'We get to learn as we move': effects and feasibility of lesson-integrated physical activity in a Swedish primary school

BACKGROUND

Physical activity (PA) promotes health in adults as well as children. At the same time, a large proportion of children do not meet the recommendations for PA, and more school-based efforts to increase PA are needed. This study investigates the effectiveness and feasibility of lesson-integrated PA in a Swedish primary school.

METHODS

We evaluate a new method called 'Physical Activity and Lesson in Combination' (abbreviated FALK in Swedish) using a mixed methods approach; a quasi-experimental study followed by qualitative interviews. Two schools participated in the study, one constituting the intervention group (I-school, n = 83) and the other the control group (C-school, n = 81). In addition to regular physical education, the I-school had three 30-minute FALK lessons each week. A total of 164 students aged 7-9 years wore pedometers for a whole week, four times over two semesters, and the number of steps per day (SPD) and the proportion of students with < 10,000 SPD were compared. Statistical differences between the schools were tested with ANOVA, Chi2, t-tests, and ANCOVA. Interviews with students (n = 17), parents (n = 9) and teachers (n = 9) were conducted and analysed using qualitative content analysis.

RESULTS

The results show that FALK led to the I-school getting more SPD and fewer students with < 10,000 SPD. Also, FALK was experienced as a positive, clear, and flexible method, simultaneously encouraging PA and learning. Challenges experienced concerned the teachers' work situation, time, finding suitable learning activities, outdoor school environment changes, and extreme weather conditions.

CONCLUSIONS

This study indicates that FALK has the desired effects on PA and is a feasible method of integrating PA into theoretical teaching. We conclude that FALK is worth testing at more schools, given that implementation and sustainment of FALK considers both general enablers and barriers, as well as context-specific factors at the individual school.

Drivers of changing urban flood risk: A framework for action

This study focuses on drivers for changing urban flood risk. We suggest a framework for guiding climate change adaptation action concerning flood risk and manageability in cities. The identified key drivers of changing flood hazard and vulnerability are used to provide an overview of each driver's impact on flood risk and manageability at the city level. We find that identified drivers for urban flood risk can be grouped in three different priority areas with different time horizon. The first group has high impact but is manageable at city level. Typical drivers in this group are related to the physical environment such as decreasing permeability and unresponsive engineering. The second group of drivers is represented by public awareness and individual willingness to participate and urbanization and urban sprawl. These drivers may be important and are manageable for the cities and they involve both short-term and long-term measures. The third group of drivers is related to policy and long-term changes. This group is represented by economic growth and increasing values at risk, climate change, and increasing complexity of society. They have all high impact but low manageability. Managing these drivers needs to be done in a longer time perspective, e.g., by developing long-term policies and exchange of ideas.

Prevention of Platelet Adhesion and Aggregation by a Glutardialdehyde-Stabilized Heparin Surface

A stable heparinized surface was prepared by sequential treatment of polyethylene with water solutions of hexadecylamine hydrochloride, heparin and glutardialdehyde. In order to explain the “non-thrombogenic” properties of this surface, it was evaluated with regard to prevention of platelet adhesion and aggregation.

Human heparinized blood (2 and 10 IU/ml) with 51Cr-labelled autologous platelets was rotated for 60 minutes in untreated and heparin-treated circular tubings. The surface area/blood volume ratio was varied and an air-blood interface was present. In untreated tubings, platelet adhesion and aggregation increased in proportion to the size of the surface area/blood volume ratio, irrespective of the heparin concentrations of the blood. In the heparin-treated tubings, there was no measurable platelet adhesion to the surface and no platelet aggregation in the blood. The difference between the heparinized and the untreated surfaces with regard to platelet adhesion was discernible even after 10 minutes storage of stagnant blood.

It is concluded that platelet adhesion and aggregation induced by exposure of blood to a foreign surface in an in vitro experimental model can be prevented by a stable heparin coating of the surface.

Managing workplace health promotion in municipal organizations: The perspective of senior managers

BACKGROUND

Previous research indicates that companies manage workplace health in various ways, but more in-depth empirical knowledge of how workplace health promotion (WHP) is managed in public sector organizations is needed.

OBJECTIVE

The aim of this study was to explore how WHP is managed and incorporated into the general management system in two large Swedish municipal organizations.

METHODS

A qualitative descriptive approach was used. Fourteen senior managers were purposefully selected and interviewed using semi-structured interviews. Documents were used as supplementary data. All data were analysed using qualitative content analysis.

RESULTS

The management of WHP was described as a set of components that together contribute to the organization's capacity for WHP. The informants described WHP as dominated by fitness programmes and as following a problem-solving cycle, in which the annual employee survey emerged as an important managerial tool. Achieving feasible WHP measures and appropriate follow-ups were described as challenges. The provision of leadership competence for WHP and use of supportive resources were described as additional components.

CONCLUSIONS

The WHP management approach needs to be broadened to include work environment and organizational factors. Further integration with occupational health and safety and the general management system in the organizations is also needed.

Effects of Femoral Arteriography and Low Osmolar Contrast Agents on Renal Function

The contrast media-induced renal effects of 3 different low osmolar contrast agents were prospectively evaluated with creatinine, beta-2-microglobulin, and urea in serum before and after femoral arteriography in 110 consecutive patients. Forty-two patients (38%) had at least one of the 2 major risk factors for contrast media-induced nephropathy; diabetes mellitus or renal dysfunction. Six patients (5%) had both risk factors. There were statistically significant increases of S-creatinine (6.5%, p < 0.001) and S-beta-2-microglobulin (7.4%, p < 0.001) but no increase of S-urea, in the total patient material. This effect was independent of preexaminatory renal function, the presence of diabetes mellitus and type of low osmolar contrast agent used in these patients who were properly hydrated before the examination. The amount of administered contrast medium did not correlate with the degree of contrast agent-induced renal function impairment.

