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Leptin modulates pancreatic {beta}-cell membrane potential through Src kinase-mediated phosphorylation of NMDA receptors [Membrane Biology]

The adipocyte-derived hormone leptin increases trafficking of KATP and Kv2.1 channels to the pancreatic β-cell surface, resulting in membrane hyperpolarization and suppression of insulin secretion. We have previously shown that this effect of leptin is mediated by the NMDA subtype of glutamate receptors (NMDARs). It does so by potentiating NMDAR activity, thus enhancing Ca2+ influx and the ensuing downstream signaling events that drive channel trafficking to the cell surface. However, the molecular mechanism by which leptin potentiates NMDARs in β-cells remains unknown. Here, we report that leptin augments NMDAR function via Src kinase–mediated phosphorylation of the GluN2A subunit. Leptin-induced membrane hyperpolarization diminished upon pharmacological inhibition of GluN2A but not GluN2B, indicating involvement of GluN2A-containing NMDARs. GluN2A harbors tyrosine residues that, when phosphorylated by Src family kinases, potentiate NMDAR activity. We found that leptin increases phosphorylation of Tyr-418 in Src, an indicator of kinase activation. Pharmacological inhibition of Src or overexpression of a kinase-dead Src mutant prevented the effect of leptin, whereas a Src kinase activator peptide mimicked it. Using mutant GluN2A overexpression, we show that Tyr-1292 and Tyr-1387 but not Tyr-1325 are responsible for the effect of leptin. Importantly, β-cells from db/db mice, a type 2 diabetes mouse model lacking functional leptin receptors, or from obese diabetic human donors failed to respond to leptin but hyperpolarized in response to NMDA. Our study reveals a signaling pathway wherein leptin modulates NMDARs via Src to regulate β-cell excitability and suggests NMDARs as a potential target to overcome leptin resistance.




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Functional impact of a congenital stationary night blindness type 2 mutation depends on subunit composition of Cav1.4 Ca2+ channels [Neurobiology]

Voltage-gated Cav1 and Cav2 Ca2+ channels are comprised of a pore-forming α1 subunit (Cav1.1-1.4, Cav2.1-2.3) and auxiliary β (β1-4) and α2δ (α2δ−1−4) subunits. The properties of these channels vary with distinct combinations of Cav subunits and alternative splicing of the encoding transcripts. Therefore, the impact of disease-causing mutations affecting these channels may depend on the identities of Cav subunits and splice variants. Here, we analyzed the effects of a congenital stationary night blindness type 2 (CSNB2)-causing mutation, I745T (IT), in Cav1.4 channels typical of those in human retina: Cav1.4 splice variants with or without exon 47 (Cav1.4+ex47 and Cav1.4Δex47, respectively), and the auxiliary subunits, β2X13 and α2δ-4. We find that IT caused both Cav1.4 splice variants to activate at significantly more negative voltages and with slower deactivation kinetics than the corresponding WT channels. These effects of the IT mutation, along with unexpected alterations in ion selectivity, were generally larger in channels lacking exon 47. The weaker ion selectivity caused by IT led to hyperpolarizing shifts in the reversal potential and large outward currents that were evident in channels containing the auxiliary subunits β2X13 and α2δ-4 but not in those with β2A and α2δ-1. We conclude that the IT mutation stabilizes channel opening and alters ion selectivity of Cav1.4 in a manner that is strengthened by exclusion of exon 47 and inclusion of β2X13 and α2δ-4. Our results reveal complex actions of IT in modifying the properties of Cav1.4 channels, which may influence the pathological consequences of this mutation in retinal photoreceptors.




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Analytical Guidelines for co-fractionation Mass Spectrometry Obtained through Global Profiling of Gold Standard Saccharomyces cerevisiae Protein Complexes [Research]

Co-fractionation MS (CF-MS) is a technique with potential to characterize endogenous and unmanipulated protein complexes on an unprecedented scale. However this potential has been offset by a lack of guidelines for best-practice CF-MS data collection and analysis. To obtain such guidelines, this study thoroughly evaluates novel and published Saccharomyces cerevisiae CF-MS data sets using very high proteome coverage libraries of yeast gold standard complexes. A new method for identifying gold standard complexes in CF-MS data, Reference Complex Profiling, and the Extending 'Guilt-by-Association' by Degree (EGAD) R package are used for these evaluations, which are verified with concurrent analyses of published human data. By evaluating data collection designs, which involve fractionation of cell lysates, it is found that near-maximum recall of complexes can be achieved with fewer samples than published studies. Distributing sample collection across orthogonal fractionation methods, rather than a single high resolution data set, leads to particularly efficient recall. By evaluating 17 different similarity scoring metrics, which are central to CF-MS data analysis, it is found that two metrics rarely used in past CF-MS studies – Spearman and Kendall correlations – and the recently introduced Co-apex metric frequently maximize recall, whereas a popular metric—Euclidean distance—delivers poor recall. The common practice of integrating external genomic data into CF-MS data analysis is also evaluated, revealing that this practice may improve the precision and recall of known complexes but is generally unsuitable for predicting novel complexes in model organisms. If studying nonmodel organisms using orthologous genomic data, it is found that particular subsets of fractionation profiles (e.g. the lowest abundance quartile) should be excluded to minimize false discovery. These assessments are summarized in a series of universally applicable guidelines for precise, sensitive and efficient CF-MS studies of known complexes, and effective predictions of novel complexes for orthogonal experimental validation.




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High-dimensional Cytometry (ExCYT) and Mass Spectrometry of Myeloid Infiltrate in Clinically Localized Clear Cell Renal Cell Carcinoma Identifies Novel Potential Myeloid Targets for Immunotherapy [Research]

Renal Cell Carcinoma (RCC) is one of the most commonly diagnosed cancers worldwide with research efforts dramatically improving understanding of the biology of the disease. To investigate the role of the immune system in treatment-naïve clear cell Renal Cell Carcinoma (ccRCC), we interrogated the immune infiltrate in patient-matched ccRCC tumor samples, benign normal adjacent tissue (NAT) and peripheral blood mononuclear cells (PBMCs isolated from whole blood, focusing our attention on the myeloid cell infiltrate. Using flow cytometric, MS, and ExCYT analysis, we discovered unique myeloid populations in PBMCs across patient samples. Furthermore, normal adjacent tissues and ccRCC tissues contained numerous myeloid populations with a unique signature for both tissues. Enrichment of the immune cell (CD45+) fraction and subsequent gene expression analysis revealed a number of myeloid-related genes that were differentially expressed. These data provide evidence, for the first time, of an immunosuppressive and pro-tumorigenic role of myeloid cells in early, clinically localized ccRCC. The identification of a number of immune proteins for therapeutic targeting provides a rationale for investigation into the potential efficacy of earlier intervention with single-agent or combination immunotherapy for ccRCC.




