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M Jonsson

Publications and source records attributed to M Jonsson.

At least 19 recordsLinked to original sources
PubMed1998

A comparative study of the effectiveness of calcium propionate and calcium chloride for the prevention of parturient paresis in dairy cows.

The efficacy of calcium propionate for the prevention of parturient paresis (milk fever) was compared with that of calcium chloride using 194 cows that had experienced milk fever during the previous calving. The cows were mainly of the Swedish Red and White and Swedish Friesian breeds and were divided randomly into an experimental group (n = 99) and a control group (n = 95). The cows in the experimental group received up to six boluses of 20 g of calcium as calcium propionate between 36 h before and 24 h after calving; the cows in the control group received up to four doses of 54 g of calcium as a commercially available oily solution of calcium chloride during the same period. Incidence of milk fever was recorded as the percentage of cows that were treated by a veterinarian because they showed clinical signs of the disease and had a blood calcium concentration less than 8.0 mg/dl. Twenty-five (25.3%) cows in the experimental group and 22 cows (23.2%) in the control group developed milk fever. The incidence of milk fever for cows in both groups was significantly lower than the 36.0% found in 713 cows that had experienced milk fever during their previous calving but received no prophylactic treatment. Therefore, calcium propionate was considered to have had a significant preventive effect, comparable with that of calcium chloride.

Animals↗
PubMed1997

Effects of local changes in the helix flexibility on electrophoretic migration of DNA in agarose gel.

We present a study of how kinks, flexible bends, and flexible joints in the DNA helix, induced by binding cis-diamminedichloroplatinum(II) (cis-DDP), transdiamminedichloroplatinum(II) (trans-DDP), and chlorodiethylenetriammineplatinum(II) (dien-Pt) to the DNA, affect the electrophoretic migration of DNA in agarose gels. For long DNA the conformation oscillates between extended and compact states during the migration, as for native DNA. The presence of flexible joints decreases both the length of time and the step length of the cycles, but in a compensatory manner so that there is no net effect on the mobility. This demonstrates that in some cases mobility alone cannot detect pertubations in the DNA helix. Kinks and flexible bends reduce the mobility because they both lead to longer time periods of the cycles. With kinks the reduction is strongest at low fields because at high fields the kinks are straightened out; the steps thus become even longer than for native DNA. The results suggest that a combination of mobility and orientation measurements on reptating DNA can be used for distinguishing different kinds of structural alterations in the DNA.

Bacteriophage lambda↗
PubMed1997

Acetowhitening of the cervix and vulva as a predictor of subclinical human papillomavirus infection: sensitivity and specificity in a population-based study.

OBJECTIVE: To evaluate acetowhite changes of the cervix and vulva as a predictor of human papillomavirus (HPV) infection. METHODS: In this population-based study all women aged 19, 21, 23, and 25 years and registered as living in a primary health care area within the city of Umeå, Sweden were eligible for inclusion. Each participant underwent a gynecologic examination with sampling of epithelial cells for HPV-DNA detection and Papanicolaou smear. Colposcopy was performed 5 minutes after application of 5% acetic acid. A two-step polymerase chain reaction (PCR) technique was employed for HPV-DNA detection. RESULTS: Colposcopy and sampling of epithelial cells could be performed in 535 women. The sensitivity of detection of HPV infection by the acetowhitening of the cervix was 22% (95% confidence interval [CI] 18%, 26%). The specificity of detection of HPV infection by the acetowhitening of the cervix was 90% (95% CI 87%, 93%). The sensitivity of detection of HPV infection by cytology was 13% (95% CI 10%, 16%), and the specificity was 99% (95% CI 98%, 100%). The combination of acetowhitening and cytology did not improve the diagnostic value. CONCLUSION: Acetowhitening of the cervix and vulva has low sensitivity as a predictor of HPV infections as determined by PCR.

Acetic Acid↗
PubMed1997

The associations between risk behaviour and reported history of sexually transmitted diseases, among young women: a population-based study.

