RESUMEN
The highly automated macromolecular crystallography beamline AMX/17-ID-1 is an undulator-based high-intensity (>5 × 1012â photonsâ s-1), micro-focus (7â µm × 5â µm), low-divergence (1â mrad × 0.35â mrad) energy-tunable (5-18â keV) beamline at the NSLS-II, Brookhaven National Laboratory, Upton, NY, USA. It is one of the three life science beamlines constructed by the NIH under the ABBIX project and it shares sector 17-ID with the FMX beamline, the frontier micro-focus macromolecular crystallography beamline. AMX saw first light in March 2016 and started general user operation in February 2017. At AMX, emphasis has been placed on high throughput, high capacity, and automation to enable data collection from the most challenging projects using an intense micro-focus beam. Here, the current state and capabilities of the beamline are reported, and the different macromolecular crystallography experiments that are routinely performed at AMX/17-ID-1 as well as some plans for the near future are presented.
Asunto(s)
Sincrotrones , Cristalografía por Rayos X , Sustancias Macromoleculares/químicaRESUMEN
Three-dimensional structures derived from X-ray diffraction of protein crystals provide a wealth of information. Features and interactions important for the function of macromolecules can be deduced and catalytic mechanisms postulated. Still, many questions can remain, for example regarding metal oxidation states and the interpretation of `mystery density', i.e. ambiguous or unknown features within the electron density maps, especially at â¼2 Å resolutions typical of most macromolecular structures. Beamline X26-C at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), provides researchers with the opportunity to not only determine the atomic structure of their samples but also to explore the electronic and vibrational characteristics of the sample before, during and after X-ray diffraction data collection. When samples are maintained under cryo-conditions, an opportunity to promote and follow photochemical reactions in situ as a function of X-ray exposure is also provided. Plans are in place to further expand the capabilities at beamline X26-C and to develop beamlines at NSLS-II, currently under construction at BNL, which will provide users access to a wide array of complementary spectroscopic methods in addition to high-quality X-ray diffraction data.
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Cristalografía por Rayos X/métodos , Espectrometría Raman/métodos , Insulina/química , Proteínas/química , Sincrotrones , Difracción de Rayos X/métodosRESUMEN
The research philosophy and new capabilities installed at NSLS beamline X26-C to support electronic absorption and Raman spectroscopies coupled with X-ray diffraction are reviewed. This beamline is dedicated full time to multidisciplinary studies with goals that include revealing the relationship between the electronic and atomic structures in macromolecules. The beamline instrumentation has been fully integrated such that optical absorption spectra and X-ray diffraction images are interlaced. Therefore, optical changes induced by X-ray exposure can be correlated with X-ray diffraction data collection. The installation of Raman spectroscopy into the beamline is also briefly reviewed. Data are now routinely generated almost simultaneously from three complementary types of experiments from the same sample. The beamline is available now to the NSLS general user population.
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Cristalografía por Rayos X/métodosRESUMEN
BACKGROUND: Artesunate is an antimalarial agent with broad anti-cancer activity in in vitro and animal experiments and case reports. Artesunate has not been studied in rigorous clinical trials for anticancer effects. AIM: To determine the anticancer effect and tolerability of oral artesunate in colorectal cancer (CRC). METHODS: This was a single centre, randomised, double-blind, placebo-controlled trial. Patients planned for curative resection of biopsy confirmed single primary site CRC were randomised (n = 23) by computer-generated code supplied in opaque envelopes to receive preoperatively either 14 daily doses of oral artesunate (200 mg; n = 12) or placebo (n = 11). The primary outcome measure was the proportion of tumour cells undergoing apoptosis (significant if > 7% showed Tunel staining). Secondary immunohistochemical outcomes assessed these tumour markers: VEGF, EGFR, c-MYC, CD31, Ki67 and p53, and clinical responses. FINDINGS: 20 patients (artesunate = 9, placebo = 11) completed the trial per protocol. Randomization groups were comparable clinically and for tumour characteristics. Apoptosis in > 7% of cells was seen in 67% and 55% of patients in artesunate and placebo groups, respectively. Using Bayesian analysis, the probabilities of an artesunate treatment effect reducing Ki67 and increasing CD31 expression were 0.89 and 0.79, respectively. During a median follow up of 42 months 1 patient in the artesunate and 6 patients in the placebo group developed recurrent CRC. INTERPRETATION: Artesunate has anti-proliferative properties in CRC and is generally well tolerated.
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Artemisininas/administración & dosificación , Artemisininas/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Administración Oral , Anciano , Artemisininas/efectos adversos , Artesunato , Biomarcadores de Tumor/metabolismo , Antígeno Carcinoembrionario/metabolismo , Demografía , Método Doble Ciego , Femenino , Humanos , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Masculino , Proyectos Piloto , Placebos , Coloración y Etiquetado , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
This manuscript chronicles the evolution of software used originally to control a diffractometer at a macromolecular crystallography beamline. The system has been augmented and rewritten. A modular and carefully organized suite of programs now handles the whole experimental environment from a single vantage point. It provides automatic logging of the experiment and communication with the user, all the way from an initial proposal to perform the work to the end of data collection. This has included construction of a relational database to organize all details of the experiment and incorporation of a robotic specimen changer to provide automation for high-throughput applications.