bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Alterations in Haemolytic Immune-body which occur during the Process of Immunisation
Authors: Browning Carl H. , Wilson G. Haswell 
Published: May 2009

(1) When rabbits are injected intraperitoneally with ox's red blood corpuscles the haemolytic immune-body which is developed shows qualitative differences at different stages of immunisation.(2) The immune-body molecules which appear in the serum in the early stage of immunisation (e.g. four to eight days after a single injection of 2 to 4 c.c. of red blood corpuscles) are deficient in the power of causing absorption of complement when added to the corresponding blood corpuscles. This is most clearly brought out by the very slight increase in complement absorbed under the influence of multiple doses of immune-body as compared with the amount absorbed by one dose. The deficient complement absorption does not depend to any marked degree on deficient combination of immune-body with the receptors of the red corpuscles.(3) When, after repeated injections of blood corpuscles, immunisation has been carried to such a stage that an immune-body is produced which is very active in causing absorption of complement, then it is found that on ceasing to give further injections the relative complement-combining power remains high after the immune-body content of the serum as measured by the haemolytic dose has fallen to a very considerable extent.So far as we are aware the occurrence of such alterations in the properties of immune-body during the process of immunisation has not hitherto been noted.
On the Varieties ofBacillus Coliassociated with the House-fly (Musca Domestica)
Authors: Nicoll William 
Published: May 2009

1. A study of the natural bacterial flora of the house-fly appears to be essential in forming a correct estimate of the part played by flies in transmitting pathogenic bacteria.2. The house-fly may carry at least 27 varieties ofBacillus coli, by far the most frequent of which areB. coli communisand MacConkey's bacillus No. 71.3. As far as can be judged from the character of these colon bacilli the house-fly derives its bacterial flora equally from excremental matter and from other sources.4. Certain non-lactose fermenting bacilli appear to be capable of multiplying in the intestine of the house-fly. Of these Morgan's bacillus No. 1 is a not infrequent inhabitant of the fly's intestine andB. paratyphosus βhas been found on two occasions.
Further Studies in Anti-Rabies Immunisation. Rabies Virus—Exalted and Classical Strains Compared
Authors: Stuart G. , Krikorian K. S. 
Published: May 2009

1. The occurrence of an exalted strain of rabies virus has been recorded and a definition given of virus de rue renforcé.2. The characteristics of exalted virus have been examined in respect of incubation time, fixation rate and absence of Negri bodies.3. An adequate classification of street virus strains has been suggested.4. Cross-immunity experiments have been carried out and, as a result of cross-protection tests and of crossed serum reactions, identity of exalted virus with the classical strain has been established.5. The employment of autogenous and polyvalent vaccines has been shown to be unnecessary in anti-rabies immunisation.
Pleomorphism ofProteus VulgarisDetermined by Sodium Chloride Content of Culture Medium, and Simulating Stages in a Life Cycle
Authors: Dunlop E. M. , Maitland H. E. 
Published: May 2009

A strain ofProteus vulgaris, recovered from a case of cystitis, showed extreme pleomorphism in a primary culture onordinary agar.Pleomorphism was not found in sub-cultures on media free from added NaCl, but it appeared in the presence of a limited range of NaCl concentrations; with still higher concentrations it was not observed, although growth occurred. It was rarely found in cultures which grew with difficulty.Pleomorphism, occurring under the conditions mentioned as to salt concentration, was most marked in young cultures which grew vigorously; it usually disappeared as the cultures aged; and it became less and less evident in serial sub-cultures on medium containing the same amount of salt.The morphology of the organism differed on different media,e.g. filamentous on salt-free agar, short bacillary on MacConkey's agar, but it was practically constant in repeated sub-cultures on any one type of medium.Pleomorphism could be re-induced on any of the media used by suitable alteration of its NaCl content (increase or decrease). Pleomorphism was not determined by variation of the H-ion concentration of salt-free media; nor by variation of the temperature of incubation of cultures; nor by growth in fluid media as opposed to solid media.After nearly 4 years under laboratory conditions the organism is still sensitive to variation in the NaCl concentration of its environment, as evidenced by pleomorphism; but pleomorphism is now less extreme than it was originally.Pleomorphism is still most marked in young sub-cultures on media with suitably altered salt concentration, but it is sometimes difficult now to induce pleomorphism unless a stock culture several weeks old is used as the inoculum.The pleomorphism comprises aberrant forms similar to many of those which are regarded by certain observers as evidence of stages in a life cycle; but, in the case of the organism described, these forms can be induced by the simple expedient of altering the salt concentration of the medium on which it is grown. The occurrence of such forms is thus, of itself, no proof of a life cycle.
The Comparative Bactericidal Action of Normal Serum, “Whole” Blood and Serum-Leucocyte Mixtures; with Further Observations on the Bactericidal Mechanism of Normal Serum
Authors: Mackie T. J. , Finkelstein M. H. , Van Rooyen C. E. 
Published: May 2009

