Respiratory complications and sleep disorders in children with chronic kidney disease: A correlation often underestimated.

Chronic Kidney Disease (CKD) is characterized by a progressive and irreversible loss of kidney function which gradually leads to end-stage kidney disease (ESKD). Virtually all the organs are damaged by the toxicity of uremic compounds. The lungs may be affected and the impaired pulmonary function may be the direct result of fluid retention and metabolic, endocrine and cardiovascular alterations, as well as systemic activation of the inflammation. An increased prevalence in sleep disorders (SD) is also reported in patients with CKD, leading to a further negative impact on overall health and quality of life. While these complex relationships are well documented in the adult population, these aspects remain relatively little investigated in children. The aim of this review is to provide a brief overview of the pathophysiology between lung and kidney and to summarize how CKD may affect respiratory function and sleep in children.

Light-induced charge generation in polymeric nanoparticles restores vision in advanced-stage retinitis pigmentosa rats.

Retinal dystrophies such as Retinitis pigmentosa are among the most prevalent causes of inherited legal blindness, for which treatments are in demand. Retinal prostheses have been developed to stimulate the inner retinal network that, initially spared by degeneration, deteriorates in the late stages of the disease. We recently reported that conjugated polymer nanoparticles persistently rescue visual activities after a single subretinal injection in the Royal College of Surgeons rat model of Retinitis pigmentosa. Here we demonstrate that conjugated polymer nanoparticles can reinstate physiological signals at the cortical level and visually driven activities when microinjected in 10-months-old Royal College of Surgeons rats bearing fully light-insensitive retinas. The extent of visual restoration positively correlates with the nanoparticle density and hybrid contacts with second-order retinal neurons. The results establish the functional role of organic photovoltaic nanoparticles in restoring visual activities in fully degenerate retinas with intense inner retina rewiring, a stage of the disease in which patients are subjected to prosthetic interventions.

Automated source of squeezed vacuum states driven by finite state machine based software.

In the last few decades, much effort has been made for the production of squeezed vacuum states in order to reduce quantum noise in the audio-frequency band. This technique has been implemented in all running gravitational-wave interferometric detectors and helped to improve their sensitivity. While the detectors are acquiring data for astrophysical observations, they must be kept in the operating condition, also called "science mode," that is, a state that requires the highest possible duty-cycle for all the instrumental parts and controls. We report the development of a highly automated setup for the generation of optical squeezed states, where all the required control loops are supervised by a software based on finite state machines; we took special care to grant ease of use, stability of operation, and possibility of auto-recovery. Moreover, the setup has been designed to be compatible with the existing software and hardware infrastructure of the Virgo detector. In this paper, we discuss the optical properties of this squeezing setup, the locking techniques, and the automation algorithms.

Delivery of Brain-Derived Neurotrophic Factor by 3D Biocompatible Polymeric Scaffolds for Neural Tissue Engineering and Neuronal Regeneration.

Biopolymers are increasingly employed for neuroscience applications as scaffolds to drive and promote neural regrowth, thanks to their ability to mediate the upload and subsequent release of active molecules and drugs. Synthetic degradable polymers are characterized by different responses ranging from tunable distension or shrinkage to total dissolution, depending on the function they are designed for. In this paper we present a biocompatible microfabricated poly-ε-caprolactone (PCL) scaffold for primary neuron growth and maturation that has been optimized for the in vitro controlled release of brain-derived neurotrophic factor (BDNF). We demonstrate that the designed morphology confers to these devices an enhanced drug delivery capability with respect to monolithic unstructured supports. After incubation with BDNF, micropillared PCL devices progressively release the neurotrophin over 21 days in vitro. Moreover, the bioactivity of released BDNF is confirmed using primary neuronal cultures, where it mediates a consistent activation of BDNF signaling cascades, increased synaptic density, and neuronal survival. These results provide the proof-of-principle on the fabrication process of micropatterned PCL devices, which represent a promising therapeutic option to enhance neuronal regeneration after lesion and for neural tissue engineering and prosthetics.

REST-Dependent Presynaptic Homeostasis Induced by Chronic Neuronal Hyperactivity.

