Cytokine changes in the postoperative period

Postcolectomy Peritoneal Environment Increases Colon Cancer Cell Migration Capacity

Background. Clinical data and animal models support an association between postoperative inflammatory response and the risk of colorectal cancer recurrence. Our aim was to evaluate postoperative peritoneal inflammation and its impact on cultured colon cancer cells' migration capacity. Methods. 23 patients undergoing elective colorectal resection with uneventful recovery were prospectively enrolled. Patients were operated on for both malignant and benign etiologies. Peritoneal fluids collected at surgery initiation and after surgery were evaluated for their effect on migration potential of human colon cancer cells using an in vitro scratch assay and on TNF-α, IL-1β, IL-6, and IL-10 levels using bead-based fluorokine-linked multianalyte profiling. Results. Postoperative peritoneal fluid from all patients increased the migration capacity of colon cancer cells compared to preoperative levels. This effect was significant during the first two postoperative days and decreased thereafter. The increase in colon cancer cell migration capacity correlated with increased levels of peritoneal TNF-α and IL-10. Conclusion. In this pilot study, we have demonstrated that the intraperitoneal environment following colorectal resection significantly enhances colon cancer cells migration capacity. This effect is associated with postoperative intra-abdominal cytokines level. A larger scale study in colorectal cancer patients is needed in order to correlate these findings with perioperative parameters and clinical outcome.

Cytokine response and reactive oxygen species production after low- and intermediate-risk surgery

BACKGROUND

Cytokines are secreted locally in response to surgery and may be released into the systemic circulation. Reactive oxygen species (ROS) production is involved in various inflammatory conditions. The aims of the study were to examine the magnitude of surgical stress on the modulation of immune response and ROS production.

METHODS

Patients undergoing low- and intermediate-risk surgery (n=32) were enrolled. Blood samples for tumor necrosis factor (TNF)α, interleukin (IL)1β and IL10 assays were obtained before anesthesia, immediately after extubation, at 24 and 72 h after surgery. Measurement in whole-blood cultures of ex vivo lipopolysaccharide (LPS) and Staphylococcus aureus Cowan (SAC)-stimulated production of cytokines was carried out. The pro-oxidant potency of the whole serum was assessed in human umbilical vein endothelial cells using a fluorescent probe after stimulation by the plasma collected at the same time intervals.

RESULTS

TNFα, IL1β and IL10 did not increase significantly after surgery in either group. Whole-blood cultures response to LPS and SAC stimulation decreased for IL1β at the end of surgery in the two groups and returned to normal within 24 h after surgery. LPS- and SAC-induced IL10 production increased significantly at 24 h in the low-risk surgery group. ROS production was greater after more stressful surgery and was correlated to morphine consumption.

CONCLUSION

Cytokine release in the systemic circulation was not well correlated to the magnitude of surgical stress, whereas transient immune hyporesponsiveness was seen after moderately stressful surgery. ROS production might be a more accurate indicator of the severity of surgical trauma.

Oral antibiotics attenuate bowel segment reversal-induced systemic inflammatory response and body weight loss in massively bowel-resected rats

BACKGROUND

Using a massively bowel-resected rat model, our previous study demonstrated that small bowel segment reversal stimulates jejunal hyperplasia but may also increase the possibility of bacterial translocation and the elevation of circulating white blood cells and serum interleukin-6 that may reduce the whole-body anabolism. The aim of this study is to investigate whether oral antibiotics might attenuate the inflammatory responses and might therefore facilitate the beneficial effects of bowel segment reversal.

METHODS

Male Wistar rats (approximately 270 g) underwent a 70% small bowel resection with (REV group) or without (CON group) a 3-cm small bowel segment reversal, or underwent a sham operation (SHAM group). After surgeries, half of the animals in the REV group were given oral clindamycin plus amoxicillin (50 plus 50 mg/kg/d, ANT group) for 3 weeks.

RESULTS

Oral antibiotics administration significantly attenuated the decreases in feeding efficiency (g of body weight/100 kcal diet) and increases in the circulation of white blood cells, serum nitric oxide, and interleukin-6 (1-way ANOVA, p < .05), which are associated with bowel segment reversal. In addition, antibiotics significantly increased serum concentrations of insulin-like growth factor-I, significantly decreased the total numbers of bacteria in the intestine, and tended to reduce the extent of jejunal hyperplasia in rats with bowel segment reversal.

