Oral Bisphosphonate Exposure and the Risk of Upper Gastrointestinal Cancers

The association between oral bisphosphonate use and upper gastrointestinal cancer has been controversial. Therefore, we examined the association with esophageal and gastric cancer within the Kaiser Permanente, Northern California population. A total of 1,011 cases of esophageal (squamous cell carcinoma and adenocarcinoma) and 1,923 cases of gastric adenocarcinoma (cardia, non-cardia and other) diagnosed between 1997 and 2011 from the Kaiser Permanente, Northern California cancer registry were matched to 49,886 and 93,747 controls, respectively. Oral bisphosphonate prescription fills at least one year prior to the index date were extracted. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for the associations between prospectively evaluated oral bisphosphonate use with incident esophageal and gastric cancer diagnoses with adjustment for potential confounders. After adjustment for potential confounders, no significant associations were found for esophageal squamous cell carcinoma (OR 0.88; 95% CI: 0.51, 1.52), esophageal adenocarcinoma (OR 0.68; 95% CI: 0.37, 1.24), or gastric non-cardia adenocarcinoma (OR 0.83, 95% CI: 0.59, 1.18), but we observed an adverse association with gastric cardia adenocarcinoma (OR 1.64; 95% CI: 1.07, 2.50). In conclusion, we observed no association between oral bisphosphonate use and esophageal cancer risk within a large community-based population. A significant association was detected with gastric cardia and other adenocarcinoma risk, although this needs to be replicated.

A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

Devices resident in the stomach-used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery-typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric-retentive devices.

[THE TREATMENT TACTICS AND PERIOPERATIVE INTENSIVE THERAPY IN STENOSING ESOPHAGEAL DISEASES]

The treatment tactics and intensive therapy in stenosing esophageal diseases for 222 patients in 2003 - 2015 yrs were analyzed. Expediency of application of the proposed treatment tactics was noted.

Drug-induced lesions of the oesophageal mucosa

Lesions of the oesophageal mucosa are observed in various situations: most often with gastrooesophageal reflux disease, but also with infections, cancer, contact with a toxic substance, etc. When they are symptomatic, these lesions provoke burning sensations, dysphagia, regurgitation and sometimes dorsal pain. The changes to the oesophageal mucosa may take various forms: inflammation, erosion, ulceration or necrosis. Serious or even fatal complications can develop but are rare; they include oesophageal perforation, stricture and haemorrhage. Some oral drugs damage the oesophageal mucosa through direct contact. The symptoms often develop several hours after ingestion. The pain is of sudden onset. The resulting lesions are solitary or multiple ulcers that vary in depth and usually occur in the upper portion of the oesophagus. Various factors prolong contact between a drug and the oesophageal mucosa, in particular: swallowing the drug with insufficient liquid or just before lying down; capsule forms; and oesophageal abnormalities. The drugs most frequently implicated are tetracyclines, particularly doxycycline, bisphosphonates and various nonsteroidal anti-inflammatory drugs (NSAIDs). Many drugs, used in various situations, provoke gastro-oesophageal reflux disease, sometimes causing mucosal lesions in the lower oesophagus: calcium-channel blockers, nitrates, exenatide and liraglutide, drugs with antimuscarinic effects, theophylline, etc. Some drugs affect all mucous membranes in the body, including the oesophageal mucosa, irrespective of their route of administration: cancer drugs, isotretinoin, and nicorandil.

TRPV1 Channels and Gastric Vagal Afferent Signalling in Lean and High Fat Diet Induced Obese Mice

Aim

Within the gastrointestinal tract vagal afferents play a role in control of food intake and satiety signalling. Activation of mechanosensitive gastric vagal afferents induces satiety. However, gastric vagal afferent responses to mechanical stretch are reduced in high fat diet mice. Transient receptor potential vanilloid 1 channels (TRPV1) are expressed in vagal afferents and knockout of TRPV1 reduces gastro-oesophageal vagal afferent responses to stretch. We aimed to determine the role of TRPV1 on gastric vagal afferent mechanosensitivity and food intake in lean and HFD-induced obese mice.

