Igor Sukhotnik

Treatment with glutamine is associated with down-regulation of Toll-like receptor-4 and myeloid differentiation factor 88 expression and decrease in intestinal mucosal injury caused by lipopolysaccharide endotoxaemia in a rat

Recent evidence suggests that lipopolysaccharide (LPS) endotoxaemia in a rat causes significant mucosal injury. Our objective was to determine the effects of glutamine (Gln) on Toll‐like receptor 4 (TLR‐4), myeloid differentiation factor 88 (Myd88) and tumour necrosis factor (TNF)‐α receptor‐associated factor 6 (TRAF6) expression in intestinal mucosa following LPS endotoxaemia in a rat. For this purpose, male Sprague–Dawley rats were assigned randomly to one of three experimental groups of 10 rats each: (i) control rats underwent intraperitoneal (i.p.) injection of sterile saline once a day; (ii) rats were treated with LPS given i.p. once a day at a dose of 10 mg/kg for 48 h (two doses); and (iii) rats were pretreated with oral Gln given in drinking water (2%) 48 h before and following injection of LPS. Intestinal mucosal parameters, enterocyte proliferation and apoptosis were determined at death. TLR‐4 and MyD88 mRNA expression was measured with reverse transcription–polymerase chain reaction (RT–PCR). TLR‐4 and MyD88 protein expression were analysed by Western immunoblotting. We observed a statistically significant (P < 0·05) decrease in mucosal weight, mucosal DNA and enterocyte proliferation and a significant increase in enterocyte apoptosis in rat intestine, following LPS administration. These changes were attenuated significantly by dietary Gln. Expression of TLR‐4, MyD88 and TRAF6 mRNA in the mucosal ileum was significantly higher in LPS rats versus control rats (P = 0·0006, P = 0·0015, P = 0·03, respectively) as well as TLR‐4 and MyD88 protein expression. The administration of Gln reduced significantly the expression of TLR‐4, MyD88 and TRAF6 (P = 0·023, P = 0·014, P = 0·035, respectively) mRNA as well as TLR‐4 and MyD88 protein expression in ileum compared to LPS animals. We did not find a significant change in the expression of TLR‐4, MyD88 or TRAF6 in the jejunum of different groups. We conclude that treatment with Gln was associated with down‐regulation of TLR‐4, MyD88 and TRAF6 expression and concomitant decrease in intestinal mucosal injury caused by LPS endotoxaemia in a rat.

Effect of dietary fat on early morphological intestinal adaptation in a rat with short bowel syndrome

Among factors promoting mucosal hyperplasia after bowel resection, long-chain fatty acids may have a special role. The purpose of the present study was to evaluate the effects of high-fat diet (HFD) on early intestinal adaptation in rats with short bowel syndrome (SBS). Male Sprague-Dawley rats underwent either a bowel transection with re-anastomosis (Sham rats) or 75% small bowel resection (SBS rats). Animals were randomly assigned to one of three groups: Sham rats fed normal chow (Sham-NC); SBS rats fed NC (SBS-NC); and SBS rats fed HFD (SBS-HFD). Rats were killed on days 3 or 14. Body weight and parameters of intestinal adaptation (overall bowel and mucosal weight, mucosal DNA and protein, villus height, and crypt depth) were determined at time of killing. By day 3, SBS-HFD rats demonstrated higher duodenal and jejunal bowel and mucosal weights and ileal villus height and jejunal crypt depth vs SBS-NC rats. By day 14 SBS-HFD rats continued to demonstrate increased duodenal and jejunal bowel weight and duodenal mucosal weight vs SBS-NC animals. We conclude that early exposure to HFD both augmented and accelerated structural bowel adaptation in a rat model of SBS.

