PubMed Health⌕ Search

Biomedical subjects

A Nygren

Publications and source records attributed to A Nygren.

At least 55 records · Page 3Linked to original sources
PubMed1997

[A new surgical technique in atrial fibrillation. The maze procedure restores sinus rhythm].

Atrial fibrillation (AF) is a common arrhythmia associated with significant morbidity and increased mortality, partly due to the increased risk of stroke. The maze procedure, introduced by James Cox of the USA, is an internationally established surgical alternative in cases of unsuccessful medical or catheterised treatment of paroxysmal or chronic AF. It is an open heart procedure, involving multiple transmural incisions and continuous suture lines in both atria. By creating a maze of atrial tissue, the re-entrant circuits causing the AF are interrupted, hence re-establishing regular sinus rhythm and atrioventricular synchronization. The article reviews the initial 3-year experience of the procedure in 10 patients with AF, either paroxysmal (n = 5) or chronic (n = 5). The indications for surgery were disabling symptoms in all 10 cases, medical treatment failure in nine cases, previous AF-associated stroke in three cases, and a significant atrial septal defect in one case. All patients underwent extensive investigation both pre- and post-operatively. Postoperatively, nine of the 10 patients manifested regular sinus or atrial rhythm and freedom from or amelioration of preoperative symptoms associated with AF. There were no deaths, neurological complications or long-term recurrence of arrhythmia. One patient had an early recurrence of AF that was not amenable to medical treatment, and was subsequently treated with His' bundle ablation. Of the remaining nine patients, seven manifested signs of some postoperative atrial contraction at echocardiography, the occurrence of which needs to be borne in mind with a view to reducing the risk of future thromboembolic events. We recommend the maze procedure as an attractive surgical option in cases of unsuccessful medical treatment of paroxysmal or chronic AF.

Adult↗
PubMed1997

Measurements of oxygen tension in the rat kidney after contrast media using an oxygen microelectrode with a guard cathode.

The oxygen tension (PO2) in the rat kidney was studied by modified Clark microelectrodes. Changes in PO2 were measured in the renal cortex and outer medulla after intravenous injections of the X-ray contrast medium (CM) diatrizoate, 370 mg iodine/mg body weight. Injection of diatrizoate caused a slight fall in PO2 in the renal cortex (from 42 +/- 4 to 38 +/- 4 mm Hg). In the medulla PO2 decreased significantly (from 34 +/- 6 to 20 +/- 4 mm Hg). Ringer's solution did not induce any changes.

Animals↗
PubMed1997

Intrarenal oxygen tension measured by a modified clark electrode at normal and low blood pressure and after injection of x-ray contrast media.

The oxygen tension (pO2) in the rat kidney was studied using a Clark microelectrode with a guard cathode behind the sensing cathode. The mean (+/- SEM) outer tip diameter of the electrodes used was 5.5 +/- 1.9 microm. The zero-pO2 current amounted to 12.5 +/- 0.9 pA at 37 degrees C; at air saturation it was 252 +/- 22.9 pA. Rats with a systolic blood pressure (BP) above 80 mmHg (where 1 mmHg = 133 Pa) showed an average pO2 in the cortex of 45 +/- 2 mmHg and in the outer medulla of 31 +/-1 mmHg. In rats with a BP below 80 mmHg a paradoxically high outer medullary pO2 of 40 +/- 4 mmHg was found, while the pO2 in the cortex was 27 +/- 4 mmHg. Changes in pO2 were also noted in the renal cortex and outer medulla after intravenous injections of the x-ray contrast medium diatrizoate (370 mg iodine/ml). In rats with normal BP, injection of diatrizoate caused a slight fall in pO2 in the renal cortex, from 42 +/- 4 to 38 +/-4 mmHg. In the medulla pO2 decreased significantly from 34 +/- 6 to 20 +/-4 mmHg. Ringer's solution did not induce any changes.

Animals↗
PubMed1997

Injury severity assessment for car occupants in frontal impacts, using disability scaling.

