Diagnostic accuracy of abdominal contrast-enhanced multi-slice spiral CT after oral diluted iodide in a time segment for gastrointestinal fistula in patients with severe acute pancreatitis.

PURPOSE: To evaluate the diagnostic accuracy of abdominal contrast-enhanced multi-slice spiral CT after oral diluted iodide in a time segment (post-ODI ACE-MSCT) for gastrointestinal fistula (GIF) in severe acute pancreatitis (SAP). MATERIALS AND METHODS: Patients with SAP who underwent both post-ODI ACE-MSCT and endoscopy/surgery from 2017 to 2023 were continuously retrospectively involved. Their demographic information and clinical features were recorded prospectively in an in-hospital database. Using endoscopy/surgery results as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of post-ODI ACE-MSCT for diagnosing GIF in SAP were calculated by a four-cell table. The consistency of the two diagnostic methods was evaluated by the Kappa test and McNemar's test. RESULTS: Using endoscopy/surgery as the reference standard, a total of 86 cases were divided into the GIF group (N = 52) and the non-GIF group (N = 34). Among the 52 cases of GIF, 88.5% (46/52) cases had a positive result and 11.5% (5/52) cases had a negative result of post-ODI ACE-MSCT for GIF. Among the 34 cases of non-GIF, 2.9% (1/34) case had a positive result and 97.1% (33/34) cases had a negative result of post-ODI ACE-MSCT for GIF. Post-ODI ACE-MSCT had a sensitivity of 88.5% (95% CI 75.9%-95.2%), a specificity of 97.1% (95% CI 82.9%-99.8%), a positive predictive value of 97.9% (95% CI 87.3%-99.9%), a negative predictive value of 84.6% (95% CI 68.8%-93.6%), and an accuracy of 91.9% (83.4%-96.4%). The kappa value was 0.834, and P < 0.001 by McNemar's test. There were no significant differences in diagnostic test characteristics between the two modalities. CONCLUSION: Post-ODI ACE-MSCT can diagnose GIF in SAP in a simple, noninvasive, and accurate way, and can provide earlier imaging evidence for clinical diagnosis and treatment.

[Adsorption and desorption of dyes by waste-polymer-derived activated carbons].

Mesoporous activated carbons with high surface area were prepared from three waste polymers, i. e., tire rubber, polyvinyl chloride (PVC) and polyethyleneterephtalate (PET), by KOH activation. The adsorption/desorption characteristics of dyes (methylene blue and methyl orange) on the carbons were studied. The effects of pH, ionic strength and surface surfactants in the solution on the dye adsorption were also investigated. The results indicated that the carbons derived from PVC and PET exhibited high surface area of 2 666 and 2 831 m2 x g(-1). Their mesopore volume were as high as 1.06 and 1.30 cm3 g(-1), respectively. 98.5% and 97.0% of methylene blue and methyl orange were removed in 15 min by PVC carbon, and that of 99.5% and 95.0% for PET carbon. The Langmuir maximum adsorption capacity to these dyes was more than 2 mmol x g(-1), much higher than that of commercial activated carbon F400. Compared with Freundlich model, the adsorption data was fitted better by Langmiur model, indicating monolayer coverage on the carbons. The adsorption was highly dependent on solution pH, ionic strength and concentration of surface surfactants. The activated carbons exhibited higher adsorption to methylene blue than that of methyl orange, and it was very hard for both of the dyes to be desorbed. The observation in this study demonstrated that activated carbons derived from polymer waste could be effective adsorbents for the treatment of wastewater with dyes.

[The effect of aloesin on melanocytes in the pigmented skin equivalent model].

OBJECTIVE: To observe the effect of aloesin, tea polyphenols, arbutin on melanocytes in the pigmented skin equivalent model. METHODS: First, we constructed the pigmented skin equivalent model in vitro. And then we detected the effect of aloesin, tea polyphenols and arbutin on the cells' shape, tyrosinase activity and formation of melanin in the constructed pigmented skin equivalent. RESULTS: Three depigmenting agents showed an inhibition effect on the tyrosinase activity of melanocytes and reduced significantly melanin content in the pigmented skin equivalent model, in which the tea polyphenols had the strongest effect, and then was the aloesin. But the tea polyphenols showed the strongest toxicity, while the aloesin and arbutin had a much lower toxicity. CONCLUSIONS: All the three depigmenting agents showed a concentration dependent suppression effect on the tyrosinase activity and formation of melanin, in which the tea polyphenols was the strongest effect( P <0.05). Aoesin has a good suppression effect on the tyrosinase activity and formation of melanin, but has a much lower toxicity, which could be used as a safe depigmenting agent.

[Construction of an in vitro equivalent of the pigmented skin].

OBJECTIVE: To construct an in vitro equivalent of the pigmented skin using tissue engineering methods. METHODS: Surgically removed foreskins was used as the source of keratinocytes and melanocytes harvested by routine tissue digestion. The fibroblasts were enriched by tissue block culture and seeded into the scaffold constructed using mouse tail collagens to construct the pigmented skin equivalent model. The general structure and the melanocyte distribution and growth status in this model were observed with HE staining and Fontana Masson staining. The ultrastructure of the constructed pigmented skin equivalent was observed by transmission electron microscope. RESULTS AND CONCLUSION: The pigmented skin equivalent model was structurally intact, and allowed optimal cell growth. Fontana Masson staining identified in the basal layer numerous melanocytes in normal growth, and the constructed model was structurally similar to normal skin tissue, suggesting successful construction of the pigmented skin equivalent model.