The longevity of cycad pollen in storage

An investigation was made into the effects of temperature, headspace atmosphere and humidity on the longevity of stored pollen from several Encephalartos species and from Cycas thouarsii. Samples were assayed by in vitro germination tests and by in vivo pollination trials. Encephalartos pollen rapidly lost germinability at ambient temperatures but retained 50% germinability for approximately two years at 0°C and three years at −15°C. Storage in ambient atmosphere resulted in better germinability than storage in a nitrogen atmosphere. Pre-drying for 24h was beneficial but storage over a desiccant was disadvantageous. Pollen stored for 2 years at 0 – 4°C gave rise to a 58% seed germination when used to pollinate a female Encephalartos transvenosus cone. Pollen of Cycas thouarsii stored at reduced temperatures exhibited a pronounced seasonal variation in germinability with reduction in maxima over a 3-year period, implying the operation of a hitherto undocumented biological clock

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Longitudinal changes in rich club organization and cognition in cerebral small vessel disease

Contains fulltext : 209499.pdf (publisher's version ) (Open Access)Cerebral small vessel disease (SVD) is considered the most important vascular contributor to the development of cognitive impairment and dementia. There is increasing awareness that SVD exerts its clinical effects by disrupting white matter connections, predominantly disrupting connections between rich club nodes, a set of highly connected and interconnected regions. Here we examined the progression of disturbances in rich club organization in older adults with SVD and their associations with conventional SVD markers and cognitive decline. We additionally investigated associations of baseline network measures with dementia. In 270 participants of the RUN DMC study, we performed diffusion tensor imaging (DTI) and cognitive assessments longitudinally. Rich club organization was examined in structural networks derived from DTI followed by deterministic tractography. Global efficiency (p<0.05) and strength of rich club connections (p<0.001) declined during follow-up. Decline in strength of peripheral connections was associated with a decline in overall cognition (β=0.164; p<0.01), psychomotor speed (β=0.151; p<0.05) and executive function (β=0.117; p<0.05). Baseline network measures were reduced in participants with dementia, and the association between WMH and dementia was causally mediated by global efficiency (p = =0.037) and peripheral connection strength (p = =0.040). SVD-related disturbances in rich club organization progressed over time, predominantly in participants with severe SVD. In this study, we found no specific role of rich club connectivity disruption in causing cognitive decline or dementia. The effect of WMH on dementia was mediated by global network efficiency and the strength of peripheral connections, suggesting an important role for network disruption in causing cognitive decline and dementia in older adults with SVD.9 p

Plasma Abeta (Amyloid-beta) Levels and Severity and Progression of Small Vessel Disease

BACKGROUND AND PURPOSE: Cerebral small vessel disease (SVD) is a frequent pathology in aging and contributor to the development of dementia. Plasma Abeta (amyloid beta) levels may be useful as early biomarker, but the role of plasma Abeta in SVD remains to be elucidated. We investigated the association of plasma Abeta levels with severity and progression of SVD markers. METHODS: We studied 487 participants from the RUN DMC study (Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Imaging Cohort) of whom 258 participants underwent 3 MRI assessments during 9 years. We determined baseline plasma Abeta38, Abeta40, and Abeta42 levels using ELISAs. We longitudinally assessed volume of white matter hyperintensities semiautomatically and manually rated lacunes and microbleeds. We analyzed associations between plasma Abeta and SVD markers by ANCOVA adjusted for age, sex, and hypertension. RESULTS: Cross-sectionally, plasma Abeta40 levels were elevated in participants with microbleeds (mean, 205.4 versus 186.4 pg/mL; P<0.01) and lacunes (mean, 194.8 versus 181.2 pg/mL; P<0.05). Both Abeta38 and Abeta40 were elevated in participants with severe white matter hyperintensities (Abeta38, 25.3 versus 22.7 pg/mL; P<0.01; Abeta40, 201.8 versus 183.3 pg/mL; P<0.05). Longitudinally, plasma Abeta40 levels were elevated in participants with white matter hyperintensity progression (mean, 194.6 versus 182.9 pg/mL; P<0.05). Both Abeta38 and Abeta40 were elevated in participants with incident lacunes (Abeta38, 24.5 versus 22.5 pg/mL; P<0.05; Abeta40, 194.9 versus 181.2 pg/mL; P<0.01) and Abeta42 in participants with incident microbleeds (62.8 versus 60.4 pg/mL; P<0.05). CONCLUSIONS: Plasma Abeta levels are associated with both presence and progression of SVD markers, suggesting that Abeta pathology might contribute to the development and progression of SVD. Plasma Abeta levels might thereby serve as inexpensive and noninvasive measure for identifying individuals with increased risk for progression of SVD

Learning Curve of Laparoscopic Gastrectomy: A Multicenter Study.

