Search PubMed⌕ Search

Biomedical subjects

L Svensson

Publications and source records attributed to L Svensson.

At least 37 records · Page 2Linked to original sources
PubMed2004

Can we define patients with no chance of survival after out-of-hospital cardiac arrest?

OBJECTIVE: To evaluate whether subgroups of patients with no chance of survival can be defined among patients with out-of-hospital cardiac arrest. PATIENTS: Patients in the Swedish cardiac arrest registry who fulfilled the following criteria were surveyed: cardiopulmonary resuscitation (CPR) was attempted; the arrest was not crew witnessed; and patients were found in a non-shockable rhythm. SETTING: Various ambulance organisations in Sweden. DESIGN: Prospective observational study. RESULTS: Among the 16,712 patients who fulfilled the inclusion criteria, the following factors were independently associated with a lower chance of survival one month after cardiac arrest: no bystander CPR; non-witnessed cardiac arrest; cardiac arrest occurring at home; increasing interval between call for and arrival of the ambulance; and increasing age. When these factors were considered simultaneously two groups with no survivors were defined. In both groups patients were found in a non-shockable rhythm, no bystander CPR was attempted, the arrest was non-witnessed, the arrest took place at home. In one group the interval between call for and arrival of ambulance exceeded 12 minutes. In the other group patients were older than 80 years and the interval between call for and arrival of the ambulance exceeded eight minutes. CONCLUSION: Among patients who had an out-of-hospital cardiac arrest and were found in a non-shockable rhythm the following factors were associated with a low chance of survival: no bystander CPR, non-witnessed cardiac arrest, the arrest took place at home, increasing interval between call for and arrival of ambulance, and increasing age. When these factors were considered simultaneously, groups with no survivors could be defined. In such groups the ambulance crew may refrain from starting CPR.

Advanced Cardiac Life Support↗
PubMed2003

Fatty acids modulate the effect of darglitazone on macrophage CD36 expression.

BACKGROUND: Scavenger receptor-mediated uptake of cholesterol by macrophages in the arterial wall is believed to be proatherogenic. Thiazolidinediones are peroxisome proliferator-activated receptor gamma (PPARgamma)-agonists, which are used in the treatment of type II diabetes. They reduce atherogenesis in LDL receptor deficient and ApoE knockout mice, but up-regulate CD36, which may contribute to foam cell formation. The dyslipidaemia in type II diabetes is characterized by high levels of nonesterified fatty acids. Therefore we tested the effect of fatty acids and how fatty acids and the thiazolidinedione darglitazone interact in their effect on CD36 expression in human monocytes and macrophages. MATERIALS AND METHODS: Flow cytometry and reverse transcription-polymerase chain reaction were used to study CD36 expression. Cellular lipids were analyzed with high performance liquid chromatography. RESULTS: Darglitazone increased CD36 mRNA and protein expression in human macrophage cells. In the presence of 5% human serum, darglitazone increased the accumulation of triglycerides, but did not affect cholesterol ester levels. In the presence of albumin-bound oleic or linoleic acid, darglitazone did not increase CD36 mRNA, cell-surface CD36 protein or triglyceride content. Fatty acids per se increased CD36 mRNA and protein. DISCUSSION: The increase in CD36 in macrophages suggests a role for fatty acids in the regulation of foam cell formation. The results also suggest that the potentially proatherogenic CD36 up-regulating effect of thiazolidinediones in macrophages might not be present when the cells have access to physiological levels of albumin-bound fatty acids.

Arteriosclerosis↗
PubMed2003

Elevation of biochemical markers for myocardial damage prior to hospital admission in patients with acute chest pain or other symptoms raising suspicion of acute coronary syndrome.

