Biomedical subjects

Kjell Johansson

Publications and source records attributed to Kjell Johansson.

18 recordsLinked to original sources

PubMed2005

Retinal neurospheres prepared as tissue for transplantation.

The present work was conducted to study the cellular composition and developmental capacity of retinal neurospheres. Furthermore, the ability of grafted neurospheres to integrate into adult retinal tissue was studied in an in vitro model. Retinal progenitor cells isolated from rat embryos were expanded into neurospheres in vitro in the presence of basic fibroblast growth factor (bFGF), epidermal growth factor (EGF) and leukemia inhibitory factor (LIF). Neurospheres labeled with a lipophilic dye were placed onto explants, and tissue interactions were analyzed after 2-6 days of culture. Immunocytochemical analysis of neurospheres revealed the presence of neuronal and glial cells. Proliferating neuronal and glial cells were observed after 2 weeks, whereas the neuronal cell proliferation declined considerably after 4 weeks. Few apoptotic cells were observed in the neurospheres. Neurospheres cultured on explanted adult retina engrafted with the surrounding tissue, but progenitor cell migration into the explants was low. However, the grafted neurospheres appeared to limit the experimentally induced photoreceptor apoptosis in the surrounding explant tissue.

Animals↗

PubMed2005

Advice to patients in Swedish primary care regarding alcohol and other lifestyle habits: how patients report the actions of GPs in relation to their own expectations and satisfaction with the consultation.

BACKGROUND: Lifestyle advice given by general practitioners (GPs) may be a cost-effective means of health promotion; however, it is not fully put into routine practice. The aim of this study was to explore to what extent GPs' patients expect and receive advice concerning alcohol, tobacco, exercise and diet in relation to sociodemographic characteristics, type of visit and patient satisfaction. METHODS: A postal questionnaire was sent to a representative sample (n = 9750) of patients who had consulted GPs in a county in Sweden. The response rate was 69% (n = 6734). RESULTS: Exercise was the most (16%) and alcohol the least (5%) common type of advice. The patients received advice more often than they expected in all areas except alcohol. The patients reported the highest rate of unfulfilled advice expectation and the lowest rate of unexpected advice in the case of alcohol. Male gender, poorer self-rated health and scheduled appointment were independent predictors of all types of advice. Continuity of GP contact was only favourable for exercise and diet advice. The patients who received advice were more satisfied with their visit to the doctor. CONCLUSIONS: A tertiary preventive perspective guides GPs' practice of giving advice. Male patients with advanced illnesses are given priority. Women and patients with long-term risk habits are more neglected. The GPs tend to misjudge the expectations and needs of their patients and are too restrained in their counselling practice. Alcohol is the most disregarded area of advice in proportion to the patients' expectations and needs.

Adolescent↗

PubMed2005

Structural changes in the developing retina maintained in vitro.

The present study examined the emergence of structural remodeling in explanted neonatal rat retina. Immunohistochemical analysis demonstrated signs of glial and neuronal remodeling after 11 days in vitro and included the activation of Müller cells, the formation of ectopic neuropil areas and sprouting of photoreceptor terminals. We also observed that cholinergic and GABA-ergic amacrine cells displayed signs of disorganized laminations. These results demonstrate that retinal culturing initiates structural changes that show morphological similarities to glial and neuronal remodeling identified in retinitis pigmentosa retinas and experimentally detached retinas.

Amacrine Cells↗

PubMed2005

Feasibility of an email-based electronic screening and brief intervention (e-SBI) to college students in Sweden.

An email-based electronic screening and brief intervention (e-SBI) with personalized normative feedback on alcohol habits was offered to all 3,875 second term students at Linköping University, Sweden. The students received an email with a link to a computerized alcohol habit test and were offered personalized feedback directly on the computer screen. The students evaluated the test and were asked to state whether they were going to consider changing or actually change their alcohol habits. The response rate was 44%, with 742 female and 843 male students participating. The students displayed a strong gender difference in drinking pattern. A three-fold higher percentage of males than females were risky drinkers with regard to a high average weekly volume consumption. The gender differences were less pronounced regarding heavy episodic drinking that was reported by 51% of the females and 70.5% of the males. The email-based computerized normative feedback was appreciated by the students and one-third of the females and one-fifth of the males believed that they would benefit from the normative feedback; 8% of the females and 3% of the males believed that they would actually change their habits after the feedback. Students with a risky drinking pattern, previous experiences of blackouts, being dissatisfied with their current drinking and students that had considered to change their habits before the e-SBI, yielded a stronger motivation to change their drinking after having performed the intervention compared to students without such characteristics. The e-SBI with normative feedback was simple to administer and has the potential to be used repeatedly and on a large scale with minimum effort in terms of cost and time.