Drug screen in patient cells suggests quinacrine to be repositioned for treatment of acute myeloid leukemia

To find drugs suitable for repositioning for use against leukemia, samples from patients with chronic lymphocytic, acute myeloid and lymphocytic leukemias as well as peripheral blood mononuclear cells (PBMC) were tested in response to 1266 compounds from the LOPAC¹²⁸⁰ library (Sigma). Twenty-five compounds were defined as hits with activity in all leukemia subgroups (<50% cell survival compared with control) at 10 μM drug concentration. Only one of these compounds, quinacrine, showed low activity in normal PBMCs and was therefore selected for further preclinical evaluation. Mining the NCI-60 and the NextBio databases demonstrated leukemia sensitivity and the ability of quinacrine to reverse myeloid leukemia gene expression. Mechanistic exploration was performed using the NextBio bioinformatic software using gene expression analysis of drug exposed acute myeloid leukemia cultures (HL-60) in the database. Analysis of gene enrichment and drug correlations revealed strong connections to ribosomal biogenesis nucleoli and translation initiation. The highest drug–drug correlation was to ellipticine, a known RNA polymerase I inhibitor. These results were validated by additional gene expression analysis performed in-house. Quinacrine induced early inhibition of protein synthesis supporting these predictions. The results suggest that quinacrine have repositioning potential for treatment of acute myeloid leukemia by targeting of ribosomal biogenesis.

Membranoproliferative glomerulonephritis and inflammatory pseudotumour of the spleen

Inflammatory pseudotumour is a rare condition that can affect various organs. The clinical and histologic appearance of the pseudotumour may mimic haematological, lymphoproliferative, paraneoplastic or malignant processes. A previously healthy 39-year-old man presented with nephrotic syndrome. He had a history of headaches, nausea and swollen ankles. Computed tomography of the abdomen revealed a 6-cm mass in the spleen. Following a renal biopsy, a diagnosis of membranoproliferative glomerulonephritis (MPGN) type I was made. Splenectomy was performed and the examination revealed a mixed population of lymphocytes with predominantly T-cells, B-cells and lymphoplasmacytoid cells. Immunostaining confirmed that the small cells were mostly T-cells positive for all T-cell markers including CD2, CD3, CD4, CD5, CD7 and CD8. A diagnosis of inflammatory pseudotumour was established. The removal of the spleen was followed by remission of glomerulonephritis, but it was complicated by a subphrenic abscess and pneumonia. This association between an inflammatory pseudotumour of the spleen and MPGN has not been previously described. Abnormal immune response due to the inflammation leading to secondary glomerulonephritis might be the main pathogenic mechanism.

The novel tyrosine kinase inhibitor AKN-028 has significant antileukemic activity in cell lines and primary cultures of acute myeloid leukemia

Aberrantly expressed tyrosine kinases have emerged as promising targets for drug development in acute myeloid leukemia (AML). We report that AKN-028, a novel tyrosine kinase inhibitor (TKI), is a potent FMS-like receptor tyrosine kinase 3 (FLT3) inhibitor (IC₅₀=6 nℳ), causing dose-dependent inhibition of FLT3 autophosphorylation. Inhibition of KIT autophosphorylation was shown in a human megakaryoblastic leukemia cell line overexpressing KIT. In a panel of 17 cell lines, AKN-028 showed cytotoxic activity in all five AML cell lines included. AKN-028 triggered apoptosis in MV4-11 by activation of caspase 3. In primary AML samples (n=15), AKN-028 induced a clear dose-dependent cytotoxic response (mean IC₅₀ 1 μℳ). However, no correlation between antileukemic activity and FLT3 mutation status, or to the quantitative expression of FLT3, was observed. Combination studies showed synergistic activity when cytarabine or daunorubicin was added simultaneously or 24 h before AKN-028. In mice, AKN-028 demonstrated high oral bioavailability and antileukemic effect in primary AML and MV4-11 cells, with no major toxicity observed in the experiment. In conclusion, AKN-028 is a novel TKI with significant preclinical antileukemic activity in AML. Possible sequence-dependent synergy with standard AML drugs and good oral bioavailability has made it a candidate drug for clinical trials (ongoing).

Clinical trial update and novel therapeutic approaches for metastatic prostate cancer

Recurrent prostate cancer (PCa) remains a major clinical challenge. Invasive and metastatic PCa lesions often exhibit a partial and time-limited response to therapy before the cancer progresses and the patient succumbs to the disease. Despite recent advances in early diagnosis and treatment, approximately one-third of treated patients will relapse and become resistant to currently available treatments. In this review we evaluate current treatment practices and recent advances in therapy for localized prostate malignancy and advanced, metastatic prostate cancer. Some of the promising new drugs for PCa treatment include MDV3100, an androgen receptor (AR) antagonist that prevents androgens from binding to the AR and nuclear translocation and co-activator recruitment of the ligand-receptor complex; abiraterone, an orally administered drug that irreversibly inhibits a rate-limiting enzyme in androgen biosynthesis, CYP17; and several newer cytotoxic drugs (epothilones, satraplatin). Key new insights are that cancer stem cells play a role in PCa and that PCa cells are dependent on the AR for proliferation, even in the hormone refractory state of the disease. We also discuss potential molecular targets for new drug candidates for the treatment of metastatic PCa.

Evolution of ZDDP-derived reaction layer morphology with rubbing time

Functional additives, particularly extreme pressure and antiwear additives, in formulated oil will compete to adsorb and function in tribological contacts. A low-polarity commercial base oil, poly-α-olefin (PAO), blended with zinc dialkyl dithiophosphates (ZDDP) has been studied. The tribological performance was evaluated using a ball-on-disk test rig under mixed rolling-sliding conditions in the boundary lubrication regime at 90°C. An adapted in situ interferometry technique was used to monitor the additive-derived reaction layer formation. The thickness of the reaction layer evolves with rubbing until reaching a limiting thickness value of approximately 70  nm. The evolution of the topography and mechanical properties of the ZDDP-derived reaction layer with rubbing time were studied using Atomic Force Microscopy. A constant roughening and hardening of the additive-derived layer with rubbing time is observed and related to the different tribological performance of the layer at different rubbing times.