Injury classification and assessment is one of the most important fields of injury prevention. At present, injury assessment focuses primarily on the risk of fatalities, in spite of the fact that most people who are injured survive the trauma. The net result of a fatality-based approach is that safety and vehicle engineers must make decisions with an incomplete, and sometimes misleading, picture of the traffic safety problem. By applying disability scaling reflecting long-term consequences to injury data, the most significant disabling injuries can be identified. The priorities change with the level of disability used in the scaling. In this study, the risk of permanent medical disability due to different injuries was derived and linked to abbreviated injury scale (AIS) values for 24,087 different injured body regions. This material is based on insurance data. To study how the importance of different bodily injuries changes with different severity assessments in a realistic real-world injury distribution, Swedish insurance industry disability scaling was applied to 3066 cases of belted Volvo drivers involved in frontal collisions. Crash severity was included in the study by using equivalent barrier speed (EBS). When lower levels of disability are included, injuries to the neck and the extremities become the most important, while brain and skull injuries become the most prominent at higher levels of disability. The results presented in this article should be regarded as a contribution to the development of a suitable disability scaling method. The results can also be utilized to further injury research and vehicle design aimed at reducing injuries which have the most important long-term disability consequences.

Accidents, Traffic↗
PubMed1997

Hospital Anxiety and Depression Scale (HAD): some psychometric data for a Swedish sample.

The Hospital Anxiety and Depression Scale (HAD) was evaluated in a Swedish population sample. The purpose of the study was to compare the HAD with the Beck Depression Inventory (BDI) and Spielberger's State Trait Anxiety Inventory (STAI). A secondary aim was to examine the factor structure of the HAD. The results indicated that the factor structure was quite strong, consistently showing two factors in the whole sample as well as in different subsamples. The correlations between the total HAD scale and BDI and STAI, respectively, were stronger than those obtained using the different subscales of the HAD (the anxiety and depression subscales). As expected, there was also a stronger correlation between the HAD and the non-physical items of the BDI. It was somewhat surprising that the factor analyses were consistently extracting two factors, 'depression' and 'anxiety', while on the other hand both BDI and STAI tended to correlate more strongly with the total HAD score than with the specific depression and anxiety HAD subscales. Nevertheless, the HAD appeared to be (as was indeed originally intended) a useful clinical indicator of the possibility of depression and clinical anxiety.

Adult↗
PubMed1997

Long-term follow up study on 64 elderly patients after balloon aortic valvuloplasty.

BACKGROUND AND AIMS OF THE STUDY: The aims of this study were to evaluate symptomatic improvement and event-free/overall survival after balloon aortic valvulotomy in patients with significant sclerotic aortic valve stenosis. METHODS: Sixty-four patients with calcified aortic stenosis, in NYHA class III-IV, and of mean age 79.0 years, underwent a total of 75 scheduled attempts at balloon aortic valvulotomy, with single balloon catheters between December 1987 and June 1993. Patients were either considered as poor surgical candidates or themselves preferred such valvulotomy. RESULTS: Periprocedural major complications, including death in 6%, occurred in association with 16% of the procedures. Among 57 patients in whom initial dilatation was successful, the average period of symptom relief was 9.4 months (median 7.0, range: 0 to 47 months). Independent predictors for longer duration of symptom relief and survival were systolic arterial pressure > 115 mmHg and female gender; ejection fraction > or = 30% was only predictive of survival. Actuarial survival rates at one, two and three years were 77, 48 and 36% respectively. CONCLUSIONS: Balloon aortic valvulotomy is followed by a short period of symptomatic relief and carries a low periprocedural mortality, but considerable morbidity. By comparison, aortic valve replacement patients aged over 70 and with serious physical limitations (NYHA class IIIB-IV) showed much better overall survival. As contraindications to surgery are in most cases relative, aortic valve replacement should always be considered as the only choice in the surgical decision-making.

Aged↗
PubMed1996

Effects of contrast media and mannitol on renal medullary blood flow and red cell aggregation in the rat kidney.

