Management of acute appendicitis in pediatric patients with acute leukemia: Insights from a single-center study.

Acute appendicitis (AA) in pediatric patients with acute leukemia mandates prompt treatment. Diagnosis presents challenges, relying on clinical and radiological assessments, often leading to treatment delays that may disrupt leukemia management. Our study on 14 such cases underscores the pivotal role of swift intervention. While conservative AA treatment may pose no risk to healthy children, our findings mandate the performance of laparoscopic appendectomy within 24 hours of diagnosis. This strategy yielded successful surgical outcomes while ensuring uninterrupted leukemia care. Our experience contributes important insights to the limited understanding of navigating this complex clinical scenario.

Management of Blunt Pancreatic Trauma in Children: A Persistent Controversy-Case Report and Comprehensive Literature Review.

Blunt pancreatic injury (BPI) is relatively uncommon in children, and is associated with relatively high morbidity and mortality, especially if diagnosis is delayed. The aim of this report is to review the literature regarding controversial questions in the early diagnosis and management of pediatric BPI. A representative case of blunt pancreatic trauma in a six-year-old girl with delayed diagnosis and intraoperative and postoperative complications was described. A systematic search of databases and the grey literature in Scopus and Web of Science using relevant keywords was conducted. A total of 26 relevant articles published in last 5 years were found in PubMed. Although early CT performance is considered part of initial pancreatic trauma workup, the sensitivity of CT for detecting main pancreatic duct injuries in children is relatively low. MRCP and ERCP (if available) are useful for assessing ductal injury and should be performed when the status of the pancreatic duct is unclear on the CT. Most patients with low-grade pancreatic damage may be treated conservatively. Although surgery involving distal pancreatectomy remains the preferred approach for most children with high-grade pancreatic injury, there is growing evidence to suggest that non-operative management (NOM) is safe and effective. Most pancreatic pseudo cysts following NOM had relatively mild complications, and most resolved spontaneously. For those children who do require surgery, a conservative operative approach with the least risk is advocated. In conclusion, the optimal management for pediatric pancreatic trauma is controversial. Further clinical trials are required to generate clinical practice guidelines on pancreatic trauma in a child population.

Age as an Exclusion Criterion for Nonoperative Management in Simple Acute Appendicitis in Children.

OBJECTIVE: Nonoperative management (NOM) for simple acute appendicitis (SAA) is an acceptable mode of treatment in healthy children. Previous studies of NOM routinely excluded young children (< 5 years); however, the effect of age on NOM failure has not been directly assessed. Efficiency of NOM in young adults is questionable. Therefore, adolescents may also be at greater risk of NOM failure. Our aim was to investigate the effect of age on NOM failure. METHODS: This is a retrospective analysis of children with SAA who received NOM between January 1, 2019, and June 30, 2021, at our institution. NOM failure was defined by subsequent appendectomy. Age was assessed as a continuous variable, and we also compared different age subgroups. RESULTS: In this study, 151 children were included (60% male), mean age 11.2 ± 3.2 years (range: 5-17). Overall, 66 children (44%) failed NOM, 90% of them within the first year (median 7 weeks). Ten percent of the cohort were younger than 6 years of age and 33% of them failed NOM (p = 0.39). Per 1 year increase in age, the odds of NOM failure increased by 12% (p = 0.027). Children over 14 years of age had 2.46 times higher odds to fail NOM (p = 0.03). These higher odds remained after adjusting for appendiceal diameter and appendicolith. Linear regression showed a decrease by a factor of 12 at the time of NOM failure with every 1-year increase in age (ß = -12, p = 0.09). CONCLUSION: The risk of NOM failure in children increases with age; therefore, age should be considered when deciding on the optimal management of SAA, especially in adolescents. Effectiveness of NOM in children younger than 6 years is noninferior to older children and therefore should not be excluded.

The mechanism of intestinal stem cells differentiation after ischemia-reperfusion injury in a rat model.

