Fusion of Rabies Virus Glycoprotein or gh625 to Iduronate-2-Sulfatase for the Treatment of Mucopolysaccharidosis Type II

Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disease caused by a mutation in the IDS gene, resulting in deficiency of the enzyme iduronate-2-sulfatase (IDS) causing heparan sulfate (HS) and dermatan sulfate (DS) accumulation in all cells. This leads to skeletal and cardiorespiratory disease with severe neurodegeneration in two thirds of sufferers. Enzyme replacement therapy is ineffective at treating neurological disease, as intravenously delivered IDS is unable to cross the blood-brain barrier (BBB). Hematopoietic stem cell transplant is also unsuccessful, presumably due to insufficient IDS enzyme production from transplanted cells engrafting in the brain. We used two different peptide sequences (rabies virus glycoprotein [RVG] and gh625), both previously published as BBB-crossing peptides, fused to IDS and delivered via hematopoietic stem cell gene therapy (HSCGT). HSCGT with LV.IDS.RVG and LV.IDS.gh625 was compared with LV.IDS.ApoEII and LV.IDS in MPS II mice at 6 months post-transplant. Levels of IDS enzyme activity in the brain and peripheral tissues were lower in LV.IDS.RVG- and LV.IDS.gh625-treated mice than in LV.IDS.ApoEII- and LV.IDS-treated mice, despite comparable vector copy numbers. Microgliosis, astrocytosis, and lysosomal swelling were partially normalized in MPS II mice treated with LV.IDS.RVG and LV.IDS.gh625. Skeletal thickening was normalized by both treatments to wild-type levels. Although reductions in skeletal abnormalities and neuropathology are encouraging, given the low levels of enzyme activity compared with control tissue from LV.IDS- and LV.IDS.ApoEII-transplanted mice, the RVG and gh625 peptides are unlikely to be ideal candidates for HSCGT in MPS II and are inferior to the ApoEII peptide that we have previously demonstrated to be more effective at correcting MPS II disease than IDS alone.

Intraparenchymal convection enhanced delivery of AAV in sheep to treat Mucopolysaccharidosis IIIC

BACKGROUND

Mucopolysaccharidosis IIIC (MPSIIIC) is one of four Sanfilippo diseases sharing clinical symptoms of severe cognitive decline and shortened lifespan. The missing enzyme, heparan sulfate acetyl-CoA: α-glucosaminide-N-acetyltransferase (HGSNAT), is bound to the lysosomal membrane, therefore cannot cross the blood-brain barrier or diffuse between cells. We previously demonstrated disease correction in MPSIIIC mice using an Adeno-Associated Vector (AAV) delivering HGSNAT via intraparenchymal brain injections using an AAV2 derived AAV-truetype (AAV-TT) serotype with improved distribution over AAV9.

METHODS

Here, intraparenchymal AAV was delivered in sheep using catheters or Hamilton syringes, placed using Brainlab cranial navigation for convection enhanced delivery, to reduce proximal vector expression and improve spread.

RESULTS

Hamilton syringes gave improved AAV-GFP distribution, despite lower vector doses and titres. AAV-TT-GFP displayed moderately better transduction compared to AAV9-GFP but both serotypes almost exclusively transduced neurons. Functional HGSNAT enzyme was detected in 24-37% of a 140g gyrencephalic sheep brain using AAV9-HGSNAT with three injections in one hemisphere.

CONCLUSIONS

Despite variabilities in volume and titre, catheter design may be critical for efficient brain delivery. These data help inform a clinical trial for MPSIIIC.

Non-canonical role of the sympathetic nervous system in the day-night rhythm in heart rate

Although, for many decades, the day-night rhythm in resting heart rate has been attributed to the parasympathetic branch of the autonomic nervous system (high vagal tone during sleep), recently we have shown that there is a circadian clock in the cardiac pacemaker, the sinus node, and the day-night rhythm in heart rate involves an intrinsic rhythmic transcriptional remodelling of pacemaker ion channels, particularly Hcn4. We have now investigated the role of the sympathetic branch of the autonomic nervous system in this and shown it to have a non-canonical role. In mice, sustained long-term block of cardiac β-adrenergic receptors by propranolol administered in the drinking water abolished the day-night rhythm in pacemaking in the isolated sinus node. Concomitant with this, there was a loss of the normal day-night rhythm in many pacemaker ion channel transcripts. However, there was little or no change in the local circadian clock, indicating that the well-known day-night rhythm in sympathetic nerve activity is directly involved in pacemaker ion channel transcription. The day-night rhythm in pacemaking helps explain the occurrence of clinically significant bradyarrhythmias during sleep, and this study improves our understanding of this pathology. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