Hemodynamic factors may play a role in the development of acute renal failure following administration of contrast media (CM). In this study the effect of intravenous injection of contrast media and mannitol on red blood cell velocity (VRBC) and red blood cell aggregation in renal medullary vessels was studied in 58 rats. Renal medullary blood flow was investigated by a cross-correlation technique and by a visual aggregation score. The CM, namely diatrizoate, iopromide, iohexol, ioxaglate, iotrolan, were given in iodine equivalent doses (1600 mg/kg body wt). Mannitol (950 mOsm/liter) and Ringer's solution were used as controls. The same vessels were studied 30 minutes before and 30 minutes after injections. VRBC decreased significantly after injection of diatrizoate, iopromide, iohexol, iotrolan and mannitol. Ringer's solution and ioxaglate did not significantly alter medullary blood flow, while iotrolan and mannitol caused the largest decreases in VRBC. All CM and mannitol caused both red cell aggregation and cessation of blood flow. The decrease in blood flow and increase in red blood cell aggregation after injection of CM and mannitol may partly explain the occurrence of contrast medium-induced acute renal failure.

Acute Kidney Injury↗
PubMed1996

Rectal biopsy diagnosis in horses with clinical signs of intestinal disorders: a retrospective study of 116 cases.

The histology from rectal biopsy specimens taken 1980-1990 on 131 occasions from 116 horses, age 1-18 years, with clinical signs of intestinal disease was evaluated and classified retrospectively. In 40 horses, autopsy results were studied for comparison. Biopsy specimens (21 horses) and post mortem rectal tissue (9 horses) from 30 healthy horses, age 4-22 years, were used as controls. In 105 clinical cases, a biopsy was performed on only one occasion, while repeat biopsy was performed in 11 cases. Specimens showed pathological changes in 60 horses. The findings were classified into acute, chronic or chronic active simple proctitis, granulomatous enteritis, eosinophilic granulomatosis/gastroenteritis, eosinophilic proctitis, erosive/ulcerative proctitis, pseudomembranous proctitis, proctitis with vasculitis and malignant lymphoma. Mild scattered neutrophil infiltration in the lamina propria was found in controls, but neutrophils in crypt or surface epithelia were abnormal findings. Depletion or hyperplasia of goblet cells sometimes accompanied inflammation. Simple proctitis occurred in association with malignant lymphoma and various inflammatory disorders of the gastrointestinal tract apparent at autopsy. Eosinophilic granulomatosis/gastroenteritis and granulomatous enteritis were diagnosed from biopsy specimens in 6 of 12 and 4 of 9 cases, respectively, of these diseases confirmed at autopsy. Reduction of acid mucins in goblet cells was a prominent feature of eosinophilic granulomatosis. Rectal biopsy was found to be a useful adjunct for evaluation of intestinal disease in the horse.

Animals↗
PubMed1995

The role of the psychologist in multidisciplinary treatments for chronic neck and shoulder pain: a controlled cost-effectiveness study.

This study was designed to determine a cost-effective use of psychologist resources in multimodal cognitive-behavioural treatments (MMCBT) for chronic neck/shoulder pain. A randomised controlled trial was conducted with 66 patients divided in two groups. The first group (A) was treated following the approach of MMCBT with the clinical psychologist only functioning as a "coach" to the other health professionals. In this group, the psychologist had on average 5 hours of input per patients. The second group (B) was treated with the same inpatient MMCBT but with the behavioural component administered by the clinical psychologist directly to the patients. In this second group the psychologist had on average 17 hours of input per patient in the entire intervention. The outcome variables included physical, emotional and social factors, and sick-leave. Both groups showed significant improvements over time. The improvements were evident only in sub-groups, specifically in women. The only significant difference between the groups was in "perceived helplessness" favouring the "psychologist contact" setting. It is concluded that in terms of input of clinical psychology, the treatment setting with the "coaching" technique proved to be the most cost-effective use of the psychologist in the two treatment settings investigated.

Adult↗
PubMed1995

Seventeen year follow-up study of bone mass in patients with mild asymptomatic hyperparathyroidism some of whom were operated on.

