Synergies of THESEUS with the large facilities of the 2030s and guest observer opportunities

The proposed THESEUS mission will vastly expand the capabilities to monitor the high-energy sky. It will specifically exploit large samples of gamma-ray bursts to probe the early universe back to the first generation of stars, and to advance multi-messenger astrophysics by detecting and localizing the counterparts of gravitational waves and cosmic neutrino sources. The combination and coordination of these activities with multi-wavelength, multi-messenger facilities expected to be operating in the 2030s will open new avenues of exploration in many areas of astrophysics, cosmology and fundamental physics, thus adding considerable strength to the overall scientific impact of THESEUS and these facilities. We discuss here a number of these powerful synergies and guest observer opportunities.

Compact radio emission indicates a structured jet was produced by a binary neutron star merger

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

Charcot Neuroarthropathy: From the Laboratory to the Bedside

BACKGROUND

The diabetic Charcot foot syndrome is a serious and potentially limbthreatening lower-extremity complication of diabetes.

INTRODUCTION

The present review provides a concise account of the advances made over the last twentyfive years in understanding the pathogenesis and management of Charcot neuroarthropathy (CN).

METHODS

In this study, the widely known pathogenetic mechanisms underpinning CN are brought into focus, particularly the role of RANKL/RANK/OPG system and advanced glycation end production in the pathogenesis of CN. Furthermore, other potential triggering factors, namely nitric oxide, endothelial dysfunction, macro calcifications and body weight that influence CN have also been discussed.

RESULTS

The wide range of diagnostic tools available to clinicians for accurate staging of this pathology has been examined, particularly radiological and nuclear medicine imaging. Additionally, the difficult differential diagnosis between osteomyelitis and CN is also elucidated.

CONCLUSION

The review concludes with the comprehensive summary of the major promising therapeutic strategies, including conservative treatment involving orthopedic devices, pharmacological approach, and the most common surgical techniques currently employed in the diagnosis and treatment of this acute disease.

Platelet indices and glucose control in type 1 and type 2 diabetes mellitus: A case-control study

BACKGROUND AND AIMS

The relationship between platelet indices and glucose control may differ in type 1 (T1DM) and type 2 (T2DM) diabetes. We aimed to investigate differences in mean platelet volume (MPV), platelet count, and platelet mass between patients with T1DM, T2DM, and healthy controls and to explore associations between these platelet indices and glucose control.

METHODS AND RESULTS

A total of 691 T1DM and 459 T2DM patients and 943 control subjects (blood donors) were included. HbA1c was measured in all subjects with diabetes and 36 T1DM patients further underwent 24 h-continuous glucose monitoring to estimate short-term glucose control (glucose mean and standard deviation). Adjusting for age and sex, platelet count was higher and MPV lower in both T1DM and T2DM patients vs control subjects, while platelet mass (MPV × platelet count) resulted higher only in T2DM. Upon further adjustment for HbA1c, differences in platelet count and mass were respectively 19.5 × 10⁹/L (95%CI: 9.8-29.3; p < 0.001) and 101 fL/nL (12-191; p = 0.027) comparing T2DM vs T1DM patients. MPV and platelet count were significantly and differently related in T2DM patients vs both T1DM and control subjects; this difference was maintained also accounting for HbA1c, age, and sex. Platelet mass and the volume-count relationship were significantly related to HbA1c only in T1DM patients. No associations were found between platelet indices and short-term glucose control.

CONCLUSION

By accounting for confounders and glucose control, our data evidenced higher platelet mass and different volume-count kinetics in subjects with T2DM vs T1DM. Long-term glucose control seemed to influence platelet mass and the volume-count relationship only in T1DM subjects. These findings suggest different mechanisms behind platelet formation in T1DM and T2DM patients with long-term glycaemic control being more relevant in T1DM than T2DM.

