Expression of down stream molecules of RET (p-ERK, p-p38 MAPK, p-JNK and p-AKT) in papillary thyroid carcinomas

To evaluate the roles of 4 putative downstream molecules (ERK, p38 MAPK, JNK and AKT) of the RET signal pathway in the tumorigenesis of papillary carcinomas, the expression patterns of RET and phosphorylated forms of ERK, p38 MAPK, JNK and AKT were evaluated in 115 cases of papillary thyroid carcinomas by 3 mm-core tissue microarray based immunohistochemical staining. The prevalence of RET protein expression was 62.6%. No distinct expression of p-ERK and p-p38 MAPK was demonstrated in tumor cells of papillary carcinomas. All papillary carcinomas except 5 cases expressed nuclear p-JNK and p-JNK expression was increased in tumors compared with paired normal tissues (p < 0.05). There was no difference in the p-JNK expression between RET protein-positive and RET protein-negative papillary carcinomas (p > 0.05). Unequivocal nuclear staining for p-AKT was demonstrated only in 10 cases of papillary carcinomas, and all of them showed focal staining. Our results showing constitutive expression of p-JNK in most cases of surgically excised papillary thyroid carcinomas irrespective of RET protein expression status suggest that JNK activation may play a role in the tumorigenesis or survival of sporadic papillary thyroid carcinoma.     

Modulation of the surface expression of CD158 killer cell Ig-like receptor by interleukin-2 and transforming growth factor-beta

Killer cell Ig-like receptor (KIR) binds to HLA class I molecules on the surface of target cells, and it confers inhibitory signals to NK cells. Although NK cytotoxicity can be affected by the change of the surface expression of KIR on NK cells, the effect of cytokines on the regulation of KIR expression has not been thoroughly investigated. Here in our study, we investigated the effect of several cytokines, including IL-2, TGF-beta, IFN-gamma, IL-12 and IL-18, on the surface expression of CD158 KIR, which binds to HLA-C, by the use of FACS analysis. In the isolated NK cells, IL-2 obviously increased the surface expression of CD158 KIR after 72 hr in vitro culture, and this was evidenced by the increased percentage of CD158(+) NK cells and the increased mean fluorescence intensity of CD158 in CD158(+) NK cells. In contrast, TGF-beta decreased the surface expression of CD158 KIR after 72 hr culture. However, IFN-gamma, IL-12 and IL-18 did not change the expression of CD158 KIR. The modulated expression of KIR by IL-2 and TGF-beta can be associated with the changed NK-cytotoxic target-discriminating ability of NK cells upon their exposure to IL-2 and TGF-beta.     

Aperture maneuver with compelled breath (AMC) for moving tumors: a feasibility study with a moving phantom

Respiration causes target motion, which is known to be one of the technical bottlenecks in radiotherapy, especially for stereotactic radio-surgery and intensity modulated radiotherapy (IMRT). To overcome this problem, aperture maneuver with compelled breath (AMC) has been developed. In order to simulate compelled respiratory motion, a moving phantom using a ventilator was designed. As the air flow was forced to the bellows, which simulates the lungs, by a ventilator, a film connected to the ventilator moved like the respiratory target motion. A software was developed to transfer multileaf collimator motion from breathless to actual periodic breathing conditions. Static fields as well as step-and-shoot IMRT fields were modified in accordance with moving shapes to follow the target position, using the software with the controlled breathing information. Film dosimetry for a small field and for IMRT fields with a moving phantom was performed. To evaluate clinical implementation, five healthy volunteers were tested to breathe through a ventilator, and all of them could adapt the compelled breath without any difficulties. Additive margins for a moving target with AMC were not larger than 3 mm for respiratory organ motions up to 18 mm, while those with the static beam were 9 mm. For IMRT fields, large discrepancies were present between a static target and a moving target with the static beam, while they coincided well with AMC. Clinical acceptable differences between the dose distributions from a static target with the static beam and from a moving target with AMC revealed that this technique could be applied clinically.     

