The impact of age on the 99th percentile of cardiac troponin

Introduction

The 99th percentile upper reference limit (URL) of cardiac troponin (cTn) is diagnostic cutoff for myocardial infarction (MI). Several factors are known to lead to an increase in cTn including sex, kidney function, left ventricular function and various comorbidities. Similarly, studies have shown that cTn concentration of patients increase with age. However, the impact of age on the concentration of cTn in healthy individuals is unclear as several studies of healthy populations showed little to no impact of age.

Purpose

To determine the effect of age on the URL of cTn for the Danish population.

Methods

We invited active and retired blood donors with the aim of including 250 participants of each sex in each of four age groups, <50, 50–60, 60–70 and >70 years, for a total of about 2000 participants. cTn levels were measured by 4 cTn assays (Siemens Atellica and Vista cTnI, Roche cTnT and Abbott Alinity cTnI). The age specific URL were calculated using the non-parametric method. Quantile regression for the 99th percentile was adjusted for sex and creatinine concentration.

Results

A total of 2287 participants were sampled in the study, of which 4 (0.2%) were excluded due to a history of heart disease and 7 (0.3%) were excluded due to insufficient plasma for screening biomarkers. The median age was 58.6 (IQR 48.2–69.7), and 52.6% were female. Figure 1 shows the distribution of cTn concentrations in age intervals. There was a significant increase in cTn with age for all assays (all p<0.001). After adjusting for sex and creatinine concentration, increasing age was only significantly associated with cTnT (0.40 ng/L increase per year, p=0.03). Figure 2 panel A shows the age specific URL for each assay, where we observed a significant difference for cTnT with the URL increasing from 15.8 ng/L (90% CI 12.4–33.9 ng/L) for participants <50 years to 37.6 ng/L (90% CI 34.6–41.5 ng/L) for participants >70 years. The proportion of participants with concentrations above the manufacturers URL increased with age for cTnT from 1.5% in participants <50 years to 25.6% for participants >70 years (p<0.001), figure 2 panel B. This changed little when removing participants with decreased kidney function (eGFR <60 mL/min/1.73 m2) as 24.3% of the remaining participants >70 years had a cTnT above the URL.

Conclusions

The concentration of cTn increased with age for all assays. This was clearest for cTnT in which the 99th percentiles of participants were significantly different for participants age >70 years of whom a quarter had cTnT levels above the level for myocardial injury according to the manufacturer's URL.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): HelsefondenMauritzen La Fountaine Foundation

Cardiac surgery in cardiac implantable electronic device patients and risk of device infections: a nationwide nested case-control study

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Karen Elise Jensen’s Foundation

Background

Cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) has been associated with a higher risk of infective endocarditis, but how it influences risk of CIED-specific infections is not known.

Purpose

To examine risk of systemic CIED infections after cardiac surgery in patients with CIEDs.

Methods

Based on data obtained from Danish administrative registries and the Danish Pacemaker and ICD Register, we conducted a case-control study nested within a nationwide cohort of patients who underwent a de novo CIED implantation in Denmark between 1998-2017. Patients entered the study at six months after implantation. We defined cases as incident systemic CIED infections resulting in device system extraction. Controls were sampled 1:100 on age, sex and follow-up time using risk set sampling. Exposure was defined as coronary artery bypass graft (CABG)-, or cardiac heart valve replacement- or repair surgery.

Results

From a study cohort comprising 67,621 patients, we identified 170 cases and 16,966 controls. In the minimally adjusted model, the incidence rate ratio (IRR) for systemic CIED infection was 6.4 (95% confidence interval (CI) 3.9-17.1) with cardiac surgery, and after confounder adjustment, 7.0 (95% CI 4.1-11.9). IRRs were higher when exposure was restricted to heart valve replacement surgery (adjusted IRR (aIRR) 9.7, 95% CI 5.2-17.8), and when limiting our exposure time window to one year (aIRR 12.7, 95% CI 5.8-27.8).

Conclusion

Cardiac surgery in patients with de novo CIEDs was associated with a high risk of systemic CIED infections. Highest risk was observed after heart valve replacement surgery, and within the first year of surgery.

Lead complications after cardiac surgery in danish patients with cardiac implantable electronic devices: a nationwide nested case-control study

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Karen Elise Jensen’s Foundation

Background

Manipulation of the heart during cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) may result in lead damage or -displacement, but whether cardiac surgery truly infers an excess risk of lead failure is not known.

Purpose

The objective of this study was to examine risk of lead complications as a result of cardiac surgery in CIED patients.

Methods

We conducted a nationwide nested case-control study. Our source population comprised all patients ≥18 of age who underwent a de novo CIED implantation in Denmark between 1998 and 2017. Only patients who were alive and event-free at six months after implantation were eligible for inclusion in the case-control study. Cases were defined as incident lead complications resulting in a revision procedure, and were matched 1:30 to controls using risk set sampling. We used conditional logistic regression to estimate incidence rate ratios (IRRs) for the association between cardiac surgery and lead complications.

Results

Our population consisted of 61,869 de novo CIED patient. We identified 1324 incident cases of lead complications and 39,708 time-matched controls. 1036 cases and controls underwent cardiac surgery during follow-up; 61 cases (4.5%) and 975 controls (2.5%). Risk of lead-related reoperation was highest within the first six months of cardiac surgery (IRR 10.1, 95% CI 6.5-15.6, adjusted IRR 11.0, 95% CI 7-17.4). At one year, we observed no association between cardiac surgery and lead complications (IRR: 1.0, 95% CI 0.7-1.5 and adjusted IRR: 1.1, 95% CI 0.7-1.6).

Conclusion

Cardiac surgery was associated with a substantial risk of lead complications in patients with de novo CIEDs. Manipulation of the heart including cannulation of the right atrium is a likely explanation for the subsequent lead problems.