Study protocol: PreOperative Brain Irradiation in Glioblastoma (POBIG) - A phase I trial

Background

Glioblastoma is a high-grade aggressive neoplasm whose outcomes have not changed in decades. In the current treatment pathway, tumour growth continues and remains untreated for several weeks post-diagnosis. Intensified upfront therapy could target otherwise untreated tumour cells and improve the treatment outcome. POBIG will evaluate the safety and feasibility of single-fraction preoperative radiotherapy for newly diagnosed glioblastoma, assessed by the maximum tolerated dose (MTD) and maximum tolerated irradiation volume (MTIV).

Methods

POBIG is an open-label, dual-centre phase I dose and volume escalation trial that has received ethical approval. Patients with a new radiological diagnosis of glioblastoma will be screened for eligibility. This is deemed sufficient due to the high accuracy of imaging and to avoid treatment delay. Eligible patients will receive a single fraction of preoperative radiotherapy ranging from 6 to 14 Gy followed by their standard of care treatment comprising maximal safe resection and postoperative chemoradiotherapy (60 Gy/30 fr) with concurrent and adjuvant temozolomide). Preoperative radiotherapy will be directed to the part of the tumour that is highest risk for remaining as postoperative residual disease (hot spot). Part of the tumour will remain unirradiated (cold spot) and sampled separately for diagnostic purposes. Dose/volume escalation will be guided by a Continual Reassessment Method (CRM) model. Translational opportunities will be afforded through comparison of irradiated and unirradiated primary glioblastoma tissue.

Discussion

POBIG will help establish the role of radiotherapy in preoperative modalities for glioblastoma.

Trial registration

NCT03582514 (clinicaltrials.gov).

Urinary volatile Organic compounds in non-alcoholic fatty liver disease (NAFLD), type two diabetes mellitus (T2DM) and NAFLD-T2DM coexistence

INTRODUCTION

Accumulating evidence have shown a significant correlation between urinary volatile organic compounds (VOCs) profile and the manifestation of several physiological and pathological states, including liver diseases. Previous studies have investigated the urinary metabolic signature as a non-invasive tool for the early discrimination between non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH), which nowadays represents one of the most important challenges in this context, feasible only by carrying out liver biopsy.

OBJECTIVES

The aim of the study was to investigate the differences in the urinary VOCs profiles of non-alcoholic fatty liver disease (NAFLD) patients, diabetes mellitus (T2DM) subjects and NAFLD/T2DM patients.

METHODS

Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was applied to profile the urinary VOCs. Urine samples were analysed both under acid and alkaline conditions, to obtain a range of urinary volatiles with different physicochemical properties.

RESULTS

Urinary VOCs profiles of 13 NAFLD patients, 13 T2DM subjects and 13 NAFLD/T2DM patients were investigated by multivariate and univariate data analysis techniques which allowed to identify 21 volatiles under alkaline conditions able to describe the NAFLD/T2DM group concerning the other two groups.

CONCLUSION

Our results suggest that VOCs signatures can improve the knowledge of the pathological condition where NAFLD coexists with T2DM and discovering new features that are not simply the sum of the two diseases. These preliminary findings may be considered as hypothesis-generating, to be clearly confirmed by larger prospective investigations.

