- Volume 2, Issue 2, 1969
Volume 2, Issue 2, 1969
- Articles
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Composition of Cell Walls of Clostridium Sordellii and Clostridium Bifermentans and its Relation to Taxonomy
More LessSUMMARYThe cell walls of Clostridium sordellii and Cl. bifermentans agreed in their amino acid and amino sugar pattern, but differed strikingly in their mono- saccharide patterns. Sixteen Cl. sordellii strains contained only glucose as monosaccharide in their cell walls, whilst in Cl. bifermentans three sugars were found: in 13 strains glucose, mannose and rhamnose and in the 3 others glucose, galactose and rhamnose. The sugar pattern in formamide extracts of cells is sufficient for diagnostic purposes.
Out of 16 Cl. sordellii strains 14 are ureolytic—the remaining two (one of which is pathogenic) are not. These strains are probably mutants that have lost a postulated transport mechanism for urea. Cell-free extracts of both Cl. sordellii and Cl. bifermentans possessed urease activity. Possibly Cl. bifermentans never possessed the postulated urease transport mechanism und is therefore not ureolytic.
Antigenic heterogeneity of Cl. sordellii and Cl. bifermentans strains, as determined by agglutination tests, could not be explained by the results of simple cell-wall analysis.
The physiology of Cl. sordellii and Cl. bifermentans cell walls is similar in many respects. The autolytic properties are particularly striking; autolysis could be prevented by heating. Heated cells (60 min. at 60°C, 20 min. at 100° or 120°C) are extremely sensitive to trypsin. The optical densities of suspensions of isolated cell walls of both organisms, whether heated or not, decreased rapidly in the presence of trypsin.
Although there are many similarities between Cl. sordellii and CL bifermentans, they are better regarded as separate species; the monosaccharide pattern in their cell walls seems sufficient to distinguish them.
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Sensitivity of the Genus Proteus to Chlorhexidine
More LessSUMMARYThe action of the antiseptic chlorhexidine has been tested against 205 strains of the genus Proteus. No strain was found to survive, under the conditions of the test, a concentration of 1 in 5000. The four species of the genus, however, varied in sensitivity. In general, Pr. mirabilis was the most resistant; Pr. rettgeri and Pr. morganii were the most sensitive; Pr. vulgaris tended to be less resistant than Pr. mirabilis and more so than Pr. rettgeri and Pr. morganii.
The same strains were also tested against a number of chemotherapeutic drugs. Evidence that resistance to chlorhexidine among Pr. mirabilis strains was associated with multiple drug-resistance could not be established.
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A Comparative Study of Standard Methods and Organ Culture for the Isolation of Respiratory Viruses
More LessSUMMARYFresh unfrozen specimens from 176 cases of acute respiratory infection and from 32 normal subjects, or patients without respiratory symptoms, were tested in parallel by direct inoculation into tissue cultures and suckling mice and also after the specimen had been passed in two organ cultures of human embryonic ciliated epithelium. Thirty-two agents were isolated by both methods: 26 only by the direct inoculation of tissue cultures and suckling mice, and 9 only after passage in organ culture.
Enteroviruses, herpes simplex virus and mumps virus were more readily isolated directly from the specimens than from the corresponding organ-culture fluid.
The only viruses isolated from the organ-culture fluids and not directly from the specimens were rhinoviruses. However, an almost equal number of these viruses were isolated directly from the specimens but not from the organculture fluid. It is postulated that these differences reflect the variation in the sensitivity to rhinoviruses of both the organ cultures and the kidney tissue cultures derived from different human embryos.
It is suggested that, in view of the limited supply of foetal material, it is uneconomical to test unfrozen specimens from respiratory infections in organ culture. This approach should be restricted to the examination of those specimens that fail to yield a possible aetiological agent by the standard methods.
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An Inhibitor of Reovirus in Sheep Serum
More LessSUMMARYYields of reovirus type 3 were depressed and cytopathic changes delayed when calf or sheep serum was present inthe culture medium. Both sera also neutralised free reovirus. Fractionation of pooled serum samples by DEAE- cellulose and Sephadex G-200 chromatography showed that in thecase of calf serum the inhibitory and neutralising activities were associated with the γG globulin fractions. Therefore it is likely that the inhibitory activity ofcalf serum is due entirely to the presence of neutralising antibody. In the case of sheep serum, however, neutralising and inhibitory activities were dissociated. Virus-neutralising activity in this case was maximal in the γG globulin fractions, whilst the inhibitory activityresided in the γM fraction. The inhibitory componentof sheep serum appears to act by blocking virus release.
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Laboratory Diagnosis of Epidemic Keratoconjunctivitis
More LessSUMMARYDuring an outbreak of epidemic keratoconjunctivitis in 1967, adenovirus type 8 was recovered from 57 of 186 patients investigated. Primary human embryo kidney and human amnion cell cultures were more efficient than either HeLa or rhesus monkey kidney cultures for isolation of this virus. Serological tests detected 21 additional infections. Haemagglutination inhibition, using human group-O cells, provided a convenient technique for detecting adenovirus-8 infections.
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Direct Haemagglutination by Mycoplasma Pneumoniae and its Inhibition by Immune Serum
More LessSUMMARYDirect haemagglutination of guinea-pig red cells by Mycoplasma pneumoniae has been demonstrated. Optimal haemagglutinin yields were obtained when the organisms were grown in shaker cultures, harvested on the day when the viable count was highest and concentrated ten-fold. Haemagglutination- inhibiting antibodies were demonstrated and quantitated in sera of immunised rabbits and of patients infected with M. pneumoniae.
