E-learning course improves knowledge in tobacco dependence, electronic nicotine delivery systems and heat-not-burn products in Medical School students.

BACKGROUND: Adequate training in tobacco, nicotine dependence and treatment is lacking in Medical School education. With the rise in popularity of electronic alternatives to cigarettes, future physicians should also be provided with the more recent scientific evidence on these products during their undergraduate studies. We introduced an e-learning course for Medical School students and assessed its effec-tiveness of increasing knowledge on these topics. METHODS: We developed 16 didactic modules divided in 3 courses: tobacco dependence (TDI), treating tobacco dependence (TDII) and electronic products and tobacco control (TDIII). The course was offered to 4th, 5th, and 6th year Medical School students in Italy. To assess learning outcomes, we examined the pre- to post- changes in knowledge scores associated with each course. Paired and independent samples t-tests were performed overall, and among smokers and non-smokers separately. RESULTS: A total of 1318 students completed at least one of the courses; 21% were self-reported smokers. A significant increase in knowledge was observed at the end of TDI (pre-course: 52.1±15.9, post-course: 79.9±13.5, p<0.001), TDII (pre-course: 52.5±13.0, post-course: 66.5±12.0, p<0.001) and TDIII (pre-course: 52.2±15.3, post-course: 76.1±17.7, p<0.001). Smokers showed significantly lower improvements compared to non-smokers. CONCLUSIONS: The e-learning course was effective in increasing knowledge about tobacco dependence, treatments, and electronic ni-cotine products in advanced medical students. Given the fundamental role for healthcare practitioners in encouraging and assisting people in quitting smoking, e-learning may be a useful tool in providing up-to-date and standardized training in the area during Medical School.

The bacterial quorum sensing molecule, 2-heptyl-3-hydroxy-4-quinolone (PQS), inhibits signal transduction mechanisms in brain tissue and is behaviorally active in mice.

Interkingdom communication between bacteria and host organisms is one of the most interesting research topics in biology. Quorum sensing molecules produced by Gram-negative bacteria, such as acylated homoserine lactones and quinolones, have been shown to interact with host cell receptors, stimulating innate immunity and bacterial clearance. To our knowledge, there is no evidence that these molecules influence CNS function. Here, we have found that low micromolar concentrations of the Pseudomonas aeruginosa quorum sensing autoinducer, 2-heptyl-3-hydroxy-4-quinolone (PQS), inhibited polyphosphoinositide hydrolysis in mouse brain slices, whereas four selected acylated homoserine lactones were inactive. PQS also inhibited forskolin-stimulated cAMP formation in brain slices. We therefore focused on PQS in our study. Biochemical effects of PQS were not mediated by the bitter taste receptors, T2R4 and T2R16. Interestingly, submicromolar concentrations of PQS could be detected in the serum and brain tissue of adult mice under normal conditions. Levels increased in five selected brain regions after single i.p. injection of PQS (10 mg/kg), peaked after 15 min, and returned back to normal between 1 and 4 h. Systemically administered PQS reduced spontaneous locomotor activity, increased the immobility time in the forced swim test, and largely attenuated motor response to the psychostimulant, methamphetamine. These findings offer the first demonstration that a quorum sensing molecule specifically produced by Pseudomonas aeruginosa is centrally active and influences cell signaling and behavior. Quorum sensing autoinducers might represent new interkingdom signaling molecules between ecological communities of commensal, symbiotic, and pathogenic microorganisms and the host CNS.

End-to-end image analysis pipeline for liquid-phase electron microscopy.

