Invitation Only Research Event

Event participants

Christopher Davis, Professorial Fellow, Institute of Population Ageing, University of Oxford
Samuel Greene, Director, King's Russia Institute; Reader of Russian Politics, King’s College London
Nikolai Petrov, Senior Research Fellow, Russia and Eurasia Programme, Chatham House
Natalia Zubarevich, Director, Regional Programme, Independent Institute for Social Policy

Promise, Yellow and gold and, Crimson; Never make a promise. You cannot keep them. Never say I’ll keep a secret, you Cannot. You’re human. Have loving thoughts for yourself, And for others, Practice loving deeds for yourself, And for others, Lilac spider, Purple sunrise, Effervescent stone, Love wherever, Whomever, You can. -♦Photo – John Foot-♦ […]

Human but not mouse islets transplanted into immunodeficient NSG mice effectively accumulate lipid droplets (LDs). Because chronic lipid exposure is associated with islet β-cell dysfunction, we investigated LD accumulation in the intact human and mouse pancreas over a range of ages and states of diabetes. Very few LDs were found in normal human juvenile pancreatic acinar and islet cells, with numbers subsequently increasing throughout adulthood. While accumulation appeared evenly distributed in postjuvenile acinar and islet cells in donors without diabetes, LDs were enriched in islet α- and β-cells from donors with type 2 diabetes (T2D). LDs were also found in the islet β-like cells produced from human embryonic cell–derived β-cell clusters. In contrast, LD accumulation was nearly undetectable in the adult rodent pancreas, even in hyperglycemic and hyperlipidemic models or 1.5-year-old mice. Taken together, there appear to be significant differences in pancreas islet cell lipid handling between species, and the human juvenile and adult cell populations. Moreover, our results suggest that LD enrichment could be impactful to T2D islet cell function.

The host environment is a crucial factor for considering the transplant of stem cell–derived immature pancreatic cells in patients with type 1 diabetes. Here, we investigated the effect of insulin (INS)-deficient diabetes on the fate of immature pancreatic endocrine cell grafts and the underlying mechanisms. Human induced pluripotent stem cell–derived pancreatic endocrine progenitor cells (EPCs), which contained a high proportion of chromogranin A⁺ NK6 homeobox 1⁺ cells and very few INS⁺ cells, were used. When the EPCs were implanted under the kidney capsule in immunodeficient mice, INS-deficient diabetes accelerated increase in plasma human C-peptide, a marker of graft-derived INS secretion. The acceleration was suppressed by INS infusion but not affected by partial attenuation of hyperglycemia by dapagliflozin, an INS-independent glucose-lowering agent. Immunohistochemical analyses indicated that the grafts from diabetic mice contained more endocrine cells including proliferative INS-producing cells compared with that from nondiabetic mice, despite no difference in whole graft mass between the two groups. These data suggest that INS-deficient diabetes upregulates the INS-secreting capacity of EPC grafts by increasing the number of endocrine cells including INS-producing cells without changing the graft mass. These findings provide useful insights into postoperative diabetic care for cell therapy using stem cell–derived pancreatic cells.

PTSD may develop after exposure to exceptionally threatening or horrifying events. About 3% of the adult population has PTSD at any one time, and more than 50% in survivors of rape. In this podcast Jonathan Bisson, professor of psychiatry at the School of Medicine in Cardiff joins us to talk about the evidence for diagnosis and treatment, and...

"I say to all Australian doctors - young, old, the political and the apolitical - that on this depends not just our ethical credibility as a profession, but our shared humanity. " Following the leaked emails published in The Guardian newspaper, alleging abuse of asylum seekers detained by the Australian government on the Pacific island of Nauru,...

At evidence live this year, one of the sessions was about the work of Evidence Aid - and their attempt to bring high quality evidence to the frontline of a humanitarian crisis. In that situation, it’s very difficult to know what will work - a conflict, or even immediately post-conflict situation is characterised by chaos - and merely doing...

