The eukaryotic polypeptide chain releasing factor (eRF3/GSPT) carrying the translation termination signal to the 3'-Poly(A) tail of mRNA. Direct association of erf3/GSPT with polyadenylate-binding protein

The mammalian GTP-binding protein GSPT, whose carboxyl-terminal sequence is homologous to the eukaryotic elongation factor EF1alpha, binds to the polypeptide chain releasing factor eRF1 to function as eRF3 in the translation termination. The amino-terminal domain of GSPT was, however, not required for the binding. Search for other GSPT-binding proteins in yeast two-hybrid screening system resulted in the identification of a cDNA encoding polyadenylate-binding protein (PABP), whose amino terminus is associating with the poly(A) tail of mRNAs presumably for their stabilization. The interaction appeared to be mediated through the carboxyl-terminal domain of PABP and the amino-terminal region of GSPT. Interestingly, multimerization of PABP with poly(A), which is ascribed to the action of its carboxyl-terminal domain, was completely inhibited by the interaction with the amino-terminal domain of GSPT. These results indicate that GSPT/eRF3 may play important roles not only in the termination of protein synthesis but also in the regulation of mRNA stability. Thus, the present study is the first report showing that GSPT/eRF3 carries the translation termination signal to 3'-poly(A) tail ubiquitously present in eukaryotic mRNAs.

[Myelodysplastic syndrome after autologous peripheral blood stem cell transplantation for adult acute myelogenous leukemia]

A 65-year-old woman was admitted to our hospital with arthritis and agranulocytosis. She had given a diagnosis of acute myelogenous leukemia (FAB classification M1) a year ago and treated with 3 cycles of cytarabine and anthracycline or etoposide for 4 months, achieving complete remission state. Her bone marrow aspirate revealed normocellularity with normal karyotype (46, XX [20]) without apparent dysplastic feature at this time. She received autologous peripheral blood stem cell transplantation subsequently after conditioning regimen consisted of granulocyte colony-stimulating factor, busulfan, Ara-C and etoposide. Three months later, she started to manifest low grade fever, polyarthralgia and agranulocytosis and she admitted to our hospital after nine months. Bone marrow aspirate revealed marked hypocellularity with dysplastic features in three series of hematopoietic cells. Arthritis was dramatically improved after administration of prednisolone, but low granulocyte count continued. Bone marrow aspirate revealed karyotypic abnormality with monosomy 7 and we diagnosed her as myelodysplastic syndrome. Chemotherapy-induced myelodysplasia has been reported so far. This case would represent secondary myelodysplastic syndrome after chemotherapy. We could not clarify the etiology for polyarthritis but could be one of the paraneoplastic syndrome. We should note subsequent occurrence of myelodysplasia when planning treatment schedule.

Interferon-gamma prevents apoptosis in Epstein-Barr virus-infected natural killer cell leukemia in an autocrine fashion

The significant function of cytokines includes maintenance of cell survival as well as induction of cell differentiation and/or proliferation. We demonstrate here that interferon-gamma (IFN-gamma) plays a role for progression of Epstein-Barr virus (EBV)-infected natural killer cell leukemia (NK leukemia) through maintaining cell survival. NK leukemia cells obtained from 7 patients had clonal episomal forms of EBV, indicating that the leukemic cells were of clonal origin. Although normal NK cells constitutively expressed Bcl-2, the EBV-infected NK leukemia cells lacked endogenous Bcl-2 expression and were hypersensitive to apoptosis in vitro. The addition of IFN-gamma to the culture significantly inhibited their spontaneous apoptosis without inducing cell proliferation or upregulation of Bcl-2. The NK leukemia cells constitutively secreted IFN-gamma, and the patients' sera contained a high concentration of IFN-gamma, levels that were high enough to prevent NK leukemia cells from apoptosis. Bcl-XL was not involved in the IFN-gamma-induced NK leukemia cell survival. These data suggest that the acquisition of IFN-gamma-mediated autocrine survival signals, other than Bcl-2 or BCL-XL, might be important for the development of EBV-infected NK leukemia.

