The TNF-family cytokine TL1A drives IL-13-dependent small intestinal inflammation.

The tumor necrosis factor (TNF)-family cytokine TL1A (TNFSF15) costimulates T cells through its receptor DR3 (TNFRSF25) and is required for autoimmune pathology driven by diverse T-cell subsets. TL1A has been linked to human inflammatory bowel disease (IBD), but its pathogenic role is not known. We generated transgenic mice that constitutively express TL1A in T cells or dendritic cells. These mice spontaneously develop IL-13-dependent inflammatory small bowel pathology that strikingly resembles the intestinal response to nematode infections. These changes were dependent on the presence of a polyclonal T-cell receptor (TCR) repertoire, suggesting that they are driven by components in the intestinal flora. Forkhead box P3 (FoxP3)-positive regulatory T cells (Tregs) were present in increased numbers despite the fact that TL1A suppresses the generation of inducible Tregs. Finally, blocking TL1A-DR3 interactions abrogates 2,4,6 trinitrobenzenesulfonic acid (TNBS) colitis, indicating that these interactions influence other causes of intestinal inflammation as well. These results establish a novel link between TL1A and interleukin 13 (IL-13) responses that results in small intestinal inflammation, and also establish that TL1A-DR3 interactions are necessary and sufficient for T cell-dependent IBD.

Comparative study of NOTES alone vs. EUS-guided NOTES procedures.

BACKGROUND AND STUDY AIMS: Natural-orifice transluminal endoscopic surgery (NOTES) is in the developmental stage for various indications, but several obstacles remain to be overcome before NOTES procedures can come into routine clinical use. Of these obstacles, (1) transluminal injury due to exclusive use of endoluminal endoscopy to create the incision and (2) lack of orientation might be prevented by employing endoscopic ultrasound guidance. In this comparative study we assessed the role of endoscopic ultrasound guidance in various NOTES procedures. METHODS: Three transesophageal (mediastinoscopy/thoracoscopy) or transgastric procedures (gastrojejunostomy, adrenal gland removal) were performed in pigs using NOTES alone or with endoscopic ultrasound guidance (EUS). In NOTES alone the study end point was three major complications, at which point EUS guidance was added for the same procedures up to the same number of cases. The primary outcome was the rate of major complications; secondary outcome parameters were all complications and technical success. RESULTS: Forty-six pigs were included. Three major complications occurred in the first 24 NOTES-alone procedures: these were bleeding and organ injury, all during mediastinoscopy/thoracoscopy procedures. Adrenal gland removal failed in all procedures in which it was attempted, while gastrojejunostomy (n = 6) was performed successfully and without complications. In the next 22 animals EUS guidance enabled safe mediastinal access (n = 10) and adrenal gland removal (n = 6). For gastrojejunostomy, EUS guidance offered no additional benefit. CONCLUSIONS: EUS guidance appears to be helpful in gaining access or identifying structures in anatomically difficult areas in NOTES procedures.

Natural orifice transluminal endoscopic surgery (NOTES) in the mediastinum: long-term survival animal experiments in transesophageal access, including minor surgical procedures.

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery (NOTES) within the peritoneal cavity is rapidly evolving, using transgastric, transcolonic, or transvaginal access. There is little experience with transesophageal NOTES access to the mediastinum. This prospective long-term animal survival study was performed to explore the feasibility and safety of transesophageal intrathoracic procedures including minor surgery. MATERIAL AND METHODS: Nine pigs were used for acute (n = 2) and up to 6-week survival studies (n = 7), followed by autopsy and histological investigation. The esophageal incision site was chosen using EUS; this was followed by endoscopic mediastinoscopy and therapeutic procedures such as mediastinal lymph node removal, saline injection into myocardium, and pericardial fenestration. The wall was closed using a suturing system or endoscopic clips. RESULTS: No acute complications were recorded with respect to mediastinal structures, pericardium, cardiac rhythm, or circulatory parameters. Removal of small mediastinal lymph nodes (n = 2) was feasible, but proved to be difficult. Other procedures, specifically at the heart were all successfully performed. Endoscopy after 4 - 6 weeks showed a well-healed esophageal incision. Autopsy with histology revealed no signs of mediastinitis, infection, bleeding, or pericarditis. The esophageal scar was found to be well healed in all cases, but with a muscular gap where clip closure had been used. CONCLUSIONS: Transmural esophageal incision and endoscopic partial mediastinoscopy including therapeutic procedures on the heart or mediastinum proved feasible in long-term survival animal studies. Clip closure of the defect was effective, but did not close the esophageal muscle layer. Other means such as endoscopic suturing appear to be preferable.

