Carcinosarcoma of the extrahepatic bile duct

A rare case of a carcinosarcoma of the extrahepatic bile duct demonstrating interesting features is described. A 75-year-old woman with a history of choledocholithotomy presented with acute obstructive suppurative cholangitis. Ultrasonography and computed tomography showed a thickened choledochal wall, with calcification. Percutaneous transhepatic and endoscopic retrograde cholangiography revealed a round filling defect accompanied by an irregular obstruction in the common bile duct. Carcinosarcoma was diagnosed from a protruding lesion in the common bile duct obtained by intraoperative frozen sectioning, and pylorus-preserving pancreatoduodenectomy was performed. Histological examination by light microscopy showed a transition between the carcinomatous and sarcomatous components and positive immunoreactivity for epithelial markers in the sarcomatous component. The patient died of a local recurrence 2 years after the surgery. Polypoid growth and ossification in the tumor could be representative features of carcinosarcoma of the extrahepatic bile duct.     

Decreased expression of B7 costimulatory molecules and major histocompatibility complex class-I in human hepatocellular carcinoma

BACKGROUND AND AIM: We analyzed the expression of antigen-processing and antigen-presenting molecules in surgically resected fresh samples of human hepatocellular carcinoma (HCC) tissue to elucidate a mechanism of immune escape. We also examined the expression of interleukin (IL)-10 protein, which might act to downregulate expression of antigen-processing and antigen-presenting molecules. METHODS: Twenty-eight HCC samples obtained by surgical resection were analyzed for the expression of beta2-microglobulin, heat-shock protein (HSP)-70, human leukocyte antigen (HLA) class-I, CD80 (B7-1), CD86 (B7-2) and IL-10 by immunostaining. RESULTS: Beta2-microglobulin and HSP-70 were preserved in all samples. In contrast, the expression of HLA class-I molecules was significantly reduced according to lowering in the histological grading of tumor differentiation (P = 0.024). Furthermore, B7-1 and B7-2 expression was reduced in tumor cells compared with corresponding areas of liver tissue without malignant involvement irrespective of the histological grading of tumors (21% and 36%, respectively). Although IL-10 protein was expressed in 54% of HCC, no relationship between the expression of IL-10 and downregulation of B7-1, B7-2, and HLA class-I was evident. CONCLUSION: These findings suggest the potential role of B7 co-stimulatory molecules and HLA class-I molecules in facilitating HCC escape from immune surveillance without the involvement of IL-10.     

Imatinib mesylate-sensitive blast crisis immediately after discontinuation of imatinib mesylate therapy in chronic myelogenous leukemia: report of two cases

Although imatinib mesylate has shown encouraging activity in chronic myelogenous leukemia (CML), disease progression during therapy has been observed, manifested by clonal expansion of imatinib mesylate-resistant leukemia cells. On the other hand, myelosuppression related to treatment of imatinib mesylate is often managed with temporary interruption of treatment or dose reduction. We here report two CML patients who had imatinib mesylate-sensitive blast crisis (BC) immediately after discontinuation of imatinib mesylate therapy. The patients discontinued therapy because of neutropenia. Although there was no evidence of blastic phase during therapy, BC occurred 2 weeks after the withdrawal of treatment in both cases. Interestingly, additional chromosomal abnormalities were detected following the withdrawal of imatinib mesylate and disappeared by re-introduction of this agent. The same doses of imatinib mesylate was still effective and remission was sustained with imatinib mesylate alone again. Our report suggests the possibility that withdrawal of imatinib mesylate may lead to proliferation of blast clones even in patients showing good responses to imatinib mesylate without signs of disease progression.     

Oral therapeutic agents with highly clustered globotriose for treatment of Shiga toxigenic Escherichia coli infections

Shiga toxin (Stx) is a major virulence factor in infection with Stx-producing Escherichia coli (STEC). We developed a series of linear polymers of acrylamide, each with a different density of trisaccharide of globotriaosylceramide (Gb3), which is a receptor for Stx, and identified Gb3 polymers with highly clustered trisaccharides as Stx adsorbents functioning in the gut. The Gb3 polymers specifically bound to both Stx1 and Stx2 with high affinity and markedly inhibited the cytotoxic activities of these toxins. Oral administration of the Gb3 polymers protected mice after administration of a fatal dose of E. coli O157:H7, even when the polymers were administered after the infection had been established. In these mice, the serum level of Stx was markedly reduced and fatal brain damage was substantially suppressed, which suggests that the Gb3 polymers entrap Stx in the gut and prevent its entrance into the circulation. These results indicate that the Gb3 polymers can be used as oral therapeutic agents that function in the gut against STEC infections.     

