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Biomedical subjects

L Aro

Publications and source records attributed to L Aro.

10 recordsLinked to original sources
PubMed2002

Effect of fertilisation on the potassium and radiocaesium distribution in tree stands (Pinus sylvestris L.) and peat on a pine mire.

This paper compares the effects of single and repeated fertilisation on the contents of potassium, 134Cs and 137Cs in different Scots pine compartments at different levels above ground and in the peat profile 9 years after the Chernobyl disaster. The material was collected from a ditch spacing and fertilisation experiment in Finland. Above a needle potassium concentration of 3.0 mg g(-1) in composed crown samples, 137Cs and 134Cs concentrations remained at about the same level but below that the values were higher on average. This potassium value corresponded to the potassium concentrations of 3.5-3.6 mg g(-1) in the current-year needles of two topmost whorls. The result indicates an enhanced radiocaesium uptake by pine trees under severe potassium deficiency. Fertilisation with potassium-containing fertilisers decreased the caesium uptake considerably. The inhibiting effect of fertilisation on caesium uptake by trees seemed to be fairly long lasting. Fertilisation had sped up the penetration of caesium downwards in the peat profile and its moving out of the active circulation of elements between soil and plants.

Cesium Radioisotopes↗
PubMed1995

Intra-arterial infusion of urokinase for acute, critical ischemia in the lower limb.

OBJECTIVE: To assess the value of intra-arterial urokinase infusion in the management of acute, critical ischemia of the lower limb. DESIGN: A prospective study. SETTING: A vascular surgery department within a university hospital. PATIENTS: Twenty-five consecutive patients with acute, critical ischemia of the lower limb, excluding those requiring immediate surgical intervention. Follow-up ranged from 1 to 18 months. INTERVENTION: Angiography followed by intra-arterial infusion of urokinase. MAIN OUTCOME MEASURES: Angiographic and clinical evidence of clot lysis and limb reperfusion, any surgical procedures required and final clinical outcome. RESULTS: Urokinase was technically successful in lysing clot in 19 patients: 7 required no further treatment; in 8 an underlying lesion was identified and repaired by either percutaneous angioplasty or surgery; in the remaining 4 patients, although the clot was lysed, the limbs remained ischemic and, since reconstruction was considered impossible, amputation was required. Two patients improved clinically with little angiographic evidence of clot lysis. A total of nine patients required amputation, seven of these as a "primary" procedure after urokinase infusion. There were four episodes of significant morbidity but no deaths. CONCLUSION: Urokinase has a place in the management of acute vascular occlusion of the lower limb, not only in treating the occlusion but, equally importantly, in facilitating identification of lesions that require surgical intervention.

Acute Disease↗
PubMed1991

Angiographic assessment of arterial outflow: predictive value of a new classification system.

A prospective study with 4 years of follow-up involving 127 consecutive symptomatic patients (60.6% with claudication, 39.4% with critical ischemia) who underwent aortobifemoral bypass surgery is described. A new grading system for the classification of arterial outflow was applied to determine its usefulness in predicting the outcome of surgery. Preoperative angiograms were numerically scored according to the arterial outflow status at the level of main segmental involvement. Higher scores corresponded to worse outflows. Outflow scores ranged between 1 and 10 with a mean of 3.6 +/- 0.24. The main comparison was between patients with scores of less than 5 (group A, n = 80) and patients with scores of 5 or more (group B, n = 47). Better outflow was associated with higher postoperative mean increases in the ankle-brachial index (ABI) (group A, 0.35 +/- 0.03; group B, 0.17 +/- 0.04; P less than .001) and transcutaneous oximetry (PtcO2) (group A, 15.4 mm Hg +/- 1.8; group B, 8.4 mm Hg +/- 3.0; P = .01). At 4-year follow-up, group A had higher cumulative rates of patency (98.3% vs 78.0%, P less than .001), symptomatic relief (84.0% vs 23.3%, P less than .001), and palliation (67.0% vs 19.9%, P less than .001). In conclusion, angiographic outflow, as evaluated with the system described, successfully helped predict postoperative increases in ABI and PtcO2 and the cumulative rates of graft patency, symptomatic relief, and palliation.

