Effects of an immuno-enhanced diet containing antioxidants in esophageal cancer surgery following neoadjuvant therapy.

Neoadjuvant therapy-induced immunological deterioration may be a key factor in postoperative morbidity in patients with esophageal cancer. This study aimed to determine the effects of perioperative feeding with an immuno-enhanced diet on immune competence in patients treated with neoadjuvant therapy followed by surgery. Because an immuno-enhanced diet that contained several antioxidants was used, perioperative oxidative stress and the effects of the immuno-enhanced diet on this stress were also investigated. Of 39 patients with esophageal cancer who underwent similar surgical procedures, 26 patients who received chemotherapy or chemoradiation therapy before surgery were randomly divided into two groups: group 1 (n= 14) was given an immuno-enhanced diet for 5 days before surgery, and group 2 (n= 12) received no enteral feeding products before surgery. Group 3 (n= 13) consisted of patients that did not receive neoadjuvant therapy and received no enteral feeding products before surgery. Several markers for coagulation and fibrinolysis were determined and immunological assessments were performed for each patient. To measure reactive oxygen metabolites and the total antioxidant capacity, diacron-reactive oxygen metabolites (d-ROMs) and OXY-adsorbent tests were performed using a free radical elective evaluator. Significant depression in lymphocyte numbers was observed in groups 1 and 2 before and early after surgery as compared to group 3. Numbers of B cells, CD4/CD8 ratio, and phytohemagglutinin-induced lymphocyte transformation tests were also significantly decreased in groups 1 and 2 on postoperative day 1. Fibrin and fibrinogen degradation products were significantly elevated in group 2 compared to group 1. d-ROMs and OXY-adsorbent test values were elevated before surgery and were decreased transiently early after surgery. Compared to groups 2 and 3, d-ROMs values were significantly lower in group 1 patients throughout the postoperative period, while OXY-adsorbent test values were significantly higher in group 2 patients. Oxidative index was significantly suppressed in group 1 compared to group 3. No significant intergroup differences were observed with regard to morbidity after surgery. Although the baseline levels of immunological function might have been different because of less-advanced cancer stages in group 3, neoadjuvant therapy significantly affected several immunological parameters. Preoperative administration of an immuno-enhanced diet did not significantly prevent neoadjuvant therapy-induced immunological deterioration prior to esophageal cancer surgery. Patients with esophageal cancer had elevated levels of oxidant and antioxidant activities before surgery, which were transiently decreased early after surgery. Although the underlying mechanisms for these perioperative changes are unclear, this study showed that an immuno-enhanced diet containing several antioxidants may reduce oxidative stress following esophageal cancer surgery. After these mechanisms are studied further, oxidative stress control may become another tool for perioperative management to reduce morbidity after esophageal cancer surgery.

Experimental evaluation of photocrosslinkable chitosan hydrogel as injection solution for endoscopic resection.

BACKGROUND AND STUDY AIMS: Saline as an injection solution for endoscopic resection techniques has several disadvantages such as a short-lasting effect leading to a potentially higher risk of bleeding and perforation. The new substance of photocrosslinkable chitosan hydrogel in a DMEM/F12 medium (PCH) can be converted into an insoluble hydrogel by ultraviolet irradiation for 30 s, and was evaluated in two sets of animal experiments. METHODS: 18 pigs were used in the two parts of the study. First, mucosal resections were done with either PCH or hypertonic saline; the effects of both agents on wound healing were examined endoscopically and histologically. Second, in vivo degradation of PCH was examined using six pig stomachs. RESULT: PCH injection led to a longer-lasting elevation with clearer margins, compared with hypertonic saline, thus enabling precise endoscopic submucosal dissection (ESD) along the margins of the elevated mucosa. The endoscopic appearance after ESD was similar in both groups. PCH biodegradation was completed within 8 weeks according to endoscopic and histologic analyses. CONCLUSION: PCH is a promising agent for submucosal injection prior to various techniques of endoresection. It should be evaluated in clinical trials after biocompatibility testing for PCH is completed.

Frequent methylation-associated silencing of a candidate tumor-suppressor, CRABP1, in esophageal squamous-cell carcinoma.

