Biomedical subjects

A Johansson

Publications and source records attributed to A Johansson.

At least 37 records · Page 2Linked to original sources

PubMed2005

Reasons, methods used and decision-making for pregnancy termination among adolescents and older women in Mulago Hospital, Uganda.

OBJECTIVE: To explore the methods, reasons and decision-making process for termination of pregnancy among adolescents and older women, in Mulago hospital, Kampala, Uganda. DESIGN: Comparative study. SUBJECTS: Nine hundred and forty two women seeking postabortion care, of which 333 had induced abortion (of whom 115 were adolescents). SETTING: The emergency gynaecological ward of Mulago Hospital, Kampala, Uganda from September 2003 through June 2004. RESULTS: Women with induced abortion were single, in polygamous marital relationships and of lower parity (p<0.001); had lower education and number of living children (p<0.05), reported more (p<0.001) mistimed, unplanned or unwanted pregnancies, and were 13 times more likely to have recent history of domestic violence. Relationship issues were the most common reason for pregnancy termination for both categories. Decision-making for induced abortion was influenced by socio-economic, educational and personal considerations. Instrumentation and use of local herbs in the genitalia were the most common methods for pregnancy termination. Neither methods used for pregnancy termination nor reasons differed when adolescents were compared with older women. CONCLUSION: Relationship issues influence the decision-making process for pregnancy termination. Neither methods used for pregnancy termination nor reasons for pregnancy termination differ when adolescents are compared with older women.

Abortion, Induced↗

PubMed2004

Short-term infusion of interleukin-6 does not induce insulin resistance in vivo or impair insulin signalling in rats.

AIMS/HYPOTHESIS: Interleukin-6 has been implicated in the insulin resistance associated with obesity and impaired glucose tolerance. Previous studies in vitro have shown that IL-6 rapidly (1-2 h) impairs cellular insulin signalling and action through an increased expression of suppressor of cytokine signalling (SOCS)-3. In the present study, IL-6 or saline was infused in rats that were simultaneously in a state of hyperinsulinaemia. Muscle, liver and adipose tissue were excised after 2 h to examine potential effects on insulin signalling or gene expression. METHODS: The rats were infused with IL-6 or saline during a euglycaemic-hyperinsulinaemic clamp and the glucose infusion rate was measured after 90 to 120 min. Signal transducer and activator of transcription (STAT)3 phosphorylation and insulin-stimulated tyrosine phosphorylation of the insulin receptors and IRS were measured with immunoblotting and gene expression through real-time PCR. RESULTS: No inhibitory effect of IL-6 on insulin-stimulated whole-body glucose uptake was seen in spite of high circulating levels of IL-6 (0.85+/-0.08 nmol/l). Tyrosine phosphorylation of the insulin receptors and IRS was also unchanged in the liver, skeletal muscles and adipose tissue. However, tyrosine phosphorylation of STAT3 was increased in all tissues, showing that IL-6 signalling was activated. IL-6 mRNA tended to increase, while GLUT4, peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) and adiponectin gene expression were unchanged. CONCLUSIONS/INTERPRETATION: Infusion of IL-6 for 120 min in rats during euglycaemic-hyperinsulinaemic conditions did not alter the effect of insulin on whole-body glucose homeostasis, plasma adiponectin levels or insulin signalling in target tissues. Thus, the acute effects of IL-6, associated with SOCS-3 induction, do not lead to whole-body insulin resistance. These data further underscore the importance of the chronic, and potentially tissue-specific effects of IL-6 on insulin signalling and action.

Animals↗

PubMed2004

Charge and energy dynamics in photo-excited poly(para-phenylenevinylene) systems.

We report results from simulations of charge and energy dynamics in poly(para-phenylenevinylene) (PPV) and PPV interacting with C60. The simulations were performed by solving the time-dependent Schrodinger equation and the lattice equation of motion simultaneously and nonadiabatically. The electronic system and the coupling of the electrons to the lattice were described by an extended three-dimensional version of the Su-Schrieffer-Heeger model, which also included an external electric field. Electron and lattice dynamics following electronic excitations at different energies have been simulated. The effect of additional lattice energy was also included in the simulations. Our results show that both exciton diffusion and transitions from high to lower lying excitations are stimulated by increasing the lattice energy. Also field induced charge separation occurs faster if the lattice energy is increased. This separation process is highly nonadiabatic and involves a significant rearrangement of the electron distribution. In the case of PPV coupled to C60, we observe a spontaneous charge separation. The separation time is in this case limited by the local concentration of C60 molecules close to the PPV chain.

