Imidazole-stabilized gold nanoparticles induce neuronal apoptosis: an in vitro and in vivo study

Gold nanoparticles are increasingly being employed in innovative biological applications thanks to their advantages of material- and size-dependent physics and chemical interactions with the cellular systems. On the other hand, growing concern has emerged on the toxicity which would render gold-based nanoparticles harmful to cell cultures, animals, and humans. Emerging attention is focused on the interaction of gold nanoparticles with nervous system, especially regarding the ability to overcome the blood-brain barrier (BBB) which represents the major impediment to the delivery of therapeutics into the brain. We synthesized highly stable 2-mercapto-1-methylimidazole-stabilized gold-nanoparticles (AuNPs)-mmi to investigate their entry, accumulation, and toxicity in vitro (SH-SY5Y human neuroblastoma cells) and in vivo (brain of C57BL/6 mice) through optical and electron microscopy. After incubation in the cell culture medium at the lowest dose of 0.1 mg/mL the (AuNPs)-mmi nanoparticles were found compacted and recruited into endosome/lysosomes (1 h) before their fusion (2 h) and the onset of neuronal death by apoptosis (4 h) as proved by terminal-transferase-mediated dUTP nick end labeling assay and caspase-3 immunoreactivity. The ability of (AuNPs)-mmi to cross the BBB was assessed by injection in the caudal vein of C57BL/6 mice. Among different brain regions, the nanoparticles were found in the CaudatoPutamen area, mainly in the striatal neurons 4 h after injection. These neurons showed the typical hallmarks of apoptosis. Our findings provide, for the first time, the dynamic of 2-mercapto-1-methylimidazole nanogold uptake. The molecular mechanism which underlies the nanogold-driven apoptotic event is analyzed and discussed in order to take into account when designing nanomaterials to interface with biological structures.

Donor splice-site mutation in CUL4B is likely cause of X-linked intellectual disability

X-linked intellectual disability is the most common form of cognitive disability in males. Syndromic intellectual disability encompasses cognitive deficits with other medical and behavioral manifestations. Recently, a large family with a novel form of syndromic X-linked intellectual disability was characterized. Eight of 24 members of the family are male and had cognitive dysfunction, short stature, aphasia, skeletal abnormalities, and minor anomalies. To identify the causative gene(s), we performed exome sequencing in three affected boys, both parents, and an unaffected sister. We identified a haplotype consisting of eight variants located in cis within the linkage region that segregated with affected members in the family. Of these variants, two were novel. The first was at the splice-donor site of intron 7 (c.974+1G>T) in the cullin-RING ubiquitin ligase (E3) gene, CUL4B. This variant is predicted to result in failure to splice and remove intron 7 from the primary transcript. The second variant mapped to the 3'-UTR region of the KAISO gene (c.1127T>G). Sanger sequencing validated the variants in these relatives as well as in three affected males and five carriers. The KAISO gene variant was predicted to create a binding site for the microRNAs miR-4999 and miR-4774; however, luciferase expression assays failed to validate increased targeting of these miRNAs to the variant 3'-UTR. This SNP may affect 3'-UTR structure leading to decreased mRNA stability. Our results suggest that the intellectual disability phenotype in this family is caused by aberrant splicing and removal of intron 7 from CUL4B gene primary transcript.

Cortical metabolic deficits in a rat model of cholinergic basal forebrain degeneration

Evidence indicates that the degeneration of basal forebrain cholinergic neurons may represent an important factor underlying the progressive cognitive decline characterizing Alzheimer's disease (AD). However, the nature of the relationship between cholinergic depletion and AD is not fully elucidated. This study aimed at clarifying some aspects of the relation existing between deficits in cerebral energy metabolism and degeneration of cholinergic system in AD, by investigating the neuronal metabolic activity of several cortical areas after depletion of basal forebrain cholinergic neurons. In cholinergically depleted rats, we evaluated the neuronal metabolic activity by assaying cytochrome oxidase (CO) activity in frontal, parietal and posterior parietal cortices at four different time-points after unilateral injection of 192 IgG-saporin in the nucleus basalis magnocellularis. Unilateral depletion of cholinergic cells in the basal forebrain induced a bilateral decrease of metabolic activity in all the analyzed areas. Frontal and parietal cortices showed decreased metabolic activity even 3 days after the lesion, when the cholinergic degeneration was still incomplete. In posterior parietal cortex metabolic activity decreased only 7 days after the lesion. The possible molecular mechanisms underlying these findings were also investigated. Real-time PCR showed an increase of CO mRNA levels at 3, 7 and 15 days after the lesion both in frontal and parietal cortices, followed by normalization at 30 days. Western Blot analysis did not show any change in CO protein levels at any time-point after the lesion. Our findings support a link between metabolic deficit and cholinergic hypofunctionality characterizing AD pathology. The present model of cholinergic hypofunctionality provides a useful means to study the complex mechanisms linking two fundamental and interrelated phenomena characterizing AD from the early stages.

