Simultaneous measurements of myocardial glucose metabolism and extracellular volumes with hybrid PET/MRI using concurrent injections of Gd-DTPA and [18F]FDG.

BACKGROUND: The aims of this study were to investigate the application of a constant infusion (CI) to mitigate the issue of constantly changing Gd-DTPA contrast levels in a bolus injection for extracellular volume (ECV) measurements by (a) comparing a CI alone to a bolus alone and a bolus followed by CI in healthy myocardium, (b) evaluating the impact of glucose suppression using heparin on ECV. METHODS: Five healthy canine subjects were imaged to compare three different protocols for injecting Gd-DTPA and FDG: bolus alone, CI alone, bolus followed by CI. Suppression of myocardial glucose uptake was induced using a continuous infusion of 20% lipid at a rate of 0.25 mL·min-1·kg-1 as well as 2000 units of intravenous heparin injected 20 minutes prior to FDG/Gd-DTPA injection. RESULTS: There was no significant effect on ECV measurement when heparin was used for glucose suppression at equilibrium irrespective of infusion protocol). Measurements of ECV in myocardium, regardless of infusion protocol showed no significant difference at all time points (P = 0.21) prior to washout. CONCLUSIONS: The suppression of myocardial uptake of [18F]FDG with heparin did not alter the determination of myocardial ECV though a larger sample size may show differences. Further, the infusion protocol (bolus or constant infusion) had no effect on the calculated ECV.

Tracking the progress of inflammation with PET/MRI in a canine model of myocardial infarction.

BACKGROUND: Following myocardial infarction, tissue undergoes pathophysiological changes involving inflammation and scar tissue formation. However, little is known about the pathophysiology and prognostic significance of any corresponding changes in remote myocardium. The aim of this study was to investigate the potential application of a combined constant infusion of 18F-FDG and Gd-DTPA to quantitate inflammation and extracellular volume (ECV) from 3 to 40 days after myocardial infarction. METHODS: Eight canine subjects were imaged at multiple time points following induction of an MI with a 60-minute concurrent constant infusion of Gd-DTPA and 18F-FDG using a hybrid PET/MRI scanner. RESULTS: There was a significant increase in ECV in remote myocardium on day 14 post-MI (P = .034) and day 21 (P = .021) compared to the baseline. ECV was significantly elevated in the infarcted myocardium compared to remote myocardium at all time points post-MI (days 3, 7, 14, 21, and 40) (P < .001) while glucose uptake was also increased within the infarct on days 3, 7, 14, and 21 but not 40. CONCLUSIONS: The significant increase in ECV in remote tissue may be due to an ongoing inflammatory process in the early weeks post-infarct.

Residual disease after neoadjuvant chemoradiotherapy for oesophageal cancer: locations undetected by endoscopic biopsies in the preSANO trial.

BACKGROUND: Active surveillance has been proposed for patients with oesophageal cancer in whom there is a complete clinical response after neoadjuvant chemoradiotherapy (nCRT). However, endoscopic biopsies have limited negative predictive value in detecting residual disease. This study determined the location of residual tumour following surgery to improve surveillance and endoscopic strategies. METHODS: The present study was based on patients who participated in the prospective preSANO trial with adenocarcinoma or squamous cell carcinoma of the oesophagus or oesophagogastric junction treated in four Dutch hospitals between 2013 and 2016. Resection specimens and endoscopic biopsies taken during clinical response evaluations after nCRT were reviewed by two expert gastrointestinal pathologists. The exact location of residual disease in the oesophageal wall was determined in resection specimens. Endoscopic biopsies were assessed for the presence of structures representing the submucosal layer of the oesophageal wall. RESULTS: In total, 119 eligible patients underwent clinical response evaluations after nCRT followed by standard surgery. Residual tumour was present in endoscopic biopsies from 70 patients, confirmed on histological analysis of the resected organ. Residual tumour was present in the resection specimen from 27 of the other 49 patients, despite endoscopic biopsies being negative. Of these 27 patients, residual tumour was located in the mucosa in 18, and in the submucosa beneath tumour-free mucosa in eight. One patient had tumour in muscle beneath tumour-free mucosa and submucosa. CONCLUSION: Most residual disease after nCRT missed by endoscopic biopsies was located in the mucosa. Active surveillance could be improved by more sampling and considering submucosal biopsies.

