Biomedical subjects
Publications and source records attributed to E Mattsson.
In Gram-positive bacterial shock, little is known about the sequence of events that controls the signalling of monocytes and macrophages that leads to the release of cytokines. Cell-wall components, such as peptidoglycan and teichoic acid, are clearly important in the activation of these cells, but exotoxins may also be involved.
To ascertain both physical and psychosocial effects of knee surgery in patients with 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 were included in the study. Sixteen patients had bilateral symptoms of gonarthrosis. Patients considered that their knee ostheoarthrosis had great influence physically as well as psychosocially. All patients graded pain during walking. Thirty-five patients were treated with a medial unicompartmental knee endoprosthesis and 25 patients were treated with a valgus osteotomy. After surgery the mean values for all measured variables were improved. Superior results were found among patients with unilateral disease compared to patients with bilateral disease. No differences in results were found between patients given different surgical treatments. The physical and psychosocial influence of osteoarthrosis of the knee were more pronounced in women. 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.
Explore the source record for details and available documents.
Peptidoglycan from a Staphylococcus epidermidis strain, isolated from a patient with septicemia, was preincubated with human serum. This mixture was then investigated for its potency to induce tumor necrosis factor (TNF) secretion by human blood monocytes. TNF was measured in the supernatants by using a bioassay and/or an enzyme-linked immunosorbent assay specific for TNF alpha (TNF-alpha). Although earlier studies indicated that staphylococcal peptidoglycan alone is a relatively poor stimulator of TNF-alpha production, the present study shows that human serum highly potentiates peptidoglycan-induced TNF-alpha release by human monocytes. In the presence of serum and in the low-dose range, peptidoglycan was almost as potent as endotoxin. At high peptidoglycan concentrations, monocytes showed an extremely high TNF-alpha response, but again only in the presence of serum. At low peptidoglycan doses, the stimulatory effect of serum was abrogated by heat treatment or depleting serum of complement components C1 and C3/C4, which suggests a role for the classical complement pathway. At high doses of peptidoglycan, the serum stimulatory effect depended mainly on immunoglobulin G.
The purpose of this study was to investigate the relationship between clinical symptoms, static radiographic measurements, and of load distribution during walking at the knee, in 54 patients with moderate medial osteoarthrosis of the knee. Varus deformity of the knee was assessed from static radiographic measurements as the Hip-Knee-Ankle (HKA) angle, and range of moments at the knee in the frontal plane were assessed using a Kistler force plate system. No correlations between clinical symptoms and radiographic parameters or moments at the knee were found. The adduction moment in mid stance was more important than the peak adduction moment in differentiating between patients and normal controls. The amplitude of the peak adduction moment depended on the sex and body mass of the patients, while the amplitude of the mid stance adduction moment depended on body mass and the varus deformity of the knee. There was a weak correlation between the peak adduction moment and the HKA-angle (r = 0.32, P < 0.05) and there was a moderately high correlation between the peak adduction moment in mid stance, i.e 50% of the stance phase, and the HKA angle (r = 0.46, P < 0.001) even after normalization of the mid stance moment to body mass. Accordingly, 20% of the medio-lateral knee load in mid stance during walking could be explained by the varus deformity of the osteoarthrotic knee in our patients.
Explore the source record for details and available documents.
The present study was undertaken in 43 rabbits to determine whether endothelin or potassium are mediating substances for vasospasm originating from the vessel wall after balloon angioplasty. Thirteen aortic segments were dilated and the luminal surfaces perfused. These perfusates were investigated for their vasomotor action per se and analyzed for their concentrations of potassium and endothelin-like immunoreactivity (ET-LI). The perfusates from angioplasty segments caused a contraction of 2.4 +/- 0.8 mN, while the perfusates from control segments only resulted in a contraction of 0.4 +/- 0.2 mN, (P = 0.004). There was no difference in the concentrations of potassium or ET-LI in the perfusates. Thirty aortic segments were used to measure the concentration of ET-LI in extractions of untreated, control, and angioplasty specimens. There was no statistically significant difference between the groups. Scanning electron microscopy demonstrated the angioplasty segments to be denuded of their endothelium. In conclusion, perfusates from rabbit aortic segments treated by angioplasty in vitro have a strong vasoconstricting effect, for which neither endothelin nor potassium seems to be responsible.