Homeostatic plasticity is a regulatory feedback response in which either synaptic strength or intrinsic excitability can be adjusted up or down to offset sustained changes in neuronal activity. Although a growing number of evidences constantly provide new insights into these two apparently distinct homeostatic processes, a unified molecular model remains unknown. We recently demonstrated that REST is a transcriptional repressor critical for the downscaling of intrinsic excitability in cultured hippocampal neurons subjected to prolonged elevation of electrical activity. Here, we report that, in the same experimental system, REST also participates in synaptic homeostasis by reducing the strength of excitatory synapses by specifically acting at the presynaptic level. Indeed, chronic hyperactivity triggers a REST-dependent decrease of the size of synaptic vesicle pools through the transcriptional and translational repression of specific presynaptic REST target genes. Together with our previous report, the data identify REST as a fundamental molecular player for neuronal homeostasis able to downscale simultaneously both intrinsic excitability and presynaptic efficiency in response to elevated neuronal activity. This experimental evidence adds new insights to the complex activity-dependent transcriptional regulation of the homeostatic plasticity processes mediated by REST.

Myopathic involvement and mitochondrial pathology in Kennedy disease and in other motor neuron diseases.

Kennedy disease (spinal and bulbar muscular atrophy, or SBMA) is a motor neuron disease caused by a CAG expansion in the androgen-receptor (AR) gene. Increasing evidence shows that SBMA may have a primary myopathic component and that mitochondrial dysfunction may have some role in the pathogenesis of this disease. In this article, we review the role of mitochondrial dysfunction and of the mitochondrial genome (mtDNA) in SBMA, and we present the illustrative case of a patient who presented with increased CK levels and exercise intolerance. Molecular analysis led to definitive diagnosis of SBMA, whereas muscle biopsy showed a mixed myopathic and neurogenic process with "mitochondrial features" and multiple mtDNA deletions, supporting some role of mitochondria in the pathogenesis of the myopathic component of Kennedy disease. Furthermore, we briefly review the role of mitochondrial dysfunction in two other motor neuron diseases (namely spinal muscular atrophy and amyotrophic lateral sclerosis). Most likely, in most cases mtDNA does not play a primary role and it is involved subsequently. MtDNA deletions may contribute to the neurodegenerative process, but the exact mechanisms are still unclear. It will be important to develop a better understanding of the role of mitochondrial dysfunction in motoneuron diseases, since it may lead to the development of more effective strategies for the treatment of this devastating disorder.

Oxidative stress and APO E polymorphisms in Alzheimer's disease and in mild cognitive impairment.

A number of evidences indicates oxidative stress as a relevant pathogenic factor in Alzheimer's disease (AD) and mild cognitive impairment (MCI). Considering its recognized major genetic risk factors in AD, apolipoprotein (APO E) has been investigated in several experimental settings regarding its role in the process of reactive oxygen species (ROS) generation. The aim of this work has been to evaluate possible relationships between APO E genotype and plasma levels of selected oxidative stress markers in both AD and MCI patients. APO E genotypes were determined using restriction enzyme analysis. Plasma levels of oxidative markers, advanced oxidation protein products, iron-reducing ability of plasma and, in MCI, activity of superoxide dismutases were evaluated using spectrophotometric analysis. We found, compared to controls, increased levels of oxidized proteins and decreased values of plasma-reducing capacity in both AD patients (p < 0.0001) and MCI patients (p < 0.001); the difference between AD and MCI patients was significant only for plasma-reducing capacity (p < 0.0001), the former showing the lowest values. Superoxide dismutase activity was reduced, although not at statistical level, in MCI compared with that in controls. E4 allele was statistically associated (p < 0.05) with AD patients. When comparing different APO E genotype subgroups, no difference was present, as far as advanced oxidation protein products and iron-reducing ability of plasma levels were concerned, between E4 and non-E4 carriers, in both AD and MCI; on the contrary, E4 carriers MCI patients showed significantly decreased (p < 0.05) superoxide dismutase activity with respect to non-E4 carriers. This study, in confirming the occurrence of oxidative stress in AD and MCI patients, shows how it can be related, at least for superoxide dismutase activity in MCI, to APO E4 allele risk factor.

Atypical onset and course in a child with fulminant myocarditis.

We report a fatal case of fulminant myocarditis (FM) in a five-year-old male child. He presented to our Emergency Department having complained fever, vomiting, nausea and abdominal pain from the previous day. The ECG showed broad complex tachycardia unresponsive to treatment with both drugs and all other resuscitation measures and the child died four hours after admission. Post-mortem histological examination showed diffuse infiltration of the myocardium although no viral material could be identified. FM is relatively uncommon and late presentation at an almost irreversible stage unusual. This case indicates the necessity of a rapid transfer to a center with ECMO or MCS, when FM is diagnosed.

Tetracycline treatment in patients with progressive external ophthalmoplegia.

