| 1. |
- Beyerlein, Kenneth R., et al.
(författare)
-
Mix-and-diffuse serial synchrotron crystallography
- 2017
-
Ingår i: IUCrJ. - : INT UNION CRYSTALLOGRAPHY. - 2052-2525. ; 4:6, s. 769-777
-
Tidskriftsartikel (refereegranskat)abstract
- Unravelling the interaction of biological macromolecules with ligands and substrates at high spatial and temporal resolution remains a major challenge in structural biology. The development of serial crystallography methods at X-ray free-electron lasers and subsequently at synchrotron light sources allows new approaches to tackle this challenge. Here, a new polyimide tape drive designed for mix-and-diffuse serial crystallography experiments is reported. The structure of lysozyme bound by the competitive inhibitor chitotriose was determined using this device in combination with microfluidic mixers. The electron densities obtained from mixing times of 2 and 50 s show clear binding of chitotriose to the enzyme at a high level of detail. The success of this approach shows the potential for high-throughput drug screening and even structural enzymology on short timescales at bright synchrotron light sources.
|
|
| 2. |
- Dewan, Ramita, et al.
(författare)
-
Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
- 2021
-
Ingår i: Neuron. - : Elsevier BV. - 1097-4199 .- 0896-6273. ; 109:3
-
Tidskriftsartikel (refereegranskat)abstract
- We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered.
|
|
| 3. |
- Knoška, Juraj, et al.
(författare)
-
Ultracompact 3D microfluidics for time-resolved structural biology
- 2020
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- To advance microfluidic integration, we present the use of two-photon additive manufacturing to fold 2D channel layouts into compact free-form 3D fluidic circuits with nanometer precision. We demonstrate this technique by tailoring microfluidic nozzles and mixers for time-resolved structural biology at X-ray free-electron lasers (XFELs). We achieve submicron jets with speeds exceeding 160 m s−1, which allows for the use of megahertz XFEL repetition rates. By integrating an additional orifice, we implement a low consumption flow-focusing nozzle, which is validated by solving a hemoglobin structure. Also, aberration-free in operando X-ray microtomography is introduced to study efficient equivolumetric millisecond mixing in channels with 3D features integrated into the nozzle. Such devices can be printed in minutes by locally adjusting print resolution during fabrication. This technology has the potential to permit ultracompact devices and performance improvements through 3D flow optimization in all fields of microfluidic engineering.
|
|
| 4. |
- Nicolas, Aude, et al.
(författare)
-
Genome-wide Analyses Identify KIF5A as a Novel ALS Gene
- 2018
-
Ingår i: Neuron. - : Cell Press. - 0896-6273 .- 1097-4199. ; 97:6, s. 1268-1283.e6
-
Tidskriftsartikel (refereegranskat)abstract
- To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.
|
|
| 5. |
- Pfreundschuh, Michael, et al.
(författare)
-
Prognostic significance of maximum tumour (bulk) diameter in young patients with good-prognosis diffuse large-B-cell lymphoma treated with CHOP-like chemotherapy with or without rituximab: an exploratory analysis of the MabThera International Trial Group (MInT) study
- 2008
-
Ingår i: The Lancet Oncology. - 1474-5488. ; 9:5, s. 435-444
-
Tidskriftsartikel (refereegranskat)abstract
- Background The definition and role of bulky disease in young patients (ie, aged 18-60 years) with good-prognosis diffuse large-B-cell lymphoma (DLBCL), who have been treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone)-like chemotherapy with or without rituximab, remain controversial. We aimed to assess the effect of maximum tumour diameter (MTD) in these patients. Methods Patients from the MInT (Mabthera International Trial Group) study were eligible. We analysed event-free (EFS) and overall survival (OS) after CHOP-like chemotherapy with or without rituximab, according to MTD, by Martingale residual analyses and Cox regression models. Radiotherapy was given to sites of primary bulky disease according to national standards, and to primary extranodal disease at physician discretion. The primary endpoint was EFS and the secondary