Biomedical subjects

L Johansson

Publications and source records attributed to L Johansson.

At least 91 records · Page 5Linked to original sources

PubMed1998

Adult day care for dementia: a comparison of programs in Sweden and the United States.

Adult day care is regarded as an important respite service to family caregivers of dementia patients to assist the patient to remain in the community. This study includes 178 Swedish and 86 American day care centers serving cognitively impaired clients. Client, staff and organizational characteristics were surveyed. Although the two countries have quite different systems of elder care, client characteristics were similar, suggesting that adult day care centers are a convergent solution to a common problem of supporting disabled elderly. Differences were found between the USA and Sweden in the staff, structure, and services of the programs. The study raises questions about day care centers' goals and organization. Results provide a clearer understanding of the optimal role and function of adult day care centers.

Journal Article↗

PubMed1998

Selective binding by Helicobacter pylori of leucocyte gangliosides with 3-linked sialic acid, as identified by a new approach of linkage analysis.

The human gastric pathogen Helicobacter pylori has been shown to bind to glycoconjugates of human leucocytes in a sialic acid-dependent way. In order to improve the identification of the binding epitope, a new technique was developed to analyze the ketosidic linkage position between a terminal sialic acid and the consecutive monosaccharide. Permethylation and reduction with LiAlH4 followed by trifluoroacetolysis in 1000:1 trifluoroacetic anhydride:trifluoroacetic acid (24 h, 100 degrees C) results in the cleavage of glycosidic but not ketosidic bonds. The disaccharide products were analyzed by gas chromatography-mass spectrometry and sialyl-3 or -6 position and NeuAc or NeuGc are identified by their separate retention times and mass spectra. The method was worked out on model saccharides and applied on five-sugar gangliosides (sialylparaglobosides) of human leucocytes. Radiolabeled Helicobacter pylori was shown to bind to the upper part, but not to the lower part, of the five-sugar interval of a mixture of gangliosides separated on a thin-layer chromatogram. Using a membrane blotting procedure the active and inactive bands were isolated and shown to be NeuAcalpha2-3- and NeuAcalpha2-6-paraglobosides, respectively.

Bacterial Adhesion↗

PubMed1998

Under- and overreporting of energy intake related to weight status and lifestyle in a nationwide sample.

Desire for weight change and level of dietary consciousness may severely bias reported food intake in dietary surveys. We evaluated to what degree under- and overreporting of energy intake (EI) was related to lifestyle, sociodemographic variables, and attitudes about body weight and diet in a nationwide dietary survey. Data were gathered by a self-administered quantitative food-frequency questionnaire distributed to a representative sample of men and women aged 16-79 y in Norway, of whom 3144 subjects (63%) responded. Reported EI was related to estimated basal metabolic rate (BMR) based on self-reported body weight, age, and sex. An EI:BMR < 1.35 was considered to represent underreporting and an EI:BMR > or = 2.4 as overreporting of EI. Fewer men than women underreported EI (38% compared with 45%). The fraction of overreporters did not differ significantly between sexes (7% of the men compared with 5% of the women). A large proportion of underreporters was obese (9%) and wanted to reduce their weight (41%). Few overreporters were obese and 12% wanted to increase their weight. Underreporters consumed fewer foods rich in fat and sugar than did the other subjects. Multiple regression analysis showed that desire for weight change and physical activity score were significantly correlated with both EI and EI:BMR when adjusted for sociodemographic and lifestyle variables. Our findings indicated that attitudes about one's own body weight influenced reported EI. These attitudes are important in the interpretation of dietary data because many of the subjects (> 30%) wanted to change their body weight.

Adolescent↗

PubMed1998

Treatment difficulty and treatment outcome in orthodontic care.