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The Effect of Cyclophosphamide on Sendai Virus Infection of Mice
More LessSUMMARYCyclophosphamide was found to convert the mild Sendai virus infection of mice into a serious and sometimes fatal pneumonic illness, which appeared to be due to the failure of the mice to rid themselves of the infecting virus. The drug was shown to reduce the numbers of circulating white blood cells, to prevent the development of the mononuclear infiltration in the infected lung and to depress antibody production. It produced an initial depression of interferon production, but high concentrations of interferon were found in the lung during the late stages of the infection.
The significance of these findings is discussed in relation to the mechanisms of termination of virus infections and to the potential risk of respiratory disease during immunosuppressant therapy.
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The effect of Antilymphocyte Serum on Subcutaneous Staphylococcal Infections in Normal, Immune and Complement-Deficient Mice
More LessSUMMARYThe effect of antilymphocyte serum on subcutaneous staphylococcal lesions in normal, immune and C’5-deficient mice was studied. In general, the inflammatory response at 4 hr was suppressed or reduced, and the 24-hr count of non-virulent bacteria rose to the level normally reached by virulent strains, but no lesion developed. The effect of antilymphocyte serum on the severity of lesions due to virulent strains depended on the size of the inoculum, the strain of staphylococcus and the variety of mice used. The treatment of B10 D2 mice, whether normal or complement-deficient, with antilymphocyte serum increased the severity of the lesion.
Antilymphocyte serum had no effect on the action of α-lysin, but reduced the inflammatory response to cotton dust and to turpentine.
Immunised mice treated with antilymphocyte serum behaved more like unimmunised mice, but did not develop lesions.
When large doses of PS80 were administered, the complement-deficient strains of B10 D2 mice produced smaller early inflammatory responses, and developed bigger lesions containing more bacteria, than did normal B10 D2 mice.
The results are discussed in relation to the mode of action of antilymphocyte serum, the pathogenesis of staphylococcal lesions and the defensive role of complement.
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A note on Bacteriocine typing Techniques
More LessSUMMARYStrains of Pseudomonas pyocyanea and Shigella sonnei were tested for bacteriocine production both by the normal method and by a modification of it in which the producer strains were inoculated on to cellulose acetate membranes that had been placed on the surface of the culture medium. In only43.7 per cent, of 379 strains of Ps.pyocyanea were the results identical by the two methods.A higher correlation was noted in the case of Sh. sonnei and only 6 out of 89 strains of thisspecies gave different results by the two methods. We cannot recommend the use of cellulose acetate membranes in these bacteriocine typing techniques.
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Metabolism of the Lipoproteins of Serum by Leptospires: Degradation of the Triglycerides
More LessSUMMARYIncubation of rabbit serum for 24 hr with cultures of six strains of saprophytic leptospires brought about a large decrease, or the complete disappearance, of the triglycerides in the lipoproteins of the serum and a corresponding increase in the serum’s content of the free fatty acids. The mechanism underlying the associated changes produced in the electrophoretic pattern of the lipoproteins is discussed in relation to the analogous alteration caused by the lipoprotein lipase.
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Volumes and issues
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Volume 73 (2024)
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Volume 72 (2023 - 2024)
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Volume 71 (2022)
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Volume 70 (2021)
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Volume 69 (2020)
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Volume 68 (2019)
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Volume 67 (2018)
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Volume 66 (2017)
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Volume 65 (2016)
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Volume 64 (2015)
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Volume 63 (2014)
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Volume 61 (2012)
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Volume 60 (2011)
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Volume 58 (2009)
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Volume 54 (2005)
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Volume 53 (2004)
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Volume 52 (2003)
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Volume 51 (2002)
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Volume 50 (2001)
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Volume 49 (2000)
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Volume 48 (1999)
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Volume 47 (1998)
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Volume 46 (1997)
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Volume 45 (1996)
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Volume 44 (1996)
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Volume 43 (1995)
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Volume 42 (1995)
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Volume 41 (1994)
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Volume 40 (1994)
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Volume 39 (1993)
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Volume 38 (1993)
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Volume 37 (1992)
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Volume 36 (1992)
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Volume 35 (1991)
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Volume 34 (1991)
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Volume 33 (1990)
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Volume 32 (1990)
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Volume 31 (1990)
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Volume 30 (1989)
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Volume 29 (1989)
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Volume 28 (1989)
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Volume 27 (1988)
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Volume 26 (1988)
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Volume 25 (1988)
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Volume 24 (1987)
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Volume 23 (1987)
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Volume 22 (1986)
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Volume 21 (1986)
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Volume 20 (1985)
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Volume 19 (1985)
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Volume 18 (1984)
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Volume 17 (1984)
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Volume 16 (1983)
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Volume 15 (1982)
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Volume 14 (1981)
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Volume 13 (1980)
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Volume 12 (1979)
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Volume 11 (1978)
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Volume 10 (1977)
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Volume 9 (1976)
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Volume 8 (1975)
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Volume 7 (1974)
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Volume 6 (1973)
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Volume 5 (1972)
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Volume 4 (1971)
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Volume 3 (1970)
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Volume 2 (1969)
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Volume 1 (1968)