Anatomical region-dependent enhancement of 3-dimensional chondrogenic differentiation of human mesenchymal stem cells by soluble meniscus extracellular matrix

Extracellular matrix (ECM) derived from decellularized tissues has been found to promote tissue neogenesis, most likely mediated by specific biochemical and physical signaling motifs that promote tissue-specific differentiation of progenitor cells. Decellularized ECM has been suggested to be efficacious for the repair of tissue injuries. However, decellularized meniscus contains a dense collagenous structure, which impedes cell seeding and infiltration and is not readily applicable for meniscus repair. In addition, the meniscus consists of two distinct anatomical regions that differ in vascularity and cellular phenotype. The purpose of this study was to explore the region-specific bioactivity of solubilized ECM derived from the inner and outer meniscal regions as determined in 2D and 3D cultures of adult mesenchymal stem cells (MSCs). When added as a medium supplement to 2D cultures of MSCs, urea-extracted fractions of the inner (imECM) and outer meniscal ECM (omECM) enhanced cell proliferation while imECM most strongly upregulated fibrochondrogenic differentiation on the basis of gene expression profiles. When added to 3D cultures of MSCs seeded in photocrosslinked methacrylated gelatin (GelMA) hydrogels, both ECM fractions upregulated chondrogenic differentiation as determined by gene expression and protein analyses, as well as elevated sulfated glycosaminoglycan sGAG content, compared to ECM-free controls. The chondrogenic effect at day 21 was most pronounced with imECM supplementation, but equivalent between ECM groups by day 42. Despite increased cartilage matrix, imECM and omECM constructs possessed compressive moduli similar to controls. In conclusion, soluble meniscal ECM may be considered for use as a tissue-specific reagent to enhance chondrogenesis for MSC-based 3D cartilage tissue engineering.

STATEMENT OF SIGNIFICANCE

The inner region of the knee meniscus is frequently injured and possesses a poor intrinsic healing capacity. Solubilized extracellular matrix (ECM) derived from decellularized meniscus tissue may promote homologous differentiation of progenitor cells, thereby enhancing fibrocartilage formation within a meniscal lesion. However, the meniscus possesses regional variation in ultrastructure, biochemical composition, and cell phenotype, which may affect the bioactivity of soluble ECM derived from different regions of decellularized menisci. In this study, we demonstrate that urea-extracted fractions of ECM derived from the inner and outer regions of menisci enhance chondrogenesis in mesenchymal stem cells seeded in 3-dimensional photocrosslinkable hydrogels and that this effect is more strongly mediated by inner meniscal ECM. These findings suggest region-specific bioactivity of decellularized meniscal ECM.

Preparation of Scaffold-Free Tissue-Engineered Constructs Derived from Human Synovial Mesenchymal Stem Cells Under Low Oxygen Tension Enhances Their Chondrogenic Differentiation Capacity

Low oxygen tension (LOT) has been reported to promote chondrogenic differentiation and prevent cellular senescence of stem cells. Therefore, the introduction of LOT conditions into conventional tissue engineering processes could further improve the potential of the constructs generated for cartilage repair. The purpose of this study was to elucidate the feasibility of LOT preparation on the chondrogenic differentiation of a scaffold-free tissue-engineered construct (TEC) derived from synovial mesenchymal stem cells (MSCs), construct whose feasibility for cartilage repair has been demonstrated in previous preclinical and clinical studies. Culture of MSCs under LOT conditions prevented cellular senescence and promoted the proliferative capacity of human synovial MSCs. In addition, TEC prepared from human synovial MSCs under LOT conditions (5% O2; LOT-TEC) showed superior in vitro chondrogenic differentiation capacity compared to that prepared under the usual 20% O2 (normal oxygen tension [NOT]; NOT-TEC), with elevated glycosaminoglycan production and elevated levels of chondrogenic marker gene expression. Notably, LOT-TEC differentiated into a hyaline-like cartilaginous tissue of approximately 1 cm in diameter without the detectable presence of fibrous tissue, while conventional NOT-TEC differentiated into a mixture of hyaline-like and fibrocartilaginous tissues. This is the first demonstration of in vitro development of a hyaline-like cartilaginous tissue of an implantable size to chondral lesion that was derived from human MSCs without the use of an exogenous scaffold. The manipulation of oxygen tension is a safe procedure with low cost and, thus, may be a clinically relevant option to improve the quality of TEC-mediated cartilage repair.

Scaffold-free, stem cell-based cartilage repair

Various approaches to treat articular cartilage have been widely investigated due to its poor intrinsic healing capacity. Stem cell-based therapy could be a promising approach as an alternative to chondrocyte-based therapy and some of these therapies have been already applied in clinical condition. This review discusses the current development of stem cell-based therapies in cartilage repair, specifically focusing on scaffold-free approaches.

Cartilage Repair in the Inflamed Joint: Considerations for Biological Augmentation Toward Tissue Regeneration

Cartilage repair/regeneration procedures (e.g., microfracture, autologous chondrocyte implantation [ACI]) typically result in a satisfactory outcome in selected patients. However, the vast majority of patients with chronic symptoms and, in general, a more diseased joint, do not benefit from these surgical techniques. The aims of this work were to (1) review factors negatively influencing the joint environment; (2) review current adjuvant therapies that can be used to improve results of cartilage repair/regeneration procedures in patients with more diseased joints, (3) outline future lines of research and promising experimental approaches. Chronicity of symptoms and advancing patient age appear to be the most relevant factors negatively affecting clinical outcome of cartilage repair/regeneration. Preliminary experience with hyaluronic acid, platelet-rich plasma, and mesenchymal stem cell has been positive but there is no strong evidence supporting the use of these products and this requires further assessment with high-quality, prospective clinical trials. The use of a Tissue Therapy strategy, based on more mature engineered tissues, holds promise to tackle limitations of standard ACI procedures. Current research has highlighted the need for more targeted therapies, and (1) induction of tolerance with granulocyte colony-stimulating factor (G-CSF) or by preventing IL-6 downregulation; (2) combined IL-4 and IL-10 local release; and (3) selective activation of the prostaglandin E2 (PGE2) signaling appear to be the most promising innovative strategies. For older patients and for those with chronic symptoms, adjuvant therapies are needed in combination with microfracture and ACI.

Self-awareness of fast eating and its impact on diagnostic components of metabolic syndrome among middle-aged Japanese males and females

OBJECTIVE

The aim of the present study was to examine the association between subjects with self-awareness of fast eating and diagnostic components of metabolic syndrome in Japanese middle-aged male and female.