The influence of perceived treatment difficulty on the outcome of and investment in orthodontic treatment was studied in 19-year-old individuals treated by general practitioners or specialists within the totally subventioned Swedish system for orthodontic care. A total of 313 individuals were evaluated according to treatment outcome and treatment investment. About one-quarter of the treatments evaluated were classified as easy, one-quarter as moderately difficult, and one-half as difficult. The perceived treatment difficulty was on a group basis associated with the pretreatment need. The treatment outcome became less favourable and the treatment investment more expensive the greater the perceived difficulty. More than one-quarter of the treatments provided by general practitioners were classified as difficult compared with three-quarters of those provided by specialists. The outcomes were, in general, more favourable for specialist treatments than for those provided by general practitioners, although the individuals treated by specialists, on the average, were classified as more difficult than those provided by general practitioners. Easy treatments were found to be extremely cost-effective and should be carried out when possible. General practitioners should preferably treat uncomplicated cases, and an increased use of fixed appliances would be desirable in the treatment of moderately difficult treatments. Difficult cases should be treated exclusively by specialists. Cases with little need or benefit of treatment, or a poor prognosis should be given low treatment priority, and patients and parents should in these cases be informed about the small expected benefit and risks involved.

Adolescent↗

PubMed1998

Photonuclear production in tissue for different 50 MV bremsstrahlung beams.

Calculations of photonuclear production in "tissue approximation" and the relative heavy particle dose to photon dose at dose maximum in water have been performed. Different 50 MV spectra based on a scanned beam technique to produce flat photon fields were used. These spectra were calculated with the Monte Carlo method and correspond to different target configurations and scan patterns. Photonuclear cross sections of neutron, proton, and alpha production for oxygen, nitrogen, and carbon are taken from the literature. Activation measurements using a HpGe detector have been used to verify the calculations. The relative heavy particle dose to photon dose was found to be 0.30%-0.42%, depending on the spectra used, and the estimated uncertainty was 20%. A relative biological effect (RBE) of 1.01-1.03 in "tissue approximation" for 50 MV were estimated using a RBE for neutron and protons of 2-5 and 4-10 for alpha particles.

Alpha Particles↗

PubMed1998

A regulatory role for RIP140 in nuclear receptor activation.

Transcriptional regulation of gene expression by nuclear receptors requires negatively and positively acting cofactors. Recent models for receptor activation propose that certain receptors in the absence of ligands can recruit corepressors while ligand binding results in conformational changes leading to the recruitment of coactivators. Previous work has established a coactivator role for the SRC-1 family members as well as an involvement of the coactivators CBP/p300 in nuclear receptor signaling. However, in addition to coactivators, ligand-activated nuclear receptors bind a number of different proteins that possibly serve other functions. Using peroxisome proliferator-activated receptor-alpha (PPAR alpha) as bait in a yeast two-hybrid screening, we have isolated nuclear factor RIP140 whose function in receptor activation is unclear. We now report a detailed characterization of RIP140 action with a focus on the retinoid X receptor (RXR) heterodimeric receptors PPAR and thyroid hormone receptor (TR). We show that putative PPAR ligands enhance the interaction of RIP140 with the rat PPAR subtypes alpha and gamma in solution but not with PPAR/RXR heterodimers on DNA. However, RIP140 forms ternary complexes in the presence of RXR ligands. Similar experiments with TR support the high affinity of RIP140 to the RXR subunit and also suggest that either partner in the TR/RXR heterodimer can independently respond to ligand. Coactivation experiments in yeast and mammalian cells confirm the coactivator role for SRC-1, but not for RIP140. We provide important evidence that the in vitro binding of RIP140 and SRC-1 to nuclear receptors is competitive. Since RIP140 generally down-regulates receptor activity in mammalian cells and specifically down-regulates coactivation mediated by SRC-1, we propose a model in which RIP140 indirectly regulates nuclear receptor AF-2 activity by competition for coactivators such as SRC-1.

Adaptor Proteins, Signal Transducing↗

PubMed1998

3D surface rendering of images from multiple MR pulse sequences in the pre-operative evaluation of hepatic lesions.

PURPOSE: To develop a method for making three-dimensional (3D) reconstructions of liver vessels and hepatic lesions from different MR data sets. MATERIAL AND METHODS: To reduce the time required for segmentation and reconstructions, we used T1, T2 and phase contrast angiography, optimised for liver, lesion and vessels respectively. Following segmentation and reconstruction, the different volumes were combined on the same workstation and presented to the surgeon. RESULTS AND CONCLUSION: Segmentation and reconstruction took 1-2 h. To be able to combine the volumes from the different data sets, certain criteria had to be fulfilled: a) the field of view had to be constant; b) the same volume had to be scanned every time which meant that the slice thickness and the number of slices could be adjusted as long as the volume covered was the same; and c) the positioning of each volume had to be identical between every scan. The resulting 3D reconstruction gave the surgeon a clear appreciation of the different lesions and their relation to the different liver segments in the pre-operative planning of hepatic resections.