1. Normal “whole” blood and serum-leucocyte mixtures may exert a bactericidal effect when the serum (or plasma) is inactive in this respect, and may possess quantitatively greater bactericidal properties than serum (or plasma), when the latter is activeper se, but such effects are relatively weak.2. Leucocyte suspensions may exhibit an initial bactericidal action on certain bacteria, but this is usually weak and is followed by a pronounced growth-promoting influence on the surviving organisms.3. Under certain conditions normal “whole” blood and serum-leucocyte mixtures are inferior to serum (or plasma) in bactericidal power. This is observed when the serum (or plasma) is strongly activeper seand is due not merely to an inhibition of the bactericidal action of the leucocytes, but also to a lessened effect of the serum-bactericidins.4. The comparative bactericidal power of normal “whole” blood or serumleucocyte mixtures on the one hand and serum or plasma on the other depends on the activity of the serum; when this is relatively weak, blood shows an enhanced action; when strong, blood is less active.5. The above findings apply to a wide variety of bacteria irrespectively of biological species.6. Bacterial extracts possess marked inhibitory properties on the bactericidal action of serum (or plasma), but not to any extent on the bactericidal properties of the leucocytes as evidenced by the approximately equal influence of such extracts on whole blood and serum respectively.7. Dead bacteria in certain numbers produce inhibition of the bactericidal action of serum (or plasma), but exert a greater inhibitory influence on the reaction of “whole” blood.8. It is suggested tentatively that when the serum is strongly bactericidal the killed organisms on being phagocyted along with living bacteria interfere with the intracellular destruction of the latter which at the same time are protected from the serum-bactericidins.9. The paper also includes certain data regarding the time of maximum bactericidal action by serum towards various organisms and the occurrence of growth-promoting action following an initial bactericidal effect.
The Spermicidal Powers of Chemical Contraceptives. V. A Comparison of Human Sperms with those of the Guinea-Pig
Authors: Baker John R. 
Published: May 2009

1. Human and guinea-pig sperms are susceptible to the most diverse chemicals to almost the same degree.2. There exists a substance in human semen which protects both human and guinea-pig sperms against certain chemicals, especially sodium oleate, orthovanillin and potassium borotartrate.3. When perfectly fresh human semen is not available, the spermicidal powers of substances may be tested by using guinea-pig sperms suspended in human semen which has been kept cool.
The Dissimilarity of the Results of Precipitin Titrations Performed with a Constant Amount of Antiserum and with a Constant Amount of Antigen
Authors: Taylor G. L. 
Published: May 2009