Transduction of human progenitor hematopoietic stem cells by human immunodeficiency virus type 1-based vectors is cell cycle dependent

Human immunodeficiency virus (HIV) type 1 vectors are highly efficient in their ability to transduce human progenitor hematopoietic stem cells (PHSC). Although mitosis was not required for transduction of these cells, transduction rates were much greater once cells had been cultured in the presence of cytokines. Transduction rates, however, rarely exceeded 70%. We demonstrate here that there is a distinct subpopulation that is more easily transduced by HIV vectors. These cells were distinguished by a disproportionate population in the S/G2/M phases of the cell cycle. By sorting them prior to transduction, we found that those cells in either the G1 or S/G2/M fraction were more readily transduced than G0 cells. Maintaining the cells in G0 by omitting cytokines from the medium reduced transduction rates by up to 10-fold. Addition of cytokines to the medium immediately after transduction did not improve the transduction efficiency as measured by expression of the transgene. Analysis of replication intermediates indicated that the block to transduction of G0 cells operated near the time of initiation of reverse transcription. These results suggest that although lentivirus vectors can transduce nondividing PHSC, transduction efficiency is severalfold greater once the cells exit G0 and enter G1. Further characterization of these more transducible cells and identification of the cellular factors responsible may enhance transduction while maintaining the pluripotentiality of the PHSC.

Thermal distribution of radio-frequency inductive hyperthermia using an inductive aperture-type applicator: evaluation of the effect of tumour size and depth

A new radio-frequency (RF) inductive hyperthermia device using an inductive aperture-type applicator (IATA) is proposed. This paper reports the evaluation of the heating characteristics of the IATA using a computer simulation and clinical thermal parameters obtained during treatment of superficial and subsurface-seated tumours. The configuration of the IATA is a one-turn square column-like coil whose bottom plate is set to face the heating target. The IATA has advantages over RF capacitive-type heating, such as: generating less heat in the subcutaneous fat layer; less convergency of electric line of force at the edge of the applicator; and no physical contact with the target lesion. The induced magnetic fields and electrical currents within the heating substance are simulated using computer-assisted design software for electro-magnetic analysis. A total of 40 superficial and subsurface tumours are treated with the IATA. Invasive thermometry is performed continuously for 110 sessions using multi-sensor probes of an optical thermometer. Thermal parameters (Tmax, Tmin, Tave) are assessed based on the tumour size and depth. The treated tumours are categorised into three groups according to tumour depth: group 1 (< 3 cm, n = 28), group 2 (3-5 cm, n = 35) and group 3 (> 5 cm, n = 47). The computer simulation shows that induced electrical currents run without convergency, parallel to the surface of the heating material. All thermal parameters of group 3 are significantly higher than those of group 1 and 2 (p < 0.05), indicating that the larger lesions tend to abtain a higher temperature distribution. In conclusion, RF inductive hyperthermia using the IATA results in effective temperature distributions in superficial and subsurface tumours, with large tumours being most effectively heated.

Correlation of antiangiogenic and antitumor efficacy of N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA), an orally-active, selective matrix metalloproteinase inhibitor

The antiangiogenic activity and antitumor efficacy of a newly developed matrix metalloproteinase (MMP) inhibitor were examined. N-biphenyl sulfonyl-phenylalanine hydroxiamic acid (BPHA) potently inhibits MMP-2, -9, and -14, but not MMP-1, -3, or -7. In contrast, (-)BPHA, an enantiomer of BPHA, was inactive against all MMPs tested. Daily oral administration of 200 mg/kg BPHA, but not (-)BPHA in mice resulted in potent inhibition of tumor-induced angiogenesis, primary tumor growth, and liver metastasis. The growth inhibition activity of BPHA was 48% and 45% in a B16-BL6 melanoma and F2 hemangio-endothelioma model, respectively. BPHA also showed 42% inhibition of the liver metastasis of C-1H human colon carcinoma cells. These results indicate that selective MMP inhibition is correlated with antiangiogenic and antitumor efficacy and that the selective MMP inhibitor BPHA has therapeutic potential.

