bluuebunny/crossref_metadata_2025_split huggingface dataset:
The 6-hour soluble antigen production test for comparing the infectivity of influenza virus preparations
Authors: Finter N. B. , Beale A. J. 
Published: May 2009

1. The 6 hr. soluble antigen production test for comparing the infectivity of influenza virus preparations is described in detail. Dilutions of the preparations are inoculated intra-allantoically into groups of fertile eggs, and after 6 hr. of incubation the amounts of soluble antigen formed in their chorio-allantoic membranes are determined. Reproducible results can be obtained.2. The similar test, in which haemagglutinins in the chorio-allantoic membranes are measured 6 hr. after inoculation of seed virus, is less accurate and less sensitive.3. Eggs of different ages of incubation form different amounts of soluble antigen in their chorio-allantoic membranes in 6 hr. when inoculated with the same amounts of virus.
Further studies on the mechanism of mosquito transmission of myxomatosis in the European rabbit
Authors: Day M. F. , Fenner Frank , Woodroofe Gwendolyn M. , McIntyre G. A. 
Published: May 2009

Proof of the existence of multiplication of myxoma virus in mosquitoes has been sought by a variety of experiments with Aedes aegypti and Anopheles annulipes. All were completely negative. All features of transmission are compatible with a purely mechanical and none is compatible with a ‘biological’ mechanism.In mechanical transmission important features of the infected animal host are the number and accessibility of viruliferous skin lesions, and the location and concentration of virus in these lesions.By inducing mosquitoes to probe through infectious skin lesions and subsequently permitting them to make many successive probes on marked skin sites on the backs of susceptible rabbits, it has been possible to obtain quantitative information on the median minimum virus load of probing mosquitoes, and the rates of loss due to probing and the passage of time.A preparation of myxoma virus suspended in normal rabbit serum had a half-lifetime of 11 days at 4° C., 5 days at 18–20° C., and 31 hr. at 27–28° C. Apart from losses due to probing (about 12% of the virus load per probe) viable virus on the proboscis of the mosquito probably disappears at about the same rates.
Adsorption of tetanus toxin by brain tissue
Authors: Fulthorpe A. J. 
Published: May 2009

The potency of tetanus toxin as measured by combining power is markedly reduced by mixing with fresh or dried preparations of rabbit brain, and by dried horse brain. A number of other bacterial toxins are not so affected.Tissues other than brain were not found to have this specific effect.The state of division of the tissue, the time over which adsorption takes place, and the relative proportions of adsorbate and adsorbent affect the quantity of toxin removed. When the quantity of adsorbent and the volume of adsorbate are constant, the quantity of toxin removed per gram of adsorbent is proportional to the equilibrium concentration of the toxin, but not directly so.Some of the tetanus toxin adsorbed onto fresh or dried preparations of brain tissue can be recovered by washing with physiological saline.Brain toxin mixtures, when treated with tetanus antitoxin, neutralized an amount of antitoxin about equivalent to the toxin retained by the tissue.Successive adsorption of tetanus toxin by brain tissue leads to an alteration in the ratio L + per ml./Lf per ml. of the toxin.The adsorption capacity of brain tissue may be reduced by first washing with tetanus toxoid or heated toxoid or with diphtheria toxoid.
The Isolation of Salmonella Organisms from Fresh Fish Sold in a Colombo Fish Market
Authors: Gulasekharam J. , Velaudapillai T. , Niles G. R. 
Published: May 2009

Of 629 fresh fish (sixty-five species) and forty-two samples of fish-washings obtained from a fish-market in Colombo, and investigated bacteriologically for the presence of Salmonella, thirty-nine fish (twenty-four species) and five samples of washings were found to be harbouring the organisms.Of fifteen salmonella types found, all except Salm. chittagong and Salm. oranienberg had been previously isolated from human and animal sources in Ceylon.The presence of Salmonella in the intestines of fresh fish examined suggested that the organisms had entered the live fish, whilst their isolation from the gills and fish-washings was evidence that the fish could have been contaminated post-mortem.The significance of these findings in relation to hazard to health is discussed.
The immunization of mice, calves and pigs against Salmonella dublin and Salmonella cholerae-suis infections
Authors: Smith H. Williams 
Published: May 2009

