Automated wash and reuse of disposable pipette tips in a SARS-CoV-2 RT-qPCR diagnostic pipeline

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic led to global shortages in laboratory consumables, in particular for automated PCR. The Technical University of Denmark supported Danish hospitals from 2020 to 2022, conducting SARS-CoV-2 RT-qPCR on around 10,000 patient samples daily. We encountered shortages of disposable pipette tips used with automated liquid handlers that transferred oropharyngeal swab samples to 96-well microplates before RNA extraction. To enable tip reuse, we developed an automated protocol for washing tips with a 0.5 % sodium hypochlorite solution. This effectively eliminated carry-over of genomic material and the wash solution remained effective when stored in an open reservoir at ambient temperatures for 24 h. A three-day validation setup demonstrated the robustness of the tip wash protocol. Reducing the number of tips used for transferring samples to 96-well microplates from 96 to 8 enabled us to mitigate pipette tip shortages, lower costs, and minimize plastic waste generation.

COVID-19 Rapid Antigen Tests With Self-Collected vs Health Care Worker-Collected Nasal and Throat Swab Specimens: A Randomized Clinical Trial

Importance

Self- or health care worker (HCW)-collected nasal swab specimens are the preferred sampling method to perform rapid antigen testing for COVID-19, but it is debated whether throat specimens can improve test sensitivity.

Objective

To compare the diagnostic accuracy of self- and HCW-collected nasal vs throat swab specimens for COVID-19 rapid antigen testing.

Design, Setting, and Participants

This per-protocol multicenter randomized clinical trial was conducted from February 15 through March 25, 2022. The participants, individuals aged 16 years or older requesting a COVID-19 test for diagnostic or screening purposes, had 4 specimens collected for individual testing at 1 of 2 urban COVID-19 outpatient test centers in Copenhagen, Denmark.

Interventions

Participants were randomized 1:1 to self-collected or HCW-collected nasal and throat swab specimens for rapid antigen testing. Additional HCW-collected nasal and throat swab specimens for reverse transcriptase-polymerase chain reaction (RT-PCR) were used as the reference standard.

Main Outcomes and Measures

The primary outcome was sensitivity to diagnose COVID-19 of a self- vs HCW-collected nasal and throat specimen for rapid antigen testing compared with RT-PCR.

Results

Of 2941 participants enrolled, 2674 (90.9%) had complete test results and were included in the final analysis (1535 [57.4%] women; median age, 40 years [IQR, 28-55 years]); 1074 (40.2%) had COVID-19 symptoms, and 827 (30.9%) were positive for SARS-CoV-2 by RT-PCR. Health care worker-collected throat specimens had higher mean sensitivity than HCW-collected nasal specimens for rapid antigen testing (69.4% [95% CI, 65.1%-73.6%] vs 60.0% [95% CI, 55.4%-64.5%]). However, a subgroup analysis of symptomatic participants found that self-collected nasal specimens were more sensitive than self-collected throat specimens for rapid antigen testing (mean sensitivity, 71.5% [95% CI, 65.3%-77.6%] vs 58.0% [95% CI, 51.2%-64.7%]; P < .001). Combining nasal and throat specimens increased sensitivity for HCW- and self-collected specimens by 21.4 and 15.5 percentage points, respectively, compared with a single nasal specimen (both P < .001).

Conclusions and Relevance

This randomized clinical trial found that a single HCW-collected throat specimen had higher sensitivity for rapid antigen testing for SARS-CoV-2 than a nasal specimen. In contrast, the self-collected nasal specimens had higher sensitivity than throat specimens for symptomatic participants. Adding a throat specimen to the standard practice of collecting a single nasal specimen could improve sensitivity for rapid antigen testing in health care and home-based settings.

Trial Registration

ClinicalTrials.gov Identifier: NCT05209178.

Evaluation of four laboratory-based high-throughput SARS-CoV-2 automated antigen tests compared to RT-PCR on nasal and oropharyngeal samples

BACKGROUND

The demand for RT-PCR testing has been unprecedented during the SARS-CoV-2 pandemic. Fully automated antigen tests (AAT) are less cumbersome than RT-PCR, but data on performance compared to RT-PCR are scarce.

METHODS

The study consists of two parts. A retrospective analytical part, comparing the performance of four different AAT on 100 negative and 204 RT-PCR positive deep oropharyngeal samples divided into four groups based on RT-PCR cycle of quantification levels. In the prospective clinical part, 206 individuals positive for and 199 individuals negative for SARS-CoV-2 were sampled from either the anterior nasal cavity (mid-turbinate) or by deep oropharyngeal swabs or both. The performance of AATs was compared to RT-PCR.

RESULTS

The overall analytical sensitivity of the AATs differed significantly from 42% (95% CI 35-49) to 60% (95% CI 53-67) with 100% analytical specificity. Clinical sensitivity of the AATs differed significantly from 26% (95% CI 20-32) to 88% (95% CI 84-93) with significant higher sensitivity for mid-turbinate nasal swabs compared to deep oropharyngeal swabs. Clinical specificity varied from 97% to 100%.

CONCLUSION

All AATs were highly specific for detection of SARS-CoV-2. Three of the four AATs were significantly more sensitive than the fourth AAT both in terms of analytical and clinical sensitivity. Anatomical test location significantly influenced the clinical sensitivity of AATs.

Validation and advantages of using novel RT-qPCR melting curve analysis assays for the identification of SARS-CoV-2 variants

Reverse transcription quantitative PCR (RT-qPCR) assays are gold standard in diagnosing SARS-CoV-2 infection and play a major role in viral subtyping for rapid detection and monitoring of important mutations, containing the spread of new virus variants. We wanted to compare RT-qPCR melting curve analysis assays to Sanger Sequencing for detection of variants within the SARS-CoV-2 spike glycoprotein and examined their sensitivity and specificity. Samples positive for SARS-CoV-2 (n = 663 + 82) were subtyped using both Sanger sequencing and five RT-qPCR melting curve analysis assays specific for the mutations N501Y, P681H, E484K, K417N/T, and N439K. The results of the two methods were compared. The training cohort and the clinical validation cohort showed equally, or significantly better sensitivity of the assays compared to the Sanger sequencing. The agreement of the Sanger sequencing and the assays ranged from 92.6 to 100% for the training cohort and 99.4-100% for the clinical validation. The sensitivity, specificity, and turn-around time of the RT-qPCR melting curve analysis assays are well-suited for clinical monitoring of VOCs, making the assays an important tool in contact tracing and risk stratification. Furthermore, the assays were able to indicate the presence of new mutations in the complementary sequence to the mutation-specific probes.