Correlation of telomerase activity with development and progression of adult T-cell leukemia

Telomerase is an enzyme that adds hexameric TTAGGG nucleotide repeats to the ends of vertebrate chromosomal DNAs (i.e. telomeres) to compensate for losses that occur with each round of DNA replication. Telomerase activity, demonstrable in most human tumors, enables them to maintain telomere stability. Peripheral blood mononuclear cells were sampled from 57 patients seropositive for human T-lymphotropic virus type I (HTLV-I), including 24 asymptomatic viral carriers, ten smoldering type, five chronic type, and 18 acute type adult T-cell leukemia (ATL). Telomerase activity was determined in samples using a modified telomeric repeat amplification protocol. We semiquantitatively determined telomerase activity by serial dilution of each sample. All of 23 samples from acute and chronic type ATL patients were positive, seven of ten (70%) smoldering type patients and seven of 24 (29.2%) asymptomatic viral carriers were positive. Disease progression from asymptomatic viral carrier to acute type correlated with telomerase activity. Two samples from chronic type ATL patients with relatively high telomerase activity progressed to the acute type within 1 month. Serum lactate dehydrogenase level also correlated with telomerase activity. These results indicate that reactivation of telomerase activity is a key event in development and progression of ATL, and telomerase could be a useful marker for predicting the course of disease. Accordingly, ATL could be a good candidate disease for trials of telomerase inhibitors, as novel anticancer drugs.

Sweet's syndrome associated with chronic myelogenous leukemia: demonstration of leukemic cells within a skin lesion

We report a case of acute febrile neutrophilic dermatosis, Sweet's syndrome, associated with chronic myelogenous leukemia (CML) in which we found rearrangement of the bcr gene in DNA obtained from a skin lesion as well as in blood DNA by Southern blot analysis. This indicated the presence of CML cells within the skin lesion. To our knowledge, this is the first report in which the presence of CML cells is shown within skin lesions of Sweet's syndrome. In our patient, leukocyte alkaline phosphatase activities returned to normal levels when he was suffering from Sweet's syndrome and decreased again to below normal levels after it subsided. Whether the normalization of leukocyte alkaline phosphatase activity is common among CML patients with Sweet's syndrome remains to be determined.

HCA, an immunoglobulin-like adhesion molecule present on the earliest human hematopoietic precursor cells, is also expressed by stromal cells in blood-forming tissues

We have previously shown that the HCA/ALCAM (CD166) glycoprotein, a member of the immunoglobulin family that mediates both homophilic and heterophilic cell-cell adhesion, via the CD6 ligand, is expressed at the surface of all of the most primitive CD38(-/lo), Thy-1(+), rho123(lo), CD34(+) hematopoietic cells in human fetal liver and fetal and adult bone marrow. In the present report we show that HCA is also expressed by subsets of stromal cells in the primary hematopoietic sites that sequentially develop in the human embryo and fetus, ie, the paraaortic mesoderm, liver, thymus, and bone marrow. Adult bone marrow stromal cells established in vitro, including those derived from Stro-1(+) progenitors and cells from immortalized cell lines, express HCA. In contrast, no HCA expression could be detected in peripheral lymphoid tissues, fetal spleen, and lymph nodes. HCA membrane molecules purified from marrow stromal cells interact with intact marrow stromal cells, CD34(+) CD38(-) hematopoietic precursors, and CD3(+) CD6(+) peripheral blood lymphocytes. Finally, low but significant levels of CD6 are here for the first time detected at the surface of CD34(+) rho123(med/lo) progenitors in the bone marrow and in mobilized blood from healthy individuals. Altogether, these results indicate that the HCA/ALCAM surface molecule is involved in homophilic or heterophilic (with CD6) adhesive interactions between early hematopoietic progenitors and associated stromal cells in primary blood-forming organs.