Journal Article↗

PubMed2004

Lifetime and predissociation yield of 14N2 b 1Piu(v=1).

The lifetime of the b 1Piu(v=1) state in 14N2 has been determined experimentally using a laser-based pump-probe scheme and an exceptionally long lifetime of 2.61 ns was found. Semiempirical close-coupling calculations of the radiative lifetime, which include Rydberg-valence interactions in the singlet manifold, are consistent with this large value, giving a value of 3.61 ns and suggesting a predissociation yield of approximately 28% for this level of the b state.

Journal Article↗

PubMed2004

Antimicrobial susceptibility of Swedish, Norwegian and Danish isolates of Clostridium perfringens from poultry, and distribution of tetracycline resistance genes.

This study was undertaken to determine the in vitro susceptibility of Clostridium perfringens, isolated from poultry to antimicrobials used in poultry production. The minimal inhibitory concentration (MIC) of eight antimicrobials, including the ionophoric coccidiostat narasin, was determined for 102 C. perfringens isolates, 58 from Sweden, 24 from Norway and 20 from Denmark. Susceptibility to each antimicrobial compound was determined by broth microdilution. The isolates were obtained from broilers (89), laying hens (9) and turkeys (4), affected by necrotic enteritis (NE) or by C. perfringens associated hepatitis (CPH), and from healthy broilers. All strains, regardless of origin, proved inherently susceptible to ampicillin, narasin, avilamycin, erythromycin and vancomycin. A low frequency of resistance to virginiamycin and bacitracin was also found. Resistance to tetracycline was found in strains isolated in all three countries; Sweden (76%), Denmark (10%) and Norway (29%). In 80% of the tetracycline-resistant isolates, the two resistance genes tetA(P) and tetB(P) were amplified by PCR whereas in 20% only the tetA(P) gene was detected. No tetM gene amplicon was obtained from any of the tetracycline-resistant isolates. The uniform susceptibility to narasin revealed in this study shows that the substance can still be used to control clostridiosis. In this study, C. perfringens also showed a low degree of resistance to most other antimicrobials tested. Despite the small amounts of tetracycline used in poultry, a considerable degree of resistance to tetracycline was found in C. perfringens isolates from Swedish broilers.

Animals↗

PubMed2004

Nanoporous aluminum oxide affects neutrophil behaviour.

This study evaluates neutrophil responses on aluminum oxide membranes. Using an in vitro cell culture system, we have found that the pore size (20 and 200 nm in diameter) of alumina membranes have a significant effect on leukocyte morphology and activation. Specifically, our results show that 20-nm pore-size membranes were more potent in triggering PMN spreading and extending of pseudopodia than 200-nm pore-size membranes. The morphological changes are also associated with cell activation. In fact, adherent neutrophils on 20-nm pore-size membranes elicit much stronger initial oxygen free radical production. Overall, our results point out that membrane pore size significantly affects the extent of cellular responses of adherent neutrophils.

Aluminum Oxide↗

PubMed2004

Superconductivity-related insulating behavior.

We present the results of an experimental study of superconducting, disordered, thin films of amorphous indium oxide. These films can be driven from the superconducting phase to a reentrant insulating state by the application of a perpendicular magnetic field (B). We find that the high-B insulator exhibits activated transport with a characteristic temperature, TI. TI has a maximum value (TpI) that is close to the superconducting transition temperature (Tc) at B=0, suggesting a possible relation between the conduction mechanisms in the superconducting and insulating phases. Tp(I) and Tc display opposite dependences on the disorder strength.

Journal Article↗

PubMed2004

Fibre-optic array for curvature assessment: application in otitis diagnosis.

A contact-free sensor consisting of two parallel optical-fibre arrays was designed to assess surface shapes of diffusely scattering media. By sequentially illuminating objects using one fibre array and detecting the diffusely back-scattered photons by the other, a source-detector intensity matrix was formed, where the matrix element (i, j) was the intensity at detector j when light source i was excited. Experimental data from convex and concave polyacetal plastic surfaces were recorded. A mathematical model was used for simulating source-detector intensity matrices for the surfaces analysed in the experiments. Experimental results from the system were compared with the theoretically expected results provided by the mathematical model. The shape and relative amplitude showed similar behaviour in the experiments and simulations. A convex/concave discriminator index D, representing the detected intensity difference between two source-detector separations, was defined. The relative dynamic range of D, defined as the difference between the maximum and the minimum divided by the mean of the index, was 1.37 for convex surfaces and 0.68 for concave surfaces, at a measuring distance of 4.5 mm. The index D was positive for convex surfaces and negative for concave surfaces, which showed that the system could distinguish between convex and concave surfaces, an important result for the diagnosis of otitis media.