OBJECTIVE: To evaluate the learning curve of laparoscopic gastrectomy (LG) after an implementation program. BACKGROUND: Although LG is increasingly being performed worldwide, little is known about the learning curve. METHODS: Consecutive patients who underwent elective LG for gastric adenocarcinoma with curative intent in each of the 5 highest-volume centers in the Netherlands were enrolled. Generalized additive models and a 2-piece model with a break point were used to determine the learning curve length. Analyses were corrected for casemix and were performed for LG and for the subgroups distal gastrectomy (LDG) and total gastrectomy (LTG). The learning curve effect was assessed for (1) anastomotic leakage; and (2) the occurrence of postoperative complications, conversions to open surgery, and short-term oncological parameters. RESULTS: In total 540 patients were included for analysis, 108 patients from each center; 268 patients underwent LDG and 272 underwent LTG. First, for LG, no learning effect regarding anastomotic leakage could be identified: the rate of anastomotic leakage initially increased, then reached a plateau after 36 cases at 10% anastomotic leakage. Second, the level of overall complications reached a plateau after 20 cases, at 38% overall complications, and at 5% conversions. For both LDG and LTG, each considered separately, fluctuations in secondary outcomes and anastomotic leakage followed fluctuations in casemix. CONCLUSION: On the basis of our study of the first 108 procedures of LG in 5 high-volume centers with well-trained surgeons, no learning curve effect could be identified regarding anastomotic leakage. A learning curve effect was found with respect to overall complications and conversion rate

Surgical morbidity and mortality after neoadjuvant chemotherapy in the CRITICS gastric cancer trial

BACKGROUND: In order to determine the optimal combination of perioperative chemotherapy and chemoradiotherapy for Western patients with advanced resectable gastric cancer, the international multicentre CRITICS trial (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach) was initiated. In this trial, patients with resectable gastric cancer were randomised before start of treatment between adjuvant chemotherapy or adjuvant chemoradiotherapy following neoadjuvant chemotherapy plus gastric cancer resection. The purpose of this study was to report on surgical morbidity and mortality in this trial, and to identify factors associated with surgical morbidity. METHODS: Patients who underwent a gastrectomy with curative intent were selected. Logistic regression analyses were used to assess risk factors for developing postoperative complications. RESULTS: Between 2007 and 2015, 788 patients were included in the CRITICS trial, of whom 636 patients were eligible for current analyses. Complications occurred in 296 patients (47%). Postoperative mortality was 2.2% (n = 14). Complications due to anastomotic leakage was cause of death in 5 patients. Failure to complete preoperative chemotherapy (OR = 2.09, P = 0.004), splenectomy (OR = 2.82, P = 0.012), and male sex (OR = 1.55, P = 0.020) were associated with a greater risk for postoperative complications. Total gastrectomy and oesophago-cardia resection were associated with greater risk for morbidity compared with subtotal gastrectomy (OR = 1.88, P = 0.001 and OR = 1.89, P = 0.038). CONCLUSION: Compared to other Western studies, surgical morbidity in the CRITICS trial was slightly higher whereas mortality was low. Complications following anastomotic leakage was the most important factor for postoperative mortality. Important proxies for developing postoperative complications were failure to complete preoperative chemotherapy, splenectomy, male sex, total gastrectomy, and oesophago-cardia resection

Association between hospital volume and quality of gastric cancer surgery in the CRITICS trial

