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Biomedical subjects

L Johansson

Publications and source records attributed to L Johansson.

At least 37 records · Page 2Linked to original sources
PubMed2002

Sensitivity of a new grading system for studying nasal polyps with the potential to detect early changes in polyp size after treatment with a topical corticosteroid (budesonide).

We have previously compared different scoring systems for endoscopic staging of nasal polyps. Of the five methods evaluated, we found that two were better than the others with regard to reproducibility and agreement between physicians. One method was lateral imaging, developed by the authors, and the other was a scoring system developed by Lildholdt et al. The main objective of the present study was to compare the sensitivity of these two methods. Another aim was to study the effect on nasal polyposis of topical nasal corticosteroids over a 2-week period. Patients with bilateral nasal polyposis (n = 100) were randomized to a 2-week treatment with a topical corticosteroid (budesonide aqueous nasal spray: 128 microg b.i.d.) or placebo in a double-blind manner. Nasal symptoms were scored before treatment and after 3, 7 and 14 days of treatment, and the patients underwent nasal endoscopy at clinical visits. Patients treated with active substance had an improvement in their symptoms, an effect already detectable after 3 days of treatment, compared with those who received placebo. In addition, a statistically significant decrease in polyp size could be registered after 14 days using lateral imaging but not with the other scoring system. In conclusion, lateral imaging was more sensitive and could detect effects earlier than the other scoring system and can be recommended for the endoscopic staging of nasal polyps in clinical studies.

Administration, Topical↗
PubMed2002

Apoptosis in HeLa Hep2 cells is induced by low-dose, low-dose-rate radiation.

Radioimmunotherapy with radiolabeled antibodies may cause inhibition of the growth of epithelial tumors, despite low total radiation doses and comparatively low radiosensitivity of epithelial tumor cells. The induction of apoptosis by low-dose radiation, such as delivered in radioimmunotherapy, was investigated in vitro in human HeLa Hep2 carcinoma cells. The cultured cells were exposed to defined radiation doses from a (60)Co radiation therapy source. The radiation source delivered 0.80 +/- 0.032 (mean +/- SD) Gy/min and the cells were given total doses of 1, 2, 5, 10 and 15 Gy. Using fluorescein-labeled Annexin V, followed by flow cytometry and DNA ladder analysis, apoptotic cells were detected and quantified. Radiation doses below 2 Gy did not cause any significant increase in apoptosis. Compared to control cells, apoptosis was pronounced after 5-10 Gy irradiation and was correlated to the radiation dose, with up to 42 +/- 3.5% of the cells examined displaying apoptosis. Clonogenic assays confirmed significantly decreased viability of the cells in the interval 2 to 10 Gy with low-dose-rate radiation, 60 +/- 2% compared to 2 +/- 2%. Lethal effects on the tumor cells were also evaluated by an assay of the cytotoxic effects of the release of (51)Cr. Significant cytotoxicity, with up to 64 +/- 6% dead cells, was observed at 5 Gy. Similar results were obtained when the dose rate was reduced to 0.072 +/- 0.003 Gy/min (mean +/- SD). In the case of the (137)Cs source, the dose rate could be reduced to 0.045 Gy/h, a level comparable to radioimmunotherapy, which induced significant apoptosis, and was most pronounced at 72-168 h postirradiation. It can be concluded that in vitro low-dose and low-dose-rate radiation induces apoptosis in epithelial HeLa Hep2 cells and thus may explain a mechanism by which pronounced inhibition of growth of HeLa Hep2 tumors at doses used in radioimmunotherapy has been obtained previously.

Annexin A5↗
PubMed2001

[Stroke--and then? Considerable need of assistance two year after stroke according to a large nation-wide study].

The National Board of Health and Welfare together with Riks-Stroke (the Swedish National Registry for Quality Assessment of Acute Stroke Care) were commissioned by the government to study the circumstances of 4,023 stroke patients, two years after the event. Both physical and psychological impairments together with psychosocial consequences were common. Approximately one fifth of the patients did not receive enough help and support, and the most common reason for this was the high cost. Instead many were dependent upon next-of-kin. This indicates that the long-term care of stroke patients needs to be improved.