Autoantibodies to post-translationally modified type I and II collagen in Charcot neuroarthropathy in subjects with type 2 diabetes mellitus

AIMS

Charcot neuroarthropathy (CN) is a disabling complication, culminating in bone destruction and involving joints and articular cartilage with high inflammatory environment. Its real pathogenesis is as yet unknown. In autoinflammatory diseases, such as rheumatoid arthritis, characterized by inflammation and joint involvement, autoantibodies against oxidative post-translationally modified (oxPTM) collagen type I (CI) and type II (CII) were detected. Therefore, the aim of our study was to assess the potential involvement of autoimmunity in charcot neuroarthropathy, investigating the presence of autoantibodies oxPTM-CI and oxPTM-CII, in participants with charcot neuroarthropathy.

METHODS

In this case-control study, we enrolled 124 participants with type 2 diabetes mellitus (47 with charcot neuroarthropathy, 37 with diabetic peripheral neuropathy without charcot neuroarthropathy, and 40 with uncomplicated diabetes), and 32 healthy controls. The CI and CII were modified with ribose and other oxidant species, and the modifications were evaluated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Binding of sera from the participants was analyzed with enzyme-linked immunosorbent assay.

RESULTS

Age, body mass index, waist and hip circumferences, and lipid profile were similar across the 4 groups, as well as glycated hemoglobin and duration of diabetes among people with diabetes. An increased binding to both native and all oxidation-modified forms of CII was found in participants with CN and diabetic neuropathy. Conversely, for CI, an aspecific increased reactivity was noted.

CONCLUSIONS

Our results detected the presence of autoantibodies against oxidative post-translational modified collagen, particularly type 2 collagen, in participants with charcot neuroarthropathy and diabetic neuropathy, suggesting the possible involvement of autoimmunity. Further studies are required to understand the role of autoimmunity in the pathogenesis of charcot neuroarthropathy.

Design Strategies for Redox Active Metalloenzymes: Applications in Hydrogen Production

The last decades have seen an increased interest in finding alternative means to produce renewable fuels in order to satisfy the growing energy demands and to minimize environmental impact. Nature can serve as an inspiration for development of these methodologies, as enzymes are able to carry out a wide variety of redox processes at high efficiency, employing a wide array of earth-abundant transition metals to do so. While it is well recognized that the protein environment plays an important role in tuning the properties of the different metal centers, the structure/function relationships between amino acids and catalytic centers are not well resolved. One specific approach to study the role of proteins in both electron and proton transfer is the biomimetic design of redox active peptides, binding organometallic clusters in well-understood protein environments. Here we discuss different strategies for the design of peptides incorporating redox active FeS clusters, [FeFe]-hydrogenase organometallic mimics, and porphyrin centers into different peptide and protein environments in order to understand natural redox enzymes.

Possible Radio Interference Between Video Capsule Endoscopy and Second-Generation OmniPod Patch Pump

Video capsule endoscopy (VCE) is a noninvasive diagnostic tool used to observe the small intestinal mucosa. We report a case of a 57-year-old woman with T2DM, treated with continuous subcutaneous insulin infusion using second-generation OmniPod patch pump, undergoing VCE (Given M2A; VCE Ltd, Yoqneam, Israel) for melena and anemia. During VCE, an abnormal interruption of communication between video capsule and its receiver occurred. Two hours after capsule ingestion, the patient activated the insulin pump infusion through the Personal Diabetes Manager (PDM) because she drank a sugary beverage for the first time after ingestion. Due to this, we decided to repeat VCE after the removal of the insulin pump and PDM: at this time, the capsule recorded for more than 10 h without any interruption. The video capsule and second-generation OmniPod patch pump use the same radio frequency and this may cause interference between these two devices. In patients using second-generation OmniPod patch pump undergoing VCE, we suggest to switch to intravenous insulin infusion or multiple daily injection or to use a different model of VCE, as MiRoCam (Intromedic, Seoul, Korea).

Platelet mean volume, distribution width, and count in type 2 diabetes, impaired fasting glucose, and metabolic syndrome: a meta-analysis

BACKGROUND

Platelet activation contributes to cardiovascular disease (CVD), the main complication of type 2 diabetes mellitus (T2DM) and pre-diabetic conditions. Mean platelet volume is an easy-to-measure platelet parameter that has been associated with CVD. We sought to assess mean platelet volume, platelet distribution width, and platelet count in T2DM, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and metabolic syndrome.