The effect of cimetidine, a new histamine H2-receptor antagonist, on renal function

Serum creatinine, endogenous creatinine clearance, (51Cr)EDTA plasma clearance and the concentration of beta2-microglobulin in serum and urine were determined in 19 patients before and during treatment with cimetidine for peptic ulcer disease. The mean concentrations of creatinine and beta2-microglobulin in serum increased significantly within normal limits after 2 and 6 weeks' treatment. However, creatinine clearance and (51Cr)EDTA plasma clearance were unchanged during the treatment. Thus, the observed increases in serum creatinine and beta2-microglobulin could not be explained by a diminished glomerular filtration rate. Inhibited tubular secretion of creatinine may explain the observed increase in serum creatinine during cimetidine treatment. Another hypothetical possibility is that a small increase in tubular reabsorption of both creatinine and beta2-microglobulin would account for the observed increases in creatinine and beta2-microglobulin in serum. It is concluded that, although statistically significant, the increases in serum creatinine and beta2-microglobulin are small and therefore of little relevance for the patient's treatment with cimetidine.

The effects of cimetidine (Tagamet) on renal function in patients with renal failure

Cimetidine has been administered during 7 days to 28 patients with different degrees of renal failure. Thirteen of these patients had a further week's treatment at least one month later. The daily dose of cimetidine was reduced in relation to pretrial values of creatinine clearance. There was a clear rise in serum creatinine all through the trial (22.3 +/- 2.6% at day 7) (p < 0.001). Maximal decreases in creatinine clearance occurred on day 2 (21.8 +/- 2.2%) and day 3 (23 +/- 2.0%) (p < 0.001), but were still present on days 6 (16.4 +/- 2.9%) and 7 (17.3 +/- 2.8%) (p < 0.001). There was a small rise in serum uric acid all through the trial (p < 0.05). Three days after finished treatment there were no significant differences in serum creatinine, creatinine clearance and serum uric acid when compared to pretrial values. The pattern of changes in serum creatinine and creatinine clearance was the same in both mild and severe renal failure. Glomerular filtration rate determined by |52Cr¿ EDTA clearance before, on day 3 of treatment and 3 days after treatment did not show any differences. No change was seen in serum beta 2-microglobulin during the trial. The decrease in creatinine clearance during treatment with cimetidine is probably not caused by a reduction of glomerular filtration rate, but could be explained by competition by cimetidine for tubular secretion of creatinine. Treatment with cimetidine of patients with renal failure may invalidate measurements of serum creatinine and creatinine clearance as standard routine tests for glomerular filtration rate.

Evaluation of the sulphapyridine acetylator phenotyping test in healthy subjects and in patients with cardiac and renal diseases

The acetylator phenotype of 35 healthy, drug-free volunteers and 21 patients with cardiac and/or renal disease has been assessed using oral sulphapyridine. Comparative evaluation of a simplified and a more selective method of sulphapyridine analysis was performed. Thirteen of the patients were also phenotyped by determination of plasma isoniazid half-life. 81% of the patients were slow acetylators, compared with only 51% of the volunteers. When phenotyping healthy, drug-free subjects the analytical procedure, involving a direct estimation of sulphapyridine in urine with the Bratton-Marshall procedure, was satisfactory. On the other hand, in patients receiving concomitant drug therapy the more selective analytical procedure was necessary in order to diminish the risk of methodological interference.

Spontaneous systemic lupus erythematosus and acelylator phenotype

Fifteen patients with spontaneous systemic lupus erythematosus (SLE) have been phenotyped by determination of plasma isoniazid (INH) half-life. Seven patients had signs of renal insufficiency. Of the 15 patients, 13 were slow and only 2 rapid acetylators. No correlation was found between the plasma INH half-lives and the renal function. Thus, there is the same marked predominance of slow acetylators in patients with spontaneous SLE as in patients with the drug-induced SLE-like syndrome.

Pharmacokinetics of chloral hydrate poisoning treated with hemodialysis and hemoperfusion

In a severe case of chloral hydrate intoxication treated with combined hemodialysis and hemoperfusion the pharmacokinetics of the metabolites trichloroethanol (TCE), trichloroethanol glucuronide (TCE-Glu) and trichloroacetic acid (TCA) were studied. Indications of delayed absorption and some slowing of metabolism were found. At a blood flow rate of 200 ml/min clearances by hemodialysis and hemoperfusion, respectively, in ml/min were estimated to be 188 and 156 for TCE, 184 and 181 for TCE-Glu, 142 and 91 for TCA. Clearance by hemoperfusion declined with time. The half-lives of TCE and TCA were 3.2 and 4.3 hours during combined hemodialysis and hemoperfusion. After termination of treatment the half-life of TCE was 12.8 hours, whereas TCA was metabolized so slowly, that no reliable calculation could be performed. We conclude that hemodialysis and hemoperfusion are equally and highly efficient in the treatment of chloral hydrate poisoning, but hemoperfusion may increase the risk of gastric bleeding more than hemodialysis. Hemodialysis may therefore be preferable and should be tried in spite of low blood pressure.