A transit time flowmeter, Transonic TC101 (Transonic Inc., USA) has been evaluated to study volume flow. Two flow probes, 4 and 6 mm, were used. The experiments were carried out in vivo on the carotid arteries (n = 16) in sheep and in vitro against a pre calibrated rotational pump. Exsanguination measurements, n = 32, were used for the calculation of the error of measurement in vivo. The error of measurement in vitro was calculated on 11 different flow rates from 0 to 150 ml min-1. The variability in vivo was evaluated using data from 10, 30 s measurement periods with a 30 s pause between measurements. The variability in vitro was evaluated at three flow rates (46, 78, and 113 ml min-1). Five 1-min measurements with a 1-min pause between measurements were made. The error of measurement in vivo was 12.05% and in vitro 5.50% (4 mm probe) and 14.90% (6 mm probe). In vivo the variability was between 1.1 and 4.4% and in vitro between 1.5 and 11.2%. The correlation coefficients between the flowmeter on the one hand and exsanguination and the rotational pump on the other were 0.99, 0.99 (4 mm probe) and 0.98 (6 mm probe). It is concluded that the flowmeter has a small variability and error of measurement both in vivo and in vitro.
Cytokines play a major role in the pathophysiology of septic shock. In this study, human peripheral blood monocytes were stimulated with peptidoglycan and teichoic acid, purified from a strain of Staphylococcus epidermidis. Polymyxin B (PM-B) was added to avoid the effects of possible contamination with endotoxin. Tumour necrosis factor-alpha (TNF), interleukin-1 beta (IL-1), and interleukin-6 (IL-6) in the supernates were measured by enzyme-linked immunosorbent assays. Peptidoglycan and teichoic acid induced TNF, IL-1, and IL-6 in a concentration-dependent manner. Teichoic acid was a weaker inducer than peptidoglycan, especially for IL-1. Lipopolysaccharide from an E. coli strain was used as a control, being 100-1000 times more potent than peptidoglycan and teichoic acid.
The role of cytokines in gram-positive infections is still relatively poorly defined. The purpose of this study was to establish whether or not intact staphylococci and purified peptidoglycans and peptidoglycan components derived from staphylococci are capable of stimulating the release of tumor necrosis factor (TNF) by human monocytes. We show here that intact staphylococci and purified peptidoglycans, isolated from three Staphylococcus epidermidis and three S. aureus strains, were indeed able to induce secretion of TNF by human monocytes in a concentration-dependent fashion. TNF release was detected by both enzyme immunoassay and the L929 fibroblast bioassay. In the enzyme immunoassay, a minimal concentration of peptidoglycan of 1 micrograms/ml was required to detect TNF release by monocytes, whereas in the bioassay a peptidoglycan concentration of 10 micrograms/ml was needed to detect a similar amount of TNF release. Peptidoglycan components such as the stem peptide, tetra- and pentaglycine, and muramyl dipeptide were unable to induce TNF release from human monocytes.
Aortic segments from 47 New Zealand rabbits were used, of which 14 were denuded of endothelium. Balloon angioplasty was performed on the aortic segments in vitro. The inner surfaces were perfused and the perfusates then given to vessel segments with or without endothelium. The contraction evoked was then counteracted by adding either vasoactive intestinal polypeptide (VIP), substance P (SP), acetylcholine (ACh), or nitroglycerin (NTG) in increasing concentrations. Perfusates from aortic segments with or without endothelium and previously treated with angioplasty induced vasoconstriction of similar magnitude in the segments used for vasomotor investigation irrespective of whether the endothelium was intact in these or not. Endothelial dependent dilators (ACh, SP) did not counteract the contraction whereas endothelial independent dilators did (NTG, VIP). Neither the induction nor the reversal of vessel wall induced vasoconstriction after balloon angioplasty seems to depend on the presence of endothelial cells.