Unopposed estrogens: current and future perspectives

Estrogens and progestogens act on female reproductive tissues in opposite ways. As they counteract each other actions, the correct balance between these two classes of hormones is pivotal to avoid dangerous states. Unopposed estrogens occur when progestogen levels do not balance estrogens, primarily deriving from overproduction of estrogens via aromatase enzyme. In the endometrium, unopposed estrogens induce proliferative or invasive phenomena, which represent the first step toward different diseases. These pathologies include endometrial hyperplasia, endometrial polyps, endometriosis and adenomyosis. Endometrial hyperplasia and polyps are proliferative pathologies, while endometriosis and adenomyosis are characterized by the invasion of other tissues by endometrial cells. Current pharmacological treatments include Gonadotropin-Releasing-Hormone analogs, aromatase inhibitors and progestogens, either alone or in combination with estrogens. As these drugs usually lead to burdensome undesired effects, researchers seek to find new therapeutical molecules. Recent literature highlights the positive effects of metformin, an insulin sensitizing drug that reduces the insulin proliferative stimulus on the endometrium. d-chiro-inositol is an insulin second messenger with insulin sensitizing and mimetic properties, recently described as an aromatase down-regulator. Based on current evidence, d-chiro-inositol may be useful to treat the pathologies responsive to unopposed estrogens.

Investigating site-selection mechanisms of retroviral integration in supercoiled DNA braids

We theoretically study the integration of short viral DNA in a DNA braid made up by two entwined double-stranded DNA molecules. We show that the statistics of single integration events substantially differ in the straight and buckled, or plectonemic, phase of the braid and are more likely in the latter. We further discover that integration is most likely close to plectoneme tips, where the larger bending energy helps overcome the associated energy barrier and that successive integration events are spatio-temporally correlated, suggesting a potential mechanistic explanation of clustered integration sites in host genomes. The braid geometry we consider provides a novel experimental set-up to quantify integration in a supercoiled substrate in vitro, and to better understand the role of double-stranded DNA topology during this process.

The use of D-chiro-Inositol in clinical practice

OBJECTIVE

D-chiro-Inositol has been widely used in clinical practice to induce ovulation in women with polycystic ovary syndrome. Only recent evidence established that this molecule acts through two different mechanisms, with potentially different outcomes. On the one hand, under a metabolic perspective, D-chiro-Inositol improves insulin signaling, thus restoring physiological insulin levels in resistant subjects. On the other hand, at a cellular level, it downregulates the expression of steroidogenic enzyme aromatase, which is responsible for the conversion of androgens to estrogens.

MATERIALS AND METHODS

We reviewed current literature in different databases, searching for D-chiro-Inositol in relation with one of the following keywords: myo-inositol, PCOS, infertility, insulin resistance, aromatase, androgen and inositol, testosterone, estrogen and inositol, estradiol, hypogonadotropic hypogonadism, fat tissue, estrogens and cancer, anovulation, uterine myoma, endometriosis, endometrial hyperplasia.

RESULTS

D-Chiro-Inositol treatment may be helpful in restoring physiological hormonal levels in various clinical disorders. However, D-Chiro-Inositol intervention should be carefully designed to avoid possible undesired side effects stemming from its multiple mechanisms of action.

CONCLUSIONS

We evaluated the optimal D Chiro-Inositol administration for different pathologies, defining dosages and timing. Even though further studies are required to validate our preliminary results, this paper is primarily intended to guide researchers through some of the pathways of D-Chiro-Inositol.

Intrinsic Electrical Remodeling Underlies Atrioventricular Block in Athletes

[Figure: see text].

Actinomycin D downregulates Sox2 and improves survival in preclinical models of recurrent glioblastoma

BACKGROUND

Glioblastoma (GBM) has been extensively researched over the last few decades, yet despite aggressive multimodal treatment, recurrence is inevitable and second-line treatment options are limited. Here, we demonstrate how high-throughput screening (HTS) in multicellular spheroids can generate physiologically relevant patient chemosensitivity data using patient-derived cells in a rapid and cost-effective manner. Our HTS system identified actinomycin D (ACTD) to be highly cytotoxic over a panel of 12 patient-derived glioma stemlike cell (GSC) lines. ACTD is an antineoplastic antibiotic used in the treatment of childhood cancers. Here, we validate ACTD as a potential repurposed therapeutic for GBM in 3-dimensional GSC cultures and patient-derived xenograft models of recurrent glioblastoma.