Use of N-butyl-2-cyanoacrylate in elective surgical incisions-longterm outcomes

BACKGROUND Histoacryl Blue (N-butyl-2-cyanoacrylate) is a tissue adhesive that has been used clinically for more than 20 years. In the last decade, N-butyl-2-cyanoacrylate has been used for cutaneous closure of low-tension lacerations in children and adults and has become a preferred method for closure of pediatric facial lacerations in many emergency rooms outside the United States. Many pediatric elective surgical procedures are performed in tension-free areas and may be suitable for closure with a tissue adhesive. In order to assess this approach, a retrospective study was conducted to evaluate the cosmetic outcomes and complications of the application of N-butyl-2-cyanoacrylate for the approximation of elective surgical incisions in a pediatric population. STUDY DESIGN Records of 1,098 patients, ages 1 month to 16 years, who, between January 1995 and December 1996, underwent one of the following: orchidopexy, inguinal hernia, umbilical hernia, or hydrocele repair were analyzed. In all patients, N-butyl-2-cyanoacrylate was applied to close the surgical incision. A 12-item questionnaire was created to assess the presence of complications and to determine shortterm and longterm cosmetic outcomes of the incision. Data were collected by conducting telephone interviews of family members. RESULTS Among the 1,033 children who were treated, 66% had inguinal hernias, 15% hydroceles, 15% undescended testis, and 4% umbilical hernias. Redness or tenderness at the incision site (5.5%), discharge from the surgical wound (1.9%), and wound dehiscence (1.1%) were the main immediate complications after surgery. Overall satisfaction with the cosmetic outcomes of the surgical scar was high, with an average score of 4.73 out of 5 (94.6%). CONCLUSIONS Our results demonstrate that administration of N-butyl-2-cyanoacrylate for the closure of small low-tension surgical incisions in the pediatric population is safe, has a low complication rate, and produces excellent cosmetic outcomes.

The effect of 100% oxygen on intestinal preservation and recovery following ischemia-reperfusion injury in rats.

Objective:Inhalation of oxygen improves the hemodynamic status and attenuates the inflammatory response after intestinal ischemia-reperfusion (IR). Yet, the use of hyperoxia is hindered by concerns that it could exacerbate reperfusion injury by increasing free radical formation. We examined the effect of hyperoxia on enterocyte turnover and intestinal preservation and rehabilitation following IR injury in rats. Design:Animal study. Setting:Research laboratory. Subjects:Male Sprague-Dawley rats. Interventions:Animals were assigned to four experimental groups: 1) Sham rats underwent laparotomy without vascular occlusion and breathed air, 2) Sham-oxygen rats underwent laparotomy without vascular occlusion and breathed 100% oxygen, 3) IR rats underwent occlusion of the superior mesenteric artery and portal vein for 30 minutes and breathed air, and 4) IR group treated with oxygen (IR-O2)rats underwent IR and breathed 100% oxygen starting 10 minutes before and continued for the first 6 hours after reperfusion. Intestinal structural changes, enterocyte proliferation, and enterocyte apoptosis were determined 24 hours after IR. Measurements and Main Results:In IR rats, breathing 100% oxygen resulted in a significant decrease in Parks injury score in the ileum (p < 0.05 from untreated IR rats). Rats treated with oxygen also demonstrated a significant increase in mucosal weight (p < 0.05) and mucosal DNA (p < 0.05) in the jejunum and ileum, and an increase in villus height (p < 0.01), and crypt depth (p < 0.05) in the ileum. Enterocyte proliferation (assessed by bromodeoxyuridine uptake) was significantly decreased in the jejunum and ileum in untreated IR rats. Oxygen therapy increased enterocyte proliferation in the ileum, and diminished both the apoptosis index and Bax gene expression in the jejunum and ileum (p < 0.05). Plasma thermochemiluminescence oxidizability assay revealed significantly higher thermochemiluminescence ratios in IR group treated with oxygen than in untreated IR rats (p < 0.05) at 6 hours postreperfusion suggesting a significantly lower prior in vivo molecular oxidation. Conclusions:Hyperoxia reduces small bowel injury, accelerates enterocyte turnover, and improves intestinal rehabilitation after IR.

