A morphological study of the pacemaker cells of the aganglionic intestine in Hirschsprung's disease utilizing ls/ls model mice.

Hirschsprung's disease is a congenital aganglionic neural disorder of the segmental distal intestine characterized by unsettled pathogenesis. The relationship between Hirschsprung's disease and pacemaker cells (PMC), which almost corresponds to that of the interstitial cells of Cajal (ICC), was morphologically observed at the level of the intermuscular layer corresponding to Auerbach's plexus using ls/ls mice. These mice are an ideal model because of their large intestinal aganglionosis and gene abnormalities, which are similar to the human form of the disease. Immunostaining using anti-c-kit receptor antibody (ACK2), a marker of PMC, applied to whole-mount muscle-layer specimens, revealed the presence of c-kit immunopositive multipolar cells with many cytoplasmic processes in normal mice. For ls/ls mice, however, there were significantly fewer processes. The average number of processes per positive cell of 2.5 for the aganglionic large intestine was fewer than 3.5 for the large and small intestine of normal mice, indicating the inability to form connections between nerves and PMC in the aganglionic intestine. For normal mice with an Auerbach's plexus, the process attachment of ICC to the Auerbach's plexus was observed by scanning electron microscopy. However, for ls/ls mice no attachment to the intermuscular nerve without Auerbach's plexus was found, although transmission electron microscopy showed no difference in the cell structure and organelles of the c-kit immunopositive cells between the normal and ls/ls mice. These findings suggest that in the aganglionic intestine of Hirschsprung's disease, aplasia of enteric ganglia induces secondary disturbances during the normal development of intestinal PMC.

Postoperative pancreatic fistula following surgery for gastric and pancreatic neoplasm; is distal pancreaticosplenectomy truly safe?

BACKGROUND/AIMS: A pancreatic fistula is a potentially fatal complication in digestive tract surgery. The aim of this study was to review the prevention and treatment of pancreatic fistula as performed by our department. METHODOLOGY: Three hundred and seventeen patients with gastric neoplasm and 34 patients with pancreatic neoplasm who underwent surgical resection between 1981 and 2001 at Kochi Medical School were studied. Comparative analysis of the incidence of pancreatic fistulae and the mortality rate was carried out according to an operation type and time. RESULTS: Among the 317 patients who underwent total gastrectomy due to gastric neoplasm, 30 (9.5%) showed pancreatic fistulae. The incidence of pancreatic fistulae in patients who underwent distal pancreatectomy for pancreatic neoplasm was 29.4%. The mortality rate of patients who underwent total gastrectomy was 4.4% and there was a tendency for mortality rate to decrease in the second decade compared to the first. The mortality rate of patients who underwent distal pancreatectomy was 5.9%. CONCLUSIONS: Mortality rate tended to decrease with advanced operative procedures, however, the incidence of pancreatic fistulae did not decrease. In pancreatic fistulae, it was found that the type of treatment was important. Intraoperative and postoperative drainage management for pancreaticosplenectomy will likely become much more important.

Posterior gastric artery in angiograms and its surgical importance.

BACKGROUND/AIMS: The incidence and the clinical importance of the posterior gastric artery (PGA) have not been clarified. In Japan, as in the West, the incidence of adenocarcinoma of the upper stomach has increased recently. The purpose of this study was to clarify the features of the posterior gastric artery by analyzing a large series of digital subtraction angiography, and to determine its clinical significance. METHODOLOGY: Three hundred and fourteen patients who underwent angiography between 1991 and 2001 at the Kochi Medical School were studied. The length from the root of the splenic artery and the internal diameter of PGA were investigated celiacographically. The correlation of the body mass index (BMI) and the features of PGA were evaluated. RESULTS: PGA was visualized in 175 patients (55.7%) celiacographically. PGA averaged 3.2-7.4cm (mean 5.4) in length from the root of the splenic artery and the size was 0.7-2.1mm (mean 1.4). The rate of depiction in patients with liver cirrhosis (73.2%) was significantly higher than that in those without (30.5%). No significant difference in length or size of PGA was seen by gender, age, or hepatitis viral infection. No correlation was found between the length or size of PGA and BMI. CONCLUSIONS: Our findings show that the anatomical features of PGA can be visualized by clinical methods useful in planning surgical treatment.

Academic performance and comparative effectiveness of computer- and textbook-based self-instruction.

