Conversion of a conventional superconductor into a topological superconductor by topological proximity effect

Realization of topological superconductors (TSCs) hosting Majorana fermions is a central challenge in condensed-matter physics. One approach is to use the superconducting proximity effect (SPE) in heterostructures, where a topological insulator contacted with a superconductor hosts an effective p-wave pairing by the penetration of Cooper pairs across the interface. However, this approach suffers a difficulty in accessing the topological interface buried deep beneath the surface. Here, we propose an alternative approach to realize topological superconductivity without SPE. In a Pb(111) thin film grown on TlBiSe₂, we discover that the Dirac-cone state of substrate TlBiSe₂ migrates to the top surface of Pb film and obtains an energy gap below the superconducting transition temperature of Pb. This suggests that a Bardeen-Cooper-Schrieffer superconductor is converted into a TSC by the topological proximity effect. Our discovery opens a route to manipulate topological superconducting properties of materials.

Realizing topological superconductivity is essential for applicable fault-tolerant quantum computation. Here, Trang et al. report migration of Dirac-cone from TlBiSe₂ substrate to top surface of superconducting Pb film due to topological proximity effect, suggesting realization of topological superconductivity.

Lens Coloboma and Alport-Like Glomerulonephritis

An unusual case of bilateral lens coloboma and Alport-like glomerulonephritis is reported. In a 12-year-old boy and in several family members; Alport-like glomerulonephritis was diagnosed without deafness and without ocular signs of Alport syndrome. A bilateral lens coloboma however was observed in the propositus. To our knowledge this is the first reported case of lens coloboma with Alport-like glomerulonephritis.

Development of a novel algorithm for detecting glucocorticoid-induced diabetes mellitus using a medical information database

WHAT IS KNOWN AND OBJECTIVE

Glucocorticoid-induced diabetes mellitus (GIDM) increases the risk of diabetes mellitus (DM)-related complications but is generally difficult to detect in clinical settings. The criteria for diagnosing GIDM have not been established. Recently, medical information databases (MIDs) have been used in post-marketing surveillance (PMS) studies. We conducted a pharmacoepidemiological study to develop an algorithm for detecting GIDM using MID.

METHODS

We selected 1214 inpatients who were newly prescribed with a typical glucocorticoid, prednisolone, during hospitalization from 2008 to 2014 from an MID of Hamamatsu University Hospital in Japan. GIDM was screened based on fasting blood glucose (FBG) and haemoglobin A1c (HbA1c) levels according to the current Japan Diabetes Society (JDS) DM criteria, and its predictability was evaluated by an expert's review of medical records. We investigated further candidate screening factors using receiver operating characteristics analysis.

RESULTS

Sixty-three inpatients were identified by the JDS DM criteria. Of these, 33 patients were definitely diagnosed as having GIDM by expert's review (positive predictive value = 52·4%). To develop a highly predictive algorithm, we compared the characteristics of inpatients diagnosed with definite GIDM and those diagnosed as non-GIDM. The maximum levels of HbA1c in patients with GIDM were significantly higher than those of patients with non-GIDM (66·9 mmol/mol vs. 58·7 mmol/mol, P < 0·001). The patients with GIDM had significantly higher relative increase in maximum level of HbA1c (RIM-HbA1c) than those with non-GIDM (0·3 vs. 0·03, P < 0·001). However, we did not observe a significant difference in those of fasting blood glucose (FBG) levels. We applied the RIM-HbA1c as a second screening factor to improve the detection of GIDM. It showed that a 13% increase in RIM-HbA1c separated patients with from patients without GIDM.

WHAT IS NEW AND CONCLUSIONS

Patients with GIDM had significantly higher RIM-HbA1c than patients with non-GIDM. There was a 13% increase in RIM-HbA1c in patients with GIDM compared to the others. Our detection algorithm for GIDM using an MID achieved high sensitivity and specificity, and was superior to one based only on the current JDS DM criteria. Our results suggest that monitoring changes in HbA1c levels is important for detecting GIDM and adds to current diagnostic criteria for type 2 DM.

Exposure of phosphatidylserine on the cell surface

Phosphatidylserine (PtdSer) is a phospholipid that is abundant in eukaryotic plasma membranes. An ATP-dependent enzyme called flippase normally keeps PtdSer inside the cell, but PtdSer is exposed by the action of scramblase on the cell's surface in biological processes such as apoptosis and platelet activation. Once exposed to the cell surface, PtdSer acts as an 'eat me' signal on dead cells, and creates a scaffold for blood-clotting factors on activated platelets. The molecular identities of the flippase and scramblase that work at plasma membranes have long eluded researchers. Indeed, their identity as well as the mechanism of the PtdSer exposure to the cell surface has only recently been revealed. Here, we describe how PtdSer is exposed in apoptotic cells and in activated platelets, and discuss PtdSer exposure in other biological processes.

Treatment of human mesenchymal stem cells with angiotensin receptor blocker improved efficiency of cardiomyogenic transdifferentiation and improved cardiac function via angiogenesis

To improve the modest efficacy of mesenchymal stem cell (MSC) transplantation, the treatment of human MSCs with angiotensin receptor blockers (ARBs) was investigated. MSCs were cultured with or without the medium containing 3 μmol/l of ARBs before cardiomyogenic induction. After cardiomyogenic induction in vitro, cardiomyogenic transdifferentiation efficiency (CTE) was calculated by immunocytochemistry using anticardiac troponin-I antibody. In the nude rat chronic myocardial infarction model, we injected MSCs pretreated with candesartan (A-BM; n = 18) or injected MSCs without pretreatment of candesartan (BM; n = 25), each having survived for 2 weeks. The left ventricular function, as measured by echocardiogram, was compared with cardiomyogenic transdifferentiation in vivo, as determined by immunohistochemistry. Pretreatment with ARBs significantly increased the CTE in vitro (10.1 ± 0.8 n = 12 vs. 4.6 ± 0.3% n = 25, p < .05). Transplantation of candesartan-pretreated MSCs significantly improved the change in left ventricular ejection fraction (BM; -7.2 ± 2.0 vs. A-BM; 3.3 ± 2.3%). Immunohistochemistry revealed significant improvement of cardiomyogenic transdifferentiation in A-BM in vivo (BM; 0 ± 0 vs. A-BM; 0.014 ± 0.006%). Transplantation of ARB-pretreated MSCs significantly improved cardiac function and can be a promising cardiac stem cell source from which to expect cardiomyogenesis.

