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Biomedical subjects

L Ekström

Publications and source records attributed to L Ekström.

At least 19 recordsLinked to original sources

A novel polymorphism in the 17beta-hydroxysteroid dehydrogenase type 5 (aldo-keto reductase 1C3) gene is associated with lower serum testosterone levels in caucasian men.

Genetic variation in the androgen metabolizing enzymes is important to identify and feature as they may influence the risk of prostate cancer and help clarify the etiology of the disease. Human 17beta-hydroxysteroid dehydrogenase type 5 (AKR1C3) is highly expressed in the prostate gland and plays a major role in the formation and metabolism of androgens. We identified five novel polymorphisms in the AKR1C3 gene. One of those an A>G substitution in exon 2 that confers a Glu77Gly change occurred in 4.8% in Caucasians but was completely absent in Orientals. Interestingly, the testosterone level in serum was significantly lower in subjects with the Gly77 allele. A promoter A>G polymorphism was associated with significantly altered promoter activity in reporter constructs, but was not associated with any change in testosterone levels. In conclusion, the Glu77Gly polymorphism is associated with lower testosterone levels in serum.

17-Hydroxysteroid Dehydrogenases↗

A functional C-G polymorphism in the CYP7B1 promoter region and its different distribution in Orientals and Caucasians.

Cytochrome P450 (CYP) 7B1 is involved in many metabolic processes including androgen metabolism. Genetic variation in the CYP7B1 gene may play a role in predisposition to prostate cancer. Here, we screened the human CYP7B1 gene for possible polymorphisms. Only one single polymorphism was detected, a C-G change in the promoter -104 base pair from the transcription start site. The allele frequency was investigated in Swedish men and compared to a Korean population, as it is known that the frequency of prostate cancer is low among Orientals. We found that the frequency of the G-allele was 4.04% in Swedes (n=150) but only 0.33% among Koreans (n=153). Computer analysis indicated that the two variants bind with different affinities to a CCAAT-box binding protein. Expression studies with reporter constructs showed significantly higher transcriptional activity of the G variant in Hek293 cells (2.7-fold, P<0.05). In conclusion, we report here for the first time the detection of a single polymorphism in the CYP7B1 gene. This polymorphism is associated with phenotypic differences in an expression system and a widely different allele frequency in two ethnic populations, with great differences in the incidence of prostate cancer.

Asian People↗

Psychosocial functioning in a group of Swedish adults with Asperger syndrome or high-functioning autism.

This study reports on psychosocial functioning in Swedish adults with Asperger syndrome (AS) or high-functioning autism (HFA). A systematically selected sample of patients and relatives was interviewed concerning their psychosocial situation. The majority was living independently. All persons but one were unemployed. None was married and none had children. Only a few had some kind of partner. Most persons needed a high level of public and/or private support. The overall adjustment was rated good in 12 percent, fair in 75 percent and poor in 12 percent. Adult persons with AS/HFA have extensive need for support from their families and/or society. This information is important in order to provide adequate interventions that are in accordance with the expressed needs of the individuals themselves.

Activities of Daily Living↗

The diagnostic performance of vertebral displacement measurements derived from ultrasonic indentation in an in vivo model of degenerative disc disease.

STUDY DESIGN: The diagnostic performance of a newly described variable was assessed in an in vivo model of disc degeneration using a split-pair experimental design. OBJECTIVE: To determine if vertebral displacement measures generated from ultrasonic indentation could distinguish between experimental and control groups of animals. SUMMARY OF BACKGROUND DATA: Few procedures are available that noninvasively assess subcutaneous vertebral mechanics. Information from such a procedure would be of value in determining potential clinical relevance of spinal mechanics with respect to low back pain. METHODS: Eight adolescent pigs underwent endplate perforation surgery to initiate lumbar disc degeneration. After 4 months of recovery, these and eight age-matched controls were assessed by ultrasonic indentation, a noninvasive procedure that quantifies vertebral displacements in the plane of loading-indentation. Each animal then received a facetectomy and was reindented at the same location as confirmed by ultrasonic imaging. Discal materials were removed postmortem for analysis. RESULTS: Degenerative discs exhibited morphologic changes consistent with early degenerative disc disease. Prefacetectomy comparison of vertebral displacement measures between control and experimental animals resulted in sensitivity, specificity, and diagnostic accuracy values of 75.0%, 83.3%, and 77%, respectively. After facetectomy these values increased to 87.5%, 83.3%, and 85%, respectively. These measures of diagnostic performance were comparable or superior to those of existing clinical techniques (invasive or otherwise) used to assess degenerative conditions of the spine. CONCLUSIONS: The results of this study suggest that noninvasive measures of vertebral displacement are clinically significant and possess the additional advantages of being objective and noninvasive.