Magnetic resonance imaging in patients with temporary external pacemakers

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): This work was supported by Aarhus University, the Danish Heart Foundation (grant number R140-A9482-B2407); Health Research Foundation of Central Denmark Region (grant number R64-A3194-B1667); and Gangstedfonden.

Background

Magnetic resonance imaging (MRI) is increasingly becoming the imaging modality of choice for many clinical disorders. According to guidelines, MRI can safely be performed 6 weeks after implantation of a MRI-conditional permanent pacemaker. However, there is no recommendations and only very limited evidence regarding MRI in patients treated with temporary external pacemakers. Such patients thus may be denied the opportunity for well-indicated MRI.

Purpose

To describe safety and feasibility of MRI in patients with temporary external pacemakers.

Method

We reviewed patient records of all patients treated with temporary external pacing between 2016 and 2020 at a tertiary centre. Temporary pacing was established using a transvenous standard active fixation pacing lead inserted percutaneously and connected to a MRI-conditional pacemaker taped to the skin. Information on baseline characteristics, indication, days of hospital and pacemaker function before and after MRI was gathered. Before MRI, devices were programmed according to guidelines for permanent pacemakers and the device was fixated to avoid movement due to the magnetic field of the MRI system. Patients were monitored during MRI. Values are reported as N (%), and continuous variables are presented as median (interquartile range [IQR]) or mean ± SD.

Results

A total of 827 patients received a temporary pacemaker. MRI was performed in 44 (5%) patients. Mean age was 71 ­± 13 years and 13 (30%) were females. Indication for temporary device were atrioventricular block (20 [45%]), aborted cardiac arrest (9 [21%]), infective endocarditis (9 [21%]), and other (6 [14%]). MRI was performed to rule out or confirm structural heart disease (16 [36%]), cerebral disease (9 [20%]), spondylodiscitis (7 [16%]), or other (12 [27%]), which was not able to do with other imaging modalities. Cardiac MRI was performed in 22 (50%) patients, while MRI of cerebrum, spine, abdomen, and lower extremities were performed in the remaining patients. Median (IQR) time from implantation of the temporary device to MRI was 6 (3–11) days. During MRI, we observed no device-related malfunction or arrhythmia. Nor did we detect any change in lead sensing, impedance, or pacing threshold. A final diagnosis was confirmed in 27 (61%) patients after MRI. However, MRI provided information to guide the clinical management in all cases without artifacts compromising the diagnostic image quality. Instead of a dual chamber pacemaker, 7 (22%) patients had implanted a cardiac resynchronization therapy and/or implantable cardioverter defibrillator due to the MRI diagnosis. A permanent pacemaker was implanted in 32 (73%) patients within median (IQR) 12 (7–23) days after temporary pacing was established.

Conclusion

MRI is feasible and safe in patients with temporary external pacing established with a regular MRI-conditional device and a standard active fixation lead. The MRI was helpful in determining type of permanent device.

No prognostic benefit of multimodality imaging-guided left ventricular lead placement in cardiac resynchronization therapy: Long-term follow-up of the ImagingCRT study

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Aarhus University, the Danish Heart Foundation, Health Research Foundation of Central Denmark Region, and Gangstedfonden.

Background

 

Observational data indicate that left ventricular (LV) lead placement at the latest contracting region and separate from myocardial scar is associated with improved prognosis in cardiac resynchronization therapy (CRT). In a double-blinded, randomized controlled trial (ImagingCRT), we tested the strategy of multimodality imaging-guided LV lead placement towards the latest mechanically activated non-scarred myocardial segment in CRT. Patients were included between 2011 and 2014 and allocated either to (1) imaging-guided LV lead placement using cardiac computed tomography, 99mTechnetium myocardial perfusion imaging, and speckle-tracking echocardiography (imaging group, n = 89) or to (2) routine LV lead implantation in a posterolateral region with late electrical activation (control group, n = 93). The multimodality imaging-guided strategy was found to reduce proportion of non-responders to CRT after 6 months. Impact on long-term clinical outcome is unknown.

Purpose

To evaluate the long-term effect of individualized multimodality imaging-guided LV lead placement compared to a routine fluoroscopic approach on the composite endpoint of death or heart failure (HF) hospitalization after CRT.

Method

We reviewed follow-up data until November 2020 for all 182 patients included in the ImagingCRT trial for the occurrence of HF hospitalization and all-cause death. Continuous variables are presented as median (interquartile range) or mean ± standard deviation. We used Kaplan-Meier plot and Cox proportional hazard regression analysis (unadjusted) to assess the risk of HF hospitalization and all-cause death, and used log-rank test for comparison between the two groups.

Results

All patients had standard CRT indication (left bundle branch block, New York Heart Association functional class II/ III/ IV 84 [46%]/ 92 [51%]/ 6 [3%], LV ejection fraction 25 ± 6%, QRS width 166 ± 22 milliseconds). Mean age was 70 ± 9 years, and 39 (21%) were female. During a median follow-up period of 6.7 years (3.3–7.9 years), the proportion of patients meeting the composite endpoint of HF hospitalization (n = 45 [25%]) or all-cause death (n = 56 [31%]) was 60% (n = 53) in the imaging group compared with 52% (n = 48) in the control group (hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.83–1.81, p = 0.31) (Figure 1).

Neither the risk of HF hospitalization (HR 1.11, 95% CI 0.62–1.99, p = 0.72) or of all-cause death differed between the two groups (HR 1.23, 95% CI 0.82–1.85, p = 0.32).

