Changes in glial cell activation and extracellular vesicles production precede the onset of disease symptoms in transgenic hSOD1G93A pigs

SOD1 gene is associated with progressive motor neuron degeneration in the familiar forms of amyotrophic lateral sclerosis. Although studies on mutant human SOD1 transgenic rodent models have provided important insights into disease pathogenesis, they have not led to the discovery of early biomarkers or effective therapies in human disease. The recent generation of a transgenic swine model expressing the human pathological hSOD1G93A gene, which recapitulates the course of human disease, represents an interesting tool for the identification of early disease mechanisms and diagnostic biomarkers. Here, we analyze the activation state of CNS cells in transgenic pigs during the disease course and investigate whether changes in neuronal and glial cell activation state can be reflected by the amount of extracellular vesicles they release in biological fluids. To assess the activation state of neural cells, we performed a biochemical characterization of neurons and glial cells in the spinal cords of hSOD1G93A pigs during the disease course. Quantification of EVs of CNS cell origin was performed in cerebrospinal fluid and plasma of transgenic pigs at different disease stages by Western blot and peptide microarray analyses. We report an early activation of oligodendrocytes in hSOD1G93A transgenic tissue followed by astrocyte and microglia activation, especially in animals with motor symptoms. At late asymptomatic stage, EV production from astrocytes and microglia is increased in the cerebrospinal fluid, but not in the plasma, of transgenic pigs reflecting donor cell activation in the spinal cord. Estimation of EV production by biochemical analyses is corroborated by direct quantification of neuron- and microglia-derived EVs in the cerebrospinal fluid by a Membrane Sensing Peptide enabled on-chip analysis that provides fast results and low sample consumption. Collectively, our data indicate that alteration in astrocytic EV production precedes the onset of disease symptoms in the hSODG93A swine model, mirroring donor cell activation in the spinal cord, and suggest that EV measurements from the cells first activated in the ALS pig model, i.e. OPCs, may further improve early disease detection.

Bipolar Disorder: Identity, Social Support, Religiosity and Spirituality. Can Religiosity/Spirituality be a Mood Balancing Factor? An Italian Case Report

This paper presents a case study to support the hypothesis that religiosity and spirituality (R/S), as mood balancing factors, could facilitate the recovery process for patients suffering from bipolar disorder (BD) once they have been stabilized and are receiving appropriate support (e.g., in a residential rehabilitative center). After a succinct review of BD and R/S, the patient's medical history and rehabilitation pathway are described, with a particular focus on the role played by R/S. The authors found that in this case, once the patient was stabilized, R/S helped to consolidate her feelings of well-being, increasing her positive perception of social support services and ultimately her self-confidence.

International Society for Extracellular Vesicles Workshop. QuantitatEVs: multiscale analyses, from bulk to single extracellular vesicle

The 'QuantitatEVs: multiscale analyses, from bulk to single vesicle' workshop aimed to discuss quantitative strategies and harmonized wet and computational approaches toward the comprehensive analysis of extracellular vesicles (EVs) from bulk to single vesicle analyses with a special focus on emerging technologies. The workshop covered the key issues in the quantitative analysis of different EV-associated molecular components and EV biophysical features, which are considered the core of EV-associated biomarker discovery and validation for their clinical translation. The in-person-only workshop was held in Trento, Italy, from January 31st to February 2nd, 2023, and continued in Milan on February 3rd with "Next Generation EVs", a satellite event dedicated to early career researchers (ECR). This report summarizes the main topics and outcomes of the workshop.

Particle profiling of EV-lipoprotein mixtures by AFM nanomechanical imaging

The widely overlapping physicochemical properties of lipoproteins (LPs) and extracellular vesicles (EVs) represents one of the main obstacles for the isolation and characterization of these pervasive biogenic lipid nanoparticles. We herein present the application of an atomic force microscopy (AFM)-based quantitative morphometry assay to the rapid nanomechanical screening of mixed LPs and EVs samples. The method can determine the diameter and the mechanical stiffness of hundreds of individual nanometric objects within few hours. The obtained diameters are in quantitative accord with those measured via cryo-electron microscopy (cryo-EM); the assignment of specific nanomechanical readout to each object enables the simultaneous discrimination of co-isolated EVs and LPs even if they have overlapping size distributions. EVs and all classes of LPs are shown to be characterised by specific combinations of diameter and stiffness, thus making it possible to estimate their relative abundance in EV/LP mixed samples in terms of stoichiometric ratio, surface area and volume. As a side finding, we show how the mechanical behaviour of specific LP classes is correlated to distinctive structural features revealed by cryo-EM. The described approach is label-free, single-step and relatively quick to perform. Importantly, it can be used to analyse samples which prove very challenging to assess with several established techniques due to ensemble-averaging, low sensibility to small particles, or both, thus providing a very useful tool for quickly assessing the purity of EV/LP isolates including plasma- and serum-derived preparations.