ANTECEDENTES: Se ha propuesto un seguimiento activo para los pacientes con cáncer de esófago en los que se logra una respuesta clínica completa tras quimiorradioterapia neoadyuvante (neoadjuvant chemoradiotherapy, nCRT). Sin embargo, las biopsias endoscópicas tienen un valor predictivo limitado para detectar la enfermedad residual. En este estudio se evaluó la localización del tumor residual tras la cirugía para poder determinar estrategias de seguimiento y endoscópicas. MÉTODOS: Este estudio se basa en pacientes que participaron en el ensayo prospectivo preSANO (adenocarcinoma o carcinoma escamoso del esófago o unión esofagogástrica en cuatro hospitales de los Países Bajos entre 2013 y 2016). Los especímenes quirúrgicos, así como las biopsias endoscópicas efectuadas durante las evaluaciones de la respuesta clínica después de nCRT fueron revisadas por dos patólogos gastrointestinales expertos. En los especímenes de resección, se determinó la localización exacta de la enfermedad residual en la pared del esófago. Se evaluaron las biopsias endoscópicas para identificar estructuras que constituyeran la capa submucosa de la pared del esófago. RESULTADOS: En total, 119 pacientes elegibles fueron sometidos a evaluaciones de la respuesta clínica tras nCRT seguida de cirugía estándar. Se detectó tumor residual en las biopsias endoscópicas de 70 pacientes, luego confirmadas en la histología de la pieza extirpada. Se identificó tumor residual en la pieza de resección de 27 de los otros 49 pacientes, a pesar de que las biopsias endoscópicas fueron negativas. En estos 27 pacientes, 18 presentaban tumor residual en la mucosa y ocho pacientes en la submucosa mas allá de una mucosa libre de tumor. Un paciente tenía tumor en el músculo más allá de una mucosa y submucosa libres de tumor. CONCLUSIÓN: La mayoría de los casos de enfermedad residual tras nCRT que no se detectaron en las biopsias endoscópicas, se localizaban en la mucosa. El seguimiento activo podría mejorar con la toma de más muestras y considerando las biopsias submucosas.

Same day comparison of PET/CT and PET/MR in patients with cardiac sarcoidosis.

BACKGROUND: Inflammatory cardiac disorders, in particular, sarcoidosis, play an important role in left ventricular dysfunction, conduction abnormalities, and arrhythmias. In this study, we compared the imaging characteristics and diagnostic information obtained when patients were imaged sequentially with PET/CT and then with hybrid PET/MRI on the same day following a single 18F-FDG injection. METHODS: Ten patients with known or suspected sarcoidosis underwent imaging in sequence of (a) 99mTc-MIBI, (b) 18F-FDG with PET/CT, and (c) 18F-FDG with 3T PET/MRI. Images were compared quantitatively by determination of SUVmax and SUV on a voxel by voxel basis, and qualitatively by two experienced observers. RESULTS: When both platforms were compared quantitatively, similar data for the evaluation of enhanced 18F-FDG uptake were obtained. Qualitatively, there were (1) several instances of normal perfusion with delayed enhancement and/or focal 18F-FDG uptake, (2) comparable enhanced 18F-FDG uptake on PET/CT vs. PET/MRI, and (3) diversity in disease patterns with delayed enhancement only, increased 18F-FDG uptake only, or both. CONCLUSION: In this limited patient study, PET/CT and PET/MR provided similar diagnostic data for 18F-FDG uptake, and the concurrent acquisition of MR images provided further insight into the disease process.

Hybrid PET/MR imaging in myocardial inflammation post-myocardial infarction.

