Transfection of antisense p53 tumor suppressor gene oligodeoxynucleotides into rat carotid artery results in abnormal growth of vascular smooth muscle cells

BACKGROUND

Although loss of activity of an antioncogene, the p53 tumor suppressor gene product, has been postulated in the pathogenesis of human restenosis, little is known about the role of p53 in the regulation of vascular smooth muscle cell (VSMC) growth. In this study, to clarify the role of p53 in the pathogenesis of restenosis, we examined transfection of antisense p53 oligodeoxynucleotides (ODN) into VSMC in vitro and rat carotid artery in vivo.

METHODS AND RESULTS

The specificity of antisense p53 ODN was confirmed by a significant decrease in p53 protein. Transfection of antisense p53 ODN into VSMC resulted in a significant increase in DNA synthesis and cell number as compared with sense and scrambled ODN (P<0.01). Importantly, transfection of antisense p53 ODN into rat intact carotid artery resulted in a significant increase in the ratio of neointima to medial area at 2 and 4 weeks after transfection, accompanied by a significant decrease in p53 protein (P<0.01). Moreover, cotransfection of wild-type p53 plasmid completely abolished neointimal formation induced by antisense p53 ODN. The sustained effect of a single antisense ODN administration was confirmed by the kinetics of ODN in the vessel wall with the use of FITC-labeled ODN.

CONCLUSIONS

Overall, the present study demonstrated that loss of p53 by antisense p53 ODN resulted in an abnormal VSMC growth in vitro and in vivo. These results demonstrated the potential contribution of p53 to the pathogenesis of restenosis.

Mammaglobin B gene as a novel marker for lymph node micrometastasis in patients with abdominal cancers

Mammaglobin B is a recently-isolated gene speculated to belong to the uteroglobin gene family and is overexpressed in primary breast cancers. We investigated mammaglobin B mRNA expression in various cancers of the digestive system. Given the absence of mammaglobin B expression in normal lymph nodes, we also assessed the usefulness of mammaglobin B as a marker for lymph node micrometastases in cancer patients. Mammaglobin B gene transcripts were frequently detected by reverse transcriptase-polymerase chain reaction (RT-PCR) assay in primary tumors of the esophagus (2/3), stomach (7/7), colon (15/15), pancreas (4/6), common bile duct (6/6), cholangioma (2/2) and gall bladder (1/1). Mammaglobin B overexpression was observed in three of 15 cases (20%) of colon cancer, suggesting its possible contribution to colon carcinogenesis. Down-regulated mammaglobin B expression was observed in hepatoma cells in comparison with corresponding non-cancerous livers (3/3). RT-PCR assay of mammaglobin B detected 14 of 15 histologically positive lymph nodes from patients with gastric cancer, colon cancer and cholangioma. Seven of 32 (22%), three of nine (33%), and three of seven (43%) histologically negative nodes from patients with gastric, colon and cholangiocellular carcinoma, respectively, were found to express mammaglobin B mRNA. Our results showed that expression of mammaglobin B was frequently detected in cancers originating in digestive organs, especially adenocarcinomas, and that mammaglobin B gene detected by RT-PCR may be a potentially useful molecular marker for lymph node micrometastases of various digestive organ cancers.

Strong inverse correlation between serum TPO level and platelet count in essential thrombocythemia

Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels were measured at two points with different platelet counts. ET patients showed significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001) than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three previously untreated ET patients also showed significantly higher serum TPO levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with normal platelet counts. Furthermore, a strong inverse correlation was found between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0. 0001). This inverse correlation also held for each of nine cases with two-point TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel the platelet mass before and after chemotherapy. Although it is unknown whether overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass, i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.

Strong inverse correlation between serum TPO level and platelet count in essential thrombocythemia

Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels were measured at two points with different platelet counts. ET patients showed significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001) than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three previously untreated ET patients also showed significantly higher serum TPO levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with normal platelet counts. Furthermore, a strong inverse correlation was found between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0. 0001). This inverse correlation also held for each of nine cases with two-point TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel the platelet mass before and after chemotherapy. Although it is unknown whether overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass, i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.

