Visual stimulus brightness influences the efficiency of attractant-baited traps for catching Drosophila suzukii Matsumura (Diptera: Drosophilidae).

Drosophila suzukii (Matsumura) is an exotic pest of economic importance that affects several soft-skinned fruits in Mexico. Previously, we found that yellow or yellow-green rectangular cards inside a transparent trap baited with attractants improved D. suzukii capture. In this study, we evaluated the influence of rectangular cards with different yellow shades inside a transparent multi-hole trap baited with apple cider vinegar (ACV) on D. suzukii capture in the field. Second, we tested whether ACV-baited traps with cards of other geometric shapes affected D. suzukii catches compared to traps with rectangular cards. Third, we evaluated the effects of commercial lures combined with a more efficient visual stimulus from previous experiments on trapping D. suzukii flies. We found that ACV-baited traps plus a yellow-shaded rectangle card with 67% reflectance at a 549.74 nm dominant wavelength captured more flies than ACV-baited traps with yellow rectangle cards with a higher reflectance. Overall, ACV-baited traps with rectangles and squares caught more flies than did ACV-baited traps without visual stimuli. The traps baited with SuzukiiLURE-Max, ACV and Z-Kinol plus yellow rectangles caught 57, 70 and 101% more flies, respectively, than the traps baited with the lure but without a visual stimulus.

Single-molecule imaging of Tau reveals how phosphorylation affects its movement and confinement in living cells.

Tau is a microtubule-associated protein that is regulated by post-translational modifications. The most studied of these modifications is phosphorylation, which affects Tau's aggregation and loss- and gain-of-functions, including the interaction with microtubules, in Alzheimer's disease and primary tauopathies. However, little is known about how Tau's phosphorylation state affects its dynamics and organisation at the single-molecule level. Here, using quantitative single-molecule localisation microscopy, we examined how mimicking or abrogating phosphorylation at 14 disease-associated serine and threonine residues through mutagenesis influences the behaviour of Tau in live Neuro-2a cells. We observed that both pseudohyperphosphorylated Tau (TauE14) and phosphorylation-deficient Tau (TauA14) exhibit a heterogeneous mobility pattern near the plasma membrane. Notably, we found that the mobility of TauE14 molecules was higher than wild-type Tau molecules, while TauA14 molecules displayed lower mobility. Moreover, TauA14 was organised in a filament-like structure resembling cytoskeletal filaments, within which TauA14 exhibited spatial and kinetic heterogeneity. Our study provides a direct visualisation of how the phosphorylation state of Tau affects its spatial and temporal organisation, presumably reflecting the phosphorylation-dependent changes in the interactions between Tau and its partners. We suggest that alterations in Tau dynamics resulting from aberrant changes in phosphorylation could be a critical step in its pathological dysregulation.

Break and accelerator-The mechanics of Tau (and amyloid) toxicity.

Aggregates of the microtubule-associated protein Tau define more than a dozen primary tauopathies, and together with amyloid-ß, the secondary tauopathy Alzheimer's disease (AD). Historically, Tau has been viewed as executor of amyloid-ß toxicity, with the two molecules working together as "trigger and bullet." Given the two protein's opposing roles in protein translation, we wish to introduce another metaphor, borrowing from the mechanics of a car, with amyloid-ß boosting Tau translation, whereas Tau puts a break on global translation. The underlying studies entail an alternative hypothesis regarding Tau's subcellular accumulation in AD, namely its de novo synthesis in the somatodendritic domain rather than the relocalization from the axon upon dissociation from microtubules. We contest that it may be worth (given Tau's 50th birthday) to revisit some entrenched dogmas about Tau's pathophysiology.

How to repel a killer; chemical identification and effective repellent activity of commercial essential oils against kissing bugs.