Hybrid PET/MR imaging is an emerging imaging modality combining positron emission tomography (PET) and magnetic resonance imaging (MRI) in the same system. Since the introduction of clinical PET/MRI in 2011, it has had some impact (e.g., imaging the components of inflammation in myocardial infarction), but its role could be much greater. Many opportunities remain unexplored and will be highlighted in this review. The inflammatory process post-myocardial infarction has many facets at a cellular level which may affect the outcome of the patient, specifically the effects on adverse left ventricular remodeling, and ultimately prognosis. The goal of inflammation imaging is to track the process non-invasively and quantitatively to determine the best therapeutic options for intervention and to monitor those therapies. While PET and MRI, acquired separately, can image aspects of inflammation, hybrid PET/MRI has the potential to advance imaging of myocardial inflammation. This review contains a description of hybrid PET/MRI, its application to inflammation imaging in myocardial infarction and the challenges, constraints, and opportunities in designing data collection protocols. Finally, this review explores opportunities in PET/MRI: improved registration, partial volume correction, machine learning, new approaches in the development of PET and MRI pulse sequences, and the use of novel injection strategies.

Interventions that Facilitate Shared Decision-Making in Cancers with Active Surveillance as Treatment Option: a Systematic Review of Literature.

PURPOSE OF REVIEW: Medical decisions concerning active surveillance are complex, especially when evidence on superiority of one of the treatments is lacking. Decision aids have been developed to facilitate shared decision-making on whether to pursue an active surveillance strategy. However, it is unclear how these decision aids are designed and which outcomes are considered relevant. The purpose of this study is to systematically review all decision aids in the field of oncological active surveillance strategies and outcomes used by authors to assess their efficacy. RECENT FINDINGS: A search was performed in Embase, Medline, Web of Science, Cochrane, PsycINFO Ovid and Google Scholar until June 2019. Eligible studies concerned interventions aiming to facilitate shared decision-making for patients confronted with several treatment alternatives, with active surveillance being one of the treatment alternatives. Twenty-three eligible articles were included. Twenty-one articles included patients with prostate cancer, one with thyroid cancer and one with ovarian cancer. Interventions mostly consisted of an interactive web-based decision aid format. After categorization of outcomes, seven main groups were identified: knowledge, involvement in decision-making, decisional conflict, treatment preference, decision regret, anxiety and health-related outcomes. Although active surveillance has been implemented for several malignancies, interventions that facilitate shared decision-making between active surveillance and other equally effective treatment alternatives are scarce. Future research should focus on developing interventions for malignancies like rectal cancer and oesophageal cancer as well. The efficacy of interventions is mostly assessed using short-term outcomes.

Pro-inflammatory gene expression profile in obese adults with high plasma GIP levels.

BACKGROUND: Glucose-dependent insulinotropic peptide (GIP) provides a novel link between the immune system and the gut, although results from different experimental and observational studies are contradictory, ranging from anti-inflammatory, through neutral to pro-inflammatory action of GIP. Thus, the aim of this study was to analyze inflammatory pathways on the level of gene expression and circulating inflammatory markers in relation to plasma GIP level. SUBJECTS/METHODS: The study included 128 obese adults. Two groups of obese subjects were created according to fasting GIP levels, with cutoff point at the 66th percentile and compared in respect with molecular and circulating markers of inflammation. GIP, interleukin (IL)-6 and adipokines: leptin, adiponectin, visfatin were measured by enzyme-linked immunosorbent assay. Inflammatory markers: monocyte chemoattractant protein-1 (MCP-1), sE-Selectin, sVCAM-1, sPECAM-1 were studied at fasting and after nutrient challenges. Gene expression in blood cells was determined by human gene microarray. RESULTS: Obese patients with high GIP levels had elevated fasting glucose (Q2 (Q1-Q3): 5.6 (5.0-6.0) vs 5.0 (4.8-5.4), P<0.001), homeostasis model assessment of insulin resistance (Q2 (Q1-Q3): 3.68 (2.72-5.42) vs 2.70 (2.13-4.33), P=0.021), thus increased markers of insulin resistance as well as elevated inflammatory markers Il-6 (Q2 (Q1-Q3): 1.34 (1.0-2.04) vs 1.12 (0.76-1.64), P=0.045), MCP-1 (Q2 (Q1-Q3): 363 (287-447) vs 323 (263-389), P=0.026). Leptin to adiponectin ratio was significantly associated with fasting plasma GIP levels (ß (95% CI): 0.84 (0.10-1.59)) independently of glucose levels. sE-Selectin was found to be a factor influencing GIP response to oral glucose intake (ß (95% CI): 0.47 (0.14-0.81)) and sVCAM was found to be a factor influencing GIP response to high-fat meal intake (ß (95% CI): 0.19 (0.01-0.37)). We identified 32 genes of inflammatory pathways differentially expressed in subjects with a high plasma GIP level compared to low GIP. Most upregulated genes play a role in leukocyte chemotaxis and tissue infiltration. CONCLUSIONS: These findings support the hypothesis that increased GIP signaling has a role in chronic low-grade inflammation.

