Glutamate responsiveness enhanced in neurones expressing amyloid precursor protein

Although the neurotoxicity of beta-amyloid peptide is well established, the cellular functions of amyloid precursor protein (APP) remain unclear. Using an adenoviral vector, we introduced cDNA encoding human APP holoprotein into rat hippocampal neurones in culture. Neurones expressing the membrane-bound form of APP showed greater responsiveness to applied glutamate than non-expressing control neurones, as revealed by Ca2+ fluorometry. This increased responsiveness was not the result of secreted APP, as confirmed by observations of closely spaced APP-expressing and non-expressing cells in the same culture dish. These data suggest that one function of APP may be the regulation of glutamate receptors in neurones.

Tissue-specific expression of HSV-tk gene can induce efficient antitumor effect and protective immunity to wild-type hepatocellular carcinoma

The efficacy of expression of the herpes simplex virus thymidine kinase (HSV-tk) gene under the transcriptional control of the liver-specific albumin gene promoter, followed by ganciclovir treatment, was investigated both in vitro and in vivo. Murine and rat hepatocellular carcinoma (HCC) cells infected with retroviruses carrying the HSV-tk gene under the control of the murine albumin gene promoter were selectively killed by ganciclovir treatment in vitro, whereas non-HCC cells, such as murine mammary tumor cells and fibroblast cells, which were infected with the same retroviruses, were not. Susceptibility of the retroviral-infected HCC cells to ganciclovir was more than 100-fold higher than that of the retroviral-infected non-HCC cells. When mice bearing a bulky HCC mass consisting of the retroviral-infected HCC cells were treated with systemic ganciclovir administration, complete regression of the tumors was observed without any signs of overt toxicity. Profound antitumor effects on preestablished murine HCCs were observed when wild-type HCC cells were implanted into animals with a small percentage of the retroviral-infected counterparts. When only 5% of the cells were infected with retroviruses carrying the HSV-tk gene, significant inhibition of tumor development was observed with systemic ganciclovir treatment. Importantly, animals that were treated with implantation of mixtures of the retroviral-infected and parental HCC cells, followed by ganciclovir administration, did not exhibit tumor formation and resisted subsequent rechallenge with wild-type HCC cells. Our results indicate the feasibility of combination therapy with the HSV-tk gene and ganciclovir for the treatment of HCC.

Shift work and risk factors for coronary heart disease in Japanese blue-collar workers: serum lipids and anthropometric characteristics

This study was conducted to determine if there is an association between shift work and risk factors for coronary heart disease (CHD) in Japanese male blue-collar shift workers. Health check-up data on serum lipid concentration and anthropometric indices of 33 three-shift workers and 27 two-shift workers were compared with those of day workers. The average years in age of the shift workers and day workers were 34.5 (SD = 7.1) and 32.7 (SD = 7.6), respectively. Serum total cholesterol levels of three-shift, two-shift and day workers were 5.70 (SD = 1.19) mmol/l, 4.81 (SD = 1.01) mmol/l, 4.98 (SD = 0.95) mmol/l, respectively, and the cholesterol levels of three-shift workers were significantly higher than the other workers (p < 0.05). In addition, the abdominal to hip circumference ratios were 0.905 (SD = 0.060) for three-shift workers and 0.877 (SD = 0.054) for day workers, with a significant difference (p < 0.05). In the present Japanese population, three-shift workers had higher risks of CHD than day workers, which was characterized by higher levels of serum total cholesterol and tendency to central obesity. These findings held when lifestyle factors were taken into account.

