Management of lenticule detachment and epithelial downgrowth after Descemet stripping automated endothelial keratoplasty: a novel technique and brief literature review.

BACKGROUND: Epithelial downgrowth is a rare complication after Descemet stripping automated endothelial keratoplasty (DSAEK), which usually leads to poor visual outcome despite multiple available options of treatment. CASE PRESENTATION: A 50-year-old man underwent DSAEK procedure due to pseudophakic bullous keratopathy. Three months later, the patient presented with gradual visual loss; slit-lamp examination revealed detachment and folding of the DSAEK lenticule, which was confirmed by anterior segment optical coherence tomography. On confocal scanning, epithelial cell sheets were detected in the interface leading to the wrinkling of the donor tissue and donor detachment. Surgical debridement and transient fixating with straight 10-0 prolene needles were performed followed by air injection into the anterior chamber. The cornea turned clear in the one-year follow-up with uncorrected-visual acuity of 20/30 and best-corrected visual acuity of 20/25. CONCLUSIONS: Early diagnosis and treatment of epithelial downgrowth may be associated with a good prognosis and prevent from more aggressive treatments such as repeat of grafting. In this case, mechanical debridement and transient fixation of lenticule by 10-0 prolene needles was performed to manage post-DSAEK epithelial downgrowth and lenticule detachment, which was successful without requiring of additional re-grafting. It seems this is a feasible technique with acceptable long-term outcomes.

Postbiotics produced by lactic acid bacteria: The next frontier in food safety.

There are many critical challenges in the use of primary and secondary cultures and their biological compounds in food commodities. An alternative is the application of postbiotics from the starter and protective lactic acid bacteria (LAB). The concept of postbiotics is relatively new and there is still not a recognized definition for this term. The word "postbiotics" is currently used to refer to bioactive compounds, which did not fit to the traditional definitions of probiotics, prebiotics, and paraprobiotics. Therefore, the postbiotics may be presently defined as bioactive soluble factors (products or metabolic byproducts), produced by some food-grade microorganisms during the growth and fermentation in complex microbiological culture (in this case named cell-free supernatant), food, or gut, which exert some benefits to the food or the consumer. Many LAB are considered probiotic and their postbiotic compounds present similar or additional health benefits to the consumer; however, this review aimed to address the most recent applications of the postbiotics with food safety purposes. The potential applications of postbiotics in food biopreservation, food packaging, and biofilm control were reviewed. The current uses of postbiotics in the reduction and biodegradation of some food safety-related chemical contaminants (e.g., biogenic amines) were considered. We also discussed the safety aspects, the obstacles, and future perspectives of using postbiotics in the food industry. This work will open up new insights for food applications of postbiotics prepared from LAB.

The intestinal barrier as an emerging target in the toxicological assessment of mycotoxins.

Mycotoxins, the secondary metabolites of fungal species, are the most frequently occurring natural food contaminants in human and animal diets. Risk assessment of mycotoxins focused as yet on their mutagenic, genotoxic and potential carcinogenic effects. Recently, there is an increasing awareness of the adverse effects of various mycotoxins on vulnerable structures in the intestines. In particular, an impairment of the barrier function of the epithelial lining cells and the sealing tight junction proteins has been noted, as this could result in an increased translocation of luminal antigens and pathogens and an excessive activation of the immune system. The current review aims to provide a summary of the available evidence regarding direct effects of various mycotoxins on the intestinal epithelial barrier. Available data, based on different cellular and animal studies, show that food-associated exposure to certain mycotoxins, especially trichothecenes and patulin, affects the intestinal barrier integrity and can result in an increased translocation of harmful stressors. It is therefore hypothesized that human exposure to certain mycotoxins, particularly deoxynivalenol, as the major trichothecene, may play an important role in etiology of various chronic intestinal inflammatory diseases, such as inflammatory bowel disease, and in the prevalence of food allergies, particularly in children.

Galacto-oligosaccharides Protect the Intestinal Barrier by Maintaining the Tight Junction Network and Modulating the Inflammatory Responses after a Challenge with the Mycotoxin Deoxynivalenol in Human Caco-2 Cell Monolayers and B6C3F1 Mice.

