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Biomedical subjects

T Björkman

Publications and source records attributed to T Björkman.

18 recordsLinked to original sources
PubMed2002

Predictors of improvement in quality of life of long-term mentally ill individuals receiving case management.

One hundred and thirteen long-term mentally ill clients receiving case management were investigated with regard to psychosocial and clinical predictors of changes in subjective quality of life during an 18-month follow-up. Better psychosocial functioning and fewer psychiatric symptoms at baseline predicted a greater improvement in quality of life. A larger decrease in symptom severity and a greater improvement in the social network during the follow-up were identified as the most important predictors of a greater improvement in subjective quality of life. The results of the study suggest that an emphasis should be put on effective symptom management, a reduction of needs for care and social support in order to fulfill the aims of improving subjective quality of life in patients receiving case management.

Adult↗
PubMed2001

Regulation of osteoprotegerin secretion from primary cultures of human bone marrow stromal cells.

Osteoprotegerin (OPG) is a soluble receptor for receptor activator of NF kappa B-ligand, a factor required for osteoclastogenesis. OPG secreted from bone marrow stromal cells is believed to inhibit osteoclast differentiation and several agents known to influence bone resorption have been demonstrated to regulate mRNA levels of OPG. In this report we have investigated the secretion of OPG protein from primary cultures of human bone marrow stromal cells. An ELISA was developed for measuring the concentration of OPG in culture medium. OPG secretion was decreased by 50% when the human bone marrow stromal cells were treated with 1 microM of prostaglandin E(2), possibly through activation of the protein kinase A-pathway since stimulation of protein kinase A by forskolin also inhibited OPG secretion. Treatment with phorbol 12,13 di butyrate, an activator of the protein kinase C-pathway, potently stimulated the secretion of OPG from human bone marrow stromal cells. The cells were also stimulated with inflammatory mediators and glucocorticoids. Treatment with interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) stimulated OPG secretion to 500% and 400% of control whereas dexamethasone decreased OPG production by 40%. In conclusion, an ELISA measuring OPG in cell culture media was developed. Using this ELISA, the amount of OPG secreted from human bone marrow stromal cells was clearly detectable, and the secretion of OPG-protein was potently regulated by prostaglandin E(2), forskolin, phorbol 12,13 di butyrate, IL-1 alpha, TNF-alpha, and dexamethasone.

Bone Marrow Cells↗
PubMed2000

What do case managers do? An investigation of case manager interventions and their relationship to client outcome.

BACKGROUND: The aim of the present study, which forms part of a wider case management multicenter study, was to explore the content of case managers' work, service patterns, and their relationship to client outcome. METHODS: Client background characteristics were registered at admission, and needs of care and psychosocial functioning were assessed at admission to the service and after 18 months. In seven of the services an extended follow-up was performed, which included assessments regarding quality of life, level of symptoms and social network. The study comprised 176 severely mentally ill clients, of whom 153 participated in a general 18-month follow-up (87%), with 113 clients out of 134 participating in an extended follow-up sample (84%). RESULTS: The investigation of service patterns showed that clients received services in a great variety of life areas using a number of different types of interventions. The results support the assumption that severely mentally ill clients are in need of case management services that offer more than brokerage services and coordination. A more active rehabilitation-oriented approach was found towards younger clients and clients who had a job, which may reflect a higher level of ambition in assisting younger clients to gain access to and stay in education and the labor market. Several types of intervention were related to client outcome. Brokerage, intervention planning and more interventions in the area of skills relating to activities of daily living were related to a more pronounced decrease in needs of care. More time spent on indirect work on behalf of the clients was related to a better outcome with regard to psychiatric symptoms and social network. CONCLUSIONS: The results indicate that specific service components have a more obvious distinct impact than others on outcome, and that this increase in effectiveness varies with the outcome targeted.

Adult↗
PubMed1997

Circulating hyaluronan, chondroitin sulphate and dextran sulphate bind to a liver receptor that does not recognize heparin.