PATIENTS AND METHODS

Subjects consisted of 3208 males (average age 50.6 years) and 2055 females (average age 50.0 years). Associations between subjects with self-awareness of fast eating and multiple components of metabolic syndrome (waist circumference, body mass index [BMI], blood pressure, and related blood sample tests) were evaluated.

RESULTS

Significantly more males (57.7%) acknowledged themselves as "fast eater" than females (46.5%). Self-reported fast eaters showed significantly elevated body weight, BMI, and waist circumference in both genders. However, only male self-reported fast eaters showed high levels of blood pressure, fasting blood glucose, uric acid, and low-density lipoprotein (LDL)-cholesterol.

CONCLUSION

Fast eating is associated with diagnostic components of metabolic syndrome. The effect of acknowledging themselves as fast eater presents a higher impact on males than on females in the middle-aged Japanese population. The present study indicates that finding subjects with self-awareness of fast eating may lead to the prevention of developing metabolic syndrome.

In Vitro Repair of Meniscal Radial Tear Using Aligned Electrospun Nanofibrous Scaffold

Radial tears of the meniscus represent one of the most common injuries of the knee, and result in loss of biomechanical meniscal function. However, there have been no established, effective treatments for radial meniscal tears. Nanofibrous materials produced by electrospinning have shown high promise in the engineering of soft musculoskeletal tissues. The goal of our study is to apply these technologies to develop a functional cell-seeded scaffold as a potential, new surgical method to enhance meniscal radial repair. Cylinder-shaped explants were excised from the inner avascular region of bovine meniscus and a radial tear was created in the center of the explant. The torn site was wrapped with either nanofibrous scaffold alone or scaffold seeded with meniscal fibrochondrocytes (MFC). A control group was prepared as explants without scaffolds or cells. The composite constructs in each group were cultured in vitro for 4 and 8 weeks, and these were then assessed histologically and mechanically. Histological analysis showed partial repair of the radial tear was observed with adherence between scaffold and native meniscal tissue in either the scaffold alone or cell-seeded scaffold group. Only the cell-seeded scaffold exhibited significant positive Picrosirius red staining and Safranin O staining. Mechanical testing of the repaired meniscus showed that the load-to-failure and stiffness values were significantly improved in the cell-seeded group. These results demonstrated the applicability of the MFC-seeded nanofibrous scaffold for meniscal radial tear repair based on both histological and mechanical analyses. In particular, the highly adhesive property of the cell-seeded scaffold to the meniscal tissue should be beneficial in helping to preserve the meniscal function by stabilizing meniscal fibers.

Next Generation Mesenchymal Stem Cell (MSC)-Based Cartilage Repair Using Scaffold-Free Tissue Engineered Constructs Generated with Synovial Mesenchymal Stem Cells

Because of its limited healing capacity, treatments for articular cartilage injuries are still challenging. Since the first report by Brittberg, autologous chondrocyte implantation has been extensively studied. Recently, as an alternative for chondrocyte-based therapy, mesenchymal stem cell-based therapy has received considerable research attention because of the relative ease in handling for tissue harvest, and subsequent cell expansion and differentiation. This review summarizes latest development of stem cell therapies in cartilage repair with special attention to scaffold-free approaches.

Cyclic compressive loading on 3D tissue of human synovial fibroblasts upregulates prostaglandin E2 via COX-2 production without IL-1β and TNF-α

Objective

Excessive mechanical stress on synovial joints causes osteoarthritis (OA) and results in the production of prostaglandin E2 (PGE2), a key molecule in arthritis, by synovial fibroblasts. However, the relationship between arthritis-related molecules and mechanical stress is still unclear. The purpose of this study was to examine the synovial fibroblast response to cyclic mechanical stress using an in vitro osteoarthritis model.

Method

Human synovial fibroblasts were cultured on collagen scaffolds to produce three-dimensional constructs. A cyclic compressive loading of 40 kPa at 0.5 Hz was applied to the constructs, with or without the administration of a cyclooxygenase-2 (COX-2) selective inhibitor or dexamethasone, and then the concentrations of PGE2, interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), IL-6, IL-8 and COX-2 were measured.

Results

The concentrations of PGE2, IL-6 and IL-8 in the loaded samples were significantly higher than those of unloaded samples; however, the concentrations of IL-1β and TNF-α were the same as the unloaded samples. After the administration of a COX-2 selective inhibitor, the increased concentration of PGE2 by cyclic compressive loading was impeded, but the concentrations of IL-6 and IL-8 remained high. With dexamethasone, upregulation of PGE2, IL-6 and IL-8 was suppressed.

Conclusion

These results could be useful in revealing the molecular mechanism of mechanical stress in vivo for a better understanding of the pathology and therapy of OA.

Cite this article: Bone Joint Res 2014;3:280–8.

Osteochondral repair using a scaffold-free tissue-engineered construct derived from synovial mesenchymal stem cells and a hydroxyapatite-based artificial bone

For an ideal osteochondral repair, it is important to facilitate zonal restoration of the subchondral bone and the cartilage, layer by layer. Specifically, restoration of the osteochondral junction and secure integration with adjacent cartilage could be considered key factors. The purpose of the present study was to investigate the feasibility of a combined material comprising a scaffold-free tissue-engineered construct (TEC) derived from synovial mesenchymal stem cells (MSCs) and a hydroxyapatite (HA) artificial bone using a rabbit osteochondral defect model. Osteochondral defects were created on the femoral groove of skeletally mature rabbits. The TEC and HA artificial bone were hybridized to develop a combined implant just before use, which was then implanted into defects (N=23). In the control group, HA alone was implanted (N=18). Histological evaluation and micro-indentation testing was performed for the evaluation of repair tissue. Normal knees were used as an additional control group for biomechanical testing (N=5). At hybridization, the TEC rapidly attached onto the surface of HA artificial bone block, which was implantable to osteochondral defects. Osteochondral defects treated with the combined implants exhibited more rapid subchondral bone repair coupled with the development of cartilaginous tissue with good tissue integration to the adjacent host cartilage when assessed at 6 months post implantation. Conversely, the control group exhibited delayed subchondral bone repair. In addition, the repair cartilaginous tissue in this group had poor integration to adjacent cartilage and contained clustered chondrocytes, suggesting an early osteoarthritis (OA)-like degenerative change at 6 months post implantation. Biomechanically, the osteochondral repair tissue treated with the combined implants at 6 months restored tissue stiffness, similar to normal osteochondral tissue. The combined implants significantly accelerated and improved osteochondral repair. Specifically, earlier restoration of subchondral bone, as well as good tissue integration of repair cartilage to adjacent host tissue could be clinically relevant in terms of the acceleration of postoperative rehabilitation and longer-term durability of repaired articular surface in patients with osteochondral lesions, including those with OA. In addition, the combined implant could be considered a promising MSC-based bio-implant with regard to safety and cost-effectiveness, considering that the TEC is a scaffold-free implant and HA artificial bone has been widely used in clinical practice.