Low-fat diet impairs postresection intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND Low-fat diets (LFD) are utilized frequently in patients with short bowel syndrome (SBS). The purpose of this study was to investigate the effects of LFD on intestinal adaptation, enterocyte proliferation, and enterocyte cell death in a rat model of SBS. METHODS Adult male Sprague-Dawley rats were divided into 3 experimental groups: Sham-NC rats underwent bowel transection and reanastomosis and were fed normal chow (NC), SBS-NC rats underwent 75% small bowel resection and were fed NC, and SBS-rats were fed a low-fat diet (SBS-LFD). Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 14 after operation. RESULTS SBS-NC rats showed a significant increase (v Sham-NC) in jejunal and ileal bowel and mucosal weight, mucosal DNA and protein, villus height, and crypt depth. A significant 67% increase in crypt cell proliferation rate and 265% increase in villus enterocyte apoptosis was seen in the ileum of SBS-NC rats compared with control animals (P <.05). SBS-LFD animals showed lower ileal mucosal weight (29%; P <.05), jejunal crypt depth (20%; P <.05), and ileal villus height (21%; P <.05). A significant decrease in villus apoptosis in jejunum (74%; P <.05) and ileum (67%; P <.05) and a decrease in cell proliferation in ileum (35%; P <.05) was seen also after exposure to LFD compared with SBS-NC. CONCLUSIONS In a rat model of SBS, early LFD appears to inhibit parameters of intestinal adaptation. A possible mechanisms for this effect may be decreased cell proliferation. Decreased enterocyte loss via apoptosis, found in this study, may reflect a reduced number of enterocyte.

Sandostatin Impairs Postresection Intestinal Adaptation in a Rat Model of Short Bowel Syndrome

Because of its antisecretory properties, sandostatin has been advocated for the treatment of patients with short bowel syndrome (SBS). This study was conducted to determine the effect of sandostatin on structural intestinal adaptation, cell proliferation and apoptosis in a rat model of SBS. Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection, SBS rats underwent 75% small bowel resection, and SBS-sandostatin rats underwent bowel resection and were treated with sandostatin (SBS-SND). Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 14 following operation. We have demonstrated that SBS-SND animals demonstrated lower (vs SBS rats) duodenal and jejunal bowel weights, jejunal and ileal mucosal weight, jejunal and ileal mucosal DNA and protein, jejunal and ileal villus height, cell proliferation index in the ileum, and enterocyte apoptosis in jejunum and ileum. We conclude that in a rat model of SBS sandostatin decreases cell proliferation and inhibits structural intestinal adaptation.

Gastrointestinal tract as a target organ for orally administered insulin

ABSTRACT The intestine is not considered to be a classic target tissue for insulin. Recent in vitro and in vivo experiments suggest that intestinal as well as systemic effects are observed following oral administration of insulin. Local effects include enhancement of intestinal growth, cell maturation, enzyme expression, gut adaptation after intestinal resection and reduction of intestinal permeability. Systemic effects, at least in animal models, include favorable effects on blood glucose and lipid profile and on the prevention of autoimmunity and attenuating the atherosclerosic process.

Divergent effects of oxygen therapy in four models of uncontrolled hemorrhagic shock

Treatment with oxygen exerts beneficial effects and prolongs survival in hemorrhagic shock induced by controlled bleeding. We evaluated the effects of inhalation of 100% oxygen in four models of uncontrolled bleeding in rats: amputation of the tail, laceration of two branches of the ileocolic artery, incision of the spleen, and laceration of the lateral lobe of the liver. After tail amputation, oxygen caused a short and transient increase in mean arterial blood pressure (MABP;P < 0.01), decreased distal aorta (DA) blood flow by 27% (P < 0.01), and induced transient redistribution of blood flow to the superior mesenteric artery (SMA;P < 0.01). Later on, MABP in the oxygen group decreased gradually and was significantly lower than in air controls (P < 0.01). Oxygen therapy increased the mean blood loss by 40% (P < 0.01), increased blood lactate (P < 0.01), and shortened the survival time (P < 0.01). After laceration of two branches of the ileocolic artery, oxygen treatment caused a transient increase in MABP and redistribution of blood flow to the SMA that was followed by a comparable decrease in MABP, increase in vascular resistance, and decreased blood flow in the DA and SMA. In this model, oxygen did not affect bleeding volume, blood lactate, or survival. A similar transient regional hemodynamic effect was found when oxygen was administered after spleen or liver injury; however, in both models, oxygen maintained MABP at significantly higher values (P < 0.05). The results point to differential effects of oxygen in uncontrolled bleeding with benefits in bleeding from small parenchymal vessels and possible detrimental effect in bleeding from large size vessels.

