Biomedical subjects

Masaki Kitajima

Publications and source records attributed to Masaki Kitajima.

At least 199 records · Page 11Linked to original sources

PubMed2002

Sentinel node mapping for colorectal cancer with radioactive tracer.

PURPOSE: The aim of this study was to test the feasibility and accuracy of radioactivity-guided mapping of the first lymph nodes found in draining the primary tumor site for colorectal cancer. METHODS: We enrolled 56 consecutive patients with preoperative diagnosis of curatively resectable colorectal cancer. Endoscopic injection of technetium Tc 99m-labeled tin colloid (15 MBq) was performed preoperatively, and radioactive sentinel nodes were identified intraoperatively with a gamma probe. Standard radical resection with lymph node dissection was performed in all patients, and all resected nodes were evaluated by routine histopathologic examination. RESULTS: Radioactivity-guided methods were used to detect sentinel nodes in 51 (91 percent) of 56 patients. The number of lymph nodes resected was 23.9 +/- 15.2 per case. The number of sentinel nodes was 3.5 +/- 2.1 (range, 0-8) per case. In 18 of 22 patients with lymph node metastasis, the sentinel node was positive. The incidence of metastasis in the sentinel node (22 percent) was significantly higher than that in nonsentinel nodes (3 percent, P < 0.01). Diagnostic accuracy according to sentinel node status was 92 percent (47/51). Four false-negative cases in this study were advanced cases with T3 primary tumors. The detection rate and diagnostic accuracy for patients with T1 or T2 primary tumors (29 cases) were 100 percent each. CONCLUSION: Intraoperative radioactivity-guided sentinel node mapping was accurate for patients with colorectal cancer with T1 or T2 tumors. The results suggest that sentinel node mapping and intraoperative biopsy may be a sensitive and specific diagnostic method for detecting metastasis in regional lymph nodes in patients with colorectal cancer.

Adult↗

PubMed2002

Prognostic significance of laminin-5 gamma2 chain expression in colorectal carcinoma: immunohistochemical analysis of 103 cases.

PURPOSE: The laminin-5 gamma2 chain plays an important role in cell migration during tumor invasion and tissue remodeling. Although this chain has been reported to be expressed in tumor-stroma interface of colorectal carcinoma, prognostic significance of its expression has not been elucidated in these tumors, so we investigated the clinicopathologic significance of Laminin-5 gamma2 chain expression in colorectal carcinoma. METHODS: Laminin-5 gamma2 chain expression was investigated immunohistochemically in 103 colorectal carcinoma patients with Stage II, III, and IV disease. The patients were categorized into three groups according to the number of immunopositive tumor cells in the sections containing the maximum diameter of the tumor as follows: +, less than 20 tumor cells were positive; ++, 20 to 500 tumor cells were positive; +++, more than 500 tumor cells were positive. RESULTS: Laminin-5 gamma2 chain expression was observed in cytoplasm of tumor cells, especially those in the invasive front of the tumor penetration. Eighteen (17 percent) of tumors showed +, 60 (58 percent) showed ++, and 25 (24 percent) showed +++. The increased number of immunopositive tumor cells was significantly associated with synchronous liver metastasis (P = 0.048). The univariate (P = 0.036) and multivariate (P = 0.001) analysis of the patients' survival revealed that the prognosis became significantly poorer in patients with the increased number of immunopositive tumor cells. CONCLUSIONS: Increased laminin-5 gamma2 chain immunoreactivity, suggesting a high invasive potential of tumor cells, was a significant poor prognostic indicator for the patients with colorectal carcinoma.

Adenocarcinoma↗

PubMed2002

Prospective evaluation of laparoscopic surgery for rectosigmoidal and rectal carcinoma.