Epigenetic alterations and the resulting inactivation of tumor suppressor genes often contribute to the development of various cancers. To identify novel candidates that may be silenced by aberrant methylation in esophageal squamous-cell carcinoma (ESCC), we analysed ESCC cell lines by a recently developed method known as bacterial artificial chromosome array-based methylated CpG island amplification (BAMCA), and selected candidates through BAMCA-assisted strategy. In the course of this program, we identified frequent CpG methylation-dependent silencing of the gene encoding cellular retinoic acid binding protein 1 (CRABP1) in our panel of ESCC cell lines. Expression of CRABP1 mRNA was restored in gene-silenced ESCC cells after treatment with 5-aza 2'-deoxycytidine. The DNA methylation status of the CRABP1 CpG island with clear promoter activity correlated inversely with expression of this gene. CpG methylation of CRABP1 was frequently observed in primary ESCC tissues as well. Restoration of CRABP1 expression in ESCC cells lacking the protein reduced cell growth by inducing arrest at G(0)-G(1), whereas knockdown of the gene in cells expressing CRABP1 promoted cell growth. Among 113 primary ESCC tumors, the absence of immunoreactive CRABP1 was significantly associated with de-differentiation of cancer cells and with distant lymph-node metastases in the patients. These results indicate that CRABP1 appears to have a tumor-suppressor function in esophageal epithelium, and its epigenetic silencing may play a pivotal role during esophageal carcinogenesis. Its expression status in biopsies or resected tumors might serve as an index for identifying ESCC patients for whom combined therapeutic modalities would be recommended.

Submucosal injection, for endoscopic mucosal resection, of photocrosslinkable chitosan hydrogel in DMEM/F12 medium.

BACKGROUND AND STUDY AIMS: We studied the ability of a photocrosslinkable chitosan in DMEM/F12 medium to maintain submucosal thickness and to reduce bleeding after mucosal resection. We also investigated the behavior of chitosan hydrogels with regard to wound healing. METHODS: The gastric submucosal layer of heparinized rats was injected with the photocrosslinkable chitosan in medium (which was then irradiated with ultraviolet light to form a hydrogel), or with sodium hyaluronate, or hypertonic saline, and three investigations were done, using three different sets of rats. The first and second were measurement of the thickness of the layer, and of the amount of bleeding induced by mucosal resection, respectively. Thirdly, the effects of the chitosan hydrogel on wound healing were examined histologically. RESULTS: Gastric submucosal layers of chitosan hydrogel-treated animals remained significantly thicker than those of other groups for at least 6 h after injection. The total amount of bleeding 20 min after mechanical mucosal resection was 170.0 +/- 20.0 mg, 678.3 +/- 226.3 mg, and 1020.0 +/- 104.1 mg in the chitosan hydrogel, sodium hyaluronate, and hypertonic saline groups, respectively. Histological study revealed that the focus of bleeding was surrounded by chitosan hydrogel and that almost all the hydrogel was biodegraded within 4 weeks. Furthermore, a discernible, but not statistically significant effect of the chitosan hydrogel on wound healing was observed. CONCLUSIONS: The chitosan hydrogel produced mucosal elevation after submucosal injection with ultraviolet irradiation, and it significantly reduced bleeding after mucosal resection. Our newly developed chitosan hydrogel in medium might be a promising submucosal agent for endoscopic mucosal resection.

Long-term facilitation of expiratory and sympathetic activities following acute intermittent hypoxia in rats.