Conclusion

An individualized multimodality imaging-guided strategy targeting LV lead placement towards the latest mechanically activated non-scarred myocardial segment during CRT implantation did not reduce the composite outcome of HF hospitalization or all-cause death during long-term follow-up. Abstract Figure 1

A safety and feasibility study comparing an intermittent high dose with a daily standard dose of liposomal amphotericin B for persistent neutropenic fever

A high intermittent dose regimen (group A: 10 mg kg(-1) on day 1, 5 mg kg(-1) on days 3 and 6) was compared with standard dosing (group B: 3 mg kg(-1) per day for 14 days) of liposomal amphotericin B (LAB) for empirical treatment of persistent febrile neutropenia. A total cumulative dose of 1275 mg (group A) and 2800 mg (group B) was administered. Infusion-related adverse drug events, mainly rigors/chills, occurred more frequently with group A (11/45, 24 % infusions) than with group B (12/201, 6 % infusions) (P=0.002), which extended the mean infusion time by 20 min (P=0.001). Creatinine levels were similar in the two regimens: the A : B ratio of the area under the curve for creatinine (AUC(CREATININE)) for days 2-7 was 1.09 (P=0.27) and for days 2-14 was 1.05 (P=0.51). Rises in creatinine were mild (clinical toxicity criteria 1) in all patients with elevations. Hypokalaemia tended to be less severe in group A with a lower proportion of hypokalaemic days [57/143 (39 %) vs 80/137 (58 %), P=0.21], a higher AUC(POTASSIUM) (A : B ratio of 1.06, P=0.12), a lower proportion of patients with hypokalaemia at the end of study (10 vs 61 %, P=0.01) and fewer potassium-supplemented days [12/210 (6 %) vs 41/210 (19.5 %), P<0.1]. There were mildly elevated median levels of serum bilirubin, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase, which were similar for the two regimens and were usually associated with other co-existing co-morbid conditions. The AUC for these enzymes was also similar in the two groups. No patient had discontinuation of the study drug due to toxicity. Composite success was identical for each regimen (11/15 patients, 73 %). Three of the fifteen patients in group B and none in group A developed invasive fungal infections (IFIs). Beta-D-Glucan levels were similar in both groups for patients without an IFI [AUC(GLUCAN) of 362 and 683 (P=0.36) for groups A and B, respectively]. The rate of defervescence was similar for each regimen (P=0.75). This feasibility study suggests that a short intermittent high-dose course of 10/5/5 mg LAB kg(-1) on days 1, 3 and 6 may be as safe and effective as a standard 14 day course of 3 mg kg(-1) per day, with drug-acquisition cost savings and reduced drug exposure. A larger study is indicated for confirmation of this.

Clinical trial: the glucagon-like peptide-1 analogue ROSE-010 for management of acute pain in patients with irritable bowel syndrome: a randomized, placebo-controlled, double-blind study

BACKGROUND

There is currently no treatment available to manage acute pain attacks in IBS patients regardless of subtype.

AIMS

To evaluate efficacy and safety of the GLP-1 analogue ROSE-010 in patients with irritable bowel syndrome (IBS) through a randomized, double-blind, placebo-controlled study.

METHODS

Eligible patients (n = 166) meeting Rome II criteria were randomly assigned to receive single subcutaneous injections of ROSE-010 100 microg, 300 microg and placebo in a cross-over design. Safety was assessed from spontaneously reported adverse events and measurement of vital signs. Patient-rated pain relief and intensity were measured on a 100-mm visual analogue scale. The primary efficacy variable was proportion of patients with >50% maximum total pain relief response from 10 to 60 min after treatment. Secondary endpoints included the maximum summed pain intensity difference, time to meaningful pain relief and patient ratings of satisfaction with treatment.

RESULTS

Twice as many patients were responders in the primary efficacy endpoint after both ROSE-010 injections compared to placebo (24%P = 0.011, 23%P = 0.005, and 12% after 300 microg, 100 microg and placebo injections, respectively). Similar results were obtained for the proportion of patients with total pain intensity response. Times to meaningful and total pain relief were shorter for both doses of ROSE-010 compared with placebo. Compared with placebo, more patients (P < 0.05) were satisfied with ROSE-010 and considered ROSE-010 better than previous IBS medications used.

CONCLUSION

ROSE-010 was well tolerated and provided fast and effective relief of acute pain attacks on demand in IBS patients.

GLP-1 suppresses gastrointestinal motility and inhibits the migrating motor complex in healthy subjects and patients with irritable bowel syndrome

Glucagon-like peptide-1 (GLP-1) is released after food intake to act as an incretin. GLP-1 also inhibits gastric emptying and increases satiety. In rats, GLP-1 inhibits small bowel motility. Our aim was to study the effects of GLP-1 on gastrointestinal motility in healthy subjects and patients with irritable bowel syndrome (IBS). Antro-duodeno-jejunal manometry was carried out during a 4-h control period with saline, followed by a 4-h period with intravenous GLP-1 (healthy: 0.7 and 1.2 pmol kg(-1) min(-1) (n = 16); IBS, 1.2 and 2.5 pmol kg(-1) min(-1) (n = 14). Plasma was analysed for GLP-1 and gut hormones, and gut tissue expression of GLP-1 receptor was studied. In healthy subjects, GLP-1 0.7 pmol kg(-1) min(-1) reduced the migrating motor complexes (MMCs) from a median of 2 (range 2-3) to 0.5 (0-2), and motility index from 4.9 +/- 0.1 to 4.3 +/- 0.3 ln Sigma(mmHg*s min(-1)) in jejunum, while GLP-1 1.2 pmol kg(-1) min(-1) diminished MMCs from 2 (2-3) to 1.5 (1-2.5), and motility index from 5.2 +/- 0.2 to 4.4 +/- 0.2. In IBS patients, GLP-1 1.2 pmol kg(-1) min(-1) reduced the MMCs from 2.5 (2-3.5) to 1 (0-1.5) without affecting motility index. At 2.5 pmol kg(-1) min(-1) GLP-1 decreased MMCs from 2 (1.5-3) to 1 (0.5-1.5), and motility index from 5.2 +/- 0.2 to 4.0 +/- 0.5. Motility responses to GLP-1 were similar in antrum and duodenum. Presence of the GLP-1 receptor in the gut was verified by reverse transcriptase PCR. In conclusion, the gut peptide GLP-1 decreases motility in the antro-duodeno-jejunal region and inhibits the MMC in healthy subjects and IBS patients.

