A novel approach for preventing esophageal stricture formation: sphingosylphosphorylcholine-enhanced tissue remodeling

The Effects of Ellagic Acid on Experimental Corrosive Esophageal Burn Injury

This study aimed to investigate the antioxidant effect of Ellagic acid (EA) on wound healing in sodium hydroxide (NaOH)-induced corrosive esophageal burn injury. The interaction networks and functional annotations were conducted using Cytoscape software. A total of 24 Wistar albino rats were divided into control, corrosive esophageal burn (CEB) and CEB + EA groups. Burn injury was created by 20% NaOH and 30 mg/kg EA was per oral administered to rats. At the end of the 28-day experimental period, Malondialdehyde (MDA) content was measured. Esophageal tissue samples were processed for histological staining. The EA-target interaction network was revealed to be involved in regulating crucial cellular mechanisms for burn wound healing, with epidermal growth factor (EGF) identified as a central mediator. An increase in animal weight in the CEB + EA group was observed in the EA-treated group after CEB injury. Burn injury increased MDA content, but EA treatment decreased its level after CEB injury. Stenosis index, collagen degeneration, inflammation, fibrosis and necrosis levels were increased after CEB injury. EA treatment improved histopathology in the CEB + EA group compared to the CEB group. The expression of EGF was decreased in the CEB group but upregulated in the EA-treated group, suggesting a potential involvement of EA in cellular processes and tissue regeneration. EA, through its antioxidative and tissue regenerative properties, significantly contributes to alleviating the adverse effects of CEB injury, promoting wound healing.

Role of N-acetylcysteine and vitamin B complex in improving outcomes of corrosive ingestion

Background

Corrosive ingestion remains a worldwide public health problem. To date, there are no specific medications with approved efficacy in reducing gastrointestinal injury progression following corrosive ingestion.

Aim

The current study assessed the efficacy of N-acetylcysteine (NAC) and vitamin B complex as adjuvant therapy in improving the outcome of patients with corrosive ingestion.

Subjects and methods

The study included 92 patients with acute corrosive ingestion admitted to Alexandria Poison Center. Patients were distributed into four equal-sized groups and managed as such; Group I received the standard treatment protocol. The other three groups received IV antioxidants in addition to the standard treatment; Group II received NAC, Group III received vitamin B complex, and Group IV received both NAC and vitamin B complex. To assess occurrence of delayed complications, barium swallow and meal were done 21 days after acute corrosive ingestion, and every patient was followed up for one year.

Results

Start of oral intake was earliest among patients in Group II, and as a result, the need for parenteral nutrition decreased significantly with a subsequent decrease in duration of hospitalization. The highest percentage of patients showing normal findings of barium swallow and meal was among the two groups that received NAC (72.7% in Group II and 77.8% in Group IV). Group IV patients who received NAC and vitamin B complex had no esophageal strictures with improved outcomes.

Conclusion

NAC and vitamin B complex enhanced recovery in the acute stage, in addition to prevention of delayed complications, especially esophageal strictures.

Highlights

Acute corrosive ingestion is associated with high morbidity because of its catastrophic presentation and lifelong complications.This study was conducted on 92 patients admitted to Alexandria Poison Center (APC).IV NAC significantly decreased the time needed for starting oral intake after acute corrosive ingestion and consequently, the need for parenteral nutrition and duration of hospitalization.No patients suffered from esophageal strictures in the group which received both IV NAC and vitamin B complex.Both NAC and vitamin B complex improved the outcome of patients after ingestion of corrosives whether acids or alkalis.

Effects of Carvacrol in an Experimentally Induced Esophageal Burn Model: Expression of VEGF and Caspase-3 Proteins

