190 research outputs found

    Advances in ultrahigh throughput hit discovery with tandem mass spectrometry encoded libraries

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    Discovering new bioactive molecules is crucial for drug development. Finding a hit compound for a new drug target usually requires screening of millions of molecules. Affinity selection based technologies have revolutionized early hit discovery by enabling the rapid screening of libraries with millions or billions of compounds in short timeframes. In this Perspective, we describe recent technology breakthroughs that enable the screening of ultralarge synthetic peptidomimetic libraries with a barcode-free tandem mass spectrometry decoding strategy. A combination of combinatorial synthesis, affinity selection, automated de novo peptide sequencing algorithms, and advances in mass spectrometry instrumentation now enables hit discovery from synthetic libraries with over 100 million members. We provide a perspective on this powerful technology and showcase success stories featuring the discovery of high affinity binders for a number of drug targets including proteins, nucleic acids, and specific cell types. Further, we show the usage of the technology to discover synthetic peptidomimetics with specific functions and reactivity. We predict that affinity selection coupled with tandem mass spectrometry and automated de novo decoding will rapidly evolve further and become a broadly used drug discovery technology.Medicinal Chemistr

    Dissipative Particle Dynamics with energy conservation

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    Dissipative particle dynamics (DPD) does not conserve energy and this precludes its use in the study of thermal processes in complex fluids. We present here a generalization of DPD that incorporates an internal energy and a temperature variable for each particle. The dissipation induced by the dissipative forces between particles is invested in raising the internal energy of the particles. Thermal conduction occurs by means of (inverse) temperature differences. The model can be viewed as a simplified solver of the fluctuating hydrodynamic equations and opens up the possibility of studying thermal processes in complex fluids with a mesoscopic simulation technique.Comment: 5 page

    “One Health” or Three? Publication Silos Among the One Health Disciplines

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    The One Health initiative is a global effort fostering interdisciplinary collaborations to address challenges in human, animal, and environmental health. While One Health has received considerable press, its benefits remain unclear because its effects have not been quantitatively described. We systematically surveyed the published literature and used social network analysis to measure interdisciplinarity in One Health studies constructing dynamic pathogen transmission models. The number of publications fulfilling our search criteria increased by 14.6% per year, which is faster than growth rates for life sciences as a whole and for most biology subdisciplines. Surveyed publications clustered into three communities: one used by ecologists, one used by veterinarians, and a third diverse-authorship community used by population biologists, mathematicians, epidemiologists, and experts in human health. Overlap between these communities increased through time in terms of author number, diversity of co-author affiliations, and diversity of citations. However, communities continue to differ in the systems studied, questions asked, and methods employed. While the infectious disease research community has made significant progress toward integrating its participating disciplines, some segregation—especially along the veterinary/ecological research interface—remains

    Comparison of the efficacy of four drug combinations for immobilization of wild pigs

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    Field immobilization of native or invasive wild pigs (Sus scrofa) is challenging. Drug combinations commonly used often result in unsatisfactory immobilization, poor recovery, and adverse side effects, leading to unsafe handling conditions for both animals and humans. We compared four chemical immobilization combinations, medetomidine–midazolam–butorphanol (MMB), butorphanol–azaperone–medetomidine (BAM™), nalbuphine–medetomidine–azaperone (NalMed-A), and tiletamine– zolazepam–xylazine (TZX), to determine which drug combinations might provide better chemical immobilization of wild pigs. We achieved adequate immobilization with no post-recovery morbidity withMMB. Adequate immobilization was achieved with BAM™; however, we observed post-recovery morbidity. Both MMB and BAM™ produced more optimal results relative to body temperature, recovery, and post-recovery morbidity and mortality compared to TZX. Adequate immobilization was not achieved with NalMed-A. Of the four drug combinations examined, we conclude that MMB performed most optimally for immobilization and recovery of wild pigs

    A meta-analysis of oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 discordance between primary breast cancer and metastases