Effects of prostaglandin E1 on the preparation of platelet concentrates in dogs

BACKGROUND

Platelet concentrates (PC) are prepared by centrifugation of platelet-rich plasma (PRP) that is prepared by centrifugation of whole blood. The resuspension of the platelet pellet during PC preparation from dogs is difficult because of platelet activation induced by centrifugation.

OBJECTIVES

To investigate the efficacy of adding prostaglandin E(1) (PGE(1) ) to prevent platelet activation during PC preparation from dogs.

ANIMALS

Fifteen healthy Beagle dogs.

METHODS

Prospective, experimental trial: PGE(1) was added to PRP before the high-speed centrifugation during PC preparation. To estimate the effect of this addition, we assessed the platelet aggregability before transfusion, the survival of the platelets after transfusion, and the platelet reactivity after transfusion, which is estimated by the P-selectin expression of the platelets when stimulated by thrombin.

RESULTS

The difficulty associated with platelet resuspension was resolved by PGE(1.) PGE(1) strongly inhibited platelet aggregation induced by collagen and ADP; however, it recovered after the platelets were resuspended in plasma without PGE(1) (mean aggregation ratio; collagen: 10.00-80.80%, ADP: 8.20-53.60%). Survival of the platelets after transfusion was not affected by PGE(1) (mean 8.04 and 7.56 days, without and with PGE(1) ), and thrombin-induced P-selectin expression after transfusion in PGE(1) -treated PC was also well maintained (mean positive ratio 53.7 and 47.9%, before and 24 hours after transfusion).

CONCLUSIONS AND CLINICAL IMPORTANCE

The addition of PGE(1) in PRP before the centrifugation of PRP can improve the preparation efficiency of PC from dogs, while maintaining the therapeutic efficacy of the platelets.

Pretreatment of human mesenchymal stem cells with pioglitazone improved efficiency of cardiomyogenic transdifferentiation and cardiac function

The efficacy of transplantation of default human marrow-derived mesenchymal stem cells (MSCs) was modest. In this study, our challenge was to improve the efficacy of MSC transplantation in vivo by pretreatment of MSCs with pioglitazone. MSCs were cultured with or without medium containing 1 μM of pioglitazone before cardiomyogenic induction. After cardiomyogenic induction in vitro, cardiomyogenic transdifferentiation efficiency (CTE) was calculated by immunocytochemistry using anti-cardiac troponin-I antibody. For the in vivo experiments, myocardial infarction (MI) at the anterior left ventricle was made in nude rats. Two weeks after MI, MSCs pretreated with pioglitazone (p-BM; n = 30) or without pioglitazone (BM; n = 17) were injected, and then survived for 2 weeks. We compared left ventricular function by echocardiogram and immunohistochemistry to observe cardiomyogenic transdifferentiation in vivo. Pretreatment with pioglitazone significantly increased the CTE in vitro (1.9% ± 0.2% n = 47 vs. 39.5% ± 4.7% n = 13, p < .05). Transplantation of pioglitazone pretreated MSCs significantly improved change in left ventricular % fractional shortening (BM; -4.8% ± 2.1%, vs. p-BM; 5.2% ± 1.5%). Immunohistochemistry revealed significant improvement of cardiomyogenic transdifferentiation in p-BM in vivo (BM; 0% ± 0% n = 5, vs. p-BM; 0.077% ± 0.041% n = 5). Transplantation of pioglitazone-pretreated MSCs significantly improved cardiac function and can be a promising cardiac stem cell source to expect cardiomyogenesis.

Serum-independent cardiomyogenic transdifferentiation in human endometrium-derived mesenchymal cells

Media with high concentrations of serum are commonly used to induce cardiomyogenic transdifferentiation in mesenchymal stem cells; however, serum contains numerous unknown growth factors and interferes with definition of specific cardiomyogenic transdifferentiation factors secreted from feeder cells. In the present study, we determined whether the transdifferentiation of human mesenchymal cells can be observed in a FBS-free medium. The efficiency of transdifferentiation was observed in 10% FBS-containing standard medium (10%FBS) and in FBS-free medium containing insulin and thyroxin (FBS-free). In the present study, we used human uterine endometrium-derived mesenchymal cells (EMC100, EMC214) and menstrual blood-derived mesenchymal cells (MMCs). After cardiomyogenic transdifferentiation, the efficiency and physiological properties of cardiomyogenesis (fractional shortening of the cell [%FS] and action potential [AP]) were evaluated. The efficiency of transdifferentiation in EMC100 and in MMCs increased 36%* and 163%* (*P < 0.05), respectively. The %FS in EMCs increased to 103%*. AP-duration more than 250 ms with a marked plateau was only observed in FBS-free (3/19), and not in 10% FBS (0/41). The cardiomyogenic transdifferentiation of human mesenchymal cells can be observed in the FBS-free medium. Phenotypes of generated cardiomyocytes were significantly more physiological in FBS-free than in 10% FBS.

Xenografted human amniotic membrane-derived mesenchymal stem cells are immunologically tolerated and transdifferentiated into cardiomyocytes

RATIONALE

Amniotic membrane is known to have the ability to transdifferentiate into multiple organs and is expected to stimulate a reduced immunologic reaction.

OBJECTIVE

Determine whether human amniotic membrane-derived mesenchymal cells (hAMCs) can be an ideal allograftable stem cell source for cardiac regenerative medicine.

