The latter are essential for food security in the African Great Lakes Region where banana is a major staple crop that already suffers from manifold other pests and diseases, such as nematodes, ...weevils, Xanthomonas bacterial wilt, and black leaf streak disease, also known as Black Sigatoka. ...sooner or later, every diagnostic will retrieve false positives, such as by a non-TR4 strain that nevertheless tests positive 18. ...multiple diagnostics should be used that target different genomic areas for confirmatory reasons. ...comparative analyses of the genomes from new versus previous incursions enables only provisional associations. ...the proximity of the sampling sites to these farms and the applied disease management practices strongly suggest that TR4 was not successfully contained. ...TR4 was recently reported on Mayotte, an island in the Indian Ocean approximately 700 km from the infested farms in Mozambique 24.
Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research ...into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the "Gros Michel" based banana industry in Central America. The epidemic was eventually quenched by planting "Cavendish" bananas. However, 50 years ago the disease recurred, but now on "Cavendish" bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of
f.sp.
Tropical Race 4 (Foc TR4) in "Cavendish" plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS), which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas-GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4.
Accurate preoperative staging of gastric cancer and the assessment of tumor response to neoadjuvant treatment is of importance for treatment and prognosis. Current imaging techniques, mainly ...endoscopic ultrasonography (EUS), computed tomography (CT) and
F-fluorodeoxyglucose positron emission tomography (
F-FDG PET), have their limitations. Historically, the role of magnetic resonance imaging (MRI) in gastric cancer has been limited, but with the continuous technical improvements, MRI has become a more potent imaging technique for gastrointestinal malignancies. The accuracy of MRI for T- and N-staging of gastric cancer is similar to EUS and CT, making MRI a suitable alternative to other imaging strategies. There is limited evidence on the performance of MRI for M-staging of gastric cancer specifically, but MRI is widely used for diagnosing liver metastases and shows potential for diagnosing peritoneal seeding. Recent pilot studies showed that treatment response assessment as well as detection of lymph node metastases and systemic disease might benefit from functional MRI (
diffusion weighted imaging and dynamic contrast enhancement). Regarding treatment guidance, additional value of MRI might be expected from its role in better defining clinical target volumes and setup verification with MR-guided radiation treatment.
Background and Aims Accurate determination of residual cancer status after neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer could assist in selecting the optimal treatment strategy. The aim ...of this study was to review the evidence on the diagnostic accuracy of endoscopic biopsy and EUS after nCRT for detecting residual cancer at the primary tumor site (ypT+) and regional lymph nodes (ypN+) as opposed to a pathologic complete response (ypT0 and ypN0). Methods PubMed/Medline, Embase, and the Cochrane library were systematically searched. The analysis included diagnostic studies reporting on the accuracy of endoscopic biopsy or EUS in detecting residual cancer versus complete response after nCRT for esophageal cancer with histopathology as the reference standard. Bivariate random-effects models were used to estimate pooled sensitivities and specificities and examine sources of heterogeneity. Results Twenty-three studies comprising 12 endoscopic biopsy studies (1281 patients), 11 EUS studies reporting on ypT status (593 patients), and 10 EUS studies reporting on ypN status (602 patients), were included. Pooled estimates for sensitivity of endoscopic biopsy after nCRT for predicting ypT+ were 34.5% (95% confidence interval CI, 26.0%-44.1%) and for specificity 91.0% (95% CI, 85.6%-94.5%). Pooled estimates for sensitivity of EUS after nCRT were 96.4% (95% CI, 91.7%-98.5%) and for specificity were 10.9% (95% CI, 3.5%-29.0%) for detecting ypT+, and 62.0% (95% CI, 46.0%-75.7%) and 56.7% (95% CI, 41.8%-70.5%) for detecting ypN+, respectively. Conclusions Endoscopic biopsy after nCRT is a specific but not sensitive method for detecting residual esophageal cancer. Although EUS after nCRT yields a high sensitivity, only a limited number of patients will have negative findings at EUS with still a substantial false-negative rate. Furthermore, EUS provides only moderate accuracy for detecting residual lymph node involvement. Based on these findings, these endoscopic modalities cannot be used to withhold surgical treatment in test-negative patients after nCRT. (Clinical trial registration number: CRD42015016527.)
Cell-based bone tissue engineering Meijer, Gert J; de Bruijn, Joost D; Koole, Ron ...
