A case of Crohn's disease with recurrent massive life-threatening hemorrhage from terminal ileum

A case of Crohn's disease that underwent bowel resection two times at 3-year intervals due to life-threatening hemorrhage from ileum is presented. The bleeding sites were located in the ulcer lesions of ileum, in the oral side near to the ileum-colon transition. The first bleeding point was at the longitudinal ulcer of the terminal ileum and the secondary bleeding site was at the profound ulcer of ileum appearing in the oral side near to the ileo-colic anastomosis. This is the first case of Crohn's disease with recurrent life-threatening massive hemorrhage in the terminal region of ileum, for which operative bowel resections were necessary. This case suggests that we should search for the bleeding site in ileal lesions developed in the circumference of and especially the oral side near to the anastomosis due to prior resection, when intestinal massive bleeding occurs again after bowel resection, and that the careful follow-up and strict treatment with diet therapy and/or anti-inflammatory drugs are necessary for the protection of recurrence in patients with Crohn's disease.

Handling characteristics of braided suture materials for tight tying

To establish criteria for characterizing synthetic sutures, the handling characteristics of silk suture were analyzed. The characteristics that distinguish silk suture from other braided suture materials are its good "knot security" and relatively low "tiedown resistance." Analytic consideration of knot security suggests that not only superficial friction but also resistance force produced by cross-sectional deformity of braided threads plays an important role in silk's superior performance. Results of a "pullout friction test," developed to quantitatively evaluate resistance produced by surface friction and cross-sectional deformity suggest that the superiority of silk thread can be explained in terms of high static withdrawal resistance under low loads and relatively low dynamic withdrawal resistance under high loads.

Biomaterials lubricated for minimum frictional resistance

To improve the frictional characteristics of a biomaterial, the mechanical performance of a lubricated surface was studied. In vitro friction tests showed that the coefficient of dynamic friction of the lubricated surface was about 0.01 against rabbit bladder and the coefficient of static friction increased with the preload period. The efficacy of a lubricated cystoscope was evaluated by an in vivo test simulating cystoscope operation. The maximal and the total resistance force on the cystoscope model were found to decrease with the surface lubrication. Histological study revealed that urethral damage caused by rubbing with the cystoscope model was reduced by this lubrication technique. Presumably, prolonged retention of water on the lubricated surface region prevented tissue adhesion to the foreign material.

Enhancement of the anti-tumor effect of 5'-deoxy-5-fluorouridine by transfection of thymidine phosphorylase gene into human colon cancer cells

Thymidine phosphorylase (dThdPase) is an enzyme that converts 5'-deoxy-5-fluorouridine (5'DFUR) to the toxic substance 5-fluorouracil (5-FU); it is also known to be a platelet-derived endothelial cell growth factor. In order to investigate the feasibility of suicide gene therapy against colorectal cancer by means of the combination of 5'DFUR and the converting enzyme dThdPase, we transfected the dThdPase gene into the human colon cancer cell line SW480 and analyzed the growth pattern as well as the sensitivity to 5-FU or 5'DFUR of the dThdPase-transfected cells. The 50% inhibition (IC50) values of 5-FU against the SW480 parental cells, control vector-transfected cells SW480/V1, and dThdPase-transfected cells SW480/dThdPase were approximately 4.9, 6.3, and 2.9 microM, respectively. The IC50 of SW480/dThdPase was lower than that of SW480 or SW480/V1, although the differences were not statistically significant. The IC50 values of 5'DFUR for SW480, SW480/V1, and SW480/dThdPase were approximately 300, 330, and 3.2 microM, respectively. The sensitivity to 5'DFUR of SW480/dThdPase was increased by about 100-fold compared with that of SW480 or SW480/V1. With only 10% transfection efficacy, a high enough sensitivity to 5'DFUR was obtained to suppress the cell growth, indicating that a strong bystander effect was induced by this system. The in vivo growth of the s.c. transplanted SW480/dThdPase tumor in nude mice was significantly suppressed by i.p. injection of 5'DFUR compared with that in control mice that received phosphate-buffered saline (PBS) treatment. These results suggest that gene therapy using the combination of 5'DFUR and the dThdPase gene may be a useful approach for treatment of colon cancer.