METHODS AND RESULTS

We established hAMCs. After cardiomyogenic induction in vitro, hAMCs beat spontaneously, and the calculated cardiomyogenic transdifferentiation efficiency was 33%. Transplantation of hAMCs 2 weeks after myocardial infarction improved impaired left ventricular fractional shortening measured by echocardiogram (34+/-2% [n=8] to 39+/-2% [n=11]; P<0.05) and decreased myocardial fibrosis area (18+/-1% [n=9] to 13+/-1% [n=10]; P<0.05), significantly. Furthermore hAMCs transplanted into the infarcted myocardium of Wistar rats were transdifferentiated into cardiomyocytes in situ and survived for more than 4 weeks after the transplantation without using any immunosuppressant. Immunologic tolerance was caused by the hAMC-derived HLA-G expression, lack of MHC expression of hAMCs, and activation of FOXP3-positive regulatory T cells. Administration of IL-10 or progesterone, which is known to play an important role in feto-maternal tolerance during pregnancy, markedly increased HLA-G expression in hAMCs in vitro and, surprisingly, also increased cardiomyogenic transdifferentiation efficiency in vitro and in vivo.

CONCLUSIONS

Because hAMCs have a high ability to transdifferentiate into cardiomyocytes and to acquire immunologic tolerance in vivo, they can be a promising cellular source for allograftable stem cells for cardiac regenerative medicine.

Novel cardiac precursor-like cells from human menstrual blood-derived mesenchymal cells

Stem cell therapy can help repair damaged heart tissue. Yet many of the suitable cells currently identified for human use are difficult to obtain and involve invasive procedures. In our search for novel stem cells with a higher cardiomyogenic potential than those available from bone marrow, we discovered that potent cardiac precursor-like cells can be harvested from human menstrual blood. This represents a new, noninvasive, and potent source of cardiac stem cell therapeutic material. We demonstrate that menstrual blood-derived mesenchymal cells (MMCs) began beating spontaneously after induction, exhibiting cardiomyocyte-specific action potentials. Cardiac troponin-I-positive cardiomyocytes accounted for 27%-32% of the MMCs in vitro. The MMCs proliferated, on average, 28 generations without affecting cardiomyogenic transdifferentiation ability, and expressed mRNA of GATA-4 before cardiomyogenic induction. Hypothesizing that the majority of cardiomyogenic cells in MMCs originated from detached uterine endometrial glands, we established monoclonal endometrial gland-derived mesenchymal cells (EMCs), 76%-97% of which transdifferentiated into cardiac cells in vitro. Both EMCs and MMCs were positive for CD29, CD105 and negative for CD34, CD45. EMCs engrafted onto a recipient's heart using a novel 3-dimensional EMC cell sheet manipulation transdifferentiated into cardiac tissue layer in vivo. Transplanted MMCs also significantly restored impaired cardiac function, decreasing the myocardial infarction (MI) area in the nude rat model, with tissue of MMC-derived cardiomyocytes observed in the MI area in vivo. Thus, MMCs appear to be a potential novel, easily accessible source of material for cardiac stem cell-based therapy.

Tyrosine kinase inhibitor, methyl 2,5-dihydromethylcinnimate, induces PML nuclear body formation and apoptosis in tumor cells

Promyelocytic leukemia (PML) nuclear bodies (PML-NBs) are the nuclear structure consisting of various proteins such as PML, SUMO-1, and p53. PML-NBs are implicated in the regulation of tumor suppression, antiviral responses, and apoptosis. In this study, we searched for bioactive metabolites that would promote the formation of PML-NBs in tumor cells. As a result, methyl 2,5-dihydromethylcinnimate (2,5-MeC), a tyrosine kinase inhibitor, enhanced expression and/or stability of PML proteins and induced PML-NB formation in p53 null H1299 cells established from non-small cell lung cancer (NSCLC) and wild-type p53-expressing U2OS cells derived from osteosarcoma. Furthermore, it enhanced apoptosis by exogenously expressed wild type p53 and the expression of p53-responsive genes, such as PUMA and p21, in H1299 cells. 2,5-MeC also activated endogenous p53 and induced apoptosis in U2OS cells. The results suggest that 2,5-MeC is likely to be a promising candidate drug for the clinical treatment of terminal cancer-expressing wild-type p53.

The significant cardiomyogenic potential of human umbilical cord blood-derived mesenchymal stem cells in vitro

We tested the cardiomyogenic potential of the human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs). Both the number and function of stem cells may be depressed in senile patients with severe coronary risk factors. Therefore, stem cells obtained from such patients may not function well. For this reason, UCBMSCs are potentially a new cell source for stem cell-based therapy, since such cells can be obtained from younger populations and are being routinely utilized for clinical patients. The human UCBMSCs (5 x 10(3) per cm(2)) were cocultured with fetal murine cardiomyocytes ([CM] 1 x 10(5) per cm(2)). On day 5 of cocultivation, approximately half of the green fluorescent protein (GFP)-labeled UCBMSCs contracted rhythmically and synchronously, suggesting the presence of electrical communication between the UCBMSCs. The fractional shortening of the contracted UCBMSCs was 6.5% +/- 0.7% (n = 20). The UCBMSC-derived cardiomyocytes stained positive for cardiac troponin-I (clear striation +) and connexin 43 (diffuse dot-like staining at the margin of the cell) by the immunocytochemical method. Cardiac troponin-I positive cardiomyocytes accounted for 45% +/- 3% of GFP-labeled UCBMSCs. The cardiomyocyte-specific long action potential duration (186 +/- 12 milliseconds) was recorded with a glass microelectrode from the GFP-labeled UCBMSCs. CM were observed in UCBMSCs, which were cocultivated in the same dish with mouse cardiomyocytes separated by a collagen membrane. Cell fusion, therefore, was not a major cause of CM in the UCBMSCs. Approximately half of the human UCBMSCs were successfully transdifferentiated into cardiomyocytes in vitro. UCBMSCs can be a promising cellular source for cardiac stem cell-based therapy. Disclosure of potential conflicts of interest is found at the end of this article.

