Thin-film solid-phase microextraction of pesticides from cereal samples using electrospun polyvinyl alcohol/modified chitosan/porous organic framework nanofibers

In this study, a coating of electrospun polyvinyl alcohol/modified chitosan/hydroxy-containing porous organic framework (PVA/MCS/HC-POF) was fabricated and applied as a novel sorbent for thin-film solid-phase microextraction of pesticides from cereal samples, followed by HPLC-UV. The successful fabrication of PVA/MCS/HC-POF was confirmed through characterization tests. The functional group of MCS and a large number of hydroxyl groups on the HC-POF structure contributed to the co-extraction of pesticides. Under the optimum conditions, the calibration plots were linear within the range of 5.0-800 ng mL-1 (r2 ≥ 0.978), and the limits of detection were obtained below 4.0 ng mL-1. The method's precision was investigated through intra-day, inter-day, and film-to-film RSD (%) measurements, all of which were less than 6.5 %, 8.2 %, and 10.0 %, respectively. Furthermore, satisfactory recoveries ranging from 63.3 % to 79.0 % were obtained. Accordingly, the proposed method can be considered a suitable alternative for measuring trace amounts of pesticides in cereal samples.

Thermoresponsive in situ forming and self-healing double-network hydrogels as injectable dressings for silymarin/levofloxacin delivery for treatment of third-degree burn wounds

Our study aimed to introduce a novel double-cross-linked and thermoresponsive hydrogel with remarkable potential for accelerating third-degree burn wound healing. Burn injuries are recognized as challenging, critical wounds. Especially in third-degree burns, treatment is demanding due to extended wounds, irregular shapes, significant exudation, and intense pain during dressing changes. In this work, hydrogels made of zwitterionic chitosan and dialdehyde starch (ZCS and ZDAS) were created to deliver silymarine (SM) and levofloxacin (LEV). The hydrogels were effortlessly produced using dynamic Schiff base linkages and ionic interactions between ZCS and ZDAS at appropriate times. The pore uniformity, gel fraction, and commendable swelling properties can imply a suitable degree of Schiff base cross-link. The hydrogel demonstrated outstanding shape retention, and significant self-healing and flexibility abilities, enabling it to uphold its form even during bodily movements. After injecting biocompatible hydrogel on the wound, a notable acceleration in wound closure was observed on day 21 (98.1 ± 1.10 %) compared to the control group (75.1 ± 6.13 %), and histopathological analysis revealed a reduction of inflammation that can be linked to remarkable antioxidant and antibiotic properties. The results demonstrate the hydrogel's efficacy in promoting burn wound healing, making it a promising candidate for medical applications.

A8 REPEATED SUBMERGENCE OF AIR-LIQUID INTERFACE COLONOID CULTURES IMPAIRS INFLAMMATORY AND REGENERATIVE RESPONSES

Background

Damage in the intestinal epithelium is repaired via de-differentiation of mature intestinal epithelial cells to a stem-like state. Indeed, literature has primarily focused on acute forms of intestinal damage, but there is a lack of models to study how intestinal stem cells function after chronic injury, such as in inflammatory bowel disease (IBD). A previous report found that growth of mouse intestinal organoids in air-liquid interface (ALI) follows by submergence caused differentiation and reversible injury, but this has not been demonstrated in human cells or with repeated cycles of injury. Understanding how chronic damage alters human intestinal stem cell fate and function is imperative to developing novel therapies that repair the epithelium in people with IBD

Aims

To develop a robust in vitro model to differentiate and damage human intestinal epithelial cells, with or without the addition of bacterial flagellin to mimic pathogen exposure.

Methods

Human colonoid monolayers were seeded on Transwell inserts for 10 days until fully confluent and then differentiated by removing the apical media to create ALI growth conditions for 7 days. To induce damage, media was added to the apical side of the Transwell, with or without the addition of flagellin in the basolateral compartment. Following submergence induced damage, the apical media was removed and collected for chemokine analysis, and the cells were grown back in ALI for 3 days to recover them from injury. This cycle was repeated 5 times to induce chronic damage. Cells were collected for qPCR analysis, immunofluorescence imaging, RNA sequencing and DNA methylation analysis

Results

Repeated rounds of damage impaired the ability of intestinal epithelial cells (IECs) to respond to TLR stimulation (a decrease in basolateral IL-8 with each round), likely due to a decrease in TLR signaling pathways, as demonstrated by GSEA and qPCR. Chronic submergence damage led to an increase in differentiation of cells expressing MUC2, SLC26a3 and CHGA, and a decrease in stemness as shown by qPCR for BMI1, HOPX, and LGR5. After several rounds of damage, colonoid monolayers were unable to regrow as monolayers after passaging, likely due to a decrease in YAP signaling. We also identified mRNA expression and DNA methylation changes in genes associated with IBD and colon cancer.