Head-to-Head Comparison of Tissue Factor-Dependent Procoagulant Potential of Small and Large Extracellular Vesicles in Healthy Subjects and in Patients with SARS-CoV-2 Infection

The relative contribution of small (sEVs) and large extracellular vesicles (lEVs) to the total plasma procoagulant potential is not yet well defined. Thus, we compared total and TFpos-sEVs and -lEVs isolated from healthy subjects and COVID-19 patients during the acute phase of the infection and after symptom remission in terms of (1) vesicle enumeration using nanoparticle tracking assay, imaging flow cytometry, and TF immunofluorescence localization in a single-vesicle analysis using microarrays; (2) cellular origin; and (3) TF-dependent Xa generation capacity, as well as assessing the contribution of the TF inhibitor, TFPI. In healthy subjects, the plasma concentration of CD9/CD63/CD81pos sEVs was 30 times greater than that of calceinpos lEVs, and both were mainly released by platelets. Compared to lEVs, the levels of TFpos-sEVs were 2-fold higher. The TF-dependent Xa generation capacity of lEVs was three times greater than that of sEVs, with the latter being hindered by TFPI. Compared to HSs, the amounts of total and TFpos-sEVs and -lEVs were significantly greater in acute COVID-19 patients, which reverted to the physiological values at the 6-month follow-up. Interestingly, the FXa generation of lEVs only significantly increased during acute infection, with that of sEV being similar to that of HSs. Thus, in both healthy subjects and COVID-19 patients, the TF-dependent procoagulant potential is mostly sustained by large vesicles.

Proof of concept of using a membrane-sensing peptide for sEVs affinity-based isolation

Introduction: One main limitation in biomarker studies using EVs is the lack of a suitable isolation method rendering high yield and purity samples in a quick and easily standardized procedure. Here we report an affinity isolation method with a membrane-sensing peptide (MSP) derived from bradykinin. Methods: We designed a protocol based on agarose beads carrying cation chelates to specifically bind to the 6His-tagged membrane-sensing peptide. This approach presents several advantages: 1) cation-carrying agaroses are widely used and standardized for His-tagged protein isolation, 2) the affinity protocol can be performed in small volumes, feasible and manageable for clinical routine and 3) elution with imidazole or EDTA allows a gentle and easy recovery without EV damage, facilitating subsequent characterization and functional analyses. Results: The optimized final procedure incubates 0.5 mg of peptide for 10 min with 10 µL of Long-arm Cobalt agarose before an overnight incubation with concentrated cell conditioned medium. EV downstream analyses can be directly performed on the agarose beads adding lysis or nucleic-acid extraction buffers, or gently eluted with imidazole or EDTA, rendering a fully competent EV preparation. Discussion: This new isolation methodology is based on the recognition of general membrane characteristics independent of surface markers. It is thus unbiased and can be used in any species EV sample, even in samples from animal or plant species against which no suitable antibodies exist. Being an affinity method, the sample handling protocol is very simple, less time-consuming, does not require specialized equipment and can be easily introduced in a clinical automated routine. We demonstrated the high purity and yield of the method in comparison with other commercially available kits. This method can also be scale up or down, with the possibility of analyzing very low amounts of sample, and it is compatible with any downstream analyses thanks to the gentle elution procedure.

Amniotic Mesenchymal-Derived Extracellular Vesicles and Their Role in the Prevention of Persistent Post-Breeding Induced Endometritis

Persistent post-breeding induced endometritis (PPBIE) is considered a major cause of subfertility in mares. It consists of persistent or delayed uterine inflammation in susceptible mares. There are many options for the treatment of PPBIE, but in this study, a novel approach aimed at preventing the onset of PPBIE was investigated. Stallion semen was supplemented with extracellular vesicles derived from amniotic mesenchymal stromal cells (AMSC-EVs) at the time of insemination to prevent or limit the development of PPBIE. Before use in mares, a dose–response curve was produced to evaluate the effect of AMSC-EVs on spermatozoa, and an optimal concentration of 400 × 106 EVs with 10 × 106 spermatozoa/mL was identified. At this concentration, sperm mobility parameters were not negatively affected. Sixteen susceptible mares were enrolled and inseminated with semen (n = 8; control group) or with semen supplemented with EVs (n = 8; EV group). The supplementation of AMSC-EVs to semen resulted in a reduction in polymorphonuclear neutrophil (PMN) infiltration as well as intrauterine fluid accumulation (IUF; p < 0.05). There was a significant reduction in intrauterine cytokine levels (p < 0.05) for TNF-α and IL-6 and an increase in anti-inflammatory IL-10 in mares in the EV group, suggesting successful modulation of the post-insemination inflammatory response. This procedure may be useful for mares susceptible to PPBIE.