1. Antisera prepared in rabbits or calves against live Salmonella dublin gave mice some degree of protection against oral infection with this organism. Both antiserum prepared against heat-killed S. dublin and dead vaccines prepared in a variety of ways produced little or no immunity.2. A rough variant of S. dublin of low virulence for mice, no. 17 A, produced a reasonably good immunity against oral infection with S. dublin in mice but not in calves. Mice that survived injection with another rough variant that possessed a considerable degree of virulence for these animals, no. 51, were immune to oral infection with S. dublin. Experimentally and naturally, this variant and, to a lesser extent, 9S, a smooth variant of S. gallinarum of reduced virulence, produced an appreciable degree of immunity in calves against S. dublin infection; none of the calves injected with these variants showed any signs of ill-health as a result.3. Two rough variants of S. cholerae-suis, nos. 3 and 6, possessed a considerable degree of virulence for mice; those that survived were resistant to oral infection with S. cholerae-suis. Experimentally and naturally, both variants produced an appreciable degree of immunity in pigs.4. Mice that survived vaccination with the rough S. cholerae-suis variant no. 6 were resistant to oral infection with S. dublin. Those that survived vaccination with the rough S. dublin variant no. 51 were resistant to oral infection with S. cholerae-suis and S. typhi-murium; they were fully susceptible to parenteral administration of Escherichia coli and Erysipelothrix rhusiopathiae.5. Vaccination with S. cholerae-suis variants 3 and 6 and S. dublin variant 51 provoked the formation of H but not O antibodies. These variants were never found to mutate from rough to smooth in vitro or in vivo.
Viruses in acute respiratory infection in a general community
Authors: Banatvala J. E. , Anderson T. B. , Reiss B. B. 
Published: May 2009

The aetiology of acute respiratory infections between September 1962 and August 1963 was studied in two general practices in Cambridge. These practices were reasonably representative of the permanent community of Cambridge.There were 592 spells of acute respiratory infection in the combined practices, representing an incidence of 11·4 spells per 100 persons. Children aged 0–4 had the highest rates (51·6 spells per 100 persons).It was possible to establish a diagnosis in 62·5% of cases investigated. Influenza and parainfluenza infections featured prominently, being responsible between them for 46·6% of all respiratory infections investigated. From September 1962 to January 1963, parainfluenza viruses were prevalent, causing acute laryngo-tracheo-bronchitis in children (croup), and an influenza-like illness in adults. From February to April 1963, influenza A (Asian) was epidemic, a clinical diagnosis of influenza being frequently confirmed by laboratory studies at this time. There were nine cases of Eaton agent infection, seven of which had PAP, the other two being family contacts who later developed influenza-like illnesses.Adenovirus (four cases), and RS virus (three cases) were not prevalent to any large extent in Cambridge during the survey.
A comparative study of a plaque and quantal method for assaying the neutralizing activity of antisera to type 1 poliovirus
Authors: Higgins P. G. 
Published: May 2009

Sera from two rabbits bled after one, two and three inoculations of concentrated type 1 poliovirus tissue culture fluid were assayed for neutralizing activity by a quantal and a plaque method. The plaque counts in these tests have been shown to approximate to a Poisson distribution as determined by the relationship between the variance and the mean of replicate counts. However, there is a considerable scatter of the points in such a comparison and this accounts for the absence of the expected increase in accuracy of this plaque method over the quantal.The relationship between the antibody content of the sera determined by the two methods is non-linear. This can be attributed to inhomogeneity of the antibody produced which increases with the number of antigenic stimuli given.
Experiments on the spread of colds: II. Studies in volunteers with coxsackievirus A21
Authors: Buckland F. E. , Bynoe M. L. , Tyrrell D. A. J. 
Published: May 2009