Effects of streptozotocin-induced diabetes in domestic pigs with focus on the amino acid metabolism

Streptozotocin (STZ) given intravenously destroys pancreatic beta cells and is widely used in animal models to mimic type 1 diabetes. The effects of STZ on the clinical state of health and metabolism were studied in six high health certified domestic pigs weighing 19+/-1.3 kg at the start of the experiment. A single STZ dose of 150 mg/kg of body weight successfully induced hyperglycaemia and alterations in amino acid metabolism. Within 9 h after STZ administration, the blood glucose values fell from 5.4-7.5 mmol/L to 0.8-2.2 mmol/L. Hypoglycaemia was treated with 0.5 g glucose/kg body weight. In all pigs, hyperglycaemia was produced 24 h after STZ treatment, and 3 days after STZ injection, the glucose concentration was >25 mmol/L. Mean C-peptide concentration was 0.25+/-0.16 microg/L since 2 days after STZ injection until the end of the study. The serum concentration of the branched-chain amino acids (BCAA) increased four-fold, and alanine and taurine decreased by approximately 70% and 50%, respectively, after STZ treatment. All but one pig remained brisk and the physical examination was normal except for a retarded growth rate and a reduction of the skeletal muscle. At the end of the study, the pigs were moderately emaciated. Postmortem examination confirmed muscle wasting and a reduction of abdominal and subcutaneous fat. In conclusion, STZ-induced diabetes in pigs fulfils the requirements for a good animal model for type 1 diabetes with respect to clinical signs of the disease and alterations in the carbohydrate and amino acid metabolism.

Heterogeneous activity of cytotoxic drugs in patient samples of peritoneal carcinomatosis

AIMS

To investigate if the pattern of cytotoxic drug sensitivity in vitro in patient samples of peritoneal carcinomatosis (PC) is supportive to the current standardized approach for drug selection for perioperative intraperitoneal chemotherapy (IPC).

METHODS

The cytotoxic effect of cisplatin, oxaliplatin, irinotecan, 5-fluorouracil, mitomycin-C, doxorubicin and melphalan was investigated in vitro on tumour cells from 223 patient tumour samples of different PC origins.

RESULTS

Considerable differences in cytotoxic drug sensitivity between tumour types of the PC entity and within each tumour type were observed. Cisplatin showed high cross-resistance with oxaliplatin but low cross-resistance with doxorubicin and irinotecan. No cross-resistance was found between irinotecan and doxorubicin. The dose-response relationships for melphalan and irinotecan in individual samples showed great variability.

CONCLUSIONS

The activity in vitro of cytotoxic drugs commonly used in IPC for PC is very heterogeneous. Efforts for individualizing drug selection for PC patients undergoing IPC seem justified.

Surface-adsorbed fibrinogen and fibrin may activate the contact activation system

INTRODUCTION

This study was designed to investigate whether fibrinogen, soluble desAA-fibrin, and insoluble desAABB-fibrin are able to induce clotting by triggering the plasma contact activation system when adsorbed to polystyrene.

MATERIALS AND METHODS

The above-mentioned substances were individually prepared on polystyrene meshwork squares, and then exposed to a purified FXII solution or non-calcium containing plasma (citrated and dialyzed normal pooled plasma) in polystyrene cuvettes coated with surface-immobilized heparin, to completely block contact activation and the coagulation mechanism that might be induced by the cuvette surfaces. Sodium glass beads were used as the reference material.

RESULTS

On exposure to purified FXII solution and plasma, all the tested materials adsorbed and activated FXII to varying degrees. This activation led to the formation of FXIa in the exposed plasma, with the highest activation occurring upon exposure to glass, desAA-fibrin and desAABB-fibrin and the lowest upon exposure to fibrinogen-adsorbed or unmodified polystyrene meshwork squares. Following recalcification, in cuvettes with surface-immobilized heparin, a spectrophotometric assay showed that the surface-exposed plasma aliquots clotted within 5 min after contact with glass, within 10 to 15 min after contact with the two forms of fibrin, and somewhat longer after contact with adsorbed fibrinogen. The longest lag phase, close to 20 min, occurred in plasma exposed to unmodified polystyrene meshwork. Whole blood deposited in surface heparinized cuvettes directly from the cubital vein did not clot during the observation time (2 h).

CONCLUSIONS

These results indicate that domains induced by conformational changes in adsorbed fibrinogen and fibrin are capable of activating adsorbed proenzymes and that various forms of fibrin are considerably stronger activators of the contact activation system than are adsorbed fibrinogen or a polystyrene meshwork. The delayed coagulation in plasma exposed to the unmodified polystyrene meshwork can be explained by a two-step process: first, adsorption of fibrinogen, and second, activation of FXII. Under our experimental conditions, the adsorption and activation of FXII on fibrinogen and fibrin seems to be an important mechanism for triggering coagulation.

The functional heterogeneity of eosinophil cationic protein is determined by a gene polymorphism and post-translational modifications

BACKGROUND

The eosinophil is a cytotoxic cell and takes part in parasite killing and tissue-destructive processes by secretion of proteins such as eosinophil cationic protein (ECP). A polymorphism was demonstrated in the ECP gene, giving rise to a substitution of arginine at position 97 with threonine. This polymorphism is related to disease development.

OBJECTIVE

To investigate the functional and molecular heterogeneity of native ECP and the functional consequences of the replacement of arginine with a threonine.

METHODS

ECP was purified from healthy blood donors by gel filtration, ion-exchange chromatography and reversed-phase chromatography. Recombinant ECPs i.e. rECP 97(arg) and rECP 97(thr) were produced by the pFASTBAC baculovirus expression system. The cytotoxic activity was determined against an erythroleukaemia or a small cell lung cancer cell line.

