Diagnosis of deep vein thrombosis using multi-detector helical CT

PURPOSE: To evaluate the usefulness of multi-detector helical CT (MDHCT) with contrast medium in the diagnosis of deep vein thrombosis (DVT). Materials and Methods: The bilateral veins of the dorsal pedis in 45 patients (12 men, 33 women; average age, 64 years) under clinical suspicion of DVT were first punctured using 22-G needles. Then CT scanning from the level of the foot to the inferior vena cava was started 20 sec after the initial injection of 200 mL of dilute contrast medium (50 mL nonionic iodinated contrast medium of 300 mgI/mL and 150 mL saline) at a rate of 5 mL/sec. RESULTS: Two patients were excluded because of unsuccessful venous puncture. The average scanning time in 43 patients was 38.5 +/- 7.9 seconds. Images of veins from the foot to the inferior vena cava were clearly demonstrated in each case. MDHCT showed DVT in 32 cases and patent deep vein in 11 cases. Simultaneous venography of the lower extremity in 18 patients clearly visualized DVT at the same level detected by contrast MDHCT. CONCLUSION: MDHCT for the diangosis of DVT has the advantages of wider scanning range, shorter scanning time, and finer Z-axis resolution than the other diagnostic modalities.     

Anti-tumor Effect of Chemically Synthesized Sulfolipids Based on Sea Urchin's Natural Sulfonoquinovosylmonoacylglycerols

We recently reported that 3'-sulfonoquinovosyl-1'-monoacylglycerol (designatedA-5) extracted from sea urchin intestine was effective in suppressing the growth of solid tumors. Although the major fatty acid component of A-5 was a saturated C₁₆ acid, there were five other fatty acids, 14:0, 18:0, 14:1, 16:1, and 18:1, which constitute minor components of A-5. Therefore, it remains unclear as to which of these six fatty acid components of A-5 has the anti-tumor effect. In this study, we synthesized sulfolipids each containing only one of these six fatty acids and tested their cytotoxicity against tumor cells and in vivo anti-tumor effects on nude-mice bearing solid tumors of human lung adenocarcinoma cell line A-549. The IC₅₀ values of all products against tumor cells were more than 10^-5 M , suggesting weak cytotoxic activity compared with other chemotherapeutic compounds for cancer. On the other hand, in vivo anti-tumor assay showed that sulfoquinovosyl-monoacylglycerols (SQMG) composed of 14:1 and 18:1 (designated SQMG(14:1) and SQMG(18:1), respectively) were significantly effective in suppressing the growth of solid tumors. Our data suggested that these two SQMGs had a substantial anti-tumor effect in vivo , and they are of interest as candidate drugs for anti-cancer treatment.     

Optimal Covering Material for Stent-Grafts Placed in the Portal Vein in a Canine Model

Purpose We evaluated the suitability of Dacron, polytetrafluoroethylene (PTFE), and small intestinal submucosa (SIS) as a covering material for stent-grafts placed in the portal vein as compared with a bare stent. Methods Using 24 beagle dogs, either bare stents or stent-grafts covered with Dacron, PTFE, or SIS were placed in the main trunk of the portal vein in 6 animals each. Portography was performed immediately after stent placement, and at 2, 4, and 12 weeks thereafter. Next, the extracted stents or stent-grafts were examined histopathologically. Neointimal thickness adjacent to the stent wire and at the midportion between the stent wires was compared among the groups. Then, the neointimal thickness at the sub- and supragraft sites was compared between each stent-graft group. Serial changes in the histologic features of the thickened neointima were also investigated. Results No significant difference was noted in the mean stenotic ratio of the portal vein diameter between the bare stent and PTFE groups, whereas it was significantly higher in the Dacron and SIS groups compared with the bare stent group. In neither of the studies on neointimal thickness adjacent to the stent wire and at the midportion between the stent wires were any significant differences noted between the neointimal thickness of the bare stent group and the sum of the neointimal thickness of the PTFE group, whereas the sum of the neointimal thickness of the Dacron and SIS groups was significantly greater than that of the bare stent group at both sites. In the comparison of the supragraft neointimal thickness, the SIS group showed significantly greater thickness than the PTFE group, while the difference between the Dacron and PTFE groups was not significant. In the comparison of the subgraft neointimal thickness, the Dacron and SIS groups showed significantly greater thickness than the PTFE group. Conclusion The present results indicate that of the three covering materials examined here, PTFE is the most suitable material for grafts placed in the portal vein.     

