bluuebunny/crossref_metadata_2025 huggingface dataset:
The epidemiology of the common cold. I
Authors: Lidwell O. M. , Williams R. E. O.
Published: May 2009

The number and some characteristics of the colds experienced by office workers in London and Newcastle upon Tyne are described.

Age was the only factor found to be strongly associated with the number of colds experienced by an individual. Female staff suffered only 10–15% more colds than male staff. The presence of children in the household had little or no effect. The daily use of public transport also appears to be unrelated to the number of colds suffered.

We are grateful to the Ministry of Pensions and National Insurance for affording us the facilities necessary for the carrying out of this investigation, and particularly to the staffs of the offices who collaborated with us in providing the records and to the members of the Establishment Department and to the staff representatives for their help in the organization of the study. We are also indebted to the Medical Department of the Ministry for their interest and advice. We also wish to record our gratitude to the Shell Petroleum Company, its officers and staff, and particularly the chief medical officer, for their assistance and collaboration, to the management and staffs of the two other London offices studied and to the nurses, Mrs E. Hodgson, Miss M. Petts, Miss L. Waddell and Mrs E. A. Wilson, who collected the records.
Diagnostic tables for the common medical bacteria
Authors: Cowan S. T. , Steel K. J.
Published: May 2009

A simple device by which the characters of an unknown organism can be com pared with those of named genera and species is described. The comparison is made by using ‘diagnostic tables’ of characters found to have differential value.

Separate tables for Gram-positive and Gram-negative bacteria were made; the first stage indicated the probable genus into which the unknown fell and a second (and occasionally a third) stage was needed to identify the species or subspecies.

We wish to thank Dr Ruth E. Gordon for much unpublished data which were invaluable in constructing Table 1gg, Miss Helen E. Ross for helping with Table 1f, Dr Oleg Lysenko for letting us use data from a paper about to be published, and Mr W. Clifford for the photographs and figures.
The serological response of sheep to infection with louping-ill virus
Authors: Williams H. , Thorburn H.
Published: May 2009

1. An H.A.I. test for louping ill in sheep is described and its potentiality investigated alongside a standard C.F. test.

2. Sheep free from infection with, or which have not been vaccinated against, louping ill do not possess serum antibody demonstrable by the C.F., H.A.I. or neutralization techniques as described here.

3. After the administration of commercial vaccine followed by infective virus, C.F., H.A.I. and neutralizing antibodies are detectable. The C.F. antibodies are the least stable and in many instances disappear entirely from the peripheral circulation within 4 months of their appearance; they also appear to be susceptible to fluctuation unassociated with the disease. H.A.I. antibodies elicited under the same circumstances reach a high level early, are maintained for longer periods than C.F. antibodies, and fall to a basic level which tends to be maintained.

4. H.A.I. antibodies do not appear to be elicited in response to inoculation with vaccine only, in contrast to C.F. and neutralizing antibodies which are so elicited. It is suggested in these circumstances, measurement of H.A.I. antibody is the most useful of the serological tests available for surveys and for diagnostic purposes in sheep.

We wish to thank Mr A. Sharman, B.Sc., M.R.C.V.S., formerly of the North of Scotland College of Agriculture, Aberdeen, under whose care and supervision the flock was maintained and who inoculated and bled the animals.

We are particularly indebted to Dr C. E. Gordon Smith, of the London School of Hygiene and Tropical Medicine, for valuable criticism and advice.
A sampling study of the power function of the binomial χ2 ‘index of dispersion’ test
Authors: Bennett B. M. , Hsu P.
Published: May 2009

A total of 375 separate sampling experiments were performed on groupings of 100 samples each from distinct binomial populations in order to obtain estimates of the frequency of rejection of the hypotheses of homogeneity against alternatives of a trend by means of the usual χ2 or binomial index of dispersion test. These artificial realizations are presented in Figs. 1–5, and compared graphically with corresponding non-central χ2 distributions.

The authors would like to acknowledge the technical assistance of the Research Computer Laboratory of this University in programming and supervising the computational phases of this investigation, which was partially supported by the State of Washington Initiative 171 Funds for Research in Biology and Medicine and the Boeing Employees' Good Neighbor Fund.
Antigens of cowpox virus
Authors: Rondle C. J. M. , Dumbell K. R.
Published: May 2009

Cowpox soluble antigen is shown by gel-diffusion studies to contain at least nine precipitable substances whose presence is induced by virus infection. One of these substances, pattern componentd, is not produced in white cowpox infections, and its production in vaccinia infection can be inferred only from the presence of small amounts of anti-din anti-vaccinia sera.

Comparison of cowpox with vaccinia has led to the recognition of a further line pattern componentfwhich is readily demonstrated as a soluble precipitable substance in simple buffer extracts of vaccinia-infected tissue, but is demonstrated in extracts of cowpox-infected tissue only with difficulty; anti-fantibody is readily detected in antisera prepared against cowpox, white cowpox, and vaccinia.
Blankets and air hygiene: a report of a trial of blanket disinfection
Authors:   A Newcastle Regional Hospital Board Working Party
Published: May 2009

1. The effect of blanket-disinfection on aerial contamination of exposed culture plates was studied during a six-month trial in six hospital units, containing a total of 270 beds.