Conclusions

We have developed a novel chronic damage model of recurrent IEC injury, which possibly mimics pathologies seen in people with inflammatory bowel disease. This model can be used to understand how chronic damage alters the ability of IECs to respond to pathogens and regenerate to repair and protect the epithelium from further damage.

Funding Agencies

CCC

[Less is more… in infectious diseases]

BACKGROUND

The increasing development of antimicrobial resistance has been identified as one of the greatest threats to public health and is caused to a relevant extent by falsely indicated antibiotic treatment.

OBJECTIVE

The main aim of this article is to identify areas in infectious disease diagnostics and treatment where overuse occurs and to provide recommendations on how to avoid it.

MATERIAL AND METHODS

The authors identified current and relevant studies on the topic of medical overuse in infectious diseases via a literature search. In particular, contributions from international "less is more" initiatives were included. The focus was on areas in which a reduction of diagnostic and therapeutic measures leads to an optimization of patient outcomes.

RESULTS

In many cases overuse in the context of diagnostics and treatment of infectious diseases not only leads to an unnecessary financial burden on the healthcare system and is not beneficial but can also increase the risk of development of antimicrobial resistance and have adverse consequences for patients.

CONCLUSION

Correct indications as well as focused selection and adequate application of antimicrobial agents is crucial to provide the best possible medical care. Diagnostic and antibiotic stewardship measures, which should be implemented in collaboration with infectious disease specialists, can help to identify and reduce areas of overuse and misuse.

Extracorporeal shock wave lithotripsy (ESWL) monotherapy in children: Predictors of successful outcome

INTRODUCTION AND OBJECTIVES

Although extracorporeal shock wave lithotripsy (ESWL) is the first choice for pediatric renal calculi <2 cm, the success rate after the first session is low. This is in contrast to other minimally invasive procedures like percutanous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS), which have higher rates of success. Therefore, the present study sought to identify predictors of success after one session of ESWL.

PATIENTS AND METHODS

A prospective study including 100 children with renal stone burden <2 cm who underwent ESWL at the present institution. The success rate after the first session was analyzed, and the predictors of success were investigated. The success of ESWL monotherapy was defined by absence of any residual fragments after 3 months, on non-contrast spiral computerized tomography (NCCT) scan, without need of any additional intervention.

RESULTS

Between January 2013 and October 2015, 100 children were treated with a Dornier Gemini lithotripter at the present institution. The mean patients age and stone size were 6 years (range: 1.8-14) and 13.1 mm (range: 6-20), respectively. After one session, 47% of patients showed complete clearance 3 months postoperative, those patients versus those who required an additional session or auxiliary procedures were younger in age, with smaller stone size and lower density. On multivariate analysis, only patient age was an independent predictor of success (odds ratio (OR) 0.9; P < 0.001).

CONCLUSION

Patient's age was an important predictor for response after ESWL monotherapy: not only did children respond better than adults, but age was also an independent predictor within the pediatric group.

Existe-t-il des biomarqueurs du tabagisme chez les dépendants à la nicotine ?

La dépendance à la nicotine est un comportement appris et renforcé par la consommation d’une substance psycho-active, « la nicotine », caractérisée par le besoin invincible et continu de consommer le tabac afin d’en éprouver des sensations psychiques et parfois de supprimer le malaise consécutif à son absence. Le dépendant à la nicotine ainsi que le thérapeute éprouvent de réelles difficultés d’estimation de la consommation du tabac lors d’un sevrage tabagique ou du maintien d’abstinence. Nous illustrerons notre intervention à travers une revue de littérature faite sur la base des données Pub Med entre 2010–2015 en utilisant les mots clés suivants : « tobacco », « nicotine », « dependence », « biomarkers » pour étayer à l’état actuel des nouveautés médicales, l’existence des biomarqueurs, leurs milieux et leurs techniques de dosage afin d’établir le diagnostic, apprécier le degré de dépendance nicotinique et adapter les posologies des traitements substitutifs.