Primary esophageal T cell lymphoma

A 60 year-old woman with primary esophageal T-cell lymphoma in clinical stage I(E)B is presented. Immunohistologic examination showed tumor cells to be positive for anti-LCA, anti-UCHL-1, anti-MT-1, anti-CD3 antibodies, and negative for anti-L26 antibody. Disappearance of dysphagia and improvement in esophageal findings were noted after 65 Gy of irradiation, and biopsy specimens from the esophagus revealed no malignancy. Primary esophageal lymphoma is extremely rare, and this T-cell lymphoma is only the fourth case reported in the literature.

Molecular characteristics of poorly differentiated adenocarcinoma and signet-ring-cell carcinoma of colorectum

In a series of 45 poorly differentiated adenocarcinomas (por) and 7 signet-ring-cell carcinomas (sig) of the colorectum, K-ras gene mutation, p53 immunostaining and microsatellite instability (MSI) were analyzed for a comparison with 46 cases of colorectal carcinomas of the well or moderately differentiated type (well/mod). In addition, the mutations of simple repeated sequences in the transforming-growth-factor-beta type-II receptor (T beta R-II) gene and the BAX gene were analyzed as possible targets for DNA replication errors. Mutation of the K-ras gene in the por, sig and well/mod specimens was detected in, respectively, 22%, 11% and 48%, positive immunostaining for p53 in 41.8%, 28.6% and 60.3%, and MSI in 36%, 30% and 4%. Frameshift mutation of the T beta R-II gene was detected in 27.5% of the por and none of the sig specimens, while corresponding figures for mutation of the BAX gene were 15.7% and 0%. Significant differences between the por and well/mod tumors were found in the occurrence of K-ras mutation at codons 12 and 13, and MSI. Clinicopathologically, the tumor status of por with MSI was found to significantly correlate with the tumor's location in the proximal colon. In cases without MSI and sig, no frameshift mutation of either the T beta R-II or the BAX gene was found. These results suggest that poorly differentiated and signet-ring-cell carcinomas have a genetic background different from that of well or moderately differentiated carcinomas of the colorectum, and that DNA-replication error is at least partly involved in the carcinogenesis of these specific types of colorectal carcinomas.

Molecular characteristics of poorly differentiated adenocarcinoma and signet-ring-cell carcinoma of colorectum

In a series of 45 poorly differentiated adenocarcinomas (por) and 7 signet-ring-cell carcinomas (sig) of the colorectum, K-ras gene mutation, p53 immunostaining and microsatellite instability (MSI) were analyzed for a comparison with 46 cases of colorectal carcinomas of the well or moderately differentiated type (well/mod). In addition, the mutations of simple repeated sequences in the transforming-growth-factor-beta type-II receptor (T beta R-II) gene and the BAX gene were analyzed as possible targets for DNA replication errors. Mutation of the K-ras gene in the por, sig and well/mod specimens was detected in, respectively, 22%, 11% and 48%, positive immunostaining for p53 in 41.8%, 28.6% and 60.3%, and MSI in 36%, 30% and 4%. Frameshift mutation of the T beta R-II gene was detected in 27.5% of the por and none of the sig specimens, while corresponding figures for mutation of the BAX gene were 15.7% and 0%. Significant differences between the por and well/mod tumors were found in the occurrence of K-ras mutation at codons 12 and 13, and MSI. Clinicopathologically, the tumor status of por with MSI was found to significantly correlate with the tumor's location in the proximal colon. In cases without MSI and sig, no frameshift mutation of either the T beta R-II or the BAX gene was found. These results suggest that poorly differentiated and signet-ring-cell carcinomas have a genetic background different from that of well or moderately differentiated carcinomas of the colorectum, and that DNA-replication error is at least partly involved in the carcinogenesis of these specific types of colorectal carcinomas.