OBJECTIVE: To evaluate the effect of angioplasty on the production of prostanoids in atherosclerotic vessels in rabbits. DESIGN: Open study. MATERIAL: 38 Rabbits. INTERVENTIONS: Rabbits in group A (n = 12) were given a cholesterol rich diet (2%) for 10 weeks, and then treated with angioplasty. Rabbits in group B (n = 11) were given a cholesterol rich diet for 10 weeks, and then returned to a normal diet until the serum cholesterol concentration returned to the reference range (a further 12 weeks). Rabbits in group C (n = 15) were anaesthetised, and a 3 mm balloon was introduced into the right femoral artery, fed 20 cm proximally, inflated, and pulled twice along the aorta; the animals were then given a cholesterol rich diet (2%) for eight weeks, and treated with angioplasty. MAIN OUTCOME MEASURES: Serum cholesterol concentrations were measured once a week. Prostacyclin and thromboxane were measured as 6-keto prostaglandin F1 alpha and thromboxane B2 in both treated and control segments of aorta. RESULTS: 15 Rabbits died while atherosclerosis was being induced, leaving 23 for analysis. Angioplasty reduced the amounts of prostanoids released in animals in which the atherosclerosis had been induced by diet alone. When endothelial injury and diet were used together, there was no difference between the treated and control segments in the amounts of prostanoids released. CONCLUSION: These findings could be of use in the comparison of methods used to induce atherosclerosis, and in the study of the mechanisms of thrombosis after transluminal angioplasty.
The aim of this study was to analyse gait improvement one year after high tibial osteotomy and unicompartmental knee arthroplasty in patients with strictly unilateral osteoarthrosis of the medial compartment of the knee. Thirty-six patients, 18 men and 18 women, received a unicompartmental Brigham knee prosthesis and 23 patients, 10 men and 13 women, were operated on with a high tibial osteotomy. Clinical and radiographical assessments were supplemented by a functional test, measurements of thigh muscle torque with a Cybex II dynamometer and analysis on a force plate walkway with electrogoniometers. All patients were assessed prior to, and one year after surgery. Both groups showed overall clinical improvement, as assessed by the British Orthopaedic Association (BOA) score. Pain during walking decreased. The range of knee flexion remained unchanged. The ability to ascend and descend steps improved. The isokinetic thigh muscle torque remained unchanged. In the prosthetic group free walking speed increased from 1.03 to 1.09 m/s (p < 0.001). Step frequency and step length increased (p < 0.001). Single stance phase ratio increased from 0.96 to 0.99 (p < 0.01), indicating a more symmetrical gait. Double stance phase (% gait cycle) of both legs decreased (p < 0.001), indicating a faster transfer of weight during walking. In the osteotomy group, free walking speed did not increase. Step length of the uninvolved leg increased (p < 0.01). Double stance phase of the involved leg decreased (p < 0.001) and double stance phase of the uninvolved leg decreased (p < 0.01). Both groups improved after surgery and there was no difference between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this study was to analyse the effects of preoperative physiotherapy on pain and function in 39 patients scheduled for unicompartmental prosthetic knee replacement. Nineteen patients were selected at random to receive preoperative physiotherapy. The control group received no preoperative therapy. Evaluations were performed 3 months prior to surgery, immediately before and 3 months after operation. Evaluations included: Clinical assessment, measurements of the knee muscle strength, self-selected walking speed and the oxygen cost of walking. Three months before surgery the patients in both groups had similar types and levels of problems. Before surgery patients who had received physiotherapy showed slight improvements in pain, perceived stability of the knee during walking, and faster self-selected and maximal walking speeds compared to the control group, but were unchanged in muscle strength, ROM, and oxygen cost. Three months after surgery pain was significantly decreased in all patients, however, no significant differences were found between the two groups for any variable except muscle strength. This was unchanged compared to preoperative values for patients of the control group while patients who received preoperative physiotherapy showed a decrease in strength. In summary, this study did not disclose any major benefit from the program of preoperative physiotherapy tested.
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)
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.
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.
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.