PURPOSE: This study was designed to examine the short-term results of laparoscopy in the treatment of curative cases of rectosigmoidal and rectal carcinoma. METHODS: A review was performed of a prospective registry of 70 patients who underwent curative laparoscopic resection for rectosigmoidal and rectal carcinoma between July 1993 and April 2001. Before 1997, only patients with early (Tis or T1) cancers located in the rectosigmoid and upper rectum that required bowel resection were candidates for laparoscopy. In 1997, we expanded the application of laparoscopy to include T2 cancers located anywhere in the rectum. Mesorectal transection was performed at least 5 cm below the tumor for rectosigmoidal and upper rectal lesions, and total mesorectal excision was performed for lower tumors. Primary anastomosis was performed by a double-stapling technique, or a handsewn coloanal anastomosis was performed. Patient demographics and outcomes were recorded prospectively. RESULTS: The median follow-up was 23 months. An anastomosis was performed in 92.9 percent of the operations. Oral intake was started on median postoperative Day 1, and the median length of hospitalization was 8 days. Two patients needed conversion to conventional open surgery. A total of 15 postoperative complications occurred in 13 patients (18.6 percent), including anastomotic leakage in 6 (8.6 percent) and bowel obstruction in 3 (4.3 percent). Reoperation was required in six patients. Two patients developed recurrence of cancer at the anastomotic site. The expected 5-year survival and disease-free survival rates were 100 and 92.1 percent, respectively. CONCLUSION: The findings of the present study demonstrate the feasibility and safety of laparoscopic surgery for selected patients with rectal carcinoma. Morbidity and mortality rates and oncologic outcome appear to be comparable with conventional surgery.

Adult↗

PubMed2002

Clinical significance of telomerase activity in peripheral blood of patients with esophageal squamous cell carcinoma.

BACKGROUND: The presence of tumor cells in the blood stream is considered evidence of a high risk of distant organ metastasis. We examined the usefulness of telomerase activity in peripheral blood polymorphonuclear cells as an indicator of distant metastasis in patients with esophageal squamous cell carcinoma. METHODS: Telomerase activity was measured in the peripheral blood mononuclear cell and polymorphonuclear cell fractions obtained from blood samples of healthy volunteers mixed with squamous cell carcinoma cell lines, and cell distribution was analyzed by flow cytometry. Then telomerase activity of forty-two polymorphonuclear cell fractions obtained from esophageal squamous cell carcinoma patients was measured. RESULTS: Telomerase activity was detected in polymorphonuclear cell fractions and cell distribution analysis revealed the presence of esophageal squamous cell carcinoma cells. Organ metastasis was detected in 7 (78%) of the 9 patients with telomerase-positive polymorphonuclear cell fractions as opposed to only five (15%) of the 33 with telomerase-negative cases, and there was a significant positive correlation between telomerase activity and organ metastasis (p < 0.0008). CONCLUSIONS: Measurement of telomerase activity in the polymorphonuclear cell fractions is useful for identifying a high risk group for distant organ metastasis in patients with esophageal squamous cell carcinoma.

Aged↗

PubMed2002

Intratracheal delivery of a single major histocompatibility complex class I peptide induced prolonged survival of fully allogeneic cardiac grafts and generated regulatory cells.

We have previously reported that intratracheal delivery of donor splenocytes in mice induces hyporesponsiveness to fully allogeneic cardiac grafts and generates regulatory cells. Here, we examined whether an allopeptide would produce the same results. A 15-mer (54-68) peptide corresponding to a hypervariable region of the K(b) molecule was given intratracheally or intravenously to CBA (H2(k)) mice 7 days before transplantation of a C57BL/10 (H2(b)) or BALB/c (H2(d)) heart and was also used in adoptive transfer experiments. Cardiac grafts in recipients given K(b) peptide intratracheally experienced a median survival time (MST) of 56 days, whereas those in recipients given the peptide intravenously were rejected acutely (MST=7.5 days). Adoptive transfer of splenocytes from mice pretreated intratracheally with K(b) peptide to naïve secondary recipients prolonged survival of cardiac grafts (MST = 35 days). Intratracheal delivery of a single major histocompatibility complex class I peptide induced hyporesponsiveness to allogeneic cardiac grafts and generated regulatory cells.