DE Kelley
May 1, 2000; 49:677-683
Articles

Masayuki Saito
Jul 1, 2009; 58:1526-1531
Metabolism

G Perseghin
Aug 1, 1999; 48:1600-1606
Articles

Samar I. Itani
Jul 1, 2002; 51:2005-2011
Rapid Publications

David E. Cummings
Aug 1, 2001; 50:1714-1719
Rapid Publications

Steven E Kahn
Nov 1, 1993; 42:1663-1672
Original Article

David E. Kelley
Oct 1, 2002; 51:2944-2950
Metabolism and Signal Transduction

Alexandra E. Butler
Jan 1, 2003; 52:102-110
Islet Studies

Gerald M Reaven
Dec 1, 1988; 37:1595-1607
Banting Lecture 1988

Long-term hyperglycemia in patients with diabetes leads to human serum albumin (HSA) glycation, which may impair HSA function as a transport protein and affect the therapeutic efficacy of anticoagulants in patients with diabetes. In this study, a novel mass spectrometry approach was developed to reveal the differences in the profiles of HSA glycation sites between patients with diabetes and healthy subjects. K199 was the glycation site most significantly changed in patients with diabetes, contributing to different interactions of glycated HSA and normal HSA with two types of anticoagulant drugs, heparin and warfarin. An in vitro experiment showed that the binding affinity to warfarin became stronger when HSA was glycated, while HSA binding to heparin was not significantly influenced by glycation. A pharmacokinetic study showed a decreased level of free warfarin in the plasma of diabetic rats. A preliminary retrospective clinical study also revealed that there was a statistically significant difference in the anticoagulant efficacy between patients with diabetes and patients without diabetes who had been treated with warfarin. Our work suggests that larger studies are needed to provide additional specific guidance for patients with diabetes when they are administered anticoagulant drugs or drugs for treating other chronic diseases.

We continue the positive reinforcement of humane spirit and action when humanity, as a collective, is grappling with an unprecedented calamity. “We shall overcome” is the mantra, and going by the ­indomitable strength we possess, we ­definitely...

We continue our journey highlighting the journey of Peace Corps volunteers (PCV). In this third and final instalment, the underlying and broad message is that volunteerism is a combination of one’s personal choices, external influences, and a keen...

2 July 2014 , Volume 90, Number 4

Intravenous access is difficult in some patients referred for ¹⁸F-FDG PET imaging. Extravasation at the injection site and accumulation in central catheters can lead to limited tumor ¹⁸F-FDG uptake, erroneous quantitation, and significant image artifacts. In this study, we compared the human biodistribution and dosimetry for ¹⁸F-FDG after oral and intravenous administrations sequentially in the same subjects to ascertain the dosimetry and potential suitability of orally administered ¹⁸F-FDG as an alternative to intravenous administration. We also compared our detailed intravenous ¹⁸F-FDG dosimetry with older dosimetry data. Methods: Nine healthy volunteers (6 male and 3 female; aged 19–32 y) underwent PET/CT imaging after oral and intravenous administration of ¹⁸F-FDG. Identical preparation and imaging protocols (except administration route) were used for oral and intravenous studies. During each imaging session, 9 whole-body PET scans were obtained at 5, 10, 20, 30, 40, 50, 60, 120, and 240 min after ¹⁸F-FDG administration (370 ± 16 MBq). Source organ contours drawn using CT were overlaid onto registered PET images to extract time–activity curves. Time-integrated activity coefficients derived from time–activity curves were given as input to OLINDA/EXM for dose calculations. Results: Blood uptake after orally administered ¹⁸F-FDG peaked at 45–50 min after ingestion. The oral-to-intravenous ratios of ¹⁸F-FDG uptake for major organs at 45 min were 1.07 ± 0.24 for blood, 0.94 ± 0.39 for heart wall, 0.47 ± 0.12 for brain, 1.25 ± 0.18 for liver, and 0.84 ± 0.24 for kidneys. The highest organ-absorbed doses (μGy/MBq) after oral ¹⁸F-FDG administration were observed for urinary bladder (75.9 ± 17.2), stomach (48.4 ± 14.3), and brain (29.4 ± 5.1), and the effective dose was significantly higher (20%) than after intravenous administration (P = 0.002). Conclusion: ¹⁸F-FDG has excellent bioavailability after oral administration, but peak organ activities occur later than after intravenous injection. These data suggest PET at 2 h after oral ¹⁸F-FDG administration should yield images that are comparable in biodistribution to conventional clinical images acquired 1 h after injection. Oral ¹⁸F-FDG is a palatable alternative to intravenous ¹⁸F-FDG when venous access is problematic.