The amount of virus in nasal and other secretions after infection with coxsackievirus A 21 has been measured daily in ten volunteers. Most virus was found in nasal secretion, less in throat secretion and small amounts were found intermittently in the saliva and faeces.Virus administered as small drops or on a swab was more infectious for man if put on to the nasal mucosa than on to the throat or outside the nose. It was also infectious by the conjunctival route.Virus was sprayed in droplets of about the same size range as those found in a natural sneeze. Virus survived better in larger (> 4 μ) than in smaller droplets. About one tissue culture infectious dose of virus in such droplets also infected volunteers.The symptoms produced by these experimental infections have been analysed. The disease produced was largely independent of the dosage and route of infection. Those with pre-existing antibody resisted infection better than those with no antibody. Antibody rises were detected in about two-thirds of infected volunteers.Volunteers with colds shed virus in large drops on sneezing, or into the handkerchief on blowing the nose, but virus was recovered from the air only after simulated sneezes by volunteers with high concentrations of virus in their nasal secretions. Virus died off rapidly on fabric at room temperature and humidity, and was only resuspended as airborne droplets when large doses such as 0·02 ml. of virus of high titre (107·5 TCD 50/ml.) were used.Infection was transmitted from an infected volunteer to an uninfected partner living in the same flat in three out of twenty tests. Infection was not transmitted in experiments when volunteers mixed for a few hours with subjects with colds, or inhaled air into which a subject with a cold had just sneezed.
Toxicity tests on suspected warfarin resistant house mice (Mus musculus L.)
Authors: Rowe F. P. , Redfern R. 
Published: May 2009

1. Residual populations of wild house mice (Mus musculus L.) were trapped alive in premises where poison treatments with 0·025% warfarin bait had been reported to be ineffective.2. In the laboratory the individually caged mice were fed 0·025% warfarin in a sugar/oil/coarse oatmeal base. In toxicity tests lasting 10 and 21 days, the total mortality was low and the rate of death slow compared with mice drawn from habitats not treated with warfarin.3. It is suggested that tolerance to warfarin in M. musculus either is polygenically based or is controlled by a single major gene influenced by modifiers and that these hard-to-kill populations have arisen through selection during successive control treatments.
Experiments on the communion cup
Authors: Hobbs Betty C. , Knowlden Jill A. , White Anne 
Published: May 2009

Experiments were made to find out whether the common communion cup is likely to serve as a vehicle for the transmission of infection.A silver chalice and sacramental wine containing 14·5% of alcohol were used. Observations with volunteers showed that the number of organisms deposited on the rim of the chalice varied from person to person, but was usually quite small—less than 100.Rotation of the cup was of no benefit except to those partaking during the first round, since the saliva deposited on the rim by each person in turn remained to contaminate the cup during the second round, and the combined effect of the alcohol and the silver of the chalice was not rapid enough to destroy the contaminating organisms before rotation of the cup was completed.On the other hand the use of a linen cloth or purificator led to a diminution of about 90% in the bacterial count of the cup.Organisms in saliva deposited on the interior of the dry chalice suffered some diminution in numbers within 8 min., presumably as the result of the disinfectant action of the silver, but the effect was too small to be of significance.When suspended in wine and deposited on the internal surface of the chalice Escherichia coli suffered a substantial reduction within 3 min., Streptococcus pyogenes was destroyed completely; but Staphylococcus aureus was affected to a much less extent.Various experiments designed to measure the disinfectant action of wine, and of silver and wine together, showed that the augmenting effect of silver on the disinfectant action of the alcohol was quite small. Strep. pyogenes proved to be far more sensitive to alcohol than Esch. coli, Staph. aureus and Serratia marcescens. Under the conditions of the experiment these last three organisms were not destroyed for 10–12 min., whereas Strep. pyogenes perished within 1½ min.The results of our work are in general agreement with those of previous workers, and show that the organisms deposited on the rim of the communion cup are not destroyed within the short time—5 sec. as an average—elapsing between the partaking of the sacrament by each successive communicant.It must therefore be admitted that the common communion cup may serve as a means of transmitting infection. Reasons are given, however, for believing that the risk of transmission is very small, and probably much smaller than that of contracting infection by other methods in any gathering of people.Such risk as there is could be greatly diminished by the use of a purificator for wiping the cup between each communicant, and could be abolished completely by substituting individual cups or by the practice of intinction.
Genetic marker studies of poliovirus: I. Natural variation
Authors: Cossart Yvonne E. 
Published: May 2009

