Comparison of DNA-Gold Nanoparticle Conjugation Methods: Application in Lateral Flow Nucleic Acid Biosensors.

Lateral flow nucleic acid biosensors (LFNABs) have attracted extensive attention due to their rapid turnaround time, low cost, and results that are visible to the naked eye. One of the key steps to develop LFNABs is to prepare DNA-gold nanoparticle (DNA-AuNP) conjugates, which affect the sensitivity of LFNABs significantly. To date, various conjugation methods-including the salt-aging method, microwave-assisted dry heating method, freeze-thaw method, low-pH method, and butanol dehydration method-have been reported to prepare DNA-AuNP conjugates. In this study, we conducted a comparative analysis of the analytical performances of LFNABs prepared with the above five conjugation methods, and we found that the butanol dehydration method gave the lowest detection limit. After systematic optimization, the LFNAB prepared with the butanol dehydration method had a detection limit of 5 pM for single-strand DNA, which is 100 times lower than that of the salt-aging method. The as-prepared LFNAB was applied to detect miRNA-21 in human serum, with satisfactory results. The butanol dehydration method thus offers a rapid conjugation approach to prepare DNA-AuNP conjugates for LFNABs, and it can also be extended to other types of DNA biosensors and biomedical applications.

Study on formulation and preparation technology of the composite cellulose-based enteric capsule shells.

OBJECTIVE: To study the new formulation and technology of composite cellulose-based enteric capsule shell with one-time dipping molding without organic solvent. METHODS: Hydroxypropyl methylcellulose phthalate-55S (Hp55S) was used as the main film-forming material, agar as gelling agent, and hydroxypropyl methylcellulose (HPMC) as disintegrating regulator. The preparation technology was as follows: ① Hp55S was dissolved in dilute ammonia solution with pH of 10 ∼ 11 at room temperature to obtain transparent Hp55S solution. ② The mixture of HPMC, KCl, and Tween-80 was fully dispersed in the agar solution at 90 ∼ 100 °C and cooled to 50 ∼ 55 °C under continuous stirring to obtain a transparent agar/HPMC solution. ③The Hp55S solution was heated to 50 ∼ 55 °C and poured into the agar/HPMC solution and stirred evenly to obtain the composite cellulose solution, which was kept at 50 ∼ 55 °C for standby. ④The composite cellulose-based enteric capsule shells were prepared by dipping, spinning, drying, stripping and trimming, and joining. RESULTS: The composite cellulose-based enteric capsule shell prepared according to this formula and process met the quality requirements of 'enterosoluble vacant capsules' in Chinese Pharmacopeia. CONCLUSION: Compared with the traditional formula and preparation technology of enteric capsule shell, the product is a plant type enteric capsule shell, no organic solvent is used in the formula, and the forming steps of multiple dipping solution is not used in the process. The advantages of this study are that the production steps are simplified, the production process is environmentally friendly, and the production cost is reduced.

Toxicity and detoxification of T-2 toxin in poultry.

This review summarizes the updated knowledge on the toxicity of T-2 on poultry, followed by potential strategies for detoxification of T-2 in poultry diet. The toxic effects of T-2 on poultry include cytotoxicity, genotoxicity, metabolism modulation, immunotoxicity, hepatotoxicity, gastrointestinal toxicity, skeletal toxicity, nephrotoxicity, reproductive toxicity, neurotoxicity, etc. Cytotoxicity is the primary toxicity of T-2, characterized by inhibiting protein and nucleic acid synthesis, altering the cell cycle, inducing oxidative stress, apoptosis and necrosis, which lead to damages of immune organs, liver, digestive tract, bone, kidney, etc., resulting in pathological changes and impaired physiological functions of these organs. Glutathione redox system, superoxide dismutase, catalase and autophagy are protective mechanisms against oxidative stress and apoptosis, and can compensate the pathological changes and physiological functions impaired by T-2 to some degree. T-2 detoxifying agents for poultry feeds include adsorbing agents (e.g., aluminosilicate-based clays and microbial cell wall), biotransforming agents (e.g., Eubacterium sp. BBSH 797 strain), and indirect detoxifying agents (e.g., plant-derived antioxidants). These T-2 detoxifying agents could alleviate different pathological changes to different degrees, and multi-component T-2 detoxifying agents can likely provide more comprehensive protection against the toxicity of T-2.