BACKGROUND: The integrity of the epithelial layer in the gastrointestinal tract protects organisms from exposure to luminal antigens, which are considered the primary cause of chronic intestinal inflammation and allergic responses. The common wheat-associated fungal toxin deoxynivalenol acts as a specific disruptor of the intestinal tight junction network and hence might contribute to the pathogenesis of inflammatory bowel diseases. OBJECTIVE: The aim of the current study was to assess whether defined galacto-oligosaccharides (GOSs) can prevent deoxynivalenol-induced epithelial dysfunction. METHODS: Human epithelial intestinal Caco-2 cells, pretreated with different concentrations of GOSs (0.5%, 1%, and 2%) for 24 h, were stimulated with 4.2-µM deoxynivalenol (24 h), and 6/7-wk-old male B6C3F1 mice were fed a diet supplemented with 1% GOSs for 2 wk before being orally exposed to deoxynivalenol (25 mg/kg body weight, 6 h). Barrier integrity was determined by measuring transepithelial electrical resistance (TEER) and intestinal permeability to marker molecules. A calcium switch assay was conducted to study the assembly of epithelial tight junction proteins. Alterations in tight junction and cytokine expression were assessed by quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis, or ELISA, and their localization was visualized by immunofluorescence microscopy. Sections of the proximal and distal small intestine were stained with hematoxylin/eosin for histomorphometric analysis. RESULTS: The in vitro data showed that medium supplemented with 2% GOSs improved tight junction assembly reaching an acceleration of 85% after 6 h (P < 0.05). In turn, GOSs prevented the deoxynivalenol-induced loss of epithelial barrier function as measured by TEER (114% of control), and paracellular flux of Lucifer yellow (82.7% of prechallenge values, P < 0.05). Moreover, GOSs stabilized the expression and cellular distribution of claudin3 and suppressed by >50% the deoxynivalenol-induced synthesis and release of interleukin-8 [IL8/chemokine CXC motif ligand (CXCL8)] (P < 0.05). In mice, GOSs prevented the deoxynivalenol-induced mRNA overexpression of claudin3 (P = 0.022) and CXCL8 homolog keratinocyte hemoattractant (Kc) (Cxcl1) (P = 0.06) as well as the deoxynivalenol-induced morphologic defects. CONCLUSIONS: The results demonstrate that GOSs stimulate the tight junction assembly and in turn mitigate the deleterious effects of deoxynivalenol on the intestinal barrier of Caco-2 cells and on villus architecture of B6C3F1 mice.

Testicular torsion in vivo models: Mechanisms and treatments.

BACKGROUND: Testicular torsion is a condition in which a testis rotates around its longitudinal axis and twists the spermatic cord. This in turn results in a significant decrease in blood flow and perfusion of testicular tissue. During Testicular torsion, the testicular tissue is affected by ischemia, heat stress, hypoxia, and oxidative and nitrosative stress. The testicular torsion should be considered an emergency condition and surgical intervention (testicular detorsion ) as the sole treatment option in viable cases involves counter-rotation on twisted testes associated, when possible, to orchipexy, in order to avoid recurrence. Possible testicular detorsion side-effects occur due to reperfusion and endothelial cells injury, microcirculation disturbances, and intense germ cells loss. OBJECTIVES: To discuss testicular torsion surgery-based methods, different time frames for testicular torsion induction, and the associated pathophysiology by emphasizing cellular and molecular events as well as different therapeutic agent applications for testicular torsion. MATERIALS AND METHODS: We reviewed all original research and epidemiological papers related to testicular torsion condition. RESULTS: Testicular torsion causes germ cell necrosis, arrested spermatogenesis, and diminished testosterone levels, with consequent infertility. Among different involved pathophysiological impacts, testicular torsion/detorsion-induced ischemia seems to play the key role by leading the tissue toward other series of events in testis. Numerous studies have used adjuvant antioxidants, calcium channel blockers, anti-inflammatory agents, or vasodilating agents in order to decrease these effects. DISCUSSION AND CONCLUSION: To the best of our knowledge, no previously conducted study examined therapeutical agents' beneficial effects post clinical I/R condition in humans. Different agents targeting different pathophysiological conditions were used to ameliorate the ischemia/reperfusion-induced condition in animal models, however, none of the administrated agents were tested in human cases. Although considering testicular detorsion surgery is still the golden method to reverse the testicular torsion condition and the surgical approach is undeniable, the evaluated agents with beneficial effects, need to be investigated furthermore in clinical conditions. Thus, furthermore clinical studies and case reports are required to approve the animal models proposed agents' beneficial impacts.

Lupeol attenuated the NAFLD and PCOS-induced metabolic, oxidative, hormonal, histopathological, and molecular injuries in mice.