'Working' cardiomyocytes exhibiting plateau action potentials from human placenta-derived extraembryonic mesodermal cells

The clinical application of cell transplantation for severe heart failure is a promising strategy to improve impaired cardiac function. Recently, an array of cell types, including bone marrow cells, endothelial progenitors, mesenchymal stem cells, resident cardiac stem cells, and embryonic stem cells, have become important candidates for cell sources for cardiac repair. In the present study, we focused on the placenta as a cell source. Cells from the chorionic plate in the fetal portion of the human placenta were obtained after delivery by the primary culture method, and the cells generated in this study had the Y sex chromosome, indicating that the cells were derived from the fetus. The cells potentially expressed 'working' cardiomyocyte-specific genes such as cardiac myosin heavy chain 7beta, atrial myosin light chain, cardiac alpha-actin by gene chip analysis, and Csx/Nkx2.5, GATA4 by RT-PCR, cardiac troponin-I and connexin 43 by immunohistochemistry. These cells were able to differentiate into cardiomyocytes. Cardiac troponin-I and connexin 43 displayed a discontinuous pattern of localization at intercellular contact sites after cardiomyogenic differentiation, suggesting that the chorionic mesoderm contained a large number of cells with cardiomyogenic potential. The cells began spontaneously beating 3 days after co-cultivation with murine fetal cardiomyocytes and the frequency of beating cells reached a maximum on day 10. The contraction of the cardiomyocytes was rhythmical and synchronous, suggesting the presence of electrical communication between the cells. Placenta-derived human fetal cells may be useful for patients who cannot supply bone marrow cells but want to receive stem cell-based cardiac therapy.

Membranous osteogenesis system modeled with KUSA-A1 mature osteoblasts

Several stromal cells were established from murine bone marrow cultures. One of the KUSA subclones, KUSA-A1 cells, displays osteogenic characteristics in vitro and in vivo. The calcium deposition, osteocalcin release, and parathyroid hormone (PTH) responsiveness of KUSA-A1 cells indicate that they are mature osteoblasts or osteocytes. Bone had formed in subcutaneous tissue 1 week after subcutaneous injection of cells into immunodeficient mice. The osteogenesis by KUSA-A1 was not mediated by chondrogenesis and thus was considered to be membranous ossification. These unique characteristics of KUSA-A1 cells provide an opportunity to analyze the process of membranous ossification in detail.

Can the life span of human marrow stromal cells be prolonged by bmi-1, E6, E7, and/or telomerase without affecting cardiomyogenic differentiation?

BACKGROUND

Cell transplantation has recently been challenged to improve cardiac function of severe heart failure. Human mesenchymal stem cells (hMSCs) are multipotent cells that can be isolated from adult marrow stroma, but because of their limited life span, it is difficult to study them further. To overcome this problem, we attempted to prolong the life span of hMSCs and investigate whether the hMSCs modified with cell-cycle-associated genes can differentiate into cardiomyocytes in vitro.

METHODS

We attempted to prolong the life span of hMSCs by infecting retrovirus encoding bmi-1, human papillomavirus E6 and E7, and/or human telomerase reverse transcriptase genes. To determine whether the hMSCs with an extended life span could differentiate into cardiomyocytes, 5-azacytidine-treated hMSCs were co-cultured with fetal cardiomyocytes in vitro.

RESULT

The established hMSCs proliferated over 150 population doublings. On day 3 of co-cultivation, the hMSCs became elongated, like myotubes, began spontaneously beating, and acquired automaticity. Their rhythm clearly differed from that of the surrounding fetal mouse cardiomyocytes. The number of beating cardiomyocytes increased until 3 weeks. hMSCs clearly exhibited differentiated cardiomyocyte phenotypes in vitro as revealed by immunocytochemistry, RT-PCR, and action potential recording.

CONCLUSIONS

The life span of hMSCs was prolonged without interfering with cardiomyogenic differentiation. hMSCs with an extended life span can be used to produce a good experimental model of cardiac cell transplantation and may serve as a highly useful cell source for cardiomyocytic transplantation.

Induction of apoptosis in leukemic cells by homovanillic acid derivative, capsaicin, through oxidative stress: implication of phosphorylation of p53 at Ser-15 residue by reactive oxygen species

Capsaicin (N-vanillyl-8-methyl-1-nonenamide) is a homovanillic acid derivative found in pungent fruits. Several investigators have reported the ability of capsaicin to inhibit events associated with the promotion of cancer. However, the effects of capsaicin on human leukemic cells have never been investigated. We investigated the effects of capsaicin on leukemic cells in vitro and in vivo and further examined the molecular mechanisms of capsaicin-induced apoptosis in myeloid leukemic cells. Capsaicin suppressed the growth of leukemic cells, but not normal bone marrow mononuclear cells, via induction of G(0)-G(1) phase cell cycle arrest and apoptosis. Capsaicin-induced apoptosis was in association with the elevation of intracellular reactive oxygen species production. Interestingly, capsaicin-sensitive leukemic cells were possessed of wild-type p53, resulting in the phosphorylation of p53 at the Ser-15 residue by the treatment of capsaicin. Abrogation of p53 expression by the antisense oligonucleotides significantly attenuated capsaicin-induced cell cycle arrest and apoptosis. Pretreatment with the antioxidant N-acetyl-L-cystein and catalase, but not superoxide dismutase, completely inhibited capsaicin-induced apoptosis by inhibiting phosphorylation of Ser-15 residue of p53. Moreover, capsaicin effectively inhibited tumor growth and induced apoptosis in vivo using NOD/SCID mice with no toxic effects. We conclude that capsaicin has potential as a novel therapeutic agent for the treatment of leukemia.