Comparative effects of overexpression of p27Kip1 and p21Cip1/Waf1 on growth and differentiation in human colon carcinoma cells

Recent studies have shown that decreased expression of p27Kip1 is associated with high grade tumors and an unfavorable prognosis in several types of human cancer. To clarify the role of p27Kip1 in colon cancer, we have overexpressed this protein in the HT29 colon cancer cell line. The derivatives displayed an increase in the p27Kip1 protein in cyclin E/CDK2 immunoprecipitates and a decrease in cyclin E-associated kinase activity when compared to vector control clones, providing evidence that the overexpressed protein was functional. Clones with a high level of p27Kip1 displayed partial growth inhibition in monolayer culture and a decrease in plating efficiency, even though they expressed increased levels of the cyclin D1 protein. Using alkaline phosphatase expression as a marker, we found that the p27Kip1 overexpressor clones displayed a 2-3-fold increase in sensitivity to induction of differentiation by 2 mM sodium butyrate. In contrast to these results, derivatives of HT29 cells that stably overexpressed p21Cip1/Waf1 displayed decreased sensitivity to the induction of differentiation. These findings may explain why decreased levels of p27Kip1 in certain human cancers is associated with high grade (poorly differentiated) tumors, and suggest that strategies that increase the level of p27Kip1 may be useful in cancer therapy.

Intratumoral injection of oligonucleotides to the NF kappa B binding site inhibits cachexia in a mouse tumor model

Cancer cachexia, characterized by anorexia, weight loss and progressive tissue wasting, has been postulated to be mediated by various cytokines. However, the precise mechanism of cachexia induction is not fully explained. We have developed synthetic double-stranded oligodeoxynucleotides (ODN) as 'decoy' cis-elements that block the binding of nuclear factors to promoter regions of targeted genes, resulting in the inhibition of gene transactivation in vivo as well as in vitro. This novel molecular strategy could be useful for treating a broad range of human diseases including cancer. In this study, we injected decoy ODN targeting the transcriptional factor, NF-kappa B (NF kappa B) binding cis-elements, which are essential for transactivation of gene expression of cytokines, directly into tumors of adenocarcinoma colon26 in mice, in order to examine whether or not cachexia is alleviated by inhibiting the action of cytokines. Tumor growth was not affected by transfection of NF kappa B decoy ODN as compared with scrambled decoy ODN. Nevertheless, transfection of NF kappa B decoy, but not scrambled decoy, ODN resulted in attenuation of the reductions in body weight, epididymal fat, gastrocnemius muscle mass and food intake, which were induced by the tumor presence. Interleukin 6 mRNA in the tumor was also markedly decreased by the transfection of NF kappa B decoy ODN. It is known that the transcriptional factor E2F plays a pivotal role in the coordinated transactivation of cell cycle regulatory genes. Therefore, we hypothesized that the introduction of synthetic double-stranded DNA with high affinity for E2F in vivo as 'decoy' cis-elements might inhibit the tumor growth of colon26, resulting in turn in inhibition of cachexia induction. However, injection of E2F decoy ODN failed to inhibit tumor growth and cachexia induction, as compared with mismatched decoy ODN. Overall, the present study demonstrated that cachexia induced by adenocarcinoma colon26 was inhibited by blocking of NF kappa B, using a novel molecular decoy strategy, without an effect on tumor growth, and also that tumor growth and cachexia induction in the colon26 model were not affected by E2F decoy ODN. These results suggest that cytokines regulated by NF kappa B may play a pivotal role in the induction of cachexia by colon26, providing a new therapeutic strategy for cancer cachexia.

Marrow cell culture on poly-L-lactic acid fabrics

Bone marrow cells from rat femurs were cultured in Eagle Minimum Essential Medium containing 15% fetal calf serum until confluence. After the cells were trypsinized, they were subcultured on fabrics made of biodegradable poly-L-lactic acid for 2 weeks in the medium containing fetal calf serum, ascorbic acid phosphate, beta-glycerophosphate, and with and without dexamethasone. In the presence of dexamethasone, the fabrics showed many mineralized nodules together with cuboidal shaped cells that had osteoblastic activity, as evidenced by high alkaline phosphatase activity and the appearance of osteocalcin messenger ribonucleic acid. However, in the absence of dexamethasone, nodules did not form and many fibroblastic cells appeared with no evidence of osteoblastic activity. These results indicate the possibility of making a hybrid ligament substitute having an in vitro prefabricated bone anchor.