OBJECTIVES: To evaluate the occurrence of elevation of serum biochemical markers for myocardial damage in the prehospital setting amongst patients who called for an ambulance due to a suspected acute coronary syndrome (ACS). DESIGN: Prospective observational study. SUBJECTS: All the patients who called for an ambulance due to suspected ACS. SETTING: South Hospital's catchment area in Stockholm and in the Municipality of Göteborg, Sweden between January and November in the year 2000, were included. INTERVENTIONS: On arrival of the ambulance crew, a blood sample was drawn for bedside analysis of serum myoglobin, creatine kinase MB and troponin I. A 12-lead electrocardiogram (ECG) was simultaneously recorded. MAIN OUTCOME MEASURES: Elevation of biochemical markers prior to hospital admission. RESULTS: In all, 511 patients participated on 538 occasions. Elevation of any biochemical marker was observed in 11% of all patients. The corresponding figure for patients developing myocardial infarction was 21%; for patients with myocardial ischaemia 8%; for patients with a possible myocardial ischaemia 4% and for patients with other diagnoses 5%. Amongst those who had a final diagnosis of acute myocardial infarction (AMI), 47% had ST-elevation on initial ECG and 57% had either ST-elevation or elevation of any biochemical marker. CONCLUSION: Bedside analysis of biochemical markers in serum is already feasible prior to hospital admission amongst patients with a suspected ACS. About 20% of patients with AMI have elevated biochemical markers at that stage. When found this data might increase the possibility of diagnosing an AMI very early in the course. However, false positives were found and whether this strategy will improve the triage of these patients in the prehospital setting remains to be proven.

Aged↗
PubMed2003

Stability of acetabular axis after total hip arthroplasty, repeatability using CT and a semiautomated program for volume fusion.

PURPOSE: To validate a CT method for detecting changes in acetabular cup orientation after THA. MATERIAL AND METHODS: 26 CT examinations were obtained from a pelvic model with an uncemented acetabular cup. The model position was altered between acquisitions, but the cup axis angle vis-à-vis the pelvis was maintained. Data sets were combined into 37 pairs, each containing a unique positioning error. The pelvi in different examinations were fused, creating transformed volumes. Landmarks corresponding to the cup before and after fusion were placed interactively by two independent examiners. The orientation of the acetabular axis was calculated for each volume and compared across volumes. RESULTS: Before fusion the mean angle error between the acetabular axes was 4.17 degrees (SD +/- 1.95 degrees ). After fusion the mean angle error was 0.36 degrees (SD +/- 0.17). The 95% repeatability limits were below 0.7 degrees. There was no significant interobserver difference. Analysis of the cup landmarking pattern by condition numbers and individual landmark errors showed stability. CONCLUSION: Non-invasive fusion of CT volumes and a stable landmarking pattern for the acetabular cup outperforms routine plain radiography in detecting changes in the orientation of the acetabular axis over time. The method delivers both visual and numerical output and could be used in clinical practice.

Acetabulum↗
PubMed2003

Quality assurance with regard to outcome and use of medical resources for patients hospitalized with acute chest pain: a comparison between a city university hospital and a county hospital.

This study aimed to test the hypothesis that there is a difference in mortality between patients hospitalized with acute chest pain in a university hospital and those hospitalized in a county hospital, and to describe differences in characteristics and use of medical resources in these two settings. All patients hospitalized at Sahlgrenska University Hospital in Göteborg (with a catchment population of 706 inhabitants/km(2)) and Uddevalla County Hospital (with a catchment population of 34 inhabitants/km(2)) with symptoms of acute chest pain during a registration period of 6 months were included in the study. A total of 1592 patients in the city hospital and 822 in the county hospital fulfilled the given criteria for inclusion. Patients in the urban area differed from those in the rural area in that they had a lower prevalence of previous angina pectoris and hypertension and a higher prevalence of previous cancer, previous percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) and current smoking. On admission to hospital, patients in the urban area less frequently showed clinical signs of congestive heart failure and acute ischaemia on the electrocardiogram (ECG) but more frequently had a pathological ECG without signs of ischaemia and more frequently had a heart rate >100 beats/min. The use of medical resources differed between the two hospitals. Revascularization was more frequent in the city hospital and the use of -blockers in the county hospital. The overall 30 day mortality was 4.7% in the urban area and 4.3% in the rural area (P=0.74). When correcting for differences at baseline, the risk ratio for death in the county hospital versus the city hospital was 0.84 (95% confidence interval 0.51-1.40, P=0.53). In conclusion, among patients hospitalized with acute chest pain in a city university and a county hospital the mortality during the subsequent 30 days did not differ. However, there were differences in terms of the use of medical resources and in previous history, chronic medication prior to hospital admission and status on admission between the two cohorts.

