[Surgically treated pleomorphic carcinoma of the lung].

We experienced 3 resected cases of pleomorphic carcinoma of the lung. Each cases were 74-year-old man (case 1), 74-year-old woman (case 2) and 69-year-old man (case 3). Two patients (case 1 and 2) were histologically diagnosed as pleomorphic carcinoma composed of spindle cell carcinoma with giant cell carcinoma. One patient (case 3) was similarly diagnosed as pleomorphic carcinoma composed of spindle cell carcinoma with adenocarcinoma and squamous cell carcinoma. Although lymph nodes metastasis were not recognized in all patients, invasion to vessels were recognized in 2 patients (case 1 and 3). In one patient (case 1), recurrence was recognized at contralateral side 1 month after surgery and he died of other disease 2 months after surgery. The other 2 patients were alive without recurrence 24 and 5 months after surgery. Recently it is reported that recurrence is recognized at early phase after surgery and prognosis is poor in a case with vessel invasions in spite of pathological NO state. Since one patient (case 3) had nonmetastatic lymph nodes with vessel invasions, careful observation is considered to be necessary.

[Approach by clamshell incision for bilateral pulmonary metastasis].

In recent years thoracotomy by "clamshell incision" has frequently been chosen for heart-lung transplantation, bilateral lung tumors and mediastinal tumor merging into lung tumor because this approach provides very good visibility to access the whole bilateral lung including the lower lobe and mediastinal organs. In our hospital, 4 patients underwent bilateral thoracotomy by clamshell incision for pulmonary metastasectomy between 2001 and 2005. All cases had bilateral pulmonary metastases, and multiple wedge resection was performed. All lesions that were planned for resection on preoperative computed tomography (CT) could be resected. Regarding the surgical approach to bilateral pulmonary metastases that did not need lobectomy, clamshell incision is one of the useful approaches that can allow wedge resection anywhere in the whole lung. In cases that are expected multiple procedures, bilateral thoracotomy by clamshell incision is recommended because it allows another route for thoracotomy at reoperation.

[Clinical experience with 16 cases of mediastinal lymphoma].

Sixteen cases of mediastinal lymphoma in our hospital were reviewed clinically. There were 7 men and 9 women, whose mean age is 35 years old. The histological types were non-Hodgkins' disease in 12 (B-cell type in 6 and T-cell type in 6), Hodgkins' disease in 2, mucosa-associated lymphoid tissue (MALT) lymphoma in 2. All cases except 1 in which percutaneous needle biopsy was performed were diagnosed histologically. Even small specimens by percutaneous needle biopsy can be helpful in diagnosing histological type and subtype with immunohistlogy, recommending percutaneous needle biopsy as an mitial step for diagnosis. When histological diagnosis can not be made by needle biopsy, open biopsy should be done.

[Clinical analysis of tracheoplasty and bronchoplasty in primary lung cancer].

In our department, there were 482 thoracic surgeries for primary lung cancer between 1994 and 2007. We clinically reviewed cases that underwent tracheoplasty or bronchoplasty (n = 22, 4.6%). The patients consisted of 21 males and 1 female (66.5 +/- 12.0 years-old). All patients were smokers. The tissue forms were 19 squamous cell carcinomas, 2 adenocarcinomas, 1 large cell carcinoma, 1 adenoid cystic carcinoma and 1 carcinoid, including 2 multiple carcinomas. Sleeve resections involved the trachea in 1, upper lobes in 13, lower lobes in 3, upper-middle lobes in 2 and intermediate bronchus in 1. Wedge resections were performed in the upper lobes in 2. Fourteen reconstructions were performed. We ordinarily sutured the trachea and bronchus in any case, using a single outside knot. There was no leakage at the anastomosis. There were 2 hospital deaths. There were 4 cancer deaths, including 2 local recurrences. There were 4 patients demonstrating stenosis post operatively. There were 3 stenoses among 4 preoperative radiation therapies. We considered that radiation therapy disturbed the repair of the anastomosis. There were 8 pneumonia patients who developed post operatively. There were 2 operative hospital deaths among 3 angio-bronchoplasties without coverage. Recently, we have routinely covered the anastomosis at the reconstruction site and have not experienced any major complications.

Relationship between serum levels of interleukin 6, various disease parameters and malnutrition in patients with esophageal squamous cell carcinoma.

