Characterization and identification of iridoid glucosides, flavonoids and anthraquinones in Hedyotis diffusa by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry.

The multiple bioactive constituents in Hedyotis diffusa Willd. (H. diffusa) were extracted and characterized by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS(n)). The optimized separation condition was obtained using an Agilent ZorBax SB-C18 column (4.6×150 mm, 5 µm) and gradient elution with water (containing 0.1% formic acid) and acetonitrile (containing 0.1% formic acid), under which baseline separation for the majority of compounds was achieved. Among the compounds detected, 14 iridoid glucosides, 10 flavonoids, 7 anthraquinones, 1 coumarin and 1 triterpene were unambiguously identified or tentatively characterized based on their retention times and mass spectra in comparison with the data from standards or references. The fragmentation behavior for different types of constituents was also investigated, which could contribute to the elucidation of these constituents in H. diffusa. The present study reveals that even more iridoid glycosides were found in H. diffusa than hitherto assumed. The occurrence of two iridoid glucosides and five flavonoids in particular has not yet been described. This paper marks the first report on the structural characterization of chemical compounds in H. diffusa by a developed HPLC-ESI-MS(n) method.

The Prognostic Value of Microvascular Density in Early Postoperative Recurrence and Metastasis of T1 Esophageal Squamous Cell Carcinoma.

OBJECTIVE: To identify the relation of microvascular density (MVD) to the early postoperative recurrence and metastasis of T1 esophageal squamous cell carcinoma, and to determine whether MVD could be a prognostic predictor of esophageal squamous cell carcinoma. METHODS: Patients with T1 esophageal squamous cell carcinoma were enrolled. Immunohistochemistry with primary antibody against CD-34 was performed to count MVD. ROC curve was plotted and appropriate cutoff value was determined to evaluate the potential power of MVD in predicting early recurrence and metastasis of T1 esophageal squamous cell carcinoma. Survival curves were drawn by the Kaplan-Meier method and significance were tested by the Mantel-Cox test. RESULTS: A total of 37 patients with T1 esophageal squamous cell carcinoma were enrolled. The MVD of T1 esophageal squamous cell carcinoma patients with early metastasis was significantly higher than that of T1 esophageal squamous cell carcinoma patients without early metastasis (65.83±4.39 vs. 42.26±2.34, p<0.001). MVD was available in distinguishing whether patients with early esophageal are prone to postoperative recurrence or metastasis (AUC=0.861; 95% CI 0.738-0.984, p<0.001), with 88.89% sensitivity and 68.42% specificity of MVD being obtained when the cut-off is 44.5. Kaplan-Meier survival curves showed that patients with a higher MVD had a lower survival (37.35 months) compared with those with low MVD (40.79 months) (p<0.05). CONCLUSIONS: MVD could be a promising indicator for early postoperative recurrence and metastasis of T1 esophageal squamous cell carcinoma and the prognosis of these patients.

Evaluation of a Spinosad Controlled-Release Formulation Based on Chitosan Carrier: Insecticidal Activity against Plutella xylostella (L.) Larvae and Dissipation Behavior in Soil.

Controlled-release pesticide formulations using natural polymers as carriers are highly desirable owing to their good biocompatibility, biodegradability, and improved pesticide utilization. In this study, the application potential of our previously prepared spinosad/chitosan controlled-release suspension (SCCS) was evaluated through both toxicity and dissipation tests. A comparison with the spinosad suspension concentrate and the commercial spinosad emulsion in water showed that the insecticidal activity of SCCS against Plutella xylostella larvae displayed the best quick-acting performance as well as long-term efficacy of more than 20 days. The 48 h LC50 for a 20-day efficacy was calculated to be 29.36 mg/L. The dissipation behavior of spinosad in the spinosad/chitosan microparticles in soil was found to follow the first-order kinetics, with a relatively shorter half-life (2.1 days) than that observed for the unformulated spinosad (3.1 days). This work showed the positive effect of chitosan on spinosad in improving insecticidal activity and reducing environmental risks in soil, which provided useful information on the application potential of pesticide-carrier systems based on natural polymer materials in crop protection and food safety.

Coprecipitation-based synchronous pesticide encapsulation with chitosan for controlled spinosad release.

Controlled release pesticide formulation with long-term efficacy is highly desirable for improving pesticide utilization and reducing adverse effects. In this study, an environment-friendly controlled release formulation of biological insecticide spinosad was fabricated through the coprecipitation-based synchronous encapsulation with chitosan. The resulted spinosad/chitosan formulation showed an excellent encapsulation efficiency of 60 %, obvious pH and temperature sensitivity, and outstanding ultraviolet shielding ability. The in vitro release tests displayed long sustained-release time (>18 d) and high cumulative release (>80 %) under neutral and weakly alkaline conditions. The primary interaction between spinosad and chitosan has been found to be physical adsorption and adhesion, with the release dynamics following Fickian diffusion mechanism of Ritger-Peppas model. This work contributes to the development of pesticide carrier system of natural polymer materials, with a great potential for insect pest control.

[Alterations of Cajal cells in the colon of slow transit constipation rats].

