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Biomedical subjects

A Jonsson

Publications and source records attributed to A Jonsson.

At least 19 recordsLinked to original sources
PubMed2005

Evaluation of antidecubitus mattresses.

Pressure sores are a current problem in hospitals and care of the elderly, leading to protracted hospital stays and a high care burden. The trauma for the patients is severe, and the cost of pressure sore prevention and treatment, is considerable. Antidecubitus mattresses are used for prevention and in treatment, but they also contribute to the cost of treating pressure sores. The problem highlighted in the review is that the mattresses' effectiveness in preventing and treating pressure sores has not been sufficiently evaluated. When antidecubitus mattresses are evaluated, it is often only with regard to aspects of the interface pressure and the mattresses' ability to redistribute the pressure. The review points out the important observation that, to be able to evaluate the efficacy of the antidecubitus mattress, the mattress's effect on tissue viability needs to be studied. The parameters that ought to be considered when evaluating a support surface are: interface pressure, pressure and blood flow distribution, temperature and humidity in the skin-support surface interface. The authors propose that the effect on tissue viability of external loading can be assessed by simultaneous measurement of the interface pressure and tissue perfusion.

Beds↗
PubMed2003

Proinsulin C-peptide and its C-terminal pentapeptide: degradation in human serum and Schiff base formation with subsequent CO2 incorporation.

Processing of human proinsulin C-peptide and its C-terminal pentapeptide in blood serum was studied using reverse-phase HPLC and electrospray mass spectrometry. The results reveal degradation of both peptides, with a longer half-life for intact C-peptide than for the C-terminal pentapeptide. Products from C-peptide degradation were not distinguishable from the peptide background, suggesting endopeptidase degradation of C-peptide. In contrast, a set of products from the C-terminal pentapeptide were identifiable and corresponded to successive losses from the N terminus, showing that the pentapeptide is degraded by aminopeptidase in serum. Consistent with this finding, a slower degradation was found for the N-acetyl-protected pentapeptide. Removal of serum proteins by acetone precipitation produced N-terminally carbamate-modified C-peptide via a Schiff base intermediate (a ketimine with acetone), to which CO(2) was added and acetone removed, generating a cyclic side chain via anhydride formation. The modification was not seen with the pyroglutamate form of C-peptide, with the N-terminally acetylated C-peptide, or with a control peptide having N-terminal Phe, but was found with human C-peptide, its N-terminal tetrapeptide, and a rat C-peptide fragment (all with N-terminal Glu). Hence, the modification appears to require N-terminal Glu, but this is not the only prerequisite since the C-terminal pentapeptide and another control peptide (also starting with Glu) were not modified. A peptide aldimine Schiff base leading to CO(2) incorporation was detected with formaldehyde in NaHCO(3). The observation that C-peptide forms Schiff bases with ketones/aldehydes, enhancing covalent attachment of CO(2), may have biological implications.

C-Peptide↗
PubMed2003

Post-traumatic stress among Swedish ambulance personnel.

OBJECTIVE: Emergency workers, including ambulance personnel, must cope with a variety of duty related stressors including traumatic incident exposures. Little is known about the variables that might be associated with post-traumatic stress symptom in high risk occupational groups such as ambulance personnel. This study investigated the prevalence of post-traumatic stress disorder among Swedish ambulance personnel. METHODS: To estimate the prevalence of trauma related disorders, a representative group of 362 ambulance personal from the county of Västra Götaland in Sweden was surveyed through use of a Swedish version of Antonovsky's 13-item short version of Sense of Coherence Scale, to measure reactions to traumatic events two instruments were used, Impact of Event Scale (IES-15) and the Post Traumatic Symptom Scale (PTSS-10). A total of 223 of the ambulance personnel reported that they had had experience of what they described as traumatic situations. RESULTS: Of those who reported a traumatic situation 15.2% scored 31 or more on the IES-15 sub scale. Scores over 31 indicate a stress reaction with certain likelihood of post-traumatic disorder. On the PTSS-10 subscale 12.1% scored 5 or more, which indicates a relative strong reaction. The study indicates that lower sense of coherence predicts post-traumatic stress. Other predictors for the extent of traumatic stress were longer job experience, age, physical and psychological workload. CONCLUSIONS: The high prevalence of post-traumatic stress disorder symptoms in ambulance personnel indicates an inability to cope with stress in daily work. The strong relation between post-traumatic stress and Sense of Coherence Scale may be useful in predicting vulnerability for post-traumatic symptoms among recently employed ambulance service personnel. To prevent or reduce the upcoming of post-traumatic stress disorder symptoms it must be possible to take leave of absence, or for a longer or shorter time be transferred to non-emergency duties. This study presents a better understanding between post-traumatic stress and underlying factors among ambulance personnel.

Adaptation, Psychological↗
PubMed2001

Are certain life histories particularly prone to local extinction?