INTRODUCTION

We investigated the therapeutic effects of carvacrol in an experimental esophageal burn rat model with immunohistochemical techniques. Materials and Methods: Three groups were included in this study, composed of eight Wistar albino rats each. The control group was given 1 mL 0.9% (wt/vol) NaCl; esophageal burns were induced in groups 2 and 3 by administration of 1 mL 40% NaOH in the distal 2 cm of the esophagus. The treatment group was administered 75 mg/kg carvacrol in 2 mL 0.9% NaCl for 10 days. After a routine histological examination of the tissues, sections were stained with vascular endothelial growth factor (VEGF) and caspase-3 for immunohistochemical analysis and were examined under a light microscope. Results: In the control group, there were regular cells in the cornified epithelial tissue and cylindrical cells in the basal layer, which faced toward the apical surface in the mitotic phase. The burn group displayed wide degeneration, necrosis, and abundant apoptotic cells in the epithelial tissue as well as intense inflammatory cell infiltration. In the treatment group, there was an increase in mitotic activity in the basal cells of the epithelial layer and degenerative changes, but a preserved epithelial layer and significant cornified structures. The treatment group showed positive caspase-3 expression in some apoptotic cells within the epithelial layer and in connective tissue, and there were only a small number of degenerated cells in the muscle layer. Additionally, in the treatment group, VEGF expression was evident in small numbers of inflammatory cells in the papillary region of the epithelium, and in dilated vascular endothelial cells. Conclusions: Carvacrol may contribute to a reduction in fibrosis by decreasing inflammation and preventing cell apoptosis.

Caustic ingestion in children-A review

Various domestic or industrial chemicals may cause significant upper aerodigestive tract burns. Preventive measures should be up-scaled, especially in the developing world, to reduce the epidemic of accidental victims, largely unsupervised preschool children. External signs do not predict degree of injury. Non-invasive diagnostic screening includes radio-nuclear imaging, but early oesophago-gastroduodenoscopy remains the standard to predict stricture formation from circumferential submucosal scarring. Serial dilation is the mainstay of oesophageal stricture therapy, with oesophageal replacement reserved for severe refractory strictures. Intra-lesional steroid or mitomycin C may decrease the dilatations required for severe strictures, although long-term effects are unknown. Risk of secondary oesophageal carcinoma mandates long-term surveillance.

Antioxidant and renoprotective effects of sphingosylphosphorylcholine on contrast-induced nephropathy in rats

Contrast induced nephropathy (CIN) is a major cause of morbidity, and increased costs as well as an increased risk of death. This study was evaluated effects of exogenous sphingosylphosphorylcholine (SPC) administration on CIN in rats. Eight animals were included in each of the following eight groups: control, control phosphate-buffered solution (PBS), control SPC 2, control SPC 10, CIN, CIN PBS, CIN SPC 2 and CIN SPC 10. The induced nephropathy was created by injected with 4 g iodine/kg body weight. SPC was administered 3 d at a daily two different doses of 2 μm/mL and 10 μm/mL intraperitoneally. The severity of renal injury score was determined by the histological and immunohistochemical changes in the kidney. Malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) were determined to evaluate the oxidative status in the renal tissue. Treatment with 2 and 10 μM SPC inhibited the increase in renal MDA, NO levels significantly and also attenuated the depletion of SOD in the renal injuryCIN. These data were supported by histopathological findings. The inducible nitric oxide synthase positive cells and apoptotic cells in the renal tissue were observed to be reduced with the 2 and 10 μM SPC treatment. These findings suggested that 2 and 10 μM doses can attenuate renal damage in contrast nephropathy by prevention of oxidative stress and apoptosis. The low and high dose SPC may be a promising new therapeutic agent for CIN.

A corrosive oesophageal burn model in rats: Double-lumen central venous catheter usage

BACKGROUND

We aimed to create a new and less invasive experimental corrosive oesophageal burn model using a catheter without a gastric puncture (gastrotomy).

MATERIALS AND METHODS

We conducted the study with two groups composed of 8 male rats. The experimental oesophageal burn was established by the application of 10% sodium hydroxide to the distal oesophagus under a pressure of 20 cmH 2 O, via 5-F double-lumen central venous catheter without a gastrotomy. The control group was given 0.9% sodium chloride. All rats were killed 24 h after administration of NaOH or 0.9% NaCl. Histologic damage to oesophageal tissue was scored by a single pathologist blind to groups.

RESULTS

The rats in the control group were observed to have no pathological changes. Corrosive oesophagitis (tissue congestion, oedema, inflammation, ulcer and necrosis) was observed in rats exposed to NaOH.

CONCLUSION

We believe that an experimental corrosive oesophageal burn can safely be created under same hydrostatic pressure without a gastric puncture using this model.