Detection of microsatellite alterations in nipple discharge accompanied by breast cancer

Nipple discharge in breast cancer cases was examined loss of heterozygosity (LOH). DNA samples were extracted from both supernatant and cell pellet components of the discharge, and examined for LOH at microsatellite markers, D11S1818, D11S2000, D16S402, D16S504, D16S518, D17S520, and D17S786. At least one LOH was found in either the supernatant or cell pellet in seven out of 10 patients (70%). Five of seven samples, which were cytologically negative, were LOH positive, and only one case, which was cytologically positive, showed no LOH on the markers examined. All three samples, which were judged 'negative' by CEA measurement (<400 ng/ml), were LOH positive. This method could be a useful novel diagnostic modality for nonpalpable breast cancer with nipple discharge.

Selective augmentations of intratumoral 5-fluorouracil concentration by local immunotherapy with OK-432 and fibrinogen

PURPOSE

Pyrimidine nucleoside phosphorylase is an enzyme that converts 5'-deoxy-5-fluorouridine into its active metabolite, 5-fluorouracil. In colorectal cancer tissue pyrimidine nucleoside phosphorylase has been proven to be produced by macrophages in the cancer stroma despite presence of the cancer cells. We reported that local immunotherapy with OK-432 and fibrinogen induced aggregation of macrophages in the cancer stroma and enforced their pyrimidine nucleoside phosphorylase expression. Thus it was hypothesized that if colon cancer were treated with 5'-deoxy-5-fluorouridine, the 5-fluorouracil concentration in cancer tissues would be enhanced by local immunotherapy. The present study was conducted to investigate whether local immunotherapy for colon cancer could increase the intratumoral 5-fluorouracil concentration in patients given chemotherapy with 5'-deoxy-5-fluorouridine.

METHODS

Twenty patients with resectable colorectal cancer were examined in this study. They were given 5'-deoxy-5-fluorouridine (600 mg/day) orally for seven days preoperatively. Nine randomly selected patients underwent intratumoral injection of OK-432 mixed with fibrinogen, which was performed on the third preoperative day (OK-432 and fibrinogen plus 5'-deoxy-5-fluorouridine group); eleven patients were given oral 5'-deoxy-5-fluorouridine only (5'deoxy-5-fluorouridine group). The 5-fluorouracil concentration in tumor tissue and normal colon mucosa tissue was measured, and the influence of the local immunotherapy was assessed.

RESULTS

The 5-fluorouracil concentration in the cancer tissue was increased by the local immunotherapy, whereas that in the normal colon mucosa was not influenced. Thus, the influence of local immunotherapy was selective to the cancer tissue where the mixture of OK-432 and fibrinogen was injected.

CONCLUSION

In patients with colorectal cancer, selective high 5-fluorouracil concentration in the cancer tissue could be achieved by a combination of 5'-deoxy-5-fluorouridine and local immunotherapy with a mixture of OK-432 and fibrinogen.

[Multimedia (visual collaboration) brings true nature of human life]