Animals↗

Characteristics and outcome among patients suffering in-hospital cardiac arrest in monitored and non-monitored areas.

AIM: To describe the characteristics and outcome among patients suffering in-hospital cardiac arrest in relation to whether the arrest took place in a ward with monitoring facilities. METHODS: All patients who suffered an in-hospital cardiac arrest during a 4-year period in Sahlgrenska Hospital, Göteborg, Sweden and in whom resuscitative efforts were attempted, were prospectively recorded and described in terms of characteristics and outcome. RESULTS: Among 557 patients, 292 (53%) had a cardiac arrest in wards with monitoring facilities. Those in a monitored location more frequently had a confirmed or possible acute myocardial infarction (AMI) as judged to be the cause of arrest (P < 0.0001), and the arrest was witnessed more frequently (96 vs. 79%; P < 0.0001). Ventricular fibrillation/tachycardia was observed more often as initial arrhythmia in monitored wards (56 vs. 44%; P = 0.006). The median interval between collapse and first defibrillation was 1 min in monitored wards and 5 min in non-monitored wards (P < 0.0001). Among patients with arrest in monitored wards 43.2% were discharged alive compared with 31.1% of patients in non-monitored wards (P = 0.004). Cerebral performance category (CPC-score) at discharge was somewhat better among survivors in monitored wards. CONCLUSION: In a Swedish University Hospital 47% of in-hospital cardiac arrests in which resuscitation was attempted took place in wards without monitoring facilities. These patients differed markedly from those having arrest in wards with monitoring facilities in terms of characteristics, interval to defibrillation and outcome. A shortening of the interval between collapse and defibrillation in these patients might increase survival even further.

Adolescent↗

Is there a difference between women and men in characteristics and outcome after in hospital cardiac arrest?

AIM: To describe the characteristics and outcome among patients suffering from an in-hospital cardiac arrest in women and men. METHODS: All patients who suffered an in-hospital cardiac arrest during a 4 year period in Sahlgrenska Hospital Göteborg, Sweden, where the cardiopulmonary resuscitation (CPR) team was called, were recorded and described prospectively in terms of characteristics and outcome. RESULTS: There were 557 patients suffering in-hospital cardiac arrest in whom the CPR-team was alerted. Among them, 217 (39%) were women. Women differed from men having a lower prevalence of earlier myocardial infarction, angina pectoris, renal disease and a higher prevalence of rheumatic disease. In terms of aetiology of the cardiac arrest, 47% men and 48% women were judged to have had a confirmed or possible AMI. More men than women were found in ventricular fibrillation/ventricular tachycardia (VF/VT) (57 vs. 41%; P<0.001), whereas more women were found in pulseless electrical activity (30 vs. 15%; P<0.0001). Cerebral performance categories (CPC)-score at discharge did not differ between men and women. Among women, 36.4% survived to discharge as compared with 38.0% among men (NS). Survival from VF/VT was 64.3% in women and 52.7% in men (NS). When correcting for dissimilarities at baseline, the adjusted odd ratio for being discharged alive from hospital among women as compared with men was 1.66 (95% confidence limit 1.06-2.62; P=0.028). CONCLUSION: Thirty nine percent of patients suffering in-hospital cardiac arrest for whom the CPR-team was alerted, were women. Women were less frequently found in VF/VT than men. After correcting for dissimilarities at baseline, female gender was associated with a small improvement in survival.

Aged↗

Intensive use of intravascular ultrasound during coronary angioplasty. A six-month campaign.