METHODS

Web-based literature search (PubMed, EMBASE, and Web of Science) of studies published in English through June 2014 was performed to select case-control and cross-sectional studies that reported data on mean platelet volume, platelet distribution width, or platelet count in cases (subjects with T2DM, IFG, IGT, or metabolic syndrome) and noncases. Descriptive and quantitative information was extracted, and within-study standardized mean difference was estimated from means and standard deviations. Standardized mean differences across studies were synthesized using a random random-effects model, and subgroup analyses were performed on pre-specified study-level characteristics.

RESULTS

Thirty-nine studies were included. Compared with controls, mean platelet volume was significantly higher in T2DM (standardized mean difference, 95% confidence interval: 0.70, 0.50-0.91; N = 24,245), IFG (0.14, 0.02-0.26; N = 17,389) but not in metabolic syndrome (0.15, -0.24 to 0.55; N = 14,990). Platelet distribution width was wider in T2DM (0.93, 0.09-1.76; N = 471). Platelet count resulted higher in IFG (0.18, 0.12-0.24; N = 3960) and metabolic syndrome (0.39, 0.01-0.78; N = 4070). Only two studies included IGT.

CONCLUSIONS

Available data suggest that T2DM subjects tend to have higher mean platelet volume and platelet distribution width values, but nondifferent platelet count as compared with subjects without T2DM. Whether and how these morphometric changes contribute to CVD of T2DM or can be used as CVD biomarker awaits further investigation.

Atherosclerotic coronary plaque in subjects with diabetic neuropathy: the prognostic cardiovascular role of Charcot neuroarthropathy--a case-control study

The aim of this study was to investigate the severity of coronary artery disease (CAD) and the plaque composition in neuropathic type 2 diabetic subjects with and without Charcot neuroarthropathy (CN) undergoing multidetector computed tomography coronary angiography (MDCT-CA). The study was a single-center, observational, with unmatched case-control design. We selected 17 CN patients and 18 patients with diabetic neuropathy (DN) without CN. In all the patients, multidetector computed tomography was performed to assess the coronary artery calcium score (CACS) and degree of coronary artery stenosis. Patients were classified as positive in the presence of significant CAD if there was at least one stenosis >50 % on MDCT-CA. The invasive coronary angiography was performed in case of significant stenosis detected with MDCT-CA, both as reference to standard and eventually as treatment. Groups were matched for age, sex, and traditional CAD risk factors. As compared to DN individuals, CN exhibited higher rates of significant coronary stenoses (p = 0.027; OR 7.7 [1.3-43.5]). However, no significant differences were observed in the CACS, which reflects plaque burden, in the two groups (p = 0.759). No significant differences were observed comparing CACS distribution in all subjects for stenosis higher/equal or lower than 50 % (p = 0.320). Finally, no significant differences were observed comparing CACS distribution in CN and DN subjects for coronary stenoses higher/equal or lower than 50 %. Our results suggest that CN patients have a higher prevalence of severe coronary plaques compared to DN patients. Nevertheless, coronary plaques in CN patients did not exhibit an increased degree of calcification.

A case of esomeprazole-induced transient diabetes and hepatitis: the role of liver inflammation in the pathogenesis of insulin resistance

We describe a case report of a patient who developed transient type 2 diabetes after a drug-induced (esomeprazole) sub-acute hepatitis. This case evidences the pathophysiological relevance, also in humans, of liver inflammation in the pathogenesis of type 2 diabetes.