Serum levels of interleukin 6 (IL-6) are correlated with the disease status and prognosis in cancer patients. IL-6 is also an important mediator of experimental cancer cachexia. We investigated the production of IL-6 and IL-6 receptors and expression of IL-6 mRNA by esophageal squamous carcinoma cells using immunohistochemical staining and in situ reverse transcription-PCR. We also measured levels of serum IL-6 using an ELISA in 50 patients with esophageal squamous cell carcinoma (ESCC) to determine the correlation between serum levels of IL-6 and clinicopathological factors IL-6 mRNA was expressed in the primary tumor. Esophageal squamous carcinoma cells produced both IL-6 and IL-6 receptor. IL-6 concentrations were significantly higher in the primary tumor than in the normal epithelium. The incidences of weight loss, tumor invasion to adjacent organs, and noncurative resection were significantly higher in ESCC patients with serum levels of IL-6 > or = 7 pg/ml (n = 13, group C) compared with patients with serum levels <7 pg/ml and > or = 3 pg/ml (n = 14, group B) and <3 pg/ml (n = 23, group A). Tumor size and C-reactive protein levels were significantly higher and albumin levels were significantly lower in group C. Results suggest that IL-6, which is produced by tumor cells, may be related to various disease parameters as well as to the nutritional status in patients with ESCC.

[Clinical analysis of operative and hospital deaths in primary lung cancer].

In our department, there were 313 thoracic surgeries for primary lung cancer from January 1994 to December 2003. We clinically reviewed for the operative and hospital death (n=18, 5.8%). The patients were 16 males and 2 females (70.6 +/- 5.6 years old). The surgical procedures were 4 pneumonectomies, 13 lobectomies (3 bronchoplasties) and 1 partial resection. The mean interval until postoperative death was 122.5 +/- 156.1 days. There were 5 direct operative deaths within 30 days (1.6%). There were 4 cancer deaths, 2 hemoptyses, 2 operative bleeding, 2 thromboses, 2 cerebral hemorrhages, 1 pyothorax, 1 pneumonia, 1 respiratory failure, 1 multiple organ failure after chemotherapy and 2 unexplained deaths. The patients with pneumonectomy or aged significantly had high mortality. For postoperative complications such as hemoptysis or bleeding, perioperative management that takes these issues into consideration is needed. Furthermore, we must carefully review the preoperative evaluation and combined treatment, because there were many cancer deaths among cases showing early recurrence and metastasis.

Nm23-H1 gene as a molecular switch between the free-floating and adherent states of gastric cancer cells.

The contribution of the nm23-H1 gene to metastasis in malignant tumors, including gastric cancer, is controversial. In this study, we compared nm23-H1 levels in two cell subtypes with different morphologies (floating and adherent states), but that were derived from the same gastric cancer cell line, KATO-III. A real-time quantitative reverse transcription-polymerase chain reaction showed that the number of nm23-H1 mRNA molecules in floating cells was significantly higher than that in adherent cells (P<0.0001). The average of the copies in floating cells was approximately 2.4-fold higher than that in adherent cells. Consistent with mRNA levels, intracellular levels of nm23-H1 protein were higher in floating cells than in adherent cells. There was no difference in cell cycle characteristics between the two subtypes. In conclusion, our present data indicate that expression of nm23-H1 by a tumor could be altered during the different steps in metastases, suggesting that nm23-H1 may act as a molecular switch between the free-floating and adherent states of cancer cells.

The association between nm23-H1 expression and survival in patients with esophageal squamous cell carcinoma.

The nm23 gene is a potential metastasis suppressor gene originally identified using a murine melanoma cell line. The expression of nm23-H1 protein was examined immunohistochemically in 50 eligible patients with esophageal squamous cell carcinoma (ESCC). The expression was not correlated with other prognostic factors including lymph node metastases; however, overall survival rates of nm23-H1-negative patients were significantly shorter than those of nm23-H1-positive patients (P < 0.05). Furthermore, reduced expression of nm23-H1 was associated with shorter overall survival in patients with involved lymph nodes (P < 0.01), but not in patients without involved lymph nodes. These data support the conclusion that reduced expression of nm23-H1 may be associated with poor prognosis of ESCC patients, suggesting the value of nm23-H1 expression as a prognostic marker for ESCC patients, especially ESCC patients with involved lymph nodes.

Interleukin-1 receptor antagonist mRNA expression and the progression of gastric carcinoma.