Angiography↗

PubMed1998

Epitope dissection of receptor-active gangliosides with affinity for Helicobacter pylori and influenza virus.

Receptor-active gangliosides with affinity for Helicobacter pylori and influenza virus were chemically modified and analyzed by negative ion fast atom bombardment mass spectrometry (FAB MS) or electron ionization mass spectrometry (EI MS) after permethylation. Derivatizations included mild periodate oxidation of the sialic acid glycerol tail or conversion of the carboxyl group to primary alcohol or amides. The modified gangliosides were then tested for binding affinity using thin-layer plates overlaid with labeled microbes or microbe-derived proteins. Mild periodate oxidation, which shortens sialic acid tail without destruction of sugar cores, abolished or drastically reduced binding of H. pylori and avian influenza virus to sialyl-3-paragloboside (S-3-PG). The same effect was observed in the case of binding of the human influenza virus to receptor-active gangliosides of human leukocytes. Conversion of S-3-PG or leukocyte gangliosides to primary alcohols or amides also abolished the binding. However, mild periodate oxidation had no effect on binding of NAP (neutrophil-activating protein of H. pylori) to the active ganglioside.

Binding Sites↗

PubMed1997

Radioimmunoscintigraphy with a novel monoclonal antiprostate antibody (E4): an experimental study in nude mice.

BACKGROUND: Prostate cancer is one of the leading causes of death among men, despite achievements in diagnosis and therapy. Radioimmunolocalization and radioimmunotherapy of malignant tumors have demonstrated increasing potential and may become useful tools in the management of prostate cancer. METHODS: Nude mice were inoculated subcutaneously with cells from the poorly differentiated human prostate cancer cell line DU-145. The intact monoclonal antibody (MoAb) E4 and an intact anticytokeratin-8 MoAb, TS1, used for comparison were labeled with 125I and injected intraperitoneally (i.p.) in the mice. Repetitive quantitative scintigraphic recordings were performed during 1 month. The mice were killed at Day 29 after injection of the radiolabeled MoAb. The tumors and the organs were dissected and weighed. The remaining activity was measured in a gamma well counter. One part of the tumor was immediately fixed in Bouin's solution for autoradiography and the other in formaldehyde for microscopy. RESULTS: The study demonstrated significant radioimmunolocalization of the MoAb E4 into the DU-145 prostate tumor tissue in the animal model, with an average radiation dose of 0.08 Gy/MBq in the tumor. TS1 localized preferentially in necrotic parts of the tumor, yielding a tumor dose of 0.02 Gy/MBq. CONCLUSIONS: The MoAb E4 is a promising radiotracer for prostate cancer and may be used in radioimmunotherapy. As in earlier studies, TS1 shows significant radioimmunolocalization into necrotic tumor tissue, which also exists in prostate cancer.

Animals↗

PubMed1997

Dosimetry of fractionated administration of 125I-labeled antibody at experimental radioimmunotargeting.

BACKGROUND: Radiotherapy of solid tumors is preferably performed in fractionated doses. Conversely, radioimmunotherapy with nuclide-carrying antibodies delivers a continuously decreasing low dose rate during a longer time period after a single injection. In the current study, the same total amount of 125I-labeled anticytokeratin monoclonal antibody (MoAb) was administrated in one, three, or ten injections and the dosimetry was evaluated. METHODS: Three groups of nude mice (10 mice each) with HeLa Hep 2 xenografts were injected with 1 x 100 microg/22.2 megabecquerel (MBq), 3 x 33 microg/7.4 MBq, and 10 x 10 microg/2.22 MBq 125I-labeled TS1 MoAb, respectively. The mice were examined scintigraphically over a 54-day period (total number of radio immunoscintigraphies (RISs) = approximately 700) and doses to tumor and normal tissues were estimated according to the medical internal radiation dose formalism. RESULTS: A single bolus injection caused higher tumor uptake, tumor dose, and tumor to nontumor dose ratio than administration of the same total dose of antibody and radioactivity in three or ten separate injections. The single bolus injection caused a tenfold higher tumor uptake (% injected dose, or ID) compared with the group receiving ten injections. This caused a tumor dose of 17 gray to the group receiving a single bolus injection. CONCLUSIONS: In this antigen target system, a single injection of a large amount of antibody was found to be more efficient than the same antibody dose subdivided into three or ten fractions. It was concluded that not only the radioactivity but also the amount of antibody per fraction should be considered when determining optimal fractionated radioimmunotherapy.