Immunotherapy is becoming the mainstay for treatment of a variety of malignancies, but only a subset of patients responds to treatment. Tumor-infiltrating CD8-positive (CD8+) T lymphocytes play a central role in antitumor immune responses. Noninvasive imaging of CD8+ T cells may provide new insights into the mechanisms of immunotherapy and potentially predict treatment response. We are studying the safety and utility of ⁸⁹Zr-IAB22M2C, a radiolabeled minibody against CD8+ T cells, for targeted imaging of CD8+ T cells in patients with cancer. Methods: The initial dose escalation phase of this first-in-humans prospective study included 6 patients (melanoma, 1; lung, 4; hepatocellular carcinoma, 1). Patients received approximately 111 MBq (3 mCi) of ⁸⁹Zr-IAB22M2C (at minibody mass doses of 0.2, 0.5, 1.0, 1.5, 5, or 10 mg) as a single dose, followed by PET/CT scans at approximately 1–2, 6–8, 24, 48, and 96–144 h after injection. Biodistribution in normal organs, lymph nodes, and lesions was evaluated. In addition, serum samples were obtained at approximately 5, 30, and 60 min and later at the times of imaging. Patients were monitored for safety during infusion and up to the last imaging time point. Results: ⁸⁹Zr-IAB22M2C infusion was well tolerated, with no immediate or delayed side effects observed after injection. Serum clearance was typically biexponential and dependent on the mass of minibody administered. Areas under the serum time–activity curve, normalized to administered activity, ranged from 1.3 h/L for 0.2 mg to 8.9 h/L for 10 mg. Biodistribution was dependent on the minibody mass administered. The highest uptake was always in spleen, followed by bone marrow. Liver uptake was more pronounced with higher minibody masses. Kidney uptake was typically low. Prominent uptake was seen in multiple normal lymph nodes as early as 2 h after injection, peaking by 24–48 h after injection. Uptake in tumor lesions was seen on imaging as early as 2 h after injection, with most ⁸⁹Zr-IAB22M2C–positive lesions detectable by 24 h. Lesions were visualized early in patients receiving treatment, with SUV ranging from 5.85 to 22.8 in 6 target lesions. Conclusion: ⁸⁹Zr-IAB22M2C imaging is safe and has favorable kinetics for early imaging. Biodistribution suggests successful targeting of CD8+ T-cell–rich tissues. The observed targeting of tumor lesions suggests this may be informative for CD8+ T-cell accumulation within tumors. Further evaluation is under way.

M2 macrophages play an important role in tissue repair and regeneration. They have also been found to modulate β-cell replication in mouse models of pancreatic injury and disease. We previously reported that β-cell replication is strongly increased in a subgroup of human organ donors characterized by prolonged duration of stay in an intensive care unit (ICU) and increased number of leukocytes in the pancreatic tissue. In the present study we investigated the relationship between duration of stay in the ICU, M2 macrophages, vascularization, and pancreatic cell replication. Pancreatic organs from 50 donors without diabetes with different durations of stay in the ICU were analyzed by immunostaining and digital image analysis. The number of CD68⁺CD206⁺ M2 macrophages increased three- to sixfold from ≥6 days’ duration of stay in the ICU onwards. This was accompanied by a threefold increased vascular density and a four- to ninefold increase in pancreatic cells positive for the replication marker Ki67. A strong correlation was observed between the number of M2 macrophages and β-cell replication. These results show that a prolonged duration of stay in the ICU is associated with an increased M2 macrophage number, increased vascular density, and an overall increase in replication of all pancreatic cell types. Our data show evidence of marked levels of tissue repair in the human donor pancreas.

