Kenneth Geving Andersen

Glacial Survival of Boreal Trees in Northern Scandinavia

Tree Refugia Ideas of how and when boreal plants spread to the formerly glaciated parts of the world following the retreat of the glaciers 9000 years ago are long debated. Models of the postglacial spread of boreal plants argue for dispersal from southern refugia; however, Parducci et al. (p. 1083) have shown that both spruce and pine were present in small ice-free regions of Scandinavia much earlier than thought. DNA haplotyping confirmed that a remnant mitochondrial type of spruce, once unique to Scandinavia, now lives alongside the more common spruce originating from Eastern Europe. Evidence from lake cores collected from central and northern Norway indicated the survival of conifers as early as 22,000 years before the present, when apart from ice-free pockets, most of Scandinavia was covered by ice. DNA from modern and ancient spruce and pine indicate that both survived in ice-free areas during the last glaciations. It is commonly believed that trees were absent in Scandinavia during the last glaciation and first recolonized the Scandinavian Peninsula with the retreat of its ice sheet some 9000 years ago. Here, we show the presence of a rare mitochondrial DNA haplotype of spruce that appears unique to Scandinavia and with its highest frequency to the west—an area believed to sustain ice-free refugia during most of the last ice age. We further show the survival of DNA from this haplotype in lake sediments and pollen of Trøndelag in central Norway dating back ~10,300 years and chloroplast DNA of pine and spruce in lake sediments adjacent to the ice-free Andøya refugium in northwestern Norway as early as ~22,000 and 17,700 years ago, respectively. Our findings imply that conifer trees survived in ice-free refugia of Scandinavia during the last glaciation, challenging current views on survival and spread of trees as a response to climate changes.

Meta‐barcoding of ‘dirt’ DNA from soil reflects vertebrate biodiversity

DNA molecules originating from animals and plants can be retrieved directly from sediments and have been used for reconstructing both contemporary and past ecosystems. However, the extent to which such ‘dirt’ DNA reflects taxonomic richness and structural diversity remains contentious. Here, we couple second generation high‐throughput sequencing with 16S mitochondrial DNA (mtDNA) meta‐barcoding, to explore the accuracy and sensitivity of ‘dirt’ DNA as an indicator of vertebrate diversity, from soil sampled at safari parks, zoological gardens and farms with known species compositions. PCR amplification was successful in the full pH range of the investigated soils (6.2 ± 0.2 to 8.3 ± 0.2), but inhibition was detected in extracts from soil of high organic content. DNA movement (leaching) through strata was evident in some sporadic cases and is influenced by soil texture and structure. We find that DNA from the soil surface reflects overall taxonomic richness and relative biomass of individual species. However, one species that was recently introduced was not detected. Furthermore, animal behaviour was shown to influence DNA deposition rates. The approach potentially provides a quick methodological alternative to classical ecological surveys of biodiversity, and most reliable results are obtained with spatial sample replicates, while relative amounts of soil processed per site is of less importance.

Persistent pain and sensory disturbances after treatment for breast cancer: six year nationwide follow-up study

Objective To examine the development of persistent pain after treatment for breast cancer and to examine risk factors associated with continuing pain. Design Repeated cross sectional study in a previously examined nationwide cohort. All eligible women who underwent surgery for primary breast cancer in Denmark in 2005 and 2006 and were examined in 2008 were surveyed again with the same questionnaire. Setting Surgical centres in Denmark. Main outcome measures Prevalence, location, and severity of persistent pain after treatment for breast cancer in well defined treatment groups and changes in pain reporting and sensory disturbances from 2008 to 2012. Participants In 2012, 2828 women were eligible in our database, and 108 were excluded. Exclusion criteria were death; new, recurrent, or other cancer; reconstructive breast surgery; and emigration. Results 2411 (89%) women returned the questionnaire. Prevalence of persistent pain after treatment for breast cancer ranged from 22% to 53% depending on treatment. In 2012, 903 (37%) women reported such pain, a fall from 45% in 2008. Of these, 378 (16%) reported pain of ≥4 on a numerical rating scale (scale 0-10), a fall from 19%. Among women reporting pain in 2008, 36% no longer reported it in 2012. In contrast, 15% of the women who did not report pain in 2008 reported it in 2012. Risk factors for having pain were axillary lymph node dissection rather than sentinel lymph node biopsy (odds ratio 2.04, 95% confidence interval 1.60 to 2.61; P<0.001) and age ≤49 (1.78, 1.25 to 2.54; P<0.001). No particular method of treatment or age was associated with an increase in pain from 2008 to 2012. Conclusions Persistent pain after treatment for breast cancer remains an important problem five to seven years later. The problem is not static as it can either progress or regress with time. Trial registration Clinicaltrials.gov NCT No 01543711.