Chondroitin sulphate, injected intravenously into rats and given prior to intravenous 125I-labelled hyaluronan with a mean Mw of about 400 kDa, was shown to inhibit the rapid receptor-mediated uptake of hyaluronan by the liver. The labelled hyaluronan that remained in the circulation was shown, by size exclusion chromatography of serum and urine, to be rapidly degraded down to fragments of lower Mw and filtered out into the urine and tissues. When the uptake of 125I-hyaluronan was inhibited by unlabelled hyaluronan, only very low degradation and urinary excretion were found. Liver uptake could also be inhibited by dextran sulphate but not by heparin. Unlabelled hyaluronan could inhibit the liver uptake of labelled chondroitin sulphate but not labelled heparin. Unlabelled chondroitin sulphate and dextran sulphate inhibited cell association of labelled hyaluronan to liver endothelial cells in culture more effectively than unlabelled hyaluronan. Our data show that the liver hyaluronan receptors also recognize and effectively bind chondroitin sulphate and dextran sulphate but not heparin and that a hyaluronan-specific saturable degradative mechanism exists in the circulation. Such a mechanism could explain why hyaluronan in the general circulation has a much lower Mw than the hyaluronan in lymph. The results also indicate that increased hyaluronan levels in serum, and increased urinary excretion of hyaluronan, may be secondary to increased outflow of chondroitin sulphate from the tissues during some pathological conditions.

Animals↗
PubMed1996

The rationalisation movement in perspective and some ergonomic implications.

The paper gives an overview of the Rationalisation Movement from Taylor to the most recent organisation models such as 'Business Process Reengineering'. Special emphasis is put on the estimated implications of the different rationalisation strategies in terms of ergonomics/work physiology. In addition, basic terms and concepts are defined. According to the author, Taylorism, Fordism and Lean Production seem to offer an insufficient potential for good ergonomics. However, more recent organisational models such as 'Time Based Management' and 'Business Process Reengineering', may appear more promising but unfortunately almost no research has been conducted to describe the ergonomics implications of these models.

Journal Article↗
PubMed1995

Accessible hyaluronan receptors identical to ICAM-1 in mouse mast-cell tumours.

Immunohistochemical studies of the hyaluronan (HA)-receptor (R), originally found on liver endothelial cells (LEC) and related to the intercellular adhesion molecule 1 (ICAM-1), showed that polyclonal antibodies against HARLEC (HA receptor on LEC) also stain structures in mouse mastocytomas, mainly vessels. To test if intravenously administered HA might target the tumour receptors in vivo, mice carrying an inoculated mastocytoma in one hind leg muscle were injected in the tail vein with 125I-tyrosine (T)-labelled HA and killed 75 min after injection when organs and tissues were checked for radioactivity. When doses exceeding the binding capacity of the liver were injected, a significant increase in radioactivity (up to five-fold) within the tumour tissue was found. The weight adjusted difference between control and tumour tissue was greater for smaller tumours, probably due to necrosis in the larger. HA-staining of tumours from animals receiving 125I-T-HA, showed HA in areas that also stained weakly for ICAM-1 using monoclonal antibodies. ICAM-1 staining was dramatically increased after hyaluronidase treatment of the sections, indicating that the HA is bound to these receptors and thereby blocks antibody recognition.

Animals↗
PubMed1995

The assessment of needs in psychiatric patients. Interrater reliability of the Swedish version of the Camberwell Assessment of Needs instrument and results from a cross-sectional study.

The assessment of needs has been put forth as an important dimension in both the planning, development and evaluation of psychiatric services. A needs assessment tool for routine use should ideally be brief, not require additional staff, be valid and reliable with respect to setting, gender and culture, and also be sensitive to changes in needs and differences in needs between subgroups of patients. In this study, the interrater reliability of the Swedish version of the Camberwell Assessment of Needs instruments (CAN), measuring needs in 22 areas, was investigated in a cross-sectional sample consisting of 119 psychiatric inpatients and outpatients. The prevalence and severity of needs, prevalence of unmet needs, as well as current help received was also investigated. The interrater reliability of the instrument was found to be good both measured as total percentages of agreement in ratings, where an agreement of 80% or above was found in 90% of the comparisons, and as measured by Cohen's kappa. Predominant needs in the sample were in addition to clinical needs concerning psychological distress and psychotic symptoms, social needs such as the need for company, daytime activities and information concerning condition and treatment. The CAN seems to be a instrument with a high interrater reliability also when used under routine conditions as in this study. It also seems to have a high degree of feasibility with regard to different types of patients and settings and a sensitivity concerning differences in needs in subgroups of patients.