Videoconferencing system, high-quality visual collaboration, is bringing Multimedia into a society. Multimedia, high quality media such as TV broadcast, looks expensive because it requires broadband network with 100-200 Mpbs bandwidth or 3,700 analog telephone lines. However, thanks to the existing digital-line called N-ISDN (Narrow Integrated Service Digital Network) and PictureTel's audio/video compression technologies, it becomes far less expensive. N-ISDN provides 128 Kbps bandwidth, over twice wider than analog line. PictureTel's technology instantly compress audio/video signal into 1/1,000 in size. This means, with ISDN and PictureTel technology. Multimedia is materialized over even single ISDN line. This will allow doctor to remotely meet face-to-face with a medical specialist or patients to interview, conduct physical examinations, review records, and prescribe treatments. Bonding multiple ISDN lines will further improve video quality that enables remote surgery. Surgeon can perform an operation on internal organ by projecting motion video from Endoscope's CCD camera to large display monitor. Also, PictureTel provides advanced technologies of eliminating background noise generated by surgical knives or scalpels during surgery. This will allow sound of the breath or heartbeat be clearly transmitted to the remote site. Thus, Multimedia eliminates the barrier of distance, enabling people to be just at home, to be anywhere in the world, to undergo up-to-date medical treatment by expertise. This will reduce medical cost and allow people to live in the suburbs, in less pollution, closer to the nature. People will foster more open and collaborative environment by participating in local activities. Such community-oriented life-style will atone for mass consumption, materialistic economy in the past, then bring true happiness and welfare into our life after all.

[CD16+ CD56- indolent, NK cell-lineage granular lymphocyte proliferative disorder with autoimmune hemolytic anemia]

A 64-year-old man was given a diagnosis of CD16+ CD56- natural killer cell-lineage granular lymphocyte proliferative disorder (NK-GLPD) with Coombs-negative autoimmune hemolytic anemia (AIHA). Two courses of 1,000 mg intravenous methylprednisolone for 3 days were transiently effective for both AIHA and NK-GLPD. On the recurrence of AIHA, NK-GLPD also re-appeared. The same treatment was effective in controlling both diseases again. This was a rare case of NK-GLPD combined with autoimmune disease.

Bioabsorbable thread for tight tying of bones

The purpose of this research was to develop a bioabsorbable thread for tight fixation of fractured bones and to examine its mechanical performance in an in-vitro simulation study. The thread is a blend of bioabsorbable poly(L-lactic acid); (PLLA) and poly(epsilon-caprolactone); (PCL) fibers and can be tightly connected by fusion welding of the PCL fibers. The tying strength of the PLLA-PCL blend thread was 39.7 N, which was comparable to that of stainless steel wire. A testing machine was fabricated to measure the fatigue strength of the tying by simulating bone fixation. The results showed that metal wires always failed because of breakage within 25,000 loading cycles, whereas the blend threads did not fail until 50,000 loading cycles. The looseness of tying for simulated bone fixation by the blend thread was within 1mm even after 50 000 loading cycles. In-vivo testing using rats revealed that the blend thread did not cause any severe inflammatory reaction.

Quantification of micrometastases in lymph nodes of colorectal cancer using real-time fluorescence polymerase chain reaction

The expression of carcinoembryonic antigen (CEA) mRNA was assessed in 102 lymph nodes (LNs) obtained from seven colorectal cancer patients by both the conventional non-quantitative RT-PCR and quantitative RT-PCR. The number of CEA-expressing cells was calculated compared with CEA-expressing MKN-45 cell line as a standard control. Using the quantitative RT-PCR, the relative number of CEA-expressing cells ranged between 1.3x103 and 5.7x106 in 16 histologically positive LNs and between 2.3x101 and 8.1x105 in 10 histologically negative and RT-PCR positive LNs. In both histologically and RT-PCR negative LNs, the relative cell number was <4.0x102. Our results demonstrated that quantifying the amount of metastasis might enhance the reliability of RT-PCR detection assay as a diagnostic tool for the detection of cancer micrometastases.

