Khat Use Is Associated with Impaired Working Memory and Cognitive Flexibility

Rationale Khat consumption has increased during the last decades in Eastern Africa and has become a global phenomenon spreading to ethnic communities in the rest of the world, such as The Netherlands, United Kingdom, Canada, and the United States. Very little is known, however, about the relation between khat use and cognitive control functions in khat users. Objective We studied whether khat use is associated with changes in working memory (WM) and cognitive flexibility, two central cognitive control functions. Methods Khat users and khat-free controls were matched in terms of sex, ethnicity, age, alcohol and cannabis consumption, and IQ (Raven's progressive matrices). Groups were tested on cognitive flexibility, as measured by a Global-Local task, and on WM using an N-back task. Result Khat users performed significantly worse than controls on tasks tapping into cognitive flexibility as well as monitoring of information in WM. Conclusions The present findings suggest that khat use impairs both cognitive flexibility and the updating of information in WM. The inability to monitor information in WM and to adjust behavior rapidly and flexibly may have repercussions for daily life activities

Climatic controls of decomposition drive the global biogeography of forest-tree symbioses

The identity of the dominant root-associated microbial symbionts in a forest determines the ability of trees to access limiting nutrients from atmospheric or soil pools1,2, sequester carbon3,4 and withstand the effects of climate change5,6. Characterizing the global distribution of these symbioses and identifying the factors that control this distribution are thus integral to understanding the present and future functioning of forest ecosystems. Here we generate a spatially explicit global map of the symbiotic status of forests, using a database of over 1.1 million forest inventory plots that collectively contain over 28,000 tree species. Our analyses indicate that climate variables—in particular, climatically controlled variation in the rate of decomposition—are the primary drivers of the global distribution of major symbioses. We estimate that ectomycorrhizal trees, which represent only 2% of all plant species7, constitute approximately 60% of tree stems on Earth. Ectomycorrhizal symbiosis dominates forests in which seasonally cold and dry climates inhibit decomposition, and is the predominant form of symbiosis at high latitudes and elevation. By contrast, arbuscular mycorrhizal trees dominate in aseasonal, warm tropical forests, and occur with ectomycorrhizal trees in temperate biomes in which seasonally warm-and-wet climates enhance decomposition. Continental transitions between forests dominated by ectomycorrhizal or arbuscular mycorrhizal trees occur relatively abruptly along climate-driven decomposition gradients; these transitions are probably caused by positive feedback effects between plants and microorganisms. Symbiotic nitrogen fixers—which are insensitive to climatic controls on decomposition (compared with mycorrhizal fungi)—are most abundant in arid biomes with alkaline soils and high maximum temperatures. The climatically driven global symbiosis gradient that we document provides a spatially explicit quantitative understanding of microbial symbioses at the global scale, and demonstrates the critical role of microbial mutualisms in shaping the distribution of plant species

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Reliability and validity of the range of motion scale (ROMS) in patients with abnormal postures

Sustained abnormal postures (i.e., fixed dystonia) are the most frequently reported motor abnormalities in complex regional pain syndrome (CRPS), but these symptoms may also develop after peripheral trauma without CRPS. Currently, there is no valid and reliable measurement instrument available to measure the severity and distribution of these postures. The range of motion scale (ROMS) was therefore developed to assess the severity based on the possible active range of motion of all joints (arms, legs, trunk, and neck), and the present study evaluates its reliability and validity

Impact of the COVID-19-pandemic on patients with gynecological malignancies undergoing surgery: A Dutch population-based study using data from the 'Dutch Gynecological Oncology Audit'

Objective. The COVID-19-pandemic caused drastic healthcare changes worldwide. To date, the impact of these changes on gynecological cancer healthcare is relatively unknown. This study aimed to assess the impact of the COVID-19-pandemic on surgical gynecological-oncology healthcare.Methods. This population-based cohort study included all surgical procedures with curative intent for gynecological malignancies, registered in the Dutch Gynecological Oncology Audit, in 2018-2020. Four periods were identified based on COVID-19 hospital admission rates: 'Pre-COVID-19', 'Firstwave', 'Interimperiod', and'Second wave'. Surgical volume, perioperative care processes, and postoperative outcomes from 2020 were compared with 2018-2019.Results. A total of 11,488 surgical procedureswere analyzed. For cervical cancer, surgical volume decreased by 17.2% in 2020 compared to 2018-2019 (mean 2018-2019: n= 542.5, 2020: n= 449). At nadir (interimperiod), only 51% of the expected cervical cancer procedures were performed. For ovarian, vulvar, and endometrial cancer, volumes remained stable. Patients with advanced-stage ovarian cancer more frequently received neoadjuvant chemotherapy in 2020 compared to 2018-2019 (67.7% (n = 432) vs. 61.8% (n = 783), p = 0.011). Median time to first treatmentwas significantly shorter in all four malignancies in 2020. For vulvar and endometrial cancer, the length of hospital staywas significantly shorter in 2020. No significant differences in complicated course and 30-day-mortality were observed.Conclusions. The COVID-19-pandemic impacted surgical gynecological-oncology healthcare: in 2020, surgical volume for cervical cancer dropped considerably, waiting time was significantly shorter for all malignancies, while neoadjuvant chemotherapy administration for advanced-stage ovarian cancer increased. The safety of perioperative healthcare was not negatively impacted by the pandemic, as complications and 30-day-mortality remained stable. (C) 2022 The Authors. Published by Elsevier Inc.Analysis and support of clinical decision makin

Postoperative outcomes of primary and interval cytoreductive surgery for advanced ovarian cancer registered in the Dutch Gynecological Oncology Audit (DGOA)

Objectives: The challenge when performing cytoreductive surgery (CRS) is to balance the benefits and risks. The aim of this study was to report short term postoperative morbidity and mortality in relation to surgical outcome in patients undergoing primary debulking surgery (PDS) or interval debulking (IDS) surgery in the Netherlands. Methods: The Dutch Gynecological Oncology Audit (DGOA) was used for retrospective analysis. Patients undergoing PDS or IDS between January 1st, 2015 - December 31st, 2018 were included. Outcome was frequency of postoperative complications. Median time to adjuvant chemotherapy and severity of complications were related to outcome of CRS. Complications with Clavien-Dindo ≥3 were analyzed per region and case mix corrected. Statistical analysis was performed with R.Studio. Results: 1027 patients with PDS and 1355 patients with IDS were included. Complications with re-invention were significantly higher in PDS compared to IDS (5.7% vs. 3.6%, p = 0.048). Complete cytoreduction was 69.7% in PDS and 62.1% IDS, p &lt; 0.001. Time to adjuvant chemotherapy was 49 days in patients with complete CRS and a complication with re-intervention. Regional variation for severe complications showed one region outside confidence intervals. Conclusions: Higher complete cytoreduction rate in the PDS group indicates that the correct patients have been selected, but is associated with a higher percentage of complication with re-intervention. As result, time to start adjuvant chemotherapy is longer in this group. Maintaining a balance in aggressiveness of surgery and outcome of the surgical procedure with respect to severe complications is underlined. Bench marked data should be discussed nationally to improve this balance.</p