CONCLUSIONS

Our results suggest that oral antibiotics may be used as an adjuvant to attenuate the inflammatory responses and to enhance the anabolic responses in massively bowel-resected patients with bowel segment reversal.

Simultaneous measurements of serum insulin-like growth factor-I and leptin reflect the postoperative nutrition status of oral tumor patients

OBJECTIVE

Recent evidence has shown that circulating levels of insulin-like growth factor-I (IGF-I) and leptin are regulated by nutrition support. Our objective was to investigate the reliability of IGF-I and leptin in monitoring the efficacy of nutrition support and nutrition status in oral tumor patients.

METHODS

Fifty-one male patients scheduled to receive resection operation for oral tumor were recruited. Fasted blood samples were collected before surgery (d0), on the first postoperative day before feeding (d1), and on the seventh postoperative day (d7) with nasogastric tube feeding (35 kcal x kg(-1) x d(-1)). Fifty male healthy volunteers were recruited as controls.

RESULTS

After adjustment for age, patients had significantly greater serum concentrations of transferrin and significantly lower serum concentrations of prealbumin and tumor-necrosis factor-alpha than did healthy volunteers on d0. In oral tumor patients, resection with prolonged fasting significantly increased levels of growth hormone and interleukin-6 and significantly decreased levels prealbumin, retinol-binding protein, IGF-I, and leptin, and these alterations were reversed by nutrition support for 6 d in oral tumor patients. Serum IGF-I was further increased on d7 compared with d0. In addition, leptin was the only nutrition-related serum protein showing significantly positive correlation with body mass index in healthy volunteers and patients.

CONCLUSIONS

Our results suggested that simultaneous measurements of serum IGF-I and leptin may provide information with regard to the efficacy of nutrition support and nutrition status in oral tumor patients undergoing surgery.

SYSTEMIC AND LOCAL SECRETIONS OF CYTOKINES AND NITRIC OXIDE IN MASSIVE BOWEL RESECTED RATS WITH OR WITHOUT SMALL BOWEL SEGMENT REVERSAL

Our previous study suggested that small bowel segment reversal stimulates jejunal hyperplasia, but that the elevated serum interleukin (IL-)6 eliminates whole-body anabolism in massive bowel resected rats. The aim of this study was to investigate systemic and local secretions of cytokines and nitric oxide (NO) in relation to whole-body and tissue responses in rats that underwent massive bowel resection with small bowel segment reversal. Seventy percent small bowel resection was performed in Wistar rats with (REV) or without (CON) a 5 cm reversed small bowel segment. Sham operation (SHAM) was performed on a third group of rats. Twelve days after surgery the REV group had significantly lower weight gain and greater serum levels of NO, IL-2 and IL-6 than the CON and SHAM groups. The weights of the livers in the REV and CON groups were significantly heavier, but these groups had lower levels of protein, tumour-necrosis factor-alpha, IL-2 and IL-6 than the SHAM group. The cecum weights of the REV group were significantly higher with increased protein and NO levels, but decreased IL-6 levels compared with the CON and SHAM groups. In the proximal small intestine the REV group had significantly increased protein levels and mucosal dry weights, but decreased interferon-gamma and IL-2 compared with the CON and SHAM groups. Our results suggested that cytokines and NO may have endocrine and paracrine/autocrine actions in regulating whole-body and tissue responses.

Small bowel segment reversal induces intestinal hyperplasia but reduces whole-body growth in massive bowel resected rats

BACKGROUND

Surgical reversal of a small bowel segment has been proposed as a means to improve nutritional status in individuals with extensive bowel resection. However, clinical experience remains controversial. The aim of this study was to determine the effects of bowel segment reversal on intestinal adaptation and whole-body anabolism.

METHODS

Male Wistar rats underwent a 70% small bowel resection with (REV) or without (CON) reversal of a 5-cm small bowel segment (5 cm distal to resected segment), or sham-operation (SHAM). After surgery (day 0), rats were fed with powdered diet from day 2 to day 12. Body weight, nitrogen balance, carcass compositions, and serum concentrations of albumin and insulin-like growth factor (IGF)-1 were determined to assess whole-body anabolism. The composition and architecture of the small intestine were measured to assess the intestinal growth response. Serum concentrations of tumor-necrosis factor (TNF)-alpha and interleukin (IL)-6 were measured to assess the response of postoperative cytokines.