Membrane-Sensing Peptides for Extracellular Vesicle Analysis

Analytical platforms for small extracellular vesicle (sEV) high-throughput analysis are highly desirable. These bionanoparticles present fairly distinctive lipid membrane features including high curvature, lipid-packing defects, and a relative abundance in lipids. sEV membrane could be considered as a "universal" marker, complementary or alternative to traditional surface-associated proteins. Here, we describe the use of membrane-sensing peptides as a new, highly efficient ligand to directly integrate sEV capturing and analysis on a microarray platform.

Hybrid Peptide-Agarose Hydrogels for 3D Immunoassays

Recent advances in biosensing analytical platforms have brought relevant outcomes for novel diagnostic and therapy-oriented applications. In this context, 3D droplet microarrays, where hydrogels are used as matrices to stably entrap biomolecules onto analytical surfaces, potentially provide relevant advantages over conventional 2D assays, such as increased loading capacity, lower nonspecific binding, and enhanced signal-to-noise ratio. Here, we describe a hybrid hydrogel composed of a self-assembling peptide and commercial agarose (AG) as a suitable matrix for 3D microarray bioassays. The hybrid hydrogel is printable and self-adhesive and allows analyte diffusion. As a showcase example, we describe its application in a diagnostic immunoassay for the detection of SARS-CoV-2 infection.

Epitope Mapping on Microarrays Highlights a Sequence on the N Protein with Strong Immune Response in SARS-CoV-2 Patients

In SARS-CoV-2 pandemic scenario, the identification of rapid methods to detect antibodies against coronavirus has been a wide and urgent issue. Epitope mapping on peptide microarrays is a rapid way to identify sequences with a high immunoreactivity. The process begins with a proteome-wide screening, based on immune affinity; the use of a high-density microarray is followed by a validation phase, where a restricted panel of probes is tested using peptide microarrays; peptide sequences are immobilized through a click-based strategy.COVID-19-positive sera are tested and immuno-domains regions are identified on SARS-CoV-2 spike (S), nucleocapsid (N) protein, and Orf1ab polyprotein. An epitope on N protein (region 155-171) provided good diagnostic performance in discriminating COVID-19-positive vs. healthy individuals. Using this sequence, 92% sensitivity and 100% specificity are reached for IgG detection in COVID-19 samples, and no cross-reactivity with common cold coronaviruses is detected. Overall, epitope 155-171 from N protein represents a promising candidate for further development and rapid implementation in serological tests.

Extracellular vesicles from seminal plasma to improve fertilizing capacity of bulls

Seminal plasma contains extracellular vesicles (EVs) that vehicle RNA, proteins, and other molecules able to influence the biological function of sperm. The aim of this study was to improve the fertilizing capacity of male gametes of low-fertility bulls using EVs isolated by ultracentrifugation from the seminal plasma of a bull of proven fertility. After dose-response curve, 10×106 sperm of low-fertility bulls were co-incubated for an hour with 400×106 EVs/ml. In addition, it has been verified that the incorporation of EVs, which takes place in the sperm midpiece, is maintained for 5 hours and even after cryopreservation. Subsequently, the spermatozoa of low-fertility bulls, with EVs incorporated, were used for the in vitro production of embryos. The rate of blastocyst at seventh day yield in vitro, with the use of sperm with EVs incorporated, increased by about twice the yield obtained with the same sperm in the absence of EVs: bulls having an average embryonic yield of 6.41±1.48%, 10.32±4.34% and 10.92±0.95% improved their yield to 21.21±1.99%, 22.17±6.09% and 19.99±5.78%, respectively (P<0.05). These encouraging results suggest that it might be possible to keep breeding bulls with poor fertility. Further studies will be needed to evaluate the in vivo fertility of sperm treated with EVs and understand how the content of EVs is involve in the sperm-vesicle interaction and in the improved sperm performance.