Activities of Daily Living↗
PubMed2001

Unexpected selectivities in C-H activations of toluene and p-xylene at cationic platinum(II) diimine complexes. New mechanistic insight into product-determining factors.

The C-H activation of toluene and p-xylene at cationic Pt(II) diimine complexes (N-N)Pt(CH(3))(H(2)O)(+)BF(4)(-) (N-N = Ar-N=CMe-CMe=N-Ar; 1(BF(4)(-)), N(f)-N(f), Ar = 3,5-(CF(3))(2)C(6)H(3)); 2(BF(4)(-)), N'-N', Ar = 2,6-(CH(3))(2)C(6)H(3)) has been investigated. The reactions were performed at ambient temperature in 2,2,2-trifluoroethanol (TFE), and after complete conversion of the starting material to mixtures of Pt-aryl/Pt-benzyl complexes and methane, acetonitrile was added to trap the products as more stable acetonitrile adducts. In the reactions with toluene, the relative amounts of products resulting from aromatic C-H activation were found to decrease in the order (N-N)Pt(m-tolyl)(NCMe)(+) > (N-N)Pt(p-tolyl)(NCMe)(+) > (N-N)Pt(o-tolyl)(NCMe)(+) for both 1 and 2. Unlike the reaction at 1, significant amounts of the benzylic activation product (N'-N')Pt(benzyl)(NCMe)(+) were concurrently formed in the C-H activation of toluene at 2. The C-H activation of p-xylene revealed an even more remarkable difference between 1 and 2. Here, the product ratios of (N-N)Pt(xylyl)(NCMe)(+) and (N-N)Pt(p-methylbenzyl)(NCMe)(+) were found to be 90:10 and 7:93 for reactions at 1 and 2, respectively. The elimination of toluene from (N(f)-N(f))Pt(Tol)(2) species (3a-c; a, Tol = o-tolyl; b, Tol = m-tolyl; c, Tol = p-tolyl) after protonolysis with 1 equiv of HBF(4) was investigated. Most notably, protonation in neat TFE followed by addition of acetonitrile gave a 77:23 mixture of (N(f)-N(f))Pt(m-tolyl)(NCMe)(+) (4b) and (N(f)-N(f))Pt(p-tolyl)(NCMe)(+) (4c) from all three isomeric bis(tolyl) complexes 3a-c. The presence of acetonitrile during the protonation reactions resulted in considerably less isomerization. This behavior is explained by an associative mechanism for the product-determining displacement of toluene by the solvent. For the C-H activation reactions, our findings suggest the existence of a dynamic equilibrium between the isomeric intermediates (N-N)Pt(aryl)(CH(4))(+) (aryl = tolyl/benzyl from 1; xylyl/p-methylbenzyl from 2). The observed selectivities might then be explained by steric and electronic effects in the pentacoordinate transition-state structures for the solvent-induced associative elimination of methane from these intermediates.

Journal Article↗
PubMed2001

Contrast agents in acute myocardial infarction.

The experimental design in examination of acute myocardial infarctions should be valid in terms of flow, perfusion and re-flow after intervention. The contrast agents concentration in experimental studies can be measured by microdialysis. We have assessed the usefulness of different extracellular and blood pool contrast agents for visualization of the area at risk in coronary artery occlusions. The double contrast technique, where Dy-DTPA-BMA was combined with Gd-DTPA-BMA yielded a superior infarct visualization. Blood pool agents for example NC100/150 injection is also promising in first path myocardial perfusion imaging.

Contrast Media↗
PubMed2001

Radioimmunoscintigraphy using an anti-prostate monoclonal antibody (E4): a dosimetric evaluation.

The aim of this study was to evaluate different strategies to increase the tumour radiation dose for experimental radioimmunotherapy using 125I-labelled monoclonal antibody (MAb) E4 in a nude mice model xenografted with DU-145 tumours. The effects from a single injection of the 125I-labelled MAb E4, the same total amount of radiolabelled MAb E4 divided into three repeated injections, and the effect of pre-targeting with non-labelled MAb E4 for reducing the amount of shed antigen were investigated. Based on repetitive quantitative radioimmunoscintigraphies, calculation of the tumour radiation dose delivered from the 125I-nuclide was performed for each strategy. The single injection strategy without pretargeting rendered the highest mean tumour radiation dose, i.e. 0.23 Gy/MBq. Pretargeting with non-labelled MAb E4 before a single injection of [125I]E4 resulted in a slightly lower mean tumour radiation dose, i.e. 0.19 Gy/MBq, compared to the single injection alone. An even lower mean tumour radiation dose, i.e. 0.14 Gy/MBq, was obtained when the same total administered amount of activity was divided into three separate injections given in 10-day intervals. We concluded that the single injection strategy is the most efficient when using MAb E4 in this tumour model. The tumour radiation doses were not increased by dividing the same amount of activity into three injections or by pretargeting with non-labelled MAb E4.