Effects of sphingosylphosphorylcholine against oxidative stress and acute lung ınjury ınduced by pulmonary contusion in rats

BACKGROUND/PURPOSE

The goal of this study was to evaluate effects of exogenous sphingosylphosphorylcholine (SPC) administration on acute lung injury induced by pulmonary contusion in rats.

METHODS

Eight animals were included in each of the following five groups: control, contusion, contusion phosphate-buffered solution (PBS), contusion SPC 2, contusion SPC 10. SPC was administered 3 days at a daily two different doses of 2 μm/ml and 10 μm/ml intraperitoneally. The severity of lung injury was determined by the neutrophil activation and histological and immunohistochemical changes in the lung. Malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH) were determined to evaluate the oxidative status in the lung tissue.

RESULTS

Treatment with 2 μM SPC inhibited the increase in lung MDA and NO levels significantly and also attenuated the depletion of SOD, GPx, and GSH in the lung injury induced by pulmonary contusion. These data were supported by histopathological findings. The inducible nitric oxide synthase (iNOS) positive cells and apoptotic cells in the lung tissue were observed to be reduced with the 2 μM SPC treatment. But, the 10 μM SPC treatment did not provide similar effects.

CONCLUSIONS

In conclusion, these findings suggested that 2 μM SPC can attenuate lung damage in pulmonary contusion by prevention of oxidative stress, inflammatory process and apoptosis. All these findings suggest that low dose SPC may be a promising new therapeutic agent for acute lung injury.

Effects of tenoxicam in experimental corrosive esophagitis model

Esophageal stricture, one of the important complications of corrosive esophagus, develops following edema and granulation tissue that forms during and after the inflammatory reactions. Tenoxicam, a non-steroid anti-inflammatory drug with a long half-life, prevents various leukocyte functions including phagocyte and histamine secretion by inhibiting prostaglandin synthesis and removes various oxygen radicals in the region of inflammation. We designed this as a histopathological study using tenoxicam in rats for which we created a corrosive esophagus model. After necessary authorizations were obtained, the study was performed in Çanakkale 18 Mart University experimental animal laboratory. Twenty-four Wistar albino rats, weighing 220-240 g, were used for the experiment. Experimental animals were randomized into three groups: tenoxicam group (group T, n:8), control group (group C, n:8), and sham group (group S, n:8). Tenoxicam 0.5 mg/kg/day was administered to animals in group T, where esophageal burn was developed experimentally, 5 mg/kg 0.9% NaCL was administered i.p. to rats in group C for 15 days, once in 24 hours. No procedure was applied to rats in group S. After 15 days, all animals were sacrificed under general anesthesia and their esophagi were extracted. As a result of histopathological evaluation, inflammation and fibroblast proliferation was not observed in rats in the sham group (group S). Intense inflammation was observed in six rats (6+/2-) in the control group, and fibroblast proliferation was observed as 5+/3-. And in treatment groups, inflammation was evaluated as 3+/5-, and fibroblast proliferation as 3+/5-. In our study, histopathologic damage score was higher in the control group (P < 0.005). We deduce that tenoxicam can be useful in the treatment of caustic esophageal injuries in the acute phase, but think that these drugs require further researches and clinical studies before routine clinical use.

The efficacy of mesenchymal stem cell transplantation in caustic esophagus injury: an experimental study

Introduction. Ingestion of corrosive substances may lead to stricture formation in esophagus as a late complication. Full thickness injury seems to exterminate tissue stem cells of esophagus. Mesenchymal stem cells (MSCs) can differentiate into specific cell lineages and have the capacity of homing in sites of injury. Aim and Methods. We aimed to investigate the efficacy of MSC transplantation, on prevention of esophageal damage and stricture formation after caustic esophagus injury in rats. 54 rats were allocated into four groups; 4 rats were sacrificed for MSC production. Group 1, untreated controls (n: 10). Group 2, membrane labeled MSCs-treated rats (n: 20). Group 3, biodistribution of fluorodeoxyglucose labeled MSCs via positron emission tomography (PET) imaging (n: 10). Group 4, sham operated (n: 10). Standard caustic esophageal burns were created and MSCs were transplanted 24 hours after. All rats were sacrificed at the 21st days. Results. PET scan images revealed the homing behavior of MSCs to the injury site. The histopathology damage score was not significantly different from controls. However, we demonstrated Dil labeled epithelial and muscle cells which were originating from transplanted MSCs. Conclusion. MSC transplantation after caustic esophageal injury may be a helpful treatment modality; however, probably repeated infusions are needed.