METHODS

Twelve patient-derived GSC lines were screened at 10 µM, as multicellular spheroids, in a 384-well serum-free assay with 133 FDA-approved compounds. GSCs were then treated in vitro with ACTD at established half-maximal inhibitory concentrations (IC50). Downregulation of sex determining region Y-box 2 (Sox2), a stem cell transcription factor, was investigated via western blot and through immunohistological assessment of murine brain tissue.

RESULTS

Treatment with ACTD was shown to significantly reduce tumor growth in 2 recurrent GBM patient-derived models and significantly increased survival. ACTD is also shown to specifically downregulate the expression of Sox2 both in vitro and in vivo.

CONCLUSION

These findings indicate that, as predicted by our HTS, ACTD could deplete the cancer stem cell population within the tumor mass, ultimately leading to a delay in tumor progression.

KEY POINTS

1. High-throughput chemosensitivity data demonstrated the broad efficacy of actinomycin D, which was validated in 3 preclinical models of glioblastoma.2. Actinomycin D downregulated Sox2 in vitro and in vivo, indicating that this agent could target the stem cell population of GBM tumors.

Genetic Ablation of G Protein-Gated Inwardly Rectifying K+ Channels Prevents Training-Induced Sinus Bradycardia

Background: Endurance athletes are prone to bradyarrhythmias, which in the long-term may underscore the increased incidence of pacemaker implantation reported in this population. Our previous work in rodent models has shown training-induced sinus bradycardia to be due to microRNA (miR)-mediated transcriptional remodeling of the HCN4 channel, leading to a reduction of the "funny" (I _f) current in the sinoatrial node (SAN). Objective: To test if genetic ablation of G-protein-gated inwardly rectifying potassium channel, also known as I _KACh channels prevents sinus bradycardia induced by intensive exercise training in mice. Methods: Control wild-type (WT) and mice lacking GIRK4 (Girk4 ^-/-), an integral subunit of I _KACh were assigned to trained or sedentary groups. Mice in the trained group underwent 1-h exercise swimming twice a day for 28 days, 7 days per week. We performed electrocardiogram recordings and echocardiography in both groups at baseline, during and after the training period. At training cessation, mice were euthanized and SAN tissues were isolated for patch clamp recordings in isolated SAN cells and molecular profiling by quantitative PCR (qPCR) and western blotting. Results: At swimming cessation trained WT mice presented with a significantly lower resting HR that was reversible by acute I _KACh block whereas Girk4 ^-/- mice failed to develop a training-induced sinus bradycardia. In line with HR reduction, action potential rate, density of I _f, as well as of T- and L-type Ca²⁺ currents (I _CaT and I _CaL ) were significantly reduced only in SAN cells obtained from WT-trained mice. I _f reduction in WT mice was concomitant with downregulation of HCN4 transcript and protein, attributable to increased expression of corresponding repressor microRNAs (miRs) whereas reduced I _CaL in WT mice was associated with reduced Ca_v1.3 protein levels. Strikingly, I _KACh ablation suppressed all training-induced molecular remodeling observed in WT mice. Conclusion: Genetic ablation of cardiac I _KACh in mice prevents exercise-induced sinus bradycardia by suppressing training induced remodeling of inward currents I _f, I _CaT and I _CaL due in part to the prevention of miR-mediated transcriptional remodeling of HCN4 and likely post transcriptional remodeling of Ca_v1.3. Strategies targeting cardiac I _KACh may therefore represent an alternative to pacemaker implantation for bradyarrhythmias seen in some veteran athletes.

The prognostic impact of the extent of ulceration in patients with clinical stage I-II melanoma: a multicentre study of the Italian Melanoma Intergroup (IMI)

BACKGROUND

The presence of ulceration has been recognized as an adverse prognostic factor in primary cutaneous melanoma (PCM).

OBJECTIVES

To investigate whether the extent of ulceration (EoU) predicts relapse-free survival (RFS) and overall survival (OS) in PCM.

MATERIALS AND METHODS

We retrieved data for 477 patients with ulcerated PCM from databases of the Italian Melanoma Intergroup. Univariate and multivariable Cox proportional hazard models were used to assess the independent prognostic impact of EoU.