OBJECTIVE: To compare the effect of operation and observation on bone mineral mass in patients with mild asymptomatic hyperparathyroidism (HPT). DESIGN: A randomised 17-year follow-up study. SETTING: University hospital, Sweden. SUBJECTS: 48 women who had been diagnosed as having asymptomatic HPT during a health screening survey in Stockholm, Sweden during 1971-73. INTERVENTIONS: 26 patients were operated on and 22 were observed. 46 normocalcaemic women served as a reference population. 17 years later, operated on (n = 12), not operated on (n = 8) and control subjects (n = 16) were followed up. MAIN OUTCOME MEASURES: Bone mineral content (BMC) of distal non-dominant forearm, and serum concentrations of calcium and creatinine. RESULTS: On entering the study in 1971-73, the BMC of the distal forearm was 14% lower in the patients with HPT than in age, body mass, and postmenopausal age-matched controls (mean (SD) 1.01 (0.23) compared with 1.18 (0.30) g/cm; p < 0.05). During the first 3 years after operation bone mass increased significantly in the group operated on (n = 26) to 106% of the initial values (95% confidence interval (CI) 100% to 111%), remained unchanged (mean 101%; (97% to 106%)) in the unoperated group (n = 22), and decreased significantly to 94% (92% to 97%) of the initial values in the reference group (n = 46). At follow up 17 years later BMC of distal radius in the operated group (n = 12) and patients treated conservatively (n = 8) showed similar values; that were not significantly lower than those of the controls (difference: -12 (18)%). CONCLUSIONS: Our results suggest that patients with mild asymptomatic HPT have already experienced their major bone loss when diagnosed. Parathyroidectomy had an initial positive effect on bone mineralisation, but we could find no long-term advantage in operative treatments. During the 17 year follow-up period HPT patients who were not operated on showed an improvement in bone mass compared with healthy control subjects.

Adult↗
PubMed1994

Coping with long-term musculoskeletal pain and its consequences: is gender a factor?

We did a descriptive study of 121 patients (71 women and 50 men) to explore the role of gender in coping with long-term intractable pain of the neck, shoulder and back and to determine the consequences of pain. Questionnaires used to assess the dependent variables were the Coping Strategy Questionnaire (CSQ) and the Multidimensional Pain Inventory (MPI). Distinctions were found between men and women. In particular, the coping strategies used by women were those which in previous research had been found to be associated with dysfunction and poor outcome in terms of rehabilitation. Moreover, considering the consequences of pain on daily living, a more complex pattern of related factors was found in women rather than men. Given the high proportion of working women in Sweden with long-term musculoskeletal pain and considering recent observations in controlled studies showing that the benefits of cognitive behaviourally based treatments are confined to women, our findings suggest the need to tailor rehabilitative strategies differently for men and women and point to a research agenda which pays more attention to the distinctive challenges of women in the workplace when they are affected by chronic ailments.

Adaptation, Psychological↗
PubMed1994

Cognitive-behavioural treatment for workers with chronic spinal pain: a matched and controlled cohort study in Sweden.

An ambulatory multimodal cognitive-behavioural treatment programme (MMCBT) for Swedish workers with chronic spinal pain was formally evaluated. The design was a matched cohort study with three repeated measures done in two groups of 35 referred patients (one exposed to MMCBT and controls exposed to usual care). The MMCBT package includes standardised modules of physical treatment, cognitive-behavioural treatment, education of worker patients, and education of subjects' supervisors. The primary outcome variables assessed were absenteeism, disability, pain, and depression. Because of a change in Swedish sick leave compensation laws affecting records of absence during the study period, absenteeism could not be reliably measured among controls. The trend, however, suggested a reduction of absenteeism among the subjects in the MMCBT cohort. The findings for disability, pain, and depression all showed clinically important and significant beneficial changes (ANOVA for repeated measures: disability p = 0.05; pain p = 0.001; depression p = 0.01). The direction of the improvements and the size of effect were coherent and clinically plausible. The benefits were only among the women in the study. These comprised 74% of each group. Further research on larger sample sizes and in cohorts more representative of the whole country are needed to confirm these encouraging findings and to explore how the benefits might be extended to men.