In vivo evidence of the importance of cardiac angiotensin-converting enzyme in the pathogenesis of cardiac hypertrophy

Cardiac angiotensin-converting enzyme (ACE) may play an important role in regulating cardiac hypertrophy. Angiotensin II (Ang II) stimulates cardiac hypertrophy as well as the production of extracellular matrix. However, it is still unclear whether Ang II exerts a direct effect on cardiac hypertrophy independent of its effect on blood pressure or the circulating renin-angiotensin system. Although ACE inhibitors and/or Ang II receptor antagonists have regressed cardiac hypertrophy, classic pharmacological experiments cannot exclude the contribution of hemodynamics and the circulating renin-angiotensin system. In vivo gene transfer provides the opportunity of assessing the effects of increased cardiac angiotensin in the intact animal without circulating angiotensin or blood pressure. Therefore, we used a "gain of function" approach to obtain local overexpression of cardiac ACE. Transfection of the human ACE vector into rat myocardium resulted in a significant increase in cardiac ACE activity (P<0.01). More interestingly, morphometry at 2 weeks after transfection revealed a significant increase in the thickness and areas of cardiac myocytes in hearts transfected with the ACE vector (P<0.01). In addition, transfection of the ACE vector also resulted in a significant increase in collagen content (P<0.01). This increase in cardiac hypertrophy was abolished by the administration of perindopril. Local transfection of the ACE vector into the heart did not result in systemic effects such as increased blood pressure, heart rate, or serum ACE activity. In summary, we have demonstrated that increased autocrine/paracrine angiotensin can directly cause cardiac hypertrophy independent of systemic factors and hemodynamic effects. This approach has important potentials for defining the role of autocrine/paracrine substances in cardiovascular disease.

Expression of tumor suppressor gene p16(INK4) products in primary gastric cancer

Recent studies have shown that the cyclin-dependent kinase (CDK) inhibitor p27(Kip1) represents an indicator for patients' outcome in several human malignancies including gastric cancer. However, the clinicopathologic value of another class of CDK inhibitor, p16(INK4), has not been determined. In a retrospective study, we examined the expression of p16(INK4) by immunohistochemical assay of 80 samples of primary gastric cancers and their adjacent nonneoplastic mucosas. Less than 10% of non-tumor gastric mucosal cells were p16(INK4) positive, whereas the expression of p16(INK4) in gastric cancer cells varied widely from 0 to 100% (mean, 24.5%). The expression of p16(INK4) was not seen in 11.3% (9/80) of the cancer cases, but in 65% (52/80) this protein was even overexpressed when compared with the nonneoplastic mucosa. A clinicopathologic survey indicated that a low or no expression of p16(INK4) was associated with poorly differentiated carcinoma (p = 0.0133), but the level of expression did not correlate with other parameters including patients' prognosis or with the expression of the pRb protein. In an effort to explore the underlying mechanism for the p16(INK4)-negative cases, a prospective study was also performed on 20 cases of gastric cancer to compare the level of the p16(INK4) protein with the methylation status of the p16(INK4) promoter. Gastric cancer tissues with methylation expressed significantly lower levels of the p16(INK4) protein (p = 0.0013) and two of them lacked p16(INK4) expression altogether, whereas all the cancer tissues without methylation expressed it. These findings suggest that the p16(INK4) protein may be associated with differentiation of gastric cancer tissues and that methylation of the p16(INK4) promoter may, in part, account for the loss of p16(INK4) expression.

Suppressed severity of collagen-induced arthritis by in vivo transfection of nuclear factor kappaB decoy oligodeoxynucleotides as a gene therapy

OBJECTIVE

In both rheumatoid arthritis and collagen-induced arthritis (CIA), the nuclear factor kappaB (NF-kappaB) transcription factor plays a pivotal role in the coordinated transactivation of many cytokines related to pathogenesis. This study investigated whether synthetic double-stranded DNA that show a high affinity for NF-kappaB could be introduced in vivo as "decoy" cis elements to bind the transcription factor and block the activation of such proinflammatory cytokine genes as interleukin-1 (IL-1) and tumor necrosis factor alpha (TNFalpha), and thus suppress the severity of joint destruction.

METHODS

NF-kappaB decoy oligonucleotides (ODN) were introduced by an intraarticular injection into the bilateral hind ankle joints of CIA rats using the hemagglutinating virus of Japan (HVJ)-liposome method. Joint destruction was evaluated by histology and radiography. IL-1 and TNFalpha levels were assessed by enzyme-linked immunosorbent assay and Northern blot analysis.