The aim of this study was to determine the associations between risk behaviour and women's reported sexually transmitted diseases (STDs). All the women aged 19, 21, 23 and 25, residing in a specified housing area, were invited to answer a questionnaire regarding their sexual behaviour, smoking and alcohol consumption and previous history of STD. Of the 611 women participating, one out of 4 women had a history of at least one STD. In an univariate analysis, self-reported STD was found to be related to age, having more than 4 lifetime sexual partners, having practised intercourse at first date, inconsistent use of condoms, alcohol consumption of more than 3 bottles of wine per month and smoking. These factors were, however, not independent of each other and when subjected to a multivariate logistic regression analysis 2 factors, i.e. the lifetime number of sexual partners (more than 4 partners vs one; OR 7.94, (3.41-18.50)) and coitus on first date (practised more than once vs never, OR 2.99 (1.55-5.78)) emerged as independently associated with a previous STD.

Adult↗
PubMed1997

In situ evidence that the population of Langerhans cells in normal human epidermis may be heterogeneous.

Epidermal Langerhans cells (LC) may occur in subsets with different phenotypic and functional characteristics. In this work give further evidence that the CD1a-positive LC population in the normal human epidermis may be heterogeneous. We found that one of our monoclonal antibodies (TE4B) to stratum corneum chymotryptic enzyme (SCCE) stained a population of dendritic cells in the normal epidermis in addition to high suprabasal keratinocytes. The staining of the dendritic cells was seen only when the biopsies had been fixed with formaldehyde and when the sections had been pretreated, either with proteolytic enzymes or with Triton X-100. The binding of the antibody was mediated through its antigen binding site, as it could be inhibited by adsorption with recombinant pro-SCCE. Experiments with double labelling showed that the TE4B-positive dendritic cells were also CD1a-positive. On the other hand, not all CD1a-positive cells were TE4B-positive. By means of confocal microscopy of double-labelled cells, the TE4B binding site could be localized intracellularly. SCCE-mRNA could be detected by in situ hybridization in high suprabasal keratinocytes only. A possible explanation may be that there is a subset of LC which have taken up SCCE secreted by high suprabasal keratinocytes. Alternatively, TE4B may bind to an epitope present in a subgroup of epidermal LC which cross-reacts immunologically with SCCE. It is suggested that the demonstrated heterogeneity of the population of LC in the normal epidermis should be taken into account in studies on the possible role of epidermal autoantigens in the development of immune-mediated skin diseases.

Antigens, CD1↗
PubMed1996

Influence of optical probing with YOYO on the electrophoretic behavior of the DNA molecule.

The influence of the fluorescent dye YOYO (1,1'-(4,4,8,8,-tetramethyl- 4,8-diazaundecamethylene)bis[4-[[3-methyl-benzo-1,3-oxazol-2 -yl] methylidene]-1,4-dihydroquinolinium] tetraiodide) on the electrophoretic behavior of the DNA molecule was investigated. This is important when using YOYO as a probe in capillary electrophoresis or in fluorescence microscopy studies of DNA with the purpose of studying the migration mechanism of DNA on the molecular level. We have measured the mobility and orientation dynamics (using the linear dichroism technique) for both pure DNA and the YOYO-DNA complex in agarose gel in order to compare their electrophoretic properties. Mobility decreases, the degree of orientation becomes lower, and the orientational dynamics slower, when YOYO binds to DNA. However, the dependence on field strength of the mobility, orientation and orientational dynamics, are similar for DNA and YOYO-DNA, indicating that the mode of migration does not change significantly upon binding YOYO to DNA. Furthermore, since our results show that the effect of YOYO on both the degree of orientation and orientational dynamics of the DNA can be measured and therefore be compensated for, it can be concluded that YOYO is an excellent optical probe for the study of the migrational behavior of DNA.

Bacteriophage T7↗
PubMed1996

Khabarovsk virus: a phylogenetically and serologically distinct hantavirus isolated from Microtus fortis trapped in far-east Russia.

Two hantavirus strains, MF43 and MF113, isolated from Microtus fortis trapped in the Khabarovsk region of far-eastern Russia, were analysed by direct nucleotide sequencing of PCR generated fragments of the M and S segments, by immunofluorescence and by focus reduction neutralization tests (FRNT). The nucleotide sequences revealed that the two isolates were closely related to each other but distinct from all other hantaviruses. Phylogenetic analysis of the M and S segments showed that the MF strains form a separate branch in the Hantavirus tree, positioned between the branches of Prospect Hill and Puumala viruses. The strains were shown to be serologically distinct from the other hantavirus serotypes by FRNT using immune rabbit sera. Puumala virus was the closest relative, both genetically and serologically. We propose that this new hantavirus serotype should be named Khabarovsk (KBR).