Building contrast-enhanced CT-based models for preoperatively predicting malignant potential and Ki67 expression of small intestine gastrointestinal stromal tumors (GISTs).

PURPOSE: To assess contrast-enhanced computed tomography (CE-CT) features for predicting malignant potential and Ki67 in small intestinal gastrointestinal stromal tumors (GISTs) and the correlation between them. METHODS: We retrospectively analyzed the pathological and imaging data for 123 patients (55 male/68 female, mean age: 57.2 years) with a histopathological diagnosis of small intestine GISTs who received CE-CT followed by curative surgery from May 2009 to August 2019. According to postoperatively pathological and immunohistochemical results, patients were categorized by malignant potential and the Ki67 index, respectively. CT features were analyzed to be associated with malignant potential or the Ki67 index using univariate analysis, logistic regression and receiver operating curve analysis. Then, we explored the correlation between the Ki67 index and malignant potential by using the Spearman rank correlation. RESULTS: Based on univariate and multivariate analysis, a predictive model of malignant potential of small intestine GISTs, consisting of tumor size (p < 0.001) and presence of necrosis (p = 0.033), was developed with the area under the receiver operating curve (AUC) of 0.965 (95% CI, 0.915-0.990; p < 0.001), with 91.53% sensitivity, 96.87% specificity, 96.43% PPV, 92.54% NPV, 94.31% diagnostic accuracy. For high Ki67 expression, a model made up of tumor size (p = 0.051), presence of ulceration (p = 0.054) and metastasis (p = 0.001) may be the best predictive combination with an AUC of 0.785 (95% CI, 0.702-0.854; p < 0.001), 63.33% sensitivity, 76.34% specificity, 46.34% PPV, 86.59% NPV, 73.17% diagnostic accuracy. Ki67 index showed a moderate positive correlation with mitotic count (r = 0.578, p < 0.001), a weak positive correlation with tumor size (r = 0.339, p < 0.001) and with risk stratification (r = 0.364, p < 0.001). CONCLUSION: Features on CE-CT could preoperatively predict malignant potential and high Ki67 expression of small intestine GISTs, and Ki67 index may be a promising prognostic factor in predicting the prognosis of small intestine GISTs, independent of the risk stratification system.

A scoring model for radiologic diagnosis of gastric leiomyomas (GLMs) with contrast-enhanced computed tomography (CE-CT): Differential diagnosis from gastrointestinal stromal tumors (GISTs).

OBJECTIVES: To investigate CT findings and develop a diagnostic score model to differentiate GLMs from GISTs. METHODS: This retrospective study included 109 patients with pathologically confirmed GLMs (n = 46) and GISTs (n = 63) from January 2013 to August 2018 who received CE-CT before surgery. Demographic and radiological features was collected, including lesion location, contour, presence or absence of intralesional necrosis and ulceration, growth pattern, whether the tumor involved EGJ, the long diameter (LD) /the short diameter (SD) ratio, pattern and degree of lesion enhancement. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predictors and establish a predictive model. Independent predictors for GLMs were weighted with scores based on regression coefficients. A receiver operating characteristic (ROC) curve was created to determine the diagnostic ability of the model. Overall score distribution was divided into four groups to show differentiating probability of GLMs from GISTs. RESULTS: Five CT features were the independent predictors for GLMs diagnosis in multivariate logistic regression analysis, including esophagogastric junction (EGJ) involvement (OR, 367.9; 95 % CI, 5.8-23302.8; P =  0.005), absence of necrosis (OR, 11.9; 95 % CI, 1.0-138. 1; P =  0.048) and ulceration (OR, 151.9; 95 % CI, 1.4-16899.6; P =  0.037), degree of enhancement (OR, 9.3; 95 % CI, 3.2-27.4; P <  0.001), and long diameter/ short diameter (LD/SD) ratio (OR,170.9; 95 % CI, 8.4-3493.4; P =  0.001). At a cutoff of 9 points, AUC for this score model was 0.95, with 95.65 % sensitivity, 79.37 % specificity, 77.19 % PPV, 96.15 % NPV and 86.24 % diagnostic accuracy. An increasing trend was showed in diagnostic probability of GLMs among four groups based on the score (P <  0.001). CONCLUSIONS: The newly designed scoring system is reliable and easy-to-use for GLMs diagnosis by distinguishing from GISTs, including EGJ involvement, absence of ulceration and necrosis, mild enhancement and high LD/SD ratio. The overall score of model ranged from 1 to 17 points, which was divided into 4 groups: 1-7 points, 7-10 points, 10-13 points and 13-17 points, with a diagnostic probability of GLMs 0%, 45 %, 83 % and 100 %, respectively.

