the synthetic diet. Recently, in the exceptional circumstances described in the text, we have had a few cases with rice starch.2. Like other authors, we have always found that in refected rats the caeca are always enlarged and their contents the seat of specially great bacterial activity. The nature of the dominant organisms present has varied from case to case, and in one it was apparently a yeast. Nevertheless, there is a suggestion that certain organisms are more potent in promoting refection than others. In rice starch refection, such organisms seem to be present.3. We have found that the administration of roughage in the manner described can, to a large extent, prevent the establishment of refection. The number of organisms in the caeca is then greatly reduced and the contents indeed may become nearly sterile.4. Using potato starch as the carbohydrate of the diet, we have had no difficulty in reproducing the results of the early experiments published by one of us (Hopkins, 1912), but we found that to obtain a growth induced by administering very small quantities of milk to vitamin-free diets, the presence of this starch is necessary. Indeed, the growth so promoted calls for the same particularity in the carbohydrate supply as does the establishment of refection.5. Nevertheless, we have obtained what seems to be conclusive evidence showing that the growth with milk is wholly independent of refection.6. We have obtained some evidence that potato starch contains growth factors in association with protein which only becomes soluble when liberated by treatment with pepsin HCl. As our experimental results bearing on this, for some reason at present unexplained, have lacked constancy, we can only claim, that they are suggestive.
Studies in the dynamics of disinfection. VI. Calculation of a new and constant temperature coefficient for the reaction between phenol and Bact. coli
Authors: Jordan R. C. , Jacobs S. E. 
Published: May 2009

1. The virtual sterilization time (v.s.t.) has been used as a measure of the rate of disinfection of Bact. coli cultures by phenol under carefully standardized conditions. The relationship of this time to temperature at each of five phenol concentrations has been examined from a fresh point of view, since it has previously been shown (Jordan & Jacobs, 1946) that none of the commonly accepted temperature coefficients was satisfactorily constant.2. The relationship is such that a minimum or threshold temperature exists for each concentration. A corresponding ‘maximum’ temperature has been fixed, defined as the temperature at which the v.s.t. is 10 min. The value of (v.s.t. – 10) thus varies from infinity to zero between these temperature limits.3. Sigmoid curves are obtained when log (v.s.t. –10) is plotted against temperature for given phenol concentrations. These may be regarded as asymptotic to ordinates at the minimum and maximum temperatures.4. The Pearl-Verhulst logistic equation gives a curve of the required sigmoid type, and this formula has been shown to fit the curves of log (v.s.t. – 10) against temperature very satisfactorily over the range of concentrations studied.5. One of the constants of this formula partakes of the nature of a temperature coefficient, and it has, therefore, been possible to derive a truly constant temperature coefficient for each phenol concentration.6. The values of this new temperature coefficient do not vary greatly with phenol concentration within the range studied, but it is not yet possible to establish whether it is essentially constant for all phenol concentrations with which it is possible to work.
Feeding and breeding of laboratory animals III. Observations on the feeding of guinea-pigs
Authors: Bruce H. M. , Parkes A. S. 
Published: May 2009

1. A dry pelleted diet is described which, supplemented with fresh greenstuff, dried cabbage, or ascorbic acid, is highly satisfactory for the growth and maintenance of guinea-pigs.2. No evidence could be found that the pelleted diet alone was deficient in any other factor than vitamin C required by guinea-pigs, fresh greens and dehydrated cabbage being effective because of their high content of this vitamin.3. Vitamin C added to the diet as crystalline ascorbic acid or as present in dried lucerne meal is mostly destroyed by the pelleting process and is further reduced during storage.4. The aim of evolving a dry pelleted stable diet completely adequate for guinea-pigs has not yet been realized.It is a pleasure to acknowledge our indebtedness to Miss M. Olliver, Messrs Chivers & Sons Ltd., who carried out the ascorbic acid determinations and gave us much valuable advice.Our thanks are also due to Roche Products, who gave us the ascorbic acid, to the Director of Messrs Chivers & Sons Ltd. for the generous gift of 1 cwt. of standard dehydrated cabbage, to the Dehydration Division of the Ministry of Food for supplying two samples of sub-standard dehydrated cabbage, and to Mr D. G. Short, senior technician in charge of the animals at the Institute, who prepared the small-scale diets.
The epidemiology and control ofSalmonella thompsoninfection of fowls
Authors: Buxton A. , Gordon R. F. 
Published: May 2009