Immunohistochemical characteristics of estrogen receptor alpha positive cells in glandular epithelium of the rat seminal vesicle

Epithelial cells of the rat seminal vesicle stained positively for nuclear estrogen receptor alpha (ER alpha). We studied these cells using immunohistochemical means. We demonstrated in a previous study that some glandular epithelial cells of the seminal vesicles of immature castrated rats treated with estrogen for 1-2 weeks had multilayer features. The present study shows that these glandular epithelial cells are nuclear ER and basal cell-specific cytokeratin (34betaE12) positive. These findings suggested characteristics of basal cells. Moreover, we demonstrated that these cells express transforming growth factor beta1 (TGFbeta1) as a result of castration and estrogen treatment. Our findings indicate that glandular epithelial cells with multilayer features, which stained positively for nuclear ER alpha have basal cell features and may play an important role in the expression of TGFbeta1 through an epithelial-stromal interaction.

New retraction technique to allow better visualization of Calot's triangle during laparoscopic cholecystectomy

BACKGROUND

Bile duct injuries during laparoscopic cholecystectomy (LC) are thought to occur because surgeons tend to confuse the common bile duct (CBD) with the cystic duct. Among reasons for this misidentification, the difference in the way the operating field is exposed in LC compared to open cholecystectomy should be noticed. Using Dr. Reddick's technique, which is commonly practiced, the upward and the lateral traction of the gallbladder results in a narrower Calot's triangle and angulation of the CBD. These anatomical distortions are thought to contribute to ductal injuries during LC.

METHODS

We propose a new method to expose Calot's triangle during LC. The principle of this technique is to expose the hepatic hilus by retracting the caudal surfaces of the quadrate and lateral lobes of the liver using an atraumatic curved instrument.

RESULTS

The advantages of this technique are that one gains wide exposure of the hepatic hilus, leaves Calot's triangle undistorted, and avoids tenting the CBD.

CONCLUSIONS

This new technique may make LC safer and decrease the number of bile duct injuries associated with the misidentification of the anatomy.

Growth inhibition, enhancement of intercellular adhesion, and increased expression of carcinoembryonic antigen by overexpression of phosphoinositides-specific phospholipase C beta 1 in LS174T human colon adenocarcinoma cell line

By using a retrovirus-derived system we generated derivatives of the human colon adenocarcinoma cell line LS174T (ATCC CL 188) that stably overexpress a full-length cDNA encoding the beta 1 isoform of bovine phosphoinositides-specific phospholipase C (PI-PLC). This was confirmed by the elevated levels of catalytic activity to release phosphoinositides from phosphatidylinositol (PI-PLC) or phosphatidylinositol-bis-phosphate (PIP2-PLC), and the enhanced expressions of messenger RNA and protein. PI-PLC beta 1 overexpresser clones grew to form cell clumps floating in liquid medium, whereas the pMV7-introduced control clones displayed morphologic characteristics that were very similar to those of the parent LS174T cell line. Three individual PI-PLC beta 1 overexpresser cell lines displayed increased doubling time (18.0 h, 21.5 h, and 23.8 h) when compared with 4 individual pMV7-introduced control cell lines (13.1 h, 10.7 h, 12.9 h, and 9.3 h). Anchorage-independent growth ability in soft agar medium was dramatically suppressed by overexpression of PLC beta 1, and the ability of PLC-overproducer clones to form aggregates when cultured in liquid medium was dramatically enhanced when compared with that of pMV7-introduced control clones. Tumorigenicity of PLC beta 1-overproducers was much weaker than that of vector-transduced control clones. The spontaneous release of carcinoembryonic antigen from PLC beta 1-overproducer clones was much higher than that from pMV7 control clones. The ability of PLC beta 1-overproducer clones to form aggregates during suspension culture was much stronger than that of the control clones. These results provide the first evidence that elevated levels of endogenous PI-PLC beta 1 suppress tumor cell growth, but enhance the ability to form cell aggregates and to release carcinoembryonic antigen, an intercellular adhesion molecule.

