Osamu Aizawa

Homotypic Adhesion through Carcinoembryonic Antigen Plays a Role in Hepatic Metastasis Development

We established a cell line with high metastatic potential to the liver (LS‐LM4) after four successive repetitions of splenic injection of liver‐metastatic cells in SCID mice. This cell line strongly expressed CEA and showed increased homotypic adhesion as compared with the parent cell line (LS174T). To examine the role of CEA in the increased homotypic adhesion, LS‐LM4 cells were treated with anti‐CEA antibody and subjected to an in vitro adhesion and aggregation assay. Further, to study the role of CEA in the hepatic metastasis of cells with high metastatic potential, LS‐LM4 cells were treated with anti‐CEA antibody, and the inhibition of hepatic metastasis after splenic injection in vivo was examined. There was a 62% decrease in the homotypic adhesion of anti‐CEA antibody‐treated (100 μg/ml) LS‐LM4 cells under a Ca2+‐free condition as compared with the control (P<0.01). Anti‐CEA antibody (100 μg/ml) inhibited cell aggregation under a Ca2+‐free condition (P<0.05). Treatment with anti‐E‐cadherin antibody (60 μ/ml) plus anti‐CEA antibody (100 μg/ml) inhibited cell aggregation more potently than anti‐E‐cadherin antibody treatment alone in the presence of Ca2+. In vivo, there was a 75% decrease in the number of hepatic metastatic nodules in the G125 anti‐CEA antibody‐treated group as compared with the control group (P<0.01). Similarly, there was a 40% decrease in the diameter of metastatic nodules and there was a 90% decrease in total tumor volume of hepatic metastasis in the G125 anti‐CEA antibody‐treated group as compared with the control (P<0.01). These results suggest that increased metastatic potential to the liver is at least partly due to increased homotypic binding mediated by CEA.

A case of toxic megacolon in ulcerative colitis associated with cytomegalovirus infection.

Cytomegalovirus (CMV) infection, which has been shown to complicate the course of ulcerative colitis (UC), has been implicated as a possible etiologic factor in the exacerbation of UC, especially in toxic megacolon. However, CMV infection in patients with UC accompanied by toxic megacolon has rarely been reported. Here we report a case of CMV infection of the colon accompanied by toxic megacolon occurring in UC. A 38-year-old woman had been treated with intravenous hydrocortisone, rectal steroid, and central venous alimentation for 6 weeks under the diagnosis of UC. She was transferred to Akita University Hospital because of increasing bloody diarrhea and abdominal pain. Toxic megacolon was identified by examinations on admission, and she underwent a total colectomy. Examination of the surgical specimen showed severe inflammation of the colon. Microscopically, cytomegalic inclusions were observed in and around the endothelial cells in the inflamed submucosal layer. It can be assumed that CMV infection was a secondary, opportunistic invader superimposed on UC, and that it played an important role in altering the clinical course of the patient.

Diagnostic peritoneal lavage for diagnosing blunt hollow visceral injury: The accuracy of two different criteria and their combination

PurposeTo test the usefulness of diagnostic peritoneal lavage (DPL) for identifying blunt hollow visceral injury with two different sets of criteria or a combination of the two.MethodsFifty victims with physical examinations and/or computed tomography findings equivocal for blunt hollow visceral injury underwent DPL. Whether or not to perform surgery was determined based on Otomos DPL criteria [lavage white blood cell counts (L-WBC) over lavage red blood cell counts (L-RBC) divided by 150 (L-WBC ≥ L-RBC/150) in the presence of hemoperitoneum, or L-WBC over 500/mm3 (L-WBC ≥ 500) in the absence of hemoperitoneum]. The cell count ratio, a comparison of L-WBC, L-RBC, peripheral WBC (P-WBC), and peripheral RBC (P-RBC) [(L-WBC/L-RBC)/(P-WBC/P-RBC) ≥ 1] were all calculated retrospectively.ResultsThere were one and two false-positive cases based on Otomos criteria and the cell count ratio, respectively, with corresponding accuracies of 97.8% and 95.7%, respectively. There were no false-positive or -negative cases according to the combined use of Otomos criteria and cell count ratio, yielding an accuracy of 100%.ConclusionAlthough each criterion alone is very accurate in predicting the presence of blunt hollow visceral injury, the combined use of the two would further improve the accuracy of the diagnosis and thereby reduce the number of unnecessary celiotomies.

The clinical significance of regional variations in histologic differentiation within carcinomas of the colorectum

The clinical significance of the presence or absence of regional variations in histologic differentiation within a primary colorectal carcinoma was investigated in this study. Regional variations in histologic differentiation were judged to be present when the low power field of a microscope was occupied by cancer tissue cytologically and architecturally different from that of the surrounding area. Regional variations in histologic differentiation were noted in 153 (42%) of 368 primary carcinomas. Carcinomas with regional variations were of an anaplastic histologic type and had a higher incidence of lymph node metastasis and a worse prognosis than those without regional variations. Thus, the histologic diversity within a carcinoma is thought to be important for determining the prognosis of patients with colorectal cancer.