Intravenous contrast-enhanced computed tomography in the diagnosis of acute appendicitis.

This study evaluated the usefulness of routine, nonfocused intravenous contrast-enhanced computed tomography (CT) in diagnosing acute appendicitis. Also evaluated was the diagnostic value of several findings that were clinically associated with acute appendicitis. Although a number of studies have shown various techniques using CT to be accurate in the diagnosis of acute appendicitis, few studies have focused on CT with using only intravenous contrast material. Computed tomography scan criteria for acute appendicitis have been established chiefly on the basis of appendiceal findings. We, on the other hand, have often observed the following associated conditions during appendectomy: ascites, paresis of the intestine, or thickening of adjacent tissues. In this study, we reviewed the intravenous contrast-enhanced CT scans of 78 patients who had been diagnosed as having acute appendicitis and had subsequently undergone surgery. We also compared the CT scans with patients' surgical and histological findings. As a way of evaluating clinical ancillary signs, we identified and analyzed individual CT findings that included abnormal appendix, calcified appendicolith, ascites, dilated intestine, and cecal wall thickening. The sensitivity, specificity, and accuracy of intravenous contrast-enhanced CT in surgical cases were found to be 91.9%, 87.5%, and 91.0%, respectively. Individual findings except for abnormal appendix were not significantly common among patients who had acute appendicitis. However, more positive findings were observed in patients who had appendicitis than in those who had normal appendixes. Intravenous contrast-enhanced CT scan is a useful technique in the diagnosis of acute appendicitis. The plurality of ancillary signs in CT scans also appears to be a helpful indicator in the diagnosis of acute appendicitis.

Massive hemorrhage and pseudo-obstruction of the small intestine caused by primary AL amyloidosis associated with gastric cancer: report of a case.

We report a case of AL amyloidosis in a patient diagnosed with early gastric cancer after presenting with massive gastrointestinal hemorrhage and pseudo-obstruction of the small intestine. Primary systemic amyloidosis accounts for 7% of nonhematological malignancies, but very few cases of gastric carcinoma in patients with primary amyloidosis have been described. We performed distal gastrectomy with biopsy of the small intestine in the absence of a diagnosis of systemic amyloidosis associated with early gastric cancer; however, the patient suffered severe postoperative complications secondary to the amyloidosis. Although acute pseudo-obstruction is an uncommon clinical manifestation of AL amyloidosis, the coexistence of both gastrointestinal hemorrhage and pseudo-obstruction of the small intestine should alert the clinician to a diagnosis of gastrointestinal amyloidosis. We discuss the clinical manifestations of primary amyloidosis occurring in association with gastric cancer.

Poly(ethyleneimine)-immobilized-cloth enzyme immunoassay for the detection of Salmonella lipopolysaccharide.

Poly(ethyleneimine) (PEI) was immobilized on non-woven polyester cloth and examined for application on a simple, rapid and economical "cloth enzyme immunoassay (CEIA)" which was developed originally as polymyxin-CEIA for the detection of Salmonella lipopolysaccharide (LPS). PEI-cloth regardless of the PEI molecular weight, but with the amine group contents of 0.1 to approximately 0.35 meq/g immobilized either in a physisorption-like or chemisorption-like manner, adsorbed LPS rapidly, preferentially and effectively. The captured LPS was then able to be detected qualitatively and quantitatively as an antigen by enzyme immunoassay. PEI-CEIA had a detection limit for Salmonella LPS of 10 ng/ml, which was equivalent to 1.6 x 10(5) cell/ml and was ten times more sensitive than polymyxin-CEIA. It was possible to detect Salmonella LPS in the presence of a 100-fold excess of E. coli LPS. PEI-CEIA was found to be more sensitive and much easier to carry out than polymyxin-CEIA but had the same advantages as polymyxin-CEIA.

Activation of RET tyrosine kinase regulates interleukin-8 production by multiple signaling pathways.