Triatomines are haematophagous insects, some species are vectors of Trypanosoma cruzi, the aetiological agent of Chagas disease. The main strategy for interrupting T. cruzi transmission is to avoid contact of the vector populations with humans. Volatiles from commercial essential oils are excellent candidates to serve as repellents of kissing bugs. We used an exposure device to assess the repellence effect of eight commercial essential oils on Triatoma pallidipennis. The most effective oils were blended and evaluated against T. infestans, T. pallidipennis and Rhodnius prolixus. The blend was also evaluated on parasitised T. pallidipennis. Data were compared with the commercial repellent NN-diethyl-3-methylbenzamide. We recorded the time the insects spent in the proximity of the host and determined if any of the evaluated oils served as kissing bug repellent. We found commercial essential oils and a blend that significantly reduced the time spent in the proximity of the host. The blend was effective for use by human males and females, repelling infected and non-infected insects. The study of essential oils as repellents of blood-sucking disease-vector insects could shed light on the development of new control strategies.

Attraction of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), to healthy and damaged strawberry plants mediated by volatile cues.

Tetranychus urticae Koch (Acari: Tetranychidae), the two-spotted spider mite, is a pest that limits strawberry production in Mexico. Little is known about the interactions that occur between T. urticae and healthy strawberry plants or strawberry plants infested by conspecific spider mites. Therefore, in this study we evaluated the attraction of T. urticae to healthy strawberry plants mediated by volatile organic compounds (VOCs), and to plants damaged by conspecifics mediated by herbivore-induce plant volatiles (HIPVs). First, we conducted dual-choice tests using a Y-tube olfactometer with plants and extracts obtained through dynamic aeration. The volatile composition of the extracts was identified using gas chromatography-mass spectrometry (GC-MS). Once the compounds were identified, we also conducted dual-choice tests with selected synthetic compounds. Tetranychus urticae exhibited greater attraction to both healthy and damaged plants compared to the control (clean air). However, when healthy and damaged plants were offered simultaneously, there was no significant preference observed. Bioassays with extracts obtained by dynamic aeration yielded similar results. The identified compounds were terpenes and aromatic hydrocarbons. We found qualitative and quantitative changes between the VOCs emitted by the healthy plant and the HIPVs from mite-damaged plants. The individual compounds α-pinene (10 ng), pseudocumene (10 ng), and limonene (1 ng) and 10 ng of the blend made of α-pinene + pseudocumene + mesitylene + limonene (5:34:57:4) attracted more T. urticae than the control. However, the binary blend of pseudocumene + limonene (91:9) was more attractive than the other binary or three-compound blends evaluated. These results may contribute to developing strategies for the management of this pest.

Opportunities and challenges in delivering biologics for Alzheimer's disease by low-intensity ultrasound.

Low-intensity ultrasound combined with intravenously injected microbubbles (US+MB) is a novel treatment modality for brain disorders, including Alzheimer's disease (AD), safely and transiently allowing therapeutic agents to overcome the blood-brain barrier (BBB) that constitutes a major barrier for therapeutic agents. Here, we first provide an update on immunotherapies in AD and how US+MB has been applied to AD mouse models and in clinical trials, considering the ultrasound and microbubble parameter space. In the second half of the review, we compare different in vitro BBB models and discuss strategies for combining US+MB with BBB modulators (targeting molecules such as claudin-5), and highlight the insight provided by super-resolution microscopy. Finally, we conclude with a short discussion on how in vitro findings can inform the design of animal studies, and how the insight gained may aid treatment optimization in the clinical ultrasound space.

Single-molecule imaging reveals Tau trapping at nanometer-sized dynamic hot spots near the plasma membrane that persists after microtubule perturbation and cholesterol depletion.

Accumulation of aggregates of the microtubule-binding protein Tau is a pathological hallmark of Alzheimer's disease. While Tau is thought to primarily associate with microtubules, it also interacts with and localizes to the plasma membrane. However, little is known about how Tau behaves and organizes at the plasma membrane of live cells. Using quantitative, single-molecule imaging, we show that Tau exhibits spatial and kinetic heterogeneity near the plasma membrane of live cells, resulting in the formation of nanometer-sized hot spots. The hot spots lasted tens of seconds, much longer than the short dwell time (∼ 40 ms) of Tau on microtubules. Pharmacological and biochemical disruption of Tau/microtubule interactions did not prevent hot spot formation, suggesting that these are different from the reported Tau condensation on microtubules. Although cholesterol removal has been shown to reduce Tau pathology, its acute depletion did not affect Tau hot spot dynamics. Our study identifies an intrinsic dynamic property of Tau near the plasma membrane that may facilitate the formation of assembly sites for Tau to assume its physiological and pathological functions.

