108 research outputs found

    The use of a SQUID magnetometer for middle ear research

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    A new technique is described for the measurement of vibrations in the temporal bones of an isolated middle ear. The precise recording of vibrations in the middle ear is of importance for the construction and improvement of a middle ear prosthesis.1 The method of measurement is based on a transformation of mechanical vibrations into magnetic flux variations. This is performed by attaching a small piece of permanent magnetic material to the eardrum or middle ear ossicles. The magnetic flux variations caused by vibrations of the eardrum or ossicles during application of sound can be measured by means of a SQUID magnetometer.\ud \ud Measurements showed that it is possible to measure vibratory displacement amplitudes of the eardrum down to about 10−10 m in a frequency range between 200 Hz and 10 kHz, although the acoustical and magnetometer conditions were not optimal. The method offers several advantages compared to already existing methods.2–5,

    Regulation of histone H3K4 tri-methylation and PAF complex recruitment by the Ccr4-Not complex

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    Efficient transcription is linked to modification of chromatin. For instance, tri-methylation of lysine 4 on histone H3 (H3K4) strongly correlates with transcriptional activity and is regulated by the Bur1/2 kinase complex. We found that the evolutionarily conserved Ccr4-Not complex is involved in establishing H3K4 tri-methylation in Saccharomyces cerevisiae. We observed synthetic lethal interactions of Ccr4-Not components with BUR1 and BUR2. Further analysis indicated that the genes encoding the Not-proteins are essential for efficient regulation of H3K4me3, but not H3K4me1/2, H3K36me2 or H3K79me2/3 levels. Moreover, regulation of H3K4me3 levels by NOT4 is independent of defects in RNA polymerase II loading. We found NOT4 to be important for ubiquitylation of histone H2B via recruitment of the PAF complex, but not for recruitment or activation of the Bur1/2 complex. These results suggest a mechanism in which the Ccr4-Not complex functions parallel to or downstream of the Bur1/2 kinase to facilitate H3K4me3 via PAF complex recruitment

    Phosphorylation of Not4p Functions Parallel to BUR2 to Regulate Resistance to Cellular Stresses in Saccharomyces cerevisiae

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    Background The evolutionarily conserved Ccr4-Not and Bur1/2 kinase complexes are functionally related in Saccharomyces cerevisiae. In this study, we further explore the relationship between the subunits Not4p and Bur2p. Methodology/Principal Findings First, we investigated the presence of post-translational modifications on the Ccr4-Not complex. Using mass spectrometry analyses we identified several SP/TP phosphorylation sites on its Not4p, Not1p and Caf1p subunits. Secondly, the influence of Not4p phosphorylation on global H3K4 tri-methylation status was examined by immunoblotting. This histone mark is severely diminished in the absence of Not4p or of Bur2p, but did not require the five identified Not4p phosphorylation sites. Thirdly, we found that Not4p phosphorylation is not affected by the kinase-defective bur1-23 mutant. Finally, phenotypic analyses of the Not4p phosphomutant (not4S/T5A) and bur2Δ strains showed overlapping sensitivities to drugs that abolish cellular stress responses. The double-mutant not4S/T5A and bur2Δ strain even revealed enhanced phenotypes, indicating that phosphorylation of Not4p and BUR2 are active in parallel pathways for drug tolerance. Conclusions Not4p is a phospho-protein with five identified phosphorylation sites that are likely targets of a cyclin-dependent kinase(s) other than the Bur1/2p complex. Not4p phosphorylation on the five Not4 S/T sites is not required for global H3K4 tri-methylation. In contrast, Not4p phosphorylation is involved in tolerance to cellular stresses and acts in pathways parallel to BUR2 to affect stress responses in Saccharomyces cerevisiae

    Lessons from Elwha Ecosystem Restoration: Integrating science, policy, and management

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    After decades of debate, planning, and environmental impact studies, the largest planned dam removal project in history was conducted on the Elwha River in Washington State, USA, from 2011 to 2014. Because this was such a unique and unprecedented project, the planning, implementation, and monitoring has occurred over 30 years and required diverse expertise across multiple stakeholders. This knowledge portfolio required that individuals and organizations with different missions collaborate effectively to ensure a successful project. The story of this river, with rugged headwaters, protected wilderness, legendary and culturally important salmon runs, and two hydroelectric dams whose placement marshaled wholesale socioeconomic and ecological changes, has become an iconic saga of change, perseverance and renewal. The two dams blocked fish migrations and disrupted sediment transport for a century, disrupting the ecological structure and function of the Elwha River. Removal of the 64-m and 32-m tall dams and the release of a large portion of the 21 million cubic meters of stored reservoir sediment, has provided a living laboratory to study the patterns, processes and outcomes of dam removal across freshwater, estuarine, and marine ecosystem boundaries from multiple scientific perspectives. This collaborative multidisciplinary approach has allowed us to improve our understanding of ecosystem responses and linkages while making the Elwha River one of the best studied dam removal projects