Acute Disease↗
PubMed2003

Spatial component position in total hip arthroplasty. Accuracy and repeatability with a new CT method.

PURPOSE: 3D detection of centerpoints of prosthetic cup and head after total hip arthroplasty (THA) using CT. MATERIAL AND METHODS: Two CT examinations, 10 min apart, were obtained from each of 10 patients after THA. Two independent examiners placed landmarks in images of the prosthetic cup and head. All landmarking was repeated after 1 week. Centerpoints were calculated and compared. RESULTS: Within volumes, all measurements of centerpoints of cup and head fell, with a 95% confidence, within one CT-voxel of any other measurement of the same object. Across two volumes, the mean error of distance between center of cup and prosthetic head was 1.4 mm (SD 0.73). Intra- and interobserver 95% accuracy limit was below 2 mm within and below 3 mm across volumes. No difference between intra- and interobserver measurements occurred. A formula for converting finite sets of point landmarks in the radiolucent tread of the cup to a centerpoint was stable. The percent difference of the landmark distances from a calculated spherical surface was within one CT-voxel. This data was normally distributed and not dependent on observer or trial. CONCLUSION: The true 3D position of the centers of cup and prosthetic head can be detected using CT. Spatial relationship between the components can be analyzed visually and numerically.

Arthroplasty, Replacement, Hip↗
PubMed2002

Inhibitory effects of N-acetylcysteine on scavenger receptor class A expression in human macrophages.

OBJECTIVE: The formation of foam cells from monocyte-derived macrophages involves the uptake of modified lipoproteins by scavenger receptors. Antioxidants inhibit lipoprotein oxidation and may also modulate gene expression. We investigated the effect of the antioxidant N-acetylcysteine on the expression of the class A scavenger receptor (SR-A) types I and II in human macrophages. DESIGN: Monocytes and macrophages from healthy blood donors and plaque-derived macrophages from patients undergoing carotid endarterectomy were used for experiments. SR-A mRNA was analysed with quantitative and semiquantitative reverse transcription-polymerase chain reaction, and ligand binding and uptake were assessed with 125I-labelled acetylated low-density lipoprotein (LDL). RESULTS: Incubation of monocytes and monocyte-derived macrophages with N-acetylcysteine decreased both SR-A I and II mRNA expression. N-Acetylcysteine also reduced SR-A mRNA in lesion-derived cells. Binding and uptake of 125I-acetylated LDL was decreased after brief incubation with N-acetylcysteine. After longer periods of incubation with N-acetylcysteine we observed an increased degradation of lipoproteins. CONCLUSIONS: Our results imply that N-acetylcysteine leads to a decrease in SR-A mRNA and initially also to an attenuated uptake of modified lipoproteins. This adds more to the knowledge about the cellular actions of this drug.

Acetylcysteine↗
PubMed2002

Acetabular component migration in total hip arthroplasty using CT and a semiautomated program for volume merging.

PURPOSE: To develop a non-invasive method for detection of acetabular cup migration after total hip arthroplasty (THA) with a higher degree of accuracy than routine plain radiography. MATERIAL AND METHODS: Two CT examinations, 10 min apart, were obtained from each of 10 patients that had undergone THA. Using an in-house developed semiautomated program for volume merging, the pelves in the two examinations were fused and the acetabular cup was visually and numerically evaluated to test the method's accuracy in detecting migration. RESULTS: In the visual evaluation of the best match a 1-mm translation of the cup was detectable. The numerical evaluation, comparing landmarks placed in the images of the acetabular cup and the head of the femur component in the two examinations, showed the mean difference in orientation of acetabular axes to be 2.5 degrees, the mean distance between centre of cup face to be 2.5 mm and the mean distance between centre of the head of the prosthetic femoral component to be 1 mm. CONCLUSION: This method has a significantly higher accuracy than routine plain radiography in detecting acetabular cup migration and could be used in clinical practice. It gives both a visual and a numerical correlate to migration.

Algorithms↗
PubMed2001

[Prehospital care soon to be routine in suspected acute coronary syndrome].