Liquid phase transmission electron microscopy allows the imaging of materials in liquid environments. The sample is encapsulated within electron-beam transparent windows and hence protected by the ultrahigh vacuum necessary within the electron gun. Such an approach allows to study biological and soft materials in their natural environment and offers the possibility of accessing their dynamic nature. Yet, the electron beam scattering from the windows and solvent increases the image noise and blur. Herein, we propose a pipeline to both de-noise and sharpen images obtained by liquid transmission electron microscopy. We develop the workflow in a way that it does not require any human interference, nor introduce artefacts, but actually unveils features of the imaged samples covered by the noise and the blur. LAY DESCRIPTION: Transmission Electron Microscopy TEM is one of the most powerful techniques for structural determination at the nanoscale, with the ability to image matter down to the atomic level. TEM is only possible by keeping the electron beam under high vacuum in order to avoid undesired scattering events in the beam path. High vacuum means that the TEM samples must conventionally be in solid-state. Thus, samples in liquid form or containing liquids, like water, need special preparation techniques which tend to alter the structure and chemical nature of the sample. Such alterations are particularly critical for biological and soft organic materials where the structures are controlled by the presence of water and/or other liquids. The development of new cameras, materials and sample holders have made possible for TEM to be performed on liquid samples. Liquid Phase Transmission Electron Microscopy (LTEM) offers the possibility to investigate nanoscopic structures in liquid state and monitor dynamic processes. However important limitations come from the liquid nature of samples in the imaging process such as the low contrast afforded by organic and biological materials and additional noise and blur introduced by the liquid sample and its thickness. Existing image analysis algorithms for TEM result inadequate for LTEM. The end-to-end image analysis method herein has the ability to recover the original images together with their sharpness, without introducing any artefacts. The proposed algorithms offer the great advantage of unveiling image details which are not usually seen during imaging, thus allowing a better understanding of the nature, structure and ultimately the function of the investigated structures. The fully automatised analysis method allows to efficiently process dozens of images in few hours, improving dramatically the performance of LTEM imaging.

Validación del Índice Funcional para Osteoartritis de Manos (FIHOA) en pacientes con artritis reumatoidea / Validation of the Functional Index for Hand Osteoarthritis (FIHOA) in patients with rheumatoid arthritis

El FIHOA fue desarrollado para evaluar la capacidad funcional de pacientes con OA de manos. Objetivo: Validar FIHOA en pacientes con AR. Métodos: Estudio analítico, observacional prospectivo de corte transversal. Se incluyeron pacientes consecutivos con diagnóstico de AR (ACR/EULAR 2010). Se consignaron datos demográficos y características de la enfermedad. Todos los pacientes completaron los siguientes cuestionarios autoadministrados: FIHOA, HAQ-A, HAQ-UP-A y Quick DASH. En un subgrupo de pacientes, una terapista ocupacional valoró la capacidad funcional de la mano por medio del test de SODA-A. Se evaluó la reproducibilidad de FIHOA. Análisis estadístico: Estadística descriptiva. Confiabilidad con test de Cronbach. Validez de constructo con correlación de Spearman. Reproducibilidad test re-test. Modelo de regresión lineal. Resultados: Se incluyeron 100 pacientes. La prueba alfa de Cronbach fue de 0,94. No se evidenciaron preguntas redundantes. El FIHOA mostró excelente correlación con HAQ-A (r=0,89); HAQ-UP-A (r=0,89); Quick DASH (r=0,90) y SODA-A (r=-0,80); y buena correlación con DAS28-ERS (r=0,65), y con otros parámetros de la enfermedad. La reproducibilidad fue 0,73. La regresión lineal múltiple mostró como principal determinante del FIHOA a la presencia de rigidez matinal seguida por el uso de corticoides y el EVA general de pacientes. Conclusión: El FIHOA resultó ser confiable, válido y reproducible en pacientes con AR

FIHOA was developed to evaluate the functional capacity of patients with OA hands. Objetive: To validate FIHOA in patients with RA. Methods: Analytical, observational, prospective cross-sectional study. Consecutive patients with diagnosis of RA (ACR/EULAR 2010) were included. Demographic and RA characteristics were recorded. Patients completed the following self-administered questionnaires: FIHOA, HAQ-A, HAQ-UP-A and Quick DASH. For a patient subgroup, an occupational therapist performed an objective evaluation of the functional capacity of the hands using the SODA-A. Reproducibility was assessed. Statistical analysis: Descriptive statistics. Reliability with the Cronbach test. Construct validity with Spearman correlation. Reproducibility with test-retest reliability. Linear regression model. Results: One hundred patients were included. Cronbach's alpha test was 0.94. There were no redundant questions. FIHOA showed an excellent correlation with HAQ-A (r=0.89); HAQUP-A (r=0.89); Quick DASH (r=0.90) and SODA-A (r=-0.80); and a good correlation with DAS28- ERS (r=0.65) and with other disease parameters. Questionnaire reproducibility was 0.73. A multiple linear regression showed morning stiffness as the main determinant of FIHOA, followed by glucocorticoid use and patient global assessment. Conclusion: FIHOA was found to be reliable, valid and reproducible in patients with RA

The reduction in glutamate release is predictive of cognitive and emotional alterations that are corrected by the positive modulator of AMPA receptors S 47445 in perinatal stressed rats.