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Slight Deuterium Enrichment in Water Acts as an Antioxidant: Is Deuterium a Cell Growth Regulator? [Research]

Small admixtures in water, e.g. of metal ions, often act as cell growth regulators. Here we report that enrichment of deuterium content in water, normally found at 8 mm concentration, two-three folds increases cell proliferation and lowers the oxidative stress level as well. Acting as an anti-oxidant, deuterium-enriched water prevents the toxic effect of such oxidative agents as hydrogen peroxide and auranofin. This action is opposite to that of deuterium depletion that is known to suppress cell growth and induce oxidative stress in mitochondria. We thus hypothesize that deuterium may be a natural cell growth regulator that controls mitochondrial oxidation-reduction balance. Because growth acceleration is reduced approximately by half by addition to water a minute amount (0.15%) of 18O isotope, at least part of the deuterium effect on cell growth can be explained by the isotopic resonance phenomenon. A slight (2-fold) enrichment of deuterium in water accelerates human cell growth. Quantitative MS based proteomics determined changes in protein abundances and redox states and found that deuterium-enriched water acts mainly through decreasing ROS production in mitochondria. This action is opposite to that of deuterium depletion that suppresses cell growth by inducing oxidative stress. Thus deuterium may be a natural cell growth regulator that controls mitochondrial oxidation-reduction balance. The role of isotopic resonance in this effect was validated by further experiments on bacteria.




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High-speed Analysis of Large Sample Sets - How Can This Key Aspect of the Omics Be Achieved? [Perspective]

High-speed analysis of large (prote)omics sample sets at the rate of thousands or millions of samples per day on a single platform has been a challenge since the beginning of proteomics. For many years, ESI-based MS methods have dominated proteomics because of their high sensitivity and great depth in analyzing complex proteomes. However, despite improvements in speed, ESI-based MS methods are fundamentally limited by their sample introduction, which excludes off-line sample preparation/fractionation because of the time required to switch between individual samples/sample fractions, and therefore being dependent on the speed of on-line sample preparation methods such as liquid chromatography. Laser-based ionization methods have the advantage of moving from one sample to the next without these limitations, being mainly restricted by the speed of modern sample stages, i.e. 10 ms or less between samples. This speed matches the data acquisition speed of modern high-performing mass spectrometers whereas the pulse repetition rate of the lasers (>1 kHz) provides a sufficient number of desorption/ionization events for successful ion signal detection from each sample at the above speed of the sample stages. Other advantages of laser-based ionization methods include the generally higher tolerance to sample additives and contamination compared with ESI MS, and the contact-less and pulsed nature of the laser used for desorption, reducing the risk of cross-contamination. Furthermore, new developments in MALDI have expanded its analytical capabilities, now being able to fully exploit high-performing hybrid mass analyzers and their strengths in sensitivity and MS/MS analysis by generating an ESI-like stable yield of multiply charged analyte ions. Thus, these new developments and the intrinsically high speed of laser-based methods now provide a good basis for tackling extreme sample analysis speed in the omics.




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A Comprehensive Gender-related Secretome of Plasmodium berghei Sexual Stages [Research]

Plasmodium, the malaria parasite, undergoes a complex life cycle alternating between a vertebrate host and a mosquito vector of the genus Anopheles. In red blood cells of the vertebrate host, Plasmodium multiplies asexually or differentiates into gamete precursors, the male and female gametocytes, responsible for parasite transmission. Sexual stage maturation occurs in the midgut of the mosquito vector, where male and female gametes egress from the host erythrocytes to fuse and form a zygote. Gamete egress entails the successive rupture of two membranes surrounding the parasite, the parasitophorous vacuole membrane and the erythrocyte plasma membrane. In this study, we used the rodent model parasite Plasmodium berghei to design a label-free quantitative proteomic approach aimed at identifying gender-related proteins differentially released/secreted by purified mature gametocytes when activated to form gametes. We compared the abundance of molecules secreted by wild type gametocytes of both genders with that of a transgenic line defective in male gamete maturation and egress. This enabled us to provide a comprehensive data set of egress-related molecules and their gender specificity. Using specific antibodies, we validated eleven candidate molecules, predicted as either gender-specific or common to both male and female gametocytes. All of them localize to punctuate, vesicle-like structures that relocate to cell periphery upon activation, but only three of them localize to the gametocyte-specific secretory vesicles named osmiophilic bodies. Our results confirm that the egress process involves a tightly coordinated secretory apparatus that includes different types of vesicles and may put the basis for functional studies aimed at designing novel transmission-blocking molecules.




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Citrus Vascular Proteomics Highlights the Role of Peroxidases and Serine Proteases during Huanglongbing Disease Progression [Research]

Huanglongbing (HLB) is the most devastating and widespread citrus disease. All commercial citrus varieties are susceptible to the HLB-associated bacterium, Candidatus Liberibacter asiaticus (CLas), which resides in the phloem. The phloem is part of the plant vascular system and is involved in sugar transport. To investigate the plant response to CLas, we enriched for proteins surrounding the phloem in an HLB susceptible sweet orange variety, Washington navel (Citrus sinensis (L) Osbeck). Quantitative proteomics revealed global changes in the citrus proteome after CLas inoculation. Plant metabolism and translation were suppressed, whereas defense-related proteins such as peroxidases, proteases and protease inhibitors were induced in the vasculature. Transcript accumulation and enzymatic activity of plant peroxidases in CLas infected sweet orange varieties under greenhouse and field conditions were assessed. Although peroxidase transcript accumulation was induced in CLas infected sweet orange varieties, peroxidase enzymatic activity varied. Specific serine proteases were up-regulated in Washington navel in the presence of CLas based on quantitative proteomics. Subsequent activity-based protein profiling revealed increased activity of two serine proteases, and reduced activity of one protease in two C. sinensis sweet orange varieties under greenhouse and field conditions. The observations in the current study highlight global reprogramming of the citrus vascular proteome and differential regulation of enzyme classes in response to CLas infection. These results open an avenue for further investigation of diverse responses to HLB across different environmental conditions and citrus genotypes.




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Translating Divergent Environmental Stresses into a Common Proteome Response through Hik33 in a Model Cyanobacterium [Research]

The histidine kinase Hik33 plays important roles in mediating cyanobacterial response to divergent types of abiotic stresses including cold, salt, high light (HL), and osmotic stresses. However, how these functions are regulated by Hik33 remains to be addressed. Using a hik33-deficient strain (hik33) of Synechocystis sp. PCC 6803 (Synechocystis) and quantitative proteomics, we found that Hik33 depletion induces differential protein expression highly similar to that induced by divergent types of stresses. This typically includes downregulation of proteins in photosynthesis and carbon assimilation that are necessary for cell propagation, and upregulation of heat shock proteins, chaperons, and proteases that are important for cell survival. This observation indicates that depletion of Hik33 alone mimics divergent types of abiotic stresses, and that Hik33 could be important for preventing abnormal stress response in the normal condition. Moreover, we found the majority of proteins of plasmid origin were significantly upregulated in hik33, though their biological significance remains to be addressed. Together, the systematically characterized Hik33-regulated cyanobacterial proteome, which is largely involved in stress responses, builds the molecular basis for Hik33 as a general regulator of stress responses.