Modeling of in vitro drug activity and prediction of clinical outcome in acute myeloid leukemia

The objectives of this study were to develop a population pharmacodynamic model describing the in vitro drug sensitivity of tumor cells and to relate in vitro parameters to clinical outcome. Cell samples from 179 patients with acute myelocytic leukemia were exposed to cytosine arabinoside and daunorubicin, and cytotoxicity was analyzed using the fluorometric microculture cytotoxicity assay. A sigmoid E(max)-model for daunorubicin and an E(max)-model for cytosine arabinoside described the data. The model predicted drug potency (EC(50)) adequately from 1 concentration measurement. A logistic regression on individual in vitro parameters of 46 patients treated with the daunorubicin plus cytosine arabinoside regimen showed that the probability of complete response was significantly (P < .05) related to the product of the E(max)/EC(50) ratio of the two drugs. The findings demonstrate the value of population pharmacodynamic modeling of in vitro drug sensitivity data and a significant relationship between the in vitro parameters and clinical outcome.

Improving the compaction properties of roller compacted calcium carbonate

The effects of roller compaction process parameters, morphological forms of calcium carbonate and particle size of sorbitol on flow, compaction and compression properties were investigated. The morphology of the calcium carbonate and the sorbitol particle size were more influential on the compaction properties than the settings of the roller compactor. The roller compaction process was demonstrated to be robust and stable in regard to flowability and compactibility. The flowability of the granules was improved adequately to facilitate compression in a production scale rotary tablet press. By adding sorbitol to the calcium carbonate, the compressibility - characterized by the Walker coefficient W(ID) - and the compactibility C(P) were improved considerably. A correlation between the consolidation characteristics was demonstrated. Compactibility data from the compaction simulator correlated with the tablet press for two of the calcium carbonates, the cubic form and the ground quality.

Invasive fungal infections are associated with severe depletion of circulating RANTES

Serum RANTES (regulated on activation, normal T-cell expressed and secreted) concentrations were measured in 14 patients who had haematological malignancies and developed invasive fungal infections (three of them definite, eight probable and three possible). RANTES levels fell substantially from pre-chemotherapy values at the start of and throughout the fungal infection, and recovered in patients who survived the fungal infection. However, in patients who died from the invasive fungal infection, RANTES levels did not recover. For survivors the mean ± sd levels for RANTES were 7656 ± 877 pg ml−1 on the day prior to chemotherapy, 3723 ± 2443 pg ml−1 on the first day of fungal infection diagnosis (significantly different from baseline; P = 0.001) and 9078 ± 2256 pg ml−1 at recovery from the fungal infection (significantly different from lowest value; P < 0.0001). Platelet counts were closely correlated with the RANTES levels (r = 0.63, P < 0.001). The RANTES concentrations for the three patients who died were similar to those who survived at all equivalent timepoints, but were significantly lower at the time of death (792 ± 877) compared to the values at recovery for survivors (P = 0.005). The finding that patients who died from an invasive fungal infection had very low platelet counts and RANTES concentrations suggests that these could play a role in host response to such infections.

In vitro drug resistance in B cell chronic lymphocytic leukemia: a comparison with acute myelocytic and acute lymphocytic leukemia

The aim of the study was to evaluate cellular drug resistance in B cell chronic lymphocytic leukemia (B-CLL) in vitro, and compare it with that in acute myelocytic leukemia (AML) and acute lymphocytic leukemia (ALL). In vitro drug resistance was analyzed by the fluorometric microculture cytotoxicity assay (FMCA) in all samples from patients with leukemia sent to our laboratory between 1992 and 2001. Up to 14 standard drugs were evaluated in samples from 66 patients with B-CLL, 212 patients with AML and 80 patients with ALL. B-CLL cells were found to be more sensitive than cells from both AML and ALL to cytarabine, cladribine, fludarabine, doxorubicin, idarubicin, vincristine and cyclophosphamide (p<0.05). No difference in cellular drug resistance was found between B-CLL and ALL cells for prednisolone, whereas AML cells were more resistant (p<0.0001). In B-CLL, cells from patients who had received previous chemotherapy were more resistant to almost all tested drugs as compared to cells from treatment-naive patients. In AML and ALL, in vitro drug resistance was not related to previous chemotherapy. For all drugs, there was a good agreement between the activity in vitro and the known clinical disease-specific activity. The study also demonstrated an acquired cellular drug resistance in B-CLL, but not in the acute leukemias.

Recombinant human interleukin 11 and bacterial infection in patients with [correction of] haematological malignant disease undergoing chemotherapy: a double-blind placebo-controlled randomised trial

BACKGROUND

Bacteraemia in patients with haematological malignant disease causes substantial morbidity. Recombinant human interleukin 11 (rhIL-11) prevents gastrointestinal epithelial disintegrity and has immunomodulatory actions. Our aim was to ascertain whether or not treatment with rhIL-11 can prevent gut-associated infections.

METHODS

We did a double-blind placebo-controlled randomised trial, to which we enrolled 40 patients with haematological malignant disease who were undergoing chemotherapy. Patients received either rhIL-11 50 microg/kg (n=20) or placebo (n=20) daily by subcutaneous injection from the day before the start of chemotherapy until resolution of neutropenia or for 21 days, whichever was longer. Our primary outcome measure was a reduction in bacteraemia. Analysis was by intention to treat.

FINDINGS

Significantly fewer patients who received rhIL-11 rather than placebo developed bacteraemia, particularly of gastrointestinal origin: the proportion of patients with at least one positive blood culture was 0.65 and 0.25, respectively (p=0.02). The numbers of patients (placebo vs rhIL-11) for each number of distinct isolates were: no organism isolated seven versus 15, one organism nine versus four, two organisms two versus one, three organisms one versus none, and four organisms one versus none (p=0.01), suggesting a lower bacterial load in the rhIL-11 than in the placebo group. Time to first bacteraemic event was longer in patients who received rhIL-11 (p=0.03) than in those who received placebo.

