Naganori Hayashi

Influences of soybean oil emulsion on stress response and cell-mediated immune function in moderately or severely stressed patients

OBJECTIVES We previously reported that omega-6 fat emulsion increases cytokine production in burned rats. Effects of soybean oil emulsion on surgical stress responses and lymphocyte function according to the surgical severity have not been studied in detail. We investigated the effects of soybean oil emulsion, which contains 50% omega-6 fatty acid, on postoperative stress responses and cell-mediated immune function according to the severity of surgical stress. METHODS Eight patients who underwent gastric or colorectal surgery and nine who underwent esophagectomy were fed fat-free total parenteral nutrition. Ten patients who underwent gastric or colorectal surgery and seven who underwent esophagectomy were fed total parenteral nutrition with soybean oil emulsion. Total parenteral nutrition provided 1.5 g of protein and 40 kcal per kilogram every day from 7 d before surgery to postoperative day 14. Soybean oil emulsion (Intralipid) accounted for 20% of the total calories. Serum interleukin-6, C-reactive protein, glucagon, and concanavalin A- or phytohemagglutinin-stimulated lymphocyte proliferation were determined. RESULTS In the group of moderately stressed patients, soybean oil emulsion did not amplify the measured levels. In the group of severely stressed patients, soybean oil emulsion amplified the level of serum interleukin-6 and decreased concanavalin A- or phytohemagglutinin-stimulated lymphocyte proliferation. CONCLUSIONS Soybean oil emulsion amplifies the stress responses and possibly suppresses cell-mediated immune function induced by surgical stress in severely stressed patients, but not in moderately stressed patients.

n-3 Versus n-6 Polyunsaturated Fatty Acids in Critical Illness

The effects of n-6 and n-3 polyunsaturated fatty acids (PUFA) on protein metabolism, cell-mediated immunity, and production of cytokines and prostanoids were studied in experimental animals and patients with esophageal cancer. In the experimental study using a rat burn model, n-6 PUFA increased serum interleukin-6 (IL-6) and tumor necrosis factor (TNF), alpha (P < 0.05), and decreased nitrogen balance (NB) (P < 0.05), when compared with a fat-free control. But addition of n-3 PUFA reduced TNF-alpha and IL-10 (P < 0.05) and improved NB (P < 0.05). Suppressed delayed type hypersensitivity (DTH) induced by burn injury, which was not influenced by n-6 PUFA, was significantly improved by the administration of n-3 PUFA. n-6 PUFA tended to increase, and n-3 PUFA significantly decreased the endotoxin translocation. DTH, granulocyte-macrophage colony-stimulating factor, and eicosapentaenoic acid (EPA) content increased proportionately with the intravenous dose of fish oil emulsion. The effects of n-6 and n-3 PUFA were studied in the patients who underwent surgery for esophageal cancer. In the group of patients fed by total parenteral nutrition with soybean oil emulsion, the serum IL-6 significantly increased at 2 and 6 h after operation (P < 0.05). Oral/enteral supplementation of EPA ethyl ester (1.8 g/d) significantly reduced the postoperative IL-6 production (P < 0.05 at 1, 2, and 6 h after operation), and improved cell-mediated immune function 3 wk after operation (P = 0.05). During the chemoradiation therapy, cell-mediated immune function was improved significantly in the patients fed enterally with EPA ethyl ester (n = 5), when compared with the patients without EPA (n = 14).

Effects of Soybean Oil Emulsion and Eicosapentaenoic Acid on Stress Response and Immune Function After a Severely Stressful Operation

OBJECTIVE To investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer. SUMMARY BACKGROUND DATA It has been reported that safflower oil, rich in n-6 polyunsaturated fatty acid (n-6 PUFA), affects the survival rate of septic animals and decreases the immune function. It has also been reported that the administration of fish oil, in contrast, reduces these stress responses and stress-induced immunosuppression. In humans, the effects of soybean oil emulsion and the administration of EPA on stress response and immune function after surgery have not been established. METHODS Patients who underwent esophagectomy with thoracotomy were divided into three groups. Seven patients were fed by total parenteral nutrition (TPN) with soybean oil emulsion, which accounted for 20% of total calories. Seven patients were given oral or enteral administration of 1.8 g/day EPA, in addition to TPN with soybean oil emulsion. Nine patients served as the control group; these patients received fat-free TPN. Serum interleukin-6 (IL-6), C-reactive protein, concanavalin A (con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation, natural killer cell activity, and stress hormones were measured. RESULTS The postoperative level of serum IL-6 was significantly higher in the group receiving soybean oil emulsion than in the fat-free group. Oral or enteral supplementation of EPA with soybean oil emulsion significantly reduced the level of serum IL-6 compared with the patients receiving soybean oil emulsion. Con A- or PHA-stimulated lymphocyte proliferation decreased significantly on postoperative day 7 in all groups of patients. The supplementation of EPA with soybean oil emulsion significantly improved the lymphocyte proliferation and natural killer cell activity on postoperative day 21 compared with the group receiving soybean oil emulsion. CONCLUSIONS Soybean oil emulsion amplifies, and the supplementation of EPA reduces, the stress response and stress-induced immunosuppression.

