Obesity and gastro-esophageal reflux disease: a 2009 update

The reports describing that obesity per se predisposes to gastroesophageal reflux disease (GERD) have brought conflicting results. Establishing a causal link between these two conditions would be of major public health importance, because of their present epidemic proportions. To date, some large studies examining the relationship between obesity and GERD found a strongly positively relationship while others did not. The main cause of this discordance is the vast heterogeneity of such studies: sufficiently powerful design is found only in few investigations, GERD is defined with a low degree of homogeneity, biases are obvious in the choice of diagnostic methods, thus giving room for large variations in the adjustment of potential confounding factors. Future research should take three directions: 1) prospective population-based studies in which the incidence or recurrence of GERD should be evaluated in correlation with body mass index; 2) intervention trials, focusing on the benefit of weight loss in the prevention of GERD and its recurrence; 3) studies of physiopathology (both in the animal models and humans) to understand the potential biological plausibility.

Remaining small bowel length: association with catheter sepsis in patients receiving home total parenteral nutrition: evidence of bacterial translocation

Patients with short bowel syndrome (SBS) receiving total parenteral nutrition (TPN) have a high incidence of catheter-related sepsis, one of its major complications. The aim of this study was to correlate the length of remaining small bowel (RSB) with septic episodes related to the central venous catheter in a group of patients with severe SBS with home TPN. The length of the RSB (<50 cm or > or = 50 cm) was related to the frequency of catheter sepsis, time until the first episode, and the agents responsible in eight SBS patients receiving home TPN. There were 13 episodes of catheter infection (0.88 per patient-year). The group with a shorter RSB length (five patients) presented 1.3 to 2.76 infections/year and 2 to 9 months until the first episode, compared to 0 to 0.75 infections/ year (p = 0.0357) and 11 to 65 months until the first episode (p = 0.0332) in the group with the longer RSB. In the first group, the agents isolated were Enterobacteriae (Enterobacter sp., Klebsiella sp., Pseudomonas sp., and Proteus sp.) in eight episodes and Candida sp. in one. In the latter sepsis was caused by Staphylococcus sp. in three episodes and Pseudomonas sp. in one. Therefore patients with remaining small bowel shorter than 50 cm have a higher frequency of catheter-related sepsis, particularly by enteric microorganisms. This might be an evidence of the occurrence of bacterial translocation and its role in the pathogenesis of catheter-related sepsis in patients with an extremely short RSB receiving home TPN.

[Endoscopic gastrostomy in patients with complicated heart diseases]

Complicated cardiologic patients with brain ischemia and heart failure need long term enteral nutrition. Long term nasoenteral tube feeding may cause complications that could be avoided with percutaneous endoscopic gastrostomy. The aim of this study was to evaluate the indications for percutaneous endoscopic gastrostomy and its main complications. Twelve patients were submitted to percutaneous endoscopic gastrostomy (eight male) with main age of 62.42 +/- 22.10 years old. Brain ischemia was the main indication of percutaneous endoscopic gastrostomy and occurred after 35.58 +/- 26.79 days, after initiated enteral nutrition. There were no complications during procedure. On late post operatory period there were local infection in one cases, treated with local care. In conclusion, percutaneous endoscopic gastrostomy is a secure technique with low incidence of complications and its indication should be earlier.

Lipid and lipid-free total parenteral nutrition: differential effects on macrophage phagocytosis in rats

Lipid emulsions provided with total parenteral nutrition (TPN) have been associated with mononuclear phagocytic system functional changes. The aim of the present investigation was to assess the influence of TPN with added lipid emulsions on macrophage (M phi) phagocytosis. Wistar rats (n = 70) with external jugular vein cannulation were randomized into seven groups. The rats received an oral diet or six different isocaloric (1.16 kcal/mL), isonitrogenous (1.5 g/mL), and isolipidic (30% non-protein calories) TPN regimens: (a) an oral diet with intravenous infusion of saline (OS); (b) non-lipid TPN (glucose); (c) TPN with 10% long chain triacylglycerol emulsions (LCT); (d) TPN with 90% LCT and 10% fish oil (FO) emulsion; (e) TPN with 50% LCT and 50% FO; (f) TPN with 10% lipid emulsion with 50% medium chain triacylglycerol (MCT) and 50% LCT; and (g) TPN with 45% MCT, 45% LCT, and 10% FO. After 96 h of TPN or saline infusion, colloidal carbon (Pelikan, Germany) was injected intravenously at 1.0 mL/kg body weight, and the rats were killed after 3 h. Liver, spleen, and lung were weighed and prepared by immunohistochemistry analyses with the HAM-56 anti-M phi antibody. Under light microscopy, the total M phi number (MT) and the colloidal carbon phagocytic M phi number (MP) were established, and the phagocytic index was calculated as MP/MT x 100. There were no statistical (P < 0.05) differences in liver, spleen, or lung weights among the seven groups in comparison with the OS group. Non-lipid TPN inhibited spleen and lung M phi phagocytosis when compared with the OS and lipid-TPN groups. Lipid TPN supplemented with fish oil emulsion increased total liver and lung M phi number and phagocytosis. These results indicate that TPN supplemented with fish oil increases M phi phagocytosis in rats.