Osteochondral tissue engineering with biphasic scaffold: current strategies and techniques

The management of osteoarthritis (OA) remains challenging and controversial. Although several clinical options exist for the treatment of OA, regeneration of the damaged articular cartilage has proved difficult due to the limited healing capacity. With the advancements in tissue engineering and cell-based technologies over the past decade, new therapeutic options for patients with osteochondral lesions potentially exist. This review will focus on the feasibility of tissue-engineered biphasic scaffolds, which can mimic the native osteochondral complex, for osteochondral repair and highlight the recent development of these techniques toward tissue regeneration. Moreover, basic anatomy, strategy for osteochondral repair, the design and fabrication methods of scaffolds, as well as the choice of cells, growth factor, and materials will be discussed. Specifically, we focus on the latest preclinical animal studies using large animals and clinical trials with high clinical relevance. In turn, this will facilitate an understanding of the latest trends in osteochondral repair and contribute to the future application of such clinical therapies in patients with OA.

Repair of meniscal lesions using a scaffold-free tissue-engineered construct derived from allogenic synovial MSCs in a miniature swine model

The menisci of the knee are fibro-cartilaginous tissues and play important roles in the joint, and the loss of the meniscus predisposes the knee to degenerative changes. However, the menisci have limited healing potential due to the paucity of vascularity. The purpose of the present study was to test the feasibility of a scaffold-free tissue-engineered construct (TEC) derived from synovial mesenchymal stem cells (MSCs) to repair incurable meniscal lesions. Porcine synovial MSCs were cultured in monolayers at high density in the presence of ascorbic acid followed by the suspension culture to develop a three-dimensional cell/matrix construct (TEC). A 4-mm cylindrical defect was created bilaterally in the medial meniscus of skeletally mature miniature pigs. The defects were implanted with an allogenic TEC or were left empty. After 6 months, the TEC-treated defects were consistently repaired by a fibro-cartilaginous tissue with good tissue integration to the adjacent host meniscal tissue, while the untreated were either partially or not repaired. The ratio of Safranin O positive area within the central body of the meniscus adjacent to the original defect was significantly higher in the TEC-treated group than in the control group. Moreover, TEC treatment significantly reduced the size and severity of post-traumatic chondral lesions on the tibial plateau. These results suggest that the TEC could be a promising stem cell-based implant to repair meniscal lesions with preventive effects from meniscal body degeneration and the development of post-traumatic arthritis.

Detection of abnormalities in the superficial zone of cartilage repaired using a tissue engineered construct derived from synovial stem cells

The present study investigated the surface structure and mechanical properties of repair cartilage generated from a tissue engineered construct (TEC) derived from synovial mesenchymal stem cells at six months post-implantation compared to those of uninjured cartilage. TEC-mediated repair tissue was cartilaginous with Safranin O staining, and had comparable macro-scale compressive properties with uninjured cartilage. However, morphological assessments revealed that the superficial zone of TEC-mediated tissue was more fibrocartilage-like, in contrast to the middle or deep zones that were more hyaline cartilage-like with Safranin O staining. Histological scoring of the TEC-mediated tissue was significantly lower in the superficial zone than in the middle and deep zones. Scanning electron microscopy showed a thick tangential bundle of collagen fibres at the most superficial layer of uninjured cartilage, while no corresponding structure was detected at the surface of TEC-mediated tissue. Immunohistochemical analysis revealed that PRG4 was localised in the superficial area of uninjured cartilage, as well as the TEC-mediated tissue. Friction testing showed that the lubrication properties of the two tissues was similar, however, micro-indentation analysis revealed that the surface stiffness of the TEC-repair tissue was significantly lower than that of uninjured cartilage. Permeability testing indicated that the TEC-mediated tissue exhibited lower water retaining capacity than did uninjured cartilage, specifically at the superficial zone. Thus, TEC-mediated tissue exhibited compromised mechanical properties at the superficial zone, properties which need improvement in the future for maintenance of long term repair cartilage integrity.

High-resolution mapping of a novel genetic locus regulating voluntary physical activity in mice

Both human beings and animals exhibit substantial inter-individual variation in voluntary physical activity, and evidence indicates that a significant component of this variation is because of genetic factors. However, little is known of the genetic basis underlying central regulation of voluntary physical activity in mammals. In this study, using an F(2) intercross population and interval-specific congenic strains (ISCS) derived from the C57BL/6J strain and a chromosome 13 substitution strain, C57BL/6J-Chr13A/J/NA/J, we identified a 3.76-Mb interval on chromosome 13 containing 25 genes with a significant impact on daily voluntary wheel running activity in mice. Brain expression and polymorphisms between the C57BL/6J and A/J strains were examined to prioritize candidate genes. As the dopaminergic pathway regulates motor movement and motivational behaviors, we tested its function by examining cocaine-induced locomotor responses in ISCS with different levels of activity. The low-activity ISCS exhibited a significantly higher response to acute cocaine administration than the high-activity ISCS. Expression analysis of key dopamine-related genes (dopamine transporter and D1, D2, D3, D4 and D5 receptors) revealed that expression of D1 receptor was higher in the low-activity ISCS than in the high-activity ISCS in both the dorsal striatum and nucleus accumbens. Pathway analysis implicated Tcfap2a, a gene found within the 3.76-Mb interval, involved in the D1 receptor pathway. Using a luciferase reporter assay, we confirmed that the transcriptional factor, Tcfap2a, regulates the promoter activity of the D1 receptor gene. Thus, Tcfap2a is proposed as a candidate genetic regulator of the level of voluntary physical activity through its influence on a dopaminergic pathway.