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Blockade of High-Fat Diet Proteomic Phenotypes using Exercise as Prevention or Treatment [Technological Innovation and Resources]

The increasing consumption of high-fat foods combined with a lack of exercise is a major contributor to the burden of obesity in humans. Aerobic exercise such as running is known to provide metabolic benefits, but how the over-consumption of a high fat diet (HFD) and exercise interact is not well characterized at the molecular level. Here, we examined the plasma proteome in mice for the effects of aerobic exercise as both a treatment and as a preventative regime for animals on either HFD or a healthy control diet. This analysis detected large changes in the plasma proteome induced by the HFD, such as increased abundance of SERPINA7, ALDOB, and down-regulation of SERPINA1E, CFD (adipsin). Some of these changes were significantly reverted using exercise as a preventative measure, but not as a treatment regime. To determine if either the intensity, or duration, of exercise influenced the outcome, we compared high-intensity interval training (HIIT) and endurance running. Endurance running slightly out-performed HIIT exercise, but overall, both provided similar reversion in abundance of plasma proteins modulated by the high-fat diet including SERPINA7, APOE, SERPINA1E, and CFD. Finally, we compared the changes induced by over-consumption of HFD to previous data from mice fed an isocaloric high saturated fat (SFA) or polyunsaturated fat (PUFA) diet. This identified several common changes including increased APOC2 and APOE, but also highlighted changes specific for either over-consumption of HFD (ALDOB, SERPINA7, CFD), SFA-based diets (SERPINA1E), or PUFA-based diets (Haptoglobin - Hp). Together, these data highlight the importance of early intervention with exercise to revert HFD-induced phenotypes and suggest some of the molecular mechanisms leading to the changes in the plasma proteome generated by high fat diet consumption. Web-based interactive visualizations are provided for this dataset (larancelab.com/hfd-exercise), which give insight into diet and exercise phenotypic interactions on the plasma proteome.




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Accelerating the field of epigenetic histone modification through mass spectrometry-based approaches [Review]

Histone post-translational modifications (PTMs) are one of the main mechanisms of epigenetic regulation. Dysregulation of histone PTMs leads to many human diseases, such as cancer. Due to its high-throughput, accuracy, and flexibility, mass spectrometry (MS) has emerged as a powerful tool in the epigenetic histone modification field, allowing the comprehensive and unbiased analysis of histone PTMs and chromatin-associated factors. Coupled with various techniques from molecular biology, biochemistry, chemical biology and biophysics, MS has been employed to characterize distinct aspects of histone PTMs in the epigenetic regulation of chromatin functions. In this review we will describe advancements in the field of MS that have facilitated the analysis of histone PTMs and chromatin biology.  




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Proteome Turnover in the Spotlight: Approaches, Applications & Perspectives [Review]

In all cells, proteins are continuously synthesized and degraded in order to maintain protein homeostasis and modify gene expression levels in response to stimuli. Collectively, the processes of protein synthesis and degradation are referred to as protein turnover. At steady state, protein turnover is constant to maintain protein homeostasis, but in dynamic responses, proteins change their rates of synthesis and degradation in order to adjust their proteomes to internal or external stimuli. Thus, probing the kinetics and dynamics of protein turnover lends insight into how cells regulate essential processes such as growth, differentiation, and stress response. Here we outline historical and current approaches to measuring the kinetics of protein turnover on a proteome-wide scale in both steady-state and dynamic systems, with an emphasis on metabolic tracing using stable-isotope-labeled amino acids. We highlight important considerations for designing proteome turnover experiments, key biological findings regarding the conserved principles of proteome turnover regulation, and future perspectives for both technological and biological investigation.




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Proteomic analyses identify differentially expressed proteins and pathways between low-risk and high-risk subtypes of early-stage lung adenocarcinoma and their prognostic impacts [Research]

The histopathological subtype of lung adenocarcinoma (LUAD) is closely associated with prognosis. Micropapillary or solid predominant LUAD tends to relapse after surgery at an early stage, whereas lepidic pattern shows a favorable outcome. However, the molecular mechanism underlying this phenomenon remains unknown. Here, we recruited 31 lepidic predominant LUADs (LR: low-risk subtype group) and 28 micropapillary or solid predominant LUADs (HR: high-risk subtype group). Tissues of these cases were obtained and label-free quantitative proteomic and bioinformatic analyses were performed. Additionally, prognostic impact of targeted proteins was validated using The Cancer Genome Atlas databases (n=492) and tissue microarrays composed of early-stage LUADs (n=228). A total of 192 differentially expressed proteins were identified between tumor tissues of LR and HR and three clusters were identified via hierarchical clustering excluding eight proteins. Cluster 1 (65 proteins) showed a sequential decrease in expression from normal tissues to tumor tissues of LR and then to HR and was predominantly enriched in pathways such as tyrosine metabolism and ECM-receptor interaction, and increased matched mRNA expression of 18 proteins from this cluster predicted favorable prognosis. Cluster 2 (70 proteins) demonstrated a sequential increase in expression from normal tissues to tumor tissues of LR and then to HR and was mainly enriched in pathways such as extracellular organization, DNA replication and cell cycle, and high matched mRNA expression of 25 proteins indicated poor prognosis. Cluster 3 (49 proteins) showed high expression only in LR, with high matched mRNA expression of 20 proteins in this cluster indicating favorable prognosis. Furthermore, high expression of ERO1A and FEN1 at protein level predicted poor prognosis in early-stage LUAD, supporting the mRNA results. In conclusion, we discovered key differentially expressed proteins and pathways between low-risk and high-risk subtypes of early-stage LUAD. Some of these proteins could serve as potential biomarkers in prognostic evaluation.




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High-throughput and site-specific N-glycosylation analysis of human alpha-1-acid glycoprotein offers a great potential for new biomarker discovery [Research]

Alpha-1-acid glycoprotein (AGP) is an acute phase glycoprotein in blood, which is primarily synthetized in the liver and whose biological role is not completely understood. It consists of 45% carbohydrates that are present in the form of five N-linked complex glycans. AGP N-glycosylation was shown to be changed in many different diseases and some changes appear to be disease-specific, thus it has a great diagnostic and prognostic potential. However, AGP glycosylation was mainly analyzed in small cohorts and without detailed site-specific glycan information. Here, we developed a cost-effective method for a high-throughput and site-specific N-glycosylation LC-MS analysis of AGP which can be applied on large cohorts, aid in search for novel disease biomarkers and enable better understanding of AGP’s role and function in health and disease. The method does not require isolation of AGP with antibodies and affinity chromatography, but AGP is enriched by acid precipitation from 5 μl of bloodplasma in a 96 well format. After trypsinization, AGP glycopeptides are purified using a hydrophilic interaction chromatography based solid-phase extraction and analyzed by RP-LC-ESI-MS. We used our method to show for the first time that AGP N-glycan profile is stable in healthy individuals (14 individuals in 3 time points), which is a requirement for evaluation of its diagnostic potential. Furthermore, we tested our method on a population including individuals with registered hyperglycemia in critical illness (59 cases and 49 controls), which represents a significantly increased risk of developing type 2 diabetes. Individuals at higher risk of diabetes presented increased N-glycan branching on AGP’s second glycosylation site and lower sialylation of N-glycans on AGP’s third and AGP1’s fourth glycosylation site. Although this should be confirmed on a larger prospective cohort, it indicates that site-specific AGP N-glycan profile could help distinguish individuals who are at risk of type 2 diabetes.