Acute Disease↗

PubMed2004

Assessment of cartilage thickness utilising reflectance spectroscopy.

A new principle for cartilage layer thickness assessments in joints is presented. It is based on the differences between the absorption spectra of cartilage and subchondral bone (containing blood). High-resolution ultrasound measurements of cartilage thickness were compared with reflection spectroscopy data from the same area of bovine hip joint condyles. A simple mathematical model allowed calculation of thickness and comparison with ultrasound data. The cartilage thickness was changed by being ground in short episodes. For thicker cartilage layers, a high degree of reflection in the 400-600 nm wavelength interval was seen. For thinner cartilage layers, the characteristics of the spectra of blood and bone dominated those of cartilage. The mean (+/- SD) thickness of intact cartilage was 1.21 +/- 0.30 mm (n = 30). In an exponential regression model, spectroscopic estimation of cartilage thickness showed a correlation coefficient of r = 0.69 (n = 182). For thinner cartilage layers (d < 0.5 mm), the mean model error was 0.19 +/- 0.17 mm. Results from a bi-layer Monte Carlo simulation supported the assumption of an exponential relationship between spectroscopy data and reference ultrasound data. The conclusion is that optical reflection spectroscopy can be used for cartilage layer thickness assessment.

Animals↗

PubMed2004

Increased left ventricular mass in obese adolescents.

AIMS: An increase of left ventricular mass (LVM) has been reported in obese adolescents in previous studies using echocardiography. The aim of our study was to determine the extent of the increase in LVM and correlation to other risk factors using cardiac magnetic resonance imaging in obese and lean adolescents. METHODS AND RESULTS: Nineteen obese and 20 lean adolescents were recruited. Following resting blood pressure measurements and blood sampling for insulin, triglycerides, and cholesterol levels, all subjects underwent cardiac magnetic resonance examination to assess LVM. LVM adjusted for body height was 16% greater in obese compared to lean adolescents (median 66 g/m, p = 0.0042). Obese subjects had higher resting systolic blood pressures than controls (median 115 vs. 110 mmHg, p = 0.0077) and higher fasting triglyceride and insulin levels. HDL-cholesterol levels were lower in the obese group compared with the lean group. CONCLUSIONS: Obese adolescents had a higher LVM than age-matched lean subjects, which correlated mainly with body mass index and systolic blood pressure. These findings add to the established cardiovascular risk profile of obese adolescents.

Adolescent↗

PubMed2004

Magnetic resonance imaging of the knee: a tool for prediction of joint damage in early rheumatoid arthritis?

OBJECTIVE: To evaluate the usefulness of magnetic resonance imaging (MRI) in predicting destructive rheumatoid arthritis (RA) in the knee joint, and to compare this method with clinical examination and conventional radiography (CR). METHODS: Clinical evaluations of the knee joint, followed by MRI and CR examinations were performed in 30 patients with early RA. The MRI examination included evaluation of inflammation using a synovitis score and evaluation of destruction with an erosion score. The first examinations were performed within 14 months from disease onset. Twenty-eight patients were re-examined after 1 year, and 23 patients after 3 years. 'Disease activity score' (DAS), using a 28 joints score (DAS28); health assessment questionnaire (HAQ); rheumatoid factor (RF); and C-reactive protein (CRP) were also analysed. RESULTS: At baseline, MRI found synovitis in 29 patients, of whom 18 also had clinical synovitis. At baseline five patients had 17 MRI erosions, whereas on CR two patients had one erosion each. After 1 year 17 of 35 and after 3 years 28 of 55 MRI erosions were detected also on CR. In only one case CR showed an erosion that was not visible on MRI. The MRI synovitis score (reflecting the extent of the synovitis) at baseline correlated significantly with the number of erosions on MRI both at year 1 and 3, and with the number of erosions on CR at 3 years. In logistic multiple regression analyses the MRI-synovitis score proved to be the best independent predictor of erosiveness. CONCLUSION: MRI was superior to clinical examination and CR in detecting erosions. MRI synovitis score was the best independent predictor of erosiveness in the knee joint in patients with early RA.

Adult↗

PubMed2004

Multicentre study of validity and interrater reliability of the modified Nursing Care Recording System (NCR11) for assessment of workload in the ICU.