S 47445 is a positive modulator of glutamate AMPA-type receptors, possessing neurotrophic and enhancing synaptic plasticity effects as well as pro-cognitive and anti-stress properties. Here, the drug was assessed in the perinatal stress (PRS) rat model, known to have a high predictive validity with monoaminergic antidepressants. The effects of a chronic treatment (i.p.) with S 47445 were investigated on risk-taking, motivational and cognitive behavior. S 47445 (1 and 10 mg/kg) increased the exploration of the elevated-plus maze and light/dark box as well as the time spent grooming in the splash test, and improved social memory in PRS rats. Also, the effects of S 47445 were examined on the synaptic neurotransmission. The reduced depolarization-evoked glutamate release induced by PRS was corrected with S 47445 (10 mg/kg). Remarkably, the reduction in glutamate release induced by PRS and corrected by S 47445 chronic treatment was correlated with all the behavioral changes. S 47445 at 10 mg/kg also normalized the lower levels of synaptic vesicle-associated proteins in ventral hippocampus in PRS rats. Finally, S 47445 reversed the decrease of mGlu5 receptors, GR and OXTR induced by PRS. Collectively, in an animal model of stress-related disorders, S 47445 corrected the imbalance between excitatory and inhibitory neurotransmission by regulating glutamate-evoked release that is predictive of PRS behavioral alterations, and also normalized the reduction of trafficking of synaptic vesicles induced by PRS. These results support the interest of glutamatergic-based therapeutic strategies to alleviate stress-related disorders.

Bone texture analysis using CT-simulation scans to individuate risk parameters for radiation-induced insufficiency fractures.

This study deals with the role of texture analysis as a predictive factor of radiation-induced insufficiency fractures in patients undergoing pelvic radiation. INTRODUCTION: This study aims to assess the texture analysis (TA) of computed tomography (CT) simulation scans as a predictive factor of insufficiency fractures (IFs) in patients with pelvic malignancies undergoing radiation therapy (RT). METHODS: We performed an analysis of patients undergoing pelvic RT from January 2010 to December 2014, 24 of whom had developed pelvic bone IFs. We analyzed CT-simulation images using ImageJ macro software and selected two regions of interest (ROIs), which are L5 body and the femoral head. TA parameters included mean (m), standard deviation (SD), skewness (sk), kurtosis (k), entropy (e), and uniformity (u). The IFs patients were compared (1:2 ratio) with controlled patients who had not developed IFs and matched for sex, age, menopausal status, type of tumor, use of chemotherapy, and RT dose. A reliability test of intra- and inter-reader ROI TA reproducibility with the intra-class correlation coefficient (ICC) was performed. Univariate and multivariate analyses (logistic regression) were applied for TA parameters observed both in the IFs and the controlled groups. RESULTS: Inter- and intra-reader ROI TA was highly reproducible (ICC > 0.90). Significant TA parameters on paired t test included L5 m (p = 0.001), SD (p = 0.002), k (p = 0.006), e (p = 0.004), and u (p = 0.015) and femoral head m (p < 0.001) and SD (p = 0.001), whereas on logistic regression analysis, L5 e (p = 0.003) and u (p = 0.010) and femoral head m (p = 0.027), SD (p = 0.015), and sex (p = 0.044). CONCLUSIONS: In our experience, bone CT TA could be correlated to the risk of radiation-induced IFs. Studies on a large patient series and methodological refinements are warranted.

Acid-sensing ion channel 1a is required for mGlu receptor dependent long-term depression in the hippocampus.

