Hiroshi Hikita

Pure gastric yolk sac tumor that was diagnosed after curative resection

We recently experienced an 87-yr-old man with gastric yolk sac tumor. Preoperative diagnosis was poorly differentiated adenocarcinoma in the cardia of stomach without apparent metastasis. A total gastrectomy was performed. The precise histological examination after surgery revealed the tumor was composed of pure gastric yolk sac tumor without adenocarcinomatous components. The surgical margin and the resected lymph nodes were histologically negative for the tumor and a curative resection was performed. Five months after the operation, enlargement of the intraabdominal lymph nodes occurred with elevation of serum alpha fetoprotein (AFP), and the patient died 2 mo later. Gastric yolk sac tumors are very rare, and only six cases of gastric yolk sac tumors have been previously reported in the literature. Five out of six cases are accompanied by components of adenocarcinoma, and our present case is the second report of pure gastric yolk sac tumor to the best of our knowledge.

Identification of apoptotic hepatocytes in situ in rat liver after lead nitrate administration

Apoptosis plays a major role in the regression of mitogen (lead nitrate)-induced hepatic hyperplasia. We compared the in situ end-labeling (ISEL) technique with the conventional detection of apoptotic bodies in this process. In hematoxylin and eosin (H&E) sections, apoptosis is usually recognizable by the presence of apoptotic bodies (apoptosis phase 2). Although the early phase of apoptosis (apoptosis phase 1) can be detected as a prekaryorrhectic appearance in H&E sections, it is difficult to detect and is easily overlooked. On the other hand, ISEL presents intense staining mainly in phase 1 and weak or negative staining in phase 2. Thus, simultaneous investigation by these two methods in two serial sections is the most reliable way to calculate the incidence of apoptosis and gives us precise information on the stages of apoptosis in situ. Since the colorized signals of ISEL are much easier to detect than apoptotic bodies in H&E sections, ISEL is particularly useful for liver tissues, where the incidence of apoptosis is low.

USEFULNESS OF OBLIQUE TRANSPARENT CYLINDERS IN FACILITATING COLONOSCOPY

Recently, the usefulness of the oblique transparent cylinder (OTC) in colonoscopy has been reported. In this study, the efficacy of two newly designed OTCs was evaluated. Colonoscopy performed by six experienced endoscopists in 1005 cases and by one inexperienced endoscopist in 177 cases was analyzed. Short (S) and ultra short (US) cylinders, shorter in length than a conventional long (L) cylinder, were used. The use of OTCs in colonoscopy contributed to a significantly faster insertion into the cecum. The average time to reach the cecum for experienced endoscopists were 12.4 ± 0.3 min without a cylinder, 9.0 ± 0.3 min with a US cylinder, 8.5 ± 0.4 min with an S cylinder and 6.9 ± 0.8 min with an L cylinder, respectively. The visual field and handling of the endoscope were more improved with the S cylinder than the conventional L cylinder. On the other hand, with the L cylinder, the success rate of one inexperienced endoscopist for total colonoscopy reached more than 90% and mean insertion time to reach the cecum was 16.4 ± 1.8 min 7‐months later. Both the success rate and average insertion time for the inexperienced endoscopist were satisfactory considering the rather short learning period. The OTCs were effective in reducing the insertion time. The use of the S cylinder overcame some of the disadvantages of the L cylinder; however, the L cylinder was helpful in improving the technique of an inexperienced endoscopist.

A case of solitary necrotic nodule of the liver with acute liver dysfunction: The imaging appearance correlated with pathological findings.

A 22-year-old woman was admitted to this institution because of severe liver dysfunction that looked like acute hepatitis. Abdominal ultrasonography revealed a liver mass 20 mm in diameter that resembled the bull’s-eye sign. Enhanced CT revealed a low-density mass. The mass was hypointense in T1-weighted MRI images and slightly hyperintense in T2-weighted MRI images. Needle biopsy of the liver under ultrasound guidance led to a diagnosis of solitary necrotic nodule of the liver. The tumor consisted of coagulation necrosis surrounded by fibrotic tissue. These pathologic features were consistent with the Imaging findings.

EGF binding activity of rat hepatocytes in liver regeneration after partial hepatectomy: Cell cycle analysis by cytofluorometry

Abstract To analyze EGF binding activity in liver regeneration at cell cycle level, we performed the double measurement of nuclear DNA content and cellular bound EGF content in freshly isolated rat hepatocytes from normal and regenerating liver after 67% hepatectomy using autostaging cytofluorometry. The data demonstrated that the bound EGF content of resting cells increased in proportion to their DNA content, while cycling cells had significantly consistently lower bound hEGF throughout cell cycle. These changes are supposed to reflect ‘down-regulation’ of EGF receptor at the cell cycle level, and the data suggested a major role of endogenous EGF in cell proliferation during liver regeneration.

A Comparative Study Between Laparoscopic Findings and Histological Stages in Primary Biliary Cirrhosis

Abstract: Histopathologically, early lesions of primary biliary cirrhosis (PBC) are focal within the liver and there is segmental involvement of the bile ducts. In addition, the development of PBC is variable within the liver. PBC is characterized by the following laparoscopic findings: reddish patch, mesh‐like white marking and gentle undulation, etc.