Neurological manifestations of SARS-CoV-2 infection in children in Taiwan: A cross-section, multicenter study.

BACKGROUND: The SARS-CoV-2 virus has been a global public health threat since December 2019. This study aims to investigate the neurological characteristics and risk factors of coronavirus disease 2019 (COVID-19) in Taiwanese children, using data from a collaborative registry. METHODS: A retrospective, cross-sectional, multi-center study was done using an online network of pediatric neurological COVID-19 cohort collaborative registry. RESULTS: A total of 11160 COVID-19-associated emergency department (ED) visits and 1079 hospitalizations were analyzed. Seizures were the most common specific neurological symptom, while encephalitis and acute disseminated encephalomyelitis (ADEM) was the most prevalent severe involvement. In ED patients with neurological manifestations, severe neurological diagnosis was associated with visual hallucination, seizure with/without fever, behavior change, decreased GCS, myoclonic jerk, decreased activity/fatigue, and lethargy. In hospitalized patients with neurological manifestations, severe neurological diagnosis was associated with behavior change, visual hallucination, decreased GCS, seizure with/without fever, myoclonic jerk, fatigue, and hypoglycemia at admission. Encephalitis/ADEM was the only risk factor for poor neurological outcomes at discharge in hospitalized patients. CONCLUSION: Neurological complications are common in pediatric COVID-19. Visual hallucination, seizure, behavior change, myoclonic jerk, decreased GCS, and hypoglycemia at admission are the most important warning signs of severe neurological involvement such as encephalitis/ADEM.

Myt1 overexpression mediates resistance to cell cycle and DNA damage checkpoint kinase inhibitors.

Cell cycle checkpoint kinases serve as important therapeutic targets for various cancers. When they are inhibited by small molecules, checkpoint abrogation can induce cell death or further sensitize cancer cells to other genotoxic therapies. Particularly aberrant Cdk1 activation at the G2/M checkpoint by kinase inhibitors causing unscheduled mitotic entry and mitotic arrest was found to lead to DNA damage and cell death selectively in cancer cells. Promising drugs inhibiting kinases like Wee1 (Adavosertib), Wee1+Myt1 (PD166285), ATR (AZD6738) and Chk1 (UCN-01) have been developed, but clinical data has shown variable efficacy for them with poorly understood mechanisms of resistance. Our lab recently identified Myt1 as a predictive biomarker of acquired resistance to the Wee1 kinase inhibitor, Adavosertib. Here, we investigate the role of Myt1 overexpression in promoting resistance to inhibitors (PD166285, UCN-01 and AZD6738) of other kinases regulating cell cycle progression. We demonstrate that Myt1 confers resistance by compensating Cdk1 inhibition in the presence of these different kinase inhibitors. Myt1 overexpression leads to reduced premature mitotic entry and decreased length of mitosis eventually leading to increased survival rates in Adavosertib treated cells. Elevated Myt1 levels also conferred resistance to inhibitors of ATR or Chk1 inhibitor. Our data supports that Myt1 overexpression is a common mechanism by which cancer cells can acquire resistance to a variety of drugs entering the clinic that aim to induce mitotic catastrophe by abrogating the G2/M checkpoint.

Beta Amyloid Oligomers with Higher Cytotoxicity have Higher Sidechain Dynamics.

The underlying biophysical principle governing the cytotoxicity of the oligomeric aggregates of ß-amyloid (Aß) peptides has long been an enigma. Here we show that the size of Aß40 oligomers can be actively controlled by incubating the peptides in reverse micelles. Our approach allowed for the first time a detailed comparison of the structures and dynamics of two Aß40 oligomers of different sizes, viz., 10 and 23 nm, by solid-state NMR. From the chemical shift data, we infer that the conformation and/or the chemical environments of the residues from K16 to K28 are different between the 10-nm and 23-nm oligomers. We find that the 10-nm oligomers are more cytotoxic, and the molecular motion of the sidechain of its charged residue K16 is more dynamic. Interestingly, the residue A21 exhibits unusually high structural rigidity. Our data raise an interesting possibility that the cytotoxicity of Aß40 oligomers could also be correlated to the motional dynamics of the sidechains.

Comparison of LED and LASER Colonoscopy About Linked Color Imaging and Blue Laser/Light Imaging of Colorectal Tumors in a Multinational Study.