Phospholipase D activity in human gastric carcinoma

Growth factor-stimulated phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine, generating phosphatidic acid which may act as a second messenger during cell proliferation, therefore PLD is believed to play an important role in tumorigenesis. Thus we measured PLD activity in human gastric carcinoma to evaluate its role in gastric carcinogenesis. PLD activity was assayed by a unique transphosphatidylation reaction using microsomal fraction of 21 pairs of surgically resected human gastric carcinomas and adjacent noncancerous mucosas. The mean PLD activities in gastric carcinoma and adjacent noncancerous mucosa were 63.0 +/- 69.5, 44.2 +/- 60.1 pmol/min/mg, respectively (p < 0.01; Wilcoxon signed rank test). The mean ratio of PLD activity in gastric carcinoma and adjacent noncancerous mucosa was 1.63. This ratio was significantly higher in patients with larger tumors (> or = 5 cm) (p < 0.01; Mann-Whitney U-test). Our results indicate that the elevation of PLD activity plays an important role in the promotion of gastric carcinoma.

[Augmented antitumor efficacy of combination chemotherapy of nedaplatin with 5-fluorouracil in in vivo murine and human tumor model]

Augmented antitumor activity was demonstrated in combination chemotherapy of Nedaplatin (NDP) or Cisplatin (CDDP) with 5-fluorouracil (5-FU) against murine lung carcinoma and human squamous carcinoma from head and neck. Either NDP or CDDP (1/4 to 1 maximum tolerated dose; MTD) was injected once and 5-FU (1/16 MTD) was injected daily for five days via tail vein to tumor-implanted mice. The sequential administration of either NDP or CDDP prior to 5-FU (NF or CF therapy) showed severe body weight loss followed by the toxic death of tumor-bearing mice at the MTD of NDP or CDDP. In contrast, the reverse sequence of the treatment, that is, 5-FU prior to NDP or CDDP (FN or FC therapy), resulted in the synergistically enhanced inhibition of tumor growth and the prolonged survival in comparison with NDP, CDDP or 5-FU monotherapy. The antitumor activities of the combinations of CDDP with 5-FU was less than those of the combination of NDP with 5-FU. Especially, at the MTD of NDP in FN therapy, long-term tumor-free survival was frequently observed. Thus, FN therapy was thought to be the most efficient regimen in combination of NDP with 5-FU as a clinical therapy.

Relationships between an index of body fat distribution (based on waist and hip circumferences) and stature, and biochemical complications in obese children

OBJECTIVE

To determine the clinical utility of a new age-adjusted measure of body fat distribution (based on waist and hip circumferences) and stature, in relation to biochemical complications in obese children.

DESIGN

Cross-sectional, clinical study. The formula to calculate the common standard deviation score (SDS) of waist-to-hip ratio/height (WHR/Ht) was obtained from the data of control children. The relationship between WHR/Ht SDS, as the age-adjusted measure, in obese children and their clinical laboratory data was evaluated.

SUBJECTS

Outpatient obese Japanese children (102 boys and 75 girls) and control children (508 boys and 549 girls), ranging in age from 6-15 y.

MEASUREMENTS

Height, body weight, waist girth, hip girth, triceps and subscapular skinfold thicknesses, as anthropometric measures. Percent overweight, percent body fat, waist girth, WHR and WHR/Ht SDS as criteria for obesity. Clinical laboratory analyses for fasting blood samples of obese children.

RESULTS

The WHR/Ht SDS closely correlated with age in obese children, thus reflecting the progress of abdominal obesity during growth. The obese boys were more hyperlipidaemic than the girls were, although the percent overweight was similar in both genders. The percent overweight, percent body fat, waist girth and WHR/Ht SDS all correlated well with triglyceride (TG), alanine aminotransferase (ALT) and insulin in boys, whereas only waist girth and WHR/Ht SDS showed a close correlation with TG and insulin in girls. The obese subjects were subdivided according to the number of abnormal values observed in TG, ALT and insulin. For obese boys, all five indices of obesity were higher in the groups with complications than in the group without. In the girls, only the WHR/Ht SDS constantly differed between subgroups. WHR/Ht SDS most obviously distinguished the groups with complications from the other group with a wide margin of difference (2-fold in boys and > 2-fold in girls) in the mean values.