Detection of cracks in polyethylene components of retrieved knee joint prostheses

Subsurface cracks that had formed in polyethylene artificial knee components were observed nondestructively with a new method, scanning acoustic tomography (SAT). Standardization of the SAT observation was done by in-vitro rolling fatigue testing on an unimplanted ultra high molecular weight polyethylene (UHMWPE) knee component. Retrieved knee components were of two types; KOM (Kyocera, Kyoto, Japan) sterilized with ethylene oxide gas, and MG (Zimmer, IN, USA) sterilized with gamma-irradiation. The SAT images revealed cracks in all the retrieved components, and these existed mainly 0. 3-1.0 mm from the surface. Comparison of crack formation in each portion of the contact area of the polyethylene components showed that the middle portion of the MG type had the highest concentration of cracks. When the distribution of compressive stress on the polyethylene components was assessed by mechanical testing, the strongest compressive stress was seen in the middle portion of MG type components.

Novel therapeutic strategy for atherosclerosis: ribozyme oligonucleotides against apolipoprotein(a) selectively inhibit apolipoprotein(a) but not plasminogen gene expression

BACKGROUND

Because mechanisms of atherosclerosis by lipoprotein(a) [Lp(a)] have been postulated in the decrease in active transforming growth factor-beta conversion by decreased plasmin, selective decrease in apolipoprotein(a) [apo(a)] independent of plasminogen may have therapeutic values. Although antisense can decrease apo(a), its application may be difficult because of very high homology of apo(a) gene to plasminogen. Thus we used ribozyme strategy that actively cleaves targeted genes to selectively inhibit apo(a) expression.

METHODS AND RESULTS

We constructed ribozyme oligonucleotides containing phosphorothioate DNA- and RNA-targeted kringle 4 of the apo(a) gene that showed 80% homology to plasminogen. Transfection of human apo(a) gene produced Lp(a) in medium of HepG2 cells, whereas Lp(a) could not be detected in control cells. Cotransfection of ribozyme and apo(a) gene resulted in the decrease in mRNA of apo(a) but not plasminogen. Moreover, marked decrease in Lp(a) was also observed in the medium transfected with ribozyme and apo(a) gene compared with apo(a) gene alone (P<0.01), whereas there was no significant change in plasminogen level between ribozyme-transfected and control cells. Incubation of human vascular smooth muscle cells (VSMC) with conditioned medium from apo(a)-transfected HepG2 cells resulted in a significant increase in VSMC number, whereas addition of conditioned medium from cells cotransfected with ribozyme oligonucleotides and apo(a) gene resulted in no VSMC growth (P<0.01). DNA-based control oligonucleotides and mismatched ribozyme oligonucleotides did not have an inhibitory effect on Lp(a) production.

CONCLUSIONS

Overall, our data revealed that transfection of ribozyme against the apo(a) gene resulted in the selective inhibition of the apo(a) but not the plasminogen gene, providing novel therapeutic strategy for treatment of high Lp(a), a risk factor for atherosclerosis.

[Laparoscopic splenectomy for a massive splenomegaly using a transcatheter technique]

Laparoscopic splenectomy can be performed more safely today, and therefore it is becoming the first-choice technique for splenectomy when the spleen is of normal size. However, for massive splenomegaly there have been few reports of the use of this technique and its safety has not been confirmed. We performed laparoscopic splenectomy for massive splenomegaly with transarterial embolization of the splenic artery before surgery. A 37-year-old man underwent splenectomy due to the lack of effect of an approximately 4-month course of chemotherapy for chronic myeloid leukemia whose spleen was over 20 cm in length. Before surgery, splenic artery embolization was performed to prevent intraoperative bleeding and to debulk the spleen. Under general anesthesia the patient was positioned in the lateral decubitus position lying on the right side. There was no bleeding from the capsule of the spleen throughout the procedure and no intraoperative complications occurred. Blood loss was 100 ml, and the weight of the resected spleen was 1,100 g. The postoperative course was uneventful. We conclude that laparoscopic splenectomy is safe and feasible in cases of splenomegaly, when combined with preoperative embolization of the splenic artery.

Potential role of hepatocyte growth factor in the maintenance of renal structure: anti-apoptotic action of HGF on epithelial cells

BACKGROUND

Mesangial cells (MC) are known to secrete various vasoactive substances that may control endothelial and epithelial cell growth. Therefore, the cell-cell interactions among these cells may be important in the control of renal function. However, the exact mechanisms of maintaining the cell-cell interactions are not yet understood. We have focused on the role of hepatocyte growth factor (HGF) in the regulation of cell-cell interactions, since HGF has many protective functions in the kidney. To investigate the role of HGF in renal injury, we examined (1) the effects of HGF on epithelial injury induced by serum deprivation, and (2) the role of local HGF production in the maintenance of renal structure.

