Development of a New Antithrombogenic Continuous Ultrafiltration System

By interfacing a polyacrylonitrile (PAN)-polyethyleneoxide (PEO) membrane with an ionically heparin-bound catheter, tubing, and module header, a totally antithrombogenic continuous ultrafiltration system (ACUS) was developed and its performance, persistent antithrombogenicity, and well-maintained ultrafiltration level were confirmed through animal experiments. Although the amount of heparin released and accumulated in vitro from those heparinized parts was very low and stable (on the order of 1 x 10(-2) U/cm2/min), partial thromboplastin time evaluated in vivo was not elongated during passage through the ACUS. Extracorporeal circulation time with the ACUS in unheparinized dog model was 458 +/- 302 min (n = 24), whereas those of partially modified (antithrombogenic) system did not exceed 100 min. As compared with that in a conventional continuous arteriovenous hemofiltration system, an extracorporeal circulation with the ACUS in an unheparinized dog model revealed significantly less fluctuation of platelet count, and no adherent platelets were observed on the surface of the PAN-PEO membrane. An ACUS consisting of a PAN-PEO membrane and heparinized parts was thus demonstrated to have good platelet compatibility. An ACUS with a surface area of 0.25 m2 was applied to two patients with acute renal failure. Hemofiltration without systemic heparinization lasted for 44 h per hemofilter, and a stable level of ultrafiltration was maintained. This system seems to be applicable for the clinical management of volume overload, especially in patients with bleeding tendencies or postoperative bleeding.     

Transformation of hamster spleen lymphocytes by human T-cell leukemia virus type I

Co-cultivation of spleen cells of Syrian golden hamsters with lethally irradiated MT-2 cells harboring human T-cell leukemia virus type I (HTLV-I) resulted in the establishment of lymphoid cell lines, HCT-1 and HCT-2, which exhibited the normal karyotype of golden hamsters. Cells of both the HCT-1 and HCT-2 lines lacked surface immunoglobulins and reacted with a monoclonal antibody (MAb) specific for hamster T cells. Some were positive for OKIa1. None of them expressed HTLV structural antigens (p19 and p24) or virus particles, but they contained HTLV-I proviral DNA monoclonally. By immunochemical analysis of the labelled cell antigens, sera from adult T-cell leukemia (ATL) patients reacted with the two polypeptides, p37 and p40, which may not be viral structural proteins and still remain to be characterized. HCT-1 and HCT-2 cells were transplantable into newborn hamsters, pre-treated with anti-hamster thymocyte serum and non-treated, respectively, producing diffuse malignant lymphoma. These findings indicated that HTLV-I not only immortalized but also transformed hamster T cells non-productively.     

RARE GASTRIC CALCIFYING FIBROUS PSEUDOTUMOR REMOVED BY ENDOSCOPIC SUBMUCOSAL DISSECTION

We report a case of a calcifying fibrous pseudotumor of the stomach that we resected using endoscopic submucosal dissection (ESD). A 61‐year‐old male with a gastric submucosal tumor was admitted to our hospital for treatment. By upper gastrointestinal tract endoscopy, a smooth‐surfaced submucosal tumor measuring 2 cm in diameter was observed in the anterior wall of the middle body of the stomach. By endoscopic ultrasonography, a mass was observed in the stomach submucosa; the mass had a well‐defined boundary. Internally, the mass was heterogeneous and hypoechoic; high spots were scattered throughout the mass. Continuity between the mass and the muscularis mucosae and muscularis propria was not observed. Strongly suspecting that this mass was a gastrointestinal stromal tumor arising from the stomach, we resected the mass by ESD for total biopsy. Histopathologically, the mass consisted of proliferation of eosinophilic collagen fibers with plasma cell infiltration and lymphoid follicle proliferation. Calcification was also observed in some parts of the mass. Thus, the mass was identified as calcifying fibrous pseudotumor. Calcifying fibrous pseudotumor of the stomach is extremely rare and its histogenesis remains unclear; however, its morphology became distinct by comparing endoscopic/radiological and histopathological findings.     