Elastocaloric Properties of Polycrystalline Samples of NiMnGaCu Ferromagnetic Shape Memory Alloy under Compression: Effect of Improvement of Thermoelastic Martensitic Transformation

Shape memory alloys (SMAs) and ferromagnetic shape memory alloys (FeSMAs) have recently attracted interest for solid state refrigeration applications. Among NiMnGa-based quaternary systems, NiMnGaCu exhibits an interesting giant magnetocaloric effect thanks to the overlapping of the temperatures related to the magnetic transition and the thermoelastic martensitic transformation (TMT); in particular, for compositions with Cu content of approximately 6 at%. In the present work, we investigated the improvement effect of TMT on the total entropy change (ΔS) in the elastocaloric performances of polycrystalline Ni₅₀Mn_18.5Cu_6.5Ga₂₅ at% alloy samples, just above room temperature. We report an extensive calorimetric and thermomechanical characterization to explore correlations between microstructural properties induced by the selected thermal treatment and elastocaloric response, aiming at providing the basis to develop more efficient materials based on this quaternary system. Both ΔT and ΔS values obtained from mechanical curves at different temperatures and strain recovery tests under fixed load vs. T were considered. Maximum values of ΔS = 55.9 J/KgK and ΔT = 4.5 K were attained with, respectively, a stress of 65 MPa and strain of 4%. The evaluation of the coefficient of performance (COP) was carried out from a cyclic test.

Variations of follicular fluid extracellular vesicles miRNAs content in relation to development stage and season in buffalo

In buffalo (Bubalus bubalis) reproductive seasonality, causing cycles of milk production, is one of the major factors affecting farming profitability. Follicular fluid (FF) contains extracellular vesicles (EVs) playing an important role in modulating oocyte developmental competence and carrying microRNAs (miRNAs) essential for in vitro fertilization outcomes. The aim of this work was to characterize the FF-EVs-miRNA cargo of antral (An) and preovulatory (pO) follicles collected in the breeding (BS) and non-breeding (NBS) seasons, to unravel the molecular causes of the reduced oocyte competence recorded in buffalo during the NBS. In total, 1335 miRNAs (538 known Bos taurus miRNAs, 324 homologous to known miRNAs from other species and 473 new candidate miRNAs) were found. We identified 413 differentially expressed miRNAs (DE-miRNAs) (FDR < 0.05) between An and pO groups. A subset of the most significant DE-miRNAs between An and pO groups targets genes which function is related to the lipid and steroid metabolism, response to glucocorticoid and oestradiol stimulus. Comparison between BS and NBS showed 14 and 12 DE-miRNAs in An-FF-EVs and pO-FF-EVs, which regulate IL6 release and cellular adhesion, respectively. In conclusion, these results demonstrated that the miRNA cargo of buffalo FF-EVs varies in relation to both follicular development and season.

Composite Peptide-Agarose Hydrogels for Robust and High-Sensitivity 3D Immunoassays

Canonical immunoassays rely on highly sensitive and specific capturing of circulating biomarkers by interacting biomolecular baits. In this frame, bioprobe immobilization in spatially discrete three-dimensional (3D) spots onto analytical surfaces by hydrogel encapsulation was shown to provide relevant advantages over conventional two-dimensional (2D) platforms. Yet, the broad application of 3D systems is still hampered by hurdles in matching their straightforward fabrication with optimal functional properties. Herein, we report on a composite hydrogel obtained by combining a self-assembling peptide (namely, Q3 peptide) with low-temperature gelling agarose that is proved to have simple and robust application in the fabrication of microdroplet arrays, overcoming hurdles and limitations commonly associated with 3D hydrogel assays. We demonstrate the real-case scenario feasibility of our 3D system in the profiling of Covid-19 patients' serum IgG immunoreactivity, which showed remarkably improved signal-to-noise ratio over canonical assays in the 2D format and exquisite specificity. Overall, the new two-component hydrogel widens the perspectives of hydrogel-based arrays and represents a step forward towards their routine use in analytical practices.

Structure, Immunoreactivity, and In Silico Epitope Determination of SmSPI S. mansoni Serpin for Immunodiagnostic Application

The human parasitic disease Schistosomiasis is caused by the Schistosoma trematode flatworm that infects freshwaters in tropical regions of the world, particularly in Sub-Saharan Africa, South America, and the Far-East. It has also been observed as an emerging disease in Europe, due to increased immigration. In addition to improved therapeutic strategies, it is imperative to develop novel, rapid, and sensitive diagnostic tests that can detect the Schistosoma parasite, allowing timely treatment. Present diagnosis is difficult and involves microscopy-based detection of Schistosoma eggs in the feces. In this context, we present the 3.22 Å resolution crystal structure of the circulating antigen Serine protease inhibitor from S. mansoni (SmSPI), and we describe it as a potential serodiagnostic marker. Moreover, we identify three potential immunoreactive epitopes using in silico-based epitope mapping methods. Here, we confirm effective immune sera reactivity of the recombinant antigen, suggesting the further investigation of the protein and/or its predicted epitopes as serodiagnostic Schistosomiasis biomarkers.