Mortality of Orius insidiosus by contact with spinosad in the laboratory as well as in the field and a perspective of these as controllers of Frankliniella occidentalis.

Orius insidiosus, known as the pirate bug, is widely distributed throughout the Americas. It is employed for the biological control of Frankliniella occidentalis in organic berry crops in Mexico. In conventional crops, spinosad is the main control method for this pest. The LD50 of spinosad on O. insidiosus was determined. In addition, we monitored the population density of F. occidentalis in blackberry crops under two types of management (biochemical+mass trapping, and biological control). The LD50 was 225.65 ppm 3.8 times greater than the 60 ppm dose commonly used in blackberry crops. Both types of control are efficient; however, spinosad is less effective and should be combined with other environmentally friendly strategies. The possibility of combining chromatic traps+spinosad application and chromatic traps+strategic release of O. insidiosus to effectively control thrips without compromising fruit quality is discussed.

Ultrasound-mediated delivery of novel tau-specific monoclonal antibody enhances brain uptake but not therapeutic efficacy.

Tau-specific immunotherapy is an attractive strategy for the treatment of Alzheimer's disease and other tauopathies. However, effectively targeting tau in the brain remains a considerable challenge due to the restrictive nature of the blood-brain barrier (BBB), which excludes an estimated >99% of peripherally administered antibodies. However, their transport across the BBB can be facilitated by a novel modality, low-intensity scanning ultrasound used in combination with intravenously injected microbubbles (SUS+MB). We have previously shown that SUS+MB-mediated delivery of a tau-specific antibody in a single-chain (scFv) format to tau transgenic mice enhanced brain and neuronal uptake and subsequently, reduced tau pathology and improved behavioural outcomes to a larger extent than either scFv or SUS+MB on its own. Here we generated a novel tau-specific monoclonal antibody, RNF5, and validated it in its IgG format in the presence or absence of SUS+MB by treating K369I tau transgenic K3 mice once weekly for 12 weeks. We found that both RNF5 and SUS+MB treatments on their own significantly reduced tau pathology. In the combination group (RNF5 + SUS+MB), however, despite increased antibody localization in the brain, there were no further reductions in tau pathology when compared to RNF5 treatment alone. Furthermore, following SUS+MB, RNF5 accumulated heavily within cells across the pyramidal cell layer of the hippocampus, that were negative for MAP2 and p-tau, suggesting that SUS+MB may not facilitate enhanced RNF5 engagement of intraneuronal tau. Overall, our new findings reveal the complexities of combining tau immunotherapy with SUS+MB and challenge the view that this is a straight-forward approach.

Claudin-5 binder enhances focused ultrasound-mediated opening in an in vitro blood-brain barrier model.

Rationale: The blood-brain barrier (BBB) while functioning as a gatekeeper of the brain, impedes cerebral drug delivery. An emerging technology to overcome this limitation is focused ultrasound (FUS). When FUS interacts with intravenously injected microbubbles (FUS+MB), the BBB opens, transiently allowing the access of therapeutic agents into the brain. However, the ultrasound parameters need to be tightly tuned: when the acoustic pressure is too low there is no opening, and when it is too high, tissue damage can occur. We therefore asked whether barrier permeability can be increased by combining FUS+MB with a second modality such that in a clinical setting lower acoustic pressures could be used. Methods: Given that FUS+MB achieves BBB opening in part by disruption of tight junction (TJ) proteins such as claudin-5 of brain endothelial cells, we generated a stable MDCK (Madin-Darby Canine Kidney) II cell line (eGFP-hCldn5-MDCK II) that expresses fluorescently tagged human claudin-5. Two claudin-5 binders, the peptide mC5C2 and cCPEm (truncated form of an enterotoxin), reported previously to weaken the barrier, were synthesized and assessed for their abilities to enhance the permeability of cellular monolayers. We then performed a comparative analysis of single and combination treatments, measuring transendothelial electrical resistance (TEER) and cargo leakage, combined with confocal image analysis. Results: We successfully generated a novel cell line that formed functional monolayers as validated by an increased TEER reading and a low (< 0.2%) permeability to sodium fluorescein (376 Da). We found that the binders exerted a time- and concentration-dependent effect on barrier opening when incubated over an extended period, whereas FUS+MB caused a rapid opening followed by recovery after 12 hours within the tested pressure range. Importantly, preincubation with cCPEm prior to FUS+MB treatment resulted in greater barrier opening compared to either FUS+MB or cCPEm alone as measured by reduced TEER values and an increased permeability to fluorescently labelled 40 kDa dextran (FD40). Conclusion: The data suggest that pre incubation with clinically suitable binders to TJ proteins may be a general strategy to facilitate safer and more effective ultrasound-mediated BBB opening in cellular and animal systems and potentially also for the treatment of human diseases of the brain.