AIM: Acute intermittent hypoxia (AIH) promotes persistent increases in ventilation and sympathetic activity, referred as long-term facilitation (LTF). Augmented inspiratory activity is suggested as a major component of respiratory LTF. In this study, we hypothesized that AIH also elicits a sustained increase in expiratory motor activity. We also investigated whether the expiratory LTF contributes to the development of sympathetic LTF after AIH. METHODS: Rats were exposed to AIH (10 × 6-7% O2 for 45 s, every 5 min), and the cardiorespiratory parameters were evaluated during 60 min using in vivo and in situ approaches. RESULTS: In unanesthetized conditions (n = 9), AIH elicited a modest but sustained increase in baseline mean arterial pressure (MAP, 104 ± 2 vs. 111 ± 3 mmHg, P < 0.05) associated with enhanced sympathetic and respiratory-related variabilities. In the in situ preparations (n = 9), AIH evoked LTF in phrenic (33 ± 12%), thoracic sympathetic (75 ± 25%) and abdominal nerve activities (69 ± 14%). The sympathetic overactivity after AIH was phase-locked with the emergence of bursts in abdominal activity during the late-expiratory phase. In anesthetized vagus-intact animals, AIH increased baseline MAP (113 ± 3 vs. 122 ± 2 mmHg, P < 0.05) and abdominal muscle activity (535 ± 94%), which were eliminated after pharmacological inhibition of the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG). CONCLUSION: These findings indicate that increased expiratory activity is also an important component of AIH-elicited respiratory LTF. Moreover, the development of sympathetic LTF after AIH is linked to the emergence of active expiratory pattern and depends on the integrity of the neurones of the RTN/pFRG.

[Myxoid leiomyosarcoma of the esophagus].

A 34-year-old male patient with epigastralgia was found to have an esophageal submucosal tumor based on an endoscopic evaluation 6 years previously. Because an unusual appearance composed of a heterogeneous solid area and a cyst area on the endoscopic ultrasonogram and the increased size of the tumor on esophagograms over the past 3 years were suggestive of a malignant character, an operation was thus indicated. The tumor, which measured 3.5 x 2.5 x 2.0 cm in size, was enucleated using videoassisted thoracic surgery and was diagnosed to be a very rare myxoid leiomyosarcoma with a thorough pathologic examination. To our knowledge, this is only the second case of esophageal myxoid leiomyosarcoma reported in the literature. We thus consider this case, which demonstrated an unique appearance on an endoscopic ultrasonogram, to possibly be beneficial to the overall diagnostic analysis of esophageal submucosal tumors.

Reduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapy.

Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT.

Spontaneous intestinal inflammation and nitric oxide metabolism in HLA-B27 transgenic rats.

BACKGROUND & AIMS: It has been reported that transgenic rats expressing the HLA-B27 and the beta 2- microglobulin genes develop spontaneous gastrointestinal (GI) inflammation; however, no systematic or quantitative evaluation of this GI inflammation has been reported. Therefore, the objective of this study was to characterize quantitatively the GI injury and inflammation observed in commercially available HLA-B27 transgenic rats. METHODS: HLA-B27 rats and Fisher 344 male controls were used for these studies. Gastric, ileal, and colonic blood-to-lumen clearances of 51Cr-ethylenediaminetetraacetic acid, tissue myeloperoxidase activities, and wet/dry ratios of the various tissues as well as plasma nitrate and nitrite levels were quantified for each control and transgenic animal. RESULTS: Spontaneous ileitis and colitis developed in 5 of 10 HLA-B27 transgenic rats beginning at approximately 17 weeks of age and persisting for an additional 13 weeks. Increases in mucosal permeability and myeloperoxidase activities as well as histological analysis showed intestinal injury and chronic inflammation. Plasma levels of nitrate and nitrite, the stable decomposition products of nitric oxide, were found to be significantly enhanced (fourfold) only in those rats that developed the intestinal inflammation. CONCLUSIONS: The chronic ileitis and colitis observed in HLA-B27 transgenic rats seems to be associated with enhanced NO metabolism.

Effects of nitric oxide synthase inhibition or sulfasalazine on the spontaneous colitis observed in HLA-B27 transgenic rats.

