Towards the genetic architecture of seed lipid biosynthesis and accumulation in Arabidopsis thaliana.

We report the quantitative genetic analysis of seed oil quality and quantity in six Arabidopsis thaliana recombinant inbred populations, in which the parent accessions were from diverse geographical origins, and were selected on the basis of variation for seed oil content and lipid composition. Although most of the biochemical steps involved in lipid biosynthesis are known and the key genes have been identified, the regulation of the processes that results in the final oil composition and total amount is not understood. By using physically anchored markers it was possible to compare results across populations. A total of 219 quantitative trait loci (QTLs) were identified, of which 81 were significant at P<0.001. Some of these colocalise with QTLs identified previously, but many novel QTLs were also identified. The results highlight the importance of studying traits in multiple populations, which will lead to a better understanding of the contribution that natural variation makes to the genetic architecture of a phenotype.

Binding sites of interleukin-3-mimetic monoclonal autoantibodies derived from a MRL/lpr mouse.

MRL/lpr mouse-derived interleukin-3 (IL-3)-mimetic monoclonal antibodies were examined for their binding sites. One of these five antibodies (B10, F8, F9, F12, H11), F9 interacted with the IL-3 receptor, as if it were an anti-idiotypic antibody; the IL-3-mimetic activity of F9 was blocked by a neutralizing rat monoclonal anti-IL-3 antibody. IL-3 mRNA was not detected in hybridoma F9, as analyzed by the S1 protection assay, Thus, the activity neutralized by the rat antibody is of the F9 antibody itself but not the IL-3 type. Such blocking was not observed with the IL-3-mimetic activity of the other MRL/lpr-derived monoclonal antibodies. On the other hand, the binding of all these monoclonal antibodies to IL-3-dependent cells was inhibited by each other and vice versa, as analyzed by two-color flow cytometry. This indicates that the binding sites of the five monoclonal antibodies are located so close to each other that the binding of one would interfere with the binding of any one of the others (since the binding experiment was done on ice, it is unlikely that the inhibition is due to down-modulation of the receptors). Taken together the results obtained by the enzyme digestion study, we discussed that all five IL-3-mimetic monoclonal antibodies are directed to the IL-3 receptor, but only F9 binds to the portion directly responsible for the binding of IL-3 and the other antibodies (B10, F8, F12, H11) bind to different portions, respectively, which are adjacent or overlapping to the binding site of F9.

The micronucleus test of benzo[a]pyrene with mouse and rat peripheral blood reticulocytes.

The micronucleus test using peripheral blood reticulocytes (RETs) was evaluated in CD-1 and BDF1 mice and Sprague-Dawley rats treated with benzo[a]pyrene at two independent laboratories. The maximum incidence of micronucleated reticulocytes (MNRETs) appeared in both strains of mice 48 h after the treatment; interlaboratory differences were small. The incidence of MNRETs in BDF1 mice was higher than in CD-1 mice. In rats, significant increases of MNRETs with the maximum response at 72 h were detected when B[a]P was administered i.p.; slight but significant increases were observed at 24 h or later, with the maximum at 24-48 h, when it was administered p.o. These results suggest that the new method for the micronucleus test using circulating RETs will be useful in the detection of the clastogenicity of chemicals.

Micronucleus test with potassium chromate(VI) administered intraperitoneally and orally to mice.

The effect of route of administration, intraperitoneal (i.p.) or oral gavage (p.o.), in the mouse micronucleus test was studied with K2CrO4 in 2 mouse strains (MS/Ae and CD-1). A simplified acute toxicity test to estimate the toxic dose levels of K2CrO4 showed that the LD50S were 50 mg/kg i.p. and 300 mg/kg p.o. for MS/Ae and 32 mg/kg i.p. and 180 mg/kg p.o. for CD-1. Based on results of a pilot micronucleus test to determine appropriate dose levels and the optimal sampling time, it was decided to sample bone marrow cells of both strains of mice 24 h after i.p. doses of 10-80 mg/kg and p.o. doses ranging from 20 to 320 mg/kg. K2CrO4 administered i.p. induced micronucleated polychromatic erythrocytes (MNPCEs) dose-dependently in both strains. In contrast, when administered p.o. the chemical failed to induce MNPCEs. These results suggest that this difference between i.p. and p.o. routes is related to a difference of absorption or metabolic fate of chromate in vivo.

Multiple-dosing effects of benzo[a]pyrene in the mouse bone marrow micronucleus test.

Multiple-dosing effects of benzo[a]pyrene (B[a]P) in the micronucleus test were studied using CD-1 male mice. Mice were treated orally once, twice or 3 times with 250, 500, 1000 or 2000 mg/kg, at 24-h intervals. Bone marrow cells were sampled 24 h after the last administration. The present study indicated that the incidence of polychromatic erythrocytes with micronuclei significantly increased more in the group of animals that received B[a]P twice than in those receiving it one or 3 times. The dose of 500 mg/kg B[a]P yielded the greatest response of any dose regimen.