BACKGROUND: Tetracyclines could have neuroprotective effects in neuromuscular and neurodegenerative disorders. AIMS OF THE STUDY AND METHODS: Objective of this double-blind randomized pilot study (followed by an adjunctive open-label phase) was to evaluate whether tetracycline (500 mg/day × 14 days/month × 3 months) could be useful in patients (n = 16) with progressive external ophthalmoplegia (PEO). RESULTS: Our results do not formally support any effect of tetracycline on eye motility in PEO. However, some possible protective effects could not be completely ruled out, i.e. a further analysis suggests a possible difference between the tetracycline group and the placebo group, significant at least for oblique motility, when comparing the ratio between the end of the double-blind phase and baseline. Tetracycline could modify some oxidative stress biomarkers in patients with PEO. CONCLUSIONS: Further studies are needed to confirm such effects of tetracycline in patients with PEO, if any, and to clarify the mechanisms of action for antioxidant effects of tetracyclines in mitochondrial disorders and other diseases.

The role of vascular factors in late-onset sporadic Alzheimer's disease. Genetic and molecular aspects.

Alzheimer's disease (AD) is a late-onset progressive neurodegenerative disorder which results in the irreversible loss of cortical neurons, particularly in the associative neocortex and hippocampus. AD is the most common form of dementia in the elderly. Apart from the neuronal loss, the pathological hallmarks are extracellular senile plaques, containing the peptide beta-amyloid (Abeta), and neurofibrillary tangles. The Abeta cascade hypothesis remains the main pathogenetic model, as suggested by familiar AD, mainly associated to mutation in amyloid precursor protein and presenilin genes. The remaining 95% of AD patients are mostly sporadic late-onset cases, with a complex aetiology due to interactions between environmental conditions and genetic features of the individual. A relationship between genetic and acquired vascular factors and AD has been hypothesized. Many vascular risk factors for AD, such as atherosclerosis, stroke and cardiac disease in the aging individual, could result in cerebrovascular dysfunction and trigger AD pathology. A major vascular susceptibility factor gene is the apolipoprotein E gene, found to be associated with sporadic late-onset AD cases. Another interesting vascular susceptibility gene is angiotensin converting enzyme. Other possible genes include VLDL-R, LRP, NOS3, CST3, OLR1, MTHFR, PON1 and VEGF, but many of the related studies have shown conflicting results. In this paper, we review the role of molecular vascular abnormalities and of the "vascular risk" genes supposed to be involved in the pathogenesis of AD, in an attempt to provide a comprehensive picture of what is known about the mechanisms underlying the role of vascular factors in late-onset sporadic AD.

Replication timing of two human common fragile sites: FRA1H and FRA2G.

The mammalian chromosomes present specific sites of gaps or breaks, the common fragile sites (CFSs), when the cells are exposed to DNA replication stress or to some DNA binding compounds. CFSs span hundreds or thousands of kilobases. The analysis of these sequences has not definitively clarified the causes of their fragility. There is considerable evidence that CFSs are regions of late or slowed replication in the presence of sequence elements that have the propensity to form secondary structures, and that the cytogenetic expression of CFSs may be due to unreplicated DNA. In order to analyse the relationship between DNA replication time and fragility, in this work we have investigated the timing of replication of sequences mapping within two CFSs (FRA1H and FRA2G), of syntenic non-fragile sequences and of early and late replicating control sequences by using fluorescent in situ hybridization on interphase nuclei, conventional fluorescence microscopy and confocal microscopy. Our results indicate that the fragile sequences are slow replicating and that they enter G2 phase unreplicated with very high frequency. Thus these regions could sometimes reach mitosis unreplicated or undercondensed and be expressed as chromosome gaps/breakages.

Lack of association between mtDNA haplogroups and Alzheimer's disease in Tuscany.

Mitochondrial DNA (mtDNA) haplogroup-specific polymorphisms were previously related to several neurodegenerative diseases, including Alzheimer's disease (AD). However, the precise role of mtDNA haplogroups in the neurodegenerative cascade leading to AD is still unclear. In this work we have genotyped predefined European mtDNA haplogroups in 209 patients with AD and 191 matched controls. In order to minimise the risk of "genetic contamination", which could lead to false associations between gene markers and disease, we were careful to enrol in the study only patients and controls of clear Tuscan origin (with at least three generations of Tuscanborn relatives). The frequency of the haplogroups did not differ between the two groups, and no correlation with gender, ApoE genotype, age of onset or disease status was observed. Further studies will be required to define the contribution of mtDNA haplogroups, if any, to the pathogenesis of AD. A correct population selection, in order to minimise the risk of genetic contamination, is essential in these studies.

CD99 isoforms dictate opposite functions in tumour malignancy and metastases by activating or repressing c-Src kinase activity.

