Intra-individual comparison of hepatocellular carcinoma imaging features on contrast-enhanced computed tomography, gadopentetate dimeglumine-enhanced MRI, and gadoxetic acid-enhanced MRI.

Background Gadoxetic acid is being widely used for detection and characterization of hepatic nodules. However, there are no data regarding intra-individual comparison of imaging features of hepatocellular carcinoma (HCC) on dynamic computed tomography (CT), gadopentetate dimeglumine-enhanced magnetic resonance imaging (Gd-DTPA-MRI), and gadoxetic acid-enhanced MRI (Gd-EOB-MRI). Purpose To evaluate typical imaging features of HCC and capsule appearance with dynamic CT, Gd-DTPA-MRI, and Gd-EOB-MRI. Material and Methods We retrospectively reviewed 56 HCCs in 49 patients. Lesion attenuation/signal intensity was graded using a five-point scale based on dynamic phase and hepatobiliary phase (HBP) imaging. Subjective washout and capsule appearance were evaluated on portal venous phase (PVP) or delayed/transitional phase (DP/TP) imaging. The tumor-to-liver contrast ratio (TLCR) was calculated. Results Gd-DTPA-MRI and Gd-EOB-MRI was graded higher than CT on arterial phase ( P < 0.001). Gd-EOB-MRI was graded lower than Gd-DTPA-MRI on PVP and DP/TP ( P < 0.05). The detection rate of subjective washout and capsule appearance did not differ among the three imaging studies on either PVP or DP/TP. TLCR of Gd-EOB-MRI was lower than CT on PVP ( P = 0.004) and was lower than Gd-DTPA-MRI on DP/TP ( P = 0.001). Conclusion Arterial phase hyperenhancement and washout appearance of HCC were well demonstrated in Gd-EOB-MRI. The detection of capsule appearance using Gd-EOB-MRI was not inferior to Gd-DTPA-MRI or CT.

Hairy and Enhancer of Split 6 (Hes6) Deficiency in Mouse Impairs Neuroblast Differentiation in Dentate Gyrus Without Affecting Cell Proliferation and Integration into Mature Neurons.

Hes6 is a member of the hairy-enhancer of split homolog (Hes) family of transcription factors and interacts with other Hes family genes. During development, Hes genes are expressed in neural stem cells and progenitor cells. However, the role of Hes6 in adult hippocampal neurogenesis remains unclear. We therefore investigated the effects of Hes6 on adult hippocampal neurogenesis, by comparing Hes6 knockout and wild-type mice. To this end, we immunostained for markers of neural stem cells and progenitor cells (nestin), proliferating cells (Ki67), post-mitotic neuroblasts and immature neurons (doublecortin, DCX), mature neuronal cells (NeuN), and astrocyte (S100ß). We also injected 5-bromo-2'-deoxyuridine (BrdU) to trace the fate of mitotic cells. Nestin- and Ki67-positive proliferating cells did now show any significant differences between wild and knockout groups. Hes6 knockout negatively affects neuroblast differentiation based on DCX immunohistochemistry. On the contrary, the ratio of the BrdU and NeuN double-positive cells did not show any significance, even though it was slightly higher in the knockout group. These results suggest that Hes6 is involved in the regulation of neuroblast differentiation during adult neurogenesis, but does not influence integration into mature neurons.

Alteration of gut microbiota by vancomycin and bacitracin improves insulin resistance via glucagon-like peptide 1 in diet-induced obesity.

Firmicutes and Bacteroidetes, 2 major phyla of gut microbiota, are involved in lipid and bile acid metabolism to maintain systemic energy homeostasis in host. Recently, accumulating evidence has suggested that dietary changes promptly induce the alteration of abundance of both Firmicutes and Bacteroidetes in obesity and its related metabolic diseases. Nevertheless, the metabolic roles of Firmicutes and Bacteroidetes on such disease states remain unclear. The aim of this study was to determine the effects of antibiotic-induced depletion of Firmicutes and Bacteroidetes on dysregulation of energy homeostasis in obesity. Treatment of C57BL/6J mice with the antibiotics (vancomycin [V] and bacitracin [B]), in the drinking water, before diet-induced obesity (DIO) greatly decreased both Firmicutes and Bacteroidetes in the gut as revealed by pyrosequencing of the microbial 16S rRNA gene. Concomitantly, systemic glucose intolerance, hyperinsulinemia, and insulin resistance in DIO were ameliorated via augmentation of GLP-1 secretion (active form; 2.03-fold, total form; 5.09-fold) independently of obesity as compared with untreated DIO controls. Furthermore, there were increases in metabolically beneficial metabolites derived from the gut. Together, our data suggest that Firmicutes and Bacteroidetes potentially mediate insulin resistance through modulation of GLP-1 secretion in obesity.