TH1/TH2 cytokine analysis in Iranian renal transplant recipients

The pretransplant cytokine profile of donor and recipient blood and tissues may be associated with transplant outcome. A Th1 response is generally associated with transplant rejection, while a Th2 response may lead to tolerance and stable graft survival. A total of 56 (37 male and 19 female) patients of mean 36 +/- 5 years were candidates for living unrelated kidney transplantation. Serum samples were collected 24 hours pretransplantation as well as at 1 and 2 weeks posttransplantation. Immunosuppression consisted of cyclosporine, prednisolone, and mycophenolate mofetil. Among the transplanted patients, 19 (33.9%) individuals experienced an acute rejection episode, as proven by biopsy, as well as an increased serum creatinine and blood urea nitrogen, within 14 days after transplantation. We determined serum concentrations of interleukin (IL) 2 and interferon (IFN)-gamma for Th1 and IL4 and IL10 for Th2 by an enzyme-linked immunosorbent assay method (Bender med system kits, Germany). Among Th1 cytokines, the mean concentration levels for groups with versus without acute rejection were: IL-2 pretransplant 15 pg/mL vs 6.8 pg/mL, respectively (P = .005); IL-2 at 1 week, 19 pg/mL vs 4.85 pg/mL, respectively (P = .001); IL-2 at 2 weeks, 21.1 pg/mL vs 4.65 pg/mL, respectively (P = .0001); IFN-gamma pretransplant 161.1 pg/mL vs 65.2 pg/mL, respectively (P = .001); IFN-gamma at 1 week, 175.6 pg/mL vs 66.5 pg/mL, respectively (P = .001); and IFN-gamma at 2 weeks, 173.7 pg/mL vs 77.1 pg/mL (P = .001). IL-2 and IFN-gamma levels were significantly higher in the group with acute rejection versus those without acute rejection. In conclusion, these data suggest that cytokine analysis, especially of Th1 cytokines, might be a valuable prognotic index of kidney transplant outcome.

Value of Pretransplantation Cytokine Profiles for Predicting Acute Rejection in Renal Transplant Recipients

Episodes of acute rejection may represent an important risk factor for the development of chronic allograft nephropathy. Various studies have shown that pretransplant cytokine profiles in recipient blood are associated with transplant outcome. Serum samples were collected 24 hours before transplantation from 57 patients (38 men and 19 women of age 36 +/- 5 years) receiving kidneys from unrelated living donors. Additional samples were collected at 1 and 2 weeks after transplantation, as well as during every rejection episode. The immunosuppression consisted of a cyclosporine, prednisolone, and mycophenolate mofetil. Among the transplanted patients, 19 (33.3%) individuals experienced an acute rejection episode based on an increased level of serum creatinine and blood urea nitrogen during the first 14 days after transplantation. TGF-beta, IL-2 and IFN-gamma serum levels were determined by an ELISA method using Bindermed system kits. The mean concentration of TGF-beta before transplantation tended to be lower among patients with acute rejection episodes compared to those with stable graft (75,265 versus 85,394 pg/mL; P = .34) and at 1 week after transplantation (77,558 versus 84,390 pg/mL), although the differences were not significant. Among patients with rejection the mean IL-2 concentration was significantly higher before, at 1 week, and at 2 weeks after transplantation (15.0 versus 6.8 pg/mL, P = .005; 19.0 versus 4.9 pg/mL, P = .001; and 21.1 versus 4.7 pg/mL, P = .0001). The mean concentration of IFN-gamma was significantly higher pre- and at 1 and 2 weeks posttransplantation in patients with acute rejection episodes (161.1 versus 65.2, 175.6 versus 66.5 and 173.7 versus 77.1 pg/mL, all P < .001). In conclusion, evaluation of Th1 cytokines before transplantation may represent valuable predictive marker for an acute rejection episode.

A new method for demonstrating argyrophil cells of the pancreas and intestines

A new method for demonstrating argyrophil cells of the pancreas and intestinal tract using a combined silver and reducing solution in sections of formaldehyde fixed tissue is described. Impregnating sections in a 60 C water bath, the procedure takes about 25 min. A microwave version that takes about 5 min is also given. Results are similar to those obtained with the Grimelius method for argyrophil cells.

A combined elastic, fibrin and collagen stain

A method is described which demonstrates nuclei, elastic fibers, red blood cells, collagen and fibrin. Nuclei and elastic fibers are stained by a modified Verhoeff's elastic tissue stain which was previously developed and used in the elastic-Masson combination. Both early fibrin and red blood cells are shown by lissamine fast yellow. Mature fibrin, some types of collagen and other cytoplasmic changes are stained by a combination of acid fuchsin, Biebrich scarlet and ponceau 2R, while old fibrin is demonstrated by the collagen stain. This method takes about 1 hr to perform and has the added advantage that several entities are clearly shown in a single slide.