CD99 gene encodes two distinct proteins, produced by alternative splicing of CD99 gene transcript. Full-length CD99 isoform (CD99wt) is formed by an extracellular domain, followed by a transmembrane domain and a 36 amino-acid intracytoplasmic domain, which is partially deleted in the truncated, short form (CD99sh). A differential expression of these two CD99 molecules can lead to distinct functional outcomes in lymphocytes. To investigate the functional effects of CD99 molecules on malignancy, forced overexpression of the two CD99 isoforms was induced in osteosarcoma and prostate cancer cells. The two isoforms exhibited opposite functions: the major form dramatically inhibits anchorage-independent growth, anoikis resistance, migration and metastasis, whereas the CD99sh remarkably favours the phenomena. A mechanistic analysis of CD99-transfected osteosarcoma cells points to involvement of c-Src family kinase activity in regulating CD99 functions in malignancy. Ser168 residue of CD99 plays a pivotal role in the reversion of the malignant phenotype. Our findings highlight the involvement of CD99 in crucial processes of cancer malignancy, serving as a curtain raiser for this, so far neglected molecule. In addition, a dualistic role for the two CD99 isoforms was shown in agreement with what was observed for other cell adhesion molecules.

No evidence for allelic association of serotonin 2A receptor and transporter gene polymorphisms with depression in Alzheimer disease.

Patients with Alzheimer disease (AD) often exhibit psychiatric symptoms associated with cognitive impairment. The serotoninergic system may be involved in the development of depressive symptoms in AD patients, as suggested by the evidence that antidepressant drugs having the serotonin transporter as their target are effectively used to treat depressive AD patients. The aim of this study was to investigate the role of serotonin in depression, searching for association of two serotoninergic polymorphisms (T102C of serotonin receptor 5-HT2A and serotonin transporter linked polymorphic region -5-HTTLPR- of SLC6A4 gene) with depressive symptoms and considering their possible interactions with Apolipoprotein E (ApoE) and between themselves, in a sample of 208 sporadic AD patients and 116 normal controls from Italy. 5-HTTLPR and T102C are not associated with AD when separately analysed. However, we found out an interaction between the two polymorphisms in L/L and C/C genotype carriers increasing the risk for the disease (p=0.015, OR=8.048; 95% CI: 1.497-43.262). No association of the polymorphisms was detected with depression linked to AD. No interaction between 5-HTTLPR and T102C was detected in depressive AD subjects, even after stratification according to the presence of ApoE4 allele. These results suggest that the serotoninergic system may be not involved in the pathogenesis of depressive symptoms in AD patients, and it may be involved in other aspects of disease pathophysiology like cognitive symptoms and psychosis.

Anastrozole is cost-effective vs tamoxifen as initial adjuvant therapy in early breast cancer: Canadian perspectives on the ATAC completed-treatment analysis.

GOALS OF WORK: To conduct an economic analysis comparing tamoxifen and anastrozole (Arimidex) in the adjuvant treatment of hormone receptor-positive (HR+), post-menopausal early breast cancer patients. MATERIALS AND METHODS: An economic model examined typical patients (64 years of age, HR+, 64% node negative) from the Arimidex, tamoxifen alone, or in combination (ATAC) trial over a lifetime horizon. Rates of events were derived from ATAC trial results. Post-trial event rates were drawn from the literature for tamoxifen; event rates for anastrozole were modified by the relative risks observed in the ATAC trial. Resource utilization was drawn from Statistics Canada's Population Health Model for breast cancer, supplemented by an expert panel. A public health care system perspective, 2004 Canadian prices and a 5% discount rate were employed. RESULTS: Anastrozole-taking patients incurred additional hormonal treatment costs compared to tamoxifen-taking patients (incremental lifetime cost, 6,974 Canadian dollars per patient), partially offset by reduced downstream recurrences of breast cancer (1,143 Canadian dollars lifetime savings per patient) for a net incremental cost of 5,796 Canadian dollars per patient on anastrozole. The anastrozole-treated patients were projected to experience a 5.6% absolute risk reduction of first breast cancer recurrence and a 2.8% absolute risk reduction in breast cancer death. This corresponded to 30,000 Canadian dollars per life year gained and 28,000 Canadian dollars per quality-adjusted life year gained (95% confidence interval, 17,428 to 54,605 Canadian dollars). The results were affected by the duration and extent of anastrozole benefit under sensitivity analysis but remained cost-effective. CONCLUSION: Compared to tamoxifen, anastrozole therapy is effective and cost-effective as initial adjuvant therapy in post-menopausal, HR+ early breast cancer patients.

Facioscapulohumeral muscular dystrophy type 1A in northwestern Tuscany: a molecular genetics-based epidemiological and genotype-phenotype study.