Structural elucidation of aculeximycin. III. Planar structure of aculeximycin, belonging to a new class of macrolide antibiotics.

The planar structure of aculeximycin (1) produced by Streptosporangium albidum has been determined by spectral methods and chemical degradations such as 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU)-methanol reaction, ozonolysis, and periodative oxidation. The antibiotic consists of a 30-membered polyhydroxy lactone ring, an alpha, beta-unsaturated ester group, an intramolecular hemiketal, an oligosaccharide (aculexitriose), a neutral sugar and an amino sugar. The structure of aculeximycin is closely related to those of sporaviridins produced by Streptosporangium viridogriseum. We consider that aculeximycin and sporaviridins belong to a new class of macrolide antibiotics, which is different from the polyol macrolides produced by Streptomyces.

Diffuse intrasinusoidal liver metastasis of small cell lung cancer causing fulminant hepatic failure: CT findings-a case report.

A 65-year-old man with small cell lung cancer treated with two courses of chemotherapy manifested appetite loss and abdominal distention 10 days before admission. Helical CT scanning of the abdomen and pelvis disclosed marked hepatomegaly without any visible nodular lesion in the hepatic parenchyma. He died of severe liver dysfunction with multiorgan failure on the 20th hospital day. Autopsy revealed diffuse invasion of tumor cells into the sinusoid throughout the liver.

[Comparison of combined operation and nasal CPAP treatments for sleep disorders].

UNLABELLED: Uvulopalatopharyngoplasty (UPPP) and nasal CPAP are used for the treatment of obstructive sleep apnea syndrome (OSAS) in different institutions. Although OSAS results from an abnormality in the soft-palate, almost no reports have been made on the selection of UPPP or nasal CPAP procedures according to the type of abnormality. The most probable reason for this is that a comparison of treatment methods in individuals cases is difficult. We performed CPAP titration before and after operations, and compared the treatment methods, and evaluated the medical therapy. METHOD: A sleep polygraph was performed on the first night, and cases diagnosed as OSAS received CPAP titration on the second night. The blocked region was identified by endoscopic examination. The results of the operation were evaluated after 1-2 months, and apnea hypopnea index (AHI) improvements of less than 50% received a second CPAP titration. RESULTS: The operation results were poor for cases where endoscopic examination showed full-circumference palatal type, and good for soft palate and tonsillar type abnormalities. When endoscopic examinations were performed in conjunction with nasal CPAP, the treatment was observed to act on the soft palate and expand the air way in all cases. Nasal CPAP was effective in cases with full-circumference palatal abnormalities because in these cases, the pressure was caused by inflamma. Combined medical treatments were effective in cases where CPAP alone was ineffective because the pressure was too high.

Mutagenicity studies of muroctasin.

A synthetic muramyl dipeptide derivative N2-[(N-acetylmuramoyl)-L-alanyl-D-isoglutaminyl]-N6-stearoyl-L-lysine (MDP-Lys(L18), muroctasin) was studied for mutagenicity using the Ames method, in vitro cytogenetics and micronucleus test. MDP-Lys(L18) had no mutagenic effect on S. typhimurium (TA1535, TA1537, TA1538, TA98 and TA100) or E. coli (WP2 uvrA) in the reverse mutation assay. In the cytogenetic study, MDP-Lys(L18) had no effect on the chromosomes of the Chinese hamster cells at cytotoxic doses. Single subcutaneous treatment of MDP-Lys(L18) at dose levels of 3.5, 35 or 350 mg/kg in the mouse micronucleus test did not increase the incidence of micronucleated polychromatic erythrocytes. These results show that MDP-Lys(L18) has no demonstrable mutagenic potential.

Mutagenicity study of the new cognition-enhancing agent nefiracetam.

A new cognition-enhancing agent, nefiracetam (N-(2,6-dimethylphenyl)-2- (2-oxo-1-pyrrolidinyl) acetamide, DM-9384, CAS 77191-36-7) was studied for mutagenicity by using the following short-term in vitro and in vivo tests: 1. reverse mutation test (Ames method) on S. typhimurium and E. coli, 2. cytogenetic test on Chinese hamster cells, and 3. mouse micronucleus test. In the cytogenetic study, nefiracetam caused a slight but significant increase of chromosomal aberration at the highest dose in the 48 h treatment group, but no mutagenicity was observed with the same indicator in the in vivo micronucleus test. Furthermore, nefiracetam did not show any positive response in the reverse mutation test. These results suggest that nefiracetam has no biologically significant respectively relevant mutagenic potential.

Monoclonal autoantibodies with interleukin 3-like activity derived from a MRL/lpr mouse.