Which parameters might predict complications after natural orifice endoluminal surgery (NOTES)? Results from a randomized comparison with open surgical access in pigs.

BACKGROUND AND STUDY AIMS: Natural orifice transluminal endoscopic surgery (NOTES) is currently developed and assessed mainly in pig experiments. The vast majority of studies show a good outcome in short-term follow-up. The current study aims at comparing various parameters of postinterventional assessment and surveillance in relation to clinical behavior and autopsy results to find suitable control parameters and also to assess the pig as suitable model for NOTES compared with open surgery. METHODS: Within the framework of a randomized prospective study of 20 pigs with iatrogenic colonic perforation comparing endoscopic with open surgical closure, clinical examination, including observation of behavior, food intake, and body temperature, was carried out daily. Laboratory parameters (white blood cells [WBC], granulocytes) were measured in 14 animals. Weight was measured preoperatively and on days 2 and 7 postoperatively. Results were matched with complications found during/after 2 weeks' survival. Pre-autopsy sterile cultures were taken from the peritoneal cavities to determine possible bacterial contamination. RESULTS: Three animals from the surgical group were sacrificed on days 4, 8, and 12 because they became severely ill, with autopsy revealing intussusception from adhesions, peritoneal abscess, and peritonitis, in one pig each; another animal had culture positive for ESCHERICHIA COLI. Three minor complications (2 cough, 1 continuing fever with adhesions to the bladder found on autopsy) occurred in the endoscopic group without compromised recovery. WBC were measured in 14 animals, and found to be elevated (8 - 36 x 10 (9)/l) in six on day 2 including the two animals with severe complications. Between pre- and post-procedure, WBC increased about twofold in the uneventful cases but fourfold in the two animals with severe complications. Cultures from the abdominal cavity before autopsy were negative in all but one animal. CONCLUSION: Animal behavior was a reliable indicator of severe complications. Fever, body weight, and the results of in vitro cultures of the peritoneal fluid did not indicate complications. WBC proved not to be specific but showed a larger increase in pigs with severe complications.

Increased expression of complement component C3 in the plasma of obese Zucker fa and LA/N fa(f) rats compared with their lean counterparts.

OBJECTIVES: The objectives of this study were to determine whether there are differences in the electrophoretic profiles of plasma proteins from lean and obese rats and to identify a protein that was found to be more abundant in the plasma of obese rats. RESEARCH METHODS AND PROCEDURES: Plasma proteins from lean and obese Zucker fa and LA/N fa(f) rats were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identity of a band that was differentially expressed was determined by amino acid sequencing and Western blot analysis. RESULTS: A band migrating approximately the same distance as the 116 kDa molecular weight marker was more prominent in plasma from obese rats than in plasma of lean rats. Partial sequencing of the peptide revealed that 17 of the first 18 amino acids at the amino terminus were identical with the corresponding residues in the alpha-chain of complement component C3. Western blot analysis confirmed the identity of the peptide as complement component C3. Complement C3 activity was measured using a hemolytic assay to determine whether there was a corresponding increase in the biological activity of this component in the serum of obese rats. Serum from obese rats was found to have 1.8 times as much complement component C3 activity as serum from lean rats. DISCUSSION: Elevated levels of complement C3 in genetically obese rats may be relevant because increased amounts of C3 could serve as a reservoir from which increased amounts of acylation stimulating protein, a cleavage product of complement C3, could be produced.

The rat corpulent (cp) mutation maps to the same interval on (Pgm1-Glut1) rat chromosome 5 as the fatty (fa) mutation.