A nationwide analytical and clinical evaluation of 44 rapid antigen tests for SARS-CoV-2 compared to RT-qPCR

Background

The SARS-CoV-2 pandemic has resulted in massive testing by Rapid Antigen Tests (RAT) without solid independent data regarding clinical performance being available. Thus, decision on purchase of a specific RAT may rely on manufacturer-provided data and limited peer-reviewed data.

Methods

This study consists of two parts. In the retrospective analytical part, 33 RAT from 25 manufacturers were compared to RT-PCR on 100 negative and 204 positive deep oropharyngeal cavity samples divided into four groups based on RT-PCR Cq levels. In the prospective clinical part, nearly 200 individuals positive for SARS-CoV-2 and nearly 200 individuals negative for SARS-CoV-2 by routine RT-PCR testing were retested within 72 h for each of 44 included RAT from 26 manufacturers applying RT-PCR as the reference method.

Results

The overall analytical sensitivity differed significantly between the 33 included RAT; from 2.5% (95% CI 0.5–4.8) to 42% (95% CI 35–49). All RAT presented analytical specificities of 100%. Likewise, the overall clinical sensitivity varied significantly between the 44 included RAT; from 2.5% (95% CI 0.5–4.8) to 94% (95% CI 91–97). All RAT presented clinical specificities between 98 and 100%.

Conclusion

The study presents analytical as well as clinical performance data for 44 commercially available RAT compared to the same RT-PCR test. The study enables identification of individual RAT that has significantly higher sensitivity than other included RAT and may aid decision makers in selecting between the included RAT.

Funding

The study was funded by a participant fee for each test and the Danish Regions.

Preference for artificial range enrichment design features in free-range commercial laying hens

1. This study examined what elements of artificial enrichment structures attract hens in the outdoor range, and what behaviours hens perform around these structures. Three principles of cover design (height, orientation and visual density) were tested for laying hen preference in the outdoor range of a commercial egg farm using a 2 × 3 × 3 factorial design. The factors were height: 0.5 m or 1.5 m; orientation: vertical, horizontal or horizontal cover with one vertical side; and visual density: 0% (control), 50% or 90% UV blocking cloth.2. A significant three-way interaction between all factors was found (P < 0.001). The most preferred visual density of these structures was the 90%, followed by 50% UV blocking cloth. Horizontal structures with one vertical side, of either height, were highly preferred. Short horizontal structures were preferred to tall ones, and tall vertical structures were slightly preferred over short ones.3. The most common behaviours observed around the structures were interaction with the structure (pecks, scratches and vigilance directed at the structure; 32.7%), foraging (32.2%), locomotion (9.9%), and air foraging (pecks and snapping in the air; 9.0%). A three-way interaction between the design principles influenced the proportion of hens performing each of these behaviours (P < 0.001). Hens foraged more around structures with no shade cloth and interacted more with structures that had dense shade cloth.4. These results highlighted the complexity of designing attractive outdoor environments for laying hens. By testing the combination of elements that hens prefer it is possible to understand how to design attractive outdoor ranges that attract hens and promote a diverse range of behaviours on commercial farms.

Context matters: The role of subjective arousal during Attentional Bias Modification targeting socially anxious students

BACKGROUND AND OBJECTIVES

Attentional Bias Modification (ABM) paradigms targeting anxiety aim to reduce attentional biases for threatening stimuli and thereby reduce anxiety. Based on cognitive theories of performance and learning, elevated levels of arousal during ABM might enhance its effectiveness by making training more engaging and activating fear schemas. This study investigated whether elevated levels of arousal during ABM would increase its effectiveness in reducing attentional bias, stress reactivity, and post-event processing.

METHOD

We randomly assigned 79 high socially anxious students to a session of ABM or control training preceded by either a social stress or control induction to manipulate arousal. Training outcomes were attentional bias, stress reactivity, and post-event processing. Subjective arousal was assessed before, during, and after training.

RESULTS

Results indicated that ABM was not successful in reducing attentional bias, stress reactivity or post-event processing, and that the effects of ABM were not moderated by subjective arousal. There was a trend towards ABM being more effective than control training in reducing attentional bias directly after training when participants were more aroused. However, this effect was not maintained one day after the training.

LIMITATIONS

The arousal manipulation did not result in significant between-group differences in subjective arousal.

CONCLUSIONS

This study did not provide support for the moderating role of arousal in ABM training effects. Replications with more effective mood induction procedures and more power are needed as a trend finding was observed suggesting that higher levels of arousal improved the direct ABM effects on attentional bias.

A European interlaboratory trial to evaluate the performance of different PCR methods for Mycoplasma bovis diagnosis

BACKGROUND

Several species-specific PCR assays, based on a variety of target genes are currently used in the diagnosis of Mycoplasma bovis infections in cattle herds with respiratory diseases and/or mastitis. With this diversity of methods, and the development of new methods and formats, regular performance comparisons are required to ascertain diagnostic quality. The present study compares PCR methods that are currently used in six national veterinary institutes across Europe. Three different sample panels were compiled and analysed to assess the analytical specificity, analytical sensitivity and comparability of the different PCR methods. The results were also compared, when appropriate, to those obtained through isolation by culture. The sensitivity and comparability panels were composed of samples from bronchoalveolar fluids of veal calves, artificially contaminated or naturally infected, and hence the comparison of the different methods included the whole workflow from DNA extraction to PCR analysis.

