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Biomedical subjects

E Mattsson

Publications and source records attributed to E Mattsson.

18 recordsLinked to original sources

Vessel repair after balloon angioplasty: morphological appearance and prostacyclin synthesising capacity.

Immediately after balloon dilatation of the rabbit aorta the release of prostacyclin is diminished. In this study the morphological appearance and time course for recovery of prostacyclin production after balloon dilatation have been investigated. Healthy rabbit aortas were analysed 1 h (n = 12), 1 week (n = 13) and 1 month (n = 13) after angioplasty. The production of prostacyclin, from dilated and non-dilated aortic segments, was recorded in a perfusion system. Prostacyclin was measured as its stable degradation product 6-keto-PGF1 alpha. Scanning electron microscopy and light microscopy were used to analyse the type of cells present at the luminal surfaces of the segments. When endothelial cells were found their degree of coverage was also estimated. One hour after balloon dilatation there was a lower production of prostacyclin from the angioplasty segments than from controls. Also, the response to added arachidonic acid (AA) was lower in the angioplasty segments. No endothelial cells were present in the angioplasty segments. After 1 week there was no difference in the basic production of prostacyclin but there was still a lower response from angioplasty segments to the addition of AA. The inner surfaces of the angioplasty segments were covered by three to five layers of smooth muscle cells (SMC). After 1 month, there was no difference in either the basic production or after the addition of AA between control and angioplasty segments. The angioplasty segments were covered with a multilayer of SMC. The control segments had an almost complete cover of endothelial cells at every time interval after angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon

Diet-induced atherosclerosis in rabbits alters vascular prostacyclin release.

Atherosclerosis is complicated by thrombosis and it has been suggested that a decreased prostacyclin and/or an increased thromboxane release from the vascular wall could play a part in this process. There are few reports dealing with determinations of prostanoid release from physiologically perfused normal and atherosclerotic vessel walls or from perfused atherosclerotic hearts. Therefore, fourteen rabbits were given 2% cholesterol added to the diet for 26 weeks, which led to atherosclerosis, verified by scanning electron microscopy. Five animals died, and in the surviving nine, as well as from ten healthy rabbits, the aorta was excised. The vessels were perfused with pulsatile flow at physiologic pressure five times for fifteen minutes with the addition of arachidonic acid to the last perfusate. Prostacyclin and thromboxane were determined as their stable degradation products 6-keto-PGF1 alpha and TxB2 by radio-immuno assay. Atherosclerotic and normal animals had the same initial release of prostacyclin but in the atherosclerotic animals the release did not decline with time as it did in the normal animals. The response to arachidonic acid was also higher in the atherosclerotic group. The release of thromboxane was not altered in the atherosclerotic group compared to the control group. It is concluded that prostacyclin release from aortas is altered in rabbits with diet-induced atherosclerosis compared to normal rabbit aortas, but that vascular thromboxane production is not.

Animals

Treatment of postoperative paralytic ileus with cisapride.

The effect of cisapride on postoperative colonic motility was studied in 40 patients undergoing cholecystectomy under randomized, double-blind conditions. The patients received 10 mg of cisapride or placebo by intravenous injection starting on the day of surgery and repeated every 12 h until the 3rd postoperative day. The return of propagative motility in the colon was visualized by means of radiopaque markers and serial abdominal radiographs. Cisapride induced a significantly earlier return of propulsive motility in the right colon, as indicated by the propagation of markers from the ascending colon to the transverse colon (p less than 0.05). Radiopaque markers reached the descending colon (p less than 0.05) and the rectosigmoid colon (p less than 0.05) significantly earlier in the cisapride group than in controls. The first passage of feces occurred significantly earlier in cisapride-treated patients than in controls (p less than 0.05). The first passage of gas after surgery did not differ significantly between the groups. Our results suggest that cisapride can be used to induce earlier return of propagative motility in the colon after major abdominal surgery.

Cholecystectomy

Lower-limb vasospasm and renal failure during postoperative thromboprophylaxis. Case report.

In a 73-year-old woman with trimalleolar fracture, secondary acute ischemia of the limb and renal failure developed in association with heparin-dihydroergotamine thromboprophylaxis. Earlier cases of thromboprophylaxis-related angiospasm are briefly reviewed. The condition is infrequent, but trauma of extremities and shock are risk factors. Renal failure is rare.

Acute Kidney Injury

Lack of effect of metoclopramide on colonic motility after cholecystectomy.

The effect of metoclopramide on postoperative colonic ileus was evaluated in a randomised, double-blind study in 20 patients after cholecystectomy. The start of propulsive colonic motility and colonic transit time after operation were measured by radio-opaque markers and serial abdominal radiographs. Metoclopramide 20 mg given intravenously three times a day until the fourth postoperative day (n = 10) did not significantly reduce the duration of postoperative colonic paralysis compared with control patients (n = 10), nor were there any differences between the groups when the time of first postoperative passage of gas and faeces were compared. In conclusion, the use of metoclopramide in the postoperative period did not result in a quicker return of propulsive motility in the right or left colon as judged by the radio-opaque markers and serial abdominal radiographs.