Adult↗

PubMed2005

Development of the embryonic porcine neuroretina in vitro.

PURPOSE: The objective of this study was to investigate the survival and morphology of embryonic porcine full-thickness neuroretina in culture. METHODS: Porcine fetuses were taken out by cesarian section, and the eyes were enucleated. Neuroretinas were explanted on culture plate inserts and were kept for 0-42 days in vitro under standard culture conditions. Green nucleic acid (Sytox) was used for measuring the extent of cell death, and 4,6-diaminidine-2-phenylindoldihydrochloride was used as a marker for the cellular layers. The explants were examined as whole-mount preparations and vertical sections. Sectioned tissue was stained with hematoxylin-eosin and labeled for immunohistochemistry with photoreceptor-specific antibodies raised against transducin and recoverin. RESULTS: In explants kept for 0-5 days in vitro, the developing retina consisted of multiple rows of neuroblastic cells and a more defined, but multilayered ganglion cell layer (GCL). Older explants revealed a more differentiated appearance with ultimately all normal retinal layers present, even after 42 days in vitro. Transducin- and recoverin-labeled photoreceptors were seen in these specimens, but no outer segments were found. The whole-mount preparation revealed extensively Sytox-labeled cells in the GCL at 2 days in vitro, but very few cells were labeled in older explants. CONCLUSION: This study shows that cultured fetal porcine full-thickness neuroretina can survive and develop according to its intrinsic timetable for at least 6 weeks in vitro. The in vitro system for culturing of the full-thickness retina may be useful in experiments involving retinal transplantation.

Animals↗

PubMed2005

Synchronous variation in water chemistry for 80 lakes in southern Sweden.

Variation in water chemistry was studied in 80 lakes in southern Sweden. The lakes had forest dominated catchments. The length of the time series was 14 years. Synchrony was calculated as Pearson's product moment correlation coefficients for all combinations of lakes, i.e. 3160 lake-pairs. The chemical variables studied were non-marine sulphate (SO4*), non-marine calcium (Ca*), absorbance and acid neutralising capacity (ANC). Statistically significant synchrony occurred in 93% of all lake-pairs for SO4*, and between 58 and 67% for absorbance, Ca* and ANC. In 70% of all lake-pairs, the synchrony was >0.71 for SO4*, which means that more than half of the variation in one lake could be explained by the variation in the other lake. For absorbance, Ca* and ANC, about 25% of the lake-pairs had a synchrony >0.71. The relatively high synchrony for SO4* occurred during an overall downward trend in SO4* concentration. The degree of synchrony in our study was at a level comparable to other studies in northern America and England. However, our study included lakes in a much larger area, with distances of up to 500 km between the lakes, while earlier studies were made on small lake districts with lakes located within approximately 50 km. In contrast to these earlier studies, there was no correlation between synchrony and distance, lake characteristics or catchment characteristics. However, when a small subset of 15 lakes in the southeast of Sweden was selected, such relations were found.

Calcium↗

PubMed2005

Feasibility of a computerized alcohol screening and personalized written advice in the ED: opportunities and obstacles.

This study evaluates the feasibility of a computerized alcohol screening and intervention in patients seeking care at an emergency department. The aim of the study was to explore prevailing attitudes among nursing staff to alcohol prevention in general and the computerized screening concept before the introduction of the computerized screening procedure. Interviews were performed with six nursing staff members and a written questionnaire applied to all staff participating in training before the implementation of the concept. Observation was done in order to evaluate how the screening was performed and implemented in order to gain more knowledge about possible obstacles to alcohol screening at an emergency department. The project concept of computerized screening and low staff involvement was found to be a feasible way to overcome organizational barriers such as time limitation but there were still important attitudinal barriers among staff; thus a great disparity in practices between different staff members was observed. The results suggest that it is possible, given the time limitation, to include a computerized screening and intervention in the routines of an emergency department, when the staff regard prevention as part of their responsibilities. The findings provide evidence about the acceptability by nursing staff and feasibility of a computerized screening and personalized print out as feed back to the patients.