Cilostazol improves the response to ischemia in diabetic mice by a mechanism dependent on PPARγ

Cilostazol is effective for the treatment of peripheral ischemia. This compound has several beneficial effects on platelet aggregation, serum lipids and endothelial cells, and we recently found that it enhances collateral blood flow in the ischemic hind limbs of mice. Peroxisome proliferator-activated receptor (PPAR)γ, a receptor for thiazolidinediones, plays a role in angiogenesis. The aim of this work was to investigate the underlying molecular mechanisms and effects of cilostazol in a model of peripheral ischemia in diabetic mice. We induced diabetes in mice by streptozotocin (STZ) administration and studied ischemia-induced angiogenesis in the ischemic hind limbs of cilostazol-treated and untreated control mice. We found that perfusion recovery was significantly improved in treated compared with control diabetic mice. Interestingly, we found that the expression of PPARγ is reduced in ischemic tissues of diabetic mice. Furthermore, we discovered that local inhibition of the activity of this nuclear receptor decreased the angiogenic response to cilostazol treatment. Finally, we noted that this phenomenon is dependent on VEGF and modulated by PPARγ. Cilostazol administration enhances collateral blood flow in the ischemic hind limbs of STZ-induced diabetic mice through a PPARγ-dependent mechanism.

Oxidative stress in diabetes: implications for vascular and other complications

In recent decades, oxidative stress has become a focus of interest in most biomedical disciplines and many types of clinical research. Increasing evidence shows that oxidative stress is associated with the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure. Based on these studies, an emerging concept is that oxidative stress is the “final common pathway” through which the risk factors for several diseases exert their deleterious effects. Oxidative stress causes a complex dysregulation of cell metabolism and cell–cell homeostasis; in particular, oxidative stress plays a key role in the pathogenesis of insulin resistance and β-cell dysfunction. These are the two most relevant mechanisms in the pathophysiology of type 2 diabetes and its vascular complications, the leading cause of death in diabetic patients.

Effect of proinflammatory gene polymorphisms on the risk of Alzheimer's disease

BACKGROUND

A number of studies associate Alzheimer's disease (AD) with APOE polymorphism and alleles which favor the increased expression of immunological mediators such as cytokines or acute-phase proteins.

OBJECTIVE

In this study we evaluated the distribution of a set of functionally important polymorphisms of genes encoding prototypical inflammatory molecules in individuals with AD. We also investigated whether a synergistic effect of these proinflammatory gene polymorphisms on the risk of AD could be hypothesized.

METHODS

In a genetic association study that included 533 AD patients and 713 controls, the following gene polymorphisms were analyzed: C-reactive protein (CRP) 1059 G/C, interleukin 6 (IL6) -174 G/C, interleukin 1β (IL1B) -31 T/C, tumor necrosis factor α (TNF-α) -308 G/A, macrophage migration inhibitory factor (MIF) -173 G/C, monocyte chemoattractant protein 1 (CCL2) -2518 A/G, intercellular adhesion molecule 1 (ICAM1) 469 E/K, E-selectin (SELE) Ser128Arg, macrophage inflammatory protein 1α (CCL3) -906 T/A, matrix metalloproteinase 3 (MMP3) -1171 5A/6A and matrix metalloproteinase 9 (MMP9) -1562 C/T.

RESULTS

We found that IL6, IL1B, CCL2, CCL3, SELE, ICAM1, MMP3, and MMP9 gene polymorphisms were significantly and independently associated with AD. The association remained significant even after the Bonferroni correction. We also found that these proinflammatory polymorphisms were associated with different levels of risk for AD, depending on the number of high-risk genotypes concomitantly carried by a given individual.

CONCLUSION

Proinflammatory genotypes might influence the development and progression of AD exerting a potential synergistic effect.

Fields of application of continuous subcutaneous insulin infusion in the treatment of diabetes and implications in the use of rapid-acting insulin analogues