The objective of this study was to determine the effects that certain nitric oxide synthase inhibitors have on the spontaneous intestinal and colonic inflammation that develops in HLA-B27 transgenic rats and compare these data to those obtained using sulfasalazine (SZ). In an attempt to more closely mimic the clinical situation, drug treatment was begun after the onset of colitis. HLA-B27 male rats that developed clinical signs of colitis (diarrhea/loose stools) at 17 wk of age were randomized into fours groups consisting of one untreated colitic group and three treatment groups that received either aminoguanidine (AG; 52 micromol/kg/day), NG-nitro-L-arginine methyl ester (L-NAME; 45 micromol/kg/day) or SZ (130 mg/kg/day) in their drinking water for 14 days. Aged-matched Fisher 344 male rats were used as healthy controls. After 3 wk of treatment, ileal and colonic mucosal permeabilities, granulocyte infiltration and nitric oxide were quantified using blood-to-lumen clearance of 51Cr-EDTA, tissue myeloperoxidase activity, and plasma levels of nitrate and nitrite, respectively. We found that both AG and L-NAME but not SZ significantly attenuated the increases in plasma nitrate and nitrite levels. Interestingly, all three drugs were effective at significantly attenuating the increases in myeloperoxidase activity in the distal colon. Treatment with AG and SZ but not L-NAME were effective at significantly attenuating the increase in ileal and colonic permeabilities. Quantitative histological analysis revealed that AG and L-NAME but not SZ significantly attenuated the increase in the mucosal thickness and crypt depth in the distal colon compared to untreated colitis. Taken together, these data demonstrate that oral administration of certain nitric oxide synthase inhibitors or SZ to animals with active colitis attenuates the colonic inflammation by at least two different mechanisms. One mechanism appears to be dependent on inhibition of NO production whereas the other mechanism does not.

Beneficial effects of immediate enteral nutrition after esophageal cancer surgery.

This study was conducted to determine the effects of immediate enteral nutrition (EN) on nutritional status, immunological competence, and the suppression of excessive inflammatory responses in patients following esophageal cancer surgery. Twenty-four patients who underwent the same elective operation for thoracic esophageal carcinoma were randomized into an immediate enteral nutrition (IEN) group who received EN from postoperative day (POD) 1 and a parenteral nutrition (PAN) group. Both groups received comparable volumes and calories on the same POD. Laboratory studies were carried out preoperatively and on PODs 1-7. Other nutritional and immunological assessments were repeated on PODs 1 and 7. Plasma concentrations of nitrate and nitrite were also measured. All of the patients in the IEN group tolerated enteral feeding well. There were no significant differences in the results of nutritional assessments, lymphocyte function, or plasma nitrate and nitrite levels between the two groups. The IEN group showed a significantly earlier recovery of the total lymphocyte count. The serum levels of total bilirubin and C-reactive protein were significantly attenuated in the IEN group. These results indicate that immediate EN may have beneficial effects on immunological competence and the suppression of excessive inflammatory responses in patients following esophagectomy. Patients undergoing radical esophageal surgery who are subjected to severe surgical stress might benefit the most from early EN.

Effects of cyclosporine or FK506 in chronic colitis.

The objective of this study was to quantitatively characterize the effects FK506 on the pathophysiology observed in a model of chronic granulomatous colitis in rats and compare these effects to those obtained with cyclosporin A (CyA). Chronic granulomatous colitis was induced in female Lewis rats via intramural (subserosal) injections of peptidoglycan/polysaccharide (PG/PS) into the distal colon. Rats then received daily injections (i.m.) of either vehicle for CyA (0.5 ml/kg cremophor), CyA in vehicle (25 mg/kg), saline (0.5 ml/kg) or FK506 (1 mg/kg in saline), beginning 7 days after PG/PS injection and continuing for an additional 2 weeks. On day 21, we found that the intramural injection of PG/PS produced a chronic colitis that was associated with hepatic and splenic granulomatous inflammation. Daily treatment with CyA or FK506 beginning 7 days after the induction of colitis resulted in significant inhibition in colonic mucosal permeability, colonic myeloperoxidase activity and plasma nitrate/nitrite levels when compared with their vehicle or untreated controls. In some instances, we noticed a significant vehicle-dependent anti-inflammatory activity. The incidence of peritoneal adhesions as well as the presence of hepatic and splenic granulomas induced by PG/PS were also significantly reduced in both the CyA- and FK506-treated groups. Taken together, these data suggest that immunosuppressive therapy is effective at attenuating both the colitis as well as the extraintestinal inflammation induced by PG/PS. We conclude that FK506 may be useful in the treatment of certain types of inflammatory bowel disease.

Long-term survival after gastric cancer and liver and paraaortic lymph node metastases: report of a case.