Implantable loop recorders for assessment of syncope: increased diagnostic yield and less adverse outcomes with the latest generation devices

AIM

Aim of the study was to compare the diagnostic yield of implantable loop recorders (ILR) of two successive generations for the assessment of syncope.

METHODS

Data on patients who had undergone ILR implantation for unexplained syncope in four Italian public hospitals were retrospectively acquired from the Medtronic Clinical Service database. After implantation, routine follow-up examinations were performed every 90 days, while urgent examinations were carried out in the event of syncope recurrence.

RESULTS

The following findings were regarded as diagnostic: ECG documentation of a syncope recurrence; documentation of any of the arrhythmias listed by the current guidelines as diagnostic findings even if asymptomatic. Between November 2002 and March 2010, 107 patients received an ILR (40 Medtronic Reveal® Plus; 67 Medtronic Reveal® DX/XT) and underwent at least one follow-up examination. Diagnoses were made in 7 (17.5%) and 24 (35.8%) (P=0.043) patients, with a median time of 228 and 65 days, respectively. Three (42.9%) and 21 (87.5%) (P=0.029) diagnoses were based on automatically detected events, while adverse outcomes occurred in 6 and in 1 (P=0.01) patients, respectively.

CONCLUSION

Our results show that the new-generation device offer a higher diagnostic yield, mainly as a result of its improved automatic detection function, and is associated with fewer adverse outcomes.

Charged particle's flux measurement from PMMA irradiated by 80 MeV/u carbon ion beam

Hadrontherapy is an emerging technique in cancer therapy that uses beams of charged particles. To meet the improved capability of hadrontherapy in matching the dose release with the cancer position, new dose-monitoring techniques need to be developed and introduced into clinical use. The measurement of the fluxes of the secondary particles produced by the hadron beam is of fundamental importance in the design of any dose-monitoring device and is eagerly needed to tune Monte Carlo simulations. We report the measurements carried out with charged secondary particles produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a poly-methyl methacrylate target. Charged secondary particles, produced at 90° with respect to the beam axis, have been tracked with a drift chamber, while their energy and time of flight have been measured by means of a LYSO scintillator. Secondary protons have been identified exploiting the energy and time-of-flight information, and their emission region has been reconstructed backtracking from the drift chamber to the target. Moreover, a position scan of the target indicates that the reconstructed emission region follows the movement of the expected Bragg peak position. Exploiting the reconstruction of the emission region, an accuracy on the Bragg peak determination in the submillimeter range has been obtained. The measured differential production rate for protons produced with E(Prod)(kin) > 83 MeV and emitted at 90° with respect to the beam line is dN(P)/(dN(C)dΩ) (E(Prod)(kin) > 83 MeV, θ = 90°) = (2.69 ± 0.08(stat) ± 0.12(sys)) × 10⁻⁴ sr⁻¹.

Assessing water-electrolyte changes of hyperglycaemic hyperosmolar coma

AIM

We reported new methods to accurately estimate salt and water deficits during hyperglycaemic hyperosmolar coma (HC), valid under restricted boundary conditions. The accuracy of these estimates is herein verified over the unrestricted spectrum of abnormalities, to correctly evaluate any patient with just one algorithm that recognizes the boundary conditions pertaining to each abnormality, choosing the appropriate calculations.

METHODS

A large number of cases of HC was simulated on computer by subtracting an exhaustive combination of water, sodium and chloride losses coupled to a large variety of gains in glucose. Altered solute concentrations were generated. From these true plasma concentrations generated by the computer, the losses of water and electrolytes were back-calculated with our new computational algorithm, by knowing in addition only the normal total body water and extra-cellular volume. The accuracy of the method was tested by comparing true to calculated values over the entire range of deranged values. In 100 patients admitted to hospital for HC these same computations were performed, where calculated data were validated by comparing them to true data obtained by balance studies performed during correction of the abnormality.