RESULTS

A significant interaction emerged between Breslow thickness (BT) and EoU, considering both RFS (P < 0·0001) and OS (P = 0·0006). At multivariable analysis, a significant negative impact of EoU on RFS [hazard ratio (HR) (1-mm increase) 1·26, 95% confidence interval (CI) 1·08-1·48, P = 0·0047] and OS [HR (1-mm increase) 1·25, 95% CI 1·05-1·48, P = 0·0120] was found in patients with BT ≤ 2 mm, after adjusting for BT, age, tumour-infiltrating lymphocytes, sentinel lymph node status and mitotic rate. No impact of EoU was found in patients with 2·01-4 mm and > 4 mm BT.

CONCLUSIONS

This study demonstrates that EoU has an independent prognostic impact in PCM and should be recorded as a required element in pathology reports.

Translation factor mRNA granules direct protein synthetic capacity to regions of polarized growth

mRNA localization serves key functions in localized protein production, making it critical that the translation machinery itself is present at these locations. Here we show that translation factor mRNAs are localized to distinct granules within yeast cells. In contrast to many messenger RNP granules, such as processing bodies and stress granules, which contain translationally repressed mRNAs, these granules harbor translated mRNAs under active growth conditions. The granules require Pab1p for their integrity and are inherited by developing daughter cells in a She2p/She3p-dependent manner. These results point to a model where roughly half the mRNA for certain translation factors is specifically directed in granules or translation factories toward the tip of the developing daughter cell, where protein synthesis is most heavily required, which has particular implications for filamentous forms of growth. Such a feedforward mechanism would ensure adequate provision of the translation machinery where it is to be needed most over the coming growth cycle.

Radiobiological quantities in proton-therapy: Estimation and validation using Geant4-based Monte Carlo simulations

PURPOSE

The Geant4 Monte Carlo simulation toolkit was used to reproduce radiobiological parameters measured by irradiating three different cancerous cell lines with monochromatic and clinical proton beams.

METHODS

The experimental set-up adopted for irradiations was fully simulated with a dedicated open-source Geant4 application. Cells survival fractions was calculated coupling the Geant4 simulations with two analytical radiobiological models: one based on the LEM (Local Effect Model) approach and the other on a semi-empirical parameterisation. Results was evaluated and compared with experimental data.

RESULTS AND CONCLUSIONS

The results demonstrated the Geant4 ability to reproduce radiobiological quantities for different cell lines.

Non-myeloablative busulfan chimeric mouse models are less pro-inflammatory than head-shielded irradiation for studying immune cell interactions in brain tumours

Background

Chimeric mouse models generated via adoptive bone marrow transfer are the foundation for immune cell tracking in neuroinflammation. Chimeras that exhibit low chimerism levels, blood-brain barrier disruption and pro-inflammatory effects prior to the progression of the pathological phenotype, make it difficult to distinguish the role of immune cells in neuroinflammatory conditions. Head-shielded irradiation overcomes many of the issues described and replaces the recipient bone marrow system with donor haematopoietic cells expressing a reporter gene or different pan-leukocyte antigen, whilst leaving the blood-brain barrier intact. However, our previous work with full body irradiation suggests that this may generate a pro-inflammatory peripheral environment which could impact on the brain’s immune microenvironment. Our aim was to compare non-myeloablative busulfan conditioning against head-shielded irradiation bone marrow chimeras prior to implantation of glioblastoma, a malignant brain tumour with a pro-inflammatory phenotype.

Methods

Recipient wild-type/CD45.1 mice received non-myeloablative busulfan conditioning (25 mg/kg), full intensity head-shielded irradiation, full intensity busulfan conditioning (125 mg/kg) prior to transplant with whole bone marrow from CD45.2 donors and were compared against untransplanted controls. Half the mice from each group were orthotopically implanted with syngeneic GL-261 glioblastoma cells. We assessed peripheral blood, bone marrow and spleen chimerism, multi-organ pro-inflammatory cytokine profiles at 12 weeks and brain chimerism and immune cell infiltration by whole brain flow cytometry before and after implantation of glioblastoma at 12 and 14 weeks respectively.