Methods

TRPV1+/+ and -/- mice were fed either a standard laboratory diet or high fat diet for 20wks. Gastric emptying of a solid meal and gastric vagal afferent mechanosensitivity was determined.

Results

Gastric emptying was delayed in high fat diet mice but there was no difference between TRPV1+/+ and -/- mice on either diet. TRPV1 mRNA expression in whole nodose ganglia of TRPV1+/+ mice was similar in both dietary groups. The TRPV1 agonist N-oleoyldopamine potentiated the response of tension receptors in standard laboratory diet but not high fat diet mice. Food intake was greater in the standard laboratory diet TRPV1-/- compared to TRPV1+/+ mice. This was associated with reduced response of tension receptors to stretch in standard laboratory diet TRPV1-/- mice. Tension receptor responses to stretch were decreased in high fat diet compared to standard laboratory diet TRPV1+/+ mice; an effect not observed in TRPV1-/- mice. Disruption of TRPV1 had no effect on the response of mucosal receptors to mucosal stroking in mice on either diet.

Conclusion

TRPV1 channels selectively modulate gastric vagal afferent tension receptor mechanosensitivity and may mediate the reduction in gastric vagal afferent mechanosensitivity in high fat diet-induced obesity.

In vivo pharmacokinetic and tissue distribution investigation of sustained-release cisplatin implants in the normal esophageal submucosa of 12 beagle dogs

PURPOSE

The aim of this study was to clarify the pharmacokinetic, tissue distribution, hematologic, and histopathologic characteristics of sustained-release cisplatin from implants [CDDP-nanoparticle (NP) implants].

METHODS

Eighteen dogs (six hybrids and twelve beagles) were divided into three groups. In Group A, the six hybrid dogs were intravenously administered 20 mg CDDP via a hind limb vein. In Groups B and C, CDDP-NP implants containing CDDP doses of 40 and 60 mg, respectively, were embedded into the esophageal submucosa of beagles via painless gastroscopy with an endoscopic booster. Graphite frameless atomic absorption spectrophotometry was used to measure total platinum in plasma and tissues at various timepoints. In addition, free platinum levels in Group B were determined using inductively coupled plasma mass spectrometry. Toxicologic evaluation was also conducted.

RESULTS

Pharmacokinetic results indicated that the CDDP-NP implant could achieve a smooth pharmacokinetic curve, with the plasma invalid concentration reached after almost 480 h, which is approximately ten times longer than that of standard CDDP (48 h). The peak time, peak concentration, clearance, elimination half-life, area under the curve, volume of distribution at steady state, and mean residence time of Groups B and C were 494 and 211, 0.39 and 0.42, 0.044 and 0.059, 80.11 and 87.70, 44 and 49, 38.8 and 57.9, and 12.29 and 12.39 times those of Group A, respectively (all P < 0.05). The ratio of free/total platinum concentration was 2.0-3.1% in plasma, 14.2% in liver tissue, and 14.3% in kidney tissue. Tissue distribution studies showed that the highest platinum concentrations were found in the esophagus, followed by the kidney and liver. Compared with pre-implantation (day 0), there were no significant differences in most hematological indicators in Groups B and C (P > 0.05). Furthermore, histopathologic examination of the kidneys of dogs from Group C revealed no significant kidney damage. Unlike the intravenous CDDP group (Group A), no animals in the implantation groups showed any clinical signs of toxicity.

CONCLUSION

CDDP-NP implants can be used to achieve a smooth pharmacokinetic curve and higher drug concentration, as well as a longer mean residence time at the implantation site, with reduced side effects compared with intravenous CDDP.