Detection of YMDD motif mutants by oligonucleotide chips in lamivudine-untreated patients with chronic hepatitis B virus infection

Lamivudine, a nucleoside analogue, has been used widely as an effective antiviral agent for the treatment of patients with chronic hepatitis B virus (HBV) infection. However, the YMDD motif mutation of HBV polymerase resistant to lamivudine occurs very frequently after long term therapy. We developed an oligonucleotide chip for the detection of YMDD motif mutants resistant to lamivudine and investigated the prevalence of the mutants in patients with chronic HBV infection who had not been treated by lamivudine before. Forty patients who had not been treated with lamivudine were included in this study. Serum samples were tested by the oligonucleotide chips designed for detection of wild-type YMDD motif, M552V and M552I. Samples were confirmed by restriction fragment length polymorphism (RFLP) and direct sequencing. M552I mutants were detected by the oligonucleotide chips in 7.5% (3/40) of chronic HBV infected patients (2 chronic hepatitis and 1 cirrhosis). The results were in accordance with those of RFLP. YMDD motif mutants occur as natural genome variabilities in patients with chronic HBV infection who had not been treated with lamivudine before. Oligonucleotide chip technology is a reliable and useful diagnostic tool for the detection of mutants resistant to antiviral therapy in chronic HBV infection.     

Hyalinizing spindle cell tumor with giant rosettes with pulmonary metastasis after a long hiatus: a case report

Hyalinizing spindle cell tumor with giant rosettes (HSCTGR) is a recently described tumor, which is regarded as an unusual variant of low-grade fibromyxoid sarcoma. Proof of a metastatic potential was lacking. The patient in the report was a 35-yr-old woman who showed multiple bilateral pulmonary nodules with massive pleural effusion in the right side. She had a history of a mass excision in the right thigh 11 yrs ago at another hospital, which was reported as a "leiomyoma". Two years before this presentation, the patient received a routine chest radiograph which demonstrated bilateral multiple pulmonary nodules. A lobectomy of the left upper lung was performed. The histological findings revealed a well-circumscribed nodule that was characterized by a spindle-shaped fibrous to hyalinized stroma with criss-crossing short fascicles and giant collagen rosettes surrounded by a rim of spindle-shaped cells. Electron microscopy confirmed the fibroblastic nature of the tumor. This case, in addition to at least two other cases reported in the literature, demonstrates that the HSCTGR is a malignant neoplasm with the capacity to metastasize after a long hiatus.     

Protective effect of retinoic acid on interleukin-1 beta-induced cytotoxicity of pancreatic beta-cells

Cytokines produced by immune cells in pancreatic islets infiltrating are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. In this study, the effects of retinoic acid (RA) on cytokine-induced beta-cell dysfunction were examined. RA significantly protected interleukin-1 beta (IL-1) and interferon-gamma (IFN-gamma)-mediated cytotoxicity of rat insulinoma cell (RINm5F), and also reduced in IL-1 and IFN-gamma-induced nitric oxide (NO) production, which correlated well with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism, by which RA inhibited iNOS gene expression, appeared to involve the inhibition of NF-kappa B activation. Our results suggest possible therapeutic value of RA for the prevention of diabetes mellitus progression.     

Maternal serum levels of VCAM-1, ICAM-1 and E-selectin in preeclampsia

Endothelial dysfunction is thought to be a central pathogenic feature in preeclampsia on the basis of elevated adhesion molecules. The aim of the present study was to compare the levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1) and E-selectin (sE-selectin) in sera of normal and preeclamptic pregnancies. We studied the serum levels of sVCAM-1, sICAM-1 and sE-selectin in normal pregnant women (n=63), mild preeclampsia (n=33) and severe preeclampsia (n=82). Concentrations of soluble adhesion molecules were determined with enzyme-linked immunoassay (ELISA). Serum concentrations of sVCAM-1 were significantly higher in both mild (p=0.004) and severe preeclampsia (p=0.000) than normal pregnancy. There were also significant differences in sVCAM- 1 levels between mild and severe preeclampsia (p=0.002). sICAM-1 levels of severe preeclampsia were statistically different from those of normal pregnancy (p=0.038). Levels of sE-selectin were elevated in both mild (p=0.011) and severe preeclampsia (p=0.000) compared to normal pregnancy, but no statistical difference between the mild and severe preeclampsia (p=0.345). These results suggest that all three soluble adhesion molecules are increased in severe preeclampsia, and sVCAM-1 among them may be useful in predicting the severity of preeclampsia.     