2. Disinfecting blankets after use by each patient did not significantly reduce general bacterial orStaph. aureuscounts on exposed culture plates.

3. Disinfected blankets were heavily recontaminated after only a few days' use. A quaternary-ammonium rinse during laundering conferred no self-disinfecting properties on them.

4. Cotton-cellular blankets were more economical and more popular with patients and nurses than were conventional woollen and two other types of cotton blanket.
α-Amylase in whole egg and its sensitivity to pasteurization temperatures
Authors: Brooks J.
Published: May 2009

The activity of the enzyme α-amylase of whole egg is known to be sensitive to pasteurizing temperatures and the possibility that this property could be used as a control test for the adequacy of pasteurization has been examined.

The occurrence of the enzyme, the physico-chemical characteristics of its heat inactivity, the consistency of its behaviour in large numbers of eggs and the influence on its of packing station procedures has been studied.

By sampling eggs from many sources for 11 months it was concluded that the activity of the enzyme was consistent, the inactivation by heat was a first-order reaction, and freezing, thawing, homogenization, spray-drying and in the laboratory freeze-drying did not affect its inactivation. But there was some interference from added citrate and sucrose.
A discussion of the dynamics of salmonella enrichment
Authors: Jameson J. E.
Published: May 2009

This paper elaborates a concept of enrichment dynamics introduced in an earlier paper in which the author set out to find a labour saving technique for isolating salmonellac from sources other than faeces. Extensions to the concept are summarised in the Introduction. Explanations are given why a multiplicity of isolation procedures used in combination should normally yield more isolations than any one procedure alone.

Since a limit must always be set on the number of different media and procedures which can be used during routine examinations, a corresponding limit has also to be set on the combined efficiency of the procedures used. Not even a very laborious combination of methods can be expected to yield quite 100% of the isolations that are technically possible. When this rather unpalatable conclusion is accepted, a way is opened up for compromises between endeavour and reward, in terms of salmonella isolations. Judicious application of principles and methods discussed in these papers might be expected sometimes to lead to modifications in techniques which increase their efficiency, and in other cases to modifications which reduce labour without diminishing efficiency.
An outbreak of human infection due to Salmonella typhi-murium, phage type 4, associated with the use of unpasteurized liquid egg
Authors: Essex-Cater A. J. , Jones D. M. , Swindell F.
Published: May 2009

During 1962, twenty-seven food poisoning incidents due to Salmonella typhimurium, phage type 4, comprising thirty-two cases and twelve symptomless excreters, occurred in the south-east Lancashire conurbation. The source of infection was a single small producer of English liquid egg. Pasteurization of the product coincided with the end of the outbreak. The cases were sporadic in distribution. Investigation of previous incidents due to this phage type in the City of Manchester pointed to egg from the same producer. As a result an investigation was made into the amount and source of unpasteurized egg in use in the city. This revealed the frequent presence of salmonella infection and demonstrated the need for pasteurization of liquid egg before use.
Intradermal TAB immunization against enteric infections
Authors: Bardhan P. N. , Dutta H. N. , Krishnaswami P.
Published: May 2009

To compare the effects of subcutaneous and intradermal methods of administration of TAB vaccine for primary immunization against enteric infections an investigation was carried out on 257 Army recruits.

The general and local reactions were more unfavourable by the intradermal method. The agglutinin responses were better with the intradermal route.
Colicine production as an epidemiological marker of Shigella sonnei
Authors: Gillies R. R
Published: May 2009

1. Modifications of the technique of colicine typing are reported which allow more rapid and economical identification of Shigella sonnei for epidemiological purposes without loss of accuracy.

2. The technique is epidemiologically valid as judged by the constancy of type in repeated isolations from individuals and the uniformity of type in epidemics; it is considered that the few instances of lack of uniformity in these indices are probably examples of true mixed type infection. There is no evidence of type instability in vitro.

3. Type incidence differs significantly from that reported in two other centres; a new colicine type (Type 14) is described which brings the total of recognizable types to 16. It is considered that in addition to the five types which were previously thought distinctive, three other Types, 6, 11 and 14, can now be so regarded.

4. There is a need for continued studies to resolve the few discrepancies associated with infection by more than one type either in the individual or in an epidemic; it is hoped that colicine typing will reawaken interest in Sonne dysentery.

This investigation was supported (in part) by Public Health Service Research Grant AI– 04833–01.from the National Institute of Allergy and Infectious Diseases.
The feeding of oral poliovirus vaccine to a closed community excreting faecal viruses
Authors: Gardner P. S. , Cooper Christine E.
Published: May 2009

The residential home was investigated to study the endemic virus population. During this study, oral poliovirus vaccine was given to the children and the effect of vaccination on endemic enteroviruses and adenoviruses was investigated. In the light of these findings, the problem of virus interference is discussed. The health of the children is related to their virus infections.