PURPOSE: Notch and Wnt/ß-catenin signaling are responsible for regulation of intestinal stem cells (ISCs) proliferation and differentiation. The purpose of the study was to evaluate Wnt/ß-catenin and Notch signaling roles in regulation of ISC differentiation following ischemia-reperfusion (IR) injury in a rat. METHODS: Rats were assigned into two groups: Sham rats underwent laparotomy without vascular intervention and IR rats underwent occlusion of SMA and portal vein for 20 min followed by 48 h of reperfusion. Wnt/ß-catenin and Notch-related gene expression were determined using Real-Time PCR. Enterocyte proliferation, differentiation and Wnt-related proteins were determined by immunohistochemistry. RESULTS: IR rats demonstrated a significant decrease in ß-catenin gene expression, a decrease in cyclin D1 and ß-catenin positive cells in jejunum and ileum compared to Sham rats. IR rats demonstrated a significant increase in Notch-related gene expression in jejunum and ileum compared to Sham rats. The number of secretory cells was higher mainly in the jejunum and number of absorptive cells was significantly lower in jejunum and lower in ileum in IR rats compared to Sham rats. CONCLUSIONS: Intestinal stem-cell differentiation is toward secretory cells 48 h after IR injury; however, Wnt/ß-catenin pathway inhibition and Notch-related gene expression stimulation suggest crosstalk between pathways.

Impact of Dietary Protein on the Management of Pediatric Short Bowel Syndrome.

Essential amino acids (AAs) play a key role in stimulating intestinal adaptation after massive small gut resection. The nutritional effect of dietary amino acids during intestinal regrowth has received considerable attention in recent years. This review explores the significance of dietary amino acids in the nutritional management of infants and children with intestinal failure and short bowel syndrome (SBS) as reported in the medical literature over the last three decades. A literature search was conducted using electronic databases. Breast milk emerged as the first-line enteral regimen recommended for infants with SBS. Hydrolyzed formulas (HFs) or amino acid formulas (AAFs) are recommended when breast milk is not available or if the infant cannot tolerate whole protein milk. The superiority of AAFs over HFs has never been demonstrated. Although glutamine (GLN) is the main fuel for enterocytes, GLN supplementation in infants with SBS showed no difference in the child's dependence upon parenteral nutrition (PN). Circulating citrulline is considered a major determinant of survival and nutritional prognosis of SBS patients. Early enteral nutrition and dietary supplementation of AAs following bowel resection in children are essential for the development of intestinal adaptation, thereby eliminating the need for PN.

Upper gastrointestinal series in healthy neonates with bilious vomiting-is it still obvious? A retrospective observational study.

AIM: Demand for upper gastrointestinal contrast series (UGI) to investigate bilious vomiting (BV) has increased in recent years, mostly due to greater awareness of the need to rule out malrotation and midgut volvulus (MGV). We aimed to examine predictive value of clinical parameters in the management of healthy neonates presenting with BV and re-assess the role of UGI in their management. METHODS: A retrospective cohort study including medical, imaging and surgical data of neonates who underwent UGI due to BV. RESULTS: A total of 157 term neonates, eight neonates (5.1%) had confirmed surgical diagnosis of malrotation, five of them had malrotation with MGV, including two neonates who underwent extensive intestinal resection due to necrosis. Neonates with a combination of abnormal plain radiograph and abdominal distention had 10 times higher odds of malrotation diagnosis, adjusting for age at first BV (p = 0.017). Neonates with a combination of abnormal plain radiograph, abdominal distention and abdominal tenderness had 25 times higher odds of MGV (p = 0.002). CONCLUSION: This study reaffirms the role of UGI as the current main diagnostic tool for malrotation and MGV. Physical examination and plain radiograph findings can help but cannot substitute UGI study.

The effect of hepatocyte growth factor on intestinal adaption in an experimental model of short bowel syndrome.