RESULTS

Native ECP was purified to apparent homogeneity and showed a considerable molecular heterogeneity and a corresponding functional heterogeneity with respect to cytotoxic activity. After reduction, the native cytotoxic ECP showed three bands on sodium dodecylsulphate polyacrylamide gel electrophoresis : one major band at 18-20 kDa and two minor bands at about 10 and 5 kDa, respectively. The 5 kDa contained two masses differing with 56.2 Da, which corresponds to the difference in molecular masses of arginine and threonine. rECP 97(arg) was cytotoxic in contrast to rECP97(thr). Deglycosylation with N-glycosidase F did not affect the cytotoxic activity of native ECP to any measurable extent nor the activity of rECP 97(arg), whereas rECP 97(thr) achieved cytotoxic activity. The RNase activities of the recombinant and native ECPs were similar.

CONCLUSION

We conclude that ECP is present in several molecular forms with varying biological activities. Some of this functional heterogeneity is based on the genetic polymorphism of the ECP gene and some on post-translational modifications. In subjects carrying the ECP 97(thr) variant, the cytotoxic activity may be disguised by N-linked glycosylation of the active site.

Primary lymphocytes as predictors for species differences in cytotoxic drug sensitivity

Several in vitro methods have been suggested to predict drug-induced haematotoxicity and species differences; the most commonly used being the clonogenic CFU-GM assay. The aim of the current study was to evaluate whether primary lymphocytes from peripheral blood, assayed with a short-term non-clonogenic assay, could be used to detect species differences in drug sensitivity, and offer an alternative to the CFU-GM assay. The effect of 17 different cytotoxic drugs on lymphocytes from human, dog, rat and mouse was evaluated. A higher sensitivity of human than mouse lymphocytes was seen for topotecan and for 3 of 5 antimetabolites tested. Clear species specificity was also seen for the proteasome inhibitor bortezomib where rodent cells were 50-300 times less sensitive than human cells. Good agreement between our data and published CFU-GM data was observed, suggesting that primary lymphocytes may be a useful model for species difference screening in drug development.

In Vitro Drug Sensitivity-Gene Expression Correlations Involve a Tissue of Origin Dependency

A major concern of chemogenomics is to associate drug activity with biological variables. Several reports have clustered cell line drug activity profiles as well as drug activity-gene expression correlation profiles and noted that the resulting groupings differ but still reflect mechanism of action. The present paper shows that these discrepancies can be viewed as a weighting of drug-drug distances, the weights depending on which cell lines the two drugs differ in.

Heparin coating durability on artificial heart valves studied by XPS and antithrombin binding capacity

The durability and functionality of a heparin coating on artificial heart valve leaflets were evaluated with X-ray photoelectron spectroscopy (XPS) and by the coatings' capacity to bind antithrombin. Current methods for accelerated life-time testing are based on exposing leaflets to water solutions. In this paper a method is explored, in which heart valve leaflets were exposed to a continuous high shear rate (4 L/min) of human citrated plasma. It was found that the heparin coating was stable and wear resistant enough to still be present after 3 weeks and to have about the same antithrombin uptake as coatings not exposed to circulating plasma. It was, however, partly destroyed by the test as found using XPS. We suggest that heparin chains from the upper layer of heparin have been torn off from the carrier chain, in combination with loss of heparin conjugate and plasma deposition in patches. This study showed that XPS provides additional information to biological measurements such as antithrombin uptake. XPS is therefore a valuable technique not only to characterize biomaterials but also to evaluate the effect of a performance test.

A novel application of multi-wavelength TIRF spectroscopy for real time monitoring of antithrombin interactions with immobilized heparin

Real time interactions of antithrombin (AT) with Corline Heparin Surfaces (CHS) with one and two layers of heparin conjugate have been examined using a multi-wavelength TIRF spectroscopy technique with continuous flow. Fluorescently labeled AT, adsorbed from citrated human blood plasma, showed significantly higher signals on CHS compared to the cationic surface used to attach the heparin conjugate. The AT binding to CHS was very stable, also after exposure to soluble heparin at a concentration of 1.5 IU/mL. Only a few percent of the bound AT were displaced from the surfaces by AT present in plasma after long-term exposure to plasma. In contrast, larger amounts of the freshly added AT had adsorbed to the surfaces, especially to the surface with two layers of heparin conjugate, indicating the presence of unsaturated AT binding sites. The amount of AT bound to the different surfaces was quantified after elution using an enzyme immunoassay (EIA). Characteristic emission spectra of proteins and fluorophores of labeled proteins, obtained at the surfaces after a long-term exposure to plasma, confirmed their presence at the surfaces. The multi-wavelength TIRF technique proved to be a useful tool when combined with other techniques to study the time course of interactions of fluorescently labeled proteins with biomaterials, even in a complex environment such as plasma.

Identification of molecular mechanisms for cellular drug resistance by combining drug activity and gene expression profiles

Acquired drug resistance is a major problem in cancer treatment. To explore the genes involved in chemosensitivity and resistance, 10 human tumour cell lines, including parental cells and resistant subtypes selected for resistance against doxorubicin, melphalan, teniposide and vincristine, were profiled for mRNA expression of 7400 genes using cDNA microarray technology. The drug activity of 66 cancer agents was evaluated on the cell lines, and correlations between drug activity and gene expression were calculated and ranked. Hierarchical clustering of drugs based on their drug–gene correlations yielded clusters of drugs with similar mechanism of action. Genes correlated with drug sensitivity and resistance were imported into the PathwayAssist software to identify putative molecular pathways involved. A substantial number of both proapoptotic and antiapoptotic genes such as signal transducer and activator of transcription 1, mitogen-activated protein kinase 1 and focal adhesion kinase were found to be associated to drug resistance, whereas genes linked to cell cycle control and proliferation, such as cell division cycle 25A and signal transducer of activator of transcription 5A, were associated to general drug sensitivity. The results indicate that combined information from drug activity and gene expression in a resistance-based cell line panel may provide new knowledge of the genes involved in anticancer drug resistance and become a useful tool in drug development.