We are indebted to Prof. S. D. M. Court and Prof. C. A. Green for the active interest they have taken in this investigation; to Miss J. McQuillin, B.Sc., F.I.M.L.T., for her technical assistance; also to the matron of the home and her staff for their co-operation in supplying the specimens, and to Mr L. J. Whitlock of the Royal Victoria Infirmary and his staff for arranging their transport to the laboratory.
‘False positive’ complement fixation with psittacosis—trachoma antigens due to antibodies in complement preparations
Authors: Terzin Alexander L.
Published: May 2009

Complement-fixation tests with psittacosis-trachoma group antigens, if set up with complement prepared from guinea-pigs cross-infected with any of the Bedsonia agents, may give completely false positive results. The use of C.F. positive or C.F. inhibition positive samples of guinea-pig sera as a source of complement can induce also a significant increase or decrease, respectively, of the actual C.F. titres in Bedsonia-positive serum samples tested. Observations made both in routine serology and in experimental studies show the necessity of testing carefully, for possible presence of Bedsonia titres, individual sera of guinea-pigs intended for use as source of complement in C.F. tests performed with Bedsonia group antigens.

I have pleasure in thanking Dr F. B. Gordon and Dr E. Weiss for the valuable suggestions made and HM3 C.O. Wiese for the technical assistance.
The specificity of cellular immunity
Authors: Gray David F. , Poole Rosalind
Published: May 2009

1. Non-specific stimulation of mice by a detergent lackingin vitroantibacterial activity, Triton WR 1339, produces a steady state in the course of experimental tuberculosis at about the same level as specific immunization, and does so independently of delayed allergy.

2. This effect is achieved in a much shorter time than is required by the normal immunological processes and the relative duration of enhanced resistance in each case is yet to be worked out.

3. Triton fails to enhance an existing, specifically acquired immunity.

4. There is no evidence so far that the mechanism involved is the same in both instances. If it were found to be the same, then the present concept of a specific cellular immunity would need to be revised.
An outbreak of myxomatosis caused by a moderately attenuated strain of myxoma virus
Authors: Chapple Paul J. , Lewis N. D.
Published: May 2009

Since the original epizootic of myxomatosis in this country (1953–55) carcasses of rabbits from outbreaks of the disease have been sent regularly to the Central Veterinary Laboratory, Weybridge, but no detailed investigations have been carried out on outbreaks of disease in natural populations in Great Britain since 1954 (Armour & Thompson, 1955). In July 1962 a rabbit was sent from the East Riding of Yorkshire and as a matter of routine this establishment was informed of the outbreak. The population of rabbits concerned was large and occupied an area of approximately 200 acres. The strain of virus causing the outbreak was attenuated and when this was discovered efforts were made to secure samples for as long as the outbreak lasted.
Studies on the carrier state of cattle exposed to foot-and-mouth disease virus
Authors: Burrows R.
Published: May 2009

Cattle infected with FMDV strains of different epizootiological origin developed a carrier state which persisted in the majority of animals for several months. Fluid samples taken from the oesophageal/pharyngeal region were assayed for infectivity by plaque counts on BHK monolayer cultures and by mouse inoculation. With one strain of virus, infectivity levels of up to 1000 pfu/ml. were recorded for several weeks after infection but in general the virus content of samples was below 50 pfu/ml.

The sites of virus persistence and multiplication were identified by titration of suspensions of mucosae and epithelia taken post mortem. Virus was recovered from 41 of 54 cattle killed 14–196 days after infection. The chief sites of virus multiplication based on the frequency of virus recovery and infectivity titres were the dorsal surface of the soft palate and the pharynx. Virus was recovered less frequently from the ventral surface of the soft palate and the glosso-epiglottic space and only occasionally from the tonsillar sinuses, tonsils, tongue, trachea and oesophagus. No virus was detected in the turbinates or in the epithelium of the urinary bladder.
Type-specific polysaccharide antigens of group B streptococci
Authors: Lancefield Rebecca C. , Freimer Earl H.
Published: May 2009

Rabbits immunized with whole streptococci of group B, type II, produce two immunologically distinct type-specific antibodies which are essentially equal by weight in protecting mice against infection with homologous type strains.

The capsular antigen with which these antibodies react is a polysaccharide containing galactose, glucose, glucosamine, and a labile component which has not been chemically identified. Extraction of the bacteria with TCA yields this ‘complete’ antigen, whereas extraction with HCl yields a partial antigen without the labile component. This degraded antigen can also be derived from the TCA antigen by treating the latter with hot HCl, and is indistinguishable from that extracted directly from the bacteria with HCl.

One of the antibodies produced, the TCA antibody, is directed against the labile component of the polysaccharide. The other, the HCl antibody, is directed against a β-d-galactoside determinant; and the precipitin reaction with this antibody is not masked in the ‘complete’ TCA antigen by the presence of the labile component.