Item does not contain fulltextBACKGROUND: Studies investigating the association between hospital volume and quality of gastric cancer surgery are lacking. In the present study, the effect of hospital volume on quality of gastric cancer surgery was evaluated by analysing data from the CRITICS (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach) trial. METHODS: Patients who underwent gastrectomy with curative intent in the Netherlands were selected from the CRITICS trial database. Annual hospital volume of participating centres was derived from the Netherlands Cancer Registry. Hospital volume was categorized into very low (1-10 gastrectomies per year per institution), low (11-20), medium (21-30) and high (31 or more), and linked to the CRITICS database. Quality of surgery was analysed by surgicopathological compliance (removal of at least 15 lymph nodes), surgical compliance (removal of indicated lymph node stations) and the Maruyama Index. Postoperative morbidity and mortality were also compared between hospital categories. RESULTS: Between 2007 and 2015, 788 patients were included in the CRITICS study, of whom 494 were analysed. Surgicopathological compliance was higher (86.7 versus 50.4 per cent; P < 0.001), surgical compliance was greater (52.9 versus 19.8 per cent; P < 0.001) and median Maruyama Index was lower (0 versus 6; P = 0.006) in high-volume hospitals compared with very low-volume hospitals. There was no statistically significant difference in postoperative complications or mortality between the hospital volume categories. CONCLUSION: Surgery performed in high-volume hospitals was associated with better surgical quality than surgery carried out in lower-volume hospitals

Absorção de manganês em soja RR sob efeito do glifosate

Foi levantada a hipótese de que o glifosate aplicado à soja resistente ao herbicida poderia alterar a eficiência de absorção e translocação do nutriente na planta. Com o objetivo de estudar o acúmulo e distribuição do Mn, assim como a cinética de absorção de Mn pela soja geneticamente modificada sob efeito da aplicação de glifosate, foram conduzidos dois experimentos. No primeiro, os tratamentos foram constituídos por duas cultivares de soja quase isogênicas cultivadas em solução nutritiva (Conquista e Valiosa RR com aplicação ou não do herbicida). As concentrações de Mn empregadas na solução nutritiva foram: 0; 0,085; 0,125; 0,250; e 0,500 mg L-1. Após 25 dias de cultivo, parte do total de plantas de soja transgênica foi pulverizada com o herbicida. No segundo experimento, para avaliação da cinética de absorção do Mn da cultivar Valiosa RR, as plantas foram pulverizadas com glifosate aos 26 dias de cultivo nas doses de 0, 15 e 960 g ha-1 e.a. Constatou-se que a transgenia para resistência ao herbicida não altera a nutrição mangânica na cultivar de soja Valiosa RR. Mesmo reduzindo a massa de matéria seca de raiz, o glifosate não interfere na absorção e no transporte de Mn na planta de soja transgênica. Quanto à absorção do Mn pela cultivar transgênica, os parâmetros cinéticos Km, Vmáx. e Cmín. não são alterados pelo herbicida aplicado via foliar

Trends in Distal Esophageal and Gastroesophageal Junction Cancer Care: The Dutch Nationwide Ivory Study.

OBJECTIVE: This study evaluated the nationwide trends in care and accompanied postoperative outcomes for patients with distal esophageal and gastro-esophageal junction cancer. SUMMARY OF BACKGROUND DATA: The introduction of transthoracic esophagectomy, minimally invasive surgery, and neo-adjuvant chemo(radio)therapy changed care for patients with esophageal cancer. METHODS: Patients after elective transthoracic and transhiatal esophagectomy for distal esophageal or gastroesophageal junction carcinoma in the Netherlands between 2007-2016 were included. The primary aim was to evaluate trends in both care and postoperative outcomes for the included patients. Additionally, postoperative outcomes after transthoracic and tran-shiatal esophagectomy were compared, stratified by time periods. RESULTS: Among 4712 patients included, 74% had distal esophageal tumors and 87% had adenocarcinomas. Between 2007 and 2016, the proportion of transthoracic esophagectomy increased from 41% to 81%, and neo-adjuvant treatment and minimally invasive esophagectomy increased from 31% to 96%, and from 7% to 80%, respectively. Over this 10-year period, postoperative outcomes improved: postoperative morbidity decreased from 66.6% to 61.8% ( P = 0.001), R0 resection rate increased from 90.0% to 96.5% (P <0.001), median lymph node harvest increased from 15 to 19 ( P <0.001), and median survival increased from 35 to 41 months ( P = 0.027). CONCLUSION: In this nationwide cohort, a transition towards more neo-adju-vant treatment, transthoracic esophagectomy and minimally invasive surgery was observed over a 10-year period, accompanied by decreased postoperative morbidity, improved surgical radicality and lymph node harvest, and improved survival