Animals↗
PubMed1996

Rapid subgenus identification of human adenovirus isolates by a general PCR.

In most clinical situations involving adenovirus infection, subgenus (subgroup) identification of an adenovirus isolate is as informative as a finer identification by serotype. A PCR method which allows the identification of human adenovirus isolates as members of subgenera A, B:1, B:2, C, D, E, or F is described. It is based on a simple (nonnested) PCR using primers which bind to regions immediately flanking the VA RNA-encoding regions of human adenovirus genomes. The PCR allows amplification of DNA from all 49 human adenovirus prototype strains so far described. Since there are differences in the lengths of the VA RNA-encoding regions in adenoviruses of different subgenera, it is possible to differentiate some subgenera according to the size of the PCR product determined by electrophoresis. This forms the basis of an initial broad categorization of isolates as belonging to either (i) subgenus B:1, C, D, or E or (ii) subgenus A, B:2, or F. Subgenus identification is completed by a one-step restriction enzyme digestion and gel electrophoresis. The method was assessed by blind subgenus identification of 200 miscellaneous primate adenovirus isolates prepared by the reference laboratory at Bilthoven, The Netherlands. Identification at the subgenus level by PCR correlated 91.5% with the results of serotyping. A further 5.5% of isolates were correctly identified as belonging to one of two specified subgenera. Six of the 200 identifications (3%) were unsuccessful for various reasons, including weak PCR products, intermediate strains, and mistaken primate host. The method should serve as a rapid means of confirming adenovirus cytopathic effects in laboratories performing virus culture, with simultaneous subgenus identification of the isolate. It will also have relevance as an aid to conventional serotyping for epidemiological purposes, since for all adenoviruses except those belonging to subgenus D, neutralization tests need only involve a maximum of four type-specific antisera.

Adenoviruses, Human↗
PubMed1995

Double bands in DNA gel electrophoresis caused by bis-intercalating dyes.

Many bis-intercalating dyes used for fluorescence detection of DNA in electrophoresis have been reported to give band-splitting and band-broadening, which results in poor resolution and a decreased detection sensitivity. We have studied the dimeric dye YOYO-1, and to some extent also TOTO-1 and EthD-1, and found that in complex with DNA these dyes give rise to two components with different electrophoretic mobilities. Electrophoresis experiments and spectroscopic measurements on the two components show that they differ in that the DNA molecules have different amounts of dye bound. Our results exclude that the extra bands are caused by intermolecular cross-linking. Incubation of the samples for increasing times before electrophoresis makes the bands move closer and closer to each other as the dye molecules become more homogeneously distributed among the DNA molecules. Finally, the two bands merge into one at an intermediate position. This equilibration process is extremely slow at room temperature (days), and is therefore not a practical method to eliminate band-splitting in routine analysis. However, we find that if the temperature is raised to 50 degrees C, the dye-DNA complexes equilibrate completely in only 2 h.

Bacteriophage T7↗
PubMed1995

Characterization of the binding of YO to [poly(dA-dT)]2 and [poly(dG-dC)]2, and of the fluorescent properties of YO and YOYO complexed with the polynucleotides and double-stranded DNA.

The interaction between the fluorescent dye YO (oxazole yellow) and the alternating polynucleotides [poly(dA-dT)]2 [the duplex of alternating poly(dA-dT)] and [poly(dG-dC)]2 [the duplex of alternating poly(dG-dC)] has been studied with optical spectroscopic techniques including absorbance, flow linear dichroism, CD, and fluorescence measurements. The principal features of the spectra are very similar for the two polynucleotide solutions, showing that YO binds quite similarly to AT and GC base pairs. From a strongly negative reduced linear dichroism (LDr) in the dye absorption band, an induced negative CD, and transfer of energy from the bases to bound YO, we conclude that at low mixing ratios YO is intercalated in both [poly(dA-dT)]2 and [poly(dG-dC)]2. At higher mixing ratios an external binding mode starts to contribute, evidenced from the appearance of an exciton CD. The conclusion that YO binds in a similar way to AT and GC base pairs should be valid also for the dimer YOYO since its YO units have been found to bind to double-stranded (dsDNA) in the same way as the YO monomer. The fluorescence properties of YO and YOYO complexed with DNA or the polynucleotides have been characterized by studying the dependence of fluorescence intensity on temperature, mixing ratio, and ionic strength. The fluorescence intensity and fluorescence lifetime of YO-DNA decrease strongly with increasing mixing ratio, whereas the fluorescence intensity of YOYO-DNA shows a weaker dependence, indicating that the quantum yield depends on the distance between the YO chromophores on the DNA chain. Further, the fluorescence intensity of YO depends on the base sequence; the quantum yield and fluorescence lifetime for YO complexed with [poly(dG-dC)]2 are about twice as large as for YO complexed with [poly(dA-dT)]2. Measurements of excitation spectra at different mixing ratios and different emission wavelengths indicate that the fluorescence of the externally bound chromophores is negligible compared to the intercalated ones.