Adoptive Transfer↗

PubMed2002

Sentinel lymph node biopsy in breast cancer using technetium-99m tin colloids of different sizes.

Axillary lymph node dissection (ALND) in the treatment of breast cancer is essential for predicting the prognosis and regional control of the tumor. At the same time ALND is associated with pain, numbness and sometimes lymphedema. Sentinel lymph node biopsy (SLNB) is a potential alternative procedure to conventional ALND in clinically node-negative breast cancer. In this study, we prepared the technetium-99m-labeled tin colloids with different sizes and compared their efficacy in SLNB. From September 1998 to February 2002, 184 clinically node-negative breast cancer patients were enrolled in the study at Keio University Hospital. Sentinel lymph nodes (SLNs) were identified by both blue dye and radioisotope. We prepared small-sized technetium-99m-labeled tin colloid (particle size: 200-400 nm in diameter). Regular-sized technetium-99m-labeled tin colloid is 400-1000 nm in diameter. In 74 patients, a SLNB was performed using regular-sized tin colloid; small-sized tin colloid was used in 110 patients. Subsequently, all of the patients were immediately followed by ALND. All dissected lymph nodes were evaluated by routine histopathological examination. The clinicopathological characteristics of the two groups were comparable. The lymphoscintigram detected SLN more frequently in the small-sized colloid group than in the regular-sized colloid group (P < 0.01). Small-sized tin colloid was also superior to regular-sized tin colloid in the SLN identification rate (97.3% versus 86.5%; P = 0.01). The mean value for ex vivo counts of the hottest sentinel lymph nodes of the small-sized colloid group was significantly higher than the counts of the regular-sized colloid group (P < 0.01). There was no significant difference in the accuracy between the two groups. It was concluded that SLNB using the small-sized tin colloid was technically feasible and provided higher detection and identification rates than the regular-sized tin colloid.

Adult↗

PubMed2002

Overview: current status of breast conserving therapy in Japan.

Breast conserving operations have become the standard operation for early breast cancer. They were performed in about 40% of all breast cancer patients in Japan in 2000, and the percentage is still increasing. Ductal carcinoma in situ (DCIS) accounts for about 7% of all breast cancers and breast conserving operations for DCIS have been followed by a low in-breast recurrence rate, leading to wider indications for breast conserving operations as screening mammography has come to be used in Japan. In-breast recurrence is correlated to surgical margin status. It is important to evaluate the surgical margin for volume of cancer cell nests as well as for positivity. Neoadjuvant chemotherapy has become popular as an in vivo sensitivity test and as a means of down-staging to increase the possibility of performing a breast conserving operation. There are two patterns of shrinkage when neoadjuvant chemotherapy is effective: cocentric and honeycomb, and the pattern of residual cancer cell nests must be determined before surgery. MRI is an effective method of evaluating residual cancer cell nests. The in-breast recurrence rate after down-staging to perform breast conserving operations is reported to be higher than among candidates for breast conserving operation at the start. Sentinel node biopsy techniques and endoscopic operations are now being assessed in conjunction with breast conserving operations. The current status of breast conserving operations in Japan is reviewed in comparison with their status in Western countries.

Breast Neoplasms↗

PubMed2002

Minimally invasive surgery for gastric carcinoid tumor.

Minimally invasive laparoscopic wedge resection for gastric mucosal carcinoma and submucosal tumor was first performed in Keio University hospital in 1992. Since then, 172 gastric tumor patients, including four cases of carcinoid tumor, have been successfully treated at the Keio University hospital using this procedure. No local disease recurrence or distant metastases have been observed in follow-ups over as long as 10 years. Chronic atrophic gastritis patients with carcinoid tumors occurring secondary to hypergastrinemia are candidates for the minimally invasive surgery. With careful patient selection according to tumor size, depth of invasion, and histopathological findings of malignancy grade, endoscopic and laparoscopic therapy for these patients can be a safe, curative, and minimally invasive procedure.