1. Antisera, made against crystalline egg-albumin, have been examined by titrating a constant amount of antiserum against falling amounts of the antigen (the usual Dean and Webb method), and also by the reverse procedure in which the amount of antigen was constant and that of antiserum varied. The ratios by the two methods were never found to agree; nevertheless, in the majority of cases the relationship which the ratio by one method bore to the ratio by the other method was of the same order, and it is possible that this relationship is constant for crystalline egg-albumin and its antisera.2. The conclusions reached in my previous work (1931) require modification, because in those experiments insufficiently extensive ranges were used and as a result it was found that when varying amounts of anti-horse serum were titrated against a fixed amount of antigen, particulation was quickest in the tube containing most antiserum.3. Titrations by the reverse method over a fairly considerable range have provided evidence that the proportions of crystalline egg-albumin and a given homologous antiserum favourable for the most rapid particulation are constant despite absolute quantitative changes. The proportions in which these reagents particulate most rapidly are similarly constant in titrations by the usual Dean and Webb method.4. Why the two methods of titration give different results I am unable to explain, but the point of optimal particulation found by the Dean and Webb method probably coincides with the point of neutrality of antigen and antibody. Since in the Ramon (1923) method of titrating diphtheria toxin and antitoxin the reverse method, with constant antigen and varying antiserum, is used, the work reported here suggests that the determination of the relationship to each other and to animal values of the results of titrations of toxin and antitoxin by both methods might yield helpful information.5. Some points of practical importance in the performance of optimal proportions titrations are appended.
Agglutinins for the Typhoid-Paratyphoid Group in a Random Sample of the Population of British Guiana
Authors: Giglioli George 
Published: May 2009

Enteric fever in British Guiana, according to official reports, would not appear to be excessively common: the number of notifications for the whole Colony during the years 1930 and 1931 was 244 and 250 respectively on a population of 310,000.The few observers who have studied this disease in the Colony have all insisted on its sporadic character. Rowland (1910) has clearly illustrated this peculiarity with a series of spot maps showing the distribution of enteric in Georgetown from 1909 to 1913.
The Measurement of the Opacity of Bacterial Cultures with a Photo-Electric Cell
Authors: Alper Tikvah , Sterne Max 
Published: May 2009

1. A photo-electric cell was used to measure photometrically the opacity of cultures ofSalmonella gallinarumgrowing in bouillon.2. The opacity of a culture was defined as the number of 24-hour-old bacteria which when suspended in the same type of bouillon as those under investigation would absorb the same amount of light. Seven experiments were made to compare the opacities of growing cultures with their actual numbers throughout the first 24 hours of growth. An additional experiment was made to find directly the numbers of bacteria of different ages which would absorb the same amount of light.3. The ratio between opacity and number was greatest at about 3 hours, decreasing to unity at about 7 hours; the optical behaviour of cultures 7 hours old was thus the same as of cultures 24 hours old. It is possible from the results that the ratio decreased to a minimum at about 9 hours, thereafter again rising to unity. The value of the greatest ratio was greater as the inoculum was less. The mean greatest ratio was 4·6, the mean time being 3 hours. This means that it would take about 4·6 times as many 24-hour-old bacteria as 3-hour bacteria to absorb the same amount of light.4. It was shown that the variation in the opacity-number ratio was in all likelihood due to changes in the size of the organism during growth.5. The results suggest that the opacity curves give a truer picture of actual growth than the ordinary growth curves, since the cells change in size during growth.
The Type of Coliform Bacilli Prevalent in Urine and their Significance, with Special Reference to the Sanitary Aspects
Authors: Burke-Gaffney H. J. O'D. 
Published: May 2009

1. 1000 urinary and 500 faecal cultures of coliform bacteria were studied by means of the methyl-red, citrate and indol tests and also by their fermentation reactions upon saccharose and dulcite.2. 8 per cent, of the faecal strains and 52 per cent, of the urinary strains were of theaerogenestype,i.e.methyl-red negative and citrate positive. Indol was produced in 94 per cent, and 43 per cent, of cases respectively.3. This would suggest additional evidence that thecoligroup are quickly outnumbered by theaerogenesgroup once they leave the faeces, and also that the presence of theaerogenestype is not confined even in large numbers to an extra-corporeal habitat.4. In water bacteriology the constancy or change in the relative proportions ofcoliandaerogenesstrains present is the goal at which to aim. Theaerogenesvariety cannot of itself be regarded as non-excretal or even non-faecal.5. From a sanitary standpoint, the classification of coliform bacteria by means of the methyl-red and citrate tests cannot be regarded as entirely free from error so long as (a) theaerogenesstrains are found in faeces, in however small numbers, (b) these strains occur as the predominant type in urine, and (c) intermediate strains are found in the faeces, urine, soil and water.6. The principal value of these tests lies in their comparative specificity in identifyingB. coliof immediate faecal origin. The presence of such an organism, interpreted together with the indol test, may be said to suggest dangerous faecal pollution if found prominently in a water sample. The presence of other types identified by the same tests cannot be regarded as having the same significant value in regard to a negative opinion.7. A plea is made for a further study of coliform bacteria by means of the tests described in relation to the biological behaviour of the bacteria under different environmental conditions.
Observations on the Toxic Fractions of Scarlatinal Streptococci
Authors: Green C. A. 
Published: May 2009