PLoS medicine,
02/2007, Letnik:
4, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The authors review the available data on bone tissue engineering and discuss possible new research areas that could help to make bone tissue engineering a clinical success.
To evaluate whether detection of recurrent pancreatic ductal adenocarcinoma (PDAC) in an early, asymptomatic stage increases the number of patients receiving additional treatment, subsequently ...improving survival.
International guidelines disagree on the value of standardized postoperative surveillance for early detection and treatment of PDAC recurrence.
A nationwide, observational cohort study was performed including all patients who underwent PDAC resection (2014-2016). Prospective baseline and perioperative data were retrieved from the Dutch Pancreatic Cancer Audit. Data on follow-up, treatment, and survival were collected retrospectively. Overall survival (OS) was evaluated using multivariable Cox regression analysis, before and after propensity-score matching, stratified for patients with symptomatic and asymptomatic recurrence.
Eight hundred thirty-six patients with a median follow-up of 37 months (interquartile range 30-48) were analyzed. Of those, 670 patients (80%) developed PDAC recurrence after a median follow-up of 10 months (interquartile range 5-17). Additional treatment was performed in 159/511 patients (31%) with symptomatic recurrence versus 77/159 (48%) asymptomatic patients (P < 0.001). After propensity-score matching on lymph node ratio, adjuvant therapy, disease-free survival, and recurrence site, additional treatment was independently associated with improved OS for both symptomatic patients hazard ratio 0.53 (95% confidence interval 0.42-0.67); P < 0.001 and asymptomatic patients hazard ratio 0.45 (95% confidence interval 0.29-0.70); P < 0.001.
Additional treatment of PDAC recurrence was independently associated with improved OS, with asymptomatic patients having a higher probability to receive recurrence treatment. Therefore, standardized postoperative surveillance aiming to detect PDAC recurrence before the onset of symptoms has the potential to improve survival. This provides a rationale for prospective studies on standardized surveillance after PDAC resection.
The haploid fungus Pseudocercospora fijiensis causes black Sigatoka in banana and is chiefly controlled by extensive fungicide applications, threatening occupational health and the environment. The ...14α-Demethylase Inhibitors (DMIs) are important disease control fungicides, but they lose sensitivity in a rather gradual fashion, suggesting an underlying polygenic genetic mechanism. In spite of this, evidence found thus far suggests that P. fijiensis cyp51 gene mutations are the main responsible factor for sensitivity loss in the field. To better understand the mechanisms involved in DMI resistance, in this study we constructed a genetic map using DArTseq markers on two F1 populations generated by crossing two different DMI resistant strains with a sensitive strain. Analysis of the inheritance of DMI resistance in the F1 populations revealed two major and discrete DMI-sensitivity groups. This is an indicative of a single major responsible gene. Using the DMI-sensitivity scorings of both F1 populations and the generation of genetic linkage maps, the sensitivity causal factor was located in a single genetic region. Full agreement was found for genetic markers in either population, underlining the robustness of the approach. The two maps indicated a similar genetic region where the Pfcyp51 gene is found. Sequence analyses of the Pfcyp51 gene of the F1 populations also revealed a matching bimodal distribution with the DMI resistant. Amino acid substitutions in P. fijiensis CYP51 enzyme of the resistant progeny were previously correlated with the loss of DMI sensitivity. In addition, the resistant progeny inherited a Pfcyp51 gene promoter insertion, composed of a repeat element with a palindromic core, also previously correlated with increased gene expression. This genetic approach confirms that Pfcyp51 is the single explanatory gene for reduced sensitivity to DMI fungicides in the analysed P. fijiensis strains. Our study is the first genetic analysis to map the underlying genetic factors for reduced DMI efficacy.