A mutation in KCNJ11 causing human hyperinsulinism (Y12X) results in a glucose-intolerant phenotype in the mouse

AIMS/HYPOTHESIS

We identified a mouse with a point mutation (Y12STOP) in the Kcnj11 subunit of the K(ATP) channel. This point mutation is identical to that found in a patient with congenital hyperinsulinism of infancy (HI). We aimed to characterise the phenotype arising from this loss-of-function mutation and to compare it with that of other mouse models and patients with HI.

METHODS

We phenotyped an N-ethyl-N-nitrosourea-induced mutation on a C3H/HeH background (Kcnj11 ( Y12STOP )) using intraperitoneal glucose tolerance testing to measure glucose and insulin plasma concentrations. Insulin secretion and response to incretins were measured on isolated islets.

RESULTS

Homozygous male and female adult Kcnj11 ( Y12STOP ) mice exhibited impaired glucose tolerance and a defect in insulin secretion as measured in vivo and in vitro. Islets had an impaired incretin response and reduced insulin content.

CONCLUSIONS/INTERPRETATION

The phenotype of homozygous Kcnj11 ( Y12STOP ) mice is consistent with that of other Kcnj11-knockout mouse models. In contrast to the patient carrying this mutation homozygously, the mice studied did not have hyperinsulinaemia or hypoglycaemia. It has been reported that HI patients may develop diabetes and our mouse model may reflect this clinical feature. The Kcnj11 ( Y12STOP ) model may thus be useful in further studies of K(ATP) channel function in various cell types and in investigation of the development of hyperglycaemia in HI patients.

The influence of skeletal maturity on allogenic synovial mesenchymal stem cell-based repair of cartilage in a large animal model

One of the potential factors that may affect the results of mesenchymal stem cell (MSC)-based therapy is the age of donors and recipients. However, there have been no controlled studies to investigate the influence of skeletal maturity on the MSC-based repair of cartilage. The purpose of this study was to compare the repair quality of damaged articular cartilage treated by a scaffold-free three-dimensional tissue-engineered construct (TEC) derived from synovial MSCs between immature and mature pigs. Synovial MSCs were isolated from immature and mature pigs and the proliferation and chondrogenic differentiation capacities were compared. The TEC derived from the synovial MSCs were then implanted into equivalent chondral defects in the medial femoral condyle of both immature and mature pigs, respectively. The implanted defects were morphologically and biomechanically evaluated at 6 months postoperatively. There was no skeletal maturity-dependent difference in proliferation or chondrogenic differentiation capacity of the porcine synovial MSCs. The TEC derived from synovial MSCs promoted the repair of chondral lesion in both immature and mature pigs without the evidence of immune reaction. The repaired tissue by the TEC also exhibited similar viscoelastic properties to normal cartilage regardless of the skeletal maturity. The results of the present study not only suggest the feasibility of allogenic MSC-based cartilage repair over generations but also may validate the use of immature porcine model as clinically relevant to test the feasibility of synovial MSC-based therapies in chondral lesions.

The effect of gantry and collimator angles on leaf limited velocity and position in dynamic multileaf collimator intensity-modulated radiation therapy

The purpose of the study is to evaluate the limiting velocity (LV) of a multileaf collimator and the leaf position in various collimator and gantry angles. Both leading leaves and trailing leaves began to move with a constant acceleration from 0 to 4 cm s(-1). When the beam hold occurred, the leaf velocity was defined as the leaf LV. Dynamic irradiation was performed at eight gantry angles of every 45 degrees with three different collimator angles. The analysis of the LV and the leaf position was performed with a log file from a leaf motion controller. The mean LVs for Varian Clinac 21EX (21EX) ranged from 2.51 to 3.10 cm s(-1). The mean LVs for Clinac 600C ranged from 2.91 to 3.12 cm s(-1). When only central 5 mm leaves of 21EX moved, LVs were significantly higher than those when all 60 pairs of leaf moved, while the leaf position inconsistencies of the two accelerators were within 1 mm at the leaf velocities from 0.5 to 2.0 cm s(-1). It was recognized that the LV was affected by gravity. This measurement method can be utilized as routine quality assurance for a dynamic multileaf collimator (DMLC) is and easily reproducible.

The first clinical case of a mutation at residue K185 of Kir6.2 (KCNJ11): a major ATP-binding residue

BACKGROUND

Closure of the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel plays a key role in insulin secretion from the pancreatic beta-cells. Many mutations in KCNJ11 and ABCC8, which respectively encode the pore-forming (Kir6.2) and regulatory (SUR1) subunits of the K(ATP) channel, cause neonatal diabetes. All such mutations impair the ability of metabolically generated ATP to close the channel. Although lysine 185 is predicted to be a major contributor to the ATP-binding site of Kir6.2, no mutations at this residue have been found to cause neonatal diabetes to date.

METHODS

We report a 3-year-old girl with permanent neonatal diabetes (PNDM) caused by a novel heterozygous mutation (K185Q) at residue K185 of KCNJ11. The patient presented with marked hyperglycaemia and ketoacidosis at 70 days after birth, and insulin therapy was commenced.

RESULTS

Wild-type and mutant K(ATP) channels were expressed in Xenopus oocytes and the effects of intracellular ATP on macroscopic K(ATP) currents in inside-out membrane patches were measured. In the simulated heterozygous state, the K185Q mutation caused a substantial reduction in the ability of MgATP to inhibit the channel. Heterozygous K185Q channels were still blocked effectively by the sulphonylurea tolbutamide.

CONCLUSIONS

We report the first clinical case of a PNDM caused by a mutation at K185. Functional studies indicate that the K185Q mutation causes PNDM by reducing the ATP sensitivity of the K(ATP) channel, probably via a reduction in ATP binding to Kir6.2. Based on the experimental data, the patient was successfully transferred to sulphonylurea therapy.

Genotyping of Strawberry (Fragaria ananassa Duch.) Cultivars by DNA Markers: Interlaboratory Study

Fourteen Japanese laboratories validated the reproducibility of genotyping by 25 cleavage amplified polymorphic sequence (CAPS) markers for discrimination of strawberry (Fragaria ananassa Duch.) cultivars. Both the sensitivity and specificity rate of 12 markers were 100, those of another 12 were >95, and those of 1 were >90. These results indicate that the method of genotyping by the CAPS markers was highly reproducible and could provide a useful basis for practical identification of strawberry cultivars. This is the first report of the statistical validation of crop genotyping by DNA markers.