Alcohol-Related Disorders↗

PubMed2005

Under what circumstances are nurses willing to engage in brief alcohol interventions? A qualitative study from primary care in Sweden.

To improve alcohol prevention in primary health care, it has been suggested that primary care nurses are an under-utilised resource. The aim of this study was to identify under what circumstances primary care nurses in Sweden are willing to engage in alcohol prevention. All nurses at three primary health care centres in Ostergötland, Sweden were invited to participate in focus group interviews; 26 nurses participated. The nurses considered primary health care to be just one among other sectors within the community with responsibility for alcohol prevention. The role of health care in alcohol prevention was perceived to be important but mainly secondary preventive. The nurses felt justified screening all patients' alcohol habits only when they could refer to an obligation or a time-limited project. Otherwise, they mainly wanted to engage in screening patients with alcohol-related symptoms or diagnoses and other risk groups. Reasons for refraining from alcohol screening and intervention included lack of self-efficacy, time consumption and fear of harming their relationship with the patient. New strategies for alcohol prevention in primary care are discussed.

Alcohol Drinking↗

PubMed2004

Cystatin C uptake in the eye.

BACKGROUND: As a secreted protein, cystatin C is assumed to play its role in the extracellular compartment, where it can inhibit virtually all cysteine proteases of families C1 (cathepsin B, L, S) and C13 (mammalian legumain-related proteases). Since many of its potential target enzymes in the eye reside in intracellular compartments, we sought evidence for a cellular uptake of the inhibitor in ocular tissues. METHODS: Fluorescence-labeled human cystatin C was injected intravitreally into normal rat eyes. Ocular tissues were subsequently examined using ELISA, fluorescence microscopy, and immunohistochemistry. Cystatin C uptake was additionally studied in an in vitro retina model. RESULTS: Cystatin C administered intravitreally in vivo is taken up into cells of the corneal endothelium and epithelium, the epithelial cells lining the ciliary processes, and into cells in the neuroretina (mostly ganglion cells) and the retinal pigment epithelium. The uptake is demonstrable also in vitro and was, in the neuroretina, found to be a high-affinity system, inhibited by cooling the specimens or by adding the microfilament polymerization inhibitor, cytochalasin D, to the medium. CONCLUSIONS: There is an active, temperature-dependent uptake system for cystatin C into several cell types in the cornea, ciliary body, and retina. The cell types that take up cystatin C are generally the same that contain endogenous cystatin C, suggesting that much or all cystatin C seen intracellularly in the normal eye may have been taken up from the surrounding extracellular space. The uptake indicates that the inhibitor may exert biological functions in intracellular compartments. It is also possible that this uptake system may regulate the extracellular levels of cystatin C in the eye.

Animals↗

PubMed2004

Routine screening for risky alcohol consumption at an emergency department using the AUDIT-C questionnaire.

A questionnaire including the three AUDIT-C items was used to screen for alcohol use among trauma patients. The aim was to display, in a pragmatic way, how the AUDIT-C scores can be converted into different levels and kind of risky drinking. Using AUDIT-C scores with a cut-off score of 4 points for women and 5 for men indicated that 28% of the women and 40% of the men were risky drinkers. When calculating weekly alcohol consumption from the answers in AUDIT-C, 3% of the women and 7% of the men were hazardous and/or harmful drinkers. Regarding heavy episodic drinking 7% of the women and 30% of the men was drinking 72g alcohol or more at on at least one occasion a month. These results indicate that the AUDIT-C score as such give little information about the pattern of alcohol consumption and that evaluation of risky drinking must be calculated from the three items in order to differentiate between risky drinking in terms of alcohol consumed per week and heavy episodic drinking.

Adolescent↗

PubMed2004

Apoptotic cell death and microglial cell responses in cultured rat retina.

