Selective up-regulation of I kappaB-alpha in ischemic penumbra following focal cerebral ischemia

Activation of transcription factor NF-kappaB plays a critical role in immune, inflammatory and cell death responses. In resting cells, NF-kappaB is sequestrated in the cytoplasm in an inactive form through its association with inhibitory proteins, I kappaB (e.g.I kappaB-alpha). In response to cell activation, I kappaB is degraded causing release of active NF-kappaB. Active NF-kappaB translocates into the nucleus leading to activation of transcription that may have a profound effect on cell survival, including that after ischemic stroke. Here, using Western blot analysis, we show that immunoreactivity to the major subunit of NF-kappaB, p65, as well as to the inhibitory subunit I kappaB-alpha is equally markedly decreased in the ischemic core after transient middle cerebral and common carotid artery occlusion in rats. In contrast, penumbral regions display no change in p65, and significant increase in I kappaB-alpha immunoreactivity, as compared to non-ischemic areas. In these penumbral regions with elevated I kappaB-alpha immunoreactivity, we find reduced cytosolic and increased nuclear I kappaB-alpha staining of neurons, as determined by immunohistochemistry. Altogether, these results suggest that an altered ratio between activating and inhibitory NF-kappaB pathways mediated through I kappaB-alpha may play an important role in survival of the ischemic penumbra.

Methotrexate suppresses the interleukin-6 induced generation of reactive oxygen species in the synoviocytes of rheumatoid arthritis

Various cytokines and reactive oxygen species (ROS) play a fundamental role in the inflammatory and immunologic processes of rheumatoid arthritis (RA). Methotrexate (MTX) is one of the disease-modifying anti-rheumatic drugs and its effect may be partly due to the modulation of immunologic or inflammatory reactions by some cytokines. In the present study, we investigated the effects of MTX on the gene expression and synthesis of interleukin-6 (IL-6), and the proliferative activity and the production of ROS in the fibroblast-like synoviocytes (FLSs) obtained from the patient of RA. The expression or production of IL-6 was induced spontaneously, and augmented by the addition of recombinant human IL-6 or recombinant human IL-1 beta and TNF-alpha in FLSs. These spontaneous and augmented IL-6 expressions or productions were suppressed by treatment with low-concentration of MTX (1 microg/ml). Also, IL-6 stimulated the proliferation of FLSs, and this IL-6 driven proliferation was inhibited with the treatment of MTX or N-acetylcysteine (NAC, 1 mM). Furthermore, ROS production in FLSs was increased significantly by IL-6, and its effect was also abrogated in the presence of MTX or NAC. These results suggest that inflammatory reaction in the synovium of RA patients could be augmented by the autocrine or other cytokine-induced production of IL-6 with subsequent generation of ROS in the synoviocytes, and the modulations of IL-6 synthesis and ROS production may contribute to the therapeutic effects of MTX for RA.

Spontaneous spinal subdural hematoma with spontaneous resolution

STUDY DESIGN

Single patient case report.

OBJECTIVES

To present and discuss a case of spontaneous spinal subdural hematoma that was not associated with coagulation abnormality.

SETTING

Seoul National University Hospital, Seoul, Korea.

METHODS

Clinical and radiological magnetic resonance imaging follow-up of the patient between August 1997 and December 1998.

RESULTS

The hematoma was initially extensive, ranging from T5 to L3. However, it resolved spontaneously with the subsequent development of an adhesive arachnoid cyst.

CONCLUSION

Even though urgent surgical decompression is necessary in most cases of spinal subdural hematoma, conservative management could be an option in cases with rapid resolution of the neurological deficit.

