1.
Lannering, Birgitta, 1948, et al.
(author)
Early onset group B streptococcal disease. Seven year experience and clinical scoring system.
1983
In: Acta paediatrica Scandinavica. - 0001-656X. ; 72:4, s. 597-602
Journal article (peer-reviewed) abstract
Early onset group B streptococcal disease was reviewed for the seven year period between 1975 to 1981 at Vanderbilt University Medical Center. One hundred and twenty cases were identified. The disease varied from asymptomatic bacteremia to fatal cardiopulmonary collapse. Factors associated with a poor outcome were prematurity, low Apgar score at 5 min, the presence of shock, leukopenia, rupture of membranes for more than 12 hours, and a delay in treatment after the onset of symptoms. A scoring system for probability of death based on these 6 factors was then developed. Over the seven year period mortality decreased from 50% to 10%. The only factor identified with the decrease in mortality was a significant decrease in the number of hours between the onset of symptoms and the beginning of treatment. Early recognition and prompt treatment seem to be the major causes of the decreasing mortality over the seven years of this report.
2.
Truedsson, L, et al.
(author)
Protein HC-IgA complexes carry antibody activities
1988
In: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 27:2, s. 201-208
Journal article (peer-reviewed) abstract
Polyclonal protein HC-IgA complexes (HC-IgA) were isolated from two different serum pools. Their hydrodynamic volumes were found to be slightly greater than that of monomeric IgA but less than that of dimeric IgA. Sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis of reduced and carboxymethylated complexes followed by immunoblotting showed that the complexes contained normal light and heavy Ig chains, and one polypeptide chain with Mr = 90,000, which carried both IgA alpha chain and protein HC epitopes. Enzyme-linked immunosorbent assays (ELISA) demonstrated that the isolated HC-IgA carried about 0.1 and 4%, respectively, of the antibody activities against one carbohydrate antigen (Yersinia enterocolitica serotype 0:3 lipopolysaccharide) and one protein antigen (rabbit IgG, i.e. antigen for rheumatoid factors) of the IgA populations of the two serum pools. HC-IgA with rheumatoid factor activity could also be demonstrated in the unfractionated serum pool. The binding of HC-IgA in the ELISA was not mediated through its protein HC part. The present observations show that HC-IgA carries antibody activities and constitutes a unique class of IgA complexes, since it does not dissociate under denaturating conditions after reduction. It may represent a further biological potential of the humoral immune system.
3.
Alksnis, M., et al.
(author)
Use of synthetic oligodeoxyribonucleotides for type-specific identification of coxsackie B viruses
1989
In: Molecular and Cellular Probes. - : Elsevier BV. - 0890-8508 .- 1096-1194. ; 3:2, s. 103-108
Journal article (peer-reviewed) abstract
Synthetic oligodeoxyribonucleotides were used for type-specific identification of members of the coxsackie B virus group by nucleic acid hybridization. Two pairs of oligonucleotide chains were constructed based on nucleotide sequences in the VP1 regions of coxsackieviruses B3 and B4. Each labelled probe had a length of 24 nucleotides. The results showed that the oligonucleotide hybridized in a type-specific manner when assayed with extracts from cells infected with all different coxsackie B viruses. A method based on similar principles may thus be used for enterovirus typing.
4.
Anna, B., 1960-, et al.
(author)
Animal model of rotavirus infection in rabbits - protection obtained without shedding of viral antigen.
1989
In: Archives of Virology. - : Springer. - 0304-8608 .- 1432-8798. ; 107:3-4, s. 237-251
Journal article (peer-reviewed) abstract
A small animal model was developed in order to investigate the pathogenesis and immunology of rotavirus infections and to study the interaction of different virus strains. Seronegative rabbits of the breed French Lop were used. Two rabbit rotavirus strains, belonging to the same serotype, were used: 82/311 F and R-2, both isolated during diarrhoeal outbreaks in commercial rabbitries. The animals were inoculated orally. The viral shedding and the serological response was monitored by ELISA. Initially six weeks old kits were given four different doses of strain R-2. With doses ranging from 1 x 10(3) to 1 x 10(6) TCID50 all animals seroconverted, but for the lowest dose no viral excretion could be detected. No clinical symptoms were observed. Subsequently the age periods during which the animals were susceptible to the strain R-2 was investigated. The rabbits seroconverted and shed rotavirus antigen, independent of age of six or 22 weeks. None of the animals had diarrhoea. Administration of strain 82/311 F did not result in viral shedding, independently of dose, but all the animals seroconverted. It was also shown for the strain R-2 that when challenging with the same strain four weeks post inoculation that the animals were protected; no viral shedding was detected at the second infection. Strain 82/311 F gave protection against R-2 when the rabbits were challenged four weeks post inoculation.
5.
Bergqvist, Åsa, et al.
(author)
Smittspridning av campylobacter inom fjäderfäslakteri
1986
In: XV Nordiska veterinärkongressen – 15th Nordic Veterinary Congress, Stockholm 28/7–1/8 1986. - Stockholm : Sveriges Veterinärförbund. - 9178106435 ; , s. 355-358
Conference paper (peer-reviewed)
6.