In western countries, diabetes mellitus, because of macrovascular and microvascular complications related to it, is still an important cause of death. Patients with type 1 diabetes mellitus (T1DM) have a six-time higher risk of mortality than healthy patients. Since the Diabetes Control and Complications Trial (DCCT) established how an intensive therapy is necessary to prevent diabetes mellitus complications, many studies have been conducted to understand which method is able to reach an optimal metabolic control. In the past 30 years continuous subcutaneous insulin infusion established/introduced as a validate alternative to multiple daily injections. Several trials demonstrated that, when compared to MDI, CSII brings to a better metabolic control, in terms of a reduction of glycated hemoglobin and blood glucose variability, hypoglycemic episodes and improvement in quality of life. Because of their pharmacokinetic and pharmacodynamic characteristics, rapid-action insulin analogues are imposed as best insulin to be used in CSII. The rapid onset and the fast reached peak make them better mimic the way how pancreas secretes insulin. CSII by pump is not free from issues. Catheter occlusions, blockages, clogs can arrest insulin administration. The consequent higher levels of glycemic values, can easily bring to the onset of ketoacidosis, with an high risk for patients' life. Aspart is a rapid analogue obtained by aminoacidic substitution. It is as effective as lispro and glulisine in gaining a good metabolic control and even better in reducing glucose variability. Some studies tried to compare rapid analogues in terms of stability. Obtained data are controversial. An in vivo study evidenced higher stability or glulisine, while studies in vitro highlighted a higher safety of aspart. Nowadays it is not possible to assess which analogues is safer. When the infusion set is changed every 48 hours equivalent rates of occlusions have been observed.

Nutrient infusion bypassing duodenum-jejunum improves insulin sensitivity in glucose-tolerant and diabetic obese subjects

The mechanisms of type 2 diabetes remission after bariatric surgery is still not fully elucidated. In the present study, we tried to simulate the Roux-en-Y gastric bypass with a canonical or longer biliary limb by infusing a liquid formula diet into different intestinal sections. Nutrients (Nutrison Energy) were infused into mid- or proximal jejunum and duodenum during three successive days in 10 diabetic and 10 normal glucose-tolerant subjects. Plasma glucose, insulin, C-peptide, glucagon, incretins, and nonesterified fatty acids (NEFA) were measured before and up to 360 min following. Glucose rate of appearance (Ra) and insulin sensitivity (SI), secretion rate (ISR), and clearance were assessed by mathematical models. SI increased when nutrients were delivered in mid-jejunum vs. duodenum (SI × 10⁴ min⁻¹·pM⁻¹: 1.11 ± 0.44 vs. 0.62 ± 0.22, P < 0.015, in controls and 0.79 ± 0.34 vs. 0.40 ± 0.20, P < 0.05, in diabetic subjects), whereas glucose Ra was not affected. In controls, Sensitivity of NEFA production was doubled in mid-jejunum vs. duodenum (2.80 ± 1.36 vs. 1.13 ± 0.78 × 10⁶, P < 0.005) and insulin clearance increased in mid-jejunum vs. duodenum (2.05 ± 1.05 vs. 1.09 ± 0.38 l/min, P < 0.03). Bypass of duodenum and proximal jejunum by nutrients enhances insulin sensitivity, inhibits lipolysis, and increases insulin clearance. These results may further our knowledge of the effects of bariatric surgery on both insulin resistance and diabetes.

Metformin improves endothelial function in type 1 diabetic subjects: a pilot, placebo-controlled randomized study

AIMS

Several studies have investigated the effects of metformin treatment in patients with type 1 diabetes mellitus (T1DM). No study has hitherto examined its effects on endothelial function in these patients. In this study we sought to evaluate the effect of metformin on endothelial function in type 1 diabetic patients.

METHODS

Forty-two uncomplicated T1DM patients were randomized in a placebo-controlled, double-blind, 6-month trial to treatment with either metformin or placebo. Glycometabolic and clinical parameters as well as flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) of the right brachial artery were measured at baseline and at the end of the study. Glycaemic variability (GV, calculated from continuous glucose monitoring data) and a biomarker of oxidative stress [urinary 8-iso-prostaglandin F2α (PGF2α)] were also assessed.

RESULTS

Baseline data were similar in the two groups. Compared with placebo, metformin significantly reduced body weight [-2.27 kg (95% confidence interval: -3.99; -0.54); p = 0.012] whilst improved FMD [1.32% (0.30; 2.43); p = 0.013] and increased PGF2α [149 pg/mg creatinine (50; 248); p = 0.004]. Notably, the improvement of FMD did not correlate with the decrease of body weight (r(2)  < 1%). NMD, haemoglobin A1c, GV, daily insulin dose and other parameters did not significantly change after the treatment comparing the two groups.