Ligation of ICAM-1 molecules inhibits target cell-induced granule exocytosis of IL-12-activated natural killer cells

The importance of cell adhesion molecules such as ICAM-1 is emphasized in cell-to-cell interactions that are critical in the generation of effective immune reactions. In this study, the involvement of ICAM-1 in natural killer (NK) cell activities was characterized in IL-12-activated human NK cells. To address the question of whether ligation of ICAM-1 molecules can modulate NK cell cytolytic activities, a 4-h (51)Cr-release assay was performed after pretreatment of NK cells with R6.5 mAb (anti-human ICAM-1 mAb). Ligation of membrane ICAM-1 molecules significantly inhibited IL-12-enhanced NK cytotoxicity against K562, and the pretreatment of neutralizing soluble ICAM-1 with R6.5 mAb blocked this inhibitory effect. The involvement of Ca(2+)-dependent granular exocytosis was evaluated. BLT esterase assay demonstrated that the ligation of ICAM-1 molecules inhibited granular exocytosis of NK cells. Additionally, the ICAM-1-mediated inhibition of Ca(2+) flux in NK cells was detected using Fluo-3AM, while the pretreatment of NK cells with R6.5 mAb did not affect conjugate formation between NK and K562 cells. Collectively, these results suggest that the signals transduced from ICAM-1 molecules might be sufficient to induce inhibitory effects on NK cells.

The production of nitric oxide and TNF-alpha in peritoneal macrophages is inhibited by Dichroa febrifuga Lour

Nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) have been suggested to play an important role in endotoxin-mediated shock and inflammation. In this study, we investigated the effect of aqueous extract of Dichroa febrifuga Lour. (Saxifragaceae) roots, a traditional antimalarial drug, on the production of NO and TNF-alpha. The aqueous extract of D. febrifuga roots (AEDF) inhibited the secretion of NO and TNF-alpha in lipopolysaccharide (LPS) and/or interferon-gamma (IFN-gamma)-stimulated mouse peritoneal macrophages, without affecting cell viability. The protein level of inducible nitric oxide synthase (iNOS) in peritoneal macrophages was also decreased by AEDF. In addition, the serum level of NO was reduced by i.p. administration of AEDF. These results suggest that AEDF suppresses the endotoxin-induced inflammatory responses through inhibiting the production of NO and TNF-alpha, and could be used as an anti-inflammatory drug.

Vascular complications in lumbar spinal surgery: percutaneous endovascular treatment

Four patients underwent endovascular treatment of vascular injuries complicating lumbar spinal surgery. In two patients with massive retroperitoneal hemorrhage, the extravasating lumbar arteries were successfully embolized with microcoils. Two patients with large iliac arteriovenous fistula (AVF) were treated, one with embolization using a detachable balloon and coils, which failed, and the other with placement of a stent graft after embolization of distal runoff vessels, which occluded the fistula. We conclude that acute arterial laceration or delayed AVF complicating lumbar spinal surgery can be managed effectively with selective embolization or stent-graft placement, respectively.

The visible man: three-dimensional interactive musculoskeletal anatomic atlas of the lower extremity

A personal computer-based interactive musculoskeletal anatomic atlas of the lower extremity has been created by using the Visible Human Male data set. A semiautomatic segmentation program was developed by using an intelligent scissors approach and shape-based interpolation, thus considerably reducing the laborious work of the segmentation and labeling process. Manual contour extractions at 3-mm section intervals and shape-based interpolations of intervening sections of the musculoskeletal structures of the lower extremity were performed. For interactive and realistic three-dimensional display, an efficient binary volume rendering method was developed that introduces the concept of shear-warp factorization and applies a newly developed normal calculation technique. Binary volume rendering reconstructs various structures from a series of two-dimensional sections in a few seconds, thus enabling real-time manipulations of the computerized atlas. All of the muscles, tendons, and bones of the lower extremity have been segmented and labeled. The volume-based three-dimensional interactive atlas supports various interactions including rotation, removal, highlighting with artificial colors, arbitrary cutting operation, transparent view, and descriptive knowledge representation. In addition, browsing through the two-dimensional images of transverse, coronal, and sagittal views with labeling and segmentation information is possible.