A gene variation (rs12691) in the CCAT/enhancer binding protein α modulates glucose metabolism in metabolic syndrome.

BACKGROUND AND AIMS: CCAAT/enhancer-binding protein alpha (CEBPA) is a transcription factor involved in adipogenesis and energy homeostasis. Caloric restriction reduces CEBPA protein expression in patients with metabolic syndrome (MetS). A previous report linked rs12691 SNP in CEBPA to altered concentration of fasting triglycerides. Our objective was to assess the effects of rs12691 in glucose metabolism in Metabolic Syndrome (MetS) patients. METHODS AND RESULTS: Glucose metabolism was assessed by static (glucose, insulin, adiponectin, leptin and resistin plasma concentrations) and dynamic (disposition index, insulin sensitivity index, HOMA-IR and acute insulin response to glucose) indices, performed at baseline and after 12 weeks of 4 dietary interventions (high saturated fatty acid (SFA), high monounsaturated fatty acid (MUFA), low-fat and low-fat-high-n3 polyunsaturated fatty acid (PUFA)) in 486 subjects with MetS. Carriers of the minor A allele of rs12691 had altered disposition index (p = 0.0003), lower acute insulin response (p = 0.005) and a lower insulin sensitivity index (p = 0.025) indicating a lower insulin sensitivity and a lower insulin secretion, at baseline and at the end of the diets. Furthermore, A allele carriers displayed lower HDL concentration. CONCLUSION: The presence of the A allele of rs12691 influences glucose metabolism of MetS patients.

Electrochemical determination of nitroaromatic explosives at boron-doped diamond/graphene nanowall electrodes: 2,4,6-trinitrotoluene and 2,4,6-trinitroanisole in liquid effluents.

The study is devoted to the electrochemical detection of trace explosives on boron-doped diamond/graphene nanowall electrodes (B:DGNW). The electrodes were fabricated in a one-step growth process using chemical vapour deposition without any additional modifications. The electrochemical investigations were focused on the determination of the important nitroaromatic explosive compounds, 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitroanisole (TNA). The distinct reduction peaks of both studied compounds were observed regardless of the pH value of the solution. The reduction peak currents were linearly related to the concentration of TNT and TNA in the range from 0.05-15 ppm. Nevertheless, two various linear trends were observed, attributed respectively to the adsorption processes at low concentrations up to the diffusional character of detection for larger contamination levels. The limit of detection of TNT and TNA is equal to 73 ppb and 270 ppb, respectively. Moreover, the proposed detection strategy has been applied under real conditions with a significant concentration of interfering compounds - in landfill leachates. The proposed bare B:DGNW electrodes were revealed to have a high electroactive area towards the voltammetric determination of various nitroaromatic compounds with a high rate of repeatability, thus appearing to be an attractive nanocarbon surface for further applications.

Negative pressure wound therapy in the treatment of diabetic foot ulcers may be mediated through differential gene expression.

