Atezolizumab was effective and well tolerated in pretreated Japanese patients with NSCLC. Results are consistent with the primary analysis of OAK.

Fungal isolates from gray leaf spot on perennial ryegrass (prg isolates) were characterized by DNA analyses, mating tests, and pathogenicity assays. All of the prg isolates were interfertile with Triticum isolates and clustered into the crop isolate group (CC group) on a dendrogram constructed from rDNA-internal transcribed spacer 2 sequences. Since the CC group corresponded to a newly proposed species, Magnaporthe oryzae, all of the prg isolates were designated M. oryzae. However, DNA fingerprinting with MGR586, MGR583, and Pot2 showed that the prg isolates are divided into two distinct populations, i.e., TALF isolates and WK isolates. The TALF isolates were virulent only on Lolium species, whereas the WK isolates were less specific, suggesting that gray leaf spot can be caused not only by Lolium-specific isolates but also by less specific isolates. We designated the TALF isolates as Lolium pathotype. The TALF isolates showed diverse karyotypes in spite of being uniform in DNA fingerprints, suggesting that theyare unstable in genome organization.

Objective. To investigate the relationship between transient oxidative stress and the development of osteonecrosis in a rat model.Methods. A total of 160 male Wistar rats (24 weeks old) were injected only once with the pro-oxidant DLbuthionine-(S,R)-sulfoximine (BSO) (500 mg/kg given intraperitoneally) and were killed 12 hours (group A), 1 day (group B), 3 days (group C), 4 days (group D), 5 days (group E), 7 days (group F), or 14 days (group G) after administration (n ‫؍‬ 20 per group). Twenty untreated rats were used as a control group (group N). Femurs were examined histopathologically for the presence of osteonecrosis, and reduced glutathione (GSH) in liver tissue was measured as an index of oxidative stress.Results. GSH decreased rapidly after BSO administration. Significant decreases were noted in groups A and B as compared to group N (P < 0.0001 and P ‫؍‬ 0.0007, respectively), confirming the development of transient extreme oxidative stress soon after BSO administration. The histopathologic study revealed osteonecrosis in 10% of the rats in group E, 35% of the rats in group F, and 40% of the rats in group G.Conclusion. Transient extreme oxidative stress was confirmed to induce osteonecrosis in this model. Since preparation of this model is extremely simple and because rats are well suited to genetic studies, this model may be of use in elucidating the pathophysiology of femoral head osteonecrosis in future studies.Although it has been shown that oxidative stress is related to osteonecrosis (1-3), the details of its pathogenesis remain unclear. Animal models are needed to clarify the pathophysiology of osteonecrosis and to establish prophylactic treatment strategies. Although previously rabbit models have been most commonly used for the study of osteonecrosis (1-5), we recently hypothesized that models of induced osteonecrosis in rats, which are particularly well suited for genetic studies, would be of greater use. We have previously demonstrated that subcutaneous injection of DL-buthionine-(S,R)-sulfoximine (BSO) in rats on consecutive days was by itself sufficient to induce osteonecrosis (6). However, when BSO is administered to rats for 14 consecutive days, oxidative stress persists for 14 days, making it unclear whether, as in steroid-induced osteonecrosis, osteonecrosis occurs as a single event or whether it results from cytotoxicity associated with chronic oxidation. The mechanisms underlying the process from oxidation induction to the development of osteonecrosis continue to be obscure, and we consider this type of model inadequate to explore them.Steroid-induced osteonecrosis can occur after a single exposure to these agents, and in a model using rabbits administered steroids, oxidation has been shown to also develop soon after a single exposure (2,3). This suggests to us the need for a rat model in which the development of osteonecrosis after a single application of oxidative stress can be reliably observed, to clarify the mechanisms underlying the development of steroidinduced osteonecrosis. We ...

The 5S ribosomal RNA genes (5S rDNA) are located independently from the 45S rDNA repeats containing 18S, 5.8S and 26S ribosomal RNA genes in higher eukaryotes. Southern blot and fluorescence in situ hybridization analyses demonstrated that the 5S rDNAs are encoded in the 45S rDNA repeat unit of a liverwort, Marchantia polymorpha, in contrast to higher plants. Sequencing analyses revealed that a single-repeat unit of the M. polymorpha nuclear rDNA, which is 16,103 bp in length, contained a 5S rDNA downstream of 18S, 5.8S and 26S rDNA. To our knowledge, this is the first report on co-localization of the 5S and 45S rDNAs in the rDNA repeat of land plants. Furthermore, we detected a 5S rDNA in the rDNA repeat of a moss, Funaria hygrometrica, by a homology search in a database. These findings suggest that there has been structural re-organization of the rDNAs after divergence of the bryophytes from the other plant species in the course of evolution.

An isolate of Magnaporthe grisea was collected from a blast lesion on oat in Brazil. Sequence analysis of the rDNA-ITS-2 region and DNA fingerprinting with repetitive elements revealed that the Avena isolate belongs to the "crop isolate group" and is similar to Triticum isolates. At high temperature (28°C), the Avena isolate caused severe disease symptoms on primary leaves of oat and wheat. When the temperature was decreased to 20°C, wheat leaves expressed resistance to the Avena isolate. Cytologically, this temperature-dependent resistance was associated with an increase in the incidences of papilla formation and a hypersensitive reaction. Pathogenicity tests with various plant species at 20°C revealed that the Avena isolate is exclusively parasitic on oat. To elucidate genetic mechanisms of this species-specific parasitism, the Avena isolate was crossed with a Triticum isolate and resulting F1 progenies were subjected to pathogenicity tests on oat seedlings. In the F1 population, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that the specific parasitism on oat is controlled by a single gene. This locus was designated as Pat1.Key words: Magnaporthe grisea, species-specific parasitism, oat, temperature sensitive.