1. Among a series of strains of haemolytic streptococci from thirty-five cases of scarlatina in the first week of illness, fourteen were found to correspond with one or other of Griffith's serological types I, II, III and IV.2. Of these fourteen strains, twelve were selected for further examination and found to yield a true heat-labile exotoxin completely inactivated by heating for 30 min. at 100° C.3. The concentration of exotoxin in 0·5 per cent, glucose broth cultures was at a maximum after 96 hours' incubation, and thereafter on further incubation progressively diminished.4. No qualitative difference could be detected among the exotoxins from the different strains, the test criterion being the dermal reaction in Dick-positive persons.5. Cultures of organisms of the same or different serological type isolated from the same source and thereafter similarly treated yielded approximately equivalent amounts of exotoxin.6. Broth culture filtrates also contained an acid-insoluble toxic fraction, the concentration of which increased with the age of culture and which appeared to be identical with a similar acid-insoluble fraction derived from an alkaline extract of washed bacterial bodies.7. This acid-insoluble fraction was extremely heat-resistant, 3 hours' boiling at 100° C. being required for inactivation. In this respect the acid-insoluble fraction corresponded to the bacterial endotoxins.8. The acid-insoluble fractions from cultures of the same serological type produced equivalent skin reactions in susceptible persons.9. The acid-insoluble fractions from cultures of different serological types differed qualitatively as determined by skin reactions.10. The reaction to crude filtrate was found to be the sum of the reactions to the exotoxin fraction and to the acid-insoluble fraction present in the filtrate.
The size and the duration of air-carriage of respiratory droplets and droplet-nuclei
Authors: Duguid J. P. 
Published: May 2009

1. The sizes of the droplets and droplet-nuclei produced by sneezing, by coughing and by speaking, were studied by the microscopic measurement of 12,000 droplet stain-marks found on slides exposed directly to mouth-spray, and of 21,000 stain-containing droplet-nuclei recovered from the air on to oiled slides exposed in the slit sampler.2. From these measurements it was calculated that the original diameters of the respiratory droplets ranged from 1 to 2000 μ, that 95 % were between 2 and 100 μ and that the most common were between 4 and 8 μ. Similar size distributions were exhibited by the droplets produced in sneezing, in coughing and in speaking, except that, in the case of sneezing, the smaller droplets were relatively more numerous.3. The respiratory droplet-nuclei were found to range in diameter from ¼ to 42 μ; 97 % had diameters between ½ and 12μ; the commonest diameter was between 1 and 2 μ.4. The proportion of droplets of each size which will contain bacteria, whether commensal or pathogenic, is determined by the size of the droplets and by the numbers of bacteria in the secretions atomized. Calculations made on the basis of the size distributions obtained in this investigation indicated that few of the smaller droplets, and thus few of the droplet-nuclei, are likely to contain pathogenic organisms. Droplet-spray is unlikely to give rise directly to true airborne infection unless very large numbers of pathogenic organisms are present in the secretions of the anterior mouth.5. The persistence of droplet-nuclei in the air of a 1700 cu.ft. room and of a 70 cu.ft. chamber was investigated by sampling the air with the slit sampler at intervals following sneezing.6. When the air was not artificially disturbed by a fan, the time taken for the disappearance from the air of 90% of the bacteria-carrying droplet-nuclei varied from 30 to 60 min.; the nuclei larger than 8 μ in diameter usually disappeared within 20 min., and the nuclei larger than 4 μ within 90 min.; the smaller nuclei, few of which contained bacteria, remained airborne for much longer periods, on one occasion for at least 30 hr. When a fan was run throughout the experiment, the nuclei disappeared from the air much more rapidly.
Thermal comfort in warm, humid atmospheres Observations in a warship in the tropics
Authors: Ellis F. P. , Navy Royal 
Published: May 2009

