Variable expression of tenascin‐C,osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung

Kaarteenaho R, Sormunen R, Pääkkö P. Variable expression of tenascin‐C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung. APMIS 2010; 118: 91–100. The aim of this study was to analyse the expression of tenascin‐C, osteopontin and fibronectin in inflammatory myofibroblastic tumour of the lung, which is a rare tumour of unknown aetiology. Nine patients with an inflammatory myofibroblastic tumour of lung were studied by immunohistochemistry for the presence of tenascin‐C, osteopontin, fibronectin and alpha‐smooth muscle actin, which is a common marker for myofibroblasts. The ultrastructure of myofibroblasts was confirmed by transmission electron microscopy. The expression of tenascin‐C, osteopontin, fibronectin and alpha‐smooth muscle actin was also studied by immunoelectron microscopy. All cases displayed all of the studied extracellular matrix proteins and also alpha‐smooth muscle actin‐positive spindle‐shaped fibroblastic cells that were undoubtedly myofibroblasts. The immunoelectron microscopic studies demonstrated labelling for alpha‐smooth muscle actin in intracellular filament bundles within myofibroblasts, for fibronectin in the extracellular filaments of the fibronexus and for tenascin‐C extracellularly often adjacent to myofibroblasts. Labels for osteopontin were observed within myofibroblasts and plasma cells. These results demonstrate that tenascin‐C, osteopontin and fibronectin were expressed in all three kinds of subtypes of inflammatory myofibroblastic tumours of the lung and further, variable amounts of myofibroblasts could be observed by light and transmission electron microscopy as well as by immunoelectron microscopic techniques.     

TOLERABILITY AND EFFICACY OF A SLOW-RELEASE INDOMETHACIN TABLET IN ANKYLOSING SPONDYLITIS

The efficacy and tolerability of a new formulation of slow-releaseindomethacin tablet was compared in a double-blind cross-overmanner with a conventional indomethacin capsule in 30 patientswith ankylosing spondylitis. Gastrointestinal side-effects anddizziness were less frequent during the slow-release tabletperiod than during the capsule period. KEY WORDS: Ankylosing spondylitis, Indomethacin, Tolerability, Slow-release tablet ^*This formulation of indomethacin is not available in the UK—Ed.     

Prestretch potentiation of human skeletal muscle during ballistic movement

The conditions associated prior to and during the transition from prestretch to shortering may have considerable influence on the final performance of muscle. In the present study male subjects of good physical condition performed vertical jumps on the force-platform with and without preliminary counter movement. In the counter movement jump (CMJ) the amplitude of the knee bending, velocity of the prestretch and the force attained at end of prestretch were the primary parameters of interest. In addition the coupling time indicating the transition from the eccentric (prestretch) phase to the concentric phase was recorded from the angular displacement and reaction force curves. In the final calculation the mechanical performance parameters of CMJ were always compared with those of the jumps performed without counter movement. The results indicated in general first that CMJ enhanced the average concentric force and average mechanical power by 423 N (66%) and 1158 W (81%), respectively. This potentiation effect was the higher the higher was the force at end of prestretch (p<0.001). Similarly, the prestretch speed (p<0.001) and short coupling time (p<0.01) were associated with enhanced performance during the concentric phase. The average coupling time was 23 ms. The results are interpreted through changes in the prestretch conditions to modify the acto-myosin cross-bridge formation so that the storage and utilization of elastic energy is associated with high prestretch speed, high eccentric force and short coupling time. The role of the reflex potentiation is also suggested as additional enhancement of the final performance.     

Vasoactive Peptide Release in Relation to Hemodynamic and Metabolic Changes During Rapid Ventricular Pacing

Plasma atrial natriuretic peptide (ANP) concentration increases during ventricular arrhythmias and rapid ventricular pacing but less is known about plasma brain natriuretic peptide (BNP) and endothelin (ET-1). In the present study concentrations of ANP, the amino terminal part of the proANP (NT-proANP), BNP, and ET-1 were measured in the coronary sinus and femoral artery before and at the end of rapid ventricular pacing in 15 patients with coronary arterial disease. The changes were compared with the changes in mean arterial blood pressure, pulmonary capillary wedge pressure (PCWP), transcardiac differences in pH, pCO2, lactate, and norepinephrine. There was an increase in PCWP and a transient decrease in blood pressure after initiation of pacing. Pacing caused a decrease in ST-segment, transcardiac difference of norepinephrine, lactate extraction, pCO2 difference, and an increase in pH difference. Concentration of ANP in the coronary sinus and femoral artery and its transcardiac difference increased during pacing (P < 0.001), whereas changes in NT-proANP were small and BNP and ET-1 levels remained unchanged. The change in transcardiac ANP difference correlated with the change in lactate (r = 0.53, P < 0.05) but not that of norepinephrine, PCWP, or blood pressure. The results show that the plasma concentration of ANP increases more than that of NT-proANP during rapid ventricular pacing. Ischemia-induced release of ANP and its diminished elimination may contribute to the increased plasma ANP level.     