[Effect of total++ time of extracorporeal circulation in in myocardial revascularization surgery on urinary urea nitrogen loss]

Cardiopulmonary bypass probably should be an important factor increasing surgical stress when heart surgery is focused. This study was undertaken in order to evaluate the role of cardiopulmonary bypass in proteic catabolism. Study group consisted of patients who underwent cardiac aortic bypass graft as an isolated procedure. Inclusion criteria were elective surgery and absence of comorbidities after a rigorous preoperatory evaluation. One hundred and five patients were studied prospectively and urinary nitrogen loss was measured in the first 24 hour postoperative period. Operations performed were standard cardiopulmonary bypass procedures, under cardiopulmonary bypass, moderate hypothermia and hemodilution. Saphenous veins and mammary artery grafts were performed in all cases. Correlation and multiple linear regression were used. There was found no correlation between urinary nitrogen loss and age, gender and time under cardiopulmonary bypass. A positive correlation was found between number of grafts and increased urinary nitrogen loss. Further studies comparing cardiac aortic bypass graft with and without cardiopulmonary bypass are suggested.

Small bowel adaptation with growth hormone and glutamine after massive resection of rat's small bowel

The use of glutamine (GLN) and growth hormone (GH) improves intestinal adaptation in short bowel syndrome (SBS). The present study aimed to assess the effect of a diet rich in glutamine and the use of GH on intestinal adaptation in experimental SBS. 80 Wistar rats (240 g) were randomized into 6 groups: 1) RGLN (20)--95% small bowel resection and fed on GLN diet; 2) RGLNGH (20)--95% SBR, GLN diet and GH; 3) RC (10)--95% SBR and fed on a low GLN control diet (C); 4) RCGH (10)--95% SBR and C diet and GH; 5) TAGLIN (10)--intestinal transection and anastomosis (Ta) and fed on a GLN diet; 6) TAGLNGH (10)--Ta and GLN diet and GH. GH was given SC at a dose of 0.14 mg/kg/day. The rats were weighed daily and nitrogen balance was made. Rats were sacrificed after 15 days and mucosa cell proliferation was studied with PC10 antibody. Statistical analysis was performed. All SBR rats lost weight as compared to their initial weight (8% to 13%). GH improved Ta rats weight (18.98 x 5.04%). The use of GLN diet and GH improved nitrogen balance and bowel growth on SBR groups, as compared to controls, but not cell proliferation. In conclusion, the use of GLN enriched diet and GH improves intestinal adaptation after massive resection of the small bowel in rats.

Clinical use of growth hormone and glutamine in short bowel syndrome

Growth hormone (GH) and glutamine (GLN) are considered bowel trophic factors and are used experimentally after bowel resection. Their clinical uses in short bowel syndrome (SBS) are still not standardized. It is of interest to verify metabolic, nutritional and side effects of the association of GH and GLN in SBS. Three patients, 39 (A), 33 (B), and 01 years old (C) underwent bowel resection with jejunum anastomosis 15 cm (A) and 60 cm (B) distant from the Treitz angle, and 40 cm (C) preserving the ileo cecal valve. GH Saizen (Serono-A), Genotropin (Pharmacia-B), and Norditropin (Novonordisk C) were administered in doses of 0.14 mg/kg/day. GLN (0.4 g/kg/day) was given orally for 10 days (A), 30 days (B) and 60 days to patient C (0.28 g/kg/day). Central TPN and adequate oral diet was administered according to the bowel adaptation phase. On the first day after beginning treatment patient A exhibited symptoms of hypoglycemia. There were no other side effects. After treatment, body weight was higher and analysis by bioelectrical impedance showed more lean mass and less fat mass compared to pre-treatment measurements. Nitrogen retention was progressively higher with treatment. Simultaneous treatment with GH and GLN does not cause significant side effects, and is associated with a favorable distribution of the body compartments and nitrogen retention in patients with the short bowel syndrome.