Changes in immune function following surgery for esophageal carcinoma.

Changes in immune function due to surgical injury have been well-documented. Immunosuppression is one of the causes of infectious complications leading to organ dysfunction in critical illness. It is not known what kind of surgery in the daily clinical practice causes immunosuppression. Stress response and immune function following surgery for esophageal carcinoma, assuming a highly-stressed operation, were studied and then compared with the stress response and immune function following gastric surgery, a moderately-stressed procedure. Forty patients who underwent esophagectomy and 39 patients receiving gastric operation were studied. The concentrations of serum interleukin-6 (IL-6) were measured preoperatively, at 1, 2, and 6 h, and at 1, 3, and 10 d after operation. Total protein, serum albumin, rapid turnover protein, serum CRP, and cortisol were measured before operation and at 1, 3, 7, and 21 d after operation. ConA- and PHA-stimulated lymphocyte proliferation, IgA, IgG, and IgM were also measured preoperatively, and on 7 and 21 d following surgery. The patients were fed exclusively by total parenteral nutrition (TPN). A striking rise of IL-6 was observed, with a peak in both groups at 1 to 6 h following operation. The peak values were 419+/-30 pg/mL, which was approximately twice as high in the esophagectomy patients as in the gastrectomy patients (195+/-40 pg/mL). CRP and cortisol also increased after operation, and these increases were also significantly greater in the esophagectomy patients. ConA- and PHA-stimulated lymphocyte proliferation decreased significantly 7 d after esophagectomy (P<0.05), but was unchanged in the patients receiving gastrectomy. Suppression of cellular immunity correlated significantly with serum cortisol, and was preceded by a rise in serum IL-6. The IgA, IgG, and IgM levels, however, remained unchanged from their preoperative values throughout the study in both groups. Nutritional status in terms of serum protein, albumin, and rapid turnover protein, decreased postoperatively, but there was no difference between the two groups. It is, therefore, concluded that cell-mediated immunosuppression, preceded by a hyperinflammatory response, is an observable reaction in patients following esophageal surgery, but not in patients undergoing gastric surgery.

Effect of intravenous ω-6 and ω-3 fat emulsions on nitrogen retention and protein kinetics in burned rats

Abstract The effect of ω-3 fat emulsion on nitrogen retention and kinetics in relation to fatty acid profile were investigated in burned rats receiving total parenteral nutrition (TPN). A fat emulsion of a structured symmetrical triacylglycerol containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (2:1) was prepared. Sprague-Dawley rats were fed by fat-free chow for 2 wk. Then rats were fed exclusively with one of three types of TPN for 7 d. Animals in group C received fat-free TPN ( n = 11). Group ω6 received safflower oil fat emulsion, which accounted for 20% of total caloric intake ( n = 11). Group ω3 received fat emulsion containing only EPA and DHA (1% of total calories, n = 11), in addition to safflower oil emulsion (19% of total calories). On day 5, each rat was subjected to 20% full-thickness scald burns. Rats were sacrificed under ether anesthesia 48 h after burning. The rats in group C became deficient in ω-6 essential fatty acids. Cumulative nitrogen balance was decreased significantly in group ω6. The rates of whole-body protein synthesis were increased significantly in both groups ω6 and ω3. In ω6, however, the rates of whole-body protein breakdown were increased significantly. In conclusion, the rates of whole-body protein breakdown increased and nitrogen retention was aggravated significantly in animals administered the safflower oil emulsion. Significant increases of urinary excretion of total catecholamine were also observed. Prostaglandin E 2 and thromboxane B 2 concentrations were not significantly different among three groups. Supplementation with the new ω-3 fat emulsion, however, improved protein metabolism in burned rats receiving TPN.