Adolescent↗
PubMed1994

Labelling of high molecular weight hyaluronan with 125I-tyrosine: studies in vitro and in vivo in the rat.

Studies on the metabolism of the polysaccharide hyaluronan has previously been hampered by the lack of radioactive hyaluronan of high molecular weight (MW) and high specific activity. In the present study 125I-tyrosine (T)-labelled hyaluronan was produced after CNBr-activation of the polysaccharide. A specific activity of approximately 0.1 MBq microgram-1 was achieved using 100 micrograms of 0.5 x 10(6) Da hyaluronan labelled for 2 h with 18 MBq 125I. The 125I-T-hyaluronan kept a high MW-profile upon gel filtration chromatography and was found to be cleared from the circulation with the kinetics and organ distribution reported for biosynthetically labelled hyaluronan of high MW. The 125I-labelled polysaccharide is also taken up by liver endothelial cells both in vivo and in vitro, indicating that the labelling does not interfere with the binding to specific cell-surface receptors found on these cells. The intracellular degradation is slower than that earlier reported for biosynthetically labelled hyaluronan and seems to be halted at the level of low MW oligo- or mono-saccharides that eventually leave the organism via the urine. Scintigraphic images of rats after intravenous injection of 125I-T-hyaluronan showed rapid uptake in the liver and a redistribution of radioactivity from liver to urine with time. Our results indicate that the 125I-T-hyaluronan is suitable for studies of hyaluronan-metabolism in a number of ways. The gamma emitters 125I and 131I are easy to monitor and can be used also for in vivo 3D-imaging using single photon emission computer tomography.

Animals↗
PubMed1993

What is important in psychiatric inpatient care? Quality of care from the patient's perspective.

The development of quality assurance programs for psychiatric care has increased the interest in quality of care and accountability from the patient's perspective. However, most investigations of patient satisfaction use instruments which rate aspects of care defined and held to be important by professionals and care givers. The aims of this study were 2-fold. To map descriptive characteristics of ideal inpatient psychiatric care through open patient interviews, using a sample of 78 hospitalized patients and, secondly, based on a content analysis of these interviews, to have another sample of 77 hospitalized patients rank the importance of 48 treatment characteristics extracted from the qualitative analysis. Results of the content analysis showed that characteristics of ideal inpatient treatment could be classified in six categories: staff-patient relationship, patient co-influence, treatment content, activities, ward atmosphere and staff competence. Results from the patients' rating of the importance of treatment characteristics showed that patients put the highest emphasis on staff empathic qualities: being caring, interested and understanding, respecting patients, devoting time to patients, and creating a safe treatment environment. The least importance was ascribed to characteristics of the physical environment and daily routines on the ward. It is concluded that in order to secure content validity of investigations of the quality of psychiatric inpatient care from the patient's perspective, effort should be put into including the areas of staff-patient relationships and patient information and co-influence.

Adult↗
PubMed1992

Perception of gravity by plants.

Physical principles can be used to predict some features about the gravity perception system in plants. The nature of the system has made it rather elusive, so this approach represents an additional source of information to help find it. For a gravitational stimulus to be detected, two masses must move relative to each other in a manner which causes a significant amount of work to be done on a receptor. Relative to cellular dimensions, the masses must be large, be dense and move noticeable distances. The main sources of noise are thermal motion and flexing of the plant tissue. Some new models for the function of amyloplasts as statoliths are presented.

Cell Size↗
PubMed1991

Root growth regulation and gravitropism in maize roots does not require the epidermis.