Mechanism of disopyramide-induced hypoglycaemia in a patient with Type 2 diabetes

BACKGROUND

Disopyramide, an antiarrhythmia drug, has been reported to cause hypoglycaemia. Pre-existing factors that increase the concentration of the drug in the blood increase the risk of hypoglycaemia. Furthermore, other factors can also increase the risk of hypoglycaemia even when disopyramide levels are in the therapeutic range. It has been proposed that disopyramide-induced hypoglycaemia is caused by inhibition of the pancreatic B-cell K(ATP) channels.

CASE REPORT

We report a case of severe disopyramide-induced hypoglycaemia in a 62-year-old woman with Type 2 diabetes taking low-dose glimepiride treatment. She had not experienced hypoglycaemia prior to the start of disopyramide therapy. No further hypoglycaemic episodes occurred following withdrawal of disopyramide therapy. FUNCTIONAL STUDY: Current recordings of K(ATP) channels expressed in Xenopus oocytes showed that at their estimated therapeutic concentrations, disopyramide and glimepiride inhibited K(ATP) channels by about 50-60%. However, when both drugs were applied together, K(ATP) channels were almost completely closed (approximately 95%). Such dramatic inhibition of K(ATP) channels is sufficient to cause B-cell membrane depolarization and stimulate insulin secretion.

CONCLUSIONS

Disopyramide therapy is not recommended for patients treated with K(ATP) channel inhibitors.

Overexpression of RegIV in peritoneal dissemination of gastric cancer and its potential as A novel marker for the detection of peritoneal micrometastasis

BACKGROUND

Regenerating gene type IV (RegIV) is a candidate marker for cancer and inflammatory bowel disease. In this study, its potential as a novel marker for the detection of gastric cancer peritoneal micrometastases was examined.

PATIENTS AND METHODS

RegIV mRNA levels in the peritoneal washes of 95 gastric cancer patients and 22 with benign disease were quantified by real-time RT-PCR. To examine whether expression of RegIV enhance tumorigenicity or not, thirty two mice were injected intraperitoneally or subcutaneously with RegIV transfectants of TMK-1 cells, parental TMK-1 cells, or neomycin control transfectants.

RESULTS

RegIV expression was markedly higher in patients with peritoneal metastases compared to those without. The level of RegIV mRNA in gastric cancer patients was related to the extent of wall penetration. A cut-off value for RegIV-positive expression was based on an analysis of negative control patients with benign disease, and gastric cancer patients above the cut-off value constituted the micrometastasis (MM+) group. Based on this criteria, 3 out of 43 T1 or T2 cases were MM+ (93% specificity). Among 15 patients with peritoneal dissemination (7 out of 15 cases were positive by cytology), 14 cases were positive for RegIV expression (93% sensitivity), while analysis of carcinoembryonic antigen (CEA) mRNA failed to detect micrometastases in 4 cases (73% sensitivity). Combined analysis of CEA and RegIV improved the accuracy of diagnosis to 100%. The prognosis of RegIV-positive cases was significantly worse than that of RegIV-negative cases. Multivariate analysis using the Cox proportional hazards model suggested that RegIV may be an independent prognostic factor. Stable expression of RegIV significantly enhanced peritoneal metastasis in an animal model of gastric cancer.

CONCLUSION

These findings suggest that RegIV mRNA expression has the potential to serve as a novel marker for detecting peritoneal dissemination in gastric cancer.

Hydrogen bonding in sodium alanate: a muon spin rotation study

We have detected the occurrence of hydrogen bonding involving an interstitial positive muon situated between hydrogen atoms of two independent alanate anions in sodium alanate (NaAlH4). Ti doping, which is known to dramatically improve the hydrogen cycling performance of NaAlH4, reduces the kinetic barrier of the transition of the muon from the muon-dialanate state to a mobile interstitial state. This observation strongly suggests that hydrogen bonding is the primary bottleneck for hydrogen release or uptake in sodium alanate, which might be common to other complex hydrides.

A novel mutation causing DEND syndrome: a treatable channelopathy of pancreas and brain

OBJECTIVES

Activating mutations in the human KCNJ11 gene, encoding the pore-forming subunit (Kir6.2) of the ATP-sensitive potassium (K(ATP)) channel, are one cause of neonatal diabetes mellitus. In a few patients, KCNJ11 mutations cause a triad of developmental delay, epilepsy, and neonatal diabetes (DEND syndrome). The aim of this study was to determine the clinical effects, functional cause, and sensitivity to sulfonylurea treatment of a novel KCNJ11 mutation producing DEND syndrome.

METHODS

We screened the DNA of a 3-year-old patient with neonatal diabetes, severe developmental delay, and therapy-resistant epilepsy for mutations in KCNJ11. We carried out electrophysiologic analysis of wild-type and mutant K(ATP) channels heterologously expressed in Xenopus oocytes.

RESULTS

We identified a novel Kir6.2 mutation (I167L) causing DEND syndrome. Functional analysis showed both homomeric and heterozygous mutant channels were less inhibited by MgATP leading to an increase in whole-cell K(ATP) currents. This effect was due to an increase in the intrinsic open probability. Heterozygous channels were strongly inhibited by the sulfonylurea tolbutamide. Treatment of the patient with the sulfonylurea glibenclamide not only enabled insulin therapy to be stopped, but also resulted in improvement in epilepsy and psychomotor abilities.

CONCLUSIONS

We report a case of developmental delay, epilepsy, and neonatal diabetes (DEND) syndrome that shows neurologic improvement with sulfonylurea therapy. Early recognition of patients with DEND syndrome may have considerable therapeutic benefit for the patient.

Nicotinamide nucleotide transhydrogenase: a link between insulin secretion, glucose metabolism and oxidative stress

This paper reviews recent studies on the role of Nnt (nicotinamide nucleotide transhydrogenase) in insulin secretion and detoxification of ROS (reactive oxygen species). Glucose-stimulated insulin release from pancreatic beta-cells is mediated by increased metabolism. This elevates intracellular [ATP], thereby closing KATP channels (ATP-sensitive potassium channels) and producing membrane depolarization, activation of voltage-gated Ca2+ channels, Ca2+ influx and, consequently, insulin secretion. The C57BL/6J mouse displays glucose intolerance and reduced insulin secretion, which results from a naturally occurring deletion in the Nnt gene. Transgenic expression of the wild-type Nnt gene in C57BL/6J mice rescues the phenotype. Knockdown of Nnt in the insulin-secreting cell line MIN6 with small interfering RNA dramatically reduced Ca2+ influx and insulin secretion. Similarly, mice carrying ENU (N-ethyl-N-nitrosourea)-induced loss-of-function mutations in Nnt were glucose intolerant and secreted less insulin during a glucose tolerance test. Islets isolated from these mice showed impaired insulin secretion in response to glucose, but not to the KATP channel blocker tolbutamide. This is explained by the fact that glucose failed to elevate ATP in Nnt mutant islets. Nnt is a nuclear-encoded mitochondrial protein involved in detoxification of ROS. beta-Cells isolated from Nnt mutant mice showed increased ROS production on glucose stimulation. We hypothesize that Nnt mutations enhance glucose-dependent ROS production and thereby impair beta-cell mitochondrial metabolism, possibly via activation of uncoupling proteins. This reduces ATP production and lowers KATP channel activity. Consequently, glucose-dependent electrical activity and insulin secretion are impaired.