RESULTS

Both in simulated and real cases of HC true and calculated data for the changes in Na and volume were significantly correlated (R (2)=0.76 and 0.50, respectively, P<0.01), while their mean values were not significantly different by paired "t" tests (P>0.05 for all).

CONCLUSION

Our new computation algorithm, applicable to the bed-side, useful in accurately assessing the average water-electrolyte deficits of HC, can be used to guide correct re-infusion strategies.

Effect of anesthesia in a patient with pre-existing anisocoria

In this case report, we describe an accentuation of a pre-existing anisocoria shortly after tracheal intubation in a patient undergoing thyroidectomy. A 45-yr-old female patient with unequal pupillary diameter (right 2 mm > than left) and decreased light reflex in the right eye--due to a previous eye trauma--was scheduled for thyroidectomy because of multinodular goiter. Anesthesia was induced with propofol 2,5 mg/kg, fentanyl 3 mcg/kg and cisatracurium 0.15 mcg/kg. Immediately after tracheal intubation, examination of the right eye revealed a markedly dilated pupil (8 mm) which was nonreactive to direct and consensual light reflex. The left pupil was 2 mm, and normally reactive to light. An increase in heart rate was also registered (> 20% of baseline) with spontaneous return to baseline within 2 minutes. The right pupil returned to preoperative size within approximately one hour after awakening. From this case report, it emerges that a preexisting anisocoria may be exacerbated during anesthesia probably due to incomplete abolition of response to painful stimulus, such as tracheal intubation, provided by anesthetic drugs in the affected eye. The main contributing factor for accentuation of anisocoria could be sympathetic dominance in the pupil with pre-existing mechanical interruption in compensatory parasympathetic mechanisms.

Variants of ST8SIA1 are associated with risk of developing multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system of unknown etiology with both genetic and environmental factors playing a role in susceptibility. To date, the HLA DR15/DQ6 haplotype within the major histocompatibility complex on chromosome 6p, is the strongest genetic risk factor associated with MS susceptibility. Additional alleles of IL7 and IL2 have been identified as risk factors for MS with small effect. Here we present two independent studies supporting an allelic association of MS with polymorphisms in the ST8SIA1 gene, located on chromosome 12p12 and encoding ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 1. The initial association was made in a single three-generation family where a single-nucleotide polymorphism (SNP) rs4762896, was segregating together with HLA DR15/DQ6 in MS patients. A study of 274 family trios (affected child and both unaffected parents) from Australia validated the association of ST8SIA1 in individuals with MS, showing transmission disequilibrium of the paternal alleles for three additional SNPs, namely rs704219, rs2041906, and rs1558793, with p = 0.001, p = 0.01 and p = 0.01 respectively. These findings implicate ST8SIA1 as a possible novel susceptibility gene for MS.

Highly variable penetrance in subjects affected with cavernous cerebral angiomas (CCM) carrying novel CCM1 and CCM2 mutations

Cavernous vascular malformations may affect brain and out-of-brain tissues. In most cases, cerebral cavernous malformations (CCMs) involve the brain alone, and are rarely associated with skin hemangiomas, spinal cord, retinal, hepatic or vertebral lesions. CCMs can cause seizures, intracranial and spinal haemorrhages, focal neurological deficits, and migraine-like headaches. After collecting CCM families of Italian origin and investigating the genetic basis of the disorder we disclosed two novel molecular variations in the KRIT1 and MGC4607 genes. We found a novel CCM1 gene mutation (Q66X) in a family with apparently asymptomatic old-aged mutation carriers and patients who either had skin angiomas alone or the full association of cerebral, spinal, and skin lesions. In this family we report the highest variability in mutation penetrance so far described, including the presence of CCM in one subject since birth (surgery at 19 months of age), a condition to our knowledge so far unreported. In a CCM2 affected family, we also report a novel causative mutation, (54_55delAC) in exon 2 of the MGC4607 gene, that produces a truncated protein containing only 22 amino acids. These data describe novel CCM mutations associated with a particularly high variability of the penetrance causing, in some cases, reduced expression of clinical symptoms and sporadic cases with apparent negative family history. Hence they emphasize the importance of DNA-based diagnostics and genetic counseling to identify unaffected mutation carriers subjects, even at advanced age.