The actin cytoskeleton is extremely dynamic and supports diverse cellular functions in many physiological and pathological processes, including tumorigenesis. However, the mechanisms that regulate the actin-related protein 2/3 (ARP2/3) complex and thereby promote actin polymerization and organization in cancer cells are not well-understood. We previously implicated the proline-rich 11 (PRR11) protein in lung cancer development. In this study, using immunofluorescence staining, actin polymerization assays, and siRNA-mediated gene silencing, we uncovered that cytoplasmic PRR11 is involved in F-actin polymerization and organization. We found that dysregulation of PRR11 expression results in F-actin rearrangement and nuclear instability in non-small cell lung cancer cells. Results from molecular mechanistic experiments indicated that PRR11 associates with and recruits the ARP2/3 complex, facilitates F-actin polymerization, and thereby disrupts the F-actin cytoskeleton, leading to abnormal nuclear lamina assembly and chromatin reorganization. Inhibition of the ARP2/3 complex activity abolished irregular F-actin polymerization, lamina assembly, and chromatin reorganization due to PRR11 overexpression. Notably, experiments with truncated PRR11 variants revealed that PRR11 regulates F-actin through different regions. We found that deletion of either the N or C terminus of PRR11 abrogates its effects on F-actin polymerization and nuclear instability and that deletion of amino acid residues 100–184 or 100–200 strongly induces an F-actin structure called the actin comet tail, not observed with WT PRR11. Our findings indicate that cytoplasmic PRR11 plays an essential role in regulating F-actin assembly and nuclear stability by recruiting the ARP2/3 complex in human non-small cell lung carcinoma cells.

Knowledge of the molecular events in mitochondrial DNA (mtDNA) replication is crucial to understanding the origins of human disorders arising from mitochondrial dysfunction. Twinkle helicase is an essential component of mtDNA replication. Here, we employed atomic force microscopy imaging in air and liquids to visualize ring assembly, DNA binding, and unwinding activity of individual Twinkle hexamers at the single-molecule level. We observed that the Twinkle subunits self-assemble into hexamers and higher-order complexes that can switch between open and closed-ring configurations in the absence of DNA. Our analyses helped visualize Twinkle loading onto and unloading from DNA in an open-ringed configuration. They also revealed that closed-ring conformers bind and unwind several hundred base pairs of duplex DNA at an average rate of ∼240 bp/min. We found that the addition of mitochondrial single-stranded (ss) DNA–binding protein both influences the ways Twinkle loads onto defined DNA substrates and stabilizes the unwound ssDNA product, resulting in a ∼5-fold stimulation of the apparent DNA-unwinding rate. Mitochondrial ssDNA-binding protein also increased the estimated translocation processivity from 1750 to >9000 bp before helicase disassociation, suggesting that more than half of the mitochondrial genome could be unwound by Twinkle during a single DNA-binding event. The strategies used in this work provide a new platform to examine Twinkle disease variants and the core mtDNA replication machinery. They also offer an enhanced framework to investigate molecular mechanisms underlying deletion and depletion of the mitochondrial genome as observed in mitochondrial diseases.

The action mechanisms revealed by the biochemical and structural analyses of replicative and translesion synthesis (TLS) DNA polymerases (Pols) are retained in their cellular roles. In this regard, DNA polymerase θ differs from other Pols in that whereas purified Polθ misincorporates an A opposite 1,N6-ethenodeoxyadenosine (ϵdA) using an abasic-like mode, Polθ performs predominantly error-free TLS in human cells. To test the hypothesis that Polθ adopts a different mechanism for replicating through ϵdA in human cells than in the purified Pol, here we analyze the effects of mutations in the two highly conserved tyrosine residues, Tyr-2387 and Tyr-2391, in the Polθ active site. Our findings that these residues are indispensable for TLS by the purified Pol but are not required in human cells, as well as other findings, provide strong evidence that the Polθ active site is reconfigured in human cells to stabilize ϵdA in the syn conformation for Hoogsteen base pairing with the correct nucleotide. The evidence that a DNA polymerase can configure its active site entirely differently in human cells than in the purified Pol establishes a new paradigm for DNA polymerase function.

Discussion at launch of this MPI-IOM Issue in Brief, Human Rights, Climate Change, Environmental Degradation and Migration: A New Paradigm, which focuses on the vulnerability of environmental migrants and how the international legal framework can better ensure their protection, particularly in the Asia-Pacific region.