INTRODUCTION: In light-emitting diode (LED) and LASER colonoscopy, linked color imaging (LCI) and blue light/laser imaging (BLI) are used for lesion detection and characterization worldwide. We analyzed the difference of LCI and BLI images of colorectal lesions between LED and LASER in a multinational study. METHODS: We prospectively observed lesions with white light imaging (WLI), LCI, and BLI using both LED and LASER colonoscopies from January 2020 to August 2021. Images were graded by 27 endoscopists from nine countries using the polyp visibility score: 4 (excellent), 3 (good), 2 (fair), and 1 (poor) and the comparison score (LED better/similar/LASER better) for WLI/LCI/BLI images of each lesion. RESULTS: Finally, 32 lesions (polyp size: 20.0 ± 15.2 mm) including 9 serrated lesions, 13 adenomas, and 10 T1 cancers were evaluated. The polyp visibility scores of LCI/WLI for international and Japan-expert endoscopists were 3.17 ± 0.73/3.17 ± 0.79 (p = 0.92) and 3.34 ± 0.78/2.84 ± 1.22 (p < 0.01) for LED and 3.30 ± 0.71/3.12 ± 0.77 (p < 0.01) and 3.31 ± 0.82/2.78 ± 1.23 (p < 0.01) for LASER. Regarding the comparison of lesion visibility about between LED and LASER colonoscopy in international endoscopists, a significant difference was achieved not for WLI, but for LCI. The rates of LED better/similar/LASER better for brightness under WLI were 54.5%/31.6%/13.9% (International) and 75.0%/21.9%/3.1% (Japan expert). Those under LCI were 39.2%/35.4%/25.3% (International) and 31.3%/53.1%/15.6% (Japan expert). There were no significant differences in the diagnostic accuracy and the comparison score of BLI images between LED and LASER. CONCLUSIONS: The differences of lesion visibility for WLI/LCI/BLI between LED and LASER in international endoscopists could be compared to those in Japanese endoscopists.

Patterning the cerebral cortex into distinct functional domains during development.

The cerebral cortex is compartmentalized into multiple regions, including the newly evolved neocortex and evolutionarily older paleocortex and archicortex. These broad cortical regions can be further subdivided into different functional domains, each with its own unique cytoarchitecture and distinct set of input and output projections to perform specific functions. While many excitatory projection neurons show region-specific gene expression profiles, the cells are derived from the seemingly uniform progenitors in the dorsal telencephalon. Much progress has been made in defining the genetic mechanisms involved in generating the morphological and functional diversity of the central nervous system. In this review, we summarize the current knowledge of mouse corticogenesis and discuss key events involved in cortical patterning during early developmental stages.

A fast blind zero-shot denoiser.

Image noise is a common problem in light microscopy. This is particularly true in real-time live-cell imaging applications in which long-term cell viability necessitates low-light conditions. Modern denoisers are typically trained on a representative dataset, sometimes consisting of just unpaired noisy shots. However, when data are acquired in real time to track dynamic cellular processes, it is not always practical nor economical to generate these training sets. Recently, denoisers have emerged that allow us to denoise single images without a training set or knowledge about the underlying noise. But such methods are currently too slow to be integrated into imaging pipelines that require rapid, real-time hardware feedback. Here we present Noise2Fast, which can overcome these limitations. Noise2Fast uses a novel downsampling technique we refer to as 'chequerboard downsampling'. This allows us to train on a discrete 4-image training set, while convergence can be monitored using the original noisy image. We show that Noise2Fast is faster than all similar methods with only a small drop in accuracy compared to the gold standard. We integrate Noise2Fast into real-time multi-modal imaging applications and demonstrate its broad applicability to diverse imaging and analysis pipelines.

Characterization of Piezoelectric Properties of Ag-NPs Doped PVDF Nanocomposite Fibres Membrane Prepared by Near Field Electrospinning.