We have earlier published observations showing that endogenous alterations in growth rate during gravitropism in maize roots (Zea mays L.) are unaffected by the orientation of cuts which remove epidermal and cortical tissue in the growing zone (Björkman and Cleland, 1988, Planta 176, 513-518). We concluded that the epidermis and cortex are not essential for transporting a growth-regulating signal in gravitropism or straight growth, nor for regulating the rate of tissue expansion. This conclusion has been challenged by Yang et al. (1990, Planta 180, 530-536), who contend that a shallow girdle around the entire perimeter of the root blocks gravitropic curvature and that this inhibition is the result of a requirement for epidermal cells to transport the growth-regulating signal. In this paper we demonstrate that the entire epidermis can be removed without blocking gravitropic curvature and show that the position of narrow girdles does not affect the location of curvature. We therefore conclude that the epidermis is not required for transport of a growth-regulating substance from the root cap to the growing zone, nor does it regulate the growth rate of the elongating zone of roots.

Biological Transport↗
PubMed1991

The role of extracellular free-calcium gradients in gravitropic signalling in maize roots.

Gravitropism in roots has been proposed to depend on a downward redistribution of calcium across the root cap. However, because of the many calcium-binding sites in the apoplast, redistribution might not result in a physiologically effective change in the apoplasmic calcium activity. To test whether there is such a change, we measured the effect of gravistimulation on the calcium activity of statocyte cell walls with calcium-specific microelectrodes. Such a measurement must be made on a tissue with gravity sensing cells at the surface. To obtain such a tissue, decapped maize roots (Zea mays L. cv. Golden Cross Bantam) were grown for 31 h to regenerate gravitropic sensitivity, but not root caps. The calcium activity in the apoplasm surrounding the gravity-sensing cells could then be measured. The initial pCa was 2.60 +/- 0.28 (approx 2.5 mM). The calcium activity on the upper side of the root tip remained constant for 10 min after gravistimulation, then decreased 1.7-fold. On the lower side, after a similar lag the calcium activity increased 1.6-fold. Control roots, which were decapped but measured before recovering gravisensitivity (19 h), showed no change in calcium activity. To test whether this gradient is necessary for gravitropic curvature, we eliminated the calcium activity gradient during gravitropism by applying a mobile calcium-binding site (dinitro-BAPTA; 1,2-bis(2-amino-5-nitro-phenoxy)ethane-N,N,N',N'-tetraacetic acid) to the root cap; this treatment eliminated gravicurvature. A calcium gradient may be formed by proton-induced calcium desorption if there is a proton gradient. Preventing the formation of apoplastic pH gradients, using 10 and 50 mM 2-(N-morpholino)ethanesulfonic acid (Mes) buffer or 10 mM fusicoccin to stimulate proton excretion maximally, did not inhibit curvature; therefore the calcium gradient is not a secondary effect of a proton gradient. We have found a distinct and rapid differential in the apoplasmic calcium activity between the upper and lower sides of gravistimulated maize root tips which is necessary for gravitropism.

Biological Transport↗
PubMed1989

The use of bioelectric currents to study gravity perception in roots.

Inhibitor-based studies of gravity perception in plants have yielded ambiguous results because gravitropism consists of many steps in series. Inhibiting any step eliminates gravicurvature; it cannot be shown whether gravity perception and transduction are affected by the inhibitory treatment. The use of the vibrating probe has allowed detection of a response that is measurable independent of stimulus transmission and growth, two post-transduction steps of gravitropism. This application of the vibrating probe requires particular attention to artifacts. Calmodulin action and auxin transport are both believed to be components of gravitropism and specific roles have been proposed for them in graviperception. The perception-dependent current measured with the vibrating probe is eliminated by inhibitors of calmodulin, but not by auxin inhibitors. Thus, the vibrating probe has made it possible to offer more direct evidence for a role of calmodulin in transduction, and to reject one for auxin transport in perception and transduction.

Biological Transport↗
PubMed1988

The role of the epidermis and cortex in gravitropic curvature of maize roots.