RESULTS

The participating laboratories used i) five different DNA extraction methods, ii) seven different real-time and/or end-point PCRs targeting four different genes and iii) six different real-time PCR platforms. Only one commercial kit was assessed; all other PCR assays were in-house tests adapted from published methods. The analytical specificity of the different PCR methods was comparable except for one laboratory where Mycoplasma agalactiae was tested positive. Frequently, weak-positive results with Ct values between 37 and 40 were obtained for non-target Mycoplasma strains. The limit of detection (LOD) varied from 10 to 10³ CFU/ml to 10³ and 10⁶ CFU/ml for the real-time and end-point assays, respectively. Cultures were also shown to detect concentrations down to 10² CFU/ml. Although Ct values showed considerable variation with naturally infected samples, both between laboratories and tests, the final result interpretation of the samples (positive versus negative) was essentially the same between the different laboratories.

CONCLUSION

With a few exceptions, all methods used routinely in the participating laboratories showed comparable performance, which assures the quality of diagnosis, despite the multiplicity of the methods.

Behavioural repertoire of free-range laying hens indoors and outdoors, and in relation to distance from the shed

BACKGROUND

Access to an outdoor area is believed to allow free-range hens to express a greater behavioural repertoire. However, very little research has been done in this area. We hypothesised that the type and frequency of behaviours would differ between areas that vary in their characteristics and distance from the shed.

METHODS

This preliminary study investigated the behaviour of free-range laying hens in indoor and outdoor areas on one commercial free-range farm, through video recordings and scan sampling of focal hens, with the aim of determining their behavioural repertoire and time budget.

RESULTS

While ranging, hens spent most of their time foraging. Indoors, hens preened and rested. Behaviour in the wintergarden showed similarities to both the indoor and outdoor areas, with preening, resting and foraging behaviours. Differences were not in the main behavioural repertoire, but rather in terms of time budget, with access to the range and wintergarden encouraging exploration.

CONCLUSION

There was no difference in the types of behaviours that hens performed in the outdoor range compared with inside the shed, but access to a wintergarden and the outdoor range were favoured by the hens for foraging.

Long-term effects of prenatal progesterone exposure: neurophysiological development and hospital admissions in twins up to 8 years of age

OBJECTIVES

To perform a neurophysiological follow-up at 48 or 60 months of age in children exposed prenatally to progesterone compared with a placebo and evaluate their medical histories up to 8 years of age.

METHODS

In this study, Danish participants of the PREDICT study, including 989 surviving children from 498 twin pregnancies, were followed-up. PREDICT was a placebo-controlled randomized clinical trial examining the effect of progesterone for prevention of preterm delivery in unselected twin pregnancies. Medical histories of the children were reviewed and neurophysiological development was evaluated by the parent-completed Ages and Stages Questionnaire (ASQ) at either 48 or 60 months after the estimated date of delivery. We used the method of generalized estimating equation to account for the correlation within twins.

RESULTS

A total of 492 children had been exposed prenatally to progesterone and 497 to placebo. There was no difference in the number of admissions to or length of stay in hospital between the treatment groups, and we found no overall difference in the rates of diagnoses made. However, the odds ratios (ORs) for a diagnosis concerning the heart was 1.66 (95% CI, 0.81-3.37), favoring placebo, among all children, 2.38 (95% CI, 1.07-5.30) in dichorionic twins and 8.19 (95% CI, 1.02-65.6) in all children when excluding diagnoses made at outpatient clinic visits. ASQ scores were available for 437 children (progesterone, n = 225; placebo, n = 212). Mean ASQ score was slightly higher in the progesterone group compared with the placebo group (P = 0.03). In dichorionic twins, the risk of having a low ASQ score (< 10(th) centile) was decreased in the progesterone group (OR, 0.34 (95% CI, 0.14-0.86)).

CONCLUSION

Second- and third-trimester exposure of the fetus to progesterone does not seem to have long-term harmful effects during childhood, but future studies should focus on cardiac disease in the child. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Structure–activity correlation in transfection promoted by pyridinium cationic lipids

The efficiency of transfection of a plasmid DNA promoted by a series of pyridinium lipids is correlated with molecular parameters of the lipids.

Identification of the angiogenic gene signature induced by EGF and hypoxia in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is characterised by hypoxia, which activates gene transcription through hypoxia-inducible factors (HIF), as well as by expression of epidermal growth factor (EGF) and EGF receptors, targeting of which has been demonstrated to provide therapeutic benefit in CRC. Although EGF has been demonstrated to induce expression of angiogenic mediators, potential interactions in CRC between EGF-mediated signalling and the hypoxia/HIF pathway remain uncharacterised.

METHODS

PCR-based profiling was applied to identify angiogenic genes in Caco-2 CRC cells regulated by hypoxia, the hypoxia mimetic dimethyloxallylglycine (DMOG) and/or EGF. Western blotting was used to determine the role of HIF-1alpha, HIF-2alpha and MAPK cell signalling in mediating the angiogenic responses.

RESULTS

We identified a total of 9 angiogenic genes, including angiopoietin-like (ANGPTL) 4, ephrin (EFNA) 3, transforming growth factor (TGF) β1 and vascular endothelial growth factor (VEGF), to be upregulated in a HIF dependent manner in Caco-2 CRC cells in response to both hypoxia and the hypoxia mimetic dimethyloxallylglycine (DMOG). Stimulation with EGF resulted in EGFR tyrosine autophosphorylation, activation of p42/p44 MAP kinases and stabilisation of HIF-1α and HIF-2α proteins. However, expression of 84 angiogenic genes remained unchanged in response to EGF alone. Crucially, addition of DMOG in combination with EGF significantly increased expression of a further 11 genes (in addition to the 9 genes upregulated in response to either DMOG alone or hypoxia alone). These additional genes included chemokines (CCL-11/eotaxin-1 and interleukin-8), collagen type IV α3 chain, integrin β3 chain, TGFα and VEGF receptor KDR.