Among patients with a suspected acute coronary syndrome the early phase is particularly critical. At that stage, pain is most intense and the risk of life-threatening arrhythmia is greatest. Also at that stage, the prospect of limiting infarct size and maybe even protecting patients from developing myocardial damage is at its best. Thrombolytic treatment initiated prior to hospital admission has been shown to more effectively reduce mortality in acute myocardial infarction than thrombolytic therapy initiated after admission. Swedish pre-hospital care appears to have adapted relatively well in this aspect of clinical care.

Acute Disease↗
PubMed2001

[Primary PTCA or thrombolysis in acute myocardial infarction?].

In acute ST-elevation infarction two different reperfusion strategies--thrombolytic medication and acute coronary angiography--have proved to improve the prognosis. The clinical course for patients with ST-elevation infarction is described in relation to whether they received thrombolytic medication or underwent acute coronary angiography with the aim of mechanical revascularization. The one-year mortality was high (20 percent) regardless of treatment strategy. In terms of morbidity there were no clear differences between the two treatment groups.

Aged↗
PubMed2001

Determination of Lewis FUT3 gene mutations by PCR using sequence-specific primers enables efficient genotyping of clinical samples.

We have developed a polymerase chain reaction method using sequence-specific primers (PCR-SSP) for rapid and correct genotyping of the common Lewis (FUT3) gene mutations 59T>G, 202T>C, 314C>T, 508G>A, and 1067T>A. The PCR-SSP method was validated on 20 healthy blood donors and 16 non-insulin-dependent diabetic patients. All individuals were in parallel genotyped by our established polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The FUT3 genotypes, determined with the PCR-SSP method, were in complete accordance with the results of the PCR-RFLP reference method. The PCR-SSP method could also be adapted to assign the presence of a specific mutation to the respective FUT3 alleles. We found the method to be reliable, rapid and cheap with no requirements for restriction enzyme processing.

Alleles↗
PubMed2001

The role of different protein components from the Haemophilus ducreyi cytolethal distending toxin in the generation of cell toxicity.

Cytolethal distending toxin of Haemophilus ducreyi (HdCDT) is a multicomponent toxin, encoded by an operon consisting of three genes, cdtABC. To investigate the role of the individual products in generation of toxicity, recombinant plasmids were constructed allowing expression of each of the genes individually or in different combinations in Escherichia coli and Vibrio cholerae. Expression of all three genes (cdtABC) was necessary to generate toxicity on cells, and no activity was obtained using combinations in which only one or two of the genes were expressed. Of the individual gene products, the CdtA was shown to exist in two forms with an MW of 23 and 17 kDa, respectively. The CdtB protein alone resulted in DNase activity. CdtC purified from both toxic and non-toxic extracts (from strains expressing cdtCAB and cdtC, respectively) had a molecular weight of about 20 kDa and reacted with a CdtC-specific monoclonal antibody. However, the protein isoelectric point (pI) of CdtC from toxic preparations was about 1.5 pH units more basic than from non-toxic ones. Both forms were immunogenic giving rise to toxin-neutralizing antibodies. Toxicity was reconstructed by combining non-toxic cell sonicates from E. coli, expressing CdtA, CdtB and CdtC proteins individually. Only combinations including all three products gave toxicity, indicating that all are actively involved in the generation of toxic activity on cells. The reconstruction resulted in a 1.5 pH unit shift in the PI of CdtC, making it identical to that of the protein isolated from bacteria expressing cdtABC. The results showed that the CdtB component produces DNase activity, but cell toxicity depends on the involvement of the other two components of CDT and is associated with absorption of all three proteins by HEp-2 cells.

Bacterial Proteins↗
PubMed2001

The nitric oxide synthase inhibitor, L-NAME, block phencyclidine-induced disruption of prepulse inhibition in mice.

RATIONALE: Schizophrenia is a major public health problem that affects approximately 1% of the population worldwide. Schizophrenia-like syndromes can be induced in humans by phencyclidine (PCP), a drug with marked psychomimetic properties. Recent studies show that the behavioural and biochemical effects of PCP in rats are blocked by nitric oxide synthase (NOS) inhibitors, suggesting that NO plays an important role in the pharmacological effects of PCP. OBJECTIVE: The aim of this study was to investigate if PCP-induced disruption of prepulse inhibition of acoustic startle could be blocked by the NOS inhibitor, L-NAME, in mice. RESULTS: The present study shows that PCP readily disrupts prepulse inhibition in mice normally without affecting pulse-alone trials. Furthermore, L-NAME blocked the PCP-induced disruption of prepulse inhibition in a dose-related manner. CONCLUSIONS: The PCP-induced disruption of prepulse inhibition and the ability of L-NAME to block this effect in both rats and mice suggest that this is a general and not a species-specific effect. The results of the present study further suggest that PCP exerts at least some of its actions in the central nervous system by a NO-dependent mechanism.