Using stochastic simulations and elasticity analysis, we show that there are inherent differences in the risk of extinction between life histories with different demographies. Which life history is the most vulnerable depends on which vital rate varies. When juvenile survival varies semelparous organisms with delayed reproduction are the most vulnerable ones, while a varying developmental rate puts a greater threat to semelparous organisms with rapid development. Iteroparous organisms are the most vulnerable ones when adult survival varies. Generally, we do not expect to observe organisms in nature having variation in vital rates that produce a high risk of extinction. Given the results here we therefore predict that iteroparous organisms should show low variation in adult survival. Moreover, we predict that semelparous organisms should show low variation in juvenile survival and low variation in developmental rate. The effect of temporal correlation on extinction risk is most pronounced in organisms with semelparous life histories.

Animals↗
PubMed2001

N-terminal acetylation in a third protein family of vertebrate alcohol dehydrogenase/retinal reductase found through a 'proteomics' approach in enzyme characterization.

A recent finding of a novel class of retinol-active alcohol dehydrogenase (ADH) in frog prompted analysis of this activity in other vertebrate forms. Surprisingly, yet another and still more unrelated ADH was identified in chicken tissues. It was found to be a member of the aldo-keto reductase (AKR) enzyme family, not previously known as an ADH in vertebrates. Its terminal blocking group and the N-terminal segment, not assigned by protein and cDNA structure analysis, were determined by electrospray tandem mass spectrometry after protein isolation by two-dimensional gel electrophoresis. The N terminus is Acetyl-Ala- and the N-terminal segment contains two consecutive Asn residues. The results establish the new ADH enzyme of the AKR family and show the usefulness of combined gel separation and mass spectrometry in enzyme-characterization.

Acetylation↗
PubMed2000

Esomeprazole provides improved acid control vs. omeprazole In patients with symptoms of gastro-oesophageal reflux disease.

BACKGROUND: Esomeprazole (Nexium) is a new proton pump inhibitor for the treatment of acid-related diseases. METHODS: In this double-blind crossover study, 38 patients with gastro-oesophageal reflux disease (GERD) symptoms were randomized to esomeprazole 40 and 20 mg and omeprazole 20 mg once daily for 5 days. On day 5 of each dosing period, 24-h intragastric pH and pharmacokinetic variables were measured. RESULTS: Thirty-six patients aged 29-58 (mean 45) years completed the study. Esomeprazole 40 and 20 mg maintained intragastric pH > 4 for (mean) 16.8 and 12.7 h, respectively, vs. 10.5 h for omeprazole 20 mg (P < 0.001 and P < 0. 01). Twenty-four-hour median intragastric pH was significantly higher with esomeprazole 40 mg (4.9) and 20 mg (4.1) than with omeprazole 20 mg (3.6) (P < 0.001 and P < 0.01). Area under the plasma concentration-time curve (AUC) was 80% higher for esomeprazole 20 mg vs. omeprazole, while that for esomeprazole 40 mg was more than five times higher (each P < 0.0001). Interpatient variability in intragastric pH and AUC was less with esomeprazole than with omeprazole. Esomeprazole was well tolerated and there were no safety concerns. CONCLUSIONS: Esomeprazole provides more effective acid control than omeprazole, with reduced interpatient variability, thereby offering the potential for improved efficacy in acid-related diseases.

Adult↗
PubMed2000

Dose-dependent activation of lymphocytes in endotoxin-induced airway inflammation.

Recruitment of neutrophils to lung tissue and airspaces is a hallmark of inflammatory events following inhalation of endotoxins. We studied the role of different lymphocyte subsets in this inflammation, which is assumed to primarily involve the innate immune system. Inhalation of aerosolized Escherichia coli lipopolysaccharide (LPS) in mice induced a dose-dependent increase in neutrophils in bronchoalveolar lavage fluid, reaching a maximum after 12 h at a low dose and after 24 h at a high dose. Profiles of gene expression in lung tissue indicated an early (2 h) and transient onset of proinflammatory cytokines and chemokines by a low dose of LPS, while a high dose caused more delayed and sustained (6 to 12 h) activation. Gamma interferon, interleukin-2 (IL-2), RANTES, and the alpha chain of the IL-2 receptor were not expressed at a low dose, whereas a high dose of LPS induced a strong expression of these genes, indicating a dose-dependent activation of T cells. A similar pattern was observed for IL-17, supporting a contribution of T cells to the neutrophilic inflammation only at high-dose exposure to LPS. The involvement of lymphocytes in the inflammatory response was further studied using mice with functional deficiencies in defined lymphocyte subsets. Both gammadelta T-cell- and B-cell-deficient mice displayed a response similar to that of the corresponding wild-type strains. Selective depletion of NK cells by in vivo administration of the pk136 antibody did not significantly affect the recruitment of neutrophils into airspaces. Thus, neither NK cells, B cells, nor gammadelta T cells appeared to participate in the host response, suggesting that among the lymphocyte subsets, alphabeta T cells are exclusively involved in endotoxin-induced airway inflammation.