Interleukin-8 (IL-8) is known to contribute to human cancer progression through its potential function as a mitogenic, angiogenic, or motogenic factor. We found a high level of IL-8 production in SK-N-MC human primitive neuroectodermal tumor cells transfected with the human RET gene (SK-N-MC (RET) cells) in response to glial cell line-derived neurotrophic factor (GDNF) stimulation. IL-8 was also produced at high levels in TT human medullary thyroid carcinoma and TPC-1 human papillary thyroid carcinoma cell lines both of which express activated RET tyrosine kinase. To investigate which signaling pathways are responsible for IL-8 expression, we treated SK-N-MC (RET) cells with several kinase inhibitors before GDNF stimulation. The results showed that a MEK1 inhibitor, PD98059, a p38MAPK inhibitor, SB202190, and a protein kinase C (PKC) inhibitor, Calphostin C, markedly decreased the IL-8 secretion from SK-N-MC (RET) cells at 24 h after GDNF stimulation. In contrast, a phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, increased its secretion. These results thus suggested that IL-8 production by RET tyrosine kinase is regulated by multiple signaling pathways.

Expression of glial cell line-derived neurotrophic factor correlates with perineural invasion of bile duct carcinoma.

BACKGROUND: Perineural invasion is one of the important prognostic factors for patients with bile duct carcinoma, and extensive surgery has not always improved their prognosis. It is necessary, therefore, to investigate not only clinicopathologic characteristics but also molecular mechanisms in patients with perineural invasion. The authors studied the relation between perineural invasion in patients with bile duct carcinoma and the expression of glial cell line-derived neurotrophic factor (GDNF), GDNF family receptor alpha1 (GFRalpha1), and RET receptor tyrosine kinase, which are expressed in both central and peripheral nerve tissues. METHODS: Immunohistochemical staining of GDNF, GFRalpha1, and RET was performed in 58 paraffin embedded tissue sections, including 38 sections from patients with bile duct carcinoma with perineural invasion and 20 sections from patients with bile duct carcinoma without perineural invasion. The migration of cells that expressed GDNF was analyzed by cocultivation with cells that expressed both RET and GFRalpha1. RESULTS: Moderate to strong staining of GDNF in tumor cells was observed more frequently in the sections with perineural invasion compared with the sections without invasion (P < 0.05), whereas GFRalpha1 expression in the same sections was not correlated with perineural invasion. RET expression was undetectable in specimens of bile duct carcinoma. Conversely, RET and GFRalpha1 expression were detected consistently in peripheral nerve tissues. An in vitro cell migration assay revealed that the migration of cells that expressed GDNF was enhanced by cocultivation with cells that expressed RET and GFRalpha1. The cell migration was also enhanced by the conditioned media from GDNF-treated cells that expressed RET and GFRalpha1. CONCLUSIONS: The results suggest that GDNF expression in tumor cells and GFRalpha1 and RET expression in peripheral nerve tissues may play a role in perineural invasion in patients with bile duct carcinoma through chemoattraction among these molecules.

Role for O-glycosylation of RFP in the interaction with enhancer of polycomb.

We recently demonstrated that RFP, which belongs to the large B-box RING finger protein family, interacts with Enhancer of Polycomb 1 (EPC1) and functions as a transcriptional repressor in human cultured cells. In this study, we examined the expression of RFP and EPC1 in mouse tissues by immunoblotting as well as their interaction by a pull-down assay. Both RFP and EPC1 proteins are expressed in several mouse tissues including testis, spleen, thymus, adrenal gland, cerebrum, and cerebellum. In addition, they were coprecipitated from the lysate of mouse testis. Pull-down assays using glutathione S-transferase (GST)-fused EPC1 proteins revealed that RFP is associated with the EPcA, EPcB, and carboxy-terminal (CT) regions of EPC1. Although RFP is highly expressed as 58- and 68-kDa proteins in mouse testis, the EPC1 CT region more strongly interacted with the 68-kDa form than the EPcA or EPcB region. Interaction of the 58-kDa form of RFP with each region was weak compared with that of the 68-kDa form with the EPC1 CT region. Because the 68-kDa form of RFP was almost completely digested with O-glycosidase but not with N-glycosidase, this suggested that O-glycosylation of RFP plays a role in its interaction with the EPC1 CT region that may be responsible for transcriptional repression. In addition, the luciferase reporter gene assay showed that expression of the EPcA region strongly impairs the transcriptional repressive activity of RFP.