In order to determine the role of the epidermis and cortex in gravitropic curvature of seedling roots of maize (Zea mays L. cv. Merit), the cortex on the two opposite flanks was removed from the meristem through the growing zone; gravitropic curvature was measured with the roots oriented horizontally with the cut flanks either on the upper and lower side, or on the lateral sides as a wound control. Curvature was slower in both these treatments (53 degrees in 5 h) than in intact roots (82 degrees), but there was no difference between the two orientations in extent and rate of curvature, nor in the latent time, showing that epidermis and cortex were not the site of action of the growth-regulating signal. The amount of cortex removed made no difference in the extent of curvature. Curvature was eliminated when the endodermis was damaged, raising the possibility that the endodermis or the stele-cortex interface controls gravitropic curvature in roots. The elongation rate of roots from which just the epidermis had been peeled was reduced by 0.01 mM auxin (indole-3-acetic acid) from 0.42 to 0.27 mm h-1, contradicting the hypothesis that only the epidermis responds to changes in auxin activity during gravistimulation. These observations indicate that gravitropic curvature in maize roots is not driven by differential cortical cell enlargement, and that movement of growth regulator(s) from the tip to the elongating zone is unlikely to occur in the cortex.

Gravitropism↗
PubMed1987

An electric current associated with gravity sensing in maize roots.

The study of gravisensing would be greatly enhanced if physiological events associated with gravity sensing could be detected separately from subsequent growth processes. This report presents a means to discriminate sensing from the growth processes. By using a vibrating probe, we have found an electric current generated by the gravity sensing region of the root cap of maize (Zea mays cv Merit) in response to gravistimulation. On the upper surface of the root cap, the change from the endogenous current has a density of 0.55 microampere per square centimeter away from gravity. The onset of the current shift has a characteristic of lag of three to four minutes after gravistimulation, which corresponds to the presentation time for gravity sensing in this tissue. A description of the current provides some information about the sensing mechanism, as well as being a valuable means to detect gravity sensing independently of differential growth.

Electric Conductivity↗
PubMed1987

Effect of inhibitors of auxin transport and of calmodulin on a gravisensing-dependent current in maize roots.

Some characteristics of the gravity sensing mechanism in maize root caps were investigated using a bioelectric current as an indicator of gravity sensing. This technique involves the measurement of a change in the current density which arises at the columella region coincidently with the presentation time. Two inhibitors of auxin transport, triiodobenzoic acid and naphthylphthalamic acid, blocked gravitropic curvature but not the change in current density. Two inhibitors of calmodulin activity, compound 48/80 and calmidazolium, blocked both curvature and gravity-induced current. The results suggest that auxin transport is not a component of gravity sensing in the root cap. By contrast, the results suggest that calmodulin plays an intrinsic role in gravity sensing.

Biological Transport↗
PubMed1987

Mechanisms of stimulation of acid production in parietal cells isolated from the pig gastric mucosa.

Sequential incubations with pronase and collagenase of pig gastric mucosa resulted in single cell preparations containing 10-20% parietal cells, which could be enriched further to 85-95% purity by density-gradient centrifugation followed by elutriation. Acid production of the isolated cells was measured by means of aminopyrine accumulation in their acid compartments. When small pieces of the mucosa were pretreated for 1 h in the presence of either histamine, pentagastrin or carbachol before preparation of cells, the ability of the subsequently isolated cells to produce acid was increased. In parietal cells isolated from resting (not pretreated) mucosa pentagastrin, carbachol and also adrenaline increased the histamine-stimulated aminopyrine accumulation (50-90% increase). Adrenaline alone had no significant effect on the aminopyrine accumulation. In the presence of 10(-4) M histamine the apparent EC50 for adrenaline was 5 X 10(-7) M. Adrenaline, histamine, forskolin and isobutylmethylxanthin (IBMX) increased the formation of cAMP in purified parietal cells. The three 'classical' secretagogues histamine, pentagastrin and carbachol, but also IBMX and forskolin, increased the cytosolic free Ca2+ from approximately 1.5 X 10(-7) M to 2.2-3.5 X 10(-7) M but adrenaline and dibutyryl cyclic AMP did not. Thus the present results indicate that there are - in addition to histaminergic H2 receptors - specific cholinergic, gastrinergic and adrenergic receptors on the plasma membrane and that there are separate cAMP and Ca2+-dependent stimulatory pathways in the parietal cell.

8,11,14-Eicosatrienoic Acid↗