MBSJ MCC Young Scientist Award 2009REVIEW: Selective autophagy regulates various cellular functions

Autophagy is a self‐eating system conserved among eukaryotes, in which cellular components including organelles are entrapped into a double membrane structure called the autophagosome and then degraded by lysosomal hydrolases. In addition to its role in supplying amino acids in response to nutrient starvation, autophagy is involved in quality control to maintain cell health. Thus, inactivation of autophagy causes the formation of cytoplasmic protein inclusions, which comprise misfolded proteins and the accumulation of many degenerated organelles, resulting in liver injury, diabetes, myopathy and neurodegeneration. Furthermore, although autophagy has been considered nonselective, increasing evidence points to the selectivity of autophagy in sorting vacuolar enzymes and removal of aggregate‐prone proteins and unwanted organelles. Such selectivity allows diverse cellular regulation, similar to the ubiquitin proteasome pathway. In this review, we discuss the physiological roles of selective autophagy and their molecular mechanisms.     

Loss of expression of alpha4beta7 integrin and L-selectin is associated with high-grade progression of low-grade MALT lymphoma.

Expression of adhesion molecule in low-grade B-cell mucosa-associated lymphoid tissue (MALT) lymphoma of the gastrointestinal tract has been reported in recent years, but these reports have primarily focused on low-grade gastrointestinal MALT lymphoma. In this study, we examined the lymphocytic homing receptor alpha4beta7 integrin, L-selectin, and VLA-4 and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in low-grade lymphoma of the gastrointestinal tract and other organs such as the ocular adnexa and thyroid. We also observed changes in the expression pattern associated with high-grade transformation. Neoplastic cells in the gastrointestinal low-grade lymphoma and the low-grade component of high-grade MALT lymphoma were found to be alpha4beta7 integrin(+), L-selectin(+), whereas the gastrointestinal high-grade component and diffuse large B-cell lymphoma were found to be alpha4beta7 integrin(-), L-selectin(-). High endothelial venules in the gastric MALT lymphomas expressed MAdCAM-1. In the ocular adnexa low-grade MALT lymphoma, most cases were alpha4beta7 integrin(-), L-selectin(+); and in the thyroid, most cases of both low- and high-grade MALT lymphoma were alpha4beta7 integrin(-), L-selectin(-). These findings show that alpha4beta7 integrin and L-selectin may play an important role in the lymphocyte homing of gastrointestinal low-grade MALT lymphoma and in the loss of alpha4beta7 integrin expression throughout the course of high-grade progression.     

How to manage difficulties with colonoscope insertion

Unsuccessful insertion of a colonoscope is usually as a result of bending or looping of the scope. Looping of the colonoscope increases when too much air is insufflated or the scope is inserted with undue force, resulting in increased pain and risk of perforation. Successful insertion therefore requires careful handling of the scope to keep it straight, careful regulation of air levels, shortening of the colon length by gathering of the colon folds and rapid correction of any looping that should occur. This can be complicated in cases with an unusually long colon or with adhesion. The use of a colonoscope with variable rigidity or a small‐caliber colonoscope is recommended to increase the rate of successful insertion to relieve pain and to prevent accidents.     

Surgical results of brain metastasis from lung cancer--prognostic factors.

Twenty-five patients receiving surgical treatment for brain metastasis from lung cancer were retrospectively studied to evaluate the prognostic factors for survival time. Twenty-two patients had died of respiratory distress by April, 1989. Favorable prognostic factors derived from the median survival time (MST) in these patients included; 1) resection of primary tumor (MST 10 months); 2) total or subtotal removal of metastatic tumor (MST 6.5 months); 3) adenocarcinoma (MST 13 months); 4) metachronous onset of brain metastasis (MST 12 months); 5) single metastasis (MST 8 months). These results suggest that therapy for the primary lung cancer is important before surgery for metastatic brain tumor.     

Parathyroid hormone stimulates phosphoinositide metabolism and intracellular calcium mobilization in osteoblast-like clone MC3T3-E1 cells

The effects of parathyroid hormone (rat 1–34 fragment, rPTH) on phosphoinositide metabolism and intracellular Ca²⁺ mobilization were studied in a osteoblast-like clone MC3T3-E1 cells. rPTH caused a transient rise in intracellular Ca²⁺ in a dose-dependent manner. Significant Ca²⁺ increase was still observed under the extracellular Ca²⁺-free condition. In addition, 100nM rPTH stimulated rapid formation of both 1,2-diacylglycerol (1,2-DAG) and inositol 1,4,5-trisphosphate (Ins(1,4,5)P₃), indicating agonist-triggered hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP₂). The current observations suggested that the rPTH-induced increase of intracellular Ca²⁺ was in part due to internal Ca²⁺ release mediated by Ins(1,4,5)P₃. These results indicate possible involvement of phosphoiniositide metabolism in signal transduction of PTH-stimulated osteoblastic cells.