Arvanil and anandamide up-regulate CD36 expression in human peripheral blood mononuclear cells

In this study we analysed the regulation of gene expression by arvanil and anandamide in human peripheral blood mononuclear cells (PBMCs) to clarify their immunosuppressive properties. PBMCs were activated, leading to CD36 down regulation, that was normalized by arvanil and anandamide. We used microarray technology to identify a regulatory pattern associated with cell proliferation in the presence of both substances. CD3-CD28 stimulated PBMCs showed a pattern of up-regulated and down-regulated genes after treatment with these substances. We selected and analysed several genes chosen by their function in the regulation of cell proliferation. We showed a transcriptional control of the CD36 gene by arvanil and anandamide associated with an increased protein expression, thus suggesting a possible role of CD36 in anandamide and arvanil anti-inflammatory pattern.

A novel frameshift mutation of FOXC2 gene in a family with hereditary lymphedema-distichiasis syndrome associated with renal disease and diabetes mellitus

Lymphedema-distichiasis (LD) syndrome is a clinically variable autosomal dominant disorder. The disorder is caused by mutations in the forkhead transcription factor FOXC2 gene on chromosome band 16q24.3. Here, we report the sequence of the FOXC2 gene in a German-Irish family with LD in six affected relatives over three generations and identify a single adenine base pair insertion at nt 1006--1007. This insertion creates a frameshift mutation that predicts a premature stop at codon 462. In addition to LD, four of the affected family members have renal disease and three have diabetes mellitus (DM), not usually seen in the LD syndrome. Polymorphisms of FOXC2 in diabetics have been studied in different populations. Our sequence analysis of the 5' untranslated region (UTR) C-512T shows the homozygous T allele in all family members tested. The sequencing data in this family suggests the possibility of a novel phenotype-haplotype. This novel phenotype, LD/renal disease/type 2 diabetes, might be the result of a combination of the nt 1006--1007 insA and the upstream UTR homozygous T polymorphism.

Linkage analysis conditional on HLA status in a large North American pedigree supports the presence of a multiple sclerosis susceptibility locus on chromosome 12p12

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system with a probable immune-mediated pathogenesis. Strong evidence supports the hypothesis that MS is determined by genetic and environmental factors, but these factors remain largely undefined. The genetic component is suggested by a higher concordance rate in monozygotic (28%) versus dizygotic (5%) twins as well as familial recurrence risk. Several studies have shown association of MS with the histocompatibility leukocyte antigen (HLA) class II region, specifically DR15, DQ6. However, there is no convincing evidence of a common susceptibility locus. We have identified a pedigree of Pennsylvania Dutch extraction, in which MS segregates with an autosomal dominant inheritance pattern. We have collected blood samples from 18 family members, seven of whom show typical signs of MS lesions by magnetic resonance imaging. The 18 individuals were serotyped for HLA class I and II and analyzed by a genome-wide screen for linkage analysis. We have found evidence for suggestive linkage to markers on 12p12 with a maximum multipoint LOD score of 2.71, conditional on the presence of DR15, DQ6. Contingency table analysis showed that all MS affected individuals have both the DR15, DQ6 allele and the 12p12 haplotype whereas the unaffected individuals have either one or neither of these markers (P = 0.00011). Our data suggests that both HLA DR15, DQ6 and a novel locus on chromosome 12p12 may be necessary for development of MS in this family.

Second family with hearing impairment linked to 19q13 and refined DFNA4 localisation

Until now, over 30 loci have been identified by linkage analysis of affected families that segregate non-syndromic and dominantly inherited forms of hearing impairment (DFNA). A German family with a non-syndromic progressive hearing impairment transmitted in autosomal dominant mode was linked to 19q13.3-q13.4 by a genome-wide scan. Due to the low lod-score (1.85 at theta=0.05) for APOC2-locus we extended the fine mapping attempt with further markers in the same chromosomal region. This resulted in significant evidence for linkage to the markers D19S246 and D19S553 (two-point lod-score of 4.05 and 3.55 at theta=0.0) and a candidate critical region of 14 cM between markers D19S412 and D19S571. This region shows partial overlap with the previously reported DFNA4 critical region. The human gene BAX is orthologous to the rodent Bcl2-related apoptosis gene that is temporally expressed during the postnatal period in the developing inner ear of the mouse. BAX, mapping at a distance of no more than 0.73 cM distally to marker D19S553 appeared a likely candidate in our pedigree but genomic sequencing of coding regions and exon/intron boundaries excluded disease-related mutations. However, additional ESTs in the same region remain to be tested.