RESULTS

Using the HVJ-liposome method, the presence of fluorescein isothiocyanate-labeled ODN in the synovium was confirmed until 28 days after intraarticular injection. In vivo transfection of NF-kappaB decoy ODN by an intraarticular injection into CIA rats decreased the severity of hind-paw swelling. Histologic and radiographic studies showed a marked suppression of joint destruction treated by NF-kappaB decoy ODN transfection. This treatment method also suppressed the production of IL-1 and TNFalpha in the synovium of arthritic joints.

CONCLUSION

The present results demonstrate that administration of NF-kappaB decoy ODN in arthritic joints of rats with CIA led to an amelioration of arthritis. These findings suggest that intraarticular transfection of NF-kappaB decoy ODN may provide a useful therapeutic approach for the treatment of inflammatory arthritis.

Improvement of quality of life after splenectomy in an HTLV-I carrier with T-cell prolymphocytic leukemia

A 34-year-old woman of HTLV-I carrier with T-PLL, whose quality of life improved and survival was prolonged after splenectomy, is described. The patient had marked splenomegaly, generalized lymphadenopathy and marked proliferation of abnormal lymphocytes in the peripheral blood with an irregular nucleus, deeply basophilic cytoplasm and a single prominent nucleolus, which were positive for CD2, CD3, CD5, CD7, CD4 and CD8. Although the patient had serum antibody against HTLV-I, HTLV-I proviral DNA integration was not detected. She was diagnosed as an HTLV-I carrier with T-PLL and received combination chemotherapy and 15.1 Gy splenic irradiation. However, the generalized lymphadenopathy and splenomegaly did not improve. The patient underwent splenectomy to palliate abdominal distension and hypersplenism. After the operation, her symptoms improved dramatically and within a week her hemoglobin concentration and platelet count normalized. She was discharged from hospital two weeks after the splenectomy, however 11 months later, she relapsed and despite treatment with chemotherapy and alpha-interferon, she died two months after the second admission. Autopsy findings revealed that PLL cells had invaded the bone marrow, lymph nodes, liver, lungs, kidneys, uterus, ovaries and adrenal glands.

[A case report: effective trans-arterial neoadjuvant chemotherapy with docetaxel for a local advanced breast cancer patient]

Recently, there have been some reports about the effectiveness of docetaxel for breast cancer patients who had polychemotherapy previously in vein. We report here a case of a 47-year-old woman, who had been diagnosed as local advanced breast cancer. She was given trans-arterial chemotherapy with docetaxel after four series of CEF (cyclophosphamide, epirubicin, fluorouracil) therapy resulted in PD (progressive disease). Local disease was successfully controlled, and she could undergo standard radical mastectomy.

Effect of sliding locus on subsurface crack formation in ultra-high-molecular-weight polyethylene knee component

The objective of this study was to evaluate the effect of sliding locus on fatigue destruction of ultra-high-molecular-weight polyethylene (UHMWPE) in order to design a durable total knee arthroplasty (TKA) articulation. Two-dimensional sliding fatigue testing was performed under two simplified patterns of articulating interface sliding locus. Scanning acoustic tomography (SAT) was used for observation of subsurface cracks in UHMWPE specimens. A high rate of subsurface crack formation was observed when the movement was reciprocated on two different loci, in contrast with that on a single linear locus. This finding suggests that crack formation or propagation in UHMWPE components is accelerated not only by the compressive stress but also by complicated articulating movement locus.

