Teruo Kiyama

Clinical significance of epidermal growth factor (EGF), EGF receptor, and c-erbB-2 in human gastric cancer.

The EGF stimulation system for growth regulation is implicated in normal and neoplastic cell proliferation. The role of EGF, the EGF receptor, and c‐erbB‐2 in human gastric cancer is reviewed on the basis of several reports, which have been mainly oriented toward their clinical significance. EGF has been shown immunohistochemically to be present in 26% of gastric cancers (n = 395). The presence of EGF in gastric cancer is correlated with the degree of gastric wall invasion and lymph node metastasis. The 5‐year survival of patients with EGF‐positive tumors is worse than that of patients with EGF‐negative tumors. The presence of EGF in human gastric cancer may therefore represent a higher malignant potential. Fifteen percent of gastric cancers (n = 352) were also shown to be positive for both EGF and the EGF receptor immunohistochemically, and the simultaneous occurrence of EGF and the EGF receptor suggests that these tumors grow in an autocrine fashion. Tumors exhibiting EGF and the EGF receptor simultaneously show a greater degree of local invasion and lymph node metastasis. Increased expression of EGF receptor protein in gastric cancer appears to be related to biologic aggressiveness, although gene amplification has occurred only to a small extent. Twelve percent of gastric cancers (n = 486) were found to be positive for c‐erbB‐2. This type of tumor has a frequent metastasis, and patients with c‐erbB‐2‐positive cancer have a poorer prognosis than those with c‐erbB‐2‐negative tumors. Selective blockade of the EGF receptor and c‐erbB‐2 from their ligands with monoclonal antibodies (MoAbs) inhibits the growth of human gastric cancer xenografts. These MoAbs may therefore be effective antitumor agents against gastric cancer showing overexpression of EGF receptors or c‐erbB‐2. Cancer 1995;75:1418‐25.

Postoperative changes in body composition after gastrectomy

Nutritional status is one of the most important clinical determinants of outcome after gastrectomy. The aim of this study was to compare changes in the body composition of patients undergoing laparoscopyassisted gastrectomy (LAG), distal gastrectomy (DG), or total gastrectomy (TG). Total body protein and fat mass were measured by performing a multifrequency bioelectrical impedance analysis using an inBody II machine (Biospace, Tokyo, Japan) in 108 patients (72 men, 36 women) who had undergone LAG (n = 24), DG (n = 39), or TG (n = 45). Changes between the preoperative data and results obtained on postoperative day 14 and 6 months after surgery were then evaluated. The mean preoperative body weight of the subjects was 57.6 +- 10.7 kg, the mean body mass index was 22.5 +- 3.4 kg/m2, and the mean fat % was 24% +- 7%. In the immediate postoperative period (14 days), the body weight loss in the LAG group was significantly lower than in the DG and TG groups (2.5 +- 0.9 kg vs. 3.5 +- 1.8 kg and 4.0 +- 1.9 kg, respectively; P +- 0.0001). The body composition studies demonstrated a loss of total body protein rather than fat mass. Six months after surgery, body weight was not significantly different from preoperative values in the LAG and DG groups (-1.2 +- 3.8 kg and -1.8 +- 4.7 kg, respectively), but had decreased by 8.9 +- 4.9 kg in the TG group (P = 0.0003). A body composition analysis revealed a loss of fat mass in the DG and TG groups. The patients who underwent gastrectomy lost body protein mass during the early postoperative period. The type and extent of surgery has an effect on long-term body mass and composition. Bioelectric impedance analysis can be used to assess body composition and may be useful for nutritional assessment in patients who have undergone gastrectomy.

Effect of matrix metalloproteinase inhibition on colonic anastomotic healing in rats.