Acid-sensing ion channels (ASICs), members of the degenerin/epithelial Na+ channel superfamily, are widely distributed in the mammalian nervous system. ASIC1a is highly permeable to Ca2+ and are thought to be important in a variety of physiological processes, including synaptic plasticity, learning and memory. To further understand the role of ASIC1a in synaptic transmission and plasticity, we investigated metabotropic glutamate (mGlu) receptor-dependent long-term depression (LTD) in the hippocampus. We found that ASIC1a channels mediate a component of LTD in P30-40 animals, since the ASIC1a selective blocker psalmotoxin-1 (PcTx1) reduced the magnitude of LTD induced by application of the group I mGlu receptor agonist (S)-3,5-Dihydroxyphenylglycine (DHPG) or induced by paired-pulse low frequency stimulation (PP-LFS). Conversely, PcTx1 did not affect LTD in P13-18 animals. We also provide evidence that ASIC1a is involved in group I mGlu receptor-induced increase in action potential firing. However, blockade of ASIC1a did not affect DHPG-induced polyphosphoinositide hydrolysis, suggesting the involvement of some other molecular partners in the functional crosstalk between ASIC1a and group I mGlu receptors. Notably, PcTx1 was able to prevent the increase in GluA1 S845 phosphorylation at the post-synaptic membrane induced by group I mGlu receptor activation. These findings suggest a novel function of ASIC1a channels in the regulation of group I mGlu receptor synaptic plasticity and intrinsic excitability.

Quantitative 3D investigation of Neuronal network in mouse spinal cord model.

The investigation of the neuronal network in mouse spinal cord models represents the basis for the research on neurodegenerative diseases. In this framework, the quantitative analysis of the single elements in different districts is a crucial task. However, conventional 3D imaging techniques do not have enough spatial resolution and contrast to allow for a quantitative investigation of the neuronal network. Exploiting the high coherence and the high flux of synchrotron sources, X-ray Phase-Contrast multiscale-Tomography allows for the 3D investigation of the neuronal microanatomy without any aggressive sample preparation or sectioning. We investigated healthy-mouse neuronal architecture by imaging the 3D distribution of the neuronal-network with a spatial resolution of 640 nm. The high quality of the obtained images enables a quantitative study of the neuronal structure on a subject-by-subject basis. We developed and applied a spatial statistical analysis on the motor neurons to obtain quantitative information on their 3D arrangement in the healthy-mice spinal cord. Then, we compared the obtained results with a mouse model of multiple sclerosis. Our approach paves the way to the creation of a "database" for the characterization of the neuronal network main features for a comparative investigation of neurodegenerative diseases and therapies.

From the Blood to the Central Nervous System: A Nanoparticle's Journey Through the Blood-Brain Barrier by Transcytosis.

Designing nanoparticles that effectively enter the central nervous system (CNS) rapidly and without alteration is one of the major challenges in the use of nanotechnology for the brain. In this chapter, we explore the process of transcytosis, a receptor-mediated transport pathway that permits endogenous macromolecules to enter the CNS by crossing the blood-brain barrier. Transcytosis across the blood-brain barrier involves a number of distinct stages, including receptor binding, endocytosis into a transport vesicle, trafficking of the vesicle to the opposite side of the cell, and finally exocytosis and release of cargo. For each stage, we discuss the current knowledge on biological, physiological, and physical factors that influence nanoparticle transit through that stage of transcytosis, with implications for nanoparticle design. Finally, we look at the current progress in designing nanoparticles that exploit transcytosis for CNS delivery.

Rescue of mitochondrial function in parkin-mutant fibroblasts using drug loaded PMPC-PDPA polymersomes and tubular polymersomes.

Mutations in parkin cause autosomal recessive Parkinsonism and mitochondrial defects. A recent drug screen identified a class of steroid-like hydrophobic compounds able to rescue mitochondrial function in parkin-mutant fibroblasts. Whilst these possess therapeutic potential, the size and high hydrophobicity of some may limit their ability to penetrate the blood-brain barrier from systemic circulation, something that could be improved by novel drug formulations. In the present study, the steroid-like compounds Ursolic Acid (UA) and Ursocholanic Acid (UCA) were successfully encapsulated within nanoscopic polymersomes formed by poly(2-(methacryloyloxy)ethyl phosphorylcholine)-poly(2-di-isopropylamino)ethyl methacrylate) (PMPC-PDPA) and separated into spherical and tubular morphologies to assess the effects of nanoparticle mediated delivery on drug efficacy. Following incubation with either morphology, parkin-mutant fibroblasts demonstrated time and concentration dependent increases in intracellular ATP levels, resembling those resulting from treatment with nascent UA and UCA formulated in 0.1% DMSO, as used in the original drug screen. Empty PMPC-PDPA polymersomes did not alter physiological measures related to mitochondrial function or induce cytotoxicity. In combination with other techniques such as ligand functionalisation, PMPC-PDPA nanoparticles of well-defined morphology may prove a promising platform for tailoring the pharmacokinetic profile and organ specific bio-distribution of highly hydrophobic compounds.