Acoustic Stimulation↗
PubMed2001

The Th2 cytokines IL-4 and IL-10 are not crucial for the completion of allogeneic pregnancy in mice.

The physiological protection from fetal rejection is believed to be dependent on a Th2 type of inflammatory response at the maternal-fetal interface and the cytokines IL-4 and IL-10 have been suggested to play a critical role. We here present data from breeding experiments with IL-10 and IL-4 double-deficient mice indicating that neither maternal nor feto-placental deficiency of these cytokines are crucial for fetal or neonatal survival. The present study does not analyse possible developmental effects of maternal or fetal IL-10 and IL-4 double-deficiency in detail, but shows that an apparently normal breeding can be achieved in different crossings, providing that the mice are kept under very clean conditions.

Animals↗
PubMed2001

Pathogenesis of rotavirus diarrhea.

Rotavirus diarrhea is a major cause of infantile gastroenteritis worldwide. This review is mainly devoted to the effects of Rotavirus on intestinal epithelial transport and to the pathophysiological mechanisms proposed to underlie the intestinal fluid secretion caused by the virus.

Aging↗
PubMed2001

Circulation in the breast after radiotherapy and breast conservation.

OBJECTIVE: To investigate the breast circulation after radiotherapy and breast conservation. DESIGN: Open clinical study. SETTING: University hospital, Sweden. SUBJECTS: 24 patients with breast cancer (mean age 54 years, range 41-64). INTERVENTIONS: The glandular and the subcutaneous circulation in the breast were measured by Xenon (133Xe) clearance and the skin circulation by laser Doppler fluxmetry (LDF) two to five years after radiotherapy (50 Gy) following lumpectomy. The subcutaneous circulation was measured 2 cm above and medial or lateral to the areolar border and the glandular circulation 2 cm below and medial or lateral to the areolar border in the quadrant not previously operated on for carcinoma. The skin circulation was measured at the corresponding sites. MAIN OUTCOME MEASURES: Circulation in the subcutaneous and glandular tissue measured by 133Xe clearance and in the skin by LDF. RESULTS: The subcutaneous circulation, expressed as the ratio of 133Xe clearance in the operated irradiated: non-operated non-irradiated breast, was 0.88 (0.94) (median, interquartile range) and the glandular circulation 0.93 (0.75). The skin circulation ratios over the corresponding areas were 1.00 (0.37) and 1.00 (0.38), respectively. CONCLUSION: Radiotherapy after breast conservation surgery does not lead to long-term changes in basal glandular, subcutaneous, or skin circulation in the breast.

Adult↗
PubMed2001

Evaluation of linear registration algorithms for brain SPECT and the errors due to hypoperfusion lesions.

The semiquantitative analysis of perfusion single-photon emission computed tomography (SPECT) images requires a reproducible, objective method. Automated spatial standardization (registration) of images is a prerequisite to this goal. A source of registration error is the presence of hypoperfusion defects, which was evaluated in this study with simulated lesions. The brain perfusion images measured by 99mTc-HMPAO SPECT from 21 patients with probable Alzheimer's disease and 35 control subjects were retrospectively analyzed. An automatic segmentation method was developed to remove external activity. Three registration methods, robust least squares, normalized mutual information (NMI), and count difference were implemented and the effects of simulated defects were compared. The tested registration methods required segmentation of the cerebrum from external activity, and the automatic and manual methods differed by a three-dimensional displacement of 1.4+/-1.1 mm. NMI registration proved to be least adversely effected by simulated defects with 3 mm average displacement caused by severe defects. The error in quantifying the patient-template parietal ratio due to misregistration was 2.0% for large defects (70% hypoperfusion) and 0.5% for smaller defects (85% hypoperfusion).

Aged↗