AIMS: Negative pressure wound therapy (NPWT) has been successfully used as a treatment for diabetic foot ulceration (DFU). Its mechanism of action on the molecular level, however, is not fully understood. We assessed the effect of NPWT on gene expression in patients with type 2 diabetes (T2DM) and DFU. METHODS: We included two cohorts of patients-individuals treated with either NPWT or standard therapy. The assignment to NWPT was non-randomized and based on wound characteristics. Differential gene expression profiling was performed using Illumina gene expression arrays and R Bioconductor pipelines based on the 'limma' package. RESULTS: The final cohort encompassed 21 patients treated with NPWT and 8 with standard therapy. The groups were similar in terms of age (69.0 versus 67.5 years) and duration of T2DM (14.5 versus 14.4 years). We identified four genes differentially expressed between the two study arms post-treatment, but not pre-treatment: GFRA2 (GDNF family receptor alpha-2), C1QBP (complement C1q binding protein), RAB35 (member of RAS oncogene family) and SYNJ1 (synaptic inositol 1,4,5-trisphosphate 5-phosphatase 1). Interestingly, all four genes seemed to be functionally involved in wound healing by influencing re-epithelialization and angiogenesis. Subsequently, we utilized co-expression analysis in publicly available RNA-seq data to reveal the molecular functions of GFRA2 and C1QBP, which appeared to be through direct protein-protein interactions. CONCLUSIONS: We found initial evidence that the NPWT effect on DFUs may be mediated through differential gene expression. A discovery of the specific molecular mechanisms of NPWT is potentially valuable for its clinical application and development of new therapies.

DNA methylation analysis of negative pressure therapy effect in diabetic foot ulcers.

OBJECTIVE: Negative pressure wound therapy (NPWT) has been used to treat diabetic foot ulcerations (DFUs). Its action on the molecular level, however, is only partially understood. Some earlier data suggested NPWT may be mediated through modification of local gene expression. As methylation is a key epigenetic regulatory mechanism of gene expression, we assessed the effect of NPWT on its profile in patients with type 2 diabetes (T2DM) and neuropathic non-infected DFUs. METHODS: Of 36 included patients, 23 were assigned to NPWT and 13 to standard therapy. Due to ethical concerns, the assignment was non-randomized and based on wound characteristics. Tissue samples were obtained before and 8 ± 1 days after therapy initiation. DNA methylation patterns were checked by Illumina Methylation EPIC kit. RESULTS: In terms of clinical characteristics, the groups presented typical features of T2DM; however, the NPWT group had significantly greater wound area: 16.8 cm2 vs 1.4 cm2 (P = 0.0003). Initially only one region at chromosome 5 was differentially methylated. After treatment, 57 differentially methylated genes were found, mainly located on chromosomes 6 (chr6p21) and 20 (chr20p13); they were associated with DNA repair and autocrine signaling via retinoic acid receptor. We performed differential analyses pre treatment and post treatment. The analysis revealed 426 differentially methylated regions in the NPWT group, but none in the control group. The enrichment analysis showed 11 processes significantly associated with NPWT, of which 4 were linked with complement system activation. All but one were hypermethylated after NPWT. CONCLUSION: The NPWT effect on DFUs may be mediated through epigenetic changes resulting in the inhibition of complement system activation.

Neoadjuvant chemoradiotherapy for resectable oesophageal cancer.

At present, treatment of potentially curable oesophageal cancer includes neoadjuvant chemoradiotherapy followed by oesophagectomy. Alternatively, neoadjuvant chemotherapy is used. To date, strong evidence on the superiority of one modality over the other has not been provided. Currently, up to one-third of patients show a pathologically complete response after neoadjuvant chemoradiotherapy. To optimise the efficacy of neoadjuvant treatment for individual patients, prediction of response to neoadjuvant treatment is highly desired. Therefore, several clinical diagnostic modalities have been investigated for early response evaluation, of which positron emission tomography (PET) has been studied most extensively. To identify patients who might benefit from postponing or even omitting surgery, recent advances have been made in evaluating response after completion of neoadjuvant chemoradiotherapy. This review provides an overview of current evidence and recent advances in neoadjuvant chemoradiotherapy for oesophageal cancer and discusses the use of neoadjuvant chemotherapy compared to chemoradiotherapy. Moreover, clinical response evaluation to neoadjuvant chemoradiotherapy is reviewed.