Usefulness of 99Tcm-MDP knee SPET for pre-arthroscopic evaluation of patients with internal derangements of the knee

The aim of this study was to ascertain whether knee SPET can localize lesion sites in patients with internal derangements of the knee. We performed knee SPET as a pre-arthroscopic examination in 63 consecutive patients. SPET imaging was performed with a triple-headed SPET camera 4 h after the injection of 99Tcm-methylene diphosphonate. Arthroscopic diagnoses were as follows: 28 medial meniscus injuries, 24 lateral meniscus injuries, 31 anterior cruciate ligament (ACL) injuries, three posterior cruciate ligament injuries and one medial collateral ligament injury. Of 30 patients with crescent-shaped increased activity at the medial tibial plateau, 22 had medial meniscus injuries (positive predictive value: PPV 73%); of 17 patients with crescent-shaped activity at the lateral tibial plateau, 13 had lateral meniscus injuries (PPV 76%). Of 18 patients with increased activity at ACL attachment sites (primary sign), 17 had ACL injuries (PPV 94%). Of 27 patients with increased activity at bone impaction sites of ACL injury (secondary sign), 22 had ACL injuries (PPV 81%). Of 32 patients who had either a primary or secondary sign, 26 had ACL injuries (PPV 81%). We conclude that knee SPET is very useful in the management of internal derangements of the knee, particularly in determining the need for arthroscopy by localizing lesion sites.

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM

The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features.

MATERIALS AND METHODS

Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features.

RESULTS

On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable.

CONCLUSION

Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.

MR findings of desmoplastic fibroma of the spine. A case report

We report on the MR imaging findings in a case of spinal desmoplastic fibroma (DF). DF of the bone is a rare, locally aggressive tumor. It is commonly located in long bones, pelvis or mandible. DF involving the spine is extremely rare and difficult to distinguish from other bony lesions such as giant cell tumor, chordoma and fibrous dysplasia of the spine. This case of DF of the spine showed MR findings similar to those of DF arising in the metaphysis of a long bone.

Effects of dopamine and melatonin on the regulation of the PIT-1 isotype, placental growth hormone and lactogen gene expressions in the rat placenta

Rat placenta produces several members of the placental prolactin-growth hormone (PRL-GH), including placental lactogen (PL) and placental prolactin like protein (PLP), during pregnancy. It is important to study placental local regulators that control the expression of PRL-GH genes. We have previously reported that dopamine (DA) can regulate Pit-1 and PL-II gene expressions. In this study we aimed to investigate the local expression of melatonin receptor 1a (Mel1a) and the effects of DA and melatonin on the expressions of PL-Iv, PL-II, PLP-C genes and Pit-1 gene that are involved in the expression of PRL-GH genes in the rat pituitary and placenta. According to the Northern blot analysis, DA receptor 2 (D2) was expressed in the rat placenta. We also report on the local expression of Mel1a in the rat placenta for the first time. Injected DA agonist, bromocriptine (in vivo) decreased PL-Iv, PLP-C and Pit-1 mRNA levels in the rat placenta. The melatonin agonist, chloromelatonin in culture media also decreased the levels of PL-Iv, PL-II and PLP-C mRNA. However, melatonin does not affect the Pit-1 mRNA level. These data suggest that D2 and Mel1a may control the expression of PRL-GH genes in the rat placenta and its response to the extracellular changes of DA and melatonin secreted from the maternal organ. However, Pit-1 may not be involved in the Mel1a induced inhibition of PRL-GH gene expressions in the rat placenta.

ERK/MAPK pathway is required for changes of cyclin D1 and B1 during phorbol 12-myristate 13-acetate-induced differentiation of K562 cells

Phorbol 12-myristate 13-acetate (PMA)-induced differentiation of human erythroleukemic K562 cells is characterized by growth arrest, morphological change, and expression of megakaryocyte-specific proteins. We examined the possible involvement of cell cycle regulators with PMA-induced growth arrest and megakaryocytic differentiation of K562 cells. The concentrations of cyclin D1 and p21Waf1/Cip1 were dramatically increased, whereas those of cyclin B1 and cdc2 were decreased, by PMA treatment. The concentrations of most cyclin-dependent kinases (Cdk2, Cdk4, and Cdk6), however, were unchanged by PMA treatment. PD98059, a specific inhibitor of MEK1, partially prevented the increase in cyclin D1 caused by PMA and fully reversed the down-regulation of cyclin B1 protein seen in response to PMA treatment. Thus, it is demonstrated here that the PMA-mediated changes of cyclin D1 and B1 are the result of a persistent increase in extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) activity.