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    BACKGROUND: The discordance in oestrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER2) status between primary and recurrent breast cancer is being intensively investigated and a large amount of data have been produced. However, results from different studies are heterogeneous and often conflicting. To highlight this issue, a meta-analysis of published data was performed. METHODS: A literature search was performed using Medline, and all the studies published from 1983 to 2011 comparing changes in ER, PgR and/or HER2 status in patients with matched breast primary and recurrent tumours were included. We used random-effects models to estimate pooled discordance proportions. RESULTS: We selected 48 articles, mostly reporting retrospective studies. Thirty-three, 24 and 31 articles were focused on ER, PgR and HER2 changes, respectively. A total of 4200, 2739 and 2987 tumours were evaluated for ER, PgR and HER2 discordance, respectively. The heterogeneity between study-specific discordance proportions was high for ER (I(2)=91%, p<0.0001), PgR (I(2)=79%, p<0.0001) and HER2 (I(2)=77%, p<0.0001). Pooled discordance proportions were 20% (95% confidence interval (CI): 16-35%) for ER, 33% (95% CI: 29-38%) for PgR and 8% (95% CI: 6-10%) for HER2. Pooled proportions of tumours shifting from positive to negative and from negative to positive were 24% and 14% for ER (p=0.0183), respectively. The same figures were 46% and 15% for PgR (p<0.0001), and 13% and 5% for HER2 (p=0.0004). CONCLUSION: Our findings strengthen the concept that changes in receptor expression may occur during the natural history of breast cancer, suggesting clinical implications and a possible impact on treatment choice

    Does immediate breast reconstruction after mastectomy and neoadjuvant chemotherapy influence the outcome of patients with non-endocrine responsive breast cancer?

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    Background/Aim: In breast cancer (BC) patients, breast surgery followed by immediate breast reconstruction (IBR) might favour recurrences and metastases due to extensive surgical manipulation. We retrospectively investigated whether IBR after mastectomy and neoadjuvant chemotherapy (NT) influenced the outcome in patients with early and locally advanced oestrogen receptor (ER)-negative BC. Patients and Methods: Between 1995 and 2006, 133 BC patients received NT followed by total mastectomy, 59 of whom underwent IBR. Patients receiving IBR (IBR group) were compared to patients who did not receive IBR (no-IBR group) over a prolonged median follow-up time (8.2 years). Results: Patients receiving IBR were on average younger than patients not receiving IBR (p&lt;0.00I). The percentage of patients with positive clinical nodal status (cN) was 19% in the IBR group and 7% in no-IBR group (p=0.036), whereas patients without 1BR were more frequently diagnosed as clinical T4 (59% vs. 15%, p&lt;0.001). The 5-year cumulative incidence of locoregional recurrences were 14% in the no-IBR group and 21% in the IBR group. The hazard of locoregional events, adjusted for age, clinical T and cN, was significantly greater in the IBR group than in the no-IBR group (hazard ratio (HR)=2.77, p=0.045). The 5-year cumulative incidences of distant metastases were similar in the two groups (p=0.414). Conclusion: IBR following total mastectomy in patients with ER-negative disease after NT is associated with a worse rate of local relapses. More insight in mechanisms of wound healing and extent of surgery is required to further investigate this observation

    Everything you always wanted to know about SDPD⋆ (⋆but were afraid to ask)

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    An overview of the smoothed dissipative particle dynamics (SDPD) method is presented in a format that tries to quickly answer questions that often arise among users and newcomers. It is hoped that the status of SDPD is clarified as a mesoscopic particle model and its potentials and limitations are highlighted, as compared with other methods

    Protection against Tuberculosis in Eurasian Wild Boar Vaccinated with Heat-Inactivated Mycobacterium bovis

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    Tuberculosis (TB) caused by Mycobacterium bovis and closely related members of the Mycobacterium tuberculosis complex continues to affect humans and animals worldwide and its control requires vaccination of wildlife reservoir species such as Eurasian wild boar (Sus scrofa). Vaccination efforts for TB control in wildlife have been based primarily on oral live BCG formulations. However, this is the first report of the use of oral inactivated vaccines for controlling TB in wildlife. In this study, four groups of 5 wild boar each were vaccinated with inactivated M. bovis by the oral and intramuscular routes, vaccinated with oral BCG or left unvaccinated as controls. All groups were later challenged with a field strain of M. bovis. The results of the IFN-gamma response, serum antibody levels, M. bovis culture, TB lesion scores, and the expression of C3 and MUT genes were compared between these four groups. The results suggested that vaccination with heat-inactivated M. bovis or BCG protect wild boar from TB. These results also encouraged testing combinations of BCG and inactivated M. bovis to vaccinate wild boar against TB. Vaccine formulations using heat-inactivated M. bovis for TB control in wildlife would have the advantage of being environmentally safe and more stable under field conditions when compared to live BCG vaccines. The antibody response and MUT expression levels can help differentiating between vaccinated and infected wild boar and as correlates of protective response in vaccinated animals. These results suggest that vaccine studies in free-living wild boar are now possible to reveal the full potential of protecting against TB using oral M. bovis inactivated and BCG vaccines
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