Masutaro Ichinose

Development of Aberrant Crypt Foci Involves a Fission Mechanism as Revealed by Isolation of Aberrant Crypts

Morphological analysis of isolated colonic crypts in rats, postnatally, indicated that the crypts reproduce themselves by a fission mechanism, the division beginning at the crypt base and proceeding upwards until there are two separate crypts. Occasionally, before the separation is complete, a second fission process starts on one or both sides of a bifurcating crypt and a triple‐branched or quadruple‐branched crypt results. Analysis of isolated aberrant crypt foci (ACF) in rats treated with 1,2‐dimethylhydrazine revealed that the development of ACF consisting of multiple crypts is also due to a fission mechanism. Initially, an indentation appears at the base of a single ACF crypt, with subsequent formation of a bifurcation and eventual crypt division.

Encapsulated pericardial fat necrosis treated by video-assisted thoracic surgery: report of a case.

A 55-year-old moderately obese man who was admitted to a local hospital following a traffic accident reported having experienced an episode of sharp and sudden pleuritic pain in the left anterior lower chest 2 days earlier. A computed tomographic scan on admission demonstrated a nonhomogeneous mass in the anterior left side of the chest, abutting the left cardiac margin, and a left-sided pleural effusion. As a mediastinal tumor was suspected, he was referred to our hospital for investigation and treatment. An exploratory thoracotomy was performed by video-assisted thoracic surgery (VATS) about 3 weeks later, which revealed a firm, yellowish mass on the oral side of the pericardial fat pad, adhering to the anterior chest wall. The mass was easily removed. The resected specimen consisted of a lobulated fragment of adipose tissue measuring 5.0 × 3.5 × 2.0cm, and the final pathologic diagnosis was pericardial fat necrosis. The patient had an uneventful postoperative recovery and has remained free of symptoms for 10 months since his operation. Pericardial fat necrosis remains a rare clinical entity. Surgical excision by VATS achieves symptomatic cure and probably continues to be the treatment of choice because of the need to exclude a neoplasm in the differential diagnosis.

Establishment and Characterization of Two Cell Lines from N‐Methyl‐N‐nitrosourea‐induced Mouse Glandular Stomach Carcinomas

We previously reported the induction with N‐methyl‐N‐nitrosourea (MNU) of mouse glandular stomach carcinomas showing a gastric phenotype but variation in histologic appearance, as with human gastric carcinomas. In the present study, we established two cell lines, designated MGT‐40 and MGT‐93, from MNU‐induced mouse glandular stomach carcinomas. These cell lines are keratin‐positive and grow as epithelial monolayers in culture, requiring transforming growth factor α, epidermal growth factor or insulin/transferrin for optimal growth in addition to 10% fetal bovine serum. Retention of the differentiated phenotype for gastric surface mucous cells has been confirmed by cathepsin E immunohistochemistry and reverse transcriptase‐polymerase chain reaction for mouse spasmolytic polypeptide. Neither transplantability in nude mice nor colony formation on soft agar was observed, except in one subline. Chromosome analysis revealed aneuploidy with modal chromosome numbers ranging from 58 to 78 and no specific structural abnormalities. This is the first report of cell lines derived from mouse glandular stomach carcinomas. They should prove useful for studies of the mechanisms of regulation of growth and differentiation.

Reexpansion Pulmonary Edema Due to High-Frequency Jet Ventilation: Report of a Case

Abstract Barotrauma is well known to be a relatively common complication of high-frequency jet ventilation (HFJV); however, the occurrence of reexpansion pulmonary edema (REPE) is extremely rare. We report herein a case of REPE caused by difficulties encountered with anesthesia using HFJV during video-assisted thoracic surgery (VATS) for a spontaneous pneumothorax. We believe the rapid increase in pressure in the lung after degassing for VATS resulted in REPE as well as typical barotrauma.

Autologous dendritic cells or cells expressing both B7-1 and MUC1 can rescue tumor-specific cytotoxic T lymphocytes from MUC1-mediated apoptotic cell death

We attempted to induce MUC1‐specific cytotoxic T lymphocytes (CTLs) by mixed‐lymphocyte tumor cell culture (MLTC) using two allogeneic MUC1‐positive cancer cell lines, T‐47D and MCF7. The induced CTLs exhibited MUC1‐specific cytotoxicity 16 days after the initial stimulation. However, these CTLs underwent apoptotic death within 16 days. To examine whether the B7‐1 molecule is required for the expansion of the responder cells, a B7‐1(+)/MUC1(‐) cell line was transfected with MUC1 cDNA, and the resulting transfectant was employed as a stimulator in an autologous MLTC. The CTLs exhibited MUC1 specificity but also continued to propagate. In parallel, autologous dendritic cells (DCs) were added to an MLTC containing peripheral blood lymphocytes (PBLs) and the allogeneic MUC1‐positive stimulators. The CTLs demonstrated MUC1 specificity and their number increased. This suggests that the B7‐1 molecule is required for rescuing CTLs from MUC1‐mediated apoptotic death, but not for the induction of MUC1‐specific responsiveness. This strategy to obtain the CTLs efficiently may be useful for adoptive immunotherapy against cancer.

Sparse distribution of hepatocyte growth factor-producing cells inside hepatocellular foci in rats treated with hepatocarcinogens.

The distribution of hepatocyte growth factor (HGF)–synthesizing cells in rat liver during development of glutathione S–transfcrasc P form (GST–P)–positive nodules after diethylnitrosamine initiation followed hy promotion with 2–acetylaminofluorene plus partial hepatectomy (PH) was investigated using in situ hybridization, HGF–produclng cells were iioii–parenchymal in nature, and were suspected to be mainly of Kupffer type. They were mostly located outside GST–P–positive lesions, in the surrounding parenchyma. In the oval cell proliferation phase 1 week after PH, they increased and they were mainly localized around the portal triads. It is concluded that HGF is directly involved in an endogenous paracrine growth pathway controlling proliferation in oval cells and in normal, hut not GST–P–positive, hepatocytes.

Cca3, the mRNA level of which transiently decreases before initiation of DNA synthesis in regenerating rat liver cells

Kinetics of cca1, cca2, cca3 and rat gas1 mRNA levels were compared with those of DNA synthesis level in regenerating rat liver cells after partial hepatectomy. A transient decrease of cca3 mRNA level and an increase of rat gas1 mRNA level were observed before initiation of DNA synthesis, followed by a rapid decrease of rat gas1 mRNA level. By molecular cloning and nucleotide sequencing, cca3 cDNA was found to consist of 4514 nucleotides with a large open reading frame of 3027 nucleotides, encoding a protein of 1009 amino acids with three copies of an ankyrin repeat‐like sequence.