BACKGROUND: In this study, Near-field electrospinning (NFES) technique is used with a cylindrical collector to fabricate a large area permanent piezoelectric micro and nanofibers by a prepared solution. NFES requires a small electric field to fabricate fibers Objective: The objective of this paper to investigate silver nanoparticle (Ag-NP)/ Polyvinylidene fluoride (PVDF) composite as the best piezoelectric material with improved properties to produced tremendously flexible and sensitive piezoelectric material with pertinent conductance Methods: In this paper, we used controllable electrospinning technique based on Near-field electrospinning (NFES). The process parameter for Ag-NP/PVDF composite electrospun fiber based on pure PVDF fiber. A PVDF solution concentration of 18 wt.% and 6 wt.% silver nitrate, which is relative to the weight of PVDF wt.% with 1058 µS conductivity fibers, have been directly written on a rotating cylindrical collector for aligned fiber PVDF/Ag-NP fibers are patterned on fabricated copper (Cu) interdigitated electrodes were implemented on a thin flexible polyethylene terephthalate (PET) substrate and Polydimethylsiloxane (PDMS) used as a package to enhance the durability of the PVDF/ Ag-NP device. RESULTS: A notable effect on the piezoelectric response has been observed after Ag-NP addition, confirmed by XRD characterization and tapping test of Ag-NP/PVDF composite fiber. The morphology of the PVDF/Ag-NP fibers and measure diameter by scanning electron microscopy (SEM) and Optical micrograph (OM), of fiber. Finally, a diameter of PVDF/Ag-NP fibers up to ~7 µm. The high diffraction peak at 2θ = 20.5˚ was investigated by X-ray diffraction (XRD) in the piezoelectric crystal ß-phase structure. Further addition of silver nanoparticles (Ag- NPs) in the PVDF solution resulted in enhancing the electromechanical conversion of the fibers from ~0.1 V to ~1 V. CONCLUSION: In conclusion, we can say that confirmed and validated the addition of Ag-NP in PVDF could enhance the piezoelectric property by using NFES technique with improved crystalline phase content can be useful for a wide range of power and sensing applications like biomedical devices and energy harvesting, among others.

A New Design of Porosity Gradient Ti-6Al-4V Encapsulated Hydroxyapatite Dual Materials Composite Scaffold for Bone Defects.

The tibia of New Zealand White rabbits was used as a model of critical bone defects to investigate a new design of composite scaffold for bone defects composed of dual materials. The all-in-one design of a titanium alloy (Ti-6Al-4V) scaffold comprised the structure of a bone plate and gradient porosity cage. Hydroxyapatite (HAp), a biodegradable material, was encapsulated in the center of the scaffold. The gradient pore structure was designed with 70%-65%-60%-55%-50% porosity, since the stresses could be distributed more uniformly when the all-in-one scaffold was placed on the bone contact surface. By covering the center of the scaffold with a low strength of HAp to contact the relatively low strength of bone marrow tissues, the excessive stiffness of the Ti-6Al-4V can be effectively reduced and further diminish the incidence of the stress shielding effect. The simulation results show that the optimized composite scaffold for the 3D model of tibia had a maximum stress value of 27.862 MPa and a maximum strain of 0.065%. The scaffold prepared by selective laser melting was annealed and found that the Young's coefficient increased from 126.44 GPa to 131.46 GPa, the hardness increased from 3.9 GPa to 4.12 GPa, and the strain decreased from 2.27% to 1.13%. The result demonstrates that the removal of residual stress can lead to a more stable structural strength, which can be used as a reference for the design of future clinical tibial defect repair scaffolds.

COUP-TFI specifies the medial entorhinal cortex identity and induces differential cell adhesion to determine the integrity of its boundary with neocortex.

Development of cortical regions with precise, sharp, and regular boundaries is essential for physiological function. However, little is known of the mechanisms ensuring these features. Here, we show that determination of the boundary between neocortex and medial entorhinal cortex (MEC), two abutting cortical regions generated from the same progenitor lineage, relies on COUP-TFI (chicken ovalbumin upstream promoter-transcription factor I), a patterning transcription factor with graded expression in cortical progenitors. In contrast with the classical paradigm, we found that increased COUP-TFI expression expands MEC, creating protrusions and disconnected ectopic tissue. We further developed a mathematical model that predicts that neuronal specification and differential cell affinity contribute to the emergence of an instability region and boundary sharpness. Correspondingly, we demonstrated that high expression of COUP-TFI induces MEC cell fate and protocadherin 19 expression. Thus, we conclude that a sharp boundary requires a subtle interplay between patterning transcription factors and differential cell affinity.

Phosphorylation of adducin-1 by cyclin-dependent kinase 5 is important for epidermal growth factor-induced cell migration.