The details are given of the epidemiology ofS. thompsoninfection in a flock of pullets which survived an outbreak of this disease when chicks, and also of a flock of adult birds suspected of being carriers of the organism. The results of blood testing and bacteriological examinations of cloacal swabs, random faecal samples and eggs from both flocks indicated that:(1) Many chicks which survived an outbreak ofS. thompsoncontinued to carry the organism for some months without showing any symptoms. In most cases the organism was harboured in the intestines and was excreted intermittently in the faeces. On one occasionS. thompsoninfected the gall bladder, and the bacilli were excreted in the faeces for at least 18 months after the outbreak had occurred.(2) The common method of egg infection was by the contamination of the shell with infected faeces. Under conditions of incubation the bacilli penetrated the egg shell and infected the yolk. Although there was little penetration of the organism under storage conditions, the bacilli on infected shells remained viable for at least 21 days.(3) The common methods of spreading infection in a hatchery were from:(a) The contact of infected and non-infected egg shells.(b) The handling of eggs before and during incubation.(c) The contact of egg shells with infected incubators.(d) The ingestion and inhalation of infected fluff and incubator debris at hatching time.(e) The ingestion of food and water contaminated with infected faeces from survivor chicks.For the control ofS. thompsoninfection in poultry, the following procedures have been recommended:(1) The production of agglutinins by carrier birds was not a reliable indication of infection. In known infected flocks, however, the detection of carriers by blood testing and by the examination of cloacal swabs is of value. For such a test an alcoholized antigen is preferable to a heat-treated broth antigen, and a titre of 1/20 or more should be regarded as an indication that a bird is infected.(2) Only clean eggs should be used for hatching. Dirty egg shells should be cleaned by scraping or brushing and not by wiping with a damp cloth.(3) Fertile eggs should be stored in a cool, dry atmosphere for as short a period as possible before incubation.(4) Eggs should be fumigated in the incubator with formaldehyde vapour, not later than 24 hr. after they have been set.We wish to record our appreciation of the assistance received from Mrs E. Sidery in the bacteriological examination of eggs and the preparation of agglutination tests.
Studies in the dynamics of disinfection. XI. The effect of lethal temperatures on standard cultures ofBact. coli. IV. An investigation of that portion of the population which survives prolonged exposure atpH 7·0
Authors: Jordan R. C. , Jacobs S. E. , Davies H. E. F. 
Published: May 2009

1. An attempt has been made to discover the origin and nature of the small proportion of the cells in standard cultures ofBact. coliwhich is able to withstand, apparently indefinitely, exposure to temperatures of 49, 51 and 53° C.2. The method adopted was to allow these survivors to generate fresh cultures in the same flask merely by reducing the temperature to 35° C. and to subject the resulting cultures in turn to heat treatment. Only one process of regeneration and subsequent disinfection was carried out at 49 and 53° C., but at 51° C. the process was repeated four times. The disinfection curve was determined on each occasion and the permanent population allowed to become established.3. Changes in the heat resistance of the cultures were judged by (a) the disinfection times (99·99 % mortality), (b) the maximum death-rates, (c) the levels of the surviving populations and (d) the variations in death-rate with time during each disinfection.4. Marked fluctuation in numbers of viable cells was observed during each of the phases of permanent surviving population. The exact levels of survivors were therefore uncertain, but after exposure to 49° C. the mean values were not higher than when 53° C. was used, nor was there an increase in the mean numbers of survivors in the successively regenerated cultures.5. The survivors did not grow when inoculated into either nutrient agar plates or tubes of broth held at the respective high temperatures, although they remained alive and developed readily on being transferred to 35° C.6. The maximum death-rate decreased and the disinfection time increased markedly after one regeneration of the cultures. The increase in the latter was not wholly due to the decrease in the former, as the death-rates throughout the disinfection of the regenerated culture were lower.7. After the second regeneration (at 51° C.) the maximum death-rate declined and the disinfection time rose still higher, but the process was reversed after the third and fourth regenerations.8. The shape of the graph of log survivors against time altered markedly after the second regeneration at 51° C. The initial death-rate was higher but fell sharply to a minimum before rising again to the final maximum.9. The experimental findings are discussed. An increase in the general heat resistance of these cultures may have occurred as a result of one regeneration, but the technique employed permitted the gradual alteration of the environmental conditions, and this appears to have exerted complex effects on the cultures so that the results of further regenerations are inconclusive.