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Allan Jensen

Publications and source records attributed to Allan Jensen.

7 recordsLinked to original sources
PubMed2006

Performance of clinical mammography: a nationwide study from Denmark.

Clinical mammography is the key tool for breast cancer diagnosis, but little is known about the impact of the organisational set-up on the performance. We evaluated whether organisational factors influence the performance of clinical mammography. Clinical mammography data from all clinics in Denmark in the year 2000 were collected and linked to cancer outcome. Use of the National Institute of Radiation Hygiene register for identification of radiology clinics ensured comprehensive nationwide registration. We used the final mammographic assessment at the end of the imaging work-up to determine sensitivity, specificity and accuracy, the latter using a receiver-operating characteristics (ROC) analysis. In 96,534 clinical mammography examinations, sensitivity was 75% and specificity 99%. The presence of at least one high volume-reading radiologist in the clinic increased accuracy (AUC = 0.91 for <1,000 examinations/year and 0.92 for >2,000 examinations/year, p = 0.017). The examination volume per clinic showed no clear effect on performance, as accuracy was significantly higher in clinics with a medium number of examinations (AUC = 0.93 for 2,000-4,000 examinations/year and 0.90 for >6,000 examinations/year, p = 0.003). Accuracy was significantly lower in regions with high annual utilisation rate of clinical mammography, which means the proportion of examined women in a region (AUC = 0.90 for 3.0-5.0% annual utilisation rate and AUC = 0.93 for 2.0-2.5% annual utilisation rate, and p = 0.001), indicating that clinical mammography worked best in patient populations of purely symptomatic women. Our data indicate that to increase the accuracy of clinical mammography at the community level, the presence of an experienced radiologist should be prioritized ahead of raising the clinic size.

Adult↗
PubMed2006

Isolation of human antibody repertoires with preservation of the natural heavy and light chain pairing.

The humoral immune system in higher vertebrates is unique in its ability to generate highly diverse antibody responses against most pathogens as well as against certain malignancies. Several technologies have been developed to exploit this vast source of potentially therapeutic antibodies, including hybridoma technology, phage display and yeast display. Here, we present a novel, high-throughput technology (the Symplex Technology) for rapid direct cloning and identification of human antigen-specific high-affinity antibodies from single antibody-producing cells of immune individuals. The utility of the technology was demonstrated by isolation of diverse sets of unique high-affinity antibodies against tetanus toxoid and influenza virus from immunized volunteers. Hence, the Symplex Technology is a new method for the rapid isolation of high-affinity antibodies directly from humans.

Escherichia coli↗
PubMed2006

Performance of combined clinical mammography and needle biopsy: a nationwide study from Denmark.

Clinical mammography and needle biopsy are key tools for non-operative assessment of breast lesions. We evaluated the performance of all combined tests undertaken in Denmark in 2000. Clinical mammography and needle biopsy data were collected and linked to final cancer outcome, to determine sensitivity, specificity, and predictive values of clinical mammography, needle biopsy, and combined test. In 2000, 6709 combined tests were performed in 36 mammography clinics in Denmark. The combined test was consistently more sensitive than any single test, increasing the proportion of women correctly identified with breast cancer by 9% compared with clinical mammography alone. For concordant combined tests (i.e. either both benign or both malignant), specificity and positive predictive value were 100%, sensitivity was 99.1%, and positive predictive value was 99.6%. Therefore, Danish patients with a malignant concordant combined test can proceed directly to definitive surgery without fear of a false-positive diagnosis, and Danish women with a concordant benign combined test can omit surgery without fear of a false-negative diagnosis. In discordant cases, our results showed that any of the two tests with a suspicious or malignant result indicated a high risk of cancer, and excisional diagnostic biopsy therefore still has an important role to play.

Adult↗
PubMed2006

Recombinant human polyclonal antibodies: A new class of therapeutic antibodies against viral infections.

The mammalian immune system eliminates pathogens by generating a specific antibody response. Polyclonality is a key feature of this immune response: the immune system produces antibodies which bind to different structures on a given pathogen thereby increasing the likelihood of its elimination. The vast majority of current recombinant antibody drugs rely on monospecific monoclonal antibodies. Inherently, such antibodies do not represent the benefits of polyclonality utilized by a natural immune system and this has impeded the identification of efficacious antibody drugs against infectious agents, including viruses. The development of novel technologies has allowed the identification and manufacturing of antigen-specific recombinant polyclonal human antibodies, so-called symphobodies. This review describes the rationale for designing drugs based on symphobodies against pathogenic viruses, including HIV, vaccinia and smallpox virus, and respiratory syncytial virus.

Antibodies, Monoclonal↗
PubMed2005

Do nonattenders in mammography screening programmes seek mammography elsewhere?

The objectives of our study were to analyse the use of diagnostic mammography among nonattenders and attenders in organised mammography screening in Denmark in 2000, to assess the contamination from organised screening of noninvited age groups and to measure the impact of local policy on opportunistic screening. Data on all diagnostic mammographies performed in Denmark in 2000 and data on women targeted by the 2 organised mammography screening programmes in Copenhagen and the county of Fyn were collected. All data were linked by the Danish personal identification number. Information on the official policy in 2000 with regard to opportunistic screening was collected from all counties. The proportion of women using diagnostic mammography was only 1-3% for both attenders and nonattenders in organised mammography screening, but it was significantly higher in Copenhagen than in Fyn, due to availability of mammography in private clinics. The proportion of women using diagnostic mammography varied from 1-4% across counties. The official policy on access to diagnostic mammography and contamination from organised mammography screening of adjacent age groups had no impact on the use. Instead, urbanisation was positively correlated with use of diagnostic mammography. In conclusion, our results clearly showed that nonattenders in organised mammography screening programmes do not seek mammography outside the programme. Since a positive policy toward opportunistic screening did not have any effect, our results add further evidence to existing knowledge that the only reasonable way to achieve high mammography coverage is through a well-organised screening programme.

Adult↗
PubMedDate not supplied

Is mortalin a candidate gene for T1DM ?

Mortalin has been found to be up-regulated by 2D-protein gel analysis in isolated rodent islets exposed to cytokines. In islets from two rat strains with different sensitivity to the toxic effects of cytokines we observed a significant difference in IL-1beta mediated mortalin expression. Constitutive over-expression of rat mortalin in NIH3T3 cells reduced cellular survival in accordance with mortalin being associated to cellular senescence. Hence we consider the gene encoding for mortalin at chromosome 5q31.1 a putative candidate gene in cytokine induced beta-cell destruction. We scanned the human mortalin gene for polymorphisms and identified three novel polymorphisms. Neither the SNPs individually nor as constructed haplotypes showed disease association tested by (E)TDT in a Danish type 1 diabetes (T1DM) population. Furthermore, we tested the D5S500 microsatelite located close to 5q31.1 without finding linkage to (T1DM). In conclusion, the functional data identifying a difference in mortalin expression in IL-1beta stimulated islets between two rat strains and over-expression of mortalin in NIH3T3 cells associated with decreased viability suggests a functional role for mortalin in cytokine mediated beta cell destruction; however, the identified polymorphisms did not reveal any association in the presence of linkage disequilibrium of mortalin to T1DM in the Danish population.

Animals↗