METHODS

Apoptotic changes in epithelial cells were assessed by nuclear morphology and DNA fragmentation assay. Transfection of human HGF vector into epithelial cells was performed by a highly efficient viral-liposome method. The effects of secreted HGF on the growth of renal cells were examined using a co-culture system.

RESULTS

The addition of recombinant HGF (rHGF) stimulated the growth of rat and porcine epithelial cells. Moreover, the decrease in number of epithelial cells by serum deprivation was significantly attenuated by rHGF. Interestingly, apoptotic changes in epithelial cells induced by serum deprivation were also significantly attenuated by rHGF (P < 0.01). As a model of gene therapy, the effects of overexpression of human HGF gene in epithelial cells on apoptosis induced by serum deprivation were examined. Transfection of human HGF vector into epithelial cells also attenuated epithelial cell death induced by serum deprivation through the inhibition of apoptosis, accompanied by increased HGF production (P < 0.01). In addition, HGF also prevented endothelial injury induced by tumor necrosis factor-alpha and dexamethasone. Given the presence of a local HGF system, we measured local HGF secreted from renal cells. Immunoreactive HGF was observed in the conditioned medium of MC, but not epithelial cells, while the specific receptor of HGF, c-met, was expressed in epithelial cells. Of importance, co-culture of MC with epithelial cells resulted in a significant increase in number of epithelial cells, which was significantly abolished by neutralizing anti-HGF antibody.

CONCLUSIONS

Overall, these results demonstrate that local production of HGF in MC may maintain the growth of epithelial and endothelial cells through its anti-apoptotic action.

Contribution of a vascular modulator, hepatocyte growth factor (HGF), to the pathogenesis of cardiovascular disease

HGF is a mesenchyme-derived pleiotropic factor which regulates cell growth, cell motility, and morphogenesis of various types of cells, and is thus considered a humoral mediator of epithelial-mesenchymal interactions responsible for morphogenic tissue interactions during embryonic development and organogenesis. Although HGF is originally identified as a most potent mitogen for hepatocytes, HGF is also belonged to a member of endothelium-specific growth factors. Since endothelial cells are known to secrete various anti-proliferative and vasodilating factors, an agent that promotes seeding or regeneration of endothelium may have potential therapeutic value against vascular smooth muscle cell proliferation. The mitogenic action of HGF on human endothelial cells was most potent among growth factors. Moreover, the presence of local HGF system (HGF and its specific receptor, c-met) was observed in vascular cells and cardiac myocytes in vitro as well as in vivo. Production of local HGF production in vascular cells was regulated by various cytokines including transforming growth factor (TGF)-beta and Ang II. Furthermore, HGF may be therapeutic growth factors for the treatment of restenosis after angioplasty and arteriosclerosis oblerance, etc., as gene therapy. On the other hand, serum HGF concentration was significantly correlated with blood pressure. These results suggest that HGF secretion might be elevated in response to high blood pressure as a counter-system against endothelial dysfunction, and may be considered as an index of severity of hypertension. In this review, we discussed the potential role of HGF in cardiovascular disease.

Effects of static magnetic field on bone formation of rat femurs

Effects of static magnetic fields (SMF) on bone formation of rat femurs, were evaluated using tapered rods made of magnetized and unmagnetized samarium cobalt of the same size. They were implanted transcortically into the middle diaphysis of rat femurs under press-fit loading. The bone mineral density (BMD) and bone calcium content were measured 12 weeks after implantation by dual-energy X-ray absorptiometry and chemical analysis with o-cresolphthalein complexon, respectively. The result revealed that the femurs adjacent to magnetized specimens had significantly higher BMD and calcium content than those adjacent to the unmagnetized specimen (p < 0.01). However, the value of BMD and calcium content of rats with magnetized specimens was similar to that of non-operated rats. No specific change was found in the body weight, serum Ca, activity of alkaline phosphatase, hemogram, and BMD of the tibia and humerus among the magnetized and unmagnetized. These results suggest that the long-term local SMF stimulation on the bone has a local effect to prevent the decrease in BMD caused by surgical invasion or implantation.