Angiography↗
PubMed1991

End-to-end versus end-to-side proximal anastomosis in aortobifemoral bypass surgery: does it matter?

The proximal anastomosis is still a controversial issue in vascular surgery. To compare end-to-end (EE) and end-to-side (ES) proximal anastomoses, the authors undertook a prospective study with 3 years' follow-up involving 120 patients, all of whom had aortobifemoral bypass. Fifty-one (42.5%) patients received the EE and 69 (57.5%) the ES anastomosis. The indications for surgery were abdominal aortic aneurysm (EE 51%, ES 0%; p less than 0.05), claudication (EE 33.3%, ES 53.6%; p less than 0.05) and critical ischemia (EE 15.7%, ES 46.4%; p less than 0.05). Patients in the EE group were older (mean age: EE 66.1 +/- 2.8 years, ES 60.9 +/- 1.1 years; p less than 0.05) and had more ischemic heart disease (EE 39.2%, ES 27.5%; p less than 0.05). Postoperative mean increases in transcutaneous oximetry (EE 15.5 +/- 3.9 mm Hg, ES 12.6 +/- 2.3 mm Hg) and the ankle-brachial pressure index (EE 0.34 +/- 0.05, ES 0.30 +/- 0.03) were not significantly different in the two groups. The operative death rate was higher for the EE group (EE 11.8%, ES 1.4%; p less than 0.05). Early thrombosis occurred in six patients, two in the EE group and four in the ES group. Computed tomography, done 1 year postoperatively in 95 patients, revealed two small (less than 3 cm) distal anastomotic dilatations, one in each group. At 3 years, cumulative survival and patency were similar in both groups. The authors conclude that the two anastomotic groups had very similar short- and long-term results, except for the operative death rate which was higher in the EE group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Comparison between transcutaneous oximetry and ankle-brachial pressure ratio in predicting runoff and outcome in patients who undergo aortobifemoral bypass.

In a prospective study, transcutaneous oxygen tension and ankle-brachial pressure index (ABI) were measured pre- and postoperatively in 105 symptomatic patients who underwent aortobifemoral bypass to compare the ability of these two measurements to reflect the runoff status, determined by angiography, and to predict the outcome of surgery. Postoperatively, ABI better reflected the runoff status. The difference in mean ABI for good versus poor runoff was 0.17 (p less than 0.05). The difference in mean transcutaneous oxygen tension below the knee for the two runoff categories was relatively small (6.3 mm Hg, p less than 0.05). Post-minus preoperative increases in ABI reflected the runoff status better than increases in transcutaneous oxygen tension. For good runoff, the mean ABI increase was 0.25 and for poor runoff it was only 0.14 (p less than 0.05). Runoff and transcutaneous oxygen tension were found to be the best predictors of symptomatic recurrence. Poor runoff was associated with a relative risk of 2.5 (p = 0.017) and transcutaneous oxygen pressure of less than 40 mm Hg implied a relative risk of 2.3 (p = 0.029) for symptomatic recurrence. The most important predictor of graft failure was preoperative ABI. Transcutaneous oxygen tension and the ankle-brachial pressure index appear to be valuable noninvasive techniques for vascular assessment, offering different insights and different predictions for management and prognosis of peripheral vascular disease.

Ankle↗
PubMed1988

Factors influencing results of femoropopliteal bypass operations for lower limb ischemia.