Effects of fatigue on isometric force- and relaxation-time characteristics in human muscle

Effects of intermittent one leg isometric fatigue on maximal isometric force, force production, relaxation and blood lactate were studied using 29 male students as subjects. The relative changes of variables during fatigue and recovery were intercorrelated together with muscle structure variables, which were determined using needle biopsy technique. Maximal force decreased, force production and relaxation became slower and muscle lactate increased during fatigue. Change of maximal force, force production and lactate during fatigue as well as recovery of maximal force and lactate after fatigue were correlated significantly to muscle fiber distribution. Fatiguability of the force-time characteristics was therefore influenced by the differences in the metabolic profiles of the individual muscle fibers. However, ability to relax the muscle quickly was not observed to be dependent on muscle structure. This suggests that different fatigue mechanisms might be present in relaxation than in force production.     

Activities of post-heparin plasma lipoprotein lipase and hepatic lipase during pregnancy and lactation

Abstract. The marked increase in serum triglyceride (TG) in women during pregnancy and lactation was studied. Hormone concentrations, changes in activities of post-heparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) were correlated with plasma lipoprotein concentrations. The plasma concentrations of free oestriol, oestradiol and prolactin were estimated, and analyses of very low density lipoprotein triacylgly-cerol (VLDL-TG), and low density (LDL-Chol) and high density lipoprotein cholesterol (HDL-Chol) were performed. Post-heparin plasma LPL and H L activities were selectively measured by an immunochemical method. LPL activity was unaltered during pregnancy and immediately after parturition, values ranging from ll.5 ± l.9 to 12.9 ± l.2 µimol free fatty acid (FFA)/ml/h. Eight weeks after parturition LPL activity was increased to 22.1 ± 5.5 µmiol FFA/ml/h. There was a significant negative correlation between LPL activity and VLDL-TG concentration in plasma (r= -0.58; P < 0.01). The mean HL activity was 7.8 ± 1.9 and 6.4 ± 1.5 µxmol FFA/ml/h during mid-and late pregnancy, respectively, and after parturition the activity increased from 13.5 ± 30 to 32.4 ± 7.5 µol FFA/ml/h in samples taken 3 days and 8 weeks after parturition. In spite of the changes in HL activity no correlation was found between HL activity and the concentrations of plasma lipoprotein lipids. HL activity bore a significant negative correlation with plasma free oestriol (r= -0.46; P < 005), oestradiol (r= -0.57; P < 001) and prolactin (r= -0.76; P < 0001) levels. Since oestrogens are known to reduce HL activity, the increase in plasma HL activity during the postpartum period may be caused by the concomitant fall of plasma oestrogen levels. Plasma HDL-Chol and LDL-Chol did not vary despite the considerable changes in oestrogen, prolactin and VLDL-TG levels and HL activity. The increase in plasma VLDL-TG concentration during pregnancy occurred concomitantly with the increase in unconjugated plasma oestriol, oestradiol and prolactin levels, but it was not associated with any changes in LPL activity. In the second trimester, LPL activity was 12.9 ± 116 (mean ± SEM) µmol FFA/ml/h, which is about 50% of the activity reported for the corresponding age group of nonpregnant women. Thus, lowered removal capacity by extrahepatic tissues is likely to cause the moderate rise in the VLDL-TG (0.84 ± 0–17 mmol l^-1, mean ± SEM) in the second trimester. At the 38th week of gestation LPL activity was similar to the level seen in midpregnancy, but still the VLDL-TG was greatly increased (2.85 ± 0.66 mmol l^-1, mean ± SEM). Both oestradiol and prolactin bore a significant positive correlation with the levels of plasma VLDL-TG (r= 0.52; P < 001 and r= 0.42; P < 0.05, respectively). The present data suggests that the massive pregnancy associated hypertriglyceridaemia is not caused solely by impaired removal of VLDL-TG by extrahepatic LPL, but is mainly due to the increased synthesis of VLDL-TG caused by the increased levels of plasma oestrogens.