Use of isolated mature osteoblasts in abundance acts as desired-shaped bone regeneration in combination with a modified poly-DL-lactic-co-glycolic acid (PLGA)-collagen sponge

Controlled regeneration of bone or cartilage has recently begun to facilitate a host of novel clinical treatments. An osteoblast line, which we isolated is able to form new bone matrix in vivo within 2 days and exhibits a mature osteoblast phenotype both in vitro and in vivo. Using these cells, we show that cuboidal bones can be generated into a predesigned shaped-bone with high-density bone trabeculae when used in combination with a modified poly-DL-lactic-co-glycolic acid (PLGA)-collagen sponge. PLGA coated with collagen gel serves as a good scaffold for osteoblasts. These results indicate that mature osteoblasts, in combination with a scaffold such as PLGA-collagen sponge, show promise for use in a custom-shaped bone regeneration tool for both basic research into osteogenesis and for development of therapeutic applications.

Gastrin and Helicobacter pylori in low-grade MALT lymphoma patients

BACKGROUND

This study of patients with Helicobacter pylori infection and low-grade MALT lymphoma aimed to investigate: 1) the effect of H. pylori eradication therapy on the serum gastrin level, 2) whether changes of the serum gastrin level after therapy could predict the prognosis of patients with this tumour, and 3) the relationship between the gastric H. pylori load, the serum gastrin level and the status of MALT lymphoma.

METHODS

Thirteen patients with documented low-grade MALT lymphoma and H. pylori infection were enrolled and received H. pylori eradication therapy as the sole initial treatment. The presence of H. pylori, the serum gastrin level, the endoscopic findings, the pathologic features of the biopsies and resected specimens, and the endoscopic ultrasonography findings were evaluated before and after therapy. Follow-up was carried out every 3-6 months.

RESULTS

H. pylori eradication was eventually achieved in all 13 patients. The pretreatment fasting serum gastrin level decreased from 177.1 +/- 107.4 pg/ml to 129.2 +/- 78.1, 96.4 +/- 66.6 and 80.1 +/- 42.7 pg/ml after 0-3, 3-6 and 6-9 months, respectively (all P < 0.05). Successful eradication of H. pylori was followed by a decrease of the fasting serum gastrin level and complete regression of initial low-grade MALT lymphoma was observed in all patients. However, two patients subsequently developed recurrent high-grade MALT lymphoma or high-grade lymphoma. In one of them, the serum gastrin level rose again above the pretreatment value. In the other, however, the fasting gastrin level fell throughout the study period. The median fasting serum gastrin level before H. pylori eradication therapy was higher in the patients with tumours of the gastric body (203.4 +/- 108.9 pg/ml) than in those with tumours of the antrum and angulus (89.3 +/- 28.0 pg/ml) (P = 0.06).

CONCLUSIONS

Hypergastrinaemia may be associated with an increased risk of gastric MALT lymphoma.

Overexpression of phosphatidylinositol synthase enhances growth and G1 progression in NIH3T3 cells

Phosphatidylinositol (PI) turnover is thought to play an important role in the regulation of cell growth. PI synthase (PIS, cytidine diphosphate (CDP)-diacylglycerol (DG): myo-inositol 3-phosphatidyltransferase, EC 2.7.8.11) acts at the last step in the de novo biosynthesis of PI by catalyzing the condensation of CDP-DG and myo-inositol. To study the physiological role of PIS, we established murine NIH3T3 fibroblasts that stably overexpress PIS, by transfection with PIS cDNA (NIH-PIS cells). In immunofluorescence assays, the constitutively overexpressed PIS was found to be localized in the endoplasmic reticulum, as previously reported for the native enzyme activity. NIH-PIS cells showed an increase in PI synthesis in vitro and in vivo, as well as increased cellular levels of PI-4,5-P2 and PI-3,4,5-P3. They also displayed a decrease in their doubling time and accelerated G1 progression. Overexpression of PIS increased cellular levels of the cyclin D1 and E proteins and Akt kinase activity in serum-stimulated quiescent NIH3T3 cells. Moreover, PIS overexpression potentiated the colony formation of NIH3T3 cells in soft agar. These results suggest that PIS accelerates G1 progression and stimulates growth by increasing cellular levels of cyclins D1 and E.

Both of the N-terminal and C-terminal regions of human papillomavirus type 16 E7 are essential for immortalization of primary rat cells

E7 oncoproteins of mucosal high-risk human papillomavirus type 16 and 18 (HPV16 and HPV18) immortalize primary rodent cells and transform them in collaboration with the activated ras, possibly by interaction with retinoblastoma gene product RB and its related p107. On the other hand, E7 of the cutaneous epidermodysplasia verruciformis-associated HPV5 and HPV8 possess ras-collaborative transformation but not immortalization activity. By using polymerase chain reaction, we constructed chimeric E7 from immortalizing HPV16 E7 and nonimmortalizing HPV5 E7, which have boundaries at the 37/39th, 61/62th, or 79th codon of the HPV16 E7. These chimeric E7 were cloned into the expression vectors to examine their ras-collaboration and immortalization activities. Chimeric E7 that contained N-terminal 39 amino acid residues (R), 61R and 79R of HPV16 E7, showed ras-collaboration activity in primary rat embryo fibroblast and primary baby rat kidney (BRK) cells as efficiently as HPV16 E7. Meanwhile, only the chimeric E7 containing N-terminal 79R of HPV16 E7 was able to immortalize primary BRK cells without second oncogenes. Co-transfection of two chimeric E7 carrying HPV16 N-terminus and HPV16 C-terminus induced immortalization of primary BRK cells. These results suggest that (i) in addition to the N-terminal RB-binding domain, the C-terminal region of HPV16 E7 is essential for immortalization of primary BRK cells, and (ii) two different immortalization functions are present in the two regions of HPV16 E7. By using a yeast two hybrid system, we searched for the HeLa cDNA whose products can bind the C-terminal region of HPV16 E7.

Mobility of the doped holes and the antiferromagnetic correlations in underdoped high- Tc cuprates

The emergence and the evolution of the metallic charge transport in the La2-xSrxCuO4 system from lightly to optimally doped samples (x = 0.01-0.17) are studied. We demonstrate that in high-quality single crystals the in-plane resistivity shows a metallic behavior for all values of x at moderate temperatures and that the hole mobility at 300 K changes only by a factor of 3 from x = 0.01 to 0.17, where its x dependence is found to be intriguingly similar to that of the inverse antiferromagnetic correlation length. We discuss an incoherent-metal picture and a charged-stripe scenario as candidates to account for these peculiar features.

