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Biomedical subjects

B Hansson

Publications and source records attributed to B Hansson.

At least 37 records · Page 2Linked to original sources
PubMed1997

Lung volume reduction surgery as an emergency and life-saving procedure.

Lung volume reduction surgery (LVRS) is emerging as a promising and unique therapeutic option for rigorously selected patients with severe debilitating emphysema. A 51 yr old man with generalized emphysema developed bilateral pneumothoraces during his first holiday abroad. Due to respiratory insufficiency, intubation and mechanical ventilation were necessary. In total, six chest tubes were inserted but massive air leak persisted and his respiratory condition deteriorated due to bronchopneumonia and sepsis. The patient was transferred to Belgium. As a last resort, bilateral LVRS was performed through a median sternotomy. The most diseased areas of the upper lobes containing the air leak were resected bilaterally and a pleurectomy was associated. Three months after operation, there was a remarkable improvement in spirometric values with an increase in forced expiratory volume in one second of almost 100%. The results were sustained after a follow-up of 18 months. In this dramatic case, lung volume reduction surgery proved to be effective, and was even a life saving procedure.

Chest Tubes↗
PubMed1997

Behavioural analysis of olfactory conditioning in the moth spodoptera littoralis (Boisd.) (Lepidoptera: noctuidae)

We studied the associative learning capabilities for behaviourally relevant cues in the moth Spodoptera littoralis. The moths were trained to associate a conditioned stimulus (CS), geraniol odour, with an unconditioned stimulus (US), a sucrose solution. The occurrence of a proboscis extension reflex (PER) was tested. The PER performance during acquisition increased steadily with the number of training trials. Non-associative control procedures did not result in learning. PER conditioning was achieved when the CS was presented 1-3 s before the US. A wide range of inter-trial intervals was able to support conditioning. Males and females learned equally well. Moths could to some degree learn the CS-US association after a single trial. These results demonstrate that S. littoralis females and males have a good capability to associate an odour with a reward. The neural basis of olfactory coding in moths has been well studied; thus, the moth provides a powerful system in which to examine the neurobiology of olfactory learning.

Journal Article↗
PubMed1997

Central nervous processing of sex pheromones in two strains of the European corn borer Ostrinia nubilalis (Lepidoptera: Pyralidae)

Antennal lobe neurones were investigated in the pyralid moth Ostrinia nubilalis using intracellular recording and staining techniques. Response characteristics of antennal lobe neurones from males in the so-called E and Z strains, in F1 hybrids and in parental backcrosses were studied. The antennal lobe of a male O. nubilalis comprises approximately 30 ordinary glomeruli and three enlarged glomeruli making up the macroglomerular complex (MGC). Receptor neurones enter the antennal lobe via the antennal nerve and arborize in single glomeruli. Intracellularly stained, pheromone-responding projection neurones in both parental strains arborized in different glomeruli within the MGC, irrespective of their response characteristics. Neurones were grouped according to their specificity to single pheromone components and to pheromone blends. Component-specific, blend-specific and generalist neurones were found. Specificity only occurred at low stimulus concentrations and disappeared as concentrations increased. Although all neuronal types were present in both pheromone strains and crossings, differences in abundance and sensitivity were found. In the parental strains, neurones responding to the major pheromone component and to the respective strain-specific blend were more abundant than neurones responding to the minor component and the blend produced by the other strain. Neurones investigated in ZxE hybrids responded similarly to those of E-strain males, whereas neurones in EZxZ paternal backcrosses responded similarly to those of Z males. In the hybrids and paternal backcrosses, hybrid-blend-specific neurones were present that were not found in parental-strain males.

Journal Article↗
PubMed1996

On the possible origin of giant or slow-rising miniature end-plate potentials at the neuromuscular junction.

Giant or slow-rising miniature end-plate potentials (GMEPPs) caused by vesicular release of acetylcholine (ACh) occur at any time in about 50% of mouse diaphragm neuro muscular junctions, but generally at frequencies less than 0.03 s-1. Their frequency is, unlike that of miniature end-plate potentials (MEPPs), not affected by nerve terminal depolarization. Unlike MEPPs and stimulus-evoked end-plate potentials, GMEPPs have a prolonged time-to-peak and show an increase in time-to-peak with amplitude. By using these differences in amplitude and time course, GMEPPs can be separated from MEPPs. In contrast to MEPPs, GMEPPs are not blocked by botulinum neurotoxin type A. GMEPPs have a greater temperature sensitivity than MEPPs, disappearing at temperatures below 15 degrees C. Long-term paralysis by botulinum toxin and certain drugs which inhibit protein kinase C or affect actin filament polymerization (cytochalasins) enhance the frequency of GMEPPs. End-plate current recordings show that similar postsynaptic ACh receptors are activated by MEPPs and GMEPPs. It is suggested that GMEPPs are not caused by mechanisms involved in regulated neurotransmitter release but are generated by constitutive secretion.