BACKGROUND: Optic nerve transection results in degeneration of axotomized retinal ganglion cells followed by the activation of resident microglial cells. METHODS: An organotypic culture of neonatal rat retina was used to examine the temporal aspect of retinal ganglion cell death and microglial cell recruitment. Retinas were fixed at various times after explantation and prepared for immunohistochemistry and lectin staining. RESULTS: Terminal deoxytransferase dUTP nick-end labeling (TUNEL) and immunohistochemistry for cleaved caspase-3 demonstrated a massive cascade of cell death in the ganglion cell layer (GCL) within hours after explantation. The rate of cell death in this layer was high and continued over a period of 48 h. In contrast, the rate of cell death was low in the outer nuclear layer (ONL) and apoptotic cells were evident after 6 days in vitro. Increases in the density of microglial cells in the GCL appeared to be recruited by proliferation within hours after explantation. In parallel, resident microglial cells also acquired an activated morphology as revealed by isolectin B(4) staining. Microglial cell activation in the GCL also included an upregulated expression for the lysosomal protein ED-1 and the cysteine protease inhibitor cystatin C. After 1 week of culture, immunolabeling for ED-1 demonstrated the presence of activated microglial cells also in the ONL. CONCLUSION: These data show rapid microglial cell recruitment and activation following the axotomy-induced cell death of differentiated ganglion cells. The processes of microglial cell activation and cell death are slower in the outer retina.

Animals↗

PubMed2004

Transplantation of full-thickness retina in the rhodopsin transgenic pig.

PURPOSE: To establish the morphology of full-thickness neuroretinal grafts transplanted to hosts with degenerative photoreceptor disease. METHODS: Twenty rhodopsin transgenic pigs received a neuroretinal sheet from a neonatal normal pig in one eye. Following vitrectomy and retinotomy with bleb formation, the grafts were positioned inside the bleb between the host neuroretina and retinal pigment epithelium. After a survival time of 4 months, eye specimens were studied by light and electron microscopy as well as with immunohistochemical markers. RESULTS: One eye developed endophthalmitis in the immediate postoperative period and was terminated. Laminated grafts with correct polarity were found in 13 of the remaining 19 eyes. In most cases, these grafts had well-developed organized photoreceptors with outer segments apposed to the host retinal pigment epithelium. The inner layers of the graft contained mostly Müller cells. Both eyes of the hosts had a reduction of photoreceptor cells in most of the retina, while inner layers remained relatively intact. CONCLUSIONS: Full-thickness neuroretinal grafts can be transplanted to a large animal host with photoreceptor degeneration. The transplantation procedure is relatively atraumatic to both graft and host tissue, and the grafts survive well for at least 4 months. The graft and host retina does not seem to form extensive neuronal contacts, and future work must be directed at stimulating such activity without disrupting the retinal neuronal organization.

Animals↗

PubMed2003

Growth of the postnatal rat retina in vitro: quantitative RT-PCR analyses of mRNA expression for photoreceptor proteins.

PURPOSE: To investigate whether previously reported changes in protein expression of middle and long (M/L) and short (S) wavelength cone opsin pigments in cultured retina are correlated with changes in their gene expression. Additionally, to elucidate the importance of a functional retinal pigment epithelium for the development of photoreceptor outer segments. METHODS: Neonatal rat retinas were maintained in culture for 11 days and either fixed in 4% paraformaldehyde for immunohistochemistry or prepared for RNA extraction, reverse transcription polymerase chain reaction (RT-PCR), and quantitative RT-PCR. S-cone and M/L-cone photoreceptors as well as rod photoreceptors were immunohistochemically identified using specific antibodies. Peanut agglutinin (PNA)-lectin histochemistry was used to identify interphotoreceptor matrix associated with cone photoreceptors. Immunolabeling for ED-1 and RPE65 was performed in combination with PNA-lectin staining to examine interactions between photoreceptor cells and the retinal pigment epithelium. Relative estimates of mRNA expression levels for M/L-opsin, S-opsin, recoverin, and rhodopsin in normal and cultured retina were determined by using quantitative RT-PCR. RESULTS: Strong immunolabeling for recoverin and rhodopsin accumulated in outer segments as well as photoreceptor somata in vitro. Cultured and normal retinas showed similar relative expression levels of recoverin and rhodopsin mRNA. In cultured rat retina, the density of S-cones was high and M/L-cones could not be immunohistochemically detected. However, M/L-cone photoreceptor mRNA was detectable, but at a fourfold lower level in cultured than in vivo retinas. The S-cone photoreceptor mRNA level was almost twofold lower than in vivo. Retinal pigment epithelium cells in cultured specimens showed no RPE65 immunolabeling, but expressed immunolabeling for ED-1 indicating phagocytic activity of these cells in vitro. CONCLUSIONS: We assume that the high density of S-cones and virtually no M/L-cones seen in in vitro retinas might represent an immature stage with numerous S-cones and suppressed transdifferentiation into M/L-cone phenotype. A non-functional relationship between photoreceptor cells and a dysfunctional retinal pigment epithelium may have severe consequences for the development of outer segments.