Negative-pressure wound therapy for management of chronic neuropathic noninfected diabetic foot ulcerations - short-term efficacy and long-term outcomes.

PURPOSE: Negative pressure wound therapy (NPWT) is an adjunct method used in the treatment of diabetic foot ulceration (DFU). Real world data on its effectiveness and safety is scarce. In this prospective observational study, we assessed the short-term efficacy, safety, and long-term outcomes of NPWT in patients with type 2 diabetes (T2DM) and neuropathic, noninfected DFUs. METHODS: Based on wound characteristics, mainly area (>1 vs. ≤1 cm2), 75 patients with DFUs treated in an outpatient clinic were assigned to NPWT (n = 53) or standard therapy (n = 22). Wound area reduction was evaluated after 8 ± 1 days. Long-term outcomes assessed included complete ulceration closure and recurrence rate. RESULTS: Patients assigned to NPWT were characterized by greater wound area (15.7 vs. 2.9 cm2). Reduction in wound area was found in both the NPWT (-1.1 cm2, -10.2%, p = 0.0001) and comparator group (-0.3 cm2, -18.0%, p = 0.0038). No serious adverse events related to NPWT were noted. Within 1 year, 55.1% (27/49) of DFUs were closed in the NPWT group and 73.7% (14/19) in the comparator group (p = 0.15). In the logistic regression, wound duration and smaller initial area, but not treatment mode, were associated with closure. One-year follow-up after DFU resolution revealed an ~30.0% recurrence rate in both groups (p = 0.88). CONCLUSIONS: NPWT is a safe treatment for neuropathic, nonischemic, and noninfected DFU in patients with T2DM, although this observational study did not prove its effectiveness over standard therapy. Additionally, we report a high rate of both closure and recurrence of ulcers, the latter irrespective of initial ulcer area.

Importance of amino acids on vasopressin-stimulated water flow.

The presence of several naturally occurring amino acids in the serosal bath of toad urinary bladder significantly alters the hydrosmotic response of this tissue to vasopressin. We found that histidine, glutamate, and lysine increase vasopressin-stimulated water flow by 75%, 60%, and 43%, respectively. In contrast, alanine did not alter vasopressin-stimulated water flow, whereas glutamine decreased it by 25%. The effect of each amino acid represents intracellular events because their effects on theophylline-stimulated water flow were similar to those found with vasopressin. However, the site of action of amino acids varied, with some operating at steps before and others at steps after cyclic AMP generation. The fact that the metabolically inactive D-histidine and D-glutamate are as effective as their metabolically active L-counterparts suggests that the action of amino acids depends upon some physicochemical properties of their molecules. The ability of amino acids to influence the hydrosmotic effects of vasopressin was shown to be independent of prostaglandin generation, ionic composition, and molecular charge. In the case of histidine, we were able to obtain some understanding of the mechanism responsible for its action. We first showed that the effect of histidine does not depend upon its metabolism. In addition to D-histidine being as effective as the metabolically active L-histidine, we also showed that histidine is effective when its metabolism is abolished by low ambient temperature and also when its incorporation into proteins was prevented by cycloheximide. These findings suggest that histidine operates through some physicochemical property localized on its molecule. We were able to show that this property resides on the imidazole part of histidine. Imidazole, similar to histidine, increases vasopressin-stimulated water flow. Methylation of histidine on the imidazole ring completely abolished its effectiveness in increasing vasopressin-stimulated water flow. In contrast, methylation of histidine at the side chain increased vasopressin action similar to that found for histidine. We provide evidence that the physicochemical property of the imidazole ring of histidine is that of chelating Zn++ intracellularly, and that the intracellular site of action of histidine is closely linked to microtubules formation and/or action.

The morphometry of the accessory leaflets of the tricuspid valve in a four cuspidal model.