Carcinoid Tumor↗

PubMed2002

Intraoperative lymphatic mapping and sentinel lymph node sampling in esophageal and gastric cancer.

Recent studies for SN mapping of esophageal and gastric carcinoma show that the SN concept is valid even for upper GI cancers with multidirectional and complicated lymphatic flow. The relatively high incidence of anatomic skip metastasis can be attributed to aberrant distribution of SNs. An individualized and minimally invasive surgical approach can be applicable to management of esophageal and gastric carcinoma based on SN status. Although there are several issues to be resolved, this novel procedure has the potential for great benefit to improve quality control in the treatment of upper GI cancer. Well-designed clinical trials of lymphatic mapping for upper GI cancer will be essential to determine whether this technique is widely applicable in the management of these tumors.

Esophageal Neoplasms↗

PubMed2002

Reactive oxygen species and vascular cell adhesion molecule-1 in distant organ failure following bile duct obstruction in mice.

Pulmonary injury with leukocyte infiltration is a frequent occurrence in obstructive cholangitis patients. We wished to evaluate the roles of reactive oxygen species and vascular cell adhesion molecule-1 (VCAM-1) in this distant organ failure. Wild type (WT) and transgenic (SODtg) mice overexpressing superoxide dismutase underwent bile duct ligation and transection (BDL). VCAM-1 expression was quantified, and histopathology was assessed for the liver and lung. BDL resulted in increased leukocyte infiltration to the lung at five days in WT mice. VCAM-1 expression significantly increased in WT mouse liver at three days and WT mouse lung at five days. When these same experiments were performed in SODtg mice, these increases in leukocyte infiltration and VCAM-1 expression in lung were significantly attenuated. These data suggest that reactive oxygen species produced in response to BDL may up-regulate VCAM-1 expression in the lung and play an important role in the pathophysiology of this pulmonary injury.

Animals↗

PubMed2002

In situ cancer vaccination with a replication-conditional HSV for the treatment of liver metastasis of colon cancer.

In this study, we investigated the therapeutic efficacy of a replication-conditional mutant HSV, G207, for the treatment of liver metastasis of colon carcinoma. Three liver metastasis models in syngeneic BALB/c mice were developed: (i) splenic injection, (ii) splenic and subcutaneous (s.c.) injection, and (iii) orthotopic implantation of CT26 colon carcinoma. In the splenic injection model, G207 was injected into the established splenic tumor on day 7. In the splenic and s.c. injection model, G207 were injected into the established s.c. tumor on days 5 and 8. In the orthotopic implantation model, a piece of CT26 tumor tissue was transplanted onto the wall of the cecum and G207 was injected in the established cecum tumor on day 7. On day 21 or 28, animals were sacrificed and liver metastases were evaluated. In all three models in immunocompetent mice, liver metastases were significantly reduced by intratumoral inoculation with G207 compared to the control. In athymic mice, however, there was no significant therapeutic effect of intratumoral inoculation with G207 on liver metastases. Tumor-specific cytotoxic T-lymphocyte responses were induced in mice treated with G207 in the orthotopic implantation model. These results suggest that intratumoral inoculation of G207, as an in situ cancer vaccine, can be an effective approach against liver metastasis of colon cancer and the efficacy involves tumor-specific T-cell responses.

Animals↗

PubMed2002

Tumor necrosis factor suppression and microcirculatory disturbance amelioration in ischemia/reperfusion injury of rat liver after ischemic preconditioning.