Acridine Orange↗
PubMed1994

Inter-institutional reproducibility of flow cytometric DNA-analysis in breast carcinomas.

In order to study interinstitutional reproducibility of flow cytometric DNA-analysis (DNA-FCM), frozen pieces from 30 consecutive breast carcinomas were analysed by 5 laboratories. Different instruments, preparation and DNA staining methods were used. A concordance in DNA-ploidy status was obtained in 26 of the 30 tumours. The discrepancy can mainly be explained by intratumoural DNA-heterogeneity since a complete agreement in ploidy status was obtained when four of the laboratories analysed the same cell suspension, where solid bits showed differing results. The sampling method seems therefore to be a crucial step for the results and needs further studies. As far as the estimation of S-phase fraction was concerned, one laboratory obtained significantly higher values compared to the other four. The correlation between the other four laboratories varied between r = 0.66-0.92.

Academies and Institutes↗
PubMed1993

Quality of life: status and change (QLsc) reliability, validity and sensitivity of a generic assessment approach tailored for diabetes.

The aim was to review the psychometric properties of a generic strategy for assessing status and change in quality of life (QLsc) partly tailored for patients with insulin-dependent diabetes mellitus. Quality of life was defined as perceived well-being and life satisfaction, globally as well as within key domains and functions. The strategy has been developed iteratively and, thereby, proven psychometrically satisfactory across groups and settings. Seventy-three consecutive outpatients were examined in 1988, after a period on multiple injection treatment by insulin pen; 66 were re-examined in 1990. In 1988 and 1990, perceived well-being and life domain status were self-rated. Life domain changes attributed to pen treatment were rated retrospectively in 1988 and subsequent general changes over 2 years rated similarly in 1990. Shortened parallel ratings were performed by significant others. Series of cross-sectional and longitudinal analyses yielded convincing reliability, validity and sensitivity evidence of various kinds for all ratings, irrespective of rater-self or significant other. As expected, a consistent correlational pattern emerged between status self-ratings, suggesting 'the better/worse off' in one sense, the 'better/worse off' in other senses assessed. Moreover, congruent change linkages, suggesting 'the greater change for the better/worse' according to the one type, the 'greater change for the better/worse' according to the other one, were also salient. Fourteen persons with less congruence in the disparate, but parallel change rating parameters appeared to be in a critical disease phase, applying reaction formation or denial like defence mechanisms. In conclusion, the entire cohesive strategy also functioned well in the current setting. It may probably be applied in search for other vulnerable sub-groups and in analyses of coping strategies. It offers rich analytic options especially in evaluational contexts. The study outcome may stimulate development of methodology within this field.

Adult↗
PubMed1993

Effects of stonefish (Synanceia trachynis) venom on murine and frog neuromuscular junctions.

The neuromuscular toxicity of stonefish (Synanceia trachynis) venom was characterized by electrophysiological and electron microscopic examination of isolated murine and frog nerve-skeletal muscle preparations exposed to various concentrations of venom. Low concentrations of venom (2.5-10 micrograms/ml) acted presynaptically by causing release and depletion of neurotransmitter from the nerve terminal. The response was Na+ channel-independent (resistant to tetrodotoxin), required the presence of either Ca2+ or Mg2+, and was observed with botulinum neurotoxin-paralyzed nerve-muscle preparations. Higher concentrations of venom (100-300 micrograms/ml) acted postsynaptically and presynaptically. They caused irreversible depolarization of muscle cells and microscopically observable muscle and nerve damage. We conclude that the previously observed neuromuscular toxicity of stonefish venom is a consequence of the venom's dose-dependent, presynaptic and postsynaptic actions at the myoneural junction.

Acetylcholine↗
PubMed1993

Improved removal of anti-A and anti-B antibodies from plasma using blood-group-active haptens.

Highly efficient anti-blood group A and B immunoadsorbents for extracorporeal treatment were developed by immobilizing A and B trisaccharide and A tetrasaccharide haptens on Sepharose 4FF and Fractogel TSK using three different methods. The adsorption of the IgG and IgM anti-A antibodies was essentially the same regardless of the A hapten used or the method of oligosaccharide coupling. The adsorption of IgM anti-A was found to be more sensitive than IgG anti-A to changes in column flow rate. The binding of both the IgM and IgG antibodies was slightly lower at 37 degrees C than at 22 degrees C. An anti-A/anti-B adsorbent column potentially suitable for treatment of patients was prepared. A column switching system resulted in a more efficient adsorption of antibodies. Hapten leakage from the column was very low. No nonspecific adsorption of plasma proteins to the column (other than traces of albumin) could be detected.