BACKGROUND: Reliable assessment of nursing workload is necessary for the quantitative approach to staffing of intensive care units. The Nursing Care Recording System (NCR11) scores both the nursing contribution to patient care and those related to medical procedures. The purpose of the present work was to compare NCR11 scoring with the Therapeutic Intervention Scoring System (TISS) and Nine Equivalents of Nurse Manpower use Score (NEMS) and to examine the interrater reliability of NCR11 scoring. METHODS: Bias and precision of workload scores (NCR11 vs. TISS or NEMS) were assessed for 6126 consecutive admissions (23910 ICU-days) at three intensive care units. Inter-rater reliability was analyzed by having nurses at nine ICUs score workload using NCR11 for three dummy intensive care patient cases presented over a 3-year period. Variability in scoring was analyzed using the coefficient of variation. RESULTS: Agreement between NCR11 and TISS or NEMS was poor and limits of agreement were wide. Linear relationships between NCR11 and TISS or NEMS scores differed between units. Variability in NCR11 scoring decreased significantly from 10.4% to 5.9% between dummy cases 1 and 2 and remained low for patient case 3. CONCLUSION: The NCR11 does not measure the same elements of workload in the ICU as do TISS and NEMS. Inter-rater reliability with NCR11 is good, showing little variation in scoring between nurses.

Analysis of Variance↗

PubMed2004

Relationship of airway symptoms from chemicals to capsaicin cough sensitivity in atopic subjects.

BACKGROUND: It is well known that some patients with allergy complain of airway symptoms from chemicals (ASCs) and strong odours. However, the importance of such information for the treatment of allergic disease is not known. Such symptoms in non-allergic patients have previously been shown to be related to increased sensory nerve reactivity, which is expressed as increased cough sensitivity to inhaled capsaicin. OBJECTIVE: The aim of this study was to examine ASC in atopic patients and relate it to cough reaction to capsaicin inhalation. MATERIALS AND METHODS: Fifty-seven consecutively chosen, skin prick-positive patients with symptoms of the upper and/or lower airways completed a questionnaire concerning ASC. The patients were then divided into two groups, those with and those without such symptoms. Both groups were provoked with inhaled capsaicin in three increments and compared with 73 healthy control subjects. RESULTS: Out of 57 atopic patients, 34 reported ASC agents and 23 did not. The patients with ASC were older (P<0.01) and coughed significantly more on capsaicin provocation (P<0.001), but did not differ from them with respect to the allergic disease or its treatment or to smoking habits. Patients with atopy but without ASC did not differ from healthy controls with regard to sensitivity to capsaicin inhalation. The scored degree of ASC was directly related to the number of coughs during the capsaicin provocation. CONCLUSION: ASC in atopic patients are related to increased airway sensory nerve reactivity. There is still no explanation for this in certain patients with atopy, but age may be a confounding factor.

Adolescent↗

PubMed2004

Cell cycle arrest of human gingival fibroblasts and periodontal ligament cells by Actinobacillus actinomycetemcomitans: involvement of the cytolethal distending toxin.

The cytolethal distending toxin (Cdt) is produced by several Gram-negative bacterial species and causes growth arrest and morphological alterations in mammalian cells. Actinobacillus actinomycetemcomitans, which is involved in the pathogenesis of localized aggressive periodontitis, also produces a Cdt that affects periodontal connective tissue cells. The aim of this study was to investigate in which phase of the cell cycle these cells are arrested and enlarged when challenged with A. actinomycetemcomitans, and to evaluate the involvement of its Cdt. Human gingival fibroblasts and periodontal ligament cells were challenged with A. actinomycetemcomitans extract, or with purified Cdt, and cell cycle analysis was performed by propidium iodide staining and flow cytometry. Cells exposed to an A. actinomycetemcomitans wild-type strain, or to purified Cdt, were arrested in both G1 and G2/M phases, and appeared enlarged compared to the corresponding controls. The cellular enlargement occurred in both G1 and G2/M arrested cells. In contrast, cells exposed to an A. actinomycetemcomitans cdt-knockout mutant strain showed cell cycle phase distribution and size similar to the controls. In conclusion, A. actinomycetemcomitans causes a combined G1 and G2/M growth arrest and enlargement in periodontal connective tissue cells, which is attributed to its Cdt.

Aggregatibacter actinomycetemcomitans↗

PubMed2004

Subgingival plaque microbiota in Saudi Arabians after use of miswak chewing stick and toothbrush.