Analysis of children with type 1 diabetes in Korea: high prevalence of specific anti-islet autoantibodies, immunogenetic similarities to Western populations with "unique" haplotypes, and lack of discrimination by aspartic acid at position 57 of DQB

This study analyzed the expression of anti-islet autoantibodies and HLA-DR and -DQ genotypes in Korean children with type 1 diabetes mellitus (T1DM). The positivity of the anti-ICA512, anti-GAD65, and anti-insulin autoantibodies in the newly onset T1DM patients (n = 15) was 66.7%, 86.7%, and 46.7%, respectively, and all of them had one or more of the autoantibodies. HLA analysis showed higher frequencies of HLA-DRB1*0301, *0405, *09012 and -DQB1*0201, *0401, *03032 alleles in T1DM patients compared to controls (P(c) < 0.05). Because HLA-DQB1*0401, *03032 alleles carry aspartic acid at position 57 of DQB, susceptibility to T1DM in Korean children was not related to the presence of aspartic acid at position 57 of DQB1 locus. We suggest this unique HLA-DR, -DQ allele distribution might be an important factor for the low incidence of T1DM in Korea, and the combined anti-islet autoantibody assays could be valuable screening markers for the early detection of T1DM in Korea.     

Activation of extracellular signal-regulated kinases in the sciatic nerves of rats with experimental autoimmune neuritis

To investigate whether the phosphorylation of extracellular signal-regulated kinase (ERK) is involved in autoimmune injury of the peripheral nervous system (PNS), the expression of phosphorylated ERK (p-ERK) was analyzed in experimental autoimmune neuritis (EAN) in rats. Western blot analysis showed that the level of p-ERK was increased significantly in the sciatic nerves of rats on days 14 (p<0.05) and 24 (p<0.01) post-immunization, compared with controls, and its reaction declined at day 30 post-immunization. Immunohistochemistry showed that p-ERK protein was weakly expressed in Schwann cells and vascular endothelial cells in the sciatic nerves of CFA-immunized control rats. In EAN-affected sciatic nerves, p-ERK immunoreactivity was found mainly in ED1-positive macrophages on days 14 and 24 post-immunization. Moreover, on days 24 and 30 post-immunization, p-ERK immunoreactivity increased gradually in the Schwann cells of rat sciatic nerves with EAN. Based on these results, we postulated that the phosphorylation of ERK has an important role in the differentiation and survival of cells, including inflammatory cells and Schwann cells, in the rat sciatic nerve in EAN. Specifically, the activation of ERK in the recovery phase of EAN paralysis seems to be related in the survival of Schwann cells.     

Persistent changes in the intrinsic excitability of rat deep cerebellar nuclear neurones induced by EPSP or IPSP bursts

The deep cerebellar nuclei (DCN) are the major output of the cerebellum, and have been proposed as a site of memory storage for certain forms of motor learning. Microelectrode and whole-cell patch recordings were performed on DCN neurones in acute slices of juvenile rat cerebellum. DCN neurones display tonic and bursting basal firing patterns. In tonically firing neurones, a stimulus consisting of EPSP bursts produced a brief increase in dendritic Ca²⁺ concentration and a persistent increase in the number of spikes elicited by a depolarizing test pulse, along with a decrease in spike threshold. In intrinsically bursting DCN neurones, EPSP bursts induced an increase in the number of depolarization-evoked spikes in some neurones, but in others produced a change to a more tonic firing pattern. Application of IPSP bursts evoked a large number of rebound spikes and an associated dendritic Ca²⁺ transient, which also produced a persistent increase in the number of spikes elicited by a test pulse. Intracellular perfusion of the Ca²⁺ chelator BAPTA prevented the increase in intrinsic excitability. Thus, rapid changes in intrinsic excitability in the DCN may be driven by bursts of both EPSPs and IPSPs, and may result in persistent changes to both firing frequency and pattern.