The use of collagen content as determined by spectral domain polarization-sensitive optical coherence tomography to assess colon anastomosis healing in a rat model

BACKGROUND/PURPOSE

Many studies have been undertaken to prevent anastomosis leakage of the colon, and several methods have been used to assess anastomosis healing, such as measurement of bursting pressure or hydroxyproline (a marker of collagen) content at the anastomosis site. However, these methods are inappropriate for comparing anastomosis healing at two time points in the same animals. In the present study, we measured the collagen level by spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) to assess anastomosis healing.

METHODS

Sprague-Dawley rats were divided into groups C (saline-administered controls; study group) and M [a 5-fluorouracil (5-FU)-administered experimental group]. Immediately after end-to-end anastomosis of the colon, SD-PS-OCT images of anastomoses were taken (baseline). Animals were administered saline or 5-FU for 7 days. On the 7th postoperative day, SD-PS-OCT images were acquired, a histopathologic exam was performed, and hydroxyproline levels as well as mRNA expressions of collagen-1 and collagen-3 were measured at the anastomosis site.

RESULTS

Fibroblast proliferation and inflammatory cell infiltration were greater in group C than in group M. The mRNA expressions of collagen-1 and collagen-3 were substantially higher in group C. Hydroxyproline levels were higher in group M than in group C. Though collagen levels measured by SD-PS-OCT at 7 days were elevated compared with baseline in group C, no such changes were observed for group M.

CONCLUSION

Collagen levels at the colon anastomosis site, measured with SD-PS-OCT, were not increased at 7 days postoperatively versus baseline when 5-FU was injected, but were increased in saline-treated controls. The measurement of collagen content by SD-PS-OCT was found to provide a good means of assessing anastomosis healing, because it allows in situ assessment of collagen contents at baseline and during the postoperative period.

Comparison of mitomycin-c and heparin affects in experimental corrosive esophagitis on rats

OBJECTIVE

We comparative effects of mitomycin-c and heparin which have different mechanism of action in a minimal invasive corrosive esophagitis model which was formed by NaOH 40%.

METHOD

The study was performed on forty female Wistar albino rats; were divided into four equal groups each including ten animals. Group C (n=10); control, the group that esophagus was washed with normal saline, group I (n=10); injury group; alkali esophagus burn, not treated, group M (n=10); alkali esophagus burn, mitomycin-c treatment group, group H (n=10); alkali esophagus burn, heparin treatment group. The study was performed on a minimal invasive model which did not require general anesthesia and abdominal operation. In 28 day, all subjects were killed and their esophagus's were removed by thoraco-abdominal cut. Total esophagi from oropharynx to stomach were removed and they were examined macroscopically and microscopically and evaluated for esophageal tissue collagen deposition and histopathologic damage score.

RESULTS

When group C is compared with each of the other groups, statistically significant weight losses were detected; [(p<0.005, p<0.05, p<0.005), respectively]. Significant inflammation increase was detected in groups I, M and H in comparison to group C [(p<0.001, p<0, 0001, p<0.005)]. When granulation scores of groups were compared; statistically significant granulation increases were detected in groups I, M, and H [(p<0.05, p<0.05, p<0.05) compared to group C]. Significant collagen increase was detected in all 3 layers in groups; I, M and H according to group C [(p<0.05, p<0.05, p<0.05)]. Collagen increase in every 3 layers in groups M and H were significantly less according to group I [(p<0.05, p<0.05, p<0.05)]. Collagen increase in every 3 layers was less in group M than group H (p<0.05).

CONCLUSION

In corrosive esophagitis due to NaOH, heparin treatment is more effective in inflammation and granulation formation, mitomycin-c treatment is more effective in preventing the collagen accumulation step. Heparin decreases the tissue damage by preventing the inflammation and granulation formation; and prevents collagen accumulation and stricture development. As completing the effect of heparin; mitomycin prevents fibroblastic activity inhibition with direct collagen accumulation and stricture development strongly.