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Exploring Transatlantic Responses to Far-right Populism in Europe: Simulation Exercise

Exploring Transatlantic Responses to Far-right Populism in Europe: Simulation Exercise Research paper sysadmin 1 May 2018

A new paper summarizes the findings of a recent simulation exercise exploring how governments on both sides of the Atlantic might respond to a descent towards populist authoritarianism in an EU member state.

Young protester, Serbia. Photo: urbazon/Getty Images.

Summary

  • To better understand how governments on both sides of the Atlantic might respond to a descent towards populist authoritarianism in an EU member state, Chatham House organized a simulation event involving a group of experts drawn from the public sector, academia and NGOs.
  • Simulation exercises enable the testing and modelling of the responses of different actors when presented with specific situations; participants’ interactions in a given set of circumstances are explored, and patterns of negotiation are captured and analysed.
  • In this simulation, European, US and multilateral representatives were given the task of managing relations with Baltia, a fictional Eastern European state on the verge of electing a far-right nationalist, Eurosceptic government. They were then challenged to manage their relationship with Baltia after it had elected such a government, which was pushing for a ‘leave’ vote in a planned referendum on the country’s continued EU membership.
  • The simulation highlighted a number of issues:
    • Limited instruments are available to liberal democratic governments where there is cause for concern regarding the outcome of an election in an allied country. There are relatively few tools at the disposal of governments to support political allies, or to prevent outcomes that are perceived as threatening democratic norms. The simulation reinforced the view that interventionist moves, either from the European Commission or from individual national governments, would be more likely to come in response to an unfavourable development rather than pre-emptively.
    • The EU, and caucuses of European states, are the main international interlocutors in this type of political crisis involving an EU member state. The US opted to play a limited role in the negotiations; the same was largely true for NATO, aside from its action in sharing intelligence about a potential coup in Baltia. France and Germany formed a natural working partnership, taking meetings together and coordinating policies first before discussing them with a wider European circle, although their positions did not always align.
    • The UK’s capacity to shape the outcome of collective EU discussions appeared more restricted, while Brexit also seemed to shape the response of other EU states to the developing situation in Baltia. Although member states were undoubtedly reluctant to see another country go down this route, they were also resolute in demonstrating a unity of approach and limited flexibility in the face of the new populist government’s attempt to divide them.




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Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part One

Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part One Other resource sysadmin 29 October 2018

As part of a roundtable series, Chatham House and China University of Political Science and Law (CUPL) jointly organized this four-day meeting at Chatham House for international lawyers to discuss a wide range of issues related to public international law and the rights of individuals.

The Representative of China at the 19th Session of the Human Rights Council, Palais des Nations, Geneva. 27 February 2012. Photo: UN Photo Geneva/Violaine Martin.

The specific objectives were to:

  • create a platform for Chinese international law academics working on international human rights law issues to present their thinking and exchange ideas with counterparts from outside China;
  • build stronger understanding within the wider international law community of intellectual debates taking place in China about the international human rights system and China’s role within it;
  • support networking between Chinese and non-Chinese academics working on international human rights and related areas of international law.

The roundtable forms part of a wider Chatham House project exploring China’s impact on the international human rights system and was inspired by early discussions with a burgeoning community of Chinese academics thinking, writing (mainly in Chinese) and teaching about international human rights law.

For China University of Political Science and Law, one of the largest and most prestigious law schools in China and perhaps the only university in the world with an entire faculty of international law, the initiative is part of a drive to forge partnerships beyond China in the international law field.

The roundtable had a total of 22 participants, 10 Chinese (from universities and other academic institutions in Beijing and Shanghai) and 12 non-Chinese (from Australia, Germany, the Netherlands, Switzerland, the United Kingdom and the United States).

All discussions were held in English under the Chatham House Rule.




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Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part Two

Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part Two Other resource sysadmin 30 October 2018

As part of a roundtable series, Chatham House and China University of Political Science and Law (CUPL) held a two-day roundtable meeting in Beijing on public international law and the rights of individuals.

The Representative of China at the 19th Session of the Human Rights Council, Palais des Nations, Geneva. 27 February 2012. Photo: UN Photo Geneva/Violaine Martin.

The specific objectives were to:

  • create a platform for Chinese international law academics working on international human rights law issues to present their thinking and exchange ideas with counterparts from outside China;
  • build stronger understanding within the wider international law community of intellectual debates taking place in China about the international human rights system and China’s role within it;
  • support networking between Chinese and non-Chinese academics working on international human rights and related areas of international law.

The roundtable forms part of a wider Chatham House project exploring China’s impact on the international human rights system and was inspired by early discussions with a burgeoning community of Chinese academics thinking, writing (mainly in Chinese) and teaching about international human rights law.

For CUPL, one of the largest and most prestigious law schools in China and perhaps the only university in the world with an entire faculty of international law, the initiative is part of a drive to forge partnerships beyond China in the international law field.

The meeting in Beijing was hosted by CUPL and involved 20 participants, 10 Chinese (from universities and other academic institutions in Beijing) and 10 non-Chinese (from Australia, the Netherlands, South Africa, Switzerland, the United Kingdom and the United States).

To ensure continuity while also expanding the experts network being built, the second meeting included a mix of participants from the first meeting and some new participants.

All discussions were held in English under the Chatham House Rule.




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Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part Three

Exploring Public International Law and the Rights of Individuals with Chinese Scholars - Part Three Other resource sysadmin 30 October 2018

As part of a roundtable series, Chatham House, China University of Political Science and Law (CUPL) and the Graduate Institute Geneva held a two-day roundtable meeting in Geneva on public international law and the rights of individuals.

The Representative of China at the 19th Session of the Human Rights Council, Palais des Nations, Geneva. 27 February 2012. Photo: UN Photo Geneva/Violaine Martin.

The specific objectives were to:

  • create a platform for Chinese international law academics working on international human rights law issues to present their thinking and exchange ideas with counterparts from outside China;
  • build stronger understanding within the wider international law community of intellectual debates taking place in China about the international human rights system and China’s role within it;
  • support networking between Chinese and non-Chinese academics working on international human rights and related areas of international law.

The roundtable forms part of a wider Chatham House project exploring China’s impact on the international human rights system and was inspired by early discussions with a burgeoning community of Chinese academics thinking, writing (mainly in Chinese) and teaching about international human rights law.

For CUPL, one of the largest and most prestigious law schools in China and perhaps the only university in the world with an entire faculty of international law, the initiative is part of a drive to forge partnerships beyond China in the international law field.

The meeting in Geneva was co-hosted by the Graduate Institute Geneva and involved 19 participants, 9 Chinese (from six research institutions in Beijing and Shanghai) and 11 non-Chinese (from eight research institutions in Australia, Germany, the Netherlands, Switzerland, the United Kingdom and the United States).