Abstract Purpose To explore the value of diffusion-weighted magnetic resonance imaging (DW-MRI) for the prediction of pathologic response to neoadjuvant chemoradiotherapy (nCRT) in esophageal cancer. ...Material and methods In 20 patients receiving nCRT for esophageal cancer DW-MRI scanning was performed before nCRT, after 8–13 fractions, and before surgery. The median tumor apparent diffusion coefficient (ADC) was determined at these three time points. The predictive potential of initial tumor ADC, and change in ADC (ΔADC) during and after treatment for pathologic complete response (pathCR) and good response were assessed. Good response was defined as pathCR or near-pathCR (tumor regression grade TRG 1 or 2). Results A pathCR after nCRT was found in 4 of 20 patients (20%), and 8 patients (40%) showed a good response to nCRT. The ΔADCduring was significantly higher in pathCR vs. non-pathCR patients (34.6% ± 10.7% mean ± SD vs. 14.0% ± 13.1%, p = 0.016), as well as in good vs. poor responders (30.5% ± 8.3% vs. 9.5% ± 12.5%, p = 0.002). The ΔADCduring was predictive of residual cancer at a threshold of 29% (sensitivity of 100%, specificity of 75%, PPV of 94%, and NPV of 100%), and for poor pathologic response at a threshold of 21% (sensitivity of 82%, specificity of 100%, PPV of 100%, and NPV of 80%). Conclusions In this exploratory study, the treatment-induced change in ADC during the first 2–3 weeks of nCRT for esophageal cancer seemed highly predictive of histopathologic response. Larger series are warranted to verify these results.
Cellular strategies play an important role in bone tissue engineering and regenerative medicine (BTE/RM). Variability in cell culture procedures (e.g., cell types, cell isolation and expansion, cell ...seeding methods, and preculture conditions before in vivo implantation) may influence experimental outcome. The present review provides an overview of the critical procedures during in vitro and in vivo phases for cell‐based strategies (both monoculture and coculture) in BTE/RM.
Cellular strategies play an important role in bone tissue engineering and regenerative medicine (BTE/RM). Variability in cell culture procedures (e.g., cell types, cell isolation and expansion, cell seeding methods, and preculture conditions before in vivo implantation) may influence experimental outcome. Meanwhile, outcomes from initial clinical trials are far behind those of animal studies, which is suggested to be related to insufficient nutrient and oxygen supply inside the BTE/RM constructs as some complex clinical implementations require bone regeneration in too large a quantity. Coculture strategies, in which angiogenic cells are introduced into osteogenic cell cultures, might provide a solution for improving vascularization and hence increasing bone formation for cell‐based constructs. So far, preclinical studies have demonstrated that cell‐based tissue‐engineered constructs generally induce more bone formation compared with acellular constructs. Further, cocultures have been shown to enhance vascularization and bone formation compared with monocultures. However, translational efficacy from animal studies to clinical use requires improvement, and the role implanted cells play in clinical bone regeneration needs to be further elucidated. In view of this, the present review provides an overview of the critical procedures during in vitro and in vivo phases for cell‐based strategies (both monoculture and coculture) in BTE/RM to achieve more standardized culture conditions for future studies, and hence enhance bone formation.
Objective
To investigate the influence of different surgical techniques on the primary and secondary implant stability using trabecular bone of goats as an implantation model.
Material and methods
In ...the iliac crest of eight goats, 48 cylindrical‐screw‐type implants with a diameter of 4.2 mm (Dyna®; Bergen op Zoom, the Netherlands) were installed, using three different surgical techniques: (i) 5% undersized, using a final drill diameter of 4 mm; (ii) 15% undersized, using a final drill diameter of 3.6 mm; and (iii) 25% undersized, using a final drill diameter of 3.2 mm. Peak insertion torque values were measured by a Digital® (MARK‐10 Corporation, New York, NY, USA) torque gauge instrument during placement. At 3 weeks after implantation, removal torque was measured. Histomorphometrically, the peri‐implant bone volume was measured in three zones; the inner zone (0–500 μm), the middle zone (500–1000 μm) and the outer zone (1000–1500 μm).
Results
Evaluation of the obtained data demonstrated no statistically significant difference between different surgical techniques regarding removal torque values. With respect to the percentage peri‐implant bone volume (%BV), also no significant difference could be observed between all three applied surgical techniques for both the inner, middle and outer zone. However, irrespective of the surgical technique, it was noticed that the %BV was significantly higher for the inner zone as compared to middle and outer zone (P < 0.05) around the implant.
Conclusion
At 3 weeks after implant installation, independent of the used undersized surgical technique, the %BV in the inner zone (0–500 μm) peri‐implant area was improved due to both condensation of the surrounding bone as also the translocation of host bone particles along the implant surface. Surprisingly, no mechanical beneficial effect of the 25% undersized surgical technique could be observed as compared to the 5% or 15% undersized surgical technique to improve primary or secondary implant stability.
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