SARS-CoV-2 Epitope Mapping on Microarrays Highlights Strong Immune-Response to N Protein Region

A workflow for rapid SARS-CoV-2 epitope discovery on peptide microarrays is herein reported. The process started with a proteome-wide screening of immunoreactivity based on the use of a high-density microarray followed by a refinement and validation phase on a restricted panel of probes using microarrays with tailored peptide immobilization through a click-based strategy. Progressively larger, independent cohorts of Covid-19 positive sera were tested in the refinement processes, leading to the identification of immunodominant regions on SARS-CoV-2 spike (S), nucleocapsid (N) protein and Orf1ab polyprotein. A summary study testing 50 serum samples highlighted an epitope of the N protein (region 155-71) providing good diagnostic performance in discriminating Covid-19 positive vs. healthy individuals. Using this epitope, 92% sensitivity and 100% specificity were reached for IgG detection in Covid-19 samples, and no cross-reactivity with common cold coronaviruses was detected. Likewise, IgM immunoreactivity in samples collected within the first month after symptoms onset showed discrimination ability. Overall, epitope 155-171 from N protein represents a promising candidate for further development and rapid implementation in serological tests.

Membrane-binding peptides for extracellular vesicles on-chip analysis

Small extracellular vesicles (sEVs) present fairly distinctive lipid membrane features in the extracellular environment. These include high curvature, lipid-packing defects and a relative abundance in lipids such as phosphatidylserine and ceramide. sEV membrane could be then considered as a "universal" marker, alternative or complementary to traditional, characteristic, surface-associated proteins. Here, we introduce the use of membrane-sensing peptides as new, highly efficient ligands to directly integrate sEV capturing and analysis on a microarray platform. Samples were analysed by label-free, single-particle counting and sizing, and by fluorescence co-localisation immune staining with fluorescent anti-CD9/anti-CD63/anti-CD81 antibodies. Peptides performed as selective yet general sEV baits and showed a binding capacity higher than anti-tetraspanins antibodies. Insights into surface chemistry for optimal peptide performances are also discussed, as capturing efficiency is strictly bound to probes surface orientation effects. We anticipate that this new class of ligands, also due to the versatility and limited costs of synthetic peptides, may greatly enrich the molecular toolbox for EV analysis.

From Brain Disease to Brain Health: Primary Prevention of Alzheimer's Disease and Related Disorders in a Health System Using an Electronic Medical Record-Based Approach

BACKGROUND

Alzheimer's disease and aging brain disorders are progressive, often fatal neurodegenerative diseases. Successful aging, modern lifestyles and behaviors have combined to result in an expected epidemic. Risks for these diseases include genetic, medical, and lifestyle factors; over 20 modifiable risks have been reported.

OBJECTIVES

We aim to primarily prevent Alzheimer's disease and related disorders through electronic medical record (EMR)-based screening, risk assessments, interventions, and surveillance.

DESIGN

We identified modifiable risks; developed human, systems and infrastructural resources; developed interventions; and targeted at-risk groups for the intervention.

SETTING

A Community Based Health System.

PARTICIPANTS

In year one (June 2015 to May 2016), 133 at-risk patients received brain health services with the goal of delaying or preventing Alzheimer's disease and related disorders.

MEASUREMENTS

We created mechanisms to identify patients at high risk of neurodegenerative disease; EMR-based structured clinical documentation support tools to evaluate risk factors and history; evidence-based interventions to modify risk; and the capacity for annual surveillance, pragmatic trials, and practice-based and genomic research using the EMR.

RESULTS

This paper describes our Center for Brain Health, our EMR tools, and our first year of healthy but at-risk patients.

CONCLUSION

We are translating research into primary prevention of Alzheimer's disease and related disorders in our health system and aim to shift the paradigm in Neurology from brain disease to brain health.