Increased expression of transforming growth factor-beta1 during gastric ulcer healing in rats

This study was done to investigate the expression and localization of transforming growth factor-beta1 (TGF-beta1) in the gastric ulcerated tissues produced by acetic-acid during the healing process, by northern blot analysis and immunohistochemical technique. Ulcerated TGF-beta1 mRNA levels were significantly increased from days 3 to 18, in a similar manner to extracellular matrix proteins, and returned to control levels at the scarred phase. Immunoreactive TGF-beta1 was localized in epithelial cells beneath proliferative zone in intact tissues. In ulcerated tissues, TGF-beta1 was localized in macrophages in the ulcer bed and in fibroblasts or myofibroblasts in the granulation tissues. Treatment with prostaglandin E1 (PGE1) further stimulated ulcerated TGF-beta1 expression, being associated with the acceleration of gastric ulcer healing, while treatment with indomethacin reduced TGF-beta1 expression, being accompanied by the delayed ulcer healing. The combination of PGE1 and indomethacin reversed the indomethacin-induced decrease in ulcerated TGF-beta1. Thus, TGF-beta1 may be implicated in the acceleration of gastric ulcer healing.

A phase I study of irinotecan and infusional cisplatin with recombinant human granulocyte colony-stimulating factor support in the treatment of advanced non-small cell lung cancer

We conducted a phase I study to examine whether support with recombinant human granulocyte colony-stimulating factor (rG-CSF) would permit dose intensification of irinotecan (CPT-11) in combination with cisplatin (20 mg/m2 x 5 days) in non-small cell lung cancer (NSCLC) patients. CPT-11 was administered by bolus infusion at a starting dose of 100 mg/m2 on day 1, followed by serial increments at 20 mg/m2, given every 4 weeks. The major toxic effects were granulocytopenia and diarrhoea. The response rate was 55% (11/20). The optimum dose for phase II studies appears to be 20 mg/m2/day (5-day continuous infusion) for cisplatin and 160 mg/m2 (day 1) for CPT-11 with rG-CSF support in NSCLC.

Tumor lysis syndrome in invasive thymoma with peripheral blood T-cell lymphocytosis

Tumor lysis syndrome has rarely been observed in solid tumors. We report a case of a patient with advanced invasive thymoma associated with peripheral blood T-cell lymphocytosis in whom tumor lysis syndrome developed after chemotherapy. The potential for tumor lysis syndrome should be anticipated when treating extensive thymoma.

[Idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia in a patient who died of progressive peripheral polyneuritis and cerebral dysfunction]

We reported a 59-year-old woman who received a diagnosis of psoriasis vulgaris at the age of 35 and had been under medical treatment. She was admitted to our department on August 16, 1993 because of lymphadenopathy, arthralgia and neuralgia. We observed cervical and axillar lymphadenopathy 1-3 cm in diameter, anemia and leukothrombocytosis. Elevated levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and immunoglobulin G (IgG), but not M-protein were observed by immunological analysis of the serum. Bone marrow aspiration biopsy revealed hypercellularity with myeloid hyperplasia and slight increase in plasma cells. Elevated levels of serum interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF) were detected; IL-6 was 62.1 pg/ml and G-CSF was 66 pg/ml, but IL-1 alpha, IL-1 beta and TNF-alpha were within the normal range. Idiopathic plasmacytic lymphadenopathy (IPL) with polyclonal hyperimmunoglobulinemia was diagnosed by lymph-node biopsy and the patient received following treatment with prednisolone and hydroxyurea. Leukocytes, platelets and skin eruptions increased again when the steroid dose was tapered, so we changed treatments to MP (melphalan, prednisolone) therapy. In addition, various neurological abnormalities such as convulsions, loss of consciousness and peripheral polyneuritis were observed. Despite treatment her condition deteriorated and she finally died. Very few reports show these neurological abnormalities in IPL or Castleman's disease therefore we think this is a very rare case.