In vivo molecular imaging of HER2 expression in a rat model of Barrett's esophagus adenocarcinoma.

Human epidermal growth factor receptor 2 (HER2) is involved in the malignant progression of several human cancers, including esophageal adenocarcinoma (EAC). The purpose of this study was to evaluate HER2 overexpression and to explore the feasibility of confocal laser endomicroscopy for in vivo molecular imaging of HER2 status in an animal model of Barrett's-related EAC. Rats underwent esophagojejunostomy with gastric preservation. At 30 weeks post-surgery, the esophagus of 46 rats was studied; endoscopic and histological findings were correlated with HER2 immunofluorescence on excised biopsies and gross specimens. At this age, 23/46 rats developed Barrett's esophagus (BE), and 6/46 had cancer (four EAC and two squamous cell carcinomas). A significant overexpression of HER2 was observed in esophageal adenocarcinoma compared with normal squamous esophagus (9.4-fold) and BE (6.0-fold). AKT and its phosphorylated form were also overexpressed in cancer areas. Molecular imaging was performed at 80 weeks post-surgery in four rats after tail injection of fluorescent-labeled anti-HER2 antibody. At this age, 3/4 rats developed advance adenocarcinoma and showed in vivo overexpression of HER2 by molecular confocal laser endomicroscopy with heterogeneous distribution within cancer; no HER2 signal was observed in normal or Barrett's tissues. Therefore, HER2 overexpression is a typical feature of the surgical induced model of EAC that can be easily quantified in vivo using an innovative mini-invasive approach including confocal endomicroscopy; this approach may avoid limits of histological evaluation of HER2 status on 'blinded' biopsies.

Influence of a sport-specific training background on vertical jumping and throwing performance in young female basketball and volleyball players.

AIM: The purpose of this study was to evaluate the influence of 3 years of sport-specific training background (SSTB) on vertical jumping and throwing performance in young female basketball and volleyball players. METHODS: Thirty-one healthy adolescent girls, of which 11 age-matched control subjects [C], 10 basketballers (BP) and 10 volleyballers (VP) participated to the study. The throwing performance was assessed by seated backward overhead ball throw (SBOMBT) and seated chest pass throw (SCPT) using a 3-kg rubber medicine ball. Instead, the vertical jumping performance was evaluated by squat jump (SJ) and countermovement jump with (CMJ-AS) and without arm swing (CMJ) using Optojump system (Microgate srl, Italy). RESULTS: During SJ and CMJ with and without arm swing VP group showed a higher vertical jump performance than BP and C ones. In particular we showed that VP exhibited a higher flight time and jump height than C (P<0.05) in SJ, CMJ and CMJ-AS tests. Players showed higher performances than C in SCPT and SBOMBT. However, we found only a significant difference (P<0.05) in the comparison between BP and C during SCPT. Moreover, we found significant correlations between SBOBMT performances and CMJ-AS jump heights in C (r= 0.60; p= 0.02) and VP (r= 0.81; p<0.01) groups compared to BP one (r= -0.47; p= 0.08). CONCLUSION: These data suggest that 3 years of SSTB might be able to promote significant neuromuscular adaptations in volleyball and basketball athletes' maximal power compared to age-matched control subjects.

Plasmonic ELISA for the detection of gp120 at ultralow concentrations with the naked eye.

The technique of plasmonic ELISA is utilised here to detect the HIV-1 protein gp120 with the ultralow limit of detection of 8 × 10(-20) M (10(-17) g mL(-1)) in an independent laboratory. It was corroborated that changes in the concentration of hydrogen peroxide as small as 0.05 µM could lead to nanoparticle solutions of completely different tonality.

[Renal cysts: current indications for ultrasound study]. / Le lesioni renali cistiche: attuali indicazioni per lo studio ultrasonografico.

In order to optimize the use of ultrasound in the characterization of cystic or nodular lesions, the incidence of simple cysts in the general population, their growth and evolution is discussed considering some follow-up studies. After studying the typical sonographic criteria of simple cyst, we describe the sonographic features of cancer and the incidence of various types of tumors. In such cases radiological evaluations are required and the Bosniak classification is useful in the clinical choice of waiting, more detailed diagnosis or excision of the lesion. The use of the radiological means will decrease when EcocolorDoppler with contrast is widely available. Nevertheless, this technique has already found its way into peculiar fields and in certain cases, it has a higher sensitivity compared to TAC with contrast medium.

