Publications by authors named "Guang Wen Chen"

The paper details new geographic records of two species of the genus Polycelis Ehrenberg,1831 (Platyhelminthes, Tricladida, Planariidae) for the Qinling Mountains and the Loess Plateau in China and provides redescriptions of these species based on an integrative taxonomic study involving morphology, karyology, and histology. This new information considerably expands our knowledge on these species, for which until now only limited data was available. The species Polycelis asiatica Selinova, 1985 is characterized by the following features: 63-80 eyes; sperm ducts that exhibit an intrabulbar knee-shaped bend towards the ventral surface before opening separately and symmetrically into the antero-dorsal portion of a large seminal vesicle; the latter is ventrally displaced, thus creating a narrow ventral lip on the penis papilla; dorsal wall of the seminal vesicle is provided with several well-developed folds; more or less bulbous penis papilla protrudes from the dorsal wall of the male atrium and is provided with a slender and flexible tip; chromosome complement diploid with 30 metacentric chromosomes, 8 submetacentric chromosomes, and 2 subtelocentric chromosomes.

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As one of the most widely used herbicides in agricultural industry, the residues of glyphosate (GLY) are frequent environmental pollutants. Freshwater planarian Dugesia japonica has been developed as a model for neurotoxicology. In this study, the effects of GLY on locomotion and feeding behavior, as well as neuroenzyme activities and mRNA expressions of D.

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Background: Freshwater planarians of the genus Dugesia (Platyhelminthes, Tricladida, Dugesiidae) are distributed in a major part of the Old World and Australia, although until recently only very few species were known from China.

Results: Two new species of Dugesia from Southern China are described on the basis of an integrative taxonomic approach. BI and ML phylogenetic trees based on the independent genes and on the concatenated dataset had similar topologies, only differing in some nodes that were weakly supported.

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Glyphosate (GLY) is one of the most widely used agrochemicals in the world, and its exposure has become a public health concern. The freshwater planarian is an ideal test organism for detecting the toxicity of pollutants and has been an emerging animal model in toxicological studies. Nevertheless, the underlying toxicity mechanism of GLY to planarians has not been thoroughly explored.

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Objective: To investigate the diagnostic performance of the apparent diffusion coefficient (ADC) derived from intratumoral and peritumoral zones for assessing pathologic prognostic factors in rectal cancer.

Materials And Methods: One hundred forty-six patients with rectal cancer who underwent preoperative MRI were prospectively enrolled. Two radiologists independently placed free-hand regions of interest (ROIs) in the largest tumor cross section and three small ROIs on the peritumoral zone adjacent to the tumor contour.

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Objective: This study investigates the association of the liver and spleen signal intensity on MRI with anemia in patients with gynecologic cancer.

Methods: 332 patients with gynecological cancer and 78 healthy women underwent MRI examination. Liver and spleen MRI parameters and laboratory tests were obtained within 1 week.

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Objective: To assess the role of region of interest (ROI) selection of intravoxel incoherent motion (IVIM) for predicting lymph node metastases (LNM) and tumor response after chemoradiation therapy (CRT) in locally advanced rectal cancer.

Materials And Methods: Seventy-nine patients with biopsy-proven rectal adenocarcinoma who underwent pre- and post-CRT MRI and surgery were prospectively enrolled. The exclusion criteria included nonresectable and/or metastatic disease and loss of follow-up.

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Two new species of the genus (Platyhelminthes, Tricladida, Dugesiidae) from the tropical monsoon forest in southern China are described on the basis of an integrative taxonomic study involving morphology, karyology, histology, and molecular analyses. The new species Chen & Dong, is characterised by asymmetrical openings of the oviducts; right vas deferens opening at anterior portion of the seminal vesicle and the left one opening at mid-lateral portion of the seminal vesicle; two diaphragms in ejaculatory duct, the latter being ventrally displaced and opening at the tip of the penis papilla, which is provided with a nozzle; wide duct connecting male atrium and common atrium; chromosome complement triploid with 24 metacentric chromosomes. The other new species, Chen & Dong, , is characterised by the large size of the living worm, usually exceeding 3.

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Autophagy-related gene 6 () plays an essential role in autophagy, and loss of its function impairs neurogenesis. Planarian is a good model for the study of the central nervous system (CNS) regeneration. It can regenerate a new head in 1 week following decapitation.

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Two new species of the genus (Platyhelminthes, Tricladida, Dugesiidae) from Hainan Island of China are described on the basis of morphological, karyological and molecular data. Chen & Dong, . is mainly characterized by a hemispherical, asymmetrical penis papilla with ventrally displaced ejaculatory duct opening terminally at tip of penis papilla; vasa deferentia separately opening into mid-dorsal portion of intrabulbar seminal vesicle; two diaphragms in the ejaculatory duct; copulatory bursa formed by expansion of bursal canal, lined with complex stratified epithelium, which projects through opening in bursa towards intestine, without having open communication with the gut; mixoploid chromosome complement diploid (2n = 16) and triploid (3n = 24), with metacentric chromosomes.

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Objective: To determine diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) volume and apparent diffusion coefficient values (ADCs) for assessing lymph node metastases (LNM) and good response after chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC).