Animals↗
PubMed2001

Frankia KB5 possesses a hydrogenase immunologically related to membrane-bound.

The immunological relationship of the hydrogenase in Frankia KB5 to hydrogenases in other microorganisms was investigated using antisera raised against holo-[NiFe]-hydrogenases isolated from Alcaligenes latus, Azotobacter vinelandii, Ralstonia eutropha, and the small and large hydrogenase subunits from Bradyrhizobium japonicum. The antisera raised against the A. latus, R. eutropha, and B. japonicum (large subunit) polypeptides were found to recognize two polypeptides, corresponding to the unprocessed and processed forms of the hydrogenase subunit in Frankia KB5. None of the antisera, including the antibodies produced against the small hydrogenase subunit isolated from B. japonicum, recognized any polypeptide related to the small hydrogenase subunit in Frankia KB5. An immunogold localization study of the intracellular distribution of hydrogenase in Frankia KB5, with the cryo-section technique, showed that labeling in the membrane of both hyphae and vesicles was positively correlated with hydrogenase activity.

Actinomycetales↗
PubMed2001

Soman-induced interleukin-1 beta mRNA and protein in rat brain.

Exposure to high doses of the toxic organophosphate compound soman, also known as a chemical warfare agent, causes a progression of toxic symptoms including hyper-secretions, convulsions, respiratory depression, and finally death. In previous studies, we have demonstrated pronounced effects following soman intoxication in dopaminergic, GABAergic, and cholinergic systems in rat brain. The aim of this study was to investigate the effects on the pro-inflammatory cytokine interleukin-1beta (IL-1beta), indicated as mRNA and protein production, at different time intervals following soman intoxication. The peak levels of mRNA was observed 30 min following soman exposure, while a significant increase in the protein was observed at 6 h. Immunohistochemistry analysis revealed the presence of IL-1beta protein in astrocytes and endothelial cells. In addition to the previously observed effects of soman, there is an induction of IL-1beta in the brain. This effect, which is highly correlated to convulsions, implicates IL-1beta as a possible mediator for long-term brain damage observed after soman intoxication.

Animals↗
PubMed2001

Disparities in vegetable and fruit consumption: European cases from the north to the south.

OBJECTIVE: To present disparities in consumption of vegetables and fruits in Europe and to discuss how educational level, region and level of consumption influence the variation. DESIGN: A review of selected studies from 1985 to 1997. SETTING/SUBJECTS: 33 studies (13 dietary surveys, nine household budget surveys and 11 health behaviour surveys) representing 15 European countries were selected based on criteria developed as part of the study. Association between educational level and consumption of vegetables and fruits was registered for each study and common conclusions were identified. RESULTS: In the majority of the studies, with the exception of a few in southern and eastern Europe, consumption of vegetables and fruits was more common among those with higher education. The results suggest that in regions where consumption of vegetables and fruits is more common, the lower social classes tend to consume more of these than the higher social classes. CONCLUSIONS: The differences in the patterns of disparities in vegetable and fruit consumption between regions, as well as within populations, need to be considered when efforts to improve nutrition and health are planned.

Educational Status↗
PubMed2001

Soluble pilin of Neisseria gonorrhoeae interacts with human target cells and tissue.