[Effect of glucidic and fat total parenteral nutrition on macrophage phagocytosis in rats]

Fat lipid emulsions in Total Parenteral Nutrition (TPN) have been associated to Mononuclear Phagocytary System (MPS) changes. Intravenous lipid emulsions may alter macrophage membrane composition but there are controversies about their effects on MPS function. The aim of the present investigation was to assess the influence of fat free TPN and fat emulsions TPN on the macrophage phagocytosis. Wistar rats (70) with external jugular vein canulation were divided in seven groups. The rats received, intravenously (i.v.) different isocaloric (1.16 kcal/mL), isonitrogenous (1.5 g/mL), and isolipidic (30 to 32% of non-proteic caloric value) TPN regimens or oral diet: 1) Group OS: oral diet with i.v. infusion of saline; 2) Group GLU: fat-free TPN; 3) Group LCT: TPN with 10% long chain triglecide emulsion (TCL); 6) Group MCT: TPN with 10% lipid emulsion with medium chain triglycerides (TCM-50%) and TCL (50%). After 96 hours of TPN or saline infusion, colloidal carbon was i.v. injected at 1.0 mL/kg body weight. The rats were sacrificed after three hours. Liver, spleen and lung were weighted and studied by immunohistochemistry by the avidine-biotine method. Under light microscopy the total macrophage number (MT) and colloidal carbon phagocytic macrophages number (MF) were established. Phagocytic index was MT/MF x 100. The results were statistically analysed (p < 0.05). The group under oral diet (OS) was the only one to gain weight. There were no differences in organ weight in any group. There were changes in MT, MF and phagocytic index in all TPN groups. Fat free TPN inhibited liver, spleen and lung macrophage phagocytosis. Fat TPN with TCL inhibited liver and lung macrophage phagocytosis. At conclusion fat free TPN or with long chain tryglicerides may inhibit MPS phagocytosis. Further studies are necessary to estabilish the effect of TPN on other MPS function.

[Technical and histological standardization of experimental colitis with trinitrobenzenosulfonic acid (TNBS)]

Attempts to reproduce inflammatory colitis have created many experimental models. Since the pioneer work of Morris et al. (1989), trinitrobenzenosulfonic (TNBS) solutions have been used with different dosages. The aims of this work were standardize the induction of colitis, evaluate the clinical and intestinal effects of different doses and verify the reproducibility of the intestinal inflammatory process. Wistar rats were inoculated endo rectally with 2.5 ml solutions of different concentrations of TNBS and ethanol, and the rats were sacrificed after 14 days. According to the solution concentrations of TNBS (mg) and ethanol (%), six groups of animals were established: Control (saline), 30 mg/30%, 30 mg/40%, 30 mg/50%, 50 mg/10% and 50 mg/30%. Statistical analysis of food ingestion showed no differences between groups (p = 0.247). The 30/50 group presented greater weight loss when compared to 50/10 and 50/30 groups (p = 0.012). Groups 30/50 and 30/40 showed greater degrees of macroscopic lesion than control and 50/10 group (p < 0.05). Histologic lesion was not uniform to all rats regardless of the solution employed. Group 50/10 presented the less severe histologic alterations; on the other hand, 30/40 and 30/50 groups had important changes on mucosal thickness, on vascularization and ulceration. The authors conclude that experimental colitis with TNBS 1) cause intestinal lesions that are not uniform to all animals, although they may be reproduced in many of them; 2) with the same doses of TNBS, the increase in ethanol concentrations leads to a greater inflammatory process, intestinal thickness, vascularization, abscess formation and intestinal ulceration; 3) 50/10 and 50/30 solutions make less severe lesions when compared to 30/40 and 30/50 solutions; 4) 30/50 solution was the best one, as it produces inflammation 90% of the animals, increases in wall thickness in 50%, abscess in 70% and ulceration in 38%.

[Biological activity of fish oil]

Omega-3 fatty acids (n-3) found specially on fish oil are represented by the acid alfa-linolenic, eicosapeniaenoic and docosahexaenoic. After 72 hours of n-3 fatty acids intake there are changes on membrane composition and decrease of synthesis of prostaglandin (PG), leucotriens (LT) and thromboxanes (TX) of the 2 and 4 series production and substitution for prostaglandin, thromboxanes and leucotriens of 3 and 5 series respectively. These alterations can modulate the inflammatory response in some diseases. N-3 fatty acid have been used in cardiology on hypercholesterolemy and hypertension control and on immunologic diseases as psoriasis, rheumatoid arthritis and Crohn disease. Experimentally the n-3 fatty acid inhibit tumor growth and metastasis. The authors consider the biophysiological actions of n-3 fatty acids and discuss the results of its use on clinical results.