Visualization of femorotibial contact in total knee arthroplasty using X-ray fluoroscopy

The purpose of this study was to build a visualization technique of the femorotibial contact in fixed-bearing total knee arthroplasty (TKA) using X-ray fluoroscopy, and to apply this technique to a TKA patient during dynamic motion. In vivo kinametcis of the metallic knee implant was determined using a 2D/3D registration technique, which uses computer assisted design (CAD) model of the implant to estimate the 3D pose of radiopaque metallic femoral and tibial components from a single-plane fluoroscopic image. In fixed-bearing TKA, a 3D pose of radiolucent tibial polyethylene insert can be determined from the estimated pose of the tibial component. To visualize femorotibial contact, the proximity between surfaces of femoral component and tibial insert was calculated, and mapped onto the insert surface model. For the clinical application, dynamic states of contact on the tibial insert were observed including axial rotation and unilateral loading during knee flexion, and post-cam contact of posterior stabilized TKA. The present technique provided us new information and enabled us to better understand the relationship between in vivo knee kinematics and articular shape of the implant.     

Thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in hepatocellular carcinoma and metastatic liver cancer

Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are considered to be key enzymes affecting the prognosis for patients with various cancers. We tried to prove the correlation of TP and DPD expression in hepatocellular carcinoma (HCC) and liver metastasis. We quantified TP and DPD levels by an enzyme-linked immunosorbent assay (ELISA) in the tumor (T) and adjacent normal tissue (N) obtained from 8 HCC patients, and 11 liver metastasis patients together with 9 of their primary cancers. TP levels were higher in the primary cancer, liver metastasis, and HCC compared with each adjacent tissue. TP levels were higher in HCC than in liver metastasis, and TP levels in the adjacent tissues of HCC were also higher than those in adjacent tissues of liver metastasis. TP levels were higher in liver metastasis than in primary cancer, and TP levels in adjacent tissues of liver metastasis were also higher than those in adjacent tissues of primary cancer. However, there were no differences in TP T/N ratio between HCC and liver metastasis, and between primary cancer and liver metastasis. DPD levels were lower in the liver metastasis compared with the adjacent liver tissues, and DPD levels in liver metastasis or its adjacent liver tissues were higher than those in primary cancer or its adjacent tissues. There were no differences in DPD T/N ratio between HCC and liver metastasis, and between primary cancer and liver metastasis. Thus, we demonstrated that TP was highly expressed in liver malignancy. We may be able to increase the success of anticancer chemotherapy for liver malignancy while decreasing the side effects by analysis of T/N ratios in TP, DPD, and TP/DPD in addition to TP expression.     

Phenylarsine oxide (PAO) more intensely induces apoptosis in acute promyelocytic leukemia and As2O3-resistant APL cell lines than As2O3 by activating the mitochondrial pathway

We studied the cytotoxic effect of an organic arsenical compound, phenylarsine oxide (PAO) on an acute promyelocytic leukemia (APL) cell line (NB4) and an As₂O₃-resistant NB4 subline (NB4/As). Cell growth was inhibited by 50% (IC₅₀) upon 2-day treatment with As₂O₃ or PAO at 0.54 and 0.06 μM, respectively in NB4 cells (P = 0.025), and 2.80 and 0.08 μM, respectively in NB4/As (P = 0.030). 0.1 μM PAO increased the proportion of hypodiploid cells (50.3%) by a greater degree than the same dose of As₂O₃ (3.8%) in NB4 cells. In NB4 cells, 0.1 μM PAO reduced the mitochondrial transmembrane potential (20.5% in a PI^negative-Rhodamine123^low fraction) by a greater degree than 1 μM As₂O₃ (7.1%). Western blotting showed that 0.1 μM PAO downregulated the expression of both Bcl-2 and Bcl-X_L proteins, whereas I μM As₂O₃ downregulated only Bcl-2 expression. These results suggest that the cytotoxic effect of PAO on an APL cell line and As₂O₃-resistant subline is significantly higher than that of As₂O₃. PAO-induced apoptosis seems to be related to the activation of the mitochondrial pathway and downregulation of both Bcl-2 and Bcl-X_L. PAO is a considerable agent for relapsed/refractory APL and for purging APL cells following stem cell transplantation.     

Prognostic significance of surface markers expressed in multiple myeloma: CD56 and other antigens

Multiple myeloma (MM) is characterized by increased numbers of malignant plasma cells. Plasma cells, that represent the terminal differentiation of B lymphocytes, have considerable heterogeneity of surface markers expressed on them. Some studies showed the prognostic significance of several immunophenotypic molecules on MM cells. Here, we review several surface markers related to their prognostic significance in MM patients. We also report that CD56-negative MM is the unique entity characterized by poor prognosis with high incidence of extramedullary disease, Bence Jones protein, renal insufficiency, thrombocytopenia and plasmablastic morphology.     