Cyclin-dependent kinase 5 (Cdk5) is predominantly expressed in neuron and plays an important role in neuronal physiology. Increasing evidence also indicates that Cdk5 may contribute to malignant progression of some types of cancers; however, the underlying mechanism remains elusive. In this study, we found that Cdk5 directly phosphorylated the actin-binding protein adducin-1 (ADD1) at T724 in vitro and in intact cells. The capability of the phosphomimetic T724D mutant to bind to actin filaments was lower than that of wild type ADD1 and the T724A mutant. Cdk5 co-localized with ADD1 at the lamellipodia upon epidermal growth factor (EGF) stimulation. The increased lamellipodia formation and cell migration of human breast cancer cells MDA-MB-231 by EGF were accompanied by Cdk5 activation and increased phosphorylation of ADD1 at T724. Depletion of Cdk5 in MDA-MB-231 cells abrogated the effects of EGF on ADD1 T724 phosphorylation, lamellipodia formation, and cell migration. Likewise, depletion of ADD1 suppressed the effects of EGF on lamellipodia formation, cell migration, and invasion, all of which were restored by FLAG-ADD1 WT and the T724D mutant, but not the T724A mutant. Together, our results suggest that phosphorylation of ADD1 at T724 by Cdk5 is important for EGF-induced cell migration and invasion.

Correction: Src and SHP2 coordinately regulate the dynamics and organization of vimentin filaments during cell migration.

The original version of this article contained error in Fig. 6b, where several panels were missing from the published version. The corrected version of this Figure now appears in the article.

Src and SHP2 coordinately regulate the dynamics and organization of vimentin filaments during cell migration.

Vimentin intermediate filaments (VIFs), expressed in most mesenchymal and cancer cells, undergo dramatic reorganization during cell migration; however, the mechanism remains obscure. This study demonstrates that upon growth-factor stimulation, Src directly phosphorylates vimentin at Tyr117, leading to VIF disassembly into squiggles and particles at the cell edge during lamellipodia formation. The protein tyrosine phosphatase SHP2 counteracted the Src effects on VIF tyrosine phosphorylation and organization. VIFs formed by vimentin Y117D mutant were more soluble and dynamic than those formed by the wild-type and Y117F mutant. Increased expression of vimentin promoted growth-factor induced lamellipodia formation and cell migration, whereas the mutants suppressed both. The vimentin-induced increase in lamellipodia formation correlated with the activation of Rac and Vav2, with the latter associated with VIFs and recruited to the plasma membrane upon growth-factor stimulation. These results reveal a novel mechanism for regulating VIF dynamics through Src and SHP2 and demonstrate that proper VIF dynamics are important for Rac activation and cell migration.

Adducin-1 is essential for spindle pole integrity through its interaction with TPX2.

Bipolar spindle assembly is necessary to ensure the proper progression of cell division. Loss of spindle pole integrity leads to multipolar spindles and aberrant chromosomal segregation. However, the mechanism underlying the maintenance of spindle pole integrity remains unclear. In this study, we show that the actin-binding protein adducin-1 (ADD1) is phosphorylated at S726 during mitosis. S726-phosphorylated ADD1 localizes to centrosomes, wherein it organizes into a rosette-like structure at the pericentriolar material. ADD1 depletion causes centriole splitting and therefore results in multipolar spindles during mitosis, which can be restored by re-expression of ADD1 and the phosphomimetic S726D mutant but not by the S726A mutant. Moreover, the phosphorylation of ADD1 at S726 is crucial for its interaction with TPX2, which is essential for spindle pole integrity. Together, our findings unveil a novel function of ADD1 in maintaining spindle pole integrity through its interaction with TPX2.

COUP-TFII is required for morphogenesis of the neural crest-derived tympanic ring.

Chicken Ovalbumin Upstream Promoter-Transcription Factor II (COUP-TFII) plays pivotal roles in cell growth, cell differentiation, and cell fate determination. Although genome-wide studies have identified COUP-TFII binding on gene sets mainly involved in neural crest cell (NCC) development and craniofacial morphogenesis, the direct functional connection between COUP-TFII and NCCs in vivo has not been well characterized. In this study, we show that COUP-TFII is expressed in the subpopulation of NCCs and its derivatives, and targeted ablation of COUP-TFII in mouse NCCs results in markedly shortened and bifurcated tympanic rings, which in turn disturb the caudal direction of external acoustic meatus invagination. However, formation of the manubrium of the malleus (MM) in Wnt1-Cre/+;COUP-TFII flox/flox mice is not perturbed, suggesting that the rostral half of the tympanic ring is sufficient to support proper MM development. Interestingly, we found that loss of COUP-TFII up-regulates Sox9 in the tympanic ring primordium and affects the distribution of preosteoblasts before mesenchymal condensation. Together, our results demonstrate that COUP-TFII plays an essential role in regulating the patterning of the NCC-derived tympanic ring.

Adducin family proteins possess different nuclear export potentials.