PURPOSE: Nowadays, the standard therapy for patients with short bowel syndrome is parenteral nutrition (PN). Various growth factors have been tested to achieve weaning from prolonged PN administration. We evaluated the effect of hepatocyte growth factor (HGF) on structural intestinal adaptation and cell proliferation in a rat model of SBS. METHODS: Thirty Sprague-Dawley rats were divided into three groups; group A rats (sham) underwent bowel transection, group B rats underwent a 75% bowel resection, and group C rats underwent the same procedure but were treated postoperatively with HGF. Histopathologic parameters of intestinal adaptation were determined, while microarray and rt-PCR analyses of ileal RNA were also performed. RESULTS: Treatment with HGF resulted in significant increase in body weight, while the jejunal and ileal villus height and crypt depth were increased in HGF rats (36%, p < 0.05 and 27%, p < 0.05 respectively). Enterocyte proliferation was also significantly increased in HGF rats (21% p < 0.05). Microarray and quantitative rt-PCR analyses showed that the genes hgfac, rac 1, cdc42, and akt 1 were more than twofold up-regulated after HGF treatment. CONCLUSION: HGF emerges as a growth factor that enhances intestinal adaptation. The future use of HGF may potentially reduce the requirement for PN in SBS patients.

The role of gastrostomy feeding during intestinal rehabilitation for children with short bowel syndrome.

PURPOSE: Following extensive bowel resection, many children with short bowel syndrome (SBS) are routinely offered a placement of gastrostomy tube (G-tube) for feeding. This nutritional pathway is aimed to accommodate the gastric and small bowel motor disturbances related to SBS, and to promote weaning off parenteral nutrition (PN) to achieve enteral autonomy (EA). The aim of this study was to investigate the effect of gastrostomy feeding in outcomes of children with SBS. METHODS: A retrospective cohort of all SBS children managed at our multidisciplinary Intestinal Rehabilitation Center as part of an Intestinal Rehabilitation Program. SBS was defined as PN dependence for more than six weeks following extensive bowel resection. Patients treated with G-tube feeding were compared with patients without G-tube in terms of PN duration, reaching EA, physical development, and surgical parameters. RESULTS: A total of 36 SBS patients diagnosed between 2003 and 2022 were included. The most common etiologies included congenital intestinal atresia (31%) and necrotizing enterocolitis (25%). SBS-G-tube (group A) contained 20 children, and SBS (group B) contained 16 children. A total of 21 children reached EA (58%); ten from group A (50%), and 11 from group B (69%) (p > 0.05). Within EA patients, mean PN duration was 49 ± 44 months in group A, and 24 ± 33 months in group B (p > 0.05). Patients who reached EA had 22% longer residual small bowel when compared with PN-dependent patients (p = 0.003). However, the outcomes were adjusted for residual small and large bowel length and percentages, a residual ileocecal valve, and a colon in continuity with no differences between the groups. Two-thirds of children from group A reported G-tube related complications (mechanical, bleeding, or infections). We did not find differences in mean height and weight percentiles between the groups (p > 0.05). CONCLUSION: We did not find significant advantage of gastrostomy feeding in reaching EA. Because there are surgical and mechanical complications related to this procedure, further prospective studies are required to determine G-tube relevance for children with SBS.

Transanal ileal pouch anal anastomosis for ulcerative colitis in children and adults: a systematic review and meta-analysis.