Effect of peroxisome proliferator-activated receptor alpha ligand fenofibrate on K(v) channels in the insulin-secreting cell line HIT-T15

Ligands for peroxisome proliferator-activated receptors alpha (PPARalpha) are clinically used for the treatment of patients with hyperlipidemia. As we have previously shown, a synthetic ligand of PPARalpha, fenofibrate, has a stimulatory effect on insulin secretion in clonal hamster insulinoma beta-cell line HIT-T15 cells. We have also demonstrated that fenofibrate directly inhibits ATP-sensitive potassium (K(ATP)) channels, an effect independent of PPARalpha. In this study, fenofibrate was shown to be able to reduce voltage-dependent K(+) (K(v)) channel currents in voltage-independent manner. Therefore, fenofibrate may modulate insulin secretion not only via inhibition of K(ATP) channels but also via reduction of the K(v) channel current.

Introduction and evaluation of a newly established holiday work system in the pharmacy ward at Municipal Ikeda Hospital

At the Municipal Ikeda Hospital, a system in which pharmacists stationed in one ward pharmacy dispense drugs to be administered by injection and injectable preparations delivered to patients' bedsides was introduced in April 2000. This system was aimed at minimizing risks related to injections. Initially, however, on holidays, nurses played the roles of pharmacists in terms of the injections, and there were concerns over a possible rise in the incidence of errors (adverse events/near-misses) related to injections on these days compared with weekdays. Later, when planning to introduce a new holiday work system in the ward pharmacy, we took into account such factors as the number of pharmacists needed on holidays, their duties on holidays and the influence on weekday pharmacy activity of compensatory days-off taken by such pharmacists. In May 2004, the new holiday work system was introduced in the ward pharmacy. Under the new system, 5 pharmacists work at the ward pharmacy on holidays. After this system was put into operation, the number of injections dispensed at the ward pharmacy averaged 230 per day, and 177 per holiday. To evaluate the validity of this system, we recently conducted a questionnaire survey of nurses at our hospital. The survey involved 139 nurses. Of these nurses, 69.1% responded that the number of incidents (adverse events/near-misses) related to dispensing injections on holidays had decreased. Furthermore, 65.4% of the nurses reported a decrease in incidents related to the delivery and administration of injectable preparations. More than half of the nurses answered that the new system had made it easier for them to collect information on medicines and helped them provide better nursing services. When the nurses were asked to make a general assessment of the new system, 90% rated the system as "good." The results of this survey indicate that keeping the ward pharmacy open on holidays contributes to the promotion of the proper use of medicines, reduction of risks related to injections and improvement in the quality of medical care.

Responses of transformed root culture of Atropa belladonna to salicylic acid stress

The effect of salicylic acid (SA) on tropane alkaloid production and the responses to SA stress of transformed root cultures of Atropa belladonna (belladonna) were investigated. Treatment of A. belladonna transformed roots with 0.2 mM SA did not have any effect on tropane alkaloid production, but two compounds were produced in the medium. These were identified as the SA derivatives methylsalicylate and methyl-o-methoxybenzoate by high-resolution mass spectrometry and UV spectrometry. In contrast, treatment with 2 mM salicylic acid stimulated tropane alkaloid release from the transformed roots into the medium by up to 35% of the total alkaloids after 24 h, and the SA derivatives were not observed in the medium. These results revealed that transformed root of A. belladonna exhibits distinct by different responses to SA stress depending on the SA concentration.

A genetic and physiological study of impaired glucose homeostasis control in C57BL/6J mice

AIMS/HYPOTHESIS

C57BL/6J mice exhibit impaired glucose tolerance. The aims of this study were to map the genetic loci underlying this phenotype, to further characterise the physiological defects and to identify candidate genes.

METHODS

Glucose tolerance was measured in an intraperitoneal glucose tolerance test and genetic determinants mapped in an F2 intercross. Insulin sensitivity was measured by injecting insulin and following glucose disposal from the plasma. To measure beta cell function, insulin secretion and electrophysiological studies were carried out on isolated islets. Candidate genes were investigated by sequencing and quantitative RNA analysis.

RESULTS

C57BL/6J mice showed normal insulin sensitivity and impaired insulin secretion. In beta cells, glucose did not stimulate a rise in intracellular calcium and its ability to close KATP channels was impaired. We identified three genetic loci responsible for the impaired glucose tolerance. Nicotinamide nucleotide transhydrogenase (Nnt) lies within one locus and is a nuclear-encoded mitochondrial proton pump. Expression of Nnt is more than sevenfold and fivefold lower respectively in C57BL/6J liver and islets. There is a missense mutation in exon 1 and a multi-exon deletion in the C57BL/6J gene. Glucokinase lies within the Gluchos2 locus and shows reduced enzyme activity in liver.

CONCLUSIONS/INTERPRETATION

The C57BL/6J mouse strain exhibits plasma glucose intolerance reminiscent of human type 2 diabetes. Our data suggest a defect in beta cell glucose metabolism that results in reduced electrical activity and insulin secretion. We have identified three loci that are responsible for the inherited impaired plasma glucose tolerance and identified a novel candidate gene for contribution to glucose intolerance through reduced beta cell activity.