Adult↗
PubMed1993

Life-threatening and disabling injuries in car-to-car side impacts--implications for development of protective systems.

Improvements to the passive safety of cars in lateral collisions are of great importance. This study of injuries in car side collisions in Sweden by the use of two evaluation methods has been performed to establish the basis for future development of protective systems for this type of accident. The Folksam car accident data file has been used. Injuries were found to be twice as common for near-side than for far-side* occupants in car to car impacts. Serious to fatal (AIS 3-6) injuries to belted front seat occupants in near side impacts (10% of all injuries) were compared with the estimated number of injuries to different parts of the body with risk of serious consequences (RSC)--either deaths or permanent disabilities (4.5% of all injuries). The two injury evaluation methods resulted in different ranking orders. AIS 3-6 injuries were received by the chest (37%), abdomen/pelvis (25%), and the head (15%). The RSC method gave a ranking order of head (25%), neck (21%), leg (15%), chest (14%), and abdomen/pelvis (11%). The method of evaluating AIS 3-6 injuries emphasizes only the threat to life. The RSC method also takes into account the risk of disabilities. Injuries to the neck and the leg were found to be most disabling, whilst the injuries to the head, chest, and abdomen/pelvis were the most life threatening. The study also shows that elderly people receive significantly more chest injuries (relative to the number of head injuries), on average four times more than young people.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1993

Major differences in trauma care between hospitals in Sweden: a preliminary report.

The quality of trauma care has been studied at five different Swedish hospitals. The results suggest that improvements in the quality of medical care for patients with severe road traffic injuries can be achieved by reorganizing the highly decentralized trauma care system in Sweden. Above all there is a need for a better structure and organization of the on-call system and of the cooperation of physicians of different specialties within the hospital. The medical care of patients with severe injuries was delayed in 30% and was inappropriate in 7% of cases. Assessment of the quality showed great variation between the hospitals. The medical care was in fact not best at the university hospital but at one well-functioning small hospital. It was an effect of an on-call system at the small hospital, which guarantees rapid participation of senior staff in both general surgery and orthopaedic surgery. The greatest problems arose in early diagnosis and treatment of bleeding in abdominal injuries. This was caused by inexperience in the first on-call team in combination with late assessment by second on-call consultants. Fractures of the femoral shaft in almost half of the cases did not get definitive surgery until several days after the accident.

Abdominal Injuries↗
PubMed1993

Red-cell trapping in the rat renal microcirculation induced by low-osmolar contrast media and mannitol.

RATIONALE AND OBJECTIVES: In acute renal failure after ischemia, intravascular obstruction by trapped red blood cells in the microvasculature of the renal outer medulla is a consistent finding. The influence of intravenously injected contrast media (CM) on such obstruction was investigated. METHODS: Anesthetized rats were subjected to 45 minutes of unilateral renal ischemia. Red-cell trapping in ischemically injured kidneys and in the contralateral uninjured kidneys was estimated from the intrarenal distribution of 51Cr-labelled erythrocytes after injection of ioxaglate or iopamidol in a dose of 1,600 mg I/kg body weight. As an osmolar control substance, mannitol (950 mOsm/kg) was given to a third group and isotonic Ringer's solution was administered to a fourth group. RESULTS: In the uninjured kidneys, treatment with ioxaglate or mannitol resulted in no red-cell trapping, while the iopamidol-treated group showed red-cell trapping in the inner stripe of the outer medulla in a dose-dependent manner. In the ischemically injured kidneys, both CM and mannitol enhanced the red-cell trapping in the inner stripe of the renal medulla. CONCLUSION: The results indicate that intravenously administered ioxaglate and iopamidol enhance the microvascular obstructions evoked by ischemic injury and that iopamidol may induce local impairment in renal medullary microcirculation in a normal kidney.

Animals↗