PURPOSE: The incidence of pediatric onset ulcerative colitis (UC) is increasing, with increasing rate of children eventually requiring surgical treatment. Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the preferred surgical treatment. Although transanal IPAA (ta-IPAA) is becoming widely accepted for adult UC patients, data regarding this procedure in children are scarce. Nevertheless, some adult publications also include patients under 18 years old. This systematic review and meta-analysis aimed to summarize surgical and functional outcomes following ta-IPAA, and extract conclusion regarding pediatric UC patients. METHODS: PubMed, Cochrane Library databases, Embase, Web of science and Google Scholar databases were searched, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses [PRISMA] guidelines. The final search was updated in April 2022. Four comparative cohorts (n = 868) and 11 non-comparative case series (n = 241) were included. Six reports included children. Anastomotic leak, complications, operative time, conversion rate, length of stay and functional outcomes were examined. RESULTS: A total of 1103 patients, ranging 9-79 years were included in this review. We found no difference in risk for anastomotic leak (OR 1.36, 95% CI 0.46-4.06), minor and major complications (OR 0.92, 95% CI 0.48-1.76 and OR 0.78 95% CI 0.36-1.69, respectively) comparing ta-IPAA to transabdominal IPAA. Short- and long-term follow-up showed satisfying functional outcomes and quality of life. CONCLUSIONS: Our review suggests that ta-IPAA is not inferior to transabdominal IPAA. Implementation of this method in children is technically feasible due to familiarity with the dissection plane. Long-term functional outcomes and quality of life are paramount in the pediatric population and should be particularly investigated. Multicenter prospective studies are required to investigate pediatric UC patients undergoing ta-IPAA.

Motility disorders in children with intestinal failure: a national tertiary referral center experience.

PURPOSE: Intestinal dysmotility (ID) problems are common in patients with pediatric-onset intestinal failure (IF) and short bowel syndrome (SBS), leading to significant morbidity and delays in the advancement of enteral nutrition (EN). We aimed to investigate the clinical features and complications of ID in children with IF and SBS. METHODS: Retrospective chart review of all children with IF and/or SBS who required parenteral nutrition (PN) > 6 weeks or small-intestinal resection ≥ 50%. Patients were divided into SBS and non-SBS groups. SBS group was divided into two subgroups: with and without ID. Patients with ID were identified (clinically, radiologically and functionally) and analyzed with regard to demographics, intestinal anatomy, complications and outcomes (short and long term). RESULTS: A total of 42 children with IF were treated in our institution during 2003-2022. In non-SBS group (n = 10), ID was the most common cause of IF (80%). SBS-group included 32 children; 18 children (56%) developed ID. The clinical profile of SBS-ID patients (vs SBS) was: female gender (56%), remaining small bowel length ≤ 55 cm, estimated residual small bowel ≤ 28% (p = 0.045) and absence of ICV (56%). Common symptoms of the SBS-ID group were: food intolerance (61%), abdominal distension (50%), vomiting (44%), malabsorption and severe constipation. Complications included FTT (67%) (p = 0.003), bacterial overgrowth with subsequent bloodstream infection (33%) (p = 0.75), and lactic acidosis (11%). Lengthening procedure (STEP) was performed in 11 SBS-ID patients (61%) (p = 0.002). In all patients, STEP operation "rescued" their dysfunctional intestine. Eight of these patients (73%) were weaned from TPN. Survival rate was 100%; however, one SBS-ID patient is a candidate for combined intestinal and liver transplantation. CONCLUSIONS: ID is the most common complication of SBS and is the most common cause of IF in non-SBS patients. ID has a high morbidity rate and various clinical manifestations. Successful treatment of these infants may be achieved with the use of tapering enteroplasty.

The Mechanisms of the Anti-Inflammatory and Anti-Apoptotic Effects of Omega-3 Polyunsaturated Fatty Acids during Methotrexate-Induced Intestinal Damage in Cell Line and in a Rat Model.