Bergström, Sven, 1950-
(author)
Chromosomal β-lactamases in enterobacteria and in vivo evolution of β-lactam resistance
1983
Doctoral thesis (other academic/artistic) abstract
The ß-lactam antibiotics are the most important antibacterial agents in the treatment of infectious diseases. A severe problem in ß-lactam therapy is the emergence of ß-lactam resistant bacteria. Clinical ß-lactam resistance is most often due to the production of ß-lactamases. ß-lactamase genes reside either on plasmids or on the chromosome. The aim of this study was to acquire an understanding of organisation and regulation of chromosomal ß- lactamase genes in different Gram negative species and to elucidate the mechanisms for ampC hyperproduction in the in vivo situation.By DNA hybridization with an ampC probe from Escherichia coli K-12 it was shown that other Gram negative bacteria contained an artpC like chromosomal gene, suggesting a common evolutionary origin. Furthermore, the preceding frd operon that overlaps the ampC gene in E. coli K-12 was found to be much more conserved than the ampC gene in the bacterial species investigated.The ampC and frd opérons in Shigella sonnei and Citrobacter freundii were cloned and characterized by physical mapping. The respective maps were compared to the ampC and frd region in E. coli K-12. The physical map of Sh. sonnei was almost identical to the E. coli K-12 map, whereas in C. freundii only the frd region exhibited any considerable homology. Moreover, in C. freundii, the anpC and frd regions were separated by 1100 basepairs. It is suggested that this DNA is involved in the induction of ß-lactamase production in this organism. A hypothesis for the evolution of the anpC operon in enterobacteria is presented.By isolating and characterizing six ß-lactam resistant clinica], isolates of E. coli hyperproducing the dhrcmosomal ß-lactamase, genetic mechanisms for in vivo evolved resistance was aimed at. These isolates exhibited a 24-48 fold increase in ß-lactamase production. The ß-lactamase produced was found to be biochemically and immunologically identical to the ß-lactamase produced by E. coli K-12. The ampC control region of these six E. coli isolates was DNA-seqenced. The cause of ß-lactamase hyperproduction in five of the clinical E. coli isolates, identical in the DNA segment sequenced, was due to a strong novel ampC promoter displaced 5 bp upstream of the ampC promoter defined in E. coli K-12. The ß-lactamase hyperproduction in the sixth clinical isolate was shown to be caused by two mutations affecting both the promoter and the attenuator in the regulatory region defined by E. coli K- 12. The obtained changes were sufficient to explain the increase in ampC ß- 1 act ama se expression exhibited in these clinical E. coli isolates.Sequence analysis of the ampC control region in Sh. sonnei revealed that it was, with one exception, identical to the one found in the five clinical E. coli ß-lactamase hyperproducers. The only difference was in a position that creates the strong novel ampC promoter in the E. coli hyperproducers. By isolating spontaneous Sh. sonnei mutants with a 40-fold increase in ß-lactamase production carrying the same novel ampC promoter as the clinical E. coli isolates it was concluded that this DNA segment has been transferred in vivo frcm Shigella to E. coli across the species barrier.
7.
Berndtson, Eva, et al.
(author)
Incidence of campylobacter on a broiler farm
1987
In: The IVth International Workshop on Campylobacter Infections, Department of Clinical Bacteriology, University Göteborg, June 16–18, 1987, Göteborg, Sweden. ; , s. Abstract no. 17-
Conference paper (peer-reviewed)
8.
9.
Bredberg, Anders, et al.
(author)
4-quinolone antibiotics : Positive genotoxic screening tests despite an apparent lack of mutation induction
1989
In: Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis. - : Elsevier BV. - 1879-2871 .- 0027-5107. ; 211:1, s. 171-180
Journal article (peer-reviewed) abstract
The effects of different 4-quinolone antibiotic derivatives (4-Qs) in a number of short-term tests commonly employed for the evaluation of genetic toxicity were studied. Incorporation of [3H]thymidine into mitogen-stimulated peripheral blood lymphocytes was strongly enhanced at a low concentration (1.56 μg/ml) for most of the tested 4-Qs, whereas DNA strand breakage in lymphoblastoid cells was evident only for ciprofloxacin (10 μg/ml and upwards), ofloxacin (80 μg/ml) and norfloxacin (160 μg/ml). Ciphrofloxacin induced a significant amount of unscheduled DNA synthesis, but was found to be negative in a shuttle vector plasmid mutation test. Ciprofloxacin (80 μg/ml) did not inhibit enzymes involved in the early steps of pyrimidine biosynthesis. Cell growth was slightly depressed at a concentration of 20 μg/ml, becoming marked at 80 μg/ml. In conculsion, this study seeks to contribute to an improved evaluation of genotoxic screening test data, by focuding attention on the conflicting effects imposed by the 4-Qs on a battery of such tests.
10.
Byström, Anders S., et al.
(author)
A functional analysis of the repeated methionine initiator tRNA genes (IMT) in yeast
1989
In: Molecular General Genetics. - 0026-8925 .- 1432-1874. ; 216:2-3, s. 276-286
Journal article (peer-reviewed) abstract
Standard laboratory yeast strains have from four to five genes encoding the methionine initiator tRNA (IMT). Strain S288C has four IMT genes with identical coding sequences that are colinear with the RNA sequence of tRNA(IMet). Each of the four IMT genes from strain S288C is located on a different chromosome. A fifth IMT gene with the same coding sequence is present in strain A364A but not in S288C. By making combinations of null alleles in strain S288C, we show that each of the four IMT genes is functional and that tRNA(IMet) is not limiting in yeast strains with three or more intact genes. Strains containing a single IMT2, 3 or 4 gene grow only after amplification of the remaining IMT gene. Strains with only the IMT1 gene intact are viable but grow extremely slow; normal growth is restored by the addition of another IMT gene by transformation, providing a direct test for IMT function.