Angiotensinogen gene-activating elements regulate blood pressure in the brain

Although the angiotensinogen gene is a possible candidate as a determinant of hypertension, the molecular mechanisms of tissue angiotensinogen gene regulation have yet to be clarified. We identified essential transcription regulators of angiotensinogen production in the central nervous system using synthetic double-stranded oligodeoxynucleotides (ODNs) as "decoy" cis elements to block the binding of nuclear factors to promoter regions of the targeted gene. Using a gel mobility shift assay, angiotensinogen gene-activating element (AGE) 2 binding protein was detected in the brain nuclear extracts of both spontaneously hypertensive rats (SHRs) and normotensive Wistar Kyoto rats (WKYs). Importantly, the binding activity of AGE 2 and angiotensinogen mRNA level were significantly higher in the brain of SHRs than in that of WKYs. Using the decoy approach, we demonstrated a significant decrease in the blood pressure of SHRs by transfection of AGE 2 decoy, but not mismatched, ODNs into the lateral cerebroventricle, accompanied by a significant decrease in brain angiotensinogen concentration and mRNA, and angiotensin II level. That these effects, demonstrated herein, are due to central effects is confirmed by the fact that no changes in circulating levels of angiotensinogen or angiotensin II concentrations were observed. Notably, AGE 2 decoy ODNs did not decrease the blood pressure of WKYs. We conclude that the abnormal expression of AGE 2 binding protein in the central nervous system plays a crucial role in high blood pressure of a genetically hypertensive rat model.

Prevention of renal damage by angiotensin II blockade, accompanied by increased renal hepatocyte growth factor in experimental hypertensive rats

Hepatocyte growth factor (HGF) is a unique growth factor that has many protective functions against renal damage. Our previous study demonstrated that HGF stimulated the growth of endothelial and epithelial cells without the replication of mesangial cells. Moreover, angiotensin (Ang) II significantly decreased local HGF production in mesangial cells. Therefore, we examined the effects of Ang II blockade on renal HGF expression and renal damage in experimental hypertensive rats. An angiotensin-converting enzyme inhibitor (cilazapril; 10 mg. kg(-1). d(-1)), an Ang II type 1 receptor antagonist (E-4177; 30 mg. kg(-1). d(-1)), hydralazine (8 mg. kg(-1). d(-1)), and vehicle were administered to 16-week-old stroke-prone spontaneously hypertensive rats (SHR-SP) for 3 weeks. Renal damage was evaluated with a computer analysis system, and renal HGF mRNA was measured by Northern blot analysis. Blood pressure of SHR-SP was significantly decreased by all drug treatments compared with vehicle. Moreover, cilazapril, E-4177, and hydralazine significantly decreased the thickening and necrosis of blood vessels compared with vehicle. Similarly, degeneration and necrosis of glomeruli were also markedly improved by cilazapril and E-4177 (P<0.01). We next examined the effects of Ang II blockade on renal HGF expression in SHR-SP. Renal HGF mRNA was markedly decreased in SHR-SP compared with Wistar-Kyoto rats, although Ang II blockade by cilazapril and E-4177 but not hydralazine significantly increased renal HGF mRNA in SHR-SP. Ang II blockade significantly increased renal HGF (a protective growth factor for tubular epithelial cells); thus, we examined tubular histological appearance. Degeneration and necrosis of tubules were significantly improved by cilazapril and E-4177 treatment (P<0.01). In addition, cell infiltration into the glomeruli and hemorrhage were also significantly reduced in SHR-SP treated with cilazapril or E-4177. The present data demonstrated the prevention of renal damage by Ang II blockade in SHR-SP, which was accompanied by a significant increase in renal HGF mRNA. Given the strong mitogenic activity and antiapoptotic actions of HGF on endothelial and epithelial cells, we believe that increased local HGF production by the blockade of Ang II may improve renal function in hypertension.