Facioscapulohumeral muscular dystrophy type 1A (FSHD1A) is an autosomal dominant inherited disorder characterized by early involvement of facial and scapular muscles with eventual spreading to pelvic and lower limb muscles. A high degree of clinical variability with respect to age at onset, severity, and pattern of muscle involvement, both between and within families, is present. For this reason, diagnosis of FSHD1A can be sometimes difficult and molecular diagnosis is then necessary. A clinical and molecular genetic-based epidemiological investigation has been carried out in the territory of northwestern Tuscany in central Italy to calculate the prevalence rate of FSHD1A as of March, 2004. The molecular diagnosis has been based on the detection of large deletions of variable size of kpnI repeat units on chromosome 4q35. Results have been compared to those of a previous study conducted in the same area in 1981 (in the premolecular diagnosis era). The minimum prevalence rate was 4.60 x 10(-5) inhabitants, a value four times higher compared to our previous study. No significant correlation between fragment size and clinical severity has been observed. This study confirms in an Italian population a prevalence rate of FSHD1A similar to that observed in other populations. Furthermore, it underlines the usefulness of routine adoption of the genetic testing in confirming clinical suspicion of FSHD1A as well as in correctly diagnosing atypical and otherwise misclassified cases.

A non-syndromic hearing loss caused by very low levels of the mtDNA A3243G mutation.

We described a patient with progressive non-syndromic hearing loss (NSHL) harboring the A3243G mutation in the mitochondrial DNA (mtDNA). Muscle biopsy showed scattered ragged-red, cytochrome c oxidase negative fibers, whereas the biochemical analysis of the mitochondrial respiratory chain complexes was normal. Restriction fragment length polymorphism (RFLP) analysis showed A3243G mtDNA transition, present at very low in patient's muscle (3%) and in urinary sediments (1%), and not detectable in blood and buccal mucosa. The patient was submitted to a bilateral cochlear implantation with post-operative excellent hearing and communicative outcomes. Our findings indicate that A3243G mutation may be responsible both for SHL and NSHL, may be depending on the levels of mutated mtDNA. Patients with hearing loss due to mtDNA mutations should be considered as good candidates for cochlear implantation.

A novel mitochondrial tRNAPhe mutation causes MERRF syndrome.

A woman with typical features of myoclonic epilepsy with ragged red fibers (MERRF) had a novel heteroplasmic mutation (G611A) in the mitochondrial DNA tRNA phenylalanine gene. The mutation was heteroplasmic (91%) in muscle but undetectable in accessible tissues from the patient and her maternal relatives. Single-fiber PCR analysis showed that the proportion of mutant genomes was higher in cytochrome c oxidase (COX)-negative ragged red fibers (RRFs) than in COX-positive non-RRFs. This report shows that typical MERRF syndrome is not always associated with tRNA lysine mutations.

Evaluation of cytogenetic and DNA damage in mitochondrial disease patients: effects of coenzyme Q10 therapy.

Endogenous oxidative stress is believed to play a key role in the pathogenesis of mitochondrial diseases (MD). In this group of heterogeneous disorders the increased production of radical species caused by compromised mitochondrial respiratory function could affect both mitochondrial and nuclear DNA integrity. The aim of the present study was to assess the basal level of nuclear DNA (nDNA) damage in terms of chromosome and DNA alterations in leukocytes of 13 patients (age range 29-74 years) presenting several forms of MD. A further objective of this work was the evaluation of possible changes in nDNA in a subgroup of patients (10 individuals) before and after a 2 week therapy with ubidecarenone, a coenzyme Q10 analogue. The extent of cytogenetic damage, expressed as chromosome breakage and chromosome loss, was assessed employing the cytokinesis block micronucleus method in cultured peripheral blood lymphocytes, coupled with fluorescence in situ hybridization analysis using a digoxigenin-labelled pancentromeric DNA probe. A modified version of the single cell gel electrophoresis assay was used to quantify primary and oxidative DNA damage in leukocytes. In MD patients an increased level of chromosome damage, expressed as frequency of micronucleated lymphocytes, was detected in comparison with healthy individuals of corresponding sex, age and lifestyle. The FISH analysis revealed a preferential occurrence of micronuclei arising from loss of whole chromosomes in patients, with no substantial difference in frequencies observed in matched controls. The Comet assay indicated a slightly higher level of primary DNA damage in patients compared with controls and also a difference in oxidative DNA damage, however, this was not statistically significant. Patients receiving ubidecarenone showed a statistically significant reduction in the frequency of micronucleated cells after therapy, while only a slight decrease was observed in the levels of both primary DNA damage and oxidized bases.