Animals↗

PubMed2003

Differentiation of ganglion cells and amacrine cells in the rat retina: correlation with expression of HuC/D and GAP-43 proteins.

In order to understand the development of retinal cells, we have studied the temporal expression of HuC/D protein in embryonic, postnatal and adult rat retina. During development and in the adult retina, practically all cell somata in the ganglion cell layer and the vast majority of conventional amacrine cells in the inner nuclear layer displayed HuC/D immunoreactivity. Most but not all ganglion cells expressed HuC/D at embryonic day 15, suggesting a delay between final mitosis and the initiation of HuC/D expression. Immunoreactivity for HuC/D was also evident in developing but not mature horizontal cells. Combined immunohistochemical visualization of HuC/D protein and the growth-associated protein (GAP-43) showed a distinct localization of GAP-43 in a specific compartment close to the somato-dendritic region of developing HuC/D-positive cell somata. The localization of GAP-43 immunoreactivity to a specific soma compartment became less evident during maturation. Immunoreactivity for HuC/D and GAP-43 was also discernible in horizontal cells at postnatal day 14. In the adult retina, most GAP-43 immunoreactivity was seen in the inner plexiform layer. Detailed analysis showed that HuC/D and GAP-43 expression is restricted to subsets of retinal neurons during development and in the mature retina. Thus, GAP-43 appears to be correlated with initial steps of differentiation and outgrowth of dendritic processes in HuC/D-positive ganglion and amacrine cells.

Amacrine Cells↗

PubMed2003

Critical levels of atmospheric pollution: criteria and concepts for operational modelling of mercury in forest and lake ecosystems.

Mercury (Hg) is regarded as a major environmental concern in many regions, traditionally because of high concentrations in freshwater fish, and now also because of potential toxic effects on soil microflora. The predominant source of Hg in most watersheds is atmospheric deposition, which has increased 2- to >20-fold over the past centuries. A promising approach for supporting current European efforts to limit transboundary air pollution is the development of emission-exposure-effect relationships, with the aim of determining the critical level of atmospheric pollution (CLAP, cf. critical load) causing harm or concern in sensitive elements of the environment. This requires a quantification of slow ecosystem dynamics from short-term collections of data. Aiming at an operational tool for assessing the past and future metal contamination of terrestrial and aquatic ecosystems, we present a simple and flexible modelling concept, including ways of minimizing requirements for computation and data collection, focusing on the exposure of biota in forest soils and lakes to Hg. Issues related to the complexity of Hg biogeochemistry are addressed by (1) a model design that allows independent validation of each model unit with readily available data, (2) a process- and scale-independent model formulation based on concentration ratios and transfer factors without requiring loads and mass balance, and (3) an equilibration concept that accounts for relevant dynamics in ecosystems without long-term data collection or advanced calculations. Based on data accumulated in Sweden over the past decades, we present a model to determine the CLAP-Hg from standardized values of region- or site-specific synoptic concentrations in four key matrices of boreal watersheds: precipitation (atmospheric source), large lacustrine fish (aquatic receptor and vector), organic soil layers (terrestrial receptor proxy and temporary reservoir), as well as new and old lake sediments (archives of response dynamics). Key dynamics in watersheds are accounted for by quantifying current states of equilibration in both soils and lakes based on comparison of contamination factors in sediment cores. Future steady-state concentrations in soils and fish in single watersheds or entire regions are then determined by corresponding projection of survey data. A regional-scale application to southern Sweden suggests that the response of environmental Hg levels to changes in atmospheric Hg pollution is delayed by centuries and initially not proportional among receptors (atmosphere >> soils not equal sediments>fish; clearwater lakes >> humic lakes). This has implications for the interpretation of common survey data as well as for the implementation of pollution control strategies. Near Hg emission sources, the pollution of organic soils and clearwater lakes deserves attention. Critical receptors, however, even in remote areas, are humic waters, in which biotic Hg levels are naturally high, most likely to increase further, and at high long-term risk of exceeding the current levels of concern: </=0.5 mg (kg fw)(-1) in freshwater fish, and 0.5 mg (kg dw)(-1) in soil organic matter. If environmental Hg concentrations are to be reduced and kept below these critical limits, virtually no man-made atmospheric Hg emissions can be permitted.