Activation of the brain angiotensin system by in vivo human angiotensin-converting enzyme gene transfer in rats

The possibility of the brain-specific expression of a component of the renin-angiotensin system was evaluated in the present study. We used the hemagglutinating virus of Japan-liposome complex to transfect human angiotensin-converting enzyme (ACE) cDNA, driven by the cytomegalovirus enhancer and beta-actin promoter, into the lateral cerebroventricle of male Sprague-Dawley rats. We evaluated the time course of hemodynamics, the tissue levels of angiotensin (Ang) II and vasopressin, and ACE activity. Intracerebroventricular transfection of the human ACE gene increased both blood pressure and heart rate. Transfected rats exhibited higher concentrations of brain Ang II and increased brain ACE activity. This activation of the brain angiotensin system was accompanied by increased vasopressin production. The increases in blood pressure and heart rate were abolished by intracerebroventricular administration of an ACE inhibitor or Ang II type 1 receptor antagonist. The expression of the transgene was widely distributed in the periventricular cell layer, the cortex, the hypothalamic nuclei, and the brain stem. Expression in the neuronal cells persisted for up to 14 days. Thus, this hemagglutinating virus of Japan-liposome method is a highly efficient system for gene delivery and is extremely useful for functional gene transfection. This novel hypertensive model may enable characterization of the functions of the renin-angiotensin system in the brain and determination of its role in the pathogenesis of hypertension.

Cystic lymphangiomas of the colon

We report a patient with cystic lymphangiomas diagnosed by endoscopic ultrasonography and resected by partial polypectomy. A 42-year-old woman consulted a nearby physician because of a positive fecal occult blood test. Barium enema and colonoscopy revealed the presence of abnormalities. On March 11, 1997, she was admitted to our department for further evaluation and treatment. A barium enema examination revealed two protruding lesions in the transverse colon. Colonoscopy showed a teardrop-type mass in the left side of the transverse colon. The mass was cushion-sign positive, and its shape readily changed on respiration and with changes in body position. Another superficial smooth mass was found in the right side of the transverse colon. Ultrasonography of the colon confirmed the presence of a submucosal mass showing a cyst-like pattern. Cystic lymphangiomas were diagnosed and resected endoscopically. Histopathological examination revealed markedly dilated ducts consisting of a single layer of endothelial cells in the submucosa of the colon. The diagnosis was cystic lymphangioma.

Prevention of fatigue cracks in ultrahigh molecular weight polyethylene joint components by the addition of vitamin E

Flaking-type wear, so-called delamination, is often observed in polyethylene joint components. This is thought to occur partly due to crack formation and propagation at grain boundaries. This study examined the effect of vitamin E on the crack formation and/or propagation in UHMWPE by using 2-dimensional sliding fatigue testing and micro indenter testing. An in vitro sliding fatigue test was performed under two simplified articulating movements, and the cracks produced were observed by scanning acoustic tomography (SAT). Gamma-irradiated ultrahigh molecular weight polyethylene (UHMWPE) specimens demonstrated a smaller area of accumulated cracks as compared to virgin specimens, when the loading movement was reciprocated on a single linear locus. However, four out of five gamma-irradiated UHMWPE specimens exhibited severe flaking-like destruction under the complicated sliding condition, suggesting that gamma irradiation accelerated crack propagation under multidirectional loading. All the gamma-irradiated vitamin-E-containing specimens demonstrated no subsurface crack formation and no flaking-like destruction. Results using micro indenter testing showed that the dynamic hardness at grain boundary was higher than that in grain, and was increased by gamma irradiation. This hardening at grain boundary was reduced by adding vitamin E. It is possible that the presence of vitamin E prevents crack propagation partly due to reduced hardness at grain boundaries. The gamma-irradiated vitamin-E-containing UHMWPE is a promising material to prevent flaking-like destruction of polyethylene joint components.