Bilateral massive pleural effusions caused by uremic pleuritis

A 61-year-old man was started on hemodialysis in June 1998. Just after the commencement of dialysis, a chest X-ray film revealed bilateral pleural effusions. The effusions were hemorrhagic and exudative, and did not respond to dialysis. He was transferred to our university hospital on October 8,1998. Repeated thoracentesis demonstrated hemorrhagic and exudative characteristics without any diagnostic evidence. Pleural biopsies showed fibrosis and lymphocyte infiltration. The effusions were massive and did not respond to treatments including hemodialysis, repeatedly performed pleurodesis and the administration of antituberculous drugs. He died of respiratory failure on December 30, 1998. The autopsy confirmed bilateral fibrinous pleuritis without any underlying infections or malignancy. We diagnosed this case as uremic pleuritis from this clinical course and the autopsy findings. The clinical entity of uremic pleuritis was recognized as a complication of patients with hemodialysis in 1969. Uremic pleuritis generally responds to continued hemodialysis and the prognosis is usually good. However, some case reports demonstrated that surgical decortication is only indicated in cases with a severe clinical course. The clinical course of the present case was progressive and fatal. Uremic pleuritis is a serious complication of hemodialysis, which may lead to death.

Adrenomedullin inhibits the pressor effects and decrease in renal blood flow induced by norepinephrine or angiotensin II in anesthetized rats

Adrenomedullin (AM), a hypotensive peptide originally isolated from human pheochromocytoma, has been reported to regulate renal functions. In patients with glomerulonephritis, the serum levels of AM are elevated as well as hypertensive agents norepinephrine (NE) and angiotensin II (AII). The effects of AM on the NE- or AII-induced pressor effects and renal blood flow responses, however, are not well clarified. We examined the effects of AM on blood pressure and renal blood flow induced by NE or AII in anesthetized rats. Arterial blood pressure and renal blood flow were measured using a calibrated pressure transducer and a laser Doppler flowmeter, respectively. Drugs were injected into the tail vein with a syringe. Intravenous administration of AM (1-3 nmol/kg) decreased the arterial blood pressure in anesthetized rats in a dose-dependent manner, whereas it did not affect the renal blood flow. NE or AII administration in anesthetized rats caused both increases in blood pressure and decreases in renal blood flow. Simultaneous administration of AM with NE or All prevented the increasing effects of blood pressure and inhibited the decreases in renal blood flow caused by NE or AII. These findings suggest that AM may have a protective role against the pressor effects and decrease in renal blood flow caused by NE or AII.

Transport anomalies and the role of pseudogap in the 60-K phase of YBa(2)Cu(3)O(7-delta)

We report the result of our accurate measurements of the a- and b-axis resistivity, Hall coefficient, and the a-axis thermopower in untwinned YBa(2)Cu(3)O(y) single crystals in a wide range of doping. It is found that both the a-axis resistivity and the Hall conductivity show anomalous dependences on the oxygen content y in the 60-K phase below the pseudogap temperature T(*). The complete data set enables us to narrow down the possible pictures of the 60-K phase, with which we discuss a peculiar role of the pseudogap in the charge transport.

Inhibitory effects of nicorandil on rat mesangial cell proliferation via the protein kinase G pathway

We investigated the effects of nicorandil, which is a hybrid between a nitrate and an ATP-sensitive potassium channel (K(ATP)) opener, on cultured rat mesangial cell proliferation. Nicorandil (1 microM to 1 mM inhibited [(3)H]thymidine incorporation into rat mesangial cells in a concentration-dependent manner. Nicorandil (1 microM to 1 mM) also inhibited the number of cells. Nicorandil increased cyclic guanosine 3',5'-cyclic monophosphate accumulation in mesangial cells. A protein kinase G inhibitor, KT5823, partially eliminated the inhibition of mesangial cell proliferation by nicorandil. Methylene blue, a guanylate cyclase inhibitor, blocked the inhibitory effect of nicorandil on mesangial cell proliferation. We also examined the effects of K(ATP) mediators. Cromakalim, a K(ATP) activator, and glibenclamide, a K(ATP) inhibitor, had little effect on the proliferation of mesangial cells. These results suggest that the inhibitory effects of nicorandil on mesangial cell proliferation are mediated via the protein kinase G pathway.

Clinical significance of natriuretic peptides and cyclic GMP in hemodialysis patients with coronary artery disease

BACKGROUND

Plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) are suitable markers of 'dry body weight' (DW) in hemodialysis (HD) patients. However, it is still unknown whether these markers can be applied to patients with renal failure and coronary artery disease (CAD). We examined the reliability of these peptides as volume markers in HD patients with CAD. We also assessed the relationship between natriuretic peptides and indices of left ventricular (LV) function.

METHODS

Plasma concentrations of ANP, BNP and cGMP were determined before and after HD in patients with CAD (group 1, n = 19, mean age 63 +/- 12 years) and were compared with those of patients without cardiac disease (group 2, n = 20, age 61 +/- 15 years). Using data obtained by cardiac catheterization, we examined the relationship between natriuretic peptides and indices of LV function in HD patients with CAD.

RESULTS

Baseline ANP (244 +/- 205 pg/ml), BNP (713 +/- 928 pg/ml) and cGMP (29.6 +/- 21.6 pmol/ml) were significantly higher in group 1 than in 11 healthy volunteers (18.6 +/- 9.9 pg/ml, 7.7 +/- 7.6 pg/ml, cGMP 8.9 +/- 4.9 pmol/ml, respectively). HD significantly reduced plasma ANP (87 +/- 75 pg/ml) and BNP (477 +/- 702 pg/ml) although they were still above normal control. HD reduced plasma cGMP (7.2 +/- 4.5 pmol/ml) to normal values, suggesting the elimination of cGMP across the dialyzers. Baseline levels of ANP, BNP and cGMP in group 2 were less than those of group 1 but higher than the control. HD reduced natriuretic peptides in group 2 to levels lower than those in post-HD group 1. After HD, there was no significant correlation between reductions in body weight and changes in ANP or BNP. Baseline ANP and BNP levels closely correlated with pulmonary artery pressure, pulmonary artery wedge pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction. A significant correlation was observed between BNP levels and the severity of CAD.