The tricuspid valve is of great importance because of the progress made in operative techniques and invasive cardiology accidents. This structure is more differentiated during evolution than the mitral valve. Accessory leaflets, their frequency and role are still controversial, despite the fact that they have been known from the beginning of the 20th century. The number of leaflets in the tricuspid valve grows in an evolutionary line, but the rules governing their appearance are still not known. The samples were taken from a group of 107 human adult hearts. The four-cuspidal form of the tricuspid valve was used as the simplest model to show the appearance of accessory leaflets for anatomical and statistical examination. On the basis of the results of this study we conclude that the separation of accessory leaflets is a complex process.

Quantum size effect on charges and phonons ultrafast dynamics in atomically controlled nanolayers of topological insulators Bi2Te3.

Heralded as one of the key elements for next generation spintronics devices, topological insulators (TIs) are now step by step envisioned as nanodevices like charge-to-spin current conversion or as Dirac fermions based nanometer Schottky diode for example. However, reduced to few nanometers, TIs layers exhibit a profound modification of the electronic structure and the consequence of this quantum size effect on the fundamental carriers and phonons ultrafast dynamics has been poorly investigated so far. Here, thanks to a complete study of a set of high quality molecular beam epitaxy grown nanolayers, we report the existence of a critical thickness of around ~6 nm, below which a spectacular reduction of the carrier relaxation time by a factor of ten is found in comparison to bulk Bi2 Te3 In addition, we also evidence an A1g optical phonon mode softening together with the appearance of a thickness dependence of the photoinduced coherent acoustic phonons signals. This drastic evolution of the carriers and phonons dynamics might be due an important electron-phonon coupling evolution due to the quantum confinement. These properties have to be taken into account for future TIs-based spintronic devices.

A single dose of dapagliflozin, an SGLT-2 inhibitor, induces higher glycosuria in GCK- and HNF1A-MODY than in type 2 diabetes mellitus.

AIMS: SGLT2 inhibitors are a new class of oral hypoglycemic agents used in type 2 diabetes (T2DM). Their effectiveness in maturity onset diabetes of the young (MODY) is unknown. We aimed to assess the response to a single dose of 10 mg dapagliflozin in patients with Hepatocyte Nuclear Factor 1 Alpha (HNF1A)-MODY, Glucokinase (GCK)-MODY, and type 2 diabetes. METHODS: We examined 14 HNF1A-MODY, 19 GCK-MODY, and 12 type 2 diabetes patients. All studied individuals received a single morning dose of 10 mg of dapagliflozin added to their current therapy of diabetes. To assess the response to dapagliflozin we analyzed change in urinary glucose to creatinine ratio and serum 1,5-Anhydroglucitol (1,5-AG) level. RESULTS: There were only four patients with positive urine glucose before dapagliflozin administration (one with HNF1A-MODY, two with GCK-MODY, and one with T2DM), whereas after SGLT-2 inhibitor use, glycosuria occurred in all studied participants. Considerable changes in mean glucose to creatinine ratio after dapagliflozin administration were observed in all three groups (20.51 ± 12.08, 23.19 ± 8.10, and 9.84 ± 6.68 mmol/mmol for HNF1A-MODY, GCK-MODY, and T2DM, respectively, p < 0.001 for all comparisons). Post-hoc analysis revealed significant differences in mean glucose to creatinine ratio change between type 2 diabetes and each monogenic diabetes in response to dapagliflozin (p = 0.02, p = 0.003 for HNF1-A and GCK MODY, respectively), but not between the two MODY forms (p = 0.7231). Significant change in serum 1,5-AG was noticed only in T2DM and it was -6.57 ± 7.34 mg/ml (p = 0.04). CONCLUSIONS: A single dose of dapagliflozin, an SGLT-2 inhibitor, induces higher glycosuria in GCK- and HNF1A-MODY than in T2DM. Whether flozins are a valid therapeutic option in these forms of MODY requires long-term clinical studies.

Proangiogenic activity of beta-carotene is coupled with the activation of endothelial cell chemotaxis.