Interleukin-1 receptor antagonist (IL-1ra), an endogeneous inhibitor of IL-1, plays an immunosuppressive role in vivo by blocking the proinflammatory effects of IL-1. In the present study, we examined whether IL-1ra expression in human gastric carcinoma correlates with tumor progression and/or metastatic potential. The reverse transcription-polymerase chain reaction was used to compare the expression of the secreted form of IL-1ra (sIL-1ra) and the intracellular form of IL-1ra (icIL-1ra) mRNA in tumor and corresponding benign tissue obtained from 38 patients with gastric carcinoma. The incidence of sIL-1ra mRNA expression was significantly higher in tumor (52%) than in corresponding benign tissue (18%) (P = 0.002). On the contrary, icIL-1ra mRNA was detected in all tumors and benign tissues. The expression of sIL-1ra mRNA by malignant tissue correlated positively with both lymph node metastasis (P = 0.008) and liver metastasis (P = 0.015). There was no association between tumor sIL-lra mRNA expression and other clinicopathologic factors. The degree of regional lymph node reaction, such as sinus histiocytosis, in tumors expressing sI-1ra mRNA was significantly weaker than that in tumors without sIL-1ra mRNA expression (5/20 vs. 12/18, P = 0.010). These results demonstrate that the altered expression of sIL-1ra by malignant tissue may be related to the progression of gastric carcinoma via modulating host immune response.

Anticachectic effects of Coptidis rhizoma, an anti-inflammatory herb, on esophageal cancer cells that produce interleukin 6.

Herbs as alternative cancer therapies have attracted a great deal of recent attention due to their low toxicity and costs. In this study, the antitumor activity and anticachectic effect of Coptidis rhizoma, an anti-inflammatory herb, were investigated in nude mice carrying a human esophageal cancer cell line YES-2, which constitutively secretes interleukin-6 (IL-6) and induces cachexia when injected into these mice. In this study, in vivo growth of YES-2 cells was not affected by an oral supplement containing the extract powder of C. rhizoma at a final concentration of 1% (CR supplement). However, in comparison with normal diet, CR supplement significantly attenuated weight loss of tumor-bearing mice without a change in food or water intake. Tumor IL-6 levels were significantly lower in mice treated with CR supplement than in control mice (P<0.001). Serum IL-6 was detectable in four (50%) of eight control mice; IL-6 was not detected in mice treated with CR supplement. We also confirmed that berberine (8-32 microM), a major component of C. rhizoma, dose-dependently inhibited secretion of IL-6 by YES-2 cells in vitro. Moreover, reverse transcription-PCR assay showed that treatment of YES-2 cells with berberine (8-32 microM) for 24 h reduced IL-6 mRNA expression. Our results suggest that C. rhizoma may have an anticachectic effect on esophageal cancer and an effect is associated with the ability of berberine to down-regulate tumor IL-6 production.

Inhibitory effect of Coptidis Rhizoma and berberine on the proliferation of human esophageal cancer cell lines.

Our previous study demonstrated that the herbal medicine, Oren-to, had antitumor effects on esophageal cancer cells (ECCs) in vitro. The purpose of this study was to examine which of the seven constituents of Oren-to had antitumor effects on esophageal cancer cells. MTT assay showed that, of the seven constituents, only the aqueous extract of Coptidis Rhizoma had potent inhibitory effect on the proliferation of two types of ECC lines, YES-3 and YES-4. In addition, the proliferation of all six types of ECC lines (YES-1 to YES-6) was inhibited in a dose-dependent manner (P<0.001 for all), when co-cultured at each concentration of Coptidis Rhizoma for 72 h. The ID50 of Coptidis Rhizoma for YES-1 to YES-6 was 2.2 microg/ml, 3.0 microg/ml, 0.25 microg/ml, 2.8 microg/ml, 2.5 microg/ml, and 0.5 microg/ml, respectively, berberine, one of protoberberine components of Coptidis Rhizoma, showed potent antitumor effects on all six types of ECC lines as well as Coptidis Rhizoma. In addition, the ID50 of berberine showed a positive correlation with that of Coptidis Rhizoma in six types of ECC lines examined (r2 = 0.763, P = 0.023). Cell cycle analysis of Coptidis Rhizoma-treated cancer cells showed the accumulation of cells in the G0/G1 phase and relative decrease of the S phase. These results support the possibility that the use of Coptidis Rhizoma containing abundant berberine may be useful as one of alternative therapies for esophageal cancers.