Topical mithramycin-A modulates submucosal collagen deposition after esophageal burn injury in rats

OBJECTIVE

To evaluate efficacy of a drug-eluting, dissolvable esophageal (DEDE) stent for the prevention of submucosal collagen deposition in a rat model of acute esophageal injury.

SETTING

University laboratory.

STUDY DESIGN

Interventional randomized controlled trial.

SUBJECTS AND METHODS

Forty two adult, male, age-matched Sprague Dawley rats were randomized to undergo either sham esophageal surgery, esophageal burn injury, or esophageal burn injury and placement of a DEDE stent. All animals underwent open gastrotomy under anesthesia. In group 1, a cautery device was inserted through the gastrotomy into the distal esophagus and removed without creating an injury. In group 2, the cautery was placed in the distal esophagus and a circumferential thermal burn injury was created. In group 3, an identical burn injury was created and a DEDE stent was placed at the site of injury and secured. On postoperative day 28, animals were sacrificed, and the distal esophagi were harvested and processed for histology. Submucosal collagen area was quantified histologically and compared across the 3 experimental groups.

RESULTS

After the investigators controlled for luminal circumference and multiple measurements, submucosal collagen area was increased in group 2 (burn) compared with group 1 (sham) (P = .012). Submucosal collagen area was decreased in group 3 (DEDE stent) compared with group 2 (P = .042). No statistically significant difference in submucosal collagen area was observed between animals in group 1 and group 3 (P = .800). CONCLUSIONS;Topical application of mithramycin-A via a DEDE stent modulates collagen deposition after acute thermal injury in the rat esophagus.

The protective effect of erythropoietin on the acute phase of corrosive esophageal burns in a rat model

INTRODUCTION

An experimental study was conducted to investigate the effects of erythropoietin on the acute phase of esophageal burn damage induced by sodium hydroxide.

MATERIALS AND METHODS

A standard esophageal alkaline burn was produced by the application of 10% sodium hydroxide to the distal esophagus in an in vivo rat model. Fifty-six female rats were allocated into three groups: Group BC (baseline control, n = 8) rats were uninjured and untreated, Group PC (positive control, n = 24) rats were injured but untreated and Group EPO (erythropoietin-treated, n = 24) rats were injured and given subcutaneous erythropoietin (1,000 IU/kg per day), 15 min, 24, and 48 h after administration of the NaOH solution. Six animals from Group PC and six from Group EPO were killed at 4, 24, 48, and 72 h after application of NaOH to the esophagus. All of animals in Group BC were killed 4 h after exposure to 0.9% NaCl. Oxidative damage was assessed by measuring levels of malondialdehyde (MDA) and nitric oxide (NO), and activities of superoxide dismutase (SOD) and catalase (CAT) in homogenized samples of esophageal tissue. Histologic damage to esophageal tissue was scored by a single pathologist blind to groups.

RESULTS

MDA levels in the BC and EPO groups were significantly lower than those in the PC group (p < 0.05). CAT and SOD activities, and NO levels in the BC and EPO groups were significantly higher than in the PC group (p < 0.05). Esophageal tissue damage measured at 4, 24, 48, and 72 h after NaOH application was significantly less in the EPO group than in the PC group (p < 0.05).

CONCLUSIONS

When administered early after an esophageal burn induced by 10% sodium hydroxide in this rat model, erythropoietin significantly attenuated oxidative damage, as measured by biochemical markers and histologic scoring.

Effects of sphingosylphosphorylcholine against cholestatic oxidative stress and liver damage in the common bile duct ligated rats