Pili of Neisseria gonorrhoeae are phase-variable surface structures that mediate adherence to host target cells. Each pilus is composed of thousands of major pilus subunits, pilins, pilus-associated protein PilC, and possibly other components. Piliated and nonpiliated gonococcal clones may secrete a soluble smaller pilin (S-pilin) that is cleaved after amino acid 39 of the mature pilin protein. Here, purified S-pilin was found to migrate as a 61- to 64-kDa double band on nondenaturing gels, suggesting the formation of tetrameric S-pilin proteins with two isomeric forms. In situ studies of binding to formalin-fixed tissue sections demonstrated the binding of S-pilin to human tissue but not to tissue from mouse or rat organs, showing the presence of a human-specific receptor-binding domain within the pilin polypeptide. Pretreatment of the target tissues with proteinase K decreased gonococcal binding dramatically, whereas pretreatment with neuraminidase and meta-periodate, which cleave carbon-carbon linkages between vicinal hydroxyl groups in carbohydrates, did not affect gonococcal binding. In overlay assays, purified S-pilin bound to a band with a migration pattern and size similar to those of CD46, a cellular pilus receptor. Further, binding of N. gonorrhoeae to target cells and tissues could be blocked by both CD46 antibodies and purified S-pilin. These data argue that S-pilin interacts with a protein domain(s) of the CD46 receptor on human cells.

Acrylic Resins↗
PubMed2001

First-pass myocardial perfusion MR imaging with outer-volume suppression and the intravascular contrast agent NC100150 injection: preliminary results in eight patients.

The authors evaluated the feasibility of combining single-shot T2-weighted turbo spin-echo magnetic resonance (MR) imaging and first-pass myocardial perfusion MR imaging with an intravascular ultrasmall superparamagnetic iron oxide (USPIO) contrast agent, NC100150 Injection (3 mg of iron per kilogram of body weight). Eight patients with coronary vessel disease underwent T2-weighted turbo spin-echo MR imaging (in-plane resolution, 1-2 mm) during the first pass of the USPIO contrast agent. The mean decrease in signal intensity in myocardium perfused by a nonstenotic coronary artery was 59% +/- 13 (SD) (P < .012) This method is feasible for imaging of myocardial perfusion.

Adult↗
PubMed2001

Differences in long-term outcome between patients treated in stroke units and in general wards: a 2-year follow-up of stroke patients in sweden.

BACKGROUND AND PURPOSE: The long-term beneficial effects of stroke unit care have been proved in several randomized trials. However, there is a question of large-scale applicability in routine clinical practice of interventions used by dedicated investigators in small randomized trials. The objective of this study was to compare, 21/2 years after stroke, patients who had been treated in stroke units and those treated in general wards in routine clinical practice. METHODS: This is a prospective cohort study based on 8194 patients who were included, during the first 6 months in 1997, in Riks-Stroke, the Swedish National Register for quality assessment of acute stroke. Two years after the event, 5189 patients were still alive and 5104 were followed up with a postal questionnaire to which 4038 responded. RESULTS: Among the group of patients who were independent in activities of daily living (ADL) functions before the stroke, patients who were treated in stroke units were less often dependent in ADL functions, after adjustment for case mix (OR, 0.79; CI, 0.66 to 0.94). If they also lived at home before the stroke, then they had a lower case-fatality rate 2 years after the stroke (OR, 0.81; CI, 0.72 to 0.92). CONCLUSIONS: Long-term beneficial effects of treatment in stroke units were shown for patients who were independent in ADL functions before the stroke. No benefits were shown for patients who were dependent on help for primary ADL before the stroke. Further studies on this group of patients with more detailed outcome measures are needed.

Activities of Daily Living↗
PubMed2001

Teenager injury panorama in northern Sweden.

OBJECTIVES: To study non-fatal unintentional injuries among teenagers and to suggest preventive measures. SETTING: The emergency care unit of the University Hospital, Umeå, Sweden. METHODS: All injured teenagers (N = 1044) attending the emergency care unit during 1991 were asked to answer a questionnaire focusing on when, where and how the injury occurred. All available medical records were examined. Data were coded according to the Nordic Medico-Statistical Committees Classification for Accident Monitoring, NOMESCO, and to the Abbreviated Injury Scale, AIS. RESULTS: 1,043 teenagers were treated with sports and transportation related injuries as the most common ones. Most injuries were minor (AIS 1), transportation related injuries had the highest proportion of non-minor injuries (AIS > or = 2), 139 teenagers were admitted for in-patient care. Most injuries occurred during leisure/school time. CONCLUSIONS: Sports and transportation related injuries were most frequent. Body weight and length differs among teenagers, we suggest that teenagers should exercise and play together, not only by age, but also to some extent, to height and weight. Curfew laws, a compulsory bicycle helmet law are other injury reducing measures suggested.

