Research based on existing clinical data and biospecimens: a systematic study of patients' opinions.

BACKGROUND: The aim of the present survey was to investigate newly discharged hospital patients' opinions on secondary use of their hospital data and biospecimens within the context of health research in general and, more specifically, on genetic research, data sharing across borders and cooperation with the health industry. METHODS: A paper questionnaire was sent to 1049 consecutive newly discharged hospital patients. RESULTS: The vast majority of the respondents preferred to be informed (passive consent) or to receive no notification at all for secondary research on their health data and biospecimens (88% and 91% for data and biospecimens respectively). The rest wanted to be asked for active consent. The same trend applied for the other aspects also. 81% of respondents were positive towards genetic research without active consent. 95% were positive towards cooperating with the health industry, and 90% were positive towards data sharing. CONCLUSIONS: These results suggest that hospital patients generally are very positive to secondary research and support the concept of opting out rather than opting in.

CaMKII and at least two unidentified kinases phosphorylate regulatory light chain in non-contracting cardiomyocytes.

In cardiac tissue, regulatory light chain (RLC, myosin light chain 2) phosphorylation (Ser(15)) leads to modulation of muscle contraction through Ca(2+)-sensitization. To elucidate which kinases that are involved in the basal (diastolic phase) RLC phosphorylation, we studied non-contracting adult rat cardiomyocytes. RLC kinase activities in situ were unmasked by maximally inhibiting myosin light chain phosphatase (MLCP) by calyculin A in the absence and presence of various protein kinase inhibitors. Surprisingly MLCK did not contribute to the phosphorylation of RLC in the non-contracting cardiomyocytes. Two kinase activity groups were revealed by different sensitivities to staurosporine. The fraction with the highest sensitivity to staurosporine was inhibited by KN-93, a selective CaMKII inhibitor, producing a 23% ± 7% reduction in RLC phosphorylation. Calmodulin antagonism (W7) and reduction in Ca(2+) (EGTA) combined with low concentration of staurosporine caused a larger decrease in RLC phosphorylation than staurosporine alone. These data strongly suggest that in addition to CaMKII, there is another Ca(2+)/calmodulin-dependent kinase and a Ca(2+)/calmodulin-independent kinase phosphorylating RLC. Thus the RLC phosphorylation seems to be ensured by redundant kinase activities.

CaMKII in addition to MLCK contributes to phosphorylation of regulatory light chain in cardiomyocytes.

The aim was to identify kinase activities involved in the phosphorylation of regulatory light chain (RLC) in situ in cardiomyocytes. In electrically stimulated rat cardiomyocytes, phosphatase inhibition by calyculin A unmasked kinase activities evoking an increase of phosphorylated RLC (P-RLC) from about 16% to about 80% after 80 min. The phosphorylation rate in cardiomyocytes was reduced by about 40% by the myosin light chain kinase (MLCK) inhibitor, ML-7. In rat ventricular muscle strips, calyculin A induced a positive inotropic effect that correlated with P-RLC levels. The inotropic effect and P-RLC elevation were abolished by ML-7 treatment. The kinase activities phosphorylating RLC in cardiomyocytes were reduced by about 60% by the non-selective kinase inhibitor staurosporine and by about 50% by the calmodulin antagonist W7. W7 eliminated the inhibitory effect of ML-7, suggesting that the cardiac MLCK is Ca(2+)/calmodulin (CaM)-dependent. The CaM-dependent kinase II (CaMKII) inhibitor KN-93 attenuated the calyculin A-induced RLC phosphorylation by about 40%, indicating a contribution from CaMKII. The residual phosphorylation in the presence of W7 indicated that also CaM-independent kinase activities might contribute. RLC phosphorylation was insensitive to protein kinase C inhibition. In conclusion, in addition to MLCK, CaMKII phosphorylates RLC in cardiomyocytes. Involvement of other kinases cannot be excluded.

Calculating reaction rate constants and estimating the efficacy of selective enzyme inhibitors.

The dynamic steady state of a pair of forward and backward enzymatic reactions is dependent on the balance between the enzymes catalyzing the reactions. By selectively inhibiting one or more of the enzymes involved, this balance is shifted into a new steady state, making it possible to calculate the reaction rate constants after measurement of the reactants. Ideally, the inhibitors should completely eliminate either reaction, but this is often not the case. Here we present and discuss a method for calculating the reaction rate constants and, thus, for evaluating the efficacy of one or more inhibitors when introduced to a forward-backward pair of enzymatic reactions.

Markers for endothelial activation during open heart surgery.

BACKGROUND: Reliable markers for endothelial activation are needed when studying biocompatibility of cardiopulmonary bypass. METHODS: Blood samples from 21 patients undergoing combined valve and coronary artery bypass surgery were collected before anesthesia (T1), after re-transfusion of blood from the heart-lung machine (T2), and on the first postoperative morning (T3). Concentrations of soluble markers were determined using sandwich enzyme-linked immunoadsorbent assay for sICAM-1, sVCAM-1, and sE-selectin. The sera were also used to stimulate human umbilical vein endothelial cells (HUVEC) in culture for 6 hours, in which activation was measured using cell enzyme immunoassay for mICAM-1 and mVCAM-1. RESULTS: The concentrations of sICAM-1 and sVCAM-1 increased during both measurement intervals (p < 0.05). The sICAM-1 T1 was 311.0 ng/mL (range, 271.0 to 350.7 ng/mL); the sICAM-1 T2 was 341.6 ng/mL (range, 322.0 to 422.0 ng/mL), and the sICAM-1 T3 was 400.2 ng/mL (range, 348.0 to 556.4 ng/mL; the sVCAM-1 T1 was 607.5 ng/mL (range, 497.8 to 813.8 ng/mL), the sVCAM-1 T2 was 755.3 ng/mL (range, 660.6 to 834.4 ng/mL), and the sVCAM-1 T3 was 1149.0 ng/mL (946.0 to 1406.0 ng/mL); whereas the sE-selectin increased from T1 to T3 (p < 0.01). Both the mICAM-1 (p < 0.002) and the mVCAM-1 (p < 0.005) increased on the human umbilical vein endothelial cells in culture after stimulation with the patient sera. The amounts of soluble markers in vivo were not correlated with the degree of endothelial activation in vitro, but were correlated with various operative variables including age, medication, and time of aortic cross-clamping. CONCLUSIONS: Endothelial cells were activated during cardiopulmonary bypass. The soluble adhesion molecules sICAM-1, sVCAM-1, and sE-selectin displayed different kinetics, rendering it difficult to determine a simple expression for the degree of endothelial cell activation. Clinically, sVCAM-1 seemed to be the best-suited marker for endothelial cell activation, because it was only associated with aortic cross-clamping and heparin and protamine doses, and it also showed the largest numerical changes.