Wound strength depends on the balance between collagen synthesis and degradation; however, the role of collagen breakdown in wound healing is still not well understood. We investigated the role of matrix metalloproteinases in wound healing by using BE16627B, a matrix metalloproteinase inhibitor. Identical surgical procedures consisting of a colonic anastomosis (single-layer, inverted) and implantation of an osmotic pump in the back were performed in male Sprague-Dawley rats weighing 270 to 290 grams. The animals were randomly assigned to receive either BE16627B (n = 10) dissolved in dimethylsulfoxide and diluted with ethylene glycol at a dosage of 2.4 mg/rat/day for 3 days or the vehicle solution alone (n = 11). The solutions were administered through the surgically implanted osmotic pumps. The animals were killed 4 days after surgery, and the colonic bursting pressure (mm Hg) and hydroxyproline concentration (μg/mg wet tissue, index of collagen) were measured. The administration of BE16627B enhanced colonic anastomotic healing, as measured by the increase in the colonic bursting pressure (160 ±12 vs. 125 ±7 mm Hg; P <0.05) and the increase in the soluble fraction of collagen (0.27 ± 0.01 vs. 0.21 ± 0.01 μg/mg wet tissue; P <0.01) in the anastomosis. Histologic examination of the tissue revealed that the use of BE 1662 7B resulted in the preservation of the multilayered colonic structure and increased the network of collagen between both ends of the colon in the thickening submucosal layer. These findings demonstrate that the inhibition of matrix metalloproteinase activity influences colonic anastomotic healing, indicating a potential mechanism for enhancing anastomotic healing.

The Route of Nutrition Support Affects the Early Phase of Wound Healing

BACKGROUND Nutrition support via the enteral route has been shown to be superior to parenteral administration in maintaining immune function, decreasing septic complications, and increasing survival after severe trauma and surgical injury. Whether the route of nutrition support affects wound healing, another important determinant of outcome following injury, is not known. METHODS Forty-nine Sprague-Dawley rats, 290 to 360 g body wt, underwent identical surgical manipulation consisting of central venous catheterization, fashioning of gastrostomy and dorsal skin incision, and placement of polyvinyl alcohol sponges into subcutaneous pockets. Identical infusates of 25% dextrose, 4.25% amino acids, and vitamins were given, half the animals receiving the infusion via the gastrostomy and the other half via the venous catheter. Animals were killed on day 5, 7, or 10. Wound breaking strength, sponge hydroxyproline content (an index of wound collagen deposition), and types I and III collagen gene expression were measured. RESULTS There were no nutritional differences between the two groups in terms of energy intake, body weight gain, and plasma levels of albumin, total protein, or urea nitrogen. On day 5 wound breaking strength was significantly higher in the enterally supported group (89.3 +/- 90.7 vs 64.9 +/- 40.2 g for the parenteral group, p < .05). This was paralleled by enhanced wound collagen accumulation (182 +/- 19 vs 132 +/- 13 microg, p < .05). Gene expression of type I, but not type III, collagen also was increased in the enterally fed group. There were no differences noted between the two groups in wound healing parameters 7 and 10 days after injury. CONCLUSIONS The data demonstrate that the route of nutrition administration can influence wound healing. The beneficial effect of the enteral feeding route is limited to the early phases of healing.

Effect of nutritional route on colonic anastomotic healing in the rat.

Although early enteral feeding has been shown to benefit cutaneous healing when compared to parenteral feeding, the effect of the route of nutritional support in gastrointestinal anastomotic healing has not been defined. The aim of the present study was to determine whether the route of nutritional support influences colonic anastomotic healing. Twenty male Sprague-Dawley rats weighing 270 to 290 grams underwent identical surgical manipulation consisting of central venous catheterization, gastrostomy insertion, and distal colonic anastomosis (single-layer, inverted). Identical nutrient infusates composed of 4.25% amino acids, 25% dextrose, and vitamins were administered, with half the animals receiving the infusions via the gastrostomy and the other half via the venous catheter. Animals were killed 5 days after surgery. There were no differences in nutritional parameters between the parenterally and enterally fed groups. Colonic anastomotic bursting pressure was significantly higher in the enterally fed group (180 ±6 vs. 150±11 mm Hg; P<0.01). The measured insoluble collagen and total protein content in anastootic tissue were enhanced in the enterally supported group. The fraction of soluble (newly synthesized) collagen did not differ between the two groups. The data demonstrate that the route of nutrient administration influences colonic anastomotic healing. The preservation of colonic structural collagen in the enteral group may improve the ability of the gut to hold sutures and thus enhance anastomotic healing.