Air Pollutants↗

PubMed2003

Rehabilitation problems after acute disseminated encephalomyelitis: four cases.

The aim of this study is to describe rehabilitation problems in patients with acute disseminated encephalomyelitis. The study examines retrospective clinical data. Data are reported from 4 patients, who were consecutively admitted and examined with the Functional Independence Measure and magnetic resonance imaging. It was found that the lesions in the brains affected by acute disseminated encephalomyelitis are widespread, but become smaller with time. Motor symptoms dominate at first, but recovery is quite good. Social and cognitive functions are also affected, however, and require a much longer recovery time. These symptoms are, thus, the dominating problem in the rehabilitation ward. At clinical follow-up after 3 years the cognitive problems still influenced the lives of the patients. It is concluded that social and cognitive problems seem to be common in patients with acute disseminated encephalomyelitis. Recovery in these areas takes a long time and this is the main rehabilitation problem, since it affects the capability of the person to reintegrate into society.

Adult↗

PubMed2003

Identification and brief treatment of alcohol problems with medical patients: an international perspective.

This article summarizes the proceedings of a symposium at the 2002 RSA meeting in San Francisco, California. The chair was Peter Monti and co-chair was Nancy Barnett. The aim of the symposium was to bring together researchers from the United States, Sweden, and Mexico to present current findings on the development and implementation of screening and intervention research in Emergency Departments (ED). Cheryl Cherpitel presented findings on the performance of the Rapid Alcohol Problems Screen (RAPS4), a 4-item instrument used for screening for alcohol dependence and harmful drinking in the ED. Dr. Cherpitel also presented for her collaborator, Guilherme Borges, their research on the performance of a number of screening measures including the RAPS among Mexicans and Mexican-Americans with alcohol-related disorders in the ED. Preben Bendtsen described the implementation of an alcohol screening and intervention procedure delivered by ordinary ED staff in Sweden. Nancy Barnett presented data on characteristics related to readiness to change alcohol use in a sample of young adults who were treated in an ED for injury or intoxication.

Alcoholism↗

PubMedDate not supplied

Early intervention for problem drinkers: readiness to participate among general practitioners and nurses in Swedish primary health care.

An exploration was made of attitudes and practices of general practitioners (GPs) and nurses concerning early identification of, and intervention for, alcohol-related problems. Sixty-five GPs and 141 nurses in 19 primary health centres in a county in southern Sweden answered a 28-item questionnaire before implementation of an intervention programme. The questionnaire covered experiences with patients with alcohol-related health problems, knowledge and perceived capacity concerning early identification and intervention, attitudes towards the role of primary care staff in early identification and intervention and current intervention methods in use at the health centre. Self-reported frequency of asking about alcohol use was higher among GPs than nurses. Both groups reported more frequently asking about alcohol consumption in cases where they believed that the health status was influenced by alcohol. For both professions, knowledge and skills concerning identification were rated as better understood than that concerning intervention methods. Nurses rated their knowledge and skills less confidently than GPs. The overall attitude was fairly positive towards early identification and intervention, but nurses were more worried than GPs that patients would react negatively to questions about alcohol. Attitudes, self-rated capacity, and practice were related. The low level of early identification and intervention in primary care appears to be related more to insufficient practical skills than to attitudes. Nurses appear to be an unexploited resource, in need of training and support. Nurses may need to be convinced that an active role does not interfere with the nurse-patient relationship. Building teams of GPs and nurses in primary care might enhance the dissemination of alcohol prevention into regular practice.

Alcoholism↗