Alpha-synuclein, pesticides, and Parkinson disease: a case-control study

BACKGROUND

Aggregation and fibrillization of the alpha-synuclein protein (encoded by the SNCA gene) may represent key events in the pathogenesis of Parkinson disease (PD). Variability in the length of a dinucleotide repeat sequence (REP1) within the SNCA promoter confers susceptibility to sporadic PD. Pesticide exposures may also confer susceptibility to PD. Our objective was to test possible joint effects of SNCA REP1 genotypes and pesticide exposures on the risk of PD.

METHODS

This was a case-control study. Cases were recruited prospectively from the Department of Neurology of the Mayo Clinic, Rochester, MN, after June 1, 1996. The control subjects included unaffected siblings of cases and unrelated population control subjects. We assessed pesticide exposures by telephone interview and genotyped SNCA REP1. Odds ratios (ORs) and 95% CIs were determined using conditional logistic regression models.

RESULTS

There were 833 case-control pairs. We observed an increased risk of PD with increasing SNCA REP1 bp length (OR, 1.18 for each score unit; 95% CI, 1.02-1.37; p = 0.03). Pesticide exposures were associated with PD in younger subjects only (lowest quartile of age at study, <or=59.8 years; OR, 1.80; 95% CI, 1.12-2.87; p = 0.01 for all pesticides; OR, 2.46; 95% CI, 1.34-4.52; p = 0.004 for herbicides). In multivariate analyses, both SNCA REP1 score and pesticide exposures were significantly associated with PD in younger subjects, but there were no pairwise interactions.

CONCLUSIONS

Our findings suggest that SNCA REP1 genotype and herbicides have independent effects on risk of Parkinson disease, primarily in younger subjects.

Education and occupations preceding Parkinson disease: a population-based case-control study

OBJECTIVE

To investigate the association of Parkinson disease (PD) with education and occupations using a case-control study design.

METHODS

The authors used the medical records-linkage system of the Rochester Epidemiology Project to identify all subjects who developed PD in Olmsted County, MN, from 1976 through 1995. Each incident case was matched by age (+/-1 year) and sex to a general population control. The authors collected information about education and occupations using two independent sources of data: a review of the complete medical records in the system and a telephone interview. Occupations were coded using the 1980 Standard Occupational Classification.

RESULTS

Subjects with 9 or more years of education were at increased risk of PD (OR = 2.0; 95% CI = 1.1 to 3.6; p = 0.02), and there was a trend of increasing risk with increasing education (test for linear trend, p = 0.02; medical records data). Physicians were at significantly increased risk of PD using both sources of occupational data. By contrast, four occupational groups showed a significantly decreased risk of PD using one source of data: construction and extractive workers (e.g., miners, oil well drillers), production workers (e.g., machine operators, fabricators), metal workers, and engineers. These associations with increased or decreased risk did not change noticeably after adjustment for education.

CONCLUSION

Subjects with higher education and physicians have an increased risk of Parkinson disease (PD), while subjects with some occupations presumed to involve high physical activity have a decreased risk of PD.

Controversies in optic neuritis pain diagnosis

Optic neuritis (ON) refers to any inflammatory disorder of the optic nerve. In clinical practice ON is mainly diagnosed by ophthalmologists and less frequently by neurologists. ON diagnostic criteria are included in different classification systems both in neurologic and ophthalmologic fields. Diagnosis of ON is still very unsatisfactory. Indeed diagnostic criteria are not uniform and therefore the diagnosis is still mainly formulated according to the clinical experience only. A consensus on practice guidelines for ON diagnosis might be useful. Ocular pain is a milestone in ON diagnosis, but it is too often mistreated by both the patient and the clinician. The International Headache Society (IHS) Classification of Headache Disorders provides in its 1988 and 2004 versions the diagnostic criteria for ON. These criteria are not spread and followed by the large majority of neurologists, but they are mainly applied by the experts in headache disorders. On the other hand, ON is a disorder widely encountered by neurologists and ophthalmologists. The latest IHS version defines the criteria of the pain features more precisely, but it is still unsatisfactory. In a future revision, the pain should be further detailed. Further studies aimed at validation of the diagnostic criteria of ON are strongly needed.