BACKGROUND: Brief periods of hepatic ischemia produce immediate tolerance for subsequent prolonged ischemia. Although the beneficial effect of this ischemic preconditioning is recognized, the mechanism itself remains poorly understood. METHODS: Male Wistar rats were divided into two groups: a control group that was subjected to 30 min of ischemia + following reperfusion, and an ischemic preconditioning group that was subjected to 5 min of ischemia + 5 min of reperfusion + 30 min of ischemia + following reperfusion. By using this model, hepatic damage, microcirculatory disturbances, and tumor necrosis factor-alpha protein production and mRNA expression were analyzed during the course of reperfusion in both groups. For the hepatic damage evaluations, hepatic enzyme levels, histology, apoptosis analysis, and intravital microfluorography for dead cells were examined. For the microcirculatory disturbance analysis, an adhesion molecule and intravital microfluorography for endothelial-adherent leukocytes were examined. RESULTS: In the ischemic preconditioning group, ischemia/reperfusion injuries (shown by hepatic enzymes elevation, histological degeneration, and increases in the number of apoptotic cells and microfluorographic dead cells) were markedly reduced. Moreover, microcirculatory disturbances represented by intercellular adhesion molecule-1 expression and leukocyte adhesion on the endothelium were ameliorated. Tumor necrosis factor-alpha protein production and mRNA expression were also suppressed in the ischemic preconditioning group. CONCLUSION: The suppression of tumor necrosis factor-alpha and the subsequent amelioration of microcirculatory disturbances were observed, suggesting that the mechanism underlying the protective effect of ischemic preconditioning in hepatic ischemia/reperfusion injuries may involve tumor necrosis factor-alpha and microcirculatory regulation.

Animals↗

PubMed2002

Biliary complications in adult living donor liver transplantation with duct-to-duct hepaticocholedochostomy or Roux-en-Y hepaticojejunostomy biliary reconstruction.

BACKGROUND: The aim of this study was to compare the incidence of biliary complications after adult living donor liver transplantation (ALDLT) with Roux-en-Y hepaticojejunostomy (R-Y HJ) or duct-to-duct hepaticocholedochostomy (D-D HC). METHODS: Biliary complications were reviewed in 20 consecutive ALDLT recipients surviving more than 1 month, including 10 patients who underwent R-Y HJ and 10 patients who underwent D-D HC reconstructions. RESULTS: Ten biliary complications were seen in 8 patients (40%) from the study group. Specifically, 1 case of biliary leakage and 1 case of biliary hemorrhage were observed in the R-Y HJ group (20%), and 2 biliary leakages, 4 biliary strictures, and 2 C-tube related biliary leakages were seen in 6 patients from the D-D HC group (60%). Three of the 5 patients (60%) who underwent right lobe graft ALDLTs experienced biliary stricture. All cases of biliary leakage and biliary hemorrhage were stopped spontaneously by continuous drainage. Three patients in the D-D HC group with anastomotic strictures were successfully treated with percutaneous interventions. Only 1 patient with anastomotic stricture in the D-D HC group with left lobe graft required intrahepatic R-Y HJ reanastomosis. Two cases of C-tube related biliary leakages were treated with endoscopic management. CONCLUSIONS: Biliary complications such as anastomotic strictures were common in the D-D HC group rather than in the R-Y HJ group. D-D HC reconstruction should be applied cautiously, especially in the right lobe graft ALDLT cases.

Adult↗

PubMed2002

Immunosuppressive and anticancer effect of a mammalian ribonuclease that targets high-affinity interleukin-2-receptors.