The autosomal recessive obesity mutations fatty (fa) and corpulent (cp) arose in separate rat strains, 13M and Koletsky, respectively. By complementation analysis, the two mutations appear to be in the same gene. The somewhat different phenotypes of fa/fa and cp/cp animals probably reflect the fact that the mutations are segregating on different rat strains. The fa mutation has been mapped to the interval between Pgm1 and Glut1 on rat Chr 5, but cp has not been mapped genetically. We mapped cp in 30 obese progeny of a LA/N-BN cp/+ intercross using microsatellite markers for these flanking genes. Cp maps to the same genetic interval as rat fa and mouse db. Cp is flanked by Glut1 and Pgm1: Pgm1-------- cp -------- Glut1 map distance (cM) 1.67 6.67 Thus, cp and fa map to the same approximately 8 cm interval of the rat genome. In conjunction with the complementation studies alluded to above, these findings indicate that cp and fa are mutations in the same gene (Lepr).

Association between mild, routine exercise and improved insulin dynamics and glucose control in obese adolescents.

The association between mild routine exercise and glucose homeostasis, insulin dynamics, and risk factors for coronary artery disease was investigated in obese adolescent males. Subjects (n = 7; mean +/- SD age 13.3 +/- 1.4 yr) were tested before and after 15 wk of supervised mild intensity exercise. Serum glucose (GLU), insulin (IN), and C-peptide (CP) were measured in response to a mixed meal before and after the 15 wk period. Weight, body composition, peak oxygen uptake (peak VO2), resting blood pressure (BP), and blood lipid levels were also assessed pre- and post-training. After training, percent fat and body weight were not decreased compared to the initial values. Relative changes (p < or = 0.02) in mean values for GLU and peptides after training were: fasting GLU, -15%; total GLU response, -15%; peak IN response, -51%; total IN response, -46%; peak CP response, +55%; and total CP response, +53%. Following training, the subjects did not have an increased peak VO2, but showed consistent reductions in systolic BP and LDL-cholesterol (p < 0.05). Increases in hepatic insulin clearance (decreased insulin levels but increased CP levels) might be training adaptations unique to low intensity exercise or to obese youth. Decreased insulin levels with concurrent decreases in resting blood pressure and the LDL-cholesterol levels suggest that mild exercise training may reduce health risk factors without weight loss in the obese adolescent male.

Anticonvulsant effects of intracerebroventricularly administered norepinephrine are potentiated in the presence of monoamine oxidase inhibition in severe seizure genetically epilepsy-prone rats (GEPR-9s).

Pharmacological and neurochemical evidence indicates that brain noradrenergic systems play an important role in the determination of audiogenic seizure severity in genetically epilepsy-prone rats (GEPRs). In earlier studies, intracerebroventricular (ICV) injections of norepinephrine suppressed convulsions in a now extinct moderate seizure GEPR colony. Also, ICV noradrenergic agonists are known to produce dose-related anticonvulsant effects in the extant moderate seizure GEPRs (GEPR-3s). The present experiments were undertaken to determine whether ICV norepinephrine also suppresses audiogenic seizures in the extant GEPR-3s and in the severe seizure genetically epilepsy-prone rats (GEPR-9s). Injections of norepinephrine or vehicle were made into the lateral ventricle through implanted guides. GEPR-9s were pretreated systemically either with the monoamine oxidase inhibitor pargyline or with saline. GEPR-3s received no pretreatment. In pargyline pretreated GEPR-9s, seizure severity fell and the fraction of animals exhibiting an anticonvulsant response increased progressively as the dose of norepinephrine was increased. In saline pretreated GEPR-9s, the anticonvulsant dose response curve for norepinephrine was shifted to a higher dose range. Accordingly, the anticonvulsant dose50 for norepinephrine was significantly greater in saline pretreated GEPR-9s than in pargyline pretreated animals. Moreover, the dose required to produce the anticonvulsant effect in GEPR-9s was approximately 10 fold greater than in the earlier studies in the extinct moderate seizure GEPRs. Also, the current experiment with extent GEPR-3s, showed that ICV norepinephrine was anticonvulsant in the same dose that was effective in the extinct colony of moderate seizure GEPRs. In general terms, these observations provide additional evidence that noradrenergic influences are anticonvulsant in the GEPR. The neurobiological factors responsible for reduced responsiveness of the GEPR-9 are presently unknown.