BACKGROUND: The adducin (ADD) family proteins, namely ADD1, ADD2, and ADD3, are actin-binding proteins that play important roles in the stabilization of membrane cytoskeleton and cell-cell junctions. All the ADD proteins contain a highly conserved bipartite nuclear localization signal (NLS) at the carboxyl termini, but only ADD1 can localize to the nucleus. The reason for this discrepancy is not clear. METHODS: To avoid the potential effect of cell-cell junctions on the distribution of ADD proteins, HA epitope-tagged ADD proteins and mutants were transiently expressed in NIH3T3 fibroblasts and their distribution in the cytoplasm and nucleus was examined by immunofluorescence staining. Several nuclear proteins were identified to interact with ADD1 by mass spectrometry, which were further verified by co-immunoprecipitation. RESULTS: In this study, we found that ADD1 was detectable both in the cytoplasm and nucleus, whereas ADD2 and ADD3 were detected only in the cytoplasm. However, ADD2 and ADD3 were partially (~40%) sequestered in the nucleus by leptomycin B, a CRM1/exportin1 inhibitor. Upon the removal of leptomycin B, ADD2 and ADD3 re-distributed to the cytoplasm. These results indicate that ADD2 and ADD3 possess functional NLS and are quickly transported to the cytoplasm upon entering the nucleus. Indeed, we found that ADD2 and ADD3 possess much higher potential to counteract the activity of the NLS derived from Simian virus 40 large T-antigen than ADD1. All the ADD proteins appear to contain multiple nuclear export signals mainly in their head and neck domains. However, except for the leucine-rich motif (377FEALMRMLDWLGYRT391) in the neck domain of ADD1, no other classic nuclear export signal was identified in the ADD proteins. In addition, the nuclear retention of ADD1 facilitates its interaction with RNA polymerase II and zinc-finger protein 331. CONCLUSIONS: Our results suggest that ADD2 and ADD3 possess functional NLS and shuttle between the cytoplasm and nucleus. The discrepancy in the subcellular localization of the ADD isoforms arises due to their different nuclear export capabilities. In addition, the interaction of ADD1 with RNA polymerase II and zinc-finger protein 331 implicates a potential role for ADD1 in the regulation of transcription.

Annual influenza vaccination reduces total hospitalization in patients with chronic hepatitis B virus infection: A population-based analysis.

BACKGROUND: This study evaluated hospitalization and mortality in patients with chronic hepatitis B virus infection (HBV (+)) and matched comparison patients after stratifying the patients according to annual influenza vaccination (Vaccine (+)). METHODS: Data from Taiwan's National Health Insurance program from 2000 to 2009 were used to identify HBV(+)/vaccine(+) (n=4434), HBV(+)/Vaccine(-) (n=3646), HBV(-)/Vaccine(+) (n=8868), and HBV(-)/Vaccine(-) (n=8868) cohorts. The risk of pneumonia/influenza, respiratory failure, intensive care, hospitalization, and mortality in the four cohorts was evaluated. RESULTS: The total hospitalization rate was significantly lower in patients with chronic HBV infection who received an annual influenza vaccination than in chronic HBV-infected patients who did not receive an influenza vaccination (16.29 vs. 24.02 per 100 person-years), contributing to an adjusted hazard ratio (HR) of 0.56 (95% confidence interval (CI)=0.50-0.62). The HBV(+)/Vaccine(+) cohort also had lower risks than the HBV(+)/Vaccine(-) cohort for pneumonia and influenza (adjusted HR=0.79, 95% CI=0.67-0.92), intensive care unit admission (adjusted HR=0.33, 95% CI=0.25-0.43), and mortality (adjusted HR=0.19, 95% CI=0.15-0.24). CONCLUSIONS: Our results suggest that annual influenza vaccination can reduce the risk of hospitalization and mortality in patients with chronic HBV infection.

Monitoring the VEGF level in aqueous humor of patients with ophthalmologically relevant diseases via ultrahigh sensitive paper-based ELISA.

The vascular endothelial growth factor (VEGF) level in aqueous humor has been used as an indicator to monitor specific diseases in the retinal ischemic condition. For clinical diagnosis, only about 200 µL of aqueous humor can be collected from the anterior chamber before the threat of anterior chamber collapse. It is necessary to develop an inexpensive diagnostic approach with the characteristics of highly sensitive, short operation duration, and requires small clinical sample quantities. To achieve the main objective of this study, we first prepared bevacizumab to be conjugated with HRP. We then deposited 2 µL aqueous humor from patients with different diseases onto each test zone of paper-based 96-well plates. After the colorimetric results were performed via ELISA protocol, the output signals were recorded using a commercial desktop scanner for analysis. In this study, only 2 µL from the aqueous humor of each patient was required for paper-based ELISA. The mean aqueous VEGF level was 14.4 pg/mL from thirteen patients (N = 13) with senile cataract as the control. However, the mean aqueous VEGF level from other patients with proliferative diabetic retinopathy (N = 14), age-related macular degeneration (N = 17), and retinal vein occlusion (N = 10) showed VEGF increases to 740.1 pg/mL, 383 pg/mL, and 219.4 pg/mL, respectively.