Atypical facial pain: clinical considerations and differential diagnosis

Atypical facial pain (ATFP), recently defined as persistent idiopathic facial pain by the revision of the Classification of the International Headache Society (IHS), is a poorly understood condition, which still lacks clear diagnostic criteria and proper treatment. The pain is described as "persistent facial pain that does not have the characteristics of cranial neuralgias and is not attributable to another disorder". In general, however, according to the IHS criteria, a diagnosis of ATFP is possible when the pain in the face is present daily and persists for most or all of the day. The pain is confined at onset to a limited area on one side of the face, often in the nasolabial fold or side of the chin and may spread to the upper or lower jaw or a wider area of the face of neck and is deep and poorly localised. It is not associated with sensory loss or other physical signs. Laboratory investigations including X-ray of face and jaws do not demonstrate relevant abnormality. Pain may be initiated by operation or injury to face, teeth or gums but persists without any demonstrable local cause. But, the definition and the diagnostic criteria are over-simplified when we face the reality of the clinical practice. Many different disorders may be included in this diagnostic category, making differential diagnosis very complex. Diagnosis of ATFP is therefore, usually, a process of elimination. A targeted history and an accurate examination are crucial to correctly classify this facial pain.

Visual evoked potentials in migraine

Migraine is a chronic disorder. Visual symptoms and hypersensitivity to light stimuli are common. The aim of this study is the analysis of visual system in migraineurs by visual evoked potentials (VEP). We studied 53 migraineurs (21 with prophylactic migraine treatment and 32 without preventive therapy) and 20 healthy control subjects. We found lower P100 latencies in migraineurs without therapy compared to controls. In treated patients, P100 latencies showed the same trend seen in the control group. We speculate a different responsiveness of the visual system in migraineurs probably due to a dysmodulation of sensor input leading to facilitation of visual processing.

Management of headache in emergency room

Headache is one of the most common symptoms that leads patients to the emergency room (ER) and is often related to diseases requiring prompt diagnosis and immediate treatment. This consideration brought us to consider the importance of the neurologist in improving the management of patients arriving in the ER with headache. We carried out a study for testing the degree of agreement between ER physician and neurologist using patient evaluation at headache centre (HC) as the gold standard. One hundred and seventeen patients with idiopathic (78) or symptomatic (39) headache were evaluated by the ER physician, the ER neurologist and the HC expert. The ER physician and the HC expert reached a fair agreement (Kappa=0.40); the other two pairs reached a moderate agreement (Kappa=0.57-0.60). There was no significant difference in the agreement of the three evaluators in patients with impairment of daily living activities or aged over 40. The agreement between the ER physician and the neurologist was lower (Kappa=0.58), especially in patients with their first headache episode. Based on our results, patients seen at the ER for a headache episode can be fairly successfully managed by the ER physician, except those who present a first attack, for whom neurological consultation is needed.

Migrainous cerebral infarction: case reports

Migraine is a common and chronic disorder. It is considered benign but several studies have suggested it as a rare risk factor for ischaemic stroke. The association is still conflicting and seems to be restricted to particular subgroups of patients (i.e., women under the age of 45, with migraine with aura, and particularly ones who smoke and use oral contraceptives). The pathogenetic mechanisms underlying this condition are not known. We describe 6 cases of migrainous stroke fully meeting the diagnostic criteria of the International Headache Society (IHS). For each patient, demographic and anamnestic data, clinical features, results of laboratory tests and neuroimaging findings were recorded. Five of the 6 cases were women (median age of 29, range from 23 to 40). The man was 36. All patients fulfilled the IHS criteria for migraine with aura. At the time of the event, 2 patients were taking oral contraceptives and smoked, one patient smoked and three patients had no vascular risk factors. The stroke manifested as homonymous hemianopia in 3 patients, lower homonymous quadrantopia in 1 patient and sensory symptom in 1 patient. The neurological examination was normal in 1 case. All patients underwent several tests with negative results: blood test (antithrombin III, protein C or S, autoantibodies), transthoracic and transoesophageal echocardiography, extracranial and intracranial Doppler sonography, and angiography which was not performed in 1 patient. All patients had a cerebral infarct visible on neuroimaging study (MRI): posterior cerebral artery in 4, middle cerebral artery in 1 and anterior cerebral artery in 1. We support the findings reported by others that migrainous stroke is more common in young women affected by migraine with aura. In consideration of the high prevalence of migraine in the population, further research is indicated and necessary to establish if migraine is independent from other vascular risk factors.

Optic neuritis: diagnostic criteria application in clinical practice

Optic neuritis (ON) refers to any inflammatory optic neuropathy. In clinical practice ON is mainly diagnosed by ophthalmologists and less frequently by neurologists. ON diagnostic criteria are included in the Classification of International Headache Society (IHS) and in other classification systems, both in neurological and ophthalmologic fields. The aims of this study were to verify the application of IHS ON diagnostic criteria in clinical practice and the role of the ocular pain qualitative aspects. We performed a partially retrospective (140 cases) and prospective (43 cases) study analysing the clinical characteristics of patients with ON. We observed retro orbital pain in a huge percentage of patients; it was provoked or spontaneous and worsened by eye movements. We found that the new IHS classification criteria (IHS 2004) do not fully satisfy the requirements for ON diagnosis. Further study is necessary to validate the diagnostic criteria of ON in clinical practice.

