The Mre11/Rad50/NBS1 (MRN) complex maintains genomic stability by bridging DNA ends and initiating DNA damage signaling through activation of the ATM kinase. Mre11 possesses DNA nuclease activities ...that are highly conserved in evolution but play unknown roles in mammals. To define the functions of Mre11, we engineered targeted mouse alleles that either abrogate nuclease activities or inactivate the entire MRN complex. Mre11 nuclease deficiency causes a striking array of phenotypes indistinguishable from the absence of MRN, including early embryonic lethality and dramatic genomic instability. We identify a crucial role for the nuclease activities in homology-directed double-strand-break repair and a contributing role in activating the ATR kinase. However, the nuclease activities are not required to activate ATM after DNA damage or telomere deprotection. Therefore, nucleolytic processing by Mre11 is an essential function of fundamental importance in DNA repair, distinct from MRN control of ATM signaling.
A speech recognition system for continuously spoken Japanese sentences is described. The system has a knowledge source, in which syntactic, semantic and vocabulary knowledge are contained. It can ...treat not only simple sentences but also simple complex and compound sentences without any restriction regarding the tasks. Phoneme identification is performed in real time, and after a slight revision has been carried out the speech sound is represented by a pseudo-phoneme string. In the syntactic knowledge system, inflections of inflectional words are taken into account. The syntactic analyzer, using a syntactic state transition network, predicts the following words and outputs their syntactic interpretations. The semantic knowledge system deals with the meanings of each word, in particular, it deals with case structures for verbs. The semantic knowledge is used for the prediction of the following words and construction of a semantic network of the input story. Moreover, a slightly modified version can be used as a speech input device of a word processor.
The global epidemiological situation of gastric cancer has changed considerably over time, and it is essential to understand the epidemiological trends and future perspectives of gastric cancer.
...Although gastric cancer was common in the United States less than a century previously, it is no longer common in this country. Currently, over 60% of gastric cancers are found in Eastern Asia. In some Eastern Asian countries such as Japan and Korea, population-based gastric cancer screening has been conducted using upper gastrointestinal endoscopy or radiography to lower gastric cancer mortality. Due to earlier detection of gastric cancer, the survival of patients with gastric cancer is more favorable in these countries than in other Western countries. Even in Eastern Asia, a remarkable decrease in the age-standardized incidence and mortality of gastric cancer has been observed. This downward trend is mainly due to the reduced Helicobacter pylori infection, and this trend is considered to continue. Nevertheless, both the absolute number of incident cases and deaths of gastric cancer are still increasing at present due to the aging population. For the time being, the management of gastric cancer in elderly population is a critical issue in Eastern Asia. The absolute numbers of gastric cancer cases and deaths are believed to peak in the near future, following the decreasing age-standardized incidence and mortality. Key Messages: After a long period, gastric cancer may become a rare cancer even in Eastern Asia, and new efficient approaches for its prevention, screening, and treatment are warranted.
Michaelis constant, Km and relative catalytic constant, krelcatwere determined for the β-acetylglucosaminidase-catalyzed hydrolysis of a series of substituted phenyl β-acetylglucosaminides ; the ...substituents are 2, 4-dinitro, p-nitro, 4-nitro-3-methyl, m-nitro, p-chloro, m-chloro, p-methyl, m-methyl, p-methoxy and p-hydroxyl groups. The values were evaluated in terms of the ρ-σ relationship of Hammett. Plots of log Km with respect to Hammett substituent constant, σ and Hansch substituent constant, π showed the enzyme-substrate affinity to be dependent on the electronic nature of the substituents (ρ=-0.42, correlation coefficient γ=0.943) but not on the hydrophobic nature. The log krelcat value was only slightly dependent on σ value (ρ=+0.16, γ=0.626). An experiment on nucleophilic competition with methanol was carried out in an attempt to explain the small ρ value for krelcat. Methanol competes with water for the glycosyl enzyme to some extent but does not increase krelcat for the glycosides examined, indicating that the deglycosylation is not rate-limiting and hence the ρ value for krelcat pertains to the reaction of glycoside bond cleavage.
SASAKI, T., KADONO, T., ENDO, F., SEKIGUCHI, Y., SAITO, T., ARAKAWA, M., FURUYAMA, T. and YOSHINAGA, K. Relationship between Complement-Fixing (Hemolytic) Antibodies to Single-Stranded and ...Double-Stranded DNA and the Prognosis in Systemic Lupus Erythematosus. Tohoku J. exp. Med., 1982, 138 (4), 341-355-Hemolytic (complement-fixing) antibodies to single-stranded (ss) or double-stranded (ds) DNA, measured by recently developed PHL assay, occurred closely correlated with renal activity in patients with systemic lupus erythematosus (SLE). Approximately one third of the patients with renal disease had hemolytic antibodies to ss-DNA but never to ds-DNA. Hemolytic antibodies were scarcely detectable in patients with mild course. Serial studies also revealed that the estimation of the hemolytic antibodies to ds- and/or ss-DNA was particularly valuable in predicting the future course of the SLE. The emergence of hemolytic antibodies to DNA may be an omenous sign suggestive of grave prognosis in SLE.
The sixth version of the Model for Interdisciplinary Research on Climate
(MIROC), called MIROC6, was cooperatively developed by a Japanese modeling
community. In the present paper, simulated mean ...climate, internal
climate variability, and climate sensitivity in MIROC6 are evaluated and
briefly summarized in comparison with the previous version of our climate
model (MIROC5) and observations. The results show that the overall
reproducibility of mean climate and internal climate variability in MIROC6
is better than that in MIROC5. The tropical climate systems (e.g.,
summertime precipitation in the western Pacific and the eastward-propagating
Madden–Julian oscillation) and the midlatitude atmospheric circulation
(e.g., the westerlies, the polar night jet, and troposphere–stratosphere
interactions) are significantly improved in MIROC6. These improvements can
be attributed to the newly implemented parameterization for shallow
convective processes and to the inclusion of the stratosphere. While there
are significant differences in climates and variabilities between the two
models, the effective climate sensitivity of 2.6 K remains the same because
the differences in radiative forcing and climate feedback tend to offset
each other. With an aim towards contributing to the sixth phase of the
Coupled Model Intercomparison Project, designated simulations tackling a
wide range of climate science issues, as well as seasonal to decadal climate
predictions and future climate projections, are currently ongoing using
MIROC6.
Brief notes on the fruit fly eradication programs in Japan Sekiguchi, Y. (Japan. Ministry of Agriculture, Forestry and Fisheries, Tokyo. Agricultural Production Bureau)
Plant Protection (Japan),
(Jun 1982), Letnik:
36, Številka:
6
Journal Article
PDF