The effect of nitric oxide on sperm cell function and embryo development

PROBLEM

Nitric oxide (NO) has been known to have multifunctional roles both in the male and female reproductive systems. We investigated the effects of sodium nitroprusside (SNP)-dependent NO release on sperm cell function and embryo development to elucidate the mechanisms of action of NO.

METHOD OF STUDY

Semen samples from 20 healthy men were processed by the swim-up method. Sperm motility, hyperactivation, and acrosome reaction were examined following incubation with various concentrations of SNP. The concentration of 10 nM to 1 mM was used for sperm motility and hyperactivation measurement and 1 microM to 1 mM for examining the effect on acrosome reaction. Embryo development to blastocyst stage was assessed using 100 nM to 1 mM of SNP added before transferring the mouse embryos into the culture medium. Finally, to understand the mechanism of action of NO, changes in embryo development were examined after zygotes were treated with various concentrations ranging up to 1 mM of 8-bromo-cGMP, an analog of cGMP.

RESULTS

Both sperm motility and hyperactivation were significantly reduced at 100 microM and 1 mM concentrations of SNP after 6 hr of incubation. After 24 hr of incubation, they were greatly decreased with all, except the 10 nM concentration of SNP. The percentage of acrosomal-reacted spermatozoa was increased with the increasing concentration of SNP following incubation with 10 microM and 1 mM of SNP. Embryo development was arrested since the two-cell embryonic stage with all except the 100 nM concentration of SNP, and inhibited by 200 microM of SNP regardless of SNP treatment stage. However, embryo development was not influenced by 8-bromo-cGMP.

CONCLUSIONS

We concluded that SNP-inhibited sperm cell function and embryo development in a dose- and time-dependent manner, and the inhibitory effect on embryo development, may not be a stage-specific treatment mediated via a cGMP-independent pathway. This result suggests that NO may be enough to affect the fecundity potential in vivo.

Identification of heat shock protein 90-associated 84-kDa phosphoprotein

In eukaryotic cells, HSP90 is associated with several protein kinases and regulates their activities. HSP90 was also reported to possess an autophosphorylase activity. In this study, we examined in vitro autophosphorylation of HSP90, which was purified from chick muscle. We show that HSP90 was not phosphorylated in vitro, but an 84-kDa protein (p84) was highly phosphorylated. P84 was neither HSP90 nor its degradative product, as it was not detected by an antibody (BF4) specific to HSP90 in denaturing immunoprecipitation and Western blot analysis. Phosphorylation of a protein similar to p84 was also detected with purified human brain and HeLa HSP90, indicating that p84 is present in many different types of cells. P84 appeared to exist as large complexes, as determined by HPLC and native gel electrophoresis. Native immunoprecipitation using anti-HSP90 (BF4)-conjugated Affi-gel revealed that this phosphoprotein is specifically associated with HSP90. The interaction of p84 and HSP90 was not affected by p84 phosphorylation. In addition, p84 phosphorylation was prevented by the presence of divalent cations such as Mg(2+) and Mn(2+). In contrast, p84 phosphorylation was significantly activated by addition of exogenous Ca(2+) between 100 and 500 microM, although it was blocked by higher concentrations (>1 mM) of Ca(2+). HSP90, but not p84, could be phosphorylated by casein kinase II. Finally, p84 phosphorylation was specifically prevented by hemin, but not by other kinase inhibitors, indicating that p84 phosphorylation may be regulated by heme-regulated protein kinase.

Geldanamycin induces cell cycle arrest in K562 erythroleukemic cells

Geldanamycin (GA), a benzoquinone ansamycin, is one of the specific inhibitors of 90-kDa heat shock protein and induces growth inhibition and apoptosis in certain cancer cell lines. We have investigated the mechanism of GA-induced growth inhibition in K562 erythroleukemic cells. DNA flow-cytometric analysis indicated that GA-induced growth arrest was associated with G2/M phase arrest of the cell cycle. GA treatment down-regulated the expression of cyclin B1 and inhibited phosphorylation of Cdc2 protein, both key regulatory proteins at the G2/M boundary. GA also markedly inhibited the Cdc2 kinase activity, which may be in part a result of up-regulation of p27KIP1 by GA. The present results suggest a novel mechanism that p27KIP1 could be involved in the regulation of G2 to M phase transition.