BACKGROUND: The chewing stick, the miswak, is used in many developing countries as the traditional means for oral hygiene. It is prepared from the roots, twigs and stem of Salvadora persica or other alternative local plants. OBJECTIVES: To compare the effects of the chewing stick miswak (from S. persica) and toothbrush on subgingival plaque microflora among Saudi Arabian individuals. Further, to investigate whether components extracted from S. persica may interfere with the subgingival plaque micro-organisms. MATERIAL AND METHODS: Fifteen healthy Saudi Arabian male volunteers aged 21-36 years were included in a single-blind, randomized cross-over study. The participants were taught how to use each device properly. Plaque sampling for DNA test was performed at the baseline, 1 week after professional tooth cleaning, and after 3 weeks of either miswak or toothbrush use. Identification and quantification of microbial species were performed by the checkerboard method, using whole genomic, digoxigenin-labelled DNA probes. Inhibition zones around miswak were examined on agar plates with Actinobacillus actinomycetemcomitans and the leukotoxicity of this bacterium was analyzed in a bioassay with macrophages+/-extracts of miswak. RESULTS: Miswak and toothbrushing had a similar influence on the levels of the subgingival microbiota. However, A. actinomycetemcomitans was significantly more reduced by miswak (p<0.05) than by toothbrushing. These results were supported by our in vitro results which, indicated that extracts from S. persica might interfere with the growth and leukotoxicity of A. actinomycetemcomitans. CONCLUSIONS: In contrast to toothbrush use, miswak use significantly reduced the amount of A. actinomycetemcomitans in the subgingival plaque.

Adult↗

PubMed2004

Glycerol kinase deficiency: follow-up during 20 years, genetics, biochemistry and prognosis.

AIM: To follow two children with isolated glycerol kinase deficiency (GKD) with severe symptoms into adulthood. METHODS: The patients were followed during approximately 20 y and interviewed about symptoms, diet and physical activity. Fasting provocations, bicycle ergometer tests, dietary registrations, enzyme and mutation analysis were performed by standard protocols. RESULTS: The activity of glycerol kinase (GK) in fibroblasts was <10% of reference. One case had a deletion of exon 17, the other a mutation in exon 7 of the GK gene (601 A-->G). Both mothers were heterozygotes. Two maternal male cousins in one of the families were hemizygotes without symptoms. Tests performed in childhood documented pronounced sensitivity to fasting and physical exercise, whereas such tests at 23 and 31 y of age were essentially normal but with pronounced ketonaemia. After puberty, the boys had no hypoglycaemic symptoms and now report no problems with their condition; thus, their phenotype has changed over time. CONCLUSION: The greater importance of glycerol as a gluconeogenetic substrate in children than in adults may explain the episodes in young patients with GKD, often elicited by catabolic stress. With meals at frequent intervals, access to glucose and avoidance of strenuous sports, the prognosis is good for a normal adult life of a young child with isolated GKD and symptoms of hypoglycaemia.

Acetoacetates↗

PubMed2003

Some molecular characteristics of three viruses from SPVD-affected sweet potato plants in Egypt.

Sweet potato feathery mottle virus (SPFMV, genus Potyvirus, family Potyviridae), Sweet potato chlorotic stunt virus (SPCSV, genus Crinivirus, family Closteroviridae) and sweet potato virus G (SPVG) were detected in naturally infected sweet potato plants grown in the Delta region in Egypt. Before this study, SPVG was reported only from China. Two isolates of SPFMV and one isolate of SPVG were characterized for the 3'-proximal genomic sequences. Phylogenetic analyses indicated that the SPFMV isolates belong to the "russet crack" strain group (RC). Serological tests using monoclonal antibodies, and phylogenetic analysis of a partial sequence of the Hsp70 gene, indicated that the Egyptian SPCSV belongs to the so-called non-East African strain group of SPCSV.

Amino Acid Sequence↗

PubMed2003

Increased frequency of a new polymorphism in the cell division cycle 2 (cdc2) gene in patients with Alzheimer's disease and frontotemporal dementia.

Recent studies show linkage between Alzheimer's disease (AD) and two loci on chromosome 10. The cell division cycle 2 (cdc2) gene is located close to one of the chromosome 10 markers, and is a candidate gene for AD since it is involved in the pathogenesis of AD. We sequenced coding exons and flanking intronic sequences and the promoter region on the cdc2 gene and found three new single nucleotide polymorphisms (SNPs). We analyzed 272 Caucasian AD cases, 160 controls and 70 cases with frontotemporal dementia (FTD) for these SNPs. Homozygosity for one of the SNPs (Ex6+7I/D) was more frequent in both AD and FTD cases than in controls. In the combined tauopathy (AD and FTD) group the odds ratio (OR) was 1.77 (95% CI 1.19-2.63) for the Ex6+7II genotype. Our findings suggest that the Ex6+7I allele is associated with tauopathies, both AD and FTD.

Aged↗