Pulse wave velocity as an indicator of atherosclerosis in obstructive sleep apnea syndrome patients

OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular morbidity and mortality. We investigated the values of brachial-ankle pulse wave velocity as an indicator of atherosclerosis in obstructive sleep apnea syndrome patients. MATERIALS AND METHODS: Brachial-ankle pulse wave velocity (baPWV) was measured in 104 OSAS patients and 104 healthy control subjects matched for age, sex, and body mass index (BMI). BaPWV values were compared in both groups and investigated with respect to the number of risk factors for atherosclerosis, including hypertension, hypercholesterolemia, impaired glucose tolerance, smoking, and obesity. Comparisons were also made between 48 OSAS group cases and 90 control group cases free from hypertension, which has a major impact on baPWV. RESULTS: As compared to the control group, the OSAS group had significantly higher baPWV (1,645+/-349 cm/s vs 1,436+/-278 cm/s, p<0.0001), and values obtained for baPWV were significantly higher in the OSAS group than in the control group even in groups free from hypertension (1,453+/-216 cm/s vs 1,374+/-213 cm/s, p<0.05). In both groups, baPWV rose as the number of risk factors for atherosclerosis increased, but baPWV was higher in the OSAS group than in the control group even in a comparison of individuals entirely free from risk factors (1,400+/-200 cm/s vs 1,198+/-79 cm/s, p<0.05). CONCLUSION: The condition of OSAS itself is considered a possible risk factor for atherosclerosis. We believe that the usefulness of baPWV as an index of atherosclerosis merits further study in the frequently observed cases of OSAS complicated by cardiovascular disease.     

Significance of mucin expression in pancreatobiliary neoplasms

Mucins are high molecular weight glycoproteins that play important roles in carcinogenesis and tumor invasion. We have described, for the first time, that pancreatic ductal adenocarcinomas (PDACs) with an aggressive behavior and a poor outcome expressed MUC1 (pan-epithelial membrane-associated mucin) but did not express MUC2 (intestinal-type secreted mucin), whereas intraductal papillary mucinous neoplasms (IPMNs) with indolent behavior and a favorable outcome did not express MUC1 but did express MUC2. These expression profiles of MUC1 and MUC2 related to the prognoses of the patients were also observed in biliary neoplasms such as intrahepatic cholangiocarcinoma (ICC)-mass-forming type (MF), mucin-producing bile duct tumor (MPBT), and extrahepatic bile duct carcinoma (EHBDC). We also found recently that high expression of MUC4 (tracheobronchial membrane-associated mucin) in PDACs, ICCs-MF, and EHBDCs was a new independent poor prognostic factor, although MUC4 was not expressed in normal pancreatobiliary tissue. High de novo expression of MUC5AC (gastric-type secreted mucin) was observed in many types of pancreatobiliary neoplasms, including all grades of pancreatic intraepithelial neoplasia (PanIN) and biliary intraepithelial neoplasia (BilIN), and all types of IPMNs and MPBTs, as well as PDACs and ICCs-MF, although MUC5AC was not expressed in normal pancreatobiliary tissue. The combined status of MUC1, MUC2, MUC4, and MUC5AC expression may be useful for the early detection of pancreatobiliary neoplasms and evaluation of their malignancy. In regard to the mechanism of mucin expression, we have recently reported that MUC1, MUC2, MUC4, and MUC5AC gene expression is regulated by epigenetics (DNA methylation and histone H3 lysine 9 modification) in cancer cell lines, including PDAC cells. Translational research of mucin gene expression mechanisms, including epigenetics, in pancreatobiliary neoplasms may give us new tools for the early and accurate detection of these neoplasms.     

Nicotine regulates DARPP-32 (dopamine- and cAMP-regulated phosphoprotein of 32 kDa) phosphorylation at multiple sites in neostriatal neurons

Nicotinic acetylcholine receptors (nAChRs) regulate dopaminergic signaling in the striatum by modulating the release of neurotransmitters. We have recently reported that nicotine stimulates the release of dopamine via alpha4beta2(*) nAChRs and/or alpha7 nAChRs, leading to the regulation of DARPP-32 at Thr34, the site involved in regulation of protein phosphatase-1 (PP-1). In this study, we investigated the regulation of DARPP-32 phosphorylation at its other sites, Thr75 [cyclin-dependent kinase-5 (Cdk5) site], Ser97 (CK2 site), and Ser130 (CK1 site), that serve to modulate Thr34 phosphorylation and dephosphorylation. In neostriatal slices, nicotine (100 microM) increased phosphorylation of DARPP-32 at Ser97 and Ser130 at an early time point (30 s) and decreased phosphorylation of DARPP-32 at Thr75 at a late time point (3 min). The increase in Ser97 and Ser130 phosphorylation was mediated through the release of dopamine via activation of alpha4beta2(*) nAChRs and alpha7 nAChRs and the subsequent activation of dopamine D1 and D2 receptors. The decrease in Thr75 phosphorylation was mediated through the release of dopamine via activation of alpha4beta2(*) nAChRs and the subsequent activation of dopamine D1 receptors. These various actions of nicotine on modulatory sites of phosphorylation would be predicted to result in a synergistic increase in the state of phosphorylation of DARPP-32 at Thr34 and thus would contribute to increased dopamine D1 receptor/DARPP-32 Thr34/PP-1 signaling.     