OBJECTIVE: To target high-affinity interleukin (IL)-2 receptors involved in lymphocyte proliferation processes such as allograft rejection, autoimmune disorders, and certain haematological malignancies, using a minimally immunogenic mammalian-derived enzyme, bovine RNaseA, which becomes cytotoxic on entering cytoplasm. DESIGN: Laboratory study. SETTING: Teaching hospital, Japan. MATERIAL: Human lymphocytes isolated from healthy histoincompatible donors in mixed lymphocyte cultures or stimulated with phytohemagglutinin (PHA) to promote IL-2Ralpha expression. MJ, an HTLV-1-infected malignant T-cell line that overexpresses IL-2Ralpha, and the IL-2Ralpha-negative cell lines MOLT-4F and MT-1, were used as controls. INTERVENTIONS: Bovine RNaseA was chemically conjugated to 7G7B6, a monoclonal antibody to the alpha-chain of human IL-2 receptors, and several concentrations of the conjugates were added to the lymphocyte cultures. MAIN OUTCOME MEASURES: Inhibition of cell proliferation as a percentage of 3H-thymidine incorporation in 24 hours. RESULTS: 7G7B6-RNaseA dose-dependently inhibited cell proliferation in PHA-stimulated human lymphocytes at a 50% inhibitory concentration (IC50) of 2 x 10(-7) M. whereas RNase alone and RNase plus antibody had no inhibitory effect. 7G7B6-RNaseA also dose-dependently inhibited the human mixed lymphocyte reaction at an IC50 of 2 x 10(-6) M, whereas RNase alone did not. The conjugate also inhibited cell proliferation in MJ cells, a cell line that is infected with HTLV-I and overexpresses the high-affinity IL-2 receptor, at an IC50 of 5 x 10(-7) M. However the conjugate had no inhibitory effect on the IL-2 receptor non-expressing human T-cell lymphoblastic leukaemia cell lines MOLT-4F or MT-1. CONCLUSION: 7G7B6-RNaseA can inhibit cell proliferation in antigen- or mitogen-stimulated lymphocytes that overexpress high-affinity IL-2 receptors, and it may be safer than conventional chemotherapy or immunotoxins in the treatment of transplant rejection, certain lymphocytic malignancies, and other IL-2R-associated diseases, because it contains a mammalian cytotoxic enzyme.

Animals↗

PubMed2002

Laparoscopic restorative proctocolectomy for patients with ulcerative colitis.

BACKGROUND: Significant concern continues about the feasibility of laparoscopic restorative proctocolectomy (RP) with an ileal J pouch anal anastomosis in the surgical treatment of patients with ulcerative colitis (UC). The aim of this study was to clarify the feasibility of laparoscopic RP at a single institution where the surgical routine of laparoscopic colorectal surgery has already been established. PATIENTS AND METHODS: Between July 1994 and December 2001, 18 patients with UC underwent laparoscopic RP. The median age was 30 (range, 18-51) years, and the median follow-up was 20 (range, 5-89) months. Five trocars were placed. After the entire colon and rectum were mobilized and the vessels were divided intracorporeally, the rectum was divided with use of a laparoscopic linear stapler. A pouch anal anastomosis was fashioned with use of a double stapling technique. A diverting loop ileostomy was fashioned. RESULTS: There were no conversions to the open procedure. The median operative time and median blood loss were 360 (range, 290-500) minutes and 105 (range, 10-586) mL, respectively. Six postoperative complications occurred (wound sepsis, 2; bowel obstruction, 1; anastomotic stricture, 2; pouchitis, 1). In one patient, a bowel obstruction developed 3 months after the operation, which was managed conservatively. The median length of the hospital stay was 9 (range, 7-21) days. CONCLUSIONS: The laparoscopic RP is safe and feasible in selected patients with UC. New laparoscopic instrumentation, such as a linear stapler, and a more reliable laparoscopic coagulating and dividing tool should be designed, which would make it possible to perform this procedure more frequently in the surgical treatment of UC.

Adult↗

PubMed2002

Evaluation of the usefulness of percutaneous transhepatic portal catheterization for preoperatively diagnosing the localization of insulinomas.