Arylsulfatase and beta-glucuronidase expression in green sunfish, bluegill, and their reciprocal interspecific hybrids.

Fish arylsulfatases (arylsulfate sulfohydrolase; EC 3.1.6.1) were resolved into cationic arylsulfatase A-like (ARSA) and anionic arylsulfatase B-like (ARSB) fractions by DEAE-Sephacel chromatography. Green sunfish (GSF) hepatic ARSA was more acidic and more thermostable than bluegill (BG) ARSA. GSF x BG interspecific hybrids preferentially expressed GSF ARSA, while BG x GSF hybrids appeared to produce a dimeric enzyme consisting of both GSF and BG ARSA polypeptides. GSF hepatic beta-glucuronidase (GUS) also proved to be more thermostable than BG GUS. Thermostabilities of GUS produced by reciprocal interspecific hybrids were very similar to that of GSF GUS. Either GSF GUS is preferentially expressed in both interspecific hybrids or both the GSF and BG GUS polypeptides are synthesized in comparable amounts, and the GSF GUS polypeptide sufficiently stabilizes the heterotetramers produced by the hybrids to produce denaturation profiles closely approximating that of the GSF enzyme.

Exercise adaptation responses for gastric inhibitory polypeptide (GIP) and insulin in obese children. Possible extra-pancreatic effects.

Thirteen obese children and matched controls were fed a mixed meal, and responses were evaluated at fixed intervals for glucose, insulin, and gastric inhibitory polypeptide (GIP). The obese children were evaluated before and within 48 h after completion of a 5-mo exercise training program (ETP). The ETP included three aerobic exercise sessions per week and modest diet restrictions. Caloric expenditure was increased by approximately 300 kcal/exercise session. Weight gain was minimal over the 5 mo. An unexpected increase in GIP response and improved insulin tolerance were recorded for the obese children post-ETP. GIP values were higher (P less than 0.05) at 30 and 60 min and led to a highly significant elevation (P less than 0.01) of the integrated GIP response for post-ETP obese versus both pre-ETP and normal-weight controls. Insulin values were lower (P less than 0.05) at 30 and 60 min and led to a lower integrated insulin response (P less than 0.0585) for post-ETP obese children. However, the obese children continued to secrete more insulin (P less than 0.05) than normal-weight controls. Glucose tolerance, similar for pre-ETP obese subjects and controls, did not change in post-ETP children. Exercise-induced improvement in glucose utilization in these obese children was associated with an increase in GIP secretion. This contrasts with reports that calorie restriction will improve glucose utilization with decreased insulin and GIP secretion. The study demonstrates a previously unreported uncoupling of GIP and insulin secretion and suggests shifts in peripheral tissue sensitivity to insulin-induced glucose uptake. These shifts may, in part, be influenced by GIP.

Moderate diet control in children: the effects on metabolic indicators that predict obesity-related degenerative diseases.

Nine prepubertal obese boys ages 9 1/2 to 12 yr followed moderately restricted diets and moderate exercise routine for 31 wk. Foods were selected from the family's basic diet and the physical activities were tailored to the home environment. This dietary (approximate decrease of 600 kcal/day) and activity (approximate increase of 300 kcal/day) intervention program was sufficient to stop weight gain and normalize key metabolic indices for prediction of atherosclerosis, hypertension, and diabetes. Throughout the treatment period serum lipid responses included significantly lower (p less than 0.05) total cholesterol, low-density lipoprotein-cholesterol and triglycerides. High-density lipoprotein-cholesterol was constant throughout the period. Responses in carbohydrate metabolism included significantly lower (p less than 0.05) fasting insulin and glucose. Insulin and glucose levels were positively correlated with total caloric consumption and insulin was also positively correlated with sucrose consumption (p less than 0.05). Fasting insulin/glucose ratios and glycosylated Hb decreased throughout the treatment period, but serum glucagon levels remained constant. In response to a glucose load, insulin and glucose decreased significantly by wk 31 of treatment. A practical approach for normalizing metabolism in obese male children is presented.