CONCLUSION

The WHR/Ht SDS can serve as an index predicting the occurrence of biochemical complications in obese children ranging from the age of 6-15 y.

Pharmacodynamics and pharmacokinetics of a single oral dose of nitrazepam in healthy volunteers: an interethnic comparative study between Japanese and European volunteers

Potential interethnic differences in drug disposition and effects between Japanese and white subjects hamper the registration in Japan of medications already used in Western countries. This double-blind, placebo-controlled, crossover study was conducted to compare the pharmacodynamics and pharmacokinetics of a single oral dose of nitrazepam (5 mg) in age- and sex-matched Japanese (n = 8) and white (n = 8) healthy volunteers. The study was performed in centers in Japan and the Netherlands using the same methods and study design. Subjects were individually matched for gender, age, and body stature. Drug effects were measured by means of saccadic and smooth pursuit eye movements and visual analog lines obtained from the scales of Bond and Lader. There were no pharmacokinetic differences between the Japanese and white subjects. Clearance of nitrazepam was 0.91 +/- 0.165 mL/min/kg and 1.17 +/- 0.492 mL/min/kg, and half-life (t1/2) was 22.1 +/- 4.96 hours and 21.5 +/- 7.51 hours for the Japanese and European groups, respectively. Pharmacokinetic parameters showed no significant correlation with age, height, or weight. The average time-effect curves for the different parameters were comparable between groups. Compared with placebo, both groups showed similar significant reductions in average peak velocity and increases in saccadic inaccuracy and reaction time. Visual analog scores showed clear sedation in the white subjects, but insignificant effects in the Japanese subjects. Smooth pursuit did not change significantly in either group. Slope and intercept of the concentration-effect relationships for saccadic peak velocity showed considerable intersubject variability, but no clear differences between groups. The pharmacokinetics and pharmacodynamics of nitrazepam were similar in matched healthy Japanese and white subjects. Interethnic comparative studies are feasible, and provide meaningful information about potential racial differences in disposition and action of drugs. Such studies can form a rational basis for comparative clinical trials.

Repair of (6-4) photoproducts in cultured goldfish cells at confluence or treated with H2O2

Previously we reported that fluorescent light (FL) illumination prior to UV irradiation (FL preillumination) had multiple effects on the repair of cyclobutane pyrimidine dimers (CPD) and (6-4) photoproducts ([6-4] PD) in cultured goldfish cells (RBCF-1) at the exponentially growing phase. In this study, it is shown that even under the confluent condition of RBCF-1 cells, FL preillumination increased the disappearance of (6-4) PD in the dark. In addition, both at confluence and at the exponentially growing phase, the disappearance of (6-4) PD after PR treatment was increased by FL preillumination to RBCF-1 cells. Moreover, it was found that H2O2 pretreatment, followed by UV irradiation, of the exponentially growing cells also enhanced the disappearance of (6-4) PD in the dark and by photorepair treatment. The degree of enhancement by H2O2 pretreatment was almost the same as that by FL preillumination.

Sequence-dependent antitumour efficacy of combination chemotherapy of nedaplatin, a novel platinum complex, with 5-fluorouracil in an in vivo murine tumour model