CONCLUSION

These findings suggest that although EGFR phosphorylation activates the MAP kinase signalling and promotes HIF stabilisation in CRC, this alone is not sufficient to induce angiogenic gene expression. In contrast, HIF activation downstream of hypoxia/DMOG drives expression of genes such as ANGPTL4, EFNA3, TGFβ1 and VEGF. Finally, HIF activation synergises with EGF-mediated signalling to additionally induce a unique sub-group of candidate angiogenic genes. Our data highlight the complex interrelationship between tumour hypoxia, EGF and angiogenesis in the pathogenesis of CRC.

Differential effects of Th1 versus Th2 cytokines in combination with hypoxia on HIFs and angiogenesis in RA

Introduction

Hypoxia and T-helper cell 1 (Th1) cytokine-driven inflammation are key features of rheumatoid arthritis (RA) and contribute to disease pathogenesis by promoting angiogenesis. The objective of our study was to characterise the angiogenic gene signature of RA fibroblast-like synoviocytes (FLS) in response to hypoxia, as well as Th1 and T-helper cell 2 (Th2) cytokines, and in particular to dissect out effects of combined hypoxia and cytokines on hypoxia inducible transcription factors (HIFs) and angiogenesis.

Methods

Human angiogenesis PCR arrays were used to screen cDNA from RA FLS exposed to hypoxia (1% oxygen) or dimethyloxalylglycine, which stabilises HIFs. The involvement of HIF isoforms in generating the angiogenic signature of RA FLS stimulated with hypoxia and/or cytokines was investigated using a DNA-binding assay and RNA interference. The angiogenic potential of conditioned media from hypoxia-treated and/or cytokine-treated RA FLS was measured using an in vitro endothelial-based assay.

Results

Expression of 12 angiogenic genes was significantly altered in RA FLS exposed to hypoxia, and seven of these were changed by dimethyloxalylglycine, including ephrin A3 (EFNA3), vascular endothelial growth factor (VEGF), adipokines angiopoietin-like (ANGPTL)-4 and leptin. These four proangiogenic genes were dependent on HIF-1 in hypoxia to various degrees: EFNA3 >ANGPTL-4 >VEGF >leptin. The Th1 cytokines TNFα and IL-1β induced HIF-1 but not HIF-2 transcription as well as activity, and this effect was additive with hypoxia. In contrast, Th2 cytokines had no effect on HIFs. IL-1β synergised with hypoxia to upregulate EFNA3 and VEGF in a HIF-1-dependent fashion but, despite strongly inducing HIF-1, TNFα suppressed adipokine expression and had minimal effect on EFNA3. Supernatants from RA FLS subjected to hypoxia and TNFα induced fewer endothelial tubules than those from FLS subjected to TNFα or hypoxia alone, despite high VEGF protein levels. The Th2 cytokine IL-4 strongly induced ANGPTL-4 and angiogenesis by normoxic FLS and synergised with hypoxia to induce further proangiogenic activity.

Conclusion

The present work demonstrates that Th1 cytokines in combination with hypoxia are not sufficient to induce angiogenic activity by RA FLS despite HIF-1 activation and VEGF production. In contrast, Th2 cytokines induce angiogenic activity in normoxia and hypoxia, despite their inability to activate HIFs, highlighting the complex relationships between hypoxia, angiogenesis and inflammation in RA.

Influence of chorionicity on perinatal outcome in a large cohort of Danish twin pregnancies

OBJECTIVE

To assess outcome in twin pregnancies according to chorionicity.

METHODS

A cohort was retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising all twin pregnancies with two live fetuses scanned between weeks 11 and 14 in the period 1 January 2004 to 31 December 2006. Outcome data were retrieved from the National Board of Health.

RESULTS

Among 2038 twin pregnancies, 1757 (86.2%) were dichorionic (DC) and 281 (13.8%) were monochorionic diamniotic (MC). In MC pregnancies, the rate of spontaneous fetal loss in both second and third trimesters was more than threefold higher than the comparable rate in DC pregnancies: 6.0% vs. 1.9% for at least one fetus in the second trimester (P < 0.001) and 2.1% vs. 0.7% in the third trimester (P = 0.03). In 98.4% of DC pregnancies and in 91.1% of MC pregnancies, at least one infant was liveborn. Amongst pregnancies with two live fetuses at 24 weeks, the proportion with two live infants at 28 days after delivery was 97.5% and 95.1%, respectively.

CONCLUSIONS

The increased incidence of fetal loss in MC pregnancies compared with DC pregnancies predominantly occurs before 24 weeks' gestation. After this stage, although the risk of intrauterine fetal death is still higher in MC than in DC pregnancies, if both fetuses are alive at 24 weeks, the chance of a woman having two live infants 1 month after delivery is similar in MC and DC pregnancies.

Circulating endothelial progenitor cells as a link between synovial vascularity and cardiovascular mortality in rheumatoid arthritis

Cardiovascular disease refers to the class of diseases that involve the heart and/or blood vessels (arteries and veins). Most Western countries face high and ever-increasing rates of cardiovascular disease. Each year, more Americans are killed by heart disease than by cancer. Diseases of the heart alone cause 30% of all deaths, with other diseases of the cardiovascular system causing substantial further deaths and disability. Indeed, cardiovascular disease is the major cause of death and disability in the USA and most European countries. The development of the vascular systems requires an intricate interplay of molecules such as vascular endothelial growth factor and endothelial progenitor cells. A defective vascular repair/regeneration is thought to be responsible for propagation of atherosclerosis, a key feature of cardiovascular disease. This is partly attributed to a reduction in the circulating endothelial progenitor cells in peripheral blood. Patients with rheumatoid arthritis (RA) have a higher than average incidence of cardiovascular disease in comparison with the general population, with an increased risk of stroke and myocardial infarction, and an increased risk of fatality following myocardial infarction. This review focuses on the current evidence linking the role played by endothelial progenitor cells to the development of cardiovascular disease and why this might relate to the increased risk observed in RA patients.