Case Report: Radiological Features of Sclerosing Epithelioid Fibrosarcoma in the Right Fibula.

BACKGROUND: Sclerosing epithelioid fibrosarcoma (SEF) is an extremely rare, aggressive malignant subtype of fibrosarcoma. Only dozens of cases of primary SEF in the bone have been reported so far, without case involving fibula reported in literature to date. Herein we report the first case of primary SEF in the right fibula in a 19-year-old man. In this case report, we firstly give a comprehensive description of fibula SEF, including its complete clinical course and radiological findings. CASE PRESENTATION: A 19-year-old man presented with a half-year history of soreness in the right lower leg. Contrast-enhanced computed tomography (CE-CT) and magnetic resonance imaging (MRI) of the right lower leg were performed. Based on the radiological examinations, a diagnosis of malignant tumor arising in the fibular diaphysis was made. Final diagnosis of primary SEF in the right fibula was confirmed by histopathological and immunohistochemical examinations after surgical resection. The patient had no signs of recurrence or metastasis during a 24-month follow-up. CONCLUSION: We report an exceedingly rare case of primary SEF in the right fibula and its radiological features with CE-CT and MRI.

The natural history of oviposition on a ginkgophyte fruit from the Middle Jurassic of northeastern China.

A distinctive pattern of oviposition lesions occurs on a ginkgoalean seed, Yimaia capituliformis, which likely was inflicted by a kalligrammatid lacewing with a long, sword-like, plant-piercing ovipositor. This newly recorded oviposition type, DT272, occurs in the 165 million-year-old Jiulongshan Formation, of Middle Jurassic age, in Northeastern China. DT272 consists from three to seven, approximately equally spaced lesions with surrounding callus tissue, the fabricator of which targeted fleshy outer and inner tissues of a ginkgophyte fruit. This distinctive damage also is known from the fleshy attachment pad surfaces of basal bennettitalean bracts. Examination of the life history of this probable ginkgoalean-kalligrammatid oviposition interaction indicates that the spacing of the eggs in substrate tissues disfavored inter-larval contact, but little can be said of defense and counterdefense strategies between the plant host and the newly hatched immatures.

Dysregulated systemic lymphocytes affect the balance of osteogenic/adipogenic differentiation of bone mesenchymal stem cells after local irradiation.