The group-specific polysaccharide, which is located in the cell-wall, is also extracted with either TCA or HCl but can be eliminated from the preparations by fractional precipitation with ethanol. Although it is known that the type-specific polysaccharide is located in the streptococcal capsule, it is not at present clear in what form this substance occurs in the living streptococcal cell. It may be present partially as the degraded HCl form, or possibly wholly as the intact TCA form. Further immunological and chemical studies of these type-specific polysaccharides are in progress, and will be presented in another communication.
A new colicine type (type 15) of Shigella sonnei
Authors: Gillies R. R. , Brown D. O.
Published: May 2009

1. A new colicine type (type 15) of Shigella sonnei is described.

2. The epidemiological circumstances associated with its appearance in Edinburgh and Glasgow are summarized.

3. Our indices of reliability as an epidemiological marker are fulfilled by this new type.
An epidemiological study ofSalmonellain a closed pig herd
Authors: Heard T. W. , Linton A. H.
Published: May 2009

An epidemiological survey of salmonella infection in a closed herd of pigs is reported. The main cause of cross-infection resulted from the movement of animals, with subsequent mixing of infected and clean stock and exposure of non-infected animals to infected faeces. Pen-to-pen infection carried by farm attendants also proved important.

An extended survey is at present being conducted to gain further information on the processes of cross-infection.
The infectivity assay of foot-and-mouth disease virus in pigs
Authors: Burrows R.
Published: May 2009

FMDV strains were titrated in pigs by inoculation of the bulb of the heel of the foot, the coronary band region of the foot, and the tongue. Heel inoculation gave end-points approximately 300-fold higher than did the other two methods.

Parallel titrations in cattle and mice gave infectivity estimates approximately 10-fold and 100-fold higher, respectively, than did heel titration of pigs.

The average variance of individual end-points determined for heel titration was 0·46 (log10 units) and that determined for coronary-band titration was 0·74. The sources of variations in end-points given by heel titrations are discussed.
Immunogenicity of experimental trachoma vaccines in baboons: II. Experiments with adjuvants, and tests of cross-protesction
Authors: Collier L. H. , Blyth W. A.
Published: May 2009

A mineral oil adjuvant failed to enhance or to prolong the somewhat shortlived immunity induced in baboons by trachoma/inclusion conjunctivitis (TRIC) vaccines, and was of little or no value in increasing or prolonging the formation of group complement-fixing (CF) antibody. Vaccines prepared with protamine sulphate or with calcium phosphate were no more immunogenic than the untreated parent suspensions.

Cross tests with aqueous vaccines revealed antigenic differences in the TRIC agents examined, in terms of their ability to protect against conjunctival challenge. Strain MRC–1/OT differed from MRC–17 and from MRC–4, and MRC–187 from MRC–4f.

The four Gambian trachoma agents tested were much less effective than the MRC–4 strain of inclusion conjunctivitis in inducing group CF antibody in baboons. The titre of circulating antibody bore no relation to the state of immunity to conjunctival challenge.

In three baboons given mineral oil adjuvant vaccine and in one given aqueous vaccine the conjunctival responses to subsequent challenge were significantly enhanced. This reaction may be an expression of a hypersensitive state induced by relatively ineffective vaccines; like immunity, it is unrelated to the titre of CF antibody in the serum.
Aqueous and oil-adjuvant influenza vaccines and iso-immunization to group A substance
Authors: Forsyth J. R. L. , Wilson T. E.
Published: May 2009

Influenza vaccines used in trials appeared to stimulate a small increase of saline-reactive anti-A1antibodies in group O volunteers. There was no evidence that haemolysins were elicited by adjuvant vaccine. It is unlikely that influenza vaccines would cause ABO haemolytic disease in infants.
Sociological factors in the spread of variola minor in a semi-rural school district
Authors: Angulo Juan J. , Rodrigues-Da-Silva Guilherme , Rabello S. Ivo
Published: May 2009

The mechanism of spread of an epidemic of variola minor (alastrim) occurring in 1956, in Vila Guarani, a semi-rural school district of the City of São Paulo, Brazil, is examined. Cases were grouped according to time and space relationships corresponding to either a household or a school class, as once variola minor was introduced into a household or a school class spread was independent of occurrences in neighbouring social units. The constant occurrence of a single introduction in school classes and households implied that the chance for transmission of the disease outside the homes or the school was very small. The secondary attack rate was higher in households than in school classes. Twenty households with cases had more pre-school children and school children and a lower vaccination level than twenty-two neighbouring households without cases but also including one or more persons who were known to have had personal contacts with patients.

Examination of the chain of contagion clearly shows that spread in the school was directly and indirectly responsible for the majority of cases in the epidemic, for the peak of the epidemic curve and for the extent of topographical spread of the epidemic. This predominant role of the school was accentuated by incomplete preventive measures (vaccination campaign and isolation of patients) applied late in the epidemic and it is attributed to the following facts, (a) There was a single school in the district, and school children were thus concentrated, (b) The school was the only place of the district where persons living in different neighbourhoods had regular, repeated contacts, (c) The great majority of school children had had no previous variola and many had no vaccination scar, (d) The social activities of school children gave them the highest potential as transmitters of variola minor.
The serum opacity reaction ofStreptococcus pyogenes: general properties of the streptococcal factor and of the reaction in aged serum
Authors: Hill M. J. , Wannamaker Lewis W.
Published: May 2009

The capacity of certain strains ofStreptococcus pyogenesto produce opacity in aged horse serum has been studied. Cells from all stages of the growth cycle are able to produce opacity. Maximal activity is reached towards the end of the exponential phase of growth.