Animals↗

PubMed1997

Dosimetry of fractionated experimental radioimmunotargeting with idiotypic and anti-idiotypic anticytokeratin antibodies.

BACKGROUND: Repeated injections of iodine-125 (125I)-labeled tumor targeting anticytokeratin monoclonal antibody (TS1) and a nonlabeled antiidiotypic monoclonal antibody against TS1 (alphaTS1) were compared with a single injection of the radiolabeled TS1 in experimental radioimmunotargeting. Anti-TS1 was used to remove nontargeting TS1. METHODS: Nude mice were inoculated with HeLa Hep2 cells. The animals in Group A received a single injection of 13 MBq 125I-labeled TS1. The animals in Group B received four injections of 125I-labeled TS1 (8-13 MBq) followed by alphaTS1 24 hours later, at 2-week intervals. The mean absorbed doses were calculated according to the Medical Internal Radiation Dose Committee criteria based on repetitive radioimmunoscintigraphies during an observation period of 59 days. RESULTS: A 11 gray (Gy) mean dose to the tumor and 2 Gy to the whole body was achieved in Group A. Mean peak tumor uptake of 5% of the injected dose (ID), corresponding to 14% ID/g, was observed on Day 17 after a single injection of the labeled monoclonal antibody. A mean peak tumor uptake of the same order of magnitude was seen in Group B. An absolute increase in the tumor uptake was observed in Group B during the entire observation period. The mean absorbed dose to the tumors was 11 Gy at the end of the observation period, whereas the whole body dose was only 2.5 Gy in Group B. Autoradiography of the tumors at the end of the observation period confirmed an intensive heterogeneous accumulation of activity in the entire tumor. CONCLUSIONS: The fractionated strategy can contribute to a significant accumulation of radiolabeled TS1 in the tumors. Furthermore, the use of alphaTS1 makes it possible to increase the tumor-to-nontumor dose ratio and maintain a prolonged high activity accumulation in the tumor.

Animals↗

PubMed1997

Experimental radioimmunotargeting combining nonlabeled, iodine-125-labeled, and anti-idiotypic anticytokeratin monoclonal antibodies: a dosimetric evaluation.

BACKGROUND: Preinjection of a nonlabeled tumor targeting anticytokeratin monoclonal antibody (TS1) and postinjection of an anti-idiotypic anticytokeratin monoclonal antibody (alphaTS1) were evaluated separately and in combination to investigate their effects on the accumulation of iodine-125 (125I)-labeled TS1 in experimental radioimmunotargeting. TS1 targets deposited extracellular cytokeratin 8 from necrotic tumor cells. METHODS: Nude mice were inoculated with HeLa Hep 2 cells. Four different groups were followed with 504 repetitive quantitative radioimmunoscintigraphic recordings during a 78-day observation period. The absorbed doses were calculated according to criteria of the Medical International Radiation Dose Committee. RESULTS: As much as 2% of the injected dose (ID) of 125I-labeled TS1 accumulated in the tumor, and the peak tumor uptake was recorded as late as Day 30 after the injection of 125I-labeled TS1. Anti-TS1 caused a rapid decrease in the whole body activity. The highest tumor-to-nontumor activity ratios were obtained when a pre-injection of nonlabeled TS1 was combined with a postinjection of alphaTS1. The mean absorbed dose in tumor per unit activity administered was 0.44 gray/megabecquerel (Gy/MBq) and in nontumor tissues 0.15 Gy/MBq after a single injection of 125I-TS1. The efficacy was 0.34 Gy/MBq in tumor and 0.1 Gy/MBq in nontumor tissues after a combination of preinjection of nonlabeled TS1 and postinjection of nonlabeled alphaTS1. This indicates a 20% increase in tumor doses compared with a single injection of labeled TS1. CONCLUSIONS: This study confirms an extensive accumulation of TS1 in the tumor, with peak values as late as 30 days after injection of labeled TS1. Furthermore, both preinjection of nonlabeled TS1 and postinjection of alphaTS1 can improve radioimmunotargeting.