ABO Blood-Group System↗
PubMed1993

Precursors of repeated short-term sick-leave: an empirical review of some background, job and well-being characteristics.

The aim of the study was to search for bivariate associations between on the one hand samples of background, job-related and well-being characteristics, and on the other hand longitudinally recorded sick-leave in individuals with repeated short-term sick-leave. Out of altogether 123 subjects included, 113 self-rated their well-being at the onset of, and 88 also after, a supportive programme. The well-being rating covered experience of treatment by other people, reservation, loneliness, inferiority, tension, vulnerability, guilt, security and indolence. Socio-demographic and job-related characteristics and attitudes were registered and declared at the initial contact. Correlations between these separate sets of independent variables, and sick-leave occasions and days in each of the two years following the contact were computed. There was an almost complete lack of covariation between background variables and sick-leave. Neither did job-related characteristics correlate. Only an expressed wish for a job change was vaguely associated with more absence days, but not with more spells. In striking contrast, a convincing consistent longitudinal pattern between self-rated well-being and sick-leave behaviour emerged. The poorer the well-being, the greater the subsequent sick-leave. Yet, a major part of the sick-leave variance remained unexplained. Accordingly, other etiological factors may still interact with well-being in the comprehensive setting behind the sick-leave behaviour.(ABSTRACT TRUNCATED AT 250 WORDS)

Absenteeism↗
PubMed1993

In vitro toxicity of biomaterials determined with cell density, total protein, cell cycle distribution and adenine nucleotides.

Inhibition of cell growth is the most commonly used endpoint for in vitro toxicity of biomaterials. The use of several different endpoints might however generate more information concerning the nature of the toxicity. Thus, we examined the toxicity of two biomaterials, Polyvinylchloride (PVC) and Polyoximethene (POM), with different selected endpoints. The influence of cell growth on these endpoints was also investigated. Water extracts from the polymeric materials were tested on the continuous cell line L-929. Cell density, total protein, total protein per cell, fraction of cells in G0/G1- or S-phase, the concentration of ATP, ADP and AMP were used as endpoints. The PVC material did not significantly influence any of these endpoints until after 72 hours of exposure and the main part of the toxicity at 72 hours was related to higher proliferation rate in control cultures. After the cells had been incubated for 8 hour with POM the main toxic effect was on the energy parameters. In conclusion the PVC material was less toxic than the POM material. Our results also implies that the choice of endpoint will influence the evaluation of cytotoxicity.

Adenine Nucleotides↗
PubMed1992

Severity of disease and quality of life: a comparison in patients with cancer and benign disease.

The aim of our study was to compare the quality of life in patients with malignant and benign diseases. Eighty-nine females and 110 males (mean age 59 years) from the surgical unit at the University Hospital of Linköping were examined. Ninety-five subjects suffering from a gastrointestinal malignancy were compared with 104 non-malignant patients, of which 57 had benign gastrointestinal disorders, 24 endocrine and 23 vascular diseases. Quality of life was defined as perceived well-being and life satisfaction, globally as well as within key domains. Two separate types of self-ratings, a life domain (20 items) and a well-being rating (eleven subscales, each scale with ten items), were performed in the medical ward. The life domain rating covered the subject's own appraisal of his health and psychological circumstances; social network; activities and habits; of a structural domain ('ability to lead a meaningful life') and of his global life satisfaction. The well-being rating focused on emotional experiences (basic mood, security, indolence, loneliness, inferiority, and guilt together with future-orientation) and perceived behaviour (endurance, tension, sociability and attitudes of the environment). The patients who had a gastrointestinal malignancy scored consistently 'lower' than patients with benign diseases. After adjusting for age concerns, most of the significant inter-group differences remained. After adjusting for nutritional state influences (e.g., recent weight loss), differences in global life satisfaction, future-orientation and perceived attitude from the environment were still apparent. This study is contrary to several other studies undertaken in search of expected group differences but none were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1991

Long-term sick-listing, medical rehabilitation and life quality change: a patient evaluation.