Rhizoma Paridis Saponins Suppresses Tumor Growth in a Rat Model of N-Nitrosomethylbenzylamine-Induced Esophageal Cancer by Inhibiting Cyclooxygenases-2 Pathway

Rhizoma Paridis Saponins (RPS), a natural compound purified from Rhizoma Paridis, has been found to inhibit cancer growth in vitro and in animal models of cancer. However, its effects on esophageal cancer remain unexplored. The purpose of this study was to investigate the effects of RPS on tumor growth in a rat model of esophageal cancer and the molecular mechanism underlying the effects. A rat model of esophageal cancer was established by subcutaneous injection of N-nitrosomethylbenzylamine (NMBA, 1mg/kg) for 10 weeks. RPS (350 mg/kg or 100mg/kg) was administered by oral gavage once daily for 24 weeks starting at the first NMBA injection. RPS significantly reduced the size and number of tumors in the esophagus of rats exposed to NMBA and inhibited the viability, migration, and invasion of esophageal cancer cells EC9706 and KYSE150 in a dose dependent manner (all P < 0.01). Flow cytometry revealed that RPS induced apoptosis and cell cycle G2/M arrest in the esophageal cancer cells. The expression of cyclooxygenases-2 (COX-2) and Cyclin D1 in rat esophageal tissues and the esophageal cancer cells were also significantly reduced by RPS (all P < 0.01). Consistently, RPS also significantly decreased the release of prostaglandin E2, a downstream molecule of COX-2, in a dose-dependent manner (P < 0.01). Our study suggests that RPS inhibit esophageal cancer development by promoting apoptosis and cell cycle arrest and inhibiting the COX-2 pathway. RPS might be a promising therapeutic agent for esophageal cancer.

Engineering Stent Based Delivery System for Esophageal Cancer Using Docetaxel

Esophageal cancer patients are often diagnosed as "advanced" cases. These patients are subjected to palliative stenting using self-expanding metallic stents (SEMS) to maintain oral alimentation. Unfortunately, SEMS get reoccluded due to tumor growth, in and over the stent struts. To investigate potential solutions to this problem, docetaxel (DTX) delivery films were prepared using PurSil AL 20 (PUS), which can be used as a covering material for the SEMS. Drug-polymer miscibility and interactions were studied. Bilayer films were prepared by adhering the blank film to the DTX loaded film in order to maintain the unidirectional delivery to the esophagus. In vitro release and the local DTX delivery were studied using in vitro permeation experiments. It was found that DTX and PUS were physically and chemically compatible. The bilayer films exhibited sustained release (>30 days) and minimal DTX permeation through esophageal tissues in vitro. The rate-determining step for the DTX delivery was calculated. It was found that >0.9 fraction of rate control lies with the esophageal tissues, suggesting that DTX delivery can be sustained for longer periods compared to the in vitro release observed. Thus, the bilayer films can be developed as a localized sustained delivery system in combination with the stent.

Histomorphological and Immunophenotypic Features of Pill-Induced Esophagitis

The aim of this study was to investigate histomorphological and immunophenotypic features in pill-induced esophagitis. We comparatively evaluated the histomorphological, immunophenotypic features of pill-induced esophagitis vs. reflux esophagitis, as well as clinical information and endoscopic findings. Fifty-two tissue pieces from 22 cases of pill-induced esophagitis, 46 pieces from 20 reflux esophagitis, and 16 pieces from 14 control samples were subjected to immunohistochemistry for inflammatory infiltrates (CD3 for T lymphocyte, CD20 for B lymphocyte, CD56 for NK cell, CD68 for macrophage, CD117 for mast cell) and eosinophil chemotaxis-associated proteins (Erk, leptin, leptin receptor, pSTAT3, phospho-mTOR). As a result, Histomorphology showed that a diffuse pattern of dilated intercellular spaces was more frequently observed in pill-induced esophagitis, while reactive atypia and subepithelial papillary elongation were more often found in reflux esophagitis (P < 0.05, respectively). Interestingly, intraepithelial eosinophilic microabscess, intraepithelial pustule and diffuse pattern of dilated intercellular spaces were observed in 14% (3 cases), 9% (2 cases) and 32% (7 cases) of pill-induced esophagitis, respectively, but in no cases of reflux esophagitis. Regarding intraepithelial inflammatory infiltrates in pill-induced esophagitis, T lymphocytes were the most common cells, followed by eosinophil; 11 and 7 in one x400 power field, respectively. Intraepithelial pSTAT3-positive pattern was more frequently observed in pill-induced esophagitis than in reflux esophagitis, at 45% (10 cases) versus 10% (2 cases), respectively (P < 0.05). Considering the distal esophageal lesion only, intraepithelial pustule, diffuse dilated intercellular spaces and stromal macrophages were more frequently found in distal pill-induced esophagitis, whereas reactive atypia and intraepithelial mast cells in reflux esophagitis (P < 0.05, respectively). In conclusion, diffuse dilated intercellular spaces, intraepithelial eosinophil microabscess, pustule, T lymphocytes, eosinophils, and pSTAT3 positivity can be added to histopathological features of pill-induced esophagitis, other than non-specific ulcer. Besides, distal pill-induced esophagitis may be histopathologically differentiated from reflux esophagitis.