Increased Cell Proliferations and Neurogenesis in the Hippocampal Dentate Gyrus of Ahnak Deficient Mice.

Expression of the giant protein Ahnak has been reported in endothelial cells of the blood brain barrier and in non-neuronal cells including myelinating Schwann cells. However, the function of Ahnak in neurogenesis has not been determined. In the present study, we report for the first time the effects of Ahnak on adult hippocampal neurogenesis using Ahnak(-/-) mice. Proliferating cells were labeled with BrdU for a 30-day period before sacrifice. In Ahnak(-/-) mice, the incorporation of BrdU with NeuN (Neuronal Nuclei) increased significantly in both the subgranular zone and the granular cell layer of the dentate gyrus. In addition, Ahnak(-/-) mice displayed increased Doublecortin-immunoreactive neuroblasts compared with wild-type controls. Taken together, Ahnak deficiency plays a positive role for hippocampal neurogenesis in adult mice because proliferating cells were increased in Ahnak(-/-) mice and advanced to mature neurons. These findings suggest that Ahnak might be involved in modulating the differentiation of newly generated cells into neuronal or non-neuronal cells.

Proteomic analysis of kidneys from selenoprotein M transgenic rats in response to increased bioability of selenium.

BACKGROUND: To characterize changes in global protein expression in kidneys of transgenic rats overexpressing human selenoprotein M (SelM) in response to increased bioabivility of selenium (Sel), total proteins extracted from kidneys of 10-week-old CMV/hSelM Tg and wild-type rats were separated by 2-dimensional gel electrophoresis and measured for changes in expression. RESULTS: Ten and three proteins showing high antioxidant enzymatic activity were up- and down-regulated, respectively, in SelM-overexpressing CMV/hSelM Tg rats compared to controls based on an arbitrary 2-fold difference. Up-regulated proteins included LAP3, BAIAP2L1, CRP2, CD73 antigen, PDGF D, KIAA143 homolog, PRPPS-AP2, ZFP313, HSP-60, and N-WASP, whereas down-regulated proteins included ALKDH3, rMCP-3, and STC-1. After Sel treatment, five of the up-regulated proteins were significantly increased in expression in wild-type rats, whereas there were no changes in CMV/hSelM Tg rats. Only two of the down-regulated proteins showed reduced expression in wild-type and Tg rats after Sel treatment. CONCLUSIONS: These results show the primary novel biological evidences that new functional protein groups and individual proteins in kidneys of Tg rats relate to Sel biology including the response to Sel treatment and SelM expression.

Suppressor of MEK null (SMEK)/protein phosphatase 4 catalytic subunit (PP4C) is a key regulator of hepatic gluconeogenesis.

Fasting promotes hepatic gluconeogenesis to maintain glucose homeostasis. The cAMP-response element binding protein (CREB)-regulated transcriptional coactivator 2 (CRTC2) is responsible for transcriptional activation of gluconeogenic genes and is critical for conveying the opposing hormonal signals of glucagon and insulin in the liver. Here, we show that suppressor of MEK null 1 (SMEK1) and SMEK2 [protein phosphatase 4 (PP4) regulatory subunits 3a and 3b, respectively] are directly involved in the regulation of hepatic glucose metabolism in mice. Expression of hepatic SMEK1/2 is up-regulated during fasting or in mouse models of insulin-resistant conditions in a Peroxisome Proliferator-Activated Receptor-gamma Coactivator 1α (PGC-1α)-dependent manner. Overexpression of SMEK promotes elevations in plasma glucose with increased hepatic gluconeogenic gene expression, whereas depletion of the SMEK proteins reduces hyperglycemia and enhances CRTC2 phosphorylation; the effect is blunted by S171A CRTC2, which is refractory to salt-inducible kinase (SIK)-dependent inhibition. Taken together, we would propose that mammalian SMEK/PP4C proteins are involved in the regulation of hepatic glucose metabolism through dephosphorylation of CRTC2.