The antitumour efficacy of a sequential combination of nedaplatin (NDP) and 5-fluorouracil (5-FU) was evaluated using Lewis lung carcinoma in vivo. NDP was developed as a second generation platinum complex. Because it has greater antitumour activity and lower nephrotoxicity than cisplatin (CDDP), we also compared the antitumour activity of NDP plus 5-FU with that of CDDP plus 5-FU. A fixed 5-FU dose was injected daily for 5 days and increasing doses of either NDP or CDDP were injected once via the tail vein into the Lewis lung carcinoma-implanted mice. The sequential administration of either NDP or CDDP prior to 5-FU (NF or CF therapy) resulted in severe body weight loss followed by the death of the tumour-bearing mice when the high-dose of NDP or CDDP was administered. In contrast, the sequential administration of 5-FU prior to NDP or CDDP (FN or FC therapy) resulted in synergistically enhanced inhibition of tumour growth and prolonged survival in comparison with NDP, CDDP or 5-FU monotherapy. At the high-dose of NDP in FN therapy, a reduction of tumour size and long-term tumour-free survival were frequently observed. The survival effect of the combinations of NDP with 5-FU was superior to those of the combination of CDDP with 5-FU. In conclusion, the sequence-dependent antitumour efficacy and toxicity of the combination of NDP or CDDP with 5-FU was demonstrated in this study, and FN therapy appeared to be the most efficient regimen as a clinical therapy.

HIV, but not murine leukemia virus, vectors mediate high efficiency gene transfer into freshly isolated G0/G1 human hematopoietic stem cells

Recent studies have opened the possibility that quiescent, G0/G1 hematopoietic stem cells (HSC) can be gene transduced; lentiviruses (such as HIV type 1, HIV) encode proteins that permit transport of the viral genome into the nucleus of nondividing cells. We and others have recently demonstrated efficient transduction by using an HIV-1-based vector gene delivery system into various human cell types including human CD34(+) cells or terminally differentiated neurons. Here we compare the transduction efficiency of two vectors, HIV-based and murine leukemia virus (MuLV)-based vectors, on untreated and highly purified human HSC subsets that are virtually all in G0/G1. The HIV vector, but not MuLV vector supernatants, transduced freshly isolated G0/G1 HSC from mobilized peripheral blood. Single-step transduction using replication-defective HIV resulted in HSC that expressed the green fluorescent protein (GFP) transgene while retaining their stem cell phenotype; clonal outgrowths of these GFP+ HSC on bone marrow stromal cells fully retained GFP expression for at least 5 weeks. MuLV-based vectors did not transduce resting HSC, as measured by transgene expression, but did so readily when the HSC were actively cycling after culture in vitro for 3 days in a cytokine cocktail. These results suggest that resting HSC may be transduced by lentiviral-based, but not MuLV, vectors and maintain their primitive phenotype, pluripotentiality, and at least in vitro, transgene expression.

Antitumor efficacy of nedaplatin, a novel platinum complex, with cyclophosphamide in murine and human tumor model

BACKGROUND

The antitumor efficacy of the combination of Nedaplatin (NDP) with cyclophosphamide (CPM) was evaluated using murine and human carcinoma implanted mice. NDP was developed as a second generation platinum complex. Because of its superior antitumor activity and lower nephrotoxicity than Cisplatin (CDDP), we also compared the antitumor activity of NDP plus CPM with that of CDDP plus CPM.

MATERIALS AND METHODS

Various doses of NDP or CDDP (1/4 to 1 maximum tolerated dose; MTD) and CPM (58 or 78 mg/kg) were injected once via the tail vein into mice implanted with Lewis murine lung carcinoma or Ma44 human lung carcinoma.

RESULTS

Simultaneous administration of NDP or CDDP with CPM resulted in synergistically enhanced inhibition of tumor growth and prolonged survival in comparison with therapy using only NDP, CDDP or CPM. The combination therapy of NDP with CPM showed a superior survival effect with frequent long-term tumor-free survivors in comparison to that of CDDP plus CPM without increased hematotoxicity. The augmented antitumor efficacy of the combination of NDP with CPM was also demonstrated against Ma44 human lung carcinoma.

CONCLUSION

The results suggested the effectiveness of using a combination of NDP with CPM for clinical therapy.