Self-medication of achalasia with cannabis, complicated by a cannabis use disorder

Achalasia is a rare esophagus motility disorder. Medical, endoscopic and surgical treatments are available, but all endorse high relapse rates. No data has been published to date reporting a therapeutic effect of cannabis use neither in achalasia nor on its influence on manometric measurements. We report the case of a patient diagnosed with achalasia. He could benefit from a large panel of therapeutic interventions, but none of them was effective over the time. He first used cannabis at age 20 and identified benefits regarding achalasia symptoms. He maintained regular moderate cannabis use for 9 years, with minimal digestive inconvenience. A manometry performed without cannabis premedication was realized at age 26 and still found a cardiospasm. Cannabis use could explain the gap between functional symptoms assessment and manometry measurement. Further investigations are warranted to explore a therapeutic effect of cannabis in achalasia and possible influence on outcome measurements.

Successful management of oesophageal conduit necrosis by a single-stage reconstruction with the pedicled pectoralis major myocutaneous flap

Conduit necrosis is a rare but potentially devastating complication of oesophageal surgery and the subsequent reversal of oesophageal discontinuity can be challenging. An option for both cervical-oesophageal reconstruction and neck wound closure has been limited and less successful. We report a patient with colon conduit necrosis and cervical-oesophageal discontinuity whose cervial oesophagus was successfully reconstructed with a single-stage pedicled pectoralis major myocutaneous flap and neck wound closure.

[Effect of aluminum phosphate gel and Kangfuxin on esophageal pathology and IL-8 and PGE2 expressions in a rat model of reflux esophagitis]

OBJECTIVE

To explore the effect of aluminum phosphate gel and Kangfuxin on esophageal pathology and expressions of interleukin-8 (IL-8) and prostaglandin E2 (PGE2) in rats with reflux esophagitis and explore the possible mechanisms.

METHODS

Sixty SD rats were randomized into aluminum phosphate gel group (n=10), Kangfuxin group (n=10), aluminum phosphate gel+Kangfuxin group (n=10), model group (n=20), and control group (n=10). Except for those in the control group, all the rats were subjected to infusion of diluted lysolecithin with hydrochloric acid in the esophagus for 14 days. Ten rats in the model group and those in the control group were sacrificed to examine the pathological changes and contents of IL-8 and PGE2 in the esophagus using optical and electron microscopes and radioimmunoassay. The next day the rest rats were given corresponding treatments (saline in model group) administered into the esophagus on a daily basis for 14 days, after which esophageal pathologies and IL-8 and PGE2 contents were examined.

RESULTS

The model rats showed obvious esophageal pathologies including inflammatory cell infiltration, vacuolar degeneration of the epithelial cells, esophageal erosion and even ulceration, with severe detachment of the epithelial cells. The rats in all the intervention groups showed lessened esophageal pathologies and lowered esophageal IL-8 and PGE2 contents compared with those in the model group. Esophageal mucosal injury index and IL-8 and PGE2 contents were all significantly lower in rats receiving combined treatment with aluminum phosphate and Kangfuxin than in those receiving either of the treatments (P<0.05).

CONCLUSIONS

Both Kangfuxin and aluminum phosphate gel are effective in the treatment for reflux esophagitis induced by lysolecithin and hydrochloric acid, and their therapeutic effects are achieved possibly by reducing IL-8 and PGE2 levels in the esophagus.