Glycan Profile Analysis of Engineered Trastuzumab with Rationally Added Glycosylation Sequons Presents Significantly Increased Glycan Complexity.

Protein aggregation constitutes a recurring complication in the manufacture and clinical use of therapeutic monoclonal antibodies (mAb) and mAb derivatives. Antibody aggregates can reduce production yield, cause immunogenic reactions, decrease the shelf-life of the pharmaceutical product and impair the capacity of the antibody monomer to bind to its cognate antigen. A common strategy to tackle protein aggregation involves the identification of surface-exposed aggregation-prone regions (APR) for replacement through protein engineering. It was shown that the insertion of N-glycosylation sequons on amino acids proximal to an aggregation-prone region can increase the physical stability of the protein by shielding the APR, thus preventing self-association of antibody monomers. We recently implemented this approach in the Fab region of full-size adalimumab and demonstrated that the thermodynamic stability of the Fab domain increases upon N-glycosite addition. Previous experimental data reported for this technique have lacked appropriate confirmation of glycan occupancy and structural characterization of the ensuing glycan profile. Herein, we mutated previously identified candidate positions on the Fab domain of Trastuzumab and employed tandem mass spectrometry to confirm attachment and obtain a detailed N-glycosylation profile of the mutants. The Trastuzumab glycomutants displayed a glycan profile with significantly higher structural heterogeneity compared to the HEK Trastuzumab antibody, which contains a single N-glycosylation site per heavy chain located in the CH2 domain of the Fc region. These findings suggest that Fab N-glycosites have higher accessibility to enzymes responsible for glycan maturation. Further, we have studied effects on additional glycosylation on protein stability via accelerated studies by following protein folding and aggregation propensities and observed that additional glycosylation indeed enhances physical stability and prevent protein aggregation. Our findings shed light into mAb glycobiology and potential implications in the application of this technique for the development of "biobetter" antibodies.

Therapeutic Ultrasound as a Treatment Modality for Physiological and Pathological Ageing Including Alzheimer's Disease.

Physiological and pathological ageing (as exemplified by Alzheimer's disease, AD) are characterized by a progressive decline that also includes cognition. How this decline can be slowed or even reversed is a critical question. Here, we discuss therapeutic ultrasound as a novel modality to achieve this goal. In our studies, we explored three fundamental strategies, (i) scanning ultrasound on its own (SUSonly), (ii) therapeutic ultrasound in concert with intravenously injected microbubbles (which transiently opens the blood-brain barrier, SUS+MB), and (iii) SUS+MB in combination with therapeutic antibodies (SUS+MB+mAb). These studies show SUS+MB effectively clears amyloid and restores memory in amyloid-depositing mice and partially clears Tau and ameliorates memory impairments in Tau transgenic mice, with additional improvements found in combination trials (SUS+MB+mAb). Interestingly, both SUSonly and SUS+MB restored the induction of long-term potentiation (LTP, electrophysiological correlate of memory) in senescent wild-type mice. Both lead to increased neurogenesis, and SUSonly, in particular, resulted in improved spatial memory. We discuss these findings side-by-side with our findings obtained in AD mouse models. We conclude that therapeutic ultrasound is a non-invasive, pleiotropic modality that may present a treatment option not only for AD but also for enhancing cognition in physiological ageing.

