5,5′,7,7′-Tetra­meth­oxy-2,2′-ethano-1,1′-spiro­biindane

In the title compound, C23H26O4, there is a dihedral angle of 83.7 (6)° between the two benzene rings. The five-membered rings have chair conformations

The role of technetium-99m methoxyisobutyl isonitrile scintigraphy in predicting the therapeutic effect of chemotherapy against nasopharyngeal carcinoma

BACKGROUND: The authors prospectively evaluated the correlation between technetium-99m methoxyisobutyl isonitrile ( 99m Tc-MIBI) accumulation in tumors and response to induction chemotherapy in patients with nasopharyngeal carcinoma (NPC). METHODS: Eighty-six patients with locally advanced NPC underwent single-photon emission computed tomography 15 minutes after an intravenous injection of 740 megabecquerels (20 mCi) 99m Tc-MIBI before chemotherapy. The tumor uptake ratio (TUR) was calculated. Two weeks after the second cycle of combined chemotherapy with 5-fluorouracil (5-FU) and cisplatin (DDP), the tumor response rate was evaluated. The correlation between 99m Tc-MIBI accumulation in tumors and response to chemotherapy with 5-FU/DDP was examined. RESULTS: Positive accumulation of 99m Tc-MIBI in tumors was observed in 76 patients (88.4%). The tumor response was a complete response (CR) in 8 patients, a partial response (PR) in 68 patients, stable disease (SD) in 9 patients, and progressive disease (PD) in 1 patient. The response rate (CR and PR) to 5-FU/DDP chemotherapy in patients who had positive 99m Tc-MIBI accumulation (tumor uptake ratio [TUR] >1.1) was higher than that in patients who had negative 99m Tc-MIBI accumulation (TUR ≤1.1; 98.7% vs 10%; P < .001). CONCLUSIONS: Patients with negative 99m Tc-MIBI accumulation were resistant to 5-FU/DDP chemotherapy. 99m Tc-MIBI imaging in patients with NPC was capable of predicting tumor response to chemotherapy with 5-FU/DDP and can help in the selection of patients for induction chemotherapy. Cancer 2011. © 2010 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/84384/1/25802_ftp.pd

Central Role of Adenosine 5′-Phosphosulfate Reductase in the Control of Plant Hydrogen Sulfide Metabolism

Hydrogen sulfide (H2S) has been postulated to be the third gasotransmitter in both animals and plants after nitric oxide (NO) and carbon monoxide (CO). In this review, the physiological roles of H2S in plant growth, development and responses to biotic, and abiotic stresses are summarized. The enzymes which generate H2S are subjected to tight regulation to produce H2S when needed, contributing to delicate responses of H2S to environmental stimuli. H2S occupies a central position in plant sulfur metabolism as it is the link of inorganic sulfur to the first organic sulfur-containing compound cysteine which is the starting point for the synthesis of methionine, coenzyme A, vitamins, etc. In sulfur assimilation, adenosine 5′-phosphosulfate reductase (APR) is the rate-limiting enzyme with the greatest control over the pathway and probably the generation of H2S which is an essential component in this process. APR is an evolutionarily conserved protein among plants, and two conserved domains PAPS_reductase and Thioredoxin are found in APR. Sulfate reduction including the APR-catalyzing step is carried out in chloroplasts. APR, the key enzyme in sulfur assimilation, is mainly regulated at transcription level by transcription factors in response to sulfur availability and environmental stimuli. The cis-acting elements in the promoter region of all the three APR genes in Solanum lycopersicum suggest that multiple factors such as sulfur starvation, cytokinins, CO2, and pathogens may regulate the expression of SlAPRs. In conclusion, as a critical enzyme in regulating sulfur assimilation, APR is probably critical for H2S generation during plants’ response to diverse environmental factors

Solar microwave millisecond spike at 2.84 GHz

Using the high time resolution of 1 ms, the data of solar microwave millisecond spike (MMS) event was recorded more than two hundred times at the frequency of 2.84 GHz at Beijing (Peking) Observatory since May 1981. A preliminary analysis was made. It can be seen from the data that the MMS-events have a variety of the fast activities such as the dispersed and isolated spikes, the clusters of the crowded spikes, the weak spikes superimposed on the noise background, and the phenomena of absorption. The marked differences from that observed with lower time resolution are presented. Using the data, a valuable statistical analysis was made. There are close correlations between MMS-events and hard X-ray bursts, and fast drifting bursts. The MMS events are highly dependent on the type of active regions and the magnetic field configuration. It seems to be crucial to find out the accurate positions on the active region where the MMS-events happen and to make co-operative observations at different bands during the special period when specific active regions appear on the solar disk

The role of the transcription factor Rbpj in the development of dorsal root ganglia

<p>Abstract</p> <p>Background</p> <p>The dorsal root ganglion (DRG) is composed of well-characterized populations of sensory neurons and glia derived from a common pool of neural crest stem cells (NCCs), and is a good system to study the mechanisms of neurogenesis and gliogenesis. Notch signaling is known to play important roles in DRG development, but the full scope of Notch functions in mammalian DRG development remains poorly understood.</p> <p>Results</p> <p>In the present study, we used <it>Wnt1-Cre </it>to conditionally inactivate the transcription factor Rbpj, a critical integrator of activation signals from all Notch receptors, in NCCs and their derived cells. Deletion of <it>Rbpj </it>caused the up-regulation of <it>NeuroD1 </it>and precocious neurogenesis in DRG early development but led to an eventual deficit of sensory neurons at later stages, due to reduced cell proliferation and abnormal cell death. In addition, gliogenesis was delayed initially, but a near-complete loss of glia was observed finally in <it>Rbpj</it>-deficient DRG. Furthermore, we found P75 and Sox10, which are normally expressed exclusively in neuronal and glial progenitors of the DRG after the NCCs have completed their migration, were co-expressed in many cells of the DRG of <it>Rbpj </it>conditional knock-out mice.</p> <p>Conclusions</p> <p>Our data indicate that Rbpj-mediated canonical Notch signaling inhibits DRG neuronal differentiation, possibly by regulating <it>NeuroD1 </it>expression, and is required for DRG gliogenesis <it>in vivo</it>.</p

Epidemiological and virological characteristics of pandemic influenza A (H1N1) 2009 in school outbreaks in China

Background: During the 2009 pandemic influenza H1N1 (2009) virus (pH1N1) outbreak, school students were at an increased risk of infection by the pH1N1 virus. However, the estimation of the attack rate showed significant variability. Methods: Two school outbreaks were investigated in this study. A questionnaire was designed to collect information by interview. Throat samples were collected from all the subjects in this study 6 times and sero samples 3 times to confirm the infection and to determine viral shedding. Data analysis was performed using the software STATA 9.0. Findings: The attack rate of the pH1N1 outbreak was 58.3% for the primary school, and 52.9% for the middle school. The asymptomatic infection rates of the two schools were 35.8% and 37.6% respectively. Peak virus shedding occurred on the day of ARI symptoms onset, followed by a steady decrease over subsequent days (p = 0.026). No difference was found either in viral shedding or HI titer between the symptomatic and the asymptomatic infectious groups. Conclusions: School children were found to be at a high risk of infection by the novel virus. This may be because of a heightened risk of transmission owing to increased mixing at boarding school, or a lack of immunity owing to socioeconomic status. We conclude that asymptomatically infectious cases may play an important role in transmission of the pH1N1 virus