Cholecystectomy

The physical and psychosocial effect of moderate osteoarthrosis of the knee.

To illustrate both physical and psychosocial effects of moderate gonarthrosis, clinical examination of patients has been supplemented with a questionnaire SIP (Sickness Impact Profile), to describe the functional health status. Sixty patients, 35 women and 25 men, mean age 63 years, with moderate medial osteoarthrosis of the knee and no symptoms from other joints, were included in the study. The mean BOA score and the self-selected walking speed were decreased in these patients compared to normal individuals. All patients graded pain during walking. The SIP revealed both physical and psychosocial changes in these patients with moderate gonarthrosis. Patients considered that their knee osteoarthrosis had great influence physically on ambulation, during recreation and pasttimes, during sleep and rest, and psychosocially on emotional behaviour. Significant correlations (p less than 0.01) were found between pain during walking and the psychosocial questions in the SIP, between the BOA score and questions in the SIP concerning the physical performance, and between self-selected walking speed and the physical questions. It is concluded that the SIP appears to be a measure with sufficient sensitivity to detect physical and psychosocial changes in patients with moderate osteoarthrosis of the knee. In clinical practice determination of self-selected walking speed and pain during walking will appropriately reflect general function.

Activities of Daily Living

Changes in walking ability after knee replacement.

Walking ability has been assessed in 20 patients before and after knee replacement. In 8, who had severe osteoarthritis, a bicompartmental ICLH (Imperial College-London Hospital) prosthesis was used; in 12, with moderate arthritis, the medial side of the joint was replaced by a unicompartmental Brigham prosthesis. Knee function was assessed with the British Orthopaedic Association assessment chart, and walking capacity by the oxygen cost of level walking. Before operation, the function was the same in both groups, but patients with moderate osteoarthritis could walk faster with a lower energy cost than those with severe osteoarthritis. One year after operation, all the patients had improved clinically, alignment had been corrected, and the knees were stable with a satisfactory range of movement. Walking speed was improved; pain and perceived exertion were reduced. The oxygen cost of walking was decreased in patients with a unicompartmental arthroplasty, but not in patients with a total replacement. An uneconomic walking pattern, acquired before operation in those with severe osteoarthritis, was considered to be the reason why walking efficiency was not improved. The walking ability in patients with moderate osteoarthritis recovered to almost normal after unicompartmental replacement.

Aged

Influence of transluminal angioplasty on the prostanoid release from the arterial wall.

Vasospasm and thrombosis complicate percutaneous transluminal angioplasty (PTA). To study if the release of the prostanoids PGI2 and TxA2 are affected by PTA, the following experiment was undertaken: In ten rabbits, the upper or lower half of the aorta was randomised either to transluminal angioplasty or control segment. After excision the segments were simultaneously but separately perfused ex vivo with Hank's balanced salt solution for five consecutive 15 min periods. Arachidonic acid was added to the perfusate for the last 15 min period. PGI2 and TxA2 were measured by radioimmunoassay in the perfusate as the stable degradation products 6-keto-PGF1 alpha and TxB2. After perfusion, the two aortic segments were prepared for scanning electron microscopy (SEM). Angioplasty decreased the basic release of PGI2 as well as the response to arachidonic acid. This is likely to be due to endothelial denudation as seen by SEM. The release of TxA2 from the vessel wall was very low and was not increased by dilatation. The influence of angioplasty on the prostanoid system may be of importance in the complications of vasospasm and thrombosis.

Angioplasty, Balloon

Walking efficiency after cemented and noncemented total hip arthroplasty.

Clinical evaluation using the Harris hip score has been supplemented with analysis of walking capacity before and after total hip arthroplasty (THA). Twenty patients were studied, ten of whom were treated with a cemented Charnley prosthesis and ten with a noncemented HP-Garches prosthesis. Tests were performed preoperatively and three, six, and 12 months postoperatively. Harris hip scores increased from a mean of 35 points preoperatively to 85 one year after surgery. Patients with a Charnley prosthesis had significantly higher scores than those with an HP-Garches prosthesis. The hip score did not differ between patients with uni- and bilateral disease. Mean maximum walking speed before surgery was 62 m/minute and increased to 80 m/minute one year after THA. The mean oxygen cost preoperatively was 0.267 ml/kg/m and decreased to 0.221 ml/kg/m one year after surgery. A weak correlation was found between differences in Harris hip scores and the corresponding oxygen cost. The onset of and the recovery from complications as well as differences between patients with uni- and bilateral diseases were reflected in changes in oxygen cost in contrast to clinical scores. The measurement of oxygen cost gave objective and valuable information about walking efficiency after THA.

Adult

Assessment of walking before and after unicompartmental knee arthroplasty. A comparison of different methods.