Effect of Visual Cues and a Fermentation-Based Attractant Blend on Trap Catch of Two Invasive Drosophila Flies in Berry Crops in Mexico.

Drosophila suzukii (Matsumura) and Zaprionus indianus (Gupta) (Diptera: Drosophilidae) are invasive pests of economic importance worldwide. This study was undertaken as a first step to investigate the interaction between visual and chemical cues on the captures of D. suzukii and Z. indianus under field conditions. Specifically, we evaluated the effect of color cardboards and their combinations on the capture of these drosophilids by attractant-baited multihole traps in blackberry and blueberry crops. Color had a significant effect on the captures of D. suzukii and Z. indianus by attractant-baited traps in both crops. Overall, attractant-baited traps with yellow and yellow + green cards captured the highest number of flies compared to attractant-baited traps using cards of other colors or without cards. Multihole traps without attractant and color cardboards caught very few flies of both species. In general, more females than male D. suzukii were captured, but no sexual differences were found in the captures of Z. indianus. The results obtained will be useful for the development of a monitoring or mass trapping system for the management of D. suzukii and Z. indianuspopulations in Mexico.

The attractant, but not the trap design, affects the capture of Drosophila suzukii in berry crops.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is recognized as an invasive pest in Europe and North America. In Mexico, it is one of the main insect pests of soft-skinned fruits such as blueberries, strawberries, raspberries, blackberries, plums, and guava. Previous studies have shown that D. suzukii uses visual and chemical cues during host plant searching. This knowledge has been used to develop traps and attractants for monitoring D. suzukii. In this study, five trap designs were evaluated to monitor D. suzukii under field conditions. Traps were baited with SuzukiiTrap®, Z-Kinol, an attractant based on acetoin and methionol, or apple cider vinegar (ACV) enriched with 10% ethanol (EtOH) with the synergistic action of carbon dioxide (CO2). Our results suggested that the attractant was the determining factor in capturing D. suzukii, while trap design seemed to play a modest role. We found that traps baited with Z-Kinol captured the highest number of D. suzukii compared to that caught by traps baited with SuzukiiTrap®, or ACV + EtOH + CO2. The highest catch numbers occurred in blackberry, followed by strawberry, raspberry, and blueberry. Traps captured more females than males. The results obtained may be useful for monitoring D. suzukii populations in Mexico and elsewhere, particularly in states where soft fruit crops are a component of agricultural activities.

Enhancing the stability of adalimumab by engineering additional glycosylation motifs.

Monoclonal antibodies (mAbs) are of high value in the diagnostic and treatment of many debilitating diseases such as cancers, auto-immune disorders and infections. Unfortunately, protein aggregation is one of the ongoing challenges, limiting the development and application of mAbs as therapeutic products by decreasing half-life, increasing immunogenicity and reducing activity. We engineered an aggregation-prone region of adalimumab, the top selling mAb product worldwide - with additional glycosylation sites to enhance its resistance to aggregation by steric hindrance as a next generation biologic. We found that the addition of N-glycans in the Fab domain significantly enhanced its conformational stability, with some variants increasing the melting temperature of the Fab domain by >6 °C. The mutations tested had minimal impact on antigen binding affinity, or affinity to Fcγ receptors responsible for effector function. Our findings highlight the significant utility of this rational engineering approach for enhancing the conformational stability of therapeutic mAbs and other next-generation antibody formats.

The Succession of Flies of Forensic Importance Is Influenced by Volatiles Organic Compounds Emitted During the First Hours of Decomposition of Chicken Remains.