Improved generation of HLA class I/peptide tetramers

As a tetrameric major histocompatibility complex (MHC) class I-peptide complex (tetramer) is capable of detecting antigen-specific cytotoxic T lymphocyte (CTL) by flow cytometry, significant information about the generation of in vivo immunity can be obtained. It is, however, difficult to make a soluble wild type of MHC class I heavy chain by the prokaryotic expression system. Therefore, we developed a new method for making soluble mutant HLA-A*2402 heavy chain. In this method, signal sequences were deleted, and the codon was changed to silent mutated nucleotide sequences that bacteria could use as preferable codon. When purified mutant HLA-A*2402 molecules were examined for the protein generation by SDS-polyacrylamide gel electrophoresis (PAGE) and western blotting using anti-HLA class I monoclonal antibody (mAb) as compared with wild type, a large amount of mutant heavy chain could be detected. In contrast, the expression of wild-type stable HLA-A*2402 heavy chain molecule was not detected in this system. Consequently, by using mutant HLA-A*2402/peptide tetramers, CTL precursors (CTLp) that specifically recognize antigenic peptide derived from the X;18 chromosomal translocations of synovial sarcoma were detected in patients' PBL.     

Use of an N-terminal half truncated IE1 as an antagonist of IE1, an essential regulatory protein in baculovirus

An immediate-early gene product of baculovirus, IE1, is essential for viral gene expression and for viral DNA replication. It has been demonstrated for Autographa californica nuclear polyhedrosis virus (AcNPV) that the C-terminal region of IE1 is required for dimerization. And the acidic N-terminal region of IE1 has been identified as the activation domain. We constructed an N-terminal 267 amino acid (a.a.) truncated mutant of Bombyx mori nuclear polyhedrosis virus (BmNPV) IE1, which was defective as a transactivator of a viral early gene (p35) promoter. We then examined possible IE1 antagonistic functions of this defective IE1, IE1TN, in BmNPV-infected cells. A transient expression experiment demonstrated that IE1TN strongly repressed the activation of the hr5-dependent p35 promoter derived from BmNPV infection. In addition, DpnI assay elucidated an inhibitory effect of IE1TN on the hr5-dependent replication of plasmid in BmN cells induced by NPV infection. A marked reduction in the production of virus was observed when the BmN cells were infected with BmNPV after transfection with IE1TN-expression plasmids. These results suggested that IE1TN could act as an IE1 antagonist in silkworm cells infected with BmNPV. We then analyzed the ability of IE1TN to inhibit the multiplication of BmNPV using transgenic silkworms. The BmNPV-resistance of the transgenic silkworms was very weak, suggesting insufficient expression of the transgene product, IE1TN.     

Involvement of vacuolar H+ -ATPase in incorporation of risedronate into osteoclasts

Although osteoclasts incorporate bisphosphonates during bone resorption, the mechanism of this incorporation by osteoclasts is not known. We previously reported that bisphosphonates disrupt the actin rings (clear zones) formed in normal osteoclasts, but did not disrupt actin rings in osteoclasts derived from osteosclerotic oc/oc mice, which have a defect in the gene encoding vacuolar H(+)-ATPase (V-ATPase). The present study showed that V-ATPase is directly involved in the incorporation of risedronate, a nitrogen containing bisphosphonate, into osteoclasts. Treatment of osteoclasts with risedronate disrupted actin rings and inhibited pit formation by osteoclasts on dentine slices. Bafilomycin A(1), a V-ATPase inhibitor, inhibited the pit-forming activity of osteoclasts but did not disrupt actin rings. Risedronate failed to disrupt actin rings in the presence of bafilomycin A(1). E-64, a lysosomal cysteine proteinase inhibitor, showed no inhibitory effect on the demineralization of dentine by osteoclasts but inhibited the digestion of dentine matrix proteins without disrupting actin rings. Risedronate disrupted actin rings even in the presence of E-64. Treatment of osteoclasts placed on plastic plates with risedronate also disrupted actin rings. Bafilomycin A(1) but not E64 prevented the disruption of actin rings in osteoclasts treated with risedronate on plastic plates. Inhibition of V-ATPase with bafilomycin A(1) also prevented disruption of actin rings by etidronate, a non-nitrogen-containing bisphosphonate. These results suggest that V-ATPase induced acidification beneath the ruffled borders of osteoclasts and subsequent bone demineralization triggers the incorporation of both nitrogen-containing and non-nitrogen-containing bisphosphonates into osteoclasts.