CONCLUSIONS

Our pilot trial showed that, in uncomplicated type 1 diabetic subjects, metformin improved FMD and increased PGF2α, a marker of oxidative stress, irrespective of its effects on glycaemic control and body weight. Randomized, blinded clinical trials are needed to evaluate the benefits and risks of metformin added to insulin in type 1 diabetes.

Effects of GLP-1 on forearm vasodilator function and glucose disposal during hyperinsulinemia in the metabolic syndrome

OBJECTIVE

Patients with the metabolic syndrome (MetS) have impaired insulin-induced enhancement of vasodilator responses. The incretin hormone glucagon-like peptide 1 (GLP-1), beyond its effects on blood glucose, has beneficial actions on vascular function. This study, therefore, aimed to assess whether GLP-1 affects insulin-stimulated vasodilator reactivity in patients with the MetS.

RESEARCH DESIGN AND METHODS

Forearm blood flow responses to acetylcholine (ACh) and sodium nitroprusside (SNP) were assessed in MetS patients before and after the addition of GLP-1 to an intra-arterial infusion of saline (n = 5) or insulin (n = 5). The possible involvement of oxidative stress in the vascular effects of GLP-1 in this setting was investigated by infusion of vitamin C (n = 5). The receptor specificity of GLP-1 effect during hyperinsulinemia was assessed by infusing its metabolite GLP-1(9-36) (n = 5). The metabolic actions of GLP-1 were also tested by analyzing forearm glucose disposal during hyperinsulinemia (n = 5).

RESULTS

In MetS patients, GLP-1 enhanced endothelium-dependent and -independent responses to ACh and SNP, respectively, during hyperinsulinemia (P < 0.001 for both), but not during saline (P > 0.05 for both). No changes in vasodilator reactivity to ACh and SNP were seen after GLP-1 was added to insulin and vitamin C (P > 0.05 for both) and after GLP-1(9-36) was given during hyperinsulinemia (P > 0.05 for both). Also, GLP-1 did not affect forearm glucose extraction and uptake during hyperinsulinemia (P > 0.05 for both).

CONCLUSIONS

In patients with the MetS, GLP-1 improves insulin-mediated enhancement of endothelium-dependent and -independent vascular reactivity. This effect may be influenced by vascular oxidative stress and is possibly exerted through a receptor-mediated mechanism.

The oxidative modification of von Willebrand factor is associated with thrombotic angiopathies in diabetes mellitus

The thrombogenic activity of Von Willebrand factor (VWF) is proportional to its molecular size and inversely related to its proteolysis by ADAMTS-13. Oxidation of VWF severely impairs its proteolysis by the metalloprotease. This study was aimed at assessing in patients with type 1 and type 2 diabetes whether protein carbonyls, marker of oxidative stress, are associated with both the level and oxidation status of VWF as well as with micro- and macroangiopathic complications. Eighty-three diabetic patients (41 type 1 and 42 type 2 diabetic subjects) and their respective eighty-three healthy controls were studied after verifying the availability, through institutional databases, of clinical biochemistry records spanning at least 3 years. VWF and protein carbonyls were measured by immunoassays, whereas VWF multimers were studied by SDS-agarose gel electrophoresis. Type 2 diabetic subjects had higher levels of VWF antigen (VWF:ag), VWF activity (VWF:act) and plasma proteins’ carbonyls compared to both their controls and type 1 diabetic subjects. Moreover, high molecular weight VWF multimers and specific VWF-bound carbonyls were significantly increased in subjects with micro- and macro-angiopathic complications. In both type 1 and type 2 diabetic subjects, ADAMTS-13 activity was in the normal range. In a multivariable analysis, only VWF-bound carbonyls were significantly associated with any form of thrombotic angiopathy in the entire group of T1- and T2 diabetic patients. These data provide first evidence that not only high VWF levels but also its oxidation status and the presence of high molecular weight VWF multimers that are not observed in SDS-agarose gel electrophoresis of normal subjects are associated with thrombotic angiopathies in diabetes mellitus. These findings may help identify diabetic patients particularly at risk for these complications and elucidate a new pathophysiological mechanism of thrombotic angiopathies in this clinical setting.