After death, a series of primary reactions occur that produce volatile organic compounds (VOCs) that are released into the environment. In this study, we investigated if the succession of flies of forensic importance in the first hours after death is mediated by VOCs in order to better understanding of the ecology of necrophagous insects. In total, 685 adult insects (Diptera and Hymenoptera) were collected by traps baited with chicken remains at different decomposition times (0, 6, 12, 24, 36, or 48 h). Of the total of insects caught, individuals from six families of Diptera can be cataloged of forensic importance. The most abundant dipteran family was Piophilidae with 213 individuals, followed by Calliphoridae with 178 specimens. Of the total flies caught, 90% were females and the rest were males. Most of the caught females were categorized as gravid, which visited more often the decaying tissues compared to nongravid females. The abundance of the flies increased in the remains with a longer time of decomposition. Six VOCs emitted in different relative quantities were identified according to the decomposition time of the remains. An apparent association was observed between the emission of ρ-cresol with Lucilia eximia (Wiedemann), between the emission of phenol, dimethyl disulfide, and dimethyl trisulfide with Chrysomya rufifacies (Macquart), and between the emissions of indole with Cochliomyia macellaria (Fabricius).

Seguimiento a largo plazo tras disección submucosa endoscópica de lesiones colorrectales en una cohorte española / No disponible

INTRODUCCIÓN: la disección submucosa endoscópica (DSE) en colon es una técnica en expansión en países occidentales. Existen pocos estudios con seguimiento a largo plazo. OBJETIVO: analizar supervivencia libre de enfermedad a largo plazo tras DSE y comparar las tasas de recidiva en función de diferentes factores. MATERIAL Y MÉTODOS: cohorte prospectiva de pacientes con DSE planeada entre septiembre de 2008 y diciembre de 2015. Cuando no fue posible técnicamente completar DSE se realizó disección híbrida en bloque o fragmentada. Se analizó la tasa de recurrencia a cinco años mediante curvas de Kaplan-Meier y se compararon en función de diferentes factores usando test de log-rank. RESULTADOS: se incluyó una cohorte inicial de 89 pacientes en los que se consiguió seguimiento en 69. De los 69 pacientes, en 31 (45 %) se realizó DSE; en once (16 %), DSE híbrida; y en 27 (39 %), DSE híbrida fragmentada. La mediana de seguimiento fue de 27 meses. La supervivencia libre de enfermedad a cinco años fue del 81 %. La media de endoscopias para eliminar la recurrencia fueron dos (rango 1-7) y ninguna requirió cirugía. La tasa de recidiva fue significativamente menor tras DSE "en bloque" respecto a fragmentada (15 % vs. 27 %, p = 0,036) y en resecciones R0 respecto a R1 (0 % vs. 26 %, p = 0,034). Las resecciones con márgenes laterales negativos en lesiones resecadas en bloque presentaron menor tasa de recidiva respecto a aquellas con márgenes afectos/desconocidos, que no alcanzaron la significación estadística (0 % vs. 28 %, p = 0,09). CONCLUSIONES: en nuestro estudio, la supervivencia libre de enfermedad a cinco años fue del 81 % y ningún paciente requirió cirugía durante el seguimiento. Las resecciones fragmentadas y R1 se asociaron de forma significativa con mayor tasa de recurrencia

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Disección submucosa endoscópica en lesiones gástricas epiteliales: resultados a largo plazo en una cohorte española / No disponible

INTRODUCCIÓN: la disección submucosa endoscópica sobre lesiones gástricas (DSE-G) es una técnica que permite la resección de tumores gástricos precoces en bloque, con una tasa de curación similar a la cirugía y una morbimortalidad menor. OBJETIVO: analizar la supervivencia total, la supervivencia libre de enfermedad y la tasa de recidiva en pacientes sometidos a DSE-G en una cohorte española a lo largo de su evolución clínica. MATERIAL Y MÉTODOS: estudio observacional prospectivo. Inclusión de pacientes sometidos a DSE-G de 2008 a 2015, con seguimiento entre seis y 60 meses. Se analizó la recurrencia a cinco años mediante curvas de Kaplan-Meier y los resultados fueron comparados entre diferentes factores (en bloque vs. resección fragmentada, resecciones curativas R0 vs. margen lateral afecto ML+) usando test log-rank. RESULTADOS: se analizaron 35 pacientes sometidos a DSE-G, con una mediana de seguimiento de 33,62 meses. Se identificaron cuatro recidivas en este periodo (11,4%), tres de ellas tratadas mediante nueva DSE-G. La presencia de ML+ en la pieza histológica se relacionó con mayor tasa de recidiva local durante el seguimiento (p = 0,06). Las resecciones fragmentadas presentaron un mayor riesgo de recidiva pero sin detectarse diferencias estadísticamente significativas (p = 0,49). No se registraron fallecimientos por neoplasia gástrica ni gastrectomía por persistencia de enfermedad en este periodo. La tasa de supervivencia global en nuestra serie fue de 94,3%. CONCLUSIONES: la DSE-G realizada en nuestro medio permite una tasa elevada de curación a largo plazo evitando la cirugía. Estos resultados se asemejan a las series europeas publicadas y aún se encuentran lejos de las tasas de curación y recidiva de las cohortes asiáticas. Los casos de recidiva local pueden ser controlados mediante endoscopia