INTRODUCTION: The precise intraoperative localization of insulinoma is essential for successful surgical management. AIMS: To assess the usefulness of measuring insulin levels by preoperative percutaneous transhepatic portal catheterization (PTPC) and intraoperative ultrasonography (US). METHODOLOGY: PTPC and other preoperative procedures (enhanced computed tomography [CT], arteriography, and US) were performed in eight patients with insulinoma based on our experience during the past 18 years. Intraoperative US was performed in six of the eight patients. RESULTS: PTPC was undertaken in all eight patients, and increased levels of insulin at the sites corresponding to tumors were observed in all patients. Intraoperative US was performed in six patients, which made it possible to detect insulinomas as hypoechoic masses in all of these patients. All tumors were found to exist as single entities. CONCLUSION: PTPC showed the highest diagnostic accuracy in detecting the number of and accurately localizing the tumors before surgery. Meanwhile, all findings from intraoperative US were identical to those of the resection samples, suggesting that this method is a highly reliable examination technique. We conclude that a combination of PTPC and intraoperative US may be essential for the successful surgical management of insulinomas.

Angiography↗

PubMed2002

Matrix metalloproteinase inhibitor, marimastat, decreases peritoneal spread of gastric carcinoma in nude mice.

Marimastat, a matrix metalloproteinese inhibitor, was examined for the ability to prevent peritoneal dissemination of a human gastric cancer xenograft, TMK-1. Even with novel approaches such as molecular targeting of cancer chemotherapy, peritoneal dissemination of gastric cancer has little sensitivity to anticancer drugs, and it is impossible to inhibit its growth completely. Intraperitoneal injection of TMK-1 into nude mice at 5 x 10( 5) cells / body resulted in carcinomatous peritonitis that mimicked clinical cases. Continuous administration of marimastat (18 mg / kg / day) from 24 h after the tumor inoculation successfully inhibited the growth of peritoneal dissemination nodules. Combined administration of marimastat (18 mg / kg / day) and mitomycin C (MMC, 2 mg / kg) showed synergistic inhibition of growth of peritoneal dissemination, being superior to MMC alone (2 mg / kg). Although marimastat alone could not increase survival time with statistical significance, combined administration of marimastat and MMC had a survival benefit with statistical significance. The combination of marimastat and MMC increased the preventive effect on peritoneal dissemination. Marimastat seems to be a candidate for the prevention of peritoneal spread of gastric carcinoma.

Animals↗

PubMed2002

Arteriovenous shunting blood flow is intravitally observed in the stomach after thermal injury in rats.

Microcirculatory disturbance of the gastric wall is a crucial factor in the development of gastric mucosal lesions induced by Helicobacter pylori, anti-inflammatory drugs and stress. Opening of the arteriovenous shunting channel after thermal injury is one of the possible mechanisms to reduce mucosal blood flow. However, no in vivo observation of arteriovenous shunting blood flow in the stomach has been reported. To assess gastric microcirculatory disturbance, especially arteriovenous shunting blood flow after thermal injury by in vivo microsciopy, male Wistar rats were anesthetized and thermal injury was inflicted on the back skin. Gastric microvascular images were observed by in vivo microscopy. Rolling of leukocytes labelled with carboxyfluorescein diacetate, succinimidyl ester were counted and blood flow dynamics were observed by flow of a micro dye, monastral blue B (MBB). The endothelial damage was assessed by deposits of MBB 5 min after the administration. Arteriovenous shunting blood flow is difficult to detect by normal methods, but it could be observed by How of MBB after thermal injury. Statistical analysis showed a significant difference in the ratio of arteriovenous shunting blood flow detection between the control (no injury) (0%; n = 15) and thermal injury (5 hrs after thermal injury) (28.6%; n = 14) groups. In the thermal injury group, the percentage of rolling leukocytes and the area of monastral blue B deposits increased, and the venular walls tended to be irregular. The total length of erosion increased time-dependently after thermal injury, and the length at 5 hrs was approximately 2 times larger than that at 2 hrs. Arteriovenous shunting blood flow is intravitally observed after thermal injury. A-V shunting blood flow can be a cause of mucosal hypoperfusion. It is suggested that the microcirculatory disturbance seen 5 hrs after thermal injury is contributed to the final step of erosion formation.

Animals↗