Protective effects of garlic juice against embryotoxicity of methylmercuric chloride administered to pregnant Fischer 344 rats

In order to investigate the beneficial effects of 0.5 or 1.0 g/kg Korean garlic juice against the embryotoxicity of 20 mg/kg methylmercury chloride (MMC, CH3HgCl), pregnant Fisher 344 rats were simultaneously orally administered on day 7 of gestation. On day 20 of gestation the dams were laparotomized under ether anesthesia, and the fetuses were removed and examined for toxicity of methylmercury. Garlic juice depressed the toxicity in terms of some parameters. In the case of simultaneous treatment with 0.1 g/kg garlic juice and MMC, rates of increase were 17.5% in maternal body weight, 13.2% and 41.9% in fetal and litters' weight respectively, and 37.0% in fetal survival rate. Decreasing rates were 10.0% in maternal death rate, and 6.9% and 31.3% in pre- and post-implantation loss respectively. Decreasing rates of mercury levels in dams were 67.2% in liver, 57.6% in brain, 47.2% in kidney, 42.1% in spleen and 40.9% in blood. As well, decreasing rates of mercury level in fetuses were 54.9% in all body burden, 55.9% in liver, 46.7% in kidney and 37% in brain, respectively. The number of fetal ossification centers were reduced by 23.8% to 58.0% following simultaneous treatment with 1.0 g/kg garlic juice. These findings indicated that garlic juice effectively inhibited the embryotoxicity of methylmercury in pregnant Fischer 344 rats.

Geldanamycin induces heat shock protein expression through activation of HSF1 in K562 erythroleukemic cells

HSP90 is one of the most abundant heat shock proteins (HSPs) in eukaryotic cells and is found in complex with several regulatory proteins such as kinases and transcription factors. Geldanamycin (GA), a benzoquinone ansamycin, specifically binds to HSP90 and disrupts the interaction of HSP90 and target proteins. Thus, GA has been used as a specific inhibitor of HSP90. In this study, we examined whether GA could affect protein synthesis and gene expression in the human erythroleukemic cell line K562. Treatment with GA, but not herbimycin A (another benzoquinone ansamycin), highly induced a 70-kDa protein, which was revealed to be HSP70 by immunoblotting and immunoprecipitation with anti-HSP70 antibody. The expression of HSP28 was also enhanced by GA. Furthermore, GA induced the activation of heat shock factor 1 (HSF1), but not HSF2, as determined by electromobility shift and electromobility supershift assay. In addition, similar to heat shock treatment, GA induced the phosphorylation of HSF1. Heat shock element-binding activity and phosphorylation of HSF1 were attenuated 3 h after GA treatment. These results indicate that the functional inactivation of HSP90 by GA potentially stimulates the expression of heat shock proteins through activation of HSF1.

Detection of cancer in augmented breasts by positron emission tomography

OBJECTIVE

To assess the diagnostic efficiency of positron emission tomography with 18-fluorine fluorodeoxyglucose in detecting breast cancer in augmented breasts.

DESIGN

Retrospective study.

SETTING

University hospital, Korea.

SUBJECT

9 cases or 8 patients with breasts augmented with paraffin or silicone.

INTERVENTION

FDG-PET, mammography, and ultrasonography

RESULTS

The mammogram detected the breast cancer in only 1 of 3 patients, and ultrasonography gave a false positive result in 1 patient with an augmented breast. In contrast, PET predicted all the cancers and 5/6 benign lesions. 2/3 breast cancers had axillary FDG uptake interpreted as showing metastatic involvement, and in 1 case with cancer with no axillary lymph node involvement there was no FDG uptake in the axilla, which correlated with the pathological finding.