Frequent loss of RUNX3 gene expression in remnant stomach cancer and adjacent mucosa with special reference to topography

Our previous studies suggest that a lack of RUNX3 function is causally related to the genesis and progression of human gastric cancer. This study was conducted to determine whether alteration of RUNX3 gene expression could be detected in the normal-looking gastric remnant mucosa, and to ascertain any difference in the potential of gastric carcinogenesis between the anastomotic site and other areas in the remnant stomach after distal gastrectomy for peptic ulcer (RB group) or gastric cancer (RM group), by analysing RUNX3 expression with special reference to topography. A total of 89 patients underwent distal gastrectomy for gastric cancer from the intact stomach (GCI group) and 58 patients underwent resection of the remnant stomach for gastric cancer (RB group: 34 cases, RM group: 24 cases). We detected RUNX3 and gene promoter methylation by in situ hybridisation, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), and methylation-specific PCR. The interval between the initial surgery and surgery for remnant gastric cancer (interval time) was 10.4 years in the RM group, and 27.5 years in the RB group. Cancers in the RB group were significantly more predominant in the anastomosis area (P<0.05). Within the tumour, downregulation of RUNX3 expression ranged from 74.7 to 85.7% in the three groups. The rate of downregulation of RUNX3 of adjacent mucosa was 39.2% (11 in 28 cases) in RB and 47.6% (10 in 21 cases) in RM, which are significantly higher than that of the GCI group (19.5%, 17 in 87 cases). In noncancerous mucosa of the remnant stomach in the RB group, RUNX3 expression decreased more near the anastomosis area. In the RM group, however, there were no significant differences in RUNX3 expression by sampling location. Based on RUNX3 downregulation and clinical features, residual stomach mucosa of the RM group would have a higher potential of gastric carcinogenesis compared to the RB or GCI group. Gastric stump mucosa of the RB group has higher potential especially than other areas of residual stomach mucosa. Measurement of RUNX3 expression and detection of RUNX3 methylation in remnant gastric mucosa may estimate the forward risk of carcinogenesis in the remnant stomach.

Muonium as a shallow center in GaN

A paramagnetic muonium (Mu) state with an extremely small hyperfine parameter was observed for the first time in single-crystalline GaN below 25 K. It has a highly anisotropic hyperfine structure with axial symmetry along the <0001> direction, suggesting that it is located either at a nitrogen-antibonding or a bond-centered site oriented parallel to the c axis. Its small ionization energy (<or=14 meV) and small hyperfine parameter (approximately 10(-4) times the vacuum value) indicate that muonium in one of its possible sites produces a shallow state, raising the possibility that the analogous hydrogen center could be a source of n-type conductivity in as-grown GaN.

A new virus related to Satsuma dwarf virus: the nucleotide sequence of the 3'-terminal regions of Hyuganatsu virus RNAs 1 and 2. Brief Report

The sequences of the 3'-terminal 1306 and 2160 nucleotides of RNAs 1 and 2 of a virus serologically related to Satsuma dwarf virus (SDV) from Hyuganatsu ( Citrus tamurana Hort. ex Tan.) were determined, respectively. We found that the partial RNA-dependent RNA polymerase region in RNA1 and the coat proteins (CPs) region in RNA2 of the virus tentatively named Hyuganatsu virus (HV) have 78.3-84.0% and 76.9-80.7% amino acid sequence identities to those of known SDV-related viruses (SDV-RVs), i.e., SDV, Citrus mosaic virus, and Navel orange infectious mottling virus. Sequence analyses show that HV is classifiable as a new SDV-RV species.

Overexpression of dopa decarboxylase in peritoneal dissemination of gastric cancer and its potential as a novel marker for the detection of peritoneal micrometastases with real-time RT-PCR

We previously performed a global analysis of the gene expression of gastric cancer cell lines established from metastases to the peritoneal cavity with the cDNA microarray method, which made it possible to analyse the expression of approximately 21 168 genes for the identification of novel markers for the detection of micrometastases in the peritoneal cavity. One of the upregulated genes is dopa decarboxylase (DDC), which is responsible for the synthesis of the key neurotransmitters dopamine and serotonine. We have examined its potential as a novel marker for the detection of peritoneal micrometastases of gastric cancer.

DDC mRNA in the peritoneal wash from 112 gastric cancer patients was quantified for comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time reverse transcriptase–polymerase chain reaction (RT–PCR) with a fluorescently labelled probe to predict peritoneal recurrence. The quantity of DDC and CEA correlated with wall penetration. Real-time RT–PCR could quantitate 10–10⁶ DDC-expressing gastric cancer cells per 10⁷ mesothelial cells. The cutoff value was set at the upper limit of the quantitative value for noncancer patients, and those above this cutoff value constituted the micrometastasis (MM+) group. Of 15 cases with peritoneal dissemination, 13 were MM+DDC (87% sensitivity), and one of 48 t1 cases was MM+ (98% specificity). DDC levels in peritoneal washes from patients with synchronous peritoneal metastases were more than 50 times higher than in those from patients without metastasis (P<0.01). For 15 cases of peritoneal dissemination (seven cases were cytologically positive), DDC was positive in 13 cases (87% sensitivity), but CEA failed to detect micrometastases in four cases (73% sensitivity), indicating that DDC is in some cases superior to CEA for the detection of peritoneal micrometastases of gastric cancer in terms of sensitivity as well as specificity, especially for poorly differentiated adenocarcinomas. A combination of CEA and DDC improved the accuracy of diagnosis up to 94%.

These results suggest that DDC is potentially a novel marker for peritoneal dissemination of gastric cancer and that quantitative RT–PCR of DDC is reliable and efficient for the selection of patients for adjuvant intraperitoneal chemotherapy to prevent peritoneal recurrence.

Differential gene expression profiles of gastric cancer cells established from primary tumour and malignant ascites

Advanced gastric cancer is often accompanied by metastasis to the peritoneum, resulting in a high mortality rate. Mechanisms involved in gastric cancer metastasis have not been fully clarified because metastasis involves multiple steps and requires a combination of altered expressions of many different genes. Thus, independent analysis of any single gene would be insufficient to understand all of the aspects of gastric cancer peritoneal dissemination. In this study, we performed a global analysis of the differential gene expression of a gastric cancer cell line established from a primary main tumour (SNU-1) and of other cell lines established from the metastasis to the peritoneal cavity (SNU-5, SNU-16, SNU-620, KATO-III and GT3TKB). The application of a high-density cDNA microarray method made it possible to analyse the expression of approximately 21 168 genes. Our examinations of SNU-5, SNU-16, SNU-620, KATO-III and GT3TKB showed that 24 genes were up-regulated and 17 genes down-regulated besides expression sequence tags. The analysis revealed the following altered expression such as: (a) up-regulation of CD44 (cell adhesion), keratins 7, 8, and 14 (epitherial marker), aldehyde dehydrogenase (drug metabolism), CD9 and IP3 receptor type3 (signal transduction); (b) down-regulation of IL2 receptor gamma, IL4-Stat (immune response), p27 (cell cycle) and integrin beta4 (adhesion) in gastric cancer cells from malignant ascites. We then analysed eight gastric cancer cell lines with Northern blot and observed preferential up-regulation and down-regulation of these selected genes in cells prone to peritoneal dissemination. Reverse transcriptase-polymerase chain reaction confirmed that several genes selected by DNA microarray were also overexpressed in clinical samples of malignant ascites. It is therefore considered that these genes may be related to the peritoneal dissemination of gastric cancers. The results of this global gene expression analysis of gastric cancer cells with peritoneal dissemination, promise to provide a new insight into the study of human gastric cancer peritoneal dissemination.