Effect of selenium deficiency on cellular and extracellular glutathione peroxidases: immunochemical detection and mRNA analysis in rat kidney and serum

To determine the effect of selenium (Se) deficiency on expression of glutathione peroxidase (GSH-Px) 1 and 2, we measured GSH-Px activity in rat serum, liver and kidneys, serum immunoreactive GSH-Px 2, and the mRNAs of kidney GSH-Px 1 and 2. We purified rat GSH-Px 2 and raised polyclonal antibodies. Immunoreactive GSH-Px 2 was measured by rocket immunoelectrophoresis. GSH-Px 2 was purified 1470-fold with a specific activity of 250 units/mg. Immunoblotting detected only GSH-Px 2 in rat serum, and much less GSH-Px 2 than GSH-Px 1 in kidney. Immunoblot signal of kidney GSH-Px 1 and 2 decreased progressively in Se deficient rats. Serum GSH-Px activity in Se deficient rats at 1, 2, 3, and 4 weeks declined to 33, 20, 10, and 9% of the control, while the serum level of immunoreactive GSH-Px 2 was 58, 24, 15, and 10% of the control, suggesting the presence of an inactive protein at week 1. GSH-Px activity declined to 4 and 11% of the control in the liver and kidney at 4 weeks. The mRNAs of kidney GSH-Px 1 and 2 showed similar decreases, and were 24 and 23% of the control at 4 weeks. GSH-Px mRNA levels were better preserved than GSH-Px activity, suggesting that GSH-Px expression was regulated at both pre-translational and translational levels.

alpha-Catenin-vinculin interaction functions to organize the apical junctional complex in epithelial cells

alphaE-catenin, a cadherin-associated protein, is required for tight junction (TJ) organization, but its role is poorly understood. We transfected an alphaE-catenin-deficient colon carcinoma line with a series of alphaE-catenin mutant constructs. The results showed that the amino acid 326-509 domain of this catenin was required to organize TJs, and its COOH-terminal domain was not essential for this process. The 326-509 internal domain was found to bind vinculin. When an NH2-terminal alphaE-catenin fragment, which is by itself unable to organize the TJ, was fused with the vinculin tail, this chimeric molecule could induce TJ assembly in the alphaE-catenin-deficient cells. In vinculin-null F9 cells, their apical junctional organization was impaired, and this phenotype was rescued by reexpression of vinculin. These results indicate that the alphaE-catenin-vinculin interaction plays a role in the assembly of the apical junctional complex in epithelia.

Anticancer efficacy in vivo and in vitro, synergy with 5-fluorouracil, and safety of recombinant methioninase

The elevated exogenous-methionine dependency of tumors for growth has been observed in all major cancer cell types. We have previously cloned a methioninase (rMETase) from Pseudomonas putida to deplete methionine. Growth inhibition followed by apoptotic cell death was induced by treatment of tumor cells with rMETase in vitro. A single i.p. injection of 300 units of rMETase can lower the serum methionine level in the mice from 70 microM to less than 1 microM within 2 h and maintain this depleted level for 8 h. Repeated dosing of rMETase of tumor-bearing mice could be administered without acute immune-hypersensitivity. rMETase treatment demonstrated growth inhibitory activity against human tumors in nude mice, including those which were multiple drug-resistant. No body weight loss or hematotoxicity, except a slight anemia, was found throughout the therapy. The combined treatment of the Lewis lung carcinoma with a fixed rMETase dose and increasing doses of 5-fluorouracil (5-FU) resulted in a dose-dependent enhanced antitumor efficacy for survival as well as tumor growth inhibition. Thus, methionine depletion by rMETase potentiates the antitumor efficacy of 5-FU. The data presented in this report thus indicate that rMETase is active alone, is synergistic in combination with 5-FU, and has negligible toxicity suggesting a novel clinical approach for effective cancer therapy.