Walking ability was assessed in twenty patients before and one year after knee replacement with a cemented unicompartmental, Brigham prosthesis (mean age 63.4 years, nine women). All patients had moderate medial gonarthrosis. One year after surgery, knee function, assessed by the BOA score, self-selected and maximal walking speed as well as single limb support of the involved leg were increased. Pain and exertion during walking and oxygen cost of level walking were decreased at all measured speeds. Individual improvement in self-selected walking speed was correlated to improvement in maximal walking speed. Individual decrease of oxygen cost of level walking was correlated to decrease of perceived pain and exertion during walking. For clinical routine purpose clinical assessment, especially of pain, supplemented with measurement of self-selected walking speed were found to be sufficient for assessing effects of treatment such as unicompartmental prosthetic knee replacement.

Evaluation Studies as Topic

The increase in energy cost of walking with an immobilized knee or an unstable ankle.

The effect of an immobilized knee joint or of an unstable ankle joint on the walking capacity has been assessed with 50 walking tests in ten healthy subjects. The knee joint was immobilized in extension with a standard splint and an unstable ankle joint was simulated by a modified shoe. A significant decrease in convenient walking speed was found. The energy cost of walking as assessed by oxygen cost at a convenient speed was significantly increased both with an immobilized knee (23%) and with an unstable ankle (10%), compared to normal condition of the subjects. Implications for the management of patients with similar joint disorders are discussed.

Adult

Walking efficiency before and after long-term muscle stretch in patients with spastic paraparesis.

Eight patients with stationary, spastic paraparesis were treated with long-term stretch of the hip adductor muscles to improve walking ability. Gait pattern, walking speed and perceived exertion of walking were assessed. Walking efficiency was assessed before and after treatment by measuring oxygen consumption and blood lactate level. After treatment walking pattern was improved. Perceived exertion decreased but walking speed was unchanged. Oxygen cost directly after treatment was lower in six patients, unchanged in one and higher in one. In the patient with unchanged oxygen cost the blood lactate level decreased, probably due to decreased recruitment of fast, type II muscle fibres. Blood lactate was unchanged in the other patients. When assessing walking ability, measurement of energy cost was found to be a valuable supplement to clinical judgement, but in spastic patients both oxygen cost and blood lactate must be considered.

Aged

Determination of the oxygen cost of level walking.

We have developed devices and methods for the determination of the oxygen cost of level walking. Oxygen uptake is determined with an argon dilution method. The validity of this technique is demonstrated. Walking speed is recorded and controlled by means of a speedometer cart. The reproducibility of a convenient, self-selected walking speed and of a predetermined speed was studied. Coefficients of variation were below two per cent. Corresponding values of the oxygen cost of walking at a predetermined speed were three per cent or less up to an interval between tests of six months. We conclude that the proposed methods are suited for longitudinal studies of the oxygen cost of level walking, for example in patients with walking disorders.

Adult

Energy cost of level walking.

Devices and methods have been developed for determining speed and oxygen cost of level walking. Speed was recorded and controlled using a speedometer cart. Oxygen uptake was determined with an argon-dilution method using a mixing box mounted on a backpack. The method was found valid, coefficient of variation (cv) less than 2.1%, and to give excellent reproducibility with regard to self-selected speed, cv less than 1.9%, predetermined speed, cv less than 1.3%, and to oxygen cost, cv less than 3.2%. Artificially arranged immobility of the knee or instability of the ankle decreased comfortable walking speed 23% and 4% respectively. Oxygen cost increased 23% and 10% respectively. Stabilizing splints allowing some flexion could if possible be advocated, particularly with elderly patients. Patients with coxarthrosis were studied before and after THA. One year after surgery the Harris hip score had increased from 35 to 85 points and maximal walking speed from 62 to 80 m min-1 Oxygen cost had decreased from 0.267 to 0.221 ml kg-1m-1. The onset of and the recovery from complications, as well as differences between patients with uni- and bilateral diseases, were reflected in change in oxygen cost but not in clinical scoring. Patients with moderate gonarthrosis were studied before and after unicompartmental knee prosthetic replacement. No major benefit of preoperative physical therapy, mainly aiming to improve thigh muscle strength, was observed three months after surgery. One year after surgery the patients had improved in clinical score rating and recovered an almost normal walking ability. Measurements of pain and self-selected walking speed were found to be sufficient for assessing effects of treatment in these patients. Patients with severe gonarthrosis had improved in clinical score rating one year after TKR. Oxygen cost of walking was unchanged. An acquired uneconomic walking pattern was considered to be the reason for unimproved walking efficiency. Patients with spastic paraparesis were treated with long-term stretch of the hip adductor muscles. Either the oxygen cost or the blood lactate level was decreased during walking, indicating that even during moderate exercise blood lactate must be taken into consideration when energy cost is measured in these patients. Measurements of walking speed and oxygen cost of level walking were found to be useful objective parametres for assessing walking and to be a valuable supplement to clinical assessment of effects of treatment in patients with walking disorders.

Adult