Detection of hepatitis C virus by polymerase chain reaction and response to interferon-alpha therapy: relationship to genotypes of hepatitis C virus.

To investigate the relationship between genotypes of hepatitis C virus and response to interferon-alpha therapy, hepatitis C virus RNA was assayed by polymerase chain reaction with three sets of primers and probes in 70 patients with non-A, non-B chronic hepatitis who received interferon-alpha. Twenty-four patients sustained long-term remissions (complete responders). Polymerase chain reaction for 5'-terminal noncoding region detected hepatitis C virus RNA in 94.3% (66 of 70) of the patients. Polymerase chain reaction for nonstructural region 3, in which primers and a probe were synthesized to be identical to hepatitis C virus-J, detected hepatitis C virus RNA in 40 patients. Polymerase chain reaction for nonstructural region 5-in which sequences of primers and a probe were derived from hepatitis C virus-K2, a genotype different from hepatitis C virus-J--detected hepatitis C virus RNA in 17 patients. Only one patient was positive on both nonstructural region 3 and nonstructural region 5 polymerase chain reaction. Nucleotide sequence of clones obtained from 5' terminal noncoding region polymerase chain reaction products of two patients positive on polymerase chain reaction for nonstructural region 3 and negative on polymerase chain reaction for nonstructural region 5 (group 1) corresponded to that of the hepatitis C virus-J group, and those of clones from two patients negative on polymerase chain reaction for nonstructural region 3 and positive on polymerase chain reaction for nonstructural region 5 (group 2) corresponded to that of hepatitis C virus-K2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angiotensin II type I receptor blocker and endothelial function in humans: role of nitric oxide and oxidative stress

Recent large clinical trials have shown that angiotensin II type I receptor blockers (ARBs) reduce cardiovascular morbidity and mortality in patients with heart failure, acute myocardial infarction, and hypertension. However, the mechanism underlying antiatherogenic effects of ARBs remains unclear. The vascular endothelium is involved in the release of various vasodilators, including nitric oxide (NO), prostacyclin, and endothelium-derived hyperpolarizing factor as well as vasoconstrictors. NO plays an important role in the regulation of vascular tone, the inhibition of platelet aggregation, and the suppression of smooth muscle cell proliferation. Several investigators have reported impairment in endothelium-dependent vasodilation in the forearm, coronary, and renal vasculature in cardiovascular diseases, including hypertensive patients. Cardiovascular diseases are associated with alteration in endothelial function. Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis. Anti-renin-angiotensin system agents, angiotensin-converting enzyme (ACE) inhibitors improve endothelial function in patients with hypertension, diabetes mellitus, and coronary artery disease. It is well known that ACE inhibitors augment endothelium-dependent vasodilation through an increase in NO bioavailability, by an increase in NO production and a decrease in NO inactivation. ARBs are also thought to prevent cardiovascular complications through an augmentation of endothelial function. In this review, we focus on recent findings and putative mechanisms of the beneficial effects of ARBs on endothelial function.     

Esophageal carcinosarcoma with granulocyte colony-stimulating factor: a case report

A 62-year-old man was admitted to our hospital for dysphagia, leukocytosis, and pyrexia. The serum level of granulocyte colony-stimulating factor (G-CSF) was high and immunostaining of a biopsy specimen of esophageal tumor using anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF) antibody demonstrated GM-CSF expression in the cytoplasm of the tumor cells. After esophagectomy, the leukocyte count and serum G-CSF level normalized. Histologically, this tumor was diagnosed as a carcinosarcoma with two components: squamous cell carcinoma and sarcoma. Tumor cells were also positive for G-CSF receptor, suggesting autocrine growth regulation by G-CSF. Moreover, tumor cells were positive for Ki-67, cyclin D1, p53, and epidermal growth factor receptor (EGFR), which were related to the acquisition of more aggressive tumor behavior. Although G-CSF-producing esophageal carcinosarcoma is very rare, we should consider such disease when a patient has symptoms of leukemia such as leukocytosis and high fever.