This issue brief addresses the rights of migrants whose movement is induced by environmental degradation or climate change, particularly in the highly vulnerable Asia-Pacific region. The brief evaluates the current international legal framework, identifies gaps in the framework and its implementation, and reviews options available to the international community.

This MPI event, in partnership with the International Organization for Migration (IOM), discusses the critical issue of climate-related displacement in the Asia-Pacific region, focusing on the vulnerability of environmental migrants and how the international legal framework can better ensure their protection.

While skilled migration brings widely acknowledged economic benefits for destination countries and migrants, its impact on countries of origin has been the subject of more debate. Despite a growing consensus that origin countries can benefit from emigration and the circulation of skills, enabling this potential to be fully exploited remains a challenge. This report examines initiatives that develop skills and human capital.

Researchers have predicted that if climate change goes unabated, the planet will experience intolerable heat in several decades. But a new study has found that in certain global hot spots, it's already happening.

Peter J Garlick
Dec 1, 1991; 14:1189-1198
Diet and Diabetes

Bernhard J. Hering
Jul 1, 2016; 39:1230-1240
Emerging Technologies and Therapeutics

Gary F Lewis
Apr 1, 1996; 19:390-393
Symposium On Insulin Resistance

Tina Vilsbøll
Jun 1, 2007; 30:1608-1610
BR Emerging Treatments and Technologies

Robert A. Ritzel
Mar 1, 2006; 29:717-718
BR Pathophysiology/Complications

OBJECTIVE

Obesity is associated with microvascular insulin resistance, which is characterized by impaired insulin-mediated microvascular recruitment. Glucagon-like peptide 1 (GLP-1) recruits skeletal and cardiac muscle microvasculature, and this action is preserved in insulin-resistant rodents. We aimed to examine whether GLP-1 recruits microvasculature and improves the action of insulin in obese humans.

The high-stakes gambit taken by Turkish President Recep Tayyip Erdoğan to allow tens of thousands of asylum seekers and migrants free movement to the Greek border demonstrated the fragility of the EU-Turkey deal and the European Union's broader approach to outsource migration management to third countries. This article examines the causes for the tensions, the EU approach to external partnerships, and a hardening European attitude towards unwanted arrivals.

The coronavirus pandemic dramatically reshaped how human mobility is managed just as the Global Compact for Safe, Orderly, and Regular Migration was beginning to move from paper to implementation. As governments face pressing public-health, economic, and other concerns in responding to COVID-19, this MPI Europe commentary explores whether the first comprehensive global agreement on migration can adjust to a changed reality.

MPI and MPI Europe experts discuss the effects of the coronavirus pandemic on asylum systems in Europe and North America, as well as in developing regions, where 85 percent of refugees live. During this freeform conversation, our analysts also assess the implications for the principle of asylum and the future for a post-World War II humanitarian protection system that is under threat.

Dr. Loree Bolin’s humanitarian work has drawn accolades from the dental community in her home state of Washington, and now Dr. Bolin is being recognized nationally by being named the recipient of the ADA’s 2020 Humanitarian Award, bestowed by the ADA Board of Trustees.

It’s a conviction that was published in the November issue of The Journal of the American Dental Association and the basis for the October 2019 forum that Dr. Francisco Ramos-Gomez fostered, where dentists, physicians, nurses and public health and public policy experts proposed, discussed and recommended solutions for preventing early childhood caries through the lens of social justice, health equity and human rights.

Traveling with purpose is what has led Nevada City, California-based general dentist Dr. Jean Creasey to a rural district in the southwestern region of Uganda over the past 15 years as a member of the Kellermann Foundation, treating and helping educate the villagers on the importance of good oral health as a way to a better future.

The kind of trauma doctors, nurses, and others in direct contact with COVID-19 patients have endured for months now — with an uncertain future posing a threat of many more...

Alzheimer’s took my wife’s memory and her life and tortured our family. There was nothing we—or medicine—could do to stop it 

-- Read more on ScientificAmerican.com

Painted images of intriguing human-animal hybrids are signs of modern thought

-- Read more on ScientificAmerican.com

As psychologist Abraham Maslow wrote, “Perhaps human nature has been sold short”

-- Read more on ScientificAmerican.com