Animals↗

PubMed1997

Unintentional fatal paraquat poisonings among agricultural workers in Costa Rica: report of 15 cases.

This study analyzes the exposure circumstances of 15 fatal occupational paraquat poisonings. To evaluate the potential danger of dermal absorption and the amount needed to produce a fatal outcome in the event of oral intake, we reviewed the medical records and autopsy protocols and interviewed relatives. Five fatalities were due to ingestion of a mouthful of paraquat concentrate, and five to intake of a smaller amount; three cases were associated with dermal exposure, and in two, there was no evidence of either oral or dermal exposure. Several cases concerned diluted paraquat spray. The clinical and pathomorphological findings, including a "blinded" evaluation of lung slides, were consistent with paraquat poisoning in all cases. Difficulties in establishing the diagnosis and recognizing the exposure were identified, as well as classification of unintentional poisonings as suicides at autopsy. The findings suggest that paraquat may cause fatal poisonings by ingestion of small amounts, by dermal absorption of diluted paraquat, and possibly by inhalation. More conclusive studies are warranted.

Administration, Oral↗

PubMed1997

Decentralisation from acute to home care settings in Sweden.

Sweden has a regionally based, publicly operated and financed, national health care system. Implementation of policy and the provision of health care has been the responsibility of the county council. In 1992, the major responsibility and resources for care of the elderly was transferred to the municipalities. The start of this reform, unintentionally, coincided with an economic recession which caused additional difficulties for the financing of the present level of public services generally. This development, in combination with innovations in health care technology, resulted in a rapid decentralisation of certain elderly care services from acute care settings.

Aged↗

PubMed1997

Serial gadolinium-enhanced magnetic resonance imaging and assessment of facial nerve function in Bell's palsy.

Eleven patients with mild or moderate acute idiopathic peripheral facial palsy, so-called Bell's palsy, were serially examined by gadolinium-DTPA-enhanced MRI on mean days 11, 40, and 97 (third examination, n = 10) after the onset of palsy. Results of the clinical and neurophysiologic assessment of facial nerve function were compared with the gadolinium-enhanced MRI findings. Eight of the 11 patients demonstrated contrast enhancement of the facial nerve at the initial examination, but in 7 of them, the enhancement had disappeared by the time of the serial follow-up gadolinium-enhanced MRI scans. The disappearance of facial nerve enhancement was found to be related to clinical and neurophysiologic improvements in facial nerve function during recovery from Bell's palsy. The three patients whose scans were negative at the initial gadolinium-enhanced MRI examination had the same clinical severity of palsy, but initially they had milder neurophysiologic involvement than those who demonstrated enhancement; these three patients did not exhibit enhancement at serial follow-up scans. These findings indicate that the presence of enhancement at the initial MRI scan is not necessarily indicative of a poor prognosis for recovery.

Acute Disease↗

PubMed1997

Expression pattern of glutamate decarboxylase (GAD) in the developing cortex of the embryonic chick brain.

The development of the GABAergic system in the chick embryo telencephalon has been studied. Special emphasis was placed on the development of glutamate decarboxylase (GAD) between embryonic day 8 (E8) and E17. The GABA immunoreactivity and neuron-specific enolase expression was detected simultaneously in glutardialdehyde fixed sections, which confirmed that GABAergic cells exhibit neuronal phenotype. The GAD expression was studied by means of immunohistochemistry on cryo-sectioned material both at the light and electron microscopic levels. Furthermore, the presence and localization of GAD65 and GAD67 mRNAs were studied with an in situ hybridization technique with digoxigenin-labeled RNA probes. Protein expression as well as mRNA appearance mostly coincided both temporally and spatially. In the parahippocampal area, as well as in other regions of the developing cortex, GAD staining was seen from E8 onwards. The number of positive cells increased as did the intensity of staining up to E14. As observed in the electron microscope, the GAD protein was co-localized with GABA in most cases, although some GAD-positive cells devoid of GABA-staining also were observed. The pattern of GAD mRNA expression was in general similar to that of GAD immunostaining. Both GAD65 and GAD67 mRNA were detected during the entire period. Furthermore, GAD67 mRNA localization spatially was more correlated with GAD protein expression. The study provides evidence for the notion that development of the GABAergic system occurs rapidly during embryogenesis and, as suggested from mRNA data, that two forms of GAD with slight difference in distribution can contribute to this.