Effects of total parenteral nutrition on endotoxin translocation and extent of the stress response in burned rats

Postburn endotoxin translocation has been well documented. However, the relationship between the secretion of catabolic hormones, degree of endotoxin translocation, and intestinal atrophy has not been previously demonstrated. In this experiment, modulation of the secretion of catabolic hormones according to the route of nutrient administration was examined in burned animals. A total of 55 rats, with and without a burn injury, were orally or parenterally fed. Urinary excretion of epinephrine and norepinephrine (U-EN) of each rat was measured for 48 h after burn injury as an indicator of the stress response. Evaluations of intestinal atrophy and endotoxin contents in the liver and spleen were also done 48 h after burn injury. U-EN after burn injury in rats administered total parenteral nutrition (TPN) was higher than in those fed orally. Endotoxin translocation and intestinal atrophy after thermal injury were also augmented by TPN. A significant positive correlation between U-EN and endotoxin content of the liver, and a negative correlation between U-EN and weight of the intestine, were observed. TPN enhances the stress response after burn injury. An increase in endotoxin translocation and intestinal atrophy by TPN are closely related to enhancement of the stress response.

Effects of a Newly Developed Fat Emulsion Containing Eicosapentaenoic Acid and Docosahexaenoic Acid on Fatty Acid Profiles in Rats

A new fat emulsion of symmetrical triacylglycerols, containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was developed. The effects of this preparation on serum and liver fatty acid composition were investigated. Male Sprague-Dawley rats were fed a fat-free oral diet for 2 wk and were then divided into two groups. Seven rats were infused for 7 d with 1 mL of the new fat emulsion, which accounted for 1% of total caloric intake. The other 7 rats received saline. Both groups of rats received a fat-free diet during the infusion. EPA and DHA decreased to one third to one fifth of normal value after 2 wk on a fat-free diet. EPA and DHA of serum and liver remained at a low level in the control group throughout the study. But in the rats administered with the new fat emulsion, EPA and DHA increased rapidly and exceeded normal values in both serum and liver after 7 d of infusion. Decreased arachidonic acid with increased 20:3n-9 resulted in the rise of the triene/tetraene (T/T) ratio to greater than 0.4, indicating an n-6 essential fatty acid deficiency in the control rats. In the group administered the new fat emulsion, however, 20:3n-9 and total content of monounsaturated fatty acids decreased significantly, and the T/T ratio was less than than 0.4 in both serum and liver. In conclusion, the intravenous use of a newly developed fat emulsion containing EPA and DHA is useful in improving the EPA and DHA status of serum and liver without any harmful effects. Beneficial effects are expected in the modulation of inflammatory and stress response.

Effects of insulin-like growth factor-1 on endotoxin translocation in burned rats receiving total parenteral nutrition.

The purpose of this study was to investigate the effect of insulin-like growth factor-1 (IGF-1) on the translocation of endotoxin from the gut of burned rats. Twenty-eight male Sprague-Dawley rats (7-wk-old) were subjected to 20% full-thickness scald burns and were divided into two groups. One group received 4 mg.kg-1.d-1 of IGF-1 (IGF-1 group, n = 14), and the other received saline (control group, n = 13). All rats were fed exclusively by total parenteral nutrition (TPN). On the second postburn day, rats were killed. The amount of endotoxin in the liver and spleen were measured. RNA from the terminal ileum was extracted, and Northern blot analyses of alpha-tubulin, beta-actin, cell division cycle-2 (cdc2), and immunoglobulin-A (IgA) were performed. Nitrogen balance was improved (p < 0.001), and the wet weight of intestine and its mucosa were increased significantly in the burned rats that received IGF-1. Gene expression of alpha-tubulin and beta-actin were not changed. Cdc2 was elevated (P < 0.05), but IgA was decreased (P < 0.05) in the IGF-1 group. Levels of endotoxin in the liver and spleen were significantly reduced (P<0.05) by the administration of IGF-1. A negative correlation between the levels of endotoxin in the liver and the weight of the intestinal mucosa was observed. In conclusion, IGF-1 improved nitrogen balance, promoted the proliferation of intestinal mucosa and reduced the translocation of endotoxin.

An inflammatory fibroid polyp of the esophagus concomitant with a superficial flat carcinoma

Abstract We report a rare case of an inflammatory fibroid polyp (IFP) of the esophagus associated with an extensive early mucosal carcinoma. At esophagoscopy, a polypoid lesion 2 cm in length, and a non-stained area detected by the Lugol iodine spray staining method were found in the mid-thoracic portion, and esophagectomy was performed. Endoscopic polypectomy is thought to be useful for the diagnosis of IFP, but it should be kept in mind that IFP may be concomitant with carcinoma. Indeed, in our patient, early esophageal carcinoma was discovered because of the symptoms of dysphagia induced by the IFP.