To ensure continuity while also expanding the expert network being built, the third meeting included a mix of participants from the first two meetings and some new participants

All discussions were held in English under the Chatham House Rule.




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Online Disinformation and Political Discourse: Applying a Human Rights Framework

Online Disinformation and Political Discourse: Applying a Human Rights Framework Research paper sysadmin 5 November 2019

Although some digital platforms now have an impact on more people’s lives than does any one state authority, the international community has been slow to hold to account these platforms’ activities by reference to human rights law.

A man votes in Manhattan, New York City, during the US elections on 8 November 2016. Photo: Getty Images.

This paper examines how human rights frameworks should guide digital technology.

Summary

  • Online political campaigning techniques are distorting our democratic political processes. These techniques include the creation of disinformation and divisive content; exploiting digital platforms’ algorithms, and using bots, cyborgs and fake accounts to distribute this content; maximizing influence through harnessing emotional responses such as anger and disgust; and micro-targeting on the basis of collated personal data and sophisticated psychological profiling techniques. Some state authorities distort political debate by restricting, filtering, shutting down or censoring online networks.
  • Such techniques have outpaced regulatory initiatives and, save in egregious cases such as shutdown of networks, there is no international consensus on how they should be tackled. Digital platforms, driven by their commercial impetus to encourage users to spend as long as possible on them and to attract advertisers, may provide an environment conducive to manipulative techniques.
  • International human rights law, with its careful calibrations designed to protect individuals from abuse of power by authority, provides a normative framework that should underpin responses to online disinformation and distortion of political debate. Contrary to popular view, it does not entail that there should be no control of the online environment; rather, controls should balance the interests at stake appropriately.
  • The rights to freedom of thought and opinion are critical to delimiting the appropriate boundary between legitimate influence and illegitimate manipulation. When digital platforms exploit decision-making biases in prioritizing bad news and divisive, emotion-arousing information, they may be breaching these rights. States and digital platforms should consider structural changes to digital platforms to ensure that methods of online political discourse respect personal agency and prevent the use of sophisticated manipulative techniques.
  • The right to privacy includes a right to choose not to divulge your personal information, and a right to opt out of trading in and profiling on the basis of your personal data. Current practices in collecting, trading and using extensive personal data to ‘micro-target’ voters without their knowledge are not consistent with this right. Significant changes are needed.
  • Data protection laws should be implemented robustly, and should not legitimate extensive harvesting of personal data on the basis of either notional ‘consent’ or the data handler’s commercial interests. The right to privacy should be embedded in technological design (such as by allowing the user to access all information held on them at the click of a button); and political parties should be transparent in their collection and use of personal data, and in their targeting of messages. Arguably, the value of personal data should be shared with the individuals from whom it derives.
  • The rules on the boundaries of permissible content online should be set by states, and should be consistent with the right to freedom of expression. Digital platforms have had to rapidly develop policies on retention or removal of content, but those policies do not necessarily reflect the right to freedom of expression, and platforms are currently not well placed to take account of the public interest. Platforms should be far more transparent in their content regulation policies and decision-making, and should develop frameworks enabling efficient, fair, consistent internal complaints and content monitoring processes. Expertise on international human rights law should be integral to their systems.
  • The right to participate in public affairs and to vote includes the right to engage in public debate. States and digital platforms should ensure an environment in which all can participate in debate online and are not discouraged from standing for election, from participating or from voting by online threats or abuse.




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Optimized incorporation of an unnatural fluorescent amino acid affords measurement of conformational dynamics governing high-fidelity DNA replication [DNA and Chromosomes]

DNA polymerase from bacteriophage T7 undergoes large, substrate-induced conformational changes that are thought to account for high replication fidelity, but prior studies were adversely affected by mutations required to construct a Cys-lite variant needed for site-specific fluorescence labeling. Here we have optimized the direct incorporation of a fluorescent un-natural amino acid, (7-hydroxy-4-coumarin-yl)-ethylglycine, using orthogonal amber suppression machinery in Escherichia coli. MS methods verify that the unnatural amino acid is only incorporated at one position with minimal background. We show that the single fluorophore provides a signal to detect nucleotide-induced conformational changes through equilibrium and stopped-flow kinetic measurements of correct nucleotide binding and incorporation. Pre-steady-state chemical quench methods show that the kinetics and fidelity of DNA replication catalyzed by the labeled enzyme are largely unaffected by the unnatural amino acid. These advances enable rigorous analysis to establish the kinetic and mechanistic basis for high-fidelity DNA replication.




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Polymerase {gamma} efficiently replicates through many natural template barriers but stalls at the HSP1 quadruplex [Enzymology]

Faithful replication of the mitochondrial genome is carried out by a set of key nuclear-encoded proteins. DNA polymerase γ is a core component of the mtDNA replisome and the only replicative DNA polymerase localized to mitochondria. The asynchronous mechanism of mtDNA replication predicts that the replication machinery encounters dsDNA and unique physical barriers such as structured genes, G-quadruplexes, and other obstacles. In vitro experiments here provide evidence that the polymerase γ heterotrimer is well-adapted to efficiently synthesize DNA, despite the presence of many naturally occurring roadblocks. However, we identified a specific G-quadruplex–forming sequence at the heavy-strand promoter (HSP1) that has the potential to cause significant stalling of mtDNA replication. Furthermore, this structured region of DNA corresponds to the break site for a large (3,895 bp) deletion observed in mitochondrial disease patients. The presence of this deletion in humans correlates with UV exposure, and we have found that efficiency of polymerase γ DNA synthesis is reduced after this quadruplex is exposed to UV in vitro.




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New 4-year deal 'felt right' for Nola

Aaron Nola established himself as one of the best pitchers in baseball in 2018. The Phillies ensured on Wednesday that he will be the ace in their rotation for possibly the next five seasons.




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Leaner Herrera more mature after tough 2018

Odubel Herrera smiled and patted his stomach. The paunch that he carried into Spring Training 2018 is no longer there. Herrera has reported to camp leaner and, as he said Friday morning at Spectrum Field, motivated to bounce back from the worst season of his four-year career.




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MacPhail: Phils are 'uniquely poised right now'

Phillies president Andy MacPhail opened a 28-minute press conference on Friday afternoon at Spectrum Field with facts and figures about investments the organization made the past few seasons as the team wallowed at the bottom of the National League. Then MacPhail talked a lot about Bryce Harper and Manny Machado as well as manager Gabe Kapler.




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Where are Trout, Ohtani on Top 100 Right Now?

The 2019 MLB season feels so close now. Spring Training has begun. Players are taking the field. So it's time to rank the best of the best.




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HIV: Breakthrough study raises hopes of effective prevention if drug’s cost can be lowered




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Whooping cough: Health officials urge pregnant women to get vaccinated as another infant dies




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Whooping cough: Why have vaccination rates plummeted in pregnant women?