Results

Both non-myeloablative conditioning and head-shielded irradiation achieve equivalent blood and spleen chimerism of approximately 80%, although bone marrow engraftment is higher in the head-shielded irradiation group and highest in the fully conditioned group. Head-shielded irradiation stimulated pro-inflammatory cytokines in the blood and spleen but not in the brain, suggesting a systemic response to irradiation, whilst non-myeloablative conditioning showed no cytokine elevation. Non-myeloablative conditioning achieved higher donor chimerism in the brain after glioblastoma implantation than head-shielded irradiation with an altered immune cell profile.

Conclusion

Our data suggest that non-myeloablative conditioning generates a more homeostatic peripheral inflammatory environment than head-shielded irradiation to allow a more consistent evaluation of immune cells in glioblastoma and can be used to investigate the roles of peripheral immune cells and bone marrow-derived subsets in other neurological diseases.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1410-y) contains supplementary material, which is available to authorized users.

Sentinel Node Mapping for Malignant Melanoma

Sixty-seven patients with malignant melanomas were seen in our institute since 1998. We looked for a sentinel node in 26 (38%) patients with lesions thicker than 1 mm, employing a double technique: staining with methylene blue and gamma probe mapping after injection of 99mTc. Forty-six nodes were retrieved, 25% of them containing tumor cells. This approach enabled us to choose between a wait-and-see policy and radical surgery.

Neurotrophin-mimicking peptides at the biointerface with gold respond to copper ion stimuli

The peptide fragments NGF_1-14 and BDNF_1-12, encompassing the N-terminal domains, respectively, of the proteins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were used in this study for the fabrication of a hybrid gold/peptide biointerface. These peptides mimic the Trk receptor activation of the respective whole protein - with a crucial role played by copper ions - and exhibit, in bulk solution, a pH-dependent capability to complex copper. We demonstrate here the maintenance of peptide-specific responses at different pH values as well as the copper binding also for the adlayers formed upon physisorption at the gold surface. The physicochemical properties, including viscoelastic behavior of the adlayer and competitive vs. synergic interactions in sequential adsorption processes, were addressed both experimentally, by quartz crystal microbalance with dissipation monitoring (QCM-D) and circular dichroism (CD), and theoretically, by molecular dynamics (MD) calculations. Proof-of work biological assays with the neuroblastoma SY-SH5H cell line demonstrated that the developed hybrid Au/peptide nanoplatforms are very promising for implementation in pH- and metal-responsive systems for application in nanomedicine.

Iterative control strategies for nonlinear systems

In this paper, we focus on the control of the mean-field equilibrium of nonlinear networks of the Langevin type in the limit of small noise. Using iterative linear approximations, we derive a formula that prescribes a control strategy in order to displace the equilibrium state of a given system and remarkably find that the control function has a "universal" form under certain physical conditions. This result can be employed to define universal protocols useful, for example, in the optimal work extraction from a given reservoir. Generalizations and limits of application of the method are discussed.

Direct Route to Colloidal UHMWPE by Including LLDPE in Solution during Homogeneous Polymerization of Ethylene

The usual aggregation and precipitation driven by crystallization of nascent PE during homogeneous polymerization of ultra-high molecular weight polyethylene (UHMWPE) is inhibited by including linear low-density polyethylene (LLDPE) in the catalyst solution prior to addition of ethylene monomer. Co-crystallization of newly formed PE and dissolved LLDPE creates a polymer brush on the fold surfaces of the nascent crystallites. Consequently, aggregation is inhibited by steric stabilization. Scanning electron microscopy (SEM) images show that individual lamellae (approximately 10-20 nm thick) typically have lateral dimensions of 0.5 μm × 3.5 μm and form "bowtie" shaped stacks that are approximately 200-500 nm thick. This simple method for stabilizing nascent crystals against precipitation is enabling fundamental studies of their metastable "disentangled" state and may open scalable routes to compounding UHMWPE.

Serum elements and oxidative status in clinically isolated syndromes: imbalance and predictivity

BACKGROUND

Metals are suspected of being involved in the pathogenesis of various neurologic diseases. We previously found a complex imbalance in serum chemical elements and oxidative status in patients with clinically definite multiple sclerosis (CDMS).

OBJECTIVE

To understand whether this imbalance affects people with clinically isolated syndrome (CIS) and, if so, whether it predicts conversion to CDMS.