Background: The aim of this study was to examine the anti-inflammatory and anti-apoptotic patterns of omega-3 polyunsaturated fatty acids (n-3 PUFAs) during methotrexate (MTX) induced intestinal damage in cell culture and in a rat model. Methods: Non-treated and treated with MTX HT 29 and HCT116cells were exposed to increasing doses of n-3 PUFAs and cell viability was evaluated using PrestoBlue® assay. Male Sprague-Dawley rats were divided into 4 experimental groups: Control rats, CONTR+n-3 PUFA rats that were treated with oral n-3 PUFA, MTX rats were treated with MTX given IP, and MTX+n-3 PUFA rats were treated with oral n-3 PUFA before and following injection of MTX. Intestinal mucosal parameters and mucosal inflammation, enterocyte proliferation and apoptosis, TNF-α in mucosal tissue and plasma (ELISA), NF-κB, COX-2, TNF-α, Fas, FasL, Fadd, Bid, Bax and Bcl-2gene and protein levels were determined 72 h following MTX injection. Results: Exposure of HT 29 and HCT116cells to n-3 PUFA attenuated inhibiting effects of MTX on cell viability. MTX-n-3 PUFA rats demonstrated a lower intestinal injury score and enhanced intestinal repair. A significant decrease in enterocyte apoptosis in MTX+n-3 PUFA rats was accompanied by decreased TNF-α, FAS, FasL, FADD and BID mRNA levels. Decreased NF-κB, COX-2 and TNF-α levels in mucosa was accompanied by a decreased number of IELs and macrophages. Conclusions: n-3 PUFAs inhibit NF-κB/COX-2 induced production of pro-inflammatory cytokines and inhibit cell apoptosis mainly by extrinsic pathway in rats with MTX-induced intestinal damage.

Novel nanotech antioxidant cocktail prevents medical diagnostic procedures ionizing radiation effects.

Ionizing radiation (IR) exposure results in oxidative damage causing cytotoxic and genotoxic effects. Double-strand breaks (DSBs) are considered the most significant DNA lesions induced by ionizing radiation. The present study evaluates the radio protective effect of a novel antioxidant cocktail through quantification of DSB in peripheral blood lymphocytes (PBL) in vivo. The study included 16 consecutive patients who were divided into 2 groups, 6 patients received the novel antioxidant cocktail and 10 control patients. Blood samples were drawn from the patients undergoing bone scan, before the injection of the 99mTc MDP tracer and 2 h after the injection. Quantification of the IR damage was done by Immunofluorescence analysis of the phosphorylated histone, γ-H2AX, used to monitor DSB induction and repair in PBL. The radiation effect of the control group was measured by 2 variables, the average DBSs foci per nucleus and the percent of the DSB bearing cells in PBL. The findings showed a significant increase in the DSBs after isotope injection with an average increment of 0.29 ± 0.13 of foci/nucleus and 17.07% ± 7.68 more DSB bearing cells (p < 0.05). The cocktail treated group showed a lower difference average of - 2.79% ± 6.13 DSB bearing cells. A paired t-test revealed a significant difference between the groups (p < 0.005) confirming the cocktail's protective effect. The novel anti-oxidant treatment decreases the oxidative stress-induced DNA damage and can be considered as a preventative treatment before radiation exposure.

Cell death induction (extrinsic versus intrinsic apoptotic pathway) by intestinal ischemia-reperfusion injury in rats is time-depended.

PURPOSE: We investigate the mechanism of intestinal cell apoptosis and its relation to the time of reperfusion in a rat model of intestinal ischemia-reperfusion (IR). METHODS: Rats were divided into 4 groups: Sham-24 and Sham-48 rats underwent laparotomy without an intentional ischemic intervention and were sacrificed 24 or 48 h hours later; IR-24 and IR-48 rats underwent occlusion of SMA and portal vein for 20 min followed by 24 or 48 h of reperfusion, respectively. Park's injury score, cell proliferation and apoptosis were determined at sacrifice. Proliferation and apoptosis-related gene and protein expression were determined using Real-Time PCR, Western Blot and Immunohistochemistry. RESULTS: IR-24 rats demonstrated a strong increase in cell apoptosis along with an elevated Bax and decreased Bcl-2 expression and a decrease in cell proliferation (vs Sham-24). IR-48 group showed an increase in cell proliferation and a decrease in cell apoptosis compared to IR-24 animals. IR-48 rats demonstrated an increase in apoptotic rate that was accompanied by greater TNF-α mRNA, Fas mRNA and FasL mRNA compared to Sham-48 animals. CONCLUSION: While cell apoptosis in IR-24 rats is regulated mainly by intrinsic apoptotic pathway, 48 h followed ischemia extrinsic apoptotic pathway is responsible for pro-apoptotic effects of IR injury.