Cellular drug sensitivity in MLL-rearranged childhood acute leukaemia is correlated to partner genes and cell lineage

Rearrangements in the 11q23 region, the site of the mixed lineage leukaemia (MLL) gene, are found in both childhood acute myeloid (AML) and lymphoblastic (ALL) leukaemia. We studied the in vitro drug resistance by the fluorometric microculture cytotoxicity assay (FMCA) in 132 children with AML and 178 children with ALL (aged 0-17 years). In AML, children with t(9;11) (n = 10) were significantly more sensitive to cytarabine (P < 0.001) and doxorubicin (P = 0.005) than non-11q23 rearranged patients (n = 108). Children with other 11q23 rearrangements (n = 14) differed less from non-rearranged children. The 'AML-profile' common to all three groups included relative resistance to glucocorticoids and vincristine. In ALL, children with 11q23 rearrangement (n = 22) were significantly more sensitive to cytarabine (P = 0.026) than children without 11q23 rearrangement (n = 156), also after stratification for white blood cell count. In conclusion, the findings indicate that the cellular drug resistance is correlated to both the cell lineage and the type of 11q23 rearrangement. High cellular sensitivity to cytarabine and doxorubicin might explain the excellent treatment results in children with AML and t(9;11). The present study supports the strategy of contemporary protocols to include high-dose cytarabine in the treatment of 11q23-positive patients both in AML and ALL.

The influence of different heparin surface concentrations and antithrombin-binding capacity on inflammation and coagulation

The corline heparin surface (CHS) used in the extracorporeal circuit during coronary artery bypass grafting is shown to decrease the activation of inflammation and coagulation. Synchrotron radiation studies have shown that a single layer of the CHS may not completely cover the substrate surface. However, a double layer of CHS results in a uniform surface. We investigated the effect of surfaces with different surface concentrations of heparin on cell activation and coagulation compared to an uncoated surface. The CHS is prepared by a conditioning layer of polymeric amine onto which a macromolecular heparin conjugate is attached. We used PVC tubing, uncoated or modified with a single or double layer of the CHS, and circulated fresh whole blood from healthy volunteers in a loop model system at 37 degrees C up to 4 h. Blood was drawn from the loops at different times and activation of inflammation and coagulation was studied by real-time PCR, flow cytometry and ELISA. The activation of leukocytes and platelets and formation of leukocyte-platelet aggregates were reduced by use of the single-layered CHS compared to the uncoated surface. Use of double-layered CHS resulted in significantly reduced cell activation and thrombin generation. Development of the CHS obtained by the double layer of the coating has improved the biocompatibility of the surface.

Characterization of heparin surfaces using photoelectron spectroscopy and quartz crystal microbalance

In order to gain insight into the molecular structure of a new heparin surface (Corline heparin surface, CHS), quartz crystal microbalance dissipation (QCM-D) and photoelectron spectroscopy (PES) were used. Two surfaces, with different surface thickness and surface concentration of heparin, were compared. QCM-D measurements provided information on the thickness of the two different heparin surfaces and confirmed that the process of formation of the two layers were virtually identical. PES showed that the thicker coating resulted in complete coverage of the substrate, whereas with the thinner coating Fe signals originating from the stainless steel substrate could be detected. Information of the molecular surface structure of the heparin coatings could be derived from the ratios at different photon energies between S2p signals from sulfonate groups in heparin and disulfide groups originating from a cross-linking unit in the heparin conjugate.

Description and analysis of two internet-based databases of insect pathogens: EDWIP and VIDIL

In 1996, two searchable databases covering insect pathogens were posted on the World Wide Web: the Ecological Database of the World's Insect Pathogens (EDWIP) and the Viral Diseases of Insects in the Literature database (VIDIL). In this paper, we describe the format and contents of EDWIP and VIDIL on the World Wide Web. EDWIP contains over 9,400 pathogen-host association records, 677 negative test result or "no association" records, 4,454 host species, 2,285 pathogen species records, and 2,057 bibliographical references. Species of Coleoptera and Lepidoptera are the best represented groups in EDWIP. Lepidopteran species account for the most associations of any host order in EDWIP, over 2,500, or 27%. Of the pathogen groups, Protozoa (including microsporidia) accounted for nearly 66% of the pathogen species records and over 40% of the association records in EDWIP. Fungi account for only 18% of the pathogen species, but nearly 33% of the association records. Habitats dominated by human activities (e.g., crop, stored product, and human dwelling) account for most of the host habitats recorded in EDWIP. The United States and Japan are the most common locations and the Nearctic and Palearctic are the most common biogeographic regions reported in EDWIP. There are 4,801 annotated bibliographic records in VIDIL.

Population pharmacokinetic modelling of unbound and total plasma concentrations of paclitaxel in cancer patients

The aim of this study was to validate and further develop a mechanism-based population pharmacokinetic model for paclitaxel (Taxol; Bristol-Myers Squibb Co, Princeton, NJ, USA) based on the knowledge of Cremophor EL (CrEL) micelle entrapment and to evaluate the exposure/toxicity relationships. Paclitaxel (total and unbound) and CrEL concentrations were obtained according to a sparse sampling scheme with on average only 3.5 samples per course from 45 patients with solid tumours who received 3-hour infusions of paclitaxel (final dose range 112-233 mg/m(2)). The present data were predicted well by the mechanism-based model. In addition, bilirubin and body size were found to be significant as covariates. A change in body surface area (BSA) of 0.1 m(2) typically caused a change in clearance (CL) of 22.3 l/h and an increase in bilirubin of 10 microM typically caused a decrease in CL of 41 l/h. Toxicity was best described by a threshold model. In conclusion, even with a sparse sampling scheme, the same mechanism-based binding components as in the previously developed model could be identified. Once the CrEL and total paclitaxel plasma concentrations are known, the unbound concentrations, which are more closely related to the haematological toxicity, can be predicted.