Naval ratings serving in a warship in the tropics answered a questionnaire concerning their sensations of warmth at meal times on the mess-decks during two investigations carried out at an interval of 6 months when the ship was proceeding between tropical and more northerly waters. Temperature measurements were recorded at the same times as the questionnaires were completed by the subjects.It is proposed that the upper level of warmth to be accepted in the design of ventilation systems for accommodation spaces should be those conditions when either more than 80% of persons feel reasonably comfortable or less than 20% observe the presence of unevaporated sweat on their skin, which corresponds to effective temperatures of 79 and 78° F. respectively, according to the majority opinion in these two investigations. The latter figure of 78° F. is suggested as the upper level to be accepted for men living under these conditions.The upper level of the optimum or ideal zone for comfort, when equal proportions of persons reported that they were either cool or warm, was observed to be at 74° F. effective temperature.The proportions of men who were uncomfortably warm at different levels of warmth were related to the proportions who reported that their skin was wet with unevaporated sweat. Very few observed that they were sweating, whatever the air velocity or their clothing, when the dry-bulb temperature was below 83° F., and the wet-bulb temperature below 75° F.Brisk circulation of the air on the mess-decks made an increasingly large contribution to the comfort of these very lightly clad men as the air temperature rose from 85 to 89° F., but as the temperature fell below 83° F. variations in air Thermal comfort in the tropics 431 movement had little effect on the proportions of persons who were reasonably comfortable under these warm conditions.Thermal discomfort was reported by an increasing number of men within a temperature zone where others have shown by experiment that there will occur a statistically significant decrease in the skilled performance of men who are acclimatized to working at high temperatures.This paper is published by the permission of the Admiralty and the Medical Research Council's Royal Naval Personnel Research Committee. The investigations described were made possible by the active interest of Captain H. S. Hopkins, C.B.E., Royal Navy, and Commander W. Elliot, D.S.C., Royal Navy, the excellent facilities which they placed at the disposal of the observers, and the wholehearted co-operation of the naval ratings who acted as subjects. I am indebted to Dr T Bedford for advice and criticism and to Mr Cheng Swee Guan and Sick Berth Attendant W. F. Montague, Royal Navy, for care in tabulating the data, preparing the illustrations and technical assistance.
Variation of Bacillus anthracis with special reference to the non-capsulated avirulent variant
Authors: Chu H. P. 
Published: May 2009

Normal virulent B. anthracis all possess the genetical potentiality of producing capsules, but the capsule is only produced in vivo or under special cultural conditions suitable for capsule formation, especially in the presence of CO2.During multiplication the potentially capsulated cells regularly produce a small number of a stable non-capsulated avirulent variant. All laboratory stock cultures of B. anthracis examined were found to contain from 0·14 to 32·4% of this avirulent variant. The variant has also been demonstrated in hair and wool from anthrax endemic areas, which suggests that the dissociation may also occur in nature.Both the normal potentially capsulated cell and the variant incapable of producing capsules grow on plain agar in air as rough colonies with apparently non-capsulated cells. But when they are grown on serum agar in the presence of CO2, the normal potentially capsulated cell gives rise to a smooth mucoid colony with fully capsulated cells, while the variant still produces a rough colony with non-capsulated cells. If we regard the smooth mucoid colony produced by normal virulent B. anthracis on serum agar in CO2 as the normal colony form of B. anthracis, then the dissociation of the avirulent non-capsulated variant with the rough colony form falls in line with the usual S-R dissociation of other bacteria.The more widely known variation of B. anthracis, which had long been held as an exception to the usual S-R variation of other bacteria, refers to colonies grown on plain agar in air. This variation is different from the one just described and is not so clear-cut and significant. Its underlying cause is not quite clear except that the chain length of the growth appears to play some part.A summarized picture showing the whole range of variation in colony appearance and cell structure of B. anthracis is presented.