Hepatitis B virus X protein regulates hepatic glucose homeostasis via activation of inducible nitric oxide synthase.

Dysregulation of liver functions leads to insulin resistance causing type 2 diabetes mellitus and is often found in chronic liver diseases. However, the mechanisms of hepatic dysfunction leading to hepatic metabolic disorder are still poorly understood in chronic liver diseases. The current work investigated the role of hepatitis B virus X protein (HBx) in regulating glucose metabolism. We studied HBx-overexpressing (HBxTg) mice and HBxTg mice lacking inducible nitric oxide synthase (iNOS). Here we show that gene expressions of the key gluconeogenic enzymes were significantly increased in HepG2 cells expressing HBx (HepG2-HBx) and in non-tumor liver tissues of hepatitis B virus patients with high levels of HBx expression. In the liver of HBxTg mice, the expressions of gluconeogenic genes were also elevated, leading to hyperglycemia by increasing hepatic glucose production. However, this effect was insufficient to cause systemic insulin resistance. Importantly, the actions of HBx on hepatic glucose metabolism are thought to be mediated via iNOS signaling, as evidenced by the fact that deficiency of iNOS restored HBx-induced hyperglycemia by suppressing the gene expression of gluconeogenic enzymes. Treatment of HepG2-HBx cells with nitric oxide (NO) caused a significant increase in the expression of gluconeogenic genes, but JNK1 inhibition was completely normalized. Furthermore, hyperactivation of JNK1 in the liver of HBxTg mice was also suppressed in the absence of iNOS, indicating the critical role for JNK in the mutual regulation of HBx- and iNOS-mediated glucose metabolism. These findings establish a novel mechanism of HBx-driven hepatic metabolic disorder that is modulated by iNOS-mediated activation of JNK.

Hypothyroid states mitigate the diabetes-induced reduction of calbindin D-28k, calretinin, and parvalbumin immunoreactivity in type 2 diabetic rats.

In this study, we investigated the differences in calbindin D-28k (CB), calretinin, (CR) and parvalbumin (PV) immunoreactivity in the hippocampus of Zucker diabetic fatty (ZDF) rats and Zucker lean control (ZLC) rats. In addition, we observed the effects of hypothyroidism on the levels of immunoreactivity of these proteins in ZDF rats. For this study, 7-week-old ZDF rats were used, and methimazole treatment was continued for 5 weeks to induce hypothyroidism. The animals were sacrificed at 12 weeks of age. ZDF rats showed increased blood glucose levels compared to those in ZLC rats. Methimazole intervention significantly reduced total and free T3 levels, and it ameliorated the increase of blood glucose levels in ZDF rats. In ZLC rats, CB, CR, and PV immunoreactivity was detected in regions of the hippocampus proper. In vehicle-treated ZDF rats, CB, CR, and PV immunoreactivity was significantly decreased in the hippocampus. However, in the methimazole-treated rats, CB, CR, and PV immunoreactivity was significantly increased compared to that in the vehicle-treated rats. These results suggest that hypothyroidism ameliorated the diabetes-induced reduction of CB, CR, and PV immunoreactivity in the hippocampus.

Ahnak deficiency attenuates high-fat diet-induced fatty liver in mice through FGF21 induction.