Small, novel proteins from the mistletoe Phoradendron tomentosum exhibit highly selective cytotoxicity to human breast cancer cells

Four novel proteins (phoratoxins C-F) have been isolated from the North American mistletoe Phoradendron tomentosum. The amino acid sequences of these phoratoxins were determined unambiguously using a combination of Edman degradation and trypsin enzymatic digestion, and by electrospray ionization tandem mass spectrometry sequencing. Phoratoxins C, E and F consist of 46 amino acid residues; and phoratoxin D of 41. All proteins had six cysteines, similar to the earlier described phoratoxins A and B, which are thionins. The cytotoxicity of each protein was evaluated in a human cell line panel that represented several cytotoxic drug-resistance mechanisms. For the half-maximal inhibitory concentrations (IC50 values) of the different cell lines in the panel, correlation with those of standard drugs was low. The most potent cytotoxic phoratoxin C was further tested on primary cultures of human tumor cells from patients. The solid tumor samples from breast cancer cells were 18 times more sensitive to phoratoxin C than the tested hematological tumor samples.

Overview of the clinical efficacy of investigational anticancer drugs

The purpose of this overview was to make a broad inventory of investigational drugs for medicinal cancer treatment and, specifically, to indicate the evidence of clinical efficacy. Information was retrieved from electronic database searches in Medline and CANCERLIT and relevant published reviews. As the most recent findings are first reported as conference abstracts, an important basis for identification of new drugs and clinical results was a hand search of 13,392 abstracts from five major recent cancer conferences. A total of 209 investigational approaches or drugs were identified and classified into one of eight groups according to proposed mechanism of action. For 28 drugs/approaches survival data were available from randomized controlled trials. Statistically significant benefit was observed for only 12. In earlier phases no or modest anticancer activity was reported. It is speculated that the expanding knowledge in tumour biology might not easily translate into new substantially better anticancer drugs.

Cell adhesion and tissue factor upregulation in oxygenators used during coronary artery bypass grafting are modified by the Corline Heparin Surface

OBJECTIVE

Cardiopulmonary bypass (CPB) is associated with inflammatory response and activation of coagulation. We investigated the influence of a new heparin surface on the activation of cells retrieved from oxygenators used during coronary artery bypass grafting (CABG).

DESIGN

Sixty patients undergoing CABG with CPB were randomly assigned to either uncoated or completely Corline Heparin Surface (CHS)-coated circuits with one of three different levels of systemic heparin: standard, high or low. At end of surgery adhered cells were retrieved from the oxygenators and cell count, tissue factor (TF)- and CD11b-expression on monocytes and monocytic TFmRNA were analysed.

RESULTS

The heparin coating of the oxygenator prevented adhesion of granulocytes, monocytes and platelets. TF-expression on monocytes from the oxygenators was significantly higher than on circulating cells in all groups. Monocytes from the uncoated oxygenators showed low levels of TF-expression with high levels of TFmRNA. The coated group with high level of heparin showed higher surface-expression of TF with low levels of TFmRNA.

CONCLUSION

The CHS was most biocompatible with the standard level of heparin used during CABG whereas elevation of systemic heparin rather increased the activation and TF upregulation in monocytes from oxygenators.

The combination of the antitumoural pyridyl cyanoguanidine CHS 828 and etoposide in vitro--from cytotoxic synergy to complete inhibition of apoptosis

1. The present study was aimed at elucidating the apoptosis inhibitory properties of the cyanoguanidine CHS 828. CHS 828 exhibits impressive cytotoxic activity in vitro and in vivo. Apoptosis is not its main mode of cytotoxic effect, and we have previously proposed a dual mechanism, where CHS 828 inhibits its own cell death pathways. 2. Etoposide on the other hand, is a well-established anticancer agent with documented effect in a number of malignancies, induces apoptosis through extensively studied caspase dependent pathways. 3. Here we studied the combined effect of the two drugs in the human lymphoma cell line U-937 GTB. Cytotoxicity was evaluated as total viability measured by the fluorometric microculture cytotoxicity assay (FMCA). Caspase activity was assessed by colorimetric detection of specific cleavage products for caspases 3, 8 and 9, respectively. Morphology was evaluated in May-Grünwald/Giemsa stained preparations. Interaction analysis based on FMCA results of simple combination exposure revealed impressive synergistic effect on cell kill. 4. Detailed investigations of the kinetics involved showed that short pre-exposure (0-12 h) to CHS 828 enhanced caspase activation by etoposide, while longer pre-exposure (18-48 h) inhibited both caspase activation and apoptotic morphology otherwise induced by etoposide. The present results support the theory that CHS 828 block specific cell death pathways. 5. The synergistic results are promising for future combination trials in animals, however, different dosing schedules should be considered, in order to investigate whether the above findings translate into the in vivo setting.

In vitro activity of the novel cytotoxic agent CHS 828 in childhood acute leukemia

CHS 828, a pyridyl cyanoguanidine, is a new drug candidate now in phase I/II trials, that has shown promising anticancer activity in experimental tumor models and primary cultures of cancer cells from patients. In this study the fluorometric microculture cytotoxicity assay was used for evaluation of CHS 828 in primary cell cultures from children with acute leukemia. The activity of and interaction with the standard drugs, doxorubicin, melphalan, etoposide and cytosine arabinoside (Ara-C), were also assessed. Samples from 65 patients, 42 with acute lymphocytic leukemia (ALL) and 23 with acute myelocytic leukemia (AML) were tested with 72-h continuous drug exposure. There was 50% cell kill at very low CHS 828 concentrations; median IC50 was 0.01 microM in ALL and 0.03 in AML samples (NS) with large interindividual variability in both groups. ALL samples were significantly more sensitive than AML samples to melphalan, doxorubicin and etoposide, but not to Ara-C. In AML samples, combinations between CHS 828 and each of the four standard drugs resulted in significantly lower cell survival than either drug alone. This was also observed in ALL samples, except for Ara-C. Using the additive interaction model, CHS 828 showed a synergistic effect with melphalan in 67%, doxorubicin in 47%, etoposide in 38% and Ara-C in 14% of AML samples. In most ALL samples subadditive effects were found. Further exploration of CHS 828 in childhood leukemia is warranted, especially in AML.