Animals↗

PubMed1997

Response rates with different distribution methods and reward, and reproducibility of a quantitative food frequency questionnaire.

OBJECTIVES: To evaluate the use of a self-administered quantitative food frequency questionnaire (QFFQ) in a national dietary survey concerning (a) response rates with different distribution methods and reward; (b) degree of underreporting of energy intake; (c) reproducibility of the QFFQ; and (d) seasonal variation on reported intake. DESIGN AND SUBJECTS: A pilot study was performed in 1992 to test response rates to the QFFQ with three different distribution methods, with and without reward, in a random sample of 1200 adults aged 16-79 y. In another study, the QFFQ was distributed to a nation-wide, representative random sample of 5008 adults aged 16-79 y during June, September, November 1993 and March 1994. Reproducibility was evaluated among 90 responders to the survey who answered another QFFQ six weeks later. RESULTS: The distribution method combining postal distribution and collecting the QFFQ by interviewer as well as an offer to participate in a lottery, gave the highest response rate (72%). The possibility to get a reward increased the response rate by 9, 14 and 57%, respectively, depending on the distribution method used. The mean daily energy intake and the percentage of subjects claiming to have unlikely low energy intake did not differ significantly between the different ways of distribution. In the main survey the mean ratio between energy intake and estimated basal metabolic rate was 1.58 among men and 1.47 among women, and 37% of men and 45% of women had a ratio below 1.35. Spearman rank correlations between the two QFFQ ranged from 0.48 (edible fats) to 0.91 (coffee) with a median coefficient of 0.70. For nutrients correlations ranged from 0.55 (carbohydrate E%) to 0.81 (alcohol), with a median coefficient of 0.72. The season of questionnaire administration was of minor importance for the reported intake of the main foods and nutrients. CONCLUSIONS: The QFFQ-method is suitable for use in a Norwegian nutritional surveillance system. SPONSORSHIP: National Nutrition Council, Ministry for Agriculture, Ministry for Health and Social Affairs and Norwegian Research Council.

Adolescent↗

PubMed1997

Cystatin C, and inhibitor of bone resorption produced by osteoblasts.

The effects of human cystatin C on bone resorption, enzyme release, osteoclast generation, bone cell proliferation and bone matrix protein biosynthesis have been examined in different in vitro systems. The effects of cystatin C were compared with those of calcitonin and E 64 (trans-Epoxysuccinyl-L-leucyl-amido-(4-guanidino)butane). Recombinant human cystatin C and E 64 dose dependently inhibited the mobilization of 45Ca and the release of 3H (from [3H]-proline-labelled bones) in mouse calvariae stimulated to resorb by parathyroid hormone (PTH) or 1,25(OH)2-vitamin D3. Cystatin C and E 64 also inhibited the release of 45Ca from bones stimulated by thrombin, interleukin-1 and prostaglandin E2. In PTH-stimulated bones, the inhibitory action of cystatin C and E 64 on 45Ca release was observed after 6-9 h, whereas the inhibitory effect on 3H release was seen after just 2 h. In contrast, calcitonin caused an inhibition of both 45Ca and 3H release which was seen after 2 h. The PTH-stimulated release of the lysosomal enzymes was not affected by cystatin C and E 64, whereas calcitonin caused a significant inhibition. In contrast to calcitonin, cystatin C did not affect PTH-stimulated enhancement of osteoclast generation in the mouse calvariae. Using Western blot analysis and radioimmunoassay, we demonstrated that mouse calvarial bones and MC3T3-E1 cells produce cystatin C. These data show that cystatin C is synthesized by bone cells and that recombinant human cystatin C inhibits bone resorption in vitro without affecting bone cell proliferation, bone matrix formation or osteoclast generation. The mechanism seems to be due primarily to inhibition of the activity of osteoclastic proteolytic enzymes released into the resorption lacunae.

Acetylglucosaminidase↗