METHODS

We studied 22 chemical elements and the oxidative status in 49 patients with CIS, 49 patients with CDMS, and 49 healthy donors (HD). Univariate and multivariate approaches were used to identify profiles for each group. A logistic regression analysis was used to identify the predictive potential of baseline data (elements, oxidative status, and MRI findings) for conversion to CDMS over 36 months.

RESULTS

Several elements and oxidative status values differed significantly among the 3 groups. Discriminant analysis revealed a major contribution of Ca, Fe, Sn, Zn, serum antioxidant capacity, and serum oxidative status, which resulted in distinct profiles (the prediction of group membership was 96% [cross-validated 92%] for HD, 92% [cross-validated 92%] for CDMS, and 90% [cross-validated 86%] for CIS). A weighted combination of element concentrations and oxidative status values, adjusting for all other predictors, would predict a reduction in the risk of conversion to CDMS within 3 years (odds ratio 0.37; 95% confidence interval 0.18-0.76; p = 0.007), thereby proving more effective than MRI at baseline.

CONCLUSIONS

The peculiar imbalance in serum elements and oxidative status that characterizes patients with CIS and may predict conversion to CDMS warrants studies on larger sample sizes.

A multiscale study of electronic structure and quantum transport in C(6n(2))H(6n)-based graphene quantum dots

We implement a bottom-up multiscale approach for the modeling of defect localization in C(6n(2))H(6n) islands, i.e. graphene quantum dots with a hexagonal symmetry, by means of density functional and semiempirical approaches. Using the ab initio calculations as a reference, we recognize the theoretical framework under which semiempirical methods adequately describe the electronic structure of the studied systems and thereon proceed to the calculation of quantum transport within the nonequilibrium Green function formalism. The computational data reveal an impurity-like behavior of vacancies in these clusters and evidence the role of parameterization even within the same semiempirical context. In terms of conduction, failure to capture the proper chemical aspects in the presence of generic local alterations of the ideal atomic structure results in an improper description of the transport features. As an example, we show wavefunction localization phenomena induced by the presence of vacancies and discuss the importance of their modeling for the conduction characteristics of the studied structures.

Ab Initio Prediction of Boron Compounds Arising from Borozene: Structural and Electronic Properties

Structure and electronic properties of two unusual boron clusters obtained by fusion of borozene rings have been studied by means of first principles calculations based on the generalized-gradient approximation of the density functional theory. Moreover, a semiempirical tight-binding model has been appropriately calibrated for transport calculations on these clusters. Results show that the pure boron clusters are topologically planar and characterized by (3c-2e) bonds, which can explain, together with the aromaticity (estimated by means of NICS), the remarkable cohesive energy values obtained. Such feature makes these systems competitive with the most stable boron clusters to date. The energy gap values indicate that these clusters possess a semiconducting character, while when the larger system is considered, zero-values of the density of states are found exclusively within the HOMO-LUMO gap. Electron transport calculations within the Landauer formalism confirm these indications, showing semiconductor-like low bias differential conductance for these structures. Differences and similarities with carbon clusters are highlighted in the discussion.

A pilot study on the content and the release of Ni and other allergenic metals from cheap earrings available on the Italian market