Intestinal dysmotility after bowel resection in rats is associated with decreased ghrelin and vimentin expression and loss of intestinal cells of Cajal.

This study provides novel insight into the mechanisms of intestinal dysmotility following massive small bowel resection. We show that 2 wk after bowel resection in rats, impaired intestinal motility was associated with loss of interstitial cells of Cajal (ICC; downregulation of transmembrane member 16A (TMEM16A) and c-kit expression) as well as with decreased vimentin, desmin, and ghrelin levels. Impaired intestinal motility led to a decrease in final body weight, suggesting less effective nutrient absorption. The purpose of this study was to evaluate the mechanisms of intestinal motility in a rat model of short bowel syndrome (SBS). Rats were divided into three groups: Sham rats underwent bowel transection; SBS-NSI rats underwent a 75% bowel resection and presented with normal intestinal size (NSI) at euthanasia and hypermotility patterns; SBS-DYS showed dysmotile (DYS) enlarged intestine and inhibited motility patterns. Animals were euthanized after 2 wk. Illumina's digital gene expression (DGE) analysis was used to determine the intestinal motility-related gene expression profiling in mucosal samples. Intestinal motility-related and ICC genes and protein expression in intestinal muscle layer were determined using real-time PCR, Western blotting, and immunohistochemistry. Gastrointestinal tract motility was studied by microcomputer tomography. From 10 Ca2+ signaling pathway-related genes, six genes in jejunum and seven genes in ileum were downregulated in SBS vs. Sham animals. Downregulation of TMEM16A mRNA and protein was confirmed by real-time PCR. Rapid intestinal transit time in SBS-NSI rats correlated with a mild decrease in TMEM16A, c-kit, and vimentin mRNA and protein expression (vs/. Sham animals). SBS-DYS rats demonstrated enlarged intestinal loops and delayed small intestinal emptying (on imaging studies) that were correlated with marked downregulation in TMEM16A, c-kit, vimentin, and ghrelin mRNA and protein levels compared with the other two groups. In conclusion, 2 wk following massive bowel resection in rats, impaired intestinal motility was associated with decreased vimentin and ghrelin gene and protein levels as well as loss of ICC (c-kit and TMEM16A).NEW & NOTEWORTHY This study provides novel insight into the mechanisms of intestinal dysmotility following massive small bowel resection. We show that 2 weeks after bowel resection in rats, impaired intestinal motility was associated with loss of interstitial cells of Cajal (downregulation of TMEM 16A, and c-kit expression) as well as with decreased vimentin, desmin, and ghrelin levels. Impaired intestinal motility led to decrease in final body weight, suggesting less effective nutrient absorption.

Predictive Value of Alvarado Score and Pediatric Appendicitis Score in the Success of Nonoperative Management for Simple Acute Appendicitis in Children.

INTRODUCTION: During the past decade, nonoperative management (NOM) for simple acute appendicitis (SAA) in children has been proven safe with noninferior complications rate. The aim of this study was to examine Alvarado score and pediatric appendicitis score (PAS) together with other factors in predicting failure of NOM in children presenting with SAA. MATERIALS AND METHODS: Patients aged 5 to 18 years admitted to our department between 2017 and 2019 diagnosed with SAA were given a choice between surgical management and NOM. We divided the NOM patients into two groups: successful treatment and failed NOM, comparing their files for Alvarado score and PAS and other clinical and demographic factors, with a mean follow-up of 7 months. Failure was determined as need for appendectomy following conservative treatment due to any reason. RESULTS: A total of 85 patients answered criteria and chose NOM. Overall failure rate was 32.9%. We found no difference in the mean Alvarado score and PAS as well as in each component of both scores between success and failed NOM groups. However, when using the risk classification of the scores, we found a significant correlation between high-risk Alvarado score and failed NOM. After adjusting for age, gender, duration of symptoms, diagnosis of tip appendicitis, and presence of appendicolith, the odds of failure were four times higher among high-risk Alvarado group. CONCLUSION: Alvarado score of 7 or higher, older age, and diagnosis of an appendicolith on imaging are possible predictors for failure of NOM for SAA in children.