Helium ion microscopy based wall thickness and surface roughness analysis of polymer foams obtained from high internal phase emulsion.

Due to their wide range of applications, porous polymers obtained from high internal phase emulsions have been widely studied using scanning electron microscopy. However, due to their lack of electrical conductivity, quantitative information of wall thicknesses and surface roughness, which are of particular interest to tissue engineering, has not been obtained. Here, Helium Ion Microscopy is used to examine uncoated polymer foams and some very strong but unexpected contrast is observed, the origin of which is established here. Based on this analysis, a method for the measurement of wall thickness variations and wall roughness measurements has been developed, based on the modeling of Helium ion transmission. The results presented here indicate that within the walls of the void structure there exist small features with height variations of ~30 nm and wall thickness variations from ~100 nm to larger 340 nm in regions surrounding interconnecting windows within the structure. The suggested imaging method is applicable to other porous carbon based structures with wall thicknesses in the range of 40-340 nm.

Type-3 metabotropic glutamate receptors regulate chemoresistance in glioma stem cells, and their levels are inversely related to survival in patients with malignant gliomas.

Drug treatment of malignant gliomas is limited by the intrinsic resistance of glioma stem cells (GSCs) to chemotherapy. GSCs isolated from human glioblastoma multiforme (GBM) expressed metabotropic glutamate receptors (mGlu3 receptors). The DNA-alkylating agent, temozolomide, killed GSCs only if mGlu3 receptors were knocked down or pharmacologically inhibited. In contrast, mGlu3 receptor blockade did not affect the action of paclitaxel, etoposide, cis-platinum, and irinotecan. mGlu3 receptor blockade enabled temozolomide toxicity by inhibiting a phosphatidylinositol-3-kinase/nuclear factor-κB pathway that supports the expression of O(6)-methylguanine-DNA methyltransferase (MGMT), an enzyme that confers resistance against DNA-alkylating agents. In mice implanted with GSCs into the brain, temozolomide combined with mGlu3 receptor blockade substantially reduced tumor growth. Finally, 87 patients with GBM undergoing surgery followed by adjuvant chemotherapy with temozolomide survived for longer time if tumor cells expressed low levels of mGlu3 receptors. In addition, the methylation state of the MGMT gene promoter in tumor extracts influenced survival only in those patients with low expression of mGlu3 receptors in the tumor. These data encourage the use of mGlu3 receptor antagonists as add-on drugs in the treatment of GBM, and suggest that the transcript of mGlu3 receptors should be measured in tumor specimens for a correct prediction of patients' survival in response to temozolomide treatment.

Group III and subtype 4 metabotropic glutamate receptor agonists: discovery and pathophysiological applications in Parkinson's disease.

Restoring the balance between excitatory and inhibitory circuits in the basal ganglia, following the loss of dopaminergic (DA) neurons of the substantia nigra pars compacta, represents a major challenge to treat patients affected by Parkinson's disease (PD). The imbalanced situation in favor of excitation in the disease state may also accelerate excitotoxic processes, thereby representing a potential target for neuroprotective therapies. Reducing the excitatory action of glutamate, the major excitatory neurotransmitter in the basal ganglia, should lead to symptomatic improvement for PD patients and may promote the survival of DA neurons. Recent studies have focused on the modulatory action of metabotropic glutamate (mGlu) receptors on neurodegenerative diseases including PD. Group III mGlu receptors, including subtypes 4, 7 and 8, are largely expressed in the basal ganglia. Recent studies highlight the use of selective mGlu4 receptor positive allosteric modulators (PAMs) for the treatment of PD. Here we review the effects of newly-designed group-III orthosteric agonists on neuroprotection, neurorestoration and reduction of l-DOPA induced dyskinesia in animal models of PD. The combination of orthosteric mGlu4 receptor selective agonists with PAMs may open new avenues for the symptomatic treatment of PD. This article is part of a Special Issue entitled 'Metabotropic Glutamate Receptors'.

Results from an Italian multicentric registry comparing heparin-bonded ePTFE graft and autologous saphenous vein in below-knee femoro-popliteal bypasses.