We intended to clarify the influence of student academic ability on the effectiveness of CAI, using data of a study to assess the effectiveness of a new type of CAI software, cyberPatient (CP), at Kochi Medical School (KMS). A total of 59 third-year students were randomly assigned to four groups: Group-1 used a textbook for self-instruction, Group-2 used CP, Group-3 used both types of learning materials, and Group-4 did not learn. Learning performance was evaluated by multiple-choice examination and OSCE. In order to clarify the influence of students' academic ability on the effectiveness of CAI, statistical analyses were conducted, assigning students as either high or medium or low performance students. High performance students from Group-1, -2 and -3 did not differ significantly in test performance after self-instruction. However, low performance students in Group-1 scored significantly lower than those in Group-2 and -3. All students in Group-2 and -3 reported that CP stimulated willingness to learn and assisted understanding. The present analysis suggested that effectiveness of CAI might be associated with the academic ability of students.

Immunological evaluation of vaccination with pre-designated peptides frequently selected as vaccine candidates in an individualized peptide vaccination regimen.

We previously conducted a trial of an 'individualized' regimen, in which cancer patients were vaccinated with peptides after the confirmation of pre-existing peptide-specific cytotoxic T lymphocyte (CTL) precursors. In this study, we performed a new trial of 'pre-designated' regimen, in which cancer patients were vaccinated with peptides that were frequently selected as vaccine candidates in the preceding individualized regimen. Eighteen cancer patients (10 with uterine cervical cancer and 8 with gastric cancer) were enrolled in the new regimen. The pre-designated regimen was well tolerated by all patients. Although peptide-specific CTL precursors and humoral responses increased in the majority of patients with the pre-designated regimen, neither of the responses correlated with clinical outcome. Three patients had long stable disease, and their pre-vaccination peripheral blood mononuclear cells contained peptide-specific CTL precursors reactive to more than 2 of 4 peptides. With the pre-designated regimen, the levels of pre-existing immunoglobulin G reactive to non-vaccinated peptides decreased in 5 of 15 patients with progressive disease, and their time to progression was very short, whereas such a decrease was rarely observed in the preceding individualized regimen. These results suggest that the pre-designated regimen can elicit a primary immune response, but may incidentally suppress pre-existing immune responses.

Three-dimensional demonstration of cystic duct by helical CT scanning.

BACKGROUND/AIMS: We evaluated the usefulness of helical CT scanning with drip-infusion cholangiography for the delineation of choleductal anatomy in preparation for laparoscopic cholecystectomy. METHODOLOGY: One hundred and five cases underwent laparoscopic cholecystectomy for cholecystolithiasis in our department from March 1993 to July 1998. Endoscopic retrograde cholangiography was carried out in 58 cases and helical CT scanning with drip-infusion cholangiography, including, three-dimensional CT in 31 cases. We, retrospectively, investigated three-dimensional helical CT scanning with drip-infusion cholangiography in the point of three-dimensional demonstration of cystic duct anatomy and try to classify the findings. RESULTS: Three-dimensional helical CT scanning with drip-infusion cholangiography visualized three-dimensional anatomy of the cystic duct clearly. For the detection of the biliary disease such as stones and polyps, however, endoscopic retrograde cholangiography is superior (sensitivity; 89.7%) to two-dimensional helical CT scanning with drip-infusion cholangiography (sensitivity; 64.5%) and three-dimensional helical CT scanning with drip-infusion cholangiography (sensitivity; 22.6%) except for large lesions. We have classified the three dimensional helical CT scanning with drip-infusion cholangiography findings in three types. CONCLUSIONS: Three-dimensional helical CT scanning with drip-infusion cholangiography is not only less invasive but also more useful for the delineation of three-dimensional anatomy of the bile duct.

Early gastric cancer giving rise to bone and brain metastases--a review of the Japanese literature.

A forty-year-old female consulted a hospital complaining of epigastralgia. She underwent endoscopy, which showed irregular shaped ulceration with fold convergence; the biopsy specimen revealed poorly differentiated adenocarcinoma. She underwent subtotal gastrectomy and lymph node dissection. Histological findings revealed the signet-ring-cell cancer confined to the mucosa and no lymph node metastasis. The serum carcinoembryonic antigen was elevated 2 years and 11 months after operation. Bone scintigraphy demonstrated multiple accumulation and bone biopsy of the sacrum revealed the metastatic gastric cancer. She underwent chemotherapy and radiation, however, later complained of nausea, vomiting, and diminished visual acuity. Brain computed tomography revealed multiple brain metastasis. She died 3 years and 6 months after her operation. We reviewed the 39 reported cases of early gastric cancer with bone metastasis in Japan, which suggests that signet-ring-cell carcinoma and poorly differentiated carcinoma have a possibility of bone metastasis even though the early gastric cancer is confined to the mucosa.