Anti-TNF-α Therapy Exerts Intestinal Anti-inflammatory and Anti-apoptotic Effects After Massive Bowel Resection in a Rat.

OBJECTIVES: The aim of this study was to examine the effect of massive small bowel resection on proinflammatory cytokine intestinal expression and the effect of anti-TNF-α antibodies (ATA) on intestinal inflammation, epithelial cell turnover, and intestinal adaptation after bowel resection in rats. METHODS: Male Sprague-Dawley rats were divided into 4 experimental groups: Sham-rats underwent bowel transection; Sham-ATA rats underwent bowel transection and were treated with ATA; SBS-animals underwent 75% bowel resection; and SBS-ATA rats underwent bowel resection and were treated with ATA similarly to Group B. Parameters of intestinal adaptation, enterocyte proliferation, and apoptosis were determined at sacrifice. TNF-α and apoptosis-related gene and protein levels were determined by Illumina's Digital Gene Expression (DGE) analysis, Real Time PCR, Western blotting, and immunohistochemistry. RESULTS: From 25 genes related to TNF-α signalling that were investigated, 8 genes in the jejunum and 10 genes in the ileum were found to be up-regulated in resected versus sham animals. SBS rats demonstrated a significant increase in tissue and plasma TNF-α, IL-6 levels, intestinal mucosal TNF-α related gene expression, and microscopic parameters of inflammation. Treatment of resected animals with ATA resulted in a significant decrease in TNF-α levels, intestinal mucosal TNF-α-related gene expression, decreased number of intraepithelial lymphocytes and macrophages, and lower apoptotic index compared with SBS animals. CONCLUSIONS: In a rat model of SBS, ATA decreased plasma and tissue TNF-α levels, diminished mucosal inflammation, and inhibited cell apoptosis. Anti-apoptotic effects of ATA appear to be associated with an inhibited extrinsic apoptotic pathway.

Accelerated Intestinal Epithelial Cell Turnover Correlates with Stimulated BMP Signaling Cascade following Intestinal Ischemia-Reperfusion in a Rat.

INTRODUCTION: Bone morphogenetic proteins (BMPs) are a family of proteins that regulate proliferation and differentiation of intestinal epithelial cells. The purpose of this study was to evaluate the role of BMP signaling following intestinal ischemia-reperfusion (IR) in a rat model. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into four experimental groups: Sham-24 and Sham-48 rats underwent laparotomy and were sacrificed 24 or 48 hours later, respectively; IR-24 and IR-48 rats underwent occlusion of superior mesenteric artery and portal vein for 30 minutes followed by 24 or 48 hours of reperfusion, respectively. Enterocyte proliferation and apoptosis were determined at sacrifice. BMP-related genes and protein expression were determined using real-time polymerase chain reaction, Western blot, and immunohistochemistry for 48 hours followed by IR. RESULTS: IR rats demonstrated a significant increase in BMP2 (twofold increase, p < 0.05), BMP4 (sevenfold increase), STAT3 (70% increase), BMPR1 (70% increase) messenger ribonucleic acid levels in jejunum and was accompanied by a significant increase in BMP2 and BMP4 protein levels in jejunum (sixfold increase) (Western blot) and upward increase in the number of BMP-positive cells (by immunohistochemistry) in jejunal (48% increase) and ileal (56% increase) villi compared with Sham-48 animals. Elevation in BMP2 and BMP4 levels was associated with increased rates of cell proliferation and increased cell apoptosis. CONCLUSION: Forty-eight hours following intestinal IR in rats, BMP signaling pathway was stimulated. The increase in BMP signaling pathway activity correlates with accelerated cell turnover.