The properties of naturally occurring poliovirus strains of each serotype have been studied using three marker tests: the R.C.T.40test, intratypic serodifferentiation and, for type 1 strains only, inhibition by dextran sulphate.The results show that while most strains resemble the prototype strain of the same serotype, considerable natural variation exists, especially in the ability to grow at temperatures between 39° and 40° C.No correlation has been found between the results of the tests on individual strains and it is concluded that no single test is sufficient to characterize a strain.
Low-temperature preservation of Leptospira, preliminary communication
Authors: Coghlan Joyce D. , Lumsden W. H. R. , McNeillage G. J. C. 
Published: May 2009

1. A simple method for the long-term viable-preservation of samples of Leptospira suspensions is described. Quantities of about 25 μl., with the addition of 77·5 % glycerol, are introduced into capillary tubes, cooled slowly to −79° C. and stored at that temperature.2. More than half the attempts were successful in re-establishing growth in culture after storage at −79° C. for periods up to 27 months.3. The possibility that the method could be used for establishing ‘banks’ of standard Leptospira material for reference is discussed.
A prospective study of staphylococcal infection and its prevention among infants and mothers after childbirth in hospital and at home
Authors: Baber K. G. , Corner Beryl , Duncan Ethel H. L. , Eades Sheila M. , Gillespie W. A. , Walker Sarah C. B. 
Published: May 2009

Staphylococcal colonization and infection were studied prospectively in infants, mothers and households after childbirth at home and in hospital. Infants were treated prophylactically with frequent applications of ‘Ster-zac’ hexachlorophane dusting powder. Some were treated in addition with ‘Naseptin’ nasal disinfectant cream.The incidence of staphylococcal sepsis in infants was much less than before the adoption of hexachlorophane prophylaxis. The sepsis rate was further reduced when ‘Naseptin’ was used in addition to hexachlorophane. Of the two prophylactic agents, hexachlorophane was the more convenient and probably the more effective. ‘Naseptin’ was difficult to employ correctly and unsuitable for routine use.The treatment of infants with disinfectants reduced nasal carriage markedly in infants and to a smaller extent in mothers. Both agents contributed to the reductions which persisted for some weeks after treatment ceased.Breast abscesses were almost entirely confined to mothers of infants who became nasal carriers by the second week of life.Staphylococcal colonization of infant's skin was greater when they wore impervious garments, probably because skin moisture increased.
Studies on the epizootiology of rinderpest in blue wildebeest and other game species of Northern Tanzania and Southern Kenya, 1965–7
Authors: Taylor W. P. , Watson R. M. 
Published: May 2009

A serum neutralization test was used to determine the incidence of rinderpest antibodies in populations of blue wildebeest (Connochaetes taurinus albojubatusThomas) occurring in the Serengeti-Mara districts of N. Tanzania and S. Kenya. By correlating the age of animals at the time of shooting with the presence or absence of antibodies it was possible to outline the course of rinderpest in these animals over the period 1961–7.Serengeti migrant wildebeest were extensively infected in 1961, but not in 1962 or any subsequent year. No samples have been collected from this group since mid-1966. Kirawira resident wildebeest were last infected in 1961 according to samples collected in February 1967. Two of 13 animals born into the Mara resident population in late 1961 or early 1962 were found to possess antibodies, together with a high proportion (74%) of animals born in early 1961. This finding was considered indicative of a rinderpest epizootic in this group in the terminal weeks of 1961. No subsequent infection occurred in Mara wildebeest between 1962 and March 1966. Ngorongoro resident wildebeest were infected in the second half of 1962 but have remained free of rinderpest from 1963 until at least April 1966.The findings of the present survey were compared and contrasted with results of a similar study carried out some 2 to 3 years previously.Field strains of bovine rinderpest virus were isolated from the Loliondo district of N. Tanzania in November 1965 and March 1966. Serum samples from buffalo, eland, impala, warthog, and resident wildebeest which inhabited areas adjoining the two outbreaks failed to provide evidence of any recent epizootic in game animals. Circumstantial evidence indicated that the virus could have persisted in the Loliondo area since 1961. Two resident wildebeest born in 1963 and 1964 respectively, were thought to have been infected during a period when the disease went unrecognised. Serengeti migrant wildebeest were not found to have been infected after a period of potential contact with sick cattle in March 1966.
Nasal and skin carriage of Staphylococcus aureus by patients undergoing surgical operation
Authors: Polakoff Sheila , Richards I. D. G. , Parker M. T. , Lidwell O. M. 
Published: May 2009