Examination of cell fractions obtained by mechanical breakage and differential centrifugation suggested that the cell-bound activity is predominantly associated with the membrane fraction. Extraction with sodium deoxycholate yields a soluble fraction of high activity.

There is considerable strain variation in heat stability of the serum opacity factor. Cell-bound activity is often quite resistant to heat, whereas extracted activity is less stable.

Low concentrations of divalent cations have an activating effect, whereas high concentrations inhibit the serum opacity reaction. High concentrations of uni-valent cations are without effect on the cell-free enzyme but have an activating effect on the cell-bound enzyme.

For both the cell-bound and the cell-free enzyme the pH optimum was 5·8.

Although sensitive to trypsin and pepsin, the serum opacity factor appears to be resistant to streptococcal proteinase. Its activity is destroyed by formaldehyde and by periodate but is unaffected by a number of reducing agents.

Pre-heating of the serum or the addition of iodoacetate did not affect the serum opacity reaction. The enhanced cholesterol esterification previously described with fresh serum appears to be a secondary reaction. Even when isolated by relatively gentle methods, α-lipoprotein serves as a substrate only in the presence of crystalline serum albumin.
The growth of a virulent strain of African swine fever virus in domestic pigs
Authors: Plowright W. , Parker J. , Staple R. F.
Published: May 2009

Pigs were infected by the intranasal instillation of a large dose (ca. 107·0ID 50) of a highly virulent strain of African swine fever virus (ASFV) and the progress of the infection was studied by the ‘routine titration approach’ (Mims, 1964) using pig bone marrow cultures.

Virus growth was established within 16–24 hr. in the retropharyngeal but not in the alimentary or nasal mucosae or the tonsils. By 24–40 hr. the virus was consistently present in the retropharyngeal lymph nodes, almost invariably the medials; titres in these nodes exceeded those in the associated mucosa by 48–72 hr. Generalization, presumed to have occurred via the tracheal lymph ducts and the blood stream, was generally demonstrable after 72 hr., i.e. by the time of the onset of pyrexia or 24 hr. prior to this.

On average 11% of the total infectivity in the blood was present in the plasma, with the rest assumed to be cell-associated. A mean of about 45% of the total infectivity was recovered in erythrocyte fractions in which the concentration of leucocytes had been materially reduced; fractions with increased leucocyte counts contained relatively little virus and it was concluded that the great majority of circulating virus was closely associated with the erythrocytes. Adsorption of ASFV to normal pig erythrocytes was demonstratedin vitro.

The greatest concentrations of virus were recorded in the lymph nodes, especially those of the cephalic region, and in the spleen, where titres commonly attained 108·0to 109·0HAD 50/g. and exceeded those in the blood. They were, therefore, thought to be the source of much circulating virus, although there was some evidence that the liver, lungs and bone marrow may also have contributed, at least in some animals. There was no evidence that the mucosae of the alimentary and respiratory tracts or the kidney, myocardium and brain were a source of significant amounts of virus. The virus demonstrable in Peyer's patches did not exceed that in the intervening ileal mucosa.

Although contact transmission of ASF does not normally occur during the first 12–24 hr. of fever, considerable amounts of virus were usually present in the nasal and intestinal mucosae at 72 hr. It was probable that this infectivity was due to the blood content and that excretion did not occur until the epithelium was breached.

Three pigs, all of which had lesions of a portal cirrhosis, showed a delayed or restricted generalization of virus, in comparison with the other twenty-eight animals which behaved according to a regular pattern.

We are grateful to Mrs M. O'Sullivan and Mrs E. Douglas for painstaking technical assistance and to Mr C. S. Rampton, A.I.M.L.T., for the preparation of the figures.
Studies on the LS antigen of vaccinia virus
Authors: Rondle C. J. M. , Williamson J. D.
Published: May 2009

A material (LS) analogous to that described by Craigie & Wishart (1936a) has been detected in extracts of vaccinia-infected rabbit dermis. Gel-diffusion tests on this material support the view that it is a single substance possessing two distinct serologically reactive sites. The tests also show that under some conditions rabbit LS may give two lines of precipitation against suitable antisera and that this is not due usually to the dissociation of LS into discrete L and S substances.

A study of vaccinia-infected sheep dermis failed to give evidence of a single LS substance. Instead two chemically different substances were isolated, one having the serological specificity of L, the other that of S. The physical, chemical and quantitative serological properties of sheep S were such that it could not have arisen by degradation of an LS material similar to that found in vaccinia-infected rabbit dermis. On this evidence it is suggested that vaccinia virus is not necessarily synthesized in the same way in different host tissues.
The immune response to viruses in calves: II. The response in young calves
Authors: Sanderson C. J.
Published: May 2009