Angiogenesis as a therapeutic target in arthritis: learning the lessons of the colorectal cancer experience

The idea of a therapeutic modality aimed at 'starving' a tissue of blood vessels, and consequentially of oxygen and nutrients, was born from the concept that blood vessel formation (angiogenesis) is central to the progression and maintenance of diseases which involve tissue expansion/invasion. In the first instance, solid malignancies were the target for anti-angiogenic treatments, with colorectal cancer being the first disease for which an angiogenesis inhibitor--anti-vascular endothelial growth factor antibody bevacizumab--was approved in 2004. Our understanding of the pathogenesis of rheumatoid arthritis (RA) has lead to many parallels being drawn between this chronic inflammatory disease and solid tumours, in that both involve tissue expansion, invasion, expression of cytokines and growth factors and areas of hypoxia/hypoperfusion. As a result, angiogenesis blockade has been touted as a possible treatment for RA. The lessons learnt during the progression of eventually successful therapies such as bevacizumab should undoubtedly guide us in the future development of comparable treatments for RA.

ABO blood groups and risk of venous thromboembolism during pregnancy and the puerperium. A population-based, nested case-control study

OBJECTIVES

To examine possible associations of ABO blood types with the risk of venous thromboembolism (VTE) in pregnancy and the puerperium.

PATIENTS AND METHODS

We conducted a nested case-control study within a cohort of 71,729 women who gave birth to 126,783 children in the North Jutland County, Denmark, from 1980 to 2001. We identified 129 cases with VTE in pregnancy (n = 61) or the puerperium (n = 68), and 258 controls with no VTE. We collected information on ABO blood groups and possible maternal confounding factors and estimated the relative risk [odds ratio (OR)].

RESULTS

Women with an A or AB blood group had elevated risk estimates of VTE in pregnancy or the puerperium compared with women with a O blood group [adjusted ORs 2.4, 95% confidence interval (CI) 1.3, 4.3, and 2.0, 95% CI 0.7, 5.8, respectively]. No increased risk estimate was found for group B (adjusted OR 1.2, 95% CI 0.5, 3.0). The increased risk estimates of VTE for blood groups A and AB appeared present in both pregnancy (adjusted ORs of 3.9, 95% CI 1.5, 9.7, and 2.2, 95% CI 0.4, 12.5) and in the puerperium (adjusted ORs of 2.4, 95% CI 1.0, 4.9 and 2.7, 95% CI 0.8, 9.3). Furthermore, blood groups A and AB appeared to be associated with increased risk estimates for both DVT and pulmonary embolism.

CONCLUSION

Keeping the modest statistical precision of our study in mind, blood groups A and AB may be associated with increased risk estimates for VTE in pregnancy and the puerperium.

Linkage of osteoporosis to chromosome 20p12 and association to BMP2

Osteoporotic fractures are a major cause of morbidity and mortality in ageing populations. Osteoporosis, defined as low bone mineral density (BMD) and associated fractures, have significant genetic components that are largely unknown. Linkage analysis in a large number of extended osteoporosis families in Iceland, using a phenotype that combines osteoporotic fractures and BMD measurements, showed linkage to Chromosome 20p12.3 (multipoint allele-sharing LOD, 5.10; p value, 6.3 x 10(-7)), results that are statistically significant after adjusting for the number of phenotypes tested and the genome-wide search. A follow-up association analysis using closely spaced polymorphic markers was performed. Three variants in the bone morphogenetic protein 2 (BMP2) gene, a missense polymorphism and two anonymous single nucleotide polymorphism haplotypes, were determined to be associated with osteoporosis in the Icelandic patients. The association is seen with many definitions of an osteoporotic phenotype, including osteoporotic fractures as well as low BMD, both before and after menopause. A replication study with a Danish cohort of postmenopausal women was conducted to confirm the contribution of the three identified variants. In conclusion, we find that a region on the short arm of Chromosome 20 contains a gene or genes that appear to be a major risk factor for osteoporosis and osteoporotic fractures, and our evidence supports the view that BMP2 is at least one of these genes.

Psychomotor development in children exposed in utero to benzodiazepines, antidepressants, neuroleptics, and anti-epileptics

We did a follow-up study based upon a regional prescription register in Denmark. We identified all 435 women who in the period 1991-1996 had redeemed a prescription for CNS drugs during pregnancy. Among the rest of the pregnant women we randomly selected 1304 women who also had given birth to a child in the same region and period. We looked up the local health nurses Boel test results which were available for about 80%. Any abnormal test result was seen much more frequently among exposed (16%) than for not exposed (4%). The study has several limitations but raises concern that should be addressed in other and better designed studies.

Birth outcome of 1886 pregnancies after exposure to phenoxymethylpenicillin in utero

OBJECTIVE

To examine the risk of congenital abnormalities, preterm birth and low birth weight after exposure to phenoxymethylpenicillin in utero.

METHODS

A population-based follow-up study in the County of North Jutland, Denmark. Birth outcome for 1886 women, who redeemed prescriptions for phenoxymethylpenicillin during pregnancy was compared with the outcome for 9263 women who did not redeem any prescription during pregnancy.

RESULTS

The prevalence of congenital abnormalities in 654 users of phenoxymethylpenicillin with or without other drugs during the first trimester was 4.6% compared with 3.6% in the reference group, giving a prevalence odds ratio of 1.25 (95% CI: 0.84-1.86). The prevalence odds ratio was 1.35 (95% CI: 0.59-3.08) in 131 women who were exposed to phenoxymethylpenicillin only. Nine cardiovascular abnormalities were found, giving an adjusted prevalence odds ratio of 1.74 (95% CI: 0.83-3.65). The prevalence odds ratios of preterm birth and low birth weight were 0.83 (95% CI: 0.66-1.04) and 1.02 (95% CI: 0.71-1.47), respectively.

CONCLUSION

We found no significantly increased risk of congenital abnormalities, including cardiovascular abnormalities, preterm birth, or low birth weight in women who purchased phenoxymethylpenicillin during pregnancy.