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Whooping cough: Fivefold rise in US cases spells return to pre-pandemic levels




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Low molecular weight heparin does not prevent VTE after knee arthroscopy, studies show




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Higher Education in South Africa: Demands for Inclusion and the Challenges of Reform

Higher Education in South Africa: Demands for Inclusion and the Challenges of Reform 17 October 2018 — 5:00PM TO 6:00PM Anonymous (not verified) 18 September 2018 Chatham House, London

South Africa’s higher education system has come to represent public controversy and intense contestation around the social justice debates that affect the whole of society. The #RhodesMustFall campaign at the University of Cape Town encapsulated national students’ concerns about institutional racism and the slow pace of transformation at all of the country’s universities. The #FeesMustFall movement that emanated from the University of Witwatersrand garnered national support for providing access for poor black students to affordable and high quality education.
South Africa’s universities and government are faced with the challenge of ensuring that all of the country’s citizens have equitable and inclusive access to higher education in a way that protects the institutions as safe spaces for debate, maintains international competitiveness and represents an efficient use of limited available resources.
At this meeting, Professor Adam Habib will reflect on the successes and failures of social protests in South Africa and the challenges they pose for advancing social justice.




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Long term aircraft noise is linked to incidence of high blood pressure




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Helen Salisbury: Weight loss treatment—available in theory but not in practice




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Can diplomacy advance human rights?

Can diplomacy advance human rights? 25 April 2023 — 4:00PM TO 5:00PM Anonymous (not verified) 7 March 2023 Chatham House and Online

How is diplomacy contributing to advancing human rights through the multilateral system?

The international human rights system has come under significant pressure in recent years. Russia’s invasion of Ukraine and the US-China rivalry have created difficult political pressures, while major global challenges including climate change and global inequality demand answers. Effective diplomacy on human rights has become increasingly difficult, with incentives stacked against bold action.

The relationship between diplomacy and human rights is an uneasy one. Diplomacy is an art of negotiation, persuasion and compromise. Human rights are tightly defined and universal. The relationship between the two may seem paradoxical, but in the context of an unstable world order, it has never been more important.

In the 75th anniversary year of the Universal Declaration of Human Rights, this discussion will explore the critical role of diplomacy in advancing human rights in the future.

  • What are the critical human rights challenges today? What is the role of diplomacy in addressing them?

  • What is the impact of intensifying competition between the US and China on the human rights system?

  • Is there an opening for more leadership emerging from the Global South?

  • What is the future of the human rights system in the context of this polarized world?

As with all member events, questions from the audience drive the conversation.




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Former chair of BMA GP Committee wins right to tribunal for unfair dismissal

An employment judge has cleared the way for Farah Jameel, a former chair of the BMA’s General Practitioners Committee for England (GPCE), to go ahead with claims of discrimination and unfair dismissal against the association over her removal from the post during maternity leave.Jameel, who was elected the first female chair in November 2021, was put on temporary suspension in 2022 after complaints by BMA staff. The BMA told her in August 2023 that her contract was being terminated.The contract described her as a contractor providing consultancy services rather than an employee. But in a preliminary ruling the employment judge Natasha Joffe has held that Jameel was in reality an office holder and an employee, opening the way for her claims to proceed to a full hearing by an employment tribunal.The GPCE passed a vote of no confidence in Jameel in July 2023, as a means of electing a new...




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Undercurrents: Europe's far-right educational institutions

Undercurrents: Europe's far-right educational institutions Audio bhorton.drupal 8 October 2021

In Hungary, France and Spain, new political movements from the far-right are attempting to reshape their education systems.

Under the supportive eye of Prime Minister Viktor Orbán, the recently established National University of Public Service seeks to embed nationalist illiberal values in a new generation of Hungarian students. Meanwhile in France and Spain, far-right public figure Marion Maréchal has turned away from the electoral politics of the Front Nationale to set up a new conservative research institute, ISSEP.

Both of these developments represent a challenge to the liberal values which underpin the existing international order. To find out more, Ben spoke with Professor Dorit Geva and Dr Felipe Santos, whose recent article in International Affairs considers the implications of this illiberal educational turn. 




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Why Europe must end limbo for Afghans seeking asylum

Why Europe must end limbo for Afghans seeking asylum Expert comment Anonymous (not verified) 14 October 2021

With a focus on evacuations from Afghanistan, the situation in Europe is often forgotten as thousands of asylum seekers continue to wait for their cases to be settled.

Following the Taliban’s takeover of Afghanistan, European leaders shared messages to welcome those evacuated, but the reality of European responses to displacement in Afghanistan paints a more contentious picture. 

As of July 2021, 33,325 cases of Afghan asylum applicants were pending in Germany, in France 18,410 people were waiting on a decision, while in Greece the numbers were 13,660. 

Arguably, such numbers are manageable given European states’ size and their functioning asylum systems but, while 56 per cent of Afghans in Europe receive protection status, a large proportion is still in limbo in differing European countries’ asylum systems. 

Europe hosts fewer than ten per cent of the three million UN-registered displaced Afghans globally, as neighbouring countries carry the burden of Afghanistan’s forced displacement: Iran hosts almost one million Afghan refugees and Pakistan 1.5 million, and these numbers double when adding undocumented or Afghan passport holders.
 
But despite these manageable numbers, national authorities in Europe often leave people waiting for months or even years to receive an asylum decision. Deportations to Afghanistan were halted only after the Taliban’s takeover of Kabul and even then there was resistance to this from certain European countries, while Austria suggested setting up ‘deportation centres’ in countries neighbouring Afghanistan. 

Europe remains a fortress

The European Commission’s Draft Action Plan responding to the events in Afghanistan confirmed the willingness of the European Union (EU) to continue returns to non-European ‘third countries’. So Europe remains a fortress, despite pledging support for ‘the safe and orderly departure of foreign nationals and Afghans who wish to leave the country’. 

The wall by Greece at its border with Turkey and Poland’s treatment of Afghan asylum seekers trapped at its border with Belarus illustrate this hardline stance. The president of the European Council Charles Michel and EU Home Affairs Chief Ylva Johansson both confirm the priority is to secure European borders. 

This is further backed up by the European Council’s latest set of Conclusions on Afghanistan which focuses on security and ‘preventing illegal migration’ while avoiding reference to any domestic asylum efforts or the establishment of protection pathways for Afghans. 

Afghans in Europe need answers from European policymakers and, by strengthening domestic asylum responses alongside international humanitarian commitments, Europe’s actions would increasingly match its words. 

This disconnect is not new. At the national level, reports of illegal pushbacks on European land and sea borders alarmingly intensified in 2020 as authorities intercepted and sent migrants back to neighbouring countries without assessing asylum claims. 

At the EU level, development aid to countries such as Afghanistan has long been conditional on their governments’ adherence to the bloc’s migration objectives of preventing asylum seekers from reaching European borders and facilitating the repatriation of those refused asylum in Europe. 

But this latest displacement crisis from Afghanistan exposes clear inconsistencies in European approaches to asylum and humanitarianism. Migration remains a divisive issue in European politics, but European governments must act promptly to support Afghans already residing in their territories alongside establishing robust international commitments.