The goal of this study was to evaluate the possible protective effects of sphingosylphosphorylcholine (SPC) against cholestatic oxidative stress and liver damage in the common bile duct ligated rats. Fifty-six animals were included in each of the following 7 groups: control, SPC control, phosphate-buffered solution control, sham operated, bile duct ligation (BDL), BDL plus phosphate-buffered solution, and BDL plus SPC. Sphingosylphosphorylcholine was administered 14 days at a daily dose of 2 microm/mL intraperitoneally. The severity of cholestasis and hepatic injury was determined by changes in the plasma enzyme activities of aspartate aminotransferase, alanine aminotransferase, gama glutamin transferase, and levels of total bilirubin and direct bilirubin. Malondialdehyde, nitric oxide, and superoxide dismutase were determined to evaluate the oxidative status in the liver tissue. Myeloperoxidase activity and levels of tissue hydroxyproline were determined to assess neutrophil activation and collagen accumulation, respectively. Treatment with SPC markedly reduced serum transaminase activities as compared to BDL rats. Sphingosylphosphorylcholine also inhibited the increase in liver malondialdehyde; nitric oxide levels significantly and also attenuated the depletion of superoxide dismutase in the liver after BDL. Similarly, the increase in tissue myeloperoxidase activity and hydroxyproline owing to BDL was also attenuated by the SPC treatment. These data were supported by histopathologic findings. The alpha-smooth muscle actin-positive cells in the BDL were observed to be reduced with the SPC treatment. In conclusion, these findings suggested that SPC can attenuate hepatic damage in extrahepatic cholestasis by prevention of oxidative stress, and inflammatory process. All these findings suggest that SPC may be a promising new therapeutic agent for cholestatic liver injury.

A new imaging modality in detection of caustic oesophageal injury: Technetium-99m pyrophosphate scintigraphy

OBJECTIVES

Early oesophagoscopy is usually recommended in children after caustic ingestion to assess the severity of the initial digestive lesions. An oesophagoscopic procedure in children always demands to be performed under sedation and bears a certain risk of iatrogenic injury. The purpose of the study is to determine the value and sensitivity of Tc-99m pyrophosphate (99mTc-PYP) scintigraphy for the detection of caustic oesophageal injury.

METHODS

The caustic oesophageal burns were created with 25% NaOH in an experimental rat model. Seventeen rats were divided into two groups. The BURN group (n=9) included caustic oesophageal burning rats. Non-BURN group (n=8) included sham-operated rats. All animals underwent 99mTc-PYP scintigraphy 72 h after the burning experiment. Anterior static and single-photon emission computed tomography images were obtained using a low-energy all-purpose collimator, 2.55 zoom factor, 3h after intravenous injection of 10 mCi 99mTc-PYP. After the imaging, all the oesophagi were explored for external determination of the injury sites and macroautoradiographic scintigraphy as well. Rectangular region of interest were placed in the visually determined lesion of oesophagus (O) as well as non-lesion area (N), and an ON ratio was created. The severity and extension of oesophageal burn were assessed 3 days after burning by histopathologic evaluation. The injuries were graded according to the ulcer depth, ulcer width, thrombus formation, and the development of perivascular fibrinoid necrosis.

RESULTS

The oesophageal burning areas were demonstrated by visual evaluation of the Tc-99m PYP scintigraphy on all animals. The mean ON ratio of 99mTc-PYP was 21.61+/-7.01 in the BURN group and in the non-BURN group, was 2.25+/-0.24 (p<0.001). The best cut-off point of the ON ratio for caustic oesophageal injury was 5.45, with sensitivity and specificity of 100%. PYP scan findings were also confirmed by histological evidence of ulcer depth, ulcer width, thrombus formation, and perivascular fibrinoid necrosis in the same areas.

CONCLUSIONS

The caustic oesophageal injuries have been demonstrated by 99mTc-PYP scintigraphy in burning experiment. 99mTc-PYP scintigraphy is sensitive for detection of caustic oesophageal injury. This new imaging tool is found to be sensitive and specific for the detection of caustic oesophageal injury in the rats.

Responses of the murine esophageal microcirculation to acute exposure to alkali, acid, or hypochlorite

BACKGROUND/PURPOSE

Although ingestion of alkali-based and/or hypochlorite-based household cleaners as well as strong acids remains a major cause of esophageal wall injury, little is known about the mechanisms that underlie the injury response to these toxic agents. This study examined the roles of vascular dysfunction and inflammation to the esophageal injury response to different caustic substances in mice.

METHODS

The esophageal responses to sodium hydroxide (10%, 5%, and 2.5%), potassium hydroxide (10%, 5%, and 2.5%), sodium hypochlorite (5.25%), and hydrochloric acid (10%, pH 2) were evaluated by intravital videomicroscopy and histopathology. Intravital microscopy was used to monitor changes in the diameter of arterioles and venules, the adhesion and movement of leukocytes in venules, and the time of cessation of arteriolar blood flow in mouse esophagus. The esophageal mucosa was exposed to caustic substances for 0 to 60 minutes before evaluation.