The potential impact of new effervescent alendronate formulation on compliance and persistence in osteoporosis treatment

Osteoporotic fractures are a public health problem and their incidence and subsequent economic and social costs are expected to rise in the next future. Different drugs have been developed to reduce osteoporosis and the risk of osteoporotic fractures, and among them, antiresorptive agents, and in particular oral alendronate, are the most widely utilized. However, one of the most common problems with antiresorptive drugs is poor adherence to treatment, which is associated with a high fracture incidence and with an increase in hospitalization costs. One of the main reasons of poor adherence to these treatments is the occurrence of adverse events, mainly at gastrointestinal (GI) level, including dyspepsia, dysphagia, and esophageal ulcers. In light of these considerations the aim of this paper is to perform a literature review to show the pathophysiologic bases of GI alendronate-induced adverse events and how new bisphosphonate formulations like effervescent alendronate can improve compliance and persistence to treatment and decrease the fracture rate incidence in osteoporotic patients.

A versatile, stability-indicating and high-throughput ultra-fast liquid chromatography method for the determination of isoflavone aglycones in soybeans, topical formulations, and permeation assays

There is a growing interest in the pharmaceutical field concerning isoflavones topical delivery systems, especially with regard to their skin care properties and antiherpetic activity. In this context, the present work describes an ultra-fast liquid chromatography method (UFLC) for determining daidzein, glycitein, and genistein in different matrices during the development of topical systems containing isoflavone aglycones (IA) obtained from soybeans. The method showed to be specific, precise, accurate, and linear (0.1 to 5 µg mL(-1)) for IA determination in soybean acid extract, IA-rich fraction obtained after the purification process, IA loaded-nanoemulsions, and topical hydrogel, as well as for permeation/retention assays in porcine skin and porcine esophageal mucosa. The matrix effect was determined for all complex matrices, demonstrating low effect during the analysis. The stability indicating UFLC method was verified by submitting IA to acidic, alkaline, oxidative, and thermal stress conditions, and no interference of degradation products was detected during analysis. Mass spectrometry was performed to show the main compounds produced after acid hydrolysis of soybeans, as well as suggest the main degradation products formed after stress conditions. Besides the IA, hydroxymethylfurfural and ethoxymethylfurfural were produced and identified after acid hydrolysis of the soybean extract and well separated by the UFLC method. The method's robustness was confirmed using the Plackett-Burman experimental design. Therefore, the new method affords fast IA analysis during routine processes, extract purification, products development, and bioanalytical assays.

[EFFECT OF ANTIOXIDANTS ON ESOPHAGUS TISSUE REPAIR UPON EXPERIMENTAL CHEMICAL BURN FROM ACETIC ACID]

This work is an experimental study on 30 rabbits to determine the effect of antioxidants on the process of repair of the esophagus. Chemical agent was 46% acetic acid, a The antioxidant "Mexidol" were injected to core group of test animals in 2 weeks. Animals were taken from the experiment at 5, 14, 21, 30, 45 and 60 hours. We conducted morphometric study of histological exemplars, determining the number of inflammatory cells, epithelial thickness, the area of newformed blood vessels. In the study group we reported an improvement of reparative processes in the wall of the body: it was increased blood supply to the burn surface on 242% and more rapid relief of inflammatory processes on 117% (p < 0.05).

MiR-499 Enhances the Cisplatin Sensitivity of Esophageal Carcinoma Cell Lines by Targeting DNA Polymerase β

BACKGROUND

Human DNA polymerase β (DNA polymerase β, polβ) is a small monomeric protein essential for short-patch base excision repair (BER). It plays an important role in regulating the sensitivity of tumor cells to chemotherapy.

METHODS

Luciferase reporter and western blot assays were used to determine whether polβ is a major target of miR-499. CCK-8, colony-forming survival and in vivo tumor growth assays were conducted to evaluate if miR- 499 can potentially enhance the cisplatin sensitivity and therefore inhibit the proliferation of esophageal cancer (EC) cells. Flow cytometry and immunofluorescence microscopy assays were performed to evaluate whether miR-499 enhance the cisplatin sensitivity and the corresponding apoptosis in EC cells.