The AHNAK nucleoprotein has been determined to exert an anti-obesity effect in adipose tissue and further inhibit adipogenic differentiation. In this study, we examined the role of AHNAK in regulating hepatic lipid metabolism to prevent diet-induced fatty liver. Ahnak KO mice have reportedly exhibited reduced fat accumulation in the liver and decreased serum triglyceride (TG) levels when provided with either a normal chow diet or a high-fat diet (HFD). Gene expression profiling was used to identify novel factors that could be modulated by genetic manipulation of the Ahnak gene. The results revealed that fibroblast growth factor 21 (FGF21) was markedly increased in the livers of Ahnak KO mice compared with WT mice fed a HFD. Ahnak knockdown in hepatocytes reportedly prevented excessive lipid accumulation induced by palmitate treatment and was associated with increased secretion of FGF21 and the expression of genes involved in fatty acid oxidation, which are primarily downstream of PPARα. These results indicate that pronounced obesity and hepatic steatosis are attenuated in HFD-fed Ahnak KO mice. This may be attributed, in part, to the induction of FGF21 and regulation of lipid metabolism, which are considered to be involved in increased fatty acid oxidation and reduced lipogenesis in the liver. These findings suggest that targeting AHNAK may have beneficial implications in preventing or treating hepatic steatosis.

Xanthogranulomatous pancreatitis combined with intraductal papillary mucinous carcinoma in situ.

Xanthogranulomatous lesion is a rare condition in which lipid-laden histiocytes are deposited at various locations in the body. Xanthogranulomatous pancreatitis (XGP) associated with an intraductal papillary mucinous tumor (IPMT) is extremely rare. In this study, we described a case of XGP associated with IPMT and include a review of the literature. A pancreatic cystic mass was detected in a 72-yr-old woman by abdominal computed tomography. Pylorus-preserving pancreaticoduodenectomy was performed and diagnosis of XGP combined with intraductal papillary mucinous carcinoma in situ was made. After 13 months of follow-up, the patient is in good health without any evidence of tumor recurrence. Although XGP associated with IPMT is rare, we suggest that such cases should be brought to the attention of clinical investigators, as it may produce clinical features that mimic pancreatic cancer.

Intensive morphometric analysis of enormous alterations in skeletal bone system with micro-CT for AHNAK-/- mice.

AHNAK has been reported to be involved in actin cytoskeleton rearrangement of some cell types, calcium homeostasis, and activation of T cells. Although the functional role of AHNAK in muscle cells, epidermis, and brain has been determined, its association with apparent clinical impairment has not been found yet. During phenotypic analysis of AHNAK knock out (KO) mice for many years, we observed that AHNAK KO mice showed very slow growth. Snouts of these animals were very short, and their bones were easily broken compared to normal mice. It is known that AHNAK is closely related to calcium. However, intensive morphological studies on phenotypes of bone have yet been reported for AHNAK. Thus, the objective of the present study was to analyze the morphology of skull, mandibular, limbs, and caudal bones of AHNAK KO mice intensively using micro-CT with many factors for various ages of these mice (6 weeks, 18 weeks, and 40 weeks). As a result, it was found that the facial region of AHNAK KO mouse showed a large difference in mandible than skull. Their both femur and tibia were shortened, and bone strength was also significantly decreased compared to normal mice. Particularly, the tail bone of AHNAK KO mice exhibited morphological abnormality by age. Taken together, these results suggest that AHNAK plays an important role in bone shape, development, and metabolism. Although our results demonstrated that AHNAK has a distinct role in bone, further investigations are needed to determine various features of bone metabolism related to AHNAK in the future.

Identification of apolipoproteinA1 reduction in the polycystic kidney by proteomics analysis of the Mxi1-deficient mouse.

Autosomal dominant polycystic kidney disease is one of the most common human monogenic diseases in which extensive epithelial-lined cysts develop in kidney and other organs. Affected kidneys are not only characterized by the formation of cysts, but also by changes associated with the extracellular matrix and interstitial inflammation, which can progress to fibrosis and loss of renal function. Mxi1 protein, which is a c-myc antagonist, may be essential in controlling cellular growth and differentiation. Previously, multiple tubular cysts were observed in kidney of Mxi1-deficient mice aged 6 months and more. Presently, 2-DE and MALDI-TOF MS was employed to identify the differentially expressed proteins in the kidney. Several proteins were identified, among them, apolipoproteinA1 which is a major component of the high-density lipoprotein complex and has anti-inflammation effects, was significantly decreased in the Mxi1-deficient mouse. We confirm the development of inflammation and renal fibrosis and the expression of extracellular matrix molecules including transforming growth factor were also increased in cystic kidney. These results indicate that expression of proteins related with inflammation and renal fibrosis changes by Mxi1 inactivation in polycystic kidney.