Time for concrete action

European countries should firstly improve the treatment of those Afghans currently in limbo within their respective asylum systems by expediting pending Afghan asylum applications and family reunification cases, re-examining rejected asylum applications, and facilitating integration.

Secondly, national authorities should not return asylum seekers to Afghanistan or any third countries deemed ‘safe’. For Europe to coordinate evacuations from Afghanistan while simultaneously deporting asylum seekers undermines the international refugee regime and threaten Europe’s global credibility. 




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Putin’s Eurasian dream may soon become a nightmare

Putin’s Eurasian dream may soon become a nightmare Expert comment NCapeling 3 May 2022

The Ukraine invasion has detrimental consequences for the Russia-led Eurasian Economic Union, a project which has been stumbling since its inception.

The Eurasian Economic Union (EAEU) – consisting of Russia with Armenia, Belarus, Kazakhstan, and Kyrgyzstan – represents the culmination of Russia’s pursuit of regional integration with its post-Soviet neighbours.

Officially, the Union has an ambitious economic goal – the creation of a market based on common rules for its five member states and their 180 million citizens – and Russia likes to portray the EAEU as an Eurasian replica of the European Union (EU).

But although a common market was placed at the heart of the EAEU as a way to appeal to member states, it is of marginal importance for the Russian economy. For Moscow, the EAEU is primarily a geopolitical tool to help re-assert its regional and global role.

In a world of evermore powerful trading blocs, Moscow wants to use the EAEU to establish its own economic power base in the new polycentric world order. But Russia’s limited interest in the technocratic intricacies needed for the economic union to live up to its lofty proclamations exposes the real geopolitical ambitions.

The Kremlin has no qualms about disregarding the common rules when they clash with Russia’s own foreign policy, and it soon became evident the EAEU was a means to an end rather than an equitable institution within which Russia would accept constraints on its unilateral behaviour.

A crisis in the making

Although the EAEU has enabled some internal trade liberalization as well as the movement of people and labour to the benefit of its members reliant on labour migrant remittances, it has failed to tackle institutional barriers or promote growth and development policies.

Russia’s limited interest in the technocratic intricacies needed for the economic union to live up to its lofty proclamations exposes the real geopolitical ambitions

It has been hampered by weak common institutions and a lack of institutional capacity of its member states, while Russia’s dubious commitment is also problematic. The EAEU lacks the institutional features of a genuine common market and any attempts to address these shortcomings have been essentially empty promises.

EAEU membership does benefit the political elites of its member states, because its hub-and-spoke model relies on bilateral high-level political deals between Russia and each member state individually. And by using the enticement of security guarantees and both political and financial support, Moscow has succeeded in attracting new members to join.

But a member’s political survival – or defence against political and economic reform – is dependent on military, economic, financial, and political support from Russia. This has been evidenced by the Armenian-Azerbaijan conflict, and by Russia’s backing of the Lukashenka regime in Belarus and the Tokayev government in Kazakhstan.

The design of the EAEU ties it to Russia’s own fate, and so the impact of harsh sanctions imposed on Russia for invading Ukraine are in stark evidence across its member states. Both Kazakhstan and Kyrgyzstan are reeling from the adverse effects on their domestic currencies and remittances, and the trade bans of key commodities.

And although the ban Russia imposed on grain export to EAEU members has softened, it shows the extent to which Russia was prepared to disregard the rules and sacrifice the EAEU to rescue its own economy. Members are incurring direct economic losses from Putin’s war against Ukraine and the fluctuation of the rouble has created a major impediment to trade with Russia.

Russia seems to increasingly view the Union as a convenient tool to bypass sanctions, with massive implications for its partner countries. And the supposed advantages of EAEU membership – enhanced trade, growth, and modernization – have simply not materialized.

Due to the rapid economic decline of Russia – a fall of 10-15 per cent is anticipated for 2022 – the EAEU is even less likely to deliver the promised economic benefits, while also putting members at risk of secondary sanctions.

The Ukraine invasion has also reignited domestic sensitivities and regional tensions. In Kazakhstan, Tokayev has failed to endorse Russia’s justification for the invasion and refuses to recognize the ‘independence’ of the separatist LNR and DNR.

Russia’s invasion of Ukraine clearly reduces the benefits of Eurasian integration even further than before and imposes higher cost on the partner countries than were envisaged when they joined

Meanwhile Azerbaijan has pursued territorial gains in Nagorno-Karabakh while Russia is distracted by its invasion of Ukraine, and has requested the withdrawal of Russian peacekeeping from the disputed territory.

Russia is keen for partner countries to help mitigate the economic impact of sanctions by providing alternative transit routes for imports to Russia. But the EAEU faces challenges even at its most basic level because the sharing of custom duties among member states was denominated in dollars, which Russia now wants to move away from.

No easy escape

Russia’s invasion of Ukraine clearly reduces the benefits of Eurasian integration even further than before and imposes higher cost on the partner countries than were envisaged when they joined. They have been dragged into a geopolitical calamity over which they have no control – the inability of EAEU institutions to mediate or constrain Russia’s behaviour is stark.




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Improving 18F-FDG PET Quantification Through a Spatial Normalization Method

Quantification of 18F-FDG PET images is useful for accurate diagnosis and evaluation of various brain diseases, including brain tumors, epilepsy, dementia, and Parkinson disease. However, accurate quantification of 18F-FDG PET images requires matched 3-dimensional T1 MRI scans of the same individuals to provide detailed information on brain anatomy. In this paper, we propose a transfer learning approach to adapt a pretrained deep neural network model from amyloid PET to spatially normalize 18F-FDG PET images without the need for 3-dimensional MRI. Methods: The proposed method is based on a deep learning model for automatic spatial normalization of 18F-FDG brain PET images, which was developed by fine-tuning a pretrained model for amyloid PET using only 103 18F-FDG PET and MR images. After training, the algorithm was tested on 65 internal and 78 external test sets. All T1 MR images with a 1-mm isotropic voxel size were processed with FreeSurfer software to provide cortical segmentation maps used to extract a ground-truth regional SUV ratio using cerebellar gray matter as a reference region. These values were compared with those from spatial normalization-based quantification methods using the proposed method and statistical parametric mapping software. Results: The proposed method showed superior spatial normalization compared with statistical parametric mapping, as evidenced by increased normalized mutual information and better size and shape matching in PET images. Quantitative evaluation revealed a consistently higher SUV ratio correlation and intraclass correlation coefficients for the proposed method across various brain regions in both internal and external datasets. The remarkably good correlation and intraclass correlation coefficient values of the proposed method for the external dataset are noteworthy, considering the dataset’s different ethnic distribution and the use of different PET scanners and image reconstruction algorithms. Conclusion: This study successfully applied transfer learning to a deep neural network for 18F-FDG PET spatial normalization, demonstrating its resource efficiency and improved performance. This highlights the efficacy of transfer learning, which requires a smaller number of datasets than does the original network training, thus increasing the potential for broader use of deep learning–based brain PET spatial normalization techniques for various clinical and research radiotracers.