Injections of virus in calves up to about 5 weeks of age caused either the production of both IgM and IgG, or the production of only IgG, or no detectable antibody. In all but one case priming for a secondary response occurred even in the absence of a detectable primary response. These results suggest that in the young calf immunological memory is more readily induced than IgG synthesis. IgM appeared by the 7th or 10th day, which was similar to the response in older calves. IgG was more variable in its appearances but was usually considerably delayed relative to the response in older calves. In general only low levels of IgM were formed in the primary response and it was virtually absent from the secondary responses. Higher levels of IgM were formed after reovirus inoculation than after Murray Valley encephalitis virus or Getah viruses. The delay in appearance of IgG was more pronounced in response to Getah than to reovirus or Murray Valley encephalitis virus. High levels of maternally derived passive antibody inhibited the development of an active response, although in one animal a response occurred in the presence of low levels of passive antibody.
Salmonella senftenberg in the Sunderland area
Authors: Sanford D. A. , Leslie D. A. , McKeon J. A. , Crone P. B. , Hobbs Betty C.
Published: May 2009

Salmonella senftenberg was isolated from 168 patients and staff of a general hospital whereas it was isolated from only seven other sources (four of which were unquestionably associated with the hospital) in the surrounding area during the same period. It was isolated in the hospital in 19 of the 48 months of the period. Two clear-cut episodes were recognized against a background of sporadic isolation. Four-fifths of the patients and staff excreting the organism had no symptoms. Only two are known to have been severely ill, though in some patients very ill for other reasons life may have been shortened a little.

The original source of the organism, whether from the farm or from raw materials such as meat or poultry, was not found.
The chemical reactions of the haemagglutinins and neuraminidases of different strains of influenza viruses: I. Effect of reagents reacting with amino acids in the active centres
Authors: Hoyle L.
Published: May 2009

Studies of the chemical reactions of the haemagglutinins and neuraminidases of eight strains of influenza viruses have been made by the use of chemical reagents reacting with chemically active groups in the protein molecule. The results indicate a close resemblance between the active centres of the haemagglutinins and neuraminidases in all the strains tested. In all cases the activities were unaffected by reagents reacting with the —SH group of cysteine, the —CH3S group of methionine, the amino group of lysine, the guanidyl group of arginine, or the indole ring of tryptophan. In all cases both the haemagglutinating and enzymic activities were reduced or destroyed by agents reacting with amide groups or reacting with both tyrosine and histidine.

By the use of iodine under conditions in which tyrosine reacts but not histidine, and fluorodinitrobenzene under conditions in which histidine reacts more strongly than tyrosine, it was possible to detect a number of different active centres.

(1) An active centre containing histidine and an amide group but not containing tyrosine was present in all the virus strains and was the only centre detectable in A1 and A2 strains. This type of centre appeared to possess both haemagglutinating and neuraminidase activity.

(2) Active centres containing tyrosine and an amide group were detected in strains of A and B viruses. There was some evidence suggesting that tyrosine-containing centres were of two types: one possessing both haemagglutinating and enzymic activity while the other was a haemagglutinin without neuraminidase activity.

The results could be explained by supposing that the presence of histidine in the active centre was essential for neuraminidase activity and that enzymically active tyrosine-containing centres also contained histidine, but that tyrosine could substitute for histidine, but that tyrosine could substitute for histidine in haemagglutinating centres.
A cyclone separator for aerosol sampling in the field
Authors: Errington F. P. , Powell E. O.
Published: May 2009

Two cyclones for sampling dilute aerosols in the field are described. Their advantages are their robustness and reliability, the high degree of concentration achieved, and the ease with which they will provide a long uninterrupted sequence of samples.

Methods of correcting estimates of cloud concentration for transfer lag in the cyclone are derived.

The cyclones were constructed by J. Nott. We are indebted to G. J. Harper and E. J. Morris for allowing us to make use of their observations, and to Dr J. S. Paterson (Superintendent, Allington Farm) for providing the realistic aerosol at our convenience.
The source of bacteria in fresh cream, and the methylene blue reduction test as a guide to hygienic quality
Authors: Jenkins H. R. , Henderson R. J.
Published: May 2009

One hundred and twenty-nine samples of fresh cream collected in Worcestershire were examined bacteriologically. Sixty (46·5 %) creams had counts of over 100,000 bacteria/ml. The bacteria present were of many varieties, the commonest beingBacillusspp. (aerobic spore formers), Gram-negative bacilli, staphylococci and micrococci. Since most of the creams had been either pasteurized as cream or manufactured from pasteurized milk it was thought that the many bacteria were present because of contamination after pasteurization due to three main causes; unsatisfactory or unhygienic premises, unsuitable equipment, manual handling during the filling and capping process.

The methylene blue test results related well with bacterial counts but there were seven (5·4 %) anomalous results. Although the methylene blue reduction test therefore could serve as a simple and reasonable guide to the hygienic quality of fresh cream, 5·4 % of anomalous results would perhaps make it unsuitable as a statutory test.