Background and purpose: The current study aimed to study the therapeutic effects of lupeol as a nutritional triterpene on non-alcoholic fatty liver disease (NAFLD) and polycystic ovarian syndrome (PCOS) disorders in separate and concurrent models. Experimental approach: This study was performed in three sets and each set contained 4 groups of female mice (n = 6), including control, NAFLD or PCOS and/or NAFLD/PCOS, lupeol, and metformin (MET). The treatment groups following the induction of disorders were treated with lupeol (40 mg/kg, orally) or MET (500 mg/kg, orally) for 28 days. The insulin resistance index and hormonal assessments were conducted on the collected serum samples. Moreover, oxidative stress biomarkers were measured in the liver and ovaries. Histopathological studies and ultimately any changes in the expression of androgen receptors, toll-like receptor (TLR)-2 and TLR-4 were analyzed. Findings/Results: Results revealed that lupeol reduced significantly the insulin resistance index in NAFLD and NAFLD/PCOS-positive animals. Lupeol attenuated remarkably the PCOS and PCOS/NAFLD-elevated concentration of testosterone. lupeol recovered the metabolic disorders-induced oxidative stress and restored the disorders-depleted glutathione. The NAFLD/PCOS-induced hepatic damages such as microvesicular or macrovesicular steatosis and atretic follicles number in the ovary were attenuated in the lupeol-treated mice. Serum level of TNF-α was reduced and the expression of androgen receptors, TLR-4 and TLR-2 were downregulated in the lupeol-treated NAFLD/PCOS-positive animals. Conclusions and implication: The results suggest that lupeol could be a novel nutraceutical for the treatment of metabolic disorders. Lupeol's anti-metabolic disorders effects attribute to its anti-dyslipidemia, antioxidant, and anti-inflammatory properties.

Epithelial integrity, junctional complexes, and biomarkers associated with intestinal functions.

An intact intestinal barrier is crucial for immune homeostasis and its impairment activates the immune system and may result in chronic inflammation. The epithelial cells of the intestinal barrier are connected by tight junctions, which form an anastomosing network sealing adjacent epithelial cells. Tight junctions are composed of transmembrane and cytoplasmic scaffolding proteins. Transmembrane tight junction proteins at the apical-lateral membrane of the cell consist of occludin, claudins, junctional adhesion molecules, and tricellulin. Cytoplasmic scaffolding proteins, including zonula occludens, cingulin and afadin, provide a direct link between transmembrane tight junction proteins and the intracellular cytoskeleton. Each individual component of the tight junction network closely interacts with each other to form an efficient intestinal barrier. This review aims to describe the molecular structure of intestinal epithelial tight junction proteins and to characterize their organization and interaction. Moreover, clinically important biomarkers associated with impairment of gastrointestinal integrity are discussed.

The molecular mechanism behind insulin protective effects on testicular tissue of hyperglycemic rats.

AIMS: The present study assessed the possible mechanisms by which the insulin regulates the heat shock (HSPs) and transitional proteins expression and consequently ameliorates the oxidative stress-induced damages in germ and sperm cells DNA contents. MAIN METHODS: Mature male Wistar rats were distributed into control, Hyperglycemia-induced (HG) and insulin-treated HG-induced (HG-I) groups. Following 8 weeks from HG induction, testicular total antioxidant capacity (TAC), immunoreactivity of 8-oxodG, germ cells mRNA damage, Hsp70-2a, Hsp90, transitional proteins 1 and 2 (TP-1 and -2) mRNA and protein expressions were analyzed. Moreover, the sperm chromatin condensation was assessed by aniline-blue staining, and DNA integrity of germ and sperm cells were analyzed by TUNEL and acrdine-orange staining techniques. KEY FINDINGS: The HG animals exhibited significant (p < 0.05) reduction in TAC, HSp70-2a, TP-1 and TP-2 expression levels, and increment in 8-oxodG immunoreactivity, mRNA damage, and Hsp90 expression. However, insulin treatment resulted in (p < 0.05) enhanced TAC level, Hsp70-2a, Hsp90, TP-1 and TP-2 expressions, besides reduced 8-oxodG immunoreactivity and mRNA damage compared to the HG group (p < 0.05). The chromatin condensation and the germ and sperm cells DNA fragmentation were decreased in HG-I group. SIGNIFICANCE: Insulin treatment amplifies the testicular TAC level, improves the Hsp70-2a, TP-1, and TP-2 expressions, and boosts the Hsp90-mediated role in DNA repairment process. Consequently, altogether could maintain the HG-induced DNA integrity in the testicular and sperm cells.

Possible Protective Effects of Thiazolidinediones Antidiabetic Drugs in Colorectal Cancer.

Colorectal cancer (CRC) is one of the most common cancers worldwide, and it is considered the fourth most common cause of life-threatening cancers. Diabetes mellitus, especially type 2 diabetes, is an independent risk factor for CRC, due to shared risk factors like physical inactivity and obesity. Thiazolidinediones (TZDs) are among the most common medications for type 2 diabetes mellitus. Recent investigations have suggested a correlation between TZD usage (in a time-dependent manner) and reduced risk of CRC such that a longer period of TZDs treatment can lead to higher protection against CRC. TZDs have antitumor effects in a wide variety of in vitro and in vivo cancer models through different mechanisms such as the impacts on cell cycle, apoptosis, cell differentiation, and angiogenesis. These effects can be mediated via both peroxisome proliferator-activated receptors γ (PPARγ)-dependent and PPARγ-independent pathways. Due to the protective effects of TZDs in cancer prevention and treatment, they can be considered potent adjuvants in cancer treatment. In the current review, we discuss the effects of TZDs on prevention and treatment of cancers, with special emphasis on CRC and the association of TZD administration with metabolic regulation of T cells in defense against tumor cells.