Functioning of the intrathoracic stomach after esophagectomy.

OBJECTIVE: To investigate acid secretion and motility of the intrathoracic stomach with truncal vagotomy after esophagectomy. DESIGN: Case-control study of patients undergoing esophagectomy, with average follow-up of 3.2 months, compared with health controls. SETTING: Yamaguchi University School of Medicine, Kogushi, Japan. PATIENTS: A random sample of 21 patients selected from 79 patients with esophageal cancer during the period from May 1988 to August 1993 received the intrathoracic stomach after subtotal esophagectomy. A control sample consisted of 14 men. INTERVENTIONS AND MAIN OUTCOME MEASURES: For acid secretion, a pH probe was placed in the intrathoracic stomach to measure the average pH value (average of total monitoring values) and pH holding time (ratio of the period during which the pH value was 3 or higher based on the entire continuous monitoring periods). For motility, digestive tract scintigraphy was performed to obtain the time activity curve from the analog image observed when patients ate meals labeled with indium 111. In addition, hemorrhagic ulcers in the intrathoracic stomachs of three patients were reported. RESULTS: A pH value below 3 was recognized after surgery, and there was no significant difference between pH values in patients and normal volunteers (average pH value, 3.9 +/- 1.5 vs 3.3 +/- 1.9; pH holding time, 52.2 +/- 20.2% vs 57.1 +/- 24.4%, respectively). The time activity curve of the intrathoracic stomach observed by scintigraphy underwent no change after surgery. Among three patients with hemorrhagic ulcers, two exhibited improvements after receiving a histamine blocker, while in the other, it was not effective. CONCLUSION: Acid secretion ability and motility of the intrathoracic stomach with truncal vagotomy may be unchanged after esophagectomy.

Cytogenetic analysis of esophageal squamous cell carcinoma cell lines by comparative genomic hybridization: relationship of cytogenetic aberrations to in vitro cell growth.

Cancer is characterized by autonomous growth of cells, and it is widely accepted that cell proliferation is primarily influenced by individual cell genetics. To elucidate the mechanisms of cancer cell proliferation, we studied differences in genetic aberrations for different type of tumors with different proliferation characteristics. We employed comparative genomic hybridization (CGH) to detect genetic aberrations in six cell lines of esophageal squamous cell carcinoma (ESCC). Three cell lines (YES-1, -2, and -3) grow in culture without fetal calf serum (group A), while others require serum to be maintained in vitro (group B). Both groups showed very similar cytogenetic aberrations: over-representations of 11q13 (6/6), 8q23-qter (5/6), Xq25-qter (5/6), 3q26-qter (4/6), 5p (4/6), 7p15-pter (4/6), 8q21.3-q22 (4/6), 17p (4/6), and 20q13 (4/6), and under-representations of 18q21-qter (6/6), 4q28-q33 (4/6), and 9p21 (4/6). Six amplification loci were mapped to chromosomal regions of 6q23 (1 case), 7p12 (2 cases), 9p21 (1 case), 11p11.2-12 (3 cases), 11q13 (2 cases), and 17p12 (2 cases). However, some differences were detected. DNA copy number increases at 7p12-p13, 11q14-q22, and 11q22-qter and under-representations of 4p, 8p, and 11p14-pter. In contrast, gains at 12p and 20p, and losses at 3p and 5q were detected only in group-B cell lines. These observations suggest that cytogenetic differences between the two groups may be linked to differences in cell growth characteristics in vitro, and that the genes in these chromosomal regions may play important roles in cell proliferation.

Effects of FK506 on exocrine pancreas in rats.

The efficacy of FK506 on exocrine pancreas was studied in rats. Male Sprague-Dawley rats (230-250 g) received an i.m. daily injection of FK506 (0.1, 0.5, or 5.0 mg/kg), cyclosporine (CS; 25 mg/kg), or saline for 2 weeks. Isolated dispersed pancreatic acini were prepared from rats, and enzyme content of the cells and secretory response to cholecystokinin (CCK) were determined. Amylase and trypsin contents were increased in a dose-related manner by FK506 (p less than 0.01) and by CS at 25 mg/kg (p less than 0.01). The release of amylase in response to CCK was reduced by FK506 in a dose-related manner (p less than 0.01) and by CS at 25 mg/kg (p less than 0.01). Histologic examination showed that treatment of rats with FK506 at 0.1 mg/kg did not affect morphology of the acinar cells. FK506 at 0.5 mg/kg induced a minimal number of small vacuoles in cytoplasm of acinar cells and FK506 at 5.0 mg/kg, and CS at 25 mg/kg induced numerous cytoplasmic vacuoles and pyknotic nuclei. Increased enzyme storage and suppressed responsiveness of amylase release may have an association with the histologic changes. Therefore, the results of this study suggest that FK506, even when used in a low dose, may have adverse effects on the exocrine pancreas. Understanding of the mechanism of action of FK506 on pancreas will provide essential basic information that will allow transplant practitioners to more fully explore the benefits of this drug.