We thank Mr R. Colenso, M.A.P.H.E., M.A.P.H.I., Chief Public Health Inspector, and Mr H. Beckett, Milk Sampling Officer of the Worcestershire County Council, for arranging the supply of samples.
Dissemination and immunogenicity of live TRIC agent in baboons after parenteral injection: II. Experiments with a ‘slow-killing’ strain
Authors: Collier L. H. , Mogg(Née Smith) Anne E.
Published: May 2009

After a single subcutaneous injection into baboons the MRC-4 strain of trachoma/inclusion conjunctivitis (TRIC) agent underwent limited multiplication at the injection site, but was then eliminated rapidly from the skin and regional lymph nodes. Forty-eight hours after a single intravenous injection, but not thereafter, it appeared in the peripheral lymph nodes and spleen. The single parenteral injections failed to immunize baboons against conjunctival challenge with the homologous strain. These findings contrasted with those previously reported for the more virulent mutant, MRC-4 f, which multiplied readily in the skin, lymph nodes and spleen, persisted in these tissues up to 3 weeks after injection, and conferred good immunity to conjunctival challenge with MRC-4. The difference in behaviour of MRC-4 and MRC-4 f might be accounted for, at least in part, by the use of a smaller inoculum of live MRC-4; but similar findings in guinea-pigs, reported elsewhere, suggest that the differences observed are real. In conjunction with previous work, the present study suggests that the immunogenicity of TRIC agent is closely related to the mass of antigen that can be administered to or propagated within the recipient.

We are grateful to Mr D. Venters for his able technical assistance.
Salmonellas in sewage. A study in latent human infection
Authors: Harvey R. W. S. , Price T. H. , Foster D. W. , Griffiths W. C.
Published: May 2009

In a residential estate of 4000 persons, containing neither industry nor retail butchers shops, salmonellas were regularly found in the sewerage system. They were frequently found in the sewage of a portion of the estate housing 1000 persons. The range of serotypes found was wide and some types suggested an exotic origin. No overt salmonella infection in the estate was reported during the period of survey, although local general practitioners had been previously alerted. Overt infection due to serotypes found in the survey were, however, reported in other areas of Glamorgan. Multiple sampling points in the sewerage system and a serological technique for examining samples contaminated with multiple salmonella serotypes were essential for the technical success of the survey.

We should like to thank Prof. Scott Thomson for his advice in the preparation of this paper; Dr E. S. Anderson of the Central Enteric Reference Laboratory and Bureau, Colindale, for phage-typing the strains ofS. typhimuriumandS. paratyphi B; and Dr G. J. G. King of the Public Health Laboratory, Bournemouth, for identifying the serotypes isolated. We should also like to thank Mr T. R. Liddington and Mr J. H. Price for their technical assistance.
Antibody response following smallpox vaccination and revaccination
Authors: Downie A. W. , Vincent L. St , Rao A. R. , Kempe C. H.
Published: May 2009

Three groups of post-vaccination sera were studied for vaccinial antibody by precipitation, haemagglutinin-inhibition, complement-fixation and neutralization tests. All sera were negative by precipitation and many by haemagglutinin-inhibition and complement-fixation tests, but most showed neutralizing activity at serum dilutions of 1/10 or higher. The differences in antibody titres between the three groups of sera were most probably related to the past history of revaccination.

This investigation was supported in part by Public Health Service Grant AI–1632–16 VR from the National Institute of Allergy and Infectious Diseases, by the World Health Organization and by the Marcus T. Reynolds III Fund.
A new nephritogenic streptococcus
Authors: Duca Eugenia , Teodorovici Gr. , Radu C. , Vîţaˇ Alla , Talaşman-Niculescu Paula , Bernescu Elisabeta , Feldi C. , Roşca V.
Published: May 2009

A local milk-borne outbreak of 85 cases of sore throat with cervical lymphadenitis, a third of whom later developed acute glomerulonephritis as a complication, is described. Renal involvement was shown by Volhard's criteria, filtered fraction data and renal biopsy findings. From lymph-node biopsies from patients, from the pharyngeal exudate of patients and carriers, and from three samples of cow's milk, 16 strains of beta-haemolytic streptococci of Lancefield group C, type zooepidemicus subtype lactose-positive, were isolated.

The aetiological role of the streptococcus isolated in this outbreak was confirmed by autoserodiagnosis (precipitation tests with Lancefield's antigens and patients' sera) which in this case proved more valuable than antistreptolysin-O titration as evidence of infection.

Two of the 85 patients, 7 months after the acute phase of illness, show nephrotic oedema and hypertension as chronic sequelae.

We are pleased to express our gratitude to Dr M. T. Parker and Dr W. R. Maxted for much advice, and confirmation of our serological and biochemical findings.
The serological response and long-lasting resistance against infection with louping-ill virus in sheep immunized with a highly attenuated tick-borne encephalitis virus
Authors: Mayer V. , Blaškovič D. , Ernek E. , Libíková H.
Published: May 2009

The vaccination of sheep with one dose of the monkey-and mouse-attenuated tick-borne encephalitis virus (the Hy-HK 28 ‘2’ clone) causes seroconversion from negative into positive in 85% of animals. In sheep with pre-existing virus-neutralizing antibodies and increas of their titres was observed in 81%. The antibodies persisted for at least 12 months after the vaccination and during the summer period of grazing the number of serologically positive animals even increased.

The vaccinated animals, in contrast to the non-immune control sheep, developed no viraemia after challenge with the virulent louping-ill virus, performed 11 months after immunization.
The irreducible minimum in cross-infection control and isolation nursing
Authors: Hughes W. Howard
Published: May 2009

This is a survey of 10 years experience in trying to find out how to control hospital sepsis economically. We appear to have obtained reasonable improvements in hygiene by applying the teaching which has been given to students since the time of Leonard Colebrook. For our investigations we used only routine methods.