Islands in the ice: detecting past vegetation on Greenlandic nunataks using historical records and sedimentary ancient DNA Meta-barcoding

Nunataks are isolated bedrocks protruding through ice sheets. They vary in age, but represent island environments in ‘oceans’ of ice through which organism dispersals and replacements can be studied over time. The J.A.D. Jensen’s Nunataks at the southern Greenland ice sheet are the most isolated nunataks on the northern hemisphere – some 30 km from the nearest biological source. They constitute around 2 km2 of ice‐free land that was established in the early Holocene. We have investigated the changes in plant composition at these nunataks using both the results of surveys of the flora over the last 130 years and through reconstruction of the vegetation from the end of the Holocene Thermal Maximum (5528 ± 75 cal year BP) using meta‐barcoding of plant DNA recovered from the nunatak sediments (sedaDNA). Our results show that several of the plant species detected with sedaDNA are described from earlier vegetation surveys on the nunataks (in 1878, 1967 and 2009). In 1967, a much higher biodiversity was detected than from any other of the studied periods. While this may be related to differences in sampling efforts for the oldest period, it is not the case when comparing the 1967 and 2009 levels where the botanical survey was exhaustive. As no animals and humans are found on the nunataks, this change in diversity over a period of just 42 years must relate to environmental changes probably being climate‐driven. This suggests that even the flora of fairly small and isolated ice‐free areas reacts quickly to a changing climate.

Predictive factors for the development of persistent pain after breast cancer surgery.

Abstract Previous studies have reported that 15% to 25% of patients treated for breast cancer experience long-term moderate-to-severe pain in the area of surgery, potentially lasting for several years. Few prospective studies have included all potential risk factors for the development of persistent pain after breast cancer surgery (PPBCS). The aim of this prospective cohort study was to comprehensively identify factors predicting PPBCS. Patients scheduled for primary breast cancer surgery were recruited. Assessments were conducted preoperatively, the first 3 days postoperatively, and 1 week, 6 months, and 1 year after surgery. A comprehensive validated questionnaire was used. Handling of the intercostobrachial nerve was registered by the surgeon. Factors known by the first 3 weeks after surgery were modeled in ordinal logistic regression analyses. Five hundred thirty-seven patients with baseline data were included, and 475 (88%) were available for analysis at 1 year. At 1-year follow-up, the prevalence of moderate-to-severe pain at rest was 14% and during movement was 7%. Factors associated with pain at rest were age <65 years (odds ratio [OR]: 1.8, P = 0.02), breast conserving surgery (OR: 2.0, P = 0.006), axillary lymph node dissection with preservation of the intercostobrachial nerve (OR: 3.1, P = 0.0005), moderate-to-severe preoperative pain (OR: 5.7, P = 0.0002), acute postoperative pain (OR: 2.8, P = 0.0018), and signs of neuropathic pain at 1 week (OR: 2.1, P = 0.01). Higher preoperative diastolic blood pressure was associated with reduced risk of PPBCS (OR: 0.98 per mm Hg, P = 0.01). Both patient- and treatment-related risk factors predicted PPBCS. Identifying patients at risk may facilitate targeted intervention.

Persistent pain, sensory disturbances and functional impairment after adjuvant chemotherapy for breast cancer: Cyclophosphamide, epirubicin and fluorouracil compared with docetaxel + epirubicin and cyclophosphamide