Intraoperative navigation for breast cancer surgery using 3D ultrasound images

The aim of this work was to develop an intraoperative image-guidance system for breast cancer surgery using three-dimensional (3D) ultrasound imaging. Using a 10-MHz annular array mechanical sector probe, ultrasound images were obtained from nine volunteer patients with breast cancer immediately before removal of the tumor in the operating room. A 3D tumor image was reconstructed using a workstation, then superimposed on the video image of the breast based on geometrical data. These data were obtained simultaneously by an optical 3D position sensor. The 3D images of the tumors were validated by the pathological data obtained after the surgery. In eight cases, the superimposed images were successfully obtained in approximately 15-20 min following scanning of the tumor. Scattered lesions around the main tumor were also visualized in the reconstructed tumor images, but artifacts of the ductal lesion caused by noise could not be eliminated in some cases. This system should be very effective in helping the surgeon to recognize the extent of a tumor within the breast itself and to determine the margin of surgical resection for breast conservation surgery.

Paradoxical increase in retinoblastoma protein in colorectal carcinomas may protect cells from apoptosis

The retinoblastoma (Rb) gene is inactivated in a variety of human cancers, but in colorectal carcinomas there is frequently increased expression of this gene. This is paradoxical in view of the known role of Rb as a tumor suppressor gene. In the present study, we compared the levels of expression of the Rb protein (pRb) in normal human colorectal mucosa, adenomatous polyps, and carcinomas by immunohistochemistry. In vitro studies were also done to examine the phenotypic effects of an antisense oligodeoxynucleotide (AS-Rb) targeted to Rb mRNA in the HCT116 colon carcinoma cell line that expresses a relatively high level of pRb. The incidence of pRb-positive cells was increased during multistage colorectal carcinogenesis. In vitro treatment of HCT116 cells with AS-Rb decreased the level of pRb by about 70% and also decreased the levels of the cyclin D1 protein and cyclin D1-associated kinase activity. AS-Rb inhibited growth of HCT116 cells and induced apoptosis. Reporter assays indicated about a 17-fold increase in E2F activity. These findings suggest that the increased expression of pRb in colorectal carcinoma cells may provide a homeostatic mechanism that protects them from growth inhibition and apoptosis, perhaps by counterbalancing potentially toxic effects of excessive E2F activity.

Comparative genomic hybridization defines frequent loss on 16p in human anaplastic thyroid carcinoma

Anaplastic thyroid cancer (ATC) is one of the malignant tumors with the poor prognosis that is thought to arise from well-differentiated thyroid cancer (DTC). To investigate the molecular mechanism of ATC, we studied genomic alterations of eight ATC cell lines and three DTC cell lines by means of the comparative genomic hybridization (CGH) method. Loss of 16p was observed in five of eight ATC cell lines (62. 5%), but none of the three DTC cell lines showed loss of this chromosome arm. It is notable that loss of 18q [7/8 of ATC (87.5%), 2/3 of DTC (67%)] and gain of 20q [5/8 of ATC (62.5%), 3/3 of DTC (100%)] were frequently seen in both histologic types. Our results suggest that there is a gene in 16p that is closely associated with transformation from well-differentiated thyroid cancer to anaplastic cancer.

Transcription factor decoy to study the molecular mechanism of negative regulation of renin gene expression in the liver in vivo

Renin is synthesized in high quantities in the juxtaglomerular cells of the kidney, but little or none is synthesized in the liver. Our previous in vitro and biochemical studies have demonstrated that tissue-specific expression of the mouse renin gene is regulated by the specific interaction between negative regulatory element (NRE) in the 5'-flanking region of the renin gene and NRE binding protein (NREB). In this study, we examined the hypothesis that this interaction between the NRE in the promoter region of the rat renin gene and the NREB in the liver contributes to the suppressed renin gene expression in this tissue in vivo. We used in vivo transfection of NRE transcription factor decoy (TFD) double-stranded oligonucleotide into the rat liver via portal vein infusion. A gel mobility shift assay showed that transfected NRE TFD blocked endogenous NREB binding with the rat renin gene. This resulted in enhanced hepatic renin mRNA expression, immunohistochemical detection of renin in the liver, and consequently, increased plasma renin concentration. Taken together, these results document the importance of NREB in the inhibition of renin gene expression in rat liver in vivo and suggest the possibility of in vivo renin gene modulation by the TFD approach.