RESULTS

polβ was pinpointed as a target gene of miR- 499. Additionally, we identified that miR-499 can enhance cisplatin's function of inhibiting proliferation and of promoting apoptosis in EC9706 and KYSE30 cell lines.

CONCLUSIONS

We first investigated whether miR-499 modulates polβ, and observed the influence of miR-499 up-regulation on the sensitivity of EC cell lines to cisplatin treatment. Our study paves the way for more insightful understanding and application of chemotherapy in esophageal cancer in the future.

P21-activated kinase 7 mediates cisplatin-resistance of esophageal squamous carcinoma cells with Aurora-A overexpression

Aurora-A overexpression is common in various types of cancers and has been shown to be involved in tumorigenesis through different signaling pathways, yet how the deregulation affects cancer therapeutics remains elusive. Here we showed that overexpression of Aurora-A rendered esophageal cancer cells resistance to cisplatin (CDDP) by inhibiting apoptosis. By using an apoptosis array, we identified a downstream gene, p21-activated kinase 7 (PAK7). PAK7 was upregulated by Aurora-A overexpression at both mRNA and protein levels. Importantly, the expression levels of Aurora-A and PAK7 were correlated in ESCC primary samples. Chromatin immunoprecipitation (ChIP) assay revealed that binding of E2F1 to the promoter of PAK7 was significantly enhanced upon Aurora-A activation, and knockdown of transcription factor E2F1 decreased PAK7 expression, suggesting that Aurora-A regulated PAK7 through E2F1. Furthermore, we demonstrated that PAK7 knockdown led to increased apoptosis, and Aurora-A-induced resistance to CDDP was reversed by downregulation of PAK7, suggesting PAK7 was a downstream player of Aurora-A that mediated chemoresistance of ESCC cells to CDDP. Our data suggest that PAK7 may serve as an attractive candidate for therapeutics in ESCC patients with Aurora-A abnormality.

Management of aphonic patients following total laryngectomy and trachea esophageal puncture

BACKGROUND

Trachea esophageal puncture (TEP) is performed following total laryngectomy to allow speech and communication. The most common reason for long-term speech failure in this population is hypertonicity of the constrictor muscle.

OBJECTIVES

To present our experience with the treatment of aphonic patients after total laryngectomy and TEP and suggest a protocol for treatment.

METHODS

Of 50 patients who underwent total laryngectomy and TEP, 6 suffered from aphonia after surgery. All patients underwent radiotherapy with or without chemotherapy. Delay in speech continued for more than 6 months after surgery. The patients received percutaneous lidocaine injection to the neopharynx in different locations around the stoma in order to map the hypertonic segments in the neopharynx.

RESULTS

Lidocaine injection immediately enabled free speech in five patients. One patient (patient 6) suffered from aphonia and from severe dysphagia and required a feeding tube. This patient succeeded to pronounce abbreviations after lidocaine injection. Another (patient 4) gained permanent ability to speak following a single lidocaine injection; this patient was not injected with botolinium toxin (BTX). For the other five, lidocaine had a transient effect on speech. These patients received BTX percutaneous injections. After BTX injections four regained free speech within 14 days. The fifth patient (patient 6) gained a conversational voice and his swallowing improved only after additional intensive speech therapy.

CONCLUSIONS

Percutaneous lidocaine and BTX injections represent first-line treatment in this population, with good success and minimal complications.

Three-layered scaffolds for artificial esophagus using poly(ɛ-caprolactone) nanofibers and silk fibroin: An experimental study in a rat model

The purpose of this study was to determine the feasibility of an artificial esophagus using a three-layered poly(ε-caprolactone) (PCL)-silk fibroin (SF) scaffold in a rat model. The artificial esophagus was a three-layered, hybrid-type prosthesis composed of an outer and inner layer of PCL with a middle layer of SF. After depositing the inner layer of the PCL scaffold by electrospinning, the lyophilized middle SF layer was created. The outer layer of PCL was produced following the same procedure used to make the inner PCL layer. Eleven rats were anesthetized using inhaled anesthesia. Circumferential defects of the cervical esophagus (n=11) were created and reconstructed. Groups of rats were sacrificed after the 1st and 2nd weeks. Three rats died of an esophageal fistula and wound infection. No gross evidence of a fistula, perforation, abscess formation, seroma accumulation, or surrounding soft-tissue necrosis was observed in the other rats sacrificed after the 1st and 2nd weeks. The artificial esophagus constructs produced complete healing of the circumferential defects by the 2nd week. The composition of the three-layered artificial esophagus was confirmed histologically to have an outer and inner layer of PCL and a middle layer of SF. The fusion of the PCL-SF scaffold and the regenerative tissue remained intact. Our study proposes a more practical experimental model for studying a three-layered PCL-SF scaffold in the esophagus. However, further studies on circumferential defect reconstruction in a rat model are still required.