A phase I study of irinotecan and infusional cisplatin for advanced non-small-cell lung cancer

A phase I study was performed to establish the optimum dose for combination therapy with infusional cisplatin and irinotecan (CPT-11) in non-small-cell lung cancer (NSCLC). The subjects were 20 patients with a performance score of 0-2 with untreated advanced NSCLC. Cisplatin was administered by 5-day continuous intravenous infusion at 20-25 mg/m2 per day. CPT-11 was administered by bolus infusion at a starting dose of 20 mg/m2 on days 1 and 8 or 60 mg/m2 per day on day 1 alone, followed by serial increments of 20 mg/m2. Since grade 4 granulocytopenia was observed in two of the five patients receiving 20 mg/m2 per day cisplatin (days 1-5) and 100 mg/m2 CPT-11 (day 1), and since one of them developed severe pneumonia and sepsis associated with the granulocytopenia, the regimen was considered to be intolerable. In the same patient, grade 4 thrombocytopenia and grade 3 diarrhea were observed. Therefore, the optimum dose appeared to be 20 mg/m2 per day (days 1-5) for cisplatin and 80 mg/m2 (day 1) for CPT-11. The side effects were grade 2 diarrhea in one of three patients, and grade 2 vomiting in three patients, but grade > or = 2 hemotoxicity was not observed. This combined regimen resulted in a partial response in 9 out of 19 assessable patients. The dose-limiting factor in this combination therapy was granulocytopenia, and a high efficacy rate was obtained.

Rapid expression and specific localization of tenascin in gastric ulcer healing in rats

This study was done to investigate the gene expression and localization of tenascin in ulcerated gastric tissues during the healing process with Northern blot analysis and immunohistochemical technique. Gastric ulcers in rats were produced by acetic acid. Tenascin mRNA levels in the ulcerated tissue were significantly increased in a biphasic manner (12 h and day 5), preceding the increase in collagen type IV and laminin mRNA levels, and returned to control levels on day 11. In intact tissues, tenascin was mainly localized in the basement membrane above the proliferative zone, in contrast to the predominant localization of collagen type IV and laminin below the proliferative zone. On the ulcer margin from 12 h to day 5, tenascin was abundantly observed in the lamina propria around nonproliferating new epithelial cells, but collagen type IV and laminin were not seen in this lamina propria. On day 7, tenascin, expressed in the lamina propria, was replaced by collagen type IV and laminin. Thus, the rapid expression and unique localization of tenascin suggest the important role of tenascin in gastric ulcer healing.

Simple purification and functional reconstitution of octopus photoreceptor Gq, which couples rhodopsin to phospholipase C

In invertebrate photoreceptors, illuminated rhodopsin activates multiple G proteins, which are assumed to initiate multiple phototransduction cascades. In this paper, we focused on one of the phototransduction cascades, which utilizes rhodopsin, a Gq-like G protein, and phospholipase C (PLC). A Gq-like G protein from octopus photoreceptors was successfully purified to apparent homogeneity as an active form by simple two-step chromatography. The purified G protein had an alpha beta gamma-trimeric structure consisting of 44-kDa alpha, 37-kDa beta, and 9-kDa gamma subunits. The 44-kDa alpha subunit was assigned to the Gq class by western blot with antiserum against mammalian Gq alpha and by partial amino acid sequencing of its proteolytic fragments. Light-dependent binding of GTP gamma S was observed when the purified octopus Gq was reconstituted with octopus rhodopsin that had been integrated into phospholipid vesicles. Octopus Gq activated PLC beta 1 purified from bovine brain dose-dependently in the presence of A1F4-. Finally, light- and GTP-dependent activation of PLC beta 1 was observed in a reconstitution system consisting of octopus rhodopsin, Gq, and bovine PLC beta 1.

Analysis of lectin binding properties on human Burkitt's lymphoma cell lines that show high spontaneous metastasis to distant organs in SCID mice: the binding sites for soybean agglutinin lectin masked by sialylation are closely associated with metastatic lymphoma cells