An ideal way to assess the effectiveness of femoropopliteal bypass procedures is to standardize patient- and surgeon-related variables by randomization. Through statistical analysis of multiple factors influencing patency, limb loss, death rate and hospital stay, the authors reviewed retrospectively 136 bypass procedures performed over 5 years. Variables that contributed significantly to the results were: preoperative symptoms (p = 0.037), graft material used (p = 0.016), age of the patient (p = 0.007), adequacy of runoff (p = 0.041) and smoking postoperatively (p = 0.013). Autogenous vein grafts were superior to prosthetic grafts, the cumulative patency at 5 years being 67.5% and 38.2% respectively. The authors emphasize that all patients needing vascular surgery should be advised to stop smoking, since in this study postoperative smoking increased the probability of limb loss and adversely affected the cumulative patency rate by interaction with other variables such as preoperative symptoms, graft material and age.

Adult↗
PubMedDate not supplied

Predictors of surgical outcome in patients undergoing aortobifemoral bypass reconstruction.

We report a prospective study with 2 years of follow-up including 105 consecutive symptomatic patients (58.1% claudication and 41.9% severe ischemia) undergoing aortobifemoral bypass surgery (ABF/BP). Proportional-hazards, stepwise regression, and life-table analyses were used to determine predictors of the following outcome criteria: graft patency, amputation, mortality, symptomatic recurrence, and palliation. The operative mortality was 5.7% and the 2-year cumulative mortality was 15.5%. Most deaths (61.5%) were cardiac-related. There were 3 predictors of mortality: the presence of more than 1 surgical risk factor (relative risk [RR] 6.2; p less than 0.001), advanced age (RR 2.9; p = 0.03) and the presence of ischemic heart disease (RR 1.5; p = 0.045). No patient required amputation. Early graft patency rate was 94.3% and the 2-year cumulative patency was 92.8%. The only predictor of graft failure was preoperative ankle/brachial index (ABI) of less than 0.4 (RR 6.1; p = 0.003). Early symptomatic relief was 98.1% and at 2 years it was 77.3%. There were 2 predictors of symptomatic recurrence: postoperative smoking (RR 2.4; p less than 0.001) and impaired runoff (RR 2.5; p = 0.017). Cumulative palliation was 87.6% at 1 month and 66.5% at 2 years postoperatively. There were 2 predictors of palliation: the presence of more than 1 surgical risk-factor (RR 1.8; p = 0.001) and postoperative transcutaneous oximetry (PtcO2) of less than 35 mmHg (RR 3.1; p = 0.04). We conclude that the best predictors of outcome in patients undergoing ABF/BP surgery were the number of preoperative risk factors, age, ischemic heart disease, ABI, PtcO2, postoperative smoking, and angiographic runoff.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Effects of cigarette smoking on outcome of femoral popliteal bypass for limb salvage.

A retrospective 5-year follow-up study of 83 femoral-popliteal bypass operations for severe ischemia (79 patients) is presented. There were no operative deaths. At one month, cumulative patency rates (CPR) and limb salvage rates (LSR) were 86.8% and 96.4% respectively. At 5 years, CPR, LSR and cumulative survival were 50%, 79.4% and 71.6% respectively. Post-operative smoking habits were strongly related to CPR and LSR. Smoking more than 5 cigarettes per day adversely affected CPR's. At 5 years, CPR of non-smokers and smokers of up to 5 cigarettes per day (47 patients) was 67.7% and for smokers of more than 5 cigarettes per day (32 patients) it was 44.7% (P less than 0.045). Smoking more than 15 cigarettes per day had an adverse effect on LSR's. Smokers of more than 15 cigarettes per day (17 patients) had a 5-year LSR of 58.5% compared with 89% for non-smokers and smokers of up to 15 cigarettes per day (62 patients) (P = 0.009). For 20 limbs requiring thrombectomy LSR was 100% at 1 year and 57.5% at 5 years. CPR's and LSR's were not significantly influenced by pre-operative smoking, diabetes, run off or level of distal anastomosis relative to the knee joint. Based on zero operative mortality and 96.4% limb salvage at 1 year, it is concluded that an aggressive approach toward revascularization for limb salvage is well justified in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