Birth outcome and risk of neonatal hypoglycaemia following in utero exposure to pivmecillinam: a population-based cohort study with 414 exposed pregnancies

Concerns have been raised as to the safety of using pivaloyl-conjugated beta-lactam antibiotics during pregnancy as they cause carnitine depletion. Restrictions have been recommended in some Scandinavian countries as drug-induced carnitine depletion could constitute a risk to the developing foetus. One of these drugs, pivmecillinam, is widely used against urinary tract infections but few data exist concerning its safety in pregnancy. In a cohort study, we compared the prevalences of congenital abnormalities, pre-term delivery, low birth weight, low Apgar score and neonatal hypoglycaemia in the offspring of 414 women who had at least 1 prescription for pivmecillinam redeemed during pregnancy with those of the offspring of 7472 pregnant women for whom no drugs were prescribed during pregnancy. The prevalence of congenital abnormalities was 1.7% among 119 infants exposed in the first trimester and 3.7% among the reference group [odds ratio (OR) 0.46; 95% confidence interval (CI) 0.11-1.86]. We found no significantly increased risks in either pre-term delivery (OR 0.91, 95% CI 0.11-1.86), low birth weight (OR 0.57, 95%, CI 0.23-1.41), low Apgar score (OR 2.32, 95% CI 0.30-18.16) or hypoglycaemia (OR 0.73, 95% CI 0.18-3.00) that were induced by carnitine depletion. No significantly increased risk in adverse birth outcome was therefore found in women treated with pivmecillinam.

Induced abortion and placenta complications in the subsequent pregnancy

BACKGROUND

To study the risk of placenta complications following an induced abortion as a function of the interpregnancy interval.

METHODS

This study is based on three Danish national registries; the Medical Birth Registry, the Hospital Discharge Registry, and the Induced Abortion Registry. All primigravida women from 1980 to 1982 were identified in these three registries. A total of 15,727 women who terminated the pregnancy with a first trimester induced abortion were selected to the abortion cohort, and 46,026 women who did not terminate the pregnancy with an induced abortion constituted the control cohort. By register linkage all subsequent pregnancies were identified from 1980 to 1994. Only women who had a non-terminated pregnancy following the index pregnancy were selected to the study. Placenta complications were identified using either the Hospital Discharge Registry ICD-8 codes or the Medical Birth Registry records.

RESULTS

A slightly higher risk of placenta complications following an abortion was found. Retained placenta occurred more frequently in women with one, two or more previous abortions, compared with women without any previous abortion of similar gravidity. Adjusting for maternal age and residence at time of pregnancy, the interpregnancy interval, and the number of previous miscarriages (control cohort only), the odds ratios of retained placenta in deliveries of singleton live births in women with one previous abortion was 1.17 (95%CI=1.02-1.35), and for women with two or more previous abortions it was 1.68 (95%CI=1.23-2.30), respectively, compared with the control cohort of similar gravidity. Only for women who had one abortion did the results follow the predicted pattern of a higher risk of retained placenta after a short pregnancy interval. No association with placenta previa was seen.

CONCLUSIONS

The findings suggest a positive association between abortions and retained placenta in subsequent singleton live births, but the association was weak and confounding cannot be ruled out.

[Congenital malformations and fetal growth of children with intrauterine exposure to anticonvulsants]

OBJECTIVES

To examine the risk of malformations and fetal growth in the children of women treated with anticonvulsant drugs in North Jutland County, Denmark.

MATERIAL AND METHODS

All women treated with anticonvulsant drugs in the county were identified in a Pharmaco-Epidemiological Prescription Database and linked to the Danish Medical Birth Registry and the Regional Hospital Information system.

RESULTS

We identified 235 pregnancies where the mothers had used prescriptions for anticonvulsants around conception and/or during pregnancy, and 17,259 unexposed pregnancies where the mothers had not used prescriptions. One case of neural tube defect was found among 15 malformations in the exposed cohort. The overall odds ratio for malformations was 2.2 (95% confidence intervals 1.3-3.8). The odds ratios for low birth weight and preterm delivery were respectively 1.5 (95% confidence intervals 0.6-3.7) and 1.6 (95% confidence intervals 1.0-2.5).

CONCLUSION

We found an increased risk of congenital malformations and a tendency to growth retardation in the children of women taking anticonvulsants.

Smoking, sex of the offspring, and risk of placental abruption, placenta previa, and preeclampsia: a population-based cohort study

BACKGROUND

: Placental abruption, placenta previa, and preeclampsia are serious pregnancy complications with an increased risk of perinatal death. Smoking during pregnancy is associated with increased risk of abruption and placenta previa, and it reduces the risk of preeclampsia. We examined the association between mothers' smoking habits during pregnancy, taking the sex of the offspring into consideration, and the risk and prognosis of placental abruption, placenta previa, and preeclampsia

METHODS

: We conducted the study in the County of North Jutland, Denmark. Using the 10-digit personal identification number given to every Danish citizen at birth, we linked data from the Danish Medical Birth Registry, including information on mother and child, to data from the Pharmaco-Epidemiological Prescription Database with data on all reimbursed prescriptions to use selected drugs as a proxy measure for some maternal diseases, and data from the Regional Hospital Discharge Registry, including the discharge diagnoses. Among 47,932 singleton births we included only births for which we had information about the mothers' smoking habits, leaving 46,313 births for analysis.

RESULTS

: Smoking was associated with the risk of placental abruption (OR=1.99 (95% CI 1.72-2.30)) and placenta previa (OR=1.88 (95% CI 1.15-3.07)). Smoking was inversely associated with the risk of preeclampsia (OR=0.55 (95% CI 0.48-0.62)). After stratification for the sex of the offspring the risk estimate of smoking as risk factor for placenta previa decreased for male fetuses (OR=1.63 (95% CI 0.75-3.51)) and increased for female fetuses (OR=4.82 (95% CI 1.69-13.75)).

CONCLUSION

: Female fetuses are more vulnerable than male to the negative effect of maternal smoking on placenta previa.