Effect of N-Acetylserotonin on TLR-4 and MyD88 Expression during Intestinal Ischemia-Reperfusion in a Rat Model.

BACKGROUND: Accumulating evidence indicates that changes in intestinal toll-like receptors (TLRs) precede histological injury in a rodent model of necrotizing enterocolitis. N-acetylserotonin (NAS) is a naturally occurring chemical intermediate in the biosynthesis of melatonin. A recent study has shown that treatment with NAS prevents gut mucosal damage and inhibits programmed cell death following intestinal ischemia-reperfusion (IR). The objective of this study was to determine the effects of NAS on TLR-4, myeloid differentiation factor 88 (Myd88), and TNF-α receptor-associated factor 6 (TRAF6) expression in intestinal mucosa following intestinal IR in a rat. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomly assigned to one of the four experimental groups: 1) Sham rats underwent laparotomy; 2) Sham-NAS rats underwent laparotomy and were treated with intraperitoneal (IP) NAS (20 mg/kg); 3) IR rats underwent occlusion of both superior mesenteric artery and portal vein for 20 minutes followed by 48 hours of reperfusion; and 4) IR-NAS rats underwent IR and were treated with IP NAS immediately before abdominal closure. Intestinal structural changes, mucosal TLR-4, MyD88, and TRAF6 mucosal gene, and protein expression were examined using real-time PCR, Western blot, and immunohistochemistry. RESULTS: Significant mucosal damage in IR rats was accompanied by a significant upregulation of TLR-4, MyD88, and TRAF6 gene and protein expression in intestinal mucosa compared with control animals. The administration of NAS decreased the intestinal injury score, inhibited cell apoptosis, and significantly reduced the expression of TLR-4, MyD88, and TRAF6. CONCLUSION: Treatment with NAS is associated with downregulation of TLR-4, MyD88, and TRAF6 expression along with a concomitant decrease in intestinal mucosal injury caused by intestinal IR in a rat.

Antioxidant treatment ameliorates germ cell apoptosis induced by a high-dose ionizing irradiation in rats.

BACKGROUND: Exposure to ionizing radiation results in cytotoxic and genotoxic effects caused mainly by the oxidative damage. In the present study, we investigated the radioprotective effect of novel antioxidant cocktail on germ cell apoptosis and spermatogenesis in rats subjected to whole body radiation (WBIR). METHODS: Adult male rats weighing 250-270 g were divided into four groups, eight rats each. Group 1 served as untreated control, group 2 received an IP single dose of antioxidant cocktail (1 ml). Group 3 was exposed to a WBIR (6 Gy). Group 4 received antioxidant cocktail before WBIR. Rats from each group were killed after 48 h. MDA levels were measured in serum (TBARS assay). Johnsen's criteria and the number of germinal cell layers were used to categorize spermatogenesis. TUNEL assay was used to determine germ cell apoptosis. Statistical analysis was performed using one-way ANOVA test. RESULTS: WBIR resulted in histological testicular damage (decrease in Johnsen's criteria, p < 0.05) that was accompanied by a significant increase in germ cell apoptosis, expressed as the number of apoptotic cells per 100 tubules (AI-1 apoptotic index) and the number of positive tubules per 100 tubules (AI-2 apoptotic index). Treatment with antioxidant cocktail resulted in a significant decrease in germ cell apoptosis (33% decrease in AI-1, p < 0.05 and 34% decrease in AI-2, p < 0.05) that was accompanied by an improved spermatogenesis (increase in Johnsen's criteria, p < 0.05). CONCLUSIONS: In a rat model of WBIR, antioxidant treatment ameliorates oxidative stress-induced testicular damage, decreases germ cell apoptosis and improves spermatogenesis.