INTERPRETATION

rhIL-11 reduces the frequency and load of bacteraemia in patients with haematological malignant disease undergoing chemotherapy, possibly by gastrointestinal cytoprotective or immunological mechanisms [corrected].

In vitro evaluation of the efficacy of idarubicin in human tumour cells from patients with low-grade non-Hodgkin's lymphoma

Evaluating the potential benefit of the new anthracycline, idarubicin (Ida), in lymphoma, 58 tumour samples from patients suffering from low-grade non-Hodgkin's lymphoma (L-NHL), were analysed in vitro for their sensitivity to 0.5 microg/ml Ida. This was compared with the sensitivity to other anthracyclines (0.5 microg/ml), using the fluorometric microculture cytotoxicity assay. A total of 132 samples from patients with acute leukaemia and a cell-line panel representing different resistance mechanisms was included for comparison. The median cell survival of L-NHL cells did not differ after exposing the cells to Ida or daunorubicin (Dnr), whereas epirubicin, doxorubicin (Dox) and mitoxantrone (Mitox) were significantly less cytotoxic than Ida (P < 0.001). The median cell survival in L-NHL cells did not differ from that of acute leukaemia cells after exposure to 0.5 microg/ml Ida, Dnr, Dox and Mitox. Cells from previously treated patients with L-NHL had a higher median survival than cells from untreated patients after exposure to all drugs, except for Ida. In samples from previously untreated patients, Spearman rank correlations were high (Rho = 0.81-0.90) between cell survival after exposure to Ida and the other anthracyclines. The same pattern was observed in the cell-line panel (Rho = 0.78-0.91) (P < 0.05). In contrast, low correlations (Rho = 0.24-0.42) were observed among samples from previously treated patients. Our results indicate a potential benefit of Ida in previously drug-treated patients with L-NHL.

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.

Synthesis of ortho substituted arylboronic esters by in situ trapping of unstable lithio intermediates

[reaction: see text] Ortho lithiation-in situ boration using lithium 2,2,6,6-tetramethylpiperidide (LTMP) in combination with triisopropylborate (B(OiPr)(3)) is a highly efficient and experimentally straightforward process for the preparation of ortho substituted arylboronic esters. The mild reaction conditions allow the presence of functionalities such as ester or cyano groups or halogen substituents that are usually not compatible with the conditions used in directed ortho metalation of arenes. The arylboronic esters underwent Suzuki-type cross-coupling with a range of aryl halides, furnishing biaryls in 53-94% yield.

Synthesis of ortho substituted arylboronic esters by in situ trapping of unstable lithio intermediates

[reaction: see text] Ortho lithiation-in situ boration using lithium 2,2,6,6-tetramethylpiperidide (LTMP) in combination with triisopropylborate (B(OiPr)(3)) is a highly efficient and experimentally straightforward process for the preparation of ortho substituted arylboronic esters. The mild reaction conditions allow the presence of functionalities such as ester or cyano groups or halogen substituents that are usually not compatible with the conditions used in directed ortho metalation of arenes. The arylboronic esters underwent Suzuki-type cross-coupling with a range of aryl halides, furnishing biaryls in 53-94% yield.

In vivo activity of CHS 828 on hollow-fibre cultures of primary human tumour cells from patients

Fresh human tumour cells from patients with ovarian cancer and chronic lymphocytic leukaemia were cultured in semipermeable hollow fibres. The fibres were implanted on immunocompetent rats, which were treated with the cyanoguanidine N-(4-chlorophenoxyhexyl)-N'-cyano-N"-4-pyridylguanidine (CHS 828). CHS 828 showed high antitumour activity against all eight tumour samples; the fibres from control animals had a mean net growth of 73% while CHS 828 treatment induced a 37% mean reduction of cell density, without observable haematological toxicity. The results show a feasibility of using tumour cells directly from patients in the hollow-fibre rat model.

Temporal effects of the novel antitumour pyridyl cyanoguanidine (CHS 828) on human lymphoma cells

CHS 828, a novel pyridyl cyanoguanidine, has shown potent antitumour activity both in vitro and in vivo and is currently undergoing phase I evaluation in humans in collaboration with the European Organization for Research and Treatment of Cancer (EORTC). Here we study the temporal effects of CHS 828 on cytotoxicity, protein and DNA synthesis, cellular morphology and ultra structure using the lymphoma cell line U-937 GTB as the primary tumour model. In vitro analysis of tumour cell survival in response to CHS 828 revealed a cytotoxic effect progressively increased as a function of exposure time with maximum efficacy observed after 72 h. Activity of CHS 828 on U-937 GTB cells grown in vivo was also found. CHS 828 induced-cell death was dependent on intact protein synthesis and most cells appeared to lose their membrane integrity in the presence of a relatively well preserved nuclear structure. The results indicate that CHS 828 induced active and delayed cell death with a non-apoptotic morphology.

Direct pelletization in a rotary processor controlled by torque measurements. II: effects of changes in the content of microcrystalline cellulose

In the present study we investigated the effect of changes in the content of microcrystalline cellulose (MCC) on a direct pelletization process in a rotary processor in which the liquid addition was terminated once a certain increase in torque was produced. Nine different mixtures of MCC and lactose with MCC contents varying from 10% to 100% (w/w) were pelletized using 6 different torque increase levels, and the changes in pellet characteristics were investigated. The pellet characteristics investigated were pellet shape, size, and size distribution as well as the water content of the pellets at the end of liquid addition. To produce spherical agglomerates with suitable characteristics in a reproducible way, a content of at least 20% (w/w) MCC was found necessary. Linear correlations were found between the MCC content and the water content and between the torque increase and the water content, showing that the torque increase is suitable to control the process. A higher torque increase or a higher MCC content was found to increase the water content independently of each other.