Novel mechanisms and signaling pathways of esophageal ulcer healing: the role of prostaglandin EP2 receptors, cAMP, and pCREB

Clinical studies indicate that prostaglandins of E class (PGEs) may promote healing of tissue injury e.g., gastroduodenal and dermal ulcers. However, the precise roles of PGEs, their E-prostanoid (EP) receptors, signaling pathways including cAMP and cAMP response element-binding protein (CREB), and their relation to VEGF and angiogenesis in the tissue injury healing process remain unknown, forming the rationale for this study. Using an esophageal ulcer model in rats, we demonstrated that esophageal mucosa expresses predominantly EP2 receptors and that esophageal ulceration triggers an increase in expression of the EP2 receptor, activation of CREB (the downstream target of the cAMP signaling), and enhanced VEGF gene expression. Treatment of rats with misoprostol, a PGE1 analog capable of activating EP receptors, enhanced phosphorylation of CREB, stimulated VEGF expression and angiogenesis, and accelerated esophageal ulcer healing. In cultured human esophageal epithelial (HET-1A) cells, misoprostol increased intracellular cAMP levels (by 163-fold), induced phosphorylation of CREB, and stimulated VEGF expression. A cAMP analog (Sp-cAMP) mimicked, whereas an inhibitor of cAMP-dependent protein kinase A (Rp-cAMP) blocked, these effects of misoprostol. These results indicate that the EP2/cAMP/protein kinase A pathway mediates the stimulatory effect of PGEs on angiogenesis essential for tissue injury healing via the induction of CREB activity and VEGF expression.

Protective effect of lactoferrin on acute acid reflux-induced esophageal mucosal damage

BACKGROUND/AIMS

The natural immunomodulator lactoferrin is known to possess anti-inflammatory effects. However, there have been no studies examining the mode of action of lactoferrin in protecting the esophageal mucosa against damage. We investigated the effect of lactoferrin on gastric acid secretion and in protecting against acute acid reflux-induced esophagitis in rats.

METHODOLOGY

Male Wistar rats aged 8 weeks, weighing 210-240 g, were used for all the experiments. A gastric perfusion system was installed using the method of Ghosh et al. Lactoferrin was administered once via the caudate vein, starting 24 hours before an acute acid reflux (treatment mode), or saline (control). Statistical comparison of the parameters between the two test conditions was performed.

RESULTS

No significant differences in basal or stimulated gastric acid secretion, or in the serum gastrin level were observed between the two test conditions. Esophageal damage was attenuated by lactoferrin in a dose-dependent manner, as reflected by the improvement in the esophageal tissue weight and macroscopic scores. Significant reductions in the histological scores, myeloperoxidase activity and the levels of proinflammatory cytokines, tumor necrosis factor-α and interleukin-1β were also observed following lactoferrin administration.

CONCLUSIONS

We concluded that lactoferrin exerts a protective effect against acute acid reflux-induced esophageal damage in rats.

Clinical and endoscopic characteristics of drug-induced esophagitis

AIM: To investigate clinical, endoscopic and pathological characteristics of drug-induced esophagitis.

METHODS: Data for patients diagnosed with drug-induced esophagitis from April 2002 to May 2013 was reviewed. Patients diagnosed with malignancy, viral or fungal esophagitis were excluded. Clinical, endoscopic and pathological characteristics of patients diagnosed with drug-induced esophagitis were analyzed.