CONCLUSION

ANP, BNP and cGMP seem to be a useful markers for fluid overload but not for DW in HD patients with CAD. Plasma ANP and BNP might be useful markers for left ventricular function.

A clinicopathologic study of gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

It is still unclear which patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma will benefit from the eradication of Helicobacter pylori.

METHODS

The authors studied a total of 34 patients. Twenty-three patients had primary gastric lymphoma and underwent gastric resection as initial treatment. Eleven patients with gastric MALT lymphoma who received antibiotics against H. pylori as initial treatment were also included. In all 34 patients, the presence of H. pylori, endoscopic findings, and pathologic features were evaluated. Immunohistochemical expression of Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) was classified as follows: (-), no reactive cells; (+), scattered positive cells; (2+), nests of positive cells; (3+), diffuse positive cells.

RESULTS

Patients with low grade MALT lymphoma (LG) tended to be positive for H. pylori (6 of 9), to localize within the submucosa (7 of 9), not to have lymph node involvement (7 of 8), and to have lower tumor stage compared with patients with high grade MALT components (HG). Bcl-2 protein was expressed with high frequency by LG (7 of 9). Strong expression of p 53 was more common in the HG tumors (4 of 14), and strong expression of PCNA showed a significant difference between LG (1 of 8) and HG patients (12 of 13). Investigation of the patients with long term follow-up (n = 4) revealed that LG remained superficial for a long time and showed gradual progression. Most of these tumors were Bcl-2+/p53-approximately+/-/ PCNA- approximately +. There were two patients whose superficial LG (sm/Bcl-2+/p53-/PCNA- approximately +) regressed after the disappearance of H. pylori. On the other hand, one patient developed ulcerated LG (sm/Bcl-2 /p53+/PCNA3+) after disappearance of H. pylori. The authors found complete regression of MALT lymphoma in 9 of 11 patients after H. pylori eradication. Initial tumors of these 9 patients were superficial/sm/n(-)/low grade/Bcl-2+approximately +/-/p53-approximately+ (n = 9), /PCNA-approximately+(n = 6), /PCNA 2+ (n = 3). Two local recurrence and one non-Hodgkin lymphoma in other sites were observed after initial therapy.

CONCLUSIONS

Gastric MALT lymphoma with (H. pylori positive/superficial/sm/low grade/Bcl-2 +/p53- approximately +/PCNA- approximately +) pattern will disappear after a patient is cured of H. pylori infection.

A clinicopathologic study of gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND

It is still unclear which patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma will benefit from the eradication of Helicobacter pylori.

METHODS

The authors studied a total of 34 patients. Twenty-three patients had primary gastric lymphoma and underwent gastric resection as initial treatment. Eleven patients with gastric MALT lymphoma who received antibiotics against H. pylori as initial treatment were also included. In all 34 patients, the presence of H. pylori, endoscopic findings, and pathologic features were evaluated. Immunohistochemical expression of Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) was classified as follows: (-), no reactive cells; (+), scattered positive cells; (2+), nests of positive cells; (3+), diffuse positive cells.

RESULTS

Patients with low grade MALT lymphoma (LG) tended to be positive for H. pylori (6 of 9), to localize within the submucosa (7 of 9), not to have lymph node involvement (7 of 8), and to have lower tumor stage compared with patients with high grade MALT components (HG). Bcl-2 protein was expressed with high frequency by LG (7 of 9). Strong expression of p 53 was more common in the HG tumors (4 of 14), and strong expression of PCNA showed a significant difference between LG (1 of 8) and HG patients (12 of 13). Investigation of the patients with long term follow-up (n = 4) revealed that LG remained superficial for a long time and showed gradual progression. Most of these tumors were Bcl-2+/p53-approximately+/-/ PCNA- approximately +. There were two patients whose superficial LG (sm/Bcl-2+/p53-/PCNA- approximately +) regressed after the disappearance of H. pylori. On the other hand, one patient developed ulcerated LG (sm/Bcl-2 /p53+/PCNA3+) after disappearance of H. pylori. The authors found complete regression of MALT lymphoma in 9 of 11 patients after H. pylori eradication. Initial tumors of these 9 patients were superficial/sm/n(-)/low grade/Bcl-2+approximately +/-/p53-approximately+ (n = 9), /PCNA-approximately+(n = 6), /PCNA 2+ (n = 3). Two local recurrence and one non-Hodgkin lymphoma in other sites were observed after initial therapy.

CONCLUSIONS

Gastric MALT lymphoma with (H. pylori positive/superficial/sm/low grade/Bcl-2 +/p53- approximately +/PCNA- approximately +) pattern will disappear after a patient is cured of H. pylori infection.

A new bioactive steroidal saponin, furcreastatin, from the plant Furcraea foetida

Microbial and plant secondary metabolites were screened for compounds that are selectively cytotoxic to mutant p53-expressing mouse fibroblasts. As a result, furcreastatin, a novel steroidal saponin, was isolated from an EtOH extract of the leaves of Furcraea foetida. Furcreastatin consisted of hecogenin as the aglycone and a hexasaccharide containing D-galactose, L-rhamnose and four D-glucose residues. The structure was determined to be (3 beta,5 alpha,25R)- 3-hydroxyspirostan-12-one 3-O-[alpha-L-Rhap-(1-->4)-beta-D-Glcp-(1-->3)-¿beta-D-Glcp-(1-->3) -beta-D- Glcp-(1-->2)¿-beta-D-Glcp-(1-->4)-beta-D-Galp] by extensive NMR spectroscopic studies. Furcreastatin decreased the viability of mutant p53-over-expressing cells with an ED50 of 4.0 micrograms/mL, and decreased that of the parental cell-line with an ED50 of 9.6 micrograms/mL.