Glucocorticoid receptor changes associate with age in the paraventricular nucleus of type II diabetic rat model.

Diabetes is a metabolic disorder that is associated with the dysregulation of a number of systems within the body. In the present study, we investigated glucocorticoid receptor (GR) immunoreactivity and its protein levels in the paraventricular nuclei of 4-, 12-, 20- and 30-week-old Zucker diabetic fatty (fa/fa, ZDF) and in Zucker lean control (fa/+ or +/+, ZLC) rats, because the progressive induction of diabetes is detectable in this model after 7 weeks of age and chronic diabetic conditions are maintained after 12 weeks of age. GR immunoreactivity was detected in parvocellular paraventricular nuclei and this and GR protein levels were exponentially increased according to the ages. In particular, GR immunoreactivities and protein levels were markedly more increased in 30-week-old ZDF rats than in age-matched ZLC group and in younger ZDF group. The present study suggests that GR immunoreactivity and its protein level is associated with a degenerative phenotype in the hypothalamus of from 12-weeks old in the ZDF rat type II diabetes model.

Comparative study on high fat diet-induced 4-hydroxy-2E-nonenal adducts in the hippocampal CA1 region of C57BL/6N and C3H/HeN mice.

In the present study, we investigated the influences of a high fat diet (HD) fed for 12 weeks, on lipid peroxidation and antioxidant enzyme using 4-hydroxy-2E-nonenal (HNE)-modified proteins (HNE-mp) and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region (CA1) in C57BL/6N and C3H/HeN mice. Body weights and body weight gains were significantly higher in HD fed C57BL/6N mice than in low fat diet (LD) fed C57BL/6N and LD or HD fed C3H/HeN mice. In the HD fed C57BL/6N and C3H/HeN mice, HNE-mp immunoreactivity and protein levels were much higher than in the LD fed C57BL/6N or C3H/HeN mice. In particular, HNE-mp immunoreactivity and protein levels in HD fed C57BL/6N mice was higher than that in the HD fed C3H/HeN mice. SOD1 immunoreaction was detected in the non-pyramidal cells of C57BL/6N mice, while in the C3H/HeN mice SOD1 immunoreaction was observed in CA1 pyramidal cells. The SOD1 immunoreactivity in the LD fed C57BL/6N and C3H/HeN mice was slightly, but not significantly decreased compared to that in the HD fed C57BL/6N and C3H/HeN mice, respectively. In addition, ionized calcium-binding adapter molecule 1 (Iba-1) immunoreactive microglia in the HD fed C57BL/6N showed hypertrophy of cytoplasm, which is the characteristics of activated microglia. These results suggest that HD fed C57BL/6N mice are more susceptible to lipid peroxidation in the CA1 than in LD fed C57BL/6N and LD or HD fed C3H/HeN mice without any differences of SOD1 expression.

Effects of treadmill exercise on cell proliferation and differentiation in the subgranular zone of the dentate gyrus in a rat model of type II diabetes.

In the present study, we investigated the effects of a treadmill exercise on serum glucose levels and Ki67 and doublecortin (DCX) immunoreactivity, which is a marker of cell proliferation expressed during cell cycles except G0 and early G1 and a marker of progenitors differentiating into neurons, respectively, in the subgranular zone of the dentate gyrus (SZDG) using a type II diabetic model. At 6 weeks of age, Zucker lean control (ZLC) and Zucker diabetic fatty (ZDF) rats were put on a treadmill with or without running for 1 h/day/5 consecutive days at 22 m/min for 5 weeks. Body weight was significantly increased in the control (without running)-ZDF rats compared to that in the other groups. In the control groups blood glucose levels were increased by 392.7 mg/dl in the control-ZDF rats and by 143.3 mg/dl in the control-ZLC rats. However, in the exercise groups, blood glucose levels were similar between the exercise-ZLC and ZDF rats: The blood glucose levels were 110.0 and 118.2 mg/dl, respectively. Ki67 positive nuclei were detected in the SZDG in control and exercise groups. The number of Ki67 positive nuclei was significantly high in exercise groups compared to that in the control groups. In addition, Ki67 positive cells were abundant in ZLC groups compared to those in ZDF groups. DCX-immunoreactive structures in the control-ZDF rats were lower than that in the control-ZLC rats. In the exercise groups, DCX-immunoreactive structures (somata and processes with tertiary dendrites) and DCX protein levels were markedly increased in both the exercise-ZLC and ZDF rats compared to that in the control groups. These results suggest that a treadmill exercise reduces blood glucose levels in ZDF rats and increases cell proliferation and differentiation in the SZDG in ZLC and ZDF rats compared to those in control groups.

