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c-Abl is activated by DNA damage in an ataxia telangiectasia mutated (ATM)-dependent manner and plays important roles in growth arrest and apoptosis induced by DNA damage. c-Abl also interacts physically and functionally with Rad51, a key molecule in homologous recombinational (HR) DNA repair. To study further the roles of c-Abl in HR DNA repair, we generated c-Abl(-/-) and ATM(-/-)/c-Abl(-/-) mutant cell lines from a chicken B lymphocyte DT40 cell line, comparing the phenotypes of these mutants to those of ATM(-/-) DT40 cells that we had created previously. We found that the time course of radiation-induced Rad51 focus formation is abnormal in ATM(-/-) DT40 cells, consistent with the observation that ATM(-/-) DT40 cells display hypersensitivity to ionizing radiation and highly elevated frequencies of both spontaneous and radiation-induced chromosomal aberrations. In contrast, c-Abl(-/-) cells did not show these ATM-related defects in their cellular response to radiation, nor did the disruption of c-Abl in ATM(-/-) DT40 cells exacerbate these ATM-related defects. However, c-Abl(-/-) DT40 cells, but not ATM(-/-) DT40 cells, were resistant to radiation-induced apoptosis, indicating an important role for c-Abl in this cellular response to ionizing radiation. These results therefore indicate that, although ATM plays an important role in genome maintenance, c-Abl is not essential for this ATM function. These findings suggest that c-Abl and ATM play important roles in the maintenance of the cell homeostasis in response to DNA damage that are, at least in part, independent.

Intracellular components, which are picked up with the help of micromanipulator unit of histochemical chromatography are subjected to mass fragmentography, by which a biosynthetic study of alkaloidal components was carried out and it was found that cis-N-methyl-tet-rahydroberberinium salt is incorporated in the formation of allocryptopine in Macleaya cordata roots so far as cytochemical point of view is concerned.The advantages of this method in biosynthetic studies are as follows: 1; The alkaliods can be taken out directly from the alkaloidal cells and analysed without even performing the general extraction procedure. 2; It is possible to study the day to day variation of enrichment of allocryptopine in roots. 3; It is possible to perform the aforesaid study only with small amount of plant samples.

Our objective was to assess the effects of subtle increases in serum progesterone concentration (1.0-2.0 ng/ml) on the outcome of in-vitro fertilization (IVF), particularly on the quality of embryos, during the follicular phase of cycles stimulated with gonadotrophin-releasing hormone agonist (GnRHa) and human menopausal gonadotrophin (HMG). A total of 97 patients underwent 116 cycles of IVF and were stimulated with a combination of HMG and GnRHa. They were divided into two groups: those with a subtle progesterone rise and those with no progesterone rise. The two groups were compared with respect to serum oestradiol, progesterone, immunoreactive luteinizing hormone (I-LH), bioactive LH (B-LH), and results of IVF. The groups did not differ significantly in mean age or in total dose of HMG received. On the day that human chorionic gonadotrophin was administered, concentrations of oestradiol and progesterone were significantly higher in the subtle progesterone rise cycles than in the no progesterone rise cycles. In the no progesterone rise cycles, the percentages for embryos beyond the 4-cell stage, grade 1 embryos, and implantation rates were significantly higher than those in subtle progesterone rise cycles. The combination of GnRHa and HMG eliminated any significant rise in serum I-LH or B-LH concentration during the follicular phase, but did not suppress the subtle rise in progesterone. These results confirm our previous finding that a subtle progesterone rise adversely affects the outcome of IVF. It is also suggested that a reduction in embryo quality may influence the lower rate of implantation in subtle progesterone rise cycles.

15 N substituent chemical shifts (SCS) of a variety of anticonvulsant phenylacetanilides (1) and (2), with a substituent at the para or meta position of the aniline moiety, were analysed by means of DSP (dual substituent parameter) equations. For the sake of comparison, 15N scs of p-substituted anilines (3), and 13C chemical shifts of some ring carbons of (1) and (3) were also investigated. The similarity observed for the correlation of the carbon shifts para to the substituent for (1) and (3) indicates that the nitrogen shifts will be a better probe for the transmission of the substituent effect to nitrogen.