The Wilms' tumor suppressor Wt1 regulates Coronin 1B expression in the epicardium.

Coronin 1B has been shown to be critical for cell motility and various actin-dependent processes. To understand its role more extensively, the expression and transcriptional regulation of Coro1b gene during mouse development were explored. Coronin 1B is ubiquitously expressed in the whole embryo but nevertheless shows distinct expression pattern in developing heart. In addition to the localization in endocardium, Coronin 1B is specifically expressed in the endocardial cushion and epicardium where cardiac EMT processes take place as the heart develops. Promoter deletion analysis identified the positions between -1038 and -681 is important for Coro1b basal promoter activity. In addition to a correlation of Coronin 1B localization with Wt1 expression in the epicardium, we also identified putative Wt1 binding sequences within Coro1b promoter. Direct binding of Wt1 to GC-rich sequences within the Coro1b promoter is required for the regulation of Coro1b gene expression. In accordance with the motility defect found in Coronin 1B-knockdown cells, a modest decrease in expression of Coronin 1B in the remaining epicardium of Wt1(EGFPCre/EGFPCre) mutant embryos was observed. These findings seem to shed light on the role of Wt1 during cell migration and suggest that, at least in part, this involves transcriptional control of Coro1b gene expression.

Effects of intramolecular hydrogen bonding on the excited state dynamics of phenol chromophores.

The theoretical prediction and experimental confirmation of the 1πσ* excited state of phenol which is repulsive along the O-H bond has a large impact on the interpretation of phenol and tyrosine photochemistry. In this work, we demonstrate that this excited state changes significantly if the OH functional group is involved in the formation of an intramolecular hydrogen bond in the ground state. We investigate the excited state dynamics of 2-, 3-, and 4-hydroxyacetophenone (HAP) separately in a molecular beam at 193 nm using multimass ion imaging techniques. H atom elimination from the repulsive excited state and Norrish type I reactions are the major dissociation channels of 3-HAP and 4-HAP which do not have intramolecular hydrogen bonding. However, the H atom elimination channel is completely quenched for 2-HAP which shows intramolecular hydrogen bonding. In addition, the ground state and the excited state potential energy surfaces (PESs) of HAP, 2-hydroxybenzoyl fluoride, 2-hydroxybenzoyl chloride, and 2-hydroxybenzamide are investigated using ab initio calculations. The results also show that the excited state potential along the O-H bond distance of the hydroxyl group changes significantly for molecules with intramolecular hydrogen bonding. The changes include: (a) the repulsive potential energy surface becomes an attractive potential near the ground state equilibrium geometry, (b) the conical intersection between the first and the second excited states along the O-H bond moves to a much higher energy level, and (c) the conical intersection between the repulsive excited state and the ground state along the O-H bond distance disappears. The results suggest that the interpretation of the photochemistry for molecules with a phenol chromophore must take these effects into consideration.

Clinical practice of endoscopic submucosal dissection for early colorectal neoplasms by a colonoscopist with limited gastric experience.

Objectives. Endoscopic submucosal dissection (ESD) for early colorectal neoplasms is regarded as a difficult technique and should commence after receiving the experiences of ESD in the stomach. The implementation of colorectal ESD in countries where early gastric cancer is uncommon might therefore be difficult. The aim is to delineate the feasibility and the learning curve of colorectal ESD performed by a colonoscopist with limited experience of gastric ESD. Methods. The first fifty cases of colorectal ESD, which were performed by a single colonoscopist between July 2010 and April 2013, were enrolled. Results. The mean of age was 64 (±9.204) years with mean size of neoplasm at 33 (±12.63) mm. The mean of procedure time was 70.5 (±48.9) min. The rates of en bloc resection, R0 resection, and curative resection were 86%, 86%, and 82%, respectively. Three patients had immediate perforation, but no patient developed delayed perforation or delayed bleeding. Conclusion. Our result disclosed that it is feasible for colorectal ESD to be performed by a colonoscopist with little experience of gastric ESD through satisfactory training and adequate case selection.