Direct pelletization in a rotary processor controlled by torque measurements. I. Influence of process variables

The aim of this study was to elucidate the feasibility of using torque measurement to control the end point of a wet pelletization process in a rotary processor at varying levels of friction plate rotation speed, air gap pressure difference, and batch size. A 1:1 mixture of lactose monohydrate (200 mesh) and microcrystalline cellulose (PH-101) was granulated into pellets in an instrumented laboratory scale rotary processor using water as aqueous binder liquid. A full factorial designed study was performed to investigate the influence of the friction plate rotation speed (600 and 1200 rpm), the air gap pressure difference (1 and 3 kPa), the torque increase (0.4 and 0.8 N.m) and the batch size (500 and 1000 g) on the pellet properties. All pellets produced were round and showed a narrow size distribution. The geometric mean diameter varied from 400 to 1900 microns with a good reproducibility. Increasing the batch size and the rotation speed led to smaller pellets, whereas a higher torque produced larger pellets. This study showed that the process can be controlled by means of the torque increase because it was possible to produce pellets of a reproducible size by stopping the liquid addition at a certain torque level.

Evaluation of purine and pyrimidine analogues in human tumor cells from patients with low-grade lymphoproliferative disorders using the FMCA

The purine analogues fludarabine and cladribine (CdA) have recently become established to be effective treatment for low-grade non-Hodgkin's lymphoma (NHL). The pyrimidine nucleoside analogue cytarabine (AraC) has an important place in the treatment of acute leukemia, and gemcitabine is a new pyrimidin antimetabolite which has shown clinical activity against solid tumors. We have used the semiautomated fluorometric microculture cytotoxicity assay (FMCA), based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA), to study these drugs. Eighty samples from 60 patients with low-grade NHL were studied. Fifty samples from patients with acute lymphoid leukemia (ALL) and 118 samples from patients with acute myeloid leukemia (AML) were included for comparison. The results indicate that the purine- and pyrimidine nucleoside analogues tested may be as active against low-grade NHL as against acute leukemia. In low-grade NHL, AraC seems to be even more active in comparison to CdA (p=<0.0001) and fludarabine (p=0.001). Untreated patients were more drug sensitive than previously treated patients. Gemcitabine showed the highest correlation with AraC (0.90) whereas CdA showed the highest correlation with fludarabine (0.84). Based on these results we propose that AraC and gemcitabine may have a role in the treatment of low-grade NHL.

Delivery of antisense oligonucleotides using HPMA polymer: synthesis of A thiol polymer and its conjugation to water-soluble molecules

Here, we report the synthesis and characterization of an HPMA-based polymer for use as a carrier for the delivery of water soluble drugs. The polymer contains active-sulfhydryl groups for coupling of ligands through a disulfide linkage. The polymer can also be prepared containing pendant amino groups in addition to the active-sulfhydryl moiety. This allows the use of different chemistries to conjugate a variety of ligands to the polymer. We demonstrate that a sulfhydryl-terminated antisense oligonucleotide can be efficiently and rapidly conjugated to the polymer. The polymer-oligonucleotide conjugate is efficiently taken up by cultured cells.

[Significance of idiopathic preterm birth in relation to previous and future pregnancies]

This registry-based cohort study aimed to describe the relationship between pregnancy complications in the first and second pregnancy, focussing on idiopathic and indicated preterm birth of singleton infants in either pregnancy. The cohort consisted of all women living in Denmark with a first singleton birth in 1982 and a second in the period 1982-1987 (13,967 women). The risk of a second preterm birth was not significantly different between women who had an idiopathic or an indicated first preterm birth (15.2 and 12.8% respectively). Adjustment by logistic regression analysis for other risk factors for preterm birth did not influence the relative risk (6.0 before 32 weeks and 4.8 between 32 and 36 weeks) of a second preterm birth subsequent to a first one. Women with idiopathic preterm delivery in their first or second pregnancies give birth to infants with lower birth weight in previous or subsequent pregnancies. Emergency cesarean section in a first term pregnancy was a risk factor for subsequent idiopathic preterm birth.

Ampicillin-metronidazole treatment in idiopathic preterm labour: a randomised controlled multicentre trial

OBJECTIVE

To determine whether treatment with ampicillin and metronidazole in women with threatened idiopathic preterm labour will prolong the gestation and reduce maternal and neonatal infectious morbidity.

DESIGN

Randomised controlled double-blind trial.

SETTING

Six obstetric departments in the Copenhagen area.

POPULATION

One hundred and twelve women with singleton pregnancies, with threatened idiopathic preterm labour and intact amniotic membranes at 26 to 34 weeks of gestation.

METHODS

Random allocation to eight days intravenous and oral treatment with ampicillin and metronidazole, or placebo.

MAIN OUTCOME MEASURES

Number of days from admission to delivery, gestational age at delivery, rates of preterm delivery, low birthweight, maternal infections and neonatal infections.

RESULTS

Treatment with ampicillin and metronidazole was associated with a significant prolongation of pregnancy (admission to delivery 47.5 days versus 27 days, P < 0.05), higher gestational age at delivery (37 weeks versus 34 weeks, P < 0.05), decreased incidence of preterm birth (42% versus 65%, P < 0.05), and lower rate of admission to neonatal intensive care unit (40% versus 63%, P < 0.05), when compared with placebo treatment. Antibiotic treatment had no significant effects on infectious morbidity.

CONCLUSIONS

Treatment with ampicillin and metronidazole in women with threatened idiopathic preterm labour significantly prolonged the gestation, but had no effects on maternal and neonatal infectious morbidity.