Novel X-linked mental retardation syndrome with short stature maps to Xq24

We describe a large family from Sardinia, Italy, in which a novel X- linked mental retardation (XLMR) syndrome segregates. The phenotype observed in the 8 affected males includes severe mental retardation (MR), lack of speech, coarse face, distinctive skeletal features with short stature, brachydactyly of fingers and toes, small downslanting palpebral fissures, large bulbous nose, hypoplastic ear lobe and macrostomia. Carrier females are not mentally retarded, although some of them have mild dysmorphic features such as minor ear lobe abnormalities, as well as language and learning problems. Linkage analysis for X-chromosome markers resulted in a maximum lod score of 3.61 with marker DXS1001 in Xq24. Recombination observed with flanking markers identified a region of 16 cM for further study. None of the other XLMR syndromes known to map in the same region shows the same composite phenotype. This evidence strongly suggests that the genetic disease in this family is unique.

A second middle eastern kindred with autosomal recessive non-syndromic hearing loss segregates DFNB9

A second kindred has been identified which supports the previously reported location of DFNB9. Linkage has been established to markers closely linked to DFNB9 which is located on 2p22-p23. The hearing impaired individuals in this highly consanguineous kindred from Eastern Turkey have prelingual profound hearing loss which affects all frequencies. A genetic map of the 2p22-p23 region where DFNB9 resides was generated using marker genotypes available from the CEPH database. All markers were placed on this genetic map using a likelihood ratio criterion of 1000:1. This map suggests that the region for DFNB9 is less than 1.08 cM, 95% confidence interval (0-2.59 cM).

Lipoprotein profile, diet and body composition in athletes practicing mixed an anaerobic activities

OBJECTIVE

To compare lipoprotein profile, body composition and diet in a sample of athletes practicing mixed and anaerobic sports activities, and in a group of sedentary controls.

EXPERIMENTAL DESIGN

Cross selectional study.

PARTICIPANTS

Twenty professional soccer players (mixed trained), twenty body builders (anaerobic trained) and twenty sedentary subjects, all males and matched for age were studied.

RESULTS

No significant differences in total serum cholesterol, triglycerides, HDL-C, LDL-C, apolipoprotein A-I, A-II, B, C-II, C-III, and E levels were found when the three groups were compared. Bioelectrical impendance analysis disclosed significantly lower body fat percentages in both groups of athletes, and increased fat free mass only in body builders. Daily calorie intake was higher, and alcohol intake was lower in the athletes, compared with controls. Body builders had lower carbohydrate, and higher protein and cholesterol intakes, while soccer players had a lower polyunsaturated to saturated fat ratio. None of the apolipoproteins examined was correlated with any body composition of diet parameters. No correlations between lipid parameters and anthropometric or dietary variables were found by multivariate analysis when the subjects were considered as a whole.

CONCLUSIONS

Our data suggest that in healthy lean normolipemic males, the lipoprotein profile is not modified by mixed or anaerobic sport activities and the respective modifications in body composition and diet.

Genomic cloning and characterization of the human thrombin receptor gene. Structural similarity to the proteinase activated receptor-2 gene

The seven-transmembrane segment thrombin receptor (TR) represents the prototype of a putative family of proteolytically cleaved receptors that may include the proteinase activated receptor-2. A panel of somatic cell hybrids retaining distinct portions of human chromosome 5 were used to establish that the human TR gene is present as a single-copy locus within the region 5q11.2 -->q13.3, confirming our previous localization using fluorescent in situ hybridization analysis. To further characterize the TR gene, overlapping clones from a human genomic library were isolated. Genomic analysis confirmed that the TR gene is of limited complexity, spanning approximately 27 kilobases and containing two exons separated by a large approximately 22-kilobase intron. The larger second exon contains the majority of the coding sequence and the thrombin cleavage site, remarkably similar to the organization of the proteinase activated receptor-2 gene in which the putative cleavage site is also contained within the large second exon. Primer extension analysis using two 30-mer oligonucleotide primers known to be contained within the first exon identified the predominant transcription initiation site 351 base pairs upstream from the initiator methionine in both human umbilical vein endothelial and human erythroleukemia cells. Sequence analysis of the 5'-flanking region revealed the TR promoter to be TATA-less, although nucleic acid motifspotentially involved in transcriptional gene regulation were evident and include a GATA motif, octamer enhancer sequences, AP-2-like sites, and Sp1 sites. These data provide evidence for remarkable similarity at the gene level between both proteolytically cleaved receptors described to date.