Accident Prevention↗
PubMed2001

Urban impact in the history of water quality in the Stockholm archipelago.

From the historical perspective, the increasing number of inhabitants in the city of Stockholm has had a negative effect on water quality in the surrounding lakes and coastal region. Government control and measures taken to improve water quality have been in progress since the mid-19th century. Water conditions in the 19th century, compared to later years is difficult to assess from the first chemical and biological investigations, due to infrequent sampling and the different parameters and methods used. However, a retrospective evaluation of water quality can be made on the basis of results from plankton investigations, which began in the early 20th century. The occurrence of the cyanobacteria Planktothrix agardhii, which indicates nutrient-rich conditions, was surveyed during summers with similar temperature conditions throughout the 20th century. The results show that eutrophied conditions probably prevailed in the Stockholm archipelago from the beginning of 20th century until the early 1990s. In the last decade of the 20th century, water quality appeared to be better than 100 years earlier. Today's better water conditions are most probably an effect of proper measures taken in wastewater treatment.

Animals↗
PubMed2000

DAX-1 functions as an LXXLL-containing corepressor for activated estrogen receptors.

We have discovered that the orphan receptor DAX-1 (NROB1) interacts with the estrogen receptors ERalpha and ERbeta. Interaction occurs with ligand-activated ERs in solution and on DNA and is mediated by the unique DAX-1 N-terminal repeat domain. Each of the three repeats contains a leucine-rich receptor-binding motif, known as the LXXLL motif, which is usually found in nuclear receptor coactivators. We have demonstrated that DAX-1 functions as an inhibitor of ER activation in mammalian cells and suggest a mechanism involving two sequential events, occupation of the ligand-induced coactivator-binding surface and subsequent recruitment of corepressors. Accordingly, we propose that DAX-1 itself acts as a corepressor for ERs. Because DAX-1 is coexpressed with ERs in reproductive tissues, these interactions could play significant roles by influencing estrogen signaling pathways. Our results point at functional similarities between DAX-1 and the orphan receptor SHP (NROB2) in that they have acquired features of transcriptional coregulators that are unique for members of the nuclear receptor family.

DAX-1 Orphan Nuclear Receptor↗
PubMed2000

Endothelial dysfunction after repeated Chlamydia pneumoniae infection in apolipoprotein E-knockout mice.

BACKGROUND: Arterial relaxation is largely regulated by endothelial nitric oxide (NO). Its diminished activity has been associated with incipient atherosclerosis. We investigated the endothelium-dependent relaxation of aorta in apolipoprotein E-knockout (apoE-KO) mice exposed to single or repeated Chlamydia pneumoniae inoculation. METHODS AND RESULTS: Forty-eight apoE-KO mice, 8 weeks old, were inoculated intranasally with C pneumoniae (n=24) or saline (n=24) every 2 weeks over a 6-week period. Twenty mice (10 infected and 10 controls) were killed at 2 weeks and 6 weeks, respectively, after the first inoculation. The smooth muscle tone of aortic rings was measured in vitro at both time points. The norepinephrine-precontracted thoracic aortic rings were successively exposed to methacholine in the absence and presence of N:(G)-nitro-L-arginine methyl ester (L-NAME) and diclofenac. The methacholine-induced relaxation was attenuated in the infected mice at 6 weeks in both the absence and presence of L-NAME (P:<0.05 and P:<0.01, respectively). When administered together with L-NAME, diclofenac enhanced the relaxation of the L-NAME-pretreated aortas in infected mice at 2 weeks (P:<0.05) but not in noninfected mice. The relaxation response from infected mice tended to differ in the same manner at 6 weeks (P:<0.1). No intimal thickening was detected at either time point. CONCLUSIONS: C pneumoniae impairs arterial endothelial function, and the NO pathway is principally involved. Cyclooxygenase-dependent vasoconstricting products may also account for the infection-induced impaired relaxation. These findings further support the role of C pneumoniae infection in atherosclerosis development.

Alkaline Phosphatase↗