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Long-term follow-up after endoscopic submucosal dissection of colorectal lesions in a Spanish cohort.

INTRODUCTION: ESD in the colon is an increasingly important technique in Western countries. There are few studies that include long term follow-up. AIM: to analyze the long term recurrence free survival rate after ESD and to compare recurrence rates according to different variables. METHODS: this was a prospective observational study of patients with a planned ESD from September 2008 to December 2015. When it was not possible to achieve an ESD, hybrid ESD was performed, either en bloc or piecemeal. Kaplan-Meier survival curves were used to assess the five year local recurrence free survival rate and the recurrence rate. The results were compared according to different factors. RESULTS: of the 89 patients scheduled for ESD who were initially enrolled in the study, 69 were finally included for follow-up. ESD was performed in 31 (45%) patients, KAR in eleven (16%) and pKAR in 27 (39%). The median follow-up was 27 months (range 6-60). The five year disease free survival rate was 81%. The average number of endoscopies needed to eliminate recurrence was two (range 2-7) and no patient required surgery for this reason. The recurrence rate was significantly higher in piecemeal resections vs en bloc resections (27% vs 15%, p = 0.036) and R1 resections vs R0 resections (26% vs 0%, p = 0.034). The presence of affected or unknown lateral margins in en bloc resections without other poor prognosis factors had higher recurrence rates but the difference was not statistically significant (28% vs 0%, p = 0.09). CONCLUSIONS: in our study, the five year disease free survival rate was 81% and no patient required surgery during follow-up. Piecemeal and R1 resections had significantly higher recurrence rates, as well as LM involvement, although this was not statistically significant.

Endoscopic submucosal dissection for gastric epithelial lesions: long-term results in a Spanish cohort.

INTRODUCTION: endoscopic submucosal dissection for gastric lesions (ESD-G) is a technique that allows en-bloc resection of early gastric tumors, with a cure rate similar to that of surgery but lower morbidity and mortality rates. OBJECTIVE: to assess total survival, disease-free survival and relapse rate during the course of disease in a Spanish cohort of patients undergoing ESD-G. MATERIAL AND METHODS: this was a prospective observational study of patients undergoing ESD-G from 2008 to 2015, with a follow-up ranging from six to 60 months. Recurrence at five years was analyzed using Kaplan-Meier curves and the results were compared according to several factors using the log-rank test. These included en-bloc versus piecemeal resection and R0 curative resection versus resection with affected lateral margins (LM+). RESULTS: a total of 35 patients undergoing ESD-G were assessed, with a median follow-up of 33.62 months. Four relapses were identified (11.4%) during this period, of which three were managed with repeat ESD-G. A histological specimen with LM+ was associated with a higher local relapse rate during follow-up (p = 0.06). Piecemeal resections had a higher relapse risk, although no statistically significant differences were identified (p = 0.49). No deaths from gastric cancer occurred and no gastrectomies due to persistent disease were performed during this period. The overall survival rate in our series was 94.3%. CONCLUSIONS: ESD-G in our setting provides high long-term cure rates, while avoiding surgery. These results are similar to those reported by the European series and remain far removed from the cure and relapse rates obtained in Asian cohorts. Local relapse cases may be monitored with endoscopy.