We report the case of a 46-year-old man in whom successful resection of carcinoma of the stomach with liver and paraaortic lymph node metastases was carried out. The carcinoma was removed completely with combined resection of the lower esophagus, total stomach, distal pancreas, spleen, two metastatic liver nodes, and groups 1 and 2 and abdominal paraaortic lymph nodes. Adjuvant chemotherapy was administered postoperatively. The patient is currently well with a grade 1 performance status and no signs of recurrence 12 years after his operation. This experience suggests that even the presence of metastatic paraaortic lymph nodes and liver metastases is not necessarily a contraindication to surgery when the carcinoma can be resected curatively and safely.

Increased chemiluminescence and ulcer development in the low blood flow state of the gastric tube for esophageal replacement.

Peptic ulcers in the gastric tube for esophageal replacement develop in spite of reduction of acid secretion after truncal vagotomy and often result in serious conditions such as bleeding and perforation. Thirteen cases of gastric tube ulcers were detected endoscopically from 1985 to 1990 in our hospital. Most of these ulcers developed within 20 cm of the anastomosis (esophagogastrostomy), which was an especially hypoxic and ischemic area. Ischemic change due to decreased blood supply is suggested as a causative factor in ulcer development. Recent studies indicate that chemiluminescence (ChL) activity may increase even in the low-flow hypoxic condition. Therefore, we investigated the ChL of regional blood in the hypoxic gastric tube in dogs. The ChL activity of the blood sample collected from the ischemic region in the gastric tube significantly increased after construction of the gastric tube, compared with systemic blood from the femoral vein, and the number of leukocytes decreased in the ischemic region. We believe that oxygen radicals derived from neutrophils adhering to the vascular endothelium may play an important role in the damage to endothelial cells of the gastric tube and suggest the possibility of their causative effects in the process of ulcer formations.

Pedunculated esophageal leiomyosarcoma: a case report.

We report a case of esophageal leiomyosarcoma that possibly arose from the muscularis mucosae, thereby showing a particularly unusual appearance. A large polypoid intraluminal lesion in the distal esophagus was found on an endoscopic examination of a 68-year-old man with a 3-month history of dysphagia. Although the histological examination of biopsy specimens clearly revealed leiomyosarcoma, the absence of an exophytic component on computed tomography (CT) scan caused us to suspect that the tumor was carcinosarcoma. The tumor was resected by a subtotal esophagectomy. Microscopic evaluation revealed no involvement in the layer of the muscularis propria and no component of carcinoma. Clinical features of the pedunculated esophageal leiomyosarcoma shown in this case and three additional cases previously reported in the literature are reviewed.

Duration of the hemodynamic effects of N(G)-nitro-L-arginine methyl ester in vivo.

The objective of this study was to quantify the duration of the hemodynamic activity of N(G)-nitro-l-arginine methyl ester (l-NAME) in a variety of different tissues following a single bolus injection of this nitric oxide synthase inhibitor to healthy rats. l-NAME (15 micromol x kg(-1)) was injected (ip) into rats to produce maximal inhibition of endothelial cell NOS. Animals were subsequently anesthetized and blood flow was quantified using the radioactive microsphere/reference organ technique. At 1 h following a single bolus injection of l-NAME blood flow was reduced to the entire gastrointestinal tract, pancreas, and liver. Three hours following l-NAME administration, blood flow to the stomach and upper small intestine had returned to pretreatment levels; however, blood flow to the jejunum, ileal-jejunal junction, and colon remained significantly reduced. Splenic blood flow was significantly reduced and hepatic arterial blood flow was further reduced at this time as well. After 6 h following l-NAME administration, blood flow in all organs had completely recovered to control levels. Although cardiac index and total peripheral resistance had also returned to preinjection values at this time, mean arterial pressure remained elevated at 6 h posttreatment. Blood flow to the brain, lungs, and psoas muscle were unaffected by l-NAME administration at any time point. Taken together, these data demonstrate a differential regulation of vascular tone by NO in different vascular beds and, depending upon the organ system in question, the vasoactive activity of l-NAME may last from 3 to 6 h following a single bolus injection of this NOS inhibitor.