Animals↗
PubMed1997

Electronic nose for microbial quality classification of grains.

The odour of grains is in many countries the primary criterion of fitness for consumption. However, smelling of grain for quality grading should be avoided since inhalation of mould spores or toxins may be hazardous to the health and determinations of the off-odours are subjective. An electronic nose, i.e. a gas sensor array combined with a pattern recognition routine might serve as an alternative. We have used an electronic nose consisting of a sensor array with different types of sensors. The signal pattern from the sensors is collected by a computer and further processed by an artificial neural network (ANN) providing the pattern recognition system. Samples of oats, rye and barley with different odours and wheat with different levels of ergosterol, fungal and bacterial colony forming units (cfu) were heated in a chamber and the gas in the chamber was led over the sensory array. The ANN could predict the odour classes of good, mouldy, weakly and strongly musty oats with a high degree of accuracy. The ANN also indicated the percentage of mouldy barley or rye grains in mixtures with fresh grains. In wheat a high degree of correlation between ANN predictions and measured ergosterol as well as with fungal and bacterial cfu was observed. The electronic nose can be developed to provide a simple and fast method for quality classification of grain and is likely to find applications also in other areas of food mycology.

Avena↗
PubMed1996

Geriatric work-up in the Nordic countries. The Nordic approach to comprehensive geriatric assessment.

A group established by the Nordic professors of geriatrics has developed a position document presenting a shared and updated review of geriatric work-up as a way of comprehensive geriatric assessment in the Nordic countries. The main intention is that the document will serve as support and help for the clinician concerned with hospital based geriatric medicine. It may also be useful for quality control and teaching. Not least, it may be useful for health professionals other than geriatricians. To some extent, the position of geriatric medicine in the Nordic countries varies between the countries. However, the background for developing a Nordic version of geriatric work-up is shared attitudes and principally the same organization of the health care system, and collaboration within geriatrics for many years. Several trials on comprehensive geriatric assessment and management performed in different settings have shown favourable outcomes. Results from controlled Nordic trials are compiled and summaries of meta-analyses are presented. The concept of Nordic geriatric work-up is based on a model defining health and disease in old age as dimensions of pathology, impairments, functional limitations, and disability, all being modified by extra- and intraindividual factors. Handicap is defined as the disability gap. Different health professionals have varying responsibilities in the geriatric team-work, but all should be dedicated to establish common goals. The geriatric work-up is presented with success factors and barriers, stating important differences between multidisciplinary and interdisciplinary processes. Checklists and assessment scales may be very useful when performing a geriatric work-up, but they should be used with caution. Specific scales covering different functional areas of the geriatric patient are recommended for clinical practice. Such scales must be valid, reliable, acceptable to the patient, responsive to change, and should be in an appropriate format, as well as easy to administer. Prior to the use among geriatric teams in the Nordic countries the scales should be translated into all the Nordic languages, and the translated versions should ideally have been subjected to validity and reliability testing. However, so far no scale meets these demands regarding all the five Nordic languages.

Aged↗
PubMed1994

Effect of lignocaine on eicosanoid synthesis by pieces of human gastric mucosa.

Lignocaine can affect prostaglandin synthesis in various tissues, and it has anti-inflammatory activity. No studies have been made previously on human isolated gut tissues. When concentrations of 5, 50 and 250 micrograms mL-1 lignocaine were incubated with human gastric mucosa/submucosa at 37 degrees C for 30 min, only the highest concentration reduced the levels of prostaglandin E, thromboxane B2 and 6-keto-PGF1 alpha in the incubates, and leukotriene C4/D4 was unaffected. Therapeutically relevant amounts of lignocaine given parenterally would therefore seem unlikely to alter gastric mucosal prostanoids, but high doses can be given orally because of extensive first-pass metabolism in the liver.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Effect of femoral condyle configuration on disability after an anterior cruciate ligament rupture. 100 patients followed for 5 years.

We measured the configuration of the femoral condyles on lateral radiographs in 100 consecutive, prospectively-studied patients with a complete rupture of the anterior cruciate ligament, with or without associated lesions of the menisci and collateral ligaments. The patients had mainly low-to-moderate activity demands, and in all the patients the cruciate tear was primarily treated non-operatively. A quotient was calculated from the measurements of sagittal depth and axial height in order to describe the geometry of the femoral condyles. Measurements were reproducible with an intra- and interobserver coefficient of correlation of 0.89-0.98. At follow-up, after 5 (3-6) years, 16 patients had developed disability leading to reconstructive surgery. The remaining 84 patients did not have any major functional limitations, but some had reduced their activity level. Individual variations in the articular geometry were found with a more spherical shape of the femoral condyles in the patients where non-operative treatment had failed. Our findings indicate that articular geometry is of importance for function after an anterior ligament lesion.

Anterior Cruciate Ligament↗