RESULTS

The higher concentrations of sodium hydroxide and potassium hydroxide elicited rapid stasis in both arterioles and venules, which was accompanied by arteriolar constriction and thrombosis. An accumulation of adherent leukocytes in venules was not observed with any agent. Histopathological evaluation revealed marked cellular and interstitial edema in the mucosa with alkali, whereas hydrochloric acid and sodium hypochlorite decreased the thickness epithelial layer.

CONCLUSION

These findings suggest that ischemia and thrombosis are dominant processes, whereas inflammation is less important in the pathogenesis of acute corrosive injury to the esophageal mucosa.

Effect of 3-amino benzamide, a poly(adenosine diphosphate-ribose) polymerase inhibitor, in experimental caustic esophageal burn

INTRODUCTION

The enzyme poly(adenosine diphosphate-ribose) polymerase affects the repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. This study was designed to investigate the efficacy of 3-amino benzamide (3-AB), a poly(adenosine diphosphate-ribose) polymerase inhibitor, on the prevention of esophageal damage and stricture-formation development after esophageal caustic injuries in rat.

MATERIALS AND METHODS

Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH to the distal esophagus. The rats were left untreated or treated with 3-AB 10 mg/kg per day intraperitoneally. All rats were killed on the 28th day. Efficacy of the treatment was assessed by measuring the stenosis index and histopathologic damage score and biochemically by determining tissue hydroxyproline content, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and protein carbonyl content (PCC) in esophageal homogenates.

RESULTS

Treatment with 3-AB decreased the stenosis index and histopathologic damage score seen in caustic esophageal burn rats. Hydroxyproline level was significantly higher in the untreated group as compared with the group treated with 3-AB. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. On the contrary, 3-AB treatment decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities.

CONCLUSION

3-Amino benzamide has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophagitis in rats.

The effects of local and sustained release of fibroblast growth factor on wound healing in esophageal anastomoses

BACKGROUND/PURPOSE

Postsurgical complications, such as anastomotic leaks in patients with esophageal atresia, have remained unchanged during the last 3 decades. Growth factors enhance healing in several wound-healing models. Therefore, an experimental study was used to evaluate the effects of local and sustained release of basic fibroblast growth factor (FGF) on wound healing in esophageal anastomoses.

MATERIALS AND METHODS

Twenty-four male Wistar albino rats, which were subjected to a 1-cm segmental resection of the abdominal esophagus followed by end-to-end anastomosis, were allocated into 3 groups. Group I, the control group, had no gelatin film applied to the anastomosis. In group II (gelatin film without FGF) and group III (gelatin film with FGF), anastomoses were covered with unloaded and 2.55 mug FGF-loaded gelatin films, respectively. On postoperative day 7, bursting pressures, histopathologic collagen deposition, and tissue hydroxyproline concentrations of the anastomoses were then analyzed and compared.

RESULTS

Mean bursting pressures, mean submucosal and muscular collagen deposition scores, and mean tissue hydroxyproline concentrations differed significantly between groups. Mean bursting pressures were 22.5 +/- 3.1 mm Hg in group I, 29 +/- 1.6 mm Hg in group II, and 63.2 +/- 6.8 mm Hg in group III (P < .001). Mean submucosal collagen deposition scores (group I: 0.7 +/- 0.2, group II: 0.7 +/- 0.1, group III: 1.5 +/- 0.2; P = .02) and mean muscular collagen deposition scores (group I: 0.8 +/- 0.2, group II: 0.8 +/- 0.1, group III: 1.8 +/- 0.1; P = .01) were significantly higher in FGF animals than the other in the other 2 groups. Mean tissue hydroxyproline concentrations were 2.4 +/- 0.5 microg/mg in group I, 3.9 +/- 0.4 microg/mg in group II, and 6.0 +/- 1.0 microg/mg in group III (P = .007).

CONCLUSION

Local and sustained release of FGF enhanced wound healing in esophageal anastomoses in this animal model.