Humoral factors that induce alterations of the pancreas in rats with obstructive jaundice.

This study was conducted to investigate the role of humoral factors in pancreatic alterations induced by obstructive jaundice (OJ) in rats. OJ in male Sprague-Dawley rats induced significant increases in pancreatic weight, DNA content, and RNA content of acinar cells. These changes were accompanied by enlargement of eosinophilic granules and compressed nuclei. Protein, amylase, and trypsinogen contents of pancreas were also increased in OJ rats. In addition, plasma levels of bilirubin, cholecystokinin (CCK), and estradiol increased in OJ rats and were correlated positively with each other and with pancreatic weights. Administration of a specific CCK receptor, L-364,718, to OJ rats partly attenuated the changes of the pancreas, indicating that CCK is involved in these changes. These findings suggest that estradiol may be involved in regulating the pancreatic changes induced by OJ in rats.

Gastric pH monitoring after pylorus preserving pancreaticoduodenectomy with Billroth I type of reconstruction.

BACKGROUND: A late complication of pancreaticoduodenectomy is anastomotic ulcer, and the complication is lessened when pancreaticoduodenectomy is accompanied by preservation of the pylorus. However, the results of some reports suggest that acid levels are not significantly different between patients who undergo pylorus preserving pancreaticoduodenectomy (PPPD) and those having standard pancreaticoduodenectomy. In this study, we measured gastric acidity in the same patients both before and after PPPD. STUDY DESIGN: Twelve patients participated in the study. Acid was measured by monitoring pH levels for 24 hours. Average pH values were calculated for two time periods: during the day (6 AM to 6 PM) and night (6 PM to 6 AM). In addition, the percentages of time during day and night hours that gastric acid was above pH 3 and above pH 4 were calculated and designated as pH holding times. RESULTS: Average pH values and pH holding times during the day revealed no significant differences between patients preoperatively and postoperatively. At night, however, pH holding times significantly decreased in patients postoperatively when compared with patients preoperatively. Of 29 patients who underwent PPPD in our clinic, only one had an ulcer. The gastric acidity of this patient was similar to the others. CONCLUSIONS: These results indicate that gastric acidity, as it relates to pH 3 and pH 4 holding times, increases after PPPD and that gastric acidity, per se, may not be involved in ulcer formation in these PPPD patients. Furthermore, the results of the study indicate that measuring gastric acidity for longer periods of time during the day and during the night might be important in studies on acid secretion.

Interleukin-6 production in lung tissue after transthoracic esophagectomy.

BACKGROUND: The mechanisms of the reported high increase in interleukin-6 (IL-6) levels after esophagectomy are unclear. We investigated the influence of an intrathoracic procedure, esophagectomy, on IL-6 production in lung tissue. STUDY DESIGN: Fourteen paired lung tissue samples were obtained from patients before and after they underwent transthoracic esophagectomy for esophageal cancer. IL-6 levels in the lung were measured with enzyme-linked immunosorbent assay, and IL-6 mRNA expression was determined with real-time quantitative reverse transcription-polymerase chain reaction. Immunohistochemical staining was used to localize IL-6, and circulating levels were also measured. RESULTS: IL-6 protein and mRNA were significantly increased in lung tissue after this intrathoracic procedure (p < 0.05). Peak levels of plasma IL-6 after surgery were correlated with IL-6 levels in lung tissues obtained after the procedure (p < 0.05). Immunohistochemical staining revealed IL-6 production from alveolar and bronchial epithelial cells but not from alveolar macrophages. CONCLUSIONS: Transthoracic esophagectomy causes an increase in IL-6 production from airway epithelial cells, secondary to increased expression of IL-6 mRNA. Local response of lung tissue may be one source of increased serum IL-6 after this procedure.