Deoxynivalenol and Its Modified Forms: Are There Major Differences?

Considering the diverse toxic effects of the Fusarium toxin deoxynivalenol (DON), its common occurrence in wheat-based products, and its stability during processing, DON constitutes an increasing health concern for humans and animals. In addition to the parent compound DON, human and animal exposure encompasses the acetylated fungal metabolites 3-acetyl-deoxynivalenol (3ADON) and 15-acetyl-deoxynivalenol (15ADON) as well as the plant-derived DON-glucoside (DON3G) and the bacterial product de-epoxy-DON (DOM-1). In the current study we used the well-established Caco-2 cell model to compare the effects of these naturally occurring forms of DON on cell viability and markers of barrier integrity, as well as on the release of the pro-inflammatory chemokine chemokine CXC motif ligand (CXCL8). Results show that 3ADON is less potent in inducing adverse effects on barrier integrity when compared to DON, whereas 15ADON appears to be slightly more potent than DON. In contrast, DON3G and DOM-1 exerted no measurable adverse effects on the intestinal barrier. It was also demonstrated that galacto-oligosaccharides (GOS) are able to protect epithelial cells against DON and its acetylated forms, which suggests that GOS are beneficial food additives in the protection of vulnerable segments of the human population against adverse effects of DON and its derivatives.

Deoxynivalenol Impairs Weight Gain and Affects Markers of Gut Health after Low-Dose, Short-Term Exposure of Growing Pigs.

Deoxynivalenol (DON) is one of the major mycotoxins produced by Fusarium fungi, and exposure to this mycotoxin requires an assessment of the potential adverse effects, even at low toxin levels. The aim of this study was to investigate the effects of a short-term, low-dose DON exposure on various gut health parameters in pigs. Piglets received a commercial feed or the same feed contaminated with DON (0.9 mg/kg feed) for 10 days, and two hours after a DON bolus (0.28 mg/kg BW), weight gain was determined and samples of different segments of the intestine were collected. Even the selected low dose of DON in the diet negatively affected weight gain and induced histomorphological alterations in the duodenum and jejunum. The mRNA expression of different tight junction (TJ) proteins, especially occludin, of inflammatory markers, like interleukin-1 beta and interleukin-10 and the oxidative stress marker heme-oxigenase1, were affected along the intestine by low levels of DON in the diet. Taken together, our results indicate that even after low-level exposure to DON, which has been generally considered as acceptable in animal feeds, clinically-relevant changes are measurable in markers of gut health and integrity.

Protective effects of melatonin and Glycyrrhiza glabra extract on ochratoxin A--induced damages on testes in mature rats.

The effect of Glycyrrhiza glabra extract (GgE) as a natural antioxidant and melatonin (MEL) on ochratoxin A (OTA)-induced histopathological damages on the testes and oxidative stress was evaluated in male rats. The animals were assigned into four groups (n = 8) including control and test groups. The rats in control group received saline and the animals in the test groups received (200 µg/kg) of OTA, (15 mg/kg) of MEL + (200 µg/kg) OTA and (100 mg/kg) of GgE + (200 µg/kg) OTA, respectively, during 28 consecutive days. The serum total antioxidant power (TAOP) and total thiol molecules (TTM) production were assessed. Moreover, histopathological and histochemical studies were also performed. The results showed that the TAOP and TTM were decreased in OTA-exposed rats, while the animals that received MEL + OTA or GgE + OTA showed an enhancement in the serum TAOP and TTM levels. Histopathological analyses demonstrated that in OTA-exposed rats, the testicular degeneration, seminiferous tubule atrophy, dissociation of germinative epithelium, vasodilatation with vascular thrombosis, perivascular immune cell infiltration, hypertrophied leydic cells, giant cell formation, and negative tubular differentiation index (TDI) were observed. Surprisingly, both the biochemical and histopathological examinations showed that MEL and GgE, albeit with some differences, exerted a protective effect on OTA-induced damages. In conclusion, this data suggest that OTA contamination in animal feeds and human foods could cause reproductive abnormalities. Our data also indicate that OTA, at least partly by interfering in oxidative stress system, exerts its toxic effects on testes whereas MEL and GgE with antioxidant properties could fairly protect rats against OTA toxic effects.