Benzoxazoles↗
PubMed1995

Dynamic muscle strength training in stroke patients: effects on knee extension torque, electromyographic activity, and motor function.

The effects of training with isokinetic maximal voluntary knee extensions were studied in stroke patients. Two groups of 10 patients each trained twice a week for 6 weeks. One group trained exclusively eccentric movements and the other exclusively concentric movements. The effects were evaluated from the following tests before and after the training period. The maximal voluntary strength in concentric and eccentric actions of the knee extensor and flexor muscles was recorded together with surface electromyography at constant velocities of 60, 120, and 180 deg.s-1 on three different days. The body weight distribution on the legs while rising and sitting down was measured with two force plates. The self-selected and maximal walking speeds and the swing to stride ratio of the paretic leg were measured. After the training period, the knee extensor strength had increased in eccentric and concentric actions in both groups (p < .05). The eccentric and the concentric strength in the paretic leg relative to that of the nonparetic leg increased in the eccentrically trained group (p < .05) but not in the concentrically trained group. The restraint of the antagonistic muscles in concentric movements increased after concentric (p < .05) but not eccentric training. A nearly symmetrical body weight distribution on the legs in rising from a sitting position was noted after eccentric (p < .05) but not concentric training. Changes in walking variables were not significantly different between the groups. Eccentric knee extensor training was thus found to have some advantages as compared to concentric training in stroke patients.

Aged↗
PubMed1995

Subcutaneous implanted chambers in different mouse strains as an animal model to study genetic stability during infection with Lyme disease Borrelia.

Tissue metal net cages were implanted subcutaneously in BALB/cJ and C3H/Tif mice as an experimental model of Borrelia burgdorferi infection. B. burgdorferi sensu stricto strain Sh2-82 could be isolated up to 14 weeks after the inoculation. However, a significant difference in infectivity between the two mice strains was observed. C3H/Tif mice were more susceptible to developing chronic B. burgdorferi s.s. infections than BALB/cJ mice. Although a B. burgdorferi infection was established, no rearrangements in the ospA and ospB genes were observed in any of the infected mice.

Animals↗
PubMed1995

Human papillomavirus infection is transient in young women: a population-based cohort study.

The prevalence of human papillomavirus (HPV) infection in cervical cell scrapes from a cohort of 276 young women was determined by a general two-step polymerase chain reaction. HPV infection fluctuated among young women during a 2-year interval. The total prevalence of HPV infection decreased from 21% to 8.3%. The most prevalent HPV types at enrollment were HPV-16 (3.3%) and HPV-6 (2.9%). At follow-up, the most common type was HPV-16 (2.9%), while no HPV-6 was detected. In 2 women only, the same HPV type persisted. Regression of HPV infection was found in 80% of the women. A new HPV type-specific infection was detected in 7.2% of the women and was independently associated with a new sex partner or an abnormal smear since enrollment.

Adult↗
PubMed1995

The silent suffering women--a population based study on the association between reported symptoms and past and present infections of the lower genital tract.