The capability of alloys used in cheap jewellery to release metal ions on contact with the skin causing allergic contact dermatitis (ACD) is generally acknowledged. To reduce the diffusion of the Ni-induced ACD the Council Directive 94/27/EC [Council Directive 94/27/EC of 30 June 1994. Official Journal L 188, 22/07/1994, 1.] limited the total Ni content in alloys and its release rate in artificial sweat. In this work, three different aspects were explored: i) the frequency of skin sensitization to Ni-containing earrings in patients before and after the introduction of the Directive's limit; ii) metal composition of alloys by X-ray analysis; iii) metal leaching in artificial sweat followed by Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) quantification. Well-known allergenic metals, as Ni, Cr and Co, and possible emergent allergens, as Al, Ag, Au, Cd, Cu, Fe, Ir, Mn, Pb, Pd, Pt, Rh, Sn, V and Zn, were studied. Results showed that the frequency of allergy due to earrings did not decrease after the introduction of the Ni limit: in 1994 and in 2005 patients positive to Ni patch tests were 54.3% and 53.5%, respectively. The earring components analyzed were Fe-based or alloys of Cu/Zn or Fe/Cr/Ni, plated with a thin film of precious metal (Ag, Au) which, in several cases, was combined with a Ni layer beneath. Five out of 10 items were not in compliance with the Ni Directive 94/27/EC having a total Ni content >0.05%. In three cases the release of Ni concentrations was higher than the safe sensitizing limit given by the above mentioned Regulation (i.e., <0.5 microg/cm(2)/week). The release of Cu and Zn was very variable among the different pieces (Cu: 0.134-30.9 microg/cm(2)/week; Zn: 0.141-160 microg/cm(2)/week); two objects released high amounts of Fe (358 and 586 microg/cm(2)/week) and one released considerable Mn (21 microg/cm(2)/week). Lead was released from 70% of the objects, while Ag, Al, Cd, Co, Cr and Sn from ca. 30% of the items and concentrations of these elements were well below 0.5 microg/cm(2)/week. Vanadium was released by only one item whereas Au, Ir, Pd, Pt and Rh were never leached.

Levels of nickel and other potentially allergenic metals in Ni-tested commercial body creams

It is extensively well-known that Ni and other metals occurring as impurities in cosmetic products might give rise to contact dermatitis in subjects with pre-existing allergy. The present study on the content of 13 metals (Cd, Co, Cr, Cu, Hg, Ir, Mn, Ni, Pb, Pd, Pt, Rh, and V) in moisturizing creams, labelled as "Ni-tested" (i.e., Ni content <100 ng g(-1)) and available on the Italian market, provides a basis for assessing their safety for consumers. Quantification of metals was performed by sector field inductively coupled plasma mass spectrometry after microwave-assisted acid digestion of products. The developed method had limits of quantification less than 0.8 ng g(-1) for all the elements; recovery was in the interval 88% (Cd, Co) to 110% (Hg), and precision was always under 7%. Nickel was present in all the products with levels between 17.5 and 153 ng g(-1); three skin creams were slightly above the concentration reported on the label. The other elements were at levels below 1 microg g(-1). The highest concentrations, in ng g(-1), of Co, Cr, Cu, and Mn were 222, 303, 51.2, and 59.9, respectively. Mean Cd, Pb, and V were below 5 ng g(-1), while Hg was absent in all the samples. Among the new emergent allergens, Ir and Rh were in traces or even undetectable, while Pt had levels of 2.65 and 6.28 ng g(-1) in two creams and Pd was equal to 1.07 ng g(-1) in one product. The overall results are below the sensitizing limit proposed for consumer products and, thus, probably have no significant toxicological effects. Nevertheless, some creams presented amounts of Co and Cr comparable to those of Ni and therefore they have to be monitored in consideration of their cross-reactivity as well.

Metal changes in CSF and peripheral compartments of parkinsonian patients

BACKGROUND

Involvement of metals in the risk of developing Parkinson's disease (PD) has been suggested. In the present study, concentration of metals in cerebrospinal fluid (CSF), blood, serum, urine and hair of 91 PD patients and 18 controls were compared.

METHODS

Blood and hair were microwave digested, while CSF, serum and urine were water-diluted. Elements quantification was achieved by Inductively Coupled Plasma Atomic Emission Spectrometry and Sector Field Inductively Coupled Plasma Mass Spectrometry.

RESULTS

Some metal imbalances in PD were observed: i), in CSF, lower Fe and Si; ii), in blood, higher Ca, Cu, Fe, Mg and Zn; iii), in serum, lower Al and Cu; iv), in urine, lower Al and Mn, higher Ca and Fe; and v), in hair, lower Fe. The ROC analysis suggested that blood Ca, Fe, Mg and Zn were the best discriminators between PD and controls. In addition, hair Ca and Mg were at least 1.5 times higher in females than in males of patients and controls. A decrement with age of patients in hair and urine Ca and, with less extent, in urine Si was observed. Magnesium concentration in CSF decreased with the duration and severity of the disease. Elements were not influenced by the type of antiparkinsonian therapy.

CONCLUSIONS

Variation in elements with the disease do not exclude their involvement in the neurodegeneration of PD.