This evaluation of the health service at one of the hospitals of the National Insurance Board in Sweden is primarily based on the perspective of the patient. One interview group of 32 patients (I-group) made life quality ratings before-after their hospital stay. In responding to a postal questionnaire one year after discharge from hospital, another group of 93 former patients (Q-group) made parallel self-ratings. Due to prolonged sick-listing, the patients had been admitted to the hospital for rehabilitation/examination according to paragraph 2:11 in the general insurance law. The basis for their sick-listing was hereby critically reviewed. Within the framework of additional examinations (interview and structured general questions), more than 40% of the respondents stated that the hospital stay was mainly satisfying and a great majority appreciated the nursing care. However, the self-ratings showed that the patients did not ascribe any particularly great significance to the hospital stay. In the short term, it even seemed to have a certain negative impact on the life quality of the patients. No obvious positive bias seems to be built into the ratings. Thus, the assessment package applied may also work well in similar evaluative settings.

Adult↗
PubMed1991

Multiple-beam equalization radiography in chest radiology. Image quality and radiation dose considerations.

The large difference in transmission between the mediastinum and the part of the chest mainly containing lungs causes major problems in chest radiography. A system for advanced multiple beam equalization radiography has been evaluated. Evaluation of image quality has been performed both using standard phantoms and from clinical radiographs. Measurements of radiation dose burden to the patient have been made both in clinical examinations and using an anthropomorphic phantom. The image quality, in areas with low transmission, is substantially increased using the equalization system. In parts of the chest mainly containing lung tissue, conventional systems show an equal or slightly better image quality. The radiation dose burden to the patient is increased by 25 percent using the equalization system, as compared to a low-dose air-gap system. In our opinion, the slight increase in radiation dose burden is well motivated by the high overall quality of the radiographs produced.

Humans↗
PubMed1990

Repeated short-term sick-leave and quality of life. An evaluation of a clinical socio-medical intervention.

The primary aim of this study was to evaluate a clinical socio-medical supportive program for repeated short-term sickleavers who exhibited no evident reason for their prolonged absence. Attention was drawn to changes in the quality of life of the participants. Ninety-nine persons took part in the full program. The sex distribution was even and the mean age was 32 years. The average number of days of sick-leave during the year preceding the entrance into the program was 28. The most common self-stated diagnosis was upper respiratory infection or gastro-intestinal problems. The evaluation showed a significant change for the better in the quality of life and well-being of the patients, although more than every other patient did not explicitly attribute any personal benefit to the intervention itself. The results coincide irrespective of measuring method and, are by and large, consistent over most areas of life and components of well-being assessed. Thus the design and the results of the evaluation look very promising concerning reliability, validity and especially sensitivity. A corresponding model may be applicable more generally when evaluating health- and medical care.

Absenteeism↗
PubMed1988

The working capacity of the alcohol abuser. Prognostic multiple regression analyses.

Thirty-four alcohol abusers treated at various rehabilitational locations in Sweden were the subjects of an extensive and interdisciplinary study. Thereafter, the working capacity of each subject was followed over a two-year period. Twelve individuals regained capacity for work, either partially or completely. Thirteen subjects were sick-listed or remained unemployed. The remaining 9 abusers were quickly and unexpectedly pensioned. In order to predict the rehabilitational outcome from the interdisciplinary findings at the onset of the time period, stepwise multiple regression analyses were performed. Those who felt less lonely and had no drinking buddies appeared most likely to be rehabilitated vocationally. This core combination of characteristics accounted for about one third of the variability in the outcome criterion, either trichotomized or dichotomized. Rehabilitational success could be even more strongly predicted by the appearance of such features as less prolonged abuse, social introversion (not cohabiting, reserved attitudes and having only a few friends), orientation to the future and a history of psychiatric care. An elevated level of plasma albumin and a decreased plasma-IgA value raised additionally the multiple correlation coefficient.

Adult↗
PubMed1987

Prevention of intraoperative hypothermia during abdominal surgery.

Heat balance and core and skin temperatures were studied in 111 patients during abdominal surgery. In minor surgical procedures the effects of heating of inspired humidified gases (n = 23) and of a heating mattress (n = 21) were compared with the conditions in an unwarmed control group (n = 24). These two methods were about equally effective in preserving total body heat, although the major effect of the heating mattress was to conserve heat which had been redistributed to the surface, and such heat could subsequently be lost to the environment. During major abdominal surgery 18 unwarmed control patients were compared with patients (n = 25) provided with a heat supply. The combined measures of heated humidified inspired gases, a heating mattress, insulation by a heat-reflecting blanket, warming of all infusions and transfusions and a warm operating room were all needed to balance the great heat losses during the major surgical procedures. With such massive heat supply it was possible to prevent heat loss and a fall in core temperature.

Abdomen↗