MIDAS questionnaire in the emergency setting

Migraine is a common disorder and is a major cause of disability and loss of working performance in western countries. Therefore, many tools have been developed to assess migraine related disability. Among these, the Migraine Disability Assessment (MIDAS) questionnaire has been shown to be of particular interest, as it is valid, reliable and useful for therapeutic decisions. In this pilot study, we address the validity of the MIDAS questionnaire in an unselected population of migraine patients in the emergency setting. We found that the MIDAS scores in the emergency room were similar to those collected in a specialised headache centre. This result suggests that the MIDAS questionnaire could be reliably used in the emergency setting, hence avoiding unnecessary delays in the treatment of migraine patients.

Antiepileptic drugs in the treatment of chronic headaches

In recent years, anticonvulsant drugs (AEDs) have been considered promising drugs in the prevention of migraine and other forms of headache, based on their action on the metabolism of gamma-aminobutyric acid (GABA) and glutamate. To date many AEDs are being evaluated for headache preventive treatment. The results are often encouraging even if not conclusive except for valproate, which has been extensively investigated and has been found to be effective and well tolerated in the preventive therapy of migraine. Other AEDs seem to be important in the treatment of patients with resistant headaches, with both migraine and epilepsy comorbid with mood and anxiety disorders or in neuropathic pain syndromes.

Molecular and biochemical data on some glucose-6-phosphate dehydrogenase variants from southern Sardinia

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD; E.C.1.1.1.49) deficiency is the most common human enzymopathy; nearly 400 different biochemical variants of the enzyme have been described. Sardinia is the Italian region with the highest frequency of this defect.

METHODS

We examined genomic DNA of 16 subjects with G6PD Mediterranean, 2 with G6PD Athens-like, 1 with G6PD Ferrara 2 (all as biochemically defined).

RESULTS

All G6PD Mediterranean subjects had a C-->T mutation at nucleotide 563 and a C-->T transition at nucleotide 1311; G6PD Athens-like and Ferrara 2 subjects had a G-->C mutation at nucleotide 844 (the same mutation has been found in G6PD Seattle-like).

CONCLUSIONS

This study suggests that in Southern Sardinia G6PD mutations are relatively homogeneous and that the results of biochemical characterization studies must be carefully evaluated, because the same mutations might be responsible for different biochemical behavior.

Iron overload and lysosomal stability in beta zero-thalassaemia intermedia and trait: correlation between serum ferritin and serum N-acetyl-beta-D-glucosaminidase levels

Increased iron storage represents a characteristic condition in patients with beta zero-thalassaemia intermedia. Iron overload is an important factor in cellular damage. Recent studies have shown an enhanced lysosomal fragility due to increased iron storage. 13 patients with beta-thalassaemia intermedia, aged 17-44 years, were studied. Both serum ferritin and serum N-acetyl-beta-D-glucosaminidase levels were evaluated in all subjects studied. A significant linear correlation (P less than 0.05) between serum ferritin and serum N-acetyl-beta-D-glucosaminidase levels were found.

In vitro effects of pentoxifylline on hemoglobin affinity for oxygen and electrolytic equilibrium of human blood

The in vitro effects of a pentoxifylline solution on hemoglobin-oxygen affinity and electrolytic distribution between plasma and red blood cells were evaluated. Pentoxifylline increased intracellular pH and decreased extracellular pH. There were no exchanges of Na+, K+, Ca++ and Cl- between plasma and red blood cells. Red blood cell content of 2,3-diphosphoglycerate remained unchanged, while P50 was reduced as a consequence of the intracellular alkalosis. The possible implications of the metabolic effects of pentoxifylline on red blood cell deformability and 2,3-diphosphoglycerate content in vivo are discussed.

A superfusion method for the study of secretion activity of isolated cerebral and endocrine tissues

This paper describes a new kind of superfusion technique that allows for the maintenance of small fragments of nervous tissue, such as of the hypothalamus and the pituitary and pineal glands, suspended in a very small perfusion chamber with a continuous flow of medium that reproduces "in vivo" conditions. Easy reproducibility; continuous flow of medium, which avoids short feedback phenomena; controlled conditions that are very close to those "in vivo" and the possibility of sequential treatments for the study of the dynamics of hormone release are some of the advantages of this method.