Alterations in cell surface carbohydrates on human lymphoma cell lines with different spontaneous metastatic potential in the severe combined immunodeficiency (SCID) mouse model were analyzed. A difference in cell surface carbohydrates between high- (HBL-2, HBL-7 and HBL-8) and no- or low-(HBL-4, HBL-6, Daudi and Raji) spontaneous metastatic human lymphoma cell lines were analyzed on a FACScan using fluorescein-isothiocyanate (FITC)-conjugated lectins. The most consistent difference in lectin binding properties was found with soybean agglutinin (SBA) lectin. High-metastatic lymphoma cells (HBL-7 and HBL-8 cells) in vitro were found to bind the SBA lectin, but the cells in vivo (in primary tumors and metastatic tumors of SCID mice) showed considerably reduced SBA lectin binding. In addition, HBL-2 cells that almost did not bind SBA lectin in vitro and in vivo showed high spontaneous metastasis. Neuraminidase treatment revealed that SBA lectin binding sites were masked by sialic acid. On the other hand, no- or low-metastatic lymphoma cells in vitro and in vivo were found to bind SBA lectin. HBL-8 cell clones without SBA lectin binding showed high spontaneous metastasis to distant organs in SCID mice but HBL-8 cell clones with SBA lectin binding showed very low spontaneous metastasis. Sophora Japonica agglutinin (SJA) lectin is able to recognize the carbohydrates in common with SBA lectin, but it does not appear to be associated with metastatic capacity. These results suggest that the sialylation of particular carbohydrate residues on human lymphoma cells that are recognized by SBA lectin may be associated with the spontaneously metastatic capacity of human lymphoma cell lines in our SCID mouse model.

Colorimetric ELISA measurement of specific mRNA on immobilized-oligonucleotide-coated microtiter plates by reverse transcription with biotinylated mononucleotides

In this study, alpha-globin mRNA was captured on plastic plates to which alpha-globin-specific oligonucleotides had been covalently immobilized; the captured mRNA was immediately reverse-transcribed into cDNA in the presence of biotinylated dUTP. Addition of alkaline phosphatase-conjugated streptavidin to react with the biotin was followed by addition of substrate (p-nitrophenyl phosphate), and the resulting colorimetric development was measured at 405 nm. Because multiple biotin molecules are incorporated into cDNA during reverse transcription, and because synthesized cDNA is more stable than mRNA, we could successfully quantify by conventional colorimetry the amount of alpha-globin mRNA on the plate within a linear range of 100 pg to 10 ng. This is more sensitive than conventional Northern blotting. Therefore, the present method may be applicable to measurements of specific mRNAs in various test materials.

A high frequency of defective vif genes in peripheral blood mononuclear cells from HIV type 1-infected individuals

We studied the heterogeneity and intactness of the vif gene in six HIV-1-infected individuals at various clinical stages. The proviral vif sequences in peripheral blood mononuclear cells were amplified by PCR, followed by cloning and sequencing of 45 vif clones. The intraindividual diversity of the vif genes ranged from 0.45 to 3.3% and was not correlated with disease stage. Although the vif gene has been shown to be essential for infection of HIV-1 in vitro, a high frequency (31%) of defective vif genes was observed. In one patient, six vif clones carried double nonsense mutations at the same positions, five of which were clustered in the phylogenetic tree, suggesting that these vif-defective viruses may have replicated in vivo. Phylogenetic analysis revealed that the vif sequences from each individual were clustered into a separate group and that all of them belong to subtype B.

Colorimetric ELISA measurement of specific mRNA on immobilized-oligonucleotide-coated microtiter plates by reverse transcription with biotinylated mononucleotides

In this study, alpha-globin mRNA was captured on plastic plates to which alpha-globin-specific oligonucleotides had been covalently immobilized; the captured mRNA was immediately reverse-transcribed into cDNA in the presence of biotinylated dUTP. Addition of alkaline phosphatase-conjugated streptavidin to react with the biotin was followed by addition of substrate (p-nitrophenyl phosphate), and the resulting colorimetric development was measured at 405 nm. Because multiple biotin molecules are incorporated into cDNA during reverse transcription, and because synthesized cDNA is more stable than mRNA, we could successfully quantify by conventional colorimetry the amount of alpha-globin mRNA on the plate within a linear range of 100 pg to 10 ng. This is more sensitive than conventional Northern blotting. Therefore, the present method may be applicable to measurements of specific mRNAs in various test materials.