Adenovirus type 5 E1A immortalizes primary rat cells expressing wild-type p53

Adenovirus (Ad) E1A induces apoptosis in cells expressing wild-type p53, and stable transformation by Ad E1A requires the co-introduction of an anti-apoptotic gene such as Ad E1B 19K. Thus, cells immortalized by Ad E1A alone might have lost functional p53. In order to analyze the p53 in rat cells expressing Ad E1A, we established rat cell lines by transfecting primary rat embryo fibroblast (REF) and baby rat kidney (BRK) cells with cloned Ad5 E1A. By using a yeast functional assay, we analyzed p53 in six primary REF and three BRK cell lines immortalized by Ad5 E1A as well as five spontaneously immortalized rat cell lines (REF52, NRK, WFB, Rat-1 and 3Y1). The yeast functional assay revealed that all of the spontaneously and Ad5 ElA-immortalized rat cell lines except for 3Y1 expressed wild-type p53. All of the Ad5 E1A-immortalized rat cell lines contained p53 detectable by immunoprecipitation. Recombinant adenovirus expressing rat p53 cloned from a REF cell line immortalized by Ad5 E1A, as well as that expressing murine wild-type p53, induced apoptosis in p53-null cells in collaboration with E1A. Thus, it is suggested that the mutation of p53 appears to be not frequent in the spontaneous immortalization of primary rat cells, and that the functional loss of wild-type p53 is not a prerequisite of E1A-mediated immortalization.

Involvement of beta-1,4-galactosyltransferase V in malignant transformation-associated changes in glycosylation

In spite of marked changes in the glycosylation upon malignant transformation of cells, no biological significance of beta-1, 4-galactosyltransferase (beta-1,4-GalT) activities has been elucidated. When beta-1,4-GalT activities toward 1 mM GlcNAcbeta-S-pNP were determined using homogenates of NIH3T3 and its transformant, MTAg, MTAg contained 1.3 times higher activities. Northern blot analysis, however, revealed that the beta-1,4-GalT V gene expression increases by three times with a decrease in that of beta-1,4-GalT II by one-fifth and without significant changes in those of other beta-1,4-GalTs in MTAg. Analysis of beta-1,4-GalT V acceptor-specificity showed that the GlcNAcbeta1-->6Man group of the GlcNAcbeta1-->6(GlcNAbeta1-->2)Manalpha1- branch is galactosylated. These results indicate that changes in beta-1,4-GalT II and V activities are important for the altered glycosylation.

The utility of endoscopic ultrasonography and endoscopy in the endoscopic mucosal resection of early gastric cancer

OBJECTIVE

To clarify the usefulness of endoscopic ultrasonography (EUS) and endoscopy in the endoscopic mucosal resection (EMR) of early gastric cancer. Patients/Methods-EMR was performed in 61 patients with early gastric cancer over the past five years. The accuracy of the assessment of the depth of cancerous invasion was studied in 49 patients who had EUS before EMR. Forty eight patients were treated with endoscopy alone; in these patients, EUS and endoscopic findings correlated with the clinical course.

RESULTS

Forty six patients showed no changes in the submucosal layer or deeper structures on EUS. Pathologically these included 37 patients with mucosal cancer and nine with submucosal cancer showing very slight submucosal infiltration. Three patients showed diffuse low echo changes in the submucosal layer on EUS; pathologically, these included two with submucosal cancer and one with mucosal cancer with a peptic ulcer scar within the tumour focus. Of 48 patients receiving endoscopic treatment alone, 45 showed no tumour recurrence or evidence of metastases on EUS and endoscopy. Three cases of recurrence were observed. Two of these patients had a surgical gastrectomy, and one was re-treated endoscopically. In the former cases, the surgical results correlated well with assessment by EUS and endoscopy. In addition, the latter patient who was re-treated endoscopically after evaluation with EUS and endoscopy has so far had no recurrence.

CONCLUSION

The combined use of EUS and endoscopy is effective in diagnosing the depth of cancerous invasion in patients undergoing EMR as well as in clarifying changes both within and between anatomic levels during follow up.

Induction of apoptosis by the p53-273L (Arg --> Leu) mutant in HSC3 cells without transactivation of p21Waf1/Cip1/Sdi1 and bax

Codon 273 is one of the hot spots of missense mutation of the p53 tumor suppressor gene found in human cancers. We have previously reported that a mutation at codon 273, p53-273L (Arg --> Leu), suppresses cell growth despite its having no p53-specific transactivation activity. To further elucidate the mechanism of growth suppression caused by p53-273L, we used squamous cell carcinoma cell line HSC3 to isolate subclones containing Zn2+-inducible wild-type (wt) p53, p53-175H, and p53-273L. Northern blot hybridization of the HSC3 cells possessing an inducible function of p53 as well as a luciferase assay for the p21Waf1/Cip1/Sdi1 promoter showed that only wt p53 could induce p21Waf1/Cip1/Sdi1 transcription. Meanwhile, the expression of bax remained unchanged between, before, and after the induction of any analyzed p53s. When wt p53 was induced in HSC3 cells cultured in medium containing 5% fetal bovine serum, cell growth was suppressed through G1 arrest. On the other hand, in medium with 0.1% fetal bovine serum, the growth of HSC3 cells expressing p53-273L was suppressed to a greater degree than that of cells expressing wt p53. Flow cytometric analysis and DNA ladder formation revealed that, unlike wt p53-SN3- and p53-175H-expressing HSC3 cells, p53-273L-expressing cells contained a larger sub-G1 fraction under this culture condition. These findings suggest that p53-273L can induce apoptosis in HSC3 cells without transactivation of p21Waf1/Cip1/Sdi1 and bax.