Estrogens influence cholecystokinin stimulated pancreatic amylase release and acinar cell membrane cholecystokinin receptors in rat.

This study examines the influence of ovariectomy and administration of a pharmacologic dose of estradiol on amylase release from isolated-dispersed rat pancreatic acini and cholecystokinin receptors on rat acinar cell membranes. Rats were sham ovariectomized (intact) or ovariectomized (Ovx) and 21 day timed release pellets containing either estradiol (2.5 mg) or vehicle, were implanted subcutaneously. Eighteen days later, pancreatic acini were isolated from rats by collagenase digestion and differential centrifugation. Total cellular amylase, basal and cholecystokinin octapeptide (CCK8) stimulated amylase release and CCK membrane receptors were measured. Acini isolated from estradiol treated Ovx rats had significantly greater total cellular amylase, compared to acini isolated from either intact or Ovx rats. The amplitude of both total stimulated amylase release and percent total stimulated amylase release were significantly greater for acini isolated from vehicle treated Ovx rats, than acini isolated from either intact or estradiol treated Ovx rats. The magnitude of percent total amylase release of acini isolated from estradiol treated Ovx rats was significantly lower than that of acini isolated from intact rats. Cholecystokinin receptor concentration was significantly greater on membranes prepared from vehicle treated Ovx rats, compared to membranes prepared from either intact or estradiol treated Ovx rats. These data indicate that ovariectomy is associated with increased responsiveness of pancreatic acini to CCK stimulation, while chronic estradiol treatment of ovariectomized rats is associated with increased total cellular amylase and decreased acinar cell responsiveness to CCK8. Estrogen mediated alterations in acinar cell amylase content and amylase release may play a role in estrogen related pancreatitis.

Immunoregulatory effects of the antitumor polysaccharide lentinan on Th1/Th2 balance in patients with digestive cancers.

BACKGROUND: Recent studies demonstrated that patients with advanced cancer may have impaired cell-mediated immunity caused by an imbalance between Th1 and Th2 responses. We evaluated the ability of lentinan (LNT) to modulate Th1 and Th2 responses in patients with digestive cancers. METHODS: Peripheral blood samples were collected preoperatively from 28 patients with digestive cancers before and after intravenous administration of LNT (2 mg x 3 times/week). The proportions of CD4+ T-cells producing intracellular cytokines were determined with flow cytometry. RESULTS: After LNT treatment, CD4+ IFN-gamma+ T-cell percentages increased significantly (p < 0.05), whereas CD4+ IL-4+ T-cell and CD4+ IL-6+ T-cell percentages decreased significantly (p < 0.02). No significant change occurred in proportions of CD4+ IL-10+ T-cells. The after/before LNT treatment percentages ratio of CD4+ IFN-gamma+ T-cells correlated negatively with that of CD4+ IL-4+ T-cells (p < 0.01). The after/before treatment percentage ratio of CD4+ IL-4+ T-cells correlated positively with that of CD4+ IL-6+ T-cells (p < 0.05). CONCLUSION: LNT apparently can cancel Th2-dominant condition in patients with digestive cancers and may improve the balance between Th1 and Th2.

Comparison of interleukin-6, interleukin-8, and granulocyte colony-stimulating factor production by the peritoneum in laparoscopic and open surgery.

BACKGROUND: Human mesothelial cells secrete a variety of cytokines. The levels of postoperative serum inflammatory cytokines are thought to reflect the magnitude of surgical stress. METHODS: Pieces of peritoneum were obtained immediately upon and 1 h after entry into the abdominal cavity in nine patients undergoing laparoscopic surgery and 11 patients undergoing open surgery. The samples were cultured and interleukin (IL)-6, IL-8, and granylocyte colony-stimulating factor (G-CSF) levels in the supernatants were measured by enzyme-linked immunosorbent assay (ELISA). Expression of IL-6, IL-8, and G-CSF mRNAs was examined by RT-PCR. RESULTS: At 1 h after laparotomy, the amounts of IL-6 and G-CSF produced by the peritoneum were significantly greater than those obtained immediately after the procedure, but this difference was not observed with laparoscopic surgery. Reverse transcription-polymerase chain reaction (RT-PCR), which showed an increase in the expression of cytokine mRNAs at 1 h after laparotomy, was compatible with these results. CONCLUSION: The lower levels of cytokine production by the peritoneum suggest that laparoscopic surgery is associated with lower degree of surgical stress.