Relative therapeutic index between inhaled formoterol and salbutamol in asthma patients

A double-blind, randomized crossover study in 28 asthmatic patients assessed the relative therapeutic index for inhaled formoterol and salbutamol. Pre-drug administration FEV1 (mean 2.08 l) was 49-93% of predicted and reversibility 16-82% after inhalation of salbutamol. Patients inhaled single doses of formoterol (Oxis) (4.5,18 and 54 microg, delivered doses) via Turbuhaler, salbutamol (Ventolin) (200 and 1800 microg) via pressurized metered dose inhaler (pMDI) and placebo at intervals of 48 h or more. Individual maximum FEV1 and minimum S-K+ were calculated. Relative local (maximum FEV1) and systemic (minimum S-K+) dose potencies, and their ratio, the relative therapeutic index, were estimated using a non-linear mixed effect model. The drug effects were well tolerated and dose dependent. A log-linear approximation was used to describe the bronchodilatory effect, whereas a sigmoid approximation was more apt to describe the decrease in serum potassium concentration. A bivariate dose-response model based on these principles was fitted simultaneously to all data. The mean relative therapeutic index between formoterol 4.5-54 microg given via Turbuhaler and salbutamol 200-1800 microg given via pMDI was estimated to be 2.5 in favour of formoterol; this trend was not statistically significant.

DNA-dependent protein kinase in leukaemia cells and correlation with drug sensitivity

We investigated whether the levels of the DNA-dependent protein kinase (DNA-PK) activity and content correlate with drug sensitivity in different tumour materials and if this can be utilised in predicting treatment outcome. DNA-PK activity and expression were investigated in tumour cells from 8 patients with chronic lymphocytic leukaemia (CLL) and 18 patients with acute myeloid leukaemia (AML), using Western blot and DNA-PK kinase activity assay. Tumour cells from the patients were investigated for their drug sensitivity to topoisomerase II inhibitors (doxorubicin and etoposide), DNA reactive agents (melphalan, 4-hydroxycyclophosphamide and cisplatinum), an antimetabolite (cytosine arabinoside) and an antimicrotubule agent (vincristine) by fluorometric microculture cytotoxicity assay (FMCA). Within each group of leukaemia there was a large variation in both DNA-PK activity and DNA-PKcs expression, while the Ku subunits were expressed more homogeneously. In CLL cells, sensitivity to topoisomerase II inhibitors correlated with DNA-PKcs protein expression (r=0.7174, p=0.0452). In AML samples, sensitivity to DNA cross-linking alkylating agents correlated with Ku86 (r=-0.7512, p=0.0031) and Ku70 (r=-0.6134, p=0.0258) expression. Unexpectedly, DNA-PK activity was found to correlate with sensitivity to vincristine in both CLL (r=0.8557, p=0.0067) and AML (r=0.5480, p=0.0228) cells. The results indicate that DNA-PK is not only involved in the recognition of DNA double-strand breaks (DSB), but also other DNA lesions.

Model for time dependency of cytotoxic effect of CHS 828 in vitro suggests two different mechanisms of action

CHS 828 is a novel drug belonging to the cyanoguanidines. It has shown promising anticancer activity in many preclinical systems and is currently in early clinical trials. Our aim in this study was to assess the growth inhibitory effect of CHS 828 in comparison with paclitaxel, etoposide, and topotecan as a function of concentration and time. U937 GTB, RPMI 8226/S, MDA 231, primary cells from chronic lymphocytic leukemia, and normal mononuclear cells were exposed to CHS 828 and U937 GTB cells were exposed to paclitaxel, etoposide, and topotecan in 18 concentrations for times ranging from 1 to 72 h. Cell survival was measured after 72-h incubation by using the fluorometric microculture cytotoxicity assay. Nonlinear mixed effect modeling was used to model the concentration-effect curves with a modified Hill equation. Patterns of change of drug potency (IC(50)), slope of the concentration-effect curves, and plateau with time were studied. The log IC(50) for CHS 828 decreased with log time in a sigmoid manner for all cell types tested. Although very steep at short and long incubation, the concentration-effect curves became shallow at intermediate times. The log IC(50) for etoposide and topotecan was decreased with log time in a sigmoid manner. The log IC(50) for paclitaxel decreased linearly with log time. The information obtained from modeling the cytotoxic effect of CHS 828 and changes of IC(50) and slope parameters with exposure time suggests a heterogeneous cell response to CHS 828. This could indicate two distinct mechanisms of induction of cell death.

Activity of CHS 828 in primary cultures of human hematological and solid tumors in vitro

CHS 828 is a pyridyl cyanoguanidine that has shown promising preclinical anticancer activity against various experimental tumor models and is presently being tested in a phase II trial in man. In the present study the fluorometric microculture cytotoxicity assay was used for in vitro evaluation of CHS 828 activity in primary cell cultures from hematological and solid tumors. In total, 156 samples from various diagnoses were tested with 72-h continuous drug exposure. CHS 828 showed high relative in vitro activity against tumor cells from chronic lymphocytic leukemia as well as from acute leukemia and high-grade lymphoma. Activity was also observed in several solid tumor cell samples, although the group as a whole appeared less responsive. CHS 828 was significantly more active against hematological malignancies compared to normal lymphocytes. Correlation analysis with standard drugs revealed low to moderate correlation coefficients. The results show that CHS 828 has potent antitumor activity against primary cultures of human tumor cells from patients and might have a unique mechanism of action.