Replacement of the ascending aorta and aortic valve with a composite graft: operative and long-term results

The purpose of this study is to analyze our treatment experience on patients with ascending aortic aneurysms, with aortic regurgitation. From January 1974 to December 1995, 49 patients underwent replacement of the aortic valve and ascending aorta with a composite graft, in which primary operation cases were 44 and reoperation ones were 5. The Bentall technique was used in 20 patients, the button technique in 11, the interposition graft technique in 11, and a combination of the interposition graft and button technique in 7. All but one reoperation cases underwent the interposition graft technique. Hospital mortality was 30% for the Bentall technique, and 9.1% for the button technique and 9.1% for the interposition graft technique; there was no hospital mortality in the combination of the interposition graft and button technique. Hospital mortality of interposition graft technique in primary operation cases was 9.1%, and that in reoperation cases was 0%. Hospital mortality in patients underwent from 1974 to 1985 was 30.8%, 27.8% from 1986 to 1991, and 0% from 1992 to 1995. Five late deaths occurred in the Bentall group (35.7%) and one late death in the button technique (9.1%). Not late deaths in the other groups have occurred. In summary, operative mortality in Bentall technique group was higher than that of the other groups. Operative results were improved by the change of operative methods. The interposition graft technique is preferable for patients undergoing reoperation or when tension on the ostial anastomoses may occur. The button technique is best for patients with aortic dissection or inflammation involving the coronary ostia.

High doses of purified stem cells cause early hematopoietic recovery in syngeneic and allogeneic hosts

In humans, autologous transplants derived from bone marrow (BM) usually engraft more slowly than transplants derived from mobilized peripheral blood. Allogeneic BM transplants show a further delay in engraftment and have an apparent requirement for donor T cells to facilitate engraftment. In mice, Thy-1.1(lo)Lin-/loSca-1+ hematopoietic stem cells (HSCs) are the principal population in BM which is responsible for engraftment in syngeneic hosts at radioprotective doses, and higher doses of HSCs can radioprotect an allogeneic host in the absence of donor T cells. Using the mouse as a preclinical model, we wished to test to what extent engraftment kinetics was a function of HSC content, and whether at high doses of c-Kit+Thy-1.1(lo)Lin-/loSca-1+ (KTLS) cells rapid allogeneic engraftment could also be achieved. Here we demonstrate that engraftment kinetics varied greatly over the range of KTLS doses tested (100-10,000 cells), with the most rapid engraftment being obtained with a dose of 5,000 or more syngeneic cells. Mobilized splenic KTLS cells and the rhodamine 123(lo) subset of KTLS cells were also able to engraft rapidly. Higher doses of allogeneic cells were needed to produce equivalent engraftment kinetics. This suggests that in mice even fully allogeneic barriers can be traversed with high doses of HSCs, and that in humans it may be possible to obtain rapid engraftment in an allogeneic context with clinically achievable doses of purified HSCs.

Glutamate-stimulated proliferation of rat retinal pigment epithelial cells

We investigated the effects of glutamate on cell proliferation and the expression of basic fibroblast growth factor (bFGF) and its receptor (FGF-R1) mRNA in cultured rat retinal pigment epithelial (RPE) cells. The number of primary RPE cells was significantly higher after treatment with 0.2 to 1.0 mM glutamate (maximum at 1.0 mM) for 7 days than in controls. Glutamate-stimulated cell proliferation was abolished by (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), but not by 6,7-dinitroquinoxaline-2,3-dione or L(+)-2-amino-3-phosphonopropionic acid. Proliferation was increased to a similar extent by N-methyl-D-aspartate (NMDA), but not by kainate, alpha-amino-3-hydroxy-3-methyl-4-isoxazolepropionic acid or trans-(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid. NMDA-receptor-like immunoreactivity was detected in most cells cultured. Treatment of cells with glutamate increased the level of bFGF mRNA and, to a lesser extent, that of FGF-R1 mRNA, which peaked 2 and 4 days, respectively, after glutamate was added. The increase in bFGF mRNA induced by glutamate was inhibited by MK-801. These findings suggest that glutamate might stimulate proliferation of RPE cells through activation of NMDA receptors and expression of bFGF and further suggest that glutamate may be involved in the proliferative changes of RPE cells in retinal wound healing.