BACKGROUND: Compared to coronary angiography, intravascular ultrasound (IVUS) gives additional information important for the percutaneous transluminal coronary angioplasty (PTCA) procedure, but is time-consuming and may cause complications. AIM: To evaluate, during a period of intensive use of IVUS, the impact of IVUS on the final decision on balloon/stent diameter, consumption of devices, time-consumption and IVUS-related complications. METHOD: During a 6-month period, IVUS was contemplated in all PTCA procedures and the reason for not using IVUS was specified. We used CVIS during the first, and Endosonics during the last 3 months, and both periods started with 1 week of hands-on practice. All procedures were to be planned according to an initial quantitative coronary angiography (QCA), and the finally achieved result, material used and complications were registered. RESULTS: The proportion of IVUS/PTCA was 37% during, 8% 6 months before and 12% 6 months after the study period. Three hundred and twenty-three patients were included in the study (57% of all patients), 199 of them were subjected to IVUS. The indications for PTCA during the study period were stable angina (58%), unstable angina (32%) and acute myocardial infarction (10%). The main reasons for not doing IVUS were use of 6F guiding catheter (13%), urgent procedure (12%) and occluded vessel (11%). Initial QCA detected 253 stenoses in 199 patients and 64 additional stenoses were treated, most of them probably detected by IVUS. QCA systematically underestimated vessel size, particularly in small vessels. There was a non-significant trend to more accurate estimations towards the end of the study in small vessels. Dissection, probably due to IVUS, occurred in two cases (1%). There were no significant differences in the number of devices used in IVUS compared to non-IVUS patients. The procedural time was 24 min longer in IVUS than in non-IVUS cases and more stenoses were treated per procedure in the IVUS group. CONCLUSION: Coronary angiography often underestimated balloon/stent size but in an unpredictable way, with a substantial proportion of significant stenoses being undetected. IVUS had few serious complications, did not increase device consumption but prolonged procedural time.

Adult↗

[Improved survival after in-hospital cardiac arrest].

Internationally, survival among patients suffering in-hospital cardiac arrest is relatively low and unchanged at about 15%. Our experience at Sahlgrenska Hospital in Göteborg indicates a higher rate. We found survival to be related to the type of arrhythmia initially encountered, the highest rate having been observed among patients in ventricular fibrillation. We also found survival among patients suffering cardiac arrest to be higher in monitored as opposed to non-monitored wards. Whether the improved survival rate observed at Sahlgrenska as compared with international observations among patients suffering cardiac arrest is due to improvements in the organization or to patient selection is not clear. In order to achieve a higher survival rate after in-hospital cardiac arrest an efficient organization in which health care providers are given regular training and feed back is most likely of the utmost importance.

Cardiopulmonary Resuscitation↗

Exposure of the porcine spine to mechanical compression: differences in injury pattern between adolescents and adults.

Recent studies of the spine in adolescents who have sustained trauma have shown injuries to the growth zone, whereas injuries to the vertebral body have been described in other studies of only adults. There are also reports on different clinical signs and radiological findings in adolescents with lumbar disc herniation when compared to adults. In order to find an explanation for these differences between adolescents and adults, this experimental study was performed. Six cadaveric lumbar motion segments (vertebral body-disc-vertebral body) obtained from three young male pigs and six lumbar motion segments obtained from three mature male pigs were tested in axial compression to failure. All units were examined with plain radiography and magnetic resonance imaging before and after compression. After the compression, histological samples were taken from the injury site. In the adolescents, a fracture was consistently found in the endplate through the posterior part of the growth zone, displacing the anulus fibrosus with a bony fragment at the point of insertion to the vertebra. This type of injury could not be detected in any of the adults; instead, there was a fracture of the vertebra in four cases, and in two cases, a rupture of the anulus fibrosus without a bony fragment was seen. This study showed that, when compressed to failure, the weakest part of the lumbar spine of the adolescent pig differs from that of the mature pig in the same way that studies on human spinal units have shown.

Age Factors↗

A comparison between patients suffering in-hospital and out-of-hospital cardiac arrest in terms of treatment and outcome.