Birth outcome following maternal use of fluoroquinolones

The aim of the study was to examine fetal risk associated with intrauterine exposure to fluoroquinolones. By using on record linkage between a Prescription Database and the Birth Registry in Denmark, the offspring of 57 users of fluoroquinolones and of 17259 patients who had no prescriptive medication during pregnancy, were compared in a cohort study. Among the users, the prevalence rate ratios of congenital abnormalities, preterm birth and low birth weight were 1.30 (95% CI: 0.30-5.30),1.53 (95% CI: 0.62-3.80) and 1.17 (95% CI: 0.15-8.90), respectively. The risk of congenital abnormalities among users of fluoroquinolones during pregnancy was close to unity. Despite these limitations of statistical analysis the study suggested that the use of fluoroquinolones during pregnancy may not be a major risk factor to the foetus.

Risk of adverse birth outcome and miscarriage in pregnant users of non-steroidal anti-inflammatory drugs: population based observational study and case-control study

OBJECTIVE

To estimate the risk of adverse birth outcome in women who take non-steroidal anti-inflammatory drugs during pregnancy.

DESIGN AND SETTING

Population based cohort study and a case-control study, both based on data from a prescription registry, the Danish birth registry, and one county's hospital discharge registry.

PARTICIPANTS

COHORT STUDY: 1462 pregnant women who had taken up prescriptions for non-steroidal anti-inflammatory drugs in the period from 30 days before conception to birth and 17 259 pregnant women who were not prescribed any drugs during pregnancy. CASE-CONTROL STUDY: 4268 women who had miscarriages, of whom 63 had taken non-steroidal anti-inflammatory drugs, and 29 750 primiparous controls who had live births.

MAIN OUTCOME MEASURES

Incidences of congenital abnormality, low birth weight, preterm birth, and miscarriage.

RESULTS

Odds ratios for congenital abnormality, low birth weight, and preterm birth among women who took up prescriptions for non-steroidal anti-inflammatory drugs were 1.27 (95% confidence interval 0.93 to 1.75), 0.79 (0.45 to 1.38), and 1.05 (0.80 to 1.39) respectively. Odds ratios for the taking up of prescriptions in the weeks before miscarriage ranged from 6.99 (2.75 to 17.74) when prescriptions were taken up during the last week before the miscarriage to 2.69 (1.81 to 4.00) when taken up between 7 and 9 weeks before. The risk estimates were no different when the analysis was restricted to missed abortions.

CONCLUSIONS

Use of non-steroidal anti-inflammatory drugs during pregnancy does not seem to increase the risk of adverse birth outcome but is associated with increased risk of miscarriage.

Effect of diuretics on fetal growth: A drug effect or confounding by indication? Pooled Danish and Scottish cohort data

AIMS

The diabetogenic effect of diuretics, as well as the indication for prescribing them, may impact on fetal growth. We analysed whether the purchase of prescription drugs for diuretics during pregnancy was associated with measures of fetal growth.

METHODS

During 1991-98 all women who purchased prescription drugs for diuretics during pregnancy were identified in the Northern Jutland Prescription Database (NJDP), Denmark, and in the Medicines Monitoring Unit's Database (MEMO), Scotland. Information on birth weight and gestational age was obtained from the Danish Birth Registry, the Danish Hospital Discharge Registry and the Scottish Tayside Neonatal Database. Information on diabetes, hypertension and prepregnancy weight were obtained by hospital record review in a sample of women in the Danish cohort. Women who did not purchase prescription diuretics during pregnancy were used as a reference group in both cohorts.

RESULTS

Danish women who purchased prescription loop diuretics during pregnancy gave birth to infants with higher birth weights than women who did not use diuretics; mean difference 104.7 g (95% CI; 2.6, 206.9). However, the high prevalence of diabetes (10.3%) among Danish women who purchased prescription loop diuretics during pregnancy might explain this result. Both the Danish and the Scottish women who purchased prescription diuretics during their pregnancy were at increased risk of preterm delivery (< 37 completed weeks); ORs: 1.8 (CI; 1.2, 2.7)NJDP, 1.9 (CI; 0.9, 4.3)MEMO. The proportion of hypertension among women who purchased prescription thiazides was 15.8%, and the risk of having an infant with a birth weight (BW) < 2500 g was increased; ORs: 2.6 (CI; 1.4, 5.0)NJDP, 2.4 (CI; 0.8, 7.8)MEMO.

CONCLUSIONS

Prescribing diuretics during pregnancy was associated with differences in birth weight and incidence of preterm delivery. Confounding by indication may explain the findings.

Birth outcomes in pregnant women treated with low-molecular-weight heparin

BACKGROUND

Pregnancy and puerperium are associated with an increased risk of venous thromboembolism. Low-molecular-weight heparin is the anticoagulant of choice in pregnant women because, unlike warfarin, it does not cross the placenta. However, there are limited data on the risk of adverse birth outcomes following use of low-molecular-weight heparin in pregnancy.

PATIENTS AND METHODS

We performed a population-based cohort study to examine the safety of low-molecular-weight heparin use in pregnancy using data from the Pharmacoepidemiological Prescription Database, The Danish Medical Birth Registry and the Regional Hospital Discharge Registry in North Jutland County, Denmark. The birth outcomes in a cohort of 66 pregnant women treated with low-molecular-weight heparin between 1991-98 were compared with the birth outcomes of 17,259 pregnant women who did not receive any prescriptive drugs during pregnancy.

RESULTS

No increased risk of malformations, low birth weight or stillbirth was found. However, an increased risk of pre-term delivery was found (odds ratio: 2.11, 95%, confidence interval: 0.96-4.65), which could reflect inherited thrombophilia as an indication of low-molecular-weight heparin.

CONCLUSION

We have provided additional evidence of the safety of low-molecular-weight heparin use in pregnancy.

A follow-up study of birth outcome in users of pivampicillin during pregnancy

BACKGROUND

Pivampicillin is a prodrug which is widely used in Scandinavian countries for oral antibiotic therapy. The pivaloyl moiety has a carnitine depleting effect, which has caused doubts about the safety of administering pivampicillin during pregnancy. The aim of the study was to evaluate the risk of congenital malformations in general, preterm delivery and low birth weight in users of pivampicillin.