The order of importance of the factors in reducing cross-infection would appear to be: (1) single rooms for all septic cases and for those requiring protective isolation; (2) a sister supported in complete authority over anyone entering the unit; (3) a simple, inflexible drill to introduce an impermeable layer between the nurse or doctor and the patient—gloves and apron provide this; (4) overshoes and barrier mats; (5) hygienic disposal of linen; (6) an efficient wet dusting and floor cleaning system. Anything beyond this must be justified by saving of nursing time or some factor other than prevention of infection.
Further investigations on the airborne excretion of foot-and-mouth disease virus
Authors: Donaldson A. I. , Herniman K. A. J. , Parker J. , Sellers R. F.
Published: May 2009

Calf thyroid tissue cultures were found to be the most sensitive system in detecting virus collected in a large volume air sampler from boxes, where cattle, sheep and pigs infected with A and C strains of foot-and-mouth disease (FMD) virus were housed. It was confirmed with all strains of FMD virus tested that pigs excreted the most virus followed by cattle and sheep, but there was variation between strains, the highest virus recoveries being obtained from animals infected with O1and C Noville viruses. The results are discussed in relation to outbreaks of foot-and-mouth disease in Great Britain since 1954.
The late detection of respiratory syncytial virus in cells of respiratory tract by immunofluorescence
Authors: Gardner P. S. , McQuillin Joyce , McGuckin Rosemary
Published: May 2009

Paired nasopharyngeal secretions were studied in 27 infants infected with respiratory syncytial virus, one taken at onset of illness and one about 7 days later. Both specimens were examined by immunofluorescence and tissue culture for respiratory syncytial virus. In 25 out of 27 (93%) specific fluorescence was still present in cells of the convalescent specimen but was much duller. Virus was difficult to isolate in convalescent specimens; only 8 out of 27 (26 %) proved to be positive. Eight single secretions which were taken late in a respiratory illness were also shown to have this altered fluorescence with absence of virus isolation. Preliminary experiments using antihuman globulin suggest that the findings may be due to the attachment of local secretory antibody to the cells causing ‘blocking’ of staining reaction.
Respiratory disease in a colony of rats: I. The natural disease
Authors: Lane-Petter W. , Olds R. J. , Hacking M. R. , Lane-Petter M. E.
Published: May 2009

An epidemic of acute respiratory disease in a colony of CFE rats is described, the main laboratory findings are recorded and its aetiology discussed.

The epidemic showed that severe respiratory disease varying from peracute to chronic was associated with infection of the lungs with a mycoplasma but that mycoplasmas could be present in rats, even in the lungs, without signs of disease, thus suggesting that one or more other factors were involved. It is also evident that there are strain differences in the susceptibility of rats to this disease.
Some properties of calciferol as a rodenticide
Authors: Greaves J. H. , Redfern R. , King R. E.
Published: May 2009

The potentiality of calciferol (alone and combined with warfarin) for the control of commensal rats and mice has been examined in the laboratory. Nearly all animals fed on 0·1% calciferol for 2 days died. Though illness usually reduced food intake after the first 24 hr. there was no sign of aversion to the poison at 0·1 % – which is considered to be the lowest concentration suitable for use against Rattus norvegicus, R. rattus and Mus musculus in the field. There was some indication that resistance to warfarin in R. norvegicus may be correlated with susceptibility to calciferol. Toxicity tests with calciferol combined with warfarin indicated an additive effect between the compounds. No evidence for synergism was found however, although elsewhere there is some evidence for this.
The Globe Thermometer in Studies of Heating and Ventilation
Authors: Bedford T. , Warner C. G.
Published: May 2009

The effects of radiation and convection on the globe thermometer have been studied.

Equations have been obtained, and alignment charts constructed, for the calculation of mean radiation intensity and of equivalent temperature from readings of the globe thermometer, air temperature and air velocity.

The accuracy of these methods has been tested on observations made under industrial conditions. Taking direct thermopile observations as the standard, the mean radiation intensity values calculated from globe thermometer readings had an average error of 1·2 B.Th.U. per sq. ft. per hour. With eupatheoscope readings as standard, equivalent temperature estimates had a mean error of 1·2°.

It is concluded that, while globe thermometer readings alone are unreliable as indications of the effects of the thermal environment, valuable results can be obtained by using the instrument along with an ordinary thermometer and a silvered kata-thermometer.
The Relation between Health and Intelligence in School Children
Authors: England Norman J.
Published: May 2009

The object of the inquiry reported upon in this paper was to determine whether there was any measurable association between the development of intelligence and the incidence of disease in school children.
Two Serologically Different Groups among the True Cholera Vibrios
Authors: Heiberg Børge
Published: May 2009

By careful investigation of the somatic antigens of the true cholera vibrios —the strains containing O factor I according to Gardner's grouping (1935)— it was found, as did Scholtens (1933), that the cholera vibrios may be divided into two serological groups: one containing the antigenic factor A and the other the antigenic factors AB.

This finding may be of importance in epidemiological investigations and in the preparation of vaccines.