CONCLUSIONS

Although the high cost of PET makes its use as a screening test for all patients with augmented breasts unrealistic, it would be the best diagnostic choice if other methods failed.

The loss of p27 protein has an independent prognostic significance in gastric cancer

BACKGROUND

p27 and cyclin E are regulators of the G1 to S phase transition. This study was performed to determine whether two cell cycle regulators--p27 and cyclin E--provided prognostic information in gastric cancer patients.

MATERIALS AND METHODS

A total of 115 gastric cancer patients were eligible for this study from Jan. 1988 through Dec. 1994, and their paraffin blocks were chosen for immunohistochemical staining against p27 and cyclin E.

RESULTS

Consequently, 35 patients were stained positively for p27 (30.4%) and 24 for cyclin E (20.9%). A high level of p27 expression was more frequently observed in intestinal type (43.9%) than in diffuse (23.0%) (p = 0.019). Concerning patients' survival, univariate analysis showed that the depth of invasion (p = 0.043), the number of metastatic nodes (p = 0.024) and the expression of p27 (p = 0.031) were significant prognostic factors. In particular, p27 negative group showed a worse overall survival than their counterpart (42.42 +/- 9.63% Vs 26.63 +/- 4.17%). On multivariate analysis by Cox regression model, the expression of p27 (p = 0.048) and number of metastatic nodes (p = 0.026) were significant prognostic factors on overall survival.

CONCLUSIONS

Loss of the p27 protein has independent prognostic significance in gastric carcinomas, and whether p27 negative gastric cancer requires more radical therapies can be elucidated by future clinical trials.

Roles of RhoA and phospholipase A2 in the elevation of intracellular H2O2 by transforming growth factor-beta in Swiss 3T3 fibroblasts

We have investigated the mechanisms by which transforming growth factor-beta (TGF-beta) increased intracellular H2O2 in Swiss 3T3 fibroblasts. Increase of intracellular H2O2 by TGF-beta was maximal at 30 min and blocked by catalase from Aspergillus niger. Scrape-loading of C3 transferase, which down-regulated RhoA, inhibited the production of H2O2 in response to TGF-beta. TGF-beta stimulated release of arachidonic acid, which was completely inhibited by mepacrine, a phospholipase A2 inhibitor. Mepacrine also blocked the increase of H2O2 by TGF-beta. In addition, arachidonic acid increased intracellular H2O2. Furthermore, TGF-beta stimulated stress fibre formation, which was blocked by catalase, without membrane ruffling. Catalase also inhibited stimulation of thymidine incorporation by TGF-beta. These results suggested that TGF-beta increased intracellular H2O2 through RhoA and phospholipase A2, and also suggested that intracellular H2O2 was required for the stimulation of stress fibre formation and DNA synthesis in response to TGF-beta.

Intramuscular vascular malformations of an extremity: findings on MR imaging and pathologic correlation

OBJECTIVE

To analyze the findings of intramuscular vascular malformations of an extremity on MR imaging and to correlate these findings with histopathologic examination.

DESIGN AND PATIENTS

The findings on MR imaging and the medical records of 14 patients with an intramuscular vascular malformation of the extremity were retrospectively studied. All patients underwent surgical excision. Diagnoses were based on the results of pathologic examination. Findings on MR imaging were noted and correlated with the histopathologic findings.

RESULTS

Intramuscular vascular malformations of an extremity showed multi-septate, honeycomb, or mixed appearance on MR imaging. Multi-septate areas correlated with dilated and communicating vascular spaces with flattened endothelium. Honeycomb areas corresponded to vascular spaces with inconspicuous small lumina and thickened vascular walls. Areas of increased signal intensity on T2-weighted images were found in all intramuscular vascular malformations. Infiltrative margins were more commonly seen in intramuscular lymphaticovenous malformations. Adherence to neurovascular structures and orientation of the lesion along the long axis of the affected muscle were more commonly seen in intramuscular venous malformations.