Abstract Background. Taxanes used in adjuvant therapy for breast cancer are neurotoxic, and thereby being a potential risk factor for persistent pain after breast cancer treatment (PPBCT) and sensory disturbances. The purpose was to compare patients treated with cyclophosphamide, epirubicin and fluorouracil (CEF) and cyclophosphamide and epirubicin + docetaxel (CE + T) in relation to PPBCT, sensory disturbances, peripheral sensory disturbances and functional impairment. Material and methods. A comparative nationwide cross-sectional questionnaire study on two cohorts treated with CEF respectively CE + T, based on the Danish Breast Cancer Cooperative Groups database. Inclusion criteria: women treated with chemotherapy as adjuvant treatment for primary breast cancer, age 18–69 years, without recurrence. Results. One thousand two hundred and forty-one patients allocated to CEF in 2005–2006 and 1652 patients allocated to CE + T in 2007–2008 were included. Six hundred and sixty-four (53%) with CEF and 861 (53%) patients with CE + T reported pain. In the multivariate analysis including available risk factors, CE + T did not confer an increased risk of PPBCT, OR 0.95 (95% CI 0.81–1.11), p = 0.52, compared to CEF. Patients treated with CE + T had a lower risk of sensory disturbances in the area of surgery compared with CEF, OR 0.75 (95% CI 0.62–0.90), p = 0.002. More CE + T patients reported peripheral sensory disturbances in the hands, OR 1.56 (95%CI 1.27–1.92), p < 0.0001, and in the feet, OR 2.0 (95% CI 1.66–2.42) p < 0.0001, compared to CEF. There was no difference in functional impairment (p = 0.62). Conclusion. Docetaxcel as adjuvant treatment for breast cancer does not increase the risk of PPBCT, sensory disturbances in the surgical area or functional impairment, but increase risk for peripheral sensory disturbances.

Optimization of DNA Recovery and Amplification from Non-Carbonized Archaeobotanical Remains

Ancient DNA (aDNA) recovered from archaeobotanical remains can provide key insights into many prominent archaeological research questions, including processes of domestication, past subsistence strategies, and human interactions with the environment. However, it is often difficult to isolate aDNA from ancient plant materials, and furthermore, such DNA extracts frequently contain inhibitory substances that preclude successful PCR amplification. In the age of high-throughput sequencing, this problem is even more significant because each additional endogenous aDNA molecule improves analytical resolution. Therefore, in this paper, we compare a variety of DNA extraction techniques on primarily desiccated archaeobotanical remains and identify which method consistently yields the greatest amount of purified DNA. In addition, we test five DNA polymerases to determine how well they replicate DNA extracted from non-charred ancient plant remains. Based upon the criteria of resistance to enzymatic inhibition, behavior in quantitative real-time PCR, replication fidelity, and compatibility with aDNA damage, we conclude these polymerases have nuanced properties, requiring researchers to make educated decisions as to which one to use for a given task. The experimental findings should prove useful to the aDNA and archaeological communities by guiding future research methodologies and ensuring precious archaeobotanical remains are studied in optimal ways, and may thereby yield important new perspectives on the interactions between humans and past plant communities.

Neural blockade for persistent pain after breast cancer surgery.

Abstract Persistent pain after breast cancer surgery is predominantly a neuropathic pain syndrome affecting 25% to 60% of patients and related to injury of the intercostobrachial nerve, intercostal nerves, and other nerves in the region. Neural blockade can be useful for the identification of nerves involved in neuropathic pain syndromes or to be used as a treatment in its own right. The purpose of this review was to examine the evidence for neural blockade as a potential diagnostic tool or treatment for persistent pain after breast cancer surgery. In this systematic review, we found only 7 studies (n = 135) assessing blocks directed at 3 neural structures—stellate ganglion, paravertebral plexus, and intercostal nerves—but none focusing on the intercostobrachial nerve. The quality of the studies was low and efficacy inconclusive, suggesting a need for well-designed, high-quality studies for this common clinical problem.

Pain following the repair of an abdominal hernia

Pain and other types of discomfort are frequent symptoms following the repair of an abdominal hernia. After 1 year, the incidence of light to moderate pain following inguinal hernia repair is as high as 10% and 2% for severe disabling chronic pain. Postoperative chronic pain not only affects the individual patient, but may also have a great impact on relatives and society, and may be a cause of concern for the responsible surgeon. This paper provides an overview of the anatomy, surgical procedures, and disposing factors (age, gender, ethnicity, genotype, previous hernia repair, pain prior to surgery, psychosocial characteristics, and surgical procedures) related to the postoperative pain conditions. Furthermore, the mechanisms for both acute and chronic pain are presented. We focus on inguinal hernia repair, which is the most frequent type of abdominal hernia surgery that leads to chronic pain. Finally, the paper provides an update on the diagnostic and treatment routines for postoperative pain.

Intercostobrachial nerve handling and pain after axillary lymph node dissection for breast cancer.

Moderate to severe pain in the first week after axillary lymph node dissection (ALND) for breast cancer is experienced by approximately 50% of the patients. Damage to the intercostobrachial nerve (ICBN) has been proposed as a risk factor for the development of persistent pain following breast cancer surgery but with limited information on acute post‐operative pain. The aim of the present study was to examine the influence of ICBN handling on pain during the first week after ALND.