Genetic Polymorphisms of Aldehyde Dehydrogenase 2, Cytochrome p450 2E1 for Liver Cancer Risk in HCV Antibody-Positive Japanese Patients and the Variations of CYP2E1 mRNA Expression Levels in the Liver due to its Polymorphism

Background: Hepatocellular carcinoma (HCC) in persons with liver cirrhosis (LC) arises following hepatitis virus infection. Alcohol may accelerate the risk of development of LC and HCC. Cytochrome p450 2E1 (CYP2E1) oxidizes ethanol to form acetaldehyde and aldehyde dehydrogenase 2 (ALDH2) detoxifies acetaldehyde, which is carcinogenic in humans, and both alcohol-metabolizing enzymes show the genetic polymorphisms in a Japanese population. Methods: Using polymorphism analysis, we studied the frequency of ALDH2 functional deletion due to the G to A single-bp mutation in exon 12 and CYP2E1 polymorphism in the transcriptional region, both associated with higher levels of acetaldehyde, in 135 patients with LC and/or HCC, including 99 with HCC, and 135 non-cancer controls. The mRNA expression levels of CYP2E1 in the liver were also examined in 55 surgical specimens. Results: The allelic frequency of the homozygous ALDH2 2-2 genotype, coding for the enzyme deletion, was significantly higher compared to that of the homozygous or heterozygous ALDH2 1-1 genotypes in cases with HCC (OR r = r 5.4, 95% CI 2.1-14.0). There were no differences in the frequencies of specific genotypes of CYP2E1 in cases of HCC, but combined analysis of ALDH2 and CYP2E1 revealed that the odds ratio of occurrence of the C1/C1 homozygosity of CYP2E1 and the ALDH2 2-2 homozygosity was as high as 23.0 (2.9-182). The mRNA levels of CYP2E1 were higher in the liver of patients with the C1/C1 homozygosity of CYP2E1 than in those with other genotypes ( P r < r 0.05). Conclusions: ALDH2 and CYP2E1 polymorphisms may modify the risk of development of HCC against the background of LC in the Japanese. Polymorphism analysis of alcohol-metabolizing enzymes using molecular techniques may be useful in the risk assessment of liver cancer in patients with hepatitis C virus infection.BACKGROUND Hepatocellular carcinoma (HCC) in persons with liver cirrhosis (LC) arises following hepatitis virus infection. Alcohol may accelerate the risk of development of LC and HCC. Cytochrome p450 2E1 (CYP2E1) oxidizes ethanol to form acetaldehyde and aldehyde dehydrogenase 2 (ALDH2) detoxifies acetaldehyde, which is carcinogenic in humans, and both alcohol-metabolizing enzymes show the genetic polymorphisms in a Japanese population. METHODS Using polymorphism analysis, we studied the frequency of ALDH2 functional deletion due to the G to A single-bp mutation in exon 12 and CYP2E1 polymorphism in the transcriptional region, both associated with higher levels of acetaldehyde, in 135 patients with LC and/or HCC, including 99 with HCC, and 135 non-cancer controls. The mRNA expression levels of CYP2E1 in the liver were also examined in 55 surgical specimens. RESULTS The allelic frequency of the homozygous ALDH2 2-2 genotype, coding for the enzyme deletion, was significantly higher compared to that of the homozygous or heterozygous ALDH2 1-1 genotypes in cases with HCC (OR = 5.4, 95% CI 2.1-14.0). There were no differences in the frequencies of specific genotypes of CYP2E1 in cases of HCC, but combined analysis of ALDH2 and CYP2E1 revealed that the odds ratio of occurrence of the C1/C1 homozygosity of CYP2E1 and the ALDH2 2-2 homozygosity was as high as 23.0 (2.9-182). The mRNA levels of CYP2E1 were higher in the liver of patients with the C1/C1 homozygosity of CYP2E1 than in those with other genotypes (P < 0.05). CONCLUSIONS ALDH2 and CYP2E1 polymorphisms may modify the risk of development of HCC against the background of LC in the Japanese. Polymorphism analysis of alcohol-metabolizing enzymes using molecular techniques may be useful in the risk assessment of liver cancer in patients with hepatitis C virus infection.