We measured 13C nuclear magnetic resonance spectra of O-substituted phenyl N,N- dimethyland N-methyl- carbamates and compared the results with those for the corresponding m- and p-substituted derivatives. The additivity relationship on the basis of the substituent chemical shift for monosubstituted benzenes ( scsphx ) did not hold well because of the ortho effect. However, the scs of C2(ipso), C3(ortho) and C5(para) was correlated excellently with scsphxX . Dual substituent parameter (DSP) analyses of the scs of C5 and the carbonyl carbon in the fixed side chain showed that correlation was very good for C5 but moderate for C=O. These observations suggested that the X substituent lay in almost the same plane as the aromatic ring, whereas the OCONMe2 group may have changed its conformation somewhat. In O-substituted derivatives, the carbon nucleus that is directly attached to the aromatic ring (γ to the oxygen; OCONMe2)had a pronounced upfield shift relative to the corresponding m- and p-substituents by 4-5 ppm . This phenomenon was explained by the γ-effect caused by the oxygen atom.

The free energy of activation for rotation about the C-N bond (ΔG‡Tc) in substituted phenyl and benzyl N,N- dimethylcarbamates was determined by the 13C dynamic n.m.r. method. The ΔG‡Tc value depended linearly on Hammett's σ with positive p. We have separated the substituent effects into inductive and resonance effects by using dual substituent parameter ( d.s.p .) analysis, and found that the resonance effect is more important than the inductive effect for para derivatives, and vice versa for meta derivatives. General trends of electronic substituent effects on barriers to rotation in carbamates and structurally related amides are also discussed. The ortho steric effect was small.

When the Y chromosome of the laboratory inbred mouse strain C57BL/6 (B6) is replaced by the Y of certain strains of Mus musculus domesticus, testis determination fails and all XY fetuses develop either as hermaphrodites or XY females (XY sex reversal). This suggests the presence of at least two alleles of Sry, the male-determining gene on the Y:M. m. domesticus and B6. The B6 Y chromosome is derived from the Japanese house mouse, M. m. molossinus and therefore carries a molossinus Sry allele. As a first step to determine how the molossinus Sry allele evolved, its distribution pattern was determined in wild mice. The cumulative data of 96 M. musculus samples obtained from 58 geographical locations in Europe, North Africa, and Asia show the molossinus Sry allele is restricted to Japan and the neighboring Asian mainland and confirm that Japanese M. m. molossinus mice were derived in part from a race of M. m. musculus from Korea or Manchuria. Sry polymorphisms, as illustrated by the molossinus Sry allele, can serve as molecular markers for studies on the evolution of wild M. musculus populations and can help determine the role sex determination plays in speciation.

The 15N chemical shifts of X α and Y α, i.e., the nuclei through which the side chains, X and Y, respectively, of o-substituted phenylacetanilides (2a) are bonded to the aromatic ring were determined. There was observed a uniform upfield shift (γsyn effect). In order to explore the origin of the γ effect, other o-disubstitutes benzenes (2b-d) were also examined. The values of D, defined as the difference between γ α substituent chemical shifts of the ortho (2) and para (3) series of compounds, and considered as a measure of the γ-syn effect, were correlated with various electronic and steric substituent parameters. Correlations with electronegativity and van der Waals terms were successful. Examination of the correlations indicated that the γ-syn effect is mostly governed by electronegativity. The classic steric compression theory does not seem very convincing as a means of explaining the shielding γ-syn effect observed in the present study.

Understanding the degradation mechanism of Fe/N/C cathode catalysts in proton exchange membrane fuel cells (PEMFCs) is important. We studied the degradation of an Fe/N/C catalyst prepared from polyimide nanoparticles in an in situ cell by X-ray absorption spectroscopy (XAS). This technique enables real-time monitoring of the Fe species during a fuel cell operation. The Fe K-edge absorption spectra were recorded during the continuous operation of the fuel cell. Initially during the fuel cell operation, the Fe species were atomically isolated and their valence state was found to be 3+. The spectra gradually changed during the first few hours of operation, suggesting the dissolution of the Fe species from the active sites, whereas the fuel cell performance continued to decrease during the eight hours of operation. The demetallation from the FeNxcenters during the first few hours has been successfully monitored in real time, while the remaining FeNxcenters seem to be stable in the following fuel cell operating condition.

The 13C ASIS values produced by benzene‐d6 are obtained for 15 compounds such as (I)‐(V).

Cyclocondensation of the aldehyde (I) with the pyrrolidine (II) followed by reduction gives the indolizidine (III).