Cytotoxic activity of cyclosporin A and [3-keto-Bmt1]-[Val2]-cyclosporin (SDZ PSC 833) on tumour cells from patients with haematological malignancies

OBJECTIVE AND METHOD

The fluorometric microculture cytotoxic assay was employed for characterisation of the cytotoxic effect of cyclosporin A (CsA) and its non-immunosuppressive analogue SDZ PSC 833, [3-keto-Bmt1]-[Val2]-cyclosporin (PSC) in tumour cells from patients with haematological or solid tumours.

RESULTS

Tumour cells from patients with chronic lymphocytic leukemia (CLL) or non-Hodgkin's lymphoma (NHL) were found to be more sensitive to both drugs than those of tumour cells from patients with acute lymphocytic leukemia (ALL), acute myoblastic leukaemia (AML) and various solid tumours. There was a close correlation between the effects of the two drugs (correlation coefficient 0.71), but CsA was slightly more active than PSC in most diagnoses. No tumour cells sample showed sensitivity to PSC without also being sensitive to CsA. There was a moderate level of correlation between the activity pattern of CsA and doxorubicin (correlation coefficient 0.66), whereas the correlations with other cytostatics, such as vincristine, cytarabine and melphalan, were low (correlation coefficient -0.11 to 0.33).

CONCLUSION

The results indicate that PSC shares the direct cytotoxic properties of CsA, but is slightly less potent. Clinical testing of the cytotoxic effect of these agents in haematological malignancies seems warranted and the apparent non-cross-resistance with standard agents makes cyclosporins a potentially useful adjunct to chemotherapy in those diagnoses.

[Idiopathic preterm deliveries in Denmark]

The objective of the study was to characterize and quantify various demographic factors in idiopathic preterm delivery. All women with a permanent address in Denmark with singleton pregnancies who gave birth to an infant in 1982 (n = 51,851) are included. The material was obtained by a linkage of the Medical Birth Register and the National Register of Hospital Discharges, using the personal identification number. The incidence of singleton preterm delivery was 4.5% (n = 2330) of which 67% (n = 1557) were idiopathic. Neonatal mortality rates were significantly lower in idiopathic compared to indicated preterm birth. Following stepwise logistic regression analysis, maternal age below 20 (adjusted odds ratio 1.63, 95% confidence interval (CI) 1.07-2.47; p < 0.03), maternal age above 30 (adjusted odds ratio 0.74, 95% CI 0.60-0.90; p < 0.004) and being married (adjusted odds ratio 0.63, 95% CI 0.43-0.94; p < 0.03) correlated with idiopathic preterm birth. It is concluded that idiopathic preterm birth is more common in single, young women and associated with lower neonatal mortality rate than indicated preterm birth.

In vitro evaluation of new anticancer drugs, exemplified by vinorelbine, using the fluorometric microculture cytotoxicity assay on human tumor cell lines and patient biopsy cells

The feasibility of combined studies on a cell-line panel and primary cultures of patient tumor cells in the preclinical evaluation of new anticancer drugs was evaluated in a study of the activity and cross-resistance pattern in vitro of the new semi-synthetic vinca alkaloid vinorelbine (Vrb). The activity of Vrb was investigated in ten cell lines representing different resistance mechanisms and in a total of 256 fresh human tumor samples, using the fluorometric microculture cytotoxicity assay (FMCA). Resistance to Vrb in the cell lines was associated with expression of the multidrug resistance-mediating P-glycoprotein and the multidrug resistance-associated protein (MRP) and by a recently described tubulin-associated mechanism, while the cell lines with topoisomerase II- and glutathion-associated resistance did not show decreased sensitivity to the drug. Cross-resistance to vincristine (Vcr) and other tubulin-active agents was high in cell lines as well as in patient cells. As with most commonly used anti-cancer drugs, Vrb was more active in hematological than in solid tumor samples. Among the solid tumors investigated, the highest in vitro response rates were observed in ovarian cancer (27%), sarcoma (25%), non-small cell lung cancer (21%) and bladder cancer (20%), while no response was observed in renal or colorectal cancer. Compared to Vcr, Vrb appeared to be slightly more active in solid tumors and slightly less active in hematological tumors. The results show that although Vrb displays a high degree of cross-resistance to Vcr and other tubulin-active drugs, some difference in the activity spectrum could be detected and that the drug is sensitive to multiple mechanisms of resistance. The results also suggest that leukemias, ovarian cancer, sarcoma and bladder cancer are possible further targets for Vrb. The combination of studies on a cell-line panel and patient tumor cells from a broad spectrum of diagnoses to evaluate a new drug seems feasible and may give information on the mechanism of action and target diagnoses for phase II trials.

Validation of the Danish Birth Registration

We assessed validity and reliability of data on four serious pregnancy complications and gestational age in two national registers, the Medical Birth Register (MBR) and the National Register of Hospital Discharges (NRHD). From a cohort of all women in Denmark who gave birth to their first and second singleton infant in 1982-1987, a review was made of a selected sample of 1662 medical records. Regarding registration of pregnancy complications, there was good agreement (kappa above 0.6) between medical records and the registers, and between the registers. However, there was a tendency toward understatement evidenced by low sensitivity of three of four pregnancy complications. The level of agreement (43%) for length of gestation was disappointing. The number of systematic and nonsystematic errors indicate that there was about 52% more singleton preterm deliveries in Denmark in 1982 than previously reported (6.9% instead of 4.5%). It is concluded that the validity of the Danish birth registers should be improved by explicit definitions, increased use of raw data, and data collection by motivated professionals at birth.