Effect of early postoperative feeding on the healing of colonic anastomoses in the presence of intra-abdominal sepsis in rats

PURPOSE: Intra-abdominal infection is generally considered a major risk factor for dehiscence of primary colon anastomosis. To elucidate the indications for nutritional support during intra-abdominal sepsis, we investigated the healing of anastomoses in an animal model. METHODS: Twenty male Sprague-Dawley rats (280–320 g) underwent cecal ligation and single puncture. After 24 hours the perforated cecum was removed, and the left colon was transected and anastomosed in a single-layer inverted fashion. Animals were randomly assigned to receive both chow and water (early-fed group; n=10) or water alone for the first 72 hours and chow thereafter (late-fed group; n=10). Colon-bursting pressure was measured five days after the anastomosis, at which time the anastomosis was excised. RESULTS: The survival rate after cecal ligation and single puncture was 100 percent, and blood cultures were positive in 20 percent of animals five days after surgery. All data are expressed as means ± standard error of the mean. Body weight increased more in the early-fed group than in the late-fed group (15.6±3vs. −6.3±2.8 g;P<0.001). Early feeding resulted in increased anastomotic bursting pressure (200±11vs. 161±12 mmHg;P<0.05) and total collagen concentration at the site of anastomosis (2.36±0.09vs. 2.01±0.07 µg/mg wet tissue;P<0.01) compared with the late-fed group. CONCLUSION: Early feeding has a positive effect on anastomotic healing in the presence of intra-abdominal sepsis. The mechanism by which early feeding enhances the colonic anastomotic healing is unclear, although preservation of colonic collagen seems to play a significant role.

Inflammation of the gastric remnant after gastrectomy: mucosal erythema is associated with bile reflux and inflammatory cellular infiltration is associated with Helicobacter pylori infection

BackgroundControversy exists concerning the role of bile reflux and Helicobacter pylori (H. pylori) infection in the development of inflammation of the gastric remnant after gastrectomy. This study was designed to investigate association of bile reflux and H. pylori infection or both with inflammatory changes in the gastric remnant.MethodsA questionnaire on GI symptoms was returned by 200 gastrectomy patients, and 24-h bilirubin monitoring in the gastric remnant was performed on 55 patients with Bilitec 2000. Upper GI endoscopy evaluated reflux gastritis in the gastric remnant, and the presence of H. pylori infection and chronic, active inflammatory cellular infiltration in the biopsy specimens were examined microscopically with the updated Sydney system.ResultsNo difference in the incidence of GI symptoms was observed among individual gastrectomy patients. Bile reflux was lower in patients who had undergone a gastrectomy with jejunal interposition, a pylorus-preserving gastrectomy, and a gastrectomy with Roux–Y anastomosis than those who had undergone a Billroth-II (B-II) anastomosis (P < 0.05). Endoscopy showed positive correlation between mucosal erythema and bile reflux (P < 0.001). No correlation was observed between the mucosal erythema and chronic and active inflammatory cellular infiltration. Infection of H. pylori correlated with chronic and active inflammatory cellular infiltration (P < 0.001). Bile reflux did not correlate with the severity of chronic and active inflammatory cellular infiltration or H. pylori infection.ConclusionsBile reflux into the gastric remnant was observed by Bilitec 2000. Mucosal erythema and chronic, active inflammatory cell infiltration in the gastric remnant after gastrectomy may be caused by bile reflux or H. pylori infection, respectively.