OBJECTIVE: To investigate the association of expression of c-kit (marker of interstitial cells of Cajal, ICC) in colon with slow transit constipation (STC) in rats. METHODS: Slow transit constipation (STC) rat model was induced by intragastric administration of compound diphenoxylate. Western blotting was used to measure the expression of c-kit in colon of STC rats (model group) and normal rats (control group). Gray scale ratio of c-kit to ß-actin was used as the relative quantity of c-kit. RESULTS: Fecal quantity per day of STC group was (1.3±0.7) g/100 g, significantly lower than that in normal rats [(1.6±0.9) g/100 g, t=10.798, P<0.05]. In model rats, the time of discharge of the first black fecal was (461.6±150.8) min, significantly longer than that in normal rats [(351.3±119.9) min, t=2.291, P<0.05]. Western blotting revealed that the average values of gray scale ratio of c-kit in proximal colon were 0.277±0.077 and 0.576±0.081 (t=10.719, P<0.05), in distal colon were 0.280±0.075 and 0.571±0.079 (t=10.700, P<0.05) in model group and control group respectively. CONCLUSION: Down-regulation of c-kit expression in proximal colon and distal colon is associated to the pathogenesis of slow transit constipation in rats.

[Surface characteristics of alkali modified activated carbon and the adsorption capacity of methane].

Coconut shell based activated carbon was modified by alkali with different concentrations. The surface structures of tested carbons were observed and analyzed by SEM and BET methods. Boehm's titration and SEM/EDS methods were applied to assay the functional groups and elements on the carbon surface. The adsorption of methane on tested carbons was investigated and adsorption behavior was described by the adsorption isotherms. Results showed that surface area and pore volume of modified carbon increased and surface oxygen groups decreased as the concentration of the alkali used increased, with no obvious change in pore size. When concentration of alkali was higher than 3.3 mol x L(-1), the specific surface area and pore volume of modified carbon was larger than that of original carbon. Methane adsorption capacity of alkali modified carbon increased 24%. Enlargement of surface area and pore volume, reduction of surface oxygen groups will benefit to enhance the methane adsorption ability on activated carbon. Adsorption behavior of methane followed the Langmuir isotherm and the adsorption coefficient was 163.7 m3 x mg(-1).

Zebrafish krüppel-like factor 4a represses intestinal cell proliferation and promotes differentiation of intestinal cell lineages.

BACKGROUND: Mouse krüppel-like factor 4 (Klf4) is a zinc finger-containing transcription factor required for terminal differentiation of goblet cells in the colon. However, studies using either Klf4(-/-) mice or mice with conditionally deleted Klf4 in their gastric epithelia showed different results in the role of Klf4 in epithelial cell proliferation. We used zebrafish as a model organism to gain further understanding of the role of Klf4 in the intestinal cell proliferation and differentiation. METHODOLOGY/PRINCIPAL FINDINGS: We characterized the function of klf4a, a mammalian klf4 homologue by antisense morpholino oligomer knockdown. Zebrafish Klf4a shared high amino acid similarities with human and mouse Klf4. Phylogenetic analysis grouped zebrafish Klf4a together with both human and mouse Klf4 in a branch with high bootstrap value. In zebrafish, we demonstrate that Klf4a represses intestinal cell proliferation based on results of BrdU incorporation, p-Histone 3 immunostaining, and transmission electron microscopy analyses. Decreased PepT1 expression was detected in intestinal bulbs of 80- and 102-hours post fertilization (hpf) klf4a morphants. Significant reduction of alcian blue-stained goblet cell number was identified in intestines of 102- and 120-hpf klf4a morphants. Embryos treated with γ-secretase inhibitor showed increased klf4a expression in the intestine, while decreased klf4a expression and reduction in goblet cell number were observed in embryos injected with Notch intracellular domain (NICD) mRNA. We were able to detect recovery of goblet cell number in 102-hpf embryos that had been co-injected with both klf4a and Notch 1a NICD mRNA. CONCLUSIONS/SIGNIFICANCE: This study provides in vivo evidence showing that zebrafih Klf4a is essential for the repression of intestinal cell proliferation. Zebrafish Klf4a is required for the differentiation of goblet cells and the terminal differentiation of enterocytes. Moreover, the regulation of differentiation of goblet cells in zebrafish intestine by Notch signaling at least partially mediated through Klf4a.

[Clinical analysis of 60 thyroglossal tract cyst cases].

OBJECTIVE: To study the characteristics of thyroglossal tract cyst epidemiology and summarize how to improve the operation therapeutic effect. METHODS: The clinic appearance, the pathological characteristics and the therapeutic effect of the 60 thyroglossal tract cyst cases were analyzed. RESULTS: Thyroglossal tract cyst mostly occurred in children and teenagers. The incidence of female patients was more than that of male patients. Most of thyroglossal tract cyst located in the middle line of the neck and were explored tubular-objects and fibroropes. The histopathological feature was variform. CONCLUSION: The clinical appearance and pathology characteristic of thyroglossal tract cyst are variform. Thyroglossal tract cyst may be recurred easily if it is not operated well.