Expression of MUC1, MUC2, MUC5AC and MUC6 in cholangiocarcinoma: prognostic impact.

Mucin is a high molecular weight glycoprotein that plays an important role to protect the gastrointestinal tract epithelium. However, in cancer cells and during cancer progression, the expression profile of mucins is altered and expression of some mucins is correlated with prognosis for certain malignancies. The aim of this study was to determine the relationship between the expression of MUC1, MUC2, MUC5AC and MUC6 in cholangiocarcinoma and clinicopathological parameters as well as patient survival. In addition, this study was performed to identify whether immunohistochemical staining for mucins is useful to differentiate cholangiocarcinoma from adenocarcinoma of the pancreas and gallbladder. Immunohistochemical staining for MUC1, MUC2, MUC5AC and MUC6 was performed for 85 cases of cholangiocarcinoma, including 34 cases of intrahepatic cholangiocarcinoma (ICC), 51 cases of extrahepatic cholangiocarcinoma (ECC), 11 cases of gallbladder adenocarcinoma and 14 cases of pancreas adenocarcinoma. For cholangiocarcinomas, positivity of immunohistochemical staining for MUC1, MUC2, MUC5AC and MUC6 was 65.8, 23.5, 61.1 and 14.1%, respectively. For cholangiocarcinomas, MUC1 positivity was determined to be statistically significant for poor differentiation (p=0.002), T category (p=0.003), gross type (ICC, p=0.005; ECC, p=0.006) and poor patient survival (p=0.015). MUC5AC was more frequently expressed in advanced tumors (p=0.013). MUC6 expression was significantly detected in well-differentiated cholangiocarcinomas (p=0.006). There was no significant difference for the mucin staining patterns of cholangiocarcinomas, pancreatic adenocarcinomas and gallbladder adenocarcinomas. These results indicate that MUC1 expression in cholangiocarcinomas is closely related to dedifferentiation, infiltrative growth pattern and patient survival. Our results suggest that the expression of MUC1 might be associated with the progression of cholangiocarcinoma.

Effects of high cholesterol diet on newly generated cells in the dentate gyrus of C57BL/6N and C3H/HeN mice.

In this study, we observed and compared the effects of a high cholesterol diet (HCD) on cell proliferation and differentiation in the subgranular zone of the dentate gyrus of C57BL/6N (B6, susceptible strain) and C3H/HeN (C3H, resistant strain) mice. Ki67 (a marker for cell proliferation) positive cells) were significantly decreased in HCD-fed B6 mice compared to those in B6 (49.7%) and C3H mice fed a low cholesterol diet (LCD). In addition, doublecortin (DCX, a marker for cell differentiation or neuroblasts)-immunoreactive cells in HCD-fed B6 mice were significantly decreased compared to those in LCD-fed B6 and C3H mice. These results suggest that B6 strains are sensitive to HCD, which impairs cell proliferation and differentiation.

Effects of methimazole on the onset of type 2 diabetes in leptin receptor-deficient rats.

We investigated the effects of methimazole, an anti-thyroid drug, on the onset of type 2 diabetes in Zucker diabetic fatty (ZDF) rats. For this, 0.03% methimazole was administered to 7-week-old, pre-diabetic ZDF rats in drinking water for 5 weeks and the animals were sacrificed at 12 weeks of age. Methimazole treatment to ZDF rats significantly reduced blood glucose levels, food intake, body weight, and serum T3 levels. Hepatocytes in ZDF-methi rats were more densely stained with eosin than those in ZDF rats because of low fat accumulation in ZDF-methi hepatocytes. The pancreatic islet in ZDF-methi rats was normal compared to that in ZDF rats. Glucagon, not insulin, immunoreactivity in ZDF-methi rats was significantly higher than that in ZDF-methi rats. These suggest that methimazole treatment may delay the onset of type 2 diabetes in leptin receptor-deficient rats and also suggests that thyroid hormones may be necessary for the onset of diabetes.