Isoquinoline alkaloid production by transformed cultures of Papaver somniferum

Three clones of transformed cultures of opium poppy (Papaver somniferum L.) were established by infection with Agrobacterium rhizogenes MAFF 03-01724. MAFF clone 1 being capable of forming somatic embryos was selected and its growth and isoquinoline alkaloid production was investigated. The illumination, temperature and nutrient medium composition greatly affected growth, cell morphology and alkaloid accumulation. The MAFF clone 1 cultured in Root Culture medium in the dark at 22 degrees C accumulated a high quantity of sanguinarine (652 micrograms/g dry weight) though the growth was poor (4.4 fold as fresh weight basis after 2 months of culture). The MAFF clone 1 cultured in a quarter macro salt strength Woody Plant medium under 14 h/day light at 22 degrees C developed into plantlets and accumulated significant quantity of codeine (648 micrograms/g dry wt) together with papaverine, noscapine, and sanguinarine. This clone was applied to a rotating drum fermenter (2 L working volume), and ca. 0.3 mg codeine and 0.06 mg sanguinarine were obtained after 4 weeks of culture. One quarter of the codeine produced was found in the culture medium.

Minilaparotomy wound edge protector (Lap-Protector): a new device

Laparoscopic-assisted or minimally invasive surgery involving minilaparotomy is occasionally complicated by infection of the minilaparotomy wound caused by intestinal bacteria. Furthermore, when this procedure is performed to excise colorectal or gastric cancer, tumor recurrence may develop in the minilaparotomy wound. In an attempt to minimize the risk of these complications, we developed a new, easy-to-use device which we named the "Lap-Protector." Minilaparotomy was performed using the Lap-Protector in 28 patients with colon cancer and eight patients with early gastric cancer who underwent minimally invasive surgery between January and September, 1999. During a median follow-up period of 15.9 (range 12.4-21.0) months, none of the 36 patients showed any sign of wound infection or tumor recurrence in the minilaparotomy wound. These results indicated that the Lap-Protector is a safe and useful device that may help to prevent infections and cancer cell contamination of the minilaparotomy wound.

[Characteristics of Papaver somniferum L. cv. ikkanshu cultivated in Izu]

The seeds of Papaver somniferum L. cv. Ikkanshu were sown in November (Autumn sowing: AS) and March (Spring sowing: SS) in a field at Izu Experimental Station for Medicinal Plants of National Institute of Health Sciencs, and both AS and SS plants were cultivated to investigate their growth, opium yield and alkaloid content in the opium. Growing periods from the sowing to the opium harvest were approximately six months for AS plants and three months for SS plants. Sizes of plants and capsules in AS were bigger than those in SS, reflecting their growth period. Opium yields per an are in AS and SS were 212.09 g and 142.03 g, respectively. The opium was able to be collected four times in the AS plants though the SS plants ceased to exude opium after the second incision. Therefore higher yield of opium in AS plants seems to be attributed to an amount of opium in the third and fourth incision. Average morphine content in the total opium was 15.61% in AS plants and 15.04% in SS plants, and the estimated amounts of morphine per an are in AS and SS plants were 33.16 g and 21.38 g, respectively.

Development of an ultrasonically activated trocar system

BACKGROUND

Although rare, visceral and vascular injuries related to the insertion of conventional laparoscopic trocars may have disastrous consequences. Most of these injuries are due to the high puncture force applied to the trocar. We present the results of an animal laboratory evaluation of a newly developed ultrasonically activated trocar.

METHODS

A total of 40 punctures were made in four pigs with an average weight of 53 kg. An 11-mmHg pneumoperitoneum was created through a Veress needle. A 10-mm diameter trocar was inserted in the midline for a laparoscope. A series of five trocars were then inserted on each lateral wall under laparoscopic control. Twenty punctures were made with a conventional reusable 11-mm trocar (CT) whose tip was sharp and conical. Twenty punctures were made with an 11-mm ultrasonically activated trocar (UT), whose fequency was 23.5 KHz and amplitude 150 mm. The cutaneous incision was made large enough so that the skin did not interfere with the trocar insertion. The force applied to the trocar was measured with a push-pull gauge connected to a computer. The following data were recorded: maximal force applied to the trocar to obtain insertion of the tip through the abdominal wall, maximum abdominal pressure increase during trocar insertion, and time for abdominal penetration.

RESULTS

The average time needed for trocar penetration was 12.8 s with CT and 4.5 s with UT (p < 0.001). The average maximal force was 6.8 kgF with CT and 0.4 kgF with UT (p < 0.001). The average abdominal pressure increase was 7.6 mmHg with CT and 0.8 mmHg with UT (p < 0.001). At 30 days, no necrosis was found. Pathological findings were similar in both groups.

CONCLUSION

Ultrasonically activated trocars required less time and much less force to be inserted. This may be a breakthrough in the safety of trocar insertion.

[Analysis of the action of dextran sulfate as a prophylaxis for peritoneal cancer metastasis, and its acting mechanism]

Although peritoneal cancer metastasis has the highest frequency of postoperative recurrence among digestive organ malignant tumors, there is no still decisive treatment. Dextran sulfate (DS) as a prophylaxis for cancer metastasis was examined with respect to its effect on cultured cells. DS was made to act on a strong adhesive neoplasm cell, and the action and acting mechanism were examined with respect to 1. readhesiveness, 2. cell cycle, and 3. gene analysis. The results suggest that: i) Once tumor cells are detached by DS, the free cells do not attach even when DS is removed, and ii) DS causes the cells to stop in the G1/G0 phase.