RESULTS: Seventy-eight patients were diagnosed with drug-induced esophagitis. Their mean age was 43.9 ± 18.9 years and 35.9% were male. Common symptoms were chest pain (71.8%), odynophagia (38.5%) and dysphagia (29.5%). The endoscopic location was in the middle third of esophagus in 78.2%. Endoscopic findings were ulcer (82.1%), erosion (17.9%), ulcer with bleeding (24.4%), coating with drug material (5.1%), impacted pill fragments (3.8%) and stricture (2.6%). Kissing ulcers were observed in 43.6%. The main causative agents were antibiotics and non-steroidal anti-inflammatory drugs. All the patients were treated with proton pump inhibitors (PPIs) or sucralfate, and the causative drugs were discontinued. Nineteen patients with drug-induced esophagitis were followed up with endoscopy and revealed normal findings, scars or healing ulcers.

CONCLUSION: Drug-induced esophagitis mainly presents as chest pain, odynophagia and dysphagia, and may be successfully treated with PPIs and discontinuation of the causative drug. Kissing ulcers were observed in 43.6%.

Proton pump inhibitor responsive esophageal eosinophilia, a distinct disease entity?

Recent studies have suggested the existence of a patient population with esophageal eosinophilia that responds to proton pump inhibitor therapy. These patients are being referred to as having proton pump inhibitor responsive esophageal eosinophilia (PPI-REE), which is currently classified as a distinct and separate disease entity from both gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE). The therapeutic effect of proton pump inhibitor (PPI) on PPI-REE is thought to act directly at the level of the esophageal mucosa with an anti-inflammatory capacity, and completely independent of gastric acid suppression. The purpose of this manuscript is to review the mechanistic data of the proposed immune modulation/anti-inflammatory role of the PPI at the esophageal mucosa, and the existence of PPI-REE as a distinct disease entity from GERD and EoE.

Proton pump inhibitors decrease eotaxin-3 expression in the proximal esophagus of children with esophageal eosinophilia

Objective

Besides reducing gastric acid secretion, proton pump inhibitors (PPIs) suppress Th2-cytokine-stimulated expression of an eosinophil chemoattractant (eotaxin-3) by esophageal epithelial cells through acid-independent, anti-inflammatory mechanisms. To explore acid-inhibitory and acid-independent, anti-inflammatory PPI effects in reducing esophageal eosinophilia, we studied eotaxin-3 expression by the proximal and distal esophagus of children with esophageal eosinophilia before and after PPI therapy. In vitro, we studied acid and bile salt effects on IL-13-stimulated eotaxin-3 expression by esophageal epithelial cells.

Design

Among 264 children with esophageal eosinophilia seen at a tertiary pediatric hospital from 2008 through 2012, we identified 10 with esophageal biopsies before and after PPI treatment alone. We correlated epithelial cell eotaxin-3 immunostaining with eosinophil numbers in those biopsies. In vitro, we measured eotaxin-3 protein secretion by esophageal squamous cells stimulated with IL-13 and exposed to acid and/or bile salt media, with or without omeprazole.

Results

There was strong correlation between peak eosinophil numbers and peak eotaxin-3-positive epithelial cell numbers in esophageal biopsies. Eotaxin-3 expression decreased significantly with PPIs only in the proximal esophagus. In esophageal cells, exposure to acid-bile salt medium significantly suppressed IL-13-induced eotaxin-3 secretion; omeprazole added to the acid-bile salt medium further suppressed that eotaxin-3 secretion, but not as profoundly as at pH-neutral conditions.

Conclusion

In children with esophageal eosinophilia, PPIs significantly decrease eotaxin-3 expression in the proximal but not the distal esophagus. In esophageal squamous cells, acid and bile salts decrease Th2 cytokine-stimulated eotaxin-3 secretion profoundly, possibly explaining the disparate PPI effects on the proximal and distal esophagus. In the distal esophagus, where acid reflux is greatest, a PPI-induced reduction in acid reflux (an effect that could increase eotaxin-3 secretion induced by Th2 cytokines) might mask the acid-independent, anti-inflammatory PPI effect of decreasing cytokine-stimulated eotaxin-3 secretion.