Endothelial cells play an important role in angiogenesis (formation of new vessels from preexisting ones), which is essential for organogenesis, tissue remodeling but also inflammatory response, carcinogenesis in all periods of our life. Beta-carotene (BC) in non-toxic concentrations (up to 3 microM) had no detectable effect on HUVECs (human umbilical vein endothelial cells) proliferation or apoptosis, despite significant changes of the expression patterns of pro- and anti-apoptotic genes. However beta-carotene did not change the tubulogenic activity of HUVEC in the in vitro angiogenesis model, it potently accelerated the bFGF-induced development of microcapillaries, as well as the migration of endothelial cells, in matrigel plug injected subcutaneously to mice. Potent activation of endothelial cell migration in the in vitro model of chemotaxis was also observed. According to the microarray data, genes involved in cell/cell and cell/matrix adhesion, matrix reorganization, activation of chemotaxis, the G-protein regulated intracellular signaling as well as genes involved in the rapid remodeling of protein cytoskeleton were the most affected by BC in HUVEC. We conclude that beta-carotene in the physiological concentration range stimulates early steps of angiogenesis by the activation of cellular migration as well as matrix reorganization and decrease of cell adhesion.

Functional linkage between the active site of alpha-lytic protease and distant regions of structure: scanning alanine mutagenesis of a surface loop affects activity and substrate specificity.

Previous structural and kinetic characterization of mutations within the active site of alpha-lytic protease have demonstrated that amino acid residues in direct contact with the substrate are major substrate specificity determinants. The experiments described here identify residues 216-226 of alpha-lytic protease as a region of structure peripheral to the active site that also plays an important role in establishing the substrate specificity of the enzyme. Alanine substitution mutations within this surface loop of 19 amino acid residues significantly perturb the enzyme's specificity profile, despite being as far as 21 A from the hydroxyl group of Ser195. The kinetic consequences of the mutations are remarkably independent of position within the loop and suggest that active site plasticity is affected more than static structure. Kinetic characterization of double mutants with the Met190-->Ala broad-specificity active site mutation reveals varying degrees of non-additivity and indicates that active site plasticity can be influenced through multiple sets of interactions. Although these results clearly demonstrate that tuning of serine protease activity is possible through remodelling of structure surrounding the active site, practical issues such as retaining compatibility with the folding mechanism and stability of the mature enzyme present significant obstacles to general application of the technique.

Ambulatory blood pressure, left ventricular mass and vascular phenotypes in relation to the endothelial nitric oxide synthase gene Glu298Asp and intron 4 polymorphisms in a population-based family study.

Reduced nitric oxide production is associated with pathological changes in the cardiovascular system. In a study of randomly chosen families, we analysed the relationship between two polymorphisms (Glu298Asp and intron 4) of the endothelial nitric oxide synthase (eNOS) and ambulatory blood pressure (ABP), left ventricular mass index (LVMI) and vascular phenotypes. The study population consisted of 127 parents and 167 offspring. All subjects underwent 24 h ABP monitoring using a SpaceLabs 90207 device. 2D and M-mode echocardiograms were obtained. Pulse wave velocity between the common carotid and femoral artery was measured with the Complior device, and the carotid intima-media thickness (IMT) was assessed by ultrasound. For statistical analysis, covariables and correlations between relatives were taken into account. The frequency of genotypes was as follows: for Glu298Asp: 55.1%-Glu/Glu, 40.1%-Glu/Asp and 4.8%-Asp/Asp; for intron 4: 65.0%-4 b/b, 33.3%-4 b/a and 1.7%-4 a/a, being in Hardy-Weinberg equilibrium (P > or = 0.29). There was no relationship between the eNOS gene polymorphisms and ABP or LVMI either in parents or their offspring. Among parents, carriers of the 298Asp allele had higher IMT values as compared with Glu/Glu homozygotes (0.94 vs 0.70 mm; P = 0.007). Among offspring, there was a similar tendency (0.60 vs 0.53 mm; P = 0.10), which was confirmed by transmission disequilibrium tests for quantitative variables (P > or = 0.07). Our findings indicate that the Glu298Asp polymorphism of eNOS identifies patients with larger carotid IMT, also in younger subjects.