Tacrolimus enhances colon anastomotic healing in rats

Tacrolimus inhibits T‐cell function and neutrophil chemotaxis during inflammation. We hypothesized that tacrolimus would enhance healing of a rat colon anastomosis by reducing the inflammatory response. Fifty‐five male Sprague Dawley rats, 230–260 g body weight, underwent identical surgical manipulation consisting of a single‐layer, inverted colon anastomosis and the implantation of osmotic pumps subcutaneously in the left flank area. The animals were randomly assigned to receive tacrolimus, at a dose of 0.01, 0.1, or 1.0 mg/kg/day, or only the control solvent solution. The animals were euthanized 4 days after surgery. Colon‐bursting pressure (mmHg), anastomotic collagen content (µg hydroxyproline/mg wet tissue), and anastomotic type IV collagenase activity (mU/mg protein) were measured. Tacrolimus significantly increased colon‐bursting pressure at all doses used (146 ± 9, 158 ± 10, 151 ± 6 mmHg; 0.01, 0.1, and 1.0 mg/kg/day, respectively) vs. control (119 ± 7 mmHg, p < 0.01). There was no effect on collagen accumulation except at a dose of 0.01 mg/kg/day, which significantly decreased anastomotic collagen content (p < 0.05). Tacrolimus at a dose of 0.01 mg/kg/day increased anastomotic collagenase activity, which was not changed by treatment with the higher doses. Microscopic examination revealed the preservation of the multilayered structure, including the mucosal muscle, a thickened submucosa, and the proper muscle of the anastomotic site in the tacrolimus‐treated groups. These data suggest that tacrolimus enhances wound strength during acute anastomotic healing despite a reduction in collagen content.(WOUND REP REG 2002;10:308–313)

Maximal Sterile Barrier Precautions Do Not Reduce Catheter-Related Bloodstream Infections in General Surgery Units: A Multi-Institutional Randomized Controlled Trial

Objective:To investigate whether maximal sterile barrier precautions (MSBPs) during central venous catheter (CVC) insertion are truly effective in preventing catheter-related bloodstream infections (CRBSIs) in patients in general surgical units. Summary Background Data:The reported effectiveness of MSBPs was based on the results of a single-center randomized controlled trial by Raad et al and the majority of the patients (99%) in the study were chemotherapy outpatients. Methods:Between March 14, 2004 and December 28, 2006, the patients scheduled for CVC insertion in surgical units at 9 medical centers in Japan were randomly assigned to either an MSBP group (n = 211) or a standard sterile barrier precaution (SSBP) group (n = 213). This study was registered in the UMIN Clinical Trials Registry (registration ID number: UMIN000001400). Results:The median (range) duration of catheterization was 14 days (0–92 days) in the MSBP group and 14 days (0–112 days) in the SSBP group. There were 5 cases (2.4%) of CRBSI in the MSBP group and 6 cases (2.8%) in the SSBP group (relative risk, 0.84; 95% confidence interval, 0.26–2.7; P = 0.77). The rate of CRBSIs per 1000 catheter days was 1.5 in the MSBP group and 1.6 in the SSBP group. There were 8 cases (3.8%) of catheter-related infections in the MSBP group and 7 cases (3.3%) in the SSBP group (relative risk, 1.2; 95% confidence interval, 0.43–3.1; P = 0.78). The rate of catheter-related infection per 1000 catheter days was 2.4 in the MSBP group and 1.9 in the SSBP group. Conclusions:This study is larger in sample size than the one performed by Raad et al and could not demonstrate better prevention of CRBSIs by MSBP compared with SSBP. A large randomized controlled trial or at least a meta-analysis of any other studies in the literature is necessary to reach to a conclusion on this issue.