endpoint was OS. Analyses were by intention to treat. This trial is registered with ClinicalTrials. gov, number NCT 00064116. Findings Of the 824 patients enrolled in the MInT study, the informed-consent form of one patient was missing, leaving 823 patients evaluable for intention-to-treat analysis. Data on MTD of involved sites were available for 802 patients. Martingale residual analysis showed an adverse prognostic effect of MTD on EFS and OS, which increased linearly. In a multivariable analysis with MTD as a linear regression variable, the effect of MTD was significant after CHOP-like treatment alone for EFS (hazard ratio 1.090 [95% CI 1.051-1-130], p<0.0001) and OS (1-119 [1-057-1-184], p=0.0001), and after CHOP-like treatment and rituximab for OS (1-089 [1-003-1-183],p=0.043), but not for EFS (1-044 [0-991-1-099], p=0.103). For CHOP-like treatment alone, 3-year EFS ranged from 78-2% (MTD <5.0 cm, 95% CI 68.3-85.4) to 41.3% (MTD >= 10.0 cm, 31.8-50.4). For CHOP-like treatment and rituximab, 3-year EFS ranged from 83.2% (MTD <5.0 cm, 72.8-89.9) to 72.7% (MTD >= 10.0 cm, 63.8-79.7). With CHOP-like treatment alone, 3-year OS decreased from 92.9% (MTD <5.0 cm, 84.9-96.8) to 73.5% (MTD >= 10.0 cm, 63.9-81.0); for CHOP-like treatment and rituximab, 3-year OS decreased from 98.0% (MTD <5.0 cm, 92.2-99.5) to 85.2% (MTD >= 10.0 cm, 77.0-90.6). For CHOP-like treatment, any cut-off point between 5.0 cm and 10.0 cm separated two populations with a significant EFS difference (p<0.0001 for all log-rank tests) and OS difference (p <= 0.003 for all log-rank tests). For CHOP-like treatment and rituximab, only a cut-off point of 10.0 cm separated two populations with a significant EFS difference (log-rank p=0.047), but any cut-off point of 6.0 cm or more separated two populations with a significant OS difference (log-rank p values 0.0009-0.037). Interpretation Rituximab decreased, but did not eliminate the adverse prognostic effect of MTD in young patients with good-prognosis DLBCL. Due to the linear prognostic effect of MTD on outcome, arbitrary cut-off points for bulky disease can be set between 5.0 cm and 10.0 cm, depending on clinical considerations. Based on this study, a cut-off point of 10.0 cm might be a suitable margin in the rituximab era to delineate those patients with bulky disease. Funding Roche, Basel, Switzerland (M39045).
|
|
| 6. |
- Villanueva Perez, Pablo, et al.
(författare)
-
Megahertz X-ray Multi-projection imaging
- 2023
-
Ingår i: arXiv.org. - 2331-8422.
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- X-ray time-resolved tomography is one of the most popular X-raytechniques to probe dynamics in three dimensions (3D). Recent developments in time-resolved tomography opened the possibility of recordingkilohertz-rate 3D movies. However, tomography requires rotating thesample with respect to the X-ray beam, which prevents characterization of faster structural dynamics. Here, we present megahertz (MHz)X-ray multi-projection imaging (MHz-XMPI), a technique capable ofrecording volumetric information at MHz rates and micrometer resolution without scanning the sample. We achieved this by harnessing theunique megahertz pulse structure and intensity of the European X-rayFree-electron Laser with a combination of novel detection and reconstruction approaches that do not require sample rotations. Our approachenables generating multiple X-ray probes that simultaneously record several angular projections for each pulse in the megahertz pulse burst.We provide a proof-of-concept demonstration of the MHz-XMPI technique’s capability to probe 4D (3D+time) information on stochasticphenomena and non-reproducible processes three orders of magnitudefaster than state-of-the-art time-resolved X-ray tomography, by generating 3D movies of binary droplet collisions. We anticipate that MHz-XMPIwill enable in-situ and operando studies that were impossible before,either due to the lack of temporal resolution or because the systemswere opaque (such as for MHz imaging based on optical microscopy).
|
|
| 7. |
- Wiedorn, Max O., et al.
(författare)
-
Megahertz serial crystallography
- 2018
-
Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a beta-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source.
|
|