CONCLUSIONS

Intramuscular vascular malformations showed either a multi-septate, honeycomb, or mixed appearance, reflecting the size of the vascular spaces and the thickness of the smooth muscles of the vessel walls. Prediction of the subtype of an intramuscular vascular malformation of an extremity on MR imaging seems to be difficult, although there are associated findings that may be helpful in the differential diagnosis of each subtype.

Roles of IFN consensus sequence binding protein and PU.1 in regulating IL-18 gene expression

IL-18 is expressed from a variety of cell types. Two promoters located upstream of exon 1 (5'-flanking region) and upstream of exon 2 (intron 1) regulate its expression. Both promoter regions were cloned into pCAT-Basic plasmid to yield p1-2686 for the 5'-flanking promoter and p2-2.3 for the intron 1 promoter. Both promoters showed basal constitutive activity and LPS inducibility when transfected into RAW 264.7 macrophages. To learn the regulatory elements of both promoters, 5'-serial deletion and site-directed mutants were prepared. For the activity of the p1-2686 promoter, the IFN consensus sequence binding protein (ICSBP) binding site between -39 and -22 was critical. EMSA using an oligonucleotide probe encompassing the ICSBP binding site showed that LPS treatment increased the formation of DNA binding complex. In addition, when supershift assays were performed, retardation of the protein-DNA complex was seen after the addition of anti-ICSBP Ab. For the activity of the p2-2.3 promoter, the PU.1 binding site between -31 and -13 was important. EMSA using a PU.1-specific oligonucleotide demonstrated that LPS treatment increased PU.1 binding activity. The addition of PU.1-specific Ab to LPS-treated nuclear extracts resulted in the formation of a supershifted complex. Furthermore, cotransfection of ICSBP or PU.1 expression vector increased p1 promoter activity or IL-18 expression, respectively. Taken together, these results indicate that ICSBP and PU.1 are critical elements for IL-18 gene expression.

Three-tiered integration of PACS and HIS toward next generation total hospital information system

The Seoul National University Hospital (SNUH) started a project to innovate the hospital information facilities. This project includes installation of high speed hospital network, development of new HIS, OCS (order communication system), RIS and PACS. This project aims at the implementation of the first total hospital information system by seamlessly integrating these systems together. To achieve this goal, we took three-tiered systems integration approach: network level, database level, and workstation level integration. There are 3 loops of networks in SNUH: proprietary star network for host computer based HIS, Ethernet based hospital LAN for OCS and RIS, and ATM based network for PACS. They are linked together at the backbone level to allow high speed communication between these systems. We have developed special communication modules for each system that allow data interchange between different databases and computer platforms. We have also developed an integrated workstation in which both the OCS and PACS application programs run on a single computer in an integrated manner allowing the clinical users to access and display radiological images as well as textual clinical information within a single user environment. A study is in progress toward a total hospital information system in SNUH by seamlessly integrating the main hospital information resources such as HIS, OCS, and PACS. With the three-tiered systems integration approach, we could successfully integrate the systems from the network level to the user application level.

Arachidonic acid induces the activation of the stress-activated protein kinase, membrane ruffling and H2O2 production via a small GTPase Rac1

Arachidonic acid (AA) is generated via Rac-mediated phospholipase A2 (PLA2) activation in response to growth factors and cytokines and is implicated in cell growth and gene expression. In this study, we show that AA activates the stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) in a time- and dose-dependent manner. Indomethacin and nordihydroguaiaretic acid, potent inhibitors of cyclooxygenase and lipoxygenase, respectively, did not exert inhibitory effects on AA-induced SAPK/JNK activation, thereby indicating that AA itself could activate SAPK/JNK. As Rac mediates SAPK/JNK activation in response to a variety of stressful stimuli, we examined whether the activation of SAPK/JNK by AA is mediated by Rac1. We observed that AA-induced SAPK/JNK activation was significantly inhibited in Rat2-Rac1N17 dominant-negative mutant cells. Furthermore, treatment of AA induced membrane ruffling and production of hydrogen peroxide, which could be prevented by Rac1N17. These results suggest that AA acts as an upstream signal molecule of Rac, whose activation leads to SAPK/JNK activation, membrane ruffling and hydrogen peroxide production.