Stimulatory effect of lipoprotein (a) on proliferation of human mesangial cells: role of lipoprotein (a) in renal disease

As lipoprotein (a) [Lp(a)] abnormalities would accelerate glomerular injury, we studied the effect of Lp (a) on proliferation of cultured human mesangial cells (MC). Transfection of human apo (a) gene into human hepatoma cells, HepG2 cells, producing human apo B, resulted in the formation of Lp (a), while no Lp (a) was detected in control cells. In contrast, free apo (a) was detected in the medium of apo (a)-transfected MC. Incubation of cultured medium of HepG2 cells transfected with apo (a) gene with MC resulted in a significant increase in cell number compared to control (P<0.01). In contrast, little effect of transfection of apo (a) gene directly into MC on growth of MC was observed. Of importance, addition of LDL into the medium of MC transfected with apo (a) vector resulted in a significant increase in number of MC compared to control, whereas LDL did not show any effects on MC growth. As active TGF-beta was not detected in the medium of MC, and addition of neutralizing anti-TGF-beta antibody did not alter growth of MC, Lp (a) stimulated growth of MC via the independent mechanisms from the inhibition of TGF-beta activation.

A new method for accurate measurement of displacement of the knee menisci

It is difficult to measure the displacement of the menisci under external forces by the radiographic method using markers because the movement may be smaller than the detecting limit. A device with a flexible needle attached to a journal of a miniature linear bearing is developed to investigate the meniscal functions which depend on the mobility. The needle tip is fixed to the target point in the meniscus and the axial displacement is measured with a laser sensor. According to the test, the lower limit for detection was 10 microns, the error due to non-linearity was less than 5 per cent and the reactive force was less than 0.15 N in the operating range of +/- 3 mm. Displacement vectors were determined at four points in a pair of menisci in a porcine knee subjected to external forces. This accurate method will lead to further investigation into the mechanical function of the menisci.

An oligonucleotide decoy for transcription factor E2F inhibits mesangial cell proliferation in vitro

The transcription factor E2F controls expression of several genes involved in cell proliferation including c-myc, c-myb, proliferating cell nuclear antigen (PCNA), and cdk2 kinase. Having established that both PCNA and cdk2 kinase are induced in rat mesangial cells (MC) by serum stimulation, we attempted to inhibit MC proliferation in vitro by transfecting these cells with cationic liposomes containing a synthetic double-stranded oligodeoxynucleotide (ODN) with high affinity for E2F. Using a gel mobility shift assay, we detected increased specific binding of E2F in MC following serum stimulation. This binding was completely inhibited by preincubation of MC nuclear extracts with the double-stranded ODN with high affinity for E2F but not by preincubation with a missense ODN containing two point mutations. MC were also transfected with a luciferase reporter gene construct containing three E2F binding sites. Luciferase activity was enhanced by serum stimulation of MC, and this effect was specifically abolished by cotransfection of MC with E2F decoy ODN. Furthermore, RT-PCR analysis revealed that serum-induced upregulation of PCNA and cdk2 kinase gene expression was inhibited by E2F decoy ODN transfection but not by transfection of missense ODN. These changes in gene expression were paralleled by a reduction in PCNA and cdk2 kinase protein expression in E2F decoy ODN transfected cells. MC number increased following serum stimulation. This effect was blunted by transfection with E2F decoy ODN but not by transfection of missense ODN. These data suggest that the transcription factor E2F plays a crucial role in the regulation of MC proliferation and that this factor can be successfully targeted to inhibit MC cell cycle progression.