METHODS

Seven hundred and ninety-one women who had redeemed a prescription of pivampicillin during their first pregnancy from 1 January 1991 to 31 December 1996 were identified in the North Jutland Pharmaco-Epidemiological Prescription Database. By linkage to the Danish Medical Birth Registry and Regional Hospital Discharge Registry we compared their birth outcomes (malformations, preterm delivery and low birth weight) with the outcomes in 7472 reference pregnancies on which the mother had not redeemed any prescription at all during pregnancy.

RESULTS

The prevalence of malformations was 5.5% (11 cases) in offspring of 199 women who had used pivampicillin during the first trimester, and 5.6% (420 cases) in offspring of controls (OR: 0.95, 95% CI: 0.51-1.76). Furthermore, we did not find any significant risk of preterm delivery (OR: 0.75, 95% CI: 0.54-1.05) or low birth weight (OR: 0.93, 95% CI: 0.55-1.57).

CONCLUSION

This study showed no increased risk of congenital malformations, preterm delivery or low birth weight in offspring of women who had redeemed a prescription for pivampicillin during pregnancy.

Birth outcomes in women exposed to anticonvulsant drugs

OBJECTIVES

To examine the risk of malformations and fetal growth in women treated with anticonvulsant drugs in North Jutland County, Denmark.

MATERIAL AND METHODS

All women treated with anticonvulsant drugs in the county were identified in a Pharmaco-Epidemiological Prescription Database and linked to the Danish Medical Birth Registry and the Regional Hospital Discharge Registry.

RESULTS

We identified 235 pregnancies exposed to anticonvulsants around conception and/or during pregnancy as well as 17,259 unexposed pregnancies where the mother had not received any prescription. There was 1 case of neural tube defect among 15 malformations in the exposed cohort. The overall risk of malformations was 2.2 (95% confidence intervals 1.3-3.8). The risk of low birth weight and preterm delivery was 1.5 (95% confidence intervals 0.6-3.7) and 1.6 (95% confidence intervals 1.0-2.5), respectively.

CONCLUSION

We found an increased risk of congenital malformations and a tendency to growth retardation in children of women exposed to anticonvulsants.

Metastatic pattern in non-resectable non-small cell lung cancer

This study describes the metastatic pattern at autopsy in patients with non-resectable non-small cell lung cancer (NSCLC) and evaluates the impact of various pretreatment variables and treatment outcomes on the metastatic spread. In eight phase II chemotherapy trials from 1985 through 1993, 337 patients were treated and 51 autopsies were performed (autopsy rate 15%). The male/female ratio was 31/20, median age 56 years (range 36-71), response rate to chemotherapy 8%, and median survival 88 days (range 3-899). Histologic types included adenocarcinoma, 31 cases (60%), squamous cell carcinoma, 9 cases (18%), large cell carcinoma, 9 cases (18%), and unclassified NSCLC, 2 cases (4%). Patients who were autopsied had a shorter median survival than patients without autopsy (p = 0.002, log-rank test). Most commonly involved metastatic sites found at autopsy were mediastinal lymph nodes (84%), pleura (51%), liver (47%), bone (34%), brain (32%), pericardium (29%), adrenals (29%). The median number of involved organs was 5 (range 1-16), with a median of 3 intrathoracic sites (range 1-8) and 2 extrathoracic sites (range 0-11). Patients who initially had metastatic NSCLC also had significantly more metastatic sites at autopsy both extrathoracic (p = 0.004) and totally (p = 0.03) compared to patients with locally advanced disease. No other relation to pretreatment variables was found.

Risk of malformations and other outcomes in children exposed to fluconazole in utero

AIM

Fluconazole is an active drug systematically used in the oral treatment of vaginal candidiasis and other fungal diseases. We examined the risk of malformations and other birth outcomes following pregnancy related exposures.

METHOD

From 1 January 1991 to 31 December 1996 we identified 165 women who had taken fluconazole just before or during pregnancy in the Pregnancy Outcome Section of the North Jutland Pharmacoepidemiological Prescription Database, Denmark, which is linked to the Danish Medical Birth Registry. We compared their birth outcomes (malformation, low birth weight and preterm delivery) with the outcomes among 13 327 women who did not receive any prescriptions during their pregnancies.

RESULTS

The prevalence of malformation was 3.3% (four cases) among the 121 women, who had used fluconazole in the first trimester, and 5.2% (697 cases) in offspring to controls (odds ratio: 0.65, 95% confidence limits: 0.24-1.77). Furthermore, we did not find any significantly elevated risk of preterm delivery (odds ratio: 1.17, 95% confidence limits: 0.63-2.17) and low birth weight (odds ratio: 1.19, 95% confidence limits: 0.37-3.79).

CONCLUSION

The study showed no increased risk of congenital malformations, low birth weight or preterm birth in offspring to women who had used single dose fluconazole before conception or during pregnancy.

Double-stapled esophagogastric anastomosis for resection of esophagogastric or cardia cancer: new application for an old technique

In colorectal surgery, the double-stapled technique is used extensively, because it is a fairly safe and simple procedure and is useful in relatively inaccessible areas. For these reasons, we adapted the procedure to the upper gastrointestinal tract. The present study reports our first experiences of the surgical efficacy using an esophagogastric double-stapled end-to-end anastomosis for subtotal esophagectomy and cardia resection. We retrospectively studied 31 patients treated between January 1991 and January 1997 with respect to hospital mortality, anastomotic leakage, cancer recurrence, and benign stricture rate. No hospital mortality was seen. One nonfatal anastomotic leak occurred (3%). In three patients, esophageal resection was not radical (10%). Of the remaining 28 patients, one had an anastomotic cancer recurrence (4%). Eleven of the remaining 27 patients (41%) developed a benign anastomotic stricture. All achieved normal swallowing after a median of two endoscopic dilatation procedures using TTS balloons. In conclusion, the double-stapled end-to-end anastomosis technique after resection for esophagogastric or cardia cancer is a simple and expeditious procedure, carrying an acceptable perioperative morbidity and cancer recurrence rate. Larger staplers are recommended to lower the high stricture rate observed after the usage of a 21-mm stapler in this study.