Hybridomas that secrete monoclonal antibodies with interleukin 3 (IL-3)-like activity were established from spleen cells of a nonimmunized autoimmune MRL/lpr mouse. Five of the monoclonal antibodies thus obtained bound selectively to IL-3-dependent cells and supported their growth. These monoclonal antibodies inhibited the binding of IL-3 to FDC-P2 cells and vice versa. Thus, these antibodies were probably directed to IL-3 receptor sites, or at least to some cell surface proteins related to the growth of the IL-3-dependent cells. These MRL/lpr-derived monoclonal antibodies reacted strongly with cells from bone marrow, spleen, and lymph node of MRL/lpr mice, but minimally with such cells of MRL/+ or BALB/c mice. The findings were consistent with our earlier suggestion that the IL-3-like activity in MRL/lpr sera is not caused by IL-3 itself but is associated with IgG that is probably an autoantibody directed to the IL-3 receptor.

Mutagenicity of the new quinolone antibacterial agent levofloxacin.

UNLABELLED: A new quinolone antibacterial agent (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10- (4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6- carboxylic acid hemihydrate (levofloxacin, DR-3355, CAS 100986-85-4), was studied for mutagenicity using the following short-term in vitro and in vivo tests. 1. IN VITRO STUDIES: reverse mutation test (Ames method) on S. typhimurium and E. coli; and HGPRT forward mutation test, cytogenetic test, and sister chromatid exchange (SCE) test, all on Chinese hamster cells. 2. In vivo studies: mouse micronucleus test, SCE test on mouse bone marrow cell, in vivo-in vitro unscheduled DNA synthesis (UDS) test on rat primary hepatocytes, and dominant lethal test in BDF1 mice. In the in vitro tests for SCE and for chromosomal aberration, DR-3355 gave dose-dependent positive responses, but no mutagenicity was observed in the same indicators of the in vivo studies, even at the maximum tolerated doses. This strongly suggested that DR-3355 would have no mutagenic effects when used in the treatment of infectious diseases. DR-3355 did not show any positive response in the reverse mutation test, the HGPRT mutation test, the in vivo-in vitro UDS test or the dominant lethal test. These results suggest that chemotherapy with DR-3355 should have no mutagenic effect in man.

Tumorigenicity depends on angiogenic potential of tumor cells: dominant role of vascular endothelial growth factor and/or fibroblast growth factors produced by tumor cells.

The aim of this study was to determine the role of tumor-derived angiogenic factors in solid tumor formation. We compared the angiogenic potential of tumorigenic and non-tumorigenic human tumor cell lines. All tumorigenic cell lines induced angiogenesis in vivo and their angiogenesis-inducing abilities were higher than those of the other non-tumorigenic cell lines. This in vivo angiogenic potential was well correlated with the in vitro endothelial cell growth-stimulating activity contained in the cell extract or conditioned medium of each cell line. The endothelial cell growth-stimulating activities of these cell lines were completely inhibited by neutralizing antibodies to basic fibroblast growth factor (bFGF), acidic FGF (aFGF) or vascular endothelial growth factor (VEGF). Furthermore, the levels of tumor-derived endothelial cell growth-stimulating activities depended on the amounts of angiogenic factors such as VEGF and bFGF produced by tumor cells. Although VEGF transcripts were detected in all of the cell lines by RT-PCR assay, the non-tumorigenic cell lines showed poor productivity of VEGF as well as FGFs and had less or non-potency for endothelial cell growth stimulation. These findings suggest that the increase in production of angiogenic factors by tumor cells is necessary for their in vivo angiogenic and tumorigenic potentials, and that VEGF and FGFs are the major mediators of tumor-induced angiogenesis.

Vascular endothelial growth factor overproduced by tumour cells acts predominantly as a potent angiogenic factor contributing to malignant progression.

To elucidate the role of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, in tumour angiogenesis and malignant progression, an expression vector harboring human VEGF cDNA was stably transfected into three human cancer cell lines with poor VEGF productivity. Though their in vitro growth rate and intrinsic productivity of another angiogenic factor, basic fibroblast growth factor (bFGF), were not changed by transfection, those clones with higher VEGF production were endowed with tumorigenic and angiogenic potentials as follows: firstly, nontumorigenic, lung carcinoma QG90 cells having lower bFGF productivity acquired tumorigenicity as well as significant in vivo angiogenesis-inducing ability, secondly, tumorigenic colorectal carcinoma RPMI4788 cells having higher potency for bFGF production could form more vascularized solid tumour with faster growth rate and thirdly, oestrogen-dependent breast carcinoma MCF-7 cells, which did not produce detectable bFGF, acquired tumorigenicity even in the absence of oestrogen and the solid tumour growth rate was remarkably enhanced, accompanied with increased vascularization, in the presence of oestrogen. These results suggest that tumour progression closely depends on angiogenesis, and VEGF significantly contributes to malignant progression of a variety of tumour cells through its potent angiogenic activity, independent on the bFGF productivity of tumour cells.