AIM: To compare treatment and outcome amongst patients suffering in-hospital and out-of-hospital cardiac arrest in the same community. PATIENTS: All patients suffering in-hospital cardiac arrest in Sahlgrenska University Hospital covering half the catchment area of the community of Göteborg (500 000 inhabitants) and all patients suffering out-of-hospital cardiac arrest in the community of Göteborg. Criteria for inclusion were that resuscitation efforts should have been attempted. TIME OF SURVEY: From 1 November 1994 to 1 November 1997. METHODS: Data were recorded both prospectively and retrospectively. RESULTS: In total, 422 patients suffered in-hospital cardiac arrest and 778 patients suffered out-of-hospital cardiac arrest. Patients with in-hospital cardiac arrest included more women and were more frequently found in ventricular fibrillation. The median interval between collapse and defibrillation was 2 min in in-hospital cardiac arrest compared with 7 min in out-of-hospital cardiac arrest (< 0.001). The proportion of patients being discharged from hospital was 37.5% after in-hospital cardiac arrest, compared with 8.7% after out-of-hospital cardiac arrest (P < 0.001). Corresponding figures for patients found in ventricular fibrillation were 56.9 vs. 19.7% (P < 0.001) and for patients found in asystole 25.2 vs. 1.8% (P < 0.001). CONCLUSION: In a survey evaluating patients with in-hospital and out-of-hospital cardiac arrest in whom resuscitation efforts were attempted, we found that the former group had a survival rate more than four times higher than the latter. Possible strong contributing factors to this observation are: (i) shorter time interval to start of treatment, and (ii) a prepared selection for resuscitation efforts.

Adolescent↗

Laser angioplasty of restenosed coronary stents: results of a multicenter surveillance trial. The Laser Angioplasty of Restenosed Stents (LARS) Investigators.

OBJECTIVES: This study evaluated safety and efficacy of excimer laser angioplasty for treatment of restenosed or occluded coronary stents. BACKGROUND: Balloon angioplasty of in-stent restenosis is limited by a high recurrence rate. Debulking by laser angioplasty is a novel concept to treat in-stent restenosis. METHODS: A total of 440 patients with restenoses or occlusions in 527 stents were enrolled for treatment with concentric or eccentric laser catheters and adjunctive balloon angioplasty. RESULTS: Laser angioplasty success (< or =50% diameter stenosis after laser treatment or successful passage with a 2.0-mm or 1.7-mm eccentric laser catheter) was achieved in 92% of patients. Adjunctive balloon angioplasty was performed in 99%. Procedural success (laser angioplasty success followed by < or =30% stenosis with or without balloon angioplasty) was 91%. There was neither a significant difference in success with respect to lesion length, nor were there differences between small and large vessels or native vessels and vein grafts. Success was higher and residual stenosis lower using large or eccentric catheters. Serious adverse events included death (1.6%, not directly laser catheter related), Q-wave myocardial infarction (0.5%), non-Q-wave infarction (2.7%), cardiac tamponade (0.5%) and stent damage (0.5%). Perforations after laser treatment occurred in 0.9% of patients and after balloon angioplasty in 0.2%. Dissections were visible in 4.8% of patients after laser treatment and in 9.3% after balloon angioplasty. Reinterventions during hospitalization were necessary in 0.9% of patients; bypass surgery was performed in 0.2%. CONCLUSIONS: Excimer laser angioplasty with adjunctive balloon angioplasty is a safe and efficient technology to treat in-stent restenoses. These data justify a randomized comparison with balloon angioplasty.

Adult↗

Continuous vectorcardiographic monitoring of ischemia during coronary angioplasty in patients with bundle-branch block.

BACKGROUND: Patients with the combination of bundle-branch block and ischemic heart disease have a poor outcome. There is no established criterion for detection of transient ischemia when bundle-branch block is present. OBJECTIVE: To elucidate vectorcardiographic changes during coronary angioplasty of patients with bundle-branch block. DESIGN AND METHODS: The QRS complex and ST-segment changes of 29 patients with bundle-branch block were studied during elective coronary angioplasty using continuous vectorcardiography. Data for the patients with bundle-branch block were compared with data for narrow-QRS-complex controls, matched for the vessel dilated, sex, and age. RESULTS: Patients with bundle-branch block were found to have more pronounced changes in the QRS-vector difference as a response to coronary occlusion than did controls. ST-vector magnitude responded in a similar way during coronary occlusion of patients with and without bundle-branch block but from different baselines. ST change-vector magnitude was found to be the most sensitive parameter for detection of ischemia in patients with bundle-branch block as well as for controls. CONCLUSION: Monitoring of transient ischemia during coronary angioplasty for patients with bundle-branch block is feasible using continuous vectorcardiography. A change in ST vector magnitude > 100 microV is suggested to indicate significant ischemia in the presence of bundle-branch block.