    Принципи управління персоналом сільськогосподарських підприємств (на прикладі Луганської області)

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    У статті проаналізовано сучасний стан сільськогосподарського виробництва в Луганській області та здійснена оцінка перспектив реформування управління персоналом на підприємствах АПК. Регресійним аналізом оцінено ступінь впливу деяких факторів на рентабельність персоналу. Рекомендується використання SWOT-аналізу для дослідження й формування раціонального управління персоналом підприємств АПК.Performed analysis of the current state of agriculture in the Luhansk region, evaluated the prospects for personnel resources reforming for the agricultural enterprises. The degree of factors influencing on profitability of personnel is appraised by the regressive analysis. SWOT-analysis is recommended for research and forming of agrarian enterprises rational management of a personnel

    Planning, implementation, and monitoring Pacific salmonid recovery following the removal of two hydroelectric dams on Washington\u27s Elwha River

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    The removal of Elwha and Glines Canyon dams on the Elwha River is the largest existing dam removal project in the United States. Project planning, implementation, and monitoring have occurred over 30 years and has required diverse technical expertise. Because of the size and nature of the project—two high-head dams releasing massive amounts of sediment into the river, estuary, and nearshore ecosystem—the project was unprecedented and required a great deal of technical expertise to plan, execute, and monitor. The relative success of this project required effective collaboration among individuals and organizations with varying missions. Individuals with diverse technical expertise (i.e., engineering, geomorphology, hydrology, botany, wildlife, fisheries, stream ecology, ecological monitoring) have successfully collaborated to develop several technical plans ensuring dam removal was completed, while at the same time protecting a city water supply, infrastructure, and listed and unlisted salmonids in the basin. This collaboration has continued following dam removal through the implementation of a monitoring and adaptive management plan. Our monitoring strategy often uses multiple scientific methods to evaluate metrics or performance indicators to create multiple lines of evidence, reduce uncertainty, and ensure data availability. Employing such diverse methods would not have been possible without multidisciplinary and multiagency collaboration. Collaboration and extensive monitoring has allowed project partners to identify potential barriers, assess the rate and extent of recolonization, estimate abundance, life history attributes, and productivity. This collaborative multidisciplinary approach has allowed us to monitor salmonid recovery, while also improving our understanding of ecosystem response and linkages. This has resulted in the Elwha River being one of the best studied dam removal projects in history

    Expression of the RNA helicase DDX3 and the hypoxia response in breast cancer

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    <p>Aims: DDX3 is an RNA helicase that has antiapoptotic properties, and promotes proliferation and transformation. In addition, DDX3 was shown to be a direct downstream target of HIF-1α (the master regulatory of the hypoxia response) in breast cancer cell lines. However, the relation between DDX3 and hypoxia has not been addressed in human tumors. In this paper, we studied the relation between DDX3 and the hypoxic responsive proteins in human breast cancer.</p> <p>Methods and Results: DDX3 expression was investigated by immunohistochemistry in breast cancer in comparison with hypoxia related proteins HIF-1α, GLUT1, CAIX, EGFR, HER2, Akt1, FOXO4, p53, ERα, COMMD1, FER kinase, PIN1, E-cadherin, p21, p27, Transferrin receptor, FOXO3A, c-Met and Notch1. DDX3 was overexpressed in 127 of 366 breast cancer patients, and was correlated with overexpression of HIF-1α and its downstream genes CAIX and GLUT1. Moreover, DDX3 expression correlated with hypoxia-related proteins EGFR, HER2, FOXO4, ERα and c-Met in a HIF-1α dependent fashion, and with COMMD1, FER kinase, Akt1, E-cadherin, TfR and FOXO3A independent of HIF-1α.</p> <p>Conclusions: In invasive breast cancer, expression of DDX3 was correlated with overexpression of HIF-1α and many other hypoxia related proteins, pointing to a distinct role for DDX3 under hypoxic conditions and supporting the oncogenic role of DDX3 which could have clinical implication for current development of DDX3 inhibitors.</p&gt

    Surgical quality and prospective quality control of the D2-gastrectomy for gastric cancer in the multicenter randomized LOGICA-trial