RESULTS

Surgical reversal significantly increased the intestinal protein and DNA contents in the proximal segment compared with surgical resection. REV rats had a significantly slower rate of weight gain and lower serum levels of albumin and IGF-1, and had significantly greater levels of circulating white blood cells, blood urea nitrogen, and IL-6 compared with CON and SHAM rats. There were no significant differences in serum concentrations of TNF-alpha and carcass percentages of water, protein, and fat among groups.

CONCLUSIONS

Small bowel segment reversal stimulates jejunal hyperplasia but the surgical reversal induced-elevation in serum IL-6 may eliminate the whole-body anabolism in massive bowel-resected rats.

The stressful condition as a nutritionally dependent adaptive dichotomy

The injured body manifests a cascade of cytokine-induced metabolic events aimed at developing defense mechanisms and tissue repair. Rising concentrations of counterregulatory hormones work in concert with cytokines to generate overall insulin and insulin-like growth factor 1 (IGF-1), postreceptor resistance and energy requirements grounded on lipid dependency. Salient features are self-sustained hypercortisolemia persisting as long as cytokines are oversecreted and down-regulation of the hypothalamo-pituitary-thyroid axis stabilized at low basal levels. Inhibition of thyroxine 5'-deiodinating activity (5'-DA) accounts for the depressed T3 values associated with the sparing of both N and energy-consuming processes. Both the liver and damaged territories adapt to stressful signals along up-regulated pathways disconnected from the central and peripheral control systems. Cytokines stimulate liver 5'-DA and suppress the synthesis of transthyretin (TTR), causing the drop of retinol-binding protein (RBP) and the leakage of increased amounts of T4 and retinol in free form. TTR and RBP thus work as prohormonal reservoirs of precursor molecules which need to be converted into bioactive derivatives (T3 and retinoic acids) to reach transcriptional efficiency. The converting steps (5'-DA and cellular retinol-binding protein-I) are activated by T4 and retinol, themselves operating as limiting factors of positive feedback loops. Healthy adults with normal macrophage functioning and liver parenchymal integrity, who submitted to a stress of medium severity, are characterized by TTR-RBP plasma levels reduced by half and an estimated ten-fold increase in free ligand disposal to target cells during the days ensuing injury. This transient hyperthyroid and hyperretinoid climate creates a second defense line strengthening and fine-tuning the effects primarily initiated by cytokines. The suicidal behavior of thyroxine-binding globulin (TBG), corticosteroid-binding globulin (CBG), and IGFBP-3 allows the occurrence of peak endocrine and mitogenic influences at the site of inflammation. The production rate of TTR by the liver is the main determinant of both the hepatic release and blood transport of holoRBP, which explains why poor nutritional status concomitantly impairs thyroid- and retinoid-dependent acute-phase responses, hindering the stressed body to appropriately face the survival crisis. The prognostic significance of low TT4 blood levels may be assigned to the exhaustion of extrathyroidal hormonal pools normally stored in liver and plasma but markedly shrunken in protein-depleted states. These data offer new insights into the mechanisms whereby preexisting malnutrition and stressful complications are interrelated, emphasizing the pivotal role played by TTR in that context.

The influence of surgery on cytokines in patients with intra-abdominal sepsis

The cytokine cascade which is triggered by severe sepsis may contribute to progressive organ dysfunction and death from sepsis. This cascade may be accentuated by surgery for sepsis and pre-treatment with cytokine blockers could possibly ameliorate the response. This prospective controlled study determined the effect of surgery in 11 haemodynamically stable patients undergoing laparotomy for intra-abdominal sepsis. Serum levels of endotoxin, IL-1, IL-6, IL-8 and TNF-alpha were determined; blood cultures, features of systemic inflammatory response, and organ dysfunction were monitored over the peri-operative period. There was considerable variation in the serum cytokine levels. The preoperative IL-6 levels were significantly elevated in the septic patients and a threefold increase in IL-6 levels occurred in both groups postoperatively. An increase in TNF-alpha did not achieve significance because of high levels in control patients with cancer. Cytokine release which occurs during abdominal surgery is increased in patients with intra-abdominal sepsis.