Cardiopulmonary effects of iloprost in experimental acute lung injury

Iloprost, a prostacyclin analogue with a prolonged plasma half-life has beneficial effects in chronic pulmonary hypertension, whereas the effects in acute lung injury (ALI) are unknown. The present study was performed to evaluate the cardiopulmonary effects of iloprost in experimental ALI. ALI was induced in 18 pigs by repeated lung lavage. Animals were randomised to controls, i.v. or inhaled iloprost for 15 min. Haemodynamics, gas exchange and ventilation-perfusion distribution were measured at the end of iloprost application and after 1 and 2 h. As a short-term effect, both i.v. and inhaled iloprost significantly decreased pulmonary artery pressure without major effects on gas exchange or systemic haemodynamics. After 1 and 2 h, a reduction of pulmonary hypertension was no longer present. As a long-term effect, inhaled, but not i.v., iloprost decreased pulmonary shunt and significantly improved gas exchange after 1 and 2 h. In conclusion, the single application of iloprost revealed short-term pulmonary vasodilation without other major cardiopulmonary effects. However, inhaled iloprost improved gas exchange due to a decrease of pulmonary shunt as a long-term effect, possibly as a result of a reduction of lung oedema formation.

[Psychological satiation: a new experimental study of an old construct]

The present experiment on the phenomenon of psychic satiation expands on the work of Karsten (1928) and Lewin (1928). Psychic satiation denotes a loss of intrinsic motivation when the same action is performed repeatedly. Although many studies have shown the high theoretical and practical relevance of this phenomenon, the conditions which lead to or reinforce psychic satiation have rarely been investigated empirically. Based on the concept of psychic satiation as formulated by Karsten and Lewin and refined by Schulz-Hardt, Rott, Meinken, and Frey (in press), we predicted that psychic satiation will increase if the task does not lend itself to being carried out "peripherally" (i.e., as an almost unconscious incidental action) and if it has high personal relevance. These predictions were investigated in an experiment with 66 high-school students who performed different versions of the "Konzentrations-Leistungs-Test" (concentration-performance-test, KLT). The results are largely in line with our predictions. In addition, the results indicate that the relation between satiation and performance is moderated by personal relevance and the induced task characteristic.

[Endoluminal stent prosthesis implantation in thoracic aneurysm of the descending aorta--a case report]

We report on a 72-year old male with a large aneurysm of descending thoracic aorta which was treated by implantation of a Dacron-covered self-expanding Nitinol stent graft (Talent, HOSMED). The patient was unfit for surgical aneurysm resection because of generalised atherosclerosis and cardiomyopathy. We think that stent implantation for descending thoracic aortic aneurysms is an attractive alternative to surgical aneurysm resection, especially in patients with enhanced operative risk. However, further experience, and especially long term-results, are required before more widespread application of intra-luminal stent implantation in the management of thoracic aortic aneurysms can be recommended.

Effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease

This double-blinded, randomized, placebo-controlled study was designed to investigate the acute effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease (PAOD). Thirty men with PAOD were treated with a single dose of 5 mg felodipine or placebo. Systolic blood pressure (SBP), Doppler ankle pressure (DAP), calf blood flow (CBF) by venous occlusion plethysmography and calf transcutaneous oxygen tension (tcpO2) were measured during a cycle ergometry. Felodipine reduced SBP significantly (from 149 to 136 mmHg, p < 0.05), while placebo did not. DAP increased slightly but not significantly in both groups. The pressure gradient between SBP and DAP fell significantly in the felodipine group (60 vs 39 mmHg, p < 0.01) but not in the placebo group (59 vs 56 mmHg). There was a trend for lower velocity in tcpO2 decrease during the stress test and higher velocity of tcpO2 increase during recovery from exercise in the felodipine group although the differences between both groups were not significant. In the felodipine group, CBF increased by 35.6% (p < 0.05) whereas it did not change in the placebo group. In conclusion, while lowering SBP, felodipine increased slightly, or at least maintained, the blood supply to the calves in PAOD patients, which probably results from reducing collateral vascular resistance.

Molecular basis of artifacts in the detection of telomerase activity and a modified primer for a more robust 'TRAP' assay

Human somatic cells have essentially no telomerase activity. Telomerase is linked to tumor genesis and is a valuable marker for malignant growth. Extreme paucity of the enzyme neccessitated development of a PCR-based assay, 'telomeric repeat amplification protocol' (TRAP). Unfortunately, this method is not without difficulties. Amplification products are not related to the size of the amplified telomerase products. Furthermore, false positive results can occur, and careful control of reaction conditions is crucial. We analyzed in detail the molecular basis of artifacts. Based on these data, reverse PCR primer was changed and both problems in the TRAP assay were eliminated.

Measurement of 24,25 dihydroxyvitamin D in sera of neonates and children

Serum concentration of 25OHD and 24,25(OH)2D were measured in lipid extracts of serum by competitive radioassay following separation of the metabolits by Sephadex LH-20 column chromatography. The concentration of 24,25(OH)2D in children and adolescents (3.3 +/- 1.3 SD ng/ml) was significantly greater (P less than 0.01) than the levels recorded in neonates (1.8 +/- 0.6 ng/ml), and was approximately one-tenth the concentration of 25OHD in the two populations (children 35.2 +/- 9.2 ng/ml; neonates 14.4 +/- 3.4 ng/ml, P less than 0.01). Although 24,25(OH)2D is present in significant quantities in the sera of children and adolescents, its metabolic function remains unknown at present.