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    Background: Quality of gastric cancer surgery is crucial for favorable prognosis. Generally, prospective trials lack quality control measures. This study assessed surgical quality and a novel D2-lymphadenectomy photo-scoring in the LOGICA-trial. Methods: The multicenter LOGICA-trial randomized laparoscopic versus open total/distal D2-gastrectomy for resectable gastric cancer (cT1-4aN0-3M0) in 10 Dutch hospitals. During the trial, two reviewers prospectively analyzed intraoperative photographs of dissected nodal stations for quality control, and provided centers weekly feedback on their D2-lymphadenectomy, as continuous quality-enhancing incentive. After the trial, these photographs were reanalyzed to develop a photo-scoring for future trials, rating the D2-lymphadenectomy dissection quality (optimal-good-suboptimal-unevaluable). Interobserver variability was calculated (weighted kappa). Regression analyses related the photo-scoring to nodal yield, recurrence and 5-years survival. Results: Between 2015 and 2018, 212 patients underwent total/distal D2-gastrectomy (n = 122/n = 90), and 158 (75%) received neoadjuvant chemotherapy. R0-resection rate was 95%. Rate of ≥15 retrieved lymph nodes was 95%. Moderate agreement was obtained in stations 8 + 9 (κ = 0.522), 11p/11d (κ = 0.446) and 12a (κ = 0.441). Consensus was reached for discordant cases (30%). Stations 8 + 9, 11p/11d and 12a were rated ‘optimal’ in 76%, 63% and 68%. Laparoscopic photographs could be rated better than open (2% versus 12% ‘unevaluable’; 73% versus 50% ‘optimal’; p = 0.042). The photo-scoring did not show associations with nodal yield (p = 0.214), recurrence (p = 0.406) and survival (p = 0.988). Conclusions: High radicality and nodal yield demonstrated good quality of D2-gastrectomy. The prospective quality control probably contributed to this. The photo-scoring did not show good performance, but can be refined. Laparoscopic D2-gastrectomy was better suited for standardized surgical photo-evaluation than open surgery.</p

    Chromosomal Instability by Inefficient Mps1 Auto-Activation Due to a Weakened Mitotic Checkpoint and Lagging Chromosomes

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    BACKGROUND: Chromosomal instability (CIN), a feature widely shared by cells from solid tumors, is caused by occasional chromosome missegregations during cell division. Two of the causes of CIN are weakened mitotic checkpoint signaling and persistent merotelic attachments that result in lagging chromosomes during anaphase. PRINCIPAL FINDINGS: Here we identify an autophosphorylation event on Mps1 that is required to prevent these two causes of CIN. Mps1 is phosphorylated in mitotic cells on at least 7 residues, 4 of which by autophosphorylation. One of these, T676, resides in the activation loop of the kinase domain and a mutant that cannot be phosphorylated on T676 is less active than wild-type Mps1 but is not kinase-dead. Strikingly, cells in which endogenous Mps1 was replaced with this mutant are viable but missegregate chromosomes frequently. Anaphase is initiated in the presence of misaligned and lagging chromosomes, indicative of a weakened checkpoint and persistent merotelic attachments, respectively. CONCLUSIONS/SIGNIFICANCE: We propose that full activity of Mps1 is essential for maintaining chromosomal stability by allowing resolution of merotelic attachments and to ensure that single kinetochores achieve the strength of checkpoint signaling sufficient to prevent premature anaphase onset and chromosomal instability. To our knowledge, phosphorylation of T676 on Mps1 is the first post-translational modification in human cells of which the absence causes checkpoint weakening and CIN without affecting cell viability

    Body Composition Is a Predictor for Postoperative Complications After Gastrectomy for Gastric Cancer:a Prospective Side Study of the LOGICA Trial

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    PURPOSE: There is a lack of prospective studies evaluating the effects of body composition on postoperative complications after gastrectomy in a Western population with predominantly advanced gastric cancer. METHODS: This is a prospective side study of the LOGICA trial, a multicenter randomized trial on laparoscopic versus open gastrectomy for gastric cancer. Trial patients who received preoperative chemotherapy followed by gastrectomy with an available preoperative restaging abdominal computed tomography (CT) scan were included. The CT scan was used to calculate the mass (M) and radiation attenuation (RA) of skeletal muscle (SM), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). These variables were expressed as Z-scores, depicting how many standard deviations each patient’s CT value differs from the sex-specific study sample mean. Primary outcome was the association of each Z-score with the occurrence of a major postoperative complication (Clavien-Dindo grade ≥ 3b). RESULTS: From 2015 to 2018, a total of 112 patients were included. A major postoperative complication occurred in 9 patients (8%). A high SM-M Z-score was associated with a lower risk of major postoperative complications (RR 0.47, 95% CI 0.28–0.78, p = 0.004). Furthermore, high VAT-RA Z-scores and SAT-RA Z-scores were associated with a higher risk of major postoperative complications (RR 2.82, 95% CI 1.52–5.23, p = 0.001 and RR 1.95, 95% CI 1.14–3.34, p = 0.015, respectively). VAT-M, SAT-M, and SM-RA Z-scores showed no significant associations. CONCLUSION: Preoperative low skeletal muscle mass and high visceral and subcutaneous adipose tissue radiation attenuation (indicating fat depleted of triglycerides) were associated with a higher risk of developing a major postoperative complication in patients treated with preoperative chemotherapy followed by gastrectomy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11605-022-05321-0
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