Effect of low fat diet on lipid absorption and fatty-acid transport following bowel resection

Abstract Low-fat diets (LFD) are used extensively in many different clinical conditions. However, the effect of this diet on lipid absorption and cellular long-chain fatty-acid (LCFA) transport is unknown. Fatty-acid translocase (FAT), the rat homologue of human CD36, is one of several LCFA plasma-membrane transport proteins that may play an important role in intestinal lipid uptake. The purpose of this study was to investigate the effects of a LFD on intestinal expression of FAT/CD36, enterocyte fatty-acid transport, and in-vivo lipid absorption in rats following bowel resection. Adult male Sprague-Dawley rats were divided into five experimental groups: normal rats fed normal chow(NR-NC) (10 kcal% fat), normal rats fed a LFD (NR-LFD) (3 kcal% fat), sham rats fed normal chow (Sham-NC), short-bowel syndrome rats fed normal chow (SBS-NC), and SBS rats fed a LFD (SBS-LFD). SBS rats underwent 75% small-bowel resection, while sham animals underwent bowel transection and re-anastomosis. Food intake, fecal mass, and fecal fat were measured over the last 3 days before death on day 14. Final body weight, plasma lipids and protein, and tissue total lipids in liver, adipose tissue, and intestine were determined at death. Total RNA from the mucosa of the duodenum, jejunum, and ileum was extracted for Northern blot analysis to determine fatty-acid translocase (FAT)/CD36 mRNA levels. An established cellular LCFA transport assay was used to determine isolated enterocyte [3H]-oleate uptake. Studentss t-test was used to determine statistical significance (P < 0.05). NR-LFD rats demonstrated a small increase in overall food absorption and no change in fat absorption compared to NR-NC animals. A significant decrease in FAT/CD36 mRNA levels was seen in the duodenum and jejunum in NF-LFD rats (vs NR-NC) and was accompanied by reduced LCFA transport by isolated enterocytes from the jejunum and ileum. SBS-LFD rats demonstrated decreased FAT/CD36 mRNA levels in all three segments and a concomitant decrease in LCFA uptake enterocytes compared to the SBS-NC group. In addition, SBS-LFD rats showed significantly lower final body weight and plasma lipids compared to SBS-NC animals.

Oral insulin enhances intestinal regrowth following massive small bowel resection in rat.

Experimental studies have suggested that insulin (INS) plays an important role in small intestinal growth and development. In the present study we investigated the effect of oral INS on structural intestinal adaptation and enterocyte proliferation and loss via apoptosis in a rat model of short bowel syndrome (SBS). Male Sprague–Dawley rats were divided into three experimental groups: sham rats underwent bowel transection, SBS rats underwent 75% small bowel resection, and SBS-INS rats underwent bowel resection and were treated with oral INS given in the drinking water from the 3rd to the 15th postoperative day. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villous height, and crypt depth), enterocyte proliferation, and apoptosis were determined on day 15. SBS-INS rats demonstrated a significant increase (vs SBS rats) in jejunal and ileal overall bowel and mucosal weight, ileal mucosal DNA and protein, ileal villous height, and crypt depth. SBS-INS rats also showed an increased cell proliferation index in jejunum and ileum and decreased apoptotic index in jejunum compared to SBS animals. In conclusion, in a rat model of SBS, oral INS strongly enhances intestinal adaptation.Possible mechanisms may include increased cell proliferation and decreased enterocyte loss via apoptosis.