Nasal, perineal, axillary and hand swabs collected from 361 patients immediately before operation were examined for Staphylococcus aureus.The organism was isolated more often from all three skin sites in nasal carriers of Staph. aureus than in non-carriers.Twelve per cent of the patients, and 4 % of those with negative nose swabs were perineal carriers. Two per cent were heavy perineal carriers of Staph. aureus strains which could not be isolated by direct culture from a nasal swab. Staphylococcal strains from these heavy, independent, perineal carriers were more often resistant to tetracycline than were strains from nasal carriers.
Carrier rate of salmonellas in sheep and goats and its public health significance
Authors: Kumar S. , Saxena S. P. , Gupta B. K. 
Published: May 2009

SUMMARYTo find out the salmonella carrier rate, 1980 samples comprising faeces, mesenteric lymph nodes, liver and spleen were collected from 812 sheep and 683 goats slaughtered for food. In all 72 salmonella strains from 51 animals (25 sheep and 26 goats) were isolated. These represented 22 salmonella serotypes. The public health significance of these findings is discussed.
Elevated temperature technique for the isolation of salmonellas from sewage and human faeces
Authors: Nabbut Nassim H. 
Published: May 2009

SUMMARYModified Moore's swabs, placed in sewers for 5 days, were used to concentrate salmonellas from sewage. Duplicate cultures of swab strips in selenite broth were incubated at 41 and 37°C. respectively.Salmonellaorganisms were recovered consistently from the swabs when the enrichment broths were incubated at 41°C., However, when equal portions of the same swabs were incubated at 37°C., only 22% of them yieldedSalmonellaorganisms. These results indicate an advantage in incubating the selenite broths at 41°C. rather than 37°C. in attempting to isolate salmonellas from sewage.One hundred and fifty faecal samples were examined for salmonellas by culture in selenite broths incubated at 41 and 37°C. Twelve (8%) samples were positive at 41°C. compared to only 10 (6·7%) positive samples at 37°C. This difference is not statistically significant to indicate an advantage of the elevated-temperature of incubation over the conventional temperature in attempting to isolate salmonellas from human faeces. Moreover, results of the recovery rates ofS. paratyphi B, S. typhi, andS. typhimuriumindicate that an incubation temperature of 37°C. is more appropriate for recovering salmonellas from artificially infected faecal samples than an incubation temperature of 41°C. This stresses the inability of laboratory studies to mimic conditions in nature.
Salmonella serotypes isolated from tortoises and frogs in Istanbul
Authors: AnĞ Ö. , Özek Ö. , Çetin E. T. , Töreci K. 
Published: May 2009

SUMMARYThe incidence of Salmonella in tortoises and frogs captured in Istanbul was studied. From 31 out of 40 tortoises (77·5%) and from 16 out of 311 frogs (5·1%) salmonella strains belonging to 18 and 14 serotypes respectively were isolated.
Electron-microscopic study of measles virus in lymphocytes of affected children
Authors: Narang H. K. 
Published: May 2009

SUMMARYTwo different types of inclusion bodies have been found by electron-microscopy in the cytoplasm of sectioned lymphocytes from children infected with measles.The first is tubular, 18 nm. internal diameter, embedded in osmiophilic material, and is found during the incubation period. It is not thought to be specific for measles, and is probably identical with structures recently reported in HEp-2 cell lines and tumour tissue.The second type is less obviously tubular and morphologically resembles measles nucleocapsid. This was found only after the rash had appeared.