Viscothionin purified from mistletoe (Viscum album var. coloratum Ohwi) induces insulin secretion from pancreatic beta cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Mistletoe (Viscum album), an evergreen parasitic plant, has been widely used as an oriental phytomedicine to treat diabetes mellitus. However, it is unknown which mistletoe constituent exerts the beneficial effect against the disease. In this study, we examined the hypoglycemic activity of mistletoe and investigated whether the polypeptide viscothionin, purified from mistletoe, was responsible for the activity. MATERIALS AND METHODS: Mistletoe extracts were prepared by heating mistletoe powder made of leaves and twigs in water for 3, 6, 9, and 12 h. Rat insulinoma RINm5F cells were used to test the cytotoxicity of the extracts and their effects on the secretion of insulin and its precursor, C-peptide. The inhibitory effects of a mistletoe extract on glucose absorption were measured using an α-glucosidase inhibition assay. To determine the component of mistletoe responsible for the observed effects, the mistletoe extract was precipitated with ethanol or hydrolyzed with a protease for further testing. A potential active constituent of mistletoe was isolated by chromatography and molecular weight cut-off fractionation, and its ability to induce insulin secretion was investigated. RESULTS: A 12-h heat-treated mistletoe extract, showing no cytotoxicity, significantly increased the secretion of insulin and C-peptide by RINm5F cells and enhanced the expression of glucose transporter type 4 (GLUT-4), insulin receptor substrate 1 (IRS-1), and protein kinase B (also known as AKT) in differentiated C2C12 cells. The extract also inhibited α-glucosidase activity. After ethanol precipitation, the extract showed much stronger effects on insulin- and C-peptide-secreting activities of cells, whereas the enzyme-hydrolyzed extract was less effective than the original extract, suggesting that the effect was mediated by a proteinaceous constituent of mistletoe. Subsequent analysis showed that viscothionin, a heat-stable 6-kDa polypeptide isolated from mistletoe, increased the level of insulin secretion by more than 20-fold compared to that induced by the extract. CONCLUSIONS: Our study indicates that the hypoglycemic effect of mistletoe is mediated by its insulinotropic action and α-glucosidase inhibitory activity, and the effect is due to viscothionin, one of the major bioactive constituents of mistletoe.

Epithelioid sarcoma arising from the temporal space: A case report.

INTRODUCTION: Epithelioid sarcoma is a malignant soft tissue tumor arising from mesenchymal tissue and usually occurs in the extremities. The tumor involving the head and neck region is extremely rare. We present radiologically well-documented case of an epithelioid sarcoma arising from the temporal space. CASE PRESENTATION: A 35-year-old woman presented with a slowly growing, painless palpable mass in the left temporal area. Ultrasound (US) revealed a lobulated hypoechoic mass with internal vascularity. On magnetic resonance (MR) imaging, the mass showed heterogeneous signal intensity with a central necrotic area and peritumoral infiltration. On the basis of the clinical and radiological characteristics, the lesion was considered to be a malignant tumor originating from soft tissue. An incisional biopsy was performed. The diagnosis of epithelioid sarcoma was based on microscopic examination and immunohistochemical analysis. F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was used to stage the tumor and demonstrated intense FDG uptake in the mass without regional lymph node or distant metastasis. After the pathologic diagnosis of epithelioid sarcoma, the patient underwent total surgical resection of the tumor followed by postoperative irradiation. There was no evidence of recurrent disease during the follow-up period of 18 months. CONCLUSION: An epithelioid sarcoma should be considered in the differential diagnosis of a locally aggressive lesion occurring in the temporal space of head and exhibiting a heterogeneous appearance on imaging studies, including a central necrotic area and signal intensity suggestive of infiltration of soft tissue adjacent to the tumor. It is, however, true that head-and-neck involvement is very rare, and the radiological findings are not pathognomonic.