Inflammatory response and bacterial dissemination after laparotomy and abdominal CO2 insufflation in a murine model of peritonitis.

BACKGROUND: The immunologic repercussions due to cavity insufflation are the focus of great discussion. The aim of this study was to compare the inflammatory response and bacterial dissemination after laparotomy and abdominal CO2 insufflation in a murine model of peritonitis. METHODS: Swiss mice were inoculated intraperitoneally with 0.5 ml of a solution containing 1 x 10(8) colony-forming units (CFU)/ml of Escherichia coli and were divided into three groups as follow: control (anesthesia for 30 min), laparotomy (2.5-cm midline incision for 30 min), and CO2 pneumoperitoneum (CO2 cavity insufflation for 30 min). The number of leukocytes, CFU/ml counting, and the levels of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and IL-10 were evaluated in blood, peritoneal, and pleural fluid samples obtained at 90 min and 18 h after the procedures. RESULTS: The laparotomy group showed a greater bacterial dissemination to the blood, peritoneum, and pleural cavity and also greater neutrophil migration to the peritoneal cavity compared to the CO2 insufflated and control groups. The 24-h mortality was also significantly higher in the laparotomy group. The IL-6 levels showed a precocious rise in all groups submitted to bacterial inoculation at the 90-min time point. At the 18-h time point, IL-6 levels in the peritoneum were significantly higher in the laparotomy group than in the control or CO2 insufflated groups. At the same time, TNF-alpha levels were higher in the laparotomy and CO2 insufflated groups than in controls; IL-10 levels showed no differences among the groups. CONCLUSIONS: Our results suggest that cavity insufflation with CO2 is a more effective method of access, inducing less bacterial dissemination and also a less intense inflammatory response. Cavity insufflation with CO2 may present a good option for the surgical treatment of patients with bacterial peritonitis.

Oxidative stress effects on the central nervous system of rats after acute exposure to ultra high frequency electromagnetic fields.

Mobile telephones and their base stations are an important source of ultra high frequency electromagnetic fields (UHF-EMFs; 800-1800 MHz) and their utilization is increasing all over the world. Epidemiological studies have suggested that low energy UHF-EMFs may have biological effects, such as changes in oxidative metabolism after exposure. Therefore, we have investigated the effect of acute UHF-EMF exposure on non-enzymatic antioxidant defense and lipid and protein oxidative damage in the rat frontal cortex and hippocampus. We have used malondialdehyde (MDA) and carbonyl assays to assess lipid and protein oxidative damages, respectively. No changes in lipid and protein damage, and also in non-enzymatic defense were found in frontal cortex or hippocampus. These results suggest that acute UHF-EMF exposure is not able to produce detectable oxidative stress in rats from any age tested. However, more tests using a longer period of exposure and evaluating other tissues are necessary to ensure that there is no health risk associated with the use of mobile phones.

Uptake of a cholesterol-rich emulsion by neoplastic ovarian tissues.

OBJECTIVE: Previously, it was shown that a lipidic emulsion (LDE) composed of phospholipids and cholesterol esters which binds to low-density lipoprotein (LDL) receptors may concentrate in acute myeloid leukemia cells. In this study, we aimed to verify whether LDE also has the ability to concentrate in malignant ovarian cancer after being injected into the blood circulation of the patients. METHODS: Three groups of women scheduled for surgery were included in the survey: 13 bearing malignant tumors, 9 with benign ovarian tumors, and 13 without ovarian tumor who were scheduled to undergo oophorectomy due to malignant disease of the uterine cervix or endometrium. On the day prior to surgery they were injected with LDE labeled with [(14)C]cholesteryl oleate. Specimens of tumors and normal ovaries excised during surgery were lipid extracted and analyzed for radioactivity counting. Results were expressed in radioactive count (cpm) per gram of tissue. RESULTS: The mean of the uptakes of the emulsion radioactivity by the malignant tumors was roughly eightfold greater when compared with that of the contralateral normal ovaries (2261 +/- 1444 and 275 +/- 137 cpm/g, respectively, P < 0.012), benign tumors, and normal ovaries of the patients without ovarian tumors. CONCLUSION: LDE has the ability to concentrate in malignant ovarian tumor tissue. Therefore, it can be used as a vehicle to direct cytotoxic drugs against malignant ovarian tumors, thus diminishing the side effects of chemotherapy.