[Diagnosis of pleural dissemination lung cancer by thin-section CT--a prospective study]

In this prospective study, thin-section CT was used to diagnose pleural dissemination in patients with pulmonary adenocarcinomas in which the primary lesion was found to be adjacent to the pleural surface by conventional CT. The subjects were 32 patients (25) who had undergone resection and 7 who had not with pulmonary adenocarcinoma without pleural effusion from among the 136 patients with pulmonary adenocarcinoma examined at our institution over 3 years. Thin-section CT images of three regions were obtained, and these included the pleural surface adjacent to the lesion, the minor fissure, and the diaphragmatic dome. Histopathological examination revealed pleural dissemination in 12 patients (5 who had undergone resection and who had not), in 2 of whom a diagnosis could not be made preoperatively. Pleural dissemination was diagnosed by CT in 12 patients; there were 2 false positives. In 6 patients who did not undergo resection, cancerous cells were found in fluid obtained by percutaneous pleural lavage, and mediastinal lymph node metastases or distant metastases were also detected. The diagnostic rate of CT was as follows interlobar space. 100% (7/7); mediastinum, 75% (3/4); diaphragm, 71% (5/7); and chest wall, 57% (4/7). In the patients who underwent resection, sensitivity was 100% for the interlobar space, but it was 0% to 33% for other pleural surfaces.

Absence of fetal liver hematopoiesis in mice deficient in transcriptional coactivator core binding factor beta

Core binding factor beta (CBF beta) is considered to be a transcriptional coactivator that dimerizes with transcription factors core binding factor alpha 1 (CBFA1), -2, and -3, and enhances DNA binding capacity of these transcription factors. CBF beta and CBFA2, which is also called acute myeloid leukemia 1 gene, are frequently involved in chromosomal translocations in human leukemia. To elucidate the function of CBF beta, mice carrying a mutation in the Cbfb locus were generated. Homozygous mutant embryos died between embryonic days 11.5-13.5 due to hemorrhage in the central nervous system. Mutant embryos had primitive erythropoiesis in yolk sac but lacked definitive hematopoiesis in fetal liver. In the yolk sac of mutant embryos, no erythroid or myeloid progenitors of definitive hematopoietic origin were detected, and the expression of flk-2/flt-3, the marker gene for early precursor cells of definitive hematopoiesis, was absent. These data suggest that Cbfb is essential for definitive hematopoiesis in liver, especially for the commitment to early hematopoietic precursor cells.

Evaluation of prodrugs ability to induce effective ablation of cells transduced with viral thymidine kinase gene

Transduction of the herpes simplex virus thymidine kinase (HSV-tk) gene into tumor cells followed by treatment with prodrugs is one of the most promising approaches for gene therapy in cancer. The choice of prodrugs is important in order to obtain maximum anticancer effects with minimum adverse reactions. We retrovirally transduced the HSV-tk gene into murine and rat hepatocellular carcinoma (HCC) cells, and investigated their sensitivity to ganciclovir and acyclovir. Retrovirally-mediated HSV-tk transduction did not affect cell proliferation, but led to both ganciclovir- and acyclovir-dependent cytotoxicity in the HCC cells. Ganciclovir exhibited much stronger cytotoxicity on HSV-tk transduced cells than acyclovir. Importantly, HSV-tk transduced cells were completely abrogated at a ganciclovir concentration which was lower than the minimum plasma level achieved in the clinical usage of ganciclovir. Furthermore, HSV-tk transduced cells induced stronger killing of neighboring untransduced cells in the presence of ganciclovir than acyclovir. Ganciclovir may be preferable to acyclovir in the HSV-tk transduction system.