Cdk2/cdc2 expression in colon carcinogenesis and effects of cdk2/cdc2 inhibitor in colon cancer cells

Cyclin dependent kinases propel the cell cycle in collaboration with cyclins. We have examined the expression of cdk2/cdc2 in adenoma and focal carcinoma in adenomatous tissue to explore their role in tumorigenesis of colorectum. Immunohistochemical study revealed that cdk2/cdc2 was overexpressed in a subsets of adenoma (14/50; 28.0%) but this overexpression was much more obvious in focal carcinoma (13/15; 86.7%). These results suggest that cdk2/cdc2 is remarkably upregulated together with a malignant change. In an effort to demonstrate a significant role for cdk2/cdc2 in colon cancer, we investigated growth and apoptosis with butyrolactone I, a specific inhibitor for cdk2/cdc2, using 4 colon carcinoma cell lines (HCT116, LoVo, HT29, Colo 320DM). Butyrolactone I inhibited proliferation of all colon carcinoma cell lines at 100 microM and it induced apoptosis in LoVo cell line with induction of p53. Our findings suggest that inhibition of cdk2/cdc2 may be a useful strategy against colon cancer.

Conditioned medium from HepG2 cells transfected with human apolipoprotein(a) gene stimulates growth of human vascular smooth muscle cells: effects of overexpression of human apolipoprotein(a) gene

Lipoprotein(a) [Lp(a)] is well known to stimulate growth of vascular smooth muscle cells (VSMCs), resulting in atherosclerosis. Its mechanism is postulated to be decreased in active transforming growth factor (TGF)-beta. However, the exact mechanisms and cellular processing from apolipoprotein(a) [apo(a)] to Lp(a) have not yet been clarified because no cultured cells producing apo(a) are available. Therefore, it is necessary to establish apo(a)-producing cells to study the role of apo(a). We evaluated the effects of overexpression of human apo(a) gene on human aortic VSMC growth. First, we tested whether transfection of apo(a) gene into human hepatoma cells, HepG2 cells, producing human apoB resulted in the formation of Lp(a). Transfection of apo(a) gene into HepG2 cells resulted in detectable levels of Lp(a) in the medium, as assessed by ELISA and Western blot, whereas no Lp(a) was detected in the medium of HepG2 cells transfected with control vector and untransfected HepG2 cells. Expression of apo(a) mRNA was also confirmed by reverse transcription-polymerase chain reaction. In contrast, Western blotting showed a single band detected by specific anti-apo(a) antibody, but not anti-apoB antibody, in the medium of apo(a)-transfected VSMCs. These results demonstrate that Lp(a) can be formed from apo(a) on HepG2 cells, whereas transfection of apo(a) gene into VSMCs resulted in the production of apo(a) alone but not Lp(a). Next, we examined the biological effects of overexpression of apo(a) gene on growth of VSMCs and endothelial cells. Incubation of cultured medium of HepG2 cells transfected with apo(a) gene with human VSMCs or endothelial cells resulted in a significant increase in cell number compared with the conditioned medium of HepG2 cells transfected with control vector. In contrast, transfection of apo(a) gene directly into VSMCs caused no significant effect on VSMC growth. Therefore, we measured TGF-beta concentration in the conditioned medium of VSMCs. However, using ELISA, only latent but not active TGF-beta was detected in the medium of VSMCs. Moreover, addition of neutralizing anti-TGF-beta antibody did not alter VSMC growth. These results suggest that Lp(a) could stimulate growth of VSMCs via the independent mechanisms from the inhibition of TGF-beta activation. Overall, these data demonstrate that overexpression of apo(a) gene in cells producing apoB results in formation of Lp(a), resulting in a mitogenic action on human endothelial cells and VSMCs. These results provide new information to understand the mechanisms of the mitogenic action of Lp(a) and suggest the role of Lp(a) in the pathogenesis of atherosclerosis.

Oligonucleotide-based gene therapy for cardiovascular disease

Gene therapy is emerging as a potential strategy for the treatment of cardiovascular disease such as restenosis after angioplasty, vascular bypass graft occlusion, transplant coronary vasculopathy, homozygous familial hypercholesterolemia and cystic fibrosis, for which no known effective therapy exists. Gene therapy requires efficient in vivo gene transfer technology. During the past decade, many gene transfer methods including viral transfer techniques have been developed, and some are being applied clinically in human gene therapy studies. Molecular biology and pathophysiology of the cardiovascular system have started to emerge, and the time is ripe for the introduction of gene therapy to the management of cardiovascular disorders. In this review, we have focused on the future potential of oligonucleotide-based gene therapy for the treatment of cardiovascular disease.