BACKGROUND: While it is known that irradiation can induce local and systemic bone loss over time, how focal irradiation induces systemic bone complications remains unclear. Immune cells are thought to be crucial to bone homeostasis, and abnormal immune cells lead to serious disruption of bone homeostasis, such as in acute lymphoblastic leukaemia. This disruption primarily occurs due to inhibition of the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). METHODS: In this study, we detected local and systemic bone loss in trabecular bone by micro-computed tomography (micro-CT) and measurement of peroxisome proliferator-activated receptor gamma (PPARγ) and runt-related transcription factor 2 (RUNX2) expression in BMSCs using real-time polymerase chain reaction and western blotting. Additionally, changes in lymphocytes (B cells and CD4+ and CD8+ T cells) in the peripheral blood and bone marrow were analysed by flow cytometry. BMSC-derived osteoblasts and adipocytes, cultured in osteogenic or adipogenic media or co-cultured with lymphocytes, were detected by BCIP/NBT, Alizarin Red S and Oil Red O staining. RESULTS: Focal irradiation induced local and systemic bone loss in trabecular bone. Increased PPARγ expression and decreased RUNX2 expression were observed, accompanied by upregulated adipogenesis and downregulated osteogenesis of BMSCs. B cells and CD8+ T lymphocytes were increased in the blood and bone marrow after irradiation, while CD4+ T lymphocytes were decreased in the blood. Inhibition of RUNX2 expression and reduction of alkaline phosphatase activity and mineralization deposits were observed in lymphocyte-co-cultured BMSCs, accompanied by an increase in PPARγ expression and in the number of lipid droplets. CONCLUSIONS: Focal irradiation induced local and systemic bone loss in trabecular bone. Increased B cells and CD8+ T lymphocytes led to systemic bone loss by decreasing BMSC osteogenesis.

Bone marrow stem cell dysfunction in radiation-induced abscopal bone loss.

BACKGROUND: Bone-related complications are commonly reported in cancer patients receiving radiotherapy and are collectively referred to as the abscopal effect of irradiation, the mechanism of which remains poorly understood. When patients receive targeted radiotherapy to a tumor, the local skeleton is exposed to radiation, particularly within the bone marrow. We therefore investigated the hypothesis that single bone irradiation can induce deterioration of the skeleton outside the radiation field and is mediated by the bone marrow. METHODS: Using 4-month-old male Sprague-Dawley rats, the effects of irradiation (20 Gy, right distal femur and proximal tibia) on bone quality, microarchitecture and bone marrow, were evaluated prospectively by microcomputed tomography, histomorphometry, real-time polymerase chain reaction, and Western blot analysis. RESULTS: At 12 weeks post-irradiation, bone loss of the non-irradiated bone was induced and marrow adiposity was increased. Expression of runt-related transcription factor-2 by bone mesenchymal stem cells (BMSCs) decreased after irradiation by 88.0 % (P < 0.01) at the contralateral and 82.3 % (P < 0.01) at the irradiation site 2 weeks post-irradiation and decreased by 94.5 % (P < 0.001) at the contralateral and 44.1 % (P < 0.05) at the irradiation site 12 weeks post-irradiation. Interestingly, peroxisome proliferator-activated receptor gamma expression decreased by 61.8 % (P < 0.05) at the contralateral and by 48.3 % (P < 0.05) at the irradiation site 2 weeks post-irradiation but increased by 9-fold at the contralateral (P < 0.001) and by 13-fold (P < 0.001) at the irradiation site 12 weeks post-irradiation. CONCLUSIONS: These data highlight that radiation-induced bone complications are partly BMSC-mediated, with important implications for bone health maintenance in patients receiving radiotherapy.

Jurassic mimicry between a hangingfly and a ginkgo from China.

A near-perfect mimetic association between a mecopteran insect species and a ginkgoalean plant species from the late Middle Jurassic of northeastern China recently has been discovered. The association stems from a case of mixed identity between a particular plant and an insect in the laboratory and the field. This confusion is explained as a case of leaf mimesis, wherein the appearance of the multilobed leaf of Yimaia capituliformis (the ginkgoalean model) was accurately replicated by the wings and abdomen of the cimbrophlebiid Juracimbrophlebia ginkgofolia (the hangingfly mimic). Our results suggest that hangingflies developed leaf mimesis either as an antipredator avoidance device or possibly as a predatory strategy to provide an antiherbivore function for its plant hosts, thus gaining mutual benefit for both the hangingfly and the ginkgo species. This documentation of mimesis is a rare occasion whereby exquisitely preserved, co-occurring fossils occupy a narrow spatiotemporal window that reveal likely reciprocal mechanisms which plants and insects provide mutual defensive support during their preangiospermous evolutionary histories.