AIM: The aim of this study was to evaluate early and follow-up results of below-knee bypasses performed with a bioactive heparin-treated ePTFE graft in patients with peripheral arterial obstructive disease (PAOD) in a multicentric retrospective registry involving seven Italian vascular centers and to compare them with those obtained in patients operated on with autologous saphenous vein (ASV) in the same centres in the same period of time. METHODS: Over a nine-year period, ending in 2010, a heparin bonded prosthetic graft (Propaten Gore-Tex, W.L. Gore & Associates Inc, Flagstaff, AZ, USA) was implanted in 556 patients undergoing below-knee revascularization for PAOD (HePTFE group). In the same period of time 394 below-knee bypasses with ipsilateral ASV were performed (ASV group). Data concerning these interventions were retrospectively collected in a multicenter registry with a dedicated database. Early (<30 days) results were analyzed in terms of graft patency, major amputation rates and mortality. Follow-up results were analyzed in terms of primary and secondary graft patency, limb salvage and survival. RESULTS: Among patients of HePTFE group, 413 had critical limb ischemia (74%); the corresponding figure for ASV group was 84% (332 interventions, P<0.001). Eighty-nine patients in HePTFE group (16%) and 207 patients in ASV group (52.5%; P<0.001) had distal tibial anastomosis. Patients in HePTFE group had more frequently adjunctive procedures performed at distal anastomotic sites in order to improve run-off status. Thirty-day death rate was 1.9% in HePTFE group and 0.5% in ASV group (P=0.08). The rates of perioperative thromboses and amputations were 6% and 3.5% in HePTFE group, and 5% and 1.7% in ASV group, without significant differences between the two groups. Mean duration of follow-up was 28.5±22.1 months; 921 patients (97%) had at least one postoperative clinical and ultrasonographic control. Estimated 48-month survival rates were 81% in HePTFE group and 74% in ASV group (P=0.7, log rank 0.1). Primary patency rate at 48 months was significantly better in ASV group (61%) than in HePTFE group (44.5%; P=0.004, log rank 8.1). The rates of secondary patency at 48 months were 57% in HePTFE group and 67.5% in ASV group (P=0.1, log rank 1.9); the corresponding values in terms of limb salvage in patients with critical limb ischemia were 77% and 79.5% (P=0.3, log rank 0.9), respectively. CONCLUSION: Data from this large, retrospective registry confirmed that the indexed heparin-bonded ePTFE graft provides satisfactory early and mid-term results in patients undergoing surgical below-knee revascularization. While autologous saphenous vein maintains its superiority in terms of primary patency, secondary patency and limb salvage rates are comparable.

Cinnabarinic acid, an endogenous metabolite of the kynurenine pathway, activates type 4 metabotropic glutamate receptors.

Cinnabarinic acid is an endogenous metabolite of the kynurenine pathway that meets the structural requirements to interact with glutamate receptors. We found that cinnabarinic acid acts as a partial agonist of type 4 metabotropic glutamate (mGlu4) receptors, with no activity at other mGlu receptor subtypes. We also tested the activity of cinnabarinic acid on native mGlu4 receptors by examining 1) the inhibition of cAMP formation in cultured cerebellar granule cells; 2) protection against excitotoxic neuronal death in mixed cultures of cortical cells; and 3) protection against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice after local infusion into the external globus pallidus. In all these models, cinnabarinic acid behaved similarly to conventional mGlu4 receptor agonists, and, at least in cultured neurons, the action of low concentrations of cinnabarinic acid was largely attenuated by genetic deletion of mGlu4 receptors. However, high concentrations of cinnabarinic acid were still active in the absence of mGlu4 receptors, suggesting that the compound may have off-target effects. Mutagenesis and molecular modeling experiments showed that cinnabarinic acid acts as an orthosteric agonist interacting with residues of the glutamate binding pocket of mGlu4. Accordingly, cinnabarinic acid did not activate truncated mGlu4 receptors lacking the N-terminal Venus-flytrap domain, as opposed to the mGlu4 receptor enhancer, N-phenyl-7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxamide (PHCCC). Finally, we could detect endogenous cinnabarinic acid in brain tissue and peripheral organs by high-performance liquid chromatography-tandem mass spectrometry analysis. Levels increased substantially during inflammation induced by lipopolysaccharide. We conclude that cinnabarinic acid is a novel endogenous orthosteric agonist of mGlu4 receptors endowed with neuroprotective activity.