Influence of "Solcoseryl" during culture on the sex-dependent repair of bovine demi-embryos

The purpose of this experiment was to determine the effect of culture conditions on the development of split embryos after bisection and on the sex ratio of resultant bovine demi-embryos. Embryos that had developed into blastocysts on days 6 1/2 to 7 or on days 7 1/2 to 8 from oocytes matured and fertilized in vitro were bisected in BMOC-3 medium supplemented with 33% calf serum. The medium also contained 0%, 0.1% or 1.0% Solcoseryl, a deproteinized hemodialysate product from calf blood. The demi-embryos were first cultured for 4 hours in the same medium in which they had been bisected and then co-cultured with cumulus cells in TCM199 supplemented with 1% calf serum for an additional 20 hr. The rate of production of good to excellent quality demi-embryos obtained from days 6 1/2 to 7 blastocysts was higher than from those on days 7 1/2 to 8. The rate was also significantly improved when blastocysts were bisected in medium containing 0.1% or 1.0% Solcoseryl, compared to the medium without Solcoseryl. Male embryos seemed to recover more rapidly than female embryos, as assessed by morphological quality at 4 hr, although the quality of female embryos had improved by 24 hr. The percentage of males after culture was higher in the medium without Solcoseryl than in its presence. Thus, addition of Solcoseryl at either 0.1% or 1.0% to BMOC-3 medium seemed to improve the production efficiency of good quality demi-embryos, but did not influence the sex ratio. It appears as if female demi-embryos required more time than male embryos to be repaired after bisection.

Thymocyte proliferation-inducing activity of high molecular weight fraction from the culture supernatant of thymic epithelial cell line established from normal rat thymus

Precursor T cells originated from bone marrow proliferate, differentiate and maturate (thymic education process) to relatively mature T cells under the influence of thymic epithelial cells (TECs). Thymic hormonal factors (THFs) released from TECs presumably play a pivotal role in the thymic education. The THFs related to the thymocyte differentiation and maturation were carefully examined and some of them identified. However, the relation of THFs with thymocyte proliferation (TPIFs) are poorly understood. Consequently we attempted to study the activities of TPIFs under physiological conditions. In this investigation, we employed a TEC line derived from normal rat thymus, disposable reversed-phase column cartridge for concentrating the culture supernatant of TEC (TECS) and high-performance liquid chromatography. By separating TECS sample with ion exchange chromatography, the thymocyte proliferation-inducing activity (TPIA) was efficiently separated from the thymocyte proliferation-suppressing activity. The TPIA was detected in the fraction with high molecular weight (198 to 310 kDa) by gel filtration chromatography. The TPIA was completely reduced by trypsin digestion, while heat-treatment affected only slightly the TPIA.

Cavity-dumped femtosecond Kerr-lens mode locking in a chromium-doped forsterite laser

We report the operation of a cavity-dumped self-mode-locked chromium-doped forsterite laser with pulse energies exceeding 30 nJ and pulse durations as short as 54 fs (FWHM) at 1260 nm. By frequency doubling in a beta-barium borate crystal, pulse energies as high as 3 nJ and pulse durations as short as 49 fs (FWHM) at 630 nm were generated. The high stability and ultrashort pulse widths with a variable repetition rate in both the infrared (1260 nm) and the red (630 nm) make this system an attractive light source for ultrafast spectroscopy.

Suppression of glucocorticoid-induced thymocyte apoptosis by co-culture with thymic epithelial cells

There are many reports concerning glucocorticoid-induced thymocyte apoptosis, but little is known about the participation of thymic stromal cells, especially the thymic epithelial (TE) cells, in the apoptosis. In this study, we investigated the in vitro effect of TE cells on dexamethasone-induced DNA fragmentation of thymocytes as a parameter for apoptosis. By co-culture of thymocytes with TE cell line, at the condition without cell-cell contact, the DNA fragmentation of thymocytes caused by physiological level of glucocorticoid was significantly suppressed. Same effect was detected when treated the thymocytes with the supernatant from the cultures of TE cell line. These results suggest that the humoral factors released from TE cells rescue the thymocytes from the glucocorticoid-induced apoptosis. Chemical and physico-chemical nature of the factors are discussed.