Aged↗

Injuries in the adolescent porcine spine exposed to mechanical compression.

STUDY DESIGN: An experimental porcine study in which functional lumbar spinal units were tested in compression to failure. Biomechanical, radiographic, magnetic resonance imaging, and histological characteristics are described. OBJECTIVES: To explain the different patterns of injury seen in adults and adolescents resulting from traumatic injury to the vertebrae and to explain the mechanism behind traumatic displacement of the ring apophysis seen in athletes. SUMMARY OF BACKGROUND DATA: Recent investigations of the spine in adolescent who have sustained trauma have shown injuries to the growth zone, whereas studies of adults have shown injuries to the vertebral body. A higher frequency of abnormalities in the discs, the vertebral bodies, the endplates, and the ring apophyses has been demonstrated in athletes with high loads on the spine. There is controversy over the etiology of these changes. METHODS: Twelve functional lumbar spinal units (vertebra-disc-vertebra) obtained from six young male pigs were tested in compression to failure. All units were examined with plain radiography and magnetic resonance imaging before and after compression. After the compression, histologic samples were taken from the injury site. RESULTS: Identical traumatic changes were seen in all functional lumbar spinal units, i.e., fracture in the endplate through the growth zone posteriorly and displacement of the anulus fibrosus with a bony fragment at the point of insertion of the vertebra. The nucleus pulposus was ruptured and displaced through the fracture line in all cases. The injuries were not seen on radiographs but were detected on magnetic resonance images, as confirmed on microscopic and histologic examination. CONCLUSION: This study shows that the weakest part of the lumbar spine of the juvenile pig, when compressed, is the growth zone and the junction between the point of insertion of the anulus fibrosus and the vertebra. This location of weakness may explain the high frequency of disc degeneration and "persisting apophysis" seen in the spine of athletes.

Animals↗

Axial stiffness of human lumbar motion segments, force dependence.

This paper addresses the axial stiffness of human lumbar motion segments while subjected to moderate loads. Impacts in axial direction were applied to Functional Spinal Units while they were subjected to weights acting as static pre-load. Accelerations were recorded proximal and distal of the FSU. The transfer function and the resonant frequency were calculated from this data. The stiffness was calculated from the resonant frequency and the load. A simple non-linear model was fitted to the data and a linear relationship was found between stiffness squared and force. The non-linear component in the model strongly affected the stiffness within the chosen load range. The present model may allow in vivo dynamic force determination with improved accuracy, e.g. in experiments where accelerometers have been fixated to pins inserted into the spinous processes of lumbar vertebrae if the static force is known.

Aged↗

Factors surrounding cardiopulmonary resuscitation influencing bystanders' psychological reactions.

The incidence of Sweden's out-of-hospital cardiac arrests averages 10000 annually. Each year bystanders initiate cardiopulmonary resuscitation (CPR) approximately 2000 times prior to arrival of emergency medical service (EMS). The aim of this study was to identify factors influencing the bystanders psychological reactions to performing CPR. We mailed a questionnaire to all bystanders who reported performing CPR to the CPR Centre of Sweden from autumn 1992 to 1995. The study included 544 bystander reports. Nine factors were found to be associated with bystanders experience in a univariate analysis. Among these were victim outcome (p < 0.0001), CPR duration (p = 0.0009) and their experience of the attitude of the EMS personnel (p = 0.004). In a multivariate logistic regression model, lack of debriefing following the intervention (p = 0.0001) and fatal victim outcome (p = 0.03) were independent predictors of a negative bystander psychological reaction. The importance of having someone to talk to following an intervention and the EMS personnel concern for the rescuer should be emphasised. The goal should be that critical incident debriefing is available to every bystander following his or her CPR attempt.

Attitude of Health Personnel↗