Evaluation of platelet function using the in vitro bleeding time and corrected count increment of transfused platelets. Comparison between platelet concentrates derived from pooled buffy coates and apheresis

The functional capacity of transfused platelets was evaluated with in vitro bleeding time (IVBT) and corrected count increment (CCI) in order to compare platelet concentrates (PCs) derived from pooled buffy coats (BC-PCs) with PCs collected by apheresis (A-PCs). The suspension medium in the BC-PCs was 30% CPD plasma and 70% of an additive solution (containing sodium and potassium chloride, sodium citrate and phosphate, mannitol), and in the A-PCs the medium was 100% CPD plasma. IVBT was evaluated using a Thrombostat 4000/2. BC-PC and A-PC were transfused 57 and 41 times, respectively to 36 patients with chemotherapy-induced thrombocytopenia. PCs transfused within 2 days of donation were considered fresh, and those transfused within 3-5 days were considered stored. IVBT was determined before, as well as 10-30 min and 24 h after transfusion; CCI was determined 10-30 min and 24 h after transfusion. The median pretransfusion IVBT value was 486 s. It was measurable in 21 of 98 (21%) of the transfusions, i.e. below the cutoff limit of 486 s. Ten to 30 min after transfusion, the IVBT showed a measurable reduction in 90% of the transfusions with fresh BC-PCs, 92% of those with fresh a-PCs, 63% of those with stored BC-PCs and 79% of those with stored A-PCs. After 24 h, the corresponding values were 63% for fresh BC-PCs, 50% for fresh A-PCs, 26% for stored BC-PCs and 38% for stored A-PCs. The median value of CCI 10-30 min after transfusion was 20 for fresh BC-PCs, 17 for fresh A-PCs, 16 for stored BC-PCs and 14 for stored A-PCs. The difference in IVBT between fresh and stored BC-PCs was significant (p = 0.032), unlike that between fresh and stored A-PC. After 24 h the corresponding values were 7 for fresh BC-PCs, 4 for fresh A-PCs, 4 for stored BC-PCs and 3 for stored A-PCs. When all transfusions with fresh PCs (BC-PCs + A-PCs) were compared with all transfusions with stored PCs, a statistical difference was demonstrated in both CCI (p = 0.027) and IVBT (p = 0.043). Spearman's rank correlation coefficient (rs) was -0.41 between CCI and IVBT < 486 s 10-30 min after transfusion, and -0.55 between the posttransfusion platelet count and IVBT, indicating a relatively poor correlation between CCI and IVBT, and a slightly better correlation between platelet count and IVBT. In conclusion, BC-PCs showed a slightly higher CCI and a better response in IVBT than A-PCs. No statistical difference was demonstrated between BC-PCs and A-PCs transfused within 2 days after donation, with respect to function and recovery in vivo. BC-PCs stored for 3 days or more showed about the same CCI and IVBT as stored A-PC but significantly lower CCI and higher IVBT than fresh BC-PCs. This may indicate that the preparation and/or storage conditions were not optimal. IVBT seems to be a useful possibility to test the in vivo behavior of transfused platelets.

Intrauterine growth and gestational age in preterm infants with cerebral palsy

In a case-control study, gestational age and intrauterine growth of 191 preterm singleton infants 1971-82 with cerebral palsy were compared to all preterm live-born singletons in Denmark in 1982 (N = 2203). The distribution of gestational age among preterm cases was slightly bimodal with maximum values at 29 and 32 weeks. The risk for cerebral palsy was highest in the infants with gestational age 28-30 weeks (OR = 5.6 (4.0-7.8), 95% confidence interval). Birth weight deviation, in the 34-36 weeks infants, expressed as the number of standard deviations from the mean birth weight for gestational age, was more negative in cases than in controls (P < 0.001). The frequency of small for gestational age (SGA) was 13% in cases and 9% in controls (OR = 1.5 (0.96-2.3), 95% confidence interval). The odds for cerebral palsy being SGA, was lower in 28-30 weeks (OR = 0.22 (0.06-0.86), 95% confidence interval), the same in 31-33 weeks (OR = 0.83 (0.35-2.0), 95% confidence interval) and higher in 34-36 weeks (OR = 5.2 (2.9-9.5), 95% confidence interval). In conclusion, preterm infants with cerebral palsy are born earlier than other preterm infants. Small for gestational age is associated with cerebral palsy in preterm infants only above 33 weeks.

Effects of nabumetone on platelet function in healthy volunteers

Non-steroidal anti-inflammatory drugs (NSAID) are frequently prescribed but gastrointestinal haemorrhages and inhibition of platelet function are two side effects that limit their use. Nabumetone belongs to a new prostaglandin-sparing class of NSAID with a low potential for causing gastrointestinal mucosal irritancy and inhibition of platelet function. We have used flow cytometry and in vitro bleeding time (IVBT) to measure the effects of nabumetone on platelet function in healthy volunteers. Nabumetone was found to cause a significant decrease in platelet-bound fibrinogen after adenosine diphosphate (ADP) activation using flow cytometry and a significant increase in IVBT when using CaCl(2) as activating substance. The platelet inhibitory effect was less pronounced than the changes seen with low dose aspirin. Flow cytometry and IVBT are two sensitive methods well suited for clinical use and could both be used to monitor drug-induced inhibition of platelet function.

Clinical experience with recombinant factor VIIa in patients with thrombocytopenia

Platelets play a central role in primary hemostasis. The role of the coagulation mechanism during early stages of hemostasis is less clear, although increasing evidence is emerging indicating the ultimate importance of the factor VII (FVII)-tissue factor-dependent coagulation system in providing the first thrombin molecules necessary for the platelet activation to occur. Supporting this, early fibrin formation has been reported to occur within the bleeding time wound and infusion of recombinant FVIIa (rFIIa) has been shown to shorten the bleeding time in rabbits. We have investigated whether infusion of rFVIIa would enhance fibrin formation in bleeding time wounds in patients with thrombocytopenia as reflected by a shortening of the bleeding time. A reduction of the bleeding time was found in 55/105 cases (52%). The decrease was significantly more pronounced when the platelet count exceeded 20 x 10(9)/l. With the exception of an anaphylactoid reaction in 1 patient, no major adverse reactions related to the study drug were observed. Nine infusions of rFVIIa were given to 8 thrombocytopenic patients with overt bleeding. One patient received two infusions. Bleeding decreased in all patients and stopped in 6 patients.