OBJECTIVES: To assess the prevalence of lower genital tract symptoms and the association between reported symptoms and past and present signs of sexually transmitted diseases (STD) in young women. DESIGN: All women belonging to the 19-, 21-, 23- and 25-year age cohorts and living in the catchment area of the community health centre, were invited by mail to take part in a population-based study. The participants answered a structured questionnaire and a gynaecologic examination was performed. Samples for wet smear, cervical Pap smear, HPV DNA determination and Chlamydia trachomatis culture were taken at the gynaecologic examination. The presence of genital warts was noted. A blood sample was analysed for antibodies against C trachomatis and HSV-2. SETTING: The community health care centre was located in Umeå, a city in Northern Sweden. RESULTS: Of the 886 women who were eligible, 611 (70%) participated in the investigation. One out of four women reported symptoms from the lower genital tract. The most commonly reported symptoms were itching, followed by discharge, and soreness. The most commonly reported STD was C trachomatis (15%). The most prevalent present STD was HPV infection (20%) whereas C trachomatis infection could be isolated from 2.7% of the women. Antibodies against C trachomatis and HSV-2 were present among 22% and 6% of the women, respectively. There was a significant correlation between the women's complaint of vaginal discharge and previous C trachomatis infection, lack of lactobacilli and presence of leucocytosis in wet smear. CONCLUSIONS: We have in a population-based study of young healthy women found that one out of four women had some kind of lower genital tract complaint. Itching was the most commonly reported symptom and was associated with pseudohyphae and acetowhite patches. Reported vaginal discharge and soreness were associated with the history of a past C trachomatis infection and signs of a disturbed vaginal flora.

Adult↗
PubMed1994

A bactericidal antibody to Borrelia burgdorferi is directed against a variable region of the OspB protein.

Borrelia burgdorferi, an agent of Lyme disease, is killed by some monoclonal antibodies in the absence of complement or phagocytes. In the present study, the bactericidal action of monoclonal antibodies against B. burgdorferi and B. hermsii, a cause of relapsing fever, was further characterized. H6831, an antibody recognizing the OspB proteins of some B. burgdorferi strains, and H4825, an antibody specific for one serotype of B. hermsii, were purified, and Fab fragments of the antibodies were prepared. In time-kill studies, more than 99.9% of strain B31 B. burgdorferi cells were killed after 30 min of exposure to H6831 Fab fragments. The MBC of the Fab fragments was 10 micrograms/ml. Electron microscopy revealed that the bactericidal Fab fragments produced numerous blebs and cell lysis of the borrelias for which they were specific. To identify the epitope for H6831, the OspB sequences of H6831-susceptible and -resistant strains and mutants were determined. The deduced OspB proteins of all H6831-resistant strains and mutants differed from the strain B31 OspB at residue 253. Murine antisera raised against a 21-mer synthetic peptide representing the region around residue 253 were specific for strain B31 by Western blot (immunoblot) and growth inhibition assays. Furthermore, the antipeptide serum inhibited the binding of H6831 to whole borrelias. These findings indicated that the linear component of the bactericidal antibody's epitope was located at or near residue 253.

Amino Acid Sequence↗
PubMed1994

Identification of a highly cross-reactive outer surface protein B epitope among diverse geographic isolates of Borrelia spp. causing Lyme disease.

The outer surface lipoprotein B (OspB) of Borrelia burgdorferi is a major component of the borrelial protein profile and has been shown to be highly immunogenic in experimentally immunized and infected mammals. However, the ospB loci of different strains show considerable heterology at the nucleic acid sequence level, and the progeny of a clonal strain of B. burgdorferi exhibited OspB polymorphisms with respect to apparent molecular weights and reactivities with monoclonal antibodies. These data suggest that OspB is not a good candidate for vaccination or diagnostic purposes. The present study describes a monoclonal antibody, designated 84C, directed against a very highly conserved domain of the OspB lipoprotein. Western immunoblot analysis with 84C demonstrated reactivity in 84.2% of human, tick, and other vertebrate isolate strains examined from widely diverse geographic regions, including strains of B. burgdorferi sensu stricto and two closely related species, B. garinii and B. afzelii. The 84C-binding region was delimited to a highly conserved 11-amino-acid region in the carboxyl terminus of OspB as demonstrated by (i) DNA sequence analysis of wild-type and 84C-resistant mutant ospB alleles and (ii) deletion mutagenesis of a recombinant ospB gene in Escherichia coli. Finally, the 84C epitope was demonstrated to be exposed on the borrelial surface in situ as (i) the monoclonal antibody 84C was able to agglutinate borrelias in culture and (ii) 84C-resistant escape variants were isolated. These data suggest that the potential value of OspB as a vaccine candidate or diagnostic tool be examined more closely, in the context of the 84C-reactive domain.

Amino Acid Sequence↗