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Design, Synthesis, and Preclinical Evaluation of a High-Affinity 18F-Labeled Radioligand for Myocardial Growth Hormone Secretagogue Receptor Before and After Myocardial Infarction

The peptide hormone ghrelin is produced in cardiomyocytes and acts through the myocardial growth hormone secretagogue receptor (GHSR) to promote cardiomyocyte survival. Administration of ghrelin may have therapeutic effects on post–myocardial infarction (MI) outcomes. Therefore, there is a need to develop molecular imaging probes that can track the dynamics of GHSR in health and disease to better predict the effectiveness of ghrelin-based therapeutics. We designed a high-affinity GHSR ligand labeled with 18F for imaging by PET and characterized its in vivo properties in a canine model of MI. Methods: We rationally designed and radiolabeled with 18F a quinazolinone derivative ([18F]LCE470) with subnanomolar binding affinity to GHSR. We determined the sensitivity and in vivo and ex vivo specificity of [18F]LCE470 in a canine model of surgically induced MI using PET/MRI, which allowed for anatomic localization of tracer uptake and simultaneous determination of global cardiac function. Uptake of [18F]LCE470 was determined by time–activity curve and SUV analysis in 3 regions of the left ventricle—area of infarct, territory served by the left circumflex coronary artery, and remote myocardium—over a period of 1.5 y. Changes in cardiac perfusion were tracked by [13N]NH3 PET. Results: The receptor binding affinity of LCE470 was measured at 0.33 nM, the highest known receptor binding affinity for a radiolabeled GHSR ligand. In vivo blocking studies in healthy hounds and ex vivo blocking studies in myocardial tissue showed the specificity of [18F]LCE470, and sensitivity was demonstrated by a positive correlation between tracer uptake and GHSR abundance. Post-MI changes in [18F]LCE470 uptake occurred independently of perfusion tracer distributions and changes in global cardiac function. We found that the regional distribution of [18F]LCE470 within the left ventricle diverged significantly within 1 d after MI and remained that way throughout the 1.5-y duration of the study. Conclusion: [18F]LCE470 is a high-affinity PET tracer that can detect changes in the regional distribution of myocardial GHSR after MI. In vivo PET molecular imaging of the global dynamics of GHSR may lead to improved GHSR-based therapeutics in the treatment of post-MI remodeling.




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The Emission of Internal Conversion Electrons Rather Than Auger Electrons Increased the Nucleus-Absorbed Dose for 161Tb Compared with 177Lu with a Higher Dose Response for [161Tb]Tb-DOTA-LM3 Than for [161Tb]Tb-DOTATATE

Preclinical data have shown that 161Tb-labeled peptides targeting the somatostatin receptor are therapeutically more effective for peptide receptor radionuclide therapy than are their 177Lu-labeled counterparts. To further substantiate this enhanced therapeutic effect, we performed cellular dosimetry to quantify the absorbed dose to the cell nucleus and compared dose–response curves to evaluate differences in relative biological effectiveness in vitro. Methods: CA20948 cell survival was assessed after treatment with [161Tb]Tb- and [177Lu]Lu-DOTATATE (agonist) and with [161Tb]Tb- and [177Lu]Lu-DOTA-LM3 (antagonist) via a clonogenic assay. Cell binding, internalization, and dissociation assays were performed up to 7 d to acquire time-integrated activity coefficients. Separate S values for each type of particle emission (Auger/internal conversion [IC] electrons and β particles) were computed via Monte Carlo simulations, while considering spheric cells. Once the absorbed dose to the cell nucleus was calculated, survival curves were fitted to the appropriate linear or linear-quadratic model and corresponding relative biological effectiveness was evaluated. Results: Although the radiopeptide uptake was independent of the radionuclide, [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 delivered a 3.6 and 3.8 times higher dose to the nucleus, respectively, than their 177Lu-labeled counterparts on saturated receptor binding. This increased nucleus-absorbed dose was mainly due to the additional emission of IC and not Auger electrons by 161Tb. When activity concentrations were considered, both [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 showed a lower survival fraction than did labeling with 177Lu. When the absorbed dose to the nucleus was considered, no significant difference could be observed between the dose–response curves for [161Tb]Tb- and [177Lu]Lu-DOTATATE. [161Tb]Tb-DOTA-LM3 showed a linear-quadratic dose response, whereas [161Tb]Tb-DOTATATE showed only a linear dose response within the observed dose range, suggesting additional cell membrane damage by Auger electrons. Conclusion: The IC, rather than Auger, electrons emitted by 161Tb resulted in a higher absorbed dose to the cell nucleus and lower clonogenic survival for [161Tb]Tb-DOTATATE and [161Tb]Tb-DOTA-LM3 than for the 177Lu-labeled analogs. In contrast, [161Tb]Tb-DOTATATE showed no higher dose response than [177Lu]Lu-DOTATATE, whereas for [161Tb]Tb-DOTA-LM3 an additional quadratic response was observed. Because of this quadratic response, potentially caused by cell membrane damage, [161Tb]Tb-DOTA-LM3 is a more effective radiopeptide than [161Tb]Tb-DOTATATE for labeling with 161Tb.




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Navigating the Future of Prostate Cancer Care: AI-Driven Imaging and Theranostics Through the Lens of RELAINCE




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Is ChatGPT a Reliable Ghostwriter?




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Qantas flight lands safely at Sydney after suffering engine failure during takeoff

A Qantas airlines flight made an emergency landing at Sydney Airport on Friday afternoon after suffering engine failure shortly after takeoff, the company said.




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Xsight Labs Launches E1 SoC Built on TSMC’s 5nm Tech for AI Workloads

Oct. 16, 2024 — Xsight Labs, a leading fabless semiconductor company providing end-to-end connectivity solutions for next-generation hyperscale, edge, and AI data center networks, has announced the tape-out of the […]

The post Xsight Labs Launches E1 SoC Built on TSMC’s 5nm Tech for AI Workloads appeared first on HPCwire.




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Microchip Expands 64-Bit Portfolio with High-Performance PIC64HX Microprocessors for Edge Computing

CHANDLER, Ariz., Oct. 23, 2024 — The global edge computing market is expected to grow by more than 30 percent in the next five years, serving mission-critical applications in the […]

The post Microchip Expands 64-Bit Portfolio with High-Performance PIC64HX Microprocessors for Edge Computing appeared first on HPCwire.





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Ukraine blasts Russia with massive overnight drone strike

Ukraine launched a massive drone attack on Moscow overnight, the largest on the Russian capital since the Russian invasion more than two years ago, forcing three airports to divert traffic and causing casualties.




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Spirit Airlines flight hit by bullets while flying over gang-war region of Haiti

A flight of Florida-based Spirit Airlines was hit by gunfire while attempting to land in Haiti with a crew member that sustained "minor injuries."




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D-Wave Expands Board with Industry Veterans John DiLullo and Rohit Ghai

PALO ALTO, Calif., Oct. 30, 2024 — D-Wave Quantum Inc. today announced the appointments of veteran technology industry leaders, John DiLullo and Rohit Ghai, to its board of directors. The new […]

The post D-Wave Expands Board with Industry Veterans John DiLullo and Rohit Ghai appeared first on HPCwire.