Materials And Methods: This retrospective study consisted of 61 patients with LARC who underwent pre- and post-CRT DW images. Two radiologists independently placed free-hand regions of interest in each tumor-containing section on DW images to calculate pre- and post-CRT tumor volume and tumor volume reduction rates (Δvolume).

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This study is to investigate optimum apparent diffusion coefficient (ADC) parameter for predicting lymphovascular invasion (LVI), lymph node metastasis (LNM) and histology type in resectable rectal cancer. 58 consecutive patients with resectable rectal cancer were retrospectively identified. The minimum, maximum, average ADC and ADC difference value were obtained on ADC maps.

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Background: Pulmonary artery aneurysm (PAA), usually associated with congenital heart disease (CHD), is a very rare clinical condition. Pulmonary artery dissection (PAD) is considered the most life-threatening complication of PAA, and patients can progress from being asymptomatic to sudden death. We report the following case of PAA associated with complicated congenital heart disease and simultaneous chronic PAD.

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As the worldwide top-selling herbicide, glyphosate is ubiquitously distributed in the natural environment, and its influence on the ecological safety and human health has being increasingly concerned. In this study, mRNA expressions of GPX and three heat shock protein genes in freshwater planarian Dugesia japonica in response to glyphosate were determined, and two oxidative stress parameters were measured. The results suggested that GPX activity can be used as a more sensitive biomarker in contrast with GPX gene expression, and mRNA expressions of Hsp70, Hsp90 genes are more sensitive than Hsp40 for planarians in response to glyphosate stress.

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As the top-selling herbicide in the world, glyphosate distributes widely in natural environment and its influence on the ecological security and human health has attracted more and more concern. Glutathione S-transferases (GSTs) are a well-characterized superfamily of isoenzymes for cellular defense against exogenous toxic substances and therefore protect organisms from injury. In this study, the complete cDNA sequence of GST gene (named as Dja-GST) in freshwater planarian Dugesia japonica was firstly cloned by means of RACE method.

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Heavy metal pollution is a global health issue affecting people worldwide, and the exploration of sensitive biomarkers to assess the toxicity of heavy metals is an important work for researchers. Cathepsin L, role as a tissue-specific biomarker to assess the biological effects of environmental pollutants, has not received much attention. In this work, the full-length cDNA of cathepsin L gene from the planarian Dugesia japonica (designated DjCatL) was cloned by rapid amplification of cDNA ends (RACE) technique.

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The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses.

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As an important antioxidant enzyme, the superoxide dismutase (SOD) can protect aerobic organisms from oxidative damage through catalyzing the dismutation of superoxide into hydrogen peroxide and oxygen. The SODs have been cloned in some species and their dynamic expression or enzymatic activity in response to environmental stressors were investigated. In the current study, the full-length cDNA of two SODs from freshwater planarian Dugesia japonica were firstly cloned (named as DjCuZnSOD and DjMnSOD, respectively).

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Catalase (CAT) is an important antioxidant enzyme that protects aerobic organisms against oxidative damage by degrading hydrogen peroxide to oxygen and water. CAT mRNAs have been cloned from many species and employed as useful biomarkers of oxidative stress. In the present study, we cloned the cDNA sequence of CAT gene from freshwater planarian Dugesia japonica (designated as DjCAT) by means of RACE method.

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Objective: To determine whether gross tumor volume (GTV) and the maximum diameter of resectable cervical cancer at magnetic resonance imaging (MRI) could predict lymph node metastasis (LNM) and lymphovascular space invasion (LVSI).

Materials And Methods: A total of 315 consecutive patients with cervical cancer were retrospectively identified. Gross tumor volume and the maximum diameter of tumor were evaluated on MRI.

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Rationale: Interrupted aortic arch (IAA) is defined as a complete luminal and anatomical interruption between the ascending and descending aortas. The majority of patients with IAA rarely reach adulthood. In most cases, IAA is associated with an intracardiac malformation, such as ventricular septal defect, bicuspidaortic valve, and patent ductus arteriosus.

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Purpose: To determine whether gross tumor volume of resectable gastric adenocarcinoma on multidetector computed tomography could predict presence of lymphovascular invasion and T-stages.

Results: Gross tumor volume increased with the lymphovascular invasion ( = 0.426, < 0.

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The aim of this study was to evaluate the genotoxic potential of an urban river - the Wei River in Xinxiang, China using randomly amplified polymorphic DNA (RAPD) assay in planarians. The results showed that the total number of polymorphic bands and varied bands in RAPD patterns of treated planarians decreased with the water sample site far away from the sewage outlet of a factory. In addition, the genome template stability of treated groups decreased and the degree of the decline was negatively related to the distance between the sample site and the sewage outlet, suggesting that the Wei River water had genotoxicity effects on planarians and strengthening the management of the Wei River was necessary.

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The randomly amplified polymorphic DNA (RAPD) assay has been used to detect DNA alternation and mutation recently. However, the effectiveness of this method in detecting DNA damage in planarians, a model organism for assessing the toxicity of environmental pollutants is unknown